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Sample records for candu nuclear power

  1. CANDU nuclear power system

    International Nuclear Information System (INIS)

    This report provides a summary of the components that make up a CANDU reactor. Major emphasis is placed on the CANDU 600 MW(e) design. The reasons for CANDU's performance and the inherent safety of the system are also discussed

  2. CANDU 9 nuclear power plant design description

    International Nuclear Information System (INIS)

    Atomic Energy of Canada limited (AECL) has make significant design improvements in the latest CANDU nuclear power plant (NPP)-the CANDU 9. The CANDU 9 operates with the energy efficient heavy water moderated reactor and natural uranium fuel and utilizes proven technology. The CANDU 9 NPP design is similar to the world leading CANDU 6 but is based upon the single unit adaptation of the 900 MWe class reactors currently operating in Canada (as multiunit configurations). The CANDU 9 NPP was developed as part of the comprehensive AECL product development program which addresses all aspects of CANDU technology including such disciplines as safety, reactor systems and components, constructability, instrumentation and control, health and environment, fuel and fuel cycles and heavy water systems. This paper will provide an overview for some of the key features of the CANDU 9 NPP such as plant layout, safety enhancements and operability improvements implemented in this design as well as outlining some of the advantages that can be expected by the operating utility

  3. CANDU 9 nuclear power plant simulator

    International Nuclear Information System (INIS)

    Simulators are playing, an important role in the design and operations of CANDU reactors. They are used to analyze operating procedures under standard and upset conditions. The CANDU 9 nuclear power plant simulator is a low fidelity, near full scope capability simulator. It is designed to play an integral part in the design and verification of the control centre mock-up located in the AECL design office. It will also provide CANDU plant process dynamic data to the plant display system (PDS), distributed control system (DCS) and to the mock-up panel devices. The simulator model employs dynamic mathematical models of the various process and control components that make up a nuclear power plant. It provides the flexibility to add, remove or update user supplied component models. A block oriented process input is provided with the simulator. Individual blocks which represent independent algorithms of the model are linked together to generate the required overall plant model. As a design tool the simulator will be used for control strategy development, human factors studies (information access, readability, graphical display design, operability), analysis of overall plant control performance, tuning estimates for major control loops and commissioning strategy development. As a design evaluation tool, the simulator will be used to perform routine and non-routine procedures, practice 'what if' scenarios for operational strategy development, practice malfunction recovery procedures and verify human factors activities. This paper will describe the CANDU 9 plant simulator and demonstrate its implementation and proposed utility as a tool in the control system and control centre design of a CANDU 9 nuclear power plant. (author). 2 figs

  4. Development situation about the Canadian CANDU Nuclear Power Generating Stations

    International Nuclear Information System (INIS)

    The CANDU reactor is the most versatile commercial power reactor in the world. The acronym 'CANDU', a registered trademark of Atomic Energy of Canada Limited, stands for 'CANada Deuterium Uranium'. CANDU uses heavy water as moderator and uranium (originally, natural uranium) as fuel. All current power reactors in Canada are of the CANDU type. Canada exports CANDU type reactor in abroad. CANDU type is used as the nuclear power plants to produce electrical. Today, there are 41 CANDU reactors in use around the world, and the design has continuously evolved to maintain into unique technology and performance. The CANDU-6 power reactor offers a combination of proven, superior and state-of-the-art technology. CANDU-6 was designed specifically for electricity production, unlike other major reactor types. One of its characteristics is a very high operating and fuel efficiency. Canada Nuclear Power Generating Stations were succeeded in a commercial reactor of which the successful application of heavy water reactor, natural uranium method and that on-power fuelling could be achieved. It was achieved through the joint development of a major project by strong support of the federal government, public utilities and private enterprises. The potential for customization to any country's needs, with competitive development and within any level of domestic industrial infrastructure, gives CANDU technology strategic importance in the 21st century

  5. Periodic inspection of CANDU nuclear power plant containment components

    International Nuclear Information System (INIS)

    This Standard is one in a series intended to provide uniform requirements for CANDU nuclear power plants. It provides requirements for the periodic inspection of containment components including the containment pressure suppression systems

  6. Nuclear Archeology for CANDU Power Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Broadhead, Bryan L [ORNL

    2011-01-01

    The goal of this work is the development of so-called 'nuclear archeology' techniques to predict the irradiation history of both fuel-related and non-fuel-related materials irradiated in the CANDU (CANada Deuterium Uranium) family of nuclear reactors. In this application to CANDU-type reactors, two different scenarios for the collection of the appropriate data for use in these procedures will be assumed: the first scenario is the removal of the pressure tubes, calandria tubes, or fuel cladding and destructive analysis of the activation products contained in these structural materials; the second scenario is the nondestructive analysis (NDA) of the same hardware items via high-resolution gamma ray scans. There are obvious advantages and disadvantages for each approach; however, the NDA approach is the central focus of this work because of its simplicity and lack of invasiveness. The use of these techniques along with a previously developed inverse capability is expected to allow for the prediction of average flux levels and irradiation time, and the total fluence for samples where the values of selected isotopes can be measured.

  7. A short history of the CANDU nuclear power system

    International Nuclear Information System (INIS)

    This paper provides a short historical summary of the evolution of the CANDU nuclear power system with emphasis on the roles played by Ontario Hydro and private sector companies in Ontario in collaboration with Atomic Energy of Canada Limited (AECL). (author). 1 fig., 61 refs

  8. CANDU 6 nuclear power plant tritium control and release

    International Nuclear Information System (INIS)

    The issues drawing people's attention, such as ways of CANDU plant tritium generation, measures to control tritium release to environment in the design of nuclear power plants as well as public dose due to tritium released to the environment are presented

  9. Safety of CANDU nuclear power stations

    International Nuclear Information System (INIS)

    A nuclear plant contains a large amount of radioactive material which could be a potential threat to public health. The plant is therefore designed, built and operated so that the risk to the public is low. Careful design of the normal reactor systems is the first line of defense. These systems are highly resistant to an accident happening in the first place, and can also be effective in stopping it if it does happen. Independent and redundant safety sytems minimize the effects of an accident, or stop it completely. They include shutdown systems, emergency core cooling systems, and containment systems. Massive impairment of any one safety system together with an accident can be tolerated. This 'defence in depth' approach recognizes that men and machines are imperfect and that the unexpected happens. The nuclear power plant need not be perfect to be safe. To allow meaningful judgements we must know how safe the plant is. The Atomic Energy Control Board guidelines give one such measure, but they may overestimate the true risk. We interpret these guidelines as an upper limit to the total risk, and trace their evolution. (author)

  10. CANDU nuclear reactor technology

    International Nuclear Information System (INIS)

    AECL has over 40 years of experience in the nuclear field. Over the past 20 years, this unique Canadian nuclear technology has made a worldwide presence, In addition to 22 CANDU reactors in Canada, there are also two in India, one in Pakistan, one in Argentina, four in Korea and five in Romania. CANDU advancements are based on evolutionary plant improvements. They consist of system performance improvements, design technology improvements and research and development in support of advanced nuclear power. Given the good performance of CANOU plants, it is important that this CANDU operating experience be incorporated into new and repeat designs

  11. CANDU nuclear power alternative development advantages for Romania

    International Nuclear Information System (INIS)

    Romania has one reactor in operation since 1996, a second one in construction and other three in preservation, all on the same site-Cernavoda, the unique one selected in the 70's. The reactor is operated by Societatea Nationala 'Nuclearelectrica' SA (SNN SA), a state owned company, reporting to the Ministry of Industry and Resources. Cernavoda 2 provides the least--cost alternative for new generating capacity in Romania, as evidenced by 'Least cost power and heat generation capacity development study' and considered by Romania's Strategy for Energy Sector -- Middle Term ((2001--2004)) and Forecast ((2010)). Romania's Strategy for Energy Sector is a component of the National Development Strategy for Romania, presented to the European Union, as a main step in the integration process. We are expecting to complete Cernavoda Unit 2 by 2005. Romanian NPP Units are medium size (700 MWe), PHWR (Pressurized Heavy Water Reactor), Canadian type (CANDU - Canadian Deuterium Uranium). The fuel bundles are CANDU 6 type with pellets based on natural uranium. Though Romania is not under the pressure of Kyoto Protocol in the first range, we consider the air pollution a very important issue, taking into account that the atmosphere has no boundaries, and the delay in implementing of global effective measures to reduce green-house gases should be avoided. It is important for all the countries to have technologies that do not pollute the environment; Romania is oriented firmly towards nuclear power technology, taking into account the specific circumstances regarding our country's resources, as well as the low requirement for fuel transportation which NPPs imply. Also, we have to mention the poor quality of coal and the important costs of mining and also the need to import about 50% of the oil and gas, mainly to ensure the fuel for co-generation thermal plants, from quite unreliable sources in Ukraine and Russia. Aside from some hydro-electric plants, most of Romania's conventional

  12. General requirements for pressure-retaining systems and components in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    This standard specifies the general requirements for the design, fabrication and installation of pressure-retaining systems, components, and their supports in CANDU nuclear power plants. (16 figs., 2 tabs., 25 refs.)

  13. Advancement of safeguards inspection technology for CANDU nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Park, W. S.; Cha, H. R.; Ham, Y. S.; Lee, Y. G.; Kim, K. P.; Hong, Y. D

    1999-04-01

    The objectives of this project are to develop both inspection technology and safeguards instruments, related to CANDU safeguards inspection, through international cooperation, so that those outcomes are to be applied in field inspections of national safeguards. Furthermore, those could contribute to the improvement of verification correctness of IAEA inspections. Considering the level of national inspection technology, it looked not possible to perform national inspections without the joint use of containment and surveillance equipment conjunction with the IAEA. In this connection, basic studies for the successful implementation of national inspections was performed, optimal structure of safeguards inspection was attained, and advancement of safeguards inspection technology was forwarded. The successful implementation of this project contributed to both the improvement of inspection technology on CANDU reactors and the implementation of national inspection to be performed according to the legal framework. In addition, it would be an opportunity to improve the ability of negotiating in equal shares in relation to the IAEA on the occasion of discussing or negotiating the safeguards issues concerned. Now that the national safeguards technology for CANDU reactors was developed, the safeguards criteria, procedure and instruments as to the other item facilities and fabrication facilities should be developed for the perfection of national inspections. It would be desirable that the recommendations proposed and concreted in this study, so as to both cope with the strengthened international safeguards and detect the undeclared nuclear activities, could be applied to national safeguards scheme. (author)

  14. Advancement of safeguards inspection technology for CANDU nuclear power plants

    International Nuclear Information System (INIS)

    The objectives of this project are to develop both inspection technology and safeguards instruments, related to CANDU safeguards inspection, through international cooperation, so that those outcomes are to be applied in field inspections of national safeguards. Furthermore, those could contribute to the improvement of verification correctness of IAEA inspections. Considering the level of national inspection technology, it looked not possible to perform national inspections without the joint use of containment and surveillance equipment conjunction with the IAEA. In this connection, basic studies for the successful implementation of national inspections was performed, optimal structure of safeguards inspection was attained, and advancement of safeguards inspection technology was forwarded. The successful implementation of this project contributed to both the improvement of inspection technology on CANDU reactors and the implementation of national inspection to be performed according to the legal framework. In addition, it would be an opportunity to improve the ability of negotiating in equal shares in relation to the IAEA on the occasion of discussing or negotiating the safeguards issues concerned. Now that the national safeguards technology for CANDU reactors was developed, the safeguards criteria, procedure and instruments as to the other item facilities and fabrication facilities should be developed for the perfection of national inspections. It would be desirable that the recommendations proposed and concreted in this study, so as to both cope with the strengthened international safeguards and detect the undeclared nuclear activities, could be applied to national safeguards scheme. (author)

  15. Licensing evaluation of CANDU-PHW nuclear power plants relative to U.S. regulatory requirements

    International Nuclear Information System (INIS)

    Differences between the U.S. and Canadian approach to safety and licensing are discussed. U.S. regulatory requirements are evaluated as regards their applicability to CANDU-PHW reactors; vice-versa the CANDU-PHW reactor is evaluated with respect to current Regulatory Requirements and Guides. A number of design modifications are proposed to be incorporated into the CANDU-PHW reactor in order to facilitate its introduction into the U.S. These modifications are proposed solely for the purpose of maintaining consistency within the current U.S. regulatory system and not out of a need to improve the safety of current-design CANDU-PHW nuclear power plants. A number of issues are identified which still require resolution. Most of these issues are concerned with design areas not (yet) covered by the ASME code. (author)

  16. Requirements for the support power systems of CANDU nuclear power plants

    International Nuclear Information System (INIS)

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

  17. Implementation of an on-line monitoring system for transmitters in a CANDU nuclear power plant

    Science.gov (United States)

    Labbe, A.; Abdul-Nour, G.; Vaillancourt, R.; Komljenovic, D.

    2012-05-01

    Many transmitters (pressure, level and flow) are used in a nuclear power plant. It is necessary to calibrate them periodically to ensure that their measurements are accurate. These calibration tasks are time consuming and often contribute to worker radiation exposure. Human errors can also sometimes degrade their performance since the calibration involves intrusive techniques. More importantly, experience has shown that the majority of current calibration efforts are not necessary. These facts motivated the nuclear industry to develop new technologies for identifying drifting instruments. These technologies, well known as on-line monitoring (OLM) techniques, are non-intrusive and allow focusing the maintenance efforts on the instruments that really need a calibration. Although few OLM systems have been implemented in some PWR and BWR plants, these technologies are not commonly used and have not been permanently implemented in a CANDU plant. This paper presents the results of a research project that has been performed in a CANDU plant in order to validate the implementation of an OLM system. An application project, based on the ICMP algorithm developed by EPRI, has been carried out in order to evaluate the performance of an OLM system. The results demonstrated that the OLM system was able to detect the drift of an instrument in the majority of the studied cases. A feasibility study has also been completed and has demonstrated that the implementation of an OLM system at a CANDU nuclear power plant could be advantageous under certain conditions.

  18. Expert systems use in present and future CANDU nuclear power supply systems

    International Nuclear Information System (INIS)

    As CANDU nuclear power plants become more complex, and are operated under tighter constraints for longer periods between outages, plant operations staff will have to absorb more information to correctly and rapidly respond to upsets. A development program is underway at Atomic Energy of Canada Limited to use expert systems and interactive media tools to assist operations staff of existing and future CANDU plants. The complete system for plant information access and display, on-line advice and diagnosis, and interactive operating procedures is called the Operator Companion. This paper reports on a prototype, consisting of operator consoles, expert systems and simulation modules in a distributed architecture, currently being developed to demonstrate the concepts of the Operator Companion. Specialized advisors are also being developed using expert system technology to meet specific operational and design needs

  19. Expert systems use in present and future CANDU nuclear power supply systems

    International Nuclear Information System (INIS)

    As CANDU nuclear power plants become more complex, and are operated under tighter constraints for longer periods between outages, plant operations staff will have to absorb more information to correctly and rapidly respond to upsets. A development program is underway at Atomic Energy of Canada Limited to use expert systems and interactive media tools to assist operations staff of existing and future CANDU plants. The complete system for plant information access and display, on-line advice and diagnosis, and interactive operating procedures is called the Operator Companion. A prototype, consisting of operator consoles, expert systems and simulation modules in a distributed architecture, is currently being developed to demonstrate the concepts of the Operator Companion. Specialized advisors are also being developed using expert system technology to meet specific operational and design needs

  20. Fuel cost analysis of CANDU-PHWR Wolsung Nuclear Power Plant unit 1

    International Nuclear Information System (INIS)

    Being based on the Segal method, calculation was carried out for the natural uranium nuclear fuel cost with Zircaloy-4 cladding having design parameters of Wolsung Nuclear Power Plant, CANDU-PHWR (Unit 1), currently under construction in Korea aiming at its completion in 1982. An attempt was also made for the sensitivity analysis of each fuel component; i.e., depreciation of fuel manufacturing plant caused by its life time, its load factor, production scale expansion of plant facilities, variations of construction and operating costs of fuel manufacturing plant, fluctuation of interest rates, extent of uranium ore price increases and effect of learning factor. (author)

  1. Analysis And Evaluation Of Primary Coolant System Of Candu Nuclear Power Plant

    International Nuclear Information System (INIS)

    Analysis of primary coolant system of CANDU nuclear power plant was done using software of nuclear power plant type of CANDU. Primary coolant system has unique design. Heat transport pressure and inventory control system is a system to provide a reliable means of controlling inventory and pressure in the heat transport system. The condition of heavy water coolant which covered pressure, inventory and temperature of coolant has implicated to performance of plant operation.Therefore the primary coolant system is important. Heat transport system circulates pressurized heavy water coolant through the fuel channels to remove heat produced by fission of natural uranium fuel. The heat is carried by the reactor coolant tp steam generators where it is transferred to light water to produce steam, which subsequently drives the turbine-generator. The inventory and pressure control system consists of a pressurizer, feed and bleed valves and a storage tank. In this case the malfunction of PHT bleed valve (CV5)PHT feed valve (CV12), PHT LRV (CV20) and PHT steam bleed valve (CV22) are selected. Reactor parameters observed primary coolant pressurize pressure and level, bleed condenser pressure and level, feed flow, bleed flow. From this analysis and simulation the reactor parameter affected by malfunction is known. It is also considered that the trip, controls, safety valve are needed to maintain safety of nuclear power plant. It is also considered that the trip, controls, safety valve are needed to maintain safety of nuclear power plant. It is also observed the phenomenon of LOCA accident requirements and safety standard issued by Atomic Energy Control board of Canada and how the CANDU safety system is applied

  2. Preliminary evaluation of licensing issues associated with U. S. -sited CANDU-PHW nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    van Erp, J B

    1977-12-01

    The principal safety-related characteristics of current CANDU-PHW power plants are described, and a distinction between those characteristics which are intrinsic to the CANDU-PHW system and those that are not is presented. An outline is given of the main features of the Canadian safety and licensing approach. Differences between the U.S. and Canadian approach to safety and licensing are discussed. Some of the main results of the safety analyses, routinely performed for CANDU-PHW reactors, are presented. U.S.-NRC General Design Criteria are evaluated as regards their applicability to CANDU-PHW reactors; vice-versa the CANDU-PHW reactor is evaluated with respect to its conformance to the U.S.-NRC General Design Criteria. A number of design modifications are proposed to be incorporated into the CANDU-PHW reactor in order to facilitate its introduction into the U.S.

  3. Development strategy of the improved standard technical specification for Wolsong CANDU-6 nuclear power plants

    International Nuclear Information System (INIS)

    The Wolsong CANDU-6 can be differently treated to a certain extent in terms of operation and safety due to the wide span of commissioning dates between, namely, Unit 1 and Units 2,3,4. This fact resulted in the use of non-unified technical specification (OP and P style in Unit 1 and US standard technical specification style in Units 2,3,4). Thus, it became necessary to improve Limiting Condition for Operations (LCOs) that have been based upon insufficient selection criteria in context of safety standards in the past. The newly developed ISTS for Wolsong CANDU-6 is aimed to achieve the following points, (1) Elimination of unnecessary LCOs that are irrelevant to plant safety, (2) Unification of similar LCOs and relocating them, (3) Application of any improvements gained from operational experiences and/or research works, (4) Reinforcement of technical bases and also placing greater emphasis on human factor principles in order to make technical specification clearer and easier to understand. The goal of Wolsong CANDU-6 ISTS development is to improve plant safety practically by selecting safety significant LCOs, optimise surveillance requirements and reinforce technical bases, in order that the development of the first one for Pressurized Heavy Water Reactor (PHWR) nuclear power plants could be accomplished in the world. Furthermore, it can be utilized as the standard technical specification to prepare Wolsong-1 Improved Technical Specification (ITS) for the continuing operation after the major refurbishment. (author)

  4. CAE advanced reactor demonstrators for CANDU, PWR and BWR nuclear power plants

    International Nuclear Information System (INIS)

    CAE, a private Canadian company specializing in full scope flight, industrial, and nuclear plant simulators, will provide a license to IAEA for a suite of nuclear power plant demonstrators. This suite will consist of CANDU, PWR and BWR demonstrators, and will operate on a 486 or higher level PC. The suite of demonstrators will be provided to IAEA at no cost to IAEA. The IAEA has agreed to make the CAE suite of nuclear power plant demonstrators available to all member states at no charge under a sub-license agreement, and to sponsor training courses that will provide basic training on the reactor types covered, and on the operation of the demonstrator suite, to all those who obtain the demonstrator suite. The suite of demonstrators will be available to the IAEA by March 1997. (author)

  5. Life assesment experience for continued operation of a CANDU Nuclear Power Plant in Korea

    International Nuclear Information System (INIS)

    The first pressurized heavy water reactor (PHWR) plant in Korea, Wolsong Unit 1 reaches its 30 years' design lifetime by 2012. As the plant approaches its design life, maintaining a high level of plant safety has become a key issue as well as providing proper aging management programs. In this regard, ''Wolsong Unit 1 Lifetime Management Study (I)'' was conducted to evaluate technical and economic feasibility for the continued operation beyond design life. Korea hydro and nuclear power(KHNP) decided to perform the second phase of the study, ''Wolsong Unit 1 Lifetime Management Study (II)'' based on the results of the phase 1 study. The project covers an in-depth life assessment for systems, structures and components (SSCs) and establishment of aging management programs for the continued operation. This paper introduces Korean experiences on the process and method of life evaluation and aging management programs for the continued operation of a CANDU nuclear power plant. (author)

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

    International Nuclear Information System (INIS)

    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)

  7. Control and instrumentation systems for the 600 MWe CANDU PHW nuclear power plants

    International Nuclear Information System (INIS)

    The control and instrumentation systems for CANDU power plants are designed for high reliability and availabilty to meet stringent safety and operational requirements. To achieve these goals a 'defence-in-depth' design philosophy is employed. The diversely functioning systems designed to satisfy these requirements are described, along with the extensive use of computers for important plant control and man-machine functions

  8. Analysis of surveillance test interval by Markov process for SDS1 in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    The Canadian Nuclear Safety Commission (CNSC) requires that each shutdown system (SDS) of CANDU plant should be available more than 99.9% of the reactor operating time and be tested periodically. The compliance with the availability requirement should be demonstrated using the component failure rate data and the benefits of the tests. There are many factors that should be considered in determining the surveillance test interval (STI) for the SDSs. These includes: the desired target availability, the actual unavailability, the probability of spurious trips, the test duration, and the side effects such as wear-out, human errors, and economic burdens. A Markov process model is developed to study the effect of test interval in the shutdown system number one (SDS1) in this paper. The model can provide the quantitative data required for selecting the STI. Representing the state transitions in the SDS1 by a time-homogeneous Markov process, the model can be used to quantify the effect of surveillance test durations and interval on the unavailability and the spurious trip probability. The model can also be used to analyze the variation of the core damage probability with respect to changes in the test interval once combined with the conditional core damage model derived from the event trees and the fault trees of probabilistic safety assessment (PSA) of the nuclear power plant (NPP)

  9. Best estimate analysis of loss of flow events at CANDU nuclear power plants

    International Nuclear Information System (INIS)

    During plant operation there is a potential for a loss of forced circulation in the primary heat transport system due to a Loss of Class IV power to an single electrical bus, which leads to a loss of a main heat transport pump, or through a failure of power to multiple busses or to the plant which will lead to the loss of 2 or all 4 pumps. Historically, nuclear safety analysis for these events have adopted bounding assumptions for key parameters to ensure that the outcome of the analysis would envelope those expected during an event, and did not take credit for possible process system mitigation. While this provided conservative estimates of the consequences of these events, and met the analysis requirements for licensing at the time, the existing analyses do not provide any knowledge on true response of the plant. The objective of this work is to perform best estimate and deterministic analyses, including the impact of anticipated Reactor Regulating System actions for Loss of Flow (LOF) events in a CANDU station, and to provide the sensitivities to process system component availability. This initial work will feed into downstream Best Estimate and Uncertainty (BEAU) which will explicitly account for the uncertainties in the key parameters, and will eventually provide a measure of the true safety margins for these events. (author)

  10. Study of advanced nuclear fuel cycles in Candu type power reactors

    International Nuclear Information System (INIS)

    The fuel burn up can be increased to a large extent, up to 14, 0000 MWD/te, by using the slightly enriched uranium or Pu mixed fuel in CANDU type power reactors. In the present study, the previous work was extended to compare the isotopic inventories and corresponding activities of important nuclides for different fuel cycles of a CANDU 600 type power reactor. The detail can be found in our studies. The calculations were performed using the computer code WIMSD4. The isotopic inventories and corresponding activities were calculated versus the fuel burn-up for the natural UO/sub 2/ fuel, 1.2 % enriched UO/sub 2/ fuel and 0.45 % PuO/sub 2/-UO/sub 2/ fuel. It was found that 1.2 % enriched uranium fuel has the lowest activity as compared to other two fuel cycles. It means that improvement in the fuel cycle technology of CANDU type power reactors can lead to high burn up which results in the reduction of actinide content in the spent fuel, and hence has a good environmental impact. (orig./A.B.)

  11. Preliminary evaluation of licensing issues associated with U.S.-sited CANDU-PHW nuclear power plants

    International Nuclear Information System (INIS)

    The principal safety-related characteristics of current CANDU-PHW power plants are described, and a distinction between those characteristics which are intrinsic to the CANDU-PHW system and those that are not is presented. An outline is given of the main features of the Canadian safety and licensing approach. Differences between the U.S. and Canadian approach to safety and licensing are discussed. Some of the main results of the safety analyses, routinely performed for CANDU-PHW reactors, are presented. U.S.-NRC General Design Criteria are evaluated as regards their applicability to CANDU-PHW reactors; vice-versa the CANDU-PHW reactor is evaluated with respect to its conformance to the U.S.-NRC General Design Criteria. A number of design modifications are proposed to be incorporated into the CANDU-PHW reactor in order to facilitate its introduction into the U.S

  12. Experience teaching CD-ROM-based course on CANDU nuclear-power-plant systems and operation

    International Nuclear Information System (INIS)

    This paper presents personal experience garnered from teaching a CD-ROM-based course on CANDU Power-Plant Systems and Operation. This course was originally developed by Prof. G.T. Bereznai as research in distance-learning techniques when he was directing the Thai-Canadian Human Resources Development Project at Chulalongkorn University in Bangkok. The course has been offered in a number of universities, including McMaster University and the University of Ontario Institute of Technology. All the course material, including lectures, assignments, and a simulator, is provided on a CD-ROM. Lectures include a spoken soundtrack covering the material. The class often includes both undergraduate and graduate students. I found that most students appreciate having the material on electronic format, which they can view and review at will and on their own time. Students find this course quite intensive - it covers all major systems in the CANDU reactor and power plant in detail. A very important component of the course is the simulator, which teaches students how systems operate in normal operation, in power manoeuvres, and during process-system malfunctions. Effort in absorbing the material and performing assignments can often exceed 10 hours per week. Some of the simulator assignments involve tricky manoeuvres, requiring several tries to achieve the expected result. Some assignments may take several hours, especially if the manoeuvres requiring repetition take 30 minutes or more in real time. I found that some instruction in the basic theory of reactor physics and systems is appreciated by students. A few possible enhancements to the simulator model were identified. Graduate students taking the course are required to do an additional project; I assigned an investigation of the effects of xenon-concentration changes during 1 week of load cycling. In summary, this course provides to students the opportunity to learn a great deal about the workings of CANDU-plant systems. (author)

  13. A foundation for allocating control functions to humans and machines in future CANDU nuclear power plants

    International Nuclear Information System (INIS)

    Since the control room for the Atomic Energy of Canada Limited CANDU 6 plant was designed in the 1970s, requirements for control rooms have changed dramatically as a result of new licensing requirements, evolution of major new standards for control centre design and technological advances. The role of the human operator has become prominent in the design and operation of industrial and, in particular, nuclear plants. Major industrial accidents in the last decade have highlighted the need for paying significantly more attention to the requirements of the human as an integral part of the plant control system. A Functional Design Methodology has been defined that addresses the issues related to maximizing the strengths of the human and the machine in the next generation of CANDU plants. This method is based, in part, on the recently issued international standard IEC 964. The application of this method will lead to the definition of the requirements for detailed design of the control room, including man-machine interfaces, preliminary operating procedures, staffing and training. Further, it provides a basis for the verification and validation of the allocation of functions to the operator and the machine

  14. The transition criteria of circulating flow pattern of moderator in the calandria tank of CANDU nuclear power plant

    International Nuclear Information System (INIS)

    The moderator cooling system to the Calandria tank of CANDU nuclear power plant provides an alternative pass of heat sink during the hypothetical loss of coolant accident. Also, the neutron population in the CANDU plant can be affected by the moderator temperature change which strongly depends on the circulating flow pattern in the Calandria tank. It has been known that there are three distinguished flow patterns: the buoyancy dominated flow, the momentum dominated flow, and the mixed type flow. The Canadian Nuclear Safety Commission (CNSC) recommended that a series of experimental works should be performed to verify the three dimensional codes. Two existing facilities, SPEL (1982) and STERN (1990), have produced experimental data for these purposes. The present work is also motivated to build up a new scaled experimental facility named HGU for the same purposes. CANDU-6 was selected as the target plant to be scaled down. In the design for the scaled facility, the knowledge on the flow regime transitions in the circulating flow was imperative. In the present study, to pave the way for the scaling, the flow pattern maps of circulating flow were constructed based on the Reynolds number and Archimedes number. The CFX code was employed with real meshes to represent all calandria tubes in the tank. The flow pattern maps were constructed for SPEL, STERN, HGU, and CANDU6. As the key transition criterion useful for scaling law, a new Archimedes number considering the jet impingement of the feed water in the Calandria tank was found. The transition of flow patterns was made with the same Archimedes number for CANDU6, STERN and HGU. However, SPEL which has third of the modified Archimedes number showed different maps in the wider region of mixed flow pattern was observed. It was found that the Archimedes number considering the inlet nozzle velocity plays the key role in patterns classification. Also, it can be suggested that the moderator cooling system needs to be designed

  15. Occupational exposure in CANDU nuclear power plant: individual dosimetry program at Cernavoda NPP

    International Nuclear Information System (INIS)

    Cernavoda NPP has one CANDU 600 reactor in commercial operation since December 1996. In CANDU type reactors the major contribution (95%) to the external dose is gamma radiation. The major contributor to the internal dose of professionally exposed workers is the tritiated heavy water (DTO), at least 40% of the total effective dose. The main purpose of design and implementation of a 'Monitoring, Evaluation and Recording of Individual Doses Program' (Individual Dosimetry Program) is to measure, assign and record all significant radiation doses (Hp(10), Hp(0.07) and E50) received by an individual during activities performed at the Campus of Cernavoda NPP ensuring at the same time that all the exposure are kept ALARA. Individual dose monitoring is provided by an authorized dosimetric service, licensed by the Romanian regulatory body, National Commission for Nuclear Activities (CNCAN), at Cernavoda NPP. For all the persons entering the radiological controlled areas (NPP employee, short-term atomic radiation workers, contractors and visitors) Health Physics Department provides individual dosimetric surveillance. During fuel loading activities in 1995 individual dosimetric surveillance was provided for 30 individuals using film dosemeters. Since 'Radiation Island' in effect on February 20th, 1996, individual monitoring for external gamma radiation exposure is performed using thermoluminescent dosemeters (TLDs). When entering areas where approved dose rates could be exceeded (variable or heterogeneous gamma radiation fields) beside TLD an electronic, direct reading, Personal Alarm Dosemeter (PAD) is used. When entering working areas with significant neutron dose rates an integrating portable neutron monitor is used (both as field instrument and personal dosemeter). When contact beta-gamma dose rate exceed 10 time the dose rate at the level of the chest, thermoluminescent extremities (hand and/or feet) dosemeters are used. Professionally exposed workers are subject to a

  16. Development of a spent fuel bay operator support system for PHWR-CANDU nuclear power plant

    International Nuclear Information System (INIS)

    The safety advantages of the CANDU 600 NPPs could be further enhanced by the supplementation of the Canadian experience on plant operation with Computerised Operator Support System (COSSs) adjusted to the actual plant configuration, the idiosyncrasies of the given equipment, the errors during engineering and construction phases and the psychological features of the operation personnel. One of the most relevant systems with an important decision component that involves relatively complex procedures - thereby related human errors - is Cernavoda NPP's Spent Fuel Bay Cooling and Purification System. Strong motivations to consider a flexible COSS, both for operation and for intervention purpose, are given by the global activity stored in the systems bays and the location of the bays outside the containment. A Spent Fuel Bay Operator Support System (SFOSS) is at a research-grade at the Institute of Atomic Physics and at the Center of Technology and Engineering for Nuclear Projects in compliance with the general principles of the expert systems and under a IAEA Co-ordinate Research Program. The paper illustrates a generic description of the system and also of the SFOSS structure. (Author) 10 Refs

  17. Cracking of 304L stainless steel observed within CANDU nuclear power plants under cyclic moist environments

    International Nuclear Information System (INIS)

    The stress corrosion cracking (SCC) of stainless steel Type 304L has been observed recently in a CANDU nuclear station. The cracking occurred on the inside surface of a piping structure and was transgranular in nature. It was mainly present in sections adjacent to welds, at pipe bends, and straight pipe sections. Such cracking mechanisms are governed by specific intrinsic parameters associated with stress, environment, and material factors. In this case, environmental factors not typical, and, presumably, the stresses at the affected locations are low. This paper discusses the results of the failure analysis conducted on affected component materials. The assessment of the observed mechanism includes the investigation of the affected piping (e.g., undamaged test welds, bends, and around the crack locations) using Orientation Imaging Microscopy (OIM) to evaluate the relative degree of residual plastic strain present in the crack locations and in the general pipe microstructure. Advance surface analysis (ToF-SIMS) was used to examine metal surface oxides buried beneath deposits and at strained regions of the pipe in order to elucidate the chemical species likely involved in the cracking/degradation process. (author)

  18. Radioactive waste management methodology development for waste generated by nuclear facilities decommissioning applicable to CANDU-600 Nuclear Power Plant

    International Nuclear Information System (INIS)

    The objective of this paper is to provide information for nuclear field specialists and decision makers on opportunities for development of management methodology for radioactive wastes arising from the decontamination and decommissioning of a CANDU 600 nuclear facility. In this paper we report the waste management strategies: on-site management of the waste, centralized management, and a mixture of these two. Also we present the waste management plan in which a range of technological options shall be identified and evaluated in order to select and justify the most appropriate solution by taking into account the basic waste management principles. Because of the variety of processes, techniques and equipment available for different steps of a waste management scheme, a proper technology has to be selected for each step. A number of trends in radioactive waste management in many countries have been observed. These trends are summarized in this paper. (authors)

  19. Assessment and management of ageing of major nuclear power plant components important to safety: CANDU reactor assemblies

    International Nuclear Information System (INIS)

    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, design or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore 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 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. 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 the Soviet designed water moderated and 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

  20. CANDU nuclear plant configured for multiple oil sands and power applications

    International Nuclear Information System (INIS)

    There is a need to meet expanding demand in Alberta for electricity for an expanding economy, high-pressure steam for oil sands recovery, and hydrogen for bitumen upgrading. This demand must be satisfied in a sustainable, environmentally acceptable and economic manner. Nuclear technology, and in particular AECL's new ACR-1000 reactor, is emerging as the best way to meet these multiple demands. The ACR-1000 can be configured to supply both high-pressure steam and electricity with the steam / electricity ratio optimized to standard turbine-generator sizing and oil sands requirements - thereby affording more options for nuclear plant siting and deployment. Energy for oil sands applications can be supplied in several ways by a centralized nuclear plant with a uniquely configured Balance of Plant (BOP). Steam could be piped to one or several in-situ oil Steam Assisted Gravity Drainage (SAGD) operations within 15 km of the plant boundary. Electricity could be transmitted to more remote facilities including an electrolytic hydrogen plant for bitumen upgraders, resistance-heating devices used for extraction of oil from shale, and electric boilers that generate steam for small in-situ oil sands recovery facilities. The various product streams from the 1200 MWe Class ACR-1000 could be sold by the plant owner through a combination of long-term power purchase agreements and flexible contracts that respond to variable grid prices and demand. In addition the electrolytic hydrogen plant to also serve as an energy storage facility at times of low power demand. These flexible nuclear power plant configurations increase the potential to use clean nuclear energy for more environmentally benign oil sands recovery while still meeting future energy demands economic constraints. (author)

  1. Conceptual Study on Dismantling of CANDU Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo-Tae; Lee, Sang-Guk [KHNP-CRI, Daejeon (Korea, Republic of)

    2014-10-15

    In this paper, we reviewed 3D design model of the CANDU type reactor and suggested feasible cutting scheme. The structure of CANDU nuclear reactor, the calandria assembly was reviewed using 3-D CAD model for future decommissioning. Through the schematic diagram of CANDU nuclear power plant, we identified the differences between PWR and CANDU reactor assembly. Method of dismantling the fuel channels from the calandria assembly was suggested. Custom made cutter is recommended to cut all the fuel channels. The calandria vessel is recommended to be cut by band saw or plasma torch. After removal of the fuel channels, it was assumed that radiation level near the calandria vessel is not very high. For cutting of the end shields, various methods such as band saw, plasma torch, CAMC could be used. The choice of a specific method is largely dependent on radiological environment. Finally, method of cutting the embedment rings is considered. As we assume that operators could cut the rings without much radiation exposure, various industrial cutting methods are suggested to be applied. From the above reviews, we could conclude that decommissioning of CANDU reactor is relatively easy compared to that of PWR reactor. Technologies developed from PWR reactor decommissioning could be applied to CANDU reactor dismantling.

  2. CANDU 300

    International Nuclear Information System (INIS)

    The CANDU nuclear power system is under continuous review by AECL in order to advance the CANDU concept in a manner that will assure competitiveness in both current and future markets. Over the past three years development effort has featured the CANDU 300, a CANDU nuclear generating station with a net output in the range of 320 MW9e) to 380 MW(e). At the outset AECL recognized that coal-fired power plants would be the primary competition for the CANDU advantages such as the use of natural uranium fuel and on-power refuelling, while enhancing capacity factor, reducing man-rem exposure, reducing capital cost, and minimizing construction schedules. AECL believes that the resulting CANDU 300 nuclear generating station will have substantial appeal to many utilities, in both developed and developing countries. The key features of the CANDU 300 are presented here, with particular attention to the station layout, construction methods, and construction schedules

  3. Methodology for identifying boundaries of systems important to safety in CANDU nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Therrien, S.; Komljenovic, D.; Therrien, P.; Ruest, C.; Prevost, P.; Vaillancourt, R. [Hydro-Quebec, Nuclear Generating Station Gentilly-2, Becancour, Quebec (Canada)

    2007-07-01

    This paper presents a methodology developed to identify the boundaries of the systems important to safety (SIS) at the Gentilly-2 Nuclear Power Plant (NPP), Hydro-Quebec. The SIS boundaries identification considers nuclear safety only. Components that are not identified as important to safety are systematically identified as related to safety. A global assessment process such as WANO/INPO AP-913 'Equipment Reliability Process' will be needed to implement adequate changes in the management rules of those components. The paper depicts results in applying the methodology to the Shutdown Systems 1 and 2 (SDS 1, 2), and to the Emergency Core Cooling System (ECCS). This validation process enabled fine tuning the methodology, performing a better estimate of the effort required to evaluate a system, and identifying components important to safety of these systems. (author)

  4. Thermal stability of chloroform in the steam condensate cycle of CANDU-PHW nuclear power plant

    International Nuclear Information System (INIS)

    Analysis of samples taken at the Gentilly 2 (Quebec) CANDU-PHW (CANadian Deuterium Uranium - Pressurized Heavy Water) plant after chlorination and demineralization revealed the presence of all four trihalomethanes (THMs) (CHCl3, CHBrCl2, CHBr2Cl and CHBr3) and other unidentified halogenated volatile compounds. Among the THMs, chloroform was the major contaminant. A study of its thermal stability in water at different temperatures confirmed the degradation of the CHCl3 molecule according to the equation CHCl3 + H2O → CO + 3 HCl. The reaction follows first order kinetics and has an activation energy of 100 kJ/mol. The estimated half-life is six seconds at 260 deg C, the maximum temperature of the steam condensate cycle

  5. Exporting apocalypse: CANDU reactors and nuclear proliferation

    International Nuclear Information System (INIS)

    The author believes that the peaceful use of nuclear technology leads inevitably to the production of nuclear weapons, and that CANDU reactors are being bought by countries that are likely to build bombs. He states that exports of reactors and nuclear materials cannot be defended and must be stopped

  6. Design requirements, criteria and methods for seismic qualification of CANDU power plants

    International Nuclear Information System (INIS)

    This report describes the requirements and criteria for the seismic design and qualification of systems and equipment in CANDU nuclear power plants. Acceptable methods and techniques for seismic qualification of CANDU nuclear power plants to mitigate the effects or the consequences of earthquakes are also described. (auth)

  7. Support analysis for safety analysis development for CANDU nuclear power plant

    International Nuclear Information System (INIS)

    Probabilistic Safety Assessment analysis (PSA) is a technique used to assess the safety of a nuclear power plant. Assessments of the nuclear plant systems/components from safety point of view consist in accomplishment of a lot of support analyses that are the base for the main analysis, in order to evaluate the impact of occurrences of abnormal states for these systems. Evaluation of initiating events frequency and components failure rate is based on underlying probabilistic theory and mathematic statistics. Some of these analyses are detailed analyses and are known very well in PSA. There are also some analyses, named support analyses for PSA, which are very important but less applicable because they involve a huge human effort and hardware facilities to accomplish. The usual methods applicable in PSA such as input data extracted from the specific documentation (operation procedures, testing procedures, maintenance procedures and so on) or conservative evaluation provide a high level of uncertainty for both input and output data. The paper describes support analysis required to improve the certainty level in evaluation of reliability parameters and also in the final results (either risk, reliability or safety assessment). (author)

  8. The seismic fragility analysis for multi-story steel structure in CANDU nuclear power plant

    International Nuclear Information System (INIS)

    The Wolsong Unit 2 is a CANDU-6 type plant and is being constructed in the Wolsong site, where Design Basis Earthquake (DBE) was determined to be 0.2g. A seismic PSA for Wolsong Unit 2 is being performed as one of the conditions for the Construction Permit. One of the issues in the seismic PSA is the availability of the seismically non-qualified systems, which are located in the Turbine Building(T/B). Thus, the seismic fragility analysis for the T/B was performed to estimate the operability of the systems. The design seismic loads for the building were based on a ground response spectrum scaled down from the DBE to horizontal peak ground acceleration (pga) of 0.05g. The seismic fragility analysis for the building was performed using a factor of the safety method. It is estimated that the most critical failure is that of masonry walls and its High Confidence and Low Probability of Failure (HCLPF) capacity is 0.13g. The critical failure mode of the structure is identified to be tensile yielding failure of grip angle, and its HCLPF capacity is 0.34g. (author)

  9. Study on advanced nuclear fuel cycle of PWR/CANDU synergism

    International Nuclear Information System (INIS)

    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

  10. Power coefficient of reactivity in CANDU 6 Reactors

    International Nuclear Information System (INIS)

    The Power Coefficient of Reactivity (PCR) measures the change in reactor core reactivity per unit change in reactor power and is an integral quantity which captures the contributions of the fuel temperature, coolant void and coolant temperature reactivity feedbacks. All nuclear reactor designs provide a balance between the inherent nuclear characteristics and the engineered reactivity control features, to ensure that changes in reactivity in all operating conditions are maintained within a safe range. The CANDU reactor design takes advantage of the inherent nuclear characteristics of small reactivity coefficient, minimal excess reactivity and very long prompt neutron lifetime to mitigate the magnitude of the demand on the engineered systems for controlling reactivity. In particular, CANDU reactors have always taken advantage of the small value of the PCR associated with its design characteristics, such that the overall design of the reactor does not depend on the sign of the PCR. This is a contrast to other reactor design concepts which are dependent on a PCR which is both large and negative in the design of their engineered systems for controlling reactivity. It will be demonstrated that during a Loss of Regulation Control (LORC) event, the impact of having a positive power coefficient, or of hypothesizing a PCR larger than that estimated for CANDU, has no significant impact on the reactor safety. Since the CANDU 6 PCR is small, its role in the operation or safety of the reactor is not significant

  11. CANDU improvement

    International Nuclear Information System (INIS)

    The evolution of the CANDU family of nuclear power plants is based on a continuous product development approach. Proven equipment and system concepts from operating stations are standardized and used in new products. Due to the modular nature of the CANDU reactor concept, product features developed for CANDU 9 can easily be incorporated in other CANDU products such as CANDU 6. Design concepts are being developed for advanced CANDU 6 or larger advanced CANDU, depending on the number of fuel channels and the fuel cycle selected. This paper provides a description of the design improvements being incorporated in CANDU 9 and further design enhancements being studied for future incorporation in CANDU 6 or larger advanced CANDU meeting the requirements of future CANDU owners. The design enhancement objectives are: To improve operational simplicity by applying modern information technology; to improve safety in a cost effective way; to improve system and component reliability and to increase plant life; to improve economics and to reduce owners' risks during all phases of a project using up-front licensing, an improved engineering process and project tools during design, construction and operation; to continue to exploit the neutron economy of CANDU with the development of advanced fuels and fuel cycles. (author)

  12. Advanced CANDU reactor technology: competitive design for the nuclear renaissance

    International Nuclear Information System (INIS)

    AECL has developed the design for a new generation of CANDU nuclear power plants, the Advance CANDU Reactor or ACR. The ACR combines a set of underlying enabling technologies with well-established successful CANDU features in an optimized design with significantly lower costs. By adopting slightly enriched uranium fuel, an optimized core design with light water coolant, heavy water moderator and reflector has been defined based on the existing CANDU fuel channel module. The basic design for the complete reference ACR power plant has now been completed. This paper summarizes the main features and characteristics of the reference ACR-700 power plant design. The progress of the ACR design program in meeting challenging cost, schedule and performance targets is described. AECL's cost reduction methodology is summarized as an integral part of the design optimization process. Examples are given of cost reduction features together with the enhancement of design margins. AECL expects the detailed design and testing of ACR to be complete and pre-project licensing evaluation carried out to enable regulatory endorsement in key markets by the middle of the decade. (authors)

  13. Assessment of LOCA with loss of class IV power for CANDU-6 reactors using RELAP-CANDU/SCAN coupled code system

    International Nuclear Information System (INIS)

    Recently, there is an effort to improve the accuracy and reality in the transient simulation of nuclear power plants. In the prediction of the system transient, the system code simulates the system transient using the power transient curve predicted from the reactor core physics code. However, the pre-calculated power curve could not adequately predict the behavior of power distribution during transient since the coolant density change has influence on the power shape due to the change of the void reactivity. Therefore, the consolidation between the reactor core physics code and the system thermal-hydraulic code takes into consideration to predict more accurate and realistic for the transient simulation. In this regard, there are two codes are developed to assess the safety of CANDU reactor. RELAP-CANDU is a thermal-hydraulic system code for CANDU reactors developed on the basis of RELAP5/MOD3 in such a way to modify inside model for simulating the thermal-hydraulic characteristics of horizontal type reactors. SCAN (SNU CANDU-PHWR Neutronics) is a three dimensional neutronics nodal code to simulate the core physics characteristics for CANDU reactors. To couple SCAN code with RELAP-CANDU code, SCAN code was improved as a spatial kinetics calculation module in such a way to generate a SCAN DLL (dynamic linked library version of SCAN). The coupled code system, RELAP-CANDU/SCAN, enables real-time feedback calculations between thermal-hydraulic variables of RELAP-CANDU and reactor powers of SCAN. To verify the reliability of RELAP-CANDU/SCAN coupled code system, an assessment of 40% reactor inlet header (RIH) break loss of coolant accident (LOCA) with loss of Class IV power (LOP) for Wolsong Unit 2 conducted using RELAP/CANDU-SCAN coupled system. The LOCA with LOP is one of GAI (Generic Action Items) for CANDU reactors issued by CNSC (Canadian Nuclear Safety Commission) and IAEA (International Atomic Energy Agency)

  14. Stochastic maintenance optimization at Candu power plants

    International Nuclear Information System (INIS)

    The use of various innovative maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems as previously reported at ICONE 6 in New Orleans (1996). Further refinement of the station maintenance strategy was evaluated via the applicability of statistical analysis of historical failure data. The viability of stochastic methods in Candu maintenance was illustrated at ICONE 10 in Washington DC (2002). The next phase consists of investigating the validity of using subjective elicitation techniques to obtain component lifetime distributions. This technique provides access to the elusive failure statistics, the lack of which is often referred to in the literature as the principal impediment preventing the use of stochastic methods in large industry. At the same time the technique allows very valuable information to be captured from the fast retiring 'baby boom generation'. Initial indications have been quite positive. The current reality of global competition necessitates the pursuit of all financial optimizers. The next construction phase in the power generation industry will soon begin on a worldwide basis. With the relatively high initial capital cost of new nuclear generation all possible avenues of financial optimization must be evaluated and implemented. (authors)

  15. Utilization of spent PWR fuel-advanced nuclear fuel cycle of PWR/CANDU synergism

    Institute of Scientific and Technical Information of China (English)

    HUO Xiao-Dong; XIE Zhong-Sheng

    2004-01-01

    High neutron economy, on line refueling and channel design result in the unsurpassed fuel cycle flexibility and variety for CANDU reactors. According to the Chinese national conditions that China has both PWR and CANDU reactors and the closed cycle policy of reprocessing the spent PWR fuel is adopted, one of the advanced nuclear fuel cycles of PWR/CANDU synergism using the reprocessed uranium of spent PWR fuel in CANDU reactor is proposed, which will save the uranium resource (~22.5%), increase the energy output (~41%), decrease the quantity of spent fuels to be disposed (~2/3) and lower the cost of nuclear power. Because of the inherent flexibility of nuclear fuel cycle in CANDU reactor, and the low radiation level of recycled uranium(RU), which is acceptable for CANDU reactor fuel fabrication, the transition from the natural uranium to the RU can be completed without major modification of the reactor core structure and operation mode. It can be implemented in Qinshan Phase Ⅲ CANDU reactors with little or no requirement of big investment in new design. It can be expected that the reuse of recycled uranium of spent PWR fuel in CANDU reactor is a feasible and desirable strategy in China.

  16. Requirements for class 1C, 2C, and 3C pressure-retaining components and supports in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    This Standard applies to pressure-retaining components of CANDU nuclear power plants that have a code classification of Class 1C, 2C or 3C. These are pressure-retaining components where, because of the design concept, the rules of the ASME Boiler and Pressure Vessel Code do not exist, are not applicable, or are not sufficient. The Standard provides rules for the design, fabrication, installation, examination and inspection of these components and supports. It provides rules intended to ensure the pressure-retaining integrity of components, not the operability. It also provides rules for the support of fueling machines. The Standard applies only to new construction prior to the plant being declared in service

  17. Machine learning techniques for the verification of refueling activities in CANDU-type nuclear power plants (NPPs) with direct applications in nuclear safeguards

    International Nuclear Information System (INIS)

    This dissertation deals with the problem of automated classification of the signals obtained from certain radiation monitoring systems, specifically from the Core Discharge Monitor (CDM) systems, that are successfully operated by the International Atomic Energy Agency (IAEA) at various CANDU-type nuclear power plants around the world. In order to significantly reduce the costly and error-prone manual evaluation of the large amounts of the collected CDM signals, a reliable and efficient algorithm for the automated data evaluation is necessary, which might ensure real-time performance with maximum of 0.01 % misclassification ratio. This thesis describes the research behind finding a successful prototype implementation of such automated analysis software. The finally adopted methodology assumes a nonstationary data-generating process that has a finite number of states or basic fueling activities, each of which can emit observable data patterns having particular stationary characteristics. To find out the underlying state sequences, a unified probabilistic approach known as the hidden Markov model (HMM) is used. Each possible fueling sequence is modeled by a distinct HMM having a left-right profile topology with explicit insert and delete states. Given an unknown fueling sequence, a dynamic programming algorithm akin to the Viterbi search is used to find the maximum likelihood state path through each model and eventually the overall best-scoring path is picked up as the recognition hypothesis. Machine learning techniques are applied to estimate the observation densities of the states, because the densities are not simply parameterizable. Unlike most present applications of continuous monitoring systems that rely on heuristic approaches to the recognition of possibly risky events, this research focuses on finding techniques that make optimal use of prior knowledge and computer simulation in the recognition task. Thus, a suitably modified, approximate n-best variant of

  18. Nuclear power in Canada

    International Nuclear Information System (INIS)

    The Canadian Nuclear Association believes that the CANDU nuclear power generation system can play a major role in achieving energy self-sufficiency in Canada. The benefits of nuclear power, factors affecting projections of electric power demand, risks and benefits relative to other conventional and non-conventional energy sources, power economics, and uranium supply are discussed from a Canadian perspective. (LL)

  19. Cobalt-60 production in CANDU power reactors

    International Nuclear Information System (INIS)

    therapy machines. Today the majority of the cancer therapy cobalt-60 sources used in the world are manufactured using material from the NRU reactor in Chalk River. The same technology that was used for producing cobalt-60 in a research reactor was then adapted and transferred for use in a CANDU power reactor. In the early 1970s, in co-operation with Ontario Power Generation (formerly Ontario Hydro), bulk cobalt-60 production was initiated in the four Pickering A CANDU reactors located east of Toronto. This was the first full scale production of millions of curies of cobalt-60 per year. As the demand and acceptance of sterilization of medical products grew, MDS Nordion expanded its bulk supply by installing the proprietary Canadian technology in additional CANDUs. Over the years MDS Nordion has partnered with CANDU reactor owners to produce cobalt-60 at various sites. CANDU reactors that have, or are still producing cobalt-60, include Pickering A, Pickering B, Gentilly 2, Embalse in Argentina, and Bruce B. In conclusion, the technology for cobalt-60 production in CANDU reactors, designed and developed by MDS Nordion and Atomic Energy of Canada, has been safely, economically and successfully employed in CANDU reactors with over 195 reactor years of production. Today over forty percent of the world's disposable medical supplies are made safer through sterilization using cobalt-60 sources from MDS Nordion. Over the past 40 years, MDS Nordion with its CANDU reactor owner partners, has safely and reliably shipped more than 500 million curies of cobalt-60 sources to customers around the world. MDS Nordion is presently adding three more CANDU power reactors to its supply chain. These three additional cobalt producing CANDU's will help supplement the ability of the health care industry to provide safe, sterile, medical disposable products to people around the world. As new applications for cobalt-60 are identified, and the demand for bulk cobalt-60 increases, MDS Nordion and AECL

  20. The pressure tubes in the CANDU power reactor

    International Nuclear Information System (INIS)

    Nuclear power reactors using zirconium alloy pressure tubes generate electricity in several countries. In Ontario CANDU reactors generate about 30 percent of the electricity produced in the province. The pressure tubes of the first five CANDU reactors were made of cold-worked Zircaloy-2, an alloy of zirconium and tin developed by the US Navy. In 1958 the USSR published information on a Zr-2.5 wt percent Nb alloy, in which the Nb promotes stabilization of the β phase, thus presenting opportunities of exploiting metallurgically strong pressure tubes analogous to the heat-treatable α-β titanium alloys. After two reactors using Zr-2.5 wt percent Nb in a quenched and aged condition were constructed, an extensive development program on cold-worked Zr-2.5 wt percent Nb pressure tubes resulted in their becoming the reference tubes for all future CANDU reactors. Pressure tubes of Zr-3.3 wt percent Sn-0.8 wt percent Nb-0.8 wt percent Mo (Excel) are in an advanced state of development. These tubes will be used in an annealed condition; projections show that they will have improved dimensional stability over the lifetime of the reactors. These improvements result from experimental programs leading to an understanding of the relationship between microstructures and fabrication variables and effects of the environment during service in nuclear reactors. (author)

  1. A high-speed data acquisition system to measure low-level current from self-powered flux detectors in CANDU nuclear reactors

    International Nuclear Information System (INIS)

    Self-powered flux detectors are used in CANDU nuclear power reactors to determine the spatial neutron flux distribution in the reactor core for use by both the reactor control and safety systems. To establish the dynamic response of different types of flux detectors, the Chalk River Nuclear Laboratories have an ongoing experimental irradiation program in the NRU research reactor for which a data acquistion system has been developed. The system described in this paper is used to measure the currents from the detectors both at a slow, regular logging interval, and at a rapid, adaptive rate following a reactor shutdown. Currents that range from 100 pA to 1 mA full scale can be measured from up to 38 detectors and stored at sampling rates of up to 20 samples per second. The dynamic characteristics of the detectors can be computed from the stored records. The data acquisition system comprises a DEC LSI-11/23 microcomputer, dual cartridge disks, floppy disks, a hard copy and a video display terminal. The RT-11 operating system is used and all application programs are written in FORTRAN

  2. Generic validation of computer codes used in safety analyses of CANDU power plants

    International Nuclear Information System (INIS)

    Since the 1960s, the CANDU industry has been developing and using scientific computer codes, validated according to the quality-assurance practices of the day, for designing and analyzing CANDU power plants. To provide a systematic framework for the validation work done to date and planned for the future, the industry has decided to adopt the methodology of validation matrices, similar to that developed by the Nuclear Energy Agency of the Organization for Economic Co-operation and Development for Light Water Reactors (LWR). Specialists in six scientific disciplines are developing the matrices for CANDU plants, and their progress to date is presented. (author)

  3. Assessment and management of ageing of major nuclear power plant components important to safety: CANDU pressure tubes

    International Nuclear Information System (INIS)

    The report documents the current practices for assessment and management of the ageing of the pressure tubes in CANDU reactors and Indian PHWTRs. Chapter headings are: fuel channel and pressure tube description, design basis for the fuel channel and pressure tube, degradation mechanisms and ageing concerns for pressure tubes, inspection and monitoring methods for pressure tubes,assessment methods and fitness-for-service guidelines for pressure tubes, mitigation methods for pressure tubes, and pressure tube ageing management programme

  4. Pressure tube life management in CANDU-6 nuclear plant

    International Nuclear Information System (INIS)

    Operating parameters of pressure tube in CANDU-6 reactor, the relation between pressure tube life and plant life improvement of pressure tube by AECL in past years were summarized, and the factors affecting pressure tube life, idea and main measures of pressure tube life management in QINSHAN CANDU-6 power plant introduced

  5. Role of accident analysis in development of severe accident management guidance for multi-unit CANDU nuclear power plants

    International Nuclear Information System (INIS)

    This paper discusses the role of accident analysis in support of the development of Severe Accident Management Guidance for domestic CANDU reactors. In general, analysis can identify what types of challenges can be expected during accident progression but it cannot specify when and to what degree accident phenomena will occur. SAMG overcomes these limitations by monitoring the actual values of key plant indicators that can be used directly or indirectly to infer the condition of the plant and by establishing setpoints beyond which corrective action is required. Analysis can provide a means to correlate observed post-accident plant behavior against predicted behaviour to improve the confidence in and quality of accident mitigation decisions. (author)

  6. Plant condition assessments as a requirement before major investment in life extension for a CANDU nuclear power plant

    International Nuclear Information System (INIS)

    Full text: Since, to extend the life of a CANDU-6 reactor beyond its original design life requires the replacement of reactor components (380 pressure and calandria tubes), a major investment will have to be done. After a preliminary technical and economical feasibility study, Hydro- Quebec, owner of the Gentilly-2 NPP, has decided to perform a more detailed assessment to: 1. Get assurance that it is technically and economically viable to extend Gentilly-2 for another 20 years beyond the original design life; 2. Identify the detailed work to be done during the refurbishment period planned in 2008-2009; 3. Define the overall cost and the general schedule of the refurbishment phase; 4. Ensure an adequate licensing strategy to restart after refurbishment; 5. Complete all the Environmental Impact Studies required to obtain the government authorizations. The business case to support the refurbishment of Gentilly-2 has to take in consideration the reactor core components, which will be the major work to be completed during refurbishment. In summary the following main component will have to be changed or refreshed: The pressure and calandria tubes and the feeders (partial replacement only) (ageing mechanisms); The control computers (obsolescence); The condenser tubes (tubes plugging); The turbine control and electric-governor (obsolescence). An extensive campaign is under way to assess the 'health' of the station systems, structures and components (SSC). Two processes have been used for this assessment: Plant Life Management Studies (PLIM) for approximately 10 critical SSC or families of SSC (PLIM Studies); Condition Assessment Studies for other SSC with a lower impact on the Plant production or safety). The PLIM Studies are done on SSC's, which were judged critical because they are not replaceable (Reactor Building, Calandria), or that their failure could have a significant impact on safety or production (electrical motors, majors pumps, heat exchangers and pressure

  7. Cobalt-60 production in CANDU power reactors

    International Nuclear Information System (INIS)

    The technology for cobalt-60 production in CANDU reactors, designed and developed by MDS Nordion and AECL, has been safely,economically and successfully employed in CANDU reactors with over 195 reactor years of production. Today over forty percent of the world's disposable medical supplies are made safer through sterilization using cobalt-60 sources from MDS Nordion. Over the past 40 years, MDS Nordion with its CANDU reactor owner partners, has safely and reliably shipped more than 500 million curies of cobalt-60 sources to customers around the world

  8. CANDU advanced fuel cycles

    International Nuclear Information System (INIS)

    This report is based on informal lectures and presentations made on CANDU Advanced Fuel Cycles over the past year or so, and discusses the future role of CANDU in the changing environment for the Canadian and international nuclear power industry. The changing perspectives of the past decade lead to the conclusion that a significant future market for a CANDU advanced thermal reactor will exist for many decades. Such a reactor could operate in a stand-alone strategy or integrate with a mixed CANDU-LWR or CANDU-FBR strategy. The consistent design focus of CANDU on enhanced efficiency of resource utilization combined with a simple technology to achieve economic targets, will provide sufficient flexibility to maintain CANDU as a viable power producer for both the medium- and long-term future

  9. Integrated control centre concepts for CANDU power plants

    International Nuclear Information System (INIS)

    The size and complexity of nuclear power plants has increased significantly in the last 20 years. There is general agreement that plant safety and power production can be enhanced if more operational support systems that are significantly different from the ones based on the more conventional technologies used in plant control rooms. In particular, artificial intelligence and related technologies will play a major role in the development of innovative methods for information processing and presentation. These technologies must be integrated into the overall management and control philosophy of the plant and not be treated as vehicles to implement point solutions. The underlying philosophy behind our approach is discussed in this paper. Operator support systems will integrate into the overall control philosophy by complementing the operator. Four support systems are described; each is a prototype of a system being considered for the CANDU 3 control centre

  10. The Candu system - The way for nuclear autonomy

    International Nuclear Information System (INIS)

    The experience acquired by Canada during the development of Candu System is presented. Some basic foundations of technology transfer are defined and, the conditions of canadian nuclear industry to provide developing countries, technical assistence for acquisition of nuclear energy autonomy, are analysed. (M.C.K.)

  11. Economics of CANDU

    International Nuclear Information System (INIS)

    The cost of producing electricity from CANDU reactors is discussed. The total unit energy cost of base-load electricity from CANDU reactors is compared with that of coal-fired plants in Ontario. In 1980 nuclear power was 8.41 m$/kW.h less costly for plants of similar size and vintage. Comparison of CANDU with pressurized water reactors indicated that the latter would be about 26 percent more costly in Ontario

  12. Progresses in decontamination and radioactive waste management plans for developing the decommissioning plan of a CANDU 600 nuclear power plant

    International Nuclear Information System (INIS)

    The management of radioactive wastes generated by decontamination and decommissioning of nuclear facilities represents the main part of the decommissioning process. The aim of waste management strategy, as part of the Decommissioning Plan, is to ensure that the generation, conditioning and storage of the waste resulted in the decommissioning process is conducted according to the project goals. This article presents the progress regarding the need of integrating the Decontamination and Management Plans for Radioactive Waste into the Decommissioning Plan representing an integrated concept as part of a National Project. The optimization possibilities of the integrated system concept are much larger and could lead to lower general costs. The decommissioning activities related to the nuclear facilities raise a lot of issues regarding the additional radioactive used materials and the generated radioactive wastes. According to some available assessments, the quantity of decommissioned materials and wastes can exceed 10 - 200 times the operational waste of the facility's life. The cost of radioactive waste management can increase the overall decommissioning budget with mat least 50%. The radioactive wastes resulted from decommissioning are often different than those generated during the normal operation or normal maintenance of the nuclear plant systems. The differences are due to the diversity of chemical, physical or radiological characteristics, of physical form or to the different amounts and volumes generated during the two activity types. Due to these specific characteristics, some wastes are considered to be problematic, e.g. the wastes for which routine methods of manipulation, treatment and conditioning require more attention from safety and organization point of view. The experience and analysis of available data within the management of various problematic waste types, generated during decommissioning, is important for identifying the most adequate and efficient

  13. A CANDU-type small/medium power reactor

    International Nuclear Information System (INIS)

    This presentation reviews some of the main factors that will govern the design and operation of reactors in remote Northern Canadian communities, as applied to a small CANDU-type power plant. The central advantage of the CANDU is the fact that it is modular at the level of a single fuel channel. Examining each of the main features of this SMR plant on a hypothetical site in the Canadian Arctic reveals some of the unique characteristics that will be either desirable or mandatory for any such power plant applied to service in this remote region. (author)

  14. On-line power monitoring in CANDU using PMFD

    International Nuclear Information System (INIS)

    The use of digital computers in the on-line control of the spatial power distribution has been well established in CANDU reactors. The instantaneous spatial power distribution in a CANDU reactor is calculated on-line, once every two minutes, by the Flux mapping program. This program synthesizes the global reactor power distribution using a least-squares fit to a set of measured flux detector readings to find amplitudes for a subsequent expansion of a precalculated set of flux harmonics. The reactor control program compares the mapped power shape with the reference power shape. The difference between these two power shapes is minimized by the appropriate deployment of the zone control system. The higher fissile content and the higher fuel burnup of SEU reactors can result in higher power ripples than those in the CANDU natural uranium reactors. Also, concerns of fuel performance at high burnup require accurate on-line monitoring of individual rippled channel and bundle powers. The present Flux Mapping program cannot meet the requirements of Highly Advanced CANDU reactors. The power mapping finite difference (PMFD) program is specifically designed to supplement or replace the Flux Mapping program in the spatial control system of CANDU SEU reactors. It solves the system of three-dimensional, two-energy group neutron diffusion equations on-line. A unique feature of PMFD is its ability to use measured detector fluxes as internal boundary conditions in the flux solution. The resulting flux shape satisfies both the distribution of material properties and the measured flux values

  15. CANDU 9 - Overview

    International Nuclear Information System (INIS)

    The CANDU 9 plants are single unit versions of the very successful four unit Bruce B design, incorporating relevant technical advances made in the CANDU 6 and the newer Dalington and CANDU 3 designs. The CANDU 9 plant described in this paper is the CANDU 9 480/SEU with a net electrical output in the range of 1050 MW. In this designation 480 refers to the number of fuel channels, and SEU refers to slightly enriched uranium. Emphasis is placed on evolutionary design and the use of well-proven design features to ensure minimum financial risk to utilities choosing a CANDU 9 plant by assuring regulatory licensability and reliable operation. In addition, the CANDU 9 power plants reflect the important lessons learned by utilities in the construction and operation of CANDU units and, indeed, relevant experience gained by the world nuclear community in its operation of over 400 reactors of a variety of types. As a results, the CANDU 9 plants offer a high level of investment security to the owner, together with relatively low energy costs. The latter results from reduced specific capital cost, reduced operation and maintenance cost, and reduced radiation exposure to plant staff. A high level of standardization has always been a feature of CANDU reactors. This theme is emphasized in the CANDU 9 plants; all key components (steam generators, heat transport pumps, pressure tubes, fuelling machines, etc.) are of the same design as those proven in-service on operating CANDU power stations. The CANDU 9 power plants are readily adaptable to the individual requirements of different utilities and are suitable for a range of site conditions. (author). 12 figs

  16. Status of validation matrices for CANDU power plants

    International Nuclear Information System (INIS)

    As reported at the 1996 CNS Annual Conference, in mid-1995 the CANDU industry began to develop validation matrices for CANDU power plants. Of the eight matrices required to address all physical phenomena that could occur in all relevant accident categories, two have been prepared and tabled with the Atomic Energy Control Board, and the remaining six are targeted for submission during 1997. The matrices provide the generic, code-independent knowledge base that will be used to validate major safety analysis codes over the next four years. The unique achievement reported in this paper is the identification and listing of all physical phenomena in all relevant accident categories. (author)

  17. Operating experiences with Neutron Overpower Trip Systems in Ontario Hydro's CANDU nuclear plants

    International Nuclear Information System (INIS)

    Operating experiences with Neutron Over Power Trip (NOP) Systems in different Ontario Hydro CANDU nuclear power plants are discussed. Lessons learned from the system operation and their impact on design improvements are presented. Retrofitting of additional tools, such as Shutdown System Monitoring computers, to improve operator interaction with the system is described. Experiences with the reliability of some of the NOP system components is also discussed. Options for future enhancements of system performance and operability are identified. (author)

  18. Inspection of Candu Nuclear Reactor Fuel Channels

    International Nuclear Information System (INIS)

    The Channel Inspection and Gauging Apparatus of Reactors (CIGAR) is a fully atomated, remotely operated inspection system designed to perform multi-channel, multi-task inspection of CANDU reactor fuel channels. Ultrasonic techniques are used for flaw detection, (with a sensitivity capable of detecting a 0.075 mm deep notch with a signal to noise ratio of 10 dB) and pressure tube wall thickness and diameter measurements. Eddy currrent systems are used to detect the presence of spacers between the coaxial pressure tube and calandria tube, as well as to measure their relative spacing. A servo-accelerometer is used to estimate the sag of the fuel channels. This advanced inspection system was commissioned and declared in service in September 1985. The paper describes the inspection systems themselves and discussed the results achieved to-date. (author)

  19. The Korean nuclear power program

    International Nuclear Information System (INIS)

    Although the world nuclear power industry may appear to be in decline, continued nuclear power demand in Korea indicates future opportunities for growth and prosperity in this country. Korea has one of the world's most vigorous nuclear power programs. Korea has been an active promoter of nuclear power generation since 1978, when the country introduced nuclear power as a source of electricity. Korea now takes pride in the outstanding performance of its nuclear power plants, and has established a grand nuclear power scheme. This paper is aimed at introducing the nuclear power program of Korea, including technological development, international cooperation, and CANDU status in Korea. (author). 2 tabs

  20. CANDU 9 safety improvements

    International Nuclear Information System (INIS)

    The CANDU 9 is a family of single-unit Nuclear Power Plant designs based on proven CANDU concepts and equipment from operating CANDU plants capable of generating 900 MWe to 1300 MWe depending on the number of fuel channel used and the type of fuel, either natural uranium fuel or slightly enriched uranium fuel. The basic design, the CANDU 9 480/NU, uses the 480 fuel channel Darlington reactor and employs Natural Uranium (NU) fuel Darlington, the latest of the 900 MWe Class CANDU plants, consists of four integrated units with a total output of approximately 3740 MWe located in Ontario, Canada. AECL has completed the concept definition engineering for this design, and will be completing the design integration engineering by the end of 1996. AECL's design philosophy is to build-in product improvements in evolutionary from the initial prototype plants, NPD and Douglas Point, to today's operating CANDU's construction projects and advanced designs. CANDU 9 safety design follows the evolutionary path, including simple improvements based on existing well-proven CANDU safety concepts. The CANDU 9 builds on the experience base for the Darlington reference plant, and on AECL's extensive safety design experience with single unit CANDU 6 power plants. The latest CANDU 6 plants are being built in Korea by KEPCO at Wolsong 2,3 and 4. The Safety improvements for the CANDU 9 power plant are intended to provide the owner-operator with increased assurance of reliable, trouble-free operation, with greater safety margin, with improved public acceptance, and with ease of licensibility

  1. The Impact of Power Coefficient of Reactivity on CANDU 6 Reactors

    International Nuclear Information System (INIS)

    The combined effects of reactivity coefficients, along with other core nuclear characteristics, determine reactor core behavior in normal operation and accident conditions. The Power Coefficient of Reactivity (PCR) is an aggregate indicator representing the change in reactor core reactivity per unit change in reactor power. It is an integral quantity which captures the contributions of the fuel temperature, coolant void, and coolant temperature reactivity feedbacks. All nuclear reactor designs provide a balance between their inherent nuclear characteristics and the engineered reactivity control features, to ensure that changes in reactivity under all operating conditions are maintained within a safe range. The CANDU reactor design takes advantage of its inherent nuclear characteristics, namely a small magnitude of reactivity coefficients, minimal excess reactivity, and very long prompt neutron lifetime, to mitigate the demand on the engineered systems for controlling reactivity and responding to accidents. In particular, CANDU reactors have always taken advantage of the small value of the PCR associated with their design characteristics, such that the overall design and safety characteristics of the reactor are not sensitive to the value of the PCR. For other reactor design concepts a PCR which is both large and negative is an important aspect in the design of their engineered systems for controlling reactivity. It will be demonstrated that during Loss of Regulation Control (LORC) and Large Break Loss of Coolant Accident (LBLOCA) events, the impact of variations in power coefficient, including a hypothesized larger than estimated PCR, has no safety-significance for CANDU reactor design. Since the CANDU 6 PCR is small, variations in the range of values for PCR on the performance or safety of the reactor are not significant

  2. Public health risks associated with the CANDU nuclear fuel cycle

    International Nuclear Information System (INIS)

    This report analyzes in a preliminary way the risks to the public posed by the CANDU nuclear fuel cycle. Part 1 considers radiological risks, while part 2 (published as INFO-0141-2) evaluates non-radiological risks. The report concludes that, for radiological risks, maximum individual risks to members of the public are less than 10-5 per year for postulated accidents, are less than 1 percent of regulatory limits for normal operation and that collective doses are small, less than 3 person-sieverts. It is also concluded that radiological risks are much smaller than the non-radiological risks posed by activities of the nuclear fuel cycle

  3. Assuring CANDU nuclear safety competence in Korea: regulatory research and development program

    International Nuclear Information System (INIS)

    According to a two-reactor policy developed in the late 1980s in Korea, the national short and mid-term power reactor strategy has been established in such a way PWR should play a principal role in the development of nuclear power plants and CANDU a supplementary role taking advantage of its localization potentials. However, the diversification of reactor types and vendors has caused some difficulties in the process of the individual nuclear power plants licensing and regulation. During the licensing of Wolsong units 2, 3 and 4, every effort has been made to harmonize the Canadian regulations with those of Korea by establishing the various and specific regulatory positions and guidelines. The safety assuring method of CANDU reactors has been improved subatantially through these efforts, resulting in the improvement of regulatory system and procedure in Korea. However, the incident of heavy water leaks from Wolsong unit 3 in October 1999 and recently raised CANDU generic safety issues, such as feeder wall thinning, have motivated the need to re-emphasize the operational safety of CANDUs. As the necessity of improving and developing regulatory requirements, procedures, and technologies considering the design and operating characteristics of CANDUs was recognized, a need of a new mid-and long-term R and D program with an aim to develop and improve regulatory infrastructure such as legal system, generic regulatory requirements and technical standards for CANDUs was sought. The regulatory research programs for CANDUs were launched last August and the 1st phase of the project will go on to March 2002. The R and D program consists of four sub-programs; (i) development of regulatory requirments and technical standard, (ii) development of regulatory inspection manuals, (iii) development of performance indicators (PIs), and (iv) development of Safety Review Guides(SRGs). In this paper, the overview of the mid- and long-term regulatory R and D program for CANDU NPPs and its

  4. Post irradiation tests on CANDU fuel irradiated in power ramp conditions

    International Nuclear Information System (INIS)

    Nuclear Research Branch Pitesti disposes of facilities, which allow the testing, manipulation and examination of nuclear fuel and of irradiated structure materials in CANDU reactor from Cernavoda NPP. These facilities imply the materials testing reactor TRIGA and the Post-Irradiation Examination Laboratory (PIEL). The purpose of this work is to determine by post-irradiate examination, the behavior of CANDU indigenous fuel, irradiated in 14 MW(th) TRIGA reactor into a multiple/various power ramp tests. The results of post-irradiate examination consist of: - Visual inspection and photography of the outer appearance of sheath; - Profilometry (diameter, bending, ovalization) and length measuring; - Determination of axial and radial distribution of the fission products activity by gamma scanning and tomography; - measurement of pressure, volume and isotopic composition of fission gas; - Microstructural characterization by metallographic and ceramographic analyzes; - Isotopic composition and burn-up determination; - Mechanical properties determination. The obtained data from the post-irradiate examinations are used, on one hand, in order to confirm the security, reliability and nuclear fuel performance, and on the other hand, for further optimization of the CANDU fuel. (authors)

  5. Validation of computer codes used in safety analyses of CANDU power plants

    International Nuclear Information System (INIS)

    Since the 1960s, the CANDU industry has been developing and using scientific computer codes for designing and analysing CANDU power plants. In this endeavour, the industry has been following nuclear quality-assurance practices of the day, including verification and validation of design and analysis methodologies. These practices have resulted in a large body of experience and expertise in the development and application of computer codes and their associated documentation. Major computer codes used in safety analyses of operating plants and those under development have been, and continue to be subjected to rigorous processes of development and application. To provide a systematic framework for the validation work done to date and planned for the future, the industry has decided to adopt the methodology of validation matrices for computer-code validation, similar to that developed by the Nuclear Energy Agency of the Organization for Economic Co-operation and Development and focused on thermalhydraulic phenomena in Light Water Reactors (LWR). To manage the development of validation matrices for CANDU power plants and to engage experts who can work in parallel on several topics, the CANDU task has been divided into six scientific disciplines. Teams of specialists in each discipline are developing the matrices. A review of each matrix will show if there are gaps or insufficient data for validation purposes and will thus help to focus future research and development, if needed. Also, the industry is examining its suite of computer codes, and their specific, additional validation needs, if any, will follow from the work on the validation matrices. The team in System Thermalhydraulics is the furthest advanced, since it had the earliest start and the international precedent on LWRs, and has developed its validation matrix. The other teams are at various stages in this multiphase, multi-year program, and their progress to date is presented. (author)

  6. Post-irradiation neutron emissions from CANDU fuels and their nuclear forensics applications

    International Nuclear Information System (INIS)

    Fissile materials within a fuel pellet can be discerned rapidly and non-destructively via the analysis of post-irradiation delayed neutron emissions. The delayed neutron counting technique is well established within the Canadian nuclear industry, and uses include the detection of defective CANDU fuel. This work discusses these neutron emissions from CANDU fuel in the context of detection and attribution. Monte Carlo simulations of these emissions from current and proposed CANDU fuels (thoria and mix oxide based) have been performed. These simulations are compared to measurements of delayed neutron emissions from 233U and 235U, and the feasibility of CANDU fuel characterization is discussed. (author)

  7. 'CANDU-fueling machine head tests' at the Institute for Nuclear Research - Pitesti

    International Nuclear Information System (INIS)

    The Fueling Machine (F/M) Head is the most complex equipment of the Fuel Handling System in the CANDU reactor and performs the change of the nuclear fuel during the reactor operation. Before the installation of the F/M Head at the Nuclear Power Plant, it was required to test its technical performances, to ensure that the equipment is ready for operation. Testing of the F/M Head at the Institute for Nuclear Research - Pitesti is a part of the overall program to assimilate in Romania the CANDU technology. There was an economic contract between GEC Canada and Nuclear Power Plant Cernavoda - Unit 2 to provide the Fueling Machines no. 4 and no. 5 untested. To perform testing of these machines at the Institute for Nuclear Research - Pitesti, a special testing rig was built and is available for this goal. Both the testing rig and staff have been successfully assessed by the AECL representatives during two visits, dated on December 2001 and March 2002. In 2003 the testing of the F/M Head no. 4 (RAM 5) was successfully completed. Today, in 2004, the functional test of the F/M Head no. 5 (RAM 6) is already performing. (authors)

  8. The CANDU 3 containment structure

    International Nuclear Information System (INIS)

    The design of the CANDU 3 nuclear power plant is being developed by AECL CANDU's Saskatchewan office. There are 24 CANDU nuclear power units operating in Canada and abroad and eight units are under construction is Romania and South Korea. The design of the CANDU 3 plant has evolved on the basis of the proven CANDU design. The experiences gained during construction, commissioning and operation of the existing CANDU plants are considered in the design. Many technological enhancements have been implemented in the design processes in all areas. The object has been to develop an improved reactor design that is suitable for the current and the future markets worldwide. Throughout the design phase of CANDU 3, emphasis has been placed in reducing the cost and construction schedule of the plant. This has been achieved by implementing design improvements and using new construction techniques. Appropriate changes and improvements to the design to suit new requirements are also adopted. In CANDU plants, the containment structure acts as an ultimate barrier against the leakage of radioactive substances during normal operations and postulated accident conditions. The concept of the structural design of the containment structure has been examined in considerable detail. This has resulted in development of a new conceptual design for the containment structure for CANDU 3. This paper deals with this new design of the containment structure

  9. CANDU 9 design

    International Nuclear Information System (INIS)

    AECL has made significant design improvements in the latest CANDU nuclear power plant (NPP) - the CANDU 9. The CANDU 9 operates with the energy efficient heavy water moderated reactor and natural uranium fuel and utilizes proven technology. The CANDU 9 NPP design is similar to the world leading CANDU 6 but is based upon the single unit adaptation of the 900 MWe class reactors currently operating in Canada as in integrated four-unit configurations. The evolution of the CANDU family of heavy water reactors (HAIR) is based on a continuous product improvement approach. Proven equipment and systems from operating stations are standardized and used in new products. As a result of the flexibility of the technology, evolution of the current design will ensure that any new requirements can be met, and there is no need to change the basic concept. This paper will provide an overview for some of the key features of the CANDU 9 NPP such as nuclear systems and equipment, advanced control and computer systems, safety design and protection features, and plant layout. The safety enhancements and operability improvements implemented in this design are described and some of the advantages that can be expected by the operating utility are highlighted. (author)

  10. Explosive and corrosive concentration analysis of gases produced in a CANDU type (N2, D2, O2, H2) nuclear power plant

    International Nuclear Information System (INIS)

    The primary loop gas of an automatic control system of a nuclear power plant is of great importance as regards conservation and safety of the plant. These gases are produced by dissociation due to radiation effects on heavy water. The system is based on a sample capture equipment, a chromatographic analyzer with its associated electronics, a sample separator and conditioner, a temperature and pressure control system of the transport gas, all included in the reactor building, apart from other supporting instrumentation. (Author)

  11. Thermal-hydraulics analysis for advanced fuel to be used in Candu 600 nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Catana, Alexandru [RAAN, Institute for Nuclear Research, Str. Campului Nr. 1, Pitesti, Arges (Romania); Danila, Nicolae; Prisecaru, Ilie; Dupleac, Daniel [University POLITEHNICA of Bucharest (Romania)

    2008-07-01

    Two Candu 600 pressure tube nuclear reactors cover about 17% of Romania's electricity demand. These nuclear reactors are moderated/cooled with D{sub 2}O, fuelled on-power with Natural Uranium (NU) dioxide encapsulated in a standard (STD37) fuel bundle. High neutron economy is achieved using D{sub 2}O as moderator and coolant in separated systems. To reduce fuel cycle costs, programs were initiated in Canada, S.Korea, Argentina and Romania for the design and build new fuel bundles able to accommodate different fuel compositions. Candu core structure and modular fuel bundles, permits flexible fuel cycles. The main expected achievements are: reduced fuel cycle costs, increased discharge burn-up, plutonium and minor actinides management, thorium cycle, use of recycled PWR and in the same time waste minimization and operating cost reduction. These new fuel bundles are to be used in already operated Candu reactors. Advanced fuel bundle were proposed: CANFLEX bundle (Canada, S-Korea); the Romanian 'SEU43' bundle (Fig 1). In this paper thermal-hydraulic analysis in sub-channel approach is presented for SEU43. Comparisons with standard (STD37) fuel bundles are made using SEU-NU for NU fuel composition and SEU-0.96, for recycled uranium (RU) fuel with 0.96% U-235. Extended and comprehensive analysis must be made in order to assess the TH behaviour of SEU43. In this paper, considering STD37, SEU43-NU and SEU43-0.96 fuel bundles, main TH parameters were analysed: pressure drop, fuel highest temperatures, coolant density, critical heat flux. Differences between these fuel types are outlined. Benefits are: fuel costs reduction, spent fuel waste minimization, increase in competitiveness of nuclear power. Safety margins must be, at least, conserved. (authors)

  12. The next generation CANDU 6

    International Nuclear Information System (INIS)

    AECL's product line of CANDU 6 and CANDU 9 nuclear power plants are adapted to respond to changing market conditions, experience feedback and technological development by a continuous improvement process of design evolution. The CANDU 6 Nuclear Power Plant design is a successful family of nuclear units, with the first four units entering service in 1983, and the most recent entering service this year. A further four CANDU 6 units are under construction. Starting in 1996, a focused forward-looking development program is under way at AECL to incorporate a series of individual improvements and integrate them into the CANDU 6, leading to the evolutionary development of the next-generation enhanced CANDU 6. The CANDU 6 improvements program includes all aspects of an NPP project, including engineering tools improvements, design for improved constructability, scheduling for faster, more streamlined commissioning, and improved operating performance. This enhanced CANDU 6 product will combine the benefits of design provenness (drawing on the more than 70 reactor-years experience of the seven operating CANDU 6 units), with the advantages of an evolutionary next-generation design. Features of the enhanced CANDU 6 design include: Advanced Human Machine Interface - built around the Advanced CANDU Control Centre; Advanced fuel design - using the newly demonstrated CANFLEX fuel bundle; Improved Efficiency based on improved utilization of waste heat; Streamlined System Design - including simplifications to improve performance and safety system reliability; Advanced Engineering Tools, -- featuring linked electronic databases from 3D CADDS, equipment specification and material management; Advanced Construction Techniques - based on open top equipment installation and the use of small skid mounted modules; Options defined for Passive Heat Sink capability and low-enrichment core optimization. (author)

  13. Development of techniques for radwaste systems in CANDU power stations

    International Nuclear Information System (INIS)

    Techniques to reduce the volume of CANDU reactor wastes and to bitumenize them are being developed at Chalk River Nuclear Laboratories. Reverse osmosis is suitable for initial purification of dilute radioactive aqueous wastes. Tubular membranes are used to concentrate wastes to 5 weight percent solids, and while the membranes do foul, they may be cleaned mechanically, chemically, or with fresh feed. A wiped-film evaporator then concentrates the retentate to a 20 weight-percent slurry. A twin-screw extruder-evaporator has been used to bitumenize this slurry, and it will also handle ion exchange resin and dry incinerator ash. Work on a wiped-film evaporator as a bitumenizer for various feeds is in progress. More experience in handling solid feeds is needed before work can proceed to the demonstraton phase. (auth)

  14. A journalist's guide to nuclear power

    International Nuclear Information System (INIS)

    This guidebook is meant to assist journalists in communicating information about nuclear power. It provides basic information about the CANDU reactor and its use by Ontario Hydro, radiation, and fission, as well as background and statistics on the use of nuclear power in Canada and around the world

  15. A CANDU-type small/medium power reactor

    International Nuclear Information System (INIS)

    The assembly known as a CANDU power reactor consists of a number of standardized fuel channels or 'power modules'. Each of these channels produces about 5 thermal megawatts on average. Within practical limitations on fuel enrichment and ultimately on economics, the number of these channels is variable between about 50 and approximately 700. Small reactors suffer from inevitable disadvantages in terms of specific cost of design/construction as well as operating cost. Their natural 'niche' for application is in remote off-grid locations. At the same time this niche application imposes new and strict requirements for staff complement, power system reliability, and so on. The distinct advantage of small reactors arises if the market requires installation of several units in a coordinated installation program - a feature well suited to power requirements in Canada's far North. This paper examines several of the performance requirements and constraints for installation of these plants and presents means for designers to overcome the consequent negative feasibility factors.

  16. CANDU 9 fuelling machine carriage

    International Nuclear Information System (INIS)

    Continuous, on-power refuelling is a key feature of all CANDU reactor designs and is essential to maintaining high station capacity factors. The concept of a fuelling machine carriage can be traced to the early CANDU designs, such as the Douglas Point Nuclear Generating Station. In the CANDU 9 480NU unit, the combination of a mobile carriage and a proven fuelling machine head design comprises an effective means of transporting fuel between the reactor and the fuel transfer ports. It is a suitable alternative to the fuelling machine bridge system that has been utilized in the CANDU 6 reactor units. The CANDU 9 480NU fuel handling system successfully combines features that meet the project requirements with respect to fuelling performance, functionality, seismic qualification and the use of proven components. The design incorporates improvements based on experience and applicable current technologies. (author). 4 figs

  17. Proceedings of the Canadian Nuclear Society CANDU maintenance conference

    International Nuclear Information System (INIS)

    The conference proceedings comprise 51 papers on the following aspects of maintenance of CANDU reactors: Major maintenance projects, maintenance planning and preparation, maintenance effectiveness, future maintenance issues, safety and radiation protection. The individual papers have been abstracted separately

  18. Report of the COG/IAEA international workshop on managing nuclear safety at CANDU (PHWR) plants. Working material

    International Nuclear Information System (INIS)

    The workshop, hosted by COG and co-sponsored by the International Atomic Energy Agency (IAEA, Vienna) was held in Toronto, April 28 - May 1st, 1997. The 40 participants included senior managers from IAEA member countries operating or constructing CANDU (PHWR) stations. All the offshore utilities with PHWR stations in Korea, Romania, India, Argentina, Pakistan, and China were present with their domestic counterparts from Ontario Hydro Nuclear, Hydro Quebec, New Brunswick Power, and AECL. The objectives of the workshop were to: provide a forum for exchange of ideas among nuclear safety managers operating CANDU (PHWR) stations and to learn from each other's experiences; to foster sharing of information on different operating approaches to managing safety and, in particular, to highlight the strategies for controlling the overall plant risk to a low level; to identify and discuss issues of mutual interest pertinent to PHWR stations and to define future follow-up activities. Refs, figs

  19. Nuclear power: benefits for the future

    International Nuclear Information System (INIS)

    This paper explains how nuclear power was implemented in Romania, why Romania chose nuclear energy, and what the impact of building a power plant is on the industry and environment of Romania. In the 1960's, Romania started discussions with different partners to cooperate in the development and application of atomic energy for a peaceful purpose. In 1977, the Romanian Government decided that the Candu-600 would be the basic unit for its nuclear program. The contract between Romania and Canada was for 5 units. In 1979, the construction of the first Candu unit started in Cernavoda, on the Danube 160 km east of Bucharest. (authors)

  20. The Study of Nuclear Fuel Cycle Options Based On PWR and CANDU Reactors

    International Nuclear Information System (INIS)

    The study of nuclear fuel cycle options based on PWR and CANDU type reactors have been carried out. There are 5 cycle options based on PWR and CANDU reactors, i.e.: PWR-OT, PWR-OT, PWR-MOX, CANDU-OT, DUPIC, and PWR-CANDU-OT options. While parameters which assessed in this study are fuel requirement, generating waste and plutonium from each cycle options. From the study found that the amount of fuel in the DUPIC option needs relatively small compared the other options. From the view of total radioactive waste generated from the cycles, PWR-MOX generate the smallest amount of waste, but produce twice of high level waste than DUPIC option. For total plutonium generated from the cycle, PWR-MOX option generates smallest quantity, but for fissile plutonium, DUPIC options produce the smallest one. It means that the DUPIC option has some benefits in plutonium consumption aspects. (author)

  1. Characteristics of used CANDU fuel relevant to the Canadian nuclear fuel waste management program

    International Nuclear Information System (INIS)

    Literature data on the characteristics of used CANDU power reactor fuel that are relevant to its performance as a waste form have been compiled in a convenient handbook. Information about the quantities of used fuel generated, burnup, radionuclide inventories, fission gas release, void volume and surface area, fuel microstructure, fuel cladding properties, changes in fuel bundle properties due to immobilization processes, radiation fields, decay heat and future trends is presented for various CANDU fuel designs. (author). 199 refs., 39 tabs., 100 figs

  2. Experience of oil in CANDU moderator during A831 planned outage at Bruce Power

    International Nuclear Information System (INIS)

    In their address to the Nuclear Plant Chemistry Conference 2009, Bruce Power staff will describe the effects of oil ingress to the moderator of a CANDU reactor. During the A831 planned outage of Bruce Power Unit 3, an incident of oil ingress into moderator was discovered on Oct 17, 2008. An investigation identified the cause of the oil ingress. Atomic Energy of Canada Ltd. (AECL) assessed operability of the reactor with the oil present and made recommendations with respect to the effect on unit start-up with oil present. The principal concern was the radiolytic generation of deuterium from the breakdown of the oil in-core. Various challenges were presented during start-up which were overcome via innovative approaches. The subsequent actions and consequential effects on moderator chemistry are discussed in this paper. Examination of the plant chemistry data revealed some interesting aspects of moderator system chemistry under upset conditions which will also be presented. (author)

  3. Nuclear power

    International Nuclear Information System (INIS)

    The subject is covered in chapters entitled: nuclear power certainties and doubts; nuclear power in the Western World to 2000; the frequency of core meltdown accidents; hidden costs of the accident at Three Mile Island; costs of nuclear accidents - implications for reactor choice; defining the risks of nuclear power; the uncertain economics of a nuclear power program; the economics of enabling decisions (Sizewell B as an enabling decision); trade in nuclear electricity; some pointers to the future. (U.K.)

  4. CANDU-OCR power station options and costs

    International Nuclear Information System (INIS)

    This report updates and in some cases expands the technical and economic parameters presented originally in AECL-4441. 'Summary report on the design of a prototypical 500 MWe CANDU-OCR power station.' Updating is desirable owing to the increasing number of inquiries that have been received by Atomic Energy of Canada Ltd. from government agencies and the private sector. Each is exploring the available options in their continuing endeavour to provide sufficient and economical energy. The organic-cooled reactor (OCR) concept is particularly interesting to the oil industry because the high steam pressures it can develop allow it to be used for heavy oil extraction can also be used economically for other large thermal and electrical energy production requirements such as those encountered in district heating schemes, heavy water production and electricity production. The report describes a reference OCR-500 MWe reactor. It includes an overview of organic reactor experience and areas for further development based on 14 years of operating experience with the WR-1 reactor. A discussion of several variations on the reference design is given including estimates of costs for various reactor sizes, enrichments and operating functions. Costs are presented in a form which allow easy comparison with those of competing energy options. (auth)

  5. Passive safety features for next generation CANDU power plants

    International Nuclear Information System (INIS)

    CANDU offers an evolutionary approach to simpler and safer reactors. The CANDU 3, an advanced CANDU, currently in the detailed design stage, offers significant improvements in the areas of safety, design simplicity, constructibility, operability, maintainability, schedule and cost. These are being accomplished by retaining all of the well known CANDU benefits, and by relying on the use of proven components and technologies. A major safety benefit of CANDU is the moderator system which is separate from the coolant. The presence of a cold moderator reduces the consequences arising from a LOCA or loss of heat sink event. In existing CANDU plants even the severe accident - LOCA with failure of the emergency core cooling system - is a design basis event. Further advances toward a simpler and more passively safe reactor will be made using the same evolutionary approach. Building on the strength of the moderator system to mitigate against severe accidents, a passive moderator cooling system, depending only on the law of gravity to perform its function, will be the next step of development. AECL is currently investigating a number of other features that could be incorporated in future evolutionary CANDU designs to enhance protection against accidents, and to limit off-site consequences to an acceptable level, for even the worst event. The additional features being investigated include passive decay heat removal from the heat transport system, a simpler emergency core cooling system and a containment pressure suppression/venting capability for beyond design basis events. Central to these passive decay heat removal schemes is the availability of a short-term heat sink to provide a decay heat removal capability of at least three days, without any station services. Preliminary results from these investigations confirm the feasibility of these schemes. (author)

  6. Deuterium ingress at rolled joints in Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Deuterium ingress model at the Rolled Joint has been extensively used for CANDU Nuclear Power Plants Operators in the Life Management of the Pressure Tubes. The importance of understanding the model is vital to avoid delayed hydride cracking at the Rolled Joint. This work reports the first step on develop the model presented on literature to be used in Argentinean CANDU 6, Embalse Nuclear Power Plant. (author)

  7. Research and development for Canadian nuclear power

    International Nuclear Information System (INIS)

    Rapid expansion of the successful CANDU reactor system offers immediate substitution for scarce oil and gas, combined with long-term security of energy supplies. A continuing large and vigorous R and D program on nuclear power is essential to achieve these objectives. The program, described here, consists of tactical R and D in support of the current CANDU reactor system, strategic R and D to develop and demonstrate advanced CANDU systems, and exploratory R and D to put Canada in a position to exploit any fusion opportunities. Two support activities, management of radioactive wastes and techniques to safeguard nuclear materials against diversion, although integral components of the nuclear power programs, are identified separately because they are currently of special public interest. (author)

  8. CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This paper highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components and nuclear safety considerations both to the workers and the public

  9. Trends in CANDU licensing

    International Nuclear Information System (INIS)

    Modern utilities view nuclear power more and more as a commodity - it must compete 'today' with current alternatives to attract their investment. With its long construction times and large capital investment, nuclear plants are vulnerable to delays once they have been committed. There are two related issues. Where the purchaser and the regulator are experienced in CANDU, the thrust is a very practical one: to identify and resolve major licensing risks at a very early stage in the project. Thus for a Canadian project, the designer (AECL) and the prospective purchaser would deal directly with the AECB. However CANDU has also been successfully licensed in other countries, including Korea, Romania, Argentina, India and Pakistan. Each of these countries has its own regulatory agency responsible for licensing the plant. In addition, however, the foreign customer and regulator may seek input from the AECB, up to and including a statement of licensability in Canada; this is not normally needed for a ''repeat'' plant and/or if the customer is experienced in CANDU, but can be requested if the plant configuration has been modified significantly from an already-operating CANDU. It is thus the responsibility of the designer to initiate early discussions with the AECB so the foreign CANDU meets the expectations of its customers

  10. Experimental validation of Pu-Sm evolution model for CANDU-6 power transients

    International Nuclear Information System (INIS)

    Development of a methodology to evaluate the reactivity produced by Pu-Sm transient, effect displayed after power transients. This methodology allows to predict the behavior of liquid zones with which the fine control of CANDU reactor power is made. With this information, it is easier to foresee the refueling demand after power movements. The comparison with experimental results showed good agreement. (author)

  11. Economics of CANDU-PHW

    International Nuclear Information System (INIS)

    The CANDU-Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This paper discusses the cost of producing electricity from CANDU, presents actual cost experience of CANDU and coal in Ontario, presents projected CANDU and coal costs in Ontario and compares CANDU and Light Water Reactor cost estimates in Ontario

  12. Modelling nuclear fuel vibrations in horizontal CANDU reactors

    International Nuclear Information System (INIS)

    Flow-induced fuel vibrations in the pressure tubes of CANDU reactors are of vital interest to designers because fretting damage may result. Computer simulation is being used to study how bundles vibrate and to identify bundle design features which will reduce vibration and hence fretting. (author)

  13. Nuclear power

    OpenAIRE

    Waller, David; McDonald, Alan; Greenwald, Judith; Mobbs, Paul

    2005-01-01

    David Waller and Alan McDonald ask whether a nuclear renaissance can be predicted; Judith M. Greenwald discusses keeping the nuclear power option open; Paul Mobbs considers the availability of uranium and the future of nuclear energy.

  14. Nuclear power

    International Nuclear Information System (INIS)

    This chapter discussed the following topics related to the nuclear power: nuclear reactions, nuclear reactors and its components - reactor fuel, fuel assembly, moderator, control system, coolants. The topics titled nuclear fuel cycle following subtopics are covered: , mining and milling, tailings, enrichment, fuel fabrication, reactor operations, radioactive waste and fuel reprocessing. Special topic on types of nuclear reactor highlighted the reactors for research, training, production, material testing and quite detail on reactors for electricity generation. Other related topics are also discussed: sustainability of nuclear power, renewable nuclear fuel, human capital, environmental friendly, emission free, impacts on global warming and air pollution, conservation and preservation, and future prospect of nuclear power

  15. An investigation into the relationship between local and global power excursions in CANDU

    International Nuclear Information System (INIS)

    If a reactor exhibits large neutronic decoupling of one core region from another, it may be able to sustain localized power excursions. If such an excursion is too localized, there may be no in-core detector close enough to detect it promptly. To confirm that CANDU reactors are unlikely to support local power excursions, we selected a credible local reactivity-insertion mechanism in the CANDU 600 and calculated the resulting neutron flux transient with a three-dimensional model. A coupled neutronics-thermohydraulics simulation of the transient was performed. The transient was subdivided into appropriate time steps, and iteration between the neutronics and thermohydraulics calculations was carried out at each step, so that the proper distribution of thermohydraulic feedback reactivity was obtained. The calculation shows that, with credible reactivity insertions, the neutronic characteristics of CANDU reactors do not allow local power excursions to occur without a comparable global power increase. The latter would not escape detection by the protective systems

  16. Supporting CANDU operators-CANDU owners group

    International Nuclear Information System (INIS)

    The CANDU Owners Group (COG) was formed in 1984 by the Canadian CANDU owning utilities and Atomic Energy of Canada limited (AECL). Participation was subsequently extended to all CANDU owners world-wide. The mandate of the COG organization is to provide a framework for co-operation, mutual assistance and exchange of information for the successful support, development, operation, maintenance and economics of CANDU nuclear electric generating stations. To meet these objectives COG established co-operative programs in two areas: 1. Station Support. 2. Research and Development. In addition, joint projects are administered by COG on a case by case basis where CANDU owners can benefit from sharing of costs

  17. Environmental Impact Assessment following a Nuclear Accident to a Candu NPP

    International Nuclear Information System (INIS)

    The paper presents calculations of nuclear accident consequences to public and environment, for a Candu NPP using advanced fuel in two hypothetical accident scenarios: (1) large LOCA followed by partial core melting with early containment failure; (2) late core disassembly and containment bypass through ECCS. During both accidents a release occurs, radioactive contaminants being dispersed into atmosphere. As reference, estimations for Candu standard UO2 fuel were used. The radioactive core inventory was obtained by using ORIGEN-S computer code included in ORNL,SCALE 5 programs package. Radiological consequences assessment to public and environment was performed by means of PC COSYMA computer code

  18. System study of CANDU/LWR synergy in advanced nuclear fuel cycles

    International Nuclear Information System (INIS)

    This report proposes a study that will evaluate the effects of advanced nuclear fuel cycles on resource utilisation, repository capacity, waste streams, economics, and proliferation resistance. The proposed fuel cycles are designed to exploit the unique synergy that exists between light water and CANDU reactors. Also, several fuel cycle simulation codes have been proposed to be used. (author)

  19. Development of nuclear fuel. Development of CANDU advanced fuel bundle

    International Nuclear Information System (INIS)

    In order to develop CANDU advanced fuel, the agreement of the joint research between KAERI and AECL was made on February 19, 1991. AECL conceptual design of CANFLEX bundle for Bruce reactors was analyzed and then the reference design and design drawing of the advanced fuel bundle with natural uranium fuel for CANDU-6 reactor were completed. The CANFLEX fuel cladding was preliminarily investigated. The fabricability of the advanced fuel bundle was investigated. The design and purchase of the machinery tools for the bundle fabrication for hydraulic scoping tests were performed. As a result of CANFLEX tube examination, the tubes were found to be meet the criteria proposed in the technical specification. The dummy bundles for hydraulic scoping tests have been fabricated by using the process and tools, where the process parameters and tools have been newly established. (Author)

  20. Nuclear power

    International Nuclear Information System (INIS)

    This chapter of the final report of the Royal Commission on Electric Power Planning in Ontario updates its interim report on nuclear power in Ontario (1978) in the light of the Three Mile Island accident and presents the commission's general conclusions and recommendations relating to nuclear power. The risks of nuclear power, reactor safety with special reference to Three Mile Island and incidents at the Bruce generating station, the environmental effects of uranium mining and milling, waste management, nuclear power economics, uranium supplies, socio-political issues, and the regulation of nuclear power are discussed. Specific recommendations are made concerning the organization and public control of Ontario Hydro, but the commission concluded that nuclear power is acceptable in Ontario as long as satisfactory progress is made in the disposal of uranium mill tailings and spent fuel wastes. (LL)

  1. A proposed structural, risk-informed approach to the periodicity of CANDU-6 nuclear containment integrated leak rate testing

    Energy Technology Data Exchange (ETDEWEB)

    Saliba, N. [McGill Univ., Dept. of Civil Engineering and Applied Mechanics, Montreal, Quebec (Canada); Komljenovic, D. [Hydro-Quebec, Gentilly-2 Nuclear Power Plant, Becancour, Quebec (Canada); Chouinard, L. [McGill Univ., Dept. of Civil Engineering and Applied Mechanics, Montreal, Quebec (Canada); Vaillancourt, R.; Chretien, G. [Hydro-Quebec, Gentilly-2 Nuclear Power Plant, Becancour, Quebec (Canada); Gocevski, V. [Hydro-Quebec Equipements, Montreal, Quebec (Canada)

    2010-07-01

    As ultimate lines of defense against leakage of large amounts of radioactive material to the environment in case of major reactor accidents, containments have been monitored through well designed periodic tests to ensure their proper performance. Regulatory organizations have imposed types and frequencies of containment tests based on highly-conservative deterministic approaches, and judgments of knowledgeable experts. Recent developments in the perception and methods of risk evaluation have been applied to rationalize the leakage-rate testing frequencies while maintaining risks within acceptable levels, preserving the integrity of containments, and respecting the defense-in-depth philosophy. The objective of this paper is to introduce a proposed risk-informed decision making framework on the periodicity of nuclear containment ILRTs for CANDU-6 nuclear power plants based on five main decision criteria, namely: 1) the containment structural integrity; 2) inputs from PSA Level-2; 3) the requirements of deterministic safety analyses and defense-in-depth concepts; 4- the obligations under regulatory and standard requirements; and 5) the return of experience from nuclear containments historic performance. The concepts of dormant reliability and structural fragility will guide the assessment of the containment structural integrity, within the general context of a global containment life cycle management program. This study is oriented towards the requirements of CANDU-6 reactors, in general, and Hydro-Quebec's Gentilly-2 nuclear power plant, in particular. The present article is the first part in a series of papers that will comprehensively detail the proposed research. (author)

  2. The CANDU 9 distributed control system design process

    International Nuclear Information System (INIS)

    Canadian designed CANDU pressurized heavy water nuclear reactors have been world leaders in electrical power generation. The CANDU 9 project is AECL's next reactor design. Plant control for the CANDU 9 station design is performed by a distributed control system (DCS) as compared to centralized control computers, analog control devices and relay logic used in previous CANDU designs. The selection of a DCS as the platform to perform the process control functions and most of the data acquisition of the plant, is consistent with the evolutionary nature of the CANDU technology. The control strategies for the DCS control programs are based on previous CANDU designs but are implemented on a new hardware platform taking advantage of advances in computer technology. This paper describes the design process for developing the CANDU 9 DCS. Various design activities, prototyping and analyses have been undertaken in order to ensure a safe, functional, and cost-effective design. (author)

  3. Joint submission of the Canadian Nuclear Association and the Organization of CANDU Industries to the Ontario Nuclear Safety Review

    International Nuclear Information System (INIS)

    The manufacturing company members of the Canadian Nuclear Association and the Organization of CANDU Industries are proud to have played their part in the development of the peaceful application of nuclear technology in Ontario, and the achievement of the very real benefits discussed in this paper, which greatly outweigh the hypothetical risks

  4. CANDU 9 enhancements and licensing

    International Nuclear Information System (INIS)

    The CANDU 9 design has followed the evolutionary product development approach that has characterized the CANDU family of nuclear power plants. In addition to utilizing proven equipment and systems from operating stations, the CANDU 9 design has looked ahead to incorporate design and safety enhancements necessary to meet evolving utility and licensing requirements. With the requirement that the CANDU 9 design should be licensable for both domestic and foreign potential users, the pre-project Basic Design Engineering program included a two year formal extensive review by the Canadian Regulatory Agency, the Atomic Energy Control Board . Documentation submitted for the licensing review included the licensing basis, safety requirements and safety analyses necessary to demonstrate compliance with regulations and to assess system design and performance

  5. Exporting technology for CANDU fuel manufacturing to the People's Republic of China - a stimulating experience for the Romanian nuclear fuel plant

    International Nuclear Information System (INIS)

    Adopting CANDU type reactors to produce nuclear-generated electricity, Romania has also developed his capability to produce nuclear fuel. Since 1995, FCN Pitesti is the unique nuclear fuel supplier for Cernavoda CANDU Power Station. Fuel plant upgrading and qualification was achieved in co-operation with AECL and Zircatec Precision Industries Inc. The fuel bundles manufactured at FCN Pitesti proved to be of excellent quality, operating with a very low defect rate, all defected fuel being reported in the first period of the reactor operation. It is a fact now that FCN has the capability to solve a wide variety of aspects one of the most significant being the development of new equipment and the increase of the capacity in order to cover the future nuclear fuel needs. On this basis FCN was invited to contribute with his potential to a supplying contract with China National Nuclear Corporation - 202 Plant, for CANDU nuclear fuel technology. Following an offer including several categories of equipment and technology, the option was for beryllium coaters and coating technology and training for end cap manufacturing. The arrangements consider Romanian company as a sub-supplier, this option ensuring the consistence with the largest part of the supply for CANDU fuel technology, offered by Zircatec. Two pieces of beryllium coaters have been produced and tested in Romania and the operating demonstration was made in the presence of Zircatec staff and Chinese delegates. The Chinese delegated were trained for complete operating modes and their ability to handle the equipment was certified accordingly. They also have been trained in the end cap technology and related quality inspection. The paper includes a short presentation of the equipment and associated work to fit the specified needs. The involvement of the Romanian fuel plant in this contract could be considered as an extension of the previous co-operation with the Canadian partners on CANDU nuclear fuel and finally

  6. Assessing CANDU requirements for irradiation - Research facilities

    International Nuclear Information System (INIS)

    The Canadian nuclear program needs ongoing access to irradiation-research facilities to support the safe operation of existing CANDU reactors and the evolutionary development of CANDU components and design features. The irradiation-research program must facilitate the testing of unique CANDU technology such as the fuel bundle, on-power refueling, the pressure tube, and the heavy-water coolant and moderator. Since 1957, NRU has operated as Canada's principal irradiation facility; however, it has become clear that NRU needs costly refurbishing if its lifetime is to be significantly extended. Accordingly, AECL has reviewed the requirements for CANDU irradiation research and is presently assessing alternatives for providing the necessary future access to irradiation-research facilities. Various options are under consideration, including renting space in existing research reactors, performing irradiations in CANDU power reactors, and building a new indigenous materials testing reactor specifically to meet essential program requirements

  7. Operations quality assurance for nuclear power plants

    International Nuclear Information System (INIS)

    This standard covers the quality assurance of all activities concerned with the operation and maintenance of plant equipment and systems in CANDU-based nuclear power plants during the operations phase, the period between the completion of commissioning and the start of decommissioning

  8. Nuclear power

    International Nuclear Information System (INIS)

    The committee concludes that the nature of the proliferation problem is such that even stopping nuclear power completely could not stop proliferation completely. Countries can acquire nuclear weapons by means independent of commercial nuclear power. It is reasonable to suppose if a country is strongly motivated to acquire nuclear weapons, it will have them by 2010, or soon thereafter, no matter how nuclear power is managed in the meantime. Unilateral and international diplomatic measures to reduce the motivations that lead to proliferation should be high on the foreign policy agenda of the United States. A mimimum antiproliferation prescription for the management of nuclear power is to try to raise the political barriers against proliferation through misuse of nuclear power by strengthening the Non-Proliferation Treaty, and to seek to raise the technological barriers by placing fuel-cycle operations involving weapons-usable material under international control. Any such measures should be considered tactics to slow the spread of nuclear weapons and thus earn time for the exercise of statesmanship. The committee concludes the following about technical factors that should be considered in formulating nuclear policy: (1) rate of growth of electricity use is a primary factor; (2) growth of conventional nuclear power will be limited by producibility of domestic uranium sources; (3) greater contribution of nuclear power beyond 400 GWe past the year 2000 can only be supported by advanced reactor systems; and (4) several different breeder reactors could serve in principle as candidates for an indefinitely sustainable source of energy

  9. Nuclear power

    International Nuclear Information System (INIS)

    Nuclear power has been seen as an answer to the energy problems of the Third World and Third World markets have been seen as an answer to the problems of the nuclear power industry. For some years during the 1970s both views seemed tenable. This paper examines the progress and setbacks of nuclear power in developing countries. In concentrates mainly on the four countries with real nuclear power commitments (as opposed to all-but-abandoned ambitions) - South Korea and Taiwan, where the interest has been mainly in obtaining cheaper and reliable electricity supplies, and Argentina and India, where the main interest has been in developing indigenous nuclear technological capabilities. A number of possibilities are examined which could influence future nuclear ordering, including smaller reactors to suit Third World electricity grids and a possible way round the constraint of large external debts. (author)

  10. The status of the Canadian nuclear power program and possible future strategies

    International Nuclear Information System (INIS)

    The present Canadian nuclear power program based on the CANDU-PHW reactor, future commitments, and the status of heavy water production, are discussed, together with short term prospects over the next 20 years. The longer term favours fuels with higher fissile content than natural uranium. Possible future strategies are discussed, which include consideration of a number of different fuel cycles for the different types of CANDU reactor, i.e. CANDU-PHW, CANDU-BLW, CANDU-PLW and CANDU-OCR. It is concluded that: CANDU-PHW reactor is fully reliable and competative; organic and boiling water cooled variations promise savings of 15 to 20% in both capital and unit energy costs; the CANDU concept offers the opportunity for large improvements in uranium conservation whilst remaining economically competitive, by use of plutonium recycle and/or thorium; using the CANDU concept with thorium it is possible to limit the total uranium requirement for a given nuclear power capacity; and finally a system based on CANDU-PHW reactors could introduce FBR reactors more quickly and efficiently than one based on LWR reactors. (U.K.)

  11. Learning from experience: feedback to CANDU design

    International Nuclear Information System (INIS)

    AECL's main product line is based on two single unit CANDU nuclear power plant designs; CANDU 6 and CANDU 9, each of which is based on successfully operating CANDU plants. AECL's CANDU development program is based upon evolutionary improvement. The evolutionary design approach ensures the maximum degree of operational provenness. It also allows successful features of today's plants to be retained while incorporating improvements as they develop to the appropriate level of design maturity. A key component of this evolutionary development is a formal process of gathering and responding to feedback from: NPP operation, construction and commissioning; regulatory input; equipment supplier input; R and D results; market input. The progresses for gathering and implementing the experience feedback and a number of recent examples of design improvements from this feedback process are described in the paper. (author)

  12. Nuclear power : exploding the myths

    International Nuclear Information System (INIS)

    A critique of the Canadian government's unaccountability in terms of nuclear decisions was presented. The federal government has spent more than $13 billion building dozens of nuclear facilities, and spreading Canadian nuclear technology to India, Pakistan, Taiwan, Korea, Argentina and Romania. The author argued that this was done without any public consultation or public debate. In addition, the federal government announced in 1996 that it will play a role in nuclear disarmament and would accept tonnes of leftover plutonium from dismantled nuclear warheads to be used as fuel in CANDU reactors. Samples of weapons plutonium fuels from Russia and the United States are currently being tested in a reactor at Chalk River, Ontario. In addition, China received a $1.5 billion loan from the Treasury of Canada to help finance a CANDU reactor. It was the largest loan in Canadian history, yet had no procedure to obtain taxpayer's permission. Turkey was promised an equal amount if it would build a CANDU reactor. Despite this activity, the nuclear industry is in a dying state. No reactors have been ordered in North America for the past 25 years and there are no future prospects. Nuclear expansion has also ground to a halt in western Europe, Germany, Sweden, Switzerland and France. The author discussed the association of nuclear energy with nuclear weapons and dispelled the myth that the nuclear energy programs have nothing to do with nuclear weapons. He also dispelled the myth that plutonium extracted from dismantled warheads can be destroyed by burning it as fuel in civilian reactors. The author emphasized that nuclear warheads are rendered useless when their plutonium cores are removed, but there is no method for destroying the plutonium, which constitutes a serious danger. The third myth which he dispelled was that nuclear power can significantly reduce greenhouse gas emissions. Studies show that each dollar invested in energy efficiency saves 5 to 7 times as much carbon

  13. Enhancing the seismic capability of the on-power refueling system of the CANDU reactor

    International Nuclear Information System (INIS)

    The CANDU reactor assembly includes several hundred horizontal fuel channels, each containing twelve fuel bundles, arranged in a square lattice, and supported by the reactor structures. CANDU operates on natural uranium or other low fissile content fuel, and is refueled on-power, with either four or eight fuel bundles in a channel being replaced during each refueling operation. The fueling machines clamp onto the opposite ends of the fuel channel to be refueled. The seismic capacity of this refueling system is evaluated in terms of its dynamic response during an earthquake. This paper describes the approach adopted to enhance the seismic capability of the fueling machine and calandria assembly for earthquakes of O.3g ground acceleration covering a broad range of soil conditions ranging from soft to hard. A detailed, 3-D finite element seismic model of the fueling machine and calandria assembly system is developed to calculate the seismic responses of the structure. Some relatively simple hardware design changes have been considered to increase the seismic capacity of the CANDU 6 reactor. These changes in the fueling machine and calandria assembly of the CANDU 6 reactor are briefly described. They have been incorporated into the finite element seismic model of the system. Most of these design changes have already been considered and implemented in other CANDU reactor projects. The current CANDU 6 reactor design fully meets the requirements of seismic qualification for sites with potential for O.2g ground acceleration where the seismic loads need to be combined with the other design loads for the support and pressure boundary components to demonstrate compliance with the applicable Code requirements. In the present study it is demonstrated that, with relatively simple hardware changes, the fueling machine and calandria assembly of the CANDU 6 reactor can withstand earthquakes of O.3g ground acceleration. Based on the current study and some preliminary analysis of the

  14. CANDU safety under severe accidents

    International Nuclear Information System (INIS)

    The characteristics of the CANDU reactor relevant to severe accidents are set first by the inherent properties of the design, and second by the Canadian safety/licensing approach. Probabilistic safety assessment studies have been performed on operating CANDU plants, and on the 4 x 880 MW(e) Darlington station now under construction; furthermore a scoping risk assessment has been done for a CANDU 600 plant. They indicate that the summed severe core damage frequency is of the order of 5 x 10-6/year. CANDU nuclear plant designers and owner/operators share information and operational experience nationally and internationally through the CANDU Owners' Group (COG). The research program generally emphasizes the unique aspects of the CANDU concept, such as heat removal through the moderator, but it has also contributed significantly to areas generic to most power reactors such as hydrogen combustion, containment failure modes, fission product chemistry, and high temperature fuel behaviour. Abnormal plant operating procedures are aimed at first using event-specific emergency operating procedures, in cases where the event can be diagnosed. If this is not possible, generic procedures are followed to control Critical Safety Parameters and manage the accident. Similarly, the on-site contingency plans include a generic plan covering overall plant response strategy, and a specific plan covering each category of contingency

  15. CANDU: The fuel conserving reactor

    International Nuclear Information System (INIS)

    Because of their high neutron economy and unique design features, CANDU heavy water moderated reactors are the only established commercial reactors able to use directly low fissile content fuels such as natural uranium or uranium recovered from spent light water reactor fuel (RU). These features also help them to achieve the highest fuel utilization of all commercially available reactors, whether the fuel is based on natural uranium or mixed oxides of plutonium, uranium or thorium. As nuclear capacity growth increases demands on the world's finite uranium resources, AECL envisages near term use in CANDU reactors of a fuel incorporating RU and fuels containing thorium, with either plutonium or low enriched uranium (LEU) as the fissile 'driver' fuel. In the long term, AECL proposes the use of future 'Generation X' CANDU reactors with enhanced neutron economy to achieve a near-Self-Sufficient Equilibrium Thorium (SSET) fuel cycle. This CANDU SSET would have a conversion ratio of unity and be able to produce power indefinitely, with the need for little additional fissile material once equilibrium is reached (the amount of 233U needed in the fresh fuel is the same as is present in the discharged fuel, including processing losses.) This would also enable a CANDU-Fast Breeder Reactor (FBR) synergism that would allow each fuel-generating, though expensive, FBR to supply the initial fissile requirements of several less-expensive, CANDU SSET reactors operating on the thorium cycle. The closer the approach to an SSET that CANDUs can achieve, the higher the ratio of CANDUs to breeders in an economically optimized reactor fleet. CANDU reactors thereby become natural partners of both light water-cooled thermal reactors and fast breeder reactors, in both cases making optimum use of their spent fuel components and enhancing the overall sustainability of nuclear power. (authors)

  16. Nuclear power - a reliable future

    International Nuclear Information System (INIS)

    The Ministry of Education and Research - Department of Research has implemented a national Research and Development program taking into consideration the following: - the requirements of the European Union on research as a factor of development of the knowledge-based society; - the commitments to the assimilation and enforcement of the recommendations of the European Union on nuclear power prompted by the negotiations of the sections 'Science and Research' and ' Energy' of the aquis communautaire; - the major lines of interest in Romania in the nuclear power field established by National Framework Program of Cooperation with IAEA, signed on April 2001; - the short and medium term nuclear options of the Romanian Government; - the objectives of the National Nuclear Plan. The major elements of the nuclear research and development program MENER (Environment, Energy, Resources) supported by the Department of Research of the Ministry of Education and Research are the following: - reactor physics and nuclear fuel management; - operation safety of the Power Unit 1 of Cernavoda Nuclear Electric Power Station; - improved nuclear technological solutions at the Cernavoda NPP; - development of technologies for nuclear fuel cycle; - operation safety of the other nuclear plants in Romania; - assessment of nuclear risks and estimation of the radiological impact on the environment; - behavior of materials under the reactor service conditions and environmental conditions; - design of nuclear systems and equipment for the nuclear power stations and nuclear facilities; - radiological safety; - application of nuclear techniques and technologies in industry, agriculture, medicine and other fields of social life. Research to develop high performance methods and equipment for monitoring nuclear impact on environment are conducted to endorse the measures for radiation protection. Also mentioned are the research on implementing a new type of nuclear fuel cycle in CANDU reactors as well as

  17. Life extension, power upgrade, and return to service work for Pickering NGS and other PWR and CANDU plants

    International Nuclear Information System (INIS)

    Work on life extension, power upgrade and return to service has been performed and is in progress for a number of PWR and CANDU plants. For PWR plants, power upgrade work has been done for the new replacement steam generators in several cases. This work consists of redoing the formal equipment qualification analysis and reports for the uprated operating conditions to support the application for license adjustment. Life extension assessments have been performed for several CANDU plants. These are highly detailed assessments in which the particular steam generator is reassessed part by part as to the ability of each to sustain full life operation and also extended life operation. Return to service work for Pickering NGSA specifically has included this type of assessment and also specific repair, cleaning and retrofit activities including secondary side inspection, waterlancing, divider plate repair, eddy current inspection, etc. Steam generator modifications and retrofit work have been performed in a number of cases. The paper discusses various life extension, power upgrade, equipment modification and return to service activities all of which are part of the renewed drive in the industry to realise the full potential of nuclear plants by getting more and better performance from the extended service of existing plants. (author)

  18. Advanced CANDU control centre

    International Nuclear Information System (INIS)

    The CANDU 9 design is based upon the 900 MWe class Darlington station in Canada, which is among the world leading nuclear power stations for capacity factor with low operation, maintenance and administration costs. The CANDU 9 design provides an advanced control centre with enhanced operations features. The advanced AECL control centre design includes the proven functionality of existing CANDU control centres, those implementable characteristics identified by systematic design combined with a human factors analysis of operations requirements and features needed to improve station operability which are made possible by the application of current technology. The design strategy is to preserve the general main control room operations staff work area as unchanged as possible to facilitate the inclusion of past features and operational experience while incorporating operability improvements. The author will present those features of the advanced CANDU control centre which facilitates improved operability capabilities. As well, aspects of the design process utilized, application of simulation technology and conclusions regarding this design approach will be reviewed

  19. Nuclear fuel element design and thermal-hydraulic analysis of Wolsung-1, 600 MWe CANDU-PHWR (Part II)

    International Nuclear Information System (INIS)

    The main objective of the present thermal hydraulic analysis is to determine the thermal hydraulic characteristics of Wolsung-1 600 MWe CANDU-PHW reactor under normal operation. This is to verify and expedite the development of the nuclear fuel design and fabrication as well as the management. The computer program package developed for the stated objective are DOD81, CANREPP, PLOC81 and COBRA-CANDU. (Author)

  20. Investigation of techniques for the application of safeguards to the CANDU 600 MW(e) nuclear generating station

    International Nuclear Information System (INIS)

    A cooperative program with the Canadian Atomic Energy Control Board, Atomic Energy of Canada Limited and the IAEA was established in 1975: to determine the diversion possibilities at the CANDU type reactors using a diversion path analysis; to detect the diversion of nuclear materials using material accountancy and surveillance/containment. Specific techniques and instrumentation, some of which are unique to the CANDU reactor, were developed. 10 appendices bring together the relevant reports and memoranda of results for the Douglas Point Program

  1. Nuclear power

    International Nuclear Information System (INIS)

    After three decades of commercial development, nuclear power has failed to fulfil its promise. Why, and what does that failure imply for the future of energy policy? One reason for nuclear power's slow growth is that rich countries have repeatedly found they needed less electricity than they had forecast. Part of the problem is, as it always has been, public unease. Worries about safety affect costs. They make it harder and more time-consuming to find sites for new plants or for storing waste. Complex safety devices mean complex plants, which are more expensive to build (and to relicense when they grow old). The true cost of nuclear power is hard to calculate. However nuclear power now seems to be less economically favourable when compared with its main rival, coal. The only hope for nuclear power is that, apart from hydropower, it is the only commercial alternative to fossil fuels. Concerns over carbon dioxide emissions may tip the balance in nuclear's favour. (Author)

  2. Nuclear power: benefits for the future in Romania

    International Nuclear Information System (INIS)

    This paper explains how nuclear power was implemented in Romania, why Romania chose nuclear energy and what the impact of building a power plant is on the industry and environment of Romania. In the 1960's, Romania started discussions with different partners to cooperate in the development and application of atomic energy for peaceful purpose. In 1977 Romanian Government decided that the Candu-600 to be the basic unit for its nuclear program. The contract between Romania and Canada was for 5 units. In 1979, the construction of the first Candu - 600 unit started in Cernavoda, on the right side of Danube River, about 160 km east of Bucharest. (author)

  3. Recent experience related to neutronic transients in Ontario Hydro CANDU nuclear generating stations

    International Nuclear Information System (INIS)

    Ontario Hydro presently operates 18 CANDU reactors in the province of Ontario, Canada. All of these reactors are of the CANDU Pressurized Heavy Water design, although their design features differ somewhat reflecting the evolution that has taken place from 1971 when the first Pickering unit started operation to the present as the Darlington units are being placed in service. Over the last three years, two significant neutronic transients took place at the Pickering Nuclear Generating Station 'A' (NGS A) one of which resulted in a number of fuel failures. Both events provided valuable lessons in the areas of operational safety, fuel performance And accident analysis. The events and the lessons learned are discussed in this paper

  4. The future of nuclear power

    International Nuclear Information System (INIS)

    Canadians are heavily dependent upon reliable and affordable sources of energy to sustain their lifestyle. In a world threatened by diminishing energy resources, Canadians need to plan for the future. Canadian electrical utilities must respond to rapidly changing circumstances and uncertainties to ensure that the public's demand for electricity is met with a high quality product. There is a need to strike a proper balance between demand management alternatives and new supply options. Nuclear power will remain as an alternative supply option. The place of CANDU will depend upon its continued high performance, public acceptance and the leadership given to the program

  5. The Canadian nuclear power program

    International Nuclear Information System (INIS)

    A brief review of the Canadian nuclear power program is presented. Domestically developed CANDU (CANada Deuterium Uranium) reactors account for all of Canada's nuclear electric capacity (5000 MWe in operation and 10,000 MWe under construction or in commissioning) and have also been exported. CANDU reactors are reliable, efficient, and consistently register in the world's top ten in performance. The safety record is excellent. Canada has excess capability in heavy water and uranium production and can easily service export demands. The economic activity generated in the nuclear sector is high and supports a large number of jobs. The growth in nuclear commitments has slowed somewhat as a result of the worldwide recession; however, the nuclear share of expected electricity demand is likely to continue to rise in the next decade. Priorities in the future direction of the program lie in the areas of maintaining high response capability to in-service problems, improving technology, high-level waste management, and advanced fuel cycles. (author)

  6. Power distribution control of CANDU reactors based on modal representation of reactor kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Lingzhi, E-mail: lxia4@uwo.ca [Department of Electrical and Computer Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada); Jiang, Jin, E-mail: jjiang@eng.uwo.ca [Department of Electrical and Computer Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada); Luxat, John C., E-mail: luxatj@mcmaster.ca [Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada)

    2014-10-15

    Highlights: • Linearization of the modal synthesis model of neutronic kinetic equations for CANDU reactors. • Validation of the linearized dynamic model through closed-loop simulations by using the reactor regulating system. • Design of a LQR state feedback controller for CANDU core power distribution control. • Comparison of the results of this new controller against those of the conventional reactor regulation system. - Abstract: Modal synthesis representation of a neutronic kinetic model for a CANDU reactor core has been utilized in the analysis and synthesis for reactor control systems. Among all the mode shapes, the fundamental mode of the power distribution, which also coincides with the desired reactor power distribution during operation, is used in the control system design. The nonlinear modal models are linearized around desired operating points. Based on the linearized model, linear quadratic regulator (LQR) control approach is used to synthesize a state feedback controller. The performance of this controller has been evaluated by using the original nonlinear models under load-following conditions. It has been demonstrated that the proposed reactor control system can produce more uniform power distribution than the traditional reactor regulation systems (RRS); in particular, it is more effective in compensating the Xenon induced transients.

  7. AECL review of CANDU 6 design in light of the Ontario Hydro nuclear IIPA technical findings

    International Nuclear Information System (INIS)

    In the spring of 1997, Ontario Hydro (OH) conducted an Independent, Integrated Performance Assessment (IIPA) to address long-standing management, process and equipment issues within the Ontario Hydro Nuclear (OHN) organization and its multi-unit CANDU stations. This review included six Safety System Functional Inspections (SSFIs) on: Bruce A Emergency Coolant Injection System; Bruce B Service Water Systems; Darlington Compressed Air Systems; Pickering Electrical Distribution Systems; Fire Protection (Programmatic); In-Service Environmental Qualification Program (Programmatic). Overall, the OHN inspections found that 'the design of the CANDU plant is robust and plant hardware (including equipment and materials), for the most part, is adequately reliable.' However, the SSFIs also identified a number of deficiencies in the areas of management, control of design/engineering, operations, training, maintenance, testing and quality assurance. Atomic Energy of Canada Limited (AECL) has undertaken an in-depth review of all design-related issues to assess their applicability and impact on the current CANDU 6 design. The AECL review has determined that equipment/design and programmatic deficiencies identified at the OLIN plants have been addressed in the current CANDU 6 design through an effective design feedback process and the application of modem codes and standards that were not in place during the design of the early OHN stations. Many of the design-related SSFI findings can be attributed to inadequate configuration management and the impact of unauthorized design modifications. Problems in these areas can arise at any nuclear station and prevention requires adherence to quality engineering procedures and documentation processes. (author)

  8. Validation of the COBRA code for dry out power calculation in CANDU type advanced fuels

    International Nuclear Information System (INIS)

    Stern Laboratories perform a full scale CHF testing of the CANFLEX bundle under AECL request. This experiment is modeled with the COBRA IV HW code to verify it's capacity for the dry out power calculation . Good results were obtained: errors below 10 % with respect to all data measured and 1 % for standard operating conditions in CANDU reactors range . This calculations were repeated for the CNEA advanced fuel CARA obtaining the same performance as the CANFLEX fuel. (author)

  9. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components and nuclear safety considerations for the workers and the public

  10. Korea signs for 2nd CANDU at Wolsong

    International Nuclear Information System (INIS)

    The sale of a second CANDU 6 reactor to Korea for the Wolsong site is discussed in relation to nuclear power in Korea, the Korean economy generally, Canadian trade with Korea, and cooperation between AECL and KAERI

  11. Manufacturing opportunities in the Canadian CANDU and heavy water programs

    International Nuclear Information System (INIS)

    The volume of business available to Canadian manufacturers of CANDU power plant and heavy water plant components is analyzed over about the next 10 years. Implications of exported nuclear technology and plants are explored. (E.C.B.)

  12. Nuclear power as a regional energy supply

    International Nuclear Information System (INIS)

    The author describes the Point Lepreau nuclear power plant and its impact on the electric power grid and the economy of the small province of New Brunswick. The 600 MW CANDU reactor is considered suitable for small operations and has an excellent world record. Although nuclear energy has high capital costs, its fuel costs are low, thus rendering it comparatively inflation free. Its fuel costs of 3 to 4 mills are contrasted with 40 mills for oil-fuelled units. The cost advantage of uranium over coal and oil permits New Brunswick to put aside funds for waste management and decommissioning. Regulatory streamlining is needed to reduce both expense and time of construction. The CANDU system is ideally suited to providing base load, with coal as an intermediate load supply and hydro for peaking. There is room for tidal power as a future part of the mix

  13. Simulation-based reactor control design methodology for CANDU 9

    Energy Technology Data Exchange (ETDEWEB)

    Kattan, M.K.; MacBeth, M.J. [Atomic Energy of Canada Limited, Saskatoon, Saskatchewan (Canada); Chan, W.F.; Lam, K.Y. [Cassiopeia Technologies Inc., Toronto, Ontario (Canada)

    1996-07-01

    The next generation of CANDU nuclear power plant being designed by AECL is the 900 MWe CANDU 9 station. This design is based upon the Darlington CANDU nuclear power plant located in Ontario which is among the world leading nuclear power stations for highest capacity factor with the lowest operation, maintenance and administration costs in North America. Canadian-designed CANDU pressurized heavy water nuclear reactors have traditionally been world leaders in electrical power generation capacity performance. This paper introduces the CANDU 9 design initiative to use plant simulation during the design stage of the plant distributed control system (DCS), plant display system (PDS) and the control centre panels. This paper also introduces some details of the CANDU 9 DCS reactor regulating system (RRS) control application, a typical DCS partition configuration, and the interfacing of some of the software design processes that are being followed from conceptual design to final integrated design validation. A description is given of the reactor model developed specifically for use in the simulator. The CANDU 9 reactor model is a synthesis of 14 micro point-kinetic reactor models to facilitate 14 liquid zone controllers for bulk power error control, as well as zone flux tilt control. (author)

  14. Applicability of Operational Research Techniques in CANDU Nuclear Plant Maintenance

    International Nuclear Information System (INIS)

    As previously reported at ICONE 6 in New Orleans, 1996, and ICONE 9 in Niece, 2001, the use of various maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. Innovative practices included greatly reducing Reliability Centered Maintenance (RCM) costs while maintaining the accuracy of the analysis. The optimization strategy has undergone further evolution and at the present an Integrated Maintenance Program (IMP) is being put in place. Further cost refinement of the station preventive maintenance strategy whereby decisions are based on statistical analysis of historical failure data is being evaluated. A wide range of Operational Research (OR) literature was reviewed for implementation issues and several encouraging areas were found that will assist in the current effort of evaluating maintenance optimization techniques for nuclear power production. The road ahead is expected to consist first of resolving 25 years of data issues and preserving the data via appropriate knowledge system techniques while post war demographics permit experts to input into the system. Subsequent analytical techniques will emphasize total simplicity to obtain the requisite buy in from Corporate Executives who possibly are not trained in Operational Research. Case studies of containment airlock seal failures are used to illustrate the direct applicability of stochastic processes. Airlocks and transfer chambers were chosen as they have long been known as high maintenance items. Also, the very significant financial consequences of this type of failure will help to focus the attention of Senior Management on the effort. Despite substantial investment in research, improvement in the design of the seal material or configuration has not been achieved beyond the designs completed in the 1980's. Overall, the study showed excellent agreement of the relatively quick stochastic methods with the maintenance programs produced at

  15. Evolutionary CANDU 9 plant improvements

    International Nuclear Information System (INIS)

    The CANDU 9 is a 935 MW(e) nuclear power plant (NPP) based on the multi-unit Darlington and Bruce B designs with additional enhancements from our ongoing engineering and research programs. Added to the advantages of using proven systems and components, CANDU 9 offers improvement features with enhanced safety, improved operability and maintenance including a control centre with advanced man-machine interface, and improved project delivery in both engineering and construction. The CANDU 9 NPP design incorporated safety enhancements through careful attention to emerging licensing and safety issues. The designers assessed, revised and evolved such systems as the moderator, end shield, containment and emergency core cooling (ECC) systems while providing an integrated final design that is more passive and severe-accident-immune. AECL uses a feedback process to incorporate lessons learned from operating plants, from current projects experiences and from the implementation or construction phase of previous projects. Most of the requirements for design improvements are based on a systematic review of current operating CANDU stations in the areas of design and reliability, operability, and maintainability. The CANDU 9 Control Centre provides plant staff with improved operability and maintainability capabilities due to the combination of systematic design with human factors engineering and enhanced operating and diagnostics features. The use of advanced engineering tools and modem construction methods will reduce project implementation risk on project costs and schedules. (author)

  16. Nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, P.

    1985-01-01

    The question 'Do we really need nuclear power' is tackled within the context of Christian beliefs. First, an estimate is made of the energy requirements in the future and whether it can be got in conventional ways. The dangers of all the ways of supplying energy (eg coal mining, oil and gas production) are considered scientifically. Also the cost of each source and its environmental effects are debated. The consequences of developing a new energy source, as well as the consequences of not developing it, are considered. Decisions must also take into account a belief about the ultimate purpose of life, the relation of men to each other and to nature. Each issue is raised and questions for discussion are posed. On the whole the book comes down in favour of nuclear power.

  17. Overpressure protection requirements for primary heat transport systems in CANDU power reactors fitted with two shutdown systems

    International Nuclear Information System (INIS)

    The overpressure protection requirements of Article NB 7000 of Section III of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) are incorporated in the National Standard of Canada N285.1. These requirements do not, however, refer to a particular nuclear system design. This is recognized in paragraphs NCA-2141 and NB-7120 of the ASME Code which make reference to the requirements of the appropriate regulatory authority for guidance. For CANDU power reactors fitted with two shutdown systems, some guidance is given in the Atomic Energy Control Board (AECB) Regulatory Document R-10, but this does not address overpressure protection as a specific topic and further clarification is required. This document seeks to provide such clarification

  18. Detailed Monte Carlo Evaluation of the Power Coefficient of Reactivity of CANDU Reactor

    International Nuclear Information System (INIS)

    The value of FTC can even be positive due to the 239Pu buildup during the fuel depletion and also the neutron up-scattering by the oxygen atoms in the fuel. Unlike the pressurized light water reactor, CANDU-6 has a positive coolant void reactivity (CVR) and coolant temperature coefficient (CTC). As a result the power coefficient of reactivity (PCR) is known to be slightly positive during full power operation. To improve the inherent stability and the generic safety features, a negative PCR is essential. Due to the small value of the FTC and PCR of CANDU, high-fidelity physics approaches are necessary for the precise estimation of the safety parameters. During the reactor analysis, the asymptotic scattering kernel has been used and neglects the thermal motion of nuclides such as U-238. However, it is well accepted that in a scattering reaction, the thermal movement of the target can affect the scattering reaction in the vicinity of scattering resonance and enhance neutron capture by the capture resonance. Some recent works have revealed that the thermal motion of U-238 affects the scattering reaction and that the resulting Doppler broadening of the scattering resonance enhances the FTC of the thermal reactor including PWRs by 10-15%. In order to observe the impacts of the Doppler broadening of the scattering resonances on the criticality and FTC, a recent investigation was done for a clean and fresh CANDU fuel lattice using Monte Carlo code MCNPX for analysis. In ref. 3 the so-called DBRC (Doppler Broadened Rejection Correction) method was adopted to consider the thermal movement of U-238. In this study, the safety parameter of CANDU-6 is re-evaluated by using the continuous energy Monte Carlo code SERPENT 2 which uses the DBRC method to simulate the thermal motion of U-238. The analysis is performed for a full 3-D CANDU-6 core and the PCR is evaluated near equilibrium burnup. For a high-fidelity Monte Carlo calculation, an extremely large number of neutron

  19. Long-Term Trends in Radionuclide Distribution in the Vicinity of a CANDU Nuclear Generating Station

    International Nuclear Information System (INIS)

    The Point Lepreau monitoring programme was established in 1978 to assess the environmental impact of radioactive, thermal and chemical releases from the Point Lepreau Nuclear Generating Station (NGS), a 600 MW CANDU reactor, located on the Bay of Fundy in eastern Canada. The programme was designed on a mass-balance approach whereby measurements of radionuclides on samples from the major environmental reservoirs (sea water, fresh water, sediments and marine, terrestrial and aquatic flora and fauna and atmospheric media) would be used to determine contaminant transport rates through different environmental phases. Environmental radioactivity levels measured in the 14 years since the reactor became operational have been compared with pre-operational levels to assess the implications of operating a CANDU nuclear reactor in a coastal region and to determine the critical parameters governing the long-term transport of radionuclides through the environment. Tritium is routinely measured in the marine, terrestrial and atmospheric components of the programme and has become a useful tool in assessing local meteorological influences on atmospheric radionuclide distributions. The environmental monitoring programme has provided an important and timely perspective on environmental radionuclide transport through eastern Canada from globally significant phenomena such as nuclear weapons fallout and the 1986 Chernobyl accident, thereby illustrating the potential advantages inherent in cost-effective, long-term environmental surveillance programmes. (author)

  20. Research on the separation of hydrogen isotopes from liquid wastes from CANDU nuclear reactors

    International Nuclear Information System (INIS)

    The separation of hydrogen isotopes is very important in operation of CANDU nuclear reactors fueled with natural uranium. This paper refers to separation of tritium from liquid wastes from CANDU nuclear reactors. The tritium recovery from wastes is of importance for the following reasons: - the process has a high nuclear yield; - it contributes to the radioprotection of operation personnel and environment. The separation has been carried out through isotope exchange process between hydrogen and liquid water using metal/support catalysts. Pt/SDB/PS were used as catalysts. The experiments were performed under the following conditions: - radioactive concentration of tritiated heavy water, 4.34 mCi/ml; - pressure, 1 atm; - temperature of exchange column, 26-33 deg. C; - deuterium concentration, 10 % D/(D+H); - migration speed through catalytic bed, 0.02-0.34 m/s; - contact time: 0.22-7.2 s. The experiments have showed the catalytic efficiency of Pt/SDB/PS for both deuterium exchange and tritium exchange. The results showed that the deuterium exchange is faster than that of tritium and that, due to the high catalytic efficiency of the catalyst used, it is particularly adequate for tritium separation from liquid wastes. (authors)

  1. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on worker and public safety, operating performance and costs, and reliability of system components

  2. Candu fuel and fuel cycles

    International Nuclear Information System (INIS)

    A primary rationale for Indonesia to proceed with a nuclear power program is to diversity its energy sources and achieve freedom from future resource constraints. While other considerations, such as economy of power supply, hedging against potential future increases in the price of fossil fuels, fostering the technological development of the Indonesia economy and minimizing greenhouse and other gaseous emissions are important, the strategic resource issue is key. In considering candidate nuclear power technologies upon which to base such a program, a major consideration will be the potential for those technologies to be economically sustained in the face of large future increases in demand for nuclear fuels. The technology or technologies selected should be amenable to evaluation in a rapidly changing technical, economic, resource and environmental policy. The world's proven uranium resources which can be economically recovered represent a fairly modest energy resource if utilization is based on the currently commercialized fuel cycles, even with the use of recovered plutonium in mixed oxide fuels. In the long term, fuel cycles relying solely on the use of light water reactors will encounter increasing fuel supply constraints. Because of its outstanding neutron economy and the flexibility of on-power refueling, CANDU reactors are the most fuel resource efficient commercial reactors and offer the potential for accommodating an almost unlimited variety of advanced and even more fuel efficient cycles. Most of these cycles utilize nuclear fuels which are too low grade to be used in light water reactors, including many products now considered to be waste, such as spent light water reactor fuel and reprocessing products such as recovered uranium. The fuel-cycle flexibility of the CANDU reactor provides a ready path to sustainable energy development in both the short and the long terms. Most of the potential CANDU fuel cycle developments can be accommodated in existing

  3. Public health risks associated with the CANDU nuclear fuel cycle

    International Nuclear Information System (INIS)

    This report has been prepared in the hope that it will calculate, apparently for the first time, the non-radiological risks associated with the use of nuclear fuels. The specific risks identified and evaluated in this work should be balanced against the benefits resulting from the use of nuclear fuels or against the risks inherent in other fuels. Due to lack of sufficient data in certain areas the results obtained are subject to a large degree of uncertainty and therefore the results indicate an order of magnitude rather than exact values of hazard. The total hazard can be expressed as 6.0 ± 4.8 x 10-3 fatalities and 4.8 ± 0.7 x l0-2 injuries per 1 GWy of electricity produced

  4. Nuclear power and durable development

    International Nuclear Information System (INIS)

    This paper highlights the role that the nuclear power can play in a durable development of society. From a comparative analysis of different energy sources capable to fulfil the national energy demand it turns out that for Romania the optimal alternative is nuclear power. The nuclear power proved its attributes and characteristics in ensuring durable development by: 1. the technological maturation of the CANDU system as demonstrated by the good functioning of Cernavoda NPP Unit 1; 2. optimal utilization of the uranium national resources as well as the mining industry; 3. uranium processing and nuclear fuel and heavy water manufacturing as entailed by an educational infrastructure, research and industrial development; 4. low environmental impact; 5. high professional skill of the nuclear personnel. In addition, the low cost of the energy produced by the nuclear sector, as well as the social effects, namely, a 100% utilization of industrial infrastructure and national research capacity, urges the decision makers to develop the Cernavoda NPP, to increase the weight of nuclear energy in the energy production of the country

  5. Nuclear power and hydrogen

    International Nuclear Information System (INIS)

    Ontario has been using CANDU reactors to produce electricity since 1962. The province does not have an electricity shortage, but it does have a shortage of liquid fuels. The government of Ontario is encouraging research into the production of hydrogen using electricity generated by a dedicated nuclear plant, and the safe and economical use of hydrogen both in the production of synthetic petroleum fuels and as a fuel in its own right

  6. Nuclear power data 2016

    International Nuclear Information System (INIS)

    The brochure on nuclear power data 2016 covers the following topics: (I) nuclear power in Germany: nuclear power plants in Germany; shut-down and decommissioned nuclear power plants, gross electricity generation, primary energy consumption; (II) nuclear power worldwide: nuclear electricity production, nuclear power plants.

  7. The CANDU 6

    International Nuclear Information System (INIS)

    The CANDU 6 is a modem nuclear power plant designed and developed under the aegis of Atomic Energy of Canada, Limited (AECL) for domestic use and for export to other countries. This design has successfully met criteria for operation and redundant safety features required by Canada and by the International Atomic Energy Agency (IAEA) and has an estimable record of performance in all applications to date. Key to this success is a defined program of design enhancement in which changes are made while retaining fundamental features proven by operating experience. Basic design features and progress toward improvements are presented here. (author)

  8. Some aspects on security and safety in a potential transport of a CANDU spent nuclear fuel bundle, in Romania

    International Nuclear Information System (INIS)

    Each Member States (MS) is responsible for the security and safety of radioactive material during transport, since radioactive material is most vulnerable during transport. The paper presents some aspects on security and safety related to the potential transport of a CANDU Spent Nuclear Fuel (SNF) bundle from NPP CANDU Cernavoda to INR Pitesti. The possible environmental impact and radiological consequences following a potential event during transportation is analyzed, since the protection of the people and the environment is the essential goal to be achieved. Some testing for the package to be used for transportation will be also given. (author)

  9. Some aspects on security and safety in a potential transport of a CANDU spent nuclear fuel bundle, in Romania

    Energy Technology Data Exchange (ETDEWEB)

    Vieru, G., E-mail: gheorghe.vieru@nuclear.ro [Inst. for Nuclear Research, Pitesti (Romania)

    2010-07-01

    Each Member States (MS) is responsible for the security and safety of radioactive material during transport, since radioactive material is most vulnerable during transport. The paper presents some aspects on security and safety related to the potential transport of a CANDU Spent Nuclear Fuel (SNF) bundle from NPP CANDU Cernavoda to INR Pitesti. The possible environmental impact and radiological consequences following a potential event during transportation is analyzed, since the protection of the people and the environment is the essential goal to be achieved. Some testing for the package to be used for transportation will be also given. (author)

  10. Nuclear power. 2010 world report. Evaluation

    International Nuclear Information System (INIS)

    At the end of 2010, 443 nuclear power plants were available for power supply in 30 countries, 6 plants more than in 2009. Seven units were commissioned for the first time, 1 nuclear power plant was decommissioned for good in 2010. At a cumulated gross power of 396,126 MWe and a cumulated net power of 375,947 MWe, respectively, worldwide nuclear generating capacity has reached a high level. Nine different reactor lines are operated in commercial plants: PWR, PWR-VVER, BWR, CANDU, D2O PWR, GCR, AGR, LWGR, and LMFBR. Light water reactors (PWR and BWR) continue to top the list with 361 plants. By the end of 2010, in 15 countries 64 nuclear power plants with an aggregate gross power of 65,110 MWe and an aggregate net power of 61,097 MWe were under construction. Of these, 58 are light water reactors, 2 are CANDU-type reactors, 3 are fast breeder and 1 D2O-PWR. 128 commercial reactors with a power in excess of 5 MWe have so far been decommissioned in 19 countries. Most of them are prototype plants of low power. About 70% of the nuclear power plants in operation, namely 304 plants, were commissioned in the 1980ies and 1990ies. The energy availability and operating availability factors of the nuclear power plants reached good levels: 80.20% for operating availability. Finland with its' four nuclear power plants continues to be in the lead worldwide with a cumulated average operating capacity factor of 91,51%. (orig.)

  11. Power pulse tests on CANDU type fuel elements in TRIGA reactor of INR Pitesti

    International Nuclear Information System (INIS)

    Pulse irradiation tests on short fuel elements have been carried out in TRIGA Annular Core Pulse Reactor (TRIGA ACPR) of INR Pitesti to investigate aspects related to the thermal and mechanical behavior of CANDU type fuel elements under short duration and large amplitude power pulse conditions. Short test fuel elements were instrumented with thermocouples for cladding surface temperature measurements and pressure sensor for element internal pressure measurement. Transient histories of reactor power, cooling water pressure, fuel element internal pressure and cladding temperature were recorded during tests. The fuel elements were subjected to total energy deposition from 70 to 280cal g-1 UO2. Rapid fuel pellet expansion due to a power excursion caused radial and longitudinal deformation of the cladding. Cladding failure mechanism and the failure threshold have been established. This paper presents some recent results obtained from these power pulse tests performed in TRIGA ACPR of INR Pitesti. (author)

  12. Behavior of CANDU fuel under power pulse conditions at the TRIGA reactor of INR Pitesti

    International Nuclear Information System (INIS)

    Pulse irradiation tests on short fuel elements have been carried out in TRIGA Annular Core Pulse Reactor (TRIGA ACPR) of INR Pitesti to investigate aspects related to the thermal and mechanical behavior of CANDU type fuel elements under short duration and large amplitude power pulse conditions. Short test fuel elements were instrumented with thermocouples for cladding surface temperature measurements and pressure sensors for element internal pressure measurement. Transient histories of reactor power, cooling water pressure, fuel element internal pressure and cladding temperature were recorded during tests. The fuel elements were subjected to total energy deposition from 70 to 280 cal g-1 UO2. Rapid fuel pellet expansion due to a power excursion caused radial and longitudinal deformation of the cladding. Cladding failure mechanism and the failure threshold have been established. This paper presents some recent results obtained from these power pulse tests performed in TRIGA ACPR of INR Pitesti. (orig.)

  13. Behavior of CANDU fuel under power pulse conditions at the TRIGA reactor of INR Pitesti

    Energy Technology Data Exchange (ETDEWEB)

    Horhoianu, G.; Dobrea, D.; Parvan, M.; Stefan, V. [Institute for Nuclear Research, Pitesti (Romania)

    2009-04-15

    Pulse irradiation tests on short fuel elements have been carried out in TRIGA Annular Core Pulse Reactor (TRIGA ACPR) of INR Pitesti to investigate aspects related to the thermal and mechanical behavior of CANDU type fuel elements under short duration and large amplitude power pulse conditions. Short test fuel elements were instrumented with thermocouples for cladding surface temperature measurements and pressure sensors for element internal pressure measurement. Transient histories of reactor power, cooling water pressure, fuel element internal pressure and cladding temperature were recorded during tests. The fuel elements were subjected to total energy deposition from 70 to 280 cal g{sup -1} UO{sub 2}. Rapid fuel pellet expansion due to a power excursion caused radial and longitudinal deformation of the cladding. Cladding failure mechanism and the failure threshold have been established. This paper presents some recent results obtained from these power pulse tests performed in TRIGA ACPR of INR Pitesti. (orig.)

  14. Power pulse tests on CANDU type fuel elements in TRIGA reactor of INR Pitesti

    Energy Technology Data Exchange (ETDEWEB)

    Horhoianu, G.; Ionescu, D.; Olteanu, G. [Inst. for Nuclear Research, Pitesti (Romania)

    2008-07-01

    Pulse irradiation tests on short fuel elements have been carried out in TRIGA Annular Core Pulse Reactor (TRIGA ACPR) of INR Pitesti to investigate aspects related to the thermal and mechanical behavior of CANDU type fuel elements under short duration and large amplitude power pulse conditions. Short test fuel elements were instrumented with thermocouples for cladding surface temperature measurements and pressure sensor for element internal pressure measurement. Transient histories of reactor power, cooling water pressure, fuel element internal pressure and cladding temperature were recorded during tests. The fuel elements were subjected to total energy deposition from 70 to 280cal g{sup -1} UO{sub 2}. Rapid fuel pellet expansion due to a power excursion caused radial and longitudinal deformation of the cladding. Cladding failure mechanism and the failure threshold have been established. This paper presents some recent results obtained from these power pulse tests performed in TRIGA ACPR of INR Pitesti. (author)

  15. CANDU steam generator life management

    International Nuclear Information System (INIS)

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in PWRs. Canadian Deuterium Uranium (CANDU trademark) steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have resulted in a decrease in steam generator-related station unavailability of Canadian CANDU reactors. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development (R and D) work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermalhydraulics, fouling, inspection and cleaning, as well as provision for speciality tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service (FFS) guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. This paper will also show how recent advances in cleaning technology are integrated into a life management strategy. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New steam generator designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce-A/B, Pickering-A/B) and strategic plans to ensure that good future operation is ensured. (orig.)

  16. Technology transfer: The CANDU approach

    International Nuclear Information System (INIS)

    The many and diverse technologies necessary for the design, construction licensing and operation of a nuclear power plant can be efficiently assimilated by a recipient country through an effective technology transfer program supported by the firm long term commitment of both the recipient country organizations and the supplier. AECL's experience with nuclear related technology transfer spans four decades and includes the construction and operation of CANDU plants in five countries and four continents. A sixth country will be added to this list with the start of construction of two CANDU 6 plants in China in early 1997. This background provides the basis for addressing the key factors in the successful transfer of nuclear technology, providing insights into the lessons learned and introducing a framework for success. This paper provides an overview of AECL experience relative to the important factors influencing technology transfer, and reviews specific country experiences. (author)

  17. Nuclear power and nuclear weapons

    International Nuclear Information System (INIS)

    The proliferation of nuclear weapons and the expanded use of nuclear energy for the production of electricity and other peaceful uses are compared. The difference in technologies associated with nuclear weapons and nuclear power plants are described

  18. Nuclear power plants

    International Nuclear Information System (INIS)

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

  19. Comparative Analysis of Thermohydraulic Margins in Embalse Power Station, CARA Vs. CANDU with Cobra IV-HW

    International Nuclear Information System (INIS)

    Comparative analysis of thermohydraulic margins were studied of the CANDU 37 and CARA fuel bundles (FB) in Embalse power station with COBRA IV-HW code ., the geometry of the bundle laying on the channel was particularly modeled and discussing the results in comparison with former calculations with 1/6 simetry .The CARA design with enriched uranium (0.9 %) and extended burn up lets maintain the current thermohydraulic nominal margins , while compared with CANDU 37 rods FB enriched , the CARA design permits widely improve the current margins

  20. The evolution of the CANDU energy system - ready for Europe's energy future

    International Nuclear Information System (INIS)

    As air quality and climate change issues receive increasing attention, the opportunity for nuclear to play a larger role in the coming decades also increases. The good performance of the current fleet of nuclear plants is crucial evidence of nuclear's potential. The excellent record of Cernavoda-1 is an important part of this, and demonstrates the maturity of the Romanian program and of the CANDU design approach. However, the emerging energy market also presents a stringent economic challenge. Current NPP designs, while established as reliable electricity producers, are seen as limited by high capital costs. In some cases, the response to the economic challenge is to consider radical changes to new design concepts, with attendant development risks from lack of provenness. Because of the flexibility of the CANDU system, it is possible to significantly extend the mid-size CANDU design, creating a Next Generation product, without sacrificing the extensive design, delivery and operations information base for CANDU. This enables a design with superior safety characteristics while at the same time meeting the economic challenge of emerging markets. The Romanian nuclear program has progressed successfully forward, leading to the successful operation of Cernavoda-1, and the project to bring Cernavoda-2 to commercial operation. The Romanian nuclear industry has become a full-fledged member of the CANDU community, with all areas of nuclear technology well established and benefiting from international cooperation with other CANDU organizations. AECL is an active partner with Romanian nuclear organizations, both through cooperative development programs, commercial contracts, and also through the activities of the CANDU owners' Group (COG). The Cernavoda project is part of the CANDU 6 family of nuclear power plants developed by AECL. The modular fuel channel reactor concept can be modified extensively, through a series of incremental changes, to improve economics, safety

  1. Optimization of the self-sufficient thorium fuel cycle for CANDU power reactors

    Directory of Open Access Journals (Sweden)

    Bergelson Boris R.

    2008-01-01

    Full Text Available The results of optimization calculations for CANDU reactors operating in the thorium cycle are presented in this paper. Calculations were performed to validate the feasibility of operating a heavy-water thermal neutron power reactor in a self-sufficient thorium cycle. Two modes of operation were considered in the paper: the mode of preliminary accumulation of 233U in the reactor itself and the mode of operation in a self-sufficient cycle. For the mode of accumulation of 233U, it was assumed that enriched uranium or plutonium was used as additional fissile material to provide neutrons for 233U production. In the self-sufficient mode of operation, the mass and isotopic composition of heavy nuclei unloaded from the reactor should provide (after the removal of fission products the value of the multiplication factor of the cell in the following cycle K>1. Additionally, the task was to determine the geometry and composition of the cell for an acceptable burn up of 233U. The results obtained demonstrate that the realization of a self-sufficient thorium mode for a CANDU reactor is possible without using new technologies. The main features of the reactor ensuring a self-sufficient mode of operation are a good neutron balance and moving of fuel through the active core.

  2. CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU (CANada Deuterium Uranium) Pressurized Heavy Water (PHW) type of nuclear-electric generating station was developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This paper summarizes Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components, and nuclear safety considerations to both the workers and the public

  3. General overview of CANDU advanced fuel cycles program

    International Nuclear Information System (INIS)

    The R and D program for CANDU advanced fuel cycles may be roughly divided into two components which have a near-and long-term focus, respectively. The near-term focus is on the technology to implement improved once-through cycles and mixed oxide (plutonium-uranium oxides) recycle in CANDU and on technologies to separate zirconium isotopes. Included is work on those technologies which would allow a CANDU-LWR strategy to be developed in a growing nuclear power system. For the longer-term, activities are focused on those technologies and fuel cycles which would be appropriate in a period when nuclear fuel demand significantly exceeds mined uranium supplies. Fuel cycles and systems under study are thorium recycle, CANDU fast breeder systems and electro-nuclear fissile breeders. The paper will discuss the rationale underlying these activities, together with a brief description of activities currently under way in each of the fuel cycle technology areas

  4. Decrease of the CANDU spent nuclear waste inventories in fusion-fission (hybrid) reactors

    International Nuclear Information System (INIS)

    The possibility of spent nuclear fuel rejuvenation in fusion reactors is investigated for both (D,T) and catalyzed (D,D) modes. The analysis is conducted for a CANDU spent nuclear fuel which was used up to a total enrichment grade of 0.418%. The behavior of the spent fuel is observed during 48 months for discrete time intervals of Δt = 6 months. The cooling of the fissile fuel zone is considered with three different coolants, notably gas (preferably He), Flibe (Li2BeF4) and natural lithium. A rejuvenation period of 8 months is evaluated for a final fissile fuel enrichment grade of 1% for all coolant types in the fissile zone under a first-wall fusion neutron current load of 1,014 (2.45-MeV n/cm2.s) and 1,014 (14.1-MeV n/cm2.x), corresponding to 2.64 MW/m2 by a plant factor of 75% for the catalyzed (D,D) fusion reactor mode. The rejuvenation period increases to 12 months for the same fissile fuel enrichment grade using the (D,T) fusion reactor mode under a first-wall fusion neutron current load of 1,014 (2.45-MeV n/cm2.s), corresponding to 2.25 MW/m2 by a plant factor of 75%. This enrichment would be sufficient for a re-utilization in a CANDU reactor

  5. LOCA power pulse analysis for CANDU-6 CANFLEX-RU core

    International Nuclear Information System (INIS)

    The power pulses following a large LOCA are analyzed for CANDU-6 reactor core fuelled with CANFLEX-RU fuel. The coupled simulations for reactor physics and channel thermal-hydraulic phenomena are done using RFSP and CATHENA codes. The 55% pump suction, 35% reactor inlet header and 100% reactor outlet header breaks are selected. The highest power pulse is predicted for 100% reactor outlet header break and it is higher than that for the standard 37-element natural fuel. However, the summation of initial stored energy and transient pulse energy of hottest pin has the minimum 17% margin to the fuel break up. Therefore, it is expected that there is no fuel breakup during the LOCA for CANFLEX-RU core

  6. CANDU safety and licensing framework and process

    International Nuclear Information System (INIS)

    Nuclear Safety is a shared responsibility of the Industry, public and the Government. The International Atomic Energy Agency's (IAEA) safety fundamentals, basic objectives and safety guides lay down the principles from which requirements, recommendations and methodologies for safety design of Nuclear Power Plants (NPP) are derived. Within the framework of the international regulations and those of the Canadian Nuclear Safety Commission (CNSC), this paper will discuss the overall safety objectives, the defence in depth philosophy guiding CANDU safety, as well as the licensing process defined to meet all applicable CNSC regulations. The application of such philosophy to the ACR design and safety approach will also be discussed along with aspects of its implementation. The role of deterministic analysis, and Probabilistic Safety Analysis (PSA) in the design and licensing process of the Advanced CANDU Reactor will be discussed. Postulated initiating events and their combinations, acceptance criteria, CANDU margins and limits, supporting methodologies and computer codes used in safety analysis will be reviewed. The paper will also note intrinsic safety characteristics of CANDU, some of the ACR passive safety features built-in by design, CANDU distinctive features with respect to severe core damage, mechanisms of heat rejection in those extreme conditions, emergency coolant injection system features and other post accident mitigating systems. Update on the ACR Canadian and US licensing progress will also be provided. (authors)

  7. A study to develop the domestic functional requirements of the specific safety systems of CANDU

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Woong; Lee, Jae Young; Bang, Kwang Hyun [Handong Global Univ., Pohang (Korea, Republic of)] (and others)

    2001-03-15

    The present research has been made to develop and review critically the functional requirements of the specific safety systems of CANDU such as SOS-1, SOS-2, ECCS and containment. Based on R documents for this, a systematic study was made to develop the domestic regulation statements. Also, the conventional laws are carefully reviewed to see the compatibility to CANDU. Also, the safety assessment method for CANDU was studied by reviewing C documents and recommendation of IAEA. Through the present works, the vague policy in the CANDU safety regulation is cleaning up in a systematic form and a new frame to measure the objective risk of nuclear power plants was developed.

  8. New nuclear power plants for Ontario

    International Nuclear Information System (INIS)

    Towards the end of this year the Ontario government will select the technology for its future nuclear power plants. To clarify the differences between the contending reactors I have put together the following quick overview. Ontario's requirement is for a stand-alone two-unit nuclear power plant to provide around 2,000 to 3,500 MWe of baseload generating capacity at a site to he specified with an option for one or two additional units. It is likely that the first units will be located at either the Darlington site near Bowmanville or the Bruce site near Kincardine. However the output from the Bruce site is presently transmission constrained. All nuclear-electric generation in Ontario comes from Atomic Energy of Canada Limited's (AECL) CANDU reactors at Pickering, Darlington and Bruce. The contenders are, AECL's 1085 MWe (net) ACR-1000 (Advanced CANDU Reactor), Westinghouse Electric Company's 1117 MWe (net) AP1000 (Advanced Passive), AREVA NP's 1600 MWe (net) U.S. EPR (United States Evolutionary Pressurized Reactor) and the 1550 MWe (net) GE Hitachi Nuclear Energy's ESBWR (Economic and Simplified Boiling Water Reactor). Westinghouse has Toshiba as a majority shareholder, AREVA has the government of France as a majority shareholder and GE-Hitachi has GE as the major shareholder. AECL is a federal crown corporation and is part of Team CANDU consisting of Babcock and Wilcox Canada, GE-Hitachi Nuclear Energy Canada Inc., Hitachi Canada Limited and SNC-Lavalin Nuclear Inc. Generally the engineering split in Team CANDU would be, AECL, Mississauga, Ontario, responsible for the design of the nuclear steam plant including reactor and safety systems; Babcock and Wilcox Canada, Cambridge, Ontario, responsible for supply of the steam generators and other pressure retaining components; GE-Hitachi Nuclear Energy Canada Inc., Peterborough, Ontario for the fuel handling equipment; Hitachi Canada Limited, Mississauga, for the balance of plant steam to electricity conversion

  9. Candu 6: versatile and practical fuel technology

    International Nuclear Information System (INIS)

    CANDU reactor technology was originally developed in Canada as part of the original introduction of peaceful nuclear power in the 1960s and has been continuously evolving and improving ever since. The CANDU reactor system was defined with a requirement to be able to efficiently use natural uranium (NU) without the need for enrichment. This led to the adaptation of the pressure tube approach with heavy water coolant and moderator together with on-power fuelling, all of which contribute to excellent neutron efficiency. Since the beginning, CANDU reactors have used [NU] fuel as the fundamental basis of the design. The standard [NU] fuel bundle for CANDU is a very simple design and the simplicity of the fuel design adds to the cost effectiveness of CANDU fuelling because the fuel is relatively straightforward to manufacture and use. These characteristics -- excellent neutron efficiency and simple, readily-manufactured fuel -- together lead to the unique adaptability of CANDU to alternate fuel types, and advancements in fuel cycles. Europe has been an early pioneer in nuclear power; and over the years has accumulated various waste products from reactor fuelling and fuel reprocessing, all being stored safely but which with passing time and ever increasing stockpiles will become issues for both governments and utilities. Several European countries have also pioneered in fuel reprocessing and recycling (UK, France, Russia) in what can be viewed as a good neighbor policy to make most efficient use of fuel. The fact remains that CANDU is the most fuel efficient thermal reactor available today [NU] more efficient in MW per ton of U compared to LWR's and these same features of CANDU (on-power fuelling, D2O, etc) also enable flexibility to adapt to other fuel cycles, particularly recycling. Many years of research (including at ICN Pitesti) have shown CANDU capability: best at Thorium utilization; can use RU without re-enrichment; can readily use MOX. Our premise is that

  10. Korean experiences on nuclear power technology

    International Nuclear Information System (INIS)

    This paper describes the outstanding performance of the indigenous development program of nuclear power technology such as the design and fabrication of both CANDU and PWR fuel and in the design and construction of nuclear steam supply system in Korea. The success has been accomplished through the successful technology transfer from foreign suppliers and efficient utilization of R and D manpower in the design and engineering of nuclear power projects. In order to implement the technology transfer successfully, the joint design concept has been introduced along with effective on-the-job training and the transfer of design documents and computer codes. Korea's successful development of nuclear power program has resulted in rapid expansion of nuclear power generation capacity in a short time, and the nuclear power has contributed to the national economy through lowering electricity price by about 50 % as well as stabilizing electricity supply in 1980s. The nuclear power is expected to play a key role in the future electricity supply in Korea. Now Korea is under way of taking a step toward advanced nuclear technology. The national electricity system expansion plan includes 18 more units of NPPs to be constructed by the year 2006. In this circumstance, the country has fixed the national long-term nuclear R and D program (lgg2-2001) to enhance the national capability of nuclear technology. This paper also briefly describes future prospects of nuclear technology development program in Korea

  11. ACR-1000TM - advanced Candu reactor design

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Limited (AECL) has developed the Advanced CANDU ReactorTM- 1000 (ACR-1000TM) as an evolutionary advancement of the current CANDU 6TM reactor. This evolutionary advancement is based on AECL's in-depth knowledge of CANDU structures, systems, components and materials, gained during 50 years of continuous construction, engineering and commissioning, as well as on the experience and feedback received from operators of CANDU plants. The ACR design retains the proven strengths and features of CANDU reactors, while incorporating innovations and state-of-the-art technology. These innovations improve economics, inherent safety characteristics, and performance, while retaining the proven benefits of the CANDU family of nuclear power plants. The Canadian nuclear reactor design evolution that has reached today's stage represented by the ACR-1000, has a long history dating back to the early 1950's. In this regard, Canada is in a unique situation, shared only by a very few other countries, where original nuclear power technology has been invented and further developed. The ACR design has been reviewed by domestic and international regulatory bodies, and has been given a positive regulatory opinion about its licensability. The Canadian regulator, the Canadian Nuclear Safety Commission (CNSC) completed the Phase 1 and Phase 2 pre-project design reviews in December 2008 and August 2009, respectively, and concluded that there are no fundamental barriers to licensing the ACR-1000 design in Canada. The final stage of the ACR-1000 design is currently underway and will be completed by fall of 2011, along with the final elements of the safety analyses and probabilistic safety analyses supporting the finalized design. The generic Preliminary Safety Analysis Report (PSAR) for the ACR-1000 was completed in September 2009. The PSAR demonstrates ACR-1000 safety case and compliance with Canadian and international regulatory requirements and expectations. (authors)

  12. Qinshan CANDU NPP outage performance improvement through benchmarking

    International Nuclear Information System (INIS)

    With the increasingly fierce competition in the deregulated Energy Market, the optimization of outage duration has become one of the focal points for the Nuclear Power Plant owners around the world. People are seeking various ways to shorten the outage duration of NPP. Great efforts have been made in the Light Water Reactor (LWR) family with the concept of benchmarking and evaluation, which great reduced the outage duration and improved outage performance. The average capacity factor of LWRs has been greatly improved over the last three decades, which now is close to 90%. CANDU (Pressurized Heavy Water Reactor) stations, with its unique feature of on power refueling, of nuclear fuel remaining in the reactor all through the planned outage, have given raise to more stringent safety requirements during planned outage. In addition, the above feature gives more variations to the critical path of planned outage in different station. In order to benchmarking again the best practices in the CANDU stations, Third Qinshan Nuclear Power Company (TQNPC) have initiated the benchmarking program among the CANDU stations aiming to standardize the outage maintenance windows and optimize the outage duration. The initial benchmarking has resulted the optimization of outage duration in Qinshan CANDU NPP and the formulation of its first long-term outage plan. This paper describes the benchmarking works that have been proven to be useful for optimizing outage duration in Qinshan CANDU NPP, and the vision of further optimize the duration with joint effort from the CANDU community. (authors)

  13. CANDU-BLW-250

    International Nuclear Information System (INIS)

    The plant 'La Centrale nucleaire de Gentilly' is located between Montreal and Quebec City on the south shore of the St. Lawrence River and start-up is scheduled for 1971. A CANDU-BLW reactor is the nuclear steam generator. his reactor utilizes a heavy water moderator, natural uranium oxide fuel, and a boiling light water coolant. To be economic, this type of plant must have a minimum light water inventory in the reactor core. A minimum inventory is obtained (a) by reducing the cross-sectional area for coolant flow to a minimum, and (b) by operating at a low-coolant density. In CANDU-BLW-250, this is accomplished by operating a closed spaced fuel rod bundle at high steam quality. These features and others in the BLW concept lead to a number of areas of concern and they are summarized below: (1) Heat Transfer: It is intended that under normal operating conditions the fuel sheaths will always be wetted with coolant. (ii) Hydrodynamic Stability: Experiments and analysis indicate that the plant has a considerable over-power capacity before instability is predicted. (iii) Control: This plant does have a positive power coefficient and the transient performance with various disturbances are detailed. (iv) Safety: The positive power coefficient leads to concern over the loss of coolant accident. The results of some accident analysis are presented. (author)

  14. Seismic design features of the ACR Nuclear Power Plant

    International Nuclear Information System (INIS)

    Through their worldwide operating records, CANDU Nuclear Power Plants (NPPs) have repeatedly demonstrated safe, reliable and competitive performance. Currently, there are fourteen CANDU 6 single unit reactors operating or under construction worldwide. Atomic Energy of Canada Limited's (AECL) Advanced CANDU Reactor - the ACR. - is the genesis of a new generation of technologically advanced reactors founded on the CANDU reactor concept. The ACR is the next step in the evolution of the CANDU product line. The ACR products (ACR-700 and ACR-1000) are based on CANDU 6 (700 MWe class) and CANDU 9 (900 MWe class) reactors, therefore continuing AECL's successful approach of offering CANDU plants that appeal to a broad segment of the power generation market. The ACR products are based on the proven CANDU technology and incorporate advanced design technologies. The ACR NPP seismic design complies with Canadian standards that were specifically developed for nuclear seismic design and also with relevant International Atomic Energy Agency (IAEA) Safety Design Standards and Guides. However, since the ACR is also being offered to several markets with many potential sites and different regulatory environments, there is a need to develop a comprehensive approach for the seismic design input parameters. These input parameters are used in the design of the standard ACR product that is suitable for many sites while also maintaining its economic competitiveness. For this purpose, the ACR standard plant is conservatively qualified for a Design Basis Earthquake (DBE) with a peak horizontal ground acceleration of 0.3g for a wide range of soil/rock foundation conditions and Ground Response Spectra (GRS). These input parameters also address some of the current technical issues such as high frequency content and near field effects. In this paper, the ACR seismic design philosophy and seismic design approach for meeting the safety design requirements are reviewed. Also the seismic design

  15. CANDU-3: Features of next generation CANDU

    International Nuclear Information System (INIS)

    CANDU 3, with a net electrical output of 450 MW, is the latest and smallest version of the CANDU power system. Significant innovation built on proven CANDU reactor technology is the basis of the CANDU 3 design. This, coupled with the commitment to reduce plant cost, increase performance capacity factor, enhance safety features and incorporate technological improvements, makes CANDU 3 an advanced, world class product. This paper describes the following CANDU 3 features: A station layout to provide a flexible construction sequence, good system separation and ease of maintenance and operation. An up-front engineering and licensing process prior to beginning construction. Enhancement and simplification of safety features with extended time scales for response, thus limiting reliance on operator action for accident mitigation. Enhanced design capabilities through the use of the latest Computer Aided Design and Drafting (CADD) technology. A 38 month construction schedule achieved by using modularization and open-top construction and installation techniques. A more passive containment system incorporating a steel liner and eliminating the need for active spray. A grouping and separation philosophy for maximum protection of redundant safety systems. Ease of equipment qualification and maximum protection of critical components. Replacement of centralized control and monitoring computers with a redundant distributed control system and modern plant display system. A consistent, logical approach to control room design founded on human factors, automation and event management. (author). 6 refs, 3 figs

  16. Management of Spent Nuclear Fuel from Nuclear Power Plant Reactor

    International Nuclear Information System (INIS)

    Management of spent nuclear fuel from Nuclear Power Plant (NPP) reactor had been studied to anticipate program of NPP operation in Indonesia. In this paper the quantity of generated spent nuclear fuel (SNF) is predicted based on the national electrical demand, power grade and type of reactor. Data was estimated using Pressurized Water Reactor (PWR) NPP type 1.000 MWe and the SNF management overview base on the experiences of some countries that have NPP. There are four strategy nuclear fuel cycle which can be developed i.e: direct disposal, reprocessing, DUPlC (Direct Use of Spent PWR Fuel In Candu) and wait and see. There are four alternative for SNF management i.e : storage at the reactor building (AR), away from reactor (AFR) using wet centralized storage, dry centralized storage AFR and prepare for reprocessing facility. For the Indonesian case, centralized facility of the wet type is recommended for PWR or BWR spent fuel. (author)

  17. Nuclear power economic database

    International Nuclear Information System (INIS)

    Nuclear power economic database (NPEDB), based on ORACLE V6.0, consists of three parts, i.e., economic data base of nuclear power station, economic data base of nuclear fuel cycle and economic database of nuclear power planning and nuclear environment. Economic database of nuclear power station includes data of general economics, technique, capital cost and benefit, etc. Economic database of nuclear fuel cycle includes data of technique and nuclear fuel price. Economic database of nuclear power planning and nuclear environment includes data of energy history, forecast, energy balance, electric power and energy facilities

  18. Project planning and scheduling techniques for the CANDU programme - an overview

    International Nuclear Information System (INIS)

    The energy crisis and higher costs have imposed the need for tighter control of completion time for the construction of CANDU nuclear power plants. System procedures and techniques to meet this challenge are described

  19. An analysis to determine industry's preferred option for an initial generic reliability database for CANDU

    Energy Technology Data Exchange (ETDEWEB)

    Komljenovic, D. [Hydro Quebec, Montreal, Quebec (Canada)], E-mail: komljenovic.dragan@hydro.qc.ca; Chan, E. [Bruce Power, Tiverton, Ontario (Canada); Ganguli, S. [Ontario Power Generation, Ontario (Canada); Wu, J. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Parmar, R. [Nuclear Safety Solutions Ltd., Toronto, Ontario (Canada)

    2008-07-01

    The paper presents a multi-attribute analysis approach that was used to choose the industry's preferred option in developing a generic reliability database for CANDU. The Risk and Reliability Working Group (sponsored by CANDU Owners Group - Nuclear Safety Committee - COG NSC) was faced with the decision to assess in depth the following four options: a) Use External Data Base Only; b) Full CANDU generic database (All Utilities); c) CANDU Specific plus External Generic Databases; d) Ontario Power Generation (OPG)/ Bruce Power (BP) Experience Only. Nine decision criteria were utilized to rank the proposed options (alternatives). The Analytic Hierarchy Process (AHP) was used in carrying out the ranking process. (author)

  20. Marketing CANDU internationally

    International Nuclear Information System (INIS)

    The market for CANDU reactor sales, both international and domestic, is reviewed. It is reasonable to expect that between five and ten reactors can be sold outside Canada before the end of the centry, and new domestic orders should be forthcoming as well. AECL International has been created to market CANDU, and is working together with the Canadian nuclear industry to promote the reactor and to assemble an attractive package that can be offered abroad. (L.L.)

  1. The CANDU contribution to environmentally friendly energy production

    International Nuclear Information System (INIS)

    National prosperity is based on the availability of affordable, energy supply. However, this need is tempered by a complementary desire that the energy production and utilization will not have a major impact on the environment. The CANDU energy system, including a next generation of CANDU designs, is a major primary energy supply option that can be an important part of an energy mix to meet Canadian needs. CANDU nuclear power plants produce energy in the form of medium pressure steam. The advanced version of the CANDU design can be delivered in unit modules ranging from 400 to 1200 MWe. This Next Generation of CANDU designs features lower cost, coupled with robust safety margins. Normally this steam is used to drive a turbine and produce electricity. However, a fraction of this steam (large or small) may alternatively be used as process steam for industrial consumption. Options for such steam utilization include seawater desalination, oil sands extraction and heating. The electricity may be delivered to an electrical grid or alternatively used to produce quantities of hydrogen. Hydrogen is an ideal clean transportation fuel because its use only produces water. Thus, a combination of CANDU generated electricity and hydrogen distribution for vehicles is an available, cost-effective route to dramatically reduce emissions from the transportation sector. The CANDU energy system contributes to environmental protection and the prevention of climate change because of its very low emission. The CANDU energy system does not produce any NOx, SOx or greenhouse gas (notably CO2) emissions during operation. In addition, the CANDU system operates on a fully closed cycle with all wastes and emissions fully monitored, controlled and managed throughout the entire life cycle of the plant. The CANDU energy system is an environmentally friendly and flexible energy source. It can be an effective component of a total energy supply package, consistent with Canadian and global climate

  2. CANDU steam generator life management

    International Nuclear Information System (INIS)

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermalhydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. The research and development program, as well as operating experience, has identified where improvements in operating practices and/or designs can be made in order to ensure steam generator design life at an acceptable capacity factory. (author)

  3. Nuclear power - anyone interested

    International Nuclear Information System (INIS)

    The subject is discussed under the following headings, with illustrative strip cartoons: uranium mining (uranium exploration in Orkney); radiation (hazards); nuclear power and employment; transport (of radioactive materials); nuclear reactor safety (reference to the accident to Three Mile Island-2 reactor); energy in the future; sources of energy; nuclear weapons; suggestions for action; insulation and heating buildings; nuclear security; working in a nuclear power station; nuclear waste; the anti-nuclear movement; nuclear power and politics. (U.K.)

  4. The post-irradiation examination of CANDU type fuel irradiated in the Institute for Nuclear Research TRIGA Reactor

    International Nuclear Information System (INIS)

    The INR hot cells have 10 years of practice in post-irradiation examination (PIE) on experimental nuclear fuel elements and structure materials. This paper summarises the result of a typical PIE work carried out on an experimental CANDU type fuel element irradiated in an assembly of six rods in a power ramp test in the TRIGA 14 MV (th) materials testing reactor. The fuel element has attained practically a burnup of 188.4 MWh/kg U (10% accuracy) as determined by nondestructive gamma scanning method, and of 194.3 MWh/kg U (3 % accuracy) as determined by destructive mass spectrometry method. These results determined by nondestructive and destructive methods are in agreement. The eddy current control for clad integrity has revealed the integrity of the fuel element, a fact also confirmed by the fuel puncture for internal gas pressure measurement. The metallography control of the cladding has revealed good quality welding and an acceptable quality brazing of a bearing pad. The ceramographic control of the fuel revealed an expected two-zone structure, except one end of the fuel element where a three-zone structure was found, due to the higher thermal rating induced by the flux peak. The results are presented in measurement worksheets and are accompanied by diagrams and pictures. (author)

  5. The future of nuclear power

    International Nuclear Information System (INIS)

    When it was announced in June that France had beaten Japan in the race to host the world's next big fusion lab, the news made headlines around the world. The media reported in generally positive tones how the 10 bn Euro International Thermonuclear Experimental Reactor (ITER) will be the next step on the path to a commercially viable nuclear fusion reactor (Physics World August p5). The coverage was a clear sign of the growing debate surrounding the future of nuclear power. Nuclear Renaissance is a welcome contribution to that debate. The book bills itself as a 'semi-technical overview of modern technologies', which perhaps underplays what the author has achieved. It reviews past, current and prospective nuclear technologies, but links them clearly to the wider topics of energy policy, climate change and energy supply. Apart from being 'semi-technical', the book is also 'semi-British'. Although those sections on technology have a global scope, the lengthy first part - devoted to the 'policy landscape' - is firmly UK in its perspective. It provides a basic description of nuclear power, the economics of nuclear generation, and how nuclear energy could combat climate change. The contribution of nuclear power to a balanced energy supply and its links with weapons proliferation are also discussed. This opening part ends with a chapter on waste management. While the first part of the book could be a stand-alone introduction to nuclear power for layreaders, the second and third parts - on nuclear fission and nuclear fusion - seem to be aimed at a different readership altogether. In particular, they will help students who have some scientific training to understand in more detail how specific types of nuclear technology work. If you want to know how a Westinghouse Advanced Passive Reactor differs from a European Pressurised Water Reactor - or learn the specifics of the Canadian CANDU reactor or the South African pebble-bed modular reactor - then this is for you. Nuttall

  6. Operator companion for CANDU reactors

    International Nuclear Information System (INIS)

    As CANDU nuclear power plants become more complex, and are operated under tighter constraints and for longer periods between outages, plant operations staff will have to absorb more information to correctly and rapidly respond to upsets. A development program is underway at Atomic Energy of Canada Limited to use expert systems and interactive media tools to assist operations staff of existing and future CANDU plants. The complete system for plant information access and display, on-line advice and diagnosis, and interactive operating procedures is called the Operator Companion. A prototype, consisting of operator consoles, expert systems and simulation modules in a distributed architecture, is currently being developed to demonstrate the concepts of the Operator Companion. (author). 5 refs, 2 figs

  7. Fire hazard assessment of Candu plants

    International Nuclear Information System (INIS)

    The requirements for fire protection of CANDU nuclear power plants have evolved from the rule based requirements applied to the early plants to the performance based standards of the 1990's. The current Canadian standard, CAN/CSA N293 (1995), requires a documented fire hazard assessment to be used in the design of fire detection and extinguishing systems. The Fire Hazard Assessment method uses a standard format for all fire zones in the plant to assess the adequacy of the fire protection measures, first applied to the CANDU 6 design at Wolsong 2/3/4. The grouping of safety related systems into two independent and well separated groups was found to have a large positive impact on the ability to maintain safety functions during a fire. The new CANDU 9 design builds on the experience gained from previous designs, with improvements in grouping and separation and fire protection system design. (author)

  8. Diagnostic technology for degradation of feeder pipes and fuel channels in CANDU reactor

    International Nuclear Information System (INIS)

    Degradation of critical components of nuclear power plants has become important as the operating years of plants increase. The necessity of degradation study including detection and monitoring technology has raised its head. Because the feeder pipes and the fuel channels are particularly one of the critical components in CANDU nuclear plant, they are treated as a major research target in order to counteract the possible problems and establish the counterplan for the improvement of CANDU reactor safety. To ensure the integrity of feeder pipes and fuel channels in CANDU nuclear plant, the following 3 research tasks were performed in the first stage. - Development of a model for prediction of feeder wall thinning - Development of RFEC detection technology - Development of ICFD noise signal analysis. The technologies developed in this study could contribute to the nuclear safety and estimation of the remaining life of operating CANDU nuclear power plants

  9. Irradiation device for power cycling testing of CANDU type fuel elements

    International Nuclear Information System (INIS)

    At INR Pitesti an irradiation device (capsule-C9) was designed and realized for testing the fuel element behaviour at reactor power variations occurring during normal operation of CANDU reactors in load following regime. This device allows the study of the phenomena at which the fuel elements in CANDU reactor are subject in conditions of: - normal restarting after shutdown and reactor de-poisoning; - variations of reactor power within 50-100% rated power; - return to rated power after operation at reduced power to prevent xenon poisoning; - restart within 30 minutes from the shutdown to prevent xenon poisoning; - adjusting reactivity during the return to rated power after reactor operation at reduced power; - displacement of fuel clusters in the channel by reactor loading. The power cycling can entail failure mechanisms specific to reactor operation in load following regimes, such as: - deformation of fuel element can by fuel-can interaction; - stress crevice corrosion; - corrosion assisted can fatigue; - can thinning in the vicinity of cracked pellets; - can cracking due to relocation of pellet fragments. Power cycling on the fuel element subjected to irradiation in capsule C-9 is performed by displacing the tested section in the experimental channel. Displacing the tested section under flux allows obtaining the required power values on the tested fuel element while the capsule instrumentation allows the monitoring of irradiation parameters, namely: - the linear power on the fuel element; - instant neutron flux at the force tube level; - coolant pressure within the tested section; - coolant activity; - chemical characteristics of the coolant. The main thermal-hydraulic characteristics of the capsule C-9 are: - working fluid, demineralized and degassed water; - coolant pressure, 120 bar; - coolant temperature, 150-160 deg. C; - maximum temperature on fuel element can, 325 deg. C; - thermosyphon flow rate at the tested section level, 0.15 kg/s; - disposable maximum

  10. Overview of methods to increase dryout power in CANDU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Groeneveld, D.C., E-mail: degroeneveld@gmail.com [Chalk River Laboratories, AECL, Chalk River (Canada); University of Ottawa, Department of Mechanical Engineering, Ottawa (Canada); Leung, L.K.H. [Chalk River Laboratories, AECL, Chalk River (Canada); Park, J.H. [Korean Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-06-15

    Highlights: • Small changes in bundle geometry can have noticeable effects on the bundle CHF. • Rod spacing devices can results in increases of over 200% in CHF. • CHF enhancement decays exponentially downstream from spacers. • CHF-enhancing bundle appendages also increase the post-CHF heat transfer. - Abstract: In CANDU reactors some degradation in the CCP (critical channel power, or power corresponding to the first occurrence of CHF in any fuel channel) will occur with time because of ageing effects such as pressure-tube diametral creep, increase in reactor inlet-header temperature, increased hydraulic resistance of feeders. To compensate for the ageing effects, various options for recovering the loss in CCP are described in this paper. They include: (i) increasing the bundle heated perimeter, (ii) optimizing the bundle configuration, (iii) optimizing core flow and flux distribution, (iv) reducing the bundle hydraulic resistance, (v) use of CHF-enhancing bundle appendages, (vi) more precise experimentation, and (vii) redefining CHF. The increase in CHF power has been quantified based on experiments on full-scale bundles and subchannel code predictions. The application of several of these CHF enhancement principles has been used in the development of the 43-rod CANFLEX bundle.

  11. CANDU 9 safety enhancements and licensability

    International Nuclear Information System (INIS)

    The CANDU 9 design has followed the evolutionary product development approach that has characterized the CANDU family of nuclear power plants. In addition to utilizing proven equipment and systems from operating stations, the CANDU 9 design has looked ahead to incorporate design and safety enhancements necessary to meet evolving utility and regulatory requirements both in Canada and overseas. To demonstrate licensability in Canada, and to assure overseas customers that the design had independent regulatory review in the country of origin, the pre-project Basic Engineering Program included an extensive two year formal review by the Canadian regulatory authority, the Atomic Energy Control Board (AECB). Documentation submitted for this licensing review included the licensing basis, safety requirements and safety analysis necessary to demonstrate compliance with regulations as well as to assess system design and performance. The licensing review was successfully completed in 1997 January. In addition, to facilitate licensability in Korea, CANDU 9 incorporates feedback from the application of Korean licensing requirements to the CANDU 6 reactors at Wolsong site. (author)

  12. A comparative analysis of the linear powers of standard CANDU and SEU - 43 bundles computed by first collision probability procedure on the exact geometry

    International Nuclear Information System (INIS)

    The CP2D code (Constantin et al., 1999) was developed at INR Pitesti in the period 1997-2000. It is an integral transport code, based on the formalism of first collision probabilities. It is able to treat accurately a number of types of problems with complex geometry (as the CANDU cell, the TRIGA or PWR can, the problem of several CANDU bundle vicinity, etc). The idea underlying an exact geometrical treatment is decomposing the problem's geometry into a finite number of factor geometries (simple geometries in which the numerical integration may be carried out on the basis of simple and fast algorithms). The program allows accounting exactly for the individual structure of each fuel element and at the same time treats exactly the problem boundaries. The first CP2D version was developed and tested in 1998 while the next one, CP2D 2.0 was work out in 1999 and has the novelty of introducing supplementary factor geometries, capable of modelling many layer horizontal coolants. This multilayer model is devoted to a more accurate solution of the reactivity of the partial void effect in CANDU reactor. The third version, CP2D 3.0 (2000) embodies also a general burning scheme for evaluation the isotope inventory at the level of each geometrical region described in the input data. This work presents a thorough estimation of the linear powers (at the single pin level) for standard CANDU and SEU - 43 (enriched at 0.96%) bundles. The two types of bundles are comparatively analyzed from this point of view. In CP2D 3.0 the geometry of the two bundle types is treated exactly. To get the neutron cross sections with a 7 group energy cutting the WIMS program and its attached library were used. The results were obtained for fresh fuel and fuel of 6,211, 12,681, 19,150 and 25,621 MWd/tU and 0, 4,000 and 13,000 MWd/tU burnup degree for SEU - 43 bundle and standard bundle, respectively. The single pin linear powers were obtained without appealing to homogenizing supplementary techniques as

  13. Eddy current detection of spacers in the fuel channels of CANDU nuclear reactors

    International Nuclear Information System (INIS)

    Garter Spring (GS) spacers in the fuel channels of CANDU nuclear reactors maintain separation between the hot pressure tube and surrounding moderator cooled calandria tube. Eddy current detection of the four GSs provides assurance that spacers are at or close to design positions and are performing their intended function of maintaining a non-zero gap between pressure tube and calandria tube. Pressure tube constrictions, resulting from relatively less diametral creep at end-of-fuel bundle locations, also produce large eddy current signals. Large constrictions, present in higher service pressure tubes, can produce signals that are 10 times larger than GS signals, reducing GS detectability to 30% in standard GS-detect probes. The introduction of field-focussing elements into the design of the standard GS detection eddy current probe has been used to recover the detectability of GS spacers by increasing the signal amplitude obtained from GSs relative to that from constrictions by a factor of 10. The work presented here compares laboratory, modelling and in-reactor measurements of GS and constriction signals obtained from the standard probe with that obtained from field-focussed eddy current probe designs. (author)

  14. Overview of activities on CANDU fuel in Argentina

    International Nuclear Information System (INIS)

    This paper gives an outline of activities on CANDU fuel in Argentina. It discusses the nuclear activities and electricity production in Argentina, evolution of the activities in fuel engineering, fuel fabrication, fuel performance at Embalse nuclear power plant and spent fuel storage options.

  15. CANDU fuel cycle flexibility

    International Nuclear Information System (INIS)

    High neutron economy, on-power refuelling, and a simple bundle design provide a high degree of flexibility that enables CANDU (Canada Deuterium Uranium; registered trademark) reactors to be fuelled with a wide variety of fuel types. Near-term applications include the use of slightly enriched uranium (SEU), and recovered uranium (RU) from reprocessed spent Light Water Reactor (LWR) fuel. Plutonium and other actinides arising from various sources, including spent LWR fuel, can be accommodated, and weapons-origin plutonium could be destroyed by burning in CANDU. In the DUPIC fuel cycle, a dry processing method would convert spent Pressurized Water Reactor (PWR) fuel to CANDU fuel. The thorium cycle remains of strategic interest in CANDU to ensure long-term resource availability, and would be of specific interest to those countries possessing large thorium reserves, but limited uranium resources. (author). 21 refs

  16. The licensing process of the design modifications of Cernavoda 2 NPP resulting from the operating experience of CANDU plants

    International Nuclear Information System (INIS)

    The CANDU 6 plant now under construction in Cernavoda include over two hundred significant improvements made in order to comply with current codes and standards and licensing requirements relative to the operating CANDU 6 in Romania. These evolutionary improvements are incorporated in CANDU 6 design taking advance of CANDU operating experience, of the designer company research and development and technical advances worldwide in order to further enhance safety, reliability and economics. This paper gives a general idea of the evaluation of the modifications of the Cernavoda 2 nuclear power plant against the design of Cernavoda 1 and states the safety principles and requirements which are the basis for this evaluation. (author)

  17. Replacement of CANDU reactivity Control Devices

    International Nuclear Information System (INIS)

    Ontario Hydro operates 20 AECL designed CANDU nuclear power reactors, some of which have been in service for 20 years. These pressurized heavy water, natural uranium fuelled reactors, ranging in size from 540 to 900 MWe, have continuously provided high capacity factors and low total electricity production costs, among the world's leaders in performance. CANDU's inherently have large cores and utilize a large number of diverse types of Reactivity Control Devices (RCDs) for fully automatic, continuous measurement and regulation of bulk power level as well as spatial uniformity of fission power in the core. The devices also control start-up and power manoeuvering. Other RCDs provide two independent systems of measurement and neutron absorber insertion for fast reactor shutdown. The continuous proper operation of RCDs obviously has significant influence on plant performance and availability, yet Ontario Hydro (OH) experience is that no significant loss of capacity factor has been attributed to the RCDs. This paper focuses on these Ontario Hydro replacement practices as they apply to RCD equipment in CANDU plants. The particular practices described relate to some extent to the unique aspects of CANDU plants, but the concepts of thorough planning, operational quality and teamwork are universally valid. Practicing safe, efficient component replacements contributes to reliable, cost effective plant operation. (author)

  18. Long-term performance of the CANDU-type of vanadium self-powered neutron detectors in NRU

    Energy Technology Data Exchange (ETDEWEB)

    Leung, T.C. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)]. E-mail: leungt@aecl.ca

    2007-07-01

    The CANDU-type of in-core vanadium self-powered neutron flux detectors have been installed in NRU to monitor the axial neutron flux distributions adjacent to the loop fuel test sites since 1996. This paper describes how the thermal neutron fluxes were measured at two monitoring sites, and presents a method of correcting the vanadium burn-up effect, which can be up to 2 to 3% per year, depending on the detector locations in the reactor. It also presents the results of measurements from neutron flux detectors that have operated for over eight-years in NRU. There is good agreement between the measured and simulated neutron fluxes, to within {+-} 6.5%, and the long-term performance of the CANDU-type of vanadium neutron flux detectors in NRU is satisfactory. (author)

  19. Long-term performance of the CANDU-type of vanadium self-powered neutron detectors in NRU

    International Nuclear Information System (INIS)

    The CANDU-type of in-core vanadium self-powered neutron flux detectors have been installed in NRU to monitor the axial neutron flux distributions adjacent to the loop fuel test sites since 1996. This paper describes how the thermal neutron fluxes were measured at two monitoring sites, and presents a method of correcting the vanadium burn-up effect, which can be up to 2 to 3% per year, depending on the detector locations in the reactor. It also presents the results of measurements from neutron flux detectors that have operated for over eight-years in NRU. There is good agreement between the measured and simulated neutron fluxes, to within ± 6.5%, and the long-term performance of the CANDU-type of vanadium neutron flux detectors in NRU is satisfactory. (author)

  20. Incentives for improvement of CANDU

    International Nuclear Information System (INIS)

    CANDU is a relatively young technology which has demonstrated many achievements as an electrical power generation system. These achievements include an unsurpassed safety record, high annual and lifetime capacity factors, low electricity cost and a broad range of other performance strengths which together indicate that the CANDU technology is fundamentally sound. Known capabilities not yet fully exploited, such as advanced fuel cycle options, indicate that CANDU technology will continue to pay strong dividends on research, development and design investment. This provides a strong incentive for the improvement of CANDU on a continuing basis

  1. Development of risk monitor RiskAngel for risk-informed applications in nuclear power plants

    International Nuclear Information System (INIS)

    This paper presents the development of risk monitor software RiskAngel at FDS Team and its applications as a plant specific risk monitor, which supports risk-informed configuration risk management for the two CANDU 6 units at the Third Qinshan Nuclear Power Plant in China. It also describes the regulatory prospective on risk-informed PSA applications and the use of risk monitor at operating nuclear power plants, high level technical and functional requirements for the development of CANDU specific risk monitor software, and future development trends. (author)

  2. Nuclear power in New Brunswick

    International Nuclear Information System (INIS)

    New Brunswick's first nuclear power station was started in 1974, and construction of the major structures began in May 1975. The station is a 600 MW CANDU plant designed for salt water cooling and arranged to serve as the first of a two-unit station. It was the first nuclear plant in Canada to be subjected to the federal government requirements for environmental assessment, and the first in which design, construction and commissioning were carried out under a full quality assurance program to the CSA Z299 standard. The discovery of damage to the steam generators necessitated an extensive rebuild of these components and had a major impact on the construction schedule. Commissioning of the plant got under way in 1979, although construction continued during 1981. Point Lepreau is among the leaders in cost and schedule performance for all reactors being completed worldwide in 1982. Lessons learned during the construction of this reactor suggest that a unit of this type could be built in considerably less time and at a lower cost if a unified approach to engineering and procurement could be achieved

  3. Operation of CANDU power reactor in thorium self-sufficient fuel cycle

    Indian Academy of Sciences (India)

    B R Bergelson; A S Gerasimov; G V Tikhomirov

    2007-02-01

    This paper presents the results of calculations for CANDU reactor operation in thorium fuel cycle. Calculations are performed to estimate the feasibility of operation of heavy-water thermal neutron power reactor in self-sufficient thorium cycle. Parameters of active core and scheme of fuel reloading were considered to be the same as for standard operation in uranium cycle. Two modes of operations are discussed in the paper: mode of preliminary accumulation of 233U and mode of operation in self-sufficient cycle. For the mode of accumulation of 233U it was assumed for calculations that plutonium can be used as additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. Maximum content of 233U in target channels was estimated to be ∼ 13 kg/t of ThO2. This was achieved by irradiation for six years. The start of the reactor operation in the self-sufficient mode requires 233U content to be not less than 12 kg/t. For the mode of operation in self-sufficient cycle, it was assumed that all channels were loaded with identical fuel assemblies containing ThO2 and certain amount of 233U. It is shown that nonuniform distribution of 233U in fuel assembly is preferable.

  4. The mode of operation of CANDU power reactor in thorium self-sufficient fuel cycle

    Directory of Open Access Journals (Sweden)

    Bergelson Boris R.

    2008-01-01

    Full Text Available This paper presents the results of calculations for CANDU reactor operation in the thorium fuel cycle. The calculations were performed to estimate feasibility of operation of a heavy-water thermal neutron power reactor in the self-sufficient thorium cycle. The parameters of the active core and the scheme of fuel reloading were considered to be the same as for the standard operation in the uranium cycle. Two modes of operation are discussed in the paper: the mode of preliminary accumulation of 233U and the mode of operation in the self-sufficient cycle. For calculations for the mode of accumulation of 233U, it was assumed that plutonium was used as the additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. The maximum content of 233U in the target channels was about 13 kg/t of ThO2. This was achieved by six year irradiation. The start of reactor operation in the self-sufficient mode requires content of 233U not less than 12 kg/t. For the mode of operation in the self-sufficient cycle, it was assumed that all the channels were loaded with the identical fuel assemblies containing ThO2 and a certain amount of 233U. It was shown that the non-uniform distribution of 233U in a fuel assembly is preferable.

  5. Systems for transporting used CANDU fuel by road, rail and water

    International Nuclear Information System (INIS)

    Ontario Hydro's CANDU nuclear power stations are situated on the shores of the Great Lakes and are accessible by road, rail and water. For the off-site shipment of used CANDU fuel from the stations to a disposal, reprocessing or central storage facility, all three modes are being considered. This paper presents Ontario Hydro's 'reference transportation systems' for the shipment of used CANDU fuel as developed for the Nuclear Fuel Waste Management Program (NFWMP) in Canada. These are workable systems developed by Ontario Hydro for the purpose of showing modal feasibility. The systems have not yet been optimized

  6. Nuclear power and nuclear insurance

    International Nuclear Information System (INIS)

    Fanned by the Chernobyl reactor accident the discussion about the safety and insurability of nuclear power plants has also been affecting the insurance companies. The related analyses of the safety concepts of German nuclear power plants have been confirming the companies' risk philosophy of maintaining the insurability of nuclear power plants either meeting German safety standards or equivalent safety standards. Apart from the technical evaluation of the safety of nuclear power plants the fundamental discussion about the pros and cons of nuclear power has also been stressing the damages and liability problem. The particular relevance of possible considerable transfrontier contaminations clearly reveals the urgency of establishing internationally standardized reactor accident liability regulations. (orig./HP)

  7. Enhanced CANDU 6 Reactor

    International Nuclear Information System (INIS)

    Full text: The CANDU 6 power reactor is visionary in its approach, remarkable for its on-power refuelling capability and proven over years of safe, economical and reliable power production. Developed by Atomic Energy of Canada Ltd, the CANDU 6 design offers excellent performance utilizing state-of-the-art technology. The first CANDU 6 plants went into service in the early 1980's as leading edge technology and the design has been continuously advanced to maintain superior performance with an outstanding safety record. The first CANDU 6 plants- Gentilly 2 and Point Lepreau in Canada, Embalse in Argentina and Wolsong- Unit 1 in Korea have been in service for more than 21 years and are still producing electricity at peak performance and to the end of 2004, their average lifetime Capacity Factor was 83.2%. The newer CANDU 6 units in Romania (Cernavoda 1), Korea (Wolsong-Units 2, 3 and 4) and Qinshan (Phase III- Units 1 and 2) have also been performing at outstanding levels. The average lifetime Capacity Factor of the 10 CANDU 6 operating units around the world has been 87% to the end of 2004. Building on these successes, AECL is committed to the further development of this highly successful design, now focussing on meeting customer's needs for reduced costs, further improvements to plant operation and performance, enhanced safety and incorporating up-to-date technology as warranted. This has resulted in AECL embarking on improving the CANDU 6 design through an upgraded product termed as the 'Enhanced CANDU 6' (EC6)- which incorporates several attractive but proven features that will make the CANDU 6 reactor even more economical, safer and easier to operate. Some of the key features that will be incorporated in the EC6 include increasing the plant's power output, shortening the overall project schedule, decreasing the capital cost, dealing with obsolescence issues, optimizing maintenance outages and incorporating lessons learnt through feedback obtained from the

  8. Prospects for Nuclear Power

    OpenAIRE

    Davis, Lucas W.

    2011-01-01

    Nuclear power has long been controversial because of concerns about nuclear accidents, storage of spent fuel, and how the spread of nuclear power might raise risks of the proliferation of nuclear weapons. These concerns are real and important. However, emphasizing these concerns implicitly suggests that unless these issues are taken into account, nuclear power would otherwise be cost effective compared to other forms of electricity generation. This implication is unwarranted. Throughout the h...

  9. Applicability of a track-based multiprocess portable robot to some maintenance tasks in CANDU nuclear plants

    International Nuclear Information System (INIS)

    Hydro-Quebec has developed a six-axis, track-based, multiprocess robot. This lightweight (30 kg) compact robot travels on a bent track with a radius of curvature ranging from 1 m to infinity (straight track). Standard and tandem wires GMAW, FCAW and Narrow gap TIG welding as well as plasma gouging and cutting, electrical and pneumatic rough and precision grinding, and profile measurement functionalities have been incorporated. A description of this technology an its newly developed functionalities is given in this paper. Since 1995, a number of industrial and R and D projects have been performed using this technology now called the Scompi technology. The main field of application is the in situ repair of hydraulic turbine runners. However some applications have been developed in the nuclear field. One particular development was funded by the International Thermonuclear Experimental Reactor (ITER) project. Scompi was selected by the ITER US Home Team for a demonstration of remote techniques for welding, cutting and rewelding the 30 m diameter, 17 m high, vacuum vessel. The demonstration involved all position robotic plasma cutting and NG-TIG welding of a 316L, 40 mm thick, double wall. In 1998, two Scompi robots working in tandem performed in York, Pa, the joint welding and cutting of a full scale portion of the vacuum vessel. In 1995, the applicability of the Scompi technology to the repair of the divider plates in the four steam generators at Gentilly-2 was evaluated based on a joint proposal by Ontario Hydro Technologies (now Ontario Power Technologies-OPT) and Hydro-Quebec. A MIG welding procedure was proposed for the horizontal and vertical divider plates welds. A complete simulation of the robot and primary head demonstrated the feasibility of the concept. However, based on cost and scheduling, it was decided to proceed with a manual repair. Nevertheless it is anticipated that this technology will find its niche in the maintenance of Candu reactors. (author)

  10. Applicability of a track-based multiprocess portable robot to some maintenance tasks in CANDU nuclear plants

    Energy Technology Data Exchange (ETDEWEB)

    Hazel, B.; Fihey, J.-L.; Laroche, Y. [Hydro-Quebec, Varennes, Quebec (Canada)

    2000-07-01

    Hydro-Quebec has developed a six-axis, track-based, multiprocess robot. This lightweight (30 kg) compact robot travels on a bent track with a radius of curvature ranging from 1 m to infinity (straight track). Standard and tandem wires GMAW, FCAW and Narrow gap TIG welding as well as plasma gouging and cutting, electrical and pneumatic rough and precision grinding, and profile measurement functionalities have been incorporated. A description of this technology an its newly developed functionalities is given in this paper. Since 1995, a number of industrial and R and D projects have been performed using this technology now called the Scompi technology. The main field of application is the in situ repair of hydraulic turbine runners. However some applications have been developed in the nuclear field. One particular development was funded by the International Thermonuclear Experimental Reactor (ITER) project. Scompi was selected by the ITER US Home Team for a demonstration of remote techniques for welding, cutting and rewelding the 30 m diameter, 17 m high, vacuum vessel. The demonstration involved all position robotic plasma cutting and NG-TIG welding of a 316L, 40 mm thick, double wall. In 1998, two Scompi robots working in tandem performed in York, Pa, the joint welding and cutting of a full scale portion of the vacuum vessel. In 1995, the applicability of the Scompi technology to the repair of the divider plates in the four steam generators at Gentilly-2 was evaluated based on a joint proposal by Ontario Hydro Technologies (now Ontario Power Technologies-OPT) and Hydro-Quebec. A MIG welding procedure was proposed for the horizontal and vertical divider plates welds. A complete simulation of the robot and primary head demonstrated the feasibility of the concept. However, based on cost and scheduling, it was decided to proceed with a manual repair. Nevertheless it is anticipated that this technology will find its niche in the maintenance of Candu reactors. (author)

  11. Nuclear Power in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China’s vigorous efforts to propel development of nuclear power are paying off as the country’s nuclear power sector advances at an amazing pace. At present, China has set up three enormous nuclear power bases, one each in Qinshan of Zhejiang Province, Dayawan of Guangdong

  12. CANDU steam generator life management

    Energy Technology Data Exchange (ETDEWEB)

    Tapping, R.L. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Nickerson, J. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Spekkens, P.; Maruska, C. [Ontario Hydro, Toronto, Ontario (Canada)

    1998-01-01

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDUutilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermalhydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. The research and development program, as well as operating experience, has identified where improvements in operating practices and/or designs can be made in order to ensure steam generator design life at an acceptable capacity factory. (author)

  13. Assessment of System Behavior and Actions Under Loss of Electric Power For CANDU

    International Nuclear Information System (INIS)

    For the analysis, the CANDU-6 plant in Korea is considered and only the passive components are operable. The other systems are assumed to be at failed condition due to the loss of electric power. At this accident, only the inventories remained in the primary heat transport system (PHTS) and steam generator can be used for the decay heat removal. Due to the transfer of decay heat, the inventory of steam generator secondary side is discharged to the air through passive operation of main steam safety valves (MSSVs). After the steam generators are dried, the PHTS is over-pressurized and the coolant is discharged to fuelling machine vault through passive operation of degasser condenser tank relief valves (DCRVs). Under this situation, the maintenance of the integrity of PHTS is important for the protection of radionuclides release to the environment. Thus, deterministic analysis using CATHENA code is carried out for the simulation of the accident and the appropriate operator action is considered. The loss of electric power results in the depletion of steam generator inventory which is necessary for the decay heat removal. If only the passive system is credited, the PT can be failed after the steam generator is depleted. For the prevention of the PT failure, the feedwater should be supplied to the steam generator before 4,800s after the accident. The feedwater can be supplied using water in dousing tank if the steam generators are depressurized. The decay heat from the core is removed through natural circulation if the feedwater can be supplied continuously

  14. Nuclear power economics

    International Nuclear Information System (INIS)

    As a petroleum substitute, the nuclear power in Japan possesses the following four features. (1) Stability in supply: The import of nuclear fuel resources is performed from politically stable advanced countries and in long-term contracts. And, nuclear power can be of semi-domestic energy source due to the nuclear fuel cycle. (2) Low cost of nuclear power generation. (3) Contribution of nuclear power technology to other advanced industries. (4) Favorable effects of nuclear power siting upon the region concerned, such as labor employment and social welfare. Electricity charges are high in Japan, as compared with those in the United States and others where coal and water power are relatively abundant. For Japan without such natural resources, nuclear energy is important in lowering the power rates. (Mori, K.)

  15. Development of Off-take Model, Subcooled Boiling Model, and Radiation Heat Transfer Input Model into the MARS Code for a Regulatory Auditing of CANDU Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, C.; Rhee, B. W.; Chung, B. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ahn, S. H.; Kim, M. W. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2009-05-15

    Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to a lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use a vendor's code for a regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed the RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of the existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of the RELAP5/MOD3/CANDU code to the MARS code including a quality assurance of the developed models.

  16. Development of Off-take Model, Subcooled Boiling Model, and Radiation Heat Transfer Input Model into the MARS Code for a Regulatory Auditing of CANDU Reactors

    International Nuclear Information System (INIS)

    Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to a lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use a vendor's code for a regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed the RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of the existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of the RELAP5/MOD3/CANDU code to the MARS code including a quality assurance of the developed models

  17. The Korean strategy and experience in developing nuclear power generation capability

    International Nuclear Information System (INIS)

    The Korean nuclear energy development program and future prospects are discussed. Korea has achieved the substantial level of nuclear power plant localization through Korean Standard Nuclear Power (KSNP) Plant approach. The KSNP approach includes plant standardization, equipment, fuel and service localization and codes and standards development. Korea could develop her own decision making capability as Korea took the total project management responsibility in the KSNP approach. Current Korean nuclear R and D program includes next generation nuclear power plant development and advanced fuel development. The PWR-CANDU symbiosis is carefully considered to improve the nuclear power economy

  18. Nuclear power prospects

    International Nuclear Information System (INIS)

    A survey of the nuclear power needs of the less-developed countries and a study of the technology and economics of small and medium scale power reactors are envisioned by the General Conference. Agency makes its services available to Member States to assist them for their future nuclear power plans, and in particular in studying the technical and economic aspects of their power programs. The Agency also undertakes general studies on the economics of nuclear power, including the collection and analysis of cost data, in order to assist Member States in comparing and forecasting nuclear power costs in relation to their specific situations

  19. Applying operating experience to design the CANDU 3 process

    International Nuclear Information System (INIS)

    The CANDU 3 is an advanced, smaller (450 MWe), standardized version of the CANDU now being designed for service later in the decade and beyond. The design of this evolutionary nuclear power plant has been carefully planned and organized to gain maximum benefits from new technologies and from world experience to date in designing, building, commissioning and operating nuclear power stations. The good performance record of existing CANDU reactors makes consideration of operating experience from these plants a particularly vital component of the design process. Since the completion of the first four CANDU 6 stations in the early 1980s, and with the continuing evolution of the multi-unit CANDU station designs since then, AECL CANDU has devised several processes to ensure that such feedback is made available to designers. An important step was made in 1986 when a task force was set up to review and process ideas arising from the commissioning and early operation of the CANDU 6 reactors which were, by that time, operating successfully in Argentina and Korea, as well as the Canadian provinces of Quebec and New Brunswick. The task force issued a comprehensive report which, although aimed at the design of an improved CANDU 6 station, was made available to the CANDU 3 team. By that time also, the Institute of Power Operations (INPO) in the U.S., of which AECL is a Supplier Participant member, was starting to publish Good Practices and Guidelines related to the review and the use of operating experiences. In addition, details of significant events were being made available via the INPO SEE-IN (Significant Event Evaluation and Information Network) Program, and subsequently the CANNET network of the CANDU Owners' Group (COG). Systematic review was thus possible by designers of operations reports, significant event reports, and related documents in a continuing program of design improvement. Another method of incorporating operations feedback is to involve experienced utility

  20. An elasto-plastic model for mechanical contact between the pellets and sheath in CANDU nuclear fuel elements

    International Nuclear Information System (INIS)

    During high-temperature transients, increased mechanical contact can occur between the fuel stack and the sheath in the axial and/or radial direction. As well, there is an axial linear power gradient and an axial gradient in mechanical properties of the sheath specific to a CANDU-type fuel element. This requires a code with the capability to treat multiple axial segments. This paper describes a contact model that allows the elasto-plastic mechanical contact in radial/axial direction for multiple axial segments. (14 figs., 5 refs.)

  1. Requirements for containment system components in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    This Standard specifies the requirements and establishes the rules for design, fabrication, and installation of pressure-retaining containment system components. In this Standard the term 'components' includes non registered items

  2. Joint studies on large CANDU

    International Nuclear Information System (INIS)

    CANDU PHWRs have demonstrated generic benefits which will be continued in future designs. These include economic benefits due to low operating costs, business potential, strategic benefits due to fuel cycle flexibility and operational benefits. These benefits have been realized in Korea through the operation of Wolsong 1, resulting in further construction of PHWRs at the same site. The principal benefit, low electricity cost, is due to the high capacity factor and the low fuel cost for CANDU. The CANDU plant at Wolsong has proven to be a safe, reliable and economical electricity producer. The ability of PHWR to burn natural uranium ensures security of fuel supply. Following successful Technology Transfer via the Wolsong 2,3 and 4 project, future opportunity exists between Korea and Canada for continuing co-operation in research and development to improve the technology base, for product development partnerships, and business opportunities in marketing and building PHWR plants in third countries. High reliability, through excellent design, well-controlled operation, efficient maintenance and low operating costs is critical to the economic viability of nuclear plants. CANDU plants have an excellent performance record. The four operating CANDU 6 plants, operated by four utilities in three countries, are world performance leaders. The CANDU 9 design, with higher output capacity, will help to achieve better site utilization and lower electricity costs. Being an evolutionary design, CANDU 9 assures high performance by utilizing proven systems, and component designs adapted from operating CANDU plants (Bruce B, Darlington and CANDU 6). All system and operating parameters are within the operating proven range of current plants. KAERI and AECL have an agreement to perform joint studies on future PHWR development. The objective of the joint studies is to establish the requirements for the design of future advanced CANDU PHWR including the utility need for design improvements

  3. CANDU, building the future

    International Nuclear Information System (INIS)

    The CEO of Stern Laboratories delivered a speech on the problems and challenges facing the nuclear industry. The CANDU system is looked at as the practical choice for the future of our energy source. The people of the industry must be utilized and respected to deliver to the best of their ability

  4. CANDU market prospects

    International Nuclear Information System (INIS)

    This 1994 survey of prospective markets for CANDU reactors discusses prospects in Turkey, Thailand, the Philippines, Korea, Indonesia, China and Egypt, and other opportunities, such as in fuel cycles and nuclear safety. It was concluded that foreign partners would be needed to help with financing

  5. CANDU, building the future

    Energy Technology Data Exchange (ETDEWEB)

    Stern, F. [Stern Laboratories (Canada)

    1997-07-01

    The CEO of Stern Laboratories delivered a speech on the problems and challenges facing the nuclear industry. The CANDU system is looked at as the practical choice for the future of our energy source. The people of the industry must be utilized and respected to deliver to the best of their ability.

  6. Investigation of the Power Coefficient of Reactivity of 3D CANDU Reactor through Detailed Monte Carlo Analysis

    International Nuclear Information System (INIS)

    , an extremely large number of neutron histories are used in this investigation. A detailed 3D CANDU-6 core has been modelled to re-evaluate the power coefficient of reactivity (PCR). The continuous-energy Monte Carlo code SERPENT2 code has been used to take into account the impact of the Doppler broadened elastic scattering resonance on the fuel temperature coefficient and the PCR. For the PCR evaluation as a function of power level, two inlet temperatures (design and operating conditions) were considered for a wide range of reactor power, 60 - 120% power. From the current study, the PCR is found to be slightly negative up to 90% power level for both operating and design condition, the PCR is found to be slightly negative up to -95% in the design condition

  7. RETHINKING NUCLEAR POWER SAFETY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Fukushima nuclear accident sounds alarm bells in China’s nuclear power industry In the wake of the Fukushima nucleara ccident caused by the earthquake andt sunami in Japan,the safety of nuclearp ower plants and the development of nuclear power have raised concerns,

  8. Sustainable development of nuclear power

    International Nuclear Information System (INIS)

    A treatise consisting of the following sections: Economic efficiency of nuclear power (Growth of nuclear power worldwide; State of the art in the development of nuclear power reactors; Competitiveness of contemporary nuclear power); Environmental acceptability of nuclear power (Non-proliferation of nuclear weapons; Nuclear safety and radioactive waste disposal; Environmental awareness and environmental movements). (P.A.)

  9. CANDU 3 station layout for safety, licensability, constructability and operations

    International Nuclear Information System (INIS)

    The CANDU 3 nuclear power station conceptual layout has been arranged to meet current safety and licensing requirements, to improve constructability, commissioning and operations. This paper describes the unique and innovative features of the station layout to achieve the above objectives

  10. Safety assessment to support NUE fuel full core implementation in CANDU reactors

    International Nuclear Information System (INIS)

    The Natural Uranium Equivalent (NUE) fuel contains a combination of recycled uranium and depleted uranium, in such a manner that the resulting mixture is similar to the natural uranium currently used in CANDU® reactors. Based on successful preliminary results of 24 bundles of NUE fuel demonstration irradiation in Qinshan CANDU 6 Unit 1, the NUE full core implementation program has been developed in cooperation with the Third Qinshan Nuclear Power Company and Candu Energy Inc, which has recently received Chinese government policy and funding support from their National-Level Energy Innovation program. This paper presents the safety assessment results to technically support NUE fuel full core implementation in CANDU reactors. (author)

  11. Integration of CATHENA thermal-hydraulic model with CANDU 6 analytical simulator controller

    International Nuclear Information System (INIS)

    This paper introduces a powerful design and analysis tool named SIMCAT that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It consists of the Canadian Algorithm for THErmohydraulic Network Analysis (CATHENA), the control logics from CANDU6 Analytical Simulator (C6SIM), and a communication protocol, Parallel Virtual Machine (PVM). This is the first time that CATHENA has been successfully coupled directly with a program written in another language. The independence of CATHENA and the C6SIM controllers allows the development of both CATHENA and C6SIM controller to proceed independently. (author)

  12. Nuclear power development

    Energy Technology Data Exchange (ETDEWEB)

    Nealey, S.

    1990-01-01

    The objective of this study is to examine factors and prospects for a resumption in growth of nuclear power in the United States over the next decade. The focus of analysis on the likelihood that current efforts in the United States to develop improved and safer nuclear power reactors will provide a sound technical basis for improved acceptance of nuclear power, and contribute to a social/political climate more conducive to a resumption of nuclear power growth. The acceptability of nuclear power and advanced reactors to five social/political sectors in the U.S. is examined. Three sectors highly relevant to the prospects for a restart of nuclear power plant construction are the financial sector involved in financing nuclear power plant construction, the federal nuclear regulatory sector, and the national political sector. For this analysis, the general public are divided into two groups: those who are knowledgeable about and involved in nuclear power issues, the involved public, and the much larger body of the general public that is relatively uninvolved in the controversy over nuclear power.

  13. Nuclear Power in Sweden

    International Nuclear Information System (INIS)

    This book presents how Swedish technology has combined competence in planning, building, commissioning, maintenance, and operation of nuclear power and waste facilities. The items are elaborated in the following chapters: Nuclear power today and for the future, Sweden and its power supply, The history of nuclear power in Sweden, Nuclear Sweden today, Operating experience in 10 nuclear power units, Maintenance experience, Third-generation BWR-plants commissioned in five years, Personnel and training, Reactor safety, Quality assurance and quality control, Characteristic features of the ASEA-ATOM BWR, Experience of PWR steam generators, Nuclear fuel supply and management, Policy and techniques of radioactive waste management, Nuclear energy authorities and Inherently safe LWR. The publication is concluded by facts in brief and a statement by the Director General of IAEA. (G.B.)

  14. Ninth international conference on CANDU fuel, 'fuelling a clean future'

    International Nuclear Information System (INIS)

    The Canadian Nuclear Society's 9th International Conference on CANDU fuel took place in Belleville, Ontario on September 18-21, 2005. The theme for this year's conference was 'Fuelling a Clean Future' bringing together over 80 delegates ranging from: designers, engineers, manufacturers, researchers, modellers, safety specialists and managers to share the wealth of their knowledge and experience. This international event took place at an important turning point of the CANDU technology when new fuel design is being developed for commercial application, the Advanced CANDU Reactor is being considered for projects and nuclear power is enjoying a renaissance as the source energy for our future. Most of the conference was devoted to the presentation of technical papers in four parallel sessions. The topics of these sessions were: Design and Development; Fuel Safety; Fuel Modelling; Fuel Performance; Fuel Manufacturing; Fuel Management; Thermalhydraulics; and, Spent Fuel Management and Criticalty

  15. Thermochemical modelling of advanced CANDU reactor fuel

    Science.gov (United States)

    Corcoran, Emily Catherine

    2009-04-01

    With an aging fleet of nuclear generating facilities, the imperative to limit the use of non-renewal fossil fuels and the inevitable need for additional electricity to power Canada's economy, a renaissance in the use of nuclear technology in Canada is at hand. The experience and knowledge of over 40 years of CANDU research, development and operation in Ontario and elsewhere has been applied to a new generation of CANDU, the Advanced CANDU Reactor (ACR). Improved fuel design allows for an extended burnup, which is a significant improvement, enhancing the safety and the economies of the ACR. The use of a Burnable Neutron Absorber (BNA) material and Low Enriched Uranium (LEU) fuel has created a need to understand better these novel materials and fuel types. This thesis documents a work to advance the scientific and technological knowledge of the ACR fuel design with respect to thermodynamic phase stability and fuel oxidation modelling. For the BNA material, a new (BNA) model is created based on the fundamental first principles of Gibbs energy minimization applied to material phase stability. For LEU fuel, the methodology used for the BNA model is applied to the oxidation of irradiated fuel. The pertinent knowledge base for uranium, oxygen and the major fission products is reviewed, updated and integrated to create a model that is applicable to current and future CANDU fuel designs. As part of this thesis, X-Ray Diffraction (XRD) and Coulombic Titration (CT) experiments are compared to the BNA and LEU models, respectively. From the analysis of the CT results, a number of improvements are proposed to enhance the LEU model and provide confidence in its application to ACR fuel. A number of applications for the potential use of these models are proposed and discussed. Keywords: CANDU Fuel, Gibbs Energy Mimimization, Low Enriched Uranium (LEU) Fuel, Burnable Neutron Absorber (BNA) Material, Coulometric Titration, X-Ray Diffraction

  16. The Canadian approach to nuclear codes and standards. A CSA forum for development of standards for CANDU: radioactive waste management and decommissioning

    International Nuclear Information System (INIS)

    Together with the Canadian Standards Association (CSA), industry stakeholders, governments, and the public have developed a suite of standards for CANDU nuclear power plants that generate electricity in Canada and abroad. In this paper, we will describe: CSA's role in national and international nuclear standards development; the key issues and priority projects that the nuclear standards program has addressed; the new CSA nuclear committees and projects being established, particularly those related to waste management and decommissioning; the hierarchy of nuclear regulations, nuclear, and other standards in Canada, and how they are applied by AECL; the standards management activities; and the future trends and challenges for CSA and the nuclear community. CSA is an accredited Standards Development Organization (SDO) and part of the international standards system. CSA's Nuclear Strategic Steering Committee (NSSC) provides leadership, direction, and support for a standards committee hierarchy comprised of members from a balanced matrix of interests. The NSSC strategically focuses on industry challenges; a new nuclear regulatory system, deregulated energy markets, and industry restructuring. As the first phase of priority projects is nearing completion, the next phase of priorities is being identified. These priorities address radioactive waste management, environmental radiation management, decommissioning, structural, and seismic issues. As the CSA committees get established in the coming year, members and input will be solicited for the technical committees, subcommittees, and task forces for the following related subjects: Radioactive Waste Management; a) Dry Storage of Irradiated Fuel; b) Short-Term Radioactive Waste Management; c) Long-Term Storage and Disposal of Radioactive Waste. 2. Decommissioning Nuclear Power is highly regulated, and public scrutiny has focused Codes and Standards on public and worker safety. Licensing and regulation serves to control

  17. Nuclear power in Romania - present and future

    International Nuclear Information System (INIS)

    The paper presents the actual status of nuclear power in Romania, with one CANDU 6 unit in operation (Cernavoda Unit 1) and second unit under construction (Cernavoda Unit 2). The Cernavoda Unit 1 operation performance had an important role for the next unit completion by the Romanian nuclear utility, NUCLEARELECTRICA, together with the traditional partners in the management of the project, AECL Canada and ANSALDO Italy. Cernavoda Unit 2 status showed that 2005 is a very important year for this project, which shall start its commercial operation in March 2007. The Romanian Government plays and important role in the development of nuclear power and the energy strategy contains directions for further development of Cernavoda NPP. Starting with 2003, NUCLEARELECTRICA worked on the pre-feasibility study of Cernavoda Unit 3. Based on the private participation for the financing of this project there are potential investors which expect the results of the market and feasibility studies planned to be finalized by the end of 2005. The Project Company responsible for Cernavoda Unit 3 is planned to be registered in Romania by July 2006. The necessary commercial contracts and financing are to be concluded by March 2007, when the progress works on the site will be restarted. Based on this national nuclear power, Romania shall provide security of electricity supply and assure flexibility, by optimum utilization of the hydro, coal, nuclear and others natural and renewable resources. (author)

  18. Ludwig: A Training Simulator of the Safety Operation of a CANDU Reactor

    OpenAIRE

    Gustavo Boroni; Alejandro Clausse

    2011-01-01

    This paper presents the application Ludwig designed to train operators of a CANDU Nuclear Power Plant (NPP) by means of a computer control panel that simulates the response of the evolution of the physical variables of the plant under normal transients. The model includes a close set of equations representing the principal components of a CANDU NPP plant, a nodalized primary circuit, core, pressurizer, and steam generators. The design of the application was performed using the object-oriented...

  19. Integrated evolution of the medium power CANDU{sup MD} reactors; Evolution integree des reacteurs CANDU{sup MD} de moyenne puissance

    Energy Technology Data Exchange (ETDEWEB)

    Nuzzo, F. [AECL Accelerators, Kanata, ON (Canada)

    2002-07-01

    The aim of this document is the main improvements of the CANDU reactors in the economic, safety and performance domains. The presentation proposes also other applications as the hydrogen production, the freshening of water sea and the bituminous sands exploitation. (A.L.B.)

  20. CANDU: Shortest path to advanced fuel cycles

    International Nuclear Information System (INIS)

    Full text: The global nuclear renaissance exhibiting itself in the form of new reactor build programs is rapidly gaining momentum. Many countries are seeking to expand the use of economical and carbon-free nuclear energy to meet growing electricity demand and manage global climate change challenges. Nuclear power construction programs that are being proposed in many countries will dramatically increase the demand on uranium resources. The projected life-long uranium consumption rates for these reactors will surpass confirmed uranium reserves. Therefore, securing sufficient uranium resources and taking corresponding measures to ensure the availability of long-term and stable fuel resources for these nuclear power plants is a fundamental requirement for business success. Increasing the utilization of existing uranium fuel resources and implementing the use of alternate fuels in CANDU reactors is an important element to meet this challenge. The CANDU heavy water reactor has unequalled flexibility for using a variety of fuels, such as Natural Uranium (NU), Low Enriched Uranium (LEU), Recycled Uranium (RU), Mixed Oxide (MOX), and thorium. This CANDU feature has not been used to date simply due to lack of commercial drivers. The capability is anchored around a versatile pressure tube design, simple fuel bundle, on-power refuelling, and high neutron economy of the CANDU concept. Atomic Energy of Canada Limited (AECL) has carried out theoretical and experimental investigations on various advanced fuel cycles, including thorium, over many years. Two fuels are selected as the subject of this paper: Natural Uranium Equivalent (NUE) and thorium. NUE fuel is developed by combining RU and depleted uranium (DU) in such a manner that the resulting NUE fuel is neutronically equivalent to NU fuel. RU is recovered from reprocessed light water reactor (LWR) fuel and has a nominal 235U concentration of approximately 0.9 wt%. This concentration is higher than NU used in CANDU reactors

  1. Thermalhydraulic characteristics for fuel channels using burnable poison in the CANDU reactor

    International Nuclear Information System (INIS)

    The power coefficient is one of the most important physics parameters governing nuclear reactor safety and operational stability, and its sign and magnitude have a significant effect on the safety and control characteristics of the power reactor. Recently, for an equilibrium CANDU core, the power coefficient was reported to be slightly positive when newly developed Industry Standard Tool set reactor physics codes were used. Therefore, it is required to find a new way to effectively decrease the positive power coefficient of CANDU reactor without seriously compromising the economy. In order to make the power coefficient of the CANDU reactor negative at the operating power, Roh et al. have evaluated the various burnable poison (BP) materials and its loading scheme in terms of the fuel performance and reactor safety characteristics. It was shown that reactor safety characteristics can be greatly improved by the use of the BP in the CANDU reactor. However, the previous study has mainly focused on the safety characteristics by evaluating the power coefficient for the fuel channel using BP in the CANDU reactor. Together with the safety characteristics, the economic performance is also important in order to apply the newly designed fuel channel to the power plant. In this study, the economic performance has been evaluated by analyzing the thermal hydraulic characteristics for the fuel channel using BP in the CANDU reactor

  2. Nuclear power and safety

    International Nuclear Information System (INIS)

    The paper deals with the problem of necessity to develop nuclear power, conceivable consequences of this development, its disadvantages and advantages. It is shown that the nuclear power is capable of supplying the world's economy with practically unlimited and the most low-cost energy resources providing the transition from the epoch of organic fuel to the epoch with another energy sources. The analysis of various factors of nuclear power effects on population and environment is presented. Special attention is focused on emergency situations at NPPs. The problem of raising the nuclear power safety is considered. 11 refs.; 5 figs.; 2 tabs

  3. Candu reactors with thorium fuel cycles

    International Nuclear Information System (INIS)

    Over the last decade and a half AECL has established a strong record of delivering CANDU 6 nuclear power plants on time and at budget. Inherently flexible features of the CANDU type reactors, such as on-power fuelling, high neutron economy, fuel channel based heat transport system, simple fuel bundle configuration, two independent shut down systems, a cool moderator and a defence-in-depth based safety philosophy provides an evolutionary path to further improvements in design. The immediate milestone on this path is the Advanced CANDU ReactorTM** (ACRTM**), in the form of the ACR-1000TM**. This effort is being followed by the Super Critical Water Reactor (SCWR) design that will allow water-cooled reactors to attain high efficiencies by increasing the coolant temperature above 5500C. Adaptability of the CANDU design to different fuel cycles is another technology advantage that offers an additional avenue for design evolution. Thorium is one of the potential fuels for future reactors due to relative abundance, neutronics advantage as a fertile material in thermal reactors and proliferation resistance. The Thorium fuel cycle is also of interest to China, India, and Turkey due to local abundance that can ensure sustainable energy independence over the long term. AECL has performed an assessment of both CANDU 6 and ACR-1000 designs to identify systems, components, safety features and operational processes that may need to be modified to replace the NU or SEU fuel cycles with one based on Thorium. The paper reviews some of these requirements and the associated practical design solutions. These modifications can either be incorporated into the design prior to construction or, for currently operational reactors, during a refurbishment outage. In parallel with reactor modifications, various Thorium fuel cycles, either based on mixed bundles (homogeneous) or mixed channels (heterogeneous) have been assessed for technical and economic viability. Potential applications of a

  4. Next Generation CANDU Performance Assurance

    International Nuclear Information System (INIS)

    AECL is developing a next generation CANDU design to meet market requirements for low cost, reliable energy supplies. The primary product development objective is to achieve a capital cost substantially lower than the current nuclear plant costs, such that the next generation plant will be competitive with alternative options for large-scale base-load electricity supply. However, other customer requirements, including safety, low-operating costs and reliable performance, are being addressed as equally important design requirements. The main focus of this paper is to address the development directions that will provide performance assurance. The next generation CANDU is an evolutionary extension of the proven CANDU 6 design. There are eight CANDU 6 units in operation in four countries around the world and further three units are under construction. These units provide a sound basis for projecting highly reliable performance for the next generation CANDU. In addition, the next generation CANDU program includes development and qualification activities that will address the new features and design extensions in the advanced plant. To limit product development risk and to enhance performance assurance, the next generation CANDU design features and performance parameters have been carefully reviewed during the concept development phase and have been deliberately selected so as to be well founded on the existing CANDU knowledge base. Planned research and development activities are required only to provide confirmation of the projected performance within a modest extension of the established database. Necessary qualification tests will be carried out within the time frame of the development program, to establish a proven design prior to the start of a construction project. This development support work coupled with ongoing AECL programs to support and enhance the performance and reliability of the existing CANDU plants will provide sound assurance that the next generation

  5. Performance of candu-6 fuel bundles manufactured in romania nuclear fuel plant

    International Nuclear Information System (INIS)

    The purpose of this article is to present the performance of nuclear fuel produced by Nuclear Fuel Plant (N.F.P.) - Pitesti during 1995 - 2012 and irradiated in units U1 and U2 from Nuclear Power Plant (N.P.P.) Cernavoda and also present the Nuclear Fuel Plant (N.F.P.) - Pitesti concern for providing technology to prevent the failure causes of fuel bundles in the reactor. This article presents Nuclear Fuel Plant (N.F.P.) - Pitesti experience on tracking performance of nuclear fuel in reactor and strategy investigation of fuel bundles notified as suspicious and / or defectives both as fuel element and fuel bundle, it analyzes the possible defects that can occur at fuel bundle or fuel element and can lead to their failure in the reactor. Implementation of modern technologies has enabled optimization of manufacturing processes and hence better quality stability of achieving components (end caps, chamfered sheath), better verification of end cap - sheath welding. These technologies were qualified by Nuclear Fuel Plant (N.F.P.) - Pitesti on automatic and Computer Numerical Control (C.N.C.) programming machines. A post-irradiation conclusive analysis which will take place later this year (2013) in Institute for Nuclear Research Pitesti (the action was initiated earlier this year by bringing a fuel bundle which has been reported defective by pool visual inspection) will provide additional information concerning potential damage causes of fuel bundles due to manufacturing processes. (authors)

  6. Nuclear power debate

    International Nuclear Information System (INIS)

    A recent resurgence of interest in Australia in the nuclear power option has been largely attributed to growing concerns over climate change. But what are the real pros and cons of nuclear power? Have advances in technology solved the sector's key challenges? Do the economics stack up for Australia where there is so much coal, gas and renewable resources? Is the greenhouse footprint' of nuclear power low enough to justify its use? During May and June, the AIE hosted a series of Branch events on nuclear power across Sydney, Adelaide and Perth. In the interest of balance, and at risk of being a little bit repetitive, here we draw together four items that resulted from these events and that reflect the opposing views on nuclear power in Australia. Nuclear Power for Australia: Irrelevant or Inevitable? - a summary of the presentations to the symposium held by Sydney Branch on 8 June 2005. Nuclear Reactors Waste the Planet - text from the flyer distributed by The Greens at their protest gathering outside the symposium venue on 8 June 2005. The Case For Nuclear Power - an edited transcript of Ian Hore-Lacy's presentation to Adelaide Branch on 19 May 2005 and to Perth Branch on 28 June 2005. The Case Against Nuclear Power - an article submitted to Energy News by Robin Chappie subsequent to Mr Hore-Lacy's presentation to Perth Branch

  7. Sydkraft and nuclear power

    International Nuclear Information System (INIS)

    This article summarizes the report made by G. Ekberg for the Swedish Sydkraft Power Co. at the company's annual meeting in June 1976. The report comprises the year 1975 and the first five months of 1976 and largely discusses nuclear power. Experience with the running of Oskarshamn and Barsebaeck nuclear power stations is reported. Nuclear power has enabled production in the oil-fired power stations at Karlshamn and Malmoe to be reduced. 750 000 tons of oil have been saved. In the first five months of 1976, nuclear power accounted for 48% of Sydkraft's electricity production, water power 36% and oil only 16%. In 1975, Sydkraft produced 13% of Sweden's electricity. (H.E.G.)

  8. The nuclear power decisions

    International Nuclear Information System (INIS)

    Nuclear power has now become highly controversial and there is violent disagreement about how far this technology can and should contribute to the Western energy economy. More so than any other energy resource, nuclear power has the capacity to provide much of our energy needs but the risk is now seen to be very large indeed. This book discusses the major British decisions in the civil nuclear field, and the way they were made, between 1953 and 1978. That is, it spans the period between the decision to construct Calder Hall - claimed as the world's first nuclear power station - and the Windscale Inquiry - claimed as the world's most thorough study of a nuclear project. For the period up to 1974 this involves a study of the internal processes of British central government - what the author terms 'private' politics to distinguish them from the very 'public' or open politics which have characterised the period since 1974. The private issues include the technical selection of nuclear reactors, the economic arguments about nuclear power and the political clashes between institutions and individuals. The public issues concern nuclear safety and the environment and the rights and opportunities for individuals and groups to protest about nuclear development. The book demonstrates that British civil nuclear power decision making has had many shortcomings and concludes that it was hampered by outdated political and administrative attitudes and machinery and that some of the central issues in the nuclear debate were misunderstood by the decision makers themselves. (author)

  9. Nuclear power in Belgium

    International Nuclear Information System (INIS)

    In the energy sector Belgium is 90% dependent on imports. This was clearly felt by the electricity generating economy when the share of hydrocarbons in the energy resources used for electricity generation increased to more than 85% in 1973 as a consequence of rising electricity consumption. Although Belgium had been early to start employing nuclear power for peaceful purposes, only little use had initially been made of this possibility. After the first oil price crisis the Belgian electricity utilities turned more attention to nuclear power. To this day, seven nuclear power plants have been started up, and Belgian utilities hold a fifty percent share in a French nuclear power plant, while the French EdF holds fifty percent in one Belgian nuclear generating unit. The Belgian nuclear power plants, which were built mostly by Belgian industries, have an excellent operating record. Their availabilities are considerably above the worldwide average and they contributed some 60% to the electricity production in Belgium in 1985. Thanks to nuclear power, the cumulative percentage shares of heating oil and gas in electricity production were reduced to well over 15%, compared to 1973, thus meeting the objectives of using nuclear power, i.e., to save foreign exchange and become self-sufficient in supplying the country's needs. The use of nuclear power allowed the Belgian utilities to reduce the price per kilowatthour of electricity and, in this way, remain competitive with other countries. The introduction of nuclear power continues to have a stabilizing influence on electricity generating costs. In the light of the forecast future development of consumption it is regarded as probable that another nuclear power plant of 1390 MWe will have to be built and commissioned before the year 2000. (orig.)

  10. Thorium fuel-cycle studies for CANDU reactors

    International Nuclear Information System (INIS)

    The high neutron economy of the CANDU reactor, its ability to be refuelled while operating at full power, its fuel channel design, and its simple fuel bundle provide an evolutionary path for allowing full exploitation of the energy potential of thorium fuel cycles in existing reactors. AECL has done considerable work on many aspects of thorium fuel cycles, including fuel-cycle analysis, reactor physics measurements and analysis, fuel fabrication, irradiation and PIE studies, and waste management studies. Use of the thorium fuel cycle in CANDU reactors ensures long-term supplies of nuclear fuel, using a proven, reliable reactor technology. (author)

  11. Nuclear power economics

    International Nuclear Information System (INIS)

    The economical comparison of nuclear power plants with coal-fired plants in some countries or areas are analyzed. It is not difficult to show that nuclear power will have a significant and expanding role to play in providing economic electricity in the coming decades. (Liu)

  12. Balakovo nuclear power station

    International Nuclear Information System (INIS)

    A key means of improving the safety and reliability of nuclear power plants is through effective training of plant personnel. The goal of this paper is to show the progress of the training at the Balakovo Nuclear Power Plant, and the important role that international cooperation programs have played in that progress

  13. Nuclear Power Plants. Revised.

    Science.gov (United States)

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  14. Talk About Nuclear Power

    Science.gov (United States)

    Tremlett, Lewis

    1976-01-01

    Presents an overview of the relation of nuclear power to human health and the environment, and discusses the advantages and disadvantages of nuclear power as an energy source urging technical educators to inculcate an awareness of the problems associated with the production of energy. Describes the fission reaction process, the hazards of…

  15. Economics of nuclear power

    International Nuclear Information System (INIS)

    A comparison of the economics of nuclear and coal-fired power plants operated by Commonwealth Edison was developed. In this comparison, fuel costs, total busbar costs and plant performance were of particular interest. Also included were comparisons of construction costs of nuclear and coal-fired power plants over the past two decades

  16. Nuclear power status 1998

    International Nuclear Information System (INIS)

    The document gives general statistical information (by country) about electricity produced by nuclear power plants in the world in 1998, and in a table the number of nuclear reactors in operation, under construction, nuclear electricity supplied in 1998, and total operating experience as of 31 December 1998

  17. The Role of Nuclear Power in Pakistan

    International Nuclear Information System (INIS)

    Although the energy and electricity demand in Pakistan have been steadily growing, the per capita electricity consumption at around 300 kWh is still rather small when compared to most countries. The current installed capacity is around 17,700 MW with fossil fuels providing nearly two-third of this capacity, hydro a little less than one-third and nuclear around 2.5%. A major fraction of the oil used in Pakistan has to be imported while hydro remains subject to seasonal changes. The next 20 year projections point to a serious electrical energy generation shortfall even when the contribution from indigenous gas, coal, and hydro is increased optimistically. It is estimated that a deficit of some 3000-5000 MW may exist which will have to be met from an alternate energy resource like nuclear. Two small nuclear power plants (KANUPP, a 137 MWe CANDU which has been operating safely for nearly three decades, and CHASNUPP, the newly built 325 MWe PWR supplied by China) are already on-line. KANUPP has essentially been operated without any vendor support thanks to a systematic self-reliance program. The experience gained through procuring, operating and maintaining these power plants, coupled with the need to meet the projected electrical energy shortfall which cannot be met through conventional resources, makes nuclear a very viable option, and Pakistan an ideal case to study the current and future role of nuclear in a developing country with medium sized grid. This paper will describe an overview of the experience of development of nuclear power in Pakistan. Future strategies, which involve negotiating a case for nuclear with the energy policy makers, interacting with the vendor on matters of obtaining new plants, and increasing self-reliance in the area of nuclear power technology, will also be discussed. (author)

  18. Nuclear power plant outages

    International Nuclear Information System (INIS)

    The Finnish Radiation and Nuclear Safety Authority (STUK) controls nuclear power plant safety in Finland. In addition to controlling the design, construction and operation of nuclear power plants, STUK also controls refuelling and repair outages at the plants. According to section 9 of the Nuclear Energy Act (990/87), it shall be the licence-holder's obligation to ensure the safety of the use of nuclear energy. Requirements applicable to the licence-holder as regards the assurance of outage safety are presented in this guide. STUK's regulatory control activities pertaining to outages are also described

  19. Nuclear Power Day '86

    International Nuclear Information System (INIS)

    The proceedings in two volumes of the event ''Nuclear Power Day '86'' held in the Institute of Nuclear Research, contain full texts of 13 papers which all fall under the INIS Scope. The objective of the event was to acquaint broad technical public with the scope of the State Research and Development Project called ''Development of Nuclear Power till the Year 2000''. The papers were mainly focused on increased safety and reliability of nuclear power plants with WWER reactors, on the development of equipment and systems for disposal and burial of radioactive wastes, the introduction of production of nuclear power facilities of an output of 1,000 MW, and on the construction of nuclear heat sources. (Z.M.)

  20. Romanian nuclear power in the context of sustainable development

    International Nuclear Information System (INIS)

    Energy use is a vital force for the economic well being. It drives many aspects of the economic activity and is essential to a high quality life. However, the unwanted side-effects of energy use, including local pollution and the global warming due mainly to releases of greenhouse gases such as carbon dioxide (CO2), are detrimental to life quality and may threaten climate changes at a large-scale. The nuclear power has a lot of economical, social and environmental beneficial effects. The paper deals with aspects referring to the CANDU nuclear technology that is developed in Romania, within the sustainable development framework. (authors)

  1. Feedback of operating experience in nuclear power plants

    International Nuclear Information System (INIS)

    The feedback of operating experience of nuclear facilities to the designers, manufacturers, operators and regulators is one important means of maintaining and improving safety. The Atomic Energy Control Board's Advisory Committee on Nuclear Safety examined the means for feedback currently being employed, how effective they are and what improvements are advisable. The review found that the need for feedback of operating experience is well recognized within those institutions contributing to the safety of CANDU power reactors, and that the existing procedures are generally effective. Some recommendations, however, are submitted for improvement in the process

  2. Solutions for nuclear & renewable power generation

    International Nuclear Information System (INIS)

    AREVA Group's business globally includes mining, reactors and services and renewables. In Canada, AREVA is a leading uranium producer and globally qualified for CANDU plants. AREVA's nuclear and renewables strategy is based on the development of nuclear and renewable energies.

  3. Nuclear power in India

    International Nuclear Information System (INIS)

    Claim for economic superiority of the nuclear power over the coal-based thermal power is advanced on various grounds by the authorities concerned with organization of atomic energy in India. This claim is critically examined. At the outset, it is pointed out that data on cost of nuclear power available to the Indian researchers for detailed and rational analysis of the problem are limited only to whatever appears in official publications and are not adequate for working out reasonable cost estimates for scrutiny. Available official data are summarised. Taking into account the cost factors related to capital outlay, fuel input, transportation of fuel supplies and disposal of nuclear wastes from nuclear power plants, it is shown that the superiority of the nuclear power over the thermal one on economic grounds is not established in India in the present context. (M.G.B.)

  4. The role of nuclear power plant designers

    International Nuclear Information System (INIS)

    When design of a nuclear power plant begins its designers, owners, and regulators make a safety judgement based on their knowledge and collective experience. As time goes on safety criteria change, methods improve, new scientific understanding is gained, and the cost of safety increases in relation to the benefits gained. In spite of that, the fundamental safety of CANDU remains and will continue high. However, the designer's job has become more difficult. The process of designing a product to satisfy a customer using a perceived view of that benefits society is no longer simple. Is the customer the utility or an amalgam of government departments and various factions of the public? How is the designer to make judgements on social acceptability when society speaks with so many voices and so little leadership

  5. Nuclear power and European Union enlargement challenge

    International Nuclear Information System (INIS)

    From 1991 through 1996 the European Union signed the Association Agreements with ten East European countries (EE10), namely: Czech Republic, Estonia, Hungary, Poland, Slovenia, Latvia, Lithuania, Slovakia, Bulgaria and Romania. In the period 1994-1996 European Union received membership applications from all ten countries. The paper analyzes the approach of complying the requirements and regulations for European Union accession in the field of the Romanian nuclear power based on the CANDU technology. In this process, the real challenge is represented by the preparation and implementation of new regulations aiming to improve the general business environment by introducing International Accounting Standards simplification of bankruptcy laws, reform of taxation procedures and secureness of financial instruments. A new stand-by agreement with the International Monetary Fund and World Bank was set out in late April 1999 for an one-year loan of 475 million dollars. (authors)

  6. The nuclear power station

    International Nuclear Information System (INIS)

    The processes taking place in a nuclear power plant and the dangers arising from a nuclear power station are described. The means and methods of controlling, monitoring, and protecting the plant and things that can go wrong are presented. There is also a short discourse on the research carried out in the USA and Germany, aimed at assessing the risks of utilising nuclear energy by means of the incident tree analysis and probability calculations. (DG)

  7. Technology transfer in CANDU marketing

    International Nuclear Information System (INIS)

    The author discusses how the CANDU system lends itself to technology transfer, the scope of CANDU technology transfer, and the benefits and problems associated with technology transfer. The establishment of joint ventures between supplier and client nations offers benefits to both parties. Canada can offer varying technology transfer packages, each tailored to a client nation's needs and capabilities. Such a package could include all the hardware and software necessary to develop a self-sufficient nuclear infrastructure in the client nation

  8. CANDU development: the next 25 years

    International Nuclear Information System (INIS)

    CANDU Pressurized Heavy Water Reactors have three main characteristics that ensure viability for the very long term. First, great care has been taken in designing the CANDU reactor core so that relatively few neutrons produced in the fission process are absorbed by structural or moderator materials. The result is a reactor with high neutron economy that can burn natural uranium and a core that operates with 2-3 times less fissile content than other, similarly-sized reactors. In addition to neutron economy, the use of a simple bundle design and on-power fuelling augment the ability of CANDU reactors to burn a variety of fuels with relatively low fissile content with high efficiency. This ensures that fuel supply will not limit the applicability of the technology over the long term. Second, the presence of large water reservoirs ensures that even the severest postulated accidents are mitigated by passive means. For example, the presence of the heavy water moderator, which operates at low pressure and temperature, acts as a passive heat sink for many postulated accidents. Third, the modular nature of the core (e.g., fuel channels) means that components can be relatively easily replaced for plant life extension and upgrading. Since these factors all influence the long-term sustainability of CANDU nuclear technology, it is logical to build on this base and to add improvements to CANDU reactors using an evolutionary approach. This paper reviews AECL's product development directions and shows how the above characteristics are being exploited to improve economics, enhance safety, and ensure fuel cycle flexibility for sustainable development. (author). 21 refs., 9 figs

  9. Using Advanced Fuel Bundles in CANDU Reactors

    International Nuclear Information System (INIS)

    Improving the exit fuel burnup in CANDU reactors was a long-time challenge for both bundle designers and performance analysts. Therefore, the 43-element design together with several fuel compositions was studied, in the aim of assessing new reliable, economic and proliferation-resistant solutions. Recovered Uranium (RU) fuel is intended to be used in CANDU reactors, given the important amount of slightly enriched Uranium (~0.96% w/o U235) that might be provided by the spent LWR fuel recovery plants. Though this fuel has a far too small U235 enrichment to be used in LWR's, it can be still used to fuel CANDU reactors. Plutonium based mixtures are also considered, with both natural and depleted Uranium, either for peacefully using the military grade dispositioned Plutonium or for better using Plutonium from LWR reprocessing plants. The proposed Thorium-LEU mixtures are intended to reduce the Uranium consumption per produced MW. The positive void reactivity is a major concern of any CANDU safety assessment, therefore reducing it was also a task for the present analysis. Using the 43-element bundle with a certain amount of burnable poison (e.g. Dysprosium) dissolved in the 8 innermost elements may lead to significantly reducing the void reactivity. The expected outcomes of these design improvements are: higher exit burnup, smooth/uniform radial bundle power distribution and reduced void reactivity. Since the improved fuel bundles are intended to be loaded in existing CANDU reactors, we found interesting to estimate the local reactivity effects of a mechanical control absorber (MCA) on the surrounding fuel cells. Cell parameters and neutron flux distributions, as well as macroscopic cross-sections were estimated using the transport code DRAGON and a 172-group updated nuclear data library. (author)

  10. Nuclear power under strain

    International Nuclear Information System (INIS)

    The German citizen faces the complex problem of nuclear power industry with slight feeling of uncertainty. The topics in question can only be briefly dealt with in this context, e.g.: 1. Only nuclear energy can compensate the energy shortage. 2. Coal and nuclear energy. 3. Keeping the risk small. 4. Safety test series. 5. Status and tendencies of nuclear energy planning in the East and West. (GL)

  11. Nuclear power constructions

    International Nuclear Information System (INIS)

    The feasibility study and the project design and their role in the process of nuclear power plant construction are analyzed in detail. From the point of view of systems aspects of scientific management, the nuclear power plant is considered to be an element of the power generation and transmission system as well as an intersection of capital investment, scientific and technical development and project designing. Foreign experience is summed up with the planning, designing and building of nuclear power plants. Attention is centred to the feasibility study and project design stages of nuclear power plant construction in the CSSR. The questions are discussed of capital investment, territorial planning activities, pre-project and project documentation; a survey is presented of legislative provisions involving the project design and capital investment spheres. Briefly outlined are topics for further rationalization of feasibility studies, such as standardization and complex project designs of WWER type nuclear power plants, the introduction of data processing in capital investment provision of WWER type nuclear power plants, and international scientific and technical cooperation including the establishment of a international consultancy centre for the designing and methodology of controlling the building, repairs, reconstruction and the decommissioning of WWER type nuclear power plants. (Z.M.). 81 figs., 2 tabs., 12 refs

  12. Nuclear Power in Space

    Science.gov (United States)

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  13. CANDU passive shutdown systems

    International Nuclear Information System (INIS)

    CANDU incorporates two diverse, passive shutdown systems (Shutdown System No. 1 and Shutdown System No. 2) which are independent of each other and from the reactor regulating system. Both shutdown systems function in the low pressure, low temperature, moderator which surrounds the fuel channels; the shutdown systems do not penetrate the heat transport system pressure boundary. The shutdown systems are functionally different, physically separate, and passive since the driving force for SDS1 is gravity and the driving force for SDS2 is stored energy. The physics of the reactor core itself ensures a degree of passive safety in that the relatively long prompt neutron generation time inherent in the design of CANDU reactors tend to retard power excursions and reduces the speed required for shutdown action, even for large postulated reactivity increases. All passive systems include a number of active components or initiators. Hence, an important aspect of passive systems is the inclusion of fail safe (activated by active component failure) operation. The mechanisms that achieve the fail safe action should be passive. Consequently the passive performance of the CANDU shutdown systems extends beyond their basic modes of operation to include fail safe operation based on natural phenomenon or stored energy. For example, loss of power to the SDS1 clutches results in the drop of the shutdown rods by gravity, loss of power or instrument air to the injection valves of SDS2 results in valve opening via spring action, and rigorous self checking of logic, data and timing by the shutdown systems computers assures a fail safe reactor trip through the collapse of a fluctuating magnetic field or the discharge of a capacitor. Event statistics from operating CANDU stations indicate a significant decrease in protection system faults that could lead to loss of production and elimination of protection system faults that could lead to loss of protection. This paper provides a comprehensive

  14. A review of CANDU plant lifetime management

    International Nuclear Information System (INIS)

    In recent years, plant lifetime management(PLIM) including life extension has become the focus of the nuclear industry worldwide due to a number of factors which have arisen over the past decade : new siting difficulties, imbalance of power supply and demand, and high construction costs. In order to solve the problems, the PLIM program is being developed for the purpose of life extension and improvement of plant availability and safety. This paper describes the current activities and prospects of AECL and CANDU utilities, the conceptional evaluation results for the degradation mechanisms, and PLIM regulatory aspects. In addition, this paper provides the applicability of CANDU PLIM to Wolsong Unit 1 which has been operated for 17 years

  15. The nuclear power cycle

    International Nuclear Information System (INIS)

    Fifty years after the first nuclear reactor come on-line, nuclear power is fourth among the world's primary energy sources, after oil, coal and gas. In 2002, there were 441 reactors in operation worldwide. The United States led the world with 104 reactors and an installed capacity of 100,000 MWe, or more than one fourth of global capacity. Electricity from nuclear energy represents 78% of the production in France, 57% in Belgium, 46% in Sweden, 40% in Switzerland, 39% in South Korea, 34% in Japan, 30% in Germany, 30% in Finland, 26% in Spain, 22% in Great Britain, 20% in the United States and 16% in Russia. Worldwide, 32 reactors are under construction, including 21 in Asia. This information document presents the Areva activities in the nuclear power cycle: the nuclear fuel, the nuclear reactors, the spent fuel reprocessing and recycling and nuclear cleanup and dismantling. (A.L.B.)

  16. Commercial nuclear power 1990

    International Nuclear Information System (INIS)

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs

  17. Nuclear power - Sustainable development - Professional skill

    International Nuclear Information System (INIS)

    Sustainable development of society implies taking political decisions integrating harmoniously ingredients like these: - technological maturity; - socio-economic efficiency; - rational and equitable use of natural resources; - compliance with requirements concerning the environment and population; - professional ethics; - communications with the public and media; - professional skill; - public opinion acceptance. A rational analysis of these factors shows clearly that nuclear power appears to be an optimal ground for a sustainable power source besides the hydro and thermo-electric systems. Such a conclusion was confirmed by all types of analyses, methodologies or programs like for instance: MAED, WASP, FINPLAN, DECADES, ENPEP and more recently MESSAGE. The paper describes applications of these analytical methodologies for two scenarios of Cernavoda NPP future development. To find the optimal development strategy for the electric system, implying minimal costs the optimization analysis mode of the ELECSAM analysis module was used. The following conclusions were reached: - the majority of Romania's classical electrical stations are old; consequently, part of them should be decommissioned while others will be refurbished. Instead of installing new power groups these options will result in lowering the investment cost, as well as, in reduction of noxious gas emission; - the nuclear power system developed in Romania upon the CANDU technology appears to be one of the most performing and safe technology in the world. Cernavoda NPP Unit 1 commissioned on December 2, 1996 covers about 10% to 12% of the energy demand of the country. The CANDU systems offers simultaneously secure energy supply, safe operation, low energy costs and practically a zero impact upon the environment. The case study for Romania by means of DECADES project showed that the development program with minimal cost for electrical stations implies construction of new 706.5 MW nuclear units and new 660 MW

  18. Structural reliability modes in the containment of CANDU multi unit nuclear stations - an example: Vacuum building

    International Nuclear Information System (INIS)

    CANDU plants have vacuum buildings (VB) in which the pressure is maintained close to vacuum. In case of LOCA, the released radionuclides are drawn into subatmospheric VB, doused and contained without being released to the environment. In the pre-Darlington CANDU plants, the VB were built with flat roofs. The roofs had to be connected to the perimeter walls with rubber seals to allow for the movement of the roofs relative to the perimeter walls without significantly affecting stresses in both the roofs and the perimeter walls. This was expected to be the controlling factor in VB structural reliability. An analysis showed that a new replacement silicone rubber fabric reinforced composite would provide the seal with the same reliability as traditional structural components. The new silicone rubber spare seals will be used to replace the existing VB ones, when the need arises. This study has shown that the new selection has a structural reliability equivalent to that of reinforced or prestressed concrete. The newly selected silicone rubber material is either better than or equal to the currently existing VB roof rubber seals (neoprene or EPDM), which are no longer commercially available. (orig./HP)

  19. Remote metallurgical investigations on pressure tubes removed from CANDU power reactors

    International Nuclear Information System (INIS)

    As part of the periodic in-service inspection program for CANDU reactors, pressure tubes are periodically removed for destructive examination. The procedures, equipment, and facilities used to perform metallurgical examinations on these highly irradiated components are described. The initial examinations of the tubes from the generating station are performed underwater in inspection bays. Detailed visual examination and metallography are subsequently performed in shielded hot-cell facilities; a description of the remote metallographic equipment and preparation techniques used is given. Examinations of two recently removed Zr-2.5%Nb pressure tubes containing fretting-wear flaws and a lamination flaw are used to highlight the techniques employed

  20. Design features of Candu 9

    International Nuclear Information System (INIS)

    Thirty-two nuclear generating units with an aggregate installed capacity of 19,119 MWe worldwide are equipped with heavy water moderated and cooled pressure tube reactors of the Canadian Candu line. The list includes nine reactors of the 700 MWe category, and twelve reactors of the 900 MWe category in the Candu 6 series. On the basis of the 900 MWe units, Atomic Energy of Canada Ltd. (AECL) developed the advanced Candu 9 series by evolution. This series has been designed for a service life of sixty years. The use of modular, simplified units and systems in the Candu 9 design is to shorten the planning and construction phase, increase safety, and improve plant operation. AECL will offer this reactor on the world market, first to its customers in (South) Korea, which is one of the reasons why the safety parameters have been chosen especially under the aspect of seismic characteristics. (orig.)

  1. Development of nuclear power

    International Nuclear Information System (INIS)

    An extensive discussion of problems concerning the development of nuclear power took place at the fifth regular session of the IAEA General Conference in September-October 1961. Not only were there many references in plenary meetings to the nuclear power plans of Member States, but there was also a more specific and detailed debate on the subject, especially on nuclear power costs, in the Program, Technical and Budget Committee of the Conference. The Conference had before it a report from the Board of Governors on the studies made by the Agency on the economics of nuclear power. In addition, it had been presented with two detailed documents, one containing a review of present-day costs of nuclear power and the other containing technical and economic information on several small and medium-sized power reactors in the United States. The Conference was also informed of the report on methods of estimating nuclear power costs, prepared with the assistance of a panel of experts convened by the Agency, which was reviewed in the July 1961 issue of this Bulletin

  2. Lessons learned from current Qinshan CANDU project and the impact on future NPP's

    International Nuclear Information System (INIS)

    AECL has adopted an evolutionary approach to the development of the CANDU 6 and CANDU 9 Nuclear Power Plant (NPP) designs. Each new NPP project benefits from previous projects and contains an increasing number of fully proven enhancements. In accordance with this evolutionary design approach, AECL has built on the Wolsong and Qinshan successes and the solid performance of the reference CANDU stations to define, review and implement the enhancements for the CANDU 9 NPP. Some of these enhancements include fully integrated project information systems and databases, safety enhancements coming from PSA studies and licensing activities, distributed control systems for plant-wide control and an advanced control center which addresses human factors engineering concepts. Examples of the Qinshan CANDU project delivery enhancements are the utilization of electronic engineering tools for the complete plant, and the linking of these tools with the project material management system and document management systems. The project information is reviewed and approved at the engineering office in Canada and then transmitted to site electronically. Once the electronic data is at site the information packages are extracted as necessary to enable construction and facilitate contract needs with minimum effort. This paper will provide details of the CANDU Qinshan project experiences as well as describing some of the corresponding CANDU 9 enhancements. (author)

  3. The role of NDT in nuclear power development in Pakistan

    International Nuclear Information System (INIS)

    Pakistan has two operating nuclear power plants namely, Karachi Nuclear Power Plant (KANUPP) which is 137 MW Candu type Canadian reactor using natural uranium fuel and the Chashma Nuclear Power Plant (CHASNUPP) which is a 300 MW PWR type Chinese built reactor using 3% enriched uranium fuel. A third nuclear power plant is being negotiated for construction. This would most probably be the twin unit of CHASNUPP and the construction might begin early next year.Non destructive testing (NDT) has an important role in the development and safe operation of the nuclear power plants by providing the Pre-Service Inspection (PSI) services during the manufacturing and installation phase, and the In-Service Inspection (ISI) services during the operation and maintenance phase. ISI of various components of nuclear power plants is an essential activity which has to be carried out either on emergency basis on as and when required basis or periodically at regular intervals described in the quality assurance QA manuals of the plant. There are numerous components and systems in the nuclear power plants working together. The failure of one system affects the performance of the whole plant. There are two main divisions, called the Nuclear Island and Conventional Island. Main components of Nuclear Island are reactor pressure vessel, reactor core, steam generators, pressurizer, primary coolant pumps and primary piping, etc. and the main components in Conventional Island are turbine, condensers, pre-heaters, moisture separators, secondary heat treatment system and piping etc. (Author)

  4. Nuclear power experience

    International Nuclear Information System (INIS)

    The International Conference on Nuclear Power Experience, organized by the International Atomic Energy Agency, was held at the Hofburg Conference Center, Vienna, Austria, from 13 to 17 September 1982. Almost 1200 participants and observers from 63 countries and 20 organizations attended the conference. The 239 papers presented were grouped under the following seven main topics: planning and development of nuclear power programmes; technical and economic experience of nuclear power production; the nuclear fuel cycle; nuclear safety experience; advanced systems; international safeguards; international co-operation. The proceedings are published in six volumes. The sixth volume contains a complete Contents of Volume 1 to 5, a List of Participants, Authors and Transliteration Indexes, a Subject Index and an Index of Papers by Number

  5. 600 MW nuclear power database

    International Nuclear Information System (INIS)

    600 MW Nuclear power database, based on ORACLE 6.0, consists of three parts, i.e. nuclear power plant database, nuclear power position database and nuclear power equipment database. In the database, there are a great deal of technique data and picture of nuclear power, provided by engineering designing units and individual. The database can give help to the designers of nuclear power

  6. Nuclear power's dim future

    International Nuclear Information System (INIS)

    The future of nuclear power in the United States is behind us. At the end of 1992, about one-fifth of the U.S. supply of baseload electric power was generated by nuclear plants. The percentage of the nation's electricity produced by nuclear power will decline and the industry's prospects will remain dim. A main damper on the industry's clear plants for the United States in the last 15 years, and none are expected. Other factors that have hurt the American nuclear power industry include escalating capital and operating costs, lengthening licensing and construction times (which contributed substantially to capital cost escalation), allegations of questionable management at several facilities, and seemingly intractable technical problems that include the storage and disposal of increasing amounts of high- and low-level radioactive wastes

  7. Future nuclear power

    International Nuclear Information System (INIS)

    There is no future without nuclear power. Although this view is contested vehemently by dyed-in-the-wool nuclear opponents, more and more indications pointing to a future with nuclear power can be derived from international developments, but are also evident from first principles of the connection between technical development and power supply, especially in the light of global changes over very long periods of time. A qualitative comparison is made of pre-industrial, industrial and post-industrial modes of technical production; the characteristics of the latter are derived from the need for consistency with the unlimited technical possibilities of automation of human labor. It is seen that future requirements to be met in energy supply will be determined chiefly by contraints of reproducing nature. Given proper further development, nuclear power will be able to meet these requirements quickly and extensively. Other sources of primary energy are indispensable over interim periods of time. (orig.)

  8. Safeguarding nuclear power stations

    International Nuclear Information System (INIS)

    The basic features of nuclear fuel accounting and control in present-day power reactors are considered. Emphasis is placed on reactor operations and spent-fuel characteristics for Light-Water Reactors (LWRs) and Heavy-Water Reactors (HWRs)

  9. Nuclear power plant construction

    International Nuclear Information System (INIS)

    The legal aspects of nuclear power plant construction in Brazil, derived from governamental political guidelines, are presented. Their evolution, as a consequence of tecnology development is related. (A.L.S.L.)

  10. CANDU 9 Design improvements based on experience feedback

    International Nuclear Information System (INIS)

    An evolutionary approach utilizing advance technologies has been implenented for the enhancement introduced in the CANDU 9 Nuclear Power Plant (NPP) design. The design of these systems and associated equipment has also benfited from experience feedback from operating CANDU stations and from including advanced products from CANDU engineering and research programs. This paper highlights the design features that contribute to the safety improvements of the CANDU 9 design, summarizes the analysis results which demonstrate the improved performance and also emphasizes design features which reduce operation and maintenance (Q and M) costs. The safety design features highlighted include the increased use of passive devices and heat sinks to achieve extensive system simplification; this also improves reliability and reduces maintenance workloads. System features that contribute to improved operability are also described. The CANDU 9 Control Center provides plant staff with enhanced operating, maintenance and diagnostics features which significantly improve operability, testing and maintainability due to the integration of human factors engineering with a systematic design process. (author)

  11. Safety and nuclear power

    International Nuclear Information System (INIS)

    Representatives of the supporters and opponents of civil nuclear power put forward the arguments they feel the public should consider when making up their mind about the nuclear industry. The main argument in favour of nuclear power is about the low risk in comparison with other risks and the amount of radiation received on average by the population in the United Kingdom from different sources. The aim is to show that the nuclear industry is fully committed to the cause of safety and this has resulted in a healthy workforce and a safe environment for the public. The arguments against are that the nuclear industry is deceitful, secretive and politically motivated and thus its arguments about safety, risks, etc, cannot be trusted. The question of safety is considered further - in particular the perceptions, definitions and responsibility. The economic case for nuclear electricity is not accepted. (U.K.)

  12. Luncheon address: Development of the CANDU reactor

    International Nuclear Information System (INIS)

    The paper is a highlight of the some of the achievements in the development of the CANDU Reactor, taken from the book Canada Enters the Nuclear Age. The CANDU reactor is one of Canada's greatest scientific/engineering achievements, that started in the 1940's and bore fruit with the reactors of the 60's, 70's, and 80's. The Government decided in the 1950's to proceed with a demonstration nuclear power reactor (NPD), AECL invited 7 Canadian corporations to bid on a contract to design and construct the NPD plant. General Electric was selected. A utility was also essential for participation and Ontario Hydro was chosen. In May 1957 it was concluded that the minimum commercial size would be about 200MWe and it should use horizontal pressure tubes to contain the fuel and pressurized heavy water coolant. The book also talks of standard out-reactor components such as pumps, valves, steam generators and piping. A major in-reactor component of interest was the fuel, fuel channels and pressure tubes. A very high level of cooperation was required for the success of the CANDU program

  13. Globalization and nuclear power

    International Nuclear Information System (INIS)

    Different aspects of the experience of nuclear power as recounted by well-known commentators and new contributors are included in two special issues. In general, the discussions are historical and theoretical and most are retrospective. The current position of nuclear power world wide is considered. Its future seems less than secure especially as it will have to compete alongside other energy sources with many problems of control of its materials still unresolved. (UK)

  14. Commercial nuclear power 1989

    International Nuclear Information System (INIS)

    This report presents historical data on commercial nuclear power in the United States, with projections of domestic nuclear capacity and generation through the year 2020. The report also gives country-specific projections of nuclear capacity and generation through the year 2010 for other countries in the world outside centrally planned economic areas (WOCA). Information is also presented regarding operable reactors and those under construction in countries with centrally planned economies. 39 tabs

  15. Nuclear power plant erection

    International Nuclear Information System (INIS)

    The erection of a nuclear power plant covers all the installation operations related to mechanical and electrical equipment in buildings designed for this specific purpose. Some of these operations are described: erection of the nuclear boiler, erection work carried out in the building accomodating the nuclear auxiliary and ancillary equipment and the methods and the organization set up in order to carry out this work satisfactorily are analyzed

  16. Nuclear power and leukaemia

    International Nuclear Information System (INIS)

    This booklet describes the nature of leukaemia, disease incidence in the UK and the possible causes. Epidemiological studies observing rates of leukaemia near nuclear power stations in the UK and other parts of the world are discussed. Possible causes of leukaemia excesses near nuclear establishments include radioactive discharges into the environment, paternal radiation exposure and viral causes. (UK)

  17. Turkey's nuclear power effort

    International Nuclear Information System (INIS)

    This paper discusses the expected role of nuclear energy in the production of electric power to serve the growing needs of Turkey, examining past activities and recent developments. The paper also reviews Turkey's plans with respect to nuclear energy and the challenges that the country faces along the way

  18. No to nuclear power

    International Nuclear Information System (INIS)

    Kim Beazley has again stated a Labor Government would not pursue nuclear power because the economics 'simply don't stack up'. 'We have significant gas, coal and renewable energy reserves and do not have a solution for the disposal of low-level nuclear waste, let alone waste from nuclear power stations.' The Opposition Leader said developing nuclear power now would have ramifications for Australia's security. 'Such a move could result in our regional neighbours fearing we will use it militarily.' Instead, Labor would focus on the practical measures that 'deliver economic and environmental stability while protecting our national security'. Mr Beazley's comments on nuclear power came in the same week as Prime Minister John Howard declined the request of Indian Prime Minister Manmohan Singh for uranium exports, although seemingly not ruling out a policy change at some stage. The Prime Ministers held talks in New Delhi over whether Australia would sell uranium to India without it signing the Nuclear Non-Proliferation Treaty. An agreement reached during a visit by US President George W. Bush gives India access to long-denied nuclear technology and guaranteed fuel in exchange for allowing international inspection of some civilian nuclear facilities. Copyright (2006) Crown Content Pty Ltd

  19. Nuclear Power Plant Technician

    Science.gov (United States)

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  20. Nuclear power in space

    International Nuclear Information System (INIS)

    The development of space nuclear power and propulsion in the United States started in 1955 with the initiation of the ROVER project. The first step in the ROVER program was the KIWI project that included the development and testing of 8 non-flyable ultrahigh temperature nuclear test reactors during 1955-1964. The KIWI project was precursor to the PHOEBUS carbon-based fuel reactor project that resulted in ground testing of three high power reactors during 1965-1968 with the last reactor operated at 4,100 MW. During the same time period a parallel program was pursued to develop a nuclear thermal rocket based on cermet fuel technology. The third component of the ROVER program was the Nuclear Engine for Rocket Vehicle Applications (NERVA) that was initiated in 1961 with the primary goal of designing the first generation of nuclear rocket engine based on the KIWI project experience. The fourth component of the ROVER program was the Reactor In-Flight Test (RIFT) project that was intended to design, fabricate, and flight test a NERVA powered upper stage engine for the Saturn-class lunch vehicle. During the ROVER program era, the Unites States ventured in a comprehensive space nuclear program that included design and testing of several compact reactors and space suitable power conversion systems, and the development of a few light weight heat rejection systems. Contrary to its sister ROVER program, the space nuclear power program resulted in the first ever deployment and in-space operation of the nuclear powered SNAP-10A in 1965. The USSR space nuclear program started in early 70's and resulted in deployment of two 6 kWe TOPAZ reactors into space and ground testing of the prototype of a relatively small nuclear rocket engine in 1984. The US ambition for the development and deployment of space nuclear powered systems was resurrected in mid 1980's and intermittently continued to date with the initiation of several research programs that included the SP-100, Space Exploration

  1. Systems analysis of the CANDU 3 Reactor

    International Nuclear Information System (INIS)

    This report presents the results of a systems failure analysis study of the CANDU 3 reactor design; the study was performed for the US Nuclear Regulatory Commission. As part of the study a review of the CANDU 3 design documentation was performed, a plant assessment methodology was developed, representative plant initiating events were identified for detailed analysis, and a plant assessment was performed. The results of the plant assessment included classification of the CANDU 3 event sequences that were analyzed, determination of CANDU 3 systems that are ''significant to safety,'' and identification of key operator actions for the analyzed events

  2. Thorium fuel cycles in CANDU

    International Nuclear Information System (INIS)

    In recent years, Atomic Energy of Canada Limited has been examining in detail the implications of using thorium-based fuels tn the CANDU reactor. Various cycles initiated and enriched either with fissile plutonium or with enriched uranium, and with effective conversion ratios ranging up to 1.0, have been evaluated. We have concluded that: 1. Substantial quantities of uranium can be saved by adoption of the thorium fuel cycle, and the long-term security of fissile supply both for the domestic and overseas market can be considerably enhanced. The amount saved will depend on the details of the fuel cycle and the anticipated growth of nuclear power in Canada. 2. The fuel cycle can be introduced into the basic CANDU design without major modifications and without compromising current safety standards. 3. The economic conditions that make thorium competitive with the once-through natural uranium cycle depend a the price of uranium and on the costs both to fabricate α and γ-emitting fuels and to either enrich uranium or to extract fissile material from spent fuel. While timing is difficult to predict, we believe that competitive economic conditions will prevail toward the end of this century. 4. A twenty-year technological development program will be required to establish commercial confidence in the fuel cycle. (author)

  3. Cost comparison of 4x500 MW coal-fuelled and 4x850 MW CANDU nuclear generating stations

    International Nuclear Information System (INIS)

    The lifetime costs for a 4x850 MW CANDU generating station are compared to those for 4x500 MW bituminous coal-fuelled generating stations. Two types of coal-fuelled stations are considered; one burning U.S. coal which includes flue gas desulfurization and one burning Western Canadian coal. Current estimates for the capital costs, operation and maintenance costs, fuel costs, decommissioning costs and irradiated fuel management costs are shown. The results show: (1) The accumulated discounted costs of nuclear generation, although initially higher, are lower than coal-fuelled generation after two or three years. (2) Fuel costs provide the major contribution to the total lifetime costs for coal-fuelled stations whereas capital costs are the major item for the nuclear station. (3) The break even lifetime capacity factor between nuclear and U.S. coal-fuelled generation is projected to be 5%; that for nuclear and Canadian coal-fuelled generation is projected to be 9%. (4) Large variations in the costs are required before the cost advantage of nuclear generation is lost. (5) Comparison with previous results shows that the nuclear alternative has a greater cost advantage in the current assessment. (6) The total unit energy cost remains approximately constant throughout the station life for nuclear generation while that for coal-fuelled generation increases significantly due to escalating fuel costs. The 1978 and 1979 actual total unit energy cost to the consumer for several Ontario Hydro stations are detailed, and projected total unit energy costs for several Ontario Hydro stations are shown in terms of escalated dollars and in 1980 constant dollars

  4. Nuclear power for tomorrow

    International Nuclear Information System (INIS)

    The evolution of nuclear power has established this energy source as a viable mature technology, producing at comparative costs more than 16% of the electricity generated world-wide. After outlining the current status of nuclear power, extreme future scenarios are presented, corresponding respectively to maximum penetration limited by technical-economic characteristics, and nuclear phase-out at medium term. The situation is complex and country specific. The relative perception of the importance of different factors and the compensation of advantages vs. disadvantages, or risk vs. benefits, has predominant influence. In order to proceed with an objective and realistic estimate of the future role of nuclear power worldwide, the fundamental factors indicated below pro nuclear power and against are assessed, including expected trends regarding their evolution: Nuclear safety risk; reduction to levels of high improbability but not zero risk. Reliable source of energy; improvements towards uniform standards of excellence. Economic competitiveness vs. alternatives; stabilization and possible reduction of costs. Financing needs and constraints; availability according to requirements. Environmental effects; comparative analysis with alternatives. Public and political acceptance; emphasis on reason and facts over emotions. Conservation of fossil energy resources; gradual deterioration but no dramatic crisis. Energy supply assurance; continuing concerns. Infrastructure requirements and availability; improvements in many countries due to overall development. Non-proliferation in military uses; separation of issues from nuclear power. IAEA forecasts to the year 2005 are based on current projects, national plans and policies and on prevailing trends. Nuclear electricity generation is expected to reach about 18% of total worldwide electricity generation, with 500 to 580 GW(e) installed capacity. On a longer term, to 2030, a stabilized role and place among available viable

  5. Country nuclear power profiles

    International Nuclear Information System (INIS)

    The preparation of Country Nuclear Power Profiles was initiated within the framework of the IAEA's programme for nuclear power plant performance assessment and feedback. It responded to a need for a database and a technical document containing a description of the energy and economic situation and the primary organizations involved in nuclear power in IAEA Member States. The task was included in the IAEA's programmes for 1993/1994 and 1995/1996. In March 1993, the IAEA organized a Technical Committee meeting to discuss the establishment of country data ''profiles'', to define the information to be included in the profiles and to review the information already available in the IAEA. Two expert meetings were convened in November 1994 to provide guidance to the IAEA on the establishment of the country nuclear profiles, on the structure and content of the profiles, and on the preparation of the publication and the electronic database. In June 1995, an Advisory Group meeting provided the IAEA with comprehensive guidance on the establishment and dissemination of an information package on industrial and organizational aspects of nuclear power to be included in the profiles. The group of experts recommended that the profiles focus on the overall economic, energy and electricity situation in the country and on its nuclear power industrial structure and organizational framework. In its first release, the compilation would cover all countries with operating power plants by the end of 1995. It was also recommended to further promote information exchange on the lessons learned from the countries engaged in nuclear programmes. For the preparation of this publication, the IAEA received contributions from the 29 countries operating nuclear power plants and Italy. A database has been implemented and the profiles are supporting programmatic needs within the IAEA; it is expected that the database will be publicly accessible in the future

  6. The enhanced CANDU 6 reactor - Generation III CANDU medium size global reactor

    International Nuclear Information System (INIS)

    Full text: The Enhanced CANDU 6TM (EC6TM) is a Generation III 700 class, heavy water moderated pressure tube reactor, designed to provide safe, reliable, nuclear power. The EC6TM has evolved from the proven CANDU 6 plants licensed and operating in five countries (four continents) with over 150 reactor years of safe operation around the world. In recent years. this global CANDU 6 fleet, with over 92% average gross capacity factor has ranked in the world's top performing reactors. The EC6 reactor builds on this success of the CANDU 6 fleet by using the operation, experience and project feedback to upgrade the design and construction techniques. A key objective of the EC6 has been to review and incorporate design improvements in the CANDU 6 to meet current safety standards. The key characteristics of the highly successful CANDU 6 reactor design include: - Powered by natural Uranium; - Ease of installation with modular, horizontal fuel channel core; - Separate low-temperature, low-pressure moderator providing inherently passive heat sinks; Reactor vault filled with light water surrounding the core; - Two independent safety shutdown systems; - On-power fuelling; - The CANDU 6 plant has a highly automated control system, with plant control computers that adjust and maintain the reactor power for plant stability (which is particularly beneficial in less developed power grids-where fluctuations occur regularly and capacities are limited). The major improvements incorporated in the EC6 design include, - More robust containment and increased passive features e.g., thicker walls, steel liner; - Enhanced severe accident management with additional emergency heat removal systems; - Improved shutdown performance for improved Large LOCA margins; - Upgraded fire protection systems to meet current Canadian and International standards; - Additional design features to improve environmental protection for workers and public- ALARA principle; - Automated and unitized back-up standby

  7. Mitigating aging in CANDU plants

    International Nuclear Information System (INIS)

    Aging degradation is a phenomenon we all experience throughout life, both on a personal basis and in business. Many industries have been successful in postponing the inevitable impact on their related systems and components through programs to maintain long-term reliability, maintainability and safety. However, this has not always been the case for nuclear power. While all power plants are experiencing the world trend of increasing operating costs with age, few (if any) have been able to fully define the parameters that solve the aging equation, particularly in relation to major components. Inspection and preventive maintenance have not been effective in predicting life-limiting degradation and failure. In CANDU nuclear plants, utilities are taking a comprehensive approach in dealing with the aging problem. Programs have been established to identify the current condition and degradation mechanisms of critical components, the failure of which would impact negatively on station competitiveness and safety. These include subcomponents under the general headings of reactor components, civil structures, piping (nuclear and conventional), steam generators, turbines and cables. In support of these efforts, R and D projects have been defined under the CANDU Owners Group to deal with generic issues on aging common to its members (e.g., investigation of degradation mechanisms, development of tools and techniques to mitigate the effects of aging, etc.). This paper describes recent developments of this cost-shared program with specific reference to concrete aging and crack repairs, flow-assisted corrosion in piping, elastomer service life, cable aging, degradation mechanisms in steam generators and lubricant breakdown. (author)

  8. The reality of nuclear power

    International Nuclear Information System (INIS)

    The following matters are discussed in relation to the nuclear power programmes in USA and elsewhere: siting of nuclear power plants in relation to a major geological fault; public attitudes to nuclear power; plutonium, radioactive wastes and transfrontier contamination; radiation and other hazards; economics of nuclear power; uranium supply; fast breeder reactors; insurance of nuclear facilities; diversion of nuclear materials and weapons proliferation; possibility of manufacture of nuclear weapons by developing countries; possibility of accidents on nuclear power plants in developing countries; radiation hazards from use of uranium ore tailings; sociological alternative to use of nuclear power. (U.K.)

  9. France without nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Charmant, A.; Devezeaux de Lavergne, J.-G.; Ladoux, N.; Vielle, M. (Atomic Energy Commission, Paris (France))

    1993-01-01

    As environmental issues (particularly questions associated with the greenhouse effect) become a matter of increasing current concern, so the French nuclear power programme can, in retrospect, be seen to have had a highly positive impact upon emissions of atmospheric pollutants. The most spectacular effect of this programme has been the reduction of carbon dioxide emissions from 530 million tonnes per annum in 1973 to 387 million tonnes per annum today. Obviously, this result cannot be considered in isolation from the economic consequences of the nuclear power programme, which have been highly significant. The most obvious consequence of nuclear power has been the production of cheap electricity, while a further consequence has been the stability of electricity prices resulting from the increasing self-sufficiency of France in energy supplies (from 22% in 1937 to 47% in 1989). The French nuclear industry is also a source of exports, contributing FF 20 billion to the credit side of the balance of payments in 1989. The authors therefore feel that a numerical assessment of the macroeconomic impact of the nuclear power programme is essential to any accurate evaluation of the environmental consequences of that programme. This assessment is set out in the paper using the Micro-Melodie macroeconomic and energy supply model developed by the CEA (Atomic Energy Commission). An assessment of the role of nuclear power in combatting the greenhouse effect is made. 9 refs., 13 figs., 13 tabs.

  10. Future nuclear power generation

    International Nuclear Information System (INIS)

    The book includes an introduction then it speaks about the options to secure sources of energy, nuclear power option, nuclear plants to generate energy including light-water reactors (LWR), heavy-water reactors (HWR), advanced gas-cooled reactors (AGR), fast breeder reactors (FBR), development in the manufacture of reactors, fuel, uranium in the world, current status of nuclear power generation, economics of nuclear power, nuclear power and the environment and nuclear power in the Arab world. A conclusion at the end of the book suggests the increasing demand for energy in the industrialized countries and in a number of countries that enjoy special and economic growth such as China and India pushes the world to search for different energy sources to insure the urgent need for current and anticipated demand in the near and long-term future in light of pessimistic and optimistic outlook for energy in the future. This means that states do a scientific and objective analysis of the currently available data for the springboard to future plans to secure the energy required to support economy and welfare insurance.

  11. The nuclear power alternative

    International Nuclear Information System (INIS)

    The Director General of the IAEA stressed the need for energy policies and other measures which would help to slow and eventually halt the present build-up of carbon dioxide, methane and other so-called greenhouse gases, which are held to cause global warming. He urged that nuclear power and various other sources of energy, none of which contribute to global warming, should not be seen as alternatives, but should all be used to counteract the greenhouse effect. He pointed out that the commercially used renewable energies, apart from hydropower, currently represent only 0.3% of the world's energy consumption and, by contrast, the 5% of the world's energy consumption coming from nuclear power is not insignificant. Dr. Blix noted that opposition for nuclear power stems from fear of accidents and concern about the nuclear wastes. But no generation of electricity, whether by coal, hydro, gas or nuclear power, is without some risk. He emphasized that safety can never be a static concept, and that many new measures are being taken by governments and by the IAEA to further strengthen the safety of nuclear power

  12. Nuclear power in perspective

    International Nuclear Information System (INIS)

    The nuclear power debate hinges upon three major issues: radioactive waste disposal, reactor safety and proliferation. An alternative strategy for waste disposal is advocated which involves disposing of the radwaste (immobilized in SYNROC, a titanate ceramic waste form) in deep (4 km) drill-holes widely dispersed throughout the entire country. It is demonstrated that this strategy possesses major technical (safety) advantages over centralized, mined repositories. The comparative risks associated with coal-fired power generation and with the nuclear fuel cycle have been evaluated by many scientists, who conclude that nuclear power is far less hazardous. Considerable improvements in reactor design and safety are readily attainable. The nuclear industry should be obliged to meet these higher standards. The most hopeful means of limiting proliferation lies in international agreements, possibly combined with international monitoring and control of key segments of the fuel cycle, such as reprocessing

  13. Candu advanced fuel cycles: key to energy sustainability

    International Nuclear Information System (INIS)

    A primary rationale for Indonesia to proceed with a nuclear power program is to diversity its energy sources and achieve freedom from future resource constraints. While other considerations, such as economy of power supply, hedging against potential future increases in the price of fossil fuels, fostering the technological development of the Indonesia economy and minimizing greenhouse and other gaseous are important, the strategic resource issue is key. In considering candidate nuclear power technologies upon which to base such a program, a major consideration will be the potential for those technologies to be economically sustained in the face of large future increases in demand for nuclear fuels. the technology or technologies selected should be amenable to evaluation in a rapidly changing technical, economic, resource and environmental policy environment. the world's proven uranium resources which can be economically recovered represent a fairly modest energy resource if utilization is based on the currently commercialized fuel cycles, even with the use of recovered plutonium in mixed oxide fuels. In the long term, fuel cycles relying solely on the use of light water reactors will encounter increasing fuel supply constraints. Because of its outstanding neutron economy and the flexibility of on-power refueling, Candu reactors are the most fuel resource efficient commercial reactors and offer the potential for accommodating an almost unlimited variety of advanced and even more fuel efficient cycles. Most of these cycles utilize nuclear fuel which are too low grade to be used in light water reactors, including many products now considered to be waste, such as spent light water reactor fuel and reprocessing products such as recovered uranium. The fuel-cycle flexibility of the Candu reactor provides a ready path to sustainable energy development in both the short and the long terms. Most of the potential Candu fuel cycle developments can be accommodated in existing

  14. CANDU combined cycles featuring gas-turbine engines

    International Nuclear Information System (INIS)

    In the present study, a power-plant analysis is conducted to evaluate the thermodynamic merit of various CANDU combined cycles in which continuously operating gas-turbine engines are employed as a source of class IV power restoration. It is proposed to utilize gas turbines in future CANDU power plants, for sites (such as Indonesia) where natural gas or other combustible fuels are abundant. The primary objective is to eliminate the standby diesel-generators (which serve as a backup supply of class III power) since they are nonproductive and expensive. In the proposed concept, the gas turbines would: (1) normally operate on a continuous basis and (2) serve as a reliable backup supply of class IV power (the Gentilly-2 nuclear power plant uses standby gas turbines for this purpose). The backup class IV power enables the plant to operate in poison-prevent mode until normal class IV power is restored. This feature is particularly beneficial to countries with relatively small and less stable grids. Thermodynamically, the advantage of the proposed concept is twofold. Firstly, the operation of the gas-turbine engines would directly increase the net (electrical) power output and the overall thermal efficiency of a CANDU power plant. Secondly, the hot exhaust gases from the gas turbines could be employed to heat water in the CANDU Balance Of Plant (BOP) and therefore improve the thermodynamic performance of the BOP. This may be accomplished via several different combined-cycle configurations, with no impact on the current CANDU Nuclear Steam Supply System (NSSS) full-power operating conditions when each gas turbine is at maximum power. For instance, the hot exhaust gases may be employed for feedwater preheating and steam reheating and/or superheating; heat exchange could be accomplished in a heat recovery steam generator, as in conventional gas-turbine combined-cycle plants. The commercially available GateCycle power plant analysis program was applied to conduct a

  15. LDC nuclear power: Egypt

    International Nuclear Information System (INIS)

    This chapter reviews the evolution of Egypt's nuclear program, the major factors that influenced the successive series of nuclear decisions, and the public debate over the far-reaching program attempted by the late President Anwar El-Sadat. Egypt's program is important, not only because it was the first Arab country to enter the nuclear age, but because it is an ambitious program that includes the installation of eight reactors at a time when many countries are reducing their commitment to nuclear power. Major obstacles remain in terms of human, organizational, and natural resource constraints. 68 references, 1 table

  16. Advanced CANDU reactor, evolution and innovation

    International Nuclear Information System (INIS)

    burner for MOX and Thorium fuel and is the promising backbone technology for a largescale sustainable development of nuclear power in the world. It has also been assessed for application in hydrogen production and in the development of Canadian oil-sands resources This paper presents an overview of the Advanced CANDU Reactor concept, summarizes the advanced technologies used to achieve construction and operational improvements, and other key features introduced to enhance its competitiveness. (authors)

  17. Pre-licensing of the Advanced CANDU Reactor

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Limited (AECL) developed the Advanced CANDU Reactor-700 (ACR-700) as an evolutionary advancement of the current CANDU 6 reactor. As further advancement of the ACR design, AECL is currently developing the ACR-1000 for the Canadian and international market. The ACR-1000 is aimed at producing electrical power for a capital cost and a unit-energy cost significantly less than that of the current generation of operating nuclear plants, while achieving shorter construction schedule, high plant capacity factor, improved operations and maintenance, increased operating life, and enhanced safety features. The reference ACR-1000 plant design is based on an integrated two-unit plant, using enriched fuel and light-water coolant, with each unit having a nominal gross electrical output of 1165 MWe. The ACR-1000 design has evolved from AECL's in-depth knowledge of CANDU systems, components, and materials, as well as the experience and feedback received from owners and operators of CANDU plants. The ACR design retains the proven strengths and features of CANDU reactors, while incorporating innovations and state-of-the-art technology. It also features major improvements in economics, inherent safety characteristics, and performance, while retaining the proven benefits of the CANDU family of nuclear power plants. The CANDU system is ideally suited to this evolutionary approach since the modular fuel channel reactor design can be modified, through a series of incremental changes in the reactor core design, to increase the power output and improve the overall safety, economics, and performance. The safety enhancements made in ACR-1000 encompass improved safety margins, performance and reliability of safety related systems. In particular, the use of the CANFLEX-ACR fuel bundle, with lower linear rating and higher critical heat flux, provides increased operating and safety margins. Safety features draw from those of the existing CANDU plants (e.g., the two

  18. Nuclear power in Japan

    International Nuclear Information System (INIS)

    The Japanese movement against nuclear energy reached a climax in its upsurge in 1988 two years after the Chernobyl accident. At the outset of that year, this trend was triggered by the government acknowledgement that the Tokyo market was open to foods contaminated by the fallout from Chernobyl. Anti-nuclear activists played an agitating role and many housewives were persuaded to join them. Among many public opinion surveys conducted at that time by newspapers and broadcasting networks, I would like to give you some figures of results from the poll carried out by NHK: Sixty percent of respondents said that nuclear power 'should be promoted', either 'vigorously' 7 or 'carefully' 53%). Sixty-six percent doubted the 'safety of nuclear power', describing it as either 'very dangerous' 20%) or 'rather dangerous' (46%). Only 27% said it was 'safe'. In other words, those who acknowledged the need for nuclear power were almost equal in number with those who found it dangerous. What should these figures be taken to mean? I would take note of the fact that nearly two-thirds of valid responses were in favor of nuclear power even at the time when public opinion reacted most strongly to the impact of the Chernobyl accident. This apparently indicates that the majority of the Japanese people are of the opinion that they would 'promote nuclear power though it is dangerous' or that they would 'promote it, but with the understanding that it is dangerous'. But the anti-nuclear movement is continuing. It remains a headache for both the government and the electric utilities. But we can regard the anti-nuclear movement in Japan as not so serious as that faced by other industrial nations

  19. Steps to nuclear power

    International Nuclear Information System (INIS)

    The recent increase in oil prices will undoubtedly cause the pace at which nuclear power is introduced in developing countries to quicken in the next decade, with many new countries beginning to plan nuclear power programmes. The guidebook is intended for senior government officials, policy makers, economic and power planners, educationalists and economists. It assumes that the reader has relatively little knowledge of nuclear power systems or of nuclear physics but does have a general technical or management background. Nuclear power is described functionally from the point of view of an alternative energy source in power system expansion. The guidebook is based on an idealized approach. Variations on it are naturally possible and will doubtless be necessary in view of the different organizational structures that already exist in different countries. In particular, some countries may prefer an approach with a stronger involvement of their Atomic Energy Commission or Authority, for which this guidebook has foreseen mainly a regulatory and licensing role. It is intended to update this booklet as more experience becomes available. Supplementary guidebooks will be prepared on certain major topics, such as contracting for fuel supply and fuel cycle requirements, which the present book does not go into very deeply

  20. CANDU development

    International Nuclear Information System (INIS)

    Evolution of the 950 MW(e) CANDU reactor is summarized. The design was specifically aimed at the export market. Factors considered in the design were that 900-1000 MW is the maximum practical size for most countries; many countries have warmer condenser cooling water than Canada; the plant may be located on coastal sites; seismic requirements may be more stringent; and the requirements of international, as well as Canadian, standards must be satisfied. These considerations resulted in a 600-channel reactor capable of accepting condenser cooling water at 320C. To satisfy the requirement for a proven design, the 950 MW CANDU draws upon the basic features of the Bruce and Pickering plants which have demonstrated high capacity factors

  1. The advanced carrier bundle - comprehensive irradiation of materials in CANDU power reactors

    International Nuclear Information System (INIS)

    Improved methods of measuring element profiles on new CANDU fuel bundles were developed at the Sheridan Park Engineering Laboratory, and have now been applied in the hot cells at Whiteshell Laboratories. For the first time, the outer element profiles have been compared between new, out-reactor tested, and irradiated fuel elements. The comparison shows that irradiated element deformation is similar to that observed on elements in out-reactor tested bundles. In addition to the restraints applied to the element via appendages, the element profile appears to be strongly influenced by gravity and the end loads applied by local deformation of the endplate. Irradiation creep in the direction of gravity also tends to be a dominant factor. (author)

  2. Space technology needs nuclear power

    International Nuclear Information System (INIS)

    Space technology needs nuclear power to solve its future problems. Manned space flight to Mars is hardly feasible without nuclear propulsion, and orbital nuclear power lants will be necessary to supply power to large satellites or large space stations. Nuclear power also needs space technology. A nuclear power plant sited on the moon is not going to upset anybody, because of the high natural background radiation level existing there, and could contribute to terrestrial power supply. (orig./HP)

  3. Nuclear power: Europe report

    International Nuclear Information System (INIS)

    Last year, 2002, nuclear power plants were available for energy supply, respectively, in 18 countries all over Europe. In 8 of the 15 member countries of the European Union nuclear power plants have been in operation. In 7 of the 13 EU Candidate Countries nuclear energy was used for power production. A total of 213 plants with an aggregate net capacity of 171 814 MWe and an aggregate gross capacity of 181 135 MWe were in operation. One unit, i.e. Temelin-2 in the Czech Republic went critical for the first time and started test operation after having been connected to the grid. Temelin-2 adds about 1 000 MWe (gross) and 953 MWe (net) to the electricity production capacity. The operator of the Bradwell A-1 and Bradwell A-2 power plants in the United Kingdom decided to permanently shut down the plants due to economical reasons. The units Kozloduj-1 and Kozloduj-2 in Bulgaria were permanently shut down due to a request of the European Union. Last year, 9 plants were under construction in Romania (1), Russia (4), Slovakia (2), and the Ukraine (2), that is only in East European Countries. The Finnish parliament approved plans for the construction of the country's fifth nuclear power reactor by a majority of 107 votes to 92. It is the first decision to build a new nuclear power plant in Western Europe since ten years. In eight countries of the European Union 141 nuclear power plants have been operated with an aggregate gross capacity of 128 580 MWe and an aggregate net capacity of 122 517 MWe. Net electricity production in 2002 in the EU amounts to approx. 887.9 TWh gross, which means a share of about 34 per cent of the total production in the whole EU. Shares of nuclear power differ widely among the operator countries. They reach 81% in Lithuania, 78% in France, 58% in Belgium, 55% in the Slovak Republic, and 47% in Sweden. Nuclear power also provides a noticeable share in the electricity supply of countries, which operate no own nuclear power plants, e.g. Italy

  4. Commercial nuclear power 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-28

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs.

  5. The CANDU experience in Romania

    International Nuclear Information System (INIS)

    The CANDU program in Romania is now well established. The Cernavoda Nuclear Station presently under construction will consist of 5-CANDU 600 MWE Units and another similar size station is planned to be in operation in the next decade. Progress on the multi-unit station at Cernavoda was stalled for 18 months in 1982/83 as the Canadian Export Development Corporation had suspended their loan disbursements while the Romanian National debt was being rescheduled. Since resumption of the financing in August 1983 contracts worth almost 200M dollars have been placed with Canadian Companies for the supply of major equipment for the first two units. The Canadian design is that which was used in the latest 600 MWE CANDU station at Wolsong, Korea. The vast construction site is now well developed with the cooling water systems/channels and service buildings at an advanced stage of completion. The perimeter walls of the first two reactor buildings are already complete and slip-forming for the 3rd Unit is imminent. Many Romanian organizations are involved in the infrastructure which has been established to handle the design, manufacture, construction and operation of the CANDU stations. The Romanian manufacturing industry has made extensive preparations for the supply of CANDU equipment and components, and although a major portion of the first two units will come from Canada their intentions are to become largely self-supporting for the ensuing CANDU program. Quality assurance programs have been prepared already for many of the facilities

  6. Nuclear power industry

    International Nuclear Information System (INIS)

    This press dossier presented in Shanghai (China) in April 1999, describes first the activities of the Framatome group in the people's republic of China with a short presentation of the Daya Bay power plant and of the future Ling Ao project, and with a description of the technological cooperation with China in the nuclear domain (technology transfers, nuclear fuels) and in other industrial domains (mechanics, oil and gas, connectors, food and agriculture, paper industry etc..). The general activities of the Framatome group in the domain of energy (nuclear realizations in France, EPR project, export activities, nuclear services, nuclear fuels, nuclear equipments, industrial equipments) and of connectors engineering are presented in a second and third part with the 1998 performances. (J.S.)

  7. Nuclear power. Europe report

    International Nuclear Information System (INIS)

    Last year, 2001, nuclear power plants were available for energy supply, respectively, in 18 countries all over Europe. In 8 of the 15 member countries of the European Union nuclear power plants have been in operation. In 7 of the 13 EU Candidate Countries nuclear energy was used for power production. A total of 216 plants with an aggregate net capacity of 171 802 MWe and an aggregate gross capacity of 181 212 MWe were in operation. One unit, i.e. Volgodonsk-1 in Russia went critical for the first time and started test operation after having been connected to the grid. Volgodonsk-1 adds about 1 000 MWe (gross) nd 953 MWe (net) to the electricity production capacity. The operator of the Muehlheim-Kaerlich NPP field an application to decommission and dismantle the plant; this plant was only 13 months in operation and has been shut down since 1988 for legal reasons. Last year, 10 plants were under construction in Romania (1), Russia (4), Slovakia (2), the Czech Republic (1) and the Ukraine (2), that is only in East European Countries. In eight countries of the European Union 143 nuclear power plants have been operated with an aggregate gross capacity of 128 758 MWe and an aggregate net capacity of 122 601 MWe. Net electricity production in 2001 in the EU amounts to approx. 880.3 TWh gross, which means a share of 33,1 per cent of the total production in the whole EU. Shares of nuclear power differ widely among the operator countries. The reach 75.6% in France, 74.2% in Lithuania, 58.2% in Belgium, 53.2% in the Slovak Republic, and 47.4% in the Ukraine. Nuclear power also provides a noticeable share in the electricity supply of countries, which operate no own nuclear power plants, e.g. Italy, Portugal, and Austria. On May 24th, 2002 the Finnish Parliament voted for the decision in principle to build a fifth nuclear power plant in the country. This launches the next stage in the nuclear power plant project. The electric output of the plant unit will be 1000-1600 MW

  8. Nuclear power's burdened future

    International Nuclear Information System (INIS)

    Although governments of the world's leading nations are reiterating their faith in nuclear power, Chernobyl has brought into focus the public's overwhelming feeling that the current generation of nuclear technology is simple not working. Despite the drastic slowdown, however, the global nuclear enterprise is large. As of mid-1986, the world had 366 nuclear power plants in operation, with a generating capacity of 255,670 MW. These facilities generate about 15% of the world's electricity, ranging from 65% in France to 31% in West Germany, 23% in Japan, 16% in the United States, 10% in the Soviet Union, and non in most developing nations. Nuclear development is clearly dominated by the most economically powerful and technologically advanced nations. The United States, France, the Soviet Union, Japan, and West Germany has 72% of the world's generating capacity and set the international nuclear pace. The reasons for scaling back nuclear programs are almost as diverse as the countries themselves. High costs, slowing electricity demand growth, technical problems, mismanagement, and political opposition have all had an effect. Yet these various factors actually form a complex web of inter-related problems. For example, rising costs usually represent some combination of technical problems and mismanagement, and political opposition often occurs because of safety concerns or rising costs. 13 references

  9. France without nuclear power

    International Nuclear Information System (INIS)

    As environmental issues (particularly questions associated with the greenhouse effect) become a matter of increasing current concern, the French nuclear power programme can, in retrospect, be seen to have had a highly positive impact upon emissions of atmospheric pollutants. The most spectacular effect of this programme was the reduction of carbon dioxide emissions from 530 million tonnes per annum in 1973 to 387 million tonnes per annum today. Obviously, this result cannot be considered in isolation from the economic consequences of the nuclear power programme, which have been highly significant.The most obvious consequence of nuclear power has been the production of cheap electricity, while a further consequence has been the stability of electricity prices resulting from the increasing self-sufficiency of France in energy supplies (from 22% in 1973 to 49.% in 1992). Moreover, French nuclear industry exports. In 1993, 61.7 TW·h from nuclear production were exported, which contributed F.Fr. 14.2 billion to the credit side of the balance of payment. For the same year, Framatome exports are assessed at about F.Fr. 2 billion, corresponding to manufacturing and erection of heavy components, and maintenance services. Cogema, the French nuclear fuel operator, sold nuclear materials and services for F.Fr. 9.3 billion. Thus, nuclear activities contributed more than F.Fr. 25 billion to the balance of payment. Therefore, a numerical assessment of the macroeconomic impact of the nuclear power programme is essential for any accurate evaluation of the environmental consequences of that programme. For this assessment, which is presented in the paper, the Micro-Melodie macroeconomic and energy supply model developed by the Commissariat a l'energie atomique has been used. (author). 6 refs, 4 figs, 1 tab

  10. CANDU at the crossroads

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-11-01

    ''Ready for the challenge of the 90s'' was the theme of this year's gathering of the Canadian Nuclear Association held in Toronto, 3-6 June. What that challenge really entails is whether the CANDU system will survive as the last remaining alternative to the light water reactor in the world reactor market, or whether it will decline into oblivion along with the Advanced Gas Cooled reactor and so many other technically excellent systems which have fallen along the way. The fate of the CANDU system will not be determined by its technical merits, nor by its impeccable safety record. It will be determined by public perceptions and by the deliberations of an Environmental Assessment Panel established by the Government of Ontario. The debate at the Association meeting is reported. (author).

  11. Nuclear Power after Fukushima

    International Nuclear Information System (INIS)

    On 11 March 2011 Japan suffered an earthquake of very high magnitude, followed by a tsunami that left thousands dead in the Sendai region, the main consequence of which was a major nuclear disaster at the Fukushima power station. The accident ranked at the highest level of severity on the international scale of nuclear events, making it the biggest since Chernobyl in 1986. It is still impossible to gauge the precise scope of the consequences of the disaster, but it has clearly given rise to the most intense renewed debates on the nuclear issue. Futuribles echoes this in the 'Forum' feature of this summer issue which is entirely devoted to energy questions. Bernard Bigot, chief executive officer of the technological research organization CEA, looks back on the Fukushima disaster and what it changes (or does not change) so far as the use of nuclear power is concerned, particularly in France. After recalling the lessons of earlier nuclear disasters, which led to the development of the third generation of power stations, he reminds us of the currently uncontested need to free ourselves from dependence on fossil fuels, which admittedly involves increased use of renewables, but can scarcely be envisaged without nuclear power. Lastly, where the Fukushima disaster is concerned, Bernard Bigot shows how it was, in his view, predominantly the product of a management error, from which lessons must be drawn to improve the safety conditions of existing or projected power stations and enable the staff responsible to deliver the right response as quickly as possible when an accident occurs. In this context and given France's high level of dependence on nuclear power, the level of use of this energy source ought not to be reduced on account of the events of March 2011. (author)

  12. Reviewing nuclear power

    International Nuclear Information System (INIS)

    The UK government has proposed a review of the prospects for nuclear power as the Sizewell B pressurized water reactor project nears completion in 1994. However, a delay in the completion of Sizewell B or a change of government could put off the review for some years beyond the mid 1990s. Anticipating, though, that such a review will eventually take place, issues which it should consider are addressed. Three broad categories of possible benefit claimed for nuclear power are examined. These are that nuclear power contributes to the security of energy supply, that it provides protection against long run fossil fuel price increases and that it is a means of mitigating the greenhouse effect. Arguments are presented which cost doubt over the reality of these benefits. Even if these benefits could be demonstrated, they would have to be set against the financial, health and accident costs attendant on nuclear power. It is concluded that the case may be made that nuclear power imposes net costs on society that are not justified by the net benefits conferred. Some comments are made on how a government review, if and when it takes place, should be conducted. (UK)

  13. France without nuclear power

    International Nuclear Information System (INIS)

    As coal production declined and France found herself in a condition of energy dependency, the country decided to turn to nuclear power and a major construction program was undertaken in 1970. The consequences of this step are examined in this article, by imagining where France would be without its nuclear power. At the end of the sixties, fuel-oil incontestably offered the cheapest way of producing electricity; but the first petroleum crisis was to upset the order of economic performance, and coal then became the more attractive fuel. The first part of this article therefore presents coal as an alternative to nuclear power, describing the coal scenario first and then comparing the relative costs of nuclear and coal investment strategies and operating costs (the item that differs most is the price of the fuel). The second part of the article analyzes the consequences this would have on the electrical power market, from the supply and demand point of view, and in terms of prices. The third part of the article discusses the macro-economic consequences of such a step: the drop in the level of energy dependency, increased costs and the disappearance of electricity exports. The article ends with an analysis of the environmental consequences, which are of greater and greater concern today. The advantage here falls very much in favor of nuclear power, if we judge by the lesser emissions of sulfur dioxide, nitrogen oxides and especially carbon dioxide. 22 refs.; 13 figs.; 10 tabs

  14. Feasibility study of CANDU-9 fuel handling system

    International Nuclear Information System (INIS)

    CANDU's combination of natural uranium, heavy water and on-power refuelling is unique in its design and remarkable for reliable power production. In order to offer more output, better site utilization, shorter construction time, improved station layout, safety enhancements and better control panel layout, CANDU-9 is now under development with design improvement added to all proven CANDU advantages or applicable technologies. One of its major improvement has been applied to fuel handling system. This system is very similar to that of CANDU-3, and some parts of the system are applied to those of the existing CANDU-6 or CANDU-9. Design concepts and design requirements of fuel handling system for CANDU-9 have been identified to compare with those of the existing CANDU and the design feasibilities have been evaluated. (author). 4 tabs., 13 figs., 9 refs

  15. The politics of nuclear power

    International Nuclear Information System (INIS)

    The contents of the book are: introduction; (part 1, the economy of nuclear power) nuclear power and the growth of state corporatism, ownership and control - the power of the multi-nationals, economic and political goals - profit or control, trade union policy and nuclear power; (part 2, nuclear power and employment) nuclear power and workers' health and safety, employment and trade union rights, jobs, energy and industrial strategy, the alternative energy option; (part 3, political strategies) the anti-nuclear movement, trade unions and nuclear power; further reading; UK organisations. (U.K.)

  16. Enhanced candu 6 reactor: status

    International Nuclear Information System (INIS)

    The CANDU 6 power reactor is visionary in its approach, renowned for its on-power refuelling capability and proven over years of safe, economical and reliable power production. Developed by Atomic Energy of Canada Limited (AECL), the CANDU 6 design offers excellent performance utilizing state-of-the-art technology. The first CANDU 6 plants went into service in the early 1980s as leading edge technology and the design has been continuously advanced to maintain superior performance with an outstanding safety record. The first set of CANDU 6 plants - Gentilly 2 and Point Lepreau in Canada, Embalse in Argentina and Wolsong- Unit 1 in Korea - have been in service for more than 22 years and are still producing electricity at peak performance; to the end of 2004, their average Lifetime Capacity Factor was 83.2%. The newer CANDU 6 units in Romania (Cernavoda 1), Korea (Wolsong-Units 2, 3 and 4) and Qinshan (Phase III- Units 1 and 2) have also been performing at outstanding levels. The average lifetime Capacity Factor of the 10 CANDU 6 operating units around the world has been 87% to the end of 2004. Building on these successes, AECL is committed to the further development of this highly successful design, now focussing on meeting customers' needs for reduced costs, further improvements to plant operation and performance, enhanced safety and incorporating up-to-date technology, as warranted. This has resulted in AECL embarking on improving the CANDU 6 design through an upgraded product termed the ''Enhanced CANDU 6'' (EC6), which incorporates several attractive but proven features that make the CANDU 6 reactor even more economical, safer and easier to operate. Some of the key features that are being incorporated into the EC6 include increasing the plant's power output, shortening the overall project schedule, decreasing the capital cost, dealing with obsolescence issues, optimizing maintenance outages and incorporating lessons learnt through feedback obtained from the

  17. Environment and nuclear power

    International Nuclear Information System (INIS)

    Aimed at the general public this leaflet, one of a series prepared by AEA Technology, on behalf of the British Nuclear Industry Forum, seeks to put the case for generating electricity to meet United Kingdom and world demand using nuclear power. It examines the environmental problems linked to the use of fossil-fuels in power stations and other uses, such as the Greenhouse Effect. Problems associated with excess carbon dioxide emissions are also discussed, such as acid rain, the effects of deforestation and lead in petrol. The role of renewable energy sources is mentioned briefly. The leaflet also seeks to reassure on issues such as nuclear waste managements and the likelihood and effects of nuclear accidents. (UK)

  18. Nuclear power production costs

    International Nuclear Information System (INIS)

    The economic competitiveness of nuclear power in different highly developed countries is shown, by reviewing various international studies made on the subject. Generation costs (historical values) of Atucha I and Embalse Nuclear Power Plants, which are of the type used in those countries, are also included. The results of an international study on the economic aspects of the back end of the nuclear fuel cycle are also reviewed. This study shows its relatively low incidence in the generation costs. The conclusion is that if in Argentina the same principles of economic racionality were followed, nuclear energy would be economically competitive in the future, as it is today. This is of great importance in view of its almost unavoidable character of alternative source of energy, and specially since we have to expect an important growth in the consumption of electricity, due to its low share in the total consumption of energy, and the low energy consumption per capita in Argentina. (Author)

  19. Thai Nuclear Power Program

    International Nuclear Information System (INIS)

    The Electricity Generating Authority of Thailand (EGAT), the main power producer in Thailand, was first interested in nuclear power as an electricity option in 1967 when the electricity demand increased considerably for the first time as a result of the economic and industrial growth. Its viability had been assessed several times during the early seventies in relation to the changing factors. Finally in the late 1970s, the proceeding with nuclear option was suspended for a variety of reasons, for instance, public opposition, economic repercussion and the uncovering of the indigenous petroleum resources. Nonetheless, EGAT continued to maintain a core of nuclear expertise. During 1980s, faced with dwindling indigenous fossil fuel resources and restrictions on the use of further hydro as an energy source, EGAT had essentially reconsidered introducing nuclear power plants to provide a significant fraction to the long term future electricity demand. The studies on feasibility, siting and environmental impacts were conducted. However, the project was never implemented due to economics crisis in 1999 and strong opposition by environmentalists and activists groups. The 1986 Chernobyl disaster was an important cause. After a long dormant period, the nuclear power is now reviewed as one part of the solution for future energy supply in the country. Thailand currently relies on natural gas for 70 percent of its electricity, with the rest coming from oil, coal and hydro-power. One-third of the natural gas consumed in Thailand is imported, mainly from neighbouring Myanmar. According to Power Development Plan (PDP) 2007 rev.2, the total installed electricity capacity will increase from 28,530.3 MW in 2007 to 44,281 MW by the end of plan in 2021. Significantly increasing energy demand, concerns over climate change and dependence on overseas supplies of fossil fuels, all turn out in a favor of nuclear power. Under the current PDP (as revised in 2009), two 1,000- megawatt nuclear

  20. Nuclear power plants

    International Nuclear Information System (INIS)

    Before the economical adaptability of nuclear power plants was achieved, many ways were tried to technically use nuclear fission. In the course of a selection process, of numerous types of reactors, only a few have remained which are now taking part in the competition. The most important physical fundamentals, the occurence of various reactor concepts and the most important reactor types are the explained. (orig./TK)

  1. Nuclear power in Germany

    International Nuclear Information System (INIS)

    I want to give some ideas on the situation of public and utility acceptance of nuclear power in the Federal Republic of Germany and perhaps a little bit on Europe. Let me start with public perception. I think in Germany we have a general trend in the public perception of technology during the last decade that has been investigated in a systematic manner in a recent study. It is clear that the general acceptance of technology decreased substantially during the last twenty years. We can also observe during this time that aspects of the benefits of technology are much less reported in the media, that most reporting by the media now is related to the consequences of technologies, such as negative environmental consequences. hat development has led to a general opposition against new technological projects, in particular unusual and large. That trend is related not only to nuclear power, we see it also for new airports, trains, coal-fired plants. here is almost no new technological project in Germany where there is not very strong opposition against it, at least locally. What is the current public opinion concerning nuclear power? Nuclear power certainly received a big shock after Chernobyl, but actually, about two thirds of the German population wants to keep the operating plants running. Some people want to phase the plants out as they reach the end-of-life, some want to substitute newer nuclear technology, and a smaller part want to increase the use of nuclear power. But only a minority of the German public would really like to abandon nuclear energy

  2. Nuclear power: Europe report

    International Nuclear Information System (INIS)

    Last year, 1999, nuclear power plants were available for energy supply, respectively, in 18 countries all over Europe. In eight of the fifteen member countries of the European Union nuclear power plants have been in operation. A total of 218 plants with an aggregate net capacity of 181,120 MWe and an aggregate gross capacity of 171,802 MWe were in operation. Two units, i.e. Civaux 2 in France and Mochovce-2 in Slovakia went critical for the first time and started commercial operation after having been connected to the grid. Three further units in France, Chooz 1 and 2 and Civaux 1, started commercial operation in 1999 after the completion of technical measures in the primary circuit. Last year, 13 plants were under construction in Romania, Russia, Slovakia and the Czech Republic, that is only in East European countries. In eight countries of the European Union 146 nuclear power plants have been operated with an aggregate gross capacity of 129.772 MWe and an aggregate net capacity of 123.668 MWe. Net electricity production in 1999 in the EU amounts to approx. 840.2 TWh, which means a share of 35 per cent of the total production. Shares of nuclear power differ widely among the operator countries. They reach 75 per cent in France, 73 per cent in Lithuania, 58 per cent in Belgium and 47 per cent in Bulgaria, Sweden and Slovakia. Nuclear power also provides a noticeable share in the electricity supply of countries, which operate no own nuclear power plants, e.g. Italy, Portugal and Austria. (orig.)

  3. Independence and diversity in CANDU shutdown systems

    International Nuclear Information System (INIS)

    Atomic Energy Control Board regulations state that Canadian CANDU reactors shall have two fully effective, independent and diverse shutdown systems. The Darlington Nuclear Generating Station is the first power plant operated by Ontario Hydro to make use of software-based computer control in its shutdown systems. By virtue of the reliance placed on these systems to prevent exposure of the public to harmful radioactivity in the event of an accident, the shutdown system software has been categorized as safety critical software. An important issue that was considered in the design of the Darlington shutdown systems was how the software should be designed and incorporated into the systems to comply with the independence and diversity requirement. This paper describes how the independence and diversity requirement was complied with in previous CANDU shutdown system designs utilizing hardware components. The difference between systems utilizing hardware alone, and those utilizing both hardware and software are discussed. The results of a literature search into the issue of software diversity, the behaviour of multi-version software systems, and experience in other industries utilizing safety critical software are referred to. This paper advocates a systems approach to designing independent shutdown systems utilizing software. Opportunities exist at the system level for design decisions that can enhance software diversity and can reduce the likelihood of common mode faults in the systems. In the light of recent experience in implementing diverse safety critical software, potential improvements to the design process for CANDU shutdown systems are identified. (Author) 19 refs

  4. How nuclear power began

    International Nuclear Information System (INIS)

    Many of the features of the story of nuclear power, both in nuclear weapons and nuclear power stations, derive from their timing. Usually, in the history of science the precise timing of discovery does not make much difference, but in the case of nuclear fission there was the coincidence that crucial discoveries were made and openly published in the same year, 1939, as the outbreak of the Second World War. It is these events of the 1930s and the early post-war era that are mainly discussed. However, the story began a lot earlier and even in the early 1900s the potential power within the atom had been foreseen by Soddy and Rutherford. In the 1930s Enrico Fermi and his team saw the technological importance of their discoveries and took out a patent on their process to produce artificial radioactivity from slow neutron beams. The need for secrecy because of the war, and the personal trusts and mistrusts run through the story of nuclear power. (UK)

  5. The Candu suppliers: Growing beyond Canada

    International Nuclear Information System (INIS)

    Canada has demonstrated its ability to successfully manage Candu projects. It has been shown domestically by Ontario Hydro over a period of many years. It has been demonstrated abroad by private sector service companies, under Nuclear Construction Managers, on the 600 MW Wolsung project in South Korea, where NPM companies carried out virtually all project and construction management, the plant was in service only 60 months after the first concrete was poured for the reactor building. In the past, however, the project management team for Candu nuclear plants overseas, and for some at home, was often assembled ad hoc. Though this approach can be successful, it does not guarantee success in project and construction management. Because of the size, diversity and flexibility of the private owners of NPM, they have been able to keep their experienced nuclear power teams on staff even though the nuclear power industry has been going through slow times, assigning these people to large projects in other industries that call for the same high level of project, construction and commissioning management skills. Yet they are in a position to reassemble this team at very short notice, and have them ready to go to work on a major project within weeks of the green light

  6. Nuclear power energy mixes

    International Nuclear Information System (INIS)

    The report contains the papers presented at the conference held on 23/24 February 1994 at the RWTH in Aachen. The goal of this conference was to analyse key issues of future energy management from different viewpoints and to attempt to achieve objective estimations. This VDI Report treats the following main themes: - is the climate question relevant? - chances and limits of renewable energy sources - does nuclear power have a future? - are the nuclear and non-nuclear waste problems solvable? - external costs in energy management -company and energy management decision criteria. (orig.)

  7. CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU-PHW program is based upon 38 years of heavy water reactor experience with 35 years of operating experience. Canada has had 72 reactor years of nuclear-electric operations experience with 10 nuclear units in 4 generating stations during a period of 18 years. All objectives have been met with outstanding performance: worker safety, public safety, environmental emissions, reliable electricity production, and low electricity cost. The achievement has been realized through total teamwork involving all scientific disciplines and all project functions (research, design, manufacturing, construction, and operation). (auth)

  8. Review on the application of system engineer model in nuclear power plant

    International Nuclear Information System (INIS)

    system engineer was adopted deeply and play important roles in nuclear power plants in United States and Canada, the plant performance indicates that system engineer mode is a good practice. Qinshan CANDU nuclear power plant, established the system engineer mode since commissioning, as a core, system engineer took charge of the preparation of commissioning procedures, organization, coordination and guidance of commissioning execution. Unit 1 was put into commercial operation 43 days in advance and 112 days ahead of schedule for Unit 2 with excellent quality. Commissioning period are just 10.5 and 7.8 months for both Units respectively. Which is the shortest record in the history of CANDU nuclear power plant commissioning up to now. During operation, systems engineer has strength in routine operating and units reliability improvement. Based on the practice of Qinshan CANDU nuclear power plant commissioning and production technical management, the main form of the article in the era of knowledge: its characteristics and advantage and operating mode of the system engineer mode. System engineer is different from project engineer, he act as the master of systems and takes full responsibility for systems technical management. System engineer should do many jobs and improvement schedule to ensure his system in health status. System health monitor is a basic tool in system management, which is useful for equipment performance improvement. At last, the author made a forecast and comment on the prospects for the system engineer in the future. (author)

  9. Methodology for the control of equipment ageing in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Trudel, F. [Hydro-Quebec, Gentilly-2 Nuclear Generating Station, Gentilly, Quebec (Canada)]. E-mail: Trudel.Francis@hydro.qc.ca; Abdul-Nour, G. [Univ. du Quebec a Trois-Rivieres, Dept. of Industrial Engineering, Trois-Rivieres, Quebec (Canada); Vaillancourt, R.; Komljenovic, D. [Hydro-Quebec, Gentilly-2 Nuclear Generating Station, Gentilly, Quebec (Canada)

    2006-07-01

    This paper presents a methodology for the control of equipment ageing as it applies to CANDU 600 nuclear power plants. The methodology that has been developed is based mainly on the approach proposed in Nuclear Plant Ageing Research (NPAR), a program implemented by the Nuclear Regulatory Commission (NRC). It includes twelve steps covering the selection of the equipment, the understanding and the management of ageing. The methodology complies with the new Canadian nuclear regulations as well as recommendations made by world wide nuclear industry. It has been validated through application to three types of mechanical equipment, with results that are deemed significant. (author)

  10. Conceptual designs for very high-temperature CANDU reactors

    International Nuclear Information System (INIS)

    Although its environmental benefits are demonstrable, nuclear power must be economically competitive with other energy sources to ensure it retains, or increases, its share of the changing and emerging energy markets of the next decades. In recognition of this, AECL is studying advanced reactor concepts with the goal of significant reductions in capital cost through increased thermodynamic efficiency and plant simplification. The program, generically called CANDU-X, examines concepts for the future, but builds on the success of the current CANDU designs by keeping the same fundamental design characteristics: excellent neutron economy for maximum flexibility in fuel cycle; an efficient heavy-water moderator that provides a passive heat sink under upset conditions; and, horizontal fuel channels that enable on-line refueling for optimum fuel utilization and power profiles. Retaining the same design fundamentals takes maximum advantage of the existing experience base, and allows technological and design improvements developed for CANDU-X to be incorporated into more evolutionary CANDU plants in the short to medium term. Three conceptual designs have been developed that use supercritical water (SCW) as a coolant. The increased coolant temperature results in the thermodynamic efficiency of each CANDU-X concept being significantly higher than conventional nuclear plants. The first concept, CANDU-X Mark 1, is a logical extension of the current CANDU design to higher operating temperatures. To take maximum advantage of the high heat capacity of water at the pseudo-critical temperature, water at nominally 25 MPa enters the core at 310oC, and exits at ∼410oC. The high specific heat also leads to high heat transfer coefficients between the fuel cladding and the coolant. As a result, Zr-alloys can be used as cladding, thereby retaining relatively high neutron economy. The second concept, CANDU-X NC, is aimed at markets that require smaller simpler distributed power plants (

  11. Japan's nuclear power tightrope

    International Nuclear Information System (INIS)

    This paper reports that early in February, just as Japan's nuclear energy program was regaining a degree of popular support after three years of growing opposition, an aging pressurized-water reactor at Mihama in western Japan sprang a leak in its primary cooling system. The event occasioned Japan's first nontest use of an emergency core-cooling system. It also elicited a forecast of renewed public skepticism about nuclear power form the Ministry of International Trade and Industry (MITI), the Government body responsible for promoting and regulating Japan's ambitious nuclear power program. Public backing for this form of energy has always been a delicate flower in Japan, where virtually every school child visits the atomic bomb museums at Hiroshima and Nagasaki. Yet the country, which imports 80 percent of its energy and just about all its oil, is behind only the United States, France, and the Soviet Union in installed nuclear capacity. In fiscal 1989, which started in April, Japan's 39 nuclear power stations accounted for 25.5 percent of electricity generated - the largest contribution - followed b coal and natural gas. Twelve more plants are under construction

  12. Nuclear Power in Japan.

    Science.gov (United States)

    Powell, John W.

    1983-01-01

    Energy consumption in Japan has grown at a faster rate than in any other major industrial country. To maintain continued prosperity, the government has embarked on a crash program for nuclear power. Current progress and issues/reactions to the plan are discussed. (JN)

  13. Biblis nuclear power station

    International Nuclear Information System (INIS)

    A short constructive description of the components of the Biblis nuclear power station is given here. In addition to the heat flow diagram, the coolant cycle and the turbine control system, some details of construction and reactor safety are presented. (TK/AK)

  14. Fessenheim nuclear power station

    International Nuclear Information System (INIS)

    The Fessenheim nuclear power plant includes two PWR type units each with net electrical output of 890MW(e). The site and layout of the station, geological features and cooling water characteristics are described. Reference is made to other aspects of the environment such as population density and agronomy. (U.K.)

  15. The abuse of nuclear power

    International Nuclear Information System (INIS)

    Different aspects of possible abuse of nuclear power by countries or individuals are discussed. Special attention is paid to the advantage of nuclear power, despite the risk of weapon proliferation or terrorism. The concepts of some nuclear power critics, concerning health risks in the nuclear sector are rejected as untrue and abusive

  16. Labor and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Logan, R.; Nelkin, D.

    1980-03-01

    The AFL-CIO is officially pro-nuclear, but tensions within unions are taking issue over ideological differences. The Labor movement, having looked to nuclear power development as an economic necessity to avoid unemployment, has opposed efforts to delay construction or close plants. As many as 42% of union members or relatives of members, however, were found to oppose new power plants, some actively working against specific construction projects. The United Mine Workers and Teamsters actively challenged the nuclear industry while the auto workers have been ambivalent. The differences between union orientation reflects the history of unionism in the US and explains the emergence of social unionism with its emphasis on safety and working conditions as well as economic benefits. Business union orientation trends to prevail during periods of prosperity; social unions during recessions. The labor unions and the environmentalists are examined in this conext and found to be hopeful. 35 references. (DCK)

  17. Nuclear power and nuclear safety 2007

    International Nuclear Information System (INIS)

    The report is the fifth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe DTU and the Danish Emergency Management Agency. The report for 2007 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events of nuclear power, and international relations and conflicts. (LN)

  18. Nuclear power and nuclear safety 2006

    International Nuclear Information System (INIS)

    The report is the fourth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe National Laboratory and the Danish Emergency Management Agency. The report for 2006 covers the following topics: status of nuclear power production, regional trends, reactor development and development of emergency management systems, safety related events of nuclear power, and international relations and conflicts. (LN)

  19. Nuclear power and nuclear safety 2005

    International Nuclear Information System (INIS)

    The report is the third report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe National Laboratory and the Danish Emergency Management Agency. The report for 2005 covers the following topics: status of nuclear power production, regional trends, reactor development and development of emergency management systems, safety related events of nuclear power and international relations and conflicts. (ln)

  20. Nuclear power and nuclear safety 2004

    International Nuclear Information System (INIS)

    The report is the second report in a new series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe National Laboratory and the Danish Emergency Management Agency. The report for 2004 covers the following topics: status of nuclear power production, regional trends, reactor development and development of emergency management systems, safety related events of nuclear power and international relations and conflicts. (ln)

  1. Nuclear power and nuclear safety 2008

    International Nuclear Information System (INIS)

    The report is the fifth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe DTU and the Danish Emergency Management Agency. The report for 2008 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events of nuclear power, and international relations and conflicts. (LN)

  2. Personal reflections of international CANDU technology and knowledge transfer experience

    International Nuclear Information System (INIS)

    Starting with its first nuclear power demonstration unit (22 MWe NPD-2) in 1962, Canada has built a large fleet of CANDU units both at home and abroad. This presentation covers my personal reflections of the Canadian experience on CANDU exports to Pakistan, India, Argentina, Romania, and China. It covers highlights of typical transfer of technology and knowledge to the clients in order to efficiently manage the ,projects from its initial planning and design phase to final commissioning and operation. It also provides guidance on important elements to develop national capability to implement a nuclear power program, with special focus on in-house expertise to operate the plants safely, reliably and economically. (author)

  3. Review of Regulations on Continued Operation for CANDU Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Woong; Lee, Sang Kyu; Yoo, Kun Joong; Kim, Hyun Koon; Ryu, Yong Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Roh, Heui Young; Jin, Tae Eun [Korea Power Engineering Co., Yongin (Korea, Republic of)

    2007-10-15

    The first CANDU type reactor, Wolsong Unit 1, has been operating for twenty four years since the commencement of its commercial operation in 1983 and its lifetime will be completed until end of 2012. Hence the licensee, KHNP, is considered a continued operation for Wolsong Unit 1 in economic point of view. Regarding to the license of the continued operating of nuclear power plants including CANDU reactors, a regulatory body is developing the regulatory requirements on continued operation for reviewing the technical requirements of safety assessment and management of aging for structures, systems and components (SSC) in the nuclear power plants. Regarding to this, in this paper the review contents are described and general review results are presented.

  4. Review of Regulations on Continued Operation for CANDU Reactors

    International Nuclear Information System (INIS)

    The first CANDU type reactor, Wolsong Unit 1, has been operating for twenty four years since the commencement of its commercial operation in 1983 and its lifetime will be completed until end of 2012. Hence the licensee, KHNP, is considered a continued operation for Wolsong Unit 1 in economic point of view. Regarding to the license of the continued operating of nuclear power plants including CANDU reactors, a regulatory body is developing the regulatory requirements on continued operation for reviewing the technical requirements of safety assessment and management of aging for structures, systems and components (SSC) in the nuclear power plants. Regarding to this, in this paper the review contents are described and general review results are presented

  5. Nuclear power plant simulator

    International Nuclear Information System (INIS)

    In this paper, real time nuclear power plant simulator for student education is described. The simulator is composed of a hybrid computer and an operating console. Simulated power plant is a 36 MWt PWR plant, and the average temperature of the primary coolant within the reactor is controlled to be constant. Reactor Kinetics, fuel temperature, primary coolant temperature, temperature and pressure of steam within the steam generator, steam flow, control rod driving system, and feed water controlling system are simulated. The use of the hybrid computer made it possible to simulate a relatively large scale power plant with a comparatively small size computing system. (auth.)

  6. Facts about nuclear power

    International Nuclear Information System (INIS)

    The argument concerning the introduction and the further expansion of nuclear energy in the Federal Republic of Germany has been existing for several years in differing intensities and most different forms. The arguments and theses of the discussion deal with the various aspects of the reciprocity between nuclear energy and environment. This is the key-note for the scientists to treat the relevant problems and questions in the discussion about nuclear energy. The controversy in which often emotional theses are stated instead of reasonably deliberating the pros and contras includes civil initiatives, societies, and environment protection organisations on the one hand and authorities, producers, and operators of nuclear-technical plants on the other. And the scale of the different opinions reaches from real agreement to deep condemnation of a technology which represents an option to meet the energy need in the future. In this situation, this book is an attempt to de-emotionalize the whole discussion. Most of the authors of the articles come from research centres and have been working on the problems they deal with for years. The spectrum of the topics includes the energy-political coherences of nuclear energy, the technical fundaments of the individual reactor types, safety and security of nuclear-technical plants the fuel cycle, especially the waste management in nuclear power plants, environmental aspects of energy generation in general and nuclear energy in special, the question of Plutonium and the presentation of alternative energy sources including nuclear fusion. The arrangement of these topics is meant to help to clarify the complex coherences of nuclear energy and to help those interested in problems of energy policy to make their own personal decisions. (orig./RW)

  7. Economics of nuclear power

    International Nuclear Information System (INIS)

    The economics of electricity supply and production in the FRG is to see on the background of the unique European interconnected grid system which makes very significant contributions to the availability of standby energy and peak load power. On this basis and the existing high voltage grid system, we can build large nuclear generating units and realise the favorable cost aspects per installed KW and reduced standby power. An example of calculating the overall electricity generating costs based on the present worth method is explained. From the figures shown, the sensitivity of the generating costs with respect to the different cost components can be derived. It is apparent from the example used, that the major advantage of nuclear power stations compared with fossil fired stations lies in the relatively small percentage fraction contributed by the fuel costs to the electricity generating costs. (orig.)

  8. Thorium-Based Fuels Preliminary Lattice Cell Studies for Candu Reactors

    International Nuclear Information System (INIS)

    The choice of nuclear power as a major contributor to the future global energy needs must take into account acceptable risks of nuclear weapon proliferation, in addition to economic competitiveness, acceptable safety standards, and acceptable waste disposal options. Candu reactors offer a proven technology, safe and reliable reactor technology, with an interesting evolutionary potential for proliferation resistance, their versatility for various fuel cycles creating premises for a better utilization of global fuel resources. Candu reactors impressive degree of fuel cycle flexibility is a consequence of its channel design, excellent neutron economy, on-power refueling, and simple fuel bundle. These features facilitate the introduction and exploitation of various fuel cycles in Candu reactors in an evolutionary fashion. The main reasons for our interest in Thorium-based fuel cycles have been, globally, to extend the energy obtainable from natural Uranium and, locally, to provide a greater degree of energy self-reliance. Applying the once through Thorium (OTT) cycle in existing and advanced Candu reactors might be seen as an evaluative concept for the sustainable development both from the economic and waste management points of view. Two Candu fuel bundles project will be used for the proposed analysis, namely the Candu standard fuel bundle with 37 fuel elements and the CANFLEX fuel bundle with 43 fuel elements. Using the Canadian proposed scheme - loading mixed ThO2-SEU CANFLEX bundles in Candu 6 reactors - simulated at lattice cell level led to promising conclusions on operation at higher fuel burnups, reduction of the fissile content to the end of the cycle, minor actinide content reduction in the spent fuel, reduction of the spent fuel radiotoxicity, presence of radionuclides emitting strong gamma radiation for proliferation resistance benefit. The calculations were performed using the lattice codes WIMS and Dragon (together with the corresponding nuclear data

  9. The outlook for nuclear power in Europe by 2030

    International Nuclear Information System (INIS)

    A 57% increase in the world consumption of electricity is expected between 2004 and 2030. According to the alternative policy scenario of the world energy outlook 2006, the contribution of nuclear power would be +300 GW for a total increase of +4600 GW in power production. The economic outlook for nuclear power appears to be favorable over a long period. Between 2006 and 2030, about 30 countries will order the construction of nuclear power plants but only 5 countries (Usa, China, Japan, Russia and India) will concentrate the 2/3 of this demand. This demand will be met mostly with 10 commercial offers representing reactors of third generation (6 PWR-types + 3 BWR-types + 1 Candu-type). The existing resources of natural uranium (about 15*106 tonnes) are sufficient to ensure in 2040 a global nuclear power as high as 3 to 4 times the today's nuclear power. As for Europe, 2 scenarios are considered: an evolution of -60 GW in case of no decision concerning the construction of new nuclear plants and a likely +120 GW scenario including the replacement of 64 GW. The second scenario will lead to an installed capacity of 229 GW in 2030 compared to today's 172 GW. (A.C.)

  10. Nuclear Power Prospects

    International Nuclear Information System (INIS)

    The present trend is to construct larger plants: the average power of the plants under construction at present, including prototypes, is 300 MW(e), i.e. three times higher than in the case of plants already in operation. Examples of new large-scale plants ares (a) Wylfa, Anglesey, United Kingdom - scheduled power of 1180 MW(e) (800 MW to be installed by 1967), to be completed in 1968; (b) ''Dungeness B'', United Kingdom - scheduled power of 1200 MW(e); (c) second unit for United States Dresden power plant - scheduled power of 715 MW(e) minimum to almost 800 MW(e). Nuclear plants on the whole serve the same purpose as conventional thermal plants

  11. Space Nuclear Power Systems

    Science.gov (United States)

    Houts, Michael G.

    2012-01-01

    Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

  12. Management of a 600 MW CANDU project to facilitate electricity export

    International Nuclear Information System (INIS)

    The export of electricity from 600-MW CANDU nuclear power plants built in Canada remains feasible providing certain requirements continue to be met. The principal objective in developing nuclear power resources for export is that they must produce economically attractive electricity. A review of the experience of construction and operation of Point Lepreau Unit 1 suggests an inherent ability to reduce construction costs and shorten construction schedules so as to make electrical power output from these stations even more attractive to export customers

  13. Quality Products - The CANDU Approach

    International Nuclear Information System (INIS)

    The prime focus of the CANDU concept (natural uranium fuelled-heavy water moderated reactor) from the beginning has economy, heavy water losses and radiation exposures also were strong incentives for ensuring good design and reliable equipment. It was necessary to depart from previously accepted commercial standards and to adopt those now accepted in industries providing quality products. Also, through feedback from operating experience and specific design and development programs to eliminate problems and improve performance, CANDU has evolved into today's successful product and one from which future products will readily evolve. Many lessons have been learned along the way. On the one hand, short cuts of failures to understand basic requirements have been costly. On the other hand, sound engineering and quality equipment have yielded impressive economic advantages through superior performance and the avoidance of failures and their consequential costs. The achievement of lifetime economical performance demands quality products, good operation and good maintenance. This paper describes some of the basic approaches leading to high CANDU station reliability and overall excellent performance, particularly where difficulties have had to be overcome. Specific improvements in CANDU design and in such CANDU equipment as heat transport pumps, steam generators, valves, the reactor, fuelling machines and station computers, are described. The need for close collaboration among designers, nuclear laboratories, constructors, operators and industry is discussed. This paper has reviewed some of the key components in the CANDU system as a means of indicating the overall effort that is required to provide good designs and highly reliable equipment. This has required a significant investment in people and funding which has handsomely paid off in the excellent performance of CANDU stations. The close collaboration between Atomic Energy of Canada Limited, Canadian industry and the

  14. Nuclear power for desalination

    International Nuclear Information System (INIS)

    Water is one of the most important assets to mankind and without which the human race would cease to exist. Water is required by us right from domestic to industrial levels. As notified by the 'American Nuclear Society' and 'World Nuclear Association' about 1/5th of the world population does not access to portable water especially in the Asian and African subcontinent. The situation is becoming adverse day by day due to rise in population and industrialization. The need of alternative water resource is thus becoming vital. About 97.5% of Earth is covered by oceans. Desalination of saline water to generate potable water is thus an important topic of research. Currently about 12,500 desalination plants are operating worldwide with a capacity of about 35 million m3/day using mainly fossil fuels for generation of large amount of energy required for processing water. These thermal power station release large amount of carbon dioxide and other green house gases. Nuclear reactors are capable of delivering energy to the high energy-intensive processes without any environmental concerns for climate change etc., giving a vision to sustainable growth of desalination process. These projects are currently employed in Kazakhstan, India, Japan, and Pakistan and are coupled to the nuclear reactor for generating electricity and potable water as well. The current climatic scenario favors the need for expanding dual purpose nuclear power plants producing energy and water at the same location. (author)

  15. Economics of nuclear power projects

    International Nuclear Information System (INIS)

    Nuclear power development in Taiwan was initiated in 1956. Now Taipower has five nuclear units in smooth operation, one unit under construction, two units under planning. The relatively short construction period, low construction costs and twin unit approach had led to the significant economical advantage of our nuclear power generation. Moreover betterment programmes have further improved the availability and reliability factors of our nuclear power plants. In Taipower, the generation cost of nuclear power was even less than half of that of oil-fired thermal power in the past years ever since the nuclear power was commissioned. This made Taipower have more earnings and power rates was even dropped down in March 1983. As Taiwan is short of energy sources and nuclear power is so well-demonstrated nuclear power will be logically the best choice for Taipower future projects

  16. Development of CANDU Spent Fuel Disposal Concepts for the Improvement of Disposal Efficiency

    International Nuclear Information System (INIS)

    There are two types of spent fuels generated from nuclear power plants, CANDU type and PWR type. PWR spent fuels which include a lot of reusable material can be considered to be recycled. CANDU spent fuels are considered to directly disposed in deep geological formation, since they have little reusable material. In this study, based on the Korean Reference spent fuel disposal System(KRS) which is to dispose both PWR and CANDU spent fuels, the more effective CANDU spent fuel disposal systems have been developed. To do this, the disposal canister has been modified to hold the storage basket which can load 60 spent fuel bundles. From these modified disposal canisters, the disposal systems to meet the thermal requirement for which the temperature of the buffer materials should not be over have been proposed. These new disposals have made it possible to introduce the concept of long term storage and retrievability and that of the two-layered disposal canister emplacement in one disposal hole. These disposal concepts have been compared and analyzed with the KRS CANDU spent fuel disposal system in terms of disposal effectiveness. New CANDU spent fuel disposal concepts obtained in this study seem to improve thermal effectiveness, U-density, disposal area, excavation volume, and closure material volume up to 30 - 40 %.

  17. Nuclear power and the nuclear fuel cycle

    International Nuclear Information System (INIS)

    The report provides data and assessments of the status and prospects of nuclear power and the nuclear fuel cycle. The report discusses the economic competitiveness of nuclear electricity generation, the extent of world uranium resources, production and requirements, uranium conversion and enrichment, fuel fabrication, spent fuel treatment and radioactive waste management. A review is given of the status of nuclear fusion research

  18. Next generation CANDU plants

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water Reactors systems featuring horizontal fuel channels and heavy water moderator will continue to evolve, supported by AECL's strong commitment to comprehensive R and D programs. There are three key CANDU development strategic thrusts: improved economics, fuel cycle flexibility, and enhanced safety operation based on design feedback. Therefore, CANDU reactor products will continue to evolve by incorporating further improvements and advanced features that will be arising from our CANDU Technology R and D programs in areas such as heavy water and tritium, control and instrumentation, fuel and fuel cycles, systems and equipment and safety and constructability. Progressive CANDU development will continue in AECL to enhance the medium size product - CANDU 6, and to evolve the larger size product - CANDU 9. The development of features for CANDU 6 and CANDU 9 is carried out in parallel. Developments completed for one reactor size can then be applied to the other design with minimum costs and risk. (author)

  19. Build your own Candu reactor

    International Nuclear Information System (INIS)

    The author discusses the marketing of Candu reactors, particularly the export trade. Future sales will probably be of the nuclear side of a station only, thus striking a compromise between licensing and 'turnkey' sales. It is suggested that AECL might have made more money in the past had it not given the right to manufacture Candu fuel away to Canadian industry. Future sales to certain potential customers may be limited by the requirement of strict safeguards, which will almost certainly never be relaxed. (N.D.H.)

  20. Object-oriented simulator of the dynamics of Embalse nuclear power plant

    International Nuclear Information System (INIS)

    LUDWIG is an object-oriented simulator of the dynamics of the CANDU Nuclear power plant Embalse Rio Tercero. The tool consists in a numerical plant analyzer by means of a model of the plant dynamics during normal operation, and a graphic environment for configuration and visualization of results. The simulator was validated against plant transients occurred in the plant and recorded in the past. (author)

  1. Commissioning of Qinshan phase III PHWR nuclear power plant (2 x 700 MW)

    International Nuclear Information System (INIS)

    As the first CANDU type NPP built in China, the commissioning team established a very efficient and high standard commissioning management system. Unit 1 was put into commercial operation 43 days in advance and 112 days ahead of schedule for Unit 2. Commissioning quality achieved international advanced level. The commissioning period created new world history record of heavy water nuclear power plants. A summary for the practice and the experience of TQNPC obtained in the commissioning of the two unit was given. (authors)

  2. ACR technology for CANDU enhancements

    International Nuclear Information System (INIS)

    The ACR-1000 design retains many essential features of the original CANDU plant design. As well as further-enhanced safety, the design also focuses on operability and maintainability, drawing on valuable customer input and OPEX. The engineering development of the ACR-1000 design has been accompanied by a research and confirmatory testing program. This program has extended the database of knowledge on the CANDU design. The ACR-1000 design has been reviewed by the Canadian regulator, the Canadian Nuclear Safety Commission (CNSC) which concluded that there are no fundamental barriers to licensing the ACR-1000 design in Canada after completing three phases of the pre-project design review. The generic PSAR for the ACR-1000 design was completed in September 2009. The PSAR contains the ACR-1000 design details, the safety and design methodology, and the safety analysis that demonstrate the ACR-1000 safety case and compliance with Canadian and international regulatory requirements and expectations. The ACR technology developed during the ACR-1000 Engineering Program and the supporting development testing has had a major impact beyond the ACR program itself: Improved CANDU components and systems; Enhanced engineering processes and engineering tools, which lead to better product quality, and better project efficiency; and Improved operational performance. This paper provides a summary of technology arising from the ACR program that has been incorporated into new CANDU designs such as the EC6, or can be applied for servicing operating CANDU reactors. (author)

  3. Nuclear power and ethics

    International Nuclear Information System (INIS)

    The author can see no sense in demanding an ethical regime to be applied exclusively to nuclear power but rather calls for an approach that discusses nuclear power as one constituent of the complex energy issue in a way spanning all dimensions involved, as e.g. the technological, economic, cultural, humanitarian, and humanistic aspects. An ethical approach does not question scientific research, or science or technology, but examines their relation to man and the future of humanity, so that an ethical approach will first of all demand that society will bring forward conscientious experts as reliable partners in the process of discussing the ethical implications of progress and development in a higly industrialised civilisation. (orig./CB)

  4. Nuclear turbine power plant

    International Nuclear Information System (INIS)

    Purpose : To improve the heat cycle balance in a nuclear turbine power plant or the like equipped with a moisture separating and reheating device, by eliminating undesired overcooling of the drains in the pipes of a heat transmission pipe bundle. Constitution : A high pressure turbine is driven by main steams from a steam generator. The steams after driving the high pressure turbine are removed with moistures by way of a moisture separator and then re-heated. Extracted steams from the steam generator or the high pressure turbine are used as a heating source for the reheating. In the nuclear turbine power plant having such a constitution, a vessel for separating the drains and the steams resulted from the heat exchange is provided at the outlet of the reheating device and the steams in the vessel are introduced to the inlet of the moisture separator. (Aizawa, K.)

  5. Kruemmel nuclear power plant

    International Nuclear Information System (INIS)

    This short description of the site and the nuclear power plant with information on the presumable effects on the environment and the general public is to provide some data material to the population in a popular form so that the citizens may in form themselves about the plant. In this description which shall be presented to the safety report, the site, the technical design and the operation mode of the nuclear power plant are described. Some problems of the emission and the effects of radioactive materials as well as other issues related to the plant which are of interest to the public are dealt with. The supposed accidents and their handling are discussed. The description shows that the selected site is suitable for both setting-up and operation of the plant without affecting the safety of the people living there and that in admissible burdens of the environment shall not have to be expected. (orig./HP)

  6. Jobs and nuclear power

    International Nuclear Information System (INIS)

    To guarantee the existence of Germany as an industrialized country, and to protect jobs, the country needs a comprehensive energy consensus not restricted to the solution of the debate about the future of nuclear power. From the point of view of IGBCE, the Mining, Chemistry and Energy Workers Union, striving for continuity remains a basic prerequisite. The energy mix currently existing offers the best preconditions for a future energy supply in the light of the worldwide development to be expected. Nuclear power cannot be replaced for a foreseeable time without this giving rise to considerable damage to the national economy and ecology alike. An overall objective should be to keep electricity generation in the country. Consistent resource conservation, more efficient energy use, and stricter energy conservation must further enhance the environmental acceptability of energy generation and energy consumption. (orig.)

  7. Nuclear power plant

    International Nuclear Information System (INIS)

    Purpose: To suppress corrosion at the inner surfaces of equipments and pipeways in nuclear power plants. Constitution: An injection device comprising a chemical injection tank and a plunger type chemical injection pump for injecting hydrazine as an oxygen remover and ammonia as a pH controller is disposed to the downstream of a condensate desalter column for primary coolant circuits. Since dessolved oxygen in circuit water injected with these chemicals is substantially reduced to zero and pH is adjuted to about 10 - 11, occurrence of stress corrosion cracks in carbon steels and stainless steels as main constituent materials for the nuclear power plant and corrosion products are inhibited in high temperature water, and of corrosion products are inhibited from being introduced as they are through leakage to the reactor core, by which the operators' exposure does can be decreased significantly. (Sekiya, K.)

  8. Nuclear power generation

    International Nuclear Information System (INIS)

    The case for nuclear power, from both a world and a British standpoint, is first discussed, with particular reference to oil supply and demand. It is considered that oil and gas should in future be used as a feedstock for the chemical industry, for transportation purposes, and as a starting point for protein food for animals and later for humans; to squander so much by burning simply as a crude fuel cannot be right. It is considered that Britain should continue constructing nuclear stations at a steady modest rate, and that the fast reactor should receive increasing attention, despite the anti-nuclear lobby. The case for the fast breeder reactor is discussed in detail, including its development at UKAEA Harwell and Dounreay. Accusations against the fast reactor are considered, particularly those concerned with safety, and with the use or misuse of Pu. Public debates are discussed. (U.K.)

  9. Pragmatics of nuclear power

    International Nuclear Information System (INIS)

    In context of depletion of fossil fuels and continuous increase of global warming, nuclear power is highly solicited by world energy congress for solving energy crisis for ever. No doubt, a small amount of nuclear fuel can provide immense amount of energy but in exchange of what? Safety, security, large compensation and huge risk of lives, gift of radio-activity to environment and so many adverse effects. Yet are we in a position to reject or neglect it exclusively? Can we show such luxury? Again are we capable to control such a demon for the benefit of human being. Either is it magic lamp of Aladdin or a Frankenstein? Who will give the answer? Likely after nuclear war, is there anybody left in this planet to hide or is there any place available to hide. Answers are not yet known. (author)

  10. US nuclear power programs

    International Nuclear Information System (INIS)

    In the United States, coal provided 56 percent of the electricity generated in 1992. Nuclear energy was the next largest contributor, supplying 22 percent. Natural gas provided 9 percent, while hydro-electric and renewables together supplied another 9 percent. Currently, the 109 nuclear power plants in the U.S. have an overall generating capacity of 99,000 MWe. To improve efficiency, safety, and performance, the lessons of 30 years of experience with nuclear powerplants are being incorporated into design criteria for the next generation of U.S. plants. The new Advanced Light Water Reactor plants will feature simpler designs, which will enable more cost-effective construction and maintenance. To enhance safety, design margins are being increased, and human factors are being considered and incorporated into the designs

  11. Preparedness against nuclear power accidents

    International Nuclear Information System (INIS)

    This booklet contains information about the organization against nuclear power accidents, which exist in the four Swedish counties with nuclear power plants. It is aimed at classes 7-9 of the Swedish schools. (L.E.)

  12. Initiative against nuclear power plants

    International Nuclear Information System (INIS)

    This publication of the Initiative of Austrian Nuclear Power Plant Opponents contains articles on radiactive waste dispoasal in Austria and and discusses safety issues of the nuclear power plant 'Zwentendorf'. (kancsar)

  13. Nuclear power and public perceptions

    International Nuclear Information System (INIS)

    This text presents and analyzes a survey dealing with public opinion about nuclear power. The author suggests ways to improve communication and information in order to lead people to have a better opinion concerning nuclear power. (TEC)

  14. Nuclear Power: Epilogue or Prologue?

    OpenAIRE

    Harold R. Denton

    1983-01-01

    Judging by the continuing stream of nuclear power plant cancellations and downward revisions of nuclear energy forecasts, there is nothing riskier than predicting the future of commercial nuclear power. U.S. Nuclear Regulation Commissioner John Ahearne (1981) likens the recent events affecting the nuclear power industry in the United States to a Greek tragedy. Others, particularly other nations, take a different view about the future.

  15. Ethical aspects of nuclear power

    International Nuclear Information System (INIS)

    The nuclear controversy comprises many ethical aspects, e.g. the waste disposal problem. Nuclear opponents should not neglect the environmental protection aspect; for example, the use of nuclear power alone brought about an 8% reduction of the CO2 burden in 1987. Our responsibility towards nature and humans in the Third World leaves us no alternative to nuclear power. On the other hand, the nuclear power debate should not become a matter of religious beliefs. (DG)

  16. Vietnam and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, N.T.; Hong, L.V. [Viet Nam Atomic Energy Commission (VAEC), Hanoi (Viet Nam)

    1997-12-31

    Economy of Vietnam is developing fast and the electricity demand is growing drastically, last five years about 12.5% per year. The Government puts high target for the future with GDP rating about 8% per year up to 2020. In this case, the electricity demand in 2020 will be tenfold bigger in comparison with 1995`s level. The deficient of domestic resources and the security of energy supply invoke the favorable consideration on nuclear power. (author)

  17. Nuclear power in Sweden

    International Nuclear Information System (INIS)

    The lecture describes the energy-political situation in Sweden after the change of Government in October 1976. The present announced nuclear power plant-hostile energy politic, has to face the viewpoints of a technical and economical dependent reality. Disagreements and transgressions of political competences must be reduced, due to the fact that a constructive cooperation between politicians and energy producing corporations is a necessity, to guarantee a safe energy supply in Sweden. (orig.)

  18. Vietnam and nuclear power

    International Nuclear Information System (INIS)

    Economy of Vietnam is developing fast and the electricity demand is growing drastically, last five years about 12.5% per year. The Government puts high target for the future with GDP rating about 8% per year up to 2020. In this case, the electricity demand in 2020 will be tenfold bigger in comparison with 1995's level. The deficient of domestic resources and the security of energy supply invoke the favorable consideration on nuclear power. (author)

  19. Nuclear power generation device

    International Nuclear Information System (INIS)

    In a PWR type reactor, a free piston type stirling engine is disposed instead of a conventional steam generator and a turbine. Since the stirling engine does not cause radiation leakage in view of the structure, safety and reliability of the nuclear power generation are improved. Further, the thermal cycle, if it operates theoretically, is equivalent with a Carnot cycle having the highest thermodynamical heat efficiency, thereby enabling to obtain a high heat efficiency in an actual engine. (N.H.)

  20. Nuclear power in Italy

    International Nuclear Information System (INIS)

    As is known to most of this audience in November of 1987 a referendum determined a rejection of nuclear power in Italy. The referendum may be taken into consideration here as a large scale experiment which offers points of interest to this conference and problems to be aware of, in approaching a severe confrontation with the public. To give a synopsis of the Italian perspective I will examine: first the public acceptance in the situation before Chernobyl, then the most disturbing and sensitive factors of Chernobyl's consequences; how the opposition to nuclear energy worked with the support of most media and the strong pressures of an anti-nuclear political party, the syllogism of the opponents and the arguments used, the causes of major weakness of the defenders and how a new perception of nuclear risk was generated in the public. I will come to the topic of utility acceptance by mentioning that ENEL, as the National Utility, in its role is bound to a policy of compliance with Government decisions. It is oriented today to performance of feasibility studies and development of requirements for the next generation of reactors in order to maintain an updated proposal for a future recovery of the nuclear option. I will then try to identify in general terms the factors determining the future acceptance of nuclear power. They will be determined in the interdisciplinary area of politics, media and public interactions with the utilities the uses of the technology are forced to follow, by political constraints, two main directives: working only in new projects to achieve, if possible, new safety goals

  1. World status: nuclear power

    International Nuclear Information System (INIS)

    The nuclear power situation in 1988 in briefly reviewed. The prospects for the 1990s are then considered. Apart from the use of nuclear power to fuel spacecraft the prospects are not that bright. The European fast breeder programme is coming to a premature end with the winding down of the fast breeder research centre at Dounreay and the delay with the French programme because of the sodium leak at Superphenix. If plutonium is no longer needed to fuel the fast breeder reactors, the reprocessing of spent fuels is less attractive. However, seven new reprocessing plants are due to be commissioned in the next six years. The THORP plant in Britain may be affected by the privatization plans for the electricity supply industry. Decommissioning and waste storage/disposal are issues which will have to be resolved in the 1990s. The risk of accidents especially from aircraft crashes is discussed. Altogether the prospects for nuclear power are not very good. The keynote of the decade will be cleaning up rather than expansion. (U.K.)

  2. Submarine nuclear power plant

    International Nuclear Information System (INIS)

    Purpose: To provide a ballast tank, and nuclear power facilities within the containment shell of a pressure resistance structure and a maintenance operator's entrance and a transmission cable cut-off device at the outer part of the containment shell, whereby after the construction, the shell is towed, and installed by self-submerging, and it can be refloated for repairs by its own strength. Constitution: Within a containment shell having a ballast tank and a pressure resisting structure, there are provided nuclear power facilities including a nuclear power generating chamber, a maintenance operator's living room and the like. Furthermore, a maintenance operator's entrance and exit device and a transmission cable cut-off device are provided within the shell, whereby when it is towed to a predetermined a area after the construction, it submerges by its own strength and when any repair inspection is necessary, it can float up by its own strength, and can be towed to a repair dock or the like. (Yoshihara, H.)

  3. CANDU refurbishment - managing the life cycle

    International Nuclear Information System (INIS)

    All utilities that operate a nuclear power plant have an integrated plan for managing the condition of the plant systems, structures and components. With a sound plant life management program, after about 25 years of operation, replacement of certain reactor core components can give an additional 25 to 30 years of operation. This demonstrates the long-term economic strength of CANDU technology and justifies a long-term commitment to nuclear power. Indeed, replacement of pressure tubes and feeders with the most recent technology will also lead to increased capacity factors - due to reduced requirements for feeder inspections and repair, and eliminating the need for fuel channel spacer relocation which have caused additional and longer maintenance outages. Continuing the operation of CANDU units parallels the successful life extensions of reactors in other countries and provides the benefits of ongoing reliable operation, at an existing plant location, with the continued support of the host community. The key factors for successful, optimum management of the life cycle are: ongoing, effective plant life management programs; careful development of refurbishment scope, taking into account system condition assessments and a systematic safety review; and, a well-planned and well-executed retubing and refurbishment outage, where safety and risk management is paramount to ensure a successful project The paper will describe: the benefits of extended plant life; the outlook for refurbishment; the life management and refurbishment program; preparations for retubing of the reactor core; and, enhanced performance post-retubing. Given the potential magnitude of the program over the next 10 years, AECL will maintain a lead role providing overall support for retubing and plant Life Cycle Management programs and the CANDU Owners Group will provide a framework for collaboration among its Members. (author)

  4. The future of nuclear power

    International Nuclear Information System (INIS)

    Nuclear power is an extremely sensitive issue and its future has been hotly debated. Conflicting arguments have been put forward regarding the viability of nuclear power. The question of whether the world should look to nuclear power for its electricity generating needs is addressed. 2 ills

  5. Overview paper on nuclear power

    International Nuclear Information System (INIS)

    This paper was prepared as an input to ORNL's Strategic Planning Activity, ORNL National Energy Perspective (ONEP). It is intended to provide historical background on nuclear power, an analysis of the mission of nuclear power, a discussion of the issues, the technology choices, and the suggestion of a strategy for encouraging further growth of nuclear power

  6. Computational fluid dynamics analysis for flow accelerated corrosion in CANDU6 feeder pipes

    International Nuclear Information System (INIS)

    CANDU6 plant management over a long time period includes various ageing and degradation mechanisms like FAC manifested mainly at first and second elbow of CANDU6 outlet feeders. FAC take place at all CANDU6 built before 2000 year with feeders made from SA106 grade B low alloy carbon-steel (with chromium at 0.02%). CFD method is used in this paper to investigate the feeder's wall thinning process taking place mainly due local flow conditions in complex 3D geometrical configurations. The 380 outlet feeders grouped in 2.5'' (320) and 2.0'' feeders (60). The objective of this paper is to help, as much as possible, to focus investigation on most probable maximum thinning rate locations through 3D distribution of some TH parameters. Application of CFD methods in CANDU6 nuclear reactors implies the knowledge of real plant operating data like: long term time averaged channel power and mass flow as well as temperature, pressure, pHa etc allowing the optimization and cost reduction of wall thinning monitoring process at CANDU6 nuclear power plants. (authors)

  7. Nuclear eclectic power.

    Science.gov (United States)

    Rose, D J

    1974-04-19

    The uranium and thorium resources, the technology, and the social impacts all seem to presage an even sharper increase in nuclear power for electric generation than had hitherto been predicted. There are more future consequences. The "hydrogen economy." Nuclear power plants operate best at constant power and full load. Thus, a largely nuclear electric economy has the problem of utilizing substantial off-peak capacity; the additional energy generation can typically be half the normal daily demand. Thus, the option of generating hydrogen as a nonpolluting fuel receives two boosts: excess nuclear capacity to produce it, plus much higher future costs for oil and natural gas. However, the so-called "hydrogen economy" must await the excess capacity, which will not occur until the end of the century. Nonelectric uses. By analyses similar to those performed here, raw nuclear heat can be shown to be cheaper than heat from many other fuel sources, especially nonpolluting ones. This will be particularly true as domestic natural gas supplies become more scarce. Nuclear heat becomes attractive for industrial purposes, and even for urban district heating, provided (i) the temperature is high enough (this is no problem for district heating, but could be for industry; the HTGR's and breeders, with 600 degrees C or more available, have the advantage); (ii) there is a market for large quantities (a heat rate of 3800 Mw thermal, the reactor size permitted today, will heat Boston, with some to spare); and (iii) the social costs become more definitely resolved in favor of nuclear power. Capital requirements. Nuclear-electric installations are very capital-intensive. One trillion dollars for the plants, backup industry, and so forth is only 2 percent of the total gross national product (GNP) between 1974 and 2000, at a growth rate of 4 percent per year. But capital accumulation tends to run at about 10 percent of the GNP, so the nuclear requirements make a sizable perturbation. Also

  8. Elecnuc. Nuclear power plants worldwide

    International Nuclear Information System (INIS)

    This small folder presents a digest of some useful information concerning the nuclear power plants worldwide and the situation of nuclear industry at the end of 1997: power production of nuclear origin, distribution of reactor types, number of installed units, evolution and prediction of reactor orders, connections to the grid and decommissioning, worldwide development of nuclear power, evolution of power production of nuclear origin, the installed power per reactor type, market shares and exports of the main nuclear engineering companies, power plants constructions and orders situation, evolution of reactors performances during the last 10 years, know-how and development of nuclear safety, the remarkable facts of 1997, the future of nuclear power and the energy policy trends. (J.S.)

  9. Investigation of CANDU reactors as a thorium burner

    International Nuclear Information System (INIS)

    Large quantities of plutonium have been accumulated in the nuclear waste of civilian LWRs and CANDU reactors. Reactor grade plutonium can be used as a booster fissile fuel material in the form of mixed ThO2/PuO2 fuel in a CANDU fuel bundle in order to assure reactor criticality. The paper investigates the prospects of exploiting the rich world thorium reserves in CANDU reactors. Two different fuel compositions have been selected for investigations: (1) 96% thoria (ThO2) + 4% PuO2 and (2) 91% ThO2 + 5% UO2 + 4% PuO2. The latter is used for the purpose of denaturing the new 233U fuel with 238U. The behavior of the reactor criticality k ∞ and the burn-up values of the reactor have been pursued by full power operation for >∼8 years. The reactor starts with k ∞ = ∼1.39 and decreases asymptotically to values of k ∞ > 1.06, which is still tolerable and useable in a CANDU reactor. The reactor criticality k ∞ remains nearly constant between the 4th year and the 7th year of plant operation, and then, a slight increase is observed thereafter, along with a continuous depletion of the thorium fuel. After the 2nd year, the CANDU reactor begins to operate practically as a thorium burner. Very high burn-up can be achieved with the same fuel (>160,000 MW D/MT). The reactor criticality would be sufficient until a great fraction of the thorium fuel is burned up, provided that the fuel rods could be fabricated to withstand such high burn-up levels. Fuel fabrication costs and nuclear waste mass for final disposal per unit energy could be reduced drastically

  10. Nuclear power renaissance or demise?

    Energy Technology Data Exchange (ETDEWEB)

    Dossani, Umair

    2010-09-15

    Nuclear power is going through a renaissance or demise is widely debated around the world keeping in mind the facts that there are risks related to nuclear technology and at the same time that is it environmentally friendly. My part of the argument is that there is no better alternative than Nuclear power. Firstly Nuclear Power in comparison to all other alternative fuels is environmentally sustainable. Second Nuclear power at present is at the dawn of a new era with new designs and technologies. Third part of the debate is renovation in the nuclear fuel production, reprocessing and disposal.

  11. The need for nuclear power

    International Nuclear Information System (INIS)

    This leaflet examines our energy future and concludes that nuclear power is an essential part of it. The leaflet also discusses relative costs, but it does not deal with social and environmental implications of nuclear power in any detail, since these are covered by other British Nuclear Forum publications. Headings are: present consumption; how will this change in future; primary energy resources (fossil fuels; renewable resources; nuclear); energy savings; availability of fossil fuels; availability of renewable energy resources; the contribution of thermal nuclear power; electricity; costs for nuclear power. (U.K.)

  12. Economics of nuclear power

    International Nuclear Information System (INIS)

    Difficulties of nuclear power include higher than expected generating costs, rising construction costs, problems of safety and waste disposal, and the general level of excess capacity in the electric utilities sector. Recently, the debate has turned to cost effectiveness, with critics proposing that nuclear power is not competitive with other generating technologies. Despite the importance of costs in evaluating the nuclear option, there has never been a careful examination of the cost structure of the industry. Much of the existing literature on the subject has either focused on the rising capital costs in the industry or has made strong assumptions about the production process. Aspects of the technology, such as returns to scale or input responses to changing prices, have been omitted from consideration. This thesis, carefully examines the industry's cost structure. This study accounts for the many features peculiar to the technology such as the stoichastic nature of production and the inability of firms to optimize overall inputs. In addition, particular attention is given to make sure that capital is measured consistently. The results of the model indicate that significant substitution possibilities exist among inputs, that increasing returns to scale is present throughout the range of observed output and that plants in the sample tend to be overcapitalized. Further, no evidence of embodied technical change is found

  13. Nuclear power regional analysis

    International Nuclear Information System (INIS)

    In this study, a regional analysis of the Argentine electricity market was carried out considering the effects of regional cooperation, national and international interconnections; additionally, the possibilities of insertion of new nuclear power plants in different regions were evaluated, indicating the most suitable areas for these facilities to increase the penetration of nuclear energy in national energy matrix. The interconnection of electricity markets and natural gas due to the linkage between both energy forms was also studied. With this purpose, MESSAGE program was used (Model for Energy Supply Strategy Alternatives and their General Environmental Impacts), promoted by the International Atomic Energy Agency (IAEA). This model performs a country-level economic optimization, resulting in the minimum cost for the modelling system. Regionalization executed by the Wholesale Electricity Market Management Company (CAMMESA, by its Spanish acronym) that divides the country into eight regions. The characteristics and the needs of each region, their respective demands and supplies of electricity and natural gas, as well as existing and planned interconnections, consisting of power lines and pipelines were taken into account. According to the results obtained through the model, nuclear is a competitive option. (author)

  14. Nuclear Power Plant 1996

    International Nuclear Information System (INIS)

    Again this year, our magazine presents the details of the conference on Spanish nuclear power plant operation held in February and that was devoted to 1996 operating results. The Protocol for Establishment of a New Electrical Sector Regulation that was signed last December will undoubtedly represent a new challenge for the nuclear industry. By clearing stating that current standards of quality and safety should be maintained or even increased if possible, the Protocol will force the Sector to improve its productivity, which is already high as demonstrated by the results of the last few years described during this conference and by recent sectorial economic studies. Generation of a nuclear kWh that can compete with other types of power plants is the new challenge for the Sector's professionals, who do not fear the new liberalization policies and approaching competition. Lower inflation and the resulting lower interest rates, apart from being representative indices of our economy's marked improvement, will be very helpful in facing this challenge. (Author)

  15. Nuclear power in Sweden

    International Nuclear Information System (INIS)

    Sweden uses 16,000 kWh of electricity per person, by far the highest consumption in EU. The reason is a well-developed electricity intensive industry and a cold climate with high share of electric heating. The annual power consumption has for several years been about 140 TWh and a normal year almost 50 per cent is produced by hydro and 50 percent by nuclear. A new legislation, giving the Government the right to ordering the closure nuclear power plants of political reasons without any reference to safety, has been accepted by the Parliament. The new act, in force since January 1, 1998, is a specially tailored expropriation act. Certain rules for the economical compensation to the owner of a plant to be closed are defined in the new act. The common view in the Swedish industry is that the energy conservation methods proposed by the Government are unrealistic. During the first period of about five years the import from coal fired plants in Denmark and Germany is the only realistic alternative. Later natural gas combi units and new bioenergy plants for co-production of heat and power (CHP) might be available. (orig.)

  16. Life Assurance Strategy for CANDU NPP

    International Nuclear Information System (INIS)

    Nuclear Plants have a nominal 'design life' that forms the basis of equipment specification, economic evaluations and licensing for some jurisdictions. Some component in the plant may require replacement, refurbishing and or rehabilitation during the plant 'design life'. Components which are extremely difficult or economically impossible to replace will place a limit on plant life. Rehabilitation programs completed to date on older CANDU plants to improve reliability of plant components, coupled with R and D programs, experimental data and advanced analytical methods form the basis for CANDU plant component life assurance. Life assurance is verified during plant operation by comprehensive in-service inspection programs and laboratory examinations. The paper provides an overview of the experiences to date on Refurbishment and Rehabilitation programs and some Canadian approaches on the main activities involved in scoping and managing nuclear plant life assurance. A number of proactive programs are underway to anticipate, detect and mitigate potential aging degradation at an early stage to ensure plant safety and reliability. Some of these programs include; systematic plant condition assessment, refurbishment and upgrading programs, environmental qualification programs and a program of examination of components from decommissioned reactors. These programs are part of an overall nuclear power plant maintenance strategy. Beyond life assurance, a longer term approach would be geared towards life extension as a viable option for the future. Recent CANDU designs have benefited from the early CANDU experience and are expected to require less rehabilitation. Examples of changes in CANDU 6 include fuel channel design and adopting a closed component cooling water system. New designs are based on 'design life' longer than that used for economic evaluations. The approach is to design for easy replace ability for components that can be economically replaced. Specific examples

  17. Response strategy and hierarchy of Wolsong 2, 3, and 4 nuclear power plant abnormal operating manuals

    International Nuclear Information System (INIS)

    Wolsong 2, 3, and 4 are CANDU 6 pressurized heavy water nuclear power plants, each with a gross electrical output of 715 MW(e). The plants were constructed in the Republic of Korea during the 1990s. The three Wolsong units are based on the previous CANDU Wolsong Unit 1, declared in service in 1983. All four units are presently in commercial service. The Wolsong abnormal operating manuals were developed in a cooperative effort between Atomic Energy of Canada Limited, Korea Power Engineering Company staff, and Korea Electric Power Corporation. The role of Atomic Energy of Canada Limited in performing risk assessment studies and supporting CANDU stations for the preparation of emergency operating procedures has greatly benefited the Wolsong abnormal operating manual program. Korea Electric Power Corporation provided training and supervision, Korea Power Engineering Company Inc. prepared the documentation, and Korea Electric Power Corporation reviewed the draft reports. The Wolsong 2, 3, and 4 abnormal operating manuals have been successfully prepared and converted to Emergency Operating Procedures. The validation of the Emergency Operating Procedures via a simulator, is presently in progress at Wolsong site. The paper describes scope, response strategy to upsets and the hierarchy of the abnormal operating manuals. In addition, the structure of abnormal operating manuals is described. (author)

  18. Is nuclear power acceptable

    International Nuclear Information System (INIS)

    The energy shortage forecast for the early 21st century is considered. Possible energy sources other than fossil fuel are stated as geothermal, fusion, solar and fission, of which only fission has been demonstrated technically and economically. The environmental impacts of fission are examined. The hazards are discussed under the following headings: nuclear accident, fatality risk, safe reactor, property damage, acts of God, low-level release of radioactivity, diversion of fissile material and sabotage, radioactive waste disposal, toxicity of plutonium. The public reaction to nuclear power is analyzed, and proposals are made for a programme of safety and security which the author hopes will make it acceptable as the ultimate energy source. (U.K.)

  19. Electrical, control and information systems in the Enhanced CANDU 6

    Energy Technology Data Exchange (ETDEWEB)

    De Grosbois, J.; Raiskums, G.; Soulard, M. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada)

    2011-07-01

    This paper describes the electrical, control, and information system (EC and I) design feature improvements of the Enhanced CANDU 6 (EC6). These additional features are carefully integrated into the EC6 design platform, and are engineered with consideration of operational feedback, human factors, and leveraging the advantages of digital instrumentation and control (I and C) technology to create a coherent I and C architecture in support of safe and high performance operation. The design drivers for the selection of advanced features are also discussed. The EC6 nuclear power plant is a mid-sized Pressurized Heavy Water Reactor design, based on the highly successful CANDU 6 family of power plants, and upgraded to meet today's Canadian and international safety requirements and to satisfy Generation 3 design expectations. (author)

  20. Power systems with nuclear-electric generators - Modelling methods

    International Nuclear Information System (INIS)

    considered. The author makes use of various predictive models, search-forecasting, catastrophic, chaotic and risk approaches to select the most suitable analytic apparatus applicable to the nuclear power plant at Cernavoda. Recognizing in costs the most the essential element in decision making the author stresses the current aspects of nuclear systems engineering and refurbishment, aiming at raising the cost-efficiency and competitiveness of the nuclear power systems. Management and personnel aspects are also reviewed. By taking Cernavoda NPP as a case study for CANDU type reactors the author has worked out a valuable methodology for following up nuclear power issue starting from investment, construction, operation and development

  1. The evolution of Candu fuel cycles and their potential contribution to world peace

    International Nuclear Information System (INIS)

    The Candu(r) reactor is the most versatile commercial power reactor in the world. It has the potential to extend resource utilization significantly, to allow countries with developing industrial infrastructures access to clean and abundant energy, and to destroy long-lived nuclear waste or surplus weapons plutonium. These benefits are available by choosing from an array of possible fuel cycles. Several factors, including Canada's early focus on heavy-water technology, limited heavy-industry infrastructure at the time, and a desire for both technological autonomy and energy self-sufficiency, contributed to the creation of the first Candu reactor in 1962. With the maturation of the CANDU industry, the unique design features of the now-familiar product - on-power refuelling, high neutron economy, and simple fuel design - make possible the realization of its potential fuel-cycle versatility. Several fuel-cycle options currently under development are described. (authors)

  2. Nuclear power and the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Australian Nuclear Science and Technology Organization maintains an ongoing assessment of the world's nuclear technology developments, as a core activity of its Strategic Plan. This publication reviews the current status of the nuclear power and the nuclear fuel cycle in Australia and around the world. Main issues discussed include: performances and economics of various types of nuclear reactors, uranium resources and requirements, fuel fabrication and technology, radioactive waste management. A brief account of the large international effort to demonstrate the feasibility of fusion power is also given. 11 tabs., ills

  3. Floating nuclear power plants

    International Nuclear Information System (INIS)

    This article examines the legal regime for floating nuclear power plants (FNPs), in view of the absence of specific US legislation and the very limited references to artificial islands in the Law of the Sea Convention. The environmental impacts of FNPs are examined and changes in US regulation following the Three Mile Island accident and recent US court decisions are described. References in the Law of the Sea Convention relevant to FNPs are outlined and the current status of international law on the subject is analysed. (author)

  4. Nuclear Security for Floating Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Skiba, James M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scherer, Carolynn P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-13

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  5. Nuclear Security for Floating Nuclear Power Plants

    International Nuclear Information System (INIS)

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  6. Korea's CANDU fuel R and D program

    International Nuclear Information System (INIS)

    As the first R and D activity led to the nuclear fuel industrialization in Korea, KAERI had successfully developed the CANDU-6 fuel bundle in the period of 1981 to 1986 and has commercially produced more than 35,000 fuel bundles for the use in Wolsong Unit 1 since 1987. The commercial production of the CANDU-6 fuel in KAERI will be terminated on the end of 1997 and KNFC will take over the mission of CANDU-6 fuel production with a capacity of 400 tons of uranium per year form 1998. (author)

  7. Nuclear power and nuclear safety 2011

    International Nuclear Information System (INIS)

    The report is the ninth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe DTU and the Danish Emergency Management Agency. The report for 2011 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events, international relations and conflicts, and the Fukushima accident. (LN)

  8. Nuclear power and nuclear safety 2010

    International Nuclear Information System (INIS)

    The report is the eighth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe DTU and the Danish Emergency Management Agency. The report for 2010 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events, international relations, and conflicts and the Fukushima accident. (LN)

  9. Nuclear power and nuclear safety 2009

    International Nuclear Information System (INIS)

    The report is the seventh report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is written in collaboration between Risoe DTU and the Danish Emergency Management Agency. The report for 2009 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events, international relations, conflicts and the European safety directive. (LN)

  10. Nuclear power and nuclear safety 2012

    International Nuclear Information System (INIS)

    The report is the tenth report in a series of annual reports on the international development of nuclear power production, with special emphasis on safety issues and nuclear emergency preparedness. The report is prepared in collaboration between DTU Nutech and the Danish Emergency Management Agency. The report for 2012 covers the following topics: status of nuclear power production, regional trends, reactor development, safety related events, international relations and conflicts, and the results of the EU stress test. (LN)

  11. Overview of nuclear power plant equipment qualification issues and practices

    International Nuclear Information System (INIS)

    This report presents a view of and commentary on the current status of equipment qualification (EQ) in nuclear industries of the major western nations. The introductory chapters discuss the concepts of EQ, the elements of EQ process and highlight some of the key issues in EQ. A brief review of industry practices and some of the prevalent industrial standards is presented, followed by an overview of current regulatory positions in the USA, France, Germany and Sweden. A summary and commentary on the latest research findings on issues relating to accident simulation, to aging simulation and some special topics related to EQ, has been contributed by Franklin Research Centre of Philadelphia. The last part of the report deals with equipment qualification in Canada and gives recommendations on EQ for new plants as well as currently operational CANDU nuclear power plants

  12. Nuclear power generation modern power station practice

    CERN Document Server

    1971-01-01

    Nuclear Power Generation focuses on the use of nuclear reactors as heat sources for electricity generation. This volume explains how nuclear energy can be harnessed to produce power by discussing the fundamental physical facts and the properties of matter underlying the operation of a reactor. This book is comprised of five chapters and opens with an overview of nuclear physics, first by considering the structure of matter and basic physical concepts such as atomic structure and nuclear reactions. The second chapter deals with the requirements of a reactor as a heat source, along with the diff

  13. Results of fuel management at Embalse nuclear power plant. Analysis of performance at other plants

    International Nuclear Information System (INIS)

    The operating experience of fuel management at the Embalse nuclear power plant from new core to the present situation (approximately 937 days at full power) is described. The average core burnup is about 4000 MW d/t U and the monthly averaged discharge burnup about 7800 MW d/t U. The neutron flux distribution is calculated by means of program PUMA-C, which is periodically checked by comparison between calculated and measured values of 102 vanadium detectors. A comparison of the performance of other reactors type CANDU 600 (Point Lepreau, Gentilly 2, Wolsung) from the point of view of fuel strategy is also presented. The data to perform the comparison were obtained by means of the CANDU system of information exchange between users (COG). (Author)

  14. International nuclear power status 2002

    International Nuclear Information System (INIS)

    This report is the ninth in a series of annual reports on the international development of nuclear power with special emphasis on reactor safety. For 2002, the report contains: 1) General trends in the development of nuclear power; 2) Decommissioning of the nuclear facilities at Risoe National Laboratory: 3) Statistical information on nuclear power production (in 2001); 4) An overview of safety-relevant incidents in 2002; 5) The development in West Europe; 6) The development in East Europe; 7) The development in the rest of the world; 8) Development of reactor types; 9) The nuclear fuel cycle; 10) International nuclear organisations. (au)

  15. International nuclear power status 2001

    International Nuclear Information System (INIS)

    This report is the eighth in a series of annual reports on the international development of nuclear power with special emphasis on reactor safety. For 2001, the report contains: 1) General trends in the development of nuclear power; 2) Nuclear terrorism; 3) Statistical information on nuclear power production (in 2000); 4) An overview of safety-relevant incidents in 2001; 5) The development in West Europe; 6) The development in East Europe; 7) The development in the rest of the world; 8) Development of reactor types; 9) The nuclear fuel cycle; 10) International nuclear organisations. (au)

  16. Voices of nuclear power monitors

    International Nuclear Information System (INIS)

    The system of nuclear power monitors was started in fiscal 1977 for the purpose of hearing the opinions of general people on nuclear energy development and utilization and reflecting them to the nuclear power administration. The monitors were a total of 509 persons selected throughout the nation. First, the voices received in the period from January to March, 1980, are summarized. Then, the results of a questionnaire survey conducted in January, 1980, are presented. The survey was made by means of the questionnaire sent by mail. Of the total 509 persons, 372 (73.1%) answered the questions. The items of the questionnaire were: Atomic Energy Day, energy problem, nuclear power development, nuclear power safety administration. Three Mile Island nuclear power accident in U.S., and nuclear power P.R. activities. (J.P.N.)

  17. International nuclear power status 1999

    International Nuclear Information System (INIS)

    This report is the sixth in a series of annual reports on the international development of nuclear power with special emphasis on reactor safety. For 1999, the report contains: General trends in the development of nuclear power; The past and possible future of Barsebaeck Nuclear Power Plant; Statistical information on nuclear power production (in 1998); An overview of safety-relevant incidents in 1999; The development in Sweden; The development in Eastern Europe; The development in the rest of the world; Trends in the development of reactor types; Trends in the development of the nuclear fuel cycle. (au)

  18. The Brazilian nuclear power programme

    International Nuclear Information System (INIS)

    The booklet contains survey articles on the nuclear power problems of Brazil, the German-Brazilian nuclear power agreement, the application of international safety measures, and 'Brazil and the non-proliferation of nuclear weapons'. The agreement is given in full wording. (HP)

  19. Nuclear power plant

    International Nuclear Information System (INIS)

    The present invention provides a nuclear power plant which generates thermoelectric power by utilizing heat generated by fission reaction. Namely, a fuel/thermoelectric material is made of a semiconductor material containing fission products or a semimetal material containing fission products. A reactor container contains the fuel/thermoelectric material and a reactor core constituted by the fuel/thermoelectric material. The reactor container comprises coolants for removing heat generated by nuclear reaction of fission products from the reactor core and a high temperature side electrode connected to a central portion of the fuel/thermoelectric material and a low temperature side electrode connected to the outside of the fuel/thermoelectric material. Electromotive force is caused in the fuel/thermoelectric material by temperature difference upon combustion caused at the central portion and the outer surface of the fuel/thermoelectric material. The electromotive force is taken out of the high temperature side electrode and the low temperature side electrode. (I.S.)

  20. Simulation of a power pulse during loss of coolant accident in a CANDU-6 reactor by coupling the neutronic code PUMA and the thermalhydraulic code CATHENA

    International Nuclear Information System (INIS)

    In the frame of the safety analysis for a joint feasibility study (between Nucleoelectrica Argentina and Atomic Energy of Canada) of using slightly enriched uranium fuel (0.9 w% U235), Loss of Coolant Accidents (LOCAs) simulations were performed for Embalse NPP, a CANDU-6 type reactor (648. MWe gross). Being a reactor with a positive void reactivity coefficient, the void generation during the first seconds of LOCAs leads to an initial power increase, which is larger in the half of the reactor affected by the break. In order to simulate the power transient, which has a strong spatial variation in the flux and power distributions due to CANDU reactor features, two computer codes were used: the 3 dimensional diffusion, spatial kinetics neutronic program PUMA (developed in Argentina) and the thermal-hydraulics program CATHENA (developed in Atomic Energy of Canada). The codes were coupled by an iterative methodology: the CATHENA thermal-hydraulic simulation results (mainly temperatures of fuel and temperatures and densities of coolant) were used as input of the PUMA neutronic calculation, then the time dependent power distribution calculated by PUMA was applied as input for a new CATHENA calculation. The process was repeated up to convergence, which was obtained in a short number of iterations due to the relative minor effect of the power pulse and the strong influence of the break on the thermal-hydraulics Plant behavior during the analyzed time period. The method was utilized to simulate different accidental scenarios (break size and location, and initial conditions). (author)

  1. Three Mile Island - a review of the accident and its implications for CANDU safety

    International Nuclear Information System (INIS)

    After the accident at the Three Mile Island-2 reactor all Canadian owners of CANDU nuclear power plants were asked by the Atomic Energy Control Board (AECB) to conduct a design review to assess the reliability of feedwater supply to boilers, the availability of backup cooling systems, and the adequacy of routine and emergency operating procedures. The authors studied the available information on the accident and the replies received from licensees. Their report is in three sections: a description of the accident, the authors' opinions of the underlying causes, and recommendations to the AECB regarding what might be done to confirm or improve the safety of CANDU plants

  2. Improved CANDU fuel performance

    International Nuclear Information System (INIS)

    The fuel defect rate in CANDU power reactors has been very low (0.06 percent) since 1972. Most defects were caused by power ramping. The two measures taken to reduce the defect rate, by about an order of magnitude, were changes in the fuelling schemes and the introduction of thin coatings of graphite on the inside surface of the Zircaloy fuel cladding. Power ramping tests have demonstrated that graphite layers, and also baked poly-dimethyl-siloxane layers, between the UO2 pellets and Zircaloy cladding increase the tolerance of fuel to power ramps. These designs are termed graphite CANLUB and siloxane CANLUB; fuel performance depends on coating parameters such as thickness and wear resistance and on environmental and thermal conditions during the curing of coatings. (author)

  3. The Enhanced CANDU 6TM Reactor - Generation III CANDU Medium Size Global Reactor

    International Nuclear Information System (INIS)

    The Enhanced CANDU 6TM (EC6TM) is a 740 MWe class heavy water moderated pressure tube reactor, designed to provide safe, reliable, nuclear power. The EC6TM has evolved from the proven eleven (11) CANDU 6 plants licensed and operating in five countries (four continents) with over 150 reactor years of safe operation around the world. In recent years, this global CANDU 6 fleet has ranked in the world's top performing reactors. The EC6 reactor builds on this success of the CANDU 6 fleet by using the operation, experience and project feedback to upgrade the design and incorporate design improvements to meet current safety standards.The key characteristics of the highly successful CANDU 6 reactor design include: Powered by natural Uranium; Ease of installation with modular, horizontal fuel channel core; Separate low-temperature, low-pressure moderator providing inherently passive heat sinks; Reactor vault filled with light water surrounding the core; Two independent safety shutdown systems; On-power fuelling; The CANDU 6 plant has a highly automated control system, with plant control computers that adjust and maintain the reactor power for plant stability (which is particularly beneficial in less developed power grids-where fluctuations occur regularly and capacities are limited). The major improvements incorporated in the EC6 design include: More robust containment and increased passive features e.g., thicker walls, steel liner; Enhanced severe accident management with additional emergency heat removal systems; Improved shutdown performance for improved Large LOCA margins; Upgraded fire protection systems to meet current Canadian and International standards; Additional design features to improve environmental protection for workers and public-ALARA principle; Automated and unitized back-up standby power and water systems; Other improvements to meet higher safety goals consistent with Canadian and International standards based on PSA studies; Additional reactor trip

  4. Nuclear power, nuclear weapons, and international stability

    International Nuclear Information System (INIS)

    The National Energy Plan included as one of its key components a revision of this country's long-standing policy on the development of civilian nuclear power. The proposed change, which would have the effect of curtailing certain aspects of the U.S. nuclear-power program and of placing new restrictions on the export of nuclear materials, equipment, and services, was based explicitly on the assumption that there is a positive correlation between the worldwide spread of nuclear-power plants and their associated technology on the one hand, and the proliferation of nuclear weapons and the risk of nuclear war on the other. The authors advance here the heretical proposition that the supposed correlation may go the other way, and that the recent actions and statements of the U.S. Government have taken little account of this possibility. In brief, they suggest that if the U.S. were to forgo the option of expanding its nuclear-energy supply, the global scarcity of usable energy resources would force other countries to opt even more vigorously for nuclear power and, moreover, to do so in ways that would tend to be internationally destabilizing. Thus, actions taken with the earnest intent of strengthening world security would ultimately weaken it. They believe further that any policy that seeks to divide the world into nuclear ''have'' and ''have not'' nations by attempting to lock up the assets of nuclear technologywill lead to neither a just nor a sustainable world society but to the inverse. In any event the technology itself probably cannot be effectively contained. They believe that the dangers of nuclear proliferation can be eliminated only by building a society that sees no advantage in having nuclear weapons in the first place. Accordingly, they view the problem of the proliferation of nuclear weapons as an important issue not just in the context of nuclear power but in a larger context

  5. Obrigheim nuclear power plant

    International Nuclear Information System (INIS)

    The gross output of the 345MWe pressurized water nuclear power station at Obrigheim, operation on base load, amounted to about 2.57TWh in 1974, the net power fed to the grid being about 2.44TWh. The core was used to its full capacity until 10 May 1974. Thereafter, the reactor was on stretch-out operation with steadily decreasing load until refuelled in August 1974. Plant availability in 1974 amounted to 92.1%. Of the 7.9% non-availability, 7.87% was attributable to the refuelling operation carried out from 16 August to 14 September and to the inspection, overhaul and repair work and the routine tests performed during this period. The plant was in good condition. Only two brief shutdowns occurred in 1974, the total outage time being 21/2 hours. From the beginning of trial operation in March 1969 to the end of 1974, the plant achieved an availability factor of 85.2%. The mean core burnup at the end of the fifth cycle was 19600 MWd/tonne U, with one fuel element that had been used for four cycles achieving a mean burnup of 39000 MWd/tonne U. The sipping test on the fuel elements revealed defective fuel-rods in a prototype plutonium fuel element, a high-efficiency uranium fuel element and a uranium fuel element. The quantities of radioactive substances released to the environment in 1974 were far below the officially permitted values. In july 1974, a reference preparation made up in the nuclear power station in October 1973 was discovered by outsiders on the Obrigheim municipality rubbish tip. The investigations revealed that this reference preparation had very probably been abstracted from the plant in October 1973 and arrived at the rubbish tip in a most irregular manner shortly before its discovery

  6. Candu 600 fuelling machine testing, the romanian experience

    International Nuclear Information System (INIS)

    The Candu 600 Fuelling Machine is a complex mechanism which must run in safety conditions and with high reliability in the Candu Reactor. The testing and commissioning process of this nuclear equipment meets the high standards of NPPs requirements using special technological facilities, modern measurement instruments as well the appropriate IT resources for data acquisition and processing. The paper presents the experience of the Institute for Nuclear Research Pitesti, Romania, in testing Candu 600 Fuelling Machines, inclusive the implied facilities, and in development of four simulators: two dedicated for the training of the Candu 600 Fuelling Machine Operators, and another two to simulate some process signals and actions. (authors)

  7. CANDU fuel cycle economic efficiency assessments using the IAEA-MESSAGE-V code

    International Nuclear Information System (INIS)

    The main goal of the paper is to evaluate different electricity generation costs in a CANDU Nuclear Power Plant (NPP) using different nuclear fuel cycles. The IAEA-MESSAGE code (Model for Energy Supply Strategy Alternatives and their General Environmental Impacts) will be used to accomplish these assessments. This complex tool was supplied by International Atomic Energy Agency (IAEA) in 2002 at 'IAEA-Regional Training Course on Development and Evaluation of Alternative Energy Strategies in Support of Sustainable Development' held in Institute for Nuclear Research Pitesti. It is worthy to remind that the sustainable development requires satisfying the energy demand of present generations without compromising the possibility of future generations to meet their own needs. Based on the latest public information in the next 10-15 years four CANDU-6 based NPP could be in operation in Romania. Two of them will have some enhancements not clearly specified, yet. Therefore we consider being necessary to investigate possibility to enhance the economic efficiency of existing in-service CANDU-6 power reactors. The MESSAGE program can satisfy these requirements if appropriate input models will be built. As it is mentioned in the dedicated issues, a major inherent feature of CANDU is its fuel cycle flexibility. Keeping this in mind, some proposed CANDU fuel cycles will be analyzed in the paper: Natural Uranium (NU), Slightly Enriched Uranium (SEU), Recovered Uranium (RU) with and without reprocessing. Finally, based on optimization of the MESSAGE objective function an economic hierarchy of CANDU fuel cycles will be proposed. The authors used mainly public information on different costs required by analysis. (authors)

  8. Severe accident development modeling and evaluation for CANDU

    Energy Technology Data Exchange (ETDEWEB)

    Negut, Gheorghe [National Agency for Radioactive Waste, 1, Campului Str., 115400 Mioveni (Romania)], E-mail: gheorghe.negut@andrad.ro; Catana, Alexandru [Institute for Nuclear Research Pitesti, 1, Campului Str., Mioveni P.O. Box 78, 0300 Pitesti (Romania); Prisecaru, Ilie; Dupleac, Daniel [Politehnica University Bucharest, 313, Splaiul Independentei, Sect. 6, 060042 Bucharest (Romania)

    2009-09-15

    Romania as UE member got new challenges for its nuclear industry. Romania operates since 1996 a CANDU nuclear power reactor and since 2007 the second CANDU unit. In EU are operated mainly PWR reactors, so, ours have to meet UE standards. Safety analysis guidelines require to model nuclear reactors severe accidents. Starting from previous studies, a CANDU degraded core thermal hydraulic model was developed. The initiating event is a LOCA, with simultaneous loss of moderator cooling and the loss of emergency core cooling system (ECCS). This type of accident is likely to modify the reactor geometry and will lead to a severe accident development. When the coolant temperature inside a pressure tube reaches 1000 deg. C, a contact between pressure tube and calandria tube occurs and the decay heat is transferred to the moderator. Due to the lack of cooling, the moderator, eventually, begins to boil and is expelled, through the calandria vessel relief ducts, into the containment. Therefore the calandria tubes (fuel channels) uncover, then disintegrate and fall down to the calandria vessel bottom. All the quantity of calandria moderator is vaporized and expelled, the debris will heat up and eventually boil. The heat accumulated in the molten debris will be transferred through the calandria vessel wall to the shield tank water, which surrounds the calandria vessel. The thermal hydraulics phenomena described above are modeled, analyzed and compared with the existing data.

  9. CANDU 9 - the CANDU product to meet customer and regulator requirements now and in the future

    International Nuclear Information System (INIS)

    CANDU reactors developed under Canadian licensing regulations that placed the primary responsibility for safety on the licensee. The Atomic Energy Control Board (AECB), Canada's nuclear regulatory agency, state in their regulations what is expected in terms of safety performance so that designers are free to propose the best means of meeting this performance. This goal-oriented approach, besides encouraging innovation, allowed CANDU to be licensed in other jurisdictions. The latest design - the large, single unit, CANDU 9 - explicitly incorporates licensability in Canada through a formal AECB review of the design; lessons learned from licensing CANDU 6 in Asian countries, particularly with Wolsong 2, 3 and 4 in Korea, and more recently with Qinshan in China; utility requirements for modem evolutionary plants; and emerging international standards for safety, sponsored or issued by the IAEA. By combining the assurance of acceptability in Canada with compliance with foreign and international requirements, CANDU 9 becomes an internationally licensable product. (author)

  10. Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Analia Bonelli

    2012-01-01

    Full Text Available A description of the results for a Station Black-Out analysis for Atucha 2 Nuclear Power Plant is presented here. Calculations were performed with MELCOR 1.8.6 YV3165 Code. Atucha 2 is a pressurized heavy water reactor, cooled and moderated with heavy water, by two separate systems, presently under final construction in Argentina. The initiating event is loss of power, accompanied by the failure of four out of four diesel generators. All remaining plant safety systems are supposed to be available. It is assumed that during the Station Black-Out sequence the first pressurizer safety valve fails stuck open after 3 cycles of water release, respectively, 17 cycles in total. During the transient, the water in the fuel channels evaporates first while the moderator tank is still partially full. The moderator tank inventory acts as a temporary heat sink for the decay heat, which is evacuated through conduction and radiation heat transfer, delaying core degradation. This feature, together with the large volume of the steel filler pieces in the lower plenum and a high primary system volume to thermal power ratio, derives in a very slow transient in which RPV failure time is four to five times larger than that of other German PWRs.

  11. Extrapolating power-ramp performance criteria for current and advanced CANDU fuels

    Energy Technology Data Exchange (ETDEWEB)

    Tayal, M.; Chassie, G.G

    2000-06-01

    To improve the precision and accuracy of power-ramp performance criteria for high-burnup fuel, we have examined in-reactor fuel performance data as well as out-reactor test data. The data are consistent with some of the concepts used in the current formulations for defining fuel failure thresholds, such as size of power-ramp and extent of burnup. Our review indicates that there is a need to modify some other aspects of the current formulations; therefore, a modified formulation is presented in this paper. The improvements mainly concern corrodent concentration and its relationships with threshold stress for failure. The new formulation is consistent with known and expected trends such as strength of Zircaloy in corrosive environment, timing of the release of fission products to the pellet-to-sheath gap, CANLUB coating, and fuel burnup. Because of the increased precision and accuracy, the new formulation is better able to identify operational regimes that are at risk of power-ramp failures; this predictive ability provides enhanced protection to fuel against power-ramp defects. At die same time, by removing unnecessary conservatisms in other areas, the new formulation permits a greater range of defect-free operational envelope as well as larger operating margins in regions that are, in fact, not prone to power-ramp failures. (author)

  12. Extrapolating power-ramp performance criteria for current and advanced CANDU fuels

    International Nuclear Information System (INIS)

    To improve the precision and accuracy of power-ramp performance criteria for high-burnup fuel, we have examined in-reactor fuel performance data as well as out-reactor test data. The data are consistent with some of the concepts used in the current formulations for defining fuel failure thresholds, such as size of power-ramp and extent of burnup. Our review indicates that there is a need to modify some other aspects of the current formulations; therefore, a modified formulation is presented in this paper. The improvements mainly concern corrodent concentration and its relationships with threshold stress for failure. The new formulation is consistent with known and expected trends such as strength of Zircaloy in corrosive environment, timing of the release of fission products to the pellet-to-sheath gap, CANLUB coating, and fuel burnup. Because of the increased precision and accuracy, the new formulation is better able to identify operational regimes that are at risk of power-ramp failures; this predictive ability provides enhanced protection to fuel against power-ramp defects. At die same time, by removing unnecessary conservatisms in other areas, the new formulation permits a greater range of defect-free operational envelope as well as larger operating margins in regions that are, in fact, not prone to power-ramp failures. (author)

  13. Nuclear power: An economic geography

    Energy Technology Data Exchange (ETDEWEB)

    Mounfield, P.R.

    1988-01-01

    This book presents a major study of the economic and social geography of nuclear power. Starting with descriptions of the distribution of nuclear power on a national and international level using maps and graphs, the book goes on to discuss a whole range of topics ranging from reactor design to the socio-economic impact of nuclear power stations. The book discuses the issues as they apply throughout the world.

  14. Discharges from nuclear power stations

    International Nuclear Information System (INIS)

    HM Inspectorate of Pollution commissioned, with authorising responsibilities in England and Wales, a study into the discharges of radioactive effluents from Nuclear Power Stations. The study considered arisings from nuclear power stations in Europe and the USA and the technologies to treat and control the radioactive discharges. This report contains details of the technologies used at many nuclear power stations to treat and control radioactive discharges and gives, where information was available, details of discharges and authorised discharge limits. (author)

  15. Manpower development for nuclear power

    International Nuclear Information System (INIS)

    This Guidebook provides policy-makers and managers of nuclear power programmes with information and guidance on the role, requirements, planning and implementation of manpower development programmes. It presents and discusses the manpower requirements associated with the activities of a nuclear power programme, the technical qualifications of this manpower and the manpower development corresponding to these requirements and qualifications. The Guidebook also discusses the purpose and conditions of national participation in the activities of a nuclear power programme

  16. Nuclear power program in Korea

    International Nuclear Information System (INIS)

    Korea is a nation making great progress with its nuclear power development program despite the current worldwide nuclear industry slump resulting from the global recession. The reason for this is that Korea does not have sufficient energy resources to meet demand. Six 950 MW nuclear power plants are under construction, and these units are scheduled for completion by 1989. This paper describes the status of Korea's nuclear power development program and the activities of local nuclear industries. It also discusses the efforts being made by local industries to achieve self-reliance

  17. France's nuclear power programme

    International Nuclear Information System (INIS)

    The prospects of development of France's consumption of electricity will widen the deficit of her national energy resources. Nuclear power stations should enable this deficit to be reduced, provided a certain number of uncertainties prevailing today are resolved. The first programme, put forward by Messrs. AILLERET and TARANGER at the 1955 Geneva Conference aimed at commissioning 850 MWe by 1965; the programme was devoted to developing the natural uranium graphite-gas sequence and reaches its completion with the construction of EDF 3, the world's first unit capable of 500 MWe. Before changing over from the prototype stage to their duplication, Electricite De France decided, in agreement with the Commissariat A L'energie Atomique to build EDF 4, which, while reproducing EDF 3's reactor, together with the referring equipment, the entire control equipment and various other systems, pioneers an important innovation by incorporating the heat exchangers and fans inside the prestressed concrete pressure vessel housing the core. At the same time, studies are being carried on on the same type of reactor enabling possible use of a new annular-shaped fuel element, whose use would considerably improve the performance of EDF 5, to be envisaged. On the heavy water side, the construction of EL 4 at Brennilis jointly by the Commissariat A L'energie Atomique and Electricite De France is continuing. Design work on a 500 MWe reactor of this type has already started. As regards pressurized water reactors, the Chooz power station is built jointly by Electricite De France and Belgian Utilities. Finally, the Commissariat A L'energie Atomique is continuing the construction of the 'Rapsodie' rapid neutron reactor at Cadarache, together with studies on a larger power reactor. It may thus be seen that the technical and economic knowledge gained on these various types of reactor mean that an equipment program may be contemplated which will endow nuclear power stations with a place of ever

  18. Assessment of Feeder Wall Thinning of Wolsong Nuclear Power Plants

    International Nuclear Information System (INIS)

    The reactor of CANDUs of Wolsong Nuclear Power generating station is composed of 380 pressure tubes. The primary heat transport circuit of CANDU connects each pressure tube to headers on the way to and from the steam generators. The feeder is A-106 carbon steel, and suffers from wall thinning by Flow Accelerated Corrosion. Excessive thinning deteriorates the pressure retaining capability of piping so that the minimum allowable thickness of feeder should be maintained throughout the life of feeder. The feeder wall thinning should be monitored by in-service inspection. Knowledge-based inspection strategy needs to be developed since combination of high radiation field and geometric restriction near the tight bend location makes extensive inspection very difficult. A thermo hydraulic assessment using computational fluid dynamics software and feeder wall thinning simulation experiments using plaster of Paris may provide valuable information to understand characteristic features of the feeder wall thinning. Plant in-service inspection database may be another source of valuable information. This paper summarizes a review of feeder wall thinning in Wolsong CANDU station. W-1 feeder suffered significant thinning so that it is being replaced along with the plant refurbishment campaign. The other units, W-2∼4, are still in the early portion of their operation life. A result of feeder wall thinning simulation test using plaster of Paris is presented. The knowledge presented in this paper is important information to design a knowledge-based in-service inspection program of feeder wall thinning

  19. Nuclear power reactor physics

    International Nuclear Information System (INIS)

    The purpose of this book is to explain the physical working conditions of nuclear reactors for the benefit of non-specialized engineers and engineering students. One of the leading ideas of this course is to distinguish between two fundamentally different concepts: - a science which could be called neutrodynamics (as distinct from neutron physics which covers the knowledge of the neutron considered as an elementary particle and the study of its interactions with nuclei); the aim of this science is to study the interaction of the neutron gas with real material media; the introduction will however be restricted to its simplified expression, the theory and equation of diffusion; - a special application: reactor physics, which is introduced when the diffusing and absorbing material medium is also multiplying. For this reason the chapter on fission is used to introduce this section. In practice the section on reactor physics is much longer than that devoted to neutrodynamics and it is developed in what seemed to be the most relevant direction: nuclear power reactors. Every effort was made to meet the following three requirements: to define the physical bases of neutron interaction with different materials, to give a correct mathematical treatment within the limit of necessary simplifying hypotheses clearly explained; to propose, whenever possible, numerical applications in order to fix orders of magnitude

  20. Nuclear power ecology: comparative analysis

    International Nuclear Information System (INIS)

    Ecological effects of different energy sources are compared. Main actions for further nuclear power development - safety increase and waste management, are noted. Reasons of restrained public position to nuclear power and role of social and political factors in it are analyzed. An attempt is undertaken to separate real difficulties of nuclear power from imaginary ones that appear in some mass media. International actions of environment protection are noted. Risk factors at different energy source using are compared. The results of analysis indicate that ecological influence and risk for nuclear power are of minimum

  1. Research and development for CANDU fuel channels and fuel

    International Nuclear Information System (INIS)

    The CANDU nuclear reactor is distinctly different from BWR and PWR reactors in that it uses many small pressure tubes rather than one large pressure vessel to contain the fuel and coolant. To exploit the advantages of the natural uranium fuel, the pressure tubes, like other core components, are manufactured from zirconium alloys which have low neutron capture cross sections. Also, because natural uranium fuel only achieves a modest burnup, a simple and inexpensive fuel design has been developed. The present paper reviews the features and the research that have led to the very satisfactory performance of the pressure tubes and the fuel in CANDU reactors. Reference is made to current research and development that may lead to further economies in the design and operation of future power reactors. (author)

  2. Nuclear power perspective in China

    International Nuclear Information System (INIS)

    China started developing nuclear technology for power generation in the 1970s. A substantial step toward building nuclear power plants was taken as the beginning of 1980 s. The successful constructions and operations of Qinshan - 1 NPP, which was an indigenous PWR design with the capacity of 300 MWe, and Daya Bay NPP, which was an imported twin-unit PWR plant from France with the capacity of 900 MWe each, give impetus to further Chinese nuclear power development. Now there are 8 units with the total capacity of 6100 MWe in operation and 3 units with the total capacity of 2600 MWe under construction. For the sake of meeting the increasing demand for electricity for the sustainable economic development, changing the energy mix and mitigating the environment pollution impact caused by fossil fuel power plant, a near and middle term electrical power development program will be established soon. It is preliminarily predicted that the total power installation capacity will be 750-800GWe by the year 2020. The nuclear share will account for at least 4.0-4.5 percent of the total. This situation leaves the Chinese nuclear power industry with a good opportunity but also a great challenge. A practical nuclear power program and a consistent policy and strategy for future nuclear power development will be carefully prepared and implemented so as to maintain the nuclear power industry to be healthfully developed. (author)

  3. Nuclear power plant operator licensing

    International Nuclear Information System (INIS)

    The guide applies to the nuclear power plant operator licensing procedure referred to the section 128 of the Finnish Nuclear Energy Degree. The licensing procedure applies to shift supervisors and those operators of the shift teams of nuclear power plant units who manipulate the controls of nuclear power plants systems in the main control room. The qualification requirements presented in the guide also apply to nuclear safety engineers who work in the main control room and provide support to the shift supervisors, operation engineers who are the immediate superiors of shift supervisors, heads of the operational planning units and simulator instructors. The operator licensing procedure for other nuclear facilities are decided case by case. The requirements for the basic education, work experience and the initial, refresher and complementary training of nuclear power plant operating personnel are presented in the YVL guide 1.7. (2 refs.)

  4. Nuclear Power Plant Module, NPP-1: Nuclear Power Cost Analysis.

    Science.gov (United States)

    Whitelaw, Robert L.

    The purpose of the Nuclear Power Plant Modules, NPP-1, is to determine the total cost of electricity from a nuclear power plant in terms of all the components contributing to cost. The plan of analysis is in five parts: (1) general formulation of the cost equation; (2) capital cost and fixed charges thereon; (3) operational cost for labor,…

  5. Modeling and optimization of a nuclear power plant secondary loop

    International Nuclear Information System (INIS)

    Increasing the thermodynamic efficiency of fossil fuel or nuclear power plants can lead to significant economic gains. Consequently, the continuous quest of searching higher efficiency in power plants has resulted in the development of innovative tools to comply with these needs. Although a large inventory of simulation tools is available for industrial applications, sometimes it is more appropriate to develop in-house models that are best suitable for treating specific energy systems. In the present work, a combined simulation-optimization tool was developed and used to optimize the secondary loop of a CANDU-6 nuclear power plant (i.e., Gentilly-2 nuclear station). Based on previous studies an optimizer module has been coupled with a thermodynamic model, written in Matlab, used as a plant simulation tool. It includes models that take into account the responses of major thermal units, i.e., condenser, moisture separator reheater and feedwater heaters. The simulation package is used to estimate the behavior of the power station according to the variation of a given number of plant operation parameters. The methodology permits a set of best trade-off operating conditions of the secondary loop to be determined, and thus providing a better and more realistic support to plant operators. The results also clearly show that there is plenty of potential to improve the overall performance of the power station.

  6. Nuclear power - the Hydra's head

    International Nuclear Information System (INIS)

    Following the accident at Chernobyl, the nuclear policies of many governments have been reconsidered and restated. Those in favour of nuclear power are those with highly centralised state bureaucracies, such as France and the USSR, where public opinion is disregarded. In more democratic countries, where referenda are held, such as Austria and Sweden, the people have chosen to do away with nuclear power. Indeed, the author states that nuclear power represents the State against the people, the State against democracy. Reference is made to the IAEA Reactor Safety Conference held in September, 1986, in Vienna, and the declaration sent to it by AntiAtom International. This called for the United Nations to promote the phasing out of nuclear power facilities throughout the world. It also called on the IAEA to support the phasing out of nuclear power and promote benign energy forms instead. (UK)

  7. Nuclear power for district heating

    International Nuclear Information System (INIS)

    Current district heating trends are towards an increasing use of electricity. This report concerns the evaluation of an alternative means of energy supply - the direct use of thermal energy from CANDU nuclear stations. The energy would be transmitted via a hot fluid in a pipeline over distances of up to 40 km. Advantages of this approach include a high utilization of primary energy, with a consequent reduction in installed capacity, and load flattening due to inherent energy storage capacity and transport delays. Disadvantages include the low load factors for district heating, the high cost of the distribution systems and the necessity for large-scale operation for economic viability. This requirement for large-scale operation from the beginning could cause difficulty in the implementation of the first system. Various approaches have been analysed and costed for a specific application - the supply of energy to a district heating load centre in Toronto from the location of the Pickering reactor station about 40 km away. (author)

  8. Nuclear power and the UK

    International Nuclear Information System (INIS)

    This series of slides describes the policy of the UK government concerning nuclear power. In January 2008 the UK Government published the White Paper on the Future of Nuclear Power. The White Paper concluded that new nuclear power stations should have a role to play in this country's future energy mix. The role of the Government is neither to build nuclear power plants nor to finance them. The White Paper set out the facilitative actions the Government planned to take to reduce regulatory and planning risks associated with investing in new nuclear power stations. The White Paper followed a lengthy period of consultation where the UK Government sought a wide variety of views from stakeholders and the public across the country on the future of nuclear power. In total energy companies will need to invest in around 30-35 GW of new electricity generating capacity over the next two decades. This is equivalent to about one-third of our existing capacity. The first plants are expected to enter into service by 2018 or sooner. The Office for Nuclear Development (OND) has been created to facilitate new nuclear investment in the UK while the Nuclear Development Forum (NDF) has been established to lock in momentum to secure the long-term future of nuclear power generation in the UK. (A.C.)

  9. Nuclear power in human medicine

    International Nuclear Information System (INIS)

    The public widely associate nuclear power with the megawatt dimensions of nuclear power plants in which nuclear power is released and used for electricity production. While this use of nuclear power for electricity generation is rejected by part of the population adopting the polemic attitude of ''opting out of nuclear,'' the application of nuclear power in medicine is generally accepted. The appreciative, positive term used in this case is nuclear medicine. Both areas, nuclear medicine and environmentally friendly nuclear electricity production, can be traced back to one common origin, i.e. the ''Atoms for Peace'' speech by U.S. President Eisenhower to the U.N. Plenary Assembly on December 8, 1953. The methods of examination and treatment in nuclear medicine are illustrated in a few examples from the perspective of a nuclear engineer. Nuclear medicine is a medical discipline dealing with the use of radionuclides in humans for medical purposes. This is based on 2 principles, namely that the human organism is unable to distinguish among different isotopes in metabolic processes, and the radioactive substances are employed in amounts so small that metabolic processes will not be influenced. As in classical medicine, the application of these principles serves two complementary purposes: diagnosis and therapy. (orig.)

  10. Thermal fatigue screening criteria for identifying susceptible piping components in CANDU stations

    Energy Technology Data Exchange (ETDEWEB)

    Schefski, C.; Chen, Q.; Pentecost, S. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2011-07-01

    In December 1987, a fatigue failure in a non-isolable section of a safety injection line at the Farley-2 plant prompted the U.S. Nuclear Regulatory Commission (NRC) to issue Bulletin 88-08 requiring that U.S. utilities review all non-isolable branch lines to determine if they are susceptible to thermal fatigue. The thermal fatigue incident at Farley-2 was caused by stresses in the pipe wall resulting from large-scale temperature fluctuations. Shortly after the Farley-2 event, several other incidents with through-wall cracks due to thermal fatigue had occurred in plant subsystems and piping configurations similar to the Farley-2 safety injection line. Thermal fatigue cracks have also occurred in piping configurations with different geometries, such as drain, residual heat removal, and shutdown cooling suction lines in various pressurized water reactors (PWR) and boiling water reactors (BWR). Thermal fatigue, caused by local thermal stratification phenomena, has received significant attention in the PWR and BWR communities in the past two decades. Although CANDU stations have experienced relatively few thermal fatigue failures; the impact of this known fatigue mechanism for CANDU designs has not been rigorously assessed. Screening and evaluation methodology, which has been developed by Electric Power Research Institute (EPRI) to identify locations susceptible to thermal cycling in PWR systems, has recently been modified under a CANDU Owners Group (COG) project for application in CANDU piping systems. This paper describes a new software tool for evaluating locations susceptible to thermal fatigue in CANDU piping systems in an effort to avoid failures that lead to costly plant shutdowns. The software, combined with engineering judgement, will assist CANDU station staff to focus their inspections on key components, therefore reducing dose, time and cost during outages. Computational Fluid Dynamics (CFD) was used to form the basis for expanding the range of validity in

  11. Trends in nuclear power developments

    International Nuclear Information System (INIS)

    Modern state and prospects of nuclear power development in industrial states are considered. Structure of power consumption, dynamics of nuclear capacity commissioning, the growth of specific capital expenses for reactor construction, orders for NPP production are analyzed. Electric power production costs at NPPs and coal TPPs in Canada, USA, Western Europe and Japan are compared. It is underlined that inspite of certain depressions nuclear power is being developed further on. Increase of electric power consumption for commercial and public purposes and growth of fresh water shortage appear to be the main prerequisites of its further development

  12. Power peaking nuclear reliability factors

    International Nuclear Information System (INIS)

    The Calculational Nuclear Reliability Factor (CNRF) assigned to the limiting power density calculated in reactor design has been determined. The CNRF is presented as a function of the relative power density of the fuel assembly and its radial local. In addition, the Measurement Nuclear Reliability Factor (MNRF) for the measured peak hot pellet power in the core has been evaluated. This MNRF is also presented as a function of the relative power density and radial local within the fuel assembly

  13. Power generation costs. Coal - nuclear power

    International Nuclear Information System (INIS)

    This supplement volume contains 17 separate chapters investigating the parameters which determine power generation costs on the basis of coal and nuclear power and a comparison of these. A detailed calculation model is given. The complex nature of this type of cost comparison is shown by a review of selected parameter constellation for coal-fired and nuclear power plants. The most favourable method of power generation can only be determined if all parameters are viewed together. One quite important parameter is the load factor, or rather the hours of operation. (UA) 891 UA/UA 892 AMO

  14. Civil society involvement in informing population on potential risks of nuclear power

    International Nuclear Information System (INIS)

    In 1977 the town Cernavoda, Romania has been selected for the construction of the first Romanian Nuclear Power Plant provided with five CANDU type reactors, planned, at that time, to cover one third of the country power demand. The first Cernavoda Unit has been commissioned on December 2, 1996. The paper presents the preoccupation of different non-governmental organizations with respect to the impact of the nuclear plant operation on the environment and public health and, more generally, of the Uranium mining, heavy water production plants and radioactive waste disposal problems. Such issues, concerning the the energy efficiency and the nuclear power problems in Romania were not exposed so far to the public debate and little, if any, reliable information was provided to the population. The paper stresses the role of civil society in informing population on the risks implied by the nuclear power projects. 2 refs

  15. Nuclear power and carbon dioxide free automobiles

    International Nuclear Information System (INIS)

    Nuclear energy has been developed as a major source of electric power in Canada. Electricity from nuclear energy already avoids the emission of about 100 million tonnes of carbon dioxide to the atmosphere in Canada. This is a significant fraction of the 619 million tonnes of Canadian greenhouse gas emissions in 1995. However, the current scope of application of electricity to end use energy needs in Canada limits the contribution nuclear energy can make to carbon dioxide emission reduction. Nuclear energy can also contribute to carbon dioxide emissions reduction through expansion of the use of electricity to less traditional applications. Transportation, in particular contributed 165 million tonnes of carbon dioxide to the Canadian atmosphere in 1995. Canada's fleet of personal vehicles consisted of 16.9 million cars and light trucks. These vehicles were driven on average 21,000 km/year and generated 91 million tonnes of greenhouse gases expressed as a C02 equivalent. Technology to improve the efficiency of cars is under development which is expected to increase the energy efficiency from the 1995 level of about 10 litres/100 km of gasoline to under 3 litres/100km expressed as an equivalent referenced to the energy content of gasoline. The development of this technology, which may ultimately lead to the practical implementation of hydrogen as a portable source of energy for transportation is reviewed. Fuel supply life cycle greenhouse gas releases for several personal vehicle energy supply systems are then estimated. Very substantial reductions of greenhouse gas emissions are possible due to efficiency improvements and changing to less carbon intensive fuels such as natural gas. C02 emissions from on board natural gas fueled versions of hybrid electric cars would be decreased to approximately 25 million t/year from the current 91 million tonnes/year. The ultimate reduction identified is through the use of hydrogen fuel produced via electricity from CANDU power

  16. Radionuclide Release after LBLOCA with Loss of Class IV Power Accident in CANDU-6 Plant

    International Nuclear Information System (INIS)

    A large break in a pipe train of a primary heat transport system discharges coolant, which has high energy and large mass, into the containment building. Reactor shutdown and emergency core cooling water will limit the fuel cladding failure, but cannot prevent it entirely. The containment building is the last barrier of radionuclide release to the environment. Containment isolation and pressure suppression by dousing and local air cooler reduce the amount of radionuclide release to the environment. The objective of containment behavior analysis for large break loss of coolant with loss of class IV power accident is to assess the amount of radionuclide release to the ambient atmosphere. Radionuclide release rates in this event, with all safety system available, that is, the containment building is intact, as well as with containment system impairment, are analyzed with GOTHIC and SMART code

  17. Radionuclide Release after LBLOCA with Loss of Class IV Power Accident in CANDU-6 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hoon [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    A large break in a pipe train of a primary heat transport system discharges coolant, which has high energy and large mass, into the containment building. Reactor shutdown and emergency core cooling water will limit the fuel cladding failure, but cannot prevent it entirely. The containment building is the last barrier of radionuclide release to the environment. Containment isolation and pressure suppression by dousing and local air cooler reduce the amount of radionuclide release to the environment. The objective of containment behavior analysis for large break loss of coolant with loss of class IV power accident is to assess the amount of radionuclide release to the ambient atmosphere. Radionuclide release rates in this event, with all safety system available, that is, the containment building is intact, as well as with containment system impairment, are analyzed with GOTHIC and SMART code

  18. The effect of fuel power on the leaching of cesium and iodine from used CANDU fuel

    International Nuclear Information System (INIS)

    The safety assessment of the concept of geological disposal of used fuel requires a source term for the instantaneous release of long-lived radionuclides from used fuel. Preferential release of the gap inventories of Cs-137 and I-129 from used fuel with a variety of linear power ratings (LPR) was studied. A one-to-one and ten-to-one correlation exists between measured gap inventories of stable xenon and the amount of Cs-137 and I-129 in the gap, for high-LPR and low-LPR fuels, respectively, as obtained from 5-day leaching experiments. These differences in release patterns for high- and low-LPR fuels can be explained by differences in the microstructure, and disappear when longer leaching times (i.e. 3 months) are used. These results imply that, on a geological time scale, the entire inventory of the long-lived isotopes of cesium and iodine must be considered as part of the instantaneous release source term. Attempts to quantify inventories of cesium and technetium at grain boundaries by comparing the short-term leaching behaviour of oxidized and non-oxidized fuel indicated that either very insoluble cesium-uranium compounds may exist at the grain boundaries, or that cesium and stable xenon grain boundary inventories are not similar. More research is needed before a firm conclusion can be reached as to whether the entire grain boundary inventories of Cs-137 (and Tc-99), as estimated from power histories, should be part of the instantaneous release source term

  19. Nuclear power project in Thailand

    International Nuclear Information System (INIS)

    Full text: Thailand has been highly relied on fossil fuels for electricity generation. In fact 66% of today's electric power is supplied from natural gas. With current unprecedented increase of oil and gas prices, the country is in need of alternative energy sources more than ever. The Government recognizes the problem and seeks sustainable solution not only to improve energy security but also to reduce greenhouse gases emission, the root of threatening global warming problem. For base load power generation, however, nuclear power is perhaps the only practical option currently available. As a result, in Thailand Power Development Plan 2007-2021 (PDP 2007), there will be a 1,000 MWe nuclear power plant commercialized in 2020 and another in 2021. By the end of 2021, nuclear share of electricity generation of Thailand will be about 5%. Due to the fact that this is Thailand's first nuclear power plant, necessary infrastructures are not currently in place. To cope with this requirement, on April 11, 2007, the National Energy Policy Council (NEPC) appointed the Nuclear Power Infrastructure Preparation Committee (NPIPC) to develop the Nuclear Power Infrastructure Establishment Plan (NPIEP). NPIEP comprises two major plans: nuclear power infrastructure and nuclear power utility preparation plans. Required infrastructures include: legal and regulatory systems and international commitments; industrial infrastructure and commerce; technology development and transfer and human resources development; nuclear safety and environmental protection; and public relations and public acceptance. Utility planning comprises preparations for setting up organizational structure to accommodate a nuclear power project, technology selection, assessment of nuclear safety and technical aspects of nuclear power generation, and implementation of project feasibility study and site selection. NPIEP had been effectively developed under guidelines and technical support from the International Atomic

  20. INR Recent Contributions to Thorium-Based Fuel Using in CANDU Reactors

    International Nuclear Information System (INIS)

    The paper summarizes INR Pitesti contributions and latest developments to the Thorium-based fuel (TF) using in present CANDU nuclear reactors. Earlier studies performed in INR Pitesti revealed the CANDU design potential to use Recovered Uranium (RU) and Slightly Enriched Uranium (SEU) as alternative fuels in PHWRs. In this paper, we performed both lattice and CANDU core calculations using TF, revealing the main neutron physics parameters of interest: k-infinity, coolant void reactivity (CVR), channel and bundle power distributions over a CANDU 6 reactor core similar to that of Cernavoda, Unit 1. We modelled the so called Once Through Thorium (OTT) fuel cycle, using the 3D finite-differences DIREN code, developed in INR. The INR flexible SEU-43 bundle design was the candidate for TF carrying. Preliminary analysis regarding TF burning in CANDU reactors has been performed using the finite differences 3D code DIREN. TFs showed safety features improvement regarding lower CVRs in the case of fresh fuel use. Improvements added to the INR ELESIMTORIU- 1 computer code give the possibility to fairly simulate irradiation experiments in INR TRIGA research reactor. Efforts are still needed in order to get better accuracy and agreement of simulations to the experimental results. (author)