Life management plants at nuclear power plants PWR; Planes de gestion de vida en centrales nucleares PWR

Energy Technology Data Exchange (ETDEWEB)

Esteban, G.

2014-10-01

Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

Nuclear safety research in France

International Nuclear Information System (INIS)

Tanguy, P.

1976-01-01

As a consequence of the decision of choosing light water reactors (PWR) for the French nuclear plants of the next ten years, a large safety program has been launched referring to three physical barriers against fission product release: the fuel element cladding, main primary system boundary and the containment. The parallel development of French-designed fast breeder reactors involved safety studies on: sodium boiling, accidental fuel behavior, molten fuel-sodium interaction, core accident and protection, and external containment. The rapid development of nuclear energy resulted in a corresponding development of safety studies relating to nuclear fuel facilities. French regulations also required a special program to be developed for the realistic evaluation of the consequences of external agressions, the French cooperation to multinational safety research being also intensive

Criteria for safety-related nuclear-power-plant operator actions: 1982 pressurized-water-reactor (PWR) simulator exercises

International Nuclear Information System (INIS)

Crowe, D.S.; Beare, A.N.; Kozinsky, E.J.; Haas, P.M.

1983-06-01

The primary objective of the Safety-Related Operator Action (SROA) Program at Oak Ridge National Laboratory is to provide a data base to support development of criteria for safety-related actions by nuclear power plant operators. When compared to field data collected on similar events, a base of operator performance data developed from the simulator experiments can then be used to establish safety-related operator action design evaluation criteria, evaluate the effects of performance shaping factors, and support safety/risk assessment analyses. This report presents data obtained from refresher training exercises conducted in a pressurized water reactor (PWR) power plant control room simulator. The 14 exercises were performed by 24 teams of licensed operators from one utility, and operator performance was recorded by an automatic Performance Measurement System. Data tapes were analyzed to extract operator response times (RTs) and error rate information. Demographic and subjective data were collected by means of brief questionnaires and analyzed in an attempt to evaluate the effects of selected performance shaping factors on operator performance

Addressing the fundamental issues in reliability evaluation of passive safety of AP1000 for a comparison with active safety of PWR

International Nuclear Information System (INIS)

Hashim Muhammad; Yoshikawa, Hidekazu; Yang Ming

2013-01-01

Passive safety systems adopted in advanced Pressurized Water Reactor (PWR), such as AP1000 and EPR, should attain higher reliability than the existing active safety systems of the conventional PWR. The objective of this study is to discuss the fundamental issues relating to the reliability evaluation of AP1000 passive safety systems for a comparison with the active safety systems of conventional PWR, based on several aspects. First, comparisons between conventional PWR and AP1000 are made from the both aspects of safety design and cost reduction. The main differences between these PWR plants exist in the configurations of safety systems: AP1000 employs the passive safety system while reducing the number of active systems. Second, the safety of AP1000 is discussed from the aspect of severe accident prevention in the event of large break loss of coolant accidents (LOCA). Third, detailed fundamental issues on reliability evaluation of AP1000 passive safety systems are discussed qualitatively by using single loop models of safety systems of both PWRs plants. Lastly, methodology to conduct quantitative estimation of dynamic reliability for AP1000 passive safety systems in LOCA condition is discussed, in order to evaluate the reliability of AP1000 in future by a success-path-based reliability analysis method (i.e., GO-FLOW). (author)

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

International Nuclear Information System (INIS)

1979-01-01

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

Modeling on a PWR power conversion system with system program

International Nuclear Information System (INIS)

Gao Rui; Yang Yanhua; Lin Meng

2007-01-01

Based on the power conversion system of nuclear and conventional islands of Daya Bay Power Station, this paper models the thermal-hydraulic systems of primary and secondary loops for PWR by using the PWR best-estimate program-RELAP5. To simulate the full-scope power conversion system, not only the traditional basic system models of nuclear island, but also the major system models of conventional island are all considered and modeled. A comparison between the calculated results and the actual data of reactor demonstrates a fine match for Daya Bay Nuclear Power Station, and manifests the feasibility in simulating full-scope power conversion system of PWR by RELAP5 at the same time. (authors)

Methodology for safety classification of PWR type nuclear power plants items

International Nuclear Information System (INIS)

Oliveira, Patricia Pagetti de

1995-01-01

This paper contains the criteria and methodology which define a classification system of structures, systems and components in safety classes according to their importance to nuclear safety. The use of this classification system will provide a set of basic safety requirements associated with each safety class specified. These requirements, when available and applicable, shall be utilized in the design, fabrication and installation of structures, systems and components of Pressurized Water Reactor Nuclear Power Plants. (author). 13 refs, 1 tab

Nonlinear Fuzzy Model Predictive Control for a PWR Nuclear Power Plant

Directory of Open Access Journals (Sweden)

Xiangjie Liu

2014-01-01

Full Text Available Reliable power and temperature control in pressurized water reactor (PWR nuclear power plant is necessary to guarantee high efficiency and plant safety. Since the nuclear plants are quite nonlinear, the paper presents nonlinear fuzzy model predictive control (MPC, by incorporating the realistic constraints, to realize the plant optimization. T-S fuzzy modeling on nuclear power plant is utilized to approximate the nonlinear plant, based on which the nonlinear MPC controller is devised via parallel distributed compensation (PDC scheme in order to solve the nonlinear constraint optimization problem. Improved performance compared to the traditional PID controller for a TMI-type PWR is obtained in the simulation.

Life management plants at nuclear power plants PWR

International Nuclear Information System (INIS)

Esteban, G.

2014-01-01

Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

Nuclear Safety. 1997

International Nuclear Information System (INIS)

1998-01-01

A quick review of the nuclear safety at EDF may be summarized as follows: - the nuclear safety at EDF maintains at a rather good standard; - none of the incidents that took place has had any direct impact upon safety; - the availability remained good; - initiation of the floor 4 reactor generation (N4 unit - 1450 MW) ensued without major difficulties (the Civaux 1 NPP has been coupled to the power network at 24 december 1997); - the analysis of the incidents interesting from the safety point of view presents many similarities with earlier ones. Significant progress has been recorded in promoting actively and directly a safe operation by making visible, evident and concrete the exertion of the nuclear operation responsibility and its control by the hierarchy. The report develops the following chapters and subjects: 1. An overview on 1997; 1.1. The technical issues of the nuclear sector; 1.2. General performances in safety; 1.3. The main incidents; 1.4. Wastes and radiation protection; 2. Nuclear safety management; 2.1. Dynamics and results; 2.2. Ameliorations to be consolidated; 3. Other important issues in safety; 3.1. Probabilistic safety studies; 3.2. Approach for safety re-evaluation; 3.3. The network safety; 3.4. Crisis management; 3.5. The Lifetime program; 3.6. PWR; 3.7. Documentation; 3.8. Competence; 4. Safety management in the future; 4.1. An open future; 4.2. The fast neutron NPP at Creys-Malville; 4.3. Stabilization of the PWR reference frame; 4.4. Implementing the EURATOM directive regarding the radiation protection standards; 4.5. Development of biomedical research and epidemiological studies; 4.6. New regulations concerning the liquid and gaseous effluents; 5. Visions of an open future; 5.1. Alternative views upon safety ay EDF; 5.2. Safety authority; 5.3. International considerations; 5.4. What happens abroad; 5.5. References from non-nuclear domain. Four appendices are added referring to policy of safety management, policy of human factors in NPPs

Suggestion on the safety classification of spent fuel dry storage in China’s pressurized water reactor nuclear power plant

Science.gov (United States)

Liu, Ting; Qu, Yunhuan; Meng, De; Zhang, Qiaoer; Lu, Xinhua

2018-01-01

China’s spent fuel storage in the pressurized water reactors(PWR) is stored with wet storage way. With the rapid development of nuclear power industry, China’s NPPs(NPPs) will not be able to meet the problem of the production of spent fuel. Currently the world’s major nuclear power countries use dry storage as a way of spent fuel storage, so in recent years, China study on additional spent fuel dry storage system mainly. Part of the PWR NPP is ready to apply for additional spent fuel dry storage system. It also need to safety classificate to spent fuel dry storage facilities in PWR, but there is no standard for safety classification of spent fuel dry storage facilities in China. Because the storage facilities of the spent fuel dry storage are not part of the NPP, the classification standard of China’s NPPs is not applicable. This paper proposes the safety classification suggestion of the spent fuel dry storage for China’s PWR NPP, through to the study on China’s safety classification principles of PWR NPP in “Classification for the items of pressurized water reactor nuclear power plants (GB/T 17569-2013)”, and safety classification about spent fuel dry storage system in NUREG/CR - 6407 in the United States.

PWR reactors for BBR nuclear power plants

International Nuclear Information System (INIS)

Structure and functioning of the nuclear steam generator system developed by BBR and its components are described. Auxiliary systems, control and load following behaviour and fuel management are discussed and the main data of PWR given. The brochure closes with a perspective of the future of the Muelheim-Kaerlich nuclear power plant. (GL) [de

French PWR Safety Philosophy

International Nuclear Information System (INIS)

Conte, M. M.

1986-01-01

The first 900 MWe units, built under the American Westinghouse licence and with reference to the U. S. regulation, were followed by 28 standardized units, C P1 and C P2 series. Increasing knowledge and lessons learned from starting and operating experience of French nuclear power plants, completed by the experience learned from the operation of foreign reactors, has contributed to the improvement of French PWR design and safety philosophy. As early as 1976, this experience was taken into account by French Safety organisms to discuss, with Electricite de France, the safety options for the planned 1300 MWe units, P4 and P4 series. In 1983, the new reactor scheduled, Ni4 series 1400 MWe, is a totally French design which satisfies the French regulations and other French standards and codes. Based on a deterministic approach, the French safety analysis was progressively completed by a probabilistic approach each of them having possibilities and limits. Increasing knowledge and lessons learned from operating experience have contributed to the French safety philosophy improvement. The methodology now applied to safety evaluation develops a new facet of the in depth defense concept by taking highly unlikely events into consideration, by developing the search of safety consistency of the design, and by completing the deterministic approach by the probabilistic one

Integral type small PWR with stand-alone safety

International Nuclear Information System (INIS)

Makihara, Yoshiaki

2001-01-01

A feasibility study is achieved on an integral type small PWR with stand-alone safety. It is designed to have the following features. (1) The coolant does not leak out at any accidental condition. (2) The fuel failure does never occur while it is supposed on the large scale PWR at the design base accident. (3) At any accidental condition the safety is secured without any support from the outside (stand-alone safety secure). (4) It has self-regulating characteristics and easy controllability. The above features can be satisfied by integrate the steam generator and CRDM in the reactor vessel while the pipe line break has to be considered on the conventional PWR. Several counter measures are planned to satisfy the above features. The economy feature is also attained by several simplifications such as (1) elimination of main coolant piping and pressurizer by the integration of primary cooling system and self-pressurizing, (2) elimination of RCP by application of natural circulating system, (3) elimination of ECCS and accumulator by application of static safety system, (4) large scale volume reduction of the container vessel by application of integrated primary cooling system, (5) elimination of boric acid treatment by deletion of chemical shim. The long operation period such as 10 years can be attained by the application of Gd fuel in one batch refueling. The construction period can be shortened by the standardizing the design and the introduction of modular component system. Furthermore the applicability of the reduced modulation core is also considered. (K. Tsuchihashi)

Seismic analysis with FEM for fuel transfer system of PWR nuclear power plant

International Nuclear Information System (INIS)

Jia Xiaofeng; Liu Pengliang; Bi Xiangjun; Ji Shunying

2012-01-01

In the PWR nuclear power plant, the function of the fuel transfer system (FTS) is to transfer the fuel assembly between the reactor building and the fuel building. The seismic analysis of the transfer system structure should be carried out to ensure the safety under OBE and SSE. Therefore, the ANASYS 12.0 software is adopted to construct the finite element analysis model for the fuel transfer system in a million kilowatt nuclear power plant. For the various configurations of FTS in the operating process, the stresses of the main structures, such as the transfer tube, fuel assembly container, fuel conveyor car, lifting frame in the reactor building, lifting frame in the fuel building, support and guide structure of conveyor car and the lifting frame in both buildings, are computed. The stresses are combined with the method of square root of square sum (SRSS) and assessed under various seismic conditions based on RCCM code, the results of the assessment satisfy the code. The results show that the stresses of the fuel transfer system structure meet the strength requirement, meanwhile, it can withstand the earthquake well. (authors)

The development of emergency core cooling systems in the PWR, BWR, and HWR Candu type of nuclear power plants

International Nuclear Information System (INIS)

Mursid Djokolelono.

1976-01-01

Emergency core cooling systems in the PWR, BWR, and HWR-Candu type of nuclear power plant are reviewed. In PWR and BWR the emergency cooling can be catagorized as active high pressure, active low pressure, and a passive one. The PWR uses components of the shutdown cooling system: whereas the BWR uses components of pressure suppression contaiment. HWR Candu also uses the shutdown cooling system similar to the PWR except some details coming out from moderator coolant separation and expensive cost of heavy water. (author)

Advancements in the design of safety-related systems and components of the MARS nuclear plant

International Nuclear Information System (INIS)

Caira, M.; Caruso, G.; Naviglio, A.; Sorabella, L.; Farello, C.E.

1992-01-01

In the paper, the advancements in the design of safety-related systems and components of the MARS nuclear plant, equipped with a 600 MW th PWR, are described. These advancements are due to the special safety features of this plant, which relies completely on inherent and passive safety. In particular, the new steps of the design of the innovative, completely passive, and with an unlimited autonomy Emergency core Cooling System are described, together with the characteristics of the last version of the steam generator, developed in a new design involving disconnecting components, for a fast erection and an easy maintenance. (author)

Selection of detailed items for periodic safety review on PWR radwaste management system

Energy Technology Data Exchange (ETDEWEB)

Sung, K. B.; Ahn, Y. S.; Park, Y. S.; Kim, S. H.; Kim, J. T. [Korea Hydric and Nuclear Power Company, Taejon (Korea, Republic of)

2003-10-01

Selection of detailed-items for Periodic Safety Review on PWR radwaste management system, the main component could be faithfully clarified according to the purpose of establishment on each system and basic purpose. It is proper to select detailed-items those of radioactivities in the reactor coolant activity levels and the released volume of liquid and gaseous radioactive material on safety performance. It's also proper to select solid radwaste production quantities as detailed-item that it would be predict the next ten years trends after PSR.

Assessment and management of ageing of major nuclear power plant components important to safety: PWR pressure vessels. 2007 update

International Nuclear Information System (INIS)

2007-06-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that effective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) is one of the most important issues for plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. IAEA-TECDOC-1120 documented ageing assessment and management practices for pressurized water reactor (PWR) reactor pressure vessels (RPVs) that were current at the time of its finalization in 1997-1998. Safety significant operating events have occurred since the finalization of the TECDOC, e.g. primary water stress corrosion cracking (PWSCC) of Alloy 600 control rod drive mechanism (CRDM) penetrations and boric acid corrosion/wastage of RPV heads, which threatened the integrity of the RPV heads. These events led to new ageing management actions by both NPP operators and regulators. Therefore it was recognized that IAEA-TECDOC-1120 should be updated by incorporating those new events and their countermeasures. The objective of this report is to update IAEA-TECDOC-1120 in order to provide current ageing management guidance for PWR RPVs to all involved in the operation and regulation of PWRs and thus to help ensure PWR RPV integrity in IAEA Member States throughout their entire service life

Next generation PWR

International Nuclear Information System (INIS)

Tanaka, Toshihiko; Fukuda, Toshihiko; Usui, Shuji

2001-01-01

Development of LWR for power generation in Japan has been intended to upgrade its reliability, safety, operability, maintenance and economy as well as to increase its capacity in order, since nuclear power generation for commercial use was begun on 1970, to steadily increase its generation power. And, in Japan, ABWR (advanced BWR) of the most promising LWR in the world, was already used actually and APWR (advanced PWR) with the largest output in the world is also at a step of its actual use. And, development of the APWR in Japan was begun on 1980s, and is at a step of plan on construction of its first machine at early of this century. However, by large change of social affairs, economy of nuclear power generation is extremely required, to be positioned at an APWR improved development reactor promoted by collaboration of five PWR generation companies and the Mitsubishi Electric Co., Ltd. Therefore, on its development, investigation on effect of change in social affairs on nuclear power stations was at first carried out, to establish a design requirement for the next generation PWR. Here were described on outline, reactor core design, safety concept, and safety evaluation of APWR+ and development of an innovative PWR. (G.K.)

Assessment and management of ageing of major nuclear power plant components important to safety: PWR vessel internals: 2007 update

International Nuclear Information System (INIS)

2007-06-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that effective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) is one of the most important issues for plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wearout of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. IAEA-TECDOC-1119 documents ageing assessment and management practices for PWR Reactor Vessel Internals (RVIs) that were current at the time of its finalization in 1997-1998. Safety significant operating events have occurred since the finalization of the TECDOC, e.g. irradiation assisted stress corrosion cracking (IASCC) of baffle-former bolts, which threatened the integrity of the vessel internals. In addition, concern of fretting wear of control rod guide tubes has been raised in Japan. These events led to new ageing management actions by both NPP operators and regulators. Therefore it was recognized that IAEA-TECDOC-1119 should be updated by incorporating those new events and their countermeasures. The objective of this report is to update relevant sections of the existing IAEA-TECDOC- 1119 in order to provide current ageing management guidance for PWR RVIs to all involved in the operation and regulation of PWRs and thus to help ensure PWR safety in IAEA Member States throughout their entire service life

Annual report ''nuclear safety in France''

International Nuclear Information System (INIS)

2001-01-01

This document is the 2001 annual report of the French authority of nuclear safety (ASN). It summarizes the highlights of the year 2000 and details the following aspects: the nuclear safety in France, the organization of the control of nuclear safety, the regulation relative to basic nuclear facilities, the control of facilities, the information of the public, the international relations, the organisation of emergencies, the radiation protection, the transport of radioactive materials, the radioactive wastes, the PWR reactors, the experimental reactors and other laboratories and facilities, the nuclear fuel cycle facilities, and the shutdown and dismantling of nuclear facilities. (J.S.)

Nuclear safety research

International Nuclear Information System (INIS)

1996-01-01

The topics 'Large-sized PWR-NPP Safety Techniques Research',and 'The Key Techniques Research on the Safety Supervision and Control for Operation of Nuclear Installations' have been adopted as an apart of 'the National 9th five Year Programs for Tacking the Key Scientific and Technical Topics' which are organized by the State Planning Commission (SPC) and State Science and Technology Commission (SSTC) respectively, and have obtained a financial support from them. To play a better role with the limited fund, the NNSA laid special stress on selecting key sub-topics on nuclear safety, and carefully choosing units which would undertake sub-topics and signing technical contracts with them

The reliability data acquisition system in PWR nuclear power plants

International Nuclear Information System (INIS)

Lienart, P.

1984-01-01

In April 1978, Electricite de France put a reliability data acquisition system (SRDF) into operation at its two nuclear power plant sites: Fessenheim and Bugey. In the light of the experience acquired and the advantages offered by such a data bank, this system has been progressively extended since 1982 to cover the entire PWR network. The SRDF was originally designed for the follow-up of 4000 items of equipment per pair of units. However, the various difficulties encountered in gathering data made it necessary - in order to safeguard the quality of the information - to reduce this number initially to 800 major mechanical or electromechanical items of equipment designed to ensure the safety or availability of the units. Subsequently, an increase to 1100 was possible. The SRDF consists of a centralized information bank linked by telephone to the various nuclear sites. The software enables the data-acquisition cards to be introduced, modified or deleted. Any user can gain access to the bank by simply making queries in real time. The quality of the acquisition and processing of the data depend on a list of equipment confined to essential operational systems and on a card design combining, as far as possible, the precision and accessibility of the data. A method of logical failure analysis has also been devised, its main purposes being to provide the following: (1) aid to card instruction; (2) an easier way of checking the uniformity of information concerning a failure; and (3) compatibility between the instructions and analysis of data, thereby facilitating development of the data-processing program. (author)

Design and Development of Virtual Reactivity System for PWR

International Nuclear Information System (INIS)

Anwar, M. I.

2012-01-01

The reactivity monitoring and investigation is an important mean to ensure the safety operation of a nuclear power plant. But the reactivity of the nuclear reactor usually cannot be directly measured. It should be computed with certain estimation method. In this thesis, an effort has been made using an artificial neural network and highly fluctuating experimental data for predicting the total reactivity of the nuclear reactor based on all components of net reactivity. This virtual reactivity system is designed by taking advantage of neural network's nonlinear mapping capability. Based on analysis of the reactivity contributing factors, several neural network models are built separately for control rod, boron, poisons, fuel Doppler Effect and moderator effect. Extensive simulation and validation tests for PWR show that satisfied results have been obtained with the proposed approach. It presents a new idea to estimate the PWR's reactivity using artificial intelligence. All the design and simulation work is carried out in MATLAB and a real time programming environment is chosen for the computation and prediction of reactivity. (author)

Method and Result of Experiment for Support of Technical Solutions in the Field of Perfection of a Nuclear Fuel Cycle for Future PWR Reactors

International Nuclear Information System (INIS)

Ostrovskiy, V.; Kudryavtsev, E.; Tutnov, I.

2011-01-01

The paper presents the basics of approach of planning and carrying out of experiments to validate safety PWR reactors of the future when accepting technical solutions concerning using of improved fuel rods in fuel assembly. Basic principles and criteria used for the validation of technical solutions and developments in improving of nuclear fuel cycle of PWR reactors of the future are presented from the point of safety of future operation of modified fuel rods. We explore the questions of safety operation of PWR reactors with fuel assemblies, containing fuel rods with different length of fuel. The paper discusses the ways of solving of important tasks of critical facility experiments conducting for verification of new technical solutions in the sphere of PWR nuclear fuel cycle improvement on the base of international standards ISO 2000:9000 and functional safety recommendations of IEC (International Electromechanical Commission). New Federal laws of Russian Federation define the main principle for demands to NPP and any supplier of nuclear techniques. The principle is 'quantity indicators of risk should not exceed comprehensible social size of the established indicators of safety for any moment of operation of NPP'. On the other hand the second principle should be applied to extraction of the greatest benefit from operation of the equipment, systems or the NPP as whole: 'The long operation and full commercial use of resource and service properties of the equipment, systems and the NPP as a whole'. Realization of this principle assumes development and introduction of new technical solutions for a validation of guarantees of safety of the future operation of NPP or it separate components. Solving the practical problems of a validation of safety use of fuel rods with the increased length of a fuel column in fuel assembly in nuclear reactors of the future, we should choose new strategies and programs of verification experiments on the base of the analysis of guarantees

Proposal for a advanced PWR core with adequate characteristics for passive safety concept

International Nuclear Information System (INIS)

Perrotta, Jose Augusto

1999-01-01

This work presents a discussion upon the suitable from an advanced PWR core, classified by the EPRI as 'Passive PWR' (advanced reactor with passive safety concept to power plants with less than 600 MW electrical power). The discussion upon the type of core is based on nuclear fuel engineering concepts. Discussion is made on type of fuel materials, structural materials, geometric shapes and manufacturing process that are suitable to produce fuel assemblies which give good performance for this type of reactors. The analysis is guided by the EPRI requirements for Advanced Light Water Reactor (ALWR). By means of comparison, the analysis were done to Angra 1 (old type of 600 MWe PWR class), and the design of the Westinghouse Advanced PWR-AP600. It was verified as a conclusion of this work that the modern PWR fuels are suitable for advanced PWR's Nevertheless, this work presents a technical alternative to this kind of fuel, still using UO 2 as fuel, but changing its cylindrical form of pellets and pin type fuel element to plane shape pallets and plate type fuel element. This is not a novelty fuel, since it was used in the 50's at Shippingport Reactor and as an advanced version by CEA of France in the 70's. In this work it is proposed a new mechanical assembly design for this fuel, which can give adequate safety and operational performance to the core of a 'Passive PWR'. (author)

Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2011

International Nuclear Information System (INIS)

2012-01-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary followed by the viewpoint of the Committees for health, safety and working conditions. (J.S.)

Preliminary assessment of a combined passive safety system for typical 3-loop PWR CPR1000

Energy Technology Data Exchange (ETDEWEB)

Yang, Zijiang; Shan, Jianqiang, E-mail: jqshan@mail.xjtu.edu.cn; Gou, Junli

2017-03-15

Highlights: • A combined passive safety system was placed on a typical 3-loop PWR CPR1000. • Three accident analyses show the three different accident mitigation methods of the passive safety system. • The three mitigation methods were proved to be useful. - Abstract: As the development of the nuclear industry, passive technology turns out to be a remarkable characteristic of advanced nuclear power plants. Since the 20th century, much effort has been given to the passive technology, and a number of evolutionary passive systems have developed. Thoughts have been given to upgrade the existing reactors with passive systems to meet stricter safety demands. In this paper, the CPR1000 plant, which is one kind of mature pressurized water reactor plants in China, is improved with some passive systems to enhance safety. The passive systems selected are as follows: (1) the reactor makeup tank (RMT); (2) the advanced accumulator (A-ACC); (3) the in-containment refueling water storage tank (IRWST); (4) the passive emergency feed water system (PEFS), which is installed on the secondary side of SGs; (5) the passive depressurization system (PDS). Although these passive components is based on the passive technology of some advanced reactors, their structural and trip designs are adjusted specifically so that it could be able to mitigate accidents of the CPR1000. Utilizing the RELAP5/MOD3.3 code, accident analyses (small break loss of coolant accident, large break loss of coolant accident, main feed water line break accident) of this improved CPR1000 plant were presented to demonstrate three different accident mitigation methods of the safety system and to test whether the passive safety system preformed its function well. In the SBLOCA, all components of the passive safety system were put into work sequentially, which prevented the core uncover. The LBLOCA analysis illustrates the contribution of the A-ACCs whose small-flow-rate injection can control the maximum cladding

The Competence Promoting by NNSA for Keeping High Level Nuclear Safety: The Corner Stone of the Nuclear Safety Regulation Edifice

International Nuclear Information System (INIS)

Hu, L.

2016-01-01

Facing the fast development of the nuclear power industry and the application of radioactive sources, The MEP(NNSA) is endeavoured to promoting its competency, including: complementing the law system, training and recruiting staff to keep a capable team, constructing the R&D base to keep the basic capability, promoting safety culture both for the industry and the regulator. After the Fukushima nuclear accident, the MEP(NNSA) planned to construct R&D base, in which the Platform Nuclear Safety Monitoring and Emergency Responding, the Platform of Safety Technology of PWR Testing, the Laboratory of Safety Management Technology of Nuclear Waste Verification, the Laboratory of Environmental Radiation Monitoring and the Center of International Cooperation are included. On the other hand, the MEP(NNSA) issued Chinese nuclear safety culture policy declaration in 2014, and carried out a large scale Specialized Action for Nuclear Safety Promotion to promote the nuclear safety culture both for the industry and herself. For the nuclear regulator, It is essential to conduct the competence promoting by both “hardware” and “software”, the former is the material foundation of regulation authority, which will be effectively functioning under the facilitating of the latter. (author)

Nuclear installations safety in France. Compilation of regulatory guides

International Nuclear Information System (INIS)

1988-01-01

General plan: 1. General organization of public officials. Procedures 1.1. Texts defining the general organization and the procedures 1.2. Interventing organisms; 2. Texts presenting a technical aspect other than basic safety rules and associated organization texts; 2.1. Dispositions relating to safety of nuclear installations 2.2. Dispositions relating to pressure vessels 2.3. Dispositions relating to quality 2.4. Dispositions relating to radioactive wastes release 2.5. Dispositions relating to activities depending of classified installations; 3. Basic Safety Rules (BSR) 3.1. BSR relating to PWR 3.2. BSR relating to nuclear installations other than PWR 3.3. Other BSR [fr

Study On Safety Analysis Of PWR Reactor Core In Transient And Severe Accident Conditions

International Nuclear Information System (INIS)

Le Dai Dien; Hoang Minh Giang; Nguyen Thi Thanh Thuy; Nguyen Thi Tu Oanh; Le Thi Thu; Pham Tuan Nam; Tran Van Trung; Le Van Hong; Vo Thi Huong

2014-01-01

The cooperation research project on the Study on Safety Analysis of PWR Reactor Core in Transient and Severe Accident Conditions between Institute for Nuclear Science and Technology (INST), VINATOM and Korean Atomic Energy Research Institute (KAERI), Korea has been setup to strengthen the capability of researches in nuclear safety not only in mastering the methods and computer codes, but also in qualifying of young researchers in the field of nuclear safety analysis. Through the studies on the using of thermal hydraulics computer codes like RELAP5, COBRA, FLUENT and CFX the thermal hydraulics research group has made progress in the research including problems for safety analysis of APR1400 nuclear reactor, PIRT methodologies and sub-channel analysis. The study of severe accidents has been started by using MELCOR in collaboration with KAERI experts and the training on the fundamental phenomena occurred in postulated severe accident. For Vietnam side, VVER-1000 nuclear reactor is also intensively studied. The design of core catcher, reactor containment and severe accident management are the main tasks concerning VVER technology. The research results are presented in the 9 th National Conference on Mechanics, Ha Noi, December 8-9, 2012, the 10 th National Conference on Nuclear Science and Technology, Vung Tau, August 14-15, 2013, as well as published in the journal of Nuclear Science and Technology, Vietnam Nuclear Society and other journals. The skills and experience from using computer codes like RELAP5, MELCOR, ANSYS and COBRA in nuclear safety analysis are improved with the nuclear reactors APR1400, Westinghouse 4 loop PWR and especially the VVER-1000 chosen for the specific studies. During cooperation research project, man power and capability of Nuclear Safety center of INST have been strengthen. Three masters were graduated, 2 researchers are engaging in Ph.D course at Hanoi University of Science and Technology and University of Science and Technology, Korea

Electrical systems design applications on Japanese PWR plants in light of the Fukushima Daiichi Accident

International Nuclear Information System (INIS)

Nomoto, Tsutomu

2015-01-01

After the Fukushima Daiichi nuclear power plant (1F-NPP) accident (i.e. Station Blackout), several design enhancements have been incorporated or are under considering to Mitsubishi PWR plants' design of not only operational plants' design but also new plants' design. Especially, there are several important enhancements in the area of the electrical system design. In this presentation, design enhancements related to following electrical systems/equipment are introduced; - Offsite Power System; - Emergency Power Source; - Safety-related Battery; - Alternative AC Power Supply Systems. In addition, relevant design requirements/conditions which are or will be considered in Mitsubishi PWR plants are introduced. (authors)

Nuclear safety and radiation protection report of the Flamanville nuclear facilities - 2011

International Nuclear Information System (INIS)

2012-01-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Flamanville nuclear power plant (Manche (FR)): 2 PWR reactors in operation (INB 108 and 109), and 1 PWR under construction (Flamanville 3, INB 167). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, water consumption and waste management at Flamanville 3 construction site) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Flamanville nuclear facilities - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Flamanville nuclear power plant (Manche (FR)): 2 PWR reactors in operation (INB 108 and 109), and 1 PWR under construction (Flamanville 3, INB 167). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, water consumption and waste management at Flamanville 3 construction site) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Study of essential safety features of a three-loop 1,000 MWe light water reactor (PWR) and a corresponding heavy water reactor (HWR) on the basis of the IAEA nuclear safety standards

International Nuclear Information System (INIS)

1989-02-01

Based on the IAEA Standards, essential safety aspects of a three-loop pressurized water reactor (1,000 MWe) and a corresponding heavy water reactor were studied by the TUeV Baden e.V. in cooperation with the Gabinete de Proteccao e Seguranca Nuclear, a department of the Ministry which is responsible for Nuclear power plants in Portugal. As the fundamental principles of this study the design data for the light water reactor and the heavy water reactor provided in the safety analysis reports (KWU-SSAR for the 1,000 MWe PWR, KWU-PSAR Nuclear Power Plant ATUCHA II) are used. The assessment of the two different reactor types based on the IAEA Nuclear Safety Standards shows that the reactor plants designed according to the data given in the safety analysis reports of the plant manufacturer meet the design requirements laid down in the pertinent IAEA Standards. (orig.) [de

Report of the 17th international workshop on nuclear safety and simulation technology (IWNSST17)

International Nuclear Information System (INIS)

Yoshikawa, Hidekazu

2014-01-01

The 17th International Workshop on Nuclear Safety and Simulation Technology (IWNSST17) was held in January 21, 2014 at Kyoto University, in Kyoto, Japan. This one-day workshop was motivated to exploit advanced safety researches for nuclear power plant (NPP) , by a unique synergetic collaboration of basically two different disciplines: material science and systems sciences. There were ten invited presentations at the ISSNP2013, and the subject of the presentations ranges from (1) material corrosion issue of NPP components, (2) application of augmented reality technology for NPP decommission, (3) functional modeling method for plant control system, (4) intrinsic understanding of Fukushima Daiichi accident phenomena based on simple physical model, (5) system reliability evaluation method for PWR safety system, (6) automatic control system design for small modular reactor, and (7) validation of computerized human-machine interface and digital I and C for PWR plant. This article provides the overview of the IWNSST17 with giving condensed summaries of all invited presentations given by international experts. (author)

Valve testing for UK PWR safety applications

International Nuclear Information System (INIS)

George, P.T.; Bryant, S.

1989-01-01

Extensive testing and development has been done by the Central Electricity Generating Board (CEGB) to support the design, construction and operation of Sizewell B, the UK's first PWR. A Blowdown Rig for the Assessment of Valve Operability - (BRAVO) has been constructed at the CEGB Marchwood Engineering Laboratory to reproduce PWR Pressurizer fluid conditions for the full scale testing of Pressurizer Relief System (PRS) valves. A full size tandem pair of Pilot Operated Safety Relief Valves (POSRVs) is being tested under the full range of pressurizer fluid conditions. Tests to date have produced important data on the performance of the valve in its Cold Overpressure protection mode of operation and on methods for the in-service testing of the valve. Also, a full size pressurizer safety valve has been tested under full PRS fluid conditions to develop a methodology for the pre-service testing of the Sizewell valves. Further work will be carried out to develop procedures for the in-service testing of the valve. In the Main Steam Safety Valve test program carried out at the Siemens-KWU Test Facilities, a single MSSV from three potential suppliers was tested under full secondary system conditions. The test results have been analyzed and are reflected in the CEGB's arrangements for the pre-service and in-service testing of the Sizewell MSSVs. Valves required to interrupt pipebreak flow must be qualified for this duty by testing or a combination of testing and analysis. To obtain guidance on the performance of such tests gate and globe valves have been subjected to simulated pipebreaks under PWR primary circuit conditions. In the light of problems encountered with gate valve closure under these conditions, further tests are currently being carried out on the BRAVO facility on a gate valve, in preparation for the full scale flow interruption qualification testing of the Sizewell main steam isolation valve

Nuclear Safety. 1997; Surete Nucleaire. 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-19

A quick review of the nuclear safety at EDF may be summarized as follows: - the nuclear safety at EDF maintains at a rather good standard; - none of the incidents that took place has had any direct impact upon safety; - the availability remained good; - initiation of the floor 4 reactor generation (N4 unit - 1450 MW) ensued without major difficulties (the Civaux 1 NPP has been coupled to the power network at 24 december 1997); - the analysis of the incidents interesting from the safety point of view presents many similarities with earlier ones. Significant progress has been recorded in promoting actively and directly a safe operation by making visible, evident and concrete the exertion of the nuclear operation responsibility and its control by the hierarchy. The report develops the following chapters and subjects: 1. An overview on 1997; 1.1. The technical issues of the nuclear sector; 1.2. General performances in safety; 1.3. The main incidents; 1.4. Wastes and radiation protection; 2. Nuclear safety management; 2.1. Dynamics and results; 2.2. Ameliorations to be consolidated; 3. Other important issues in safety; 3.1. Probabilistic safety studies; 3.2. Approach for safety re-evaluation; 3.3. The network safety; 3.4. Crisis management; 3.5. The Lifetime program; 3.6. PWR; 3.7. Documentation; 3.8. Competence; 4. Safety management in the future; 4.1. An open future; 4.2. The fast neutron NPP at Creys-Malville; 4.3. Stabilization of the PWR reference frame; 4.4. Implementing the EURATOM directive regarding the radiation protection standards; 4.5. Development of biomedical research and epidemiological studies; 4.6. New regulations concerning the liquid and gaseous effluents; 5. Visions of an open future; 5.1. Alternative views upon safety ay EDF; 5.2. Safety authority; 5.3. International considerations; 5.4. What happens abroad; 5.5. References from non-nuclear domain. Four appendices are added referring to policy of safety management, policy of human factors in NPPs

Report on nuclear safety on the operation of nuclear facilities in 1989

International Nuclear Information System (INIS)

Gregoric, M.; Levstek, M. F.; Horvat, D.; Kocuvan, M.; Cresnar, N.

1990-01-01

Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1989.

Report on nuclear safety on the operation of nuclear facilities in 1990

International Nuclear Information System (INIS)

Gregoric, M.; Grlicarev, I.; Horvat, D.; Levstek, M.F.; Lukacs, E.; Kocuvan, M.; Skraban, A.

1991-06-01

Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1990.

RCC-C: Design and construction rules for fuel assemblies of PWR nuclear power plants

International Nuclear Information System (INIS)

2015-01-01

The RCC-C code contains all the requirements for the design, fabrication and inspection of nuclear fuel assemblies and the different types of core components (rod cluster control assemblies, burnable poison rod assemblies, primary and secondary source assemblies and thimble plug assemblies). The design, fabrication and inspection rules defined in RCC-C leverage the results of the research and development work pioneered in France, Europe and worldwide, and which have been successfully used by industry to design and build nuclear fuel assemblies and incorporate the resulting feedback. The code's scope covers: fuel system design, especially for assemblies, the fuel rod and associated core components, the characteristics to be checked for products and parts, fabrication methods and associated inspection methods. The RCC-C code is used by the operator of the PWR nuclear power plants in France as a reference when sourcing fuel from the world's top two suppliers in the PWR market, given that the French operator is the world's largest buyer of PWR fuel. Fuel for EPR projects is manufactured according to the provisions of the RCC-C code. The code is available in French and English. The 2005 edition has been translated into Chinese. Contents of the 2015 edition of the RCC-C code: Chapter 1 - General provisions: 1.1 Purpose of the RCC-C, 1.2 Definitions, 1.3 Applicable standards, 1.4 Equipment subject to the RCC-C, 1.5 Management system, 1.6 Processing of non-conformances; Chapter 2 - Description of the equipment subject to the RCC-C: 2.1 Fuel assembly, 2.2 Core components; Chapter 3 - Design: Safety functions, operating functions and environment of fuel assemblies and core components, design and safety principles; Chapter 4 - Manufacturing: 4.1 Materials and part characteristics, 4.2 Assembly requirements, 4.3 Manufacturing and inspection processes, 4.4 Inspection methods, 4.5 Certification of NDT inspectors, 4.6 Characteristics to be inspected for the

Secondary systems of PWR and BWR

International Nuclear Information System (INIS)

Schindler, N.

1981-01-01

The secondary systems of a nuclear power plant comprises the steam, condensate and feedwater cycle, the steam plant auxiliary or ancillary systems and the cooling water systems. The presentation gives a general review about the main systems which show a high similarity of PWR and BWR plants. (orig./RW)

Structural integrity evaluation of PWR nuclear reactor pressure vessels

International Nuclear Information System (INIS)

Cruz, Julio R.B.; Mattar Neto, Miguel

1999-01-01

The reactor pressure vessel (RPV) is the most important structural component of a PWR nuclear power plant. It contains the reactor core and is the main component of the primary system pressure boundary, the system responsible for removing the heat generated by the nuclear reactions. It is considered not replaceable and, therefore, its lifetime is a key element to define the plant life as a whole. Three critical issues related to the reliability of the RPV structural integrity come out by reason of the radiation damage imposed to the vessel material during operation. These issues concern the definition of pressure versus temperature limits for reactor heatup and cooldown, pressurized thermal shock evaluation and assessment of reactor vessels with low upper shelf Charpy impact energy levels. This work aims to present the major aspects related to these topics. The requirements for preventing fracture of the RPV are reviewed as well as the available technology for assessing the safety margins. For each mentioned problem, the several steps for structural integrity evaluation are described and the analysis methods are discussed. (author)

Safety Aspects of Radioactive Waste Management in Different Nuclear Fuel Cycle Policies, a Comparative Study

International Nuclear Information System (INIS)

Gad Allah, A.A.

2009-01-01

With the increasing demand of energy worldwide, and due to the depletion of conventional natural energy resources, energy policies in many countries have been devoted to nuclear energy option. On the other hand, adopting a safe and reliable nuclear fuel cycle concept guarantees future nuclear energy sustain ability is a vital request from environmental and economic point of views. The safety aspects of radioactive waste management in the nuclear fuel cycle is a topic of great importance relevant to public acceptance of nuclear energy and the development of nuclear technology. As a part of nuclear fuel cycle safety evaluation studies in the department of nuclear fuel cycle safety, National Center for Nuclear Safety and Radiation Control (NCNSRC), this study evaluates the radioactive waste management policies and radiological safety aspects of three different nuclear fuel cycle policies. The once-through fuel cycle (OT- fuel cycle) or the direct spent fuel disposal concept for both pressurized light water reactor ( PWR) and pressurized heavy water reactor (PHWR or CANDU) systems and the s elf-generated o r recycling fuel cycle concept in PWR have been considered in the assessment. The environmental radiological safety aspects of different nuclear fuel cycle options have been evaluated and discussed throughout the estimation of radioactive waste generated from spent fuel from these fuel cycle options. The decay heat stored in the spent fuel was estimated and a comparative safety study between the three fuel cycle policies has been implemented

Development status of nuclear power in China and fundamental research progress on PWR primary water chemistry in China

International Nuclear Information System (INIS)

Wu, Xinqiang; Liu, Xiahe; Han, En-Hou; Ke, Wei; Xu, Yuming

2015-01-01

China's non-fossil fuels are expected to reach 20% in primary energy ratio by 2030. It is urgent for China to speed up the development of nuclear power to increase energy supply, reduce gas emissions and optimize resource allocation. Chinese government slowed down the approval of new nuclear power plant (NPP) projects after Fukushima accident in 2011. At the end of 2012, the State Council approved the nuclear safety program and adjusted long-term nuclear power development plan (2011-2020), the new NPP's projects have been restarted. In June 2015, there are 23 operating units in mainland in China with total installed capacity of about 21.386 GWe; another 26 units are under construction with total installed capacity of 28.5 GWe. The main type of reactors in operation and under construction in China is pressurized water reactor (PWR), including the first AP1000 NPPs in the world (units 1 in Sanmen) and China self-developed Hualong one NPPs (units 5 and 6 in Fuqing). Currently, China's nuclear power development is facing historic opportunities and also a series of challenges. One of the most important is the safety and economy of nuclear power. The optimization of primary water chemistry is one of the most effective ways to minimize radiation field, mitigate material degradation and maintain fuel performance in PWR NPPs, which is also a preferred path to achieve both safety and economy for operating NPPs. In recent years, an increased attention has been paid to fundamental research and engineering application of PWR primary water chemistry in China. The present talk mainly consists of four parts: (1) development status of China's nuclear power industry; (2) safety of nuclear power and operating water chemistry; (3) fundamental research progress on Zn-injected water chemistry in China; (4) summary and future. (author)

Evaluation of safety implications of control systems in LWR nuclear power plants

International Nuclear Information System (INIS)

Szukiewicz, A.J.

1989-06-01

An in-depth evaluation was performed on non-safety-related control systems (see Section 1) that are typically used during normal plant operation on four nuclear steam supply system plants: a General Electric Company boiling-water reactor, a Westinghouse 3-loop pressurized-water reactor (PWR), a Babcock ampersand Wilcox Co. (B ampersand W) once-through steam generator PWR, and a Combustion Engineering PWR design. A study was also conducted to determine the generic applicability of the results to the class of plants represented by the specific plants analyzed. Generic conclusions were then developed. Steam generator and reactor vessel overfill events and reactor vessel overcooling events were identified as major classes of events having the potential to be more severe than previously analyzed. Specific substasks of this issue were to study these events to determine the need for preventive and/or mitigating design measures. This report describes the technical studies performed by the laboratories, the NRC staff assessment of the results, the generic applicability of the evaluations, and the technical findings resulting from these studies. This final report contains the staff's responses to, and resolution of, the public comments that were solicited and received before September 16,1988, in response to the draft reports issued for public comment on May 27, 1988. 39 refs, 1 fig., 7 tabs

Nuclear power reactor safety research activities in CIAE

International Nuclear Information System (INIS)

Pu Shendi; Huang Yucai; Xu Hanming; Zhang Zhongyue

1994-01-01

The power reactor safety research activities in CIAE are briefly reviewed. The research work performed in 1980's and 1990's is mainly emphasised, which is closely related to the design, construction and licensing review of Qinshan Nuclear Power Plant and the safety review of Guangdong Nuclear Power Station. Major achievements in the area of thermohydraulics, nuclear fuel, probabilistic safety assessment and severe accident researches are summarized. The foreseeable research plan for the near future, relating to the design and construction of 600 MWe PWR NPP at Qinshan Site (phase II development) is outlined

Concept of voltage monitoring for a nuclear power plant emergency power supply system (PWR 1300 MWe)

International Nuclear Information System (INIS)

Andrade, R.B. de

1988-01-01

Voltage monitoring concept for a Nuclear Power Plant Emergency Power Supply Systems (PWR 1300 MWe) is described based on the phylosophy adopted for Angra 2 and 3 NPP's. Some suggested setpoints are only guidance values and can be modified during plant commissioning for a better performance of the whole protection system. (author) [pt

Papers presented as part of the status report of the Nuclear Safety Research Project of the Karlsruhe Nuclear Center on 23 March 1994

International Nuclear Information System (INIS)

Hueper, R.

1994-05-01

The ten papers deal with the state of safety requirements on future LWR plants and with nuclear safety research with regard to fast reactors and future PWR plants. In particular, passive after-heat removal, core disruptive accidents, and actinide burning in fast reactors are analysed. For PWR type plants the fuel element behaviour in the event of accidents, hydrogen distribution and hydrogen fires, and the origin and effects of steam explosions on the reactor pressure vessel and the containment are examined. Core meltdown cooling systems are suggested. (DG) [de

PWR auxiliary systems, safety and emergency systems, accident analysis, operation

International Nuclear Information System (INIS)

Meyer, P.J.

1976-01-01

The author presents a description of PWR auxiliary systems like volume control, boric acid control, coolant purification, -degassing, -storage and -treatment system and waste processing systems. Residual heat removal systems, emergency systems and containment designs are discussed. As an accident analysis the author gives a survey over malfunctions and disturbances in the field of reactor operations. (TK) [de

Application on electrochemistry measurement of high temperature high pressure condition in PWR nuclear power plants

International Nuclear Information System (INIS)

Li Yuchun; Xiao Zhongliang; Jiang Ya; Yu Xiaowei; Pang Feifei; Deng Fenfang; Gao Fan; Zhou Nianguang

2011-01-01

High temperature high pressure electrochemistry testing system was comprehensively analyzed in this paper, according to actual status for supervision in primary and secondary circuits of PWR nuclear power plants. Three research methods were reviewed and discussed for in-situ monitor system. By combination with ECP realtime measurement it was executed for evaluation and water chemistry optimization in nuclear power plants. It is pointed out that in-situ electrochemistry measurement has great potential application for water chemistry evaluation in PWR nuclear power plants. (authors)

Effects of Burnable Absorbers on PWR Spent Nuclear Fuel

International Nuclear Information System (INIS)

O'Leary, P.M.; Pitts, M.L.

2000-01-01

Burnup credit is an ongoing issue in designing and licensing transportation and storage casks for spent nuclear fuel (SNF). To address this issue, in July 1999, the U.S. Nuclear Regulatory Commission (NRC), Spent Fuel Project Office, issued Interim Staff Guidance-8 (ISG-8), Revision 1 allowing limited burnup credit for pressurized water reactor (PWR) spent nuclear fuel (SNF) to be used in transport and storage casks. However, one of the key limitations for a licensing basis analysis as stipulated in ISG-8, Revision 1 is that ''burnup credit is restricted to intact fuel assemblies that have not used burnable absorbers''. Because many PWR fuel designs have incorporated burnable-absorber rods for more than twenty years, this restriction places an unnecessary burden on the commercial nuclear power industry. This paper summarizes the effects of in-reactor irradiation on the isotopic inventory of PWR fuels containing different types of integral burnable absorbers (BAs). The work presented is illustrative and intended to represent typical magnitudes of the reactivity effects from depleting PWR fuel with different types of burnable absorbers

Safety Test Report for the PWR S/F Dry Storage System

Energy Technology Data Exchange (ETDEWEB)

Seo, K. S.; Lee, J. H.; Koo, K. H.; Lee, J. C.; Choi, W. S.; Bang, K. S.; Park, H. Y.; Jang, S. Y

2008-10-15

This is contract report conducted by KAERI under the contract with NETEC for safety test for the PWR S/F dry storage system. Leak Test was performed after drop test and turn-over test, the measured leakage rate was lower than allowable leakage rate. It is revealed that the containment integrity of the dry storage system is maintained. In the seismic test, the moving of the model was measured at SRTH seismic response of 0.4 g and 0.8 g. Therefore the seismic test results can be used fully to the test data for verification of the seismic analysis. In the thermal test, the direction of the inlet and outlet of the air has no effect on the heat transfer performance. The passive heat removal system of the horizontal storage module was designed well.

Development of the vacuum drying process for the PWR spent nuclear fuel dry storage

Energy Technology Data Exchange (ETDEWEB)

Baeg, Chagn Yeal; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of)

2016-12-15

This paper describes the development of a dry operation process for PWR spent nuclear fuel, which is currently stored in the domestic NPP's storage pool, using a dual purpose metal cask. Domestic NNPs have had experience with wet type transportation of PWR spent nuclear fuel between neighboring NPPs since the early 1990s, but no experience with dry type operation. For this reason, we developed a specific operation process and also confirmed the safety of the major cask components and its spent nuclear fuel during the dual purpose metal cask operation process. We also describe the short term operation process that was established to be completed within 21 hours and propose the allowable working time for each step (15 hours for wet process, 3 hours for drain process and 3 hours for vacuum drying process)

Nuclear safety approach for PWRs design and operation

International Nuclear Information System (INIS)

Vignon, D.

1988-01-01

The implementation of France's major nuclear programme - 56 PWR units in service or under construction - has gone hand in hand with the development of an original philosophy in the field of nuclear safety. From an initial core of deterministic safety philosophy current in the seventies, which has been wholly retained and in some instances refined, a range of additions has been made to include consideration of a number of additional situations based on a probabilistic approach. This has resulted in a better coherence for safety and a mitigation of the severe accident probability. Furthermore, the establishment of emergency plans has enabled the Safety Authorities and the operator to adopt a coherent and logical approach to severe accidents with the aim of achieving greater defence in depth, this has resulted in the provision of certain additional measures designed to further reduce the consequences of severe accidents. This paper describes the culmination of this work, as exemplified in the new 1 400MWe - N4 advanced plant series currently under construction, of which the essential elements are also incorporated into all previous units, thereby giving them an equivalent level of safety. This now constitutes the French safety policy with respect to PWR nuclear units

Measures taken to improve nuclear safety on EdF PWRs in operation

International Nuclear Information System (INIS)

Kus, J.-P.; Norvez, G.

1993-01-01

In parallel with its major nuclear programme (56 PWR units in service or under construction), France has developed an original philosophy in the field of Nuclear Safety. This comprehensive philosophy ensures a fine balance and coordination between design and operation, it provides a methodology to design, construct and operate a safe nuclear plant. Actual experience is then continuously compared to the initial expectation and the methodology refined whenever necessary. This methodology is fully applied to the new 1400 MWe plant series presently under construction. The essential elements are also backfitted into all previous units, thereby giving them an equivalent level of safety. The French PWR park can therefore be considered as very homogeneous with regard to its safety level, regarding both its design and operation. (author)

Software Quality Assurance for Nuclear Safety Systems

International Nuclear Information System (INIS)

Sparkman, D R; Lagdon, R

2004-01-01

The US Department of Energy has undertaken an initiative to improve the quality of software used to design and operate their nuclear facilities across the United States. One aspect of this initiative is to revise or create new directives and guides associated with quality practices for the safety software in its nuclear facilities. Safety software includes the safety structures, systems, and components software and firmware, support software and design and analysis software used to ensure the safety of the facility. DOE nuclear facilities are unique when compared to commercial nuclear or other industrial activities in terms of the types and quantities of hazards that must be controlled to protect workers, public and the environment. Because of these differences, DOE must develop an approach to software quality assurance that ensures appropriate risk mitigation by developing a framework of requirements that accomplishes the following goals: (sm b ullet) Ensures the software processes developed to address nuclear safety in design, operation, construction and maintenance of its facilities are safe (sm b ullet) Considers the larger system that uses the software and its impacts (sm b ullet) Ensures that the software failures do not create unsafe conditions Software designers for nuclear systems and processes must reduce risks in software applications by incorporating processes that recognize, detect, and mitigate software failure in safety related systems. It must also ensure that fail safe modes and component testing are incorporated into software design. For nuclear facilities, the consideration of risk is not necessarily sufficient to ensure safety. Systematic evaluation, independent verification and system safety analysis must be considered for software design, implementation, and operation. The software industry primarily uses risk analysis to determine the appropriate level of rigor applied to software practices. This risk-based approach distinguishes safety

The plutonium recycle for PWR reactors from brazilian nuclear program

International Nuclear Information System (INIS)

Rubini, L.A.

1978-01-01

The purpose of this thesis is to evaluate the material requirements of the nuclear fuel cycle with plutonium recycle. The study starts with the calculation of a reference reactor and has flexibility to evaluate the demand under two alternatives of nuclear fuel cycle for Pressurized Water Reactors (PWR): Without plutonium recycle; and with plutonium recycle. Calculations of the reference reactor have been carried out with the CELL-CORE codes. Variations in the material requirements were studied considering changes in the installed nuclear capacity of PWR reactors, the capacity factor of these reactors, and the introduction of fast breeders. Recycling plutonium produced inside the system can reach economies of about 5% U 3 O 8 and 6% separative work units if recycle is assumed only after the fifth operation cycle of the thermal reactors. (author)

Plutonium recycle in PWR reactors (Brazilian Nuclear Program)

International Nuclear Information System (INIS)

Rubini, L.A.

1978-02-01

An evaluation is made of the material requirements of the nuclear fuel cycle with plutonium recycle. It starts from the calculation of a reference reactor and allows the evaluation of demand under two alternatives of nuclear fuel cycle for Pressurized Water Reactors (PWR): without plutonium recycle; and with plutonium recycle. Calculations of the reference reactor have been carried out with the CELL-CORE codes. For plutonium recycle, the concept of uranium and plutonium homogeneous mixture has been adopted, using self-produced plutonium at equilibrium, in order to get minimum neutronic perturbations in the reactor core. The refueling model studied in the reference reactor was the 'out-in' scheme with a constant number of changed fuel elements (approximately 1/3 of the core). Variations in the material requirements were studied considering changes in the installed nuclear capacity of PWR reactors, the capacity factor of these reactors, and the introduction of fast breeders. Recycling plutonium produced inside the system can reach economies of about 5%U 3 O 8 and 6% separative work units if recycle is assumed only after the 5th operation cycle of the thermal reactors. The cumulative amount of fissile plutonium obtained by the Brazilian Nuclear Program of PWR reactors by 1991 should be sufficient for a fast breeder with the same capacity as Angra 2. For the proposed fast breeder programs, the fissile plutonium produced by thermal reactors is sufficient to supply fast breeder initial necessities. Howewer, U 3 O 8 and SWU economy with recycle is not significant when the proposed fast breeder program is considered. (Author) [pt

Sizewell: proposed site for Britain's first PWR power station

International Nuclear Information System (INIS)

1980-10-01

The pamphlet covers the following points, very briefly: nuclear power - a success story; the Government's nuclear programme; why Sizewell; the PWR (with diagram); the PWR at Sizewell (with aerial view) (location; size; cooling water; road access; fuel transport; construction; employment; environment; screening; the next steps (licensing procedures, etc.); safety; further information). (U.K.)

Seismic analysis of the reactor coolant system of PWR nuclear power plants

International Nuclear Information System (INIS)

Borsoi, L.; Sollogoub, P.

1986-01-01

For safety considerations, seismic analyses are performed of the Reactor Coolant System (R.C.S.) of PWR Plants. After a brief description of the R.C.S. and R.C.S. operation, the paper presents the two types of analysis used to determine the effect of earthquake on the R.C.S.: modal spectral analysis and nonlinear time history analysis. The paper finally shows how seismic loadings are combined with other types of loadings and illustrates how the consideration of seismic loads affects R.C.S. design [fr

The AMEBA PWR, a new concept in the technology of nuclear reactor safety

Energy Technology Data Exchange (ETDEWEB)

Novelli, A

2000-05-01

AMEBA is an Italian acronym which stands for 'alta moderazione e basso arricchimento' (high moderation and low enrichment). The AMEBA reactor is nothing more than a PWR which possesses very unusual values of both volumetric ratio moderator/fuel and U-235 enrichment of UO{sub 2}. The possibility is shown of the technical realisation of a nuclear power plant equipped with an AMEBA PWR reactor. Among the most enticing properties of AMEBA are the following: self-shut-down in any abnormal condition, elimination of all need for control rods and boric acid dissolution in the water, absolute impossibility of reaching values of reactivity greater than a fraction of a dollar, intrinsic subcriticality, attaining to several dollars, in non-operative condition when the water is at ambient temperature, normal operation with a very small-sized pressurizer, self-start-up.

The AMEBA PWR, a new concept in the technology of nuclear reactor safety

International Nuclear Information System (INIS)

Novelli, A.

2000-01-01

AMEBA is an Italian acronym which stands for 'alta moderazione e basso arricchimento' (high moderation and low enrichment). The AMEBA reactor is nothing more than a PWR which possesses very unusual values of both volumetric ratio moderator/fuel and U-235 enrichment of UO 2 . The possibility is shown of the technical realisation of a nuclear power plant equipped with an AMEBA PWR reactor. Among the most enticing properties of AMEBA are the following: self-shut-down in any abnormal condition, elimination of all need for control rods and boric acid dissolution in the water, absolute impossibility of reaching values of reactivity greater than a fraction of a dollar, intrinsic subcriticality, attaining to several dollars, in non-operative condition when the water is at ambient temperature, normal operation with a very small-sized pressurizer, self-start-up

Fundamental study on applicability of resilience index for system safety assessment

International Nuclear Information System (INIS)

Suzuki, Masaaki; Demachi, Kazuyuki; Murakami, Kenta

2015-01-01

We have developed a new index called Resilience index, which evaluate the reliability of system safety of nuclear power plant under severe accident by considering the capability to recover from the situation the system safety function was lost. In this paper, a detailed evaluation procedure for the Resilience index was described. System safety of a PWR plant under severe accident was then assessed according to the Resilience index concept to discuss applicability of the index. We found that the Resilience index successfully visualize the management capability, and therefore, resilience capability of a nuclear power plant. (author)

Investigation of chloride-release of nuclear grade resin in PWR primary system coolant

International Nuclear Information System (INIS)

Cao Xiaoning; Li Yunde; Li Jinghong; Lin Fangliang

1997-01-01

A new preparation technique is developed for making the low-chloride nuclear-grade resin by commercial resin. The chloride remained in nuclear grade resin may release to PWR primary coolant. The amount of released chloride is depended on the concentration of boron, lithium, other anion impurities, and remained chloride concentration in resin

SpinlineTM, Benefits of a nuclear specific safety-critical digital I/C platform - 15102

International Nuclear Information System (INIS)

Duthou, A.; Mouly, P.; Jegou, H.

2015-01-01

Spinline TM is Rolls-Royce modular and digital solution dedicated to developing and/or upgrading safety I/C used in nuclear reactors. From the start, Spinline TM was specifically designed for Nuclear applications. Therefore, its architecture and components satisfy, from design, the most stringent safety standards required by the local Safety authorities, while they can be adapted to various types of reactors. This is a significant advantage over suppliers who tried to adapt industrial systems to the Nuclear constraints and faced unexpected delays and costs to meet Safety authorities requirements. Spinline TM was specifically designed to implement any Class 1E and category A IEC-61226 safety I/C functions. It is qualified according to European and French nuclear standard and more recently by the US NRC, notably thanks to its Fail-safe features, deterministic behavior and Physical and Functional Separation. In 2011 EDF chose Spinline TM as its safety I/C systems technology for the modernization of 20 units of its 1300 MW PWR fleet

Dependability analysis of proposed I and C architecture for safety systems of a large PWR

International Nuclear Information System (INIS)

Kabra, Ashutosh; Karmakar, G.; Tiwari, A.P.; Manoj Kumar; Marathe, P.P.

2014-01-01

Instrumentation and Control (I and C) systems in a reactor provide protection against unsafe operation during steady-state and transient power operations. Indian reactors traditionally adopted 2-out-of-3 (2oo3) architecture for safety systems. But, contemporary reactor safety systems are employing 2-out-of-4 (2oo4) architecture in spite of the increased cost due to the additional channel. This motivated us to carry out a comparative study of 2oo3 and 2oo4 architecture, especially for their dependability attributes - safety and availability. Quantitative estimation of safety and availability has been used to adjudge the worthiness of adopting 2oo4 architecture in I and C safety systems of a large PWR. Our analysis using Markov model shows that 2oo4 architecture, even with lower diagnostic coverage and longer proof test interval, can provide better safety and availability in comparison of 2oo3 architecture. This reduces total life cycle cost of system during development phase and complexity and frequency of surveillance test during operational phase. The paper also describes the proposed architecture for Reactor Protection System (RPS), a representative safety system, and determines its dependability using Markov analysis and Failure Mode Effect Analysis (FMEA). The proposed I and C safety system architecture also has been qualitatively analyzed for their effectiveness against common cause failures (CCFs). (author)

IR-360 nuclear power plant safety functions and component classification

International Nuclear Information System (INIS)

Yousefpour, F.; Shokri, F.; Soltani, H.

2010-01-01

The IR-360 nuclear power plant as a 2-loop PWR of 360 MWe power generation capacity is under design in MASNA Company. For design of the IR-360 structures, systems and components (SSCs), the codes and standards and their design requirements must be determined. It is a prerequisite to classify the IR-360 safety functions and safety grade of structures, systems and components correctly for selecting and adopting the suitable design codes and standards. This paper refers to the IAEA nuclear safety codes and standards as well as USNRC standard system to determine the IR-360 safety functions and to formulate the principles of the IR-360 component classification in accordance with the safety philosophy and feature of the IR-360. By implementation of defined classification procedures for the IR-360 SSCs, the appropriate design codes and standards are specified. The requirements of specific codes and standards are used in design process of IR-360 SSCs by design engineers of MASNA Company. In this paper, individual determination of the IR-360 safety functions and definition of the classification procedures and roles are presented. Implementation of this work which is described with example ensures the safety and reliability of the IR-360 nuclear power plant.

IR-360 nuclear power plant safety functions and component classification

Energy Technology Data Exchange (ETDEWEB)

Yousefpour, F., E-mail: fyousefpour@snira.co [Management of Nuclear Power Plant Construction Company (MASNA) (Iran, Islamic Republic of); Shokri, F.; Soltani, H. [Management of Nuclear Power Plant Construction Company (MASNA) (Iran, Islamic Republic of)

2010-10-15

The IR-360 nuclear power plant as a 2-loop PWR of 360 MWe power generation capacity is under design in MASNA Company. For design of the IR-360 structures, systems and components (SSCs), the codes and standards and their design requirements must be determined. It is a prerequisite to classify the IR-360 safety functions and safety grade of structures, systems and components correctly for selecting and adopting the suitable design codes and standards. This paper refers to the IAEA nuclear safety codes and standards as well as USNRC standard system to determine the IR-360 safety functions and to formulate the principles of the IR-360 component classification in accordance with the safety philosophy and feature of the IR-360. By implementation of defined classification procedures for the IR-360 SSCs, the appropriate design codes and standards are specified. The requirements of specific codes and standards are used in design process of IR-360 SSCs by design engineers of MASNA Company. In this paper, individual determination of the IR-360 safety functions and definition of the classification procedures and roles are presented. Implementation of this work which is described with example ensures the safety and reliability of the IR-360 nuclear power plant.

A philosophy for space nuclear systems safety

International Nuclear Information System (INIS)

Marshall, A.C.

1992-01-01

The unique requirements and contraints of space nuclear systems require careful consideration in the development of a safety policy. The Nuclear Safety Policy Working Group (NSPWG) for the Space Exploration Initiative has proposed a hierarchical approach with safety policy at the top of the hierarchy. This policy allows safety requirements to be tailored to specific applications while still providing reassurance to regulators and the general public that the necessary measures have been taken to assure safe application of space nuclear systems. The safety policy used by the NSPWG is recommended for all space nuclear programs and missions

Nuclear safety activities in the SR of Slovenia in 1986

Energy Technology Data Exchange (ETDEWEB)

Susnik, J [Inst. Jozef Stefan, Ljubljana (Slovenia)

1987-06-15

Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1986. (author)

Nuclear safety activities in the SR of Slovenia in 1986

International Nuclear Information System (INIS)

Susnik, J.

1987-06-01

Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1986. (author)

Development and application of integrated digital I and C system in Japanese PWR plants

International Nuclear Information System (INIS)

Tominaga, M.

1995-01-01

The Integrated Digital Instrumentation and Control (I and C) System has been developed and applied to non-safety grade I and C systems in the latest 5 Japanese PWR plants in 1990's. Based on the experience in these plants, the Integrated Digital I and C System will be planned to apply also to safety grade I and C systems in Advanced PWR (APWR) as the overall application of digital technology. The basic design task has been just started for APWR which is to be in commercial operation in early 2000's and under the development about various issues of safety grade digital I and C systems. On the other hand, in conventional Japanese PWR plants, digital I and C systems have been applied step by step since 1980's. For example, digital I and C systems for radio-active waste processing system have been adopted to 13 units, and dedicated digital I and C systems for Local loop control system to 8 units. The trend and status of development and application of the digital I and C systems, especially the Integrated Digital I and C System in Japanese PWR plants are presented. (5 refs., 4 figs.)

Advanced passive PWR AC-600: Development orientation of nuclear power reactors in China for the next century

International Nuclear Information System (INIS)

Huang Xueqing; Zhang Senru

1999-01-01

Based on Qinshan II Nuclear Power Plant that is designed and constructed by way of self-reliance, China has developed advanced passive PWR AC-600. The design concept of AC-600 not only takes the real situation of China into consideration, but also follows the developing trend of nuclear power in the world. The design of AC-600 has the following technical characteristics: Advanced reactor: 18-24 month fuel cycle, low neutron leakage, low power density of the core, no any penetration in the RPV below the level of the reactor coolant nozzles; Passive safety systems: passive emergency residual heat removal system, passive-active safety injection system, passive containment cooling system and main control room habitability system; System simplified and the number of components reduced; Digital I and C; Modular construction. AC-600 inherits the proven technology China has mastered and used in Qirtshan 11, and absorbs advanced international design concepts, but it also has a distinctive characteristic of bringing forth new ideas independently. It is suited to Chinese conditions and therefore is expected to become an orientation of nuclear power development by self-reliance in China for the next century. (author)

PWR plant transient analyses using TRAC-PF1

International Nuclear Information System (INIS)

Ireland, J.R.; Boyack, B.E.

1984-01-01

This paper describes some of the pressurized water reactor (PWR) transient analyses performed at Los Alamos for the US Nuclear Regulatory Commission using the Transient Reactor Analysis Code (TRAC-PF1). Many of the transient analyses performed directly address current PWR safety issues. Included in this paper are examples of two safety issues addressed by TRAC-PF1. These examples are pressurized thermal shock (PTS) and feed-and-bleed cooling for Oconee-1. The calculations performed were plant specific in that details of both the primary and secondary sides were modeled in addition to models of the plant integrated control systems. The results of these analyses show that for these two transients, the reactor cores remained covered and cooled at all times posing no real threat to the reactor system nor to the public

ALIBABA, an assistance system for the detection of confinement leaks in a PWR reactor

International Nuclear Information System (INIS)

Bedier, P.O.; Libmann, M.

1995-01-01

The objective of the Crisis Technical Center (CTC) of the French Institute for Nuclear Protection and Safety (IPSN) is to estimates the consequences of a given nuclear accident on the populations and the environment. ALIBABA is a data processing tool available at the CTC and devoted to the detection of confinement leaks in 900 MWe PWR reactors using the activity values measured by the captors of the installation. The heart of this expert system is a structural and functional representation of the different components directly involved in the leak detection (isolating valves, ventilation systems, electric boards etc..). This tool can manage the availability of each component to make qualitative and quantitative balance-sheets. This paper presents the ALIBABA software, an industrial prototype realized with the SPIRAL knowledge base systems generator at the CEA Reactor Studies and Applied Mathematics Service (SERMA) and commercialized by CRIL-Ingenierie Society. It describes the techniques used for the modeling of PWR systems and for the visualization of the survey. The functionality of the man-machine interface is discussed and the means used for the validation of the software are summarized. (J.S.). 6 refs

Effects of aging in containment spray injection system of PWR reactor containment

International Nuclear Information System (INIS)

Borges, Diogo da S.; Lava, Deise D.; Affonso, Renato R.W.; Guimaraes, Antonio C.F.; Moreira, Maria de L.

2014-01-01

This paper presents a contribution to the study of the components aging process in commercial plants of Pressurized Water Reactors (PWR). The analysis is done by applying the method of Fault trees, Monte Carlo Method and Fussell-Vesely Importance Measurement. The study on the aging of nuclear plants, is related to economic factors involved directly with the extent of their operational life, and also provides important data on issues of safety. The most recent case involving the process of extending the life of a PWR plant can be seen in Angra 1 Nuclear Power Plant by investing $ 27 million in the installation of a new reactor cover. The corrective action generated an extension of the useful life of Angra 1 estimated in twenty years, and a great savings compared to the cost of building a new plant and the decommissioning of the first, if it had reached the operation time out 40 years. The extension of the lifetime of a nuclear power plant must be accompanied by special attention from the most sensitive components of the systems to the aging process. After the application of the methodology (aging analysis of Containment Spray Injection System (CSIS)) proposed in this paper, it can be seen that increasing the probability of failure of each component, due to the aging process, generate an increased general unavailability of the system that contains these basic components. The final results obtained were as expected and can contribute to the maintenance policy, preventing premature aging in nuclear power systems

Seismic analysis for safety related structures of 900MWe PWR NPP

International Nuclear Information System (INIS)

Liu Wei

2002-01-01

Nuclear Power Plant aseismic design becomes more and more important in China due to the fact that China is a country where earthquakes occur frequently and most of plants arc unavoidably located in seismic regions. Therefore, Chinese nuclear safety authority and organizations have worked out a series of regulations and codes related to NPP anti-seismic design taking account of local conditions. The author presents here an example of structural anti-seismic design of 90GM We PWR NPP which is comprised of: ground motion input, including the principles for ground motion determination and time history generation; soil and upper-structure modelling, presenting modeling procedures and typical models of safety related buildings such as Reactor Building, Nuclear Auxiliary Building and Fuel Building; soil-structure interaction analysis; and in-structure response analysis and floor response spectrum generation. With this example, the author intends to give an overview of Chinese practice in NPP structure anti-seismic design such as the main procedures to be followed and the codes and regulations to be respected. (author)

Analysis of difficulties accounting and evaluating nuclear material of PWR fuel plant

International Nuclear Information System (INIS)

Zhang Min; Jue Ji; Liu Tianshu

2013-01-01

Background: Nuclear materials accountancy must be developed for nuclear facilities, which is required by regulatory in China. Currently, there are some unresolved problems for nuclear materials accountancy of bulk nuclear facilities. Purpose: The retention values and measurement errors are analyzed in nuclear materials accountancy of Power Water Reactor (PWR) fuel plant to meet the regulatory requirements. Methods: On the basis of nuclear material accounting and evaluation data of PWR fuel plant, a deep analysis research including ratio among random error variance, long-term systematic error variance, short-term systematic error variance and total error involving Material Unaccounted For (MUF) evaluation is developed by the retention value measure in equipment and pipeline. Results: In the equipment pipeline, the holdup estimation error and its total proportion are not more than 5% and 1.5%, respectively. And the holdup estimation can be regraded as a constant in the PWR nuclear material accountancy. Random error variance, long-term systematic error variance, short-term systematic error variance of overall measurement, and analytical and sampling methods are also obtained. A valuable reference is provided for nuclear material accountancy. Conclusion: In nuclear material accountancy, the retention value can be considered as a constant. The long-term systematic error is a main factor in all errors, especially in overall measurement error and sampling error: The long-term systematic errors of overall measurement and sampling are considered important in the PWR nuclear material accountancy. The proposals and measures are applied to the nuclear materials accountancy of PWR fuel plant, and the capacity of nuclear materials accountancy is improved. (authors)

Concept of voltage and frequency monitoring for a nuclear power plant normal power supply system - PWR 1300 MWe

International Nuclear Information System (INIS)

Andrade, R.B. de

1990-01-01

Voltage and frequency monitoring concept for a Nuclear Power Plant Normal Power Supply System (PWR 1300 MWe) is described based on the phylosophy adopted for Angra 2 and e NPP's. Some suggested setpoints are only guidance values and can be modified during plant commissioning for a better performance of the whole protection system. (author) [pt

78 FR 4477 - Review of Safety Analysis Reports for Nuclear Power Plants, Introduction

Science.gov (United States)

2013-01-22

... Analysis Reports for Nuclear Power Plants: LWR Edition.'' The new subsection is the Standard Review Plan... Nuclear Power Plants: Integral Pressurized Water Reactor (iPWR) Edition.'' DATES: Comments must be filed... NUCLEAR REGULATORY COMMISSION [NRC-2012-0268] Review of Safety Analysis Reports for Nuclear Power...

Safety aspects of the using Gd as burnable poison in PWR's

International Nuclear Information System (INIS)

Vandenberg, C.; Bonet, H.; Charlier, A.

1978-01-01

The experience of BELGONUCLEAIRE in using Gd in LWR's has indicated the safety related advantages of this burnable poison. The successfully operation of the BR3 PWR power plant with 5% of Gd rods is presented and extrapolated to large PWR's. (authro)

Diagnosis and prognosis of the source term by the French Safety Institut during an emergency on a PWR

International Nuclear Information System (INIS)

Chauliac, C.; Janot, L.; Jouzier, A.; Rague, B.

1992-01-01

The French approach for the diagnosis and the prognosis of the source term during an accident on a PWR is presented and the tools which have been developed to implement this approach at the Institute for Nuclear Protection and Safety (IPSN) are described. (author). 2 refs, 3 figs

Nuclear power systems: Their safety

International Nuclear Information System (INIS)

Myers, L.C.

1993-01-01

Mankind utilizes energy in many forms and from a variety of sources. Canada is one of a growing number of countries which have chosen to embrace nuclear-electric generation as a component of their energy systems. As of August 1992 there were 433 power reactors operating in 35 countries and accounting for more than 15% of the world's production of electricity. In 1992, thirteen countries derived at least 25% of their electricity from nuclear units, with France leading at nearly 70%. In the same year, Canada produced about 16% of its electricity from nuclear units. Some 68 power reactors are under construction in 16 countries, enough to expand present generating capacity by close to 20%. No human endeavour carries the guarantee of perfect safety and the question of whether or not nuclear-electric generation represents an 'acceptable' risk to society has long been vigorously debated. Until the events of late April 1986, nuclear safety had indeed been an issue for discussion, for some concern, but not for alarm. The accident at the Chernobyl reactor in the USSR has irrevocably changed all that. This disaster brought the matter of nuclear safety back into the public mind in a dramatic fashion. This paper discusses the issue of safety in complex energy systems and provides brief accounts of some of the most serious reactor accidents which have occurred to date. (author). 7 refs

The nuclear safety and the radiation protection in France in 2003

International Nuclear Information System (INIS)

2004-03-01

Nine points are reviewed: the law project relative to the safety and openness in nuclear field, the safety of the European PWR type Reactor, the priorities in radiation protection, inspection of radiation protection, the surveillance of patients exposure to ionizing radiations, the hot days and dryness of summer 2003 and the functioning of nuclear power plant, the national planning of radioactive waste management, the becoming of high level and years living radioactive waste, the European nuclear policy. (N.C.)

Safety of nuclear installations

International Nuclear Information System (INIS)

1991-01-01

In accordance with the Nuclear Energy Act, a Licence may only be issued if the precautions required by the state of the art have been taken to prevent damage resulting from the construction and operation of the installation. The maximum admissible body doses in the area around the installation which must be observed in planning constructional and other technical protective measures to counter accidents in or at a nuclear power station (accident planning values, are established). According to the Radiological Protection Ordinance the Licensing Authority can consider these precautions to have been taken if, in designing the installation against accidents, the applicant has assumed the accidents which, according to the Safety Criteria and Guidelines for Nuclear Power Stations published in the Federal Register by the Federal Minister of the Interior after hearing the competent senior state authorities, must determine the design of a nuclear power station. On the basis of previous experience from safety analysis, assessment and operation of nuclear power stations, the accident guidelines published here define which accidents are determinative for the safety-related design of PWR power stations and what verification -particularly with regard to compliance with the accident planning values of the Radiological Protection Ordinance -must be provided by the applicant. (author)

Nuclear Power and Safety Division activity

International Nuclear Information System (INIS)

Pazdera, F.

1991-01-01

History of the Division is briefly described. Present research is centered on reliability analyses and thermal hydraulic analyses of transients and accidents. Some results of the safety analyses have been applied at nuclear power plants. A characterization is presented of computer codes for analyzing the behavior of fuel in normal and accident conditions. Research activities in the field of water chemistry and corrosion are oriented to the corrosion process at high temperatures and high pressures, and the related mass and radioactivity transfer; the effect of some chemical processes on primary coolant circuit materials; optimization of PWR filtration systems; and the development of the requisite monitoring instrumentation. A computerized operator support system has been developed, and at present it is tested at the Dukovany nuclear power plant. A program of nuclear fuel cycle strategy and economy has been worked out for nuclear fuel performance evaluation. Various options for better fuel exploitation, alternatives for advanced fuelling, and fuel cycle costs are assessed, and out-of-reactor fuel cycle options are compared. (M.D.). 7 refs., 32 refs

RSK-guidelines for PWR reactors

International Nuclear Information System (INIS)

1979-01-01

The RSK guidelines for PWA reactors of April 24, 1974, have been revised and amended in this edition. The RSK presents a summary of safety requirements to be observed in the design, construction, and operation of PWR reactors in the form of guidelines. From January 1979 onwards these guidelines will be the basis of siting and safety considerations for new PWR reactors, and newly built nuclear power plants will have to form these guidelines. They are not binding for existing nuclear power plants under construction or in operation. It will be a matter of individual discussion whether or not the guidelines will be applied in these plants. The main purpose of the guidelines is to facilitate discussion among RSK members and to give early information on necessary safety requirements. If the guidelines are observed by producers and operators, the RSK will make statements on individual projects at short notice. (orig./HP) [de

Understanding Nuclear Safety Culture: A Systemic Approach

International Nuclear Information System (INIS)

Afghan, A.N.

2016-01-01

The Fukushima accident was a systemic failure (Report by Director General IAEA on the Fukushima Daiichi Accident). Systemic failure is a failure at system level unlike the currently understood notion which regards it as the failure of component and equipment. Systemic failures are due to the interdependence, complexity and unpredictability within systems and that is why these systems are called complex adaptive systems (CAS), in which “attractors” play an important role. If we want to understand the systemic failures we need to understand CAS and the role of these attractors. The intent of this paper is to identify some typical attractors (including stakeholders) and their role within complex adaptive system. Attractors can be stakeholders, individuals, processes, rules and regulations, SOPs etc., towards which other agents and individuals are attracted. This paper will try to identify attractors in nuclear safety culture and influence of their assumptions on safety culture behavior by taking examples from nuclear industry in Pakistan. For example, if the nuclear regulator is an attractor within nuclear safety culture CAS then how basic assumptions of nuclear plant operators and shift in-charges about “regulator” affect their own safety behavior?

The regulatory system of nuclear safety in Russia

International Nuclear Information System (INIS)

Mizoguchi, Shuhei

2013-01-01

This article explains what type of mechanism the nuclear system has and how nuclear safety is regulated in Russia. There are two main organizations in this system : ROSATOM and ROSTEKHADZOR. ROSATOM, which was founded in 2007, incorporates all the nuclear industries in Russia, including civil nuclear companies as well as nuclear weapons complex facilities. ROSTEKHNADZOR is the federal body that secures and supervises the safety in using atomic energy. This article also reviews three laws on regulating nuclear safety. (author)

Electricity supplies in a French nuclear power station

International Nuclear Information System (INIS)

2011-01-01

As the operation of a nuclear power station requires a power supply system enabling this operation as well as the installation safety, this document describes how such systems are designed in the different French nuclear power stations to meet the requirements during a normal operation (when the station produces electricity) or when it is stopped, but also to ensure power supply to equipment ensuring safety functions during an incident or an accident occurring on the installation. More precisely, these safety functions are provided by two independent systems in the French nuclear power stations. Their operation is briefly described. Two different types of nuclear reactors are addressed: pressurised water reactors (PWR) of second generation, EPR (or PWR of third generation)

Development of the Advanced Nuclear Safety Information Management (ANSIM) System

Energy Technology Data Exchange (ETDEWEB)

Sohn, Jae Min; Ko, Young Cheol; Song, Tai Gil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Korea has become a technically independent nuclear country and has grown into an exporter of nuclear technologies. Thus, nuclear facilities are increasing in significance at KAERI (Korea Atomic Energy Research Institute), and it is time to address the nuclear safety. The importance of nuclear safety cannot be overemphasized. Therefore, a management system is needed urgently to manage the safety of nuclear facilities and to enhance the efficiency of nuclear information. We have established ISP (Information Strategy Planning) for the Integrated Information System of nuclear facility and safety management. The purpose of this paper is to develop a management system for nuclear safety. Therefore, we developed the Advanced Nuclear Safety Information Management system (hereinafter referred to as the 'ANSIM system'). The ANSIM system has been designed and implemented to computerize nuclear safety information for standardization, integration, and sharing in real-time. Figure 1 shows the main home page of the ANSIM system. In this paper, we describe the design requirements, contents, configurations, and utilizations of the ANSIM system

PWR systems transient analysis

International Nuclear Information System (INIS)

Kennedy, M.F.; Peeler, G.B.; Abramson, P.B.

1985-01-01

Analysis of transients in pressurized water reactor (PWR) systems involves the assessment of the response of the total plant, including primary and secondary coolant systems, steam piping and turbine (possibly including the complete feedwater train), and various control and safety systems. Transient analysis is performed as part of the plant safety analysis to insure the adequacy of the reactor design and operating procedures and to verify the applicable plant emergency guidelines. Event sequences which must be examined are developed by considering possible failures or maloperations of plant components. These vary in severity (and calculational difficulty) from a series of normal operational transients, such as minor load changes, reactor trips, valve and pump malfunctions, up to the double-ended guillotine rupture of a primary reactor coolant system pipe known as a Large Break Loss of Coolant Accident (LBLOCA). The focus of this paper is the analysis of all those transients and accidents except loss of coolant accidents

Effect of aging on the PWR Chemical and Volume Control System

International Nuclear Information System (INIS)

Grove, E.J.; Travis, R.J.; Aggarwal, S.K.

1995-06-01

The PWR Chemical and Volume Control System (CVCS) is designed to provide both safety and non-safety related functions. During normal plant operation it is used to control reactor coolant chemistry, and letdown and charging flow. In many plants, the charging pumps also provide high pressure injection, emergency boration, and RCP seal injection in emergency situations. This study examines the design, materials, maintenance, operation and actual degradation experiences of the system and main sub-components to assess the potential for age degradation. A detailed review of the Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Report (LER) databases for the 1988--1991 time period, together with a review of industry and NRC experience and research, indicate that age-related degradations and failures have occurred. These failures had significant effects on plant operation, including reactivity excursions, and pressurizer level transients. The majority of these component failures resulted in leakage of reactor coolant outside the containment. A representative plant of each PWR design (W, CE, and B and W) was visited to obtain specific information on system inspection, surveillance, monitoring, and inspection practices. The results of these visits indicate that adequate system maintenance and inspection is being performed. In some instances, the frequencies of inspection were increase in response to repeated failure events. A parametric study was performed to assess the effect of system aging on Core Damage Frequency (CDF). This study showed that as motor-operated valve (MOV) operating failures increased, the contribution of the High Pressure Injection to CDF also increased

Nuclear safety activities in SR Slovenia in 1985

International Nuclear Information System (INIS)

1986-09-01

Currently Yugoslavia has one 632 MWe nuclear power plant of PWR design, located at Krsko in the Socialist Republic of Slovenia. NPP Krsko, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in SR Slovenia are mostly related to upgrading the safety of our NPP Krsko and to develop capabilities to be used for the future units. This report presents safety related organizations in SR Slovenia and their activities performed in 1985. (author)

Nuclear safety activities in SR Slovenia in 1985

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-09-15

Currently Yugoslavia has one 632 MWe nuclear power plant of PWR design, located at Krsko in the Socialist Republic of Slovenia. NPP Krsko, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in SR Slovenia are mostly related to upgrading the safety of our NPP Krsko and to develop capabilities to be used for the future units. This report presents safety related organizations in SR Slovenia and their activities performed in 1985. (author)

Problems of nuclear power plant safety evaluation

International Nuclear Information System (INIS)

Suchomel, J.

1977-01-01

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

Source term aspects associated with future PWR containment systems

International Nuclear Information System (INIS)

Kuczera, B.; Kebler, G.; Ehrhardt, J.; Scholtyssek, W.

1994-01-01

The overall objective of reactor safety is to protect the population against dangerous releases of radioactive materials from nuclear power plants. In context with a reinforcement of the defense-in-depth strategy the common safety requirements on future nuclear power plants converge in the objective that these plants should be so safe that even in case of a severe accident there will be no need of off-site emergency actions such as an evacuation or resettlement of the population from the vicinity of a nuclear power plant. It is shown by the example of a future 1400 MWe pressurized water reactor (PWR) plant that this goal can be attained in principle by providing a double containment with the annulus vented via an appropriate emergency standby filter. Within the framework of severe accident consequence mitigation a set of parameters for accident conditions and emergency filter efficiencies is elaborated under which the German lower levels of intervention for evacuation are not attained. (author). 10 refs., 3 tabs., 5 figs

Numerical simulation of the heating and start-up of PWR nuclear power station

International Nuclear Information System (INIS)

Faraco-Medeiros, M.A.; Leite, C.A.T.; Ramalho, F.P.

1992-01-01

The start-up of a PWR nuclear power plant must be done within safety criteria and requires a simulation. The design of some equipment, cost and time can be optimized. A computer simulator, which allows control of all the equipment and variables into the operation, has been developed and is presented in this paper. The KWU procedure and an alternative for Angra II were simulated. The results are showed up. 09 refs, 03 figs. (B.C.A.)

Summary of the nuclear safety in operation

International Nuclear Information System (INIS)

2004-01-01

This summary is a collection of general information about nuclear safety of PWR type reactors exploited by EDF. Teaching aid, this work has been conceived by operators for operators, it must not be considered nor used as a doctrine document with a regulatory or prescriptive characteristic. it summarizes the great principles of nuclear safety, places them in a global approach and shows their coherence. It consists in 6 chapters and 6 annexes. The news of this edition are the chapter 2 devoted to the safety management and the annexe 6 devoted to the principal teaching coming from the feedback. At the end a glossary explains the signs and abbreviations and an index allows to find themes in the memento text from keywords. (N.C.)

Innovation in the Safety of nuclear systems: fundamental aspects

International Nuclear Information System (INIS)

Herranz, L. E.

2009-01-01

Safety commercial nuclear reactors has been an indispensable condition for future enlargement of power generation based on nuclear technology. Its fundamental principle, defence in depth, far from being outdated, is still adopted as a key foundation in the advanced nuclear system (generations III and IV). Nevertheless, the cumulative experience gained in the operation and maintenance of nuclear reactors, the development of methodologies like the probabilistic safety analysis, the use of passive safety systems and, even, the inherent characteristics of some new design (which exclude accident scenarios), allow estimating safety figures of merit even more outstanding that those achieved in the second generation of nuclear reactors. This safety innovation of upcoming nuclear reactors has entailed a huge investigation program (generation III) that will be focused on optimizing and demonstrating the postulated safety of future nuclear systems (Generation IV). (Author)

PWR composite materials use. A particular case of safety-related service water pipes

International Nuclear Information System (INIS)

Pays, M.F.; Le Courtois, T.

1997-11-01

This paper shows the present and future uses of composite materials in French nuclear and fossil-fuel power plants. Electricite de France has decided to install composite materials in service water piping in its future nuclear power plant (PWR) at Civaux (West of France) and for the firs time in France, in safety-related applications. A wide range of studies has been performed about the durability, the control and damage mechanisms of those materials under service conditions among an ongoing Research and Development project. The main results are presented under the following headlines: selection of basic materials and manufacturing processes; aging processes (mechanical behavior during 'lifetime'); design rules; non destructive examination during manufacturing process and during operation. The studies have been focused on epoxy pipings. The importance of strong quality insurance policy requirements are outlined. A study of the use of composite pipes in power plants (hydraulic, fossil fuel, and nuclear) in France and around the world (USA, Japan, Western Europe) are presented whether it be safety related or non safety-related applications. The different technical solutions for materials and manufacturing processes are presented and an economic comparison is made between steel and composite pipes. (author)

PWR composite materials use. A particular case of safety-related service water pipes

Energy Technology Data Exchange (ETDEWEB)

Pays, M.F.; Le Courtois, T

1997-11-01

This paper shows the present and future uses of composite materials in French nuclear and fossil-fuel power plants. Electricite de France has decided to install composite materials in service water piping in its future nuclear power plant (PWR) at Civaux (West of France) and for the firs time in France, in safety-related applications. A wide range of studies has been performed about the durability, the control and damage mechanisms of those materials under service conditions among an ongoing Research and Development project. The main results are presented under the following headlines: selection of basic materials and manufacturing processes; aging processes (mechanical behavior during `lifetime`); design rules; non destructive examination during manufacturing process and during operation. The studies have been focused on epoxy pipings. The importance of strong quality insurance policy requirements are outlined. A study of the use of composite pipes in power plants (hydraulic, fossil fuel, and nuclear) in France and around the world (USA, Japan, Western Europe) are presented whether it be safety related or non safety-related applications. The different technical solutions for materials and manufacturing processes are presented and an economic comparison is made between steel and composite pipes. (author) 2 refs.

Guidelines for Safety Evaluation of a Potential for PWR Steam Generator Tube Failure due to Fluid elastic Instability

Energy Technology Data Exchange (ETDEWEB)

Jo, Jong Chull; Do, Kyu Sik; Sheen, Cheol [Nuclear System Evaluation Dept., Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-05-15

It was found that both SG tube rupture events occurred at North Anna Unit 1 in 1987 and at Mihama Unit 2 in 1991 were caused by a high cycle fatigue due to fluid elastic instability. Therefore, with regard to nuclear safety it is important to design the SG properly in a conservative manner so that the potential for SG U-tube failures due to fluid elastic instability can be minimized. This article provides guidelines for assessing the potential for SG U-tube damage due to fluid elastic instability. This article described guidelines for safety evaluation of a potential for PWR steam generator tube failure due to fluid elastic instability. The guidelines address the requirements for realistically performing the SG thermal-hydraulic analysis and the modal analysis of tubes as well as the criteria for conservatively determining the added mass, the damping ratio and the fluid elastic instability coefficient. The guidelines can be used to predict the potential SG tubes which are susceptible to failure due to fluid elastic instability at operating nuclear power plants and also to evaluate the safety and structural integrity of new SG designs at the licensing review stage. Failure of a pressurized water reactor (PWR) steam generator (SG) tube leads to a leakage of contaminated primary coolant to the secondary system, which has serious safety implications such as the potential for direct release of radioactive fission products to the environment and the loss of coolant. Excessive tube vibration excited by dynamic forces of internal or external fluid flow is called flow-induced vibration (FIV). Among the FIV mechanisms, the so-called fluid elastic instability of SG tubes in cross flow is the most important safety issue in the design of SGs because it may cause severe tube failure in a very short time.

Study on advanced nuclear fuel cycle of PWR/CANDU synergism

International Nuclear Information System (INIS)

Xie Zhongsheng; Huo Xiaodong

2002-01-01

According to the concrete condition that China has both PWR and CANDU reactors, one of the advanced nuclear fuel cycle strategy of PWR/CANDU synergism ws proposed, i.e. the reprocessed uranium of spent PWR fuel was used in CANDU reactor, which will save the uranium resource, increase the energy output, decrease the quantity of spent fuels to be disposed and lower the cost of nuclear power. Because of the inherent flexibility of nuclear fuel cycle in CANDU reactor, the transition from the natural uranium to the recycled uranium (RU) can be completed without any changes of the structure of reactor core and operation mode. Furthermore, because of the low radiation level of RU, which is acceptable for CANDU reactor fuel fabrication, the present product line of fuel elements of CANDU reactor only need to be shielded slightly, also the conditions of transportation, operation and fuel management need not to be changed. Thus this strategy has significant practical and economical benefit

A study on optimization of the nuclear safety system

International Nuclear Information System (INIS)

Lee, Sang Hoon; Koh, Byung Joon; Kim, Jin Soo; Kim, Byoung Do; Cho, Seong Won; Kwon, Seog Kwon; Choi, Kwang Sik

1986-12-01

The number of nuclear facilities (nuclear power plants, research reactors, nuclear fuel facilities) under construction or in operation in Korea continues to increase and this has brought about increased importance and concerns toward nuclear safety in Korea. Also, domestic nuclear related organizations are increasingly carrying out the design/construction of nuclear power plants and the development /supply of nuclear fuels. In order to flexibly respond to these changes and to suggest direction to take, it is necessary to re-examine the current nuclear safety regulation system. This study is carried out in two stages and this report describes the results of the analysis and the assessment of the nuclear licencing system of such foreign countries as sweden and German, as the first of the two. In this regard, this study includes the analysis on the backgrounds on the choice of nuclear licensing system, the analysis on the licensing procedures, the analysis on the safety inspection system and the enforcement laws, the analysis on the structure and function of the regulatory, business and research organizations as well as the analysis on the relationship between the safety research and the regulatory duties. In this study, the German safety inspection system and the enforcement procedures and the Swedish nuclear licensing system are analyzed in detail. By comparing and assessing the finding with the current Korea Nuclear Licensing System, this study points out some reform measures of the Korean system that needs to improved. With the changing situations in mind, this study aims to develop the nuclear safety regulation system optimized for Korean situation by re-examining the current regulation system. (Author)

The significance of the probabilistic safety analysis (PSA) in administrative procedures under nuclear law

International Nuclear Information System (INIS)

Berg, H.P.

1994-01-01

The probabilistic safety analysis (PSA) is a useful tool for safety relevant evaluation of nuclear power plant designed on the basis of deterministic specifications. The PSA yields data identifying reliable or less reliable systems, or frequent or less frequent failure modes to be taken into account for safety engineering. Performance of a PSA in administrative procedures under nuclear law, e.g. licensing, is an obligation laid down in a footnote to criterion 1.1 of the BMI safety criteria catalogue, which has been in force unaltered since 1977. The paper explains the application and achievements of PSA in the phase of reactor development concerned with the conceptual design basis and design features, using as an example the novel PWR. (orig./HP) [de

General digitalized system on nuclear power plants

International Nuclear Information System (INIS)

Akagi, Katsumi; Kadohara, Hozumi; Taniguchi, Manabu

2000-01-01

Hitherto, instrumentation control system in a PWR nuclear power plant has stepwisely adopted digital technology such as application of digital instrumentation control device to ordinary use (primary/secondary system control device, and so on), application of CRT display system to monitoring function, and so forth, to realize load reduction of an operator due to expansion of operation automation range, upgrading of reliability and maintenance due to self-diagnosis function, reduction of mass in cables due to multiple transfer, and upgrading of visual recognition due to information integration. In next term PWR plant instrumentation control system, under consideration of application practice of conventional digital technology, application of general digitalisation system to adopt digitalisation of overall instrumentation control system containing safety protection system, and central instrumentation system (new type of instrumentation system) and to intend to further upgrade economics, maintenance, operability/monitoring under security of reliability/safety is planned. And, together with embodiment of construction program of the next-term plant, verification at the general digitalisation proto-system aiming at establishment of basic technology on the system is carried out. Then, here was described on abstract of the general digitalisation system and characteristics of a digital type safety protection apparatus to be adopted in the next-term plant. (G.K.)

A study on LAN applications in nuclear safety systems

International Nuclear Information System (INIS)

Kim, Sung; Lee, Young Ryul; Koo, Jun Mo; Han, Jai Bok

1995-01-01

It is a general tendency to digitalize the conventional relay based I and C systems in nuclear power plant. But, the digitalisation of nuclear safety systems has many a difficulty to surmount. The typical one thing of many difficulties is the data communication problem between local controllers and systems. The network architecture built with LAN (Local Area Network) in digital systems of the other industries are general. But in case of nuclear safety systems many considerations in point of safety and license are required to implement it in the field. In this parer, some considerations for applying LAN in nuclear safety systems were reviewed

PWR system reliability improvement activities

International Nuclear Information System (INIS)

Yoshikawa, Yuichiro

1985-01-01

In Japan lacking in energy resources, it is our basic energy policy to accelerate the development program of nuclear power, thereby reducing our dependence. As referred to in the foregoing, every effort has been exerted on our part to improve the PWR system reliability by dint of the so-called 'HOMEMADE' TQC activities, which is our brain-child as a result of applying to the energy industry the quality control philosophy developed in the field of manufacturing industry

Strength analysis of refueling machine for large PWR in nuclear power plant

International Nuclear Information System (INIS)

Jia Xiaofeng; Zhou Guofeng; Bi Xiangjun; Ji Shunying

2010-01-01

The refueling machine of PWR plays important roles in nuclear power plant operation,and the dynamic analysis and strength assessment should be carried out to check its safety. In this paper, the finite element model (FEM) was established with the software ANSYS 12 for the refueling machine structure of large 1 000 MW PWR. The dynamic computations were performed under three work conditions, i.e. normal (cart starting and braking), abnormal (OBE) and accident(SSE) conditions, respectively. The structure responses (internal force and stress) of refueling machine under earthquake response spectrum in three directions were combined with the method of square root of square sum (SRSS). Moreover, the static response under gravity was also considered to construct the most critical conditions. With the simulated results, the strength of main structure, bold and weld joint,and the stability of landing leg for additional crane were assessed based on the RCCM code. At last, the local stress analysis of finger-form hook, which function is to take fuel assemblies, was also analyzed, while its strength was also assessed. The results show that the strengths of the refueling machine under various working conditions can meet the safety requirements. (authors)

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

International Nuclear Information System (INIS)

2005-01-01

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

Scope and procedures of fuel management for PWR nuclear power plant

International Nuclear Information System (INIS)

Yao Zenghua

1997-01-01

The fuel management scope of PWR nuclear power plant includes nuclear fuel purchase and spent fuel disposal, ex-core fuel management, in-core fuel management, core management and fuel assembly behavior follow up. A suit of complete and efficient fuel management procedures have to be created to ensure the quality and efficiency of fuel management work. The hierarchy of fuel management procedure is divided into four levels: main procedure, administration procedure, implement procedure and technic procedure. A brief introduction to the fuel management scope and procedures of PWR nuclear power plant are given

Technology, safety and costs of decommissioning nuclear reactors at multiple-reactor stations

International Nuclear Information System (INIS)

Wittenbrock, N.G.

1982-01-01

Safety and cost information is developed for the conceptual decommissioning of large (1175-MWe) pressurized water reactors (PWR) and large (1155-MWe) boiling water reactors (BWR) at multiple-reactor stations. Three decommissioning alternatives are studied: DECON (immediate decontamination), SAFSTOR (safe storage followed by deferred decontamination), and ENTOMB (entombment). Safety and costs of decommissioning are estimated by determining the impact of probable features of multiple-reactor-station operation that are considered to be unavailable at a single-reactor station, and applying these estimated impacts to the decommissioning costs and radiation doses estimated in previous PWR and BWR decommissioning studies. The multiple-reactor-station features analyzed are: the use of interim onsite nuclear waste storage with later removal to an offsite waste disposal facility, the use of permanent onsite nuclear waste disposal, the dedication of the site to nuclear power generation, and the provision of centralized services

BEACON TSM application system to the operation of PWR reactors

International Nuclear Information System (INIS)

Lozano, J. A.; Mildrum, C.; Serrano, J. F.

2012-01-01

BEACON-TSM is an advanced core monitoring system for PWR reactor cores, and also offers the possibility to perform a wide range of predictive calculation in support of reactor operation. BEACON-TSM is presently installed and licensed in the 5 Spanish PWR reactors of standard Westinghouse design. the purpose of this paper is to describe the features of this software system and to show the advantages obtainable by a nuclear power plant from its use. To illustrate the capabilities and benefits of BEACON-TSM two real case reactor operating situations are presented. (Author)

Annual report ''nuclear safety in France''; Le rapport annuel ''la surete nucleaire en France''

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This document is the 2001 annual report of the French authority of nuclear safety (ASN). It summarizes the highlights of the year 2000 and details the following aspects: the nuclear safety in France, the organization of the control of nuclear safety, the regulation relative to basic nuclear facilities, the control of facilities, the information of the public, the international relations, the organisation of emergencies, the radiation protection, the transport of radioactive materials, the radioactive wastes, the PWR reactors, the experimental reactors and other laboratories and facilities, the nuclear fuel cycle facilities, and the shutdown and dismantling of nuclear facilities. (J.S.)

Reliability of PWR type nuclear power plants

International Nuclear Information System (INIS)

Ribeiro, A.A.T.; Muniz, A.A.

1978-12-01

Results of the analysis of factors influencing the reliability of international nuclear power plants of the PWR type are presented. The reliability factor is estimated and the probability of its having lower values than a certain specified value is discussed. (Author) [pt

Establishment of joint application system of safety analysis codes between Korea and Vietnam

International Nuclear Information System (INIS)

Chung, Bub Dong; Kim, Kyung Doo; Park, Cheol; Bae, Sung Won; Baek, Won Pil; Song, Cheol hwa; Jeong, Jae Jun; Lee, Seung Wook; Hwang, Moon Kyu; Lee, Chang Sup

2011-04-01

The following KAERI-VAEI collaboration works have been performed during the 2 year project ('09.4∼'11.4). 1) On the job training of Vietnam code users(1st training for 4 VAEI staff-3 months. 2nd training for 3 VAEI staff- 3 month), 2) Lecture of nuclear safety analysis (30 hrs basic course and 30 hrs advanced course), 3) Review of safety analysis method (IAEA safety concept and requirements), 4) Collaborative assessment of safety analysis code MARS (13 conceptual problem, 2 separate effect test problem, 1 integral effect test problem), 5) Input deck preparation of standard PWR (Preparation of APR1400 input deck and safety analysis of DBA). VAEI staffs have been familiarized to Korean PWR safety assessment technology through the collaboration assessment work using a computer code developed in Korea. The lectures for Vietnamese research will be contributed to the utilization and cultivation of Korean safety technology. The collaborated assessment works will be used for the establishment of MARS based safety analysis system which is independent from US safety assessment system

Establishment of joint application system of safety analysis codes between Korea and Vietnam

Energy Technology Data Exchange (ETDEWEB)

Chung, Bub Dong; Kim, Kyung Doo; Park, Cheol; Bae, Sung Won; Baek, Won Pil; Song, Cheol hwa; Jeong, Jae Jun; Lee, Seung Wook; Hwang, Moon Kyu; Lee, Chang Sup [KAERI, Daejeon (Korea, Republic of)

2011-04-15

The following KAERI-VAEI collaboration works have been performed during the 2 year project ('09.4{approx}'11.4). 1) On the job training of Vietnam code users(1st training for 4 VAEI staff-3 months. 2nd training for 3 VAEI staff- 3 month), 2) Lecture of nuclear safety analysis (30 hrs basic course and 30 hrs advanced course), 3) Review of safety analysis method (IAEA safety concept and requirements), 4) Collaborative assessment of safety analysis code MARS (13 conceptual problem, 2 separate effect test problem, 1 integral effect test problem), 5) Input deck preparation of standard PWR (Preparation of APR1400 input deck and safety analysis of DBA). VAEI staffs have been familiarized to Korean PWR safety assessment technology through the collaboration assessment work using a computer code developed in Korea. The lectures for Vietnamese research will be contributed to the utilization and cultivation of Korean safety technology. The collaborated assessment works will be used for the establishment of MARS based safety analysis system which is independent from US safety assessment system

Safety of nuclear installations

International Nuclear Information System (INIS)

Esteves, R.G.

1987-01-01

The safety philosophy of a PWR type reactor distinguishing three levels of safety, is presented. At the first level, the concept of reactivity defining coefficients which measure the reactivity variation is introduced. At the second level, the reactor protection system establishing the design criteria to assure the high reliability, is defined. At the third level, the protection barriers to contain the consequences of accident evolution, are defined. (M.C.K.) [pt

Problems of control of WWER-type pressurized water reactors (PWR's)

International Nuclear Information System (INIS)

Drab, F.; Grof, V.

1978-01-01

The problems are dealt with of nuclear power reactor control. Special attention is paid to the reactor of the WWER type, which will play the most important part in the Czechoslovak power system in the near future. The subsystems are described which comprise the systems of reactor control and protection. The possibilities are outlined of using Czechoslovak instrumentation for the control and safety system of the WWER-type PWR. (author)

Model for transient simulation in a PWR steam circuit

International Nuclear Information System (INIS)

Mello, L.A. de.

1982-11-01

A computer code (SURF) was developed and used to simulate pressure losses along the tubes of the main steam circuit of a PWR nuclear power plant, and the steam flow through relief and safety valves when pressure reactors its thresholds values. A thermodynamic model of turbines (high and low pressure), and its associated components are simulated too. The SURF computer code was coupled to the GEVAP computer code, complementing the simulation of a PWR nuclear power plant main steam circuit. (Author) [pt

Properties of a large carbon steel casting used in French PWR nuclear plant

International Nuclear Information System (INIS)

Benhamou, C.; Roux, F.; Nectoux, G.; Delorme, A.

1980-09-01

To introduce a large casting in a PWR nuclear plant migh appear detrimental to its safety when comparing with forgings or rollings. In this paper we would like to show the constant efforts of the founder in providing a product with reproducible and high quality. Furthermore a program test covering a complete investigation of a real channel head is presented; the three following aspects have been studied: characterisation of cast flaws by non destructive and destructive examination, homogeneity of casting and fatigue and use properties

Deboration in nuclear stations of the PWR type

International Nuclear Information System (INIS)

1978-01-01

Reactivity control in nuclear power stations of the PWR type is realised with boric acid. A method to concentrate boric acid without an evaporator has been studied. A flow-sheet with reverse osmosis is proposed. (author)

RCC-M: Design and construction rules for mechanical components of PWR nuclear islands

International Nuclear Information System (INIS)

2017-01-01

AFCEN's RCC-M code concerns the mechanical components designed and manufactured for pressurized water reactors (PWR). It applies to pressure equipment in nuclear islands in safety classes 1, 2 and 3, and certain non-pressure components, such as vessel internals, supporting structures for safety class components, storage tanks and containment penetrations. RCC-M covers the following technical subjects: sizing and design, choice of materials and procurement. Fabrication and control, including: associated qualification requirements (procedures, welders and operators, etc.), control methods to be implemented, acceptance criteria for detected defects, documentation associated with the different activities covered, and quality assurance. The design, manufacture and inspection rules defined in RCC-M leverage the results of the research and development work pioneered in France, Europe and worldwide, and which have been successfully used by industry to design and build PWR nuclear islands. AFCEN's rules incorporate the resulting feedback. Use: France's last 16 nuclear units (P'4 and N4); 4 CP1 reactors in South Africa (2) and Korea (2); 44 M310 (4), CPR-1000 (28), CPR-600 (6), HPR-1000 (4) and EPR (2) reactors in service or undergoing construction in China; 4 EPR reactors in Europe: Finland (1), France (1) and UK (2). Content: Section I - nuclear island components, subsection 'A': general rules, subsection 'B': class 1 components, subsection 'C': class 2 components, subsection 'D': class 3 components, subsection 'E': small components, subsection 'G': core support structures, subsection 'H': supports, subsection 'J': low pressure or atmospheric storage tanks, subsection 'P': containment penetration, subsection 'Q': qualification of active mechanical components, subsection 'Z': technical appendices; section II - materials; section III - examination

Investigation of modeling and simulation on a PWR power conversion system with RELAP5

International Nuclear Information System (INIS)

Rui Gao; Yang Yanhua; Lin Meng; Yuan Minghao; Xie Zhengrui

2007-01-01

Based on the power conversion system of nuclear and conventional islands of Dayabay nuclear power station, this paper models the thermal-hydraulic systems for PWR by using the best-estimate program, RELAP5. To simulate the full-scope power conversion system, not only the reactor coolant system (RCP) of nuclear island, but also the main steam system (VVP), turbine steam and drain system (GPV), bypass system (GCT), feedwater system (FW), condensate extraction system (CEX), moisture separator reheater system (GSS), turbine-driven feedwater pump (APP), low-pressure and high-pressure feedwater heater systems (ABP and AHP) of conventional island are considered and modeled. A comparison between the simulated results and the actual data of reactor under full-power demonstrates a fine match for Dayabay, and also manifests the feasibility in simulating full-scope power conversion system of PWR with RELAP5. (author)

Nuclear steam supply system KLT-40 enhanced safety as independent power supply source. Employment prospects

International Nuclear Information System (INIS)

Polunichev, V.I.; Sayanov, D.G.; Ardabievsky, A.A.

1993-01-01

High quality of KLT-40 nuclear steam supply system (NSSS) providing enhanced safety is attained owing to the development and operation experience of equipments and systems in Soviet nuclear icebreakers. First of all they are the operating nuclear-powered icebreakers open-quotes Arktikaclose quotes, open-quotes Sibirclose quotes, open-quotes Rossiyaclose quotes, open-quotes Sovetsky Soyuzclose quotes, the limited draught icebreakers of joint Soviet-Finnish manufacturing open-quotes Taimyrclose quotes open-quotes Vaigachclose quotes. 30-years trouble-free operation of icebreaker open-quotes Leninclose quotes, the ancestor of nuclear powered fleet, is unprecedented. Operation life of individual equipment items amounts to 107000 hours, that testifies to high reliability and life characteristics of NSSS. Trouble-free operation of the nuclear-powered icebreakers' reactor plants (RPs) exceeded 130 reactor years, that proves high quality of design decisions being underlain in the basis of the KLT-40 NSSS for the lighter-cargo carrier open-quotes Sevmorputclose quotes, which was put into operation into 1988. Besides it testifies to the expediency of KLT-40 NSSS employment as a power source in different power installations. The KLT-40 is a reactor plant with a pwr type reactor. The design is described in detail with diagrams

The power control system of the Siemens-KWU nuclear power station of the PWR [pressurized water reactors] type

International Nuclear Information System (INIS)

Huber, Horacio

1989-01-01

Starting with the first nuclear power plant constructed by Siemens AG of the pressurized light water reactor line (PWR), the Obrigheim Nuclear Power Plant (340 MWe net), until the recently constructed plants of 1300 MWe (named 'Konvoi'), the design of the power control system of the plant was continuously improved and optimized using the experience gained in the operation of the earlier generations of plants. The reactor power control system of the Siemens - KWU nuclear power plants is described. The features of this design and of the Siemens designed heavy water power plants (PHWR) Atucha I and Atucha II are mentioned. Curves showing the behaviour of the controlled variables during load changes obtained from plant tests are also shown. (Author) [es

Future efforts on safety security at nuclear power stations

International Nuclear Information System (INIS)

Kondo, Shunsuke

2003-01-01

As operation management of nuclear power generation in Japan was at the highest level in the world at beginning of 1990s, Japan has gradually been left behind by foreign countries at indices such as its operation ratio, its employees' exposure, and so on, and is at a general level. In special, as PWR showed 89% in its operation ratio corresponding to international level on PWR at last year, BWR was concentrated to countermeasure of stress corrosion cracking (SCC) caused by storage on consideration of stress relaxation at machining of parts made of SUS-316LC at a number of nuclear reactors, and all of units in the Tokyo Electric Power Co., Ltd. had an accident on feasibility to cease them by finding out incorrect deeds at past periodical and self inspections. The minor Committee on Nuclear Regulation Rule Investigation of the Nuclear Security Party of the Advisory Committee for Energy judged this accident formed by neglecting tense feelings on inspection based on shortage of recognition on necessity to do administrative explanation obligation for natives and preparation of quality assurance system expressible on validity of safety management for local society of customers by management center in electric business companies, to propose a countermeasure to be done by government and private companies. Here was expressed future important subjects under their outlines. (G.K.)

PSA LEVEL 3 DAN IMPLEMENTASINYA PADA KAJIAN KESELAMATAN PWR

Directory of Open Access Journals (Sweden)

Pande Made Udiyani

2015-03-01

Full Text Available Kajian keselamatan PLTN menggunakan metodologi kajian probabilistik sangat penting selain kajian deterministik. Metodologi kajian menggunakan Probabilistic Safety Assessment (PSA Level 3 diperlukan terutama untuk estimasi kecelakaan parah atau kecelakaan luar dasar desain PLTN. Metode ini banyak dilakukan setelah kejadian kecelakaan Fukushima. Dalam penelitian ini dilakukan implementasi PSA Level 3 pada kajian keselamatan PWR, postulasi kecelakan luar dasar desain PWR AP-1000 dan disimulasikan di contoh tapak Bangka Barat. Rangkaian perhitungan yang dilakukan adalah: menghitung suku sumber dari kegagalan teras yang terjadi, pemodelan kondisi meteorologi tapak dan lingkungan, pemodelan jalur paparan, analisis dispersi radionuklida dan transportasi fenomena di lingkungan, analisis deposisi radionuklida, analisis dosis radiasi, analisis perlindungan & mitigasi, dan analisis risiko. Kajian menggunakan rangkaian subsistem pada perangkat lunak PC Cosyma. Hasil penelitian membuktikan bahwa implementasi metode kajian keselamatan PSA Level 3 sangat efektif dan komprehensif terhadap estimasi dampak, konsekuensi, risiko, kesiapsiagaan kedaruratan nuklir (nuclear emergency preparedness, dan manajemen kecelakaan reaktor terutama untuk kecelakaan parah atau kecelakaan luar dasar desain PLTN. Hasil kajian dapat digunakan sebagai umpan balik untuk kajian keselamatan PSA Level 1 dan PSA Level 2. Kata kunci: PSA level 3, kecelakaan, PWR   Reactor safety assessment of nuclear power plants using probabilistic assessment methodology is most important in addition to the deterministic assessment. The methodology of Level 3 Probabilistic Safety Assessment (PSA is especially required to estimate severe accident or beyond design basis accidents of nuclear power plants. This method is carried out after the Fukushima accident. In this research, the postulations beyond design basis accidentsof PWR AP - 1000 would be taken, and simulated at West Bangka sample site. The

Soft systems methodology as a systemic approach to nuclear safety management

International Nuclear Information System (INIS)

Vieira Neto, Antonio S.; Guilhen, Sabine N.; Rubin, Gerson A.; Caldeira Filho, Jose S.; Camargo, Iara M.C.

2017-01-01

Safety approach currently adopted by nuclear installations is built almost exclusively upon analytical methodologies based, mainly, on the belief that the properties of a system, such as its safety, are given by its constituent parts. This approach, however, does not properly address the complex dynamic interactions between technical, human and organizational factors occurring within and outside the organization. After the accident at Fukushima Daiichi nuclear power plant in March 2011, experts of the International Atomic Energy Agency (IAEA) recommended a systemic approach as a complementary perspective to nuclear safety. The aim of this paper is to present an overview of the systems thinking approach and its potential use for structuring socio technical problems involved in the safety of nuclear installations, highlighting the methodologies related to the soft systems thinking, in particular the Soft Systems Methodology (SSM). The implementation of a systemic approach may thus result in a more holistic picture of the system by the complex dynamic interactions between technical, human and organizational factors. (author)

Soft systems methodology as a systemic approach to nuclear safety management

Energy Technology Data Exchange (ETDEWEB)

Vieira Neto, Antonio S.; Guilhen, Sabine N.; Rubin, Gerson A.; Caldeira Filho, Jose S.; Camargo, Iara M.C., E-mail: asvneto@ipen.br, E-mail: snguilhen@ipen.br, E-mail: garubin@ipen.br, E-mail: jscaldeira@ipen.br, E-mail: icamargo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

2017-07-01

Safety approach currently adopted by nuclear installations is built almost exclusively upon analytical methodologies based, mainly, on the belief that the properties of a system, such as its safety, are given by its constituent parts. This approach, however, does not properly address the complex dynamic interactions between technical, human and organizational factors occurring within and outside the organization. After the accident at Fukushima Daiichi nuclear power plant in March 2011, experts of the International Atomic Energy Agency (IAEA) recommended a systemic approach as a complementary perspective to nuclear safety. The aim of this paper is to present an overview of the systems thinking approach and its potential use for structuring socio technical problems involved in the safety of nuclear installations, highlighting the methodologies related to the soft systems thinking, in particular the Soft Systems Methodology (SSM). The implementation of a systemic approach may thus result in a more holistic picture of the system by the complex dynamic interactions between technical, human and organizational factors. (author)

Comprehensive exergetic and economic comparison of PWR and hybrid fossil fuel-PWR power plants

International Nuclear Information System (INIS)

Sayyaadi, Hoseyn; Sabzaligol, Tooraj

2010-01-01

A typical 1000 MW Pressurized Water Reactor (PWR) nuclear power plant and two similar hybrid 1000 MW PWR plants operate with natural gas and coal fired fossil fuel superheater-economizers (Hybrid PWR-Fossil fuel plants) are compared exergetically and economically. Comparison is performed based on energetic and economic features of three systems. In order to compare system at their optimum operating point, three workable base case systems including the conventional PWR, and gas and coal fired hybrid PWR-Fossil fuel power plants considered and optimized in exergetic and exergoeconomic optimization scenarios, separately. The thermodynamic modeling of three systems is performed based on energy and exergy analyses, while an economic model is developed according to the exergoeconomic analysis and Total Revenue Requirement (TRR) method. The objective functions based on exergetic and exergoeconomic analyses are developed. The exergetic and exergoeconomic optimizations are performed using the Genetic Algorithm (GA). Energetic and economic features of exergetic and exergoeconomic optimized conventional PWR and gas and coal fired Hybrid PWR-Fossil fuel power plants are compared and discussed comprehensively.

Cost benefit analysis of reactor safety systems

International Nuclear Information System (INIS)

Maurer, H.A.

1984-01-01

Cost/benefit analysis of reactor safety systems is a possibility appropriate to deal with reactor safety. The Commission of the European Communities supported a study on the cost-benefit or cost effectiveness of safety systems installed in modern PWR nuclear power plants. The following systems and their cooperation in emergency cases were in particular investigated in this study: the containment system (double containment), the leakage exhaust and control system, the annulus release exhaust system and the containment spray system. The benefit of a safety system is defined according to its contribution to the reduction of the radiological consequences for the environment after a LOCA. The analysis is so far performed in two different steps: the emergency core cooling system is considered to function properly, failure of the emergency core cooling system is assumed (with the possible consequence of core melt-down) and the results may demonstrate the evidence that striving for cost-effectiveness can produce a safer end result than the philosophy of safety at any cost. (orig.)

Fuzzy control applied to nuclear power plant pressurizer system

International Nuclear Information System (INIS)

Oliveira, Mauro V.; Almeida, Jose C.S.

2011-01-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Fuzzy control applied to nuclear power plant pressurizer system

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

PWR accident management realated tests: some Bethsy results

International Nuclear Information System (INIS)

Clement, P.; Chataing, T.; Deruaz, R.

1993-01-01

The BETHSY integral test facility which is a scaled down model of a 3 loop FRAMATOME PWR and is currently operated at the Nuclear Center of Grenoble, forms an important part of the French strategy for PWR Accident Management. In this paper the features of both the facility and the experimental program are presented. Two accident transients: a total loss of feedwater and a 2'' cold leg break in case of High Pressure Safety Injection System failure, involving either Event Oriented - or State Oriented-Emergency Operating Procedures (EO-EOP or SO-EOP) are described and the system response analyzed. CATHARE calculation results are also presented which illustrate the ability of this code to adequately predict the key phenomena of these transients. (authors). 13 figs., 11 refs., 2 tabs

The Management System for Nuclear Installations Safety Guide

International Nuclear Information System (INIS)

2009-01-01

This Safety Guide is applicable throughout the lifetime of a nuclear installation, including any subsequent period of institutional control, until there is no significant residual radiation hazard. For a nuclear installation, the lifetime includes site evaluation, design, construction, commissioning, operation and decommissioning. These stages in the lifetime of a nuclear installation may overlap. This Safety Guide may be applied to nuclear installations in the following ways: (a)To support the development, implementation, assessment and improvement of the management system of those organizations responsible for research, site evaluation, design, construction, commissioning, operation and decommissioning of a nuclear installation; (b)As an aid in the assessment by the regulatory body of the adequacy of the management system of a nuclear installation; (c)To assist an organization in specifying to a supplier, via contractual documentation, any specific element that should be included within the supplier's management system for the supply of products. This Safety Guide follows the structure of the Safety Requirements publication on The Management System for Facilities and Activities, whereby: (a)Section 2 provides recommendations on implementing the management system, including recommendations relating to safety culture, grading and documentation. (b)Section 3 provides recommendations on the responsibilities of senior management for the development and implementation of an effective management system. (c)Section 4 provides recommendations on resource management, including guidance on human resources, infrastructure and the working environment. (d)Section 5 provides recommendations on how the processes of the installation can be specified and developed, including recommendations on some generic processes of the management system. (e)Section 6 provides recommendations on the measurement, assessment and improvement of the management system of a nuclear installation. (f

Performance Specification Shippinpark Pressurized Water Reactor Fuel Drying and Canister Inerting System for PWR Core 2 Blanket Fuel Assemblies Stored within Shippingport Spent Fuel Canisters

International Nuclear Information System (INIS)

JOHNSON, D.M.

2000-01-01

This specification establishes the performance requirements and basic design requirements imposed on the fuel drying and canister inerting system for Shippingport Pressurized Water Reactor (PWR) Core 2 blanket fuel assemblies (BFAs) stored within Shippingport spent fuel (SSFCs) canisters (fuel drying and canister inerting system). This fuel drying and canister inerting system is a component of the U.S. Department of Energy, Richland Operations Office (RL) Spent Nuclear Fuels Project at the Hanford Site. The fuel drying and canister inerting system provides for removing water and establishing an inert environment for Shippingport PWR Core 2 BFAs stored within SSFCs. A policy established by the U.S. Department of Energy (DOE) states that new SNF facilities (this is interpreted to include structures, systems and components) shall achieve nuclear safety equivalence to comparable U.S. Nuclear Regulatory Commission (NRC)-licensed facilities. This will be accomplished in part by applying appropriate NRC requirements for comparable NRC-licensed facilities to the fuel drying and canister inerting system, in addition to applicable DOE regulations and orders

Innovation research on the safety supervision system of nuclear and radiation safety in Jiangsu province

International Nuclear Information System (INIS)

Zhang Qihong; Lu Jigen; Zhang Ping; Wang Wanping; Dai Xia

2012-01-01

As the rapid development of nuclear technology, the safety supervision of nuclear and radiation becomes very important. The safety radiation frame system should be constructed, the safety super- vision ability for nuclear and radiation should be improved. How to implement effectively above mission should be a new subject of Provincial environmental protection department. Through investigating the innovation of nuclear and radiation supervision system, innovation of mechanism, innovation of capacity, innovation of informatization and so on, the provincial nuclear and radiation safety supervision model is proposed, and the safety framework of nuclear and radiation in Jiangsu is elementally established in the paper. (authors)

Safety classification of nuclear power plant systems, structures and components

International Nuclear Information System (INIS)

1992-01-01

The Safety Classification principles used for the systems, structures and components of a nuclear power plant are detailed in the guide. For classification, the nuclear power plant is divided into structural and operational units called systems. Every structure and component under control is included into some system. The Safety Classes are 1, 2 and 3 and the Class EYT (non-nuclear). Instructions how to assign each system, structure and component to an appropriate safety class are given in the guide. The guide applies to new nuclear power plants and to the safety classification of systems, structures and components designed for the refitting of old nuclear power plants. The classification principles and procedures applying to the classification document are also given

Performance of PWR Nuclear power plants, up to 1985

International Nuclear Information System (INIS)

Muniz, A.A.

1987-01-01

The performance of PWR nuclear power plants is studied, based on operational data up to 1985. The availability analysis was made with 793 unit-year and the reliability analysis was made with 5851 unit x month. The results were discussed and the availability of those nuclear power plants were estimated. (E.G.) [pt

Package Flow Model and its fuzzy implementation for simulating nuclear reactor system dynamics

International Nuclear Information System (INIS)

Matsuoka, Hiroshi; Ishiguro, Misako.

1996-01-01

A simple intuitive simulation model, which we call 'Package Flow Model', has been developed to evaluate physical processes in nuclear reactor system from a macroscopic point of view. In the previous paper, we showed the physical process of each energy generation and transfer stage in a PWR could be modeled by PFM, and its dynamics could be approximately simulated by fuzzy implementation. In this paper, a PFMs network approach for a total PWR system simulation is proposed and some transients of nuclear ship 'MUTSU' reactor system are evaluated. The simulated results are consistent with those from Nuclear Ship Engineering Simulation System developed by JAERI. Furthermore, a visual representation method is proposed to intuitively capture the profile of fuel safety transient. Using the PFMs network, we can handily calculate the transient phenomena of the system even by a notebook-type personal computer. In addition, we can easily interpret the results of calculation surveying a small number of parameters. (author)

The failure diagnoses of nuclear reactor systems

International Nuclear Information System (INIS)

Sheng Huanxing.

1986-01-01

The earlier period failure diagnoses can raise the safety and efficiency of nuclear reactors. This paper first describes the process abnormality monitoring of core barrel vibration in PWR, inherent noise sources in BWR, sodium boiling in LMFBR and nuclear reactor stability. And then, describes the plant failure diagnoses of primary coolant pumps, loose parts in nuclear reactors, coolant leakage and relief valve location

Evolutionary developments of advanced PWR nuclear fuels and cladding materials

International Nuclear Information System (INIS)

Kim, Kyu-Tae

2013-01-01

Highlights: • PWR fuel and cladding materials development processes are provided. • Evolution of PWR advanced fuel in U.S.A. and in Korea is described. • Cutting-edge design features against grid-to-rod fretting and debris are explained. • High performance data of advanced grids, debris filters and claddings are given. -- Abstract: The evolutionary developments of advanced PWR fuels and cladding materials are explained with outstanding design features of nuclear fuel assembly components and zirconium-base cladding materials. The advanced PWR fuel and cladding materials development processes are also provided along with verification tests, which can be used as guidelines for newcomers planning to develop an advanced fuel for the first time. The up-to-date advanced fuels with the advanced cladding materials may provide a high level of economic utilization and reliable performance even under current and upcoming aggressive operating conditions. To be specific, nuclear fuel vendors may achieve high fuel burnup capability of between 45,000 and 65,000 MWD/MTU batch average, overpower thermal margin of as much as 15% and longer cycle length up to 24 months on the one hand and fuel failure rates of around 10 −6 on the other hand. However, there is still a need for better understanding of grid-to-rod fretting wear mechanisms leading to major PWR fuel defects in the world and subsequently a driving force for developing innovative spacer grid designs with zero fretting wear-induced fuel failure

Impact of nuclear data uncertainty on safety calculations for spent nuclear fuel geological disposal

Directory of Open Access Journals (Sweden)

Herrero J.J.

2017-01-01

Full Text Available In the design of a spent nuclear fuel disposal system, one necessary condition is to show that the configuration remains subcritical at time of emplacement but also during long periods covering up to 1,000,000 years. In the context of criticality safety applying burn-up credit, k-eff eigenvalue calculations are affected by nuclear data uncertainty mainly in the burnup calculations simulating reactor operation and in the criticality calculation for the disposal canister loaded with the spent fuel assemblies. The impact of nuclear data uncertainty should be included in the k-eff value estimation to enforce safety. Estimations of the uncertainty in the discharge compositions from the CASMO5 burn-up calculation phase are employed in the final MCNP6 criticality computations for the intact canister configuration; in between, SERPENT2 is employed to get the spent fuel composition along the decay periods. In this paper, nuclear data uncertainty was propagated by Monte Carlo sampling in the burn-up, decay and criticality calculation phases and representative values for fuel operated in a Swiss PWR plant will be presented as an estimation of its impact.

The Conceptual Design of Innovative Safe PWR

Energy Technology Data Exchange (ETDEWEB)

Kim, Han-Gon [Centural Research Institute, Daejeon (Korea, Republic of); Heo, Sun [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2016-10-15

Most of countries operating NPPs have been performed post-Fukushima improvements as short-term countermeasure to enhance the safety of operating NPPs. Separately, vendors have made efforts on developing passive safety systems as long-term and ultimate countermeasures. AP1000 designed by Westinghouse Electric Company has passive safety systems including the passive emergency core cooling system (PECCS), the passive residual heat removal system (PRHRS), and the passive containment cooling system (PCCS). ESBWR designed by GE-Hitachi also has passive safety systems consisting of the isolation condenser system, the gravity driven cooling system and the PCCS. Other countries including China and Russia have made efforts on developing passive safety systems for enhancing the safety of their plants. In this paper, we summarize the design goals and main design feature of innovative safe PWR, iPOWER which is standing for Innovative Passive Optimized World-wide Economical Reactor, and show the developing status and results of research projects. To mitigate an accident without electric power and enhance the safety level of PWR, the conceptual designs of passive safety system and innovative safe PWR have been performed. It includes the PECCS for core cooling and the PCCS for containment cooling. Now we are performing the small scale and separate effect tests for the PECCS and the PCCS and preparing the integral effect test for the PECCS and real scale test for the PCCS.

Safety design philosophy of Mitsubishi PWRs

International Nuclear Information System (INIS)

Hakata, T.; Kitamura, T.

1993-01-01

The basic safety design philosophy of Mitsubishi pressurized water reactors (PWRs) is discussed and compared with the British PWR. PWR plants are designed in accordance with the Japanese regulatory guidelines which are similar to American and International Atomic Energy Agency (IAEA) safety criteria and are based on defence-in-depth principles. The high reliability of nuclear power plants is especially emphasized in Mitsubishi PWRs, and this has been demonstrated by the good operating experience of PWR plants in Japan. The safety system designs of six key items, which were discussed in the recent review of overseas designs by British utilities, are addressed to show the difference in the design philosophy between the United Kingdom and Japan. (Author)

Vulnerability analysis of a PWR to an external event

International Nuclear Information System (INIS)

Aruety, S.; Ilberg, D.; Hertz, Y.

1980-01-01

The Vulnerability of a Nuclear Power Plant (NPP) to external events is affected by several factors such as: the degree of redundancy of the reactor systems, subsystems and components; the separation of systems provided in the general layout; the extent of the vulnerable area, i.e., the area which upon being affected by an external event will result in system failure; and the time required to repair or replace the systems, when allowed. The present study offers a methodology, using Probabilistic Safety Analysis, to evaluate the relative importance of the above parameters in reducing the vulnerability of reactor safety systems. Several safety systems of typical PWR's are analyzed as examples. It was found that the degree of redundancy and physical separation of the systems has the most prominent effect on the vulnerability of the NPP

Guide to the declaration procedure and coding system for criteria concerning significant events related to safety, radiation protection or the environment, applicable to basic nuclear installations and the transport of radioactive materials

International Nuclear Information System (INIS)

Lacoste, Andre-Claude

2005-01-01

This guide notably contains various forms associated with the declaration of significant events, and explanations to fill them in: significant event declaration form for a basic nuclear installation, significant event declaration form for radioactive material transport, significant event report for a basic nuclear installation, significant event report for radioactive material transport, declaration criteria for significant events related to the safety of non-PWR basic nuclear installations, declaration criteria for significant events related to PWR safety, significant events declared further to events resulting in group 1 unavailability and non-compliance with technical operating specifications, declaration criteria for significant events concerning radiation protection for basic nuclear installations, declaration criteria for significant events concerning environmental protection, applicable to basic nuclear installations, and declaration criteria for significant events concerning radioactive material transport

Analysis of design of auxiliary system of Booshehr Nuclear Power Plant

International Nuclear Information System (INIS)

Naseh Hasanzadeh, M.

1999-01-01

Power plant's internal auxiliary system has an important role in its safety operation. Because of the decay heat and safety aspects in the nuclear power plants, this role is more important. In this thesis, operation of the nuclear power plant with PWR reactor is studied and deferent nuclear systems described. In the next section all electrical loads in the Booshehr Nuclear Power Plant identified and feeding methods of each load is determined. by use of the single line diagram of the internal auxiliary system, the nominal rating of all electrical devices as transformers, inverters, Ups, diesel generators and etc. is determined. In the following, short circuit calculations performed and by above conclusion, rating values of circuit breakers is determined. At last the starting problems of electrical motors is studied and the results of motor's behavior at starting moment is discussed

On the safety performance of the advanced nuclear energy systems

International Nuclear Information System (INIS)

Li Shounan

1999-01-01

Some features on the safety performances of the Advanced Nuclear Energy Systems are discussed. The advantages and some peculiar problems on the safety of Advanced Nuclear Energy Systems with subcritical nuclear reactor driven by external neutron sources are also pointed out in comparison with conventional nuclear reactors

Nuclear safety and regulation

International Nuclear Information System (INIS)

Kim, Hho Jung

2000-03-01

This book contains 12 chapters, which are atom and radiation, nuclear reactor and kinds of nuclear power plant, safeguard actuation system and stability evaluation for rock foundation of nuclear power plant, nuclear safety and principle, safety analysis and classification of incident, probabilistic safety assessment and major incident, nuclear safety regulation, system of nuclear safety regulation, main function and subject of safety regulation in nuclear facilities, regulation of fuel cycle and a nuclear dump site, protection of radiation and, safety supervision and, safety supervision and measurement of environmental radioactivity.

Sensitivity Verification of PWR Monitoring System Using Neuro-Expert For LOCA Detection

International Nuclear Information System (INIS)

Muhammad Subekti

2009-01-01

Sensitivity Verification of PWR Monitoring System Using Neuro-Expert For LOCA Detection. The present research was done for verification of previous developed method on Loss of Coolant Accident (LOCA) detection and perform simulations for knowing the sensitivity of the PWR monitoring system that applied neuro-expert method. The previous research continuing on present research, has developed and has tested the neuro-expert method for several anomaly detections in Nuclear Power Plant (NPP) typed Pressurized Water Reactor (PWR). Neuro-expert can detect the LOCA anomaly with sensitivity of primary coolant leakage of 7 gallon/min and the conventional method could not detect the primary coolant leakage of 30 gallon/min. Neuro expert method detects significantly LOCA anomaly faster than conventional system in Surry-1 NPP as well so that the impact risk is reducible. (author)

Report on nuclear safety on the operation of nuclear facilities in 1989; Porocilo o jedrski varnosti pri obratovanju jedrskih objektov v letu 1989

Energy Technology Data Exchange (ETDEWEB)

Gregoric, M; Levstek, M F; Horvat, D; Kocuvan, M; Cresnar, N [Slovenian Nuclear Safety Administration, Ljubljana (Slovenia)

1990-07-01

Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1989.

MELCOR/VISOR PWR desktop simulator

International Nuclear Information System (INIS)

With, Anka de; Wakker, Pieter

2010-01-01

Increasingly, there is a need for a learning support and training tool for nuclear engineers, utilities and students in order to broaden their understanding of advanced nuclear plant characteristics, dynamics, transients and safety features. Nuclear system analysis codes like ASTEC, RELAP5, RETRAN and MELCOR provide calculation results of and visualization tools can be used to graphically represent these results. However, for an efficient education and training a more interactive tool such as a simulator is needed. The simulator connects the graphical tool with the calculation tool in an interactive manner. A small number of desktop simulators exist [1-3]. The existing simulators are capable of representing different types of power plants and various accident conditions. However, they were found to be too general to be used as a reliable plant-specific accident analysis or training tool. A desktop simulator of the Pressurized Water Reactor (PWR) has been created under contract of the Dutch nuclear regulatory body (KFD). The desktop simulator is a software package that provides a close to real simulation of the Dutch nuclear power plant Borssele (KCB) and is used for training of the accident response. The simulator includes the majority of the power plant systems, necessary for the successful simulation of the KCB plant during normal operation, malfunctions and accident situations, and it has been successfully validated against the results of the safety evaluations from the KCB safety report. (orig.)

PWR reactor pressure vessel internals license renewal industry report; revision 1. Final report

International Nuclear Information System (INIS)

Schwirian, R.; Robison, G.

1994-07-01

The U.S. nuclear power industry, through coordination by the Nuclear Management and Resources Council (NUMARC), and sponsorship by the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), has evaluated age-related degradation effects for a number of major plant systems, structures and components, in the license renewal technical Industry Reports (IRs). License renewal applicants may choose to reference these IRs in support of their plant-specific license renewal applications, as an equivalent to the integrated plant assessment provisions of the license renewal rule (10 CFR Part 54). Pressurized water reactor (PWR) reactor pressure vessel (RPV) internals designed by all three U.S. PWR nuclear steam supply system vendors have been evaluated relative to the effects of age-related degradation mechanisms; the capability of current design limits; inservice examination, testing, repair, refurbishment, and other programs to manage these effects; and the assurance that these internals can continue to perform their intended safety functions in the license renewal term. This industry report (IR), one of a series of ten, provides a generic technical basis for evaluation of PWR reactor pressure vessel internals for license renewal

AREVA solutions to licensing challenges in PWR and BWR reload and safety analysis

Energy Technology Data Exchange (ETDEWEB)

Curca-Tivig, Florin [AREVA GmbH, Erlangen (Germany)

2016-05-15

Regulatory requirements for reload and safety analyses are evolving: new safety criteria, request for enlarged qualification databases, statistical applications, uncertainty propagation.. In order to address these challenges and access more predictable licensing processes, AVERA is implementing consistent code and methodology suites for PWR and BWR core design and safety analysis, based on first principles modeling and extremely broad verification and validation data base. Thanks to the high computational power increase in the last decades methods' development and application now include new capabilities. An overview of the main AREVA codes and methods developments is given covering PWR and BWR applications in different licensing environments.

Applicability of trends in nuclear safety analysis to space nuclear power systems

International Nuclear Information System (INIS)

Bari, R.A.

1992-01-01

A survey is presented of some current trends in nuclear safety analysis that may be relevant to space nuclear power systems. This includes: lessons learned from operating power reactor safety and licensing; approaches to the safety design of advanced and novel reactors and facilities; the roles of risk assessment, extremely unlikely accidents, safety goals/targets; and risk-benefit analysis and communication

Technical feasibility and reliability of passive safety systems of AC600

International Nuclear Information System (INIS)

Niu, W.; Zeng, X.

1996-01-01

The first step conceptual design of the 600 MWe advanced PWR (AC-600) has been finished by the Nuclear Power Institute of China. Experiments on the passive system of AC-600 are being carried out, and are expected to be completed next year. The main research emphases of AC-600 conceptual design include the advanced core, the passive safety system and simplification. The design objective of AC-600 is that the safety, reliability, maintainability, operation cost and construction period are all improved upon compared to those of PWR plant. One of important means to achieve the objective is using a passive system, which has the following functions whenever its operation is required: providing the reactor core with enough coolant when others fail to make up the lost coolant; reactor residual heat removal; cooling and reducing pressure in the containment and preventing radioactive substances from being released into the environment after occurrence of accident (e.g. LOCA). The system should meet the single failure criterion, and keep operating when a single active component or passive component breaks down during the first 72 hour period after occurrence of accident, or in the long period following the 72 hour period. The passive safety system of AC-600 is composed of the primary safety injection system, the secondary emergency core residual heat removal system and the containment cooling system. The design of the system follows some relevant rules and criteria used by current PWR plant. The system has the ability to bear single failure, two complete separate subsystems are considered, each designed for 100% working capacity. Normal operation is separate from safety operation and avoids cross coupling and interference between systems, improves the reliability of components, and makes it easy to maintain, inspect and test the system. The paper discusses the technical feasibility and reliability of the passive safety system of AC-600, and some issues and test plans are also

Design of the reactor coolant system and associated systems in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2008-01-01

This Safety Guide was prepared under the IAEA programme for establishing safety standards for nuclear power plants. The basic requirements for the design of safety systems for nuclear power plants are established in the Safety Requirements publication, Safety Standards Series No. NS-R-1 on Safety of Nuclear Power Plants: Design, which it supplements. This Safety Guide describes how the requirements for the design of the reactor coolant system (RCS) and associated systems in nuclear power plants should be met. 1.2. This publication is a revision and combination of two previous Safety Guides, Safety Series No. 50-SG-D6 on Ultimate Heat Sink and Directly Associated Heat Transport Systems for Nuclear Power Plants (1981), and Safety Series No. 50-SG-D13 on Reactor Coolant and Associated Systems in Nuclear Power Plants (1986), which are superseded by this new Safety Guide. 1.3. The revision takes account of developments in the design of the RCS and associated systems in nuclear power plants since the earlier Safety Guides were published in 1981 and 1986, respectively. The other objectives of the revision are to ensure consistency with Ref., issued in 2000, and to update the technical content. In addition, an appendix on pressurized heavy water reactors (PHWRs) has been included

An evaluation of debris mobility within a PWR reactor coolant system during the recirculation mode

International Nuclear Information System (INIS)

Andreychek, T.S.

1987-01-01

To provide for the long-term cooling of the nuclear core of a Pressurized Water Rector (PWR) following a hypothetical Loss-of-Coolant Accidnet (LOCA), water is drawn from the containment sump and pumped into the reactor coolant system (RCS). It has been postulated that debris from the containment, such as dirt, sand, and paint from containment walls and in-containment equipment, could be carried into the containment sump due to the action of the RCS coolant that escapes from the breach in the piping and then flows to the sump. Once in the sump, this debris could be pumped into the Safety Injection System (SIS) and ultimately the RCS itself, causing the performance of the SIS to be degraded. Of particular interest is the potential for core blockage that may occur due to debris transport into the core region by the recirculating flow. This paper presents a method of evaluating the potential for debris from the sump to form core blockages under recirculating flow conditions following a hypothetical LOCA for a PWR

The significance of thermohydraulic conditions for the corrosion safety of PWR steam generators

International Nuclear Information System (INIS)

Gulich, J.F.

1975-04-01

In several PWR nuclear power plants leakages have occurred in the steam generator which were caused by localised corrosion attack. While the attention of manufacturers and operators is focused on the influences of feedwater chemistry and tube material, the present work highlights the fact that the damage always occurred in those places where flow regimed are poorly defined. The investigation leads to the result that local dry out of the heating surface can be contributing cause of damage. A method is indicated for estimating the thermohydraulic conditions in the inflow region over the tube plate and measures to improve corrosion safety are discussed. (author)

11-th International conference Nuclear power safety and nuclear education - 2009. Abstracts. Part 1. Session: Safety of nuclear technology; Innovative nuclear systems and fuel cycle; Nuclear knowledge management

International Nuclear Information System (INIS)

2009-01-01

The book includes abstracts of the 11-th International conference Nuclear power safety and nuclear education - 2009 (29 Sep - 2 Oct, 2009, Obninsk). Problems of safety of nuclear technology are discussed, innovative nuclear systems and fuel cycles are treated. Abstracts on professional education for nuclear power and industry are presented. Nuclear knowledge management are discussed

New reactor technology: safety improvements in nuclear power systems.

Science.gov (United States)

Corradini, M L

2007-11-01

Almost 450 nuclear power plants are currently operating throughout the world and supplying about 17% of the world's electricity. These plants perform safely, reliably, and have no free-release of byproducts to the environment. Given the current rate of growth in electricity demand and the ever growing concerns for the environment, nuclear power can only satisfy the need for electricity and other energy-intensive products if it can demonstrate (1) enhanced safety and system reliability, (2) minimal environmental impact via sustainable system designs, and (3) competitive economics. The U.S. Department of Energy with the international community has begun research on the next generation of nuclear energy systems that can be made available to the market by 2030 or earlier, and that can offer significant advances toward these challenging goals; in particular, six candidate reactor system designs have been identified. These future nuclear power systems will require advances in materials, reactor physics, as well as thermal-hydraulics to realize their full potential. However, all of these designs must demonstrate enhanced safety above and beyond current light water reactor systems if the next generation of nuclear power plants is to grow in number far beyond the current population. This paper reviews the advanced Generation-IV reactor systems and the key safety phenomena that must be considered to guarantee that enhanced safety can be assured in future nuclear reactor systems.

Nuclear safety and radiation protection report of the Chinon nuclear facilities - 2011

International Nuclear Information System (INIS)

2012-01-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chinon nuclear power plant (Indre-et-Loire, 37 (FR)): 4 PWR reactors in operation (Chinon B, INB 107 and 132), 3 partially dismantled graphite-gas reactors (Chinon A, INB 133, 153 and 161), a workshop for irradiated materials (AMI, INB 94), and an inter-regional fuel storage facility (MIR, INB 99). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Chinon nuclear facilities - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chinon nuclear power plant (Indre-et-Loire, 37 (FR)): 4 PWR reactors in operation (Chinon B, INB 107 and 132), 3 partially dismantled graphite-gas reactors (Chinon A, INB 133, 153 and 161), a workshop for irradiated materials (AMI, INB 94), and an inter-regional fuel storage facility (MIR, INB 99). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Bugey nuclear facilities - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Bugey nuclear power plant (Ain (FR)): 4 PWR reactors in operation (INB 78 and 89), one partially dismantled graphite-gas reactor (INB 45), an inter-regional fuel storage facility (MIR, INB 102), and a radioactive waste storage and conditioning facility under construction (ICEDA, INB 173). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear-power-safety reporting system: feasibility analysis

International Nuclear Information System (INIS)

Finlayson, F.C.; Ims, J.

1983-04-01

The US Nuclear Regulatory Commission (NRC) is evaluating the possibility of instituting a data gathering system for identifying and quantifying the factors that contribute to the occurrence of significant safety problems involving humans in nuclear power plants. This report presents the results of a brief (6 months) study of the feasibility of developing a voluntary, nonpunitive Nuclear Power Safety Reporting System (NPSRS). Reports collected by the system would be used to create a data base for documenting, analyzing and assessing the significance of the incidents. Results of The Aerospace Corporation study are presented in two volumes. This document, Volume I, contains a summary of an assessment of the Aviation Safety Reporting System (ASRS). The FAA-sponsored, NASA-managed ASRS was found to be successful, relatively low in cost, generally acceptable to all facets of the aviation community, and the source of much useful data and valuable reports on human factor problems in the nation's airways. Several significant ASRS features were found to be pertinent and applicable for adoption into a NPSRS

China's nuclear safety regulatory body: The national nuclear safety administration

International Nuclear Information System (INIS)

Zhang Shiguan

1991-04-01

The establishment of an independent nuclear safety regulatory body is necessary for ensuring the safety of nuclear installations and nuclear fuel. Therefore the National Nuclear Safety Administration was established by the state. The aim, purpose, organization structure and main tasks of the Administration are presented. At the same time the practical examples, such as nuclear safety regulation on the Qinshan Nuclear Power Plant, safety review and inspections for the Daya Bay Nuclear Power Plant during the construction, and nuclear material accounting and management system in the nuclear fuel fabrication plant in China, are given in order to demonstrate the important roles having been played on nuclear safety by the Administration after its founding

Liquid radioactive waste processing improvement of PWR nuclear power plants; Melhorias no processamento de rejeitos liquidos radioativos de usinas nucleares PWR

Energy Technology Data Exchange (ETDEWEB)

Nery, Renata Wolter dos Reis; Martinez, Aquilino Senra; Monteiro, Jose Luiz Fontes [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: wolter@eletronuclear.gov.br; monteiro@peq.coppe.ufrj.br; aquilinosenra@lmp.ufrj.br

2005-07-01

The study evaluate an inorganic ion exchange to process the low level liquid radwaste of PWR nuclear plants, so that the level of the radioactivity in the effluents and the solid waste produced during the treatment of these liquid radwaste can be reduced. The work compares two types of ion exchange materials, a strong acid cation exchange resin, that is the material typically used to remove radionuclides from PWR nuclear plants wastes, and a mordenite zeolite. These exchange material were used to remove cesium from a synthetic effluent containing only this ion and another effluent containing cesium and cobalt. The breakthrough curves of the zeolite and resin using a fix bed reactor were compared. The results demonstrated that the zeolite is more efficient than the resin in removing cesium from a solution containing cesium and cobalt. The results also showed that a bed combining zeolite and resin can process more volume of an effluent containing cesium and cobalt than a bed resin alone. (author)

Reactor safety

International Nuclear Information System (INIS)

Butz, H.P.; Heuser, F.W.; May, H.

1985-01-01

The paper comprises an introduction into nuclear physics bases, the safety concept generally speaking, safety devices of pwr type reactors, accident analysis, external influences, probabilistic safety assessment and risk studies. It further describes operational experience, licensing procedures under the Atomic Energy Law, research in reactor safety and the nuclear fuel cycle. (DG) [de

Proceedings of the Digital Systems Reliability and Nuclear Safety Workshop

Energy Technology Data Exchange (ETDEWEB)

Wallace, D. R.; Cuthill, B. B.; Ippolito, L. M. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Beltracchi, L. [Nuclear Regulatory Commission, Washington, DC (United States) ed.

1994-03-01

The United States Nuclear Regulatory Commission (NRC), in cooperation with the National Institute of Standards and Technology conducted the.Digital Systems Reliability and Nuclear Safety Workshop on September 13--14, 1993, in Rockville, Maryland. The workshop provided a forum for the exchange of information among experts within the nuclear industry, experts from other industries, regulators and academia. The information presented at this workshop provided in-depth exposure of the NRC staff and the nuclear industry to digital systems design safety issues and also provided feedback to the NRC from outside experts regarding identified safety issues, proposed regulatory positions, and intended research associated with the use of digital systems in nuclear power plants. Technical presentations provided insights on areas where current software engineering practices may be inadequate for safety-critical systems, on potential solutions for development issues, and on methods for reducing risk in safety-critical systems. This report contains an analysis of results of the workshop, the papers presented panel presentations, and summaries of, discussions at this workshop. The individual papers have been cataloged separately.

Nuclear safety and radiation protection report of the Chooz nuclear facilities - 2010; Rapport sur la surete nucleaire et la radioprotection des installations nucleaires de Chooz - 2010

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-06-15

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Chooz nuclear power plant (Ardennes (FR)): 2 PWR reactors in operation (Chooz B, INB 139 and 144) and one partially dismantled PWR reactor (Chooz A, INB 163). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Flamanville nuclear facilities - 2010; Rapport sur la surete nucleaire et la radioprotection des installations nucleaires de Flamanville - 2010

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-06-15

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Flamanville nuclear power plant (Manche (FR)): 2 PWR reactors in operation (INB 108 and 109), and 1 PWR under construction (Flamanville 3, INB 167). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, water consumption and waste management at Flamanville 3 construction site) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

A Nuclear Safety System based on Industrial Computer

International Nuclear Information System (INIS)

Kim, Ji Hyeon; Oh, Do Young; Lee, Nam Hoon; Kim, Chang Ho; Kim, Jae Hack

2011-01-01

The Plant Protection System(PPS), a nuclear safety Instrumentation and Control (I and C) system for Nuclear Power Plants(NPPs), generates reactor trip on abnormal reactor condition. The Core Protection Calculator System (CPCS) is a safety system that generates and transmits the channel trip signal to the PPS on an abnormal condition. Currently, these systems are designed on the Programmable Logic Controller(PLC) based system and it is necessary to consider a new system platform to adapt simpler system configuration and improved software development process. The CPCS was the first implementation using a micro computer in a nuclear power plant safety protection system in 1980 which have been deployed in Ulchin units 3,4,5,6 and Younggwang units 3,4,5,6. The CPCS software was developed in the Concurrent Micro5 minicomputer using assembly language and embedded into the Concurrent 3205 computer. Following the micro computer based CPCS, PLC based Common-Q platform has been used for the ShinKori/ShinWolsong units 1,2 PPS and CPCS, and the POSAFE-Q PLC platform is used for the ShinUlchin units 1,2 PPS and CPCS. In developing the next generation safety system platform, several factors (e.g., hardware/software reliability, flexibility, licensibility and industrial support) can be considered. This paper suggests an Industrial Computer(IC) based protection system that can be developed with improved flexibility without losing system reliability. The IC based system has the advantage of a simple system configuration with optimized processor boards because of improved processor performance and unlimited interoperability between the target system and development system that use commercial CASE tools. This paper presents the background to selecting the IC based system with a case study design of the CPCS. Eventually, this kind of platform can be used for nuclear power plant safety systems like the PPS, CPCS, Qualified Indication and Alarm . Pami(QIAS-P), and Engineering Safety

A Nuclear Safety System based on Industrial Computer

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Hyeon; Oh, Do Young; Lee, Nam Hoon; Kim, Chang Ho; Kim, Jae Hack [Korea Electric Power Corporation Engineering and Construction, Daejeon (Korea, Republic of)

2011-05-15

The Plant Protection System(PPS), a nuclear safety Instrumentation and Control (I and C) system for Nuclear Power Plants(NPPs), generates reactor trip on abnormal reactor condition. The Core Protection Calculator System (CPCS) is a safety system that generates and transmits the channel trip signal to the PPS on an abnormal condition. Currently, these systems are designed on the Programmable Logic Controller(PLC) based system and it is necessary to consider a new system platform to adapt simpler system configuration and improved software development process. The CPCS was the first implementation using a micro computer in a nuclear power plant safety protection system in 1980 which have been deployed in Ulchin units 3,4,5,6 and Younggwang units 3,4,5,6. The CPCS software was developed in the Concurrent Micro5 minicomputer using assembly language and embedded into the Concurrent 3205 computer. Following the micro computer based CPCS, PLC based Common-Q platform has been used for the ShinKori/ShinWolsong units 1,2 PPS and CPCS, and the POSAFE-Q PLC platform is used for the ShinUlchin units 1,2 PPS and CPCS. In developing the next generation safety system platform, several factors (e.g., hardware/software reliability, flexibility, licensibility and industrial support) can be considered. This paper suggests an Industrial Computer(IC) based protection system that can be developed with improved flexibility without losing system reliability. The IC based system has the advantage of a simple system configuration with optimized processor boards because of improved processor performance and unlimited interoperability between the target system and development system that use commercial CASE tools. This paper presents the background to selecting the IC based system with a case study design of the CPCS. Eventually, this kind of platform can be used for nuclear power plant safety systems like the PPS, CPCS, Qualified Indication and Alarm . Pami(QIAS-P), and Engineering Safety

Safety of emerging nuclear energy systems

International Nuclear Information System (INIS)

Novikov, V.M.; Slesarev, I.S.

1989-01-01

The first stage of world nuclear power development based on light water fission reactors has demonstrated not only rather high rate but at the same time too optimistic attitude to safety problems. Large accidents at Three Mile Island and Chernobyl essentially affects the concept of NP development. As a result the safety and social acceptance of NP became of absolute priority among other problems. That's why emerging nuclear power systems should be first of all estimated from this point of view. In the paper some quantitative criteria of safety derived from estimations of social risk and economic-ecological damage from hypothetical accidents are formulated. On the base of these criteria we define two stages of possible way to meet safety demands: first--development of high safety fission reactors and second--that of asymptotic high safety ENEs. The limits of tolorated expenses for safety are regarded. The basis physical factors determining hazards of NES accidents are considered. This permits to classify the ways of safety demands fulfillment due to physical principals used

Robots in P.W.R. nuclear powerplants

International Nuclear Information System (INIS)

Dubourg, M.

1987-01-01

The satisfactory operation of 37 900-MWe PWR powerplants in France, Belgium and South-Africa and the start-up of 1300 MWe powerplants allowed the development of a wide range of automatic units and robots for the periodic maintenance of nuclear plants, reducing the risk of ionizing radiation for the personnel. A large number of automated tools have been built. Among them: - inspection and maintenance systems for the tube bundle of steam generators, - robotized arms ROTETA and ROMEO for the heavy maintenance and delicate operations such as tube extraction or shot peening of tubes to improve their resistance to corrosion; - the versatile manipulator T.A.M. with electrically controlled articulations. The development of functionally versatile tools and robots and the integration of new technologies such as 3-D vision allowed the construction of the self-guided vehicle FRASTAR capable of moving within a nuclear building and in a cluttered environment. This vehicle includes means for avoiding isolated obstacles and can move on stairs [fr

Reactor analysis support package (RASP). Volume 7. PWR set-point methodology. Final report

International Nuclear Information System (INIS)

Temple, S.M.; Robbins, T.R.

1986-09-01

This report provides an overview of the basis and methodology requirements for determining Pressurized Water Reactor (PWR) technical specifications related setpoints and focuses on development of the methodology for a reload core. Additionally, the report documents the implementation and typical methods of analysis used by PWR vendors during the 1970's to develop Protection System Trip Limits (or Limiting Safety System Settings) and Limiting Conditions for Operation. The descriptions of the typical setpoint methodologies are provided for Nuclear Steam Supply Systems as designed and supplied by Babcock and Wilcox, Combustion Engineering, and Westinghouse. The description of the methods of analysis includes the discussion of the computer codes used in the setpoint methodology. Next, the report addresses the treatment of calculational and measurement uncertainties based on the extent to which such information was available for each of the three types of PWR. Finally, the major features of the setpoint methodologies are compared, and the principal effects of each particular methodology on plant operation are summarized for each of the three types of PWR

Research on PWR safety in France

International Nuclear Information System (INIS)

Zammite, R.

1988-07-01

The French nuclear safety arrangements form a centralized system characterized by cooperation between the government authorities, their technical advisers and the operators of the installations, especially between the Commissariat a l'Energie Atomique (CEA) and Electricite de France (EDF). This cooperation in no way contradicts the respective responsibilities of the different parties, in particular those of EDF regarding the safety of its installations and those of CEA as the government's technical adviser and safety analyst. However, it considerably affects the research on reactor safety, which is mainly performed by the CEA Institute for Nuclear Safety and Protection (IPSN), in collaboration with EDF. For PWRs, the safety preoccupations concerning their development, commissioning and operation can be divided into the following three categories: A. Safety in design and construction, B. Safety in operation and the control of potential accidents, C. Maintaining safety - aging problems. The effort consecrated to each category has varied in the past and will continue to do so in the future. At the present stage, emphasis is being given to categories B and C. The appendix includes tables which indicate, for categories A, B and C, the relationship between the existing research programmes and the questions remaining open that they are intended to solve

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

International Nuclear Information System (INIS)

Cai Jianping; Shen Sen; Barkman, N.

1999-01-01

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

Improvement of layout and piping design for PWR nuclear power plants

International Nuclear Information System (INIS)

Nozue, Kosei; Waki, Masato; Kashima, Hiroo; Yoshioka, Tsuyoshi; Obara, Ichiro.

1983-01-01

For a nuclear power plant, a period of nearly ten years is required from the initial planning stage to commencement of transmission after passing through the design, manufacturing, installation and trial running stages. In the current climate there is a trend that the time required for nuclear power plant construction will further increase when locational problems, thorough explanation to residents in the neighborhood of the construction site and their under-standing, subsequent safety checks and measures to be taken in compliance with various controls and regulations which get tighter year after year, are taken into account. Under such circumstances, in order to satisfy requirements such as improving the reliability of the nuclear power plant design, manufacturing and construction departments, improvements in the economy as well as the quality and shortening of construction periods, the design structure for Mitsubishi PWR nuclear power plants was thoroughly consolidated with regard to layout and piping design. At the same time, diversified design improvements were made with the excellent domestic technology based on plant designs imported from the U.S.A. An outline of the priority items is introduced in this paper. (author)

Nuclear Power Safety Reporting System. Final evaluation results

International Nuclear Information System (INIS)

Finlayson, F.C.; Newton, R.D.

1986-02-01

This document presents the results of a study conducted by the US Nuclear Regulatory Commission of an unobtrusive, voluntary, anonymous third-party managed, nonpunitive human factors data gathering system (the Nuclear power Safety Reporting System - NPSRS) for the nuclear electric power production industry. The data to be gathered by the NPSRS are intended for use in identifying and quantifying the factors that contribute to the occurrence of significant safety incidents involving humans in nuclear power plants. The NPSRS has been designed to encourage participation in the System through guarantees of reporter anonymity provided by a third-party organization that would be responsible for NPSRS management. As additional motivation to reporters for contributing data to the NPSRS, conditional waivers of NRC disciplinary action would be provided to individuals. These conditional waivers of immunity would apply to potential violations of NRC regulations that might be disclosed through reports submitted to the System about inadvertent, noncriminal incidents in nuclear plants. This document summarizes the overall results of the study of the NPSRS concept. In it, a functional description of the NPSRS is presented together with a review and assessment of potential problem areas that might be met if the System were implemented. Conclusions and recommendations resulting from the study are also presented. A companion volume (NUREG/CR-4133, Nuclear Power Safety Reporting System: Implementation and Operational Specifications'') presented in detail the elements, requirements, forms, and procedures for implementing and operating the System. 13 refs

Computer code validation study of PWR core design system, CASMO-3/MASTER-α

International Nuclear Information System (INIS)

Lee, K. H.; Kim, M. H.; Woo, S. W.

1999-01-01

In this paper, the feasibility of CASMO-3/MASTER-α nuclear design system was investigated for commercial PWR core. Validation calculation was performed as follows. Firstly, the accuracy of cross section generation from table set using linear feedback model was estimated. Secondly, the results of CASMO-3/MASTER-α was compared with CASMO-3/NESTLE 5.02 for a few benchmark problems. Microscopic cross sections computed from table set were almost the same with those from CASMO-3. There were small differences between calculated results of two code systems. Thirdly, the repetition of CASMO-3/MASTER-α calculation for Younggwang Unit-3, Cycle-1 core was done and their results were compared with nuclear design report(NDR) and uncertainty analysis results of KAERI. It was found that uncertainty analysis results were reliable enough because results were agreed each other. It was concluded that the use of nuclear design system CASMO-3/MASTER-α was validated for commercial PWR core

An engineer-constructor's view of nuclear power plant safety

International Nuclear Information System (INIS)

Landis, J.W.; Jacobs, S.B.

1984-01-01

At SWEC we have been involved in the development of safety features of nuclear power plants ever since we served as the engineer-constructur for the first commerical nuclear power station at Shippingport, Pennsylvania, in the 1950s. Our personnel have pioneered a number of safety innovations and improvements. Among these innovations is the subatmospheric containment for pressurized water reactor (PWR) power plants. This type of containment is designed so that leakage will terminate within 1 to 2 hours of the worst postulated loss of coolant accident. Other notable contributions include first use of reinforced-concrete atmospheric containments for PWR power plants and of reinforced-concrete, vapor-suppression containments for boiling water reactor (BWR) power plants. Both concepts meet rigorous U.S. safety requirements. SWEC has performed a substantial amount of work on developing standardized plant designs and has developed standardized engineering and construction techniques and procedures. Standardization concepts are being developed in Canada, France, USSR, and Germany, as well as in the United States. The West German convoy concept, which involves developing a number of standardized plants in a common effort, has been quite successful. We believe standardization contributes to safety in a number of ways. Use of standardized designs, procedures, techniques, equipment, and methods increases efficiency and results in higher quality. Standardization also reduces the design variations with which plant operators, emergency teams, and regulatory personnel must be familiar, thus increasing operator capability, and permits specialized talents to be focused on important safety considerations. (orig./RW)

A Post Closure Safety Assessment for Radioactive Wastes from Advanced nuclear fuel Cycle

International Nuclear Information System (INIS)

Kang, Chul Hyung; Hwang, Yong Soo

2010-01-01

KAERI has developed the KIEP-21 (Korean, Innovative, Environmentally Friendly, and Proliferation Resistant System for the 21st Century). It is an advanced nuclear fuel cycle option with a pyro-process and a GEN-IV SFR. A pyro-process consists of two distinctive processes, an electrolytic reduction process and an electro-refining and winning process. When the pyro-process is applied, it generates five streams of wastes. To compare pyro-process advantage over the direct disposal of Spent Nuclear Fuel (SNF), the PWR SNF of the 45,000 MWD burn-up has been assumed. A safety assessment model for pyro-process wastes and representative results are presented in this report

Assessment and Management of ageing of major nuclear power plant components important to safety: PWR pressure vessels

International Nuclear Information System (INIS)

1999-10-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g., caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness-for-service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), including water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs; and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. Since the reports are written from a safety perspective, they do not address life or life-cycle management of the plant components, which involves the integration of

PWR: 10 years after and perspectives

International Nuclear Information System (INIS)

1990-01-01

These proceedings of the SFEN days on PWR (Ten years after and perspectives) comprise 13 conferences bearing on: - From the occurential approach to the state approach - Evolution of calculating tools - Human factors and safety - Reactor safety in the PWR 2000 - The PWR and the electrical power grid load follow - Fuel aspect of PWR management - PWR chemistry evolution - Balance of radiation protection - PWR modifications balance and influence on reactor operation - Design and maintenance of reactor components: 4 conferences [fr

Industrial Personal Computer based Display for Nuclear Safety System

International Nuclear Information System (INIS)

Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min

2014-01-01

The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view

Industrial Personal Computer based Display for Nuclear Safety System

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min [KEPCO, Youngin (Korea, Republic of)

2014-08-15

The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view.

Dispositions taken in France to limit gaseous releases from PWR power plants in abnormal operating conditions

International Nuclear Information System (INIS)

Collinet, J.; Guieu, S.; Mulcey, P.

1989-12-01

The implementation of France's major nuclear programme - 56 PWR units in service or under construction - has gone hand in hand with the development of an original philosophy in the field of nuclear safety. From an initial core of deterministic safety philosophy current in the seventies, which has been wholly retained and, in some instances, refined, a range of complements has been made to include consideration of a number of additional situations based on a probabilistic approach. This has resulted in a better coherence for safety and a reduction of the severe accident probability. Furthermore, the establishment of emergency plans has enabled the Safety Authorities and the utility to adopt a coherent and logical approach to severe accidents, with the aim of better achieving defence in depth. This has resulted in the provision of certain additional measures intended to further reduce the consequences of severe accidents. In a accordance with the safety philosophy, adopted in France for nuclear PWR power stations, filtration systems have been specified and installed to limit the radiological consequences of consecutive gaseous emissions, on the one hand, in accidents taken into account in the design and, on the other hand, in accidents liable to jeopardize the integrity of the containment

An integrated methodology to evaluate a spent nuclear fuel storage system

International Nuclear Information System (INIS)

Yoon, Jeong Hyoun

2008-02-01

This study introduced a methodology that can be applied for development of a dry storage system for spent nuclear fuels. It consisted of several design activities that includes development of a simplified program to analyze the amount of spent nuclear fuels from reflecting the practical situation in spent nuclear fuel management and a simplified program to evaluate the cost of 4 types of representing storage system to choose the most competitive option considering economic factor. As verification of the implementation of the reference module to practical purpose, a simplified thermal analysis code was suggested that can see fulfillment of limitation of temperature in long term storage and oxidation analysis. From the thermal related results, the reference module can accommodate full range of PHWR spent nuclear fuels and significant portion of PWR ones too. From the results, the reference storage system can be concluded that has fulfilled the important requirements in terms of long term integrity and radiological safety. Also for the purpose of solving scattered radiation along with deep penetration problems in cooling storage system, small but efficient design alternation was suggested together with its efficiency that can reduce scattered radiation by 1/3 from the original design. Along with the countermeasure for the shielding problem, in consideration of PWR spent nuclear fuels, simplified criticality analysis methodology retaining conservativeness was proposed. The results show the reference module is efficient low enrichment PWR spent nuclear fuel and even relatively high enrichment fuels too if burnup credit is taken. As conclusive remark, the methodology is simple but efficient to plan a concept design of convective cooling type of spent nuclear fuels storage. It can be also concluded that the methodology derived in this study and the reference module has feasibility in practical implementation to mitigate the current complex situation in spent fuel

New Paradigm in Nuclear Safety from Quality Assurance to Safety Management System

International Nuclear Information System (INIS)

Lim, Nam-Jin; Park, Chan-Gook; Nam, Ji-Hee; Kim, Kwan-Hyun; Kwon, Hyuk-il; Lee, Young-Gun Lee

2006-01-01

The initial concept of Quality Control (QC) controlling the quality of products is now evolving toward the Management System (MS) achieving safety, through Quality Assurance (QA) ensuring the quality of products and Quality Management (QM) managing the quality by a systematic approach. Nuclear safety can be achieved through an integrated MS that ensures the health, environmental, security, quality and economic requirements being considered together with nuclear safety requirements. MS approach is developed through realizing that most of nuclear accidents had occurred not by the malfunction of hardware or equipment, but by the human error. The MS is a set of inter-related or interacting elements (system) that establishes policies and objectives and which enables those objectives to be achieved in an efficient and effective way

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

International Nuclear Information System (INIS)

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

1994-01-01

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

Nuclear power systems: Their safety. Current issue review

International Nuclear Information System (INIS)

Myers, L.C.

1994-04-01

Human beings utilize energy in many forms and from a variety of sources. A number of countries have chosen nuclear-electric generation as a component of their energy system. At the end of 1992, there were 419 power reactors operating in 29 countries, accounting for more than 15% of the world's production of electricity. In 1992, 13 countries derived at least 25% of their electricity from nuclear units, with Lithuania leading at just over 78%, followed closely by France at 72%. In the same year, Canada produced about 16% of its electricity from nuclear units. Some 53 power reactors are under construction in 14 countries outside the former USSR. Within the ex-USSR countries, six new reactors are currently under construction. No human endeavour carries the guarantee of perfect safety and the question of whether of not nuclear-electric generation represents an 'acceptable' risk to society has long been vigorously debated. Until the events of late April 1986 in the then Soviet Union, nuclear safety had indeed been an issue for discussion, for some concern, but not for alarm. The accident at the Chernobyl reactor irrevocably changed all that. This disaster brought the matter of nuclear safety into the public mind in a dramatic fashion. Subsequent opening of the ex-Soviet nuclear power program to outside scrutiny has done little to calm people's concerns about the safety of nuclear power in that part of the world. This paper discusses the issue of safety in complex energy systems and provides brief accounts of some of the most serious reactor accidents that have occurred to date, as well as more recent, less dramatic events touching on the safety issue. (author). 7 refs

Application of CFD Codes in Nuclear Reactor Safety Analysis

Directory of Open Access Journals (Sweden)

T. Höhne

2010-01-01

Full Text Available Computational Fluid Dynamics (CFD is increasingly being used in nuclear reactor safety (NRS analyses as a tool that enables safety relevant phenomena occurring in the reactor coolant system to be described in more detail. Numerical investigations on single phase coolant mixing in Pressurised Water Reactors (PWR have been performed at the FZD for almost a decade. The work is aimed at describing the mixing phenomena relevant for both safety analysis, particularly in steam line break and boron dilution scenarios, and mixing phenomena of interest for economical operation and the structural integrity. For the experimental investigation of horizontal two phase flows, different non pressurized channels and the TOPFLOW Hot Leg model in a pressure chamber was build and simulated with ANSYS CFX. In a common project between the University of Applied Sciences Zittau/Görlitz and FZD the behaviour of insulation material released by a LOCA released into the containment and might compromise the long term emergency cooling systems is investigated. Moreover, the actual capability of CFD is shown to contribute to fuel rod bundle design with a good CHF performance.

Evaluation of fire probabilistic safety assessment for a PWR plant

International Nuclear Information System (INIS)

Wu, C.H.; Lin, T.J.; Kao, T.M.

2001-01-01

The internal fire analysis of the level 1 power operation probability safety assessment (PSA) for Maanshan (PWR) Nuclear Power Plant (MNPP) was updated. The fire analysis adopted a scenario-based PSA approach to systematically evaluate fire and smoke hazards and their associated risk impact to MNPP. The result shows that the core damage frequency (CDF) due to fire is about six times lower than the previous one analyzed by the Atomic Energy Council (AEC), Republic of China in 1987. The plant model was modified to reflect the impact of human events and recovery actions during fire. Many tabulated EXCEL spread-sheets were used for evaluation of the fire risk. The fire-induced CDF for MNPP is found to be 2.1 E-6 per year in this study. The relative results of the fire analysis will provide the bases for further risk-informed fire protection evaluation in the near future. (author)

Discussion on establishment and improvement of the nuclear safety culture system

International Nuclear Information System (INIS)

Lu Weiqiang; Na Fuli

2010-01-01

By discussion of the problems in the manufacture process of nuclear power equipment enterprisers, puts forwards the tentative idea of establishment the nuclear safety culture system, meanwhile, gives some suggestions in order to improving the nuclear safety culture system. (authors)

Optimization of control area ventilation systems for Japanese PWR plants

International Nuclear Information System (INIS)

Naitoh, T.; Nakahara, Y.

1987-01-01

The nuclear power plant has been required to reduce the cost for the purpose of making the low-cost energy since several years ago in Japan. The Heating, Ventilating and Air Conditioning system in the nuclear power plant has been also required to reduce its cost. On the other hand the ventilation system should add the improvable function according to the advanced plant design. In response to these different requirements, the ventilation criteria and the design of the ventilation system have been evaluated and optimized in Japanese PWR Plant design. This paper presents the findings of the authors' study

Expert system for the investigation of safety system availability on a 900 MWe PWR

International Nuclear Information System (INIS)

Chauliac, C.; Deplanque, B.; To, L.H.

1988-01-01

A computer program of the expert system type would appear to be an elegant and effective tool for rapid diagnosis of safety system availability in accident situations. The expert system developed for this purpose by the Institut de Protection et de Surete Nucleaire (Institute for Nuclear Safety and Protection) has been described in this paper; its logic process has been examined in detail and illustrated by means of two examples. In its present form, this expert system monitors the availability of 21 main systems. In its final form (1989), 37 main systems will be tested. It will then include descriptions of between 1500 and 2000 objects and will utilize about 1000 rules. It will be run (as is presently the case) in a workstation with windowing facilities and graphic result displays which provide the highest degree of user-friendliness

PWR AXIAL BURNUP PROFILE ANALYSIS

International Nuclear Information System (INIS)

J.M. Acaglione

2003-01-01

The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B andW 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001)

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

International Nuclear Information System (INIS)

2008-01-01

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

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

International Nuclear Information System (INIS)

2004-01-01

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

Nuclear power safety reporting system feasibility analysis and concept description

International Nuclear Information System (INIS)

Finlayson, F.C.; Ims, J.R.; Hussman, T.A.

1984-01-01

The Aerospace Corporation is assisting the US Nuclear Regulatory Commission (NRC) in the evaluation of the potential attributes of a voluntary, nonpunitive data gathering system for identifying and quantifying the factors that contribute to the occurrence of significant safety problems involving humans in nuclear power plants. The objectives of the Aerospace Administration (FAA)/National Aeronautics and Space Administration (NASA) Aviation Safety Reporting System (ASRS) in order to determine whether it would be feasible to apply part (or all) of the ASRS concepts for collecting data on human factor related incidents to the nuclear industry; and (2) to identify and define the basic elements and requirements of a Nuclear Power Safety Reporting System (NPSRS), assuming the feasibility of implementing such a system was established

Operating function tests of the PWR type RHR pump for engineering safety system under simulated strong ground excitation

International Nuclear Information System (INIS)

Uga, Takeo; Shiraki, Kazuhiro; Homma, Toshiaki; Inazuka, Hisashi; Nakajima, Norifumi.

1979-08-01

Results are described of operating function verification tests of a PWR RHR pump during an earthquake. Of the active reactor components, the PWR residual heat removal pump was chosen from view points of aseismic classification, safety function, structural complexity and past aseismic tests. Through survey of the service conditions and structure of this pump, seismic test conditions such as acceleration level, simulated seismic wave form and earthquake duration were decided for seismicity of the operating pump. Then, plans were prepared to evaluate vibration chracteristics of the pump and to estimate its aseismic design margins. Subsequently, test facility and instrumentation system were designed and constructed. Experimental results could thus be acquired on vibration characteristics of the pump and its dynamic behavior during different kinds and levels of simulated earthquake. In conclusion: (1) Stiffeners attached to the auxiliary system piping do improve aseismic performance of the pump. (2) The rotor-shaft-bearing system is secure unless it is subjected to transient disturbunces having high frequency content. (3) The motor and pump casing having resonance frequencies much higher than frequency content of the seismic wave show only small amplifications. (4) The RHR pump possesses an aseismic design margin more than 2.6 times the expected ultimate earthquake on design basis. (author)

Advancement on safety management system of nuclear power for safety and non-anxiety of society

International Nuclear Information System (INIS)

Yoshikawa, Hidekazu

2004-01-01

Advancement on safety management system is investigated to improve safety and non-anxiety of society for nuclear power, from the standpoint of human machine system research. First, the recent progress of R and D works of human machine interface technologies since 1980 s are reviewed and then the necessity of introducing a new approach to promote technical risk communication activity to foster safety culture in nuclear industries. Finally, a new concept of Offsite Operation and Maintenance Support Center (OMSC) is proposed as the core facility to assemble human resources and their expertise in all organizations of nuclear power, for enhancing safety and non-anxiety of society for nuclear power. (author)

Comparative study T-type and I-type layout of PWR nuclear power plants

International Nuclear Information System (INIS)

Eko Rudi Iswanto and Siti Alimah

2010-01-01

Determining plant layout is one of the five major stages during the life time of a nuclear power plant. Some important factors that affect in the selecting of plant layout are availability of infrastructure, economic aspects, social aspects, public and environment safety, and also easy to do. Another factor to be considered is requirements as seismic design, which refers to the principles of good security workers, communities and the environment of radiological risks. There are many layout types of nuclear power plant, two of them are T-type layout and I-type layout. Each type of the plant layout has advantage and disadvantage, therefore this study is to understand them. Good layout is able to provide a high level of security against earthquakes. In term of earthquake design, I-type layout has a higher security level than T-type layout. Therefore, I-type layout can be a good choice for PWR nuclear power plants 1000 MWe that will be built in Indonesia. (author)

Advanced nuclear control and protection system ANCAP-80

International Nuclear Information System (INIS)

Asai, Takashi; Okano, Michihiko; Ishibashi, Kengo; Hasegawa, Masakoto; Fukuda, Hiroyoshi; Hosomichi, Renichi.

1983-01-01

Advanced reactor protection systems were developed to improve operational reliability and availability and to ease the burden of operators of Mitsubishi PWR Nuclear Power Stations. (Called ANCAP-80; Advanced Nuclear Control And Protection System) For the PWR plants now being planned and in future plans, Mitsubishi will adopt these systems with the following functional features; (1) Four channel protection logic, (2) Automatic bypass logic, (3) Automatic test provision, (4) Optical isolators. (author)

Nuclear safety and radiation protection report of the Saint-Laurent-des-Eaux nuclear facilities - 2011

International Nuclear Information System (INIS)

2012-01-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Saint-Laurent-des-Eaux nuclear power plant (Saint-Laurent-Nouan (FR)): 2 partially dismantled graphite-gas reactors and a graphite sleeves storage silo (INB 46 and 74), and 2 PWR reactors in operation (INB 100). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Nuclear safety and radiation protection report of the Saint-Laurent-des-Eaux nuclear facilities - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Saint-Laurent-des-Eaux nuclear power plant (Saint-Laurent-Nouan (FR)): 2 partially dismantled graphite-gas reactors and a graphite sleeves storage silo (INB 46 and 74), and 2 PWR reactors in operation (INB 100). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

A hybrid approach to quantify software reliability in nuclear safety systems

International Nuclear Information System (INIS)

Arun Babu, P.; Senthil Kumar, C.; Murali, N.

2012-01-01

Highlights: ► A novel method to quantify software reliability using software verification and mutation testing in nuclear safety systems. ► Contributing factors that influence software reliability estimate. ► Approach to help regulators verify the reliability of safety critical software system during software licensing process. -- Abstract: Technological advancements have led to the use of computer based systems in safety critical applications. As computer based systems are being introduced in nuclear power plants, effective and efficient methods are needed to ensure dependability and compliance to high reliability requirements of systems important to safety. Even after several years of research, quantification of software reliability remains controversial and unresolved issue. Also, existing approaches have assumptions and limitations, which are not acceptable for safety applications. This paper proposes a theoretical approach combining software verification and mutation testing to quantify the software reliability in nuclear safety systems. The theoretical results obtained suggest that the software reliability depends on three factors: the test adequacy, the amount of software verification carried out and the reusability of verified code in the software. The proposed approach may help regulators in licensing computer based safety systems in nuclear reactors.

Expert systems for assisting the analysis of hazards

International Nuclear Information System (INIS)

Evrard, J.M.; Martinez, J.M.; Souchet, Y.

1990-01-01

The advantage of applying expert systems in the analysis of safety in the operation of nuclear power plants is discussed. Expert systems apply a method based on a common representation of nuclear power plants. The main steps of the method are summarized. The applications given concern in the following fields: the analysis of hazards in the electric power supplies of a gas-graphite power plant; the evaluation of the availability of safety procedures in a PWR power plant; the search for the sources of leakage in a PWR power plant. The analysis shows that expert systems are a powerful tool in the study of safety of nuclear power plants [fr

Low-density moderation in the storage of PWR fuel assemblies

International Nuclear Information System (INIS)

Alcorn, F.M.

1987-01-01

The nuclear criticality safety of PWR fuel storage arrays requires that the potential of low-density moderation within the array be considered. The calculated criticality effect of low-density moderation in a typical PWR fuel assembly array is described in this paper. Calculated reactivity due to low-density moderation can vary significantly between physics codes that have been validated for well moderated systems. The availability of appropriate benchmark experiments for low-density moderation is quite limited; attempts to validate against the one set of suitable experiments at low density have been disappointing. Calculations indicate that a typical array may be unacceptable should the array be subjected to interstitial moderation equivalent to 5 % of full density water. Array parameters (such as spacing and size) will dramatically affect the calculated maximum K-eff at low-density moderation. Administrative and engineered control may be necessary to assure maintenance of safety at low-density moderation. Potential sources for low-density moderation are discussed; in general, accidentally achieving degrees of low-density moderation which might lead to a compromise of safety are not credible. (author)

Second periodic safety review of Angra Nuclear Power Station, unit 1

Energy Technology Data Exchange (ETDEWEB)

Martins, Carlos F.O.; Crepaldi, Roberto; Freire, Enio M., E-mail: ottoncf@tecnatom.com.br, E-mail: emfreire46@gmail.com, E-mail: robcrepaldi@hotmail.com [Tecnatom do Brasil Engenharia e Servicos Ltda, Rio de Janeiro, RJ (Brazil); Campello, Sergio A., E-mail: sacampe@eletronuclear.gov.br [Eletrobras Termonuclear S.A. (ELETRONUCLEAR), Rio de Janeiro, RJ (Brazil)

2015-07-01

This paper describes the second Periodic Safety Review (PSR2-A1) of Angra Nuclear Power Station, Unit 1, prepared by Eletrobras Eletronuclear S.A. and Tecnatom do Brasil Engenharia e Servicos Ltda., during Jul.2013-Aug.2014, covering the period of 2004-2013. The site, in Angra dos Reis-RJ, Brazil, comprises: Unit 1, (640 MWe, Westinghouse PWR, operating), Unit 2 (1300 MWe, KWU/Areva, operating) and Unit 3 (1405 MWe, KWU/Areva, construction). The PSR2-A1 attends the Standards 1.26-Safety in Operation of Nuclear Power Plants, Brazilian Nuclear Regulatory Commission (CNEN), and IAEA.SSG.25-Periodic Safety Review of Nuclear Power Plants. Within 18 months after each 10 years operation, the operating organization shall perform a plant safety review, to investigate the evolution consequences of safety code and standards, regarding: Plant design; structure, systems and components behavior; equipment qualification; plant ageing management; deterministic and probabilistic safety analysis; risk analysis; safety performance; operating experience; organization and administration; procedures; human factors; emergency planning; radiation protection and environmental radiological impacts. The Review included 6 Areas and 14 Safety Parameters, covered by 33 Evaluations.After document evaluations and discussions with plant staff, it was generated one General and 33 Specific Guide Procedures, 33 Specific and one Final Report, including: Description, Strengths, Deficiencies, Areas for Improvement and Conclusions. An Action Plan was prepared by Electronuclear for the recommendations. It was concluded that the Unit was operated within safety standards and will attend its designed operational lifetime, including possible life extensions. The Final Report was submitted to CNEN, as one requisite for renewal of the Unit Permanent Operation License. (author)

Second periodic safety review of Angra Nuclear Power Station, unit 1

International Nuclear Information System (INIS)

Martins, Carlos F.O.; Crepaldi, Roberto; Freire, Enio M.; Campello, Sergio A.

2015-01-01

This paper describes the second Periodic Safety Review (PSR2-A1) of Angra Nuclear Power Station, Unit 1, prepared by Eletrobras Eletronuclear S.A. and Tecnatom do Brasil Engenharia e Servicos Ltda., during Jul.2013-Aug.2014, covering the period of 2004-2013. The site, in Angra dos Reis-RJ, Brazil, comprises: Unit 1, (640 MWe, Westinghouse PWR, operating), Unit 2 (1300 MWe, KWU/Areva, operating) and Unit 3 (1405 MWe, KWU/Areva, construction). The PSR2-A1 attends the Standards 1.26-Safety in Operation of Nuclear Power Plants, Brazilian Nuclear Regulatory Commission (CNEN), and IAEA.SSG.25-Periodic Safety Review of Nuclear Power Plants. Within 18 months after each 10 years operation, the operating organization shall perform a plant safety review, to investigate the evolution consequences of safety code and standards, regarding: Plant design; structure, systems and components behavior; equipment qualification; plant ageing management; deterministic and probabilistic safety analysis; risk analysis; safety performance; operating experience; organization and administration; procedures; human factors; emergency planning; radiation protection and environmental radiological impacts. The Review included 6 Areas and 14 Safety Parameters, covered by 33 Evaluations.After document evaluations and discussions with plant staff, it was generated one General and 33 Specific Guide Procedures, 33 Specific and one Final Report, including: Description, Strengths, Deficiencies, Areas for Improvement and Conclusions. An Action Plan was prepared by Electronuclear for the recommendations. It was concluded that the Unit was operated within safety standards and will attend its designed operational lifetime, including possible life extensions. The Final Report was submitted to CNEN, as one requisite for renewal of the Unit Permanent Operation License. (author)

Nuclear safety

International Nuclear Information System (INIS)

Tarride, Bruno

2015-10-01

The author proposes an overview of methods and concepts used in the nuclear industry, at the design level as well as at the exploitation level, to ensure an acceptable safety level, notably in the case of nuclear reactors. He first addresses the general objectives of nuclear safety and the notion of acceptable risk: definition and organisation of nuclear safety (relationships between safety authorities and operators), notion of acceptable risk, deterministic safety approach and main safety principles (safety functions and confinement barriers, concept of defence in depth). Then, the author addresses the safety approach at the design level: studies of operational situations, studies of internal and external aggressions, safety report, design principles for important-for-safety systems (failure criterion, redundancy, failure prevention, safety classification). The next part addresses safety during exploitation and general exploitation rules: definition of the operation domain and of its limits, periodic controls and tests, management in case of incidents, accidents or aggressions

Safety assessment for Generation IV nuclear systems

International Nuclear Information System (INIS)

Leahy, T.J.

2012-01-01

The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Recent RSWG work has focused on the definition of an integrated safety assessment methodology (ISAM) for evaluating the safety of Generation IV systems. ISAM is an integrated 'tool-kit' consisting of 5 analytical techniques that are available and matched to appropriate stages of Generation IV system concept development: 1) qualitative safety features review - QSR, 2) phenomena identification and ranking table - PIRT, 3) objective provision tree - OPT, 4) deterministic and phenomenological analyses - DPA, and 5) probabilistic safety analysis - PSA. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Nuclear reactor safety system

International Nuclear Information System (INIS)

Ball, R.M.; Roberts, R.C.

1983-01-01

The invention provides a safety system for a nuclear reactor which uses a parallel combination of computer type look-up tables each of which receives data on a particular parameter (from transducers located in the reactor system) and each of which produces the functional counterpart of that particular parameter. The various functional counterparts are then added together to form a control signal for shutting down the reactor. The functional counterparts are developed by analysis of experimental thermal and hydraulic data, which are used to form expressions that define safe conditions

Nuclear reactor safety systems

International Nuclear Information System (INIS)

Ball, R.M.; Roberts, R.C.

1980-01-01

A safety system for shutting down a nuclear reactor under overload conditions is described. The system includes a series of parallel-connected computer memory type look-up tables each of which receives data on a particular reactor parameter and in each of which a precalculated functional value for that parameter is stored indicative of the percentage of maximum reactor load that the parameter contributes. The various functional values corresponding to the actual measured parameters are added together to provide a control signal used to shut down the reactor under overload conditions. (U.K.)

The socio-technical system and nuclear safety

International Nuclear Information System (INIS)

Stefanescu, Petre; Mihailescu, Nicolae; Dragusin, Octavian

1999-01-01

In the field of nuclear safety there have been defined notions like 'technical factors' and 'human factors'. The technical factors depend on designing and manufacturing of components/equipment, actually depend on the people's work. The study of human factors consists in analyzing and recommending the terms that allow an individual to be a reliable and safety agent. Accordingly, he/she is placed in working conditions corresponding to human abilities, associating the means of three levels: - designing, i.e. the action upon the technical system and upon work organization; - correction, i.e. the action upon the evolution of the technical system and organizing; - formation/training, i.e. action upon operators. The paper presents a characterization of the socio-technical system and on this basis discusses the issue of individual adjustment to the socio-technical system and reciprocally, the issue of the socio-technical system adjustment to the individual. Concepts as: ergonomics, physical medium, man/machine interface and support of the operator, man/machine task sharing, the work organizing are put in relation with the central subject, the nuclear safety

Preliminary analysis of start up characteristics on SPWR with NESSY (Nuclear ship Engineering Simulation SYstem)

International Nuclear Information System (INIS)

Kusunoki, Tsuyoshi; Kyouya, Masahiko; Sako, Kiyoshi

1993-09-01

NESSY (Nuclear ship Engineering Simulation SYstem) has been developed to design advanced marine reactors. SPWR (System integrated PWR) has been designed by JAERI. It doesn't have control rod, and starts up by dilution of boron. we analyzed start up behavior of SPWR by NESSY, and evaluated the safety characteristics on start up and appropriate range of start up rate. (author)

Implementation in free software of the PWR type university nucleo electric simulator (SU-PWR); Implementacion en software libre del simulador universitario de nucleoelectrica tipo PWR (SU-PWR)

Energy Technology Data Exchange (ETDEWEB)

Valle H, J.; Hidago H, F.; Morales S, J.B. [UNAM, Laboratorio de Analisis de Ingenieria de Reactores Nucleares DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: julfi_jg@yahoo.com.mx

2007-07-01

Presently work is shown like was carried out the implementation of the University Simulator of Nucleo-electric type PWR (SU-PWR). The implementation of the simulator was carried out in a free software simulation platform, as it is Scilab, what offers big advantages that go from the free use and without cost of the product, until the codes modification so much of the system like of the program with the purpose of to improve it or to adapt it to future routines and/or more advanced graphic interfaces. The SU-PWR shows the general behavior of a PWR nuclear plant (Pressurized Water Reactor) describing the dynamics of the plant from the generation process of thermal energy in the nuclear fuel, going by the process of energy transport toward the coolant of the primary circuit the one which in turn transfers this energy to the vapor generators of the secondary circuit where the vapor is expanded by means of turbines that in turn move the electric generator producing in this way the electricity. The pressurizer that is indispensable for the process is also modeled. Each one of these stages were implemented in scicos that is the Scilab tool specialized in the simulation. The simulation was carried out by means of modules that contain the differential equation that mathematically models each stage or equipment of the PWR plant. The result is a series of modules that based on certain entrances and characteristic of the system they generate exits that in turn are the entrance to other module. Because the SU-PWR is an experimental project in early phase, it is even work and modifications to carry out, for what the models that are presented in this work can vary a little the being integrated to the whole system to simulate, but however they already show clearly the operation and the conformation of the plant. (Author)

Nuclear safety culture and nuclear safety supervision

International Nuclear Information System (INIS)

Chai Jianshe

2013-01-01

In this paper, the author reviews systematically and summarizes up the development process and stage characteristics of nuclear safety culture, analysis the connotation and characteristics of nuclear safety culture, sums up the achievements of our country's nuclear safety supervision, dissects the challenges and problems of nuclear safety supervision. This thesis focused on the relationship between nuclear safety culture and nuclear safety supervision, they are essential differences, but there is a close relationship. Nuclear safety supervision needs to introduce some concepts of nuclear safety culture, lays emphasis on humanistic care and improves its level and efficiency. Nuclear safety supervision authorities must strengthen nuclear safety culture training, conduct the development of nuclear safety culture, make sure that nuclear safety culture can play significant roles. (author)

PWR pressurizer discharge piping system on-site testing

International Nuclear Information System (INIS)

Anglaret, G.; Lasne, M.

1983-08-01

Framatome PWR systems includes the installation of safety valves and relief valves wich permit the discharge of steam from the pressurizer to the pressurizer relief tank through discharge piping system. Water seal expulsion pluration then depends on valve stem lift dynamics which can vary according to water-stem interaction. In order to approaches the different phenomenons, it was decided to perform a test on a 900 MWe French plant, test wich objectives are: characterize the mechanical response of the discharge piping to validate a mechanical model; open one, two or several valves among the following: one safety valve and three pilot operated relief valves, at a time or sequentially and measure the discharge piping transient response, the support loads, the

Safety program considerations for space nuclear reactor systems

International Nuclear Information System (INIS)

Cropp, L.O.

1984-08-01

This report discusses the necessity for in-depth safety program planning for space nuclear reactor systems. The objectives of the safety program and a proposed task structure is presented for meeting those objectives. A proposed working relationship between the design and independent safety groups is suggested. Examples of safety-related design philosophies are given

Deliberations on nuclear safety regulatory system in a changing industrial environment

International Nuclear Information System (INIS)

Kim, H.J.

2001-01-01

Nuclear safety concern, which may accompany such external environmental factors as privatization and restructuring of the electric power industry, is emerging as an international issue. In order to cope with the concern about nuclear safety, it is important to feedback valuable experiences of advanced countries that restructured their electric power industries earlier and further to reflect the current safety issues, which are raised internationally, fully into the nuclear safety regulatory system. This paper is to review the safety issues that might take place in the process of increasing competition in the nuclear power industry, and further to present a basic direction and effective measures for ensuring nuclear safety in response thereto from the viewpoint of safety regulation. It includes a political direction for a regulatory body's efforts to rationalize and enforce efficiently its regulation. It proposes to ensure that regulatory specialty and regulatory cost are stably secured. Also, this paper proposes maintaining a sound nuclear safety regulatory system to monitor thoroughly the safety management activities of the industry, which might be neglected as a result of focusing on reduction of the cost for producing electric power. (author)

Design of the reactor coolant system and associated systems in nuclear power plants. Safety guide (Spanish Edition)

International Nuclear Information System (INIS)

2010-01-01

This Safety Guide was prepared under the IAEA programme for establishing safety standards for nuclear power plants. The basic requirements for the design of safety systems for nuclear power plants are established in the Safety Requirements publication, Safety Standards Series No. NS-R-1 on Safety of Nuclear Power Plants: Design, which it supplements. This Safety Guide describes how the requirements for the design of the reactor coolant system (RCS) and associated systems in nuclear power plants should be met. This publication is a revision and combination of two previous Safety Guides, Safety Series No. 50-SG-D6 on Ultimate Heat Sink and Directly Associated Heat Transport Systems for Nuclear Power Plants (1982), and Safety Series No. 50-SG-D13 on Reactor Coolant and Associated Systems in Nuclear Power Plants (1987), which are superseded by this new Safety Guide. The revision takes account of developments in the design of the RCS and associated systems in nuclear power plants since the earlier Safety Guides were published in 1982 and 1987, respectively. The other objectives of the revision are to ensure consistency with Ref., issued in 2004, and to update the technical content. In addition, an appendix on pressurized heavy water reactors (PHWRs) has been included.

Sizewell 'B' PWR reference design

International Nuclear Information System (INIS)

1982-04-01

The reference design for a PWR power station to be constructed as Sizewell 'B' is presented in 3 volumes containing 14 chapters and in a volume of drawings. The report describes the proposed design and provides the basis upon which the safety case and the Pre-Construction Safety Report have been prepared. The station is based on a 3425MWt Westinghouse PWR providing steam to two turbine generators each of 600 MW. The layout and many of the systems are based on the SNUPPS design for Callaway which has been chosen as the US reference plant for the project. (U.K.)

The Management System for Nuclear Installations. Safety Guide (Spanish Edition)

International Nuclear Information System (INIS)

2017-01-01

This Safety Guide is applicable throughout the lifetime of a nuclear installation, including any subsequent period of institutional control, until there is no significant residual radiation hazard. For a nuclear installation, the lifetime includes site evaluation, design, construction, commissioning, operation and decommissioning. These stages in the lifetime of a nuclear installation may overlap. This Safety Guide may be applied to nuclear installations in the following ways: (a) To support the development, implementation, assessment and improvement of the management system of those organizations responsible for research, site evaluation, design, construction, commissioning, operation and decommissioning of a nuclear installation; (b) As an aid in the assessment by the regulatory body of the adequacy of the management system of a nuclear installation; (c) To assist an organization in specifying to a supplier, via contractual documentation, any specific element that should be included within the supplier's management system for the supply of products. This Safety Guide follows the structure of the Safety Requirements publication on The Management System for Facilities and Activities, whereby: (a) Section 2 provides recommendations on implementing the management system, including recommendations relating to safety culture, grading and documentation. (b) Section 3 provides recommendations on the responsibilities of senior management for the development and implementation of an effective management system. (c) Section 4 provides recommendations on resource management, including guidance on human resources, infrastructure and the working environment. (d) Section 5 provides recommendations on how the processes of the installation can be specified and developed, including recommendations on some generic processes of the management system. (e) Section 6 provides recommendations on the measurement, assessment and improvement of the management system of a nuclear

Experimental research on passive residual heat remove system for advanced PWR

International Nuclear Information System (INIS)

Huang Yanping; Zhuo Wenbin; Yang Zumao; Xiao Zejun; Chen Bingde

2003-01-01

The experimental and qualified results of MISAP in the research of passive residual heat remove system of advanced PWR performed in the Bubble physics and natural circulation laboratory in Nuclear Power Institute of China in the past ten years is overviewed. Further researches for engineering research and design are also suggested

Engineering factors influencing Corbicula fouling in nuclear-service water systems

International Nuclear Information System (INIS)

Henager, C.H.; Johnson, K.I.; Page, T.L.

1983-06-01

Corbicula fouling is a continuing problem in nuclear-service water systems. More knowledge of biological and engineering factors is needed to develop effective detection and control methods. A data base on Corbicula fouling was compiled from nuclear and non-nuclear power stations and industries using raw water. This data base was used in an analysis to identify systems and components which are conducive to fouling by Corbicula. Bounds on several engineering parameters such as velocity and temperature which support Corbicula growth are given. Service water systems found in BWR and PWR reactors are listed and those that show fouling are identified. Possible safety implications of Corbicula fouling are discussed for specific service water systems. Several effective control methods in current use include backflushing with heated water, centrifugal strainers, and continuous chlorination during spawning seasons

SCALE 5.1 Predictions of PWR Spent Nuclear Fuel Isotopic Compositions

Energy Technology Data Exchange (ETDEWEB)

Radulescu, Georgeta [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL

2010-03-01

The purpose of this calculation report is to document the comparison to measurement of the isotopic concentrations for pressurized water reactor (PWR) spent nuclear fuel determined with the Standardized Computer Analysis for Licensing Evaluation (SCALE) 5.1 (Ref. ) epletion calculation method. Specifically, the depletion computer code and the cross-section library being evaluated are the twodimensional (2-D) transport and depletion module, TRITON/NEWT,2, 3 and the 44GROUPNDF5 (Ref. 4) cross-section library, respectively, in the SCALE .1 code system.

Applications of computer based safety systems in Korea nuclear power plants

International Nuclear Information System (INIS)

Won Young Yun

1998-01-01

With the progress of computer technology, the applications of computer based safety systems in Korea nuclear power plants have increased rapidly in recent decades. The main purpose of this movement is to take advantage of modern computer technology so as to improve the operability and maintainability of the plants. However, in fact there have been a lot of controversies on computer based systems' safety between the regulatory body and nuclear utility in Korea. The Korea Institute of Nuclear Safety (KINS), technical support organization for nuclear plant licensing, is currently confronted with the pressure to set up well defined domestic regulatory requirements from this aspect. This paper presents the current status and the regulatory activities related to the applications of computer based safety systems in Korea. (author)

Study on 'Safety qualification of process computers used in safety systems of nuclear power plants'

International Nuclear Information System (INIS)

Bertsche, K.; Hoermann, E.

1991-01-01

The study aims at developing safety standards for hardware and software of computer systems which are increasingly used also for important safety systems in nuclear power plants. The survey of the present state-of-the-art of safety requirements and specifications for safety-relevant systems and, additionally, for process computer systems has been compiled from national and foreign rules. In the Federal Republic of Germany the KTA safety guides and the BMI/BMU safety criteria have to be observed. For the design of future computer-aided systems in nuclear power plants it will be necessary to apply the guidelines in [DIN-880] and [DKE-714] together with [DIN-192]. With the aid of a risk graph the various functions of a system, or of a subsystem, can be evaluated with regard to their significance for safety engineering. (orig./HP) [de

Safety aspects in decontamination operations: Lessons learned during the decommissioning of a small PWR reactor

International Nuclear Information System (INIS)

Klein, M.; Ponnet, M.; Emond, O.

2002-01-01

Decontamination operations are generally executed during the decommissioning of nuclear installations for different objectives: decontamination of loops or large pieces to reduce the dose rate inside a contaminated plant or decontamination to minimize the amount of radioactive waste. These decontamination operations raise safety issues such as radiological exposure, classical safety, environmental releases, production and management of secondary waste, management of primary resources, etc. This paper presents the return of experience from decontamination operations performed during the dismantling of the BR3 PWR reactor. The safety issues are discussed for 3 types of decontamination operations: full system decontamination of the primary loop with a chemical process to reduce the dose rate by a factor of 10; thorough decontamination with an aggressive chemical process of dismantled pieces to reach the unconditional clearance values; and thorough decontamination processes with physical processes of metals and of concrete to reach the unconditional clearance values. For the protection of the workers, we must consider the ALARA aspects and the classical safety issues. During the progress of our dismantling operations, the dose rate issue was becoming less important but the classical safety issues were becoming preponderant due to the use of very aggressive techniques. For the protection of the environment, we must take all the precautions to avoid any leakages from the plant and we must use processes which minimize the use of toxic products and which minimize the production of secondary wastes. We therefore promote the use of regenerative processes. (author)

A system for obtaining an optimized pre design of nuclear reactor core

International Nuclear Information System (INIS)

Mai, L.A.

1989-01-01

This work proposes a method for obtaing a first design of nuclear reactor cores. It takes into consideration the objectives of the project, physical limits, economical limits and the reactor safety. For this purpose, some simplifications were made in the reactor model: one-energy-group, unidimensional and homogeneous core. The adopted model represents a typical PWR core and the optimized parameters are the fuel thickness, refletor thickness, enrichement and moderating ratio. The objective is to gain a larger residual reactivity at the end of the cycle. This work also presents results for a PWR core. From the results, many conclusions are established: system efficiency, limitations and problems. Also some suggestions are proposed to improve the system performance for futures works. (author) [pt

Nuclear energy

International Nuclear Information System (INIS)

2007-01-01

This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

Periodic safety analyses; Les essais periodiques

Energy Technology Data Exchange (ETDEWEB)

Gouffon, A; Zermizoglou, R

1990-12-01

The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989.

Reliability analyses to detect weak points in secondary-side residual heat removal systems of KWU PWR plants

International Nuclear Information System (INIS)

Schilling, R.

1983-01-01

Requirements made by Federal German licensing authorities called for the analysis of the secondary-side residual heat removal systems of new PWR plants with regard to availability, possible weak points and the balanced nature of the overall system for different incident sequences. Following a description of the generic concept and the process and safety-related systems for steam generator feed and main steam discharge, the reliability of the latter is analyzed for the small break LOCA and emergency power mode incidents, weak points in the process systems identified, remedial measures of a system-specific and test-strategic nature presented and their contribution to improving system availability quantified. A comparison with the results of the German Risk Study on Nuclear Power Plants (GRS) shows a distinct reduction in core meltdown frequency. (orig.)

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

International Nuclear Information System (INIS)

2004-01-01

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

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

International Nuclear Information System (INIS)

2005-01-01

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

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

International Nuclear Information System (INIS)

2000-01-01

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

B ampersand W PWR advanced control system algorithm development

International Nuclear Information System (INIS)

Winks, R.W.; Wilson, T.L.; Amick, M.

1992-01-01

This paper discusses algorithm development of an Advanced Control System for the B ampersand W Pressurized Water Reactor (PWR) nuclear power plant. The paper summarizes the history of the project, describes the operation of the algorithm, and presents transient results from a simulation of the plant and control system. The history discusses the steps in the development process and the roles played by the utility owners, B ampersand W Nuclear Service Company (BWNS), Oak Ridge National Laboratory (ORNL), and the Foxboro Company. The algorithm description is a brief overview of the features of the control system. The transient results show that operation of the algorithm in a normal power maneuvering mode and in a moderately large upset following a feedwater pump trip

Research on the improvement of nuclear safety -Thermal hydraulic tests for reactor safety system-

Energy Technology Data Exchange (ETDEWEB)

Jung, Moon Kee; Park, Choon Kyung; Yang, Sun Kyoo; Chun, Se Yung; Song, Chul Hwa; Jun, Hyung Kil; Jung, Heung Joon; Won, Soon Yun; Cho, Yung Roh; Min, Kyung Hoh; Jung, Jang Hwan; Jang, Suk Kyoo; Kim, Bok Deuk; Kim, Wooi Kyung; Huh, Jin; Kim, Sook Kwan; Moon, Sang Kee; Lee, Sang Il [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-06-01

The present research aims at the development of the thermal hydraulic verification test technology for the safety system of the conventional and advanced nuclear power plant and the development of the advanced thermal hydraulic measuring techniques. In this research, test facilities simulating the primary coolant system and safety system are being constructed for the design verification tests of the existing and advanced nuclear power plant. 97 figs, 14 tabs, 65 refs. (Author).

Basic information about development and construction of a PWR

International Nuclear Information System (INIS)

Meyer, P.J.

1977-01-01

1.0) Plant layout of a PWR; 2.0) principle design of a PWR and the reactor coolant system; 3.0) reactor auxiliary and ancillary systems; 3.1) volume control system; 3.2) boric acid control and chemical feeding system; 3.3) coolant purification and degassing system; 3.4) coolant storage and treatment system; 3.5) nuclear component cooling system; 3.6) liquid waste processing system; 3.7) gaseous waste processing system; 4.0) residual heat removal system; 5.0) emergency feedwater system; 6.0) containment design; 7.0) fuel handling, storage and transport system in a PWR. (orig.) [de

Radioprotection and safety for a dry storage module for bare PWR fuel elements

International Nuclear Information System (INIS)

Tzontlimatzin, E.

1983-01-01

A module for dry storage of spent fuel from PWR, after a previous cooling time of 2 years, is examined. Biological protection is obtained by 185 cm of concrete. The safety study shows the impossibility of a fast increase in temperature in case of cooling system failure because in this case the module will be cooled by natural convection or thermosiphon. A project for a storage installation consisting of 5 modules for 1500 irradiated fuel assemblies is described [fr

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

International Nuclear Information System (INIS)

Tian Lu

2012-01-01

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

RCC-M - Design and Conception Rules for Mechanical Components of PWR Nuclear Islands

International Nuclear Information System (INIS)

2007-01-01

The design and construction rules applicable to mechanical components of PWR Nuclear Islands (RCC-M) are a part of the collection of design and construction rules for nuclear power plants. It covers the rules applicable to the design and manufacture of pressure boundaries of mechanical equipment of pressurized water reactors (PWR). The pressure components subject to the RCC-M are specified in A 4000. They include the reactor fluid systems (primary, secondary and auxiliary systems) and other components which are not subject to pressure: vessel internals, supports for pressure components subject to the RCC-M, nuclear island storage tanks. When a pressure equipment is subject to the RCC-M, all its elements subject to pressure are also, in accordance with the provisions of A 4000, and these elements are the same class as the component. In this case all the provisions of the RCC-M are applicable: design, procurement, manufacture, inspection and pressure testing. Elements which are not subject to pressure and which are subject to the RCC-M may be covered within the Code by limited specific provisions (procurement of materials for example). The other rules applicable to this equipment must be in contractual form. The assemblies comprising pressure equipment assembled by a manufacturer to constitute an integrated and functional whole, shall be subject to the rules indicated in this Code. Main objectives of Code Requirements are to ensure the integrity and mechanical stability over the equipment design life. Function ability and operability of equipment are not directly addressed in the Code. The RCC-M contributes to ensuring compliance with regulatory requirements. These requirements depend on the applicable regulatory context. The RCC-M is representative of the state of the art as concerns the design and manufacture of PWR components, ensuring an overall safety level tested through experience. The RCC-M consists of five sections, which provide rules for the design and

PENGEMBANGAN MODEL UNTUK SIMULASI KESELAMATAN REAKTOR PWR 1000 MWe GENERASI III+ MENGGUNAKAN PROGRAM KOMPUTER RELAP5

Directory of Open Access Journals (Sweden)

Andi Sofrany Ekariansyah

2015-04-01

rinci. Kata kunci: pemodelan, Generasi III+, RELAP5.   Westinghouse’s AP1000 reactor design is the first Generation III+ nuclear power reactor to receive final design approval from the U.S. Nuclear Regulatory Commission (NRC. Currently, the China’s utilities are starting construction several units of AP1000 on two selected sites for scheduled operation in 2013–2015. The AP1000, based on proven technology of Westinghouse-designed PWR with enhancement on the passive safety system, could be considered to be built in Indonesia referring to the requirements of government regulation No. 43/2006 regarding the Nuclear Reactor Licensing. To be accepted by the regulation agency, the design needs to be verified by independent Technical Support Organization (TSO, which can be done using RELAP5 computer code as accident analyses. Currently, NPP safety accident analysis is performed for PWR 1000 MWe of generation II or conventional type. Considering that nowadays references about the technology of AP1000 that includes passive safety technology has been available and assessed, a modeling activity used for future accident analyzes is introduced. Method for developing the model refers to IAEA guide consisting of plant data collection, engineering data and input deck development, and verification and validation of input data. The model developed should be considered preliminary but has been generally representing the AP1000 systems as the basic model. The model has been verified and validated by comparing thermalhidraulic parameter responses with design data in references with ± 13% deviation except for core pressure drop with 13% lower than design. As a basic model, the input deck is ready for further development by integrating safety system, protection system and control system model specified for AP1000 for purposes of safety simulation in detailed way. Keywords: Modeling, Generation III+ , RELAP5.

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

International Nuclear Information System (INIS)

2000-01-01

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

A study in improvement of administrative system in the nuclear safety regulation

International Nuclear Information System (INIS)

Yook, Dong Il; Kuk, Doe Hyeong; Lee, Seong Min; Kim, Jong Sam; Hwang, Sun Ho

2001-03-01

One of the most important tasks to improve nuclear safety regulation system is to separate nuclear regulatory institutes from public agencies which promote the development nuclear power. Moreover, nuclear safety regulation should be not only specialized but optimized to be adapted for new environments such as high-tech information age. Especially, it is necessary to reform the current nuclear safety regulation systems both to be effective under the local self-administration which began to operate in recent years and to be supported by local residents

A study in improvement of administrative system in the nuclear safety regulation

Energy Technology Data Exchange (ETDEWEB)

Yook, Dong Il; Kuk, Doe Hyeong; Lee, Seong Min; Kim, Jong Sam; Hwang, Sun Ho [Chungnam National Univ., Taejon (Korea, Republic of)

2001-03-15

One of the most important tasks to improve nuclear safety regulation system is to separate nuclear regulatory institutes from public agencies which promote the development nuclear power. Moreover, nuclear safety regulation should be not only specialized but optimized to be adapted for new environments such as high-tech information age. Especially, it is necessary to reform the current nuclear safety regulation systems both to be effective under the local self-administration which began to operate in recent years and to be supported by local residents.

A regulatory frame for safety digital systems in nuclear power plants

International Nuclear Information System (INIS)

Mozas Garcia, A.

1998-01-01

The paper focuses on Spanish experience regarding software based systems for safety applications from the regulator's point of view. It describes the actual situation in Spain, number and models of reactors, modernization projects, digital systems implemented and licensing documentation and processes already followed by some upgrading projects. The paper wonders what documents should be required for safety and reliability demonstration of a safety system, when they should be reviewed, and what other activities may be necessary to acquire confidence on a particular system. It describes Spanish laws regarding nuclear safety under which, national standards from the NPP design original country apply to nuclear reactors in Spain. It finally suggests that an international standard jointly used by system manufacturers, nuclear licensees and nuclear safety authorities, both from the country where the NPP is installed, and from the original design country, should be developed so that rapid and easy agreement on licensing issues is reached among all parties. The last part of the paper describes the licensing approach proposed by CSN (Spanish Nuclear Safety Authority). It is still under development and it is based on previous experience on digital systems for non-safety applications. It consists of constructing several frames: 1) databases of existing software based systems, 2) guides for inspection and 3) questionnaires for helping in verification and validation activities evaluation. The scope is to establish a well defined procedure that helps in evaluating the particular system. However, in order for such a procedure to be useful, both regulators and utilities and, perhaps also system manufacturers, should agree on it. Joint CSN-utilities working groups may be suitable for such a purpose. (author)

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

International Nuclear Information System (INIS)

Hosser, D.; Sprey, W.

1986-01-01

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

Layout of the primary circuit with its components for PWR and BWR

International Nuclear Information System (INIS)

Meyer, P.J.

1981-01-01

The light water-moderated and cooled pressurized water reactors and boiling water reactors constitute the basis of economic utilization of nuclear energy all over the world. Pressurized water reactors up to capacities of 3,800 MWth are those most used for power generation. However, their potential capacities exceed 3,800 MWth, so that already in the near future PWR are conseivable which readily generate 1,500 to 2,000 MWe. The main problem for starting the next generation of PWRs are of safety measure and licensing questions. Interesting applications of the PWRs are nuclear district heating, generation of process steam of desalination plants, steam injection into the ground for oil production or chemical factories. A new generation of natural circulation boiling water reactors with a capacity of 200 to 400 MW will be used for development of small industrial areas or for countries without an integral grid system. The natural circulation boiling water reactor will be subject of a separate lecture. Due to the fact of the majority of the PWR all over the world this lecture will discuss mainly PWR design aspects. (orig./RW)

Reactivity Impact of Difference of Nuclear Data Library for PWR Fuel Assembly Calculation by Using AEGIS Code

International Nuclear Information System (INIS)

Ohoka, Yasunori; Tatsumi, Masahiro; Sugimura, Naoki; Tabuchi, Masato

2011-01-01

In 2010, the latest version of the Japanese Evaluated Nuclear Data Library (JENDL-4.0) has been released by JAEA. JENDL-4.0 is major update from JENDL- 3.3, and confirmed to give good accuracy by integral test for fission reactor systems such as fast neutron system and thermal neutron system. In this study, we evaluated the reactivity impact due to difference between ENDF/B-VII.0 and JENDL-4.0 for PWR fuel assembly burnup calculation using AEGIS code which has been developed by Nuclear Engineering, Ltd. in cooperation with Nuclear Fuel Industries, Ltd. and Nagoya University

Nuclear safety considerations with emphasis on instrumentation and control systems

International Nuclear Information System (INIS)

Beare, J.W.

1978-01-01

The conceptual model of a nuclear power plant in Canada is that it consists basically of two kinds of systems. The first kind is the process systems, that is, those structures and components associated with the production of nuclear energy and its conversion to other forms of energy. The second kind is the special safety systems, whose purpose it is to protect the public in the event of a serious failure in the process systems which might otherwise lead to unacceptable radiological consequences. Quantitative limits are set on the unavailability of the special safety systems. These limits are low enough to be consistent with low overall risk and yet can be demonstrated by test during operation of the plant. Low unavailability is an important but not the only condition required for low unrealiability for the special safety systems. The special safety systems minimize the chance of a cross-linked failure particularly under the conditions experienced as a result of the more severe types of postulated serious process failures. Nuclear power plants must also withstand, without a major hazard to the public, certain rare events associated with natural phenomena or man-made activities off-site and also certain in-plant events such as fire or break-up of a turbine-generator which might have a cross-linking effect on process and safety systems. In the latest designs, Canadian nuclear power plants have emergency systems to deal with such events. The emergency systems have an enhanced degree of physical and functional separation from other plant systems. (author)

An Integrated Safety Assessment Methodology for Generation IV Nuclear Systems

International Nuclear Information System (INIS)

Leahy, Timothy J.

2010-01-01

The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Early work of the RSWG focused on defining a safety philosophy founded on lessons learned from current and prior generations of nuclear technologies, and on identifying technology characteristics that may help achieve Generation IV safety goals. More recent RSWG work has focused on the definition of an integrated safety assessment methodology for evaluating the safety of Generation IV systems. The methodology, tentatively called ISAM, is an integrated 'toolkit' consisting of analytical techniques that are available and matched to appropriate stages of Generation IV system concept development. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time.

Water chemistry control of PWR nuclear power plant

International Nuclear Information System (INIS)

Hino, Yuichi; Makino, Ichiro; Yamauchi, Sumio; Fukuda, Fumihito.

1992-01-01

In PWR power plants, the primary system taking heat out of nuclear reactors and the secondary system generating steam and driving turbines are completely separated by steam generators, accordingly, by mutually independent water treatment, both systems are to be maintained in the optimal conditions. Namely, primary system is the closed water circulation circuit of simple liquid phase though under high temperature, high pressure condition, therefore, water shows the stable physical and chemical properties, and the minute water treatment for restraining the corrosion of structural materials and reducing radioactivity can be done. Secondary system is similar to the condensate and feedwater system of thermal power plants, and is the circuit for liquid-vapor two-phase transformation, but due to the local concentration of impurities by evaporation, the strict requirement is set for secondary water quality. However, secondary system can be treated in the state without radioactivity, and this is a great merit. The outline, basic concept and execution of primary water quality control, and the outline, concept, control criteria, facilities and execution of secondary water quality control are reported. (K.I.)

Interrelationship between nuclear safety, safeguards and nuclear security

International Nuclear Information System (INIS)

Irie, Kazutomo

2007-01-01

As preventive activities against danger within nuclear systems, three major areas exist; nuclear safety, safeguards and nuclear security. Considering the purpose of these activities, to prevent non-peaceful use is common in nuclear security in general and safeguards. At the same time, measures against sabotage, one of the subcategory in nuclear security, is similar to nuclear safety in aiming at preventing nuclear accidents. When taking into account the insider issues in nuclear security, the distinction between measures against sabotage and nuclear safety becomes ambiguous. Similarly, the distinction between measures against theft, another subcategory in nuclear security, and safeguards also becomes vague. These distinctions are influenced by psychological conditions of members in nuclear systems. Members who have the intention to make nuclear systems dangerous to human society shall be the 'enemy' to nuclear systems and thus be the target for nuclear security. (author)

Seismic proving test of PWR reactor containment vessel

International Nuclear Information System (INIS)

Akiyama, H.; Yoshikawa, T.; Tokumaru, Y.

1987-01-01

The seismic reliability proving tests of nuclear power plant facilities are carried out by Nuclear Power Engineering Test Center (NUPEC), using the large-scale, high-performance vibration of Tadotsu Engineering Laboratory, and sponsored by the Ministry of International Trade and Industry (MITI). In 1982, the seismic reliability proving test of PWR containment vessel started using the test component of reduced scale 1/3.7 and the test component proved to have structural soundness against earthquakes. Subsequently, the detailed analysis and evaluation of these test results were carried out, and the analysis methods for evaluating strength against earthquakes were established. Whereupon, the seismic analysis and evaluation on the actual containment vessel were performed by these analysis methods, and the safety and reliability of the PWR reactor containment vessel were confirmed

Assessment and Management of Ageing of Major Nuclear Power Plant Components Important to Safety: Steam Generators. 2011 Update

International Nuclear Information System (INIS)

2011-11-01

At present there are over four hundred forty operational nuclear power plants (NPPs) in IAEA Member States. Ageing degradation of the systems, structures of components during their operational life must be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This IAEA-TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuteriumuranium (CANDU) reactor, boiling water reactor (BWR), pressurized water reactor (PWR), and water moderated, water cooled energy reactor (WWER) plants are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. Since the reports are written from a safety perspective, they do not address life or life cycle management of the plant components, which involves the integration of ageing management and economic planning. The target audience of the reports consists of technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific plant components addressed in the reports. The component addressed in the present publication is the steam

Liquid radioactive waste processing improvement of PWR nuclear power plants

International Nuclear Information System (INIS)

Nery, Renata Wolter dos Reis; Martinez, Aquilino Senra; Monteiro, Jose Luiz Fontes

2005-01-01

The study evaluate an inorganic ion exchange to process the low level liquid radwaste of PWR nuclear plants, so that the level of the radioactivity in the effluents and the solid waste produced during the treatment of these liquid radwaste can be reduced. The work compares two types of ion exchange materials, a strong acid cation exchange resin, that is the material typically used to remove radionuclides from PWR nuclear plants wastes, and a mordenite zeolite. These exchange material were used to remove cesium from a synthetic effluent containing only this ion and another effluent containing cesium and cobalt. The breakthrough curves of the zeolite and resin using a fix bed reactor were compared. The results demonstrated that the zeolite is more efficient than the resin in removing cesium from a solution containing cesium and cobalt. The results also showed that a bed combining zeolite and resin can process more volume of an effluent containing cesium and cobalt than a bed resin alone. (author)

A system to obtain an optimized first design of a nuclear reactor core

International Nuclear Information System (INIS)

Mai, L.A.

1988-01-01

This work proposes a method for obtaining a first design of nuclear reactor cores. It takes into consideration the objectives of the project, physical limits, economical limits and the reactor safety. For this purpose, some simplifications were made in the reactor model: one energy-group, one-dimensional and homogeneous core. The adopted model represents a typical PWR core and the optimized parameters are the fuel thickness, reflector thickness, enrichment and moderating ratio. The objective is to gain a larger residual reactivity at the end of the cycle. This work also presents results for a PWR core. From the results, many conclusions are established: system efficiency, limitations and problems. Also some suggestions are proposed to improve the system performance for future works. (autor)

Annual report ''nuclear safety in France''; Le rapport annuel ''la surete nucleaire en France''

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This document is the 2001 annual report of the French authority of nuclear safety (ASN). It summarizes the highlights of the year 2000 and details the following aspects: the nuclear safety in France, the organization of the control of nuclear safety, the regulation relative to basic nuclear facilities, the control of facilities, the information of the public, the international relations, the organisation of emergencies, the radiation protection, the transport of radioactive materials, the radioactive wastes, the PWR reactors, the experimental reactors and other laboratories and facilities, the nuclear fuel cycle facilities, and the shutdown and dismantling of nuclear facilities. (J.S.)

FRAMATOME nuclear services

International Nuclear Information System (INIS)

Delorme, H.; Buttin, J.

1985-05-01

FRAMATOME is a French company whose main activities since 1958 have been the design and manufacture of standardized PWR Nuclear Steam Supply Systems. FRAMATOME builds the Reactor Coolant System components and installs and starts-up the extended Nuclear Steam Supply Systems. In addition to the supply of spare parts of tooling, the services offered by Framatome are implementation of backfits aimed at performance and safety improvement and equipment reliability, technical assistance and, maintenance and repair services

Nuclear energy

International Nuclear Information System (INIS)

Hesketh, Ross.

1985-01-01

The subject is treated under the headings: nuclear energy -what is it; fusion (principles; practice); fission (principles); reactor types and systems (fast (neutron) reactors as breeders; fast reactors; thermal reactors; graphite-moderated thermal reactors; the CANDU reactor; light water reactors - the BWR and the PWR); the nuclear fuel cycle (waste storage; fuel element manufacture; enrichment processes; uranium mining); safety and risk assessment; the nuclear power industry and the economy (regulating authorities; economics; advantages and disadvantages). (U.K.)

PWR and BWR light water reactor systems in the USA and their fuel cycle

International Nuclear Information System (INIS)

Crawford, W.D.

1977-01-01

Light water reactor operating experience in the USA can be considered to date from the choice of the pressurized water reactor (PWR) for use in the naval reactor program and the subsequent construction and operation of the nuclear power plant at Shippingport, Pennsylvania in 1957. The development of the boiling water reactor (BWR) in 1954 and its selection for the plant at Dresden, Illinois in 1959 established this concept as the other major reactor type in the US nuclear power program. The subsequent growth profile is presented, leading to 31 PWR's and 23 BWR's currently in operation as well as to plants in the planning and construction phase. A significant operating record has been accumulated concerning the availability of each of these reactor types as determined by: (1) outage for refueling, (2) component reliability, (3) maintenance requirements, and (4) retrofitting required by government regulation. In addition, the use and performance of BWR's and PWR's in meeting system load requirements is discussed. The growing concern regarding possible terrorist activities and other potential threats has resulted in systems and procedures designed to assure effective safeguards at nuclear power installations. Safeguards measures currently in place are described. Environmental effects of operating plants are subject to both radiological and non-radiological monitoring to verify that results are within the limits established in the licensing process. The operating results achieved and the types of modifications that have been required of operating plants by the Nuclear Regulatory Commission are reviewed. The PWR and BWR Fuel Cycle is examined in terms of: (1) fuel burnup experience and prospects for improvement, (2) the status and outlook for natural uranium resources, (3) enrichment capacity, (4) reprocessing and recycle, and the interrelationships among the latter three factors. High level waste management currently involving on-site storage of spent fuel is discussed

Nuclear safety at the Paks Plant

International Nuclear Information System (INIS)

Bajsz, Jozsef; Vamos, Gabor

1991-01-01

The Paks Nuclear Power Plant is located on the Danube river 114 km south of Budapest. It consists of four PWR units of the Soviet VVER-440 design. These are of the second generation design VVER 440 (model 213) with safety features as of 1975. It should be emphasized that these are two different generations of VVER 440 units. This is not always clear, not only to the general public, but sometimes even to people working in the nuclear industry. The widespread criticism of the first generation type 230 reactors is often extended to model 213 reactors, as the differences between the two models are often not sufficiently emphasized. In this situation it is very important to provide balanced information about the advantages and disadvantages of this reactor type. This paper attempts to do that. (author)

Effect of component aging on PWR control rod drive systems

International Nuclear Information System (INIS)

Grove, E.; Gunther, W.; Sullivan, K.

1992-01-01

An aging assessment of PWR control rod drive (CRD) systems has been completed as part of the US NRC Nuclear Plant Aging Research (NPAR) Program. The design, construction, maintenance, and operation of the Babcock ampersand Wilcox (B ampersand W), Combustion Engineering (CE), and Westinghouse (W) systems were evaluated to determine the potential for degradation as each system ages. Operating experience data were evaluated to identify the predominant failure modes, causes, and effects. This, coupled with an assessment of the materials of construction and operating environment, demonstrate that each design is subject to degradation, which if left unchecked, could affect its safety function as the plant ages. An industry survey, conducted with the assistance of EPRI and NUMARC, identified current CRD system maintenance and inspection practices. The results of this survey indicate that some plants have performed system modifications, replaced components, or augmented existing preventive maintenance practices in response to system aging. The survey results also supported the operating experience data, which concluded that the timely replacement of degraded components, prior to failure, was not always possible using existing condition monitoring techniques. The recommendations presented in this study also include a discussion of more advanced monitoring techniques, which provide trendable results capable of detecting aging

Probabilistic reliability analyses to detect weak points in secondary-side residual heat removal systems of KWU PWR plants

International Nuclear Information System (INIS)

Schilling, R.

1984-01-01

Requirements made by Federal German licensing authorities called for the analysis of the second-side residual heat removal systems of new PWR plants with regard to availability, possible weak points and the balanced nature of the overall system for different incident sequences. Following a description of the generic concept and the process and safety-related systems for steam generator feed and main steam discharge, the reliability of the latter is analyzed for the small break LOCA and emergency power mode incidents, weak points in the process systems are identified, remedial measures of a system-specific and test-strategic nature are presented and their contribution to improving system availability is quantified. A comparison with the results of the German Risk Study on Nuclear Power Plants (GRS) shows a distinct reduction in core meltdown frequency. (orig.)

Nuclear and non-nuclear safety aspects in nuclear facilities dismantling. The example of a PWR pilot decommissioning project

International Nuclear Information System (INIS)

Massaut, V.; Deboodt, P.; Dadoumont, J.; Valenduc, P.; Denissen, L.

2002-01-01

The dismantling of nuclear facilities, and in particular of nuclear power plants, involves new challenges for the nuclear industry. Although the dismantling of various activated and contaminated components is nowadays considered as almost industrial practice, the safety aspects of decommissioning bring some specific features which are not always taken into account in the operation of the plants. Moreover, most of the plants and facilities currently decommissioned are rather old and were never foreseen to be decommissioned. The operations involved in dismantling and decontamination, often imply new or unforeseen situations. On the nuclear, or radiological side, the radioprotection optimisation of the operations involved often requires to model the environment and to analyse different scenarios to tackle the operation. Recent 3-D software (like the Visiplan software) allowing representation of the actual environment and the influence of the various sources present, is really needed to be able to minimise the radiological impact on the operators. The risk of contamination spread, by opening loops and components or by the dismantling process itself, is also an important aspect of the radiological protection study. Nevertheless, the radiological aspects of the safety approach are not the only ones to be dealt with when decommissioning nuclear facilities. Indeed, classical industrial safety aspects are also important: the dismantling can bring handling and transporting risk (heavy loads, difficult ways, uneasy access, etc.) but also the handling of toxic or hazardous materials. For instance, the removal of asbestos in contaminated areas can lead to additional hazard; the presence of alkali metals (like Na or NaK), of toxic metals (like e.g. Beryllium) or of corrosive fluids (acid,...) have to be tackled often in unstructured environment, and sometimes with limited knowledge of the actual situation. This leads to approach the operations following the ASARA principle (As

Seismic qualification of PWR plant auxiliary feedwater systems

International Nuclear Information System (INIS)

Lu, S.C.; Tsai, N.C.

1983-08-01

The NRC Standard Review Plan specifies that the auxiliary feedwater (AFW) system of a pressurized water reactor (PWR) is a safeguard system that functions in the event of a Safe Shutdown Earthquake (SSE) to remove the decay heat via the steam generator. Only recently licensed PWR plants have an AFW system designed to the current Standard Review Plan specifications. The NRC devised the Multiplant Action Plan C-14 in order to make a survey of the seismic capability of the AFW systems of operating PWR plants. The purpose of this survey is to enable the NRC to make decisions regarding the need of requiring the licensees to upgrade the AFW systems to an SSE level of seismic capability. To implement the first phase of the C-14 plan, the NRC issued a Generic Letter (GL) 81-14 to all operating PWR licensees requesting information on the seismic capability of their AFW systems. This report summarizes Lawrence Livermore National Laboratory's efforts to assist the NRC in evaluating the status of seismic qualification of the AFW systems in 40 PWR plants, by reviewing the licensees' responses to GL 81-14

Research on integrated managing system based on CIMS for nuclear power plant safety

International Nuclear Information System (INIS)

Zhou Gang

2006-01-01

In order to improve safety, economy and reliability of operation for nuclear power plant (NPP), a novel integrated managing method was proposed based on the ideas of computer and contemporary integrated manufacturing system (CIMS). The application of CIMS to nuclear power plant safety management was researched. In order to design an integrated managing system to meet the needs of NPP safety management, all work related to nuclear safety is divided into different category according to its characters. On basis of this work, general integrated managing system was designed at first. Then subsystems were designed and every subsystem implements a category of nuclear safety management work. All subsystems are independent relatively on the one hand and are interrelated on other hand by global information system. (authors)

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

International Nuclear Information System (INIS)

Zhang Yuangfang

1992-02-01

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

Description of the retest instruction for the safety injection system in a German PWR

International Nuclear Information System (INIS)

Buettner, W.E.

1982-01-01

This report is a detailed supplement to the report 'Retests for a Safety System in a German Nuclear Power Plant' presented at the CSNI Meeting of the Group of Experts on Human Error Data and Assessment, Paris, Sept. 1979. (orig./RW)

A concept of PWR using plate and shell heat exchangers

International Nuclear Information System (INIS)

Freire, Luciano Ondir; Andrade, Delvonei Alves de

2015-01-01

In previous work it was verified the physical possibility of using plate and shell heat exchangers for steam generation in a PWR for merchant ships. This work studies the possibility of using GESMEX commercial of the shelf plate and shell heat exchanger of series XPS. It was found it is feasible for this type of heat exchanger to meet operational and accidental requirements for steam generation in PWR. Additionally, it is proposed an arrangement of such heat exchangers inside the reactor pressure vessel. Such arrangement may avoid ANSI/ANS51.1 nuclear class I requirements on those heat exchangers because they are contained in the reactor coolant pressure barrier and play no role in accidental scenarios. Additionally, those plates work under compression, preventing the risk of rupture. Being considered non-nuclear safety, having a modular architecture and working under compression may turn such architectural choice a must to meet safety objectives with improved economics. (author)

A concept of PWR using plate and shell heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Freire, Luciano Ondir; Andrade, Delvonei Alves de, E-mail: luciano.ondir@gmail.com, E-mail: delvonei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

In previous work it was verified the physical possibility of using plate and shell heat exchangers for steam generation in a PWR for merchant ships. This work studies the possibility of using GESMEX commercial of the shelf plate and shell heat exchanger of series XPS. It was found it is feasible for this type of heat exchanger to meet operational and accidental requirements for steam generation in PWR. Additionally, it is proposed an arrangement of such heat exchangers inside the reactor pressure vessel. Such arrangement may avoid ANSI/ANS51.1 nuclear class I requirements on those heat exchangers because they are contained in the reactor coolant pressure barrier and play no role in accidental scenarios. Additionally, those plates work under compression, preventing the risk of rupture. Being considered non-nuclear safety, having a modular architecture and working under compression may turn such architectural choice a must to meet safety objectives with improved economics. (author)

Burst protected nuclear reactor plant with PWR

International Nuclear Information System (INIS)

Harand, E.; Michel, E.

1978-01-01

In the PWR, several integrated components from the steam raising unit and the main coolant pump are grouped around the reactor pressure vessel in a multiloop circuit and in a vertical arrangement. For safety reasons all primary circuit components and pipelines are situated in burst protection covers. To reduce the area of the plant straight tube steam raising units with forced circulation are used as steam raising units. The boiler pumps are connected to the vertical tubes and to the pressure vessel via double pipelines made as twin chamber pipes. (DG) [de

Analyzing the loss of coolant accident in PWR nuclear reactors with elevation change in cold leg by RELAP5/MOD3.2 system code

International Nuclear Information System (INIS)

Kheshtpaz, H.; Alison, C.

2006-01-01

As, the Russian designed VVER-1000 reactor of the Bushehr Nuclear Power Plant by taking into account the change from German technology to that of Russian technology, and with the design of elevation change in the cold legs has been developed; therefore safety assessment of these systems for loss of coolant accident in elevation change in the cold legs and comparison results for non change elevation in the cold legs for a typical reactor (normal design of nuclear reactors) is the main important factor to be considered for the safe operation. In this article, the main objective is the simulation of the loss of coolant accident scenario by the RELAP5/MOD3.2 code in two different cases; first, the elevation change in the cold legs, and the second, non change in it. After comparing and analyzing these two code calculations the results have been generalized for a new design feature of Bushehr reactor. The design and simulation of the elevation change in the cold legs process with RELAP5/MOD3.2 code for PWR reactor is performed for the first time in the country, where it is introducing several important results in this respect

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

International Nuclear Information System (INIS)

Araujo, Jefferson Borges

1998-01-01

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

Integrity assessment of the cold leg piping system in a PWR

International Nuclear Information System (INIS)

Mayfield, M.E.; Leis, B.N.

1981-01-01

The purpose of this paper is to examine the integrity of a nuclear piping system, designed in accordance with Section III, in the context of a damage tolerance analysis procedure. Such a procedure directly addresses the defects and cyclic loadings that are responsible for the above noted exceptions. The analysis and results reported here are for a fatigue life analysis of the Cold Leg piping in a PWR. This piping system is particularly important from a safety standpoint since a large break is a possible initiator of a core meltdown accident. The analysis employs LEFM concepts to determine the time between the initial start-up and (1) formation of a leak, (2) detection of the leak, and (3) the final fracture of the piping. Both longitudinal and circumferential defects are considered. The defects are assumed to propagate from the pipe I.D. in a self-similar manner. Inputs to the analysis were derived from information supplied by plant operators and vendors, published data, and 'expert opinions'. The life was computed using a linear damage accumulation. (orig./GL)

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

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1983-08-01

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

Prevent recurrence of nuclear disaster (2). Reconstruction of safety logic diagram of nuclear system

International Nuclear Information System (INIS)

Miyano, Hiroshi; Sekimura, Naoto; Nakamura, Takao; Narumiya, Yoshiyuki

2012-01-01

On March 11, 2011, severe accident occurred at multi units of nuclear power caused by natural disaster, which was the first of nuclear power in the world, and lead to nuclear disaster which contaminated a wide range of land and caused surrounding residents to evacuate for a long-term. Since Cyuetsu-oki earthquake and before this accident, Atomic Energy Society of Japan had activities to investigate 'safety of nuclear system' against earthquake beyond any expectation, identify research items and work out roadmap on future research activities. Correspondence against tsunami such as this accident was discussed but not included as proposal because of low tsunami hazards awareness. Based on this reflection and to prevent recurrence of nuclear disaster, reconsideration of nuclear safety from the standpoint of defense-in-depth against hazards beyond any expectation had been performed and proposed to establish roadmap for its realization. Basic principle of nuclear safety consisted of eleven principles so as to protect personnel and environment from harmful effects of radiation derived from nuclear facilities and their activities, which were categorized into three groups (responsibility and management system, personnel and environmental protection and prevention of accident initiation and effect mitigation). (T. Tanaka)

Nuclear law - Nuclear safety

International Nuclear Information System (INIS)

Pontier, Jean-Marie; Roux, Emmanuel; Leger, Marc; Deguergue, Maryse; Vallar, Christian; Pissaloux, Jean-Luc; Bernie-Boissard, Catherine; Thireau, Veronique; Takahashi, Nobuyuki; Spencer, Mary; Zhang, Li; Park, Kyun Sung; Artus, J.C.

2012-01-01

This book contains the contributions presented during a one-day seminar. The authors propose a framework for a legal approach to nuclear safety, a discussion of the 2009/71/EURATOM directive which establishes a European framework for nuclear safety in nuclear installations, a comment on nuclear safety and environmental governance, a discussion of the relationship between citizenship and nuclear, some thoughts about the Nuclear Safety Authority, an overview of the situation regarding the safety in nuclear waste burying, a comment on the Nome law with respect to electricity price and nuclear safety, a comment on the legal consequences of the Fukushima accident on nuclear safety in the Japanese law, a presentation of the USA nuclear regulation, an overview of nuclear safety in China, and a discussion of nuclear safety in the medical sector

Thermal hydraulic behavior of a PWR under beyond-design-basis accident conditions: Conclusions from an experimental program in a 4-loop test facility (PKL)

International Nuclear Information System (INIS)

Umminger, K.J.; Kastner, W.; Mandl, R.M.; Weber, P.

1993-01-01

Within the scope of German reactor safety research, extensive experiments covering the behavior of nuclear power plants under accident conditions have been carried out in the PKL test facility which simulates a 4-loop, 1,300 MWe KWU-designed PWR. While the investigations dealing with design-basis accidents and with the efficiency of the emergency core cooling systems have been largely completed, the main interest nowadays concentrates on the investigation of beyond-design-basis accidents to demonstrate the safety margins of nuclear power plants and to investigate the contribution of the built-in safety features for a further reduction of the residual risk. The thermal hydraulic behavior of a PWR under these extreme accident conditions was experimentally investigated within the PKL III B test program. This paper presents the fundamental findings with some of the most important results being discussed in detail. Future plans are also outlined

The nuclear safety and the radiation protection in France in 2003; La surete nucleaire et la radioprotection en France en 2003

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-03-15

Nine points are reviewed: the law project relative to the safety and openness in nuclear field, the safety of the European PWR type Reactor, the priorities in radiation protection, inspection of radiation protection, the surveillance of patients exposure to ionizing radiations, the hot days and dryness of summer 2003 and the functioning of nuclear power plant, the national planning of radioactive waste management, the becoming of high level and years living radioactive waste, the European nuclear policy. (N.C.)

Prevention and mitigation of steam-generator water-hammer events in PWR plants

International Nuclear Information System (INIS)

Han, J.T.; Anderson, N.

1982-11-01

Water hammer in nuclear power plants is an unresolved safety issue under study at the NRC (USI A-1). One of the identified safety concerns is steam generator water hammer (SGWH) in pressurized-water reactor (PWR) plants. This report presents a summary of: (1) the causes of SGWH; (2) various fixes employed to prevent or mitigate SGWH; and (3) the nature and status of modifications that have been made at each operating PWR plant. The NRC staff considers that the issue of SGWH in top feedring designs has been technically resolved. This report does not address technical findings relevant to water hammer in preheat type steam generators. 10 figures, 2 tables

NMC and A and nuclear criticality safety systems integration: A prospective way for enhancement of the nuclear industry facilities safety

International Nuclear Information System (INIS)

Ryazanov, Boris G.; Sviridov, Victor I.; Frolov, Vladimir V.; Shvedov, Maxim O.; Mclaughlin, Thomas P.; Pruvost, Norman L.

2003-01-01

A considerable body of data has now been acquired about the principles, parameters and consequences of nuclear (criticality) accidents at facilities of the atomic industry in Russia, the United States, Great Britain and Japan. The total number of such accidents stands at 22. Russian and US specialists have prepared a rather extensive survey and analysis of these accidents. The final and important section of this survey is the lessons implied by the results of analysis of these 22 accidents. Among these lessons is the necessity of unconditional enforcement of control over the movement and transformations of special nuclear materials (SNM), and in particular fissile materials, (those SNMs with criticality accident concerns) during production and processing. Inadequacies in such control have been among the causes of most of the accidents that have occurred. Nuclear materials control and accounting (MC and A) for the purpose of ensuring storage reliability and nonproliferation safeguards is a major task of nuclear facilities in any nation. MC and A systems use the latest techniques and hardware for periodic control of SNM in specifically organized material balance areas. Immediate checking, periodic inventory of SNM, and measurements of the parameters of SNM at key points are the main sources of data for these systems. Data about the presence and sites of location of SNM in material balance areas that are acquired in inventories can be used for objective assessment of the status of nuclear safety. On the other hand, the inventory itself involves performance of operations that are unlike routine process engineering, and require special consideration of nuclear safety. Use of the techniques and hardware of MC and A systems not only for purposes of storage reliability, but also to ensure nuclear safety, will reduce the risk of nuclear accidents. This paper gives a concise overview of nuclear accidents that have occurred due to inadequacies in MC and A, and demonstrates

Influence of probabilistic safety analysis on design and operation of PWR plants

International Nuclear Information System (INIS)

Bastl, W.; Hoertner, H.; Kafka, P.

1978-01-01

This paper gives a comprehensive presentation of the connections and influences of probabilistic safety analysis on design and operation of PWR plants. In this context a short historical retrospective view concerning probabilistic reliability analysis is given. In the main part of this paper some examples are presented in detail, showing special outcomes of such probabilistic investigations. Additional paragraphs illustrate some activities and issues in the field of probabilistic safety analysis

Nuclear safety in eastern countries. Background of IPSN's actions

International Nuclear Information System (INIS)

1999-01-01

In this document, IPSN presents its opinion about the safety level that might be reached by the nuclear power plants situated in the former-USSR countries. In these countries 2 types of fission reactors are operating: VVER and RBMK with respectively 46 units and 14 units. 3 generations of VVER-type reactors are coexisting: 440 MWe-230, 440 MWe-213 and 1000 MWe-320. The first generation (440 MWe-230) which involves 11 operating units are the least safe and by no means is it possible to make them reach the western standard of safety. The second generation (440 MWe-213) require technical modifications to near western safety standards. The last generation (1000 MWe-320) has safety levels very similar to PWR's if operating procedures are modified and adapted. RBMK-type reactors have been designed in the years 60-70, they suffer from generic defects due to their design, the poor quality of materials and their low reliability. IPSN fears that any incident in such reactors might turn into a major accident. In order to improve nuclear safety in eastern countries, the European Union has launched an international cooperation, the programmes PHARE and TACIS are presented. (A.C.)

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

Energy Technology Data Exchange (ETDEWEB)

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

1983-08-01

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

Preliminary study on direct recycling of spent PWR fuel in PWR system

International Nuclear Information System (INIS)

Waris, Abdul; Nuha; Novitriana; Kurniadi, Rizal; Su'ud, Zaki

2012-01-01

Preliminary study on direct recycling of PWR spent fuel to support SUPEL (Straight Utilization of sPEnt LWR fuel in LWR system) scenario has been conducted. Several spent PWR fuel compositions in loaded PWR fuel has been evaluated to obtain the criticality of reactor. The reactor can achieve it criticality for U-235 enrichment in the loaded fresh fuel is at least 4.0 a% with the minimum fraction of the spent fuel in the core is 15.0 %. The neutron spectra become harder with the escalating of U-235 enrichment in the loaded fresh fuel as well as the amount of the spent fuel in the core.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Overview of the Vercors programme devoted to safety studies on irradiated PWR fuel

International Nuclear Information System (INIS)

Tourasse, M.; Andre, B.; Ducros, G.; Maro, D.

1996-01-01

The first objective of the Heva-Vercors Program is to improve the data base of fission product release and behaviour after an extensive fuel temperature increase and loss of integrity of the fuel elements that occur in case of severe PWR accident. The program is co-funded by the French Nuclear Protection and Safety Institute (IPSN) and Electricite de France (EdF). The experiments are conducted in a shielded cell of the French Grenoble Nuclear Centre. For these tests, industrial fuel from French PWR reactor plants is used. In order to rebuild the short lived fission product inventory, a reirradiation is performed in the experimental Siloe reactor, prior to the test. Eight tests have been conducted in the frame of the Heva Program up to 2370 K in the 1983-1988 period. The main outcomes of these studies were linked to the volatile fission product release. This program has been extended by the Vercors one with higher fuel temperature (2600 K) and improved instrumentation : gamma spectrometry, emission tomography, metallography, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction are some of the experimental techniques used for on-line and post-test characterization. The knowledge of the behaviour of low volatile fission product has been significantly improved with the six Vercors tests. The results of the Vercors 4 test (38 GWd/t(U), 2570 K, reducing atmosphere) are presented here as an example. The key parameters are exhibited. The next step of these studies will use the Vercors HT loop that is planned to be operational at the beginning of 1996 to reach fuel melting temperature. (author)

Implementation in free software of the PWR type university nucleo electric simulator (SU-PWR)

International Nuclear Information System (INIS)

Valle H, J.; Hidago H, F.; Morales S, J.B.

2007-01-01

Presently work is shown like was carried out the implementation of the University Simulator of Nucleo-electric type PWR (SU-PWR). The implementation of the simulator was carried out in a free software simulation platform, as it is Scilab, what offers big advantages that go from the free use and without cost of the product, until the codes modification so much of the system like of the program with the purpose of to improve it or to adapt it to future routines and/or more advanced graphic interfaces. The SU-PWR shows the general behavior of a PWR nuclear plant (Pressurized Water Reactor) describing the dynamics of the plant from the generation process of thermal energy in the nuclear fuel, going by the process of energy transport toward the coolant of the primary circuit the one which in turn transfers this energy to the vapor generators of the secondary circuit where the vapor is expanded by means of turbines that in turn move the electric generator producing in this way the electricity. The pressurizer that is indispensable for the process is also modeled. Each one of these stages were implemented in scicos that is the Scilab tool specialized in the simulation. The simulation was carried out by means of modules that contain the differential equation that mathematically models each stage or equipment of the PWR plant. The result is a series of modules that based on certain entrances and characteristic of the system they generate exits that in turn are the entrance to other module. Because the SU-PWR is an experimental project in early phase, it is even work and modifications to carry out, for what the models that are presented in this work can vary a little the being integrated to the whole system to simulate, but however they already show clearly the operation and the conformation of the plant. (Author)

Operating experience with an on-line vibration control system for PWR main coolant pumps

International Nuclear Information System (INIS)

Runkel, J.; Stegemann, D.; Vortriede, A.

1996-01-01

The main circulation pumps are key components of nuclear power plants with pressurized water reactors, because the availability of the main circulation pumps has a direct influence on the availability and electrical output of the entire plant. The on-line automatic vibration control system ASMAS was developed for early failure detection during the normal operation of the main circulation pumps in order to avoid unexpected outages and to establish the possibility of preventive maintenance of the pumps. This system is permanently and successfully operating in three German 1300 MW el NPP's with PWR and has been successfully tested in a 350 MW el NPP with a PWR. (orig.)

Operating experience with an on-line vibration control system for PWR main coolant pumps

International Nuclear Information System (INIS)

Runkel, J.; Stegemann, D.; Vortriede, A.

1998-01-01

The main circulation pumps are key components of nuclear power plants with pressurized water reactors (PWRs), because the availability of the main circulation pumps has a direct influence on the availability and electrical output of the entire plant. The on-line automatic vibration control system ASMAS was developed for early failure detection during the normal operation of the main circulation pumps in order to avoid unexpected outages and to establish the possibility of preventive maintenance of the pumps. This system is permanently and successfully operating in three German 1300 MW e1 NPP's with PWR and has been successfully tested in a 350 MW e1 NPP with a PWR. (orig.)

Safety-related instrumentation and control systems for nuclear power plants

International Nuclear Information System (INIS)

1984-01-01

This Safety Guide deals mainly with design requirements for those I and C systems that are important to safety but are not safety systems. The Guide is intended to expand paragraphs 3.1, 3.2 and 3.3 of the Code of Practice on Design for Safety of Nuclear Power Plants (IAEA Safety Series No.50-C-D) in the area of I and C systems important to safety and refers to them as safety-related I and C systems. It also gives guidance and enumerates requirements for multiplexing and the use of the digital computers employed in this area

Workers doses in central European PWR NPPs

International Nuclear Information System (INIS)

Janzekovic, H.; Krizman, M.

2003-01-01

As is stated, the ISOE database which was established in 1992 forms an excellent basis for studies and comparisons of occupational exposure data between nuclear power plants. In the year 2001, 69% of all participating reactors were pressurised water reactors. The ISOE database presents workers' exposure from 213 participating pressurised reactors (PWR) from 27 countries in that year. Among these 32 PWRs belong to six Central European Countries. The analysis of the exposure of workers based on radiation protection performance indicators (collective dose, average dose etc.) in these PWRs could be related to some nuclear safety performance indicators for recent years using ISOE database. The comparison is made to ISOE world - wide data. In the six Central European Countries altogether 32 PWR operated in the year 2001.The international databases of performance indicators related to radiation protection as for example the ISOE or the UNSCEAR database can be use as an efficient tool in the management of radiation protection of workers in a nuclear facilities and regulatory bodies. The databases enable the study of performance trends and the improvement of radiation protection. (authors)

Safety of nuclear power plants: Design. Safety requirements

International Nuclear Information System (INIS)

2000-01-01

The present publication supersedes the Code on the Safety of Nuclear Power Plants: Design (Safety Series No. 50-C-D (Rev. 1), issued in 1988). It takes account of developments relating to the safety of nuclear power plants since the Code on Design was last revised. These developments include the issuing of the Safety Fundamentals publication, The Safety of Nuclear Installations, and the present revision of various safety standards and other publications relating to safety. Requirements for nuclear safety are intended to ensure adequate protection of site personnel, the public and the environment from the effects of ionizing radiation arising from nuclear power plants. It is recognized that technology and scientific knowledge advance, and nuclear safety and what is considered adequate protection are not static entities. Safety requirements change with these developments and this publication reflects the present consensus. This Safety Requirements publication takes account of the developments in safety requirements by, for example, including the consideration of severe accidents in the design process. Other topics that have been given more detailed attention include management of safety, design management, plant ageing and wearing out effects, computer based safety systems, external and internal hazards, human factors, feedback of operational experience, and safety assessment and verification. This publication establishes safety requirements that define the elements necessary to ensure nuclear safety. These requirements are applicable to safety functions and the associated structures, systems and components, as well as to procedures important to safety in nuclear power plants. It is expected that this publication will be used primarily for land based stationary nuclear power plants with water cooled reactors designed for electricity generation or for other heat production applications (such as district heating or desalination). It is recognized that in the case of

Safety of nuclear power plants: Design. Safety requirements

International Nuclear Information System (INIS)

2004-01-01

The present publication supersedes the Code on the Safety of Nuclear Power Plants: Design (Safety Series No. 50-C-D (Rev. 1), issued in 1988). It takes account of developments relating to the safety of nuclear power plants since the Code on Design was last revised. These developments include the issuing of the Safety Fundamentals publication, The Safety of Nuclear Installations, and the present revision of various safety standards and other publications relating to safety. Requirements for nuclear safety are intended to ensure adequate protection of site personnel, the public and the environment from the effects of ionizing radiation arising from nuclear power plants. It is recognized that technology and scientific knowledge advance, and nuclear safety and what is considered adequate protection are not static entities. Safety requirements change with these developments and this publication reflects the present consensus. This Safety Requirements publication takes account of the developments in safety requirements by, for example, including the consideration of severe accidents in the design process. Other topics that have been given more detailed attention include management of safety, design management, plant ageing and wearing out effects, computer based safety systems, external and internal hazards, human factors, feedback of operational experience, and safety assessment and verification. This publication establishes safety requirements that define the elements necessary to ensure nuclear safety. These requirements are applicable to safety functions and the associated structures, systems and components, as well as to procedures important to safety in nuclear power plants. It is expected that this publication will be used primarily for land based stationary nuclear power plants with water cooled reactors designed for electricity generation or for other heat production applications (such as district heating or desalination). It is recognized that in the case of

Safety management in nuclear technology. Proceedings

International Nuclear Information System (INIS)

2008-01-01

At the symposium of TueV Sued AG (Munich, Federal Republic of Germany) held in Munich on 28 and 29 October 2008, the following lectures were held: (1) Fundamental requirements of the management system in nuclear technology - Experiences from the international developments at IAEA and WENRA (M. Herttrich); (2) Information from a comparison of requirements of safety management systems (B. Kallenbach-Herbert); (3) Requirements of a modern management system in German nuclear power plants from the view of nuclear safety (D. Majer); (4) Requirements on safety management in module 8 of the regulations project (M. Maqua); (5) Requirements on the management system in nuclear power plants according to GRS-229 and developments at the KTA 1402 ''Integrated management system for safe operation of nuclear power plants (in progress)'' (C. Verstegen); (6) Experiences from the development and implementation of safety management systems in connection with the works management of a nuclear power plant (K. Ramler); (7) Design of a safety management system of a nuclear power plant in consideration of existing management systems (U. Naumann); (8) Experiences in the utilization and evaluation of a safety management system (J. Ritter); (9) Aspects of leadership of safety management systems (S. Seitz); (10) Management of safety or safety management system? Prevailing or administration? (A. Frischknecht); (11) Change management - strategies for successful transfer of new projects: How can I motivate co-workers for a further development of the safety management system? (U. Schnabel); (12) Requirements concerning indicators in integrated management systems and safety management systems (J. Stiller); (13) Integration of proactive and reactive indicators in the safety management system (B. Fahlbruch); (14) What do indicators show? About the use of indicators by regulatory authorities (A. Kern); (15) Safety management and radiation protection in nuclear technology (K. Grantner); (16) Any more

Nuclear energy; Le nucleaire

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

The reliability of nuclear power plant safety systems

International Nuclear Information System (INIS)

Susnik, J.

1978-01-01

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

Improved Management of Part Safety Classification System for Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

Fire experiences: principal lessons learned, application in PWR power plants

International Nuclear Information System (INIS)

Schoemacker, M.

1984-01-01

The article reviews the principal design rules to be borne in mind for PWR nuclear units installation. These rule takes into account: the specific character of materials involved (safety aspect for nuclear construction), experience acquired as a result of fires in EDF production units, and the results obtained from tests carried out by the EDF at Fort de Chelles between 1980 and 1982, especially in the field of PVC cables [fr

Safety and reliability assessment

International Nuclear Information System (INIS)

1979-01-01

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

Development of nuclear safety class filter elements with long life and high quality

International Nuclear Information System (INIS)

Zhang Jinghua

2009-04-01

This paper describes the development on nuclear safety class filter elements with long life and high quality used for collecting radioactive contaminants, fragments of resin and impurities in primary systems of NPPs. The filter elements made of glass fibre elements are used for PWR, and of paper elements are used for PHWR. During the research, a series of tests for optimization were performed for selection of filter material and the improvement of binder. The flow rate and comprehensive performance have been measured in simulated conditions. The result shows that the application requirements for operational NPPs can be met, and the reliability and safety of the frame are also be verified. The comprehensive performance of the filter elements is equivalent to that of oversea similar products. The products have been used in NPPs in operation. (authors)