Master curve approach to monitor fracture toughness of reactor pressure vessels in nuclear power plants

International Nuclear Information System (INIS)

2009-10-01

A series of coordinated research projects (CRPs) have been sponsored by the IAEA, starting in the early 1970s, focused on neutron radiation effects on reactor pressure vessel (RPV) steels. The purpose of the CRPs was to develop correlative comparisons to test the uniformity of results through coordinated international research studies and data sharing. The overall scope of the eighth CRP (CRP-8), Master Curve Approach to Monitor Fracture Toughness of Reactor Pressure Vessels in Nuclear Power Plants, has evolved from previous CRPs which have focused on fracture toughness related issues. The ultimate use of embrittlement understanding is application to assure structural integrity of the RPV under current and future operation and accident conditions. The Master Curve approach for assessing the fracture toughness of a sampled irradiated material has been gaining acceptance throughout the world. This direct measurement of fracture toughness approach is technically superior to the correlative and indirect methods used in the past to assess irradiated RPV integrity. Several elements have been identified as focal points for Master Curve use: (i) limits of applicability for the Master Curve at the upper range of the transition region for loading quasi-static to dynamic/impact loading rates; (ii) effects of non-homogeneous material or changes due to environment conditions on the Master Curve, and how heterogeneity can be integrated into a more inclusive Master Curve methodology; (iii) importance of fracture mode differences and changes affect the Master Curve shape. The collected data in this report represent mostly results from non-irradiated testing, although some results from test reactor irradiations and plant surveillance programmes have been included as available. The results presented here should allow utility engineers and scientists to directly measure fracture toughness using small surveillance size specimens and apply the results using the Master Curve approach

Development of an automated remote inspection system for the interior of the primary containment vessel of a nuclear power plant

International Nuclear Information System (INIS)

Senoo, Makoto; Yoshida, Tomiharu; Omote, Tatsuyuki; Tanaka, Keiji; Koga, Kazunori

1996-01-01

An automated remote inspection system has been developed for the interior of the primary containment vessel of a nuclear power plant. This system consists of an inspection robot and an operator's console. The inspection robot travels along a monorail provided in the interior of the primary containment vessel. The operator's console is located in the central control room of the power plant. We have made efforts to downsize the robot and automate the inspection and monitoring machinery. As for downsizing the robot, a 152 mm wide, 290 mm high cross-sectional area and 15 kg weight can be realized using commercially available small sensors and rearranging the parts in those sensors. As for automating the inspection and monitoring, several monitoring functions are developed using image processing, frequency analysis and other techniques applied to signals from sensors such as an ITV camera, an infrared camera and a microphone, which are mounted on the robot. Endurance tests show resistance of the robot to radiational and thermal conditions is adequate for actual use in actual power plants. (author)

The 1978 first in-service inspection of the reactor pressure vessel of the second unit of the Greifswald nuclear power plant

International Nuclear Information System (INIS)

Pastor, D.; Busch, R.; Hildebrandt, E.; Redlich, K.H.

1979-01-01

The reactor pressure vessel and the primary coolant circuit of the second 440-MW(e) unit of the Greifswald nuclear power plant were subjected to an in-service inspection. Extent of the inspection, development and construction of a reactor inspection container as well as the nondestructive materials testing methods used are described. Further, problems of performing the inspection, such as needs of time and personnel and radiation exposure, are considered. Finally, it is stated that the reactor pressure vessel was in safe operating state. (author)

UK regulatory aspects of prestressed concrete pressure vessels for gas-cooled reactor nuclear power stations

International Nuclear Information System (INIS)

Watson, P.S.

1990-01-01

Safety assessment principles for nuclear power plants and for nuclear chemical plants demand application of best proven techniques, recognised standards, adequacy margins, inspection and maintenance of all the components including prestressed concrete pressure vessels. In service inspection of prestressed concrete pressure vessels includes: concrete surface examination; anchorage inspection; tendon load check; tendon material examination; foundation settlement and tilt; log-term deformation; vessel temperature excursions; coolant loss; top cap deflection. Hartlepool and Heysham 1 power plants prestress shortfall problem is discussed. Main recommendations can be summarised as follows: at all pressure vessel stations prestress systems should be calibrated in a manner which results in all load bearing components being loaded in a representative manner; at all pressure vessel stations load measurements during calibration should be verified by a redundant and diverse system

Underwater nuclear power plant structure

International Nuclear Information System (INIS)

Severs, S.; Toll, H.V.

1982-01-01

A structure for an underwater nuclear power generating plant comprising a triangular platform formed of tubular leg and truss members upon which are attached one or more large spherical pressure vessels and one or more small cylindrical auxiliary pressure vessels. (author)

Structural materials requirements for in-vessel components of fusion power plants

International Nuclear Information System (INIS)

Schaaf, B. van der

2000-01-01

The economic production of fusion energy is determined by principal choices such as using magnetic plasma confinement or generating inertial fusion energy. The first generation power plants will use deuterium and tritium mixtures as fuel, producing large amounts of highly energetic neutrons resulting in radiation damage in materials. In the far future the advanced fuels, 3 He or 11 B, determine power plant designs with less radiation damage than in the first generation. The first generation power plants design must anticipate radiation damage. Solid sacrificing armour or liquid layers could limit component replacements costs to economic levels. There is more than radiation damage resistance to determine the successful application of structural materials. High endurance against cyclic loading is a prominent requirement, both for magnetic and inertial fusion energy power plants. For high efficiency and compactness of the plant, elevated temperature behaviour should be attractive. Safety and environmental requirements demand that materials have low activation potential and little toxic effects under both normal and accident conditions. The long-term contenders for fusion power plant components near the plasma are materials in the range from innovative steels, such as reduced activation ferritic martensitic steels, to highly advanced ceramic composites based on silicon carbide, and chromium alloys. The steels follow an evolutionary path to basic plant efficiencies. The competition on the energy market in the middle of the next century might necessitate the riskier but more rewarding development of SiCSiC composites or chromium alloys

Aseismic safety analysis of a prestressed concrete containment vessel for CPR1000 nuclear power plant

Science.gov (United States)

Yi, Ping; Wang, Qingkang; Kong, Xianjing

2017-01-01

The containment vessel of a nuclear power plant is the last barrier to prevent nuclear reactor radiation. Aseismic safety analysis is the key to appropriate containment vessel design. A prestressed concrete containment vessel (PCCV) model with a semi-infinite elastic foundation and practical arrangement of tendons has been established to analyze the aseismic ability of the CPR1000 PCCV structure under seismic loads and internal pressure. A method to model the prestressing tendon and its interaction with concrete was proposed and the axial force of the prestressing tendons showed that the simulation was reasonable and accurate. The numerical results show that for the concrete structure, the location of the cylinder wall bottom around the equipment hatch and near the ring beam are critical locations with large principal stress. The concrete cracks occurred at the bottom of the PCCV cylinder wall under the peak earthquake motion of 0.50 g, however the PCCV was still basically in an elastic state. Furthermore, the concrete cracks occurred around the equipment hatch under the design internal pressure of 0.4MPa, but the steel liner was still in the elastic stage and its leak-proof function soundness was verified. The results provide the basis for analysis and design of containment vessels.

The characteristics of the prestressed concrete reactor vessel of the HHT demonstration plant

International Nuclear Information System (INIS)

Schoening, J.; Schwiers, H.G.

1979-01-01

The paper concentrates on the design studies of the HTGR prestressed concrete reactor vessel (PCRV) for the HHT Demonstration Plant. The multi-cavity reactor pressure vessel accommodates all components carrying primary gas, including heat exchangers and gas turbine. For reasons of economics and availability of the reactor plant, generic requirements are made for the PCRV. A short description of the power plant is also presented

Study Of Severe Accident Phenomena In Nuclear Power Plant

International Nuclear Information System (INIS)

Sugiyanto; Antariksawan; Anhar, R.; Arifal

2001-01-01

Several phenomena that occurred in the light water reactor type of nuclear power plant during severe accident were studied. The study was carried out based on the results of severe accident researches in various countries. In general, severe accident phenomena can be classified into in-vessel phenomena, retention in the reactor coolant system, and ex-vessel phenomena. In-vessel retention has been recommended as a severe accident management strategy

Operating experience 1993 in Swedish nuclear power plants

International Nuclear Information System (INIS)

1995-01-01

For many years, the Swedish nuclear power plants had a very good track record, compared with the international average. This trend was broken in 1993. During the year, six power plants were shut down for extended periods of time, for different safety-related reasons. During the autumn, a reactor containment leak was detected during scheduled containment leak rate testing at Barsebaeck 2. The unit was shut down for extensive investigation and corrective action for the rest of the year. Ringhals 2 was shut down last six months of the year as crack indications were found in a weld next to a control rod penetration in the reactor vessel head. Extensive tests and analyses revealed that the crack originated from the manufacturing of the vessel head and was of minor importance to safety. Oskarshamn 1 was shut down the whole year. Cracks in cold bent pipes in the residual heat removal system and cracks in the feedwater riser pipes lead to extensive replacement of piping, including pipes inside the reactor vessel. Decontamination of the reactor vessel was successful and attracted world wide interest. A programme for plant status verification was started in order to establish long-term operating conditions. Replacement of the pipe insulation and the inlet strainers in the core and containment spray systems solved the problems with clogging at certain failures in Barsebaeck, Ringhals 1 and Oskarshamn 1 and 2. Six of the reactors had an extremely high availability, of about 90 per cent and more. By year end, eleven of the twelve reactors were in full power operation

Partner of nuclear power plants

International Nuclear Information System (INIS)

Gribi, M.; Lauer, F.; Pauli, W.; Ruzek, W.

1992-01-01

Sulzer, the Swiss technology group, is a supplier of components and systems for nuclear power plants. Important parts of Swiss nuclear power stations, such as containments, reactor pressure vessels, primary pipings, are made in Winterthur. Sulzer Thermtec AG and some divisions of Sulzer Innotec focus their activities on servicing and backfitting nuclear power plants. The European market enjoys priority. New types of valves or systems are developed as economic solutions meeting more stringent criteria imposed by public authorities or arising from operating conditions. (orig.) [de

The role of pressure vessel embrittlement in the long term operation of nuclear power plants

International Nuclear Information System (INIS)

Ballesteros, A.; Ahlstrand, R.; Bruynooghe, C.; Estorff, U. von; Debarberis, L.

2012-01-01

Highlights: ► Relevant open scientific issues for the long term operation of RPVs are discussed (flux effect, late blooming phases, etc.). ► Several European and American research programmes dealing with these open issues are reviewed. ► A method for consolidation and preservation of knowledge in this field is presented. - Abstract: The lack of new build of plants over the last twenty years has resulted in a switch within the industry from design, construction and development of new systems to the strengthening of safety systems and to the life extension, or long term operation (LTO), of existing reactors. The most relevant component of any nuclear power plan (NPP) is the reactor pressure vessel (RPV). This is because currently the RPV is still considered irreplaceable or prohibitively expensive to replace. This means, that if it degrades sufficiently, it could be the operational life limiting feature of the NPP. A RPV operational life of 60 years is being considered frequently by many utilities in their plant life management programmes. Areas of improvement facing long term operation are the reduction of uncertainties in the embrittlement parameters of irradiated vessels, and the development of embrittlement trend curves at high fluence levels, where surveillance data are scarce. Different techniques can be used to upgrade the surveillance programmes, as the use of miniature or reconstituted specimens and the application of best estimate assessment tools (e.g. Master Curve). Several relevant international research projects are on-going or have been proposed to clarify the material condition of long operated vessels. Knowledge management is a complementary tool, but not for it less important. The general context for LTO of RPVs is presented in this paper. Starting with a review of relevant embrittlement issues still open, followed by presenting the different techniques and tools that can be used to support LTO, and summarising the scopes of relevant European

Neutronic calculations for the reactor pressure vessel of Atucha I nuclear power plant

International Nuclear Information System (INIS)

Lerner, Ana M.; Madariaga, Marcelo R.

1999-01-01

In 1974 a surveillance program for the Atucha I nuclear power plant pressure vessel was initiated which included the construction of different types of specimens, distributed in 30 irradiation capsules located under the core at the lower part of some of the fuel channels. The capsules containing the irradiated specimens were withdrawn in two stages; the first set (SET 1) of 15 specimens in 1980 and the second one (SET 2) of the remaining 15, in 1987. Both fracture mechanic tests and dosimetry analysis were carried out by the designer (KWU) for SET1 and by the owner National Atomic Energy Commission (CNEA) for SET2. The calculations performed in the case of SET1 showed that there was a significant spectrum difference between the position where the specimens had been and the reactor pressure vessel (RPV) - inner surface (IS). It was established that the ratio of thermal flux (E 1 MeV) varied, approximately, from 1000 to 10 from the irradiation position to the RPV- IS. The purpose of this report is to show the calculations recently performed at the Nuclear Regulatory Authority, with particular emphasis on the difference in the results generated by the modification to sightly enriched fuel. A simplified 1-D calculations show that there is a slight increase (4% approximately) in the flux along the whole energy range. As it has already been mentioned, this is due, more than to the isotopic composition of the new fuel, to the difference in power density spatial distribution, which is a consequence of a different fuel management, necessary to preserve operational limits below their maximum allowed values with the same total thermal power generated. More detailed calculations are nevertheless foreseen in order to verify these first results. (author)

Slovenske elektrarne, a.s., Mochovce Nuclear Power Plant

International Nuclear Information System (INIS)

1998-01-01

In this booklet the uranium atom nucleus fission as well as electricity generation in a nuclear power plant (primary circuit, reactor, reactor pressure vessel, fuel assembly, control rod and reactor power control) are explained. Scheme of electricity generation in nuclear power plant and Cross-section of Mochovce Nuclear Power Plant unit are included. In next part a reactor scram, refuelling of fuel, instrumentation and control system as well as principles of nuclear safety and safety improvements are are described

Development of mobile manipulator for maintenance work in containment vessels of nuclear power plants

International Nuclear Information System (INIS)

Omichi, Takeo; Nishihara, Masatoshi; Hosaka, Shigetaka; Nakayama, Junji; Sato, Masatoshi; Ishida, Michiyasu

1985-01-01

The teleoperation system with robot is described for in the containment vessels of nuclear power plants. We have developed a high level robot system as the practical use level. The robot is designed to execute the locomotions and manipulations required for closing and opening the valve, tightening the bolt and others. The robot consists of a locomotor with four legs and two driving wheels, an articulated manipulator with seven joints, and an ITV arm with stereo-camera. The size of the robot is small, that is about 500 mm in length, 500 mm in width, 1200 mm in height and 420 kg in weight. The robot can be operated in a hostile environment, which has a 10 6 R gamma ray dose, 70 deg C temperature, 100 % relative humidity. We have added an advanced control method in order to reduce the operator's load. Also, an interlock and a fail-safe control are installed in the robot system. (author)

Study on reactor vessel replacement (RVR) for 1100 MW class BWR plants in Japan

International Nuclear Information System (INIS)

Mizutani, J.; Kawamura, S.; Aoki, M.; Mori, T.

2001-01-01

Plant Life Management (PLM) is being studied in Japan, and reactor vessel replacement (RVR) is being considered as one option. Since reactor internals, except for reusable parts, and the reactor pressure vessel (RPV) are replaced, the RVR provides an effective technology for extending the service life of nuclear power plants substantially. At ICONE 7, we reported on the technical viability of the RVR for BWR4-type 800 MWe class plants. This time, we rationalized the RVR method through a study for BWR5-type 1100 MWe class plants to reduce the RVR duration and evaluated the technical viability and the economic efficiency of the method. In addition, we discuss how to dispose of the RPV to complete a scenario of the process from the RVR to its final disposal. (author)

Nuclear power plant pressure vessels. Control of piping

International Nuclear Information System (INIS)

2000-01-01

The guide presents requirements for the pipework of nuclear facilities in Finland. According to the section 117 of the Finnish Nuclear Energy Degree (161/88), the Radiation and Nuclear Safety Authority of Finland (STUK) controls the pressure vessels of nuclear facilities in accordance with the Nuclear Energy Act (990/87) and, to the extent applicable in accordance with the Act of Pressure Vessels (98/73) and the rules and regulations issued by the virtue of these. In addition STUK is an inspecting authority of pressure vessels of nuclear facilities in accordance with the Pressure Vessel Degree (549/1973). According to the section of the Pressure Vessel Degree, a pressure vessel is a steam boiler, pressure container, pipework of other such appliance in which the pressure is above or may come to exceed the atmospheric pressure. Guide YVL 3.0 describes in general terms how STUK controls pressure vessels. STUK controls Safety Class 1, 2 and 3 piping as well as Class EYT (non-nuclear) and their support structures in accordance with this guide and applies the provisions of the Decision of the Ministry of Trade and Industry on piping (71/1975) issued by virtue of the Pressure Vessel Decree

Nuclear power plant analyzer

International Nuclear Information System (INIS)

Stritar, A.

1986-01-01

The development of Nuclear Power Plant Analyzers in USA is described. There are two different types of Analyzers under development in USA, the forst in Idaho and Los Alamos national Lab, the second in brookhaven National lab. That one is described in detail. The computer hardware and the mathematical models of the reactor vessel thermalhydraulics are described. (author)

Field vibration test of principal equipment of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Shiraki, Kazuhiro; Fujita, Katsuhisa; Kajimura, Motohiko; Ikegami, Yasuhiko; Hanzawa, Katsumi; Sakai, Yoshiyuki; Kokubo, Eiji; Igarashi, Shigeru

1984-09-01

Japan is one of the most earthquake-stricken countries in the world, and demands for aseismic design have become severer recently. In a nuclear power plant in particular, consisting of a reactor vessel and other facilities dealing with a radioactive substance in some form or other, it is essential from the standpoint of safety to eliminate any possibility of radioactive hazards for the local public, and the employees at the plant as well, if these facilities are struck by an earthquake. This paper is related to the reactor vessel, reactor primary cooling equipment and piping system and important general piping as examples of important facilities of a nuclear power plant, and discusses vibration tests of an actual plant in the field from the standpoint of enhancing the aseismic safety of the Mitsubishi PWR nuclear power plant. Especially concerning vibration test technology, the effects in the evaluation of aseismic safety and its limits are studied to prove how it contributes to the enhancement of the reliability of aseismic design of nuclear power plants.

Vibration monitoring of pressure vessel in Atucha-1 power plant

International Nuclear Information System (INIS)

Belinco, C.; Pastorini, A.; Martin Ghiselli, A.; Sacchi, M.

1994-01-01

The Vibration Monitoring Systems are described to obtain information about the mechanical state of different components in the main coolant system of nuclear power plants to ensure that changes in the mechanical integrity of this components are detected at an early point in time, even during operation. 9 figs

Poison and diluent system for nuclear power plants

International Nuclear Information System (INIS)

Parker, W.G.; Ravets, J.M.; Preble, B.S.

1978-01-01

A system to prevent supercriticality in nuclear power plants in the unlikely event of a core destructive accident terminating in the nuclear core meltdown is described. The system dilutes and poisons the molten core to maintain subcriticality, and is useful in mobile nuclear power plants, or in nuclear plants subject to seismic disturbances, where the orientation of the nuclear reactor after the accident is unknown. It is also applicable to alleviate the consequences of loss of coolant flow accidents from any cause. Aside from preventing supercriticality, the system serves the dual purpose of acting as a biological shield and/or structural member that reduces the deleterious effects of accidental core impaction, without compromising power plant weight and size constraints. A borated material, with a melting point greater than the fuel melting point, is inserted in the pressure vessel behind an inner wall. In the unlikely event of a core meltdown, the molten fuel melts through the inner wall and is diluted and poisoned by the borated material. In the event the molten fuel melts through the pressure vessel, additional borated material is provided to continue diluting and poisoning

WWER-440/230 reactor pressure vessel integrity. A publication of the extrabudgetary programme on the safety of WWER and RBMK nuclear power plants

International Nuclear Information System (INIS)

1996-08-01

This report was prepared with the objective of integrating all aspects involved and to provide plant specific information on the issue of reactor pressure vessel integrity including pressurized thermal shock assessment. Areas of the thermal hydraulic analysis including selection of transients, of the structural analysis including fracture mechanics assessment and of the material properties including embrittlement, annealing and re-embrittlement behaviour are addressed. The report also provides related recommendations and conclusions as well as detailed information on the plant specific status for operating WWER-440/230 nuclear power plants. 10 refs, 9 figs, 9 tabs

New method of safety assessment for pressure vessel of nuclear power plant--brief introduction of master curve approach

International Nuclear Information System (INIS)

Yang Wendou

2011-01-01

The new Master Curve Method is called as a revolutionary advance to the assessment of- reactor pressure vessel integrity in USA. This paper explains the origin, basis and standard of the Master Curve from the reactor pressure-temperature limit curve which assures the safety of nuclear power plant. According to the characteristics of brittle fracture which is greatly susceptible to the microstructure, the theory and the test method of the Master Curve as well as its statistical law which can be modeled using Weibull distribution are described in this paper. The meaning, advantage, application and importance of the Master Curve as well as the relation between the Master Curve and nuclear power safety are understood from the fitting formula for the fracture toughness database by Weibull distribution model. (author)

Steam explosions-induced containment failure studies for Swiss nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Zuchuat, O.; Schmocker, U. [Swiss Federal Nuclear Safety Inspectorate, Villigen (Switzerland); Esmaili, H.; Khatib-Rahbar, M.

1998-01-01

The assessment of the consequences of both in-vessel and ex-vessel energetic fuel-coolant interaction for Beznau (a Westinghouse pressurized water reactor with a large, dry containment), Goesgen (a Siemens/KWU pressurized water reactor with a large, dry containment) and Leibstadt (a General Electric boiling water reactor-6 with a free standing steel, MARK-III containment) nuclear power plants is presented in this paper. The Conditional Containment Failure Probability of the steel containment of these Swiss nuclear power plants is determined based on different probabilistic approaches. (author)

Review of nuclear power plant systems

International Nuclear Information System (INIS)

Doehler

1980-01-01

This presentation starts with a brief description of the Technischer Ueberwachungs-Verein (TUeV) and its main activities in the field of technical assessments. The TUeV-organisation is in general the assessor who performs the review if nuclear power plant systems, structures and equipment. All aspects relating to the safe operation of nuclear power plants are assessed by the TUeV. This paper stresses the review of the design of nuclear power plant systems and structures. It gives an outline on the procedure of an assessment, starting with the regulatory requirements, going into the papers of the applicant and finally ending with the TUeV-appraisal. This procedure is shown using settlement measuring requirements as an example. The review of the design of mechanical structures such as pipes, valves, pump and vessels is shown in detail. (RW)

Assessment and management of ageing of major nuclear power plant components important to safety: BWR pressure vessel internals

International Nuclear Information System (INIS)

2005-10-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (caused for instance by unanticipated phenomena and by operating maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and ware out of 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 guidance 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. Since the reports are written from a safety perspective, they do not address life or life cycle management of plant components, which involves economic considerations. 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 heavy water moderated reactors (HWRs), boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues

Analysis of failure events for expansion joints in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Sato, Masahiro [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2001-09-01

Although a large number of expansion joints are used in nuclear power plants with light water reactors, their failure events have not been paid as much attention as those of vessels and pipes. However, as the operation period of nuclear power plants becomes longer, it is necessary to pay attention to their failure events as well as those of vessels and pipes, because aging problems and latent troubles originated in design or fabrication of expansion joints may appear during their long period operation. In this work, we investigated failure event reports of expansion joints in nuclear power plants both in Japan and in U.S.A. and analyzed (1) the influence to output power level, (2) the position and (3) the cause of each failure. It is revealed that the failure events of expansion joints have continuously occurred, some of which have exerted influence upon power level and have caused fatal or injury accidents of personnel, and hence the importance of corrective actions to prevent the recurrence of such events is pointed out. The importance of countermeasures to the following individual events is also pointed out: (1) corrosion of expansion joints in service water systems, (2) degradation of rubber expansion joints in main condensers, (3) vibration and fatigue of expansion joints in extraction steam lines and (4) transgranular stress corrosion cracking of penetration bellows of containments. (author)

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

International Nuclear Information System (INIS)

2007-06-01

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

After-heat removing device in nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Mizuno, K [Nippon Atomic Industry Group Co. Ltd., Tokyo

1977-01-14

Purpose: To prevent water hammer in a BWR type reactor or the like by moving water in pipe lines having stagnant portions in an after-heat removing device. Constitution: To a reactor container, is provided a recycling pump which constitutes a closed loop type recycling system in a nuclear power plant together with a pressure vessel and pipe lines. A pump and a heat exchanger are provided outside of the reactor container and they are connected to up- and down-streams of the recycling pump to form an after-heat removing device in the plant. Upon shutdown of the nuclear power plant, since water in the stagnant portion flows to the intake port of the recycling pump and water from the reactor is spontaneously supplemented thereafter to the stagnant portion, neither pressurized water nor heated steam is generated and thus water hammer is prevented.

Surveillance dosimetry of operating power plants

International Nuclear Information System (INIS)

McElroy, W.N.; Davis, A.I.; Gold, R.

1981-01-01

The main focus of the research efforts presently underway is the LWR power reactor surveillance program in which metallurgical test specimens of the reactor PV and dosimetry sensors are placed in three or more surveillance capsules at or near the reactor PV inner wall. They are then irradiated in a temperature and neutron flux-spectrum environment as similar as possible to the PV itself for periods of about 1.5 to 15 effective full-power years (EFPY), with removal of the last capsule at a fluence corresponding to the 30- to 40-year plant end-of-life (EOL) fluence. Because the neutron flux level at the surveillance position is greater than at the vessel, the test is accelerated wit respect to the vessel exposure, allowing early assessment of EOL conditions

Analysis of the micro-structural damages by neutronic irradiation of the steel of reactor vessels of the nuclear power plant of Laguna Verde. Characterization of the design steel

International Nuclear Information System (INIS)

Moranchel y Rodriguez, M.; Garcia B, A.; Longoria G, L. C.

2010-09-01

The vessel of a nuclear reactor is one of the safety barriers more important in the design, construction and operation of the reactor. If the vessel results affected to the grade of to have fracture and/or cracks it is very probable the conclusion of their useful life in order to guarantee the nuclear safety and the radiological protection of the exposure occupational personnel, of the public and the environment avoiding the exposition to radioactive sources. The materials of the vessel of a nuclear reactor are exposed continually to the neutronic irradiation that generates the same nuclear reactor. The neutrons that impact to the vessel have the sufficient energy to penetrate certain depth in function of the energy of the incident neutron until reaching the repose or to be absorbed by some nucleus. In the course of their penetration, the neutrons interact with the nuclei, atoms, molecules and with the same crystalline nets of the vessel material producing vacuums, interstitial, precipitate and segregations among other defects that can modify the mechanical properties of the steel. The steel A533-B is the material with which is manufactured the vessel of the nuclear reactors of nuclear power plant of Laguna Verde, is an alloy that, among other components, it contains atoms of Ni that if they are segregated by the neutrons impact this would favor to the cracking of the same vessel. This work is part of an investigation to analyze the micro-structural damages of the reactor vessels of the nuclear power plant of Laguna Verde due to the neutronic irradiation which is exposed in a continuous way. We will show the characterization of the design steel of the vessel, what offers a comprehension about their chemical composition, the superficial topography and the crystalline nets of the steel A533-B. It will also allow analyze the existence of precipitates, segregates, the type of crystalline net and the distances inter-plains of the design steel of the vessel. (Author)

Power reactor pressure vessel benchmarks

International Nuclear Information System (INIS)

Rahn, F.J.

1978-01-01

A review is given of the current status of experimental and calculational benchmarks for use in understanding the radiation embrittlement effects in the pressure vessels of operating light water power reactors. The requirements of such benchmarks for application to pressure vessel dosimetry are stated. Recent developments in active and passive neutron detectors sensitive in the ranges of importance to embrittlement studies are summarized and recommendations for improvements in the benchmark are made. (author)

Improvement of pressure-vessel surveillance of a PWR-power plant of the Societe d'Energie Nucleaire Franco-Belge des Ardennes (S.E.N.A.)

International Nuclear Information System (INIS)

Bevilacqua, A.; Lloret, R.; Riehl, R.

1984-01-01

This paper describes a new dosimetry, installed inside and outside the Pressure Vessel of CHOOZ Nuclear Power Plant of the Societe d'Energie Nucleaire Franco-Belge des Ardennes (S.E.N.A.), during its 1982-83 operation cycle. The inner dosimetry deals with a simulated capsule located under the reactor plate, and includes copper, nickel, iron, niobium, copper-cobalt, neptunium and uranium dosimeters. Its aim is to qualify the information given by the existing copper dosimetry. The spectrum used with these measurements is obtained by the 1 D ANISN Code and BIP-N 2 library. The outer dosimety is the fluence determination along the outer wall of the vessel. Two tubes, equiped by neutron dosimeters, seven meters long, were fixed along the vessel. On the median plane, the results are compared to a 2 D DOT transport calculation. Preliminary results are given which improve the vessel and specimens neutronic characterisation. (Auth.)

Development of containers sealing system like part of surveillance program of the vessel in nuclear power plants; Desarrollo del sistema de sellado de contenedores como parte del programa de vigilancia de la vasija en nucleoelectricas

Energy Technology Data Exchange (ETDEWEB)

Romero C, J.; Hernandez C, R.; Fernandez T, F.; Rocamontes A, M.; Perez R, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: jesus.romero@inin.gob.mx

2009-10-15

The owners of nuclear power plants should be demonstrate that the embrittlement effects by neutronic radiation do not commit the structural integrity from the pressure vessel of nuclear reactors, during conditions of routine operation and below postulate accident. For this reason, there are surveillance programs of vessels of nuclear power plants, in which are present surveillance capsules. A surveillance capsule is compound by the support, six containers for test tubes and dosimeters. The containers for test tubes are of two types: rectangular container for test tubes, Charpy V and Cylindrical Container for tension test tubes. These test tubes are subject to a same or bigger neutronic flow to that of vessel, being representative of vessel mechanical conditions. The test tubes are rehearsed to watch over the increase of embrittlement that presents the vessel. This work describes the development of welding system to seal the containers for test tubes, these should be filled with helium of ultra high purity, to a pressure of an atmosphere. In this system the welding process Gas Tungsten Arc Welding is used, a hermetic camera that allows to place the containers with three grades of freedom, a vacuum subsystem and pressure, high technology equipment's like: power source with integrated computer, arc starter of high frequency, helium flow controller, among others. Finally, the advances in the inspection system for the qualification of sealing system are mentioned, system that should measure the internal pressure of containers and the helium purity inside these. (Author)

Neutronics requirements for a DEMO fusion power plant

Energy Technology Data Exchange (ETDEWEB)

Fischer, U., E-mail: ulrich.fischer@kit.edu [Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Bachmann, C. [EUROfusion Consortium , Boltzmannstraße 2, 85748 Garching (Germany); Palermo, I. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); Pereslavtsev, P. [Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Villari, R. [ENEA UT-FUS C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy)

2015-10-15

Highlights: • Discussion and specification of neutronic requirements for a DEMO power plant. • TBR uncertainties are reviewed/discussed and design margins are elaborated. • Limits are given for radiation loads to super-conducting magnets and steel structural components. • Available DEMO results are compared to recommended limits and TBR design target. - Abstract: This paper addresses the neutronic requirements a DEMO fusion power plant needs to fulfil for a reliable and safe operation. The major requirement is to ensure Tritium self-sufficiency taking into account the various uncertainties and plant-internal losses that occur during DEMO operation. A further major requirement is to ensure sufficient protection of the superconducting magnets against the radiation penetrating in-vessel components and vessel. Reliable criteria for the radiation loads need to be defined and verified to ensure the reliable operation of the magnets over the lifetime of DEMO. Other issues include radiation induced effects on structural materials such as the accumulated displacement damage, the generation of gases such as helium which may deteriorate the material performance. The paper discusses these issues and their impact on design options for DEMO taking into account results obtained in the frame of European Power Plant Physics and Technology (PPPT) 2013 programme activities with DEMO models employing the helium cooled pebble bed (HCPB), the helium cooled lithium lead (HCLL), and the water-cooled (WCLL) blanket concepts.

Nitrogen gas supply device in nuclear power plant

International Nuclear Information System (INIS)

Nishino, Masami

1991-01-01

The present invention concerns a nitrogen gas supply device in a nuclear power plant for supplying nitrogen gases to a reactor container and equipments working with the nitrogen gas as the load. A liquid nitrogen storage pool is disposed to a concrete nuclear buildings and has a two-vessel structure of inner and outer vessels, in which heat insulators are disposed between the inner and the outer vessels. Further, the nitrogen gas supply mechanism is disposed in an evaporation chamber disposed in adjacent with the liquid nitrogen storage pool in the reator building. Accordingly, since liquid nitrogen is stored in the liquid nitrogen storage pool having a structure surrounded by concrete walls, direct sunlight is completely interrupted, thereby enabling to prevent the heat caused by the direct sunlight from conducting to the liquid nitrogen. Further, since the outer vessel is not exposed to the surrounding atmosphere, heat conduction rate relative to the external air is small. This can reduce the amount of liquid nitrogen released to the atmospheric air due to natural evaporation. (I.N.)

In-vessel Retention Strategy for High Power Reactors - K-INERI Final Report (includes SBLB Test Results for Task 3 on External Reactor Vessel Cooling (ERVC) Boiling Data and CHF Enhancement Correlations)

Energy Technology Data Exchange (ETDEWEB)

F. B. Cheung; J. Yang; M. B. Dizon; J. Rempe

2005-01-01

In-vessel retention (IVR) of core melt is a key severe accident management strategy adopted by some operating nuclear power plants and proposed for some advanced light water reactors (ALWRs). If there were inadequate cooling during a reactor accident, a significant amount of core material could become molten and relocate to the lower head of the reactor vessel, as happened in the Three Mile Island Unit 2 (TMI-2) accident. If it is possible to ensure that the vessel head remains intact so that relocated core materials are retained within the vessel, the enhanced safety associated with these plants can reduce concerns about containment failure and associated risk. For example, the enhanced safety of the Westinghouse Advanced 600 MWe PWR (AP600), which relied upon External Reactor Vessel Cooling (ERVC) for IVR, resulted in the U.S. Nuclear Regulatory Commission (US NRC) approving the design without requiring certain conventional features common to existing LWRs. However, it is not clear that currently proposed external reactor vessel cooling (ERVC) without additional enhancements could provide sufficient heat removal for higher-power reactors (up to 1500 MWe). Hence, a collaborative, three-year, U.S. - Korean International Nuclear Energy Research Initiative (INERI) project was completed in which the Idaho National Engineering and Environmental Laboratory (INEEL), Seoul National University (SNU), Pennsylvania State University (PSU), and the Korea Atomic Energy Research Institute (KAERI) investigated the performance of ERVC and an in-vessel core catcher (IVCC) to determine if IVR is feasible for reactors up to 1500 MWe.

Lay-out of the He-cooled solid breeder model B in the European power plant conceptual study

International Nuclear Information System (INIS)

Hermsmeyer, S.; Malang, S.; Fischer, U.; Gordeev, S.

2003-01-01

The European helium cooled pebble bed (HCPB) blanket concept is the basis for one of two limited-extrapolation plant models that are being elaborated within the European power plant conceptual study (PPCS). In addition to addressing the case for fusion safety and environmental compatibility, following earlier studies like SEAFP or SEAL, this reactor study puts emphasis on plant availability and economic viability, which are closely related to specific plant models and require a detailed lay-out of the fusion power core and a consideration of the overall plant (balance of plant). Within the development of in-vessel components for the plant model, the major tasks to be carried out were: (i) adaptation of the HCPB concept--featuring separate pebble beds of ceramic breeder and Beryllium neutron multiplier and reduced-activation ferritic-martensitic steel EUROFER as structural material--to the large module segmentation chosen for reasons of plant availability in part II of the PPCS; (ii) proposal of a concept for a Helium cooled divertor compatible with a maximum of 10 MW/m 2 heat flux to satisfy the requirements of reasonably extrapolated plasma physics; (iii) lay-out of the major plant model components and integration into the in-vessel dimensions found from system code calculations for a power plant of 1500 MW electrical output and iterated data on the plant model performance. The paper defines all major in-vessel components of plant model B, as it is called in the PPCS, namely (i) the unit of FW, blanket and high temperature shield that is to be replaced regularly; (ii) the low temperature shield that is laid out as a lifetime component of the reactor; (iii) the divertor; and (iv) the in-vessel manifolding. Results are presented for the thermal-hydraulic performance of the components and for the thermal-mechanical behaviour of the blanket and the divertor target plate. These results suggest, together with results from the wider exploration of the plant model within

An investigation of temperature measurement methods in nuclear power plant reactor pressure vessel annealing

International Nuclear Information System (INIS)

Acton, R.U.; Gill, W.; Sais, D.J.; Schulze, D.H.; Nakos, J.T.

1996-05-01

The objective of this project was to provide an assessment of several methods by which the temperature of a commercial nuclear power plant reactor pressure vessel (RPV) could be measured during an annealing process. This project was a coordinated effort between DOE's Office of Nuclear Energy, Science and Technology; DOE's Light Water Reactor Technology Center at Sandia National Laboratories; and the Electric Power Research Institute's Non- Destructive Evaluation Center. Ball- thermocouple probes similar to those described in NUREG/CR-5760, spring-loaded, metal- sheathed thermocouple probes, and 1778 air- suspended thermocouples were investigated in experiments that heated a section of an RPV wall to simulate a thermal annealing treatment. A parametric study of ball material, emissivity, thermal conductivity, and thermocouple function locations was conducted. Also investigated was a sheathed thermocouple failure mode known as shunting (electrical breakdown of insulation separating the thermocouple wires). Large errors were found between the temperature as measured by the probes and the true RPV wall temperature during heat-up and cool-down. At the annealing soak temperature, in this case 454 degrees C [850'F], all sensors measured the same temperature within about ±5% (23.6 degrees C [42.5 degrees F]). Because of these errors, actual RPV wall heating and cooling rates differed from those prescribed (by up to 29%). Shunting does not appear to be a problem under these conditions. The large temperature measurement errors led to the development of a thermal model that predicts the RPV wall temperature from the temperature of a ball- probe. Comparisons between the model and the experimental data for ball-probes indicate that the model could be a useful tool in predicting the actual RPV temperature based on the indicated ball- probe temperature. The model does not predict the temperature as well for the spring-loaded and air suspended probes

French nuclear plants PWR vessel integrity assessment and life management

Energy Technology Data Exchange (ETDEWEB)

Bezdikian, G. [Electricite de France (EDF), Div. Production Nucleaire, 93 - Saint-Denis (France); Quinot, P. [FRAMATOME, Dept. Bloc Reacteur et Boucles Primaires, 92 - Paris-La-Defence (France); Faidy, C.; Churier-Bossennec, H. [Electricite de France (EDF), Div. Ingenierie et Service, 69 - Villeurbanne (France)

2001-07-01

The Reactor Pressure Vessel life management of 56 PWR 3 loop and 4 loop reactors units was engaged by the French Utility EDF (Electricite de France) a few years ago and is yet on going on. This paper will present the work carried out within the framework of justifying why the 34 three loop reactor vessels will remain acceptable for operation for a lifetime of at least 40-years. A summary of the measures will be given. An overall review of actions will be presented describing the French approach, using important existing databases, including studies related to irradiation surveillance monitoring program and end of life fluence assessment. The last results obtained are based on generic integrity analyses for all categories of situations (normal upset emergency and faulted conditions) until the end of lifetime, postulating circumferential an radial kinds of flaw located in the stainless steel cladding or shallow sub-cladding area. The results of structural integrity analyses beginning with elastic computations and completed with three-dimensional finite element elastic plastic computations for envelope cases, are compared with code criteria for operating plants. The objective is to evaluate the margins on different parameters as RTNDT (Reference Nil Ductility Transition Temperature), toughness or crack size, to justify the global fitness for service of all these Reactor Pressure Vessels. The paper introduces EDF's maintenance strategy, related to integrity assessment, for those nuclear power plants under operation, based on NDE in-service inspection of the first thirty millimeters in the thickness of the wall and major surveillance programs of the vessels. (author)

French nuclear plants PWR vessel integrity assessment and life management

International Nuclear Information System (INIS)

Bezdikian, G.; Quinot, P.; Faidy, C.; Churier-Bossennec, H.

2001-01-01

The Reactor Pressure Vessel life management of 56 PWR 3 loop and 4 loop reactors units was engaged by the French Utility EDF (Electricite de France) a few years ago and is yet on going on. This paper will present the work carried out within the framework of justifying why the 34 three loop reactor vessels will remain acceptable for operation for a lifetime of at least 40-years. A summary of the measures will be given. An overall review of actions will be presented describing the French approach, using important existing databases, including studies related to irradiation surveillance monitoring program and end of life fluence assessment. The last results obtained are based on generic integrity analyses for all categories of situations (normal upset emergency and faulted conditions) until the end of lifetime, postulating circumferential an radial kinds of flaw located in the stainless steel cladding or shallow sub-cladding area. The results of structural integrity analyses beginning with elastic computations and completed with three-dimensional finite element elastic plastic computations for envelope cases, are compared with code criteria for operating plants. The objective is to evaluate the margins on different parameters as RTNDT (Reference Nil Ductility Transition Temperature), toughness or crack size, to justify the global fitness for service of all these Reactor Pressure Vessels. The paper introduces EDF's maintenance strategy, related to integrity assessment, for those nuclear power plants under operation, based on NDE in-service inspection of the first thirty millimeters in the thickness of the wall and major surveillance programs of the vessels. (author)

BWR type nuclear power plant

International Nuclear Information System (INIS)

Matsumoto, Kosuke.

1991-01-01

In a BWR type nuclear power plant in which reactor water in a reactor pressure vessel can be drained to a waste processing system by way of reactor recycling pipeways and remaining heat removal system pipeways, a pressurized air supply device is disposed for supplying air for pressurizing reactor water to the inside of the reactor pressure vessel by way of an upper head. With such a constitution, since the pressurized air sent from the pressurized air supply device above the reactor pressure vessel for the reactor water discharging pressure upon draining, the water draining pressure is increased compared with a conventional case and, accordingly, the amount of drained water is not reduced even in the latter half of draining. Accordingly, the draining efficiency can be improved and only a relatively short period of time is required till the completion of the draining, which can improve safety and save labors. (T.M.)

Nuclear Power Plant Lifetime Management Study (I)

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

Nuclear Power Plant Lifetime Management Study (I)

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1996-12-31

As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

Reactor Vessel and Reactor Vessel Internals Segmentation at Zion Nuclear Power Station - 13230

Energy Technology Data Exchange (ETDEWEB)

Cooke, Conrad; Spann, Holger [Siempelkamp Nuclear Services: 5229 Sunset Blvd., (Suite M), West Columbia, SC, 29169 (United States)

2013-07-01

Zion Nuclear Power Station (ZNPS) is a dual-unit Pressurized Water Reactor (PWR) nuclear power plant located on the Lake Michigan shoreline, in the city of Zion, Illinois approximately 64 km (40 miles) north of Chicago, Illinois and 67 km (42 miles) south of Milwaukee, Wisconsin. Each PWR is of the Westinghouse design and had a generation capacity of 1040 MW. Exelon Corporation operated both reactors with the first unit starting production of power in 1973 and the second unit coming on line in 1974. The operation of both reactors ceased in 1996/1997. In 2010 the Nuclear Regulatory Commission approved the transfer of Exelon Corporation's license to ZionSolutions, the Long Term Stewardship subsidiary of EnergySolutions responsible for the decommissioning of ZNPS. In October 2010, ZionSolutions awarded Siempelkamp Nuclear Services, Inc. (SNS) the contract to plan, segment, remove, and package both reactor vessels and their respective internals. This presentation discusses the tools employed by SNS to remove and segment the Reactor Vessel Internals (RVI) and Reactor Vessels (RV) and conveys the recent progress. SNS's mechanical segmentation tooling includes the C-HORCE (Circumferential Hydraulically Operated Cutting Equipment), BMT (Bolt Milling Tool), FaST (Former Attachment Severing Tool) and the VRS (Volume Reduction Station). Thermal segmentation of the reactor vessels will be accomplished using an Oxygen- Propane cutting system. The tools for internals segmentation were designed by SNS using their experience from other successful reactor and large component decommissioning and demolition (D and D) projects in the US. All of the designs allow for the mechanical segmentation of the internals remotely in the water-filled reactor cavities. The C-HORCE is designed to saw seven circumferential cuts through the Core Barrel and Thermal Shield walls with individual thicknesses up to 100 mm (4 inches). The BMT is designed to remove the bolts that fasten the Baffle

Impact of radiation embrittlement on integrity of pressure vessel supports for two PWR [pressurized-water-reactor] plants

International Nuclear Information System (INIS)

Cheverton, R.D.; Pennell, W.E.; Robinson, G.C.; Nanstad, R.K.

1988-01-01

Recent pressure-vessel surveillance data from the High Flux Isotope Reactor (HFIR) indicate an embrittlement fluence-rate effect that is applicable to the evaluation of the integrity of light-water reactor (LWR) pressure vessel supports. A preliminary evaluation using the HFIR data indicated increases in the nil ductility transition temperature at 32 effective full-power years (EFPY) of 100 to 130/degree/C for pressurized-water-reactor (PWR) vessel supports located in the cavity at midheight of the core. This result indicated a potential problem with regard to life expectancy. However, an accurate assessment required a detailed, specific-plant, fracture-mechanics analysis. After a survey and cursory evaluation of all LWR plants, two PWR plants that appeared to have a potential problem were selected. Results of the analyses indicate minimum critical flaw sizes small enough to be of concern before 32 EFPY. 24 refs., 16 figs., 7 tabs

Summary of operating experience in Swiss nuclear power plants 1993

International Nuclear Information System (INIS)

1994-07-01

In 1993 the Swiss nuclear power plants produced their third highest combined annual output. The contribution to the total electricity generation in the country was close to 37%. Replacement of the steam generators in Beznau Unit 1 resulted in a longer than usual annual outage. For the other four units the availability figures were close to, or exceeded, those of previous years. The energy utilization was, however, lowered due to load reduction in autumn resulting from unusually high production by the hydro-electric power plants. The steam generator replacement at Beznau enabled an increase in electrical power of about 2% without increase in reactor power. With the approval of the Swiss government in December 1992, the output of the Muehleberg power plant was increased in two stages by a total of 10%. The application for an unlimited operating license for Beznau Unit 2, and for a power uprate at the Leibstadt power plant, are still pending. The average number of scrams at the Swiss plants remained stable, at less than one scram per reactor year. As a result of experience in the Swedish nuclear power plant at Barsebaeck, the suction strainers of the emergency core cooling systems of the boiling water reactors at Muehleberg and Leibstadt were replaced by strainers with larger surface areas. The re-inspection of crack indications previously detected in the core shroud of the Muehleberg reactor and the penetration tubes in the reactor pressure vessel closure head of Beznau revealed no growth during the intervening operating periods. Following the completion of installation activities during the annual outages at Beznau Unit 1, Goesgen and Leibstadt, all Swiss nuclear power plants are now equipped with filtered containment venting systems. (author) figs., tabs

Proposal of Ex-Vessel dosimetry for pressure vessel Atucha II

International Nuclear Information System (INIS)

Chiaraviglio, N.; Bazzana, S.

2013-01-01

Nuclear reactor dosimetry has the purpose of guarantee that changes in material mechanical properties of critical materials do not compromise the reactor safety. In PWR in which the top of the reactor vessel is open once a year, is possible to use Charpy specimens to measure the change in mechanical properties. Atucha II nuclear power plant is a reactor with on-line refueling so there is no access to the inside of the pressure vessel. Because of this, ex-vessel dosimetry must be performed and mechanical properties changes must be inferred from radiation damage estimations. This damage can be calculated using displacement per atom cross sections and a transport code such as MCNP. To increase results reliability it is proposed to make a neutron spectrum unfolding using activation dosimeters irradiated during one operation cycle of the power plant. In this work we present a dosimetry proposal for such end, made in base of unfolding procedures and experimental background. (author) [es

Fusion power core engineering for the ARIES-ST power plant

International Nuclear Information System (INIS)

Tillack, M.S.; Wang, X.R.; Pulsifer, J.; Malang, S.; Sze, D.K.; Billone, M.; Sviatoslavsky, I.

2003-01-01

ARIES-ST is a 1000 MWe fusion power plant based on a low aspect ratio 'spherical torus' (ST) plasma. The ARIES-ST power core was designed to accommodate the unique features of an ST power plant, to meet the top-level requirements of an attractive fusion energy source, and to minimize extrapolation from the fusion technology database under development throughout the world. The result is an advanced helium-cooled ferritic steel blanket with flowing PbLi breeder and tungsten plasma-interactive components. Design improvements, such as the use of SiC inserts in the blanket to extend the outlet coolant temperature range were explored and the results are reported here. In the final design point, the power and particle loads found in ARIES-ST are relatively similar to other advanced tokamak power plants (e.g. ARIES-RS [Fusion Eng. Des. 38 (1997) 3; Fusion Eng. Des. 38 (1997) 87]) such that exotic technologies were not required in order to satisfy all of the design criteria. Najmabadi and the ARIES Team [Fusion Eng. Des. (this issue)] provide an overview of ARIES-ST design. In this article, the details of the power core design are presented together with analysis of the thermal-hydraulic, thermomechanical and materials behavior of in-vessel components. Detailed engineering analysis of ARIES-ST TF and PF systems, nuclear analysis, and safety are given in the companion papers

Modular robotic applications in nuclear power plant maintenance

International Nuclear Information System (INIS)

Glass, S.W.; Ranson, C.C.; Reinholtz, C.F.; Calkins, J.M.

1996-01-01

General-purpose factory automation robots have experienced limited use in nuclear maintenance and hazardous-environment work spaces due to demanding requirements on size, weight, mobility and adaptability. Robotic systems in nuclear power plants are frequently custom designed to meet specific space and performance requirements. Examples of these custom configurations include Framatome Technologies COBRA trademark Steam Generator Manipulator and URSULA trademark Reactor Vessel Inspection Manipulator. The use of custom robots in nuclear plants has been limited because of the lead time and expense associated with custom design. Developments in modular robotics and advanced robot control software coupled with more powerful low-cost computers, however, are helping to reduce the cost and schedule for deploying custom robots. A modular robotic system allows custom robot configurations to be implemented using standard (modular) joints and adaptable controllers. This paper discusses Framatome Technologies (FTI) current and planned developments in the area of modular robot system design

Employing modern power plant simulators in nuclear power plants

International Nuclear Information System (INIS)

Niedorf, V.; Storm, J.

2005-01-01

At the present state of the art, modern power plant simulators are characterized by new qualitative features, thus enabling operators to use them far beyond the traditional field of training. In its first part, this contribution presents an overview of the requirements to be met by simulators for multivalent uses. In part two, a survey of the uses and perspectives of simulation technology in power plants is presented on the basis of experience accumulated by Rheinmetall Defence Electronics (RDE).Modern simulators are shown to have applications by far exceeding traditional training areas. Modular client - sever systems on standard computers allow inexpensive uses to be designed at several levels, thus minimizing maintenance cost. Complex development and running time environments, like the SEMS developed by RDE, have made power plant simulators the workhorses of power plant engineers in all power plant areas. (orig.)

Replacement of major nuclear power plant components for service life extension

International Nuclear Information System (INIS)

Novak, S.

1987-01-01

Problems are discussed associated with replacement of nuclear power plant components with the aim to extend their original scheduled life. The existing foreign experience shows that it is technically feasible to replace practically all basic components for which the necessity of replacement is established. Data is summed up on the replacement of steam generators in US and West German nuclear power plants showing the duration of the job, the total consumption of manhours, the collective dose equivalent and the cost. Attention is also focused on implemented and projected replacements of circulation pipes in nuclear power plants abroad. Based on these figures, the cost is estimated of the replacement of the reactor vessel and the steam generators for WWER-440 nuclear power plants. The conclusion is arrived at that even based on a conservative estimate, the extension by 20 years of the service life of a nuclear power plant is economically more effective than the construction of a new plant. (Z.M.) 2 tabs., 15 refs., 3 figs

Automatic acoustic and vibration monitoring system for nuclear power plants

International Nuclear Information System (INIS)

Tothmatyas, Istvan; Illenyi, Andras; Kiss, Jozsef; Komaromi, Tibor; Nagy, Istvan; Olchvary, Geza

1990-01-01

A diagnostic system for nuclear power plant monitoring is described. Acoustic and vibration diagnostics can be applied to monitor various reactor components and auxiliary equipment including primary circuit machinery, leak detection, integrity of reactor vessel, loose parts monitoring. A noise diagnostic system has been developed for the Paks Nuclear Power Plant, to supervise the vibration state of primary circuit machinery. An automatic data acquisition and processing system is described for digitalizing and analysing diagnostic signals. (R.P.) 3 figs

Fuel handling and storage systems in nuclear power plants

International Nuclear Information System (INIS)

1984-01-01

The scope of this Guide includes the design of handling and storage facilities for fuel assemblies from the receipt of fuel into the nuclear power plant until the fuel departs from that plant. The unirradiated fuel considered in this Guide is assumed not to exhibit any significant level of radiation so that it can be handled without shielding or cooling. This Guide also gives limited consideration to the handling and storage of certain core components. While the general design and safety principles are discussed in Section 2 of this Guide, more specific design requirements for the handling and storage of fuel are given in detailed sections which follow the general design and safety principles. Further useful information is to be found in the IAEA Technical Reports Series No. 189 ''Storage, Handling and Movement of Fuel and Related Components at Nuclear Power Plants'' and No. 198 ''Guide to the Safe Handling of Radioactive Wastes at Nuclear Power Plants''. However, the scope of the Guide does not include consideration of the following: (1) The various reactor physics questions associated with fuel and absorber loading and unloading into the core; (2) The design aspects of preparation of the reactor for fuel loading (such as the removal of the pressure vessel head for a light water reactor) and restoration after loading; (3) The design of shipping casks; (4) Fuel storage of a long-term nature exceeding the design lifetime of the nuclear power plant; (5) Unirradiated fuel containing plutonium

FFTF and CRBRP reactor vessels

International Nuclear Information System (INIS)

Morgan, R.E.

1977-01-01

The Fast Flux Test Facility (FFTF) reactor vessel and the Clinch River Breeder Reactor Plant (CRBRP) reactor vessel each serve to enclose a fast spectrum reactor core, contain the sodium coolant, and provide support and positioning for the closure head and internal structure. Each vessel is located in its reactor cavity and is protected by a guard vessel which would ensure continued decay heat removal capability should a major system leak develop. Although the two plants have significantly different thermal power ratings, 400 megawatts for FFTF and 975 megawatts for CRBRP, the two reactor vessels are comparable in size, the CRBRP vessel being approximately 28% longer than the FFTF vessel. The FFTF vessel diameter was controlled by the space required for the three individual In-Vessel Handling Machines and Instrument Trees. Utilization of the triple rotating plug scheme for CRBRP refueling enables packaging of the larger CRBRP core in a vessel the same diameter as the FFTF vessel

The use of ferritic materials in light water reactor power plants

International Nuclear Information System (INIS)

Marston, T.V.

1984-01-01

This paper reviews the use of ferritic materials in LWR power plant components. The two principal types of LWR systems, the boiling water reactor (BWR) and the pressurized water reactor (PWR) are described. The evolution of the construction materials, including plates and forgings, is presented. The fabrication process for both reactors constructed with plates and forgings are described in detail. Typical mechanical properties of the reactor vessel materials are presented. Finally, one critical issue radiation embrittlement dealing with ferritic materials is discussed. This has been one of the major issues regarding the use of ferritic material in the construction of LWR pressure vessels

Advanced Approach of Reactor Pressure Vessel In-service Inspection

International Nuclear Information System (INIS)

Matokovic, A.; Picek, E.; Pajnic, M.

2006-01-01

The most important task of every utility operating a nuclear power plant is the continuously keeping of the desired safety and reliability level. This is achieved by the performance of numerous inspections of the components, equipment and system of the nuclear power plant in operation and in particular during the scheduled maintenance periods at re-fueling time. Periodic non-destructive in-service inspections provide most relevant criteria of the integrity of primary circuit pressure components. The task is to reliably detect defects and realistically size and characterize them. One of most important and the most extensive examination is a reactor pressure vessel in-service inspection. That inspection demand high standards of technology and quality and continual innovation in the field of non-destructive testing (NDT) advanced technology as well as regarding reactor pressure vessel tool and control systems. A remote underwater contact ultrasonic technique is employed for the examination of the defined sections (reactor welds), whence eddy current method is applied for clad surface examinations. Visual inspection is used for examination of the vessel inner surface. The movement of probes and data positioning are assured by using new reactor pressure vessel tool concept that is fully integrated with NDT systems. The successful performance is attributed thorough pre-outage planning, training and successful performance demonstration qualification of chosen NDT techniques on the specimens with artificial and/or real defects. Furthermore, use of advanced approach of inspection through implementation the state of the art examination equipment significantly reduced the inspection time, radiation exposure to examination personnel, shortening nuclear power plant outage and cutting the total inspection costs. The advanced approach as presented in this paper offer more flexibility of application (non-destructive tests, local grinding action as well as taking of boat samples

Nuclear power plant component protection

International Nuclear Information System (INIS)

Michel, E.; Ruf, R.; Dorner, H.

1976-01-01

Described is a nuclear power plant installation which includes a concrete biological shield forming a pit in which a reactor pressure vessel is positioned. A steam generator on the outside of the shield is connected with the pressure vessel via coolant pipe lines which extend through the shield, the coolant circulation being provided by a coolant pump which is also on the outside of the shield. To protect these components on the outside of the shield and which are of mainly or substantially cylindrical shape, semicylindrical concrete segments are interfitted around them to form complete outer cylinders which are retained against outward separation radially from the components, by rings of high tensile steel which may be interspaced so closely that they provide, in effect, an outer steel cylinder. The invention is particularly applicable to pressurized-water coolant reactor installations

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

International Nuclear Information System (INIS)

1999-10-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness-for-service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. The guidance reports are directed at technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific plant

Nuclear Power Plant Prestressed Concrete Containment Vessel Structure Monitoring during Integrated Leakage Rate Testing Using Fiber Bragg Grating Sensors

Directory of Open Access Journals (Sweden)

Jinke Li

2017-04-01

Full Text Available As the last barrier of nuclear reactor, prestressed concrete containment vessels (PCCVs play an important role in nuclear power plants (NPPs. To test the mechanical property of PCCV during the integrated leakage rate testing (ILRT, a fiber Bragg grating (FBG sensor was used to monitor concrete strain. In addition, a finite element method (FEM model was built to simulate the progress of the ILRT. The results showed that the strain monitored by FBG had the same trend compared to the inner pressure variation. The calculation results showed a similar trend compared with the monitoring results and provided much information about the locations in which the strain sensors should be installed. Therefore, it is confirmed that FBG sensors and FEM simulation are very useful in PCCV structure monitoring.

Atucha I nuclear power plant surveillance programme

International Nuclear Information System (INIS)

Jinchuk, D.

1993-01-01

After a review of the main characteristics of the Atucha I nuclear power plant and its pressure vessel, the embrittlement surveillance capsules and the irradiation conditions are described; Charpy impact tests and tensile tests were performed on the irradiated samples, and results are discussed and compared to theoretical calculations: transition temperature shifts, displacement per atom values. 6 refs., 16 figs., 7 tabs

Atucha I nuclear power plant surveillance programme

Energy Technology Data Exchange (ETDEWEB)

Jinchuk, D [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

1994-12-31

After a review of the main characteristics of the Atucha I nuclear power plant and its pressure vessel, the embrittlement surveillance capsules and the irradiation conditions are described; Charpy impact tests and tensile tests were performed on the irradiated samples, and results are discussed and compared to theoretical calculations: transition temperature shifts, displacement per atom values. 6 refs., 16 figs., 7 tabs.

Helium turbomachine design for GT-MHR power plant

International Nuclear Information System (INIS)

McDonald, C.F.; Orlando, R.J.

1994-07-01

The power conversion system in the gas turbine modular helium reactor (GT-MHR) power plant is based on a highly recuperated closed Brayton cycle. The major component in the direct cycle system is a helium closed-cycle gas turbine rated at 286 MW(e). The rotating group consists of an intercooled helium turbocompressor coupled to a synchronous generator. The vertical rotating assembly is installed in a steel vessel, together with the other major components (i.e., recuperator, precooler, intercooler, and connecting ducts and support structures). The rotor is supported on an active magnetic bearing system. The turbine operates directly on the reactor helium coolant, and with a temperature of 850 degree C (1562 degree F) the plant efficiency is over 47%. This paper addresses the design and development planning of the helium turbomachine, and emphasizes that with the utilization of proven technology, this second generation nuclear power plant could be in service in the first decade of the 21st century

Stress analysis of pressure vessels in nuclear power plants: pt.2

International Nuclear Information System (INIS)

Kim, C.W.; Chu, Y.W.

1976-01-01

Stress analysis of tapered cylinder of reactor vessels in investigated by means of the intersection method. The tapered cylinder is approximated into three models average cylinder, conical frustum, and ring. The results are compared with those of the finite element method program and an experiment. In this paper, the following results are obtained: (1) the best approximation has been obtained by the ring model analysis: (2) the intersection analysis of the tapered cylinder by the ring model shows a sufficient accuracy for the stress analysis of reactor vessels. (author)

Proposal of In-vessel corium retention concept for Paks NPP

International Nuclear Information System (INIS)

Elter, J.; Toth, E.; Matejovic, P.

2011-01-01

The in-vessel corium retention (IVR) via external reactor vessel cooling (ERVC) seems to be a promising severe accident management strategy not only for new generation of advanced PWRs, but also for VVER-440/V213 reactors, which were designed several years ago. The basic idea of in-vessel retention of corium is to prevent RPV failure by flooding the reactor cavity so that the reactor pressure vessel is submerged in water up to its support structures, and thus the decay heat can be transferred from the corium pool through the vessel wall and into the water surrounding the vessel. An IVR concept with simple ECVR loop based only on minor modifications of existing plant technology was proposed for the Paks Nuclear Power Plant. 2 severe accident (LB and SB LOCA) without availability of HP and LP safety injection in power upgrade (108%) conditions were simulated using the ASTEC code. The analyses show that the proposed solution is effective in preserving RPV integrity in the case of severe accident. Possible uncertainties in code predictions are covered by the applied conservative assumptions

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

International Nuclear Information System (INIS)

1979-01-01

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

Assessment and management of ageing of major nuclear power plant components important to safety: BWR pressure vessels

International Nuclear Information System (INIS)

2005-10-01

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

After heat distribution of a mobile nuclear power plant

Science.gov (United States)

Parker, W. G.; Vanbibber, L. E.; Tang, Y. S.

1971-01-01

A computer program was developed to analyze the transient afterheat temperature and pressure response of a mobile gas-cooled reactor power plant following impact. The program considers (in addition to the standard modes of heat transfer) fission product decay and transport, metal-water reactions, core and shield melting and displacement, and pressure and containment vessel stress response. Analyses were performed for eight cases (both deformed and undeformed models) to verify operability of the program options. The results indicated that for a 350 psi (241 n/sq cm) initial internal pressure, the containment vessel can survive over 100,000 seconds following impact before creep rupture occurs. Recommendations were developed as to directions for redesign to extend containment vessel life.

Overview of the Italian activities in the field of life management of nuclear power plants

International Nuclear Information System (INIS)

Pini, A.

1994-01-01

Overview of the Italian activities in the field of life management of nuclear power plants is presented, including the following issues: nuclear energy scenario in Italy, study of reactor pressure vessel, piping and containment integrity, seismic risk analysis

Components production and assemble of the irradiation capsule of the Surveillance Program of Materials of the nuclear power plant of Laguna Verde

International Nuclear Information System (INIS)

Medrano, A.

2009-01-01

To predict the effects of the neutrons radiation and the thermal environment about the mechanical properties of the reactor vessel materials of the nuclear power plant of Laguna Verde, a surveillance program is implemented according to the outlines settled by Astm E185-02 -Standard practice for design of surveillance programs for light-water moderated nuclear power reactor vessels-. This program includes the installation of three irradiation capsules of similar materials to those of the reactor vessels, these samples are test tubes for mechanical practices of impact and tension. In the National Institute of Nuclear Research and due to the infrastructure as well as of the actual human resources of the Pilot Plant of Nuclear Fuel Assembles Production it was possible to realize the materials rebuilding extracted in 2005 of Unit 2 of nuclear power plant of Laguna Verde as well as the production, assemble and reassignment of the irradiation capsule made in 2006. At the present time the surveillance materials extracted in 2008 of Unit 1 of the nuclear power plant of Laguna Verde are reconstituting and the components are manufactured for the assembles of the irradiation capsule that will be reinstalled in the reactor vessel in 2010. The purpose of the present work is to describe the necessary components as well as its disposition during the assembles of the irradiation capsule for the surveillance program of the reactors vessel of the nuclear power plant of Laguna Verde. (Author)

Examination of VVER-1000 Reactor Pressure Vessel

International Nuclear Information System (INIS)

Matokovic, A.; Picek, E.; Markulin, K.

2008-01-01

The increasing demand of a higher level of safety in the operation of the nuclear power plants requires the utilisation of more precise automated equipment to perform in-service inspections. That has been achieved by technological advances in computer technology, in robotics, in examination probe technology with the development of the advanced inspection technique and has also been due to the considerable and varied experience gained in the performance of such inspections. In-service inspection of reactor pressure vessel, especially Russian-designed WWER-1000 presents one of the most important and extensive examination of nuclear power plants primary circuit components. Such examination demand high standards of inspection technology, quality and continual innovation in the field of non-destructive testing advanced technology. A remote underwater contact ultrasonic technique is employed for the examination of the base metal of vessel and reactor welds, whence eddy current method is applied for clad surface examinations. Visual testing is used for examination of the vessel interior. The movement of inspection probes and data positioning are assured by using new reactor pressure vessel tool concept that is fully integrated with inspection systems. The successful performance of reactor pressure vessel is attributed thorough pre-outage planning, training and successful performance demonstration qualification of chosen non-destructive techniques on the specimens with artificial and/or real defects. Furthermore, use of advanced approach of inspection through implementation the state-of-the-art examination equipment significantly reduced the inspection time, radiation exposure to examination personnel, shortening nuclear power plant outage and cutting the total inspection costs. This paper presents advanced approach in the reactor pressure vessel in-service inspections and it is especially developed for WWER-1000 nuclear power plants.(author)

Development of life evaluation technology for nuclear power plant components

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin; Kim, Yun Jae; Choi, Jae Boong [Sungkyunkwan Univ., Seoul (Korea, Republic of)] (and others)

2002-03-15

This project focuses on developing reliable life evaluation technology for nuclear power plant components, and is divided into two parts, development of a life evaluation system for nuclear pressure vessels and evaluation of applicability of emerging technology to operating plants. For the development of life evaluation system for nuclear pressure vessels, the following seven topics are covered in this project: defect assessment method for steam generator tubes, development of fatigue monitoring system, assessment of corroded pipes, domestic round robin analysis for constructing P-T limit curve for RPV, development of probabilistic integrity assessment technique, effect of aging on strength of dissimilar welds, applicability of LBB to cast stainless steel, and development of probabilistic piping fracture mechanics.

Current developments in mechanized non-destructive testing in nuclear power plants

International Nuclear Information System (INIS)

Zeilinger, R.

2008-01-01

Nuclear power plants require frequent in-service activities to be carried out conscientiously in areas potentially hazardous to human operators (because of the associated radiation exposure), such as non-destructive testing of pressurized components of the steam system. Locations to be inspected in this way include the reactor pressure vessel, core internals, steam generators, pressurizers, and pipes. The codes to be used as a basis of these inspections demand high absolute positioning and repeating accuracy. These requirements can be met by mechanized test procedures. Accordingly, many new applications of, mostly mobile, robots have been developed over the past few years. The innovative control and sensor systems for stationary and mobile robots now on the market offer a potential for economic application in a large number of new areas in inspection, maintenance and service in nuclear power plants. More progress in this area is expected for the near future. Areva NP founded the new NDT Center, NETEC (Non-destructive Examination Technical Center), as a global technical center for non-destructive materials testing. NETEC is to advance research and development of all basic NDT technologies, robotics included. For many years, intelligeNDT has offered solutions and products for a variety of inspection and testing purposes and locations in nuclear power plants and is involved in continuous further development of the experience collected in nuclear power plants on the spot. (orig.)

Automation and mechanization of in-service inspection of selected equipment in FRG's nuclear power plants

International Nuclear Information System (INIS)

Metke, E.

1988-01-01

The procedures and equipment are described for the automation and mechanization of in-service inspection in nuclear power plants in the FRG, used by the KWU company. Checks of the pressure vessel are done by visual means using a colour tv camera, the method of eddy currents and the ultrasonic method. An analysis is made of the time schedule of ultrasonic inspections, and the central column manipulator is described which allows to check all internal regions of the pressure vessel. Attention is also devoted to other devices, e.g., those for prestressing shanks, cleaning shanks, cleaning thread apertures, etc. A combined probe using the ultrasonic method and the eddy current method serves the inspection of heat exchange tubes in the steam generator. For inspecting the primary circuit the KWU company uses devices for checking and working the inner surface of pipes. Briefly described are examples of using KWU equipment in nuclear power plants in CMEA countries. (Z.M.). 11 figs., 6 refs

A new small HTGR power plant concept with inherently safe features--An engineering and economic challenge

International Nuclear Information System (INIS)

McDonald, C.F.; Sonn, D.L.

1983-01-01

This paper outlines a small nuclear plant concept which is not meant to replace the large nuclear power plants that will continue to be needed by the industrialized nations, but rather recognizes the needs of the smaller energy user, both for special applications in the US and for the developing nations. The small High-Temperature Gas-Cooled Reactor (HTGR), whose introduction will be very dependent on market forces, represents only one approach to meet these needs. The design of a small power plant that could be inherently safer and that might have costs less than those indicated by the traditional reverse-economy-of-scale effect is discussed. Topics considered include power plant economics, the small steam cycle HTGR thermodynamic cycle, the reactor nuclear heat source layout, the reactor heat removal system (main loop cooling, a vessel cooling system with reactor pressurized, vessel cooling system with reactor depressurized), safety considerations, investment risk protection, the technology base, and applications for the small HTGR plant concept

Analysis of aging mechanism and management for HTR-PM reactor pressure vessel

International Nuclear Information System (INIS)

Sun Yunxue; Shao Jin

2015-01-01

Reactor pressure vessel is an important part of the reactor pressure boundary, its important degree ranks high in ageing management and life assessment of nuclear power plant. Carrying out systematic aging management to ensure reactor pressure vessel keeping enough safety margins and executing design functions is one of the key factors to guarantee security and stability operation for nuclear power plant during the whole lifetime and prolong life. This paper briefly introduces the structure and aging mechanism of reactor pressure vessel in pressurized water reactor nuclear power plant, and introduces the design principle and structure characteristics of HTR-PM. At the same time, this paper carries out preliminary analysis and exploration. and discusses aging management of HTR-PM reactor pressure vessel. Finally, the advice of carring out aging management for HTR-PM reactor pressure vessel is proposed. (authors)

A new design concept for offshore nuclear power plants with enhanced safety features

International Nuclear Information System (INIS)

Lee, Kihwan; Lee, Kang-Heon; Lee, Jeong Ik; Jeong, Yong Hoon; Lee, Phill-Seung

2013-01-01

Highlights: ► A new design concept for offshore nuclear power plants is proposed. ► The total general arrangement for the concept is suggested. ► A new emergency passive containment cooling system (EPCCS) is proposed. ► A new emergency passive reactor-vessel cooling system (EPRVCS) is proposed. ► Safety features against earthquakes, tsunamis, and storms are discussed. - Abstract: In this paper, we present a new concept for offshore nuclear power plants (ONPP) with enhanced safety features. The design concept of a nuclear power plant (NPP) mounted on gravity-based structures (GBSs), which are widely used offshore structures, is proposed first. To demonstrate the feasibility of the concept, a large-scale land-based nuclear power plant model APR1400, which is the most recent NPP model in the Republic of Korea, is mounted on a GBS while minimizing modification to the original features of APR1400. A new total general arrangement (GA) and basic design principles are proposed and can be directly applied to any existing land based large scale NPPs. The proposed concept will enhance the safety of a NPP due to several aspects. A new emergency passive containment cooling system (EPCCS) and emergency passive reactor-vessel cooling system (EPRVCS) are proposed; their features of using seawater as coolant and safety features against earthquakes, Tsunamis, storms, and marine collisions are also described. We believe that the proposed offshore nuclear power plant is more robust than conventional land-based nuclear power plants and it has strong potential to provide great opportunities in nuclear power industries by decoupling the site of construction and that of installation.

Strain measurements of nuclear power plant steam generator antiseismic supports

International Nuclear Information System (INIS)

Kulichevsky, R.

1997-01-01

The nuclear power plants steam generators have different types of structural supports. One of these types are the antiseismic supports, which are intended to be under stress only if a seismic event takes place. Nevertheless, the antiseismic supports lugs, that are welded to the steam generator vessel, are subjected to thermal fatigue because of the temperature cycles related with the shut down and start up operations performed during the life of the nuclear power plant. In order to evaluate the stresses that the lugs are subjected to, several strain gages were welded on two supports lugs, positioned at two heights of one of the Embalse nuclear power plant steam generators. In this paper, the instrumentation used and the strain measurements obtained during two start up operations are presented. The influence of the plant start up operation parameters on the lugs strain evolution is also analyzed. (author) [es

Electrical discharge machining for vessel sample removal

International Nuclear Information System (INIS)

Litka, T.J.

1993-01-01

Due to aging-related problems or essential metallurgy information (plant-life extension or decommissioning) of nuclear plants, sample removal from vessels may be required as part of an examination. Vessel or cladding samples with cracks may be removed to determine the cause of cracking. Vessel weld samples may be removed to determine the weld metallurgy. In all cases, an engineering analysis must be done prior to sample removal to determine the vessel's integrity upon sample removal. Electrical discharge machining (EDM) is being used for in-vessel nuclear power plant vessel sampling. Machining operations in reactor coolant system (RCS) components must be accomplished while collecting machining chips that could cause damage if they become part of the flow stream. The debris from EDM is a fine talclike particulate (no chips), which can be collected by flushing and filtration

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

International Nuclear Information System (INIS)

1999-10-01

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

Accident prevention in power plants

International Nuclear Information System (INIS)

Steyrer, H.

Large thermal power plants are insured to a great extent at the Industrial Injuries Insurance Institute of Instrument and Electric Engineering. Approximately 4800 employees are registered. The accident frequency according to an evaluation over 12 months lies around 79.8 per year and 1000 employees in fossil-fired power plants, around 34.1 per year and 1000 employees in nuclear power plants, as in nuclear power plants coal handling and ash removal are excluded. Injuries due to radiation were not registered. The crucial points of accidents are mechanical injuries received on solid, sharp-edged and pointed objects (fossil-fired power plants 28.6%, nuclear power plants 41.5%), stumbling, twisting or slipping (fossil-fired power plants 21.8%, nuclear power plants 19.5%) and injuries due to moving machine parts (only nuclear power plants 12.2%). However, accidents due to burns or scalds obtain with 4.2% and less a lower portion than expected. The accident statistics can explain this fact in a way that the typical power plant accident does not exist. (orig./GL) [de

Erosion/corrosion-induced pipe wall thinning in US Nuclear Power Plants

International Nuclear Information System (INIS)

Wu, P.C.

1989-04-01

Erosion/corrosion in single-phase piping systems was not clearly recognized as a potential safety issue before the pipe rupture incident at the Surry Power Station in December 1986. This incident reminded the nuclear industry and the regulators that neither the US Nuclear Regulatory Commission (NRC) nor Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code require utilities to monitor erosion/corrosion in the secondary systems of nuclear power plants. This report provides a brief review of the erosion/corrosion phenomenon and its major occurrence in nuclear power plants. In addition, efforts by the NRC, the industry, and the ASME Section XI Committee to address this issue are described. Finally, results of the survey and plant audits conducted by the NRC to assess the extent of erosion/corrosion-induced piping degradation and the status of program implementation regarding erosion/corrosion monitoring are discussed. This report will support a staff recommendation for an additional regulatory requirement concerning erosion/corrosion monitoring. 21 refs., 3 tabs

Flow-accelerated corrosion in power plants. Revision 1

International Nuclear Information System (INIS)

Chexal, B.; Horowitz, J.; Dooley, B.

1998-07-01

Flow-Accelerated Corrosion (FAC) is a phenomenon that results in metal loss from piping, vessels, and equipment made of carbon steel. FAC occurs only under certain conditions of flow, chemistry, geometry, and material. Unfortunately, those conditions are common in much of the high-energy piping in nuclear and fossil-fueled power plants. Undetected, FAC will cause leaks and ruptures. Consequently, FAC has become a major issue, particularly for nuclear plants. Although major failures are rare, the consequences can be severe. In 1986, four men in the area of an FAC-induced pipe rupture were killed. Fossil plants too, are subject to FAC. In 1995, a failure at a fossil-fired plant caused two fatalities. In addition to concerns about personnel safety, FAC failures can pose challenges to plant safety. Regulatory agencies have therefore required nuclear utilities to institute formal programs to address FAC. Finally, a major FAC failure (like the one that happened in 1997 at a US nuclear power plant) can force a plant to shutdown and purchase replacement power at a price approaching a million dollars per day depending upon the MWe rating of the plant. A great deal of time and money has been spent to develop the technology to predict, detect, and mitigate FAC in order to prevent catastrophic failures. Over time, substantial progress has been made towards understanding and preventing FAC. The results of these efforts include dozens of papers, reports, calculations, and manuals, as well as computer programs and other tools. This book is written to provide a detailed treatment of the entire subject in a single document. Any complex issue requires balancing know-how, the risk of decision making, and a pragmatic engineering solution. This book addresses these by carrying out the necessary R and D and engineering along with plant knowledge to cover all quadrants of Chexal's four quadrant known-unknown diagram, as seen in Figure i

Development of life evaluation technology for nuclear power plant components

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin [Sungkyunkwan Univ., Seoul (Korea, Republic of); Kwon, J. D. [Yeungnam Univ., Gyeongsan (Korea, Republic of); Kang, K. J. [Chonnam National Univ., Gwangju (Korea, Republic of)] (and others)

2001-03-15

This research focuses on development of reliable life evaluation technology for nuclear power plant (NPP) components, and is divided into two parts, development of life evaluation systems for pressurized components and evaluation of applicability of emerging technology to operating plants. For the development of life evaluation system for nuclear pressure vessels, the following seven topics are covered: development of expert systems for integrity assessment of pressurized components, development of integrity evaluation systems of steam generator tubes, prediction of failure probability for NPP components based on probabilistic fracture mechanics, development of fatigue damage evaluation technique for plant life extension, domestic round robin analysis for pressurized thermal shock of reactor vessels, domestic round robin analysis of constructing P--T limit curves for reactor vessels, and development of data base for integrity assessment. For evaluation of applicability of emerging technology to operating plants, on the other hand, the following eight topics are covered: applicability of the Leak-Before-Break analysis to Cast S/S piping, collection of aged material tensile and toughness data for aged Cast S/S piping, finite element analyses for load carrying capacity of corroded pipes, development of Risk-based ISI methodology for nuclear piping, collection of toughness data for integrity assessment of bi-metallic joints, applicability of the Master curve concept to reactor vessel integrity assessment, measurement of dynamic fracture toughness, and provision of information related to regulation and plant life extension issues.

Nuclear power plant containment construction

International Nuclear Information System (INIS)

Schabert, H.P.; Danisch, R.; Strickroth, E.

1975-01-01

The Nuclear Power Plant Containment Construction includes the spherical steel safety enclosure for the reactor and the equipment associated with the reactor and requiring this type of enclosure. This steel enclosure is externally structurally protected against accident by a concrete construction providing a foundation for the steel enclosure and having a cylindrical wall and a hemispherical dome, these parts being dimensioned to form an annular space surrounding the spherical steel enclosure, the latter and the concrete construction heretofore being concentrically arranged with respect to each other. In the disclosed construction the two parts are arranged with their vertical axis horizontally offset from each other so that opposite to the offsetting direction of the concrete construction a relatively large space is formed in the now asymmetrical annular space in which reactor auxiliary equipment not requiring enclosure by the steel containment vessel or safety enclosure, may be located outside of the steel containment vessel and inside of the concrete construction where it is structurally protected by the latter

Study of the concrete tensile creep: application for the containment vessel of the nuclear power plants (PWR)

International Nuclear Information System (INIS)

Reviron, Nanthilde

2009-01-01

The aim of this work is to study experimentally and to conduct numerical simulations on the creep of concrete subjected to tensile stresses. The main purpose is to predict the behaviour of containment vessels of nuclear power plants (PWR) in the case of decennial test or accident. In order to satisfy to these industrial needs, it is necessary to characterize the behaviour of concrete under uniaxial tension. Thus, an important experimental study of tensile creep in concrete has been performed for different loading levels (50%, 70% and 90% of the tensile strength). In these tests, load was kept constant during 3 days. Several tests were performed: measurements of elastic properties and strength (in tension and in compression), monitoring of drying, shrinkage, basic creep and drying creep strains. Moreover, compressive creep tests were also performed and showed a difference with tensile creep. Furthermore, decrease of tensile strength and failure under tensile creep for large loading levels were observed. A numerical model has been proposed and developed in Cast3m finite element code. (author)

Development of computer-aided design and production system for nuclear power plant

International Nuclear Information System (INIS)

Ishii, Masanori

1983-01-01

The technically required matters related to the design and production of nuclear power stations tended to increase from the viewpoint of the safety and reliability, and it is indispensable to cope with such technically required matters skillfully for the rationalization of the design and production and for the construction of highly reliable plants. Ishikawajima Harima Heavy Industries Co., Ltd., has developed the computer-aided design data information and engineering system which performs dialogue type design and drawing, and as the result, the design-production consistent system is developed to do stress analysis, production design, production management and the output of data for numerically controlled machine tools consistently. In this paper, mainly the consistent system in the field of plant design centering around piping and also the computer system for the design of vessels and others are outlined. The features of the design works for nuclear power plants, the rationalization of the design and production management of piping and vessels, and the application of the CAD system to other general equipment and improvement works are reported. This system is the powerful means to meet the requirement of heightening quality and reducing cost. (Kako, I.)

Magnetic stirring welding method applied to nuclear power plant

International Nuclear Information System (INIS)

Hirano, Kenji; Watando, Masayuki; Morishige, Norio; Enoo, Kazuhide; Yasuda, Yuuji

2002-01-01

In construction of a new nuclear power plant, carbon steel and stainless steel are used as base materials for the bottom linear plate of Reinforced Concrete Containment Vessel (RCCV) to achieve maintenance-free requirement, securing sufficient strength of structure. However, welding such different metals is difficult by ordinary method. To overcome the difficulty, the automated Magnetic Stirring Welding (MSW) method that can demonstrate good welding performance was studied for practical use, and weldability tests showed the good results. Based on the study, a new welding device for the MSW method was developed to apply it weld joints of different materials, and it practically used in part of a nuclear power plant. (author)

Mitigating Capability Analysis during LOCA for Korean Standard Nuclear Power Plants in Containment Integrity

Energy Technology Data Exchange (ETDEWEB)

Choi, Young; Park, Soo Yong; Kim, D. H.; Song, Y. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2007-07-01

The objective of this paper is to establish Containment spray operational technical bases for the typical Korean Standard Nuclear Power plants (Ulchin units 3 and 4) by modeling the plant, and analyzing a loss of coolant accident (LOCA) using the MAAP code. The severe accident phenomena at nuclear power plants have large uncertainties. For the integrity of the reactor vessel and containment safety against severe accidents, it is essential to understand severe accident sequences and to assess the accident progression accurately by computer codes. Furthermore, it is important to attain the capability to analyze a advanced nuclear reactor design for a severe accident prevention and mitigation.

Cylindrical prestressed concrete pressure vessel for a nuclear power plant

International Nuclear Information System (INIS)

Horner, M.; Hodzic, A.; Haferkamp, D.

1976-01-01

A prestressed concrete pressure vessel for a HTGR is proposed which encloses, in addition to the reactor core, not only the heat-exchanging facilities but also the turbine unit. The reinforcement of the cylindrical concrete body is to be carried out with special care, it is provided for horizontal tendons, the prestressed concrete pressure vessel has a wire-winding device, while the longitudinal reinforcement is achieved by tendous guided in parallel to the vesses axes through the interspaces between the pods. (UWI) [de

Evaluation of buckling on containment metallic vessels

International Nuclear Information System (INIS)

Silveira, Renato Campos da; Mattar Neto, Miguel

2000-01-01

The buckling analysis represents one of the most important aspects of the structural projects of nuclear power plants containment metallic vessels and in this work the Case N-284-1 ASME Code is used for evaluation of those structures submitted to this failure mode. From the stress analysis, performed by using finite element method on discrete structures with shell elements, the procedure of the Code Case are applied to the evaluation of the containment metallic vessel of the Angra 2 nuclear power plant submitted to the own weight, seismic loads and uplift in case of accident. A study of pressure vessel reinforced by rings submit ed to the external pressure. Conclusions and commentaries are established based on the obtained results

Some aspects of reactor pressure vessel integrity

International Nuclear Information System (INIS)

Korosec, D.; Vojvodic, G.J.

1996-01-01

Reactor pressure vessel of the pressurized water reactor nuclear power plant is the subject of extreme interest due to the fact that presents the pressure boundary of the reactor coolant system, which is under extreme thermal, mechanical and irradiation effects. Reactor pressure vessel by itself prevents the release of fission products to the environment. Design, construction and in-service inspection of such component is governed by strict ASME rules and other forms of administrative control. The reactor pressure vessel in nuclear power plant Kriko is designed and constructed in accordance with related ASME rules. The in-service inspection program includes all requests presented in ASME Code section XI. In the present article all major requests for the periodic inspections of reactor pressure vessel and fracture mechanics analysis are discussed. Detailed and strict fulfillment of all prescribed provisions guarantee the appropriate level of nuclear safety. (author)

Nuclear power plants

International Nuclear Information System (INIS)

1985-01-01

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.) [pt

Reactor core cooling device for nuclear power plant

International Nuclear Information System (INIS)

Tsuda, Masahiko.

1992-01-01

The present invention concerns a reactor core cooling facility upon rupture of pipelines in a BWR type nuclear power plant. That is, when rupture of pipelines should occur in the reactor container, an releasing safety valve operates instantly and then a depressurization valve operates to depressurize the inside of a reactor pressure vessel. Further, an injection valve of cooling water injection pipelines is opened and cooling water is injected to cool the reactor core from the time when the pressure is lowered to a level capable of injecting water to the pressure vessel by the static water head of a pool water as a water source. Further, steams released from the pressure vessel and steams in the pressure vessel are condensed in a high pressure/low pressure emergency condensation device and the inside of the reactor container is depressurized and cooled. When the reactor is isolated, since the steams in the pressure vessel are condensed in the state that the steam supply valve and the return valve of a steam supply pipelines are opened and a vent valve is closed, the reactor can be maintained safely. (I.S.)

Reliability analysis of pipelines and pressure vessels at nuclear power plants

International Nuclear Information System (INIS)

Klemin, A.I.; Shiverskij, E.A.

1979-01-01

Reliability analysis of pipelines and pressure vessels at NPP is given. The main causes and failure mechanisms of these elements, the ways of reliability improvement and preventing of great damages are considered. The reliability estimation methods both according to the statistical operation data and under the conditions of absence of failure statistics are given. The main characteristics and actual reliability factors of pipelines and pressure vessels of three home NPP: the first in the world NPP, VK-50 and Beloyarsk NPP, are presented. From the start-up there were practically no failures of the pipelines and pressure vessels at the VK-50 pilot installation. The analysis of the operation experience of the first and second blocks of the Beloyarsk NPP, as well as the first in the world NPP, shows that the most part of failures of the pipelines and pressure vessels of these energy blocks with the channel reactors is connected with the coolant leakage at minority pipelines of a small diameter. The most part of failures at individual pipelines of the first and second blocks of the Beloyarsk NPP are connected with the leakages of stuffing boxes of switching off devices. It is noted that serious failures of large pipelines and pressure vessels at all home NPP under operation have not been observed

LNG plant combined with power plant

Energy Technology Data Exchange (ETDEWEB)

Aoki, I; Kikkawa, Y [Chiyoda Chemical Engineering and Construction Co. Ltd., Tokyo (Japan)

1997-06-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs.

LNG plant combined with power plant

International Nuclear Information System (INIS)

Aoki, I.; Kikkawa, Y.

1997-01-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs

Protecting nuclear power plants. Chapter 2. On the importance of the security and safety of the reactor pressure vessel to external threats

International Nuclear Information System (INIS)

Ballesteros, A.; Gonzalez, J.; Debarberis, L.

2006-01-01

Nuclear power plants have blong been recognized as potential targets of terrorist attacks, and critics have long questioned the adequacy of the existing measures to defend against such attacks. The 11-S 2001, 11-M 2004 and 7-J 2005 attacks in USA, Spain and UK illustrated the deadly intention and abilities of modern terrorist groups. These attacks also brought to surface long standing concerns about the vulnerability of nuclear installations to possible terrorist attacks. Commercial nuclear reactors contain large inventory of radioactive fission products which, if dispersed, could pose a direct radiation hazard on the population. The reactor pressure vessel (RPV), which contains the nuclear fuel, is the most critical component of the plant. This paper shows that small amount of explosive material can produce irreversible damage in the RPV and the release of radioactive material. Therefor, access of working personal to the vicinity of the RPV during the refuelling outage should be stricktly limited. It should be considered a high priority security issue

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

International Nuclear Information System (INIS)

2007-06-01

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

Industrial safety in power plants

International Nuclear Information System (INIS)

1987-01-01

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

Neutron doze distribution in capsules for surveillance of radiation embrittlement of pressure vessel in Krsko nuclear power plant; Porazdelitev nevtronske doze v sondah za kontrolo povecanja krhkosri tlacne posode JE Krsko

Energy Technology Data Exchange (ETDEWEB)

Najzer, M; Remec, I; Kodeli, I [Institut Jozef Stefan, Ljubljana (Yugoslavia)

1984-07-01

Calculation of neutron fluence and spectrum distribution in the capsule with samples for radiation embrittlement of PWR pressure vessel surveillance program of Krsko nuclear power plant is presented. Two dimensional computer code DOT 3 has been used and neutron cross sections were taken from DLC-2D library. result is that fluence magnitude in the capsules changes for up to 70%, so when evaluating results of mechanical tests of samples it is necessary to take into account actual position of samples within the capsule. (author)

Development of automatic pipe welder for nuclear power plant

International Nuclear Information System (INIS)

Iwamoto, Taro; Ando, Shimon; Omae, Tsutomu; Ito, Yoshitoshi; Araya, Takeshi.

1978-01-01

Numerous pipings are installed in nuclear power plants, and of course, the reliability of these pipings are very important to preserve the safety of the plants. These pipings undergo periodic inspection yearly, and when some defects are found or some reconstructions to superior systems are made, field welding in the plants is required. When the places to be welded are in containment vessels, the works must be carried out in radiation environment. In order to maintain the highest quality of welding and to reduce the radiation exposure of workers, many skilled workers are required. This automatic pipe welder was developed to solve these problems, aiming at carrying out welding works by remote control at the safe places outside containment vessels. Especially in order to obtain the highest quality of welding, it was not perfectly automated, but the man-machine system so as to enable to utilize the delicate sense of workers was adopted. The visual and contact detecting systems to monitor welding works, remote control system, computer control, light, small and easily installed welding head, grinding and supersonic flow detecting equipments, the power source of transistor switching type, air cooling equipment, and the function for setting welding conditions according to algorithm were added to the welding machine. The outline and main components of this automatic pipe welder are explained. (Kako, I.)

Actions concerning nuclear power plant life evaluation

International Nuclear Information System (INIS)

Chocron, M.; Fabbri, S.; Mizrahi, R.; Savino, E.J.; Versaci, R.A.

1998-01-01

One of the main activities to be undertaken by CNEA will be to provide technological assistance to NASA in problems concerning NPP operation. Works on life extensions of NPP are included in these activities. To fulfill these requirements the Atomic Energy National Commission (CNEA) has constituted a technical committee for Nuclear Power Plants Support (CAPCEN). CAPCEN should be the knowledge reservoir of those issues concerning the performance, safety and life extension of Nuclear Power Plants. One of CAPCEN's most important activities is to promote research work connected with such issues. The main technical areas are: Pressure Vessel and Piping, Heat Exchanges and Fuel Channels and Reactor Inner Components. Efforts are focused on the identification of the main components susceptible of ageing, the study of their ageing mechanisms, the follow-up of their behaviour during operation, and the measures taken to extend their life. (author)

Future of structural reliability methodology in nuclear power plant technology

Energy Technology Data Exchange (ETDEWEB)

Schueeller, G I [Technische Univ. Muenchen (Germany, F.R.); Kafka, P [Gesellschaft fuer Reaktorsicherheit m.b.H. (GRS), Garching (Germany, F.R.)

1978-10-01

This paper presents the authors' personal view as to which areas of structural reliability in nuclear power plant design need most urgently to be advanced. Aspects of simulation modeling, design rules, codification and specification of reliability, system analysis, probabilistic structural dynamics, rare events and particularly the interaction of systems and structural reliability are discussed. As an example, some considerations of the interaction effects between the protective systems and the pressure vessel are stated. The paper concludes with recommendation for further research.

Nuclear closed-cycle gas turbine (HTGR-GT): dry cooled commercial power plant studies

International Nuclear Information System (INIS)

McDonald, C.F.; Boland, C.R.

1979-11-01

Combining the modern and proven power conversion system of the closed-cycle gas turbine (CCGT) with an advanced high-temperature gas-cooled reactor (HTGR) results in a power plant well suited to projected utility needs into the 21st century. The gas turbine HTGR (HTGR-GT) power plant benefits are consistent with national energy goals, and the high power conversion efficiency potential satisfies increasingly important resource conservation demands. Established technology bases for the HTGR-GT are outlined, together with the extensive design and development program necessary to commercialize the nuclear CCGT plant for utility service in the 1990s. This paper outlines the most recent design studies by General Atomic for a dry-cooled commercial plant of 800 to 1200 MW(e) power, based on both non-intercooled and intercooled cycles, and discusses various primary system aspects. Details are given of the reactor turbine system (RTS) and on integrating the major power conversion components in the prestressed concrete reactor vessel

Remote dismantling of the French Brennilis nuclear power plant

International Nuclear Information System (INIS)

Studenski, Joerg

2009-01-01

The paper deals with the remote dismantling of the decommissioned EL4 prototype power plant Brennilis in France. The block contains the reactor pressure vessel including internals and biological shield, the piping and the control systems. The authors describe the general operation principle of the reactor to illustrate the peculiarities of the dismantling concept and the concept-related challenges. Detailed information is given concerning the following issues: creation of an access to the reactor block, the used remote technology, dismantling of the coolant piping and the axial shield, dismantling of the reactor pressure vessel and the lateral shield. Special attention is given on the minimization of the produced radioactive waste.

Remote dismantling of the French Brennilis nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Studenski, Joerg [NUKEM Technologies GmbH (Germany)

2009-07-01

The paper deals with the remote dismantling of the decommissioned EL4 prototype power plant Brennilis in France. The block contains the reactor pressure vessel including internals and biological shield, the piping and the control systems. The authors describe the general operation principle of the reactor to illustrate the peculiarities of the dismantling concept and the concept-related challenges. Detailed information is given concerning the following issues: creation of an access to the reactor block, the used remote technology, dismantling of the coolant piping and the axial shield, dismantling of the reactor pressure vessel and the lateral shield. Special attention is given on the minimization of the produced radioactive waste.

Development of construction technology for nuclear power plants

International Nuclear Information System (INIS)

Schnellenbach, G.

1975-01-01

Stringent safety requirements for nuclear power plants create new technological problems in their construction. The development is influenced by the mode of operation of the respective reactors which leads to different construction styles of the reactor buildings. Accomodation of extraordinary load cases such as earthquake, airplane crash, and blast due to chemical explosions, requires additional treatment. Significant new problems arise for the prestressed concrete reactor pressure vessels and concrete containments, prestressed or reinforced. (orig.) [de

Should the service life of nuclear power plants be limited for technical reasons?

International Nuclear Information System (INIS)

Schomer, E.

1995-01-01

German nuclear power plant operating licenses take into account the fact that the design lifetime of the facilities is 40 years. The technological lifetime, however, is governed by actual ageing processes and operational burden. The service life of nuclear power plants can be extended by replacement of the steam generator and by repair or replacement of the reactor pressure vessel or parts thereof. Attention is also paid to the reactor protection systems. (J.B.). 8 figs

Nuclear power plant life time improvement and management program in Korea

International Nuclear Information System (INIS)

Sung Yull Hong; Ill Seok Jeong; Taek Ho Song

1995-01-01

Korea Electric Power Research Institute (KEPRI) of Korea Electric Power Corporation (KEPCO) has performed a lifetime management of nuclear power plant program (LMNPP), ''Nuclear Power Plant Lifetime Management (PLIM) (I)'', since November 1993, which is a feasibility study of the Kori Unit 1 lifetime management including aging evaluation of the thirteen major components. The results of the PLIM(I) will provide information which is necessary for decision making of the Kori Unit 1 lifetime improvement. A plan of the work scope and schedule for the next phase, PLIM(II), will also be provided by this project. This paper introduced KEPRI's basic strategy of LMNPP, PLIM organization, current status, some interim results of the PLIM(I), and other related programs in Korea. So far, we have done field data survey, systems/structures screening, components prioritization, lifetime evaluation methodology study, and fracture mechanics tests of the Kori Unit 1 reactor pressure vessel surveillance coupons. Currently life assessment of the major components and PLIM economic evaluation of Kori Unit 1 are under way. (author)

Summary of operating experience in Swedish nuclear power plants 1994

International Nuclear Information System (INIS)

1995-01-01

1994 was a record year for nuclear power in Sweden. For the second time, electricity generation from nuclear power exceeded 70 TWh (billions of kilowatt hours). Nuclear electricity generation corresponded to 51% of the total electricity generated in Sweden. Four units had an energy availability of more than 90%, while another five units had an availability of between 84 and 90%. This can be compared with an average international availability of 75%. Barsebaeck 2 was shut down during January to complete measures to correct a leak which was detected in the containment embedded steel plating in autumn 1993. During the year, a number of events occurred at Barsebaeck which were mainly caused by human error. A special evaluation of plant activities showed that the events occurred in connection with a reorganization which had been carried out. At year-end, it was discovered that the main steam line safety relief valves in Ringhals 2 were not correctly calibrated. The cause of the error was established and corrected and the safety relief valves at the other Ringhals PWRs were checked. Oskarshamn 1 was shut down for the whole year for a further inspection and modernization program. Manual inspections of the lower plenum of the reactor vessel were carried out for the first time ever in the world. The work methods, which have attracted considerable international interest, open up completely new dimensions for the maintenance and repair of reactor pressure vessels. The radiation doses to the personnel, which during 1993 were higher than usual, showed a marked decline in 1994. At the end of 1994, all of the Swedish nuclear power plants, apart from Oskarshamn 1, were in operation

Proceedings of the topical meeting on nuclear power plant life extension

International Nuclear Information System (INIS)

Anon.

1988-01-01

This book contains the proceedings of the topical meeting on nuclear power plant life extension. The sessions are organized under the following headings: Perspectives on nuclear power plant life extension, the potential for additional years of power production, NRC and industry life extension initiatives, concrete and structures degradation and evaluation of useful remaining life, plant life extension programs, Reactor pressure vessel and intervals degradation and evaluation of useful remaining life, life extension decision making issues and institutions, systems degradation and evaluation of remaining life, monitoring and repair, design records and maintenance activities for life extension, Mechanical and electrical component degradation and evaluation of remaining life, expert systems and other techniques for enhanced and continued operation, life extension aspect of codes, standards, and related technologies, piping and valve degradation and evaluation of useful remaining life

Chiyoda Thoroughbred CT-121 clean coal project at Georgia Power`s Plant Yates

Energy Technology Data Exchange (ETDEWEB)

Burford, D.P. [Southern Company Services, Inc., Birmingham, AL (United States)

1997-12-31

The Chiyoda Thoroughbred CT-121 flue gas desulfurization (FGD) process at Georgia Power`s Plant Yates completed a two year demonstration of its capabilities in late 1994 under both high- and low-particulate loading conditions. This $43 million demonstration was co-funded by Southern Company, the Electric Power Research Institute and the DOE under the auspices of the US Department of Energy`s Round II Innovative Clean Coal Technology (ICCT) program. The focus of the Yates Project was to demonstrate several cost-saving modifications to Chiyoda`s already efficient CT-121 process. These modifications included: the extensive use of fiberglass reinforced plastics (FRP) in the construction of the scrubber vessel and other associated vessels, the elimination of flue gas reheat through the use of an FRP wet chimney, and reliable operation without a spare absorber module. This paper focuses on the testing results from the last trimester of the second phase of testing (high-ash loading). Specifically, operation under elevated ash loading conditions, the effects of low- and high-sulfur coal, air toxics verification testing results and unexpected improvements in byproduct gypsum quality are discussed.

Status of pressure vessel embrittlement study in Japan

Energy Technology Data Exchange (ETDEWEB)

Kataoka, Shigeki [Japan Power Engineering and Inspection Corp. (JAPEIC), Chiba (Japan)

1997-09-01

The number of nuclear power plants in service for more than 20 years is increasing in Japan. Subsequently, the aging of nuclear power plants will continue to increase and for this reason, the assurance of the safety and reliability of nuclear power plants is becoming more important. Under this circumstances, Japan Government issued a report: ``Specific Concepts in Dealing with Nuclear Power Plant High Aging`` in April, 1996. This report identified that continuous technology development efforts are important to deal with the issues of nuclear power plant aging, and the following items are extracted for important categories to be developed. (1) Aging phenomena evaluation technology. (2) Inspection/monitoring technology (3) Preventive maintenance/repair technology. Japan Power Engineering and Inspection Corporation (JAPEIC) have been implementing various verification test concerning the above items consigned by the Ministry of International Trade and Industry (MITI). This report outlines the Specific Concepts in Dealing with Nuclear Power Plant High Agency and the past achievements and future plans of various verification tests related to irradiation embrittlement of nuclear reactor pressure vessel, mainly related to Pressurized Thermal Shock (PTS). (author). 4 refs, 8 figs, 5 tabs.

Safety problems in decommissioning of nuclear power plants

International Nuclear Information System (INIS)

1975-12-01

The safety problems in decommissioning are presented by the example of light water reactors with an electric power of 1300 MW and 40 years of preceding specified operation. In such a plant the radioactivity in the form of activation and contamination is of the order of 10 7 Ci one year after final shut-down. The fuel elements are not taken into account. During the work at the reactor vessel dose rates of some 10 4 rem/h may occur at the flange level. According to a rough estimation the dose accumulated by the decommissioning personnel during dismantling of the radioactive components amounts to 1200 rem. During the decommissioning work the problems are caused predominantly by the direct radiation from the radioactive components and systems as well as from the release of radioactive particles, aerosols and liquids on cutting them up. In designing new plants the extent of later decommissioning problems can be reduced above all by selection of suitable materials and by decommissioning-minded design and arrangement of the components and parts of the plant. (orig./RW) [de

Development of Structural Health Monitoring System for pipes in Nuclear Power Plants

International Nuclear Information System (INIS)

Eom, H. S.; Choi, Y. C.; Shin, S. H.; Youn, D. B.; Park, J. H.

2010-01-01

Structural health monitoring (SHM) has becoming an important issue in the maintenance of various structures such as large steel plates, vessels, and pipes in nuclear power plants. There are important factors to be considered in developing an SHM system. With consideration of these factors, we have developed a computerized multi-channel ultrasonic system that can handle array transducers and generate a high-power pulse for online SHM of the plates and pipes. The proposed system is compact but has all the necessary functions for SHM of important structure such as pipes and plates in a NPP

Online condition monitoring to enable extended operation of nuclear power plants

International Nuclear Information System (INIS)

Meyer, Ryan Michael; Bond, Leonard John; Ramuhalli, Pradeep

2012-01-01

Safe, secure, and economic operation of nuclear power plants will remain of strategic significance. New and improved monitoring will likely have increased significance in the post-Fukushima world. Prior to Fukushima, many activities were already underway globally to facilitate operation of nuclear power plants beyond their initial licensing periods. Decisions to shut down a nuclear power plant are mostly driven by economic considerations. Online condition monitoring is a means to improve both the safety and economics of extending the operating lifetimes of nuclear power plants, enabling adoption of proactive aging management. With regard to active components (e.g., pumps, valves, motors, etc.), significant experience in other industries has been leveraged to build the science base to support adoption of online condition-based maintenance and proactive aging management in the nuclear industry. Many of the research needs are associated with enabling proactive management of aging in passive components (e.g., pipes, vessels, cables, containment structures, etc.). This paper provides an overview of online condition monitoring for the nuclear power industry with an emphasis on passive components. Following the overview, several technology/knowledge gaps are identified, which require addressing to facilitate widespread online condition monitoring of passive components. (author)

Study on in-core fuel management for CNP1500 nuclear power plant

International Nuclear Information System (INIS)

Li Dongsheng

2005-10-01

CNP1500 is a four-loop PWR nuclear power plant with light water as moderator and coolant. The reactor core is composed of 205 AFA-3GXL fuel assemblies. The active core height at cold is 426.4 cm and equivalent diameter is 347.0 cm. The reactor thermal output is 4250 MW, and average linear power density is 179.5 W/cm. The cycle length of equilibrium cycle core is 470 equivalent full power days. For all cycles, the moderator temperature coefficients at all conditions are negative values, the nuclear enthalpy rise factors F ΔH at hot full power, all control rods out and equilibrium xenon are less than the limit value, the maximum discharge assembly burnup is less 55000 MW·d/tU, and the shutdown margin values at the end of life meet design criteria. The low-leakage core loading reduces radiation damage on pressure vessel and is beneficial to prolong use lifetime of it. The in-core fuel management design scheme and main calculation results for CNP1500 nuclear power plant are presented. (author)

Latest feedback from a major reactor vessel dismantling project

International Nuclear Information System (INIS)

Boucau, J.; Segerud, P.; Sanchez, M.; Garcia, R.

2015-01-01

Westinghouse performed two large segmentation projects in 2010-2013 and then 2013-2015 at the Jose Cabrera nuclear power plant in Spain. The power plant is located in Almonacid de Zorita, 43 miles east of Madrid, Spain and was in operation between 1968 and 2006. This paper will describe the sequential steps required to prepare, segment, separate, and package the individual component segments using under water mechanical techniques. The paper will also include experiences and lessons learned that Westinghouse has collected from the activities performed during the reactor vessel and vessel internals segmentation projects. (authors)

Seismic proving tests on the reliability for large components and equipment of nuclear power plants

International Nuclear Information System (INIS)

Ohno, Tokue; Tanaka, Nagatoshi

1988-01-01

Since Japan has destructive earthquakes frequently, the structural reliability for large components and equipment of nuclear power plants are rigorously required. They are designed using sophisticated seismic analyses and have not yet encountered a destructive earthquake. When nuclear power plants are planned, it is very important that the general public understand the structural reliability during and after an earthquake. Seismic Proving Tests have been planned by Ministry of International Trade and Industry (Miti) to comply with public requirement in Japan. A large-scale high-performance vibration table was constructed at Tasted Engineering Laboratory of Nuclear Power Engineering Test Center (NU PEC), in order to prove the structural reliability by vibrating the test model (of full scale or close to the actual size) in the condition of a destructive earthquake. As for the test models, the following four items were selected out of large components and equipment important to the safety: Reactor Containment Vessel; Primary Coolant Loop or Primary Loop Recirculation System; Reactor Pressure Vessel; and Reactor Core Internals. Here is described a brief of the vibration table, the test method and the results of the tests on PWR Reactor Containment Vessel and BWR Primary Loop Recirculation System (author)

Are atomic power plants saver than nuclear power plants

International Nuclear Information System (INIS)

Roeglin, H.C.

1977-01-01

It is rather impossible to establish nuclear power plants against the resistance of the population. To prevail over this resistance, a clarification of the citizens-initiatives motives which led to it will be necessary. This is to say: It is quite impossible for our population to understand what really heappens in nuclear power plants. They cannot identify themselves with nuclear power plants and thus feel very uncomfortable. As the total population feels the same way it is prepared for solidarity with the citizens-initiatives even if they believe in the necessity of nuclear power plants. Only an information-policy making transparent the social-psychological reasons of the population for being against nuclear power plants could be able to prevail over the resistance. More information about the technical procedures is not sufficient at all. (orig.) [de

Mechanical Analysis of an upscaled version of the Vaporizer (pressure vessel and circulation tubes) of the incineration pilot power plant TEMO-IPP.

OpenAIRE

Kerdi, Banan El

2016-01-01

To be able to upscale the TEMO-IPP incineration plant to a commercial incineration plant in Tripoli (about40 MW) critical components shall be verified by Finite Element Analysis with the tool Abaqus. The main critical component is the pressure vessel with about 100 bar pressure difference.

Method of operating BWR type power plants

International Nuclear Information System (INIS)

Koyama, Kazuaki.

1981-01-01

Purpose: To improve the operation efficiency of BWR type reactors by reducing the time from the start-up of the reactor to the start-up of the turbine and electrical generator, as well as decrease the pressure difference in each of the sections of the pressure vessel to thereby extend its life span. Method: The operation comprises switching the nuclear reactor from the shutdown mode to the start-up mode, increasing the reactor power to a predetermined level lower than a rated power while maintaining the reactor pressure to a predetermined level lower than a rated pressure, starting up a turbine and an electrical generator in the state of the predetermined reactor pressure and the reactor power to connect the electrical generator to the power transmission system and, thereafter, increasing the reactor pressure and the reactor power to the predetermined rated pressure and rated power respectively. This can shorten the time from the start-up of the reactor to the start of the power transmission system, whereby the operation efficiency of the power plant can be improved. (Moriyama, K.)

Simulation of onboard power supply system for small hydrographic vessel «Vaygach»

Directory of Open Access Journals (Sweden)

А. И. Паньков

2016-12-01

Full Text Available Computer simulation is a method resorted to more and more frequently for the development of the prospective power supply systems, in particular the vessel power supply system. It provides valuable insights into the transient processes and indicators of electric power quality in the system without building its physical model, thus significantly improving the efficiency and quality of the physical model.Nowadays MathLab package with Simulink application is used with increasing frequency for simulation of such systems.The paper presents a model of the power supply system of small hydrographic vessel ‘Vaygach’ built in MatLab environment. The system vulnerabilities and their remedies have been identified. Changes in sinusoid before and after the non-linear load on the network have been demonstrated and solutions for improving the non-linear distortion factor are proposed. The model developed for the vessel power supply system can be used for building models of different vessels.

Pressure vessel rupture within a chamber: the pressure history on the chamber wall

International Nuclear Information System (INIS)

Baum, M.R.

1989-04-01

Generally there is a large number of pressure vessels containing high pressure gas on power stations and chemical plant. In many instances, particularly on power plant, these vessels are within the main building. If a pressure vessel were to fail, the surrounding structures would be exposed to blast loads and the forces resulting from jets of fluid issuing from the breached vessel. In the case where the vessel is in a relatively closed chamber there would also be a general overpressurisation of the chamber. At the design stage it is therefore essential to demonstrate that the plant could be safely shut down in the event of a pressure vessel failure, that is, it must be shown that the chamber will not collapse thus putting the building at risk or hazarding equipment essential for a safe shut down. Such an assessment requires the loads applied to the chamber walls, roof, etc. to be known. (author)

Nuclear challenges and progress in designing stellarator power plants

International Nuclear Information System (INIS)

El-Guebaly, L.

2007-01-01

, such as recycling (within the nuclear industry) and clearance (or unconditional release to the commercial market). The ARIES-CS bioshield, cryostat, and individual magnet constituents qualify for clearance, representing ∼80% of the total waste volume. We developed a recycling approach for the non-clearable, in-vessel components using a combination of conventional and advanced remote handling equipment that can handle high doses of 3000 Sv/h or more. Several additional nuclear-related tasks received considerable attention during the ARIES-CS design process. These include the radial build definition, the well-optimized in-vessel components that satisfy the top-level requirements, the carefully selected nuclear and engineering parameters to produce an economic optimum, and the overarching safety constraints to deliver a safe and reliable power plant. This paper provides a brief historical overview of the progress in designing stellarator power plants and a perspective to the successful integration of the nuclear activity into the final ARIES-CS design

Development of technology for creating intelligent control systems for power plants and propulsion systems for marine robotic systems

Science.gov (United States)

Iakovleva, E. V.; Momot, B. A.

2017-10-01

The object of this study is to develop a power plant and an electric propulsion control system for autonomous remotely controlled vessels. The tasks of the study are as follows: to assess remotely controlled vessels usage reasonability, to define the requirements for this type of vessel navigation. In addition, the paper presents the analysis of technical diagnostics systems. The developed electric propulsion control systems for vessels should provide improved reliability and efficiency of the propulsion complex to ensure the profitability of remotely controlled vessels.

Nuclear reactors sited deep underground in steel containment vessels

Energy Technology Data Exchange (ETDEWEB)

Bourque, Robert [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2006-07-01

Although nuclear power plants are certainly very safe, they are not perceived as safe by the general populace. Also, there are concerns about overland transport of spent fuel rods and other irradiated components. It is hereby proposed that the nuclear components of nuclear power plants be placed in deep underground steel vessels with secondary coolant fed from them to turbines at or near the surface. All irradiated components, including spent fuel, would remain in the chamber indefinitely. This general concept was suggested by the late Edward Teller, generated some activity 20-25 years ago and appears to be recently reviving in interest. Previous work dealt with issues of geologic stability of underground, possibly reinforced, caverns. This paper presents another approach that makes siting independent of geology by placing the reactor components in a robust steel vessel capable of resisting full overburden pressure as well as pressures resulting from accident scenarios. Structural analysis of the two vessel concepts and approximate estimated costs are presented. This work clears the way for the extensive discussions required to evaluate the advantages of this concept. (author)

Aging management and preventive maintenance for nuclear power plants

International Nuclear Information System (INIS)

Bessho, Toichi; Sagawa, Wataru; Oyamada, Osamu; Uchida, Shunsuke

1995-01-01

It is expected that nuclear power generation will bear main electric power supply for long term. For this purpose, by applying proper preventive maintenance to the nuclear power plants in operation, the maintenance of high reliability and the rate of plant operation is extremely important. Especially it has been strongly demanded to execute efficiently the periodic inspection which is carried out every year to shorten its period and increase the rate of operation, and to maintain the reliability by the proper maintenance for the aged plants with long operation years. As to efficient and short periodic inspection, the preparation is advanced by the guidance of electric power companies aiming at realizing it in nearest fiscal year, and further, effort is exerted for the development of technology in long term to optimize periodic inspection. For securing the reliability of aged plants, it is important to do proper inspection and diagnosis and to take the countermeasures by repair and replacement, based on the grasp of secular change mechanism and the evaluation of life of machinery, equipment and materials. In particular, effort is exerted for the development of maintenance technology for reactor pressure vessels and in-core equipment which are hard to access. The confirmation of the function of remote operation equipment and the establishment of execution condition are carried out by uisng the full scale mock-up of BWR plant. The problems in maintenance service and the activities and results of reliability improvement are reported. (K.I.)

Applicability of JIS SPV 50 steel to primary containment vessel of nuclear power station

International Nuclear Information System (INIS)

Iida, Kunihiro; Ishikawa, Koji; Sakai, Keiichi; Onozuka, Masakazu; Sato, Makoto.

1979-01-01

The space within reactor containment vessels must be expanded in order to improve the reliability of nuclear power plants, accordingly the adoption of large reactor containment vessels is investigated. SGV 42 and 49 steels in JIS G 3118 have been used for containment vessels so far, but stress relief annealing is required when the thickness exceeds 38 mm. The time has come when the use of thicker conventional plates without stress relieving or the use of high strength steel must be examined in detail. In this study, the tests of confirming material properties were carried out on SPV 50 in JIS G 3115, Steels for pressure vessels, aiming at the method of fabrication without stress relieving. The highest and lowest temperatures in use were set at 171 deg and -8 deg C, respectively. The chemical composition and the mechanical properties of the plates tested, the method of welding, the results of tensile test on the parent metal and the welds, the required lowest preheating temperature, the fracture toughness at low temperature and the brittle fracture causing test are reported. The parent metal and the welded joints of SPV 50 have the properties suitable to reactor containment vessels, namely the sufficient fracture toughness to guarantee the prevention of unstable fracture when the method of welding without stress relieving is adopted. (Kako, I.)

Heat and fluid flow in accident of Fukushima Daiichi Nuclear Power Plant, Unit 2. Accident scenario based on thermodynamic model

International Nuclear Information System (INIS)

Maruyama, Shigenao

2012-01-01

An accident scenario of Fukushima Daiichi Nuclear Power Plant, Unit 2 is analyzed from the data open to the public. Phase equilibrium process model was introduced that the vapor and water are at saturation point in the vessels. Proposed accident scenario agrees very well with the data of the plant parameters obtained just after the accident. The estimation describes that the rupture time of the reactor pressure vessel (RPV) was at 22:50 14/3/2011. The estimation shows that the rupture time of the pressure containment vessel (RCP) was at 7:40 15/3/2011. These estimations are different from the ones by TEPCO, however; many measured evidences show good accordance with the present scenario. (author)

Water releasing electric generating device for nuclear power plant

International Nuclear Information System (INIS)

Umehara, Toshihiro; Tomohara, Yasutaka; Usui, Yoshihiko.

1994-01-01

Warm sea water discharged after being used for cooling in an equipment of a coastal nuclear powder plant is discharged from a water discharge port to a water discharge pit, and a conduit vessel is disposed in front of the water discharge port for receiving overflown warm sea water. The warm sea water taken to the conduit vessel is converted to a fallen flow and charged to a turbine generator under water, and electric power is generated by the water head energy of the fallen flow before it is discharged to the water discharge pit. The conduit vessel incorporates a foam preventing unit having spiral flow channels therein, so that the warm sea water taken to the conduit vessel is flown into the water discharge pit after consuming the water head energy while partially branched and flown downwardly and gives lateral component to the downwarding flowing direction. Then, warm sea water is made calm when it is flown into the water discharge pit and, accordingly, generation of bubbles on the water surface of the water discharge pit is avoided. (N.H.)

Total system for manufacture of nuclear vessels by computer: VECTRON

International Nuclear Information System (INIS)

Inagawa, Jin; Ueno, Osamu; Hanai, Yoshiharu; Ohkawa, Isao; Washizu, Hideyuki

1980-01-01

VECTRON (Vessel Engineering by Computer Tool and Rapid Operating for the N/C System) is a CAM (Computer Aided Manufacturing) system that has been developed to produce high quality and highly accurate vessels for nuclear power plants and other industrial plants. Outputs of this system are design drawings, manufacturing information and magnetic tapes of the N/C marking machine for vessel shell plates including their attachments. And it can also output information at each stage of designing, marking, cutting, forming and assembling by treating the vessels in three dimensions and by using data filing systems and plotting program for general use. The data filing systems consist of functional and manufacturing data of each part of vessels. This system not only realizes a change from manual work to computer work, but also leads us to improve production engineering and production jigs for safety and high quality. At present, VECTRON is being applied to the manufacture of the shell plates of primary containment vessels in the Kashiwazaki-Kariwa Nuclear Power Station Unit 1 (K-1) and the Fukushima Daini Nuclear Power Station Unit 3 (2F-3), to realize increased productivity. (author)

Gundremmingen (KRB) nuclear power plant

International Nuclear Information System (INIS)

1974-03-01

Plant reliability and availability during 1973 was very good despite an unscheduled shutdown in October. A temporal availability of 79.42% and an operating availability of 79.07% yielded a usable current production of 1 634 000 000 000 kWh. In May, during the five-week inspection and refueling period, several machines and items of equipment were overhauled in addition to the major generator strip-down, and checks were also carried out on the safety and protection systems throughout the plant. Particular attention was paid to the fire-protection system so that, for example, a fire-protection valve was installed in the turbine oil circuit. The heating system was made independent of oil supplies and considerable economies were achieved by converting it from oil-firing to secondary steam operation. During October copper deposits from a feedwater pre-heater were discovered in the reactor core. The plant had to be shut down for five weeks in order to clean the reactor out with various items of cleaning equipment. After the plant had been started up again, it proved necessary to take the pre-heater releasing copper out of service. This was possible without any noteworthy loss of power. For further operation, it will be necessary to fit the pre-heater with high-grade steel tubes. Throughout the remainder of the year, the power plant operated under full load without any particular malfunction occurring. At the beginning of the year increasing amount of activity in the reactor water pointed to fuel element damage. It was possible to operate the plant at a constant, low level of water activity during the second half of the year after refuelling and the removal of the faulty elements. Faultless plant operation can likewise be expected for 1974. Owing to the officially required pressure test on the reactor pressure vessel, the inspection time will probably extend over six weeks. It is expected that plant availability during 1974 will exceed the 1973 figure

Nuclear Power Plants in the World

International Nuclear Information System (INIS)

2000-01-01

The Japan Atomic Industrial Forum (JAIF) used every year to summarize a trend survey on the private nuclear power plants in the world in a shape of the 'Developmental trends on nuclear power plants in the world'. In this report, some data at the end of 1999 was made up on bases of answers on questionnaires from 72 electric companies in 31 nations and regions in the world by JAIF. This report is comprised of 19 items, and contains generating capacity of the plants; current status of Japan; trends of generating capacity of operating the plants, the plant orders and generating capacity of the plants; world nuclear capacity by reactor type; location of the plants; the plants in the world; and so forth. And, it also has some survey results on the 'Liberalization of electric power markets and nuclear power generation' such as some 70% of respondents in nuclear power for future option, gas-thermal power seen as power source with most to gain from liberalization, merits on nuclear power generation (environmental considerations and supply stability), most commonly voiced concern about new plant orders in poor economy, and so forth. (G.K.)

Kansas Power Plants

Data.gov (United States)

Kansas Data Access and Support Center — The Kansas Power Plants database depicts, as point features, the locations of the various types of power plant locations in Kansas. The locations of the power plants...

Use of glass-reinforced plastic vessels in petrochemical production plants

International Nuclear Information System (INIS)

Makarov, V.G.; Baikin, V.G.; Perlin, S.M.

1984-01-01

At present, petrochemical plant production equipment is made of scarce high-alloy steels and alloys or carbon steel with subsequent chemical protection. Traditional methods of protection frequently do not provide reliable and safe service of equipment for the length of the normal operating life. One of the effective methods of combatting corrosion is the use of glass-reinforced plastic equipment. Glass-reinforced equipment is not subject to electrochemical corrosion and has a high chemical resistance. Weight is approximately a third of similar vessels. The paper provides recommendations and precautions for the production, installation, use and maintenance of glass-reinforced plastic vessels

Study on the combustion behavior of radiolytically generated hydrogen explosion in small scale annular vessels at the reprocessing plant

International Nuclear Information System (INIS)

Kudo, Tatsuya; Tamauchi, Yoshikazu; Arai, Nobuyuki; Dai, Wenbin; Sakaihara, Motohiro; Kanehira, Osamu

2017-01-01

Hydrogen is generated by radiolysis of water, etc. in process vessels in reprocessing plant. Usually, the hydrogen is scavenged by compressed air into vessels to prevent hydrogen explosion. When an earthquake beyond design based occurs, for example, the compressed air may stop and the hydrogen starts accumulating in the vessels, and under this condition, an ignition source might set off hydrogen explosion. Therefore, the explosion derived by the radiolytically generated hydrogen is designated as one of severe accidents on Rokkasho Reprocessing Plant in new regulatory requirements. It is important to understand the combustion behavior of hydrogen explosion inside a vessel for consideration of safety measures against the severe accident, because the influences of detonation are not considered in the design basis of vessels. Especially, the investigations about the combustion behavior which considered influence of interior obstacles inside the vessel are not performed yet. In order to investigate the combustion behavior comprehensively, explosion experiment, combustion analysis and structural analysis are carried out using the representative vessels (small scale annular vessel, small scale plate vessel, large scale annular vessel and large scale cylindrical vessel) selected from Rokkasho Reprocessing Plant. In this paper, the results of experiments and analysis of small scale annular vessel (as one of representative vessel, imitated a pulsed column in the reprocessing plant) are reported. As imitated vessels, three vessels are manufactured with different interior obstacle arrangements as follows, A) cylindrical obstacles are faithfully reproduced and are arranged based on the actual vessel, B) cylindrical obstacles are arranged more densely than the actual vessel, and C) there are no obstacles inside the vessel. Experiments of hydrogen explosion are performed under condition of stoichiometric hydrogen-air ratio (premixed hydrogen-air is used). As a result of

Lifetime-management and lifetime-extension at PAKS nuclear power plant

International Nuclear Information System (INIS)

Katona, Tamas; Ratkai, Sandor; Janosi, Agnes Biro

2002-01-01

Paks Nuclear Power Plant provides 38-40% of domestic generation at lowest price. It has an important energy-policy role in Hungary. NPP Paks shall be a decisive and perspectively permanent element of the domestic electricity generation during the next two decades, which shall be ensured by plant safe operation, the lifetime extension and power uprating. Paks Nuclear Power Plant investigated the nuclear power plant's lifetime extension possibilities and alternatives, as well as technical and business feasibility of such alternatives. The feasibility study is based on the evaluation of a representative set of systems, structures and components, operational, test, in-service inspection and maintenance practice, experience and findings of the Periodic Safety Review. The most important results of this study showing the feasibility of 20 years lifetime extension is summarised in the paper. It was found that there are no technical or safety issues or limits, which may inhibit the operation of the Nuclear Power Plant Paks up to 50 years. In case of most systems and equipment the recent monitoring, maintenance and regular reconstruction practice of the NPP Paks allows the lifetime extension without outstanding cost. Replacement or reconstruction of a few equipment and systems requires significant investment costs. Material of reactor vessels of VVER/213 incorporated at Paks, compared to vessels of the similar units, is less sensitive to the embrittlement. At units 3-4 reactor vessels do not require any measure, consequently, any additional cost, even in case of a lifetime of 50 years. At unit 2 to extend the lifetime of the reactor vessel, only heating-up of emergency core cooling tanks is needed in order to decrease thermal stress levels caused by pressure thermal shock (PST) transients. For this purpose cost-effective technical solutions are available. At unit 1, beside the heating-up of the emergency core cooling tanks annealing of the welded joint No. 5/6 close to the

Some power uprate issues in nuclear power plants

International Nuclear Information System (INIS)

Tipping, Philip

2008-01-01

Issues and themes concerned with nuclear power plant uprating are examined. Attention is brought to the fact that many candidate nuclear power plants for uprating have anyway been operated below their rated power for a significant part of their operating life. The key issues remain safety and reliability in operation at all times, irrespective of the nuclear power plant's chronological or design age or power rating. The effects of power uprates are discussed in terms of material aspects and expected demands on the systems, structures and components. The impact on operation and maintenance methods is indicated in terms of changes to the ageing surveillance programmes. Attention is brought to the necessity checking or revising operator actions after power up-rating has been implemented

Hydroelectric Power Plants Dobsina

International Nuclear Information System (INIS)

Majercak, V.; Srenkelova, Z.; Kristak, J.G.

1997-01-01

In this brochure the Hydroelectric Power Plants Dobsina, (VED), subsidiary of the utility Slovenske Elektrarne, a.s. (Slovak Electric, plc. Bratislava) are presented. VED is mainly aimed at generating peak-load electrical energy and maintenance of operational equipment. Reaching its goals, company is first of all focused on reliability of production, economy and effectiveness, keeping principles of work safety and industry safety standards and also ecology. VED operates eight hydroelectric power plants, from which PVE Ruzin I and PVE Dobsina I are pump storage ones and they are controlled directly by the Slovak Energy Dispatch Centre located in Zilina thought the system LS 3200. Those power plants participate in secondary regulation of electrical network of Slovakia. They are used to compensate balance in reference to foreign electrical networks and they are put into operation independently from VED. Activity of the branch is focused mainly on support of fulfilment of such an important aim as electric network regulation. Beginnings of the subsidiary Hydroelectric Power Plants Dobsina are related to the year of 1948. After commissioning of the pump storage Hydroelectric Power Plants Dobsina in 1953, the plant started to carry out its mission. Since that time the subsidiary has been enlarged by other seven power plants, through which it is fulfilling its missions nowadays. The characteristics of these hydroelectric power plants (The pump-storage power plant Dobsina, Small hydroelectric power plant Dobsina II, Small hydroelectric power plant Rakovec, Small hydroelectric power plant Svedlar, Hydroelectric power plant Domasa, The pump-storage power plant Ruzin, and Small hydroelectric power plant Krompachy) are described in detail. Employees welfare and public relations are presented

Elecnuc. Nuclear power plants in the world

International Nuclear Information System (INIS)

2003-01-01

This 2003 version of Elecnuc contents information, data and charts on the nuclear power plants in the world and general information on the national perspectives concerning the electric power industry. The following topics are presented: 2002 highlights; characteristics of main reactor types and on order; map of the French nuclear power plants; the worldwide status of nuclear power plants on 2002/12/3; units distributed by countries; nuclear power plants connected to the Grid by reactor type groups; nuclear power plants under construction; capacity of the nuclear power plants on the grid; first electric generations supplied by a nuclear unit; electrical generation from nuclear plants by country at the end 2002; performance indicator of french PWR units; trends of the generation indicator worldwide from 1960 to 2002; 2002 cumulative Load Factor by owners; nuclear power plants connected to the grid by countries; status of license renewal applications in Usa; nuclear power plants under construction; Shutdown nuclear power plants; exported nuclear power plants by type; exported nuclear power plants by countries; nuclear power plants under construction or order; steam generator replacements; recycling of Plutonium in LWR; projects of MOX fuel use in reactors; electricity needs of Germany, Belgium, Spain, Finland, United Kingdom; electricity indicators of the five countries. (A.L.B.)

Comparative studies between nuclear power plants and hydroelectric power plants

International Nuclear Information System (INIS)

Menegassi, J.

1984-01-01

This paper shows the quantitative evolution of the power plants in the main countries of the world. The Brazilian situation is analysed, with emphasys in the technical and economical aspects related to power production by hidroelectric or nuclear power plants. The conclusion is that the electricity produced by hidro power plants becomes not economics when is intended to be produced at large distances from the demand centers. (Author) [pt

Prestressed pressure vessel for nuclear power plants

International Nuclear Information System (INIS)

1974-01-01

The pressure vessel consists of a wall, a bottom, and a closure head, the wall being composed of annular segments. The closure head can be seated on the edge of the wall. Wall and closure head have got axial prestressing channels in which through-going steel tendons are arranged. They are concentrated in bundles and held above the head by anchoring devices. Within the prestressing channels of the head there are supporting jackets attached to the edge of the wall and projecting from the head through a coller. The anchoring devices, e.g. anchoring plates, may be optionally supported on the collars of the supporting jackets or on the closure head by means of auxiliary devices. The auxiliary devices for this purpose consist of extension nuts attached to the anchoring plates and closure head connecting shells. The closure head therefore may be drawn off over the anchoring devices. (DG) [de

Sea water pumping-up power plant system combined with nuclear power plant

International Nuclear Information System (INIS)

Ichiki, Tadaharu; Tanaka, Masayuki.

1991-01-01

It is difficult to find a site suitable to construction for a sea water pumping-up power plant at a place relatively near the electric power consumption area. Then, a nuclear power plant is set at the sea bottom or the land portion of a sea shore near the power consumption area. A cavity is excavated underground or at the bottom of the sea in the vicinity of the power plant to form a lower pond, and the bottom of the sea, as an upper pond and the lower pond are connected by a water pressure pipe and a water discharge pipe. A pump water turbine is disposed therebetween, to which electric power generator is connected. In addition, an ordinary or emergency cooling facility in the nuclear power plant is constituted such that sea water in the cavity is supplied by a sea water pump. Accordingly, the sea water pumping-up plant system in combination with the nuclear power plant is constituted with no injuring from salts to animals and plants on land in the suburbs of a large city. The cost for facilities for supplying power from a remote power plant to large city areas and power loss are decreased and stable electric power can be supplied. (N.H.)

Assessment and Management of Aging in Phenix Nuclear Power Plant

International Nuclear Information System (INIS)

Dumarcher, V.; Bourrier, J.L.; Chaucheprat, P.; Boulegue, D.

2006-01-01

The combination of one or several processes of ruins can involve the materials failure of a nuclear power plant. These processes arise from the external agents action such as the pressure, the mechanical efforts, the heat flows and the radiations constitute the whole of the 'actions' of the surrounding medium. The prolongation and the repetition of these effects can involve a deterioration of the machine. In accordance with the decree of February 26, 1974, the PWR operator must be firstly, sure that the system is controlled according to the situations considered in the file of dimensioning and secondly, be able to know anytime the life of the equipment. The physical phenomena which cause the structures ruin are less complex in the PWR than in the SFR. In the SFR, the high temperatures imposed on components for long periods can involve a significant creep. In the course of time, this deformations accelerate the release of fatigue cracks. To consider the creep, the reactor lifespan is correlated at the numbers of thermals transients envisaged initially. To realize the management of aging in Phenix power plant, it is necessary to carry out an individualized monitoring of the structures and not only on the vessel. We must ensure the good state and/or the correct operation of the significant stations for safety which are the control of the reactivity, the movement of control rods, the primary sodium containment and the decay heat removal. For that, we monitor the main vessel, the conical skirt, the IHX and the Core Cover Plug. A profound knowledge of the thermal transients of the past is necessary to carry out an effective assessment. In order to guarantee that any harmful situation is well taken into the management of aging, we monitor permanently certain measurements (primary and secondary pump speed, hot and cold pool temperatures, IHX-main vessel and reactor roof temperatures). We present in the article the scientific method used in the Physics Section. A logical

The flow effect in the irradiation embrittlement in pressure vessel steels of nuclear power plants

International Nuclear Information System (INIS)

Kempf, Rodolfo A.; Cativa Tolosa, Sebastian; Fortis, Ana M.

2009-01-01

This paper deals with the advances in the study of the mechanical behavior of the Reactor Pressure Vessel steels under accelerate irradiations. The objective is to study the effect of lead factors on the interpretation of the mechanisms that induced the embrittlement of the RPV, like those of the reactors Atucha II and CAREM. It is described a device designed to irradiate Charpy specimens with V notch of SA-508 type 3 steel at power reactor temperature, installed in the RA-1 reactor. It is presented also an automatic digital image processing technique for partitioning Charpy fracture surface into regions with a clear physical meaning and appropriate for the work in hot cells. The aim is to obtain the fracture behavior of irradiated specimens with different lead factors in the range of high fluencies and to know the dependence with the composition of the alloy and with the diffusion of other alloy elements. (author)

Nuclear power plants in populated areas

International Nuclear Information System (INIS)

Wachsmann, F.

1973-01-01

The article first deals with the permanently increasing demand for electical power. Considering the ever growing energy demand which can no longer be covered by conventional power plants, it has become necessary to set up nuclear power plants of larger range. The author presents in a survey the basic function of nuclear power plants as well as the resulting risks and safety measures. The author concludes that according to present knowledge there is no more need to erect nuclear power plants outside densely populated urban areas but there is now the possibility of erecting nuclear power plants in densely populated areas. (orig./LH) [de

Development and recent trend of design of BWR nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kani, J [Tokyo Shibaura Electric Co. Ltd., Kawasaki, Kanagawa (Japan)

1977-11-01

Many improvements have been carried out in BWR nuclear power plants from BWR-1, represented by Dresden No. 1 plant, to the present BWR-6 as the capacity has increased. In Japan, the plants up to BWR-5 have been constructed. In addition, further fine design improvements are being performed in the complete domestic manufacturing of BRWs based on the operational experiences to date. A variety of investigations on the standardization of nuclear power facilities have been progressing under the leadership of Japanese Ministry of International Trade and Industry since 1975. In this standardization, it is intended to forward the plant design taking eight concrete items into consideration, mainly aiming at carrying cut unerringly the maintenance and inspection, reduction of exposure of employees to radiation, and improvements of the rate of operation of plants and equipment reliability. The containment vessel has been developed in three forms, from Mark 1 through 3, adopting the pressure control system consistently since BWR-2. Mark 1 and 2 were constructed in Japan. However, these designs sacrificed the workability and increased radiation exposure during maintenance as a result of placing emphasis on the safety facilities, therefore Toshiba Electric has investigated the advanced Mark 1 type. Its features are the design for improving the work efficiency in a containment vessel, reducing the radiation exposure of workers, shortening plant construction period, and considering the aseismatic capability. In addition, the following themes are being planned as future standardization: (1) electrically driven control rod driving system, (2) improved design of reactor core, and (3) internal pump system as compared with external re-circulation.

Development and recent trend of disign of BWR nuclear power plants

International Nuclear Information System (INIS)

Kani, Jiro

1977-01-01

Many improvements have been carried out in BWR nuclear power plants from BWR-1, represented by Dresden No. 1 plant, to the present BWR-6 as the capacity has increased. In Japan, the plants up to BWR-5 have been constructed. In addition, further fine design improvements are being performed in the complete domestic manufacturing of BRWs based on the operational experiences to date. A variety of investigations on the standardization of nuclear power facilities have been progressing under the leadership of Japanese Ministry of International Trade and Industry since 1975. In this standardization, it is intended to forward the plant design taking eight concrete items into consideration, mainly aiming at carrying cut unerringly the maintenance and inspection, reduction of exposure of employees to radiation, and improvements of the rate of operation of plants and equipment reliability. The containment vessel has been developed in three forms, from Mark 1 through 3, adopting the pressure control system consistently since BWR-2. Mark 1 and 2 were constructed in Japan. However, these designs sacrificed the workability and increased radiation exposure during maintenance as a result of placing emphasis on the safety facilities, therefore Toshiba Electric has investigated the advanced Mark 1 type. Its features are the design for improving the work efficiency in a containment vessel, reducing the radiation exposure of workers, shortening plant construction period, and considering the aseismatic capability. In addition, the following themes are being planned as future standardization: (1) electrically driven control rod driving system, (2) improved design of reactor core, and (3) internal pump system as compared with external re-circulation. (Wakatsuki, Y.)

Chemistry in power plants 2011

International Nuclear Information System (INIS)

2011-01-01

Within the VGB Powertech conference from 25th to 27th October, 2011, in Munich (Federal Republic of Germany), the following lectures and poster contributions were presented: (1) The revised VGB standard for water-steam-cycle Chemistry; (2) Switchover from neutral operation to oxygen treatment at the power station Stuttgart-Muenster of EnBW Kraftwerke AG; (3) Steam contamination with degradation products of organic matters present in the feedwater of the Lanxess-Rubber cogeneration plant; (4) Laboratory scale on-line noble metal deposition experiments simulating BWR plant conditions; (5) Building a new demin installation for the power plant EPZ in Borssele; (6) Replacement of the cooling tower installations in the nuclear power plant Goesgen-Daenien AG; (7) Aging of IEX resins in demin plants - Cost optimisation by adaptation of regenerants; (8) The largest DOW trademark EDI System at a combined cycled plant in Europe; (9) Upgrading river Main water to boiler feed water - Experiences with ultrafiltration; (10) Experiences with treatment of the water-steam-cycle in the RDF power plant Nehlsen Stavenhagen with film-forming amines; (11) Comparative modelling of the bubbles thermal collapse and cavitations for estimation of bubbles collapse influence; (12) Overcoming the steam quality - issues from an HRSG for the production of process steam; (13) Legionella - new requirements for power plant operation; (14) How the right chemistry in the FGD helps to improve the removal in the waste water treatment plant; (15) High efficiency filtration in dry/semi-dry FGD plants; (16) Expanding the variety of renewable fuels in the biomass power plant Timelkam using the chemical input control; (17) Corrosion, operating experiences and process improvements to increase the availability and operating time of the biomass power plant Timelkam; (18) The influence of temperature on the measurement of the conductivity of highly diluted solutions; (19) A multiparameter instrumentation approach

An overview of actions concerning life management of nuclear power plants in Argentina

International Nuclear Information System (INIS)

Pochettino, A.A.

1995-01-01

An overview of actions concerning life management of nuclear power plants in Argentina is presented including the following issues: reorganization of nuclear activities in Argentina; life extension actions; main specific research and development actions (reactor pressure vessel integrity assessment project; reactor internal components project; heat exchanges project); other research and development actions (non-destructive testing developments; eddy current techniques; acoustic emission applications; materials; vibrations and fretting wear; reactor chemistry; control and instrumentation; probabilistic safety assessment)

Application of high strength steel to nuclear reactor containment vessel

International Nuclear Information System (INIS)

Susukida, H.; Sato, M.; Takano, G.; Uebayashi, T.; Yoshida, K.

1976-01-01

Nuclear reactor containment vessels are becoming larger in size with the increase in the power generating capacity of nuclear power plants. For example, a containment vessel for a PWR power plant with an output of 1,000 MWe becomes an extremely large one if it is made of the conventional JIS SGV 49 (ASTM A 516 Gr. 70) steel plates less than 38 mm in thickness. In order to design the steel containment vessel within the conventional dimensional range, therefore, it is necessary to use a high strength steel having a higher tensile strength than SGV 49 steel, good weldability and a higher fracture toughness and moreover, possessing satisfactory properties without undergoing post-weld heat treatment. The authors conducted a series of verification tests on high strength steel developed by modifying the ASTM A 543 Grade B Class 1 steel with a view to adopting it as a material for the nuclear reactor containment vessels. As the result of evaluation of the test results from various angles, we confirmed that the high strength steel is quite suitable for the manufacture of nuclear reactor containment vessels. (auth.)

Proceedings of the 2004 international congress on advances in nuclear power plants - ICAPP'04

International Nuclear Information System (INIS)

2004-01-01

The 2004 International Congress on Advances in Nuclear Power Plants (ICAPP'04) provides a forum for the industry to exchange the latest ideas and research findings on nuclear plants from all perspectives. This conference builds on the success of last year's meeting held in Cordoba, Spain, and on the 2002 inaugural meeting held in Hollywood, Florida. Because of the hard work of many volunteers from around the world, ICAPP'04 has been successful in achieving its goal. More than 325 invited and contributed papers/presentations are part of this ICAPP. There are 5 invited plenary sessions and 70 technical sessions with contributed papers. The ICAPP'04 Proceedings contain almost 275 papers prepared by authors from 25 countries covering topics related to advances in nuclear power plant technology. The program by technical track deals with: 1 - Water-Cooled Reactor Programs and Issues (Status of All New Water-Cooled Reactor Programs; Advanced PWRs: Developmental Stage I; Advanced PWRs: Developmental Stage II; Advanced PWRs: Basic Design Stage; Advanced BWRs; Economics, Regulation, Licensing, and Construction; AP1000); 2 - High Temperature Gas Cooled Reactors (Pebble Bed Modular Reactors; Very High Temperature Reactors; HTR Fuels and Materials; Innovative HTRs and Fuel Cycles); 3 - Long Term Reactor Programs and Strategies (Supercritical Pressure Water Reactors; Lead-Alloy Fast Reactors; Sodium and Gas Fast Reactors; Status of Advanced Reactor Programs; Non-classical Reactor Concepts); 4 - Operation, Performance, and Reliability Management (Information Technology Effect on Plant Operation; Operation, Maintenance and Reliability; Improving Performance and Reducing O and M Costs; Plant Modernization and Retrofits); 5 - Plant Safety Assessment and Regulatory Issues (LOCA and non-LOCA Analysis Methodologies; LOCA and non-LOCA Plant Analyses; In-Vessel Retention; Containment Performance and Hydrogen Control; Advances in Severe Accident Analysis; Advances in Severe Accident

Draft report on compilation of generic safety issues for light water reactor nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

A generally accepted approach to characterizing the safety concerns in nuclear power plants is to express them as safety issues which need to be resolved. When such safety issues are applicable to a generation of plants of a particular design or to a family of plants of similar design, they are termed generic safety issues. Examples of generic safety issues are those related to reactor vessel embrittlement, control rod insertion reliability or strainer clogging. The safety issues compiled in this document are based on broad international experience. This compilation is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. Refs.

Draft report on compilation of generic safety issues for light water reactor nuclear power plants

International Nuclear Information System (INIS)

1997-07-01

A generally accepted approach to characterizing the safety concerns in nuclear power plants is to express them as safety issues which need to be resolved. When such safety issues are applicable to a generation of plants of a particular design or to a family of plants of similar design, they are termed generic safety issues. Examples of generic safety issues are those related to reactor vessel embrittlement, control rod insertion reliability or strainer clogging. The safety issues compiled in this document are based on broad international experience. This compilation is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. Refs

Radiation embrittlement in pressure vessels of power reactors

International Nuclear Information System (INIS)

Kempf, Rodolfo; Fortis, Ana M.

2007-01-01

It is presented the project to study the effect of lead factors on the mechanical behavior of Reactor Pressure Vessel steels. It is described the facility designed to irradiate Charpy specimens with V notch of SA-508 type 3 steel at power reactor temperature, installed in the RA-1 reactor. The objective is to obtain the fracture behavior of irradiated specimens with different lead factors and to know their dependence with the diffusion of alloy elements. (author) [es

Annealing the reactor vessel at the Palisades Plant

International Nuclear Information System (INIS)

Fenech, R.A.

1996-01-01

In the way of background, Palisades was licensed in 1967 and went commercial in 1971. Jumping to two years ago, we faced at that time three issues that challenged our ability to operate to end-of-license, which would be 2007 without any extensions. The three items were regulatory performance, economic performance, and reactor vessel embrittlement. We had not been operating the plant with the kind of conservative decisions and with the kind of safety margins that one is expected to operate a plant in the United States at this time. Our economic performance was not satisfactory in that our capacity factor was low and our costs high. In the area of reactor vessel embrittlement, our analysis showed that we would reach the NRC screening criteria for embrittlement in the year 2004. Over the last two years, we have made significant improvements in the first two areas. Our decision-making has changed. Our performance, especially over the last year and a half, has been excellent. In addition, we have gotten our capacity factors up and our costs under control. Clearly, sustained performance is what is going to carry the day but from what we can see and from where we are, we are in more of a maintenance-of-performance than in a turn-around situation. On the other hand, in the area of reactor vessel embrittlement, about a year and a half ago we had a bit of a setback. We had taken material from retired steam generators that had welds identical to the welds in our reactor vessel. When we analyzed the welds from our steam generators, we were given some surprises about the chemistry makeup. When we applied the new information to our analysis, we changed the date on which we would reach our screening criteria from 2004 to late 1999

Maintenance of nuclear power plants

International Nuclear Information System (INIS)

Migaud, D.; Hutin, J.P.; Jouette, I.; Eymond, P.; Devie, P.; Cudelou, C.; Magnier, S.; Frydman, M.

2016-01-01

This document gathers different articles concerning the maintenance of the French nuclear power plants. The first article analyses the impact of the recent law on the energetic transition that sets the share of nuclear power at 50% of the electricity produced by 2025. A consequence may be the decommissioning of 17 to 20 reactors by 2025 and the huge maintenance program called 'Grand Carenage' whose aim is to extend operating life over 40 years will have to be re-considered in order to avoid useless expenses. The second article shows that in 2015 the French nuclear reactor fleet got very good results in terms of availability and safety. There were 49 scheduled outages and among them some ended ahead of time. The third article describes the specificities of the maintenance of a nuclear power plant, for instance the redundancy of some systems implies that maintenance has to deal with systems that have never functioned but must be ready to operate at any moment. Another specificity is the complexity of a nuclear power plant that implies an essential phase of preparation for maintenance operations. Because of safety requirements any maintenance operation has to be controlled, checked and may provide feedback. The fourth article presents the 'Grand Carenage' maintenance program that involves the following operations: the replacement of steam generators, the re-tubing of condensers, the replacement of the filtering drums used for cooling water, the testing of the reactor building, the hydraulic test of the primary circuit and the inspection of the reactor vessel. The fifth article focuses on the organization of the work-site for maintenance operations and the example of the Belleville-sur-Loire is described in the sixth article. Important maintenance operations like 'Grand Carenage' requires a strong collaboration with a network of specialized enterprises and as no reactor (except Flamanville EPR) is being built in France, maintenance

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

International Nuclear Information System (INIS)

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

1987-12-01

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

Nuclear power plants in post-war thought

International Nuclear Information System (INIS)

Toya, Hiroshi

2015-01-01

This paper overviews how nuclear power plants have been talked about in the post-war thought. Science and technology sometimes significantly change the thinking way of humans, and nuclear power generation is an extreme technology. This paper overviews how nuclear power plants and humans are correlated. The following three points are discussed as the major issues of contemporary thought over nuclear power plants. First, on the danger of nuclear power plants, the risk of destructive power that nuclear energy has, and the danger of unreasoning development in science and technology civilization are discussed. Second, on the ethics issues surrounding nuclear power plants, the ethics that are based on unbalanced power relations, and democratic responsibility ethics based on discussion ethics are discussed. Third, on the issues of nuclear power plants and imagination, the limitations of democratic discussion surrounding nuclear power plants, the formation of imagination commensurate with the destructive power of nuclear power plants, and the formation of imagination that can represent the distant future are discussed. (A.O.)

Sensor and Communication Technology for Harsh Environments in the Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Wan; Choi, Young Soo; Lee, Jae Chul; Choi, Yu Rak; Jung, Gwang Il; Koo, In Soo; Jung, Jong Eun; Hur Seop; Hong, Seok Boong

2009-10-15

As the result of the rapid development of IT technology, an on-line diagnostic system using the fieldbus communication network coupled with a smart sensor module will be widely used at the nuclear power plant in the near future. The smart sensor system is very useful for the prompt understanding of abnormal state of the key equipment installed in the nuclear power plant. In this paper, it is assumed that a smart sensor system based on the fieldbus communication network for the surveillance and diagnostics of safety-critical equipment will be installed in the harsh-environment of the nuclear power plant. It means that the key components of fieldbus communication system including microprocessor, FPGA, and ASIC devices, are to be installed in the RPV (reactor pressure vessel) and the RCS (reactor coolant system) area, which is the area of a high dose-rate gamma irradiation fields. Gamma radiation constraints for the DBA (design basis accident) qualification of the RTD sensor installed in the harsh environment of nuclear power plant, are typically on the order of 4 kGy/h. In order to use a fieldbus communication network as an ad-hoc diagnostics sensor network in the vicinity of the RCS pump area of the nuclear power plant, the robust survivability of IT-based micro-electronic components in such intense gamma-radiation fields therefore should be verified. An intelligent CCD camera system, which are composed of advanced micro-electronics devices based on IT technology, have been gamma irradiated at the dose rate of about 4.2 kGy/h during an hour up to a total dose of 4 kGy. The degradation performance of the gamma irradiated CCD camera system is explained.

Sensor and Communication Technology for Harsh Environments in the Nuclear Power Plant

International Nuclear Information System (INIS)

Cho, Jai Wan; Choi, Young Soo; Lee, Jae Chul; Choi, Yu Rak; Jung, Gwang Il; Koo, In Soo; Jung, Jong Eun; Hur Seop; Hong, Seok Boong

2009-10-01

As the result of the rapid development of IT technology, an on-line diagnostic system using the fieldbus communication network coupled with a smart sensor module will be widely used at the nuclear power plant in the near future. The smart sensor system is very useful for the prompt understanding of abnormal state of the key equipment installed in the nuclear power plant. In this paper, it is assumed that a smart sensor system based on the fieldbus communication network for the surveillance and diagnostics of safety-critical equipment will be installed in the harsh-environment of the nuclear power plant. It means that the key components of fieldbus communication system including microprocessor, FPGA, and ASIC devices, are to be installed in the RPV (reactor pressure vessel) and the RCS (reactor coolant system) area, which is the area of a high dose-rate gamma irradiation fields. Gamma radiation constraints for the DBA (design basis accident) qualification of the RTD sensor installed in the harsh environment of nuclear power plant, are typically on the order of 4 kGy/h. In order to use a fieldbus communication network as an ad-hoc diagnostics sensor network in the vicinity of the RCS pump area of the nuclear power plant, the robust survivability of IT-based micro-electronic components in such intense gamma-radiation fields therefore should be verified. An intelligent CCD camera system, which are composed of advanced micro-electronics devices based on IT technology, have been gamma irradiated at the dose rate of about 4.2 kGy/h during an hour up to a total dose of 4 kGy. The degradation performance of the gamma irradiated CCD camera system is explained

Elecnuc. Nuclear power plants in the world

International Nuclear Information System (INIS)

1998-01-01

This small booklet summarizes in tables all the numerical data relative to the nuclear power plants worldwide. These data come from the French CEA/DSE/SEE Elecnuc database. The following aspects are reviewed: 1997 highlights; main characteristics of the reactor types in operation, under construction or on order; map of the French nuclear power plants; worldwide status of nuclear power plants at the end of 1997; nuclear power plants in operation, under construction and on order; capacity of nuclear power plants in operation; net and gross capacity of nuclear power plants on the grid and in commercial operation; forecasts; first power generation of nuclear origin per country, achieved or expected; performance indicator of PWR units in France; worldwide trend of the power generation indicator; nuclear power plants in operation, under construction, on order, planned, cancelled, shutdown, and exported; planning of steam generators replacement; MOX fuel program for plutonium recycling. (J.S.)

Finite element method used in strength calculations of nuclear power plant pressure vessels

International Nuclear Information System (INIS)

Hanulak, E.

1987-01-01

A software system based on the use of the finite element method in linear and nonlinear elastomechanics was developed for assessing the strength and service life of steam generators and pressurizers for WWER type nuclear power plants. The individual programs are briefly described. They are written in FORTRAN IV, some modules are in ASSEMBLER. Programs EGUSAP, NEANKO, ROSYNA are designed for the calculation of stress and deformation, programs ROSYNA, NEANKO and NTEPLO are used for the calculation of temperature fields. Programs SPOJ and STATES are used for assessing the strength and service life of screw joints and other nodes of the WWER-440 type steam generators and pressurizers. (Z.M.)

Small-scale power plant potential in Finland

International Nuclear Information System (INIS)

Helynen, S.

1993-01-01

The presentation discusses the small-scale power plant potential in Finland. The study of the potential is limited to W-scale power plants producing both electric power and heat using solid fuels. The basic power plant dimensioning and electric power load determination is based on traditional boiler and gas turbine technology. The possible sites for power plants are communities using district heating, and industrialized sites needing process steam or heat. In 1990 70 % (17 TWh) of district heat was produced by gas turbines. Ten communities have an own back-pressure power plant, and 40 communities buy heat from industrial plants, owing back-pressure power generation. Additionally about 40 communes buy district heat from companies, owned by power companies and industry. Estimates of small-scale power plant potential has been made plant wise on the basis of district heat loads and industrial heat needs. The scale of the plants has been limited to scale 3 MWe or more. The choosing of the fuel depends on the local conditions. The cheapest indigenous fuels in many communes are industrial wood wastes, and both milled and sod peat. The potential of steam technology based small-scale power plants has been estimated to be about 50 plants in 1992/1993, the total power of which is 220-260 MW. The largest estimate is base situation, in which there would be energy cooperation between the communes and industry. The fuel used by the power plants would be about 5.4-6.6 TWh/a corresponding to 270-330 million FIM/a. The total investment costs of the plants would be about 2.0 billion FIM. The plants would employ about 250 persons, and the fuel supply (wood or peat) about 100 persons

Automation technology in power plants

International Nuclear Information System (INIS)

Essen, E.R.

1995-01-01

In this article a summery of the current architecture of modern process control systems in power plants and future trends have been explained. The further development of process control systems for power plants is influenced both by the developments in component and software technologies as well as the increased requirements of the power plants. The convenient and low cost configuration facilities of new process control systems have now reached a significance which makes it easy for customers to decide to purchase. (A.B.)

Less power plants

International Nuclear Information System (INIS)

TASR

2003-01-01

In the Slovak Republic the number of company power plants decreased as against 2001 by two sources. In present time only 35 companies have their own power plants. The companies Slovnaft, Kappa Sturovo, Slovensky hodvab Senica, Matador Puchov, Maytex Liptovsky MikuIas, Kovohuty Krompachy, Chemko Strazske and some Slovak sugar factories belong to the largest company power plants in force of distributing companies. Installed output of present 35 company sources is 531 MW. The largest of separate power plants as Paroplynovy cyklus Bratislava (218 MW) and VD Zilina (72 MW) belong to independent sources. Total installed output of Slovak sources was 8306 MW in the end of last year

Elecnuc. Nuclear power plants in the world

International Nuclear Information System (INIS)

2000-01-01

This small booklet summarizes in tables all the numerical data relative to the nuclear power plants worldwide. These data come from the French CEA/DSE/SEE Elecnuc database. The following aspects are reviewed: 1999 highlights; main characteristics of the reactor types in operation, under construction or on order; map of the French nuclear power plants; worldwide status of nuclear power plants at the end of 1999; nuclear power plants in operation, under construction and on order; capacity of nuclear power plants in operation; net and gross capacity of nuclear power plants on the grid and in commercial operation; grid connection forecasts; world electric power market; electronuclear owners and share holders in EU, capacity and load factor; first power generation of nuclear origin per country, achieved or expected; performance indicator of PWR units in France; worldwide trend of the power generation indicator; 1999 gross load factor by operator; nuclear power plants in operation, under construction, on order, planned, cancelled, shutdown, and exported; planning of steam generators replacement; MOX fuel program for plutonium recycling. (J.S.)

Elecnuc. Nuclear power plants in the world

International Nuclear Information System (INIS)

2005-01-01

This 2005 edition of the Elecnuc booklet summarizes in tables all numerical data relative to the nuclear power plants worldwide. These data come from the PRIS database managed by the IAEA. The following aspects are reviewed: 2004 highlights; main characteristics of reactor types; map of the French nuclear power plants on 2005/01/01; worldwide status of nuclear power plants at the end of 2004; units distributed by countries; nuclear power plants connected to the grid by reactor-type group; nuclear power plants under construction on 2004; evolution of nuclear power plant capacities connected to the grid; first electric generations supplied by a nuclear unit; electrical generation from nuclear power plants by country at the end 2004; performance indicator of PWR units in France; trend of the generation indicator worldwide; 2004 load factor by owners; units connected to the grid by countries at 12/31/2004; status of licence renewal applications in USA; nuclear power plants under construction at 12/31/2004; shutdown reactors; exported nuclear capacity in net MWe; exported and national nuclear capacity connected to the grid; exported nuclear power plants under construction or order; exported and national nuclear capacity under construction or order; recycling of plutonium in LWR; Mox licence plant projects; Appendix - historical development; acronyms, glossary

Advanced concrete structures for thermal power plants

International Nuclear Information System (INIS)

Zerna, W.

1982-01-01

The author begins with an overview on the various types of power plants depending on the fuel used in them and then in particular deals with the reinforced concrete structures. Especially for reactor buildings and prestressed concrete pressure vessels concrete is the appropriate material. The methods of construction are described as a function of load and operation. Safety requirements brought new load types for such structures as e.g. airplane crash, internal pressure caused by pipe rupture. Dimensioning is done by means of nonlinear dynamical methods of calculation accounting for plasticizing. These methods are explained. Further the constructional principles of high natural-draft cooling towers are mentioned. (orig.) [de

Management of nuclear power plants lifetime

International Nuclear Information System (INIS)

Hutin, J.P.

2006-01-01

The factors influencing the management of the service life of nuclear power plants can be of various types and the 'heaviest' ones have to be managed through robust and explicit approaches involving all actors. However, the mastery of the service life starts with the mastery of the technical problems, in particular the physical aging of the facilities. This mastery requires to foresee and anticipate the problems and thus a good understanding of the phenomena involved. This article presents: 1 - the general problem of service life management: lifetime concept, situation of French power plants, service life management policy; 2 - aging mechanisms: embrittlement of steel under irradiation, swelling of materials, thermal aging, fatigue, stress corrosion, aqueous corrosion of metals, corrosion-erosion, mechanisms of concrete degradation, mechanisms of elastomers and polymers degradation, wear; 3 - non-replaceable parts: reactor vessel, containment building; 4 - replaceable parts: cables, instrumentation and control system, core internals, primary loop piping, auxiliary primary piping, pressurizer, primary pump, steam generator tubes, other Ni-Cr-Fe alloy parts, secondary loop piping, turbine, alternator; 5 - non-technical aspects: perenniality of the industrial support, evolution of safety requirements, public acceptance, economical aspects, knowledge and information systems; 6 - situation in foreign countries: status of the world nuclear park, lifetime notion in foreign countries, situation in the USA. (J.S.)

Safety problems in decommissioning nuclear power plants

International Nuclear Information System (INIS)

Auler, I.; Bardtenschlager, R.; Gasch, A.; Majohr, N.

1975-12-01

The safety problems at decommissioning are illustrated by the example of a LWR with 1300 MW electric power after 40 years of specified normal operation. For such a facility the radioactivity in the form of activation and contamination one year after being finally taken out of service is in the order of magnitude of 10 7 Ci, not counting the fuel assemblies. The dose rates occurring during work on the reactor vessel at nozzle level may amount to some 10 4 rem/h. After a rough estimation the accumulated dose for the decommissioning personnel during total dismantling will be about 1200 rem. During performance of the decommissioning activities the problems are mainly caused by direct radiation of the active components and systems and by the release of radioactive particles, aerosols and liquids if these components are crushed. The extent of later dismantling problems may be reduced by selecting appropriate materials as well as considering the requirements for dismantling in design and arrangement of the components already in the design stage of new facilities. Apart from plant design also the concept for the disposal of the radioactive waste from decommissioning will provide important boundary conditions. E.g. the maximum size of the pieces to be stored in the ultimate storage place will very much influence the dose expenditure for handling these parts. For complete dismantling of nuclear power plants an ultimate store must be available where large amounts of bulky decommissioning waste, containing relatively low activity, can be stored. The problems and also the cost for decommissioning may be considerably reduced by delaying complete disposal of the radioactive material >= 40 years and during this period, keeping the radioactivity enclosed within the plant in the form of a safe containment. (orig./HP) [de

Nuclear power plant with a safety enclosure

International Nuclear Information System (INIS)

Keller, W.; Krueger, J.; Ropers, J.; Schabert, H.P.

1976-01-01

A nuclear power plant has a safety enclosure for a nuclear reactor. A fuel element storage basin is also located in this safety enclosure and a fuel element lock extends through the enclosure, with a cross-sectional size proportioned for the endwise passage of fuel elements, the lock including internal and external valves so that a fuel element may be locked endwise safely through the lock. The lock, including its valves, being of small size, does not materially affect the pressure resistance of the safety enclosure, and it is more easily operated than a lock large enough to pass people and fuel element transport vessels

Influence of shock waves as a result of assumed vessel failure on parts of the plant relevant to safety

International Nuclear Information System (INIS)

Danisch, R.; Graubner, U.

1981-01-01

The shock wave induced rupture is of subordinate importance for the laying out of the parts of the plant relevant to safety. It is covered by the precautions for maximum potential earthquakes, aircraft crashes and chemical explosions. The failure of vessels in the power house (WAZUe, SPWB) as the result of a maximum potential earthquake is extremely improbable. If a combination of the stresses resulting from maximum potential earthquakes with the hypothetical stresses resulting from vessel failure is undertaken, it can be seen that the total stresses are only increased by a minimal amount, due to the quadratic averaging of less than 3%. (orig./DG) [de

Human factors in nuclear power plants

International Nuclear Information System (INIS)

Pack, R.W.

1978-01-01

The Electric Power Research Institute has started research in human factors in nuclear power plants. One project, completed in March 1977, reviewed human factors problems in operating power plants and produced a report evaluating those problems. A second project developed computer programs for evaluating operator performance on training simulators. A third project is developing and evaluating control-room design approaches. A fourth project is reviewing human factors problems associated with power-plant maintainability and instrumentation and control technician activities. Human factors engineering is an interdisciplinary specialty concerned with influencing the design of equipment systems, facilities, and operational environments to promote safe, efficient, and reliable operator performance. The Electric Power Research Institute (EPRI) has undertaken four projects studying the application of human factors engineering principles to nuclear power plants. (author)

Concept of a nuclear powered submersible research vessel and a compact reactor

International Nuclear Information System (INIS)

Kusunoki, Tsuyoshi; Odano, Naoteru; Yoritsune, Tsutomu; Ishida, Toshihisa; Nishimura, Hajime; Tokunaga, Sango

2001-07-01

A conceptual design study of a submersible research vessel navigating in 600 m depth and a compact nuclear reactor were carried out for the expansion of the nuclear power utilization. The mission of the vessel is the research of mechanism of the climate change to predict the global environment. Through conditions of the Arctic Ocean and the sea at high latitude have significant impacts on the global environmental change, it is difficult to investigate those areas by ordinary ships because of thick ice or storm. Therefore the research vessel is mainly utilized in the Arctic Ocean and the sea at high latitude. By taking account of the research mission, the basic specifications of the vessel are decided; the total weight is 500 t, the submersible depth is 600 m, the maximum speed is 12 knots (22.2 km/h), and the number of crews is 16. Nuclear power has an advantage in supplying large power of electricity in the sea for long period. Based on the requirements, it has been decided that two sets of submersible compact reactor, SCR, which is light-weighted and of enhanced safety characteristics of supply the total electricity of 500 kW. (author)

Nuclear Power Plants in the World

International Nuclear Information System (INIS)

2003-01-01

The Japan Atomic Industrial Forum (JAIF) used every year to summarize a trend survey on the private nuclear power plants in the world in a shape of the 'Nuclear power plants in the world'. In this report, some data at the end of 2002 was made up on bases of answers on questionnaires from 65 electric power companies and other nuclear organizations in 28 countries and regions around the world by JAIF. This report is comprised of 19 items, and contains generating capacity of the plants; current status of Japan; trends of generating capacity of operating the plants, the plant orders and generating capacity of the plants; world nuclear capacity by reactor type; status of MOX use in the world; location of the plants; the plants in the world; directory of the plants; nuclear fuel cycle facilities; and so forth. (J.P.N.)

Nuclear power plants

International Nuclear Information System (INIS)

Margulova, T.Ch.

1976-01-01

The textbook focuses on the technology and the operating characteristics of nuclear power plants equiped with pressurized water or boiling water reactors, which are in operation all over the world at present. The following topics are dealt with in relation to the complete plant and to economics: distribution and consumption of electric and thermal energy, types and equipment of nuclear power plants, chemical processes and material balance, economical characteristics concerning heat and energy, regenerative preheating of feed water, degassing and condenser systems, water supply, evaporators, district heating systems, steam generating systems and turbines, coolant loops and pipes, plant siting, ventilation and decontamination systems, reactor operation and management, heat transfer including its calculation, design of reactor buildings, and nuclear power plants with gas or sodium cooled reactors. Numerous technical data of modern Soviet nuclear power plants are included. The book is of interest to graduate and post-graduate students in the field of nuclear engineering as well as to nuclear engineers

Lessons Learned after Nuclear Power Plants and Hydropower Plants Accidents

Energy Technology Data Exchange (ETDEWEB)

Moskalenko, A., E-mail: gce@gce.ru [GCE Group, Saint Petersburg (Russian Federation)

2014-10-15

Full text: The World is becoming more open and free for communication. However, the experience (positive or negative) is still badly cross over sectorial borders. I would like to illustrate the point with the examples, even with several unexpected ones. I would like to start with a few words regarding the Sayano – Shushenskaya Hydro Power Plant accident and the factors that caused it. Sayano – Shushenskaya Hydro Power Plant is a unique Hydro Power Plant with efficiency factor of 96 %. Nevertheless, the efficiency factor, in particular, caused a series of restrictions: hydro-electric units vibration amplitude must not exceed 4 micron!!! (Slide 1: Vibration amplitude dependence on output capacity) As it is clearly seen, there is a so called “prohibited area”, which the hydro-electric unit must pass over. Operations in the area are prohibited in accordance with the regulatory documents. However, due to the changes that occurred in Russian power supply industry, the hydro-electric unit passed through the prohibited area more than 12 times, if we take into account only the day of the accident. The bolts keeping the turbine cover, keeping water apart from the machinery hall, were too much released. The mentioned above reasons led to the hydro-electric unit disruption and the machinery hall flooding. Water inflow was possible to stop by putting down the regulating valves. However, the regulating valves control console was in the flooded machinery hall. There was standby emergency control console, but it was in the machinery hall, as well. The machinery hall was flooded, consequently, main and standby systems were destroyed. Moreover, the machinery hall, where all the units were disposed, was a huge hall without dividing walls, etc. (Photo) Take a look at the next slide. (Photo – Chernobyl Nuclear Power Plant machinery hall). Take note of Fukushima–1 Nuclear Power Plant: standby power supply source was situated in the same place and destroyed by water. All the

Nuclear Power Plants in the World

International Nuclear Information System (INIS)

2004-01-01

The Japan Atomic Industrial Forum, Inc. (JAIF) used every year to summarize a trend survey on the private nuclear power plants in the world in a shape of the 'Nuclear power plants in the world'. In this report, some data at the end of 2003 was made up on bases of answers on questionnaires from 81 electric power companies and other nuclear organizations in 33 countries and regions around the world by JAIF. This report is comprised of 19 items, and contains generating capacity of the plants; current status of Japan; trends of generating capacity of operating the plants, the plant orders and generating capacity of the plants; world nuclear capacity by reactor type; status of MOX use in the world; location of the plants; the plants in the world; directory of the plants; nuclear fuel cycle facilities; and so forth. (J.P.N.)

Application of environmentally-corrected fatigue curves to nuclear power plant components

International Nuclear Information System (INIS)

Ware, A.G.; Morton, D.K.; Nitzel, M.E.

1996-01-01

Recent test data indicate that the effects of the light water reactor (LWR) environment could significantly reduce the fatigue resistance of materials used in the reactor coolant pressure boundary components of operating nuclear power plants. Argonne National Laboratory has developed interim fatigue curves based on test data simulating LWR conditions, and published them in NUREG/CR-5999. In order to assess the significance of these interim fatigue curves, fatigue evaluations of a sample of the components in the reactor coolant pressure boundary of LWRs were performed. The sample consists of components from facilities designed by each of the four US nuclear steam supply system vendors. For each facility, six locations were studied including two locations on the reactor pressure vessel. In addition, there are older vintage plants where components of the reactor coolant pressure boundary were designed to codes that did not require an explicit fatigue analysis of the components. In order to assess the fatigue resistance of the older vintage plants, an evaluation was also conducted on selected components of three of these plants. This paper discusses the insights gained from the application of the interim fatigue curves to components of seven operating nuclear power plants

Nuclear power plants in the world

International Nuclear Information System (INIS)

2008-01-01

The Japan Atomic Industrial Forum, Inc. (JAIF) used every year to summarize a trend survey on the private nuclear power plants in the world in a shape of the 'Nuclear power plants in the world'. In this report, some data at the end of 2007/2008 was made up on bases of answers on questionnaires from electric power companies and other nuclear organizations around the world by JAIF. This report is comprised of 18 items, and contains generating capacity of the plants; effect of the Niigata-ken chuetsu-oki earthquake; current status of Japan; trends of generating capacity of operating the plants, the plant orders and generating capacity of the plants; world nuclear capacity by reactor type; status of MOX use in the world; location of the plants; the plants in the world; directory of the plants; nuclear fuel cycle facilities, and so forth. (J.P.N.)

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

International Nuclear Information System (INIS)

Kohler, H.A.G.

1977-01-01

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

3D digital dynamic management of maintenance projects for nuclear power plant

International Nuclear Information System (INIS)

Wang Baizhong; Luo Yalin; Fang Hao; Ma Li; Zhang Jie; Wang Ruobing; Xie Min

2005-01-01

The whole process for the application of digital plant technique in the equipment transport in reactor building and the dynamic management of the spatial arrangement in Daya Bay Nuclear Power Station was introduced in the paper. The establishment of 3D digital Daya Bay plant, and the method and procedure to apply it in the nuclear power plant maintenance project have been discussed. This project utilizes the outer database to preserve the maintenance status of equipments, and avoids the damage or changing of the original 3D final model. Based on the maintenance procedure, the spatial arrangement and schedule for the maintenance of nuclear power station have been simulated and optimized for the whole process. This technique can simulate and optimize the arrangement and spatial arrangement for maintenance in limited space. It has been applied successfully in the reactor vessel head replacement for Unit 2 of Daya Bay NPP to shorten the time for key routes and the total time of this project by 16 hours and 92.5 hours, respectively. (author)

Cooperation of nuclear, thermal and hydroelectric power plants in the power system

International Nuclear Information System (INIS)

1984-01-01

The conference heard 36 papers of which 23 were incorporated in INIS. The subjects discussed were: the development of power industry in Czechoslovakia, methods of statistical analysis of data regarding nuclear power plant operation, the incorporation of WWER nuclear power plants in the power supply system, the standardization of nuclear power plants, the service life of components, use of nuclear energy sources, performance of the reactor accident protection system, the use of nuclear power and heating plants in Hungary, risk analysis, optimization of nuclear power plants, accidents caused by leakage of the primary and secondary circuit. (J.P.)

New developments for optimization of automatic inspections in nuclear power plants

International Nuclear Information System (INIS)

Bollini, G.J.; Gonzalez, B.

1989-01-01

One of the most important factors to be taken into acount with respect to remote control mechanized inspection tasks carried out during refueling outages in nuclear power plants, which include components and systems as varied as the reactor vessel, nozzles, piping, vessel head closure bolts, turbine discs, etc., is the unification of systems used to control the inspection systems themselves. Likewise, the implementation in these systems of specific functions simplifying operational sequences and confirming correct execution of work implies a set of criteria that must be taken into account if the reliability of the tasks carried out is to be increased. The system presented in this paper, SIROCCO (Sistema Robotizado de Control) has been designed taking into consideration the above mentioned criteria, with two clear obectives in mind: a reduction in inspection times and in the dose received by the participating technical personnel, and an increase in the reliability of the electronic equipment used. In February and March of this year, during shutdown of a BMR-type nuclear power plant, several SIROCCO control units were usids in mechanized inspection systems of various kinds, applicable to components such as those mentioned above, with forecasts regarding the reduction of inspection times being met. The main reasons for this reduction were the familiarity of the operators with this single control system, the unification of replacement parts for equipment maintenance and the availability of interchangeable units. This philosophy of unification of electronic systems also includes data acquisition and the transmission of information between different areas, which require the unification of control systems already commented and accomplished. This course of action is currently under development at Tecnatom. (author). 4 figs

Transfer system development for a remote inspection robot in nuclear power plants

International Nuclear Information System (INIS)

Mizuno, M.; Ohnuma, M.; Hamada, K.; Mizutani, T.; Shimada, A.; Segawa, M.; Kubo, K.

1984-01-01

A remote operated robot system has been developed for inspection inside the primary containment vessel (PCV) of nuclear power plants. This system consists of an inspection vehicle, a monorail driving system, a signal transmission system, a power supply system and an operator console.. The system has two main features. First is that the operator can transfer the vehicle at any time from outside the PCV to inside or vice versa through a personnel airlock. The second feature is that the vehicle can be transported from one inspection route to another route at junction points. A prototype inspection robot system was fabricated on a trial basis. Running and inspection performances were confirmed utilizing actual size test apparatus

External Reactor Vessel Cooling Evaluation for Severe Accident Mitigation in NPP Krsko

International Nuclear Information System (INIS)

Mihalina, M.; Spalj, S.; Glaser, B.

2016-01-01

The In-Vessel corium Retention (IVR) through the External Reactor Vessel Cooling (ERVC) is mean for maintaining the reactor vessel integrity during a severe accident, by cooling and retaining the molten material inside the reactor vessel. By doing this, significant portion of severe accident negative phenomena connected with reactor vessel failure could be avoided. In this paper, analysis of NPP Krsko applicability for IVR strategy was performed. It includes overview of performed plant related analysis with emphasis on wet cavity modification, plant's site specific walk downs, new applicable probabilistic and deterministic analysis, evaluation of new possibilities for ERVC strategy implementation regarding plant's post-Fukushima improvements and adequacy with plant's procedures for severe accident mitigation. Conclusion is that NPP Krsko could perform in-vessel core retention by applying external reactor vessel cooling strategy with reasonable confidence in success. Per probabilistic and deterministic analysis, time window for successful ERVC strategy performance for most dominating plant damage state scenarios is 2.5 hours, when onset of core damage is observed. This action should be performed early after transition to Severe Accident Management Guidance's (SAMG). For loss of all AC power scenario, containment flooding could be initiated before onset of core damage within related emergency procedure. To perform external reactor vessel cooling, reactor water storage tank gravity drain with addition of alternate water is needed to be injected into the containment. ERVC strategy will positively interfere with other severe accident strategies. There are no negative effects due to ERVC performance. New flooding level will not threaten equipment and instrumentation needed for long term SAMGs performance and eventually diluted containment sump borated water inventory will not cause return to criticality during eventual recirculation phase due to the

Development of improved SGV480 steel plate for containment vessel in PWR plants

Energy Technology Data Exchange (ETDEWEB)

Murakami, Norioki [Advanced Nuclear Equipment Research Inst., Tokyo (Japan); Morikage, Yasushi; Okayama, Yutaka; Higashikubo, Tomohiro

2001-01-01

When a nuclear containment vessel made of steel plate at PWR plants in Japan is produced, SGV480 steel plate made by annealing method according to JIS G3118 is usually used in main. And, when thickness of welding portion of the vessel is larger than 38 mm, as heat treatment after welding is regulated to carry out according to the ministerial ordinance, it is difficult in actual to carry out the heat treatment of the actual welded portions. In a leading plant, approval of welding using a special method without heat treatment less than 47.25 mm of SGV480 carbon steel plate for JIS G3118 middle and ordinary pressure vessel was carried out to supply it for actual use. And, it is required for protection of welding fracture to carry out pre-heat treatment before welding. Because of increasing plate thickness requiring for lower temperature and more seismic resistance in construction condition, in order to produce a containment vessel without heat treatment after welding, more toughness is required for using material and welded portion. Therefore, a new SGV480 steel plate was developed by using TMCP method of modern steel manufacturing technology, to establish lower carbon equivalence and finer texture with upgrading of both toughness and weldability, without heat treatment after welding and pre-heat treatment before welding, at the Shin-Nippon Steel Co, Ltd. and Kawasaki Steel, Co. Ltd., respectively. (G.K.)

Limits to the Recognizability of Flaws in Non-Destructive Testing Steam-Generator Tubes for Nuclear-Power Plants

International Nuclear Information System (INIS)

Kuhlmann, A.; Adamsky, F.-J.

1965-01-01

In the Federal Republic of Germany there are nuclear reactors under construction with steam generators inside the reactor pressure-vessel. As a result design repairs of steam- generator tubes are very difficult and cause large shut-down times of the nuclear-power plant. It is known that numerous troubles in operating conventional power plants are results of steam-generator tube damages. Because of the high total costs of these reactors it. is necessary to construct the steam generators especially in such a manner that the load factor of the power plant is as high as possible. The Technischer Überwachungs-Verein Rheinland was charged to supervise and to test fabrication and construction of the steam generators to see that this part of the plant was as free of defects as possible. The experience gained during this work is of interest for manufacture and construction of steam generators for nuclear-power plants in general. This paper deals with the efficiency limits of non-destructive testing steam-generator tubes. The following tests performed will be discussed in detail: (a) Automatic ultrasonic testing of the straight tubes in the production facility; (b) Combined ultrasonic and radiographic testing of the bent tubes and tube weldings; (c) Other non-destructive tests. (author) [fr

Romanian achievement in hydro-power plants

International Nuclear Information System (INIS)

Cardu, M.; Bara, T.

1998-01-01

This paper briefly deals with the achievements relating to Hydro-electric Power Plants within the process of development of the National Power System in Romania. Also presented is the Romanian industry contribution to hydro-electrical power plant equipment manufacturing. (author)

Closed vessel miniaturized microwave assisted chelating extraction for determination of trace metals in plant materials

Science.gov (United States)

Czarnecki, Sezin; Duering, Rolf-Alexander

2013-04-01

In recent years, the use of closed vessel microwave assisted extraction (MAE) for plant samples has shown increasing research interest which will probably substitute conventional procedures in the future due to their general disadvantages including consumption of time and solvents. The objective of this study was to demonstrate an innovative miniaturized closed vessel microwave assisted extraction (µMAE) method under the use of EDTA (µMAE-EDTA) to determine metal contents (Cd, Co, Cu, Mn, Ni, Pb, Zn) in plant samples (Lolio-Cynosuretum) by inductively coupled plasma-optical emission spectrometry (ICP-OES). Validation of the method was done by comparison of the results with another miniaturized closed vessel microwave HNO3 method (µMAE-H) and with two other macro scale MAE procedures (MAE-H and MAE-EDTA) which were applied by using a mixture of nitric acid (HNO3) and hydrogen peroxide (H2O2) (MAE-H) and EDTA (MAE-EDTA), respectively. The already established MAE-H method is taken into consideration as a reference validation MAE method for plant material. A conventional plant extraction (CE) method, based on dry ashing and dissolving of the plant material in HNO3, was used as a confidence comparative method. Certified plant reference materials (CRMs) were used for comparison of recovery rates from different extraction protocols. This allowed the validation of the applicability of the µMAE-EDTA procedure. For 36 real plant samples with triplicates each, µMAE-EDTA showed the same extraction yields as the MAE-H in the determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn contents in plant samples. Analytical parameters in µMAE-EDTA should be further investigated and adapted for other metals of interest. By the reduction and elimination of the use of hazardous chemicals in environmental analysis and thus allowing a better understanding of metal distribution and accumulation process in plants and also the metal transfer from soil to plants and into the food chain, µ

Aging countermeasures for nuclear power plants in Japan and PLEC's activities

International Nuclear Information System (INIS)

Tajima, K.; Ishikawa, M.; Koyama, M.

2002-01-01

on the verification test results of the Structural Assessment of Flawed Equipment (SAF), which was conducted to confirm consistency of behavior between experiments of fracture mechanics and analyses concerning small flaws hypothesized on the nuclear power plant components, in order to verify integrity of the reactor components and piping. SAF model tests were performed to confirm flaw growth and propagation, and also to evaluate safety margin of the actual equipment using small and large test model with small flaws simulating the production pressure vessel and piping. Regarding information service for domestic and overseas, the PLEC plans to carry out these activities by means of international co-operation and sharing of information and experience related to aging. The PLEC collects aging-related information, i.e., incidents, inspection, evaluation methods countermeasures, codes and standards for aging. (author)

Instrumentation control system in nuclear power plant

International Nuclear Information System (INIS)

Hanai, Koi; Tai, Ichiro.

1982-01-01

Purpose: To improve the reliability of instrumentation control system in a nuclear power plant by using an optical fiber cable as a transmission path between a multiplexer and a central control room to thereby eliminate noises resulted from electromagnetic inductions or the likes. Constitution: Signals from neutron detectors are sent by way of ceramic-insulated cables to pre-amplifiers disposed outside of the pressure vessel of a nuclear reactor, converted into voltage pulse signals and then sent by way of coaxial cables to a multiplexer. The multiplexer receives a plurality of voltage pulse signals corresponding to the neutron detectors respectively, converts them into a time-shared electric signal train and sends it to an optical pulse transmitter. The transmitter converts the supplied signals into an optical pulse signal train corresponding to the electric signal train from the multiplexer and sends it by way of an optical fiber cable to an optical pulse receiver disposed in a central control room. (Kawakami, Y.)

Power reactor embrittlement data base (PR-EDB): Uses in evaluating radiation embrittlement of reactor vessels

International Nuclear Information System (INIS)

Kam, F.B.K.; Stallmann, F.W.; Wang, J.A.

1992-01-01

Investigations of regulatory issues such as vessel integrity over plant life, vessel failure, and sufficiency of current Codes, Standard Review Plans (SRPs), and Guides for license renewal can be greatly expedited by the use of a well-designed, computerized data base. Also, such a data is essential for the evaluation of embrittlement prediction models by researchers. The Power Reactor Embrittlement Data Base (PR-EDB) is such a comprehensive collection of data for US commercial nuclear reactors. The current compilation contains data from 92 reactors and consists of 175 data points for weld materials (79 different welds) and 395 data points for base materials (110 different base materials). The different types of data that are implemented or planned for this data base are discussed. ''User-friendly'' utility programs have been written to investigate a list of problems using this data base. The utility programs are also used to add and upgrade data, retrieve and select specific data, manipulate data, display data to the screen or printer, and to fit and plot Charpy impact data. The results of several studies investigated are presented in this paper

Solar thermal power plants

International Nuclear Information System (INIS)

Schnatbaum, L.

2009-01-01

The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

Question of right to stay of nuclear-powered vessels in foreign ports

International Nuclear Information System (INIS)

Szafranek, J.

1976-01-01

Question of right to stay of nuclear-powered vessels in foreign ports is considered in the light of London Convention on Safety of Life at Sea, Brussels Convention on Liability for Operation of Nuclear Ships and bilateral agreements. (Z.M.)

Complexity and availability for fusion power plants: The potential advantages of inertial fusion energy

International Nuclear Information System (INIS)

Perkins, L.J.

1997-01-01

Probably the single largest advantage of the inertial route to fusion energy (IFE) is the perception that its power plant embodiments could achieve acceptable capacity factors. This is a result of its relative simplicity, the decoupling of the driver and reactor chamber, and the potential to employ thick liquid walls. The author examines these issues in terms of the complexity, reliability, maintainability and, therefore, availability of both magnetic and inertial fusion power plants and compares these factors with corresponding scheduled and unscheduled outage data from present day fission experience. The author stresses that, given the simple nature of a fission core, the vast majority of unplanned outages in fission plants are due to failures outside the reactor vessel itself. Given one must be prepared for similar outages in the analogous plant external to a fusion power core, this puts severe demands on the reliability required of the fusion core itself. The author indicates that such requirements can probably be met for IFE plants. He recommends that this advantage be promoted by performing a quantitative reliability and availability study for a representative IFE power plant and suggests that databases are probably adequate for this task. 40 refs., 4 figs., 3 tabs

Power plant cycle chemistry - a currently neglected power plant chemistry discipline

International Nuclear Information System (INIS)

Bursik, A.

2005-01-01

Power plant cycle chemistry seems to be a stepchild at both utilities and universities and research organizations. It is felt that other power plant chemistry disciplines are more important. The last International Power Cycle Chemistry Conference in Prague may be cited as an example. A critical review of the papers presented at this conference seems to confirm the above-mentioned statements. This situation is very unsatisfactory and has led to an increasing number of component failures and instances of damage to major cycle components. Optimization of cycle chemistry in fossil power plants undoubtedly results in clear benefits and savings with respect to operating costs. It should be kept in mind that many seemingly important chemistry-related issues lose their importance during forced outages of units practicing faulty plant cycle chemistry. (orig.)

Transportable nuclear power plant T3C-M with two reactor plants of improved safety

International Nuclear Information System (INIS)

Ogloblin, B.G.; Gromov, B.F.

1993-01-01

Development and cultivating of districts in Siberia, North, Far East, Kamchatka and other remote or almost inaccessible district of the country depends to a large degree on their providing with power. The specific character of these districts imposes in turn a wide variety of special requirements upon the power sources. In particular, it is essential to provide the following; maximum manufacture availability of the whole equipment at the minimum volume of construction and installation work on operation site, high safety, longterm service life, ecologically, minimum scope of work on equipment in-service maintenance and inspection, etc. Taking into account the well-known difficulties connected with the delivery of conventional energy carriers to the above-mentioned districts and the situation with the alternative power sources, the application of the low-power nuclear plants (NPP) for these purposes looks definitely promising. Among the probable trends in creating the NPPs of this type as very promising is considered the possibility to apply the two-circuit reactor plant of the vessel type with the liquid lead as a primary coolant and free air as a secondary coolant and working medium in the open gas-turbine cycle. The nuclear plant T3C-M of improved safety with two of this type reactor plants with total electric power of 8 MW is developed by CDB of Machine Building with participation of several enterprises of St. Petersburg under the scientific leadership and is intended for generation of electric power and up to 4 Gcal/h of heat for populated areas and installations placed at long distance from the main electric power supply sources where it is difficult or non-efficient economically to deliver the conventional kinds of fuel. The main principles being laid as a basis when developing the proposed NPP will allow one to create mobile power sources which possess a high degree of safety and inherent self-protection

Effect of nuclear power on CO₂ emission from power plant sector in Iran.

Science.gov (United States)

Kargari, Nargess; Mastouri, Reza

2011-01-01

It is predicted that demand for electricity in Islamic Republic of Iran will continue to increase dramatically in the future due to the rapid pace of economic development leading to construction of new power plants. At the present time, most of electricity is generated by burning fossil fuels which result in emission of great deal of pollutants and greenhouse gases (GHG) such as SO₂, NOx, and CO₂. The power industry is the largest contributor to these emissions. Due to minimal emission of GHG by renewable and nuclear power plants, they are most suitable replacements for the fossil-fueled power plants. However, the nuclear power plants are more suitable than renewable power plants in providing baseload electricity. The Bushehr Nuclear Power Plant, the only nuclear power plant of Iran, is expected to start operation in 2010. This paper attempts to interpret the role of Bushehr nuclear power plant (BNPP) in CO₂ emission trend of power plant sector in Iran. In order to calculate CO₂ emissions from power plants, National CO₂ coefficients have been used. The National CO₂ emission coefficients are according to different fuels (natural gas, fuels gas, fuel oil). By operating Bushehr Nuclear Power Plant in 2010, nominal capacity of electricity generation in Iran will increase by about 1,000 MW, which increases the electricity generation by almost 7,000 MWh/year (it is calculated according to availability factor and nominal capacity of BNPP). Bushehr Nuclear Power Plant will decrease the CO₂ emission in Iran power sector, by about 3% in 2010.

Fukushima Nuclear Accident, the Third International Severe Nuclear Power Plant Accident

International Nuclear Information System (INIS)

Rashad, S.M.

2013-01-01

Japan is the world's third largest power user. Japan's last remaining nuclear reactor shutdown on Saturday 4 Th of May 2012 leaving the country entirely nuclear free. All of 50 of the nation's operable reactors (not counting for the four crippled reactors at Fukushima) are now offline. Before last year's Fukushima nuclear disaster, the country obtained 30% of its energy from nuclear plants, and had planned to produce up to 50% of its power from nuclear sources by 2030. Japan declared states of emergency for five nuclear reactors at two power plants after the units lost cooling ability in the aftermath of Friday 11 March 2011 powerful earthquake. Thousands of (14000) residents were immediately evacuated as workers struggled to get the reactors under control to prevent meltdowns. On March 11 Th, 2011, Japan experienced a sever earthquake resulting in the shutdown of multiple reactors. At Fukushima Daiichi site, the earthquake caused the loss of normal Ac power. In addition it appeals that the ensuing tsunami caused the loss of emergency Ac power at the site. Subsequent events caused damage to fuel and radiological releases offsite. The spent fuel problem is a wild card in the potentially catastrophic failure of Fukushima power plant. Since the Friday's 9.0 earthquake, the plant has been wracked by repeated explosions in three different reactors. Nuclear experts emphasized there are significant differences between the unfolding nuclear crisis at Fukushima and the events leading up to the Chernobyl disaster in 1986. The Chernobyl reactor exploded during a power surge while it was in operation and released a major cloud of radiation because the reactor had no containment structure around to. At Fukushima, each reactor has shutdown and is inside a 20 cm-thick steel pressure vessel that is designed to contain a meltdown. The pressure vessels themselves are surrounded by steel-lined, reinforced concrete shells. Chernobyl disaster was classified 7 on the International

Role of the chemistry in the occupational dose control in nuclear power plants

International Nuclear Information System (INIS)

Blesa, M.A.

1988-01-01

The safety and radioprotection problem in nuclear power plants does not only concern the plants in operation, but it also includes the design, building and decommissioning stages. The factors that determine the radiation field development and the possibility of diminishing them when they reach critical values are presented. Here are considered pressure vessel-heavy water reactors and particularly the radionucleides coming from the products of structural material corrosion. These products are removed by decontaminating compounds and primary circuit systems in general. In accordance with ALARA criterium, the factors that make the decontamination process advisable are analyzed. Firstly, the number of collective doses is discused. In case of heavily contaminated components there is another limitation to the ALARA criterion: the limits of individual dose in a fixed period of time (year, trimester, etc). Among the various decontamination processes-physical or chemical - the stages to follow just in chemical procedures are stated. As Atucha I and II Power Plants are uniques it is necessary to be ready to solve problems. The research and development programs of National Atomic Energy Commission have produced very valuable results such as the 'in situ' activation model and the HERO (high efficient electrochemical removal of oxides) decontamination procedure. (M.E.L.) [es

Control of power plants and power systems. Proceedings

International Nuclear Information System (INIS)

Canales-Ruiz, R.

1996-01-01

The 88 papers in this volume constitute the proceedings of the International Federation of Automatic Control Symposium held in Mexico in 1995. The broad areas which they cover are: self tuning control; power plant operations; dynamic stability; fuzzy logic applications; power plants modelling; artificial intelligence applications; power plants simulation; voltage control; control of hydro electric units; state estimation; fault diagnosis and monitoring systems; system expansion and operation planning; security assessment; economic dispatch and optimal load flow; adaptive control; distribution; transient stability and preventive control; modelling and control of nuclear plant; knowledge data bases for automatic learning methods applied to power system dynamic security assessment; control of combined cycle units; power control centres. Separate abstracts have been prepared for the three papers relating to nuclear power plants. (UK)

Reactor power control device in BWR power plant

International Nuclear Information System (INIS)

Kurosawa, Tsuneo.

1997-01-01

The present invention provides a device for controlling reactor power based on a start-up/shut down program in a BWR type reactor, as well as for detecting deviation, if occurs, of the power from the start-up/shut down program, to control a recycling flow rate control system or control rod drive mechanisms. Namely, a power instruction section successively executes the start-up/shut down program and controls the coolant recycling system and the control rod driving mechanisms to control the power. A current state monitoring and calculation section receives a process amount, calculates parameters showing the plant state, compares/monitors them with predetermined values, detecting the deviation, if occurs, of the plant state from the start-up/shut down program, and prevents output of a power increase control signal which leads to power increase. A forecasting and monitoring/calculation section forecasts and calculates the plant state when not yet executed steps of the start-up/shut down program are performed, stops the execution of the start-up/shut down program in the next step in a case of forecasting that the results of the calculation will deviate from the start-up/shut down program. (I.S.)

Alternative off-site power supply improves nuclear power plant safety

International Nuclear Information System (INIS)

Gjorgiev, Blaže; Volkanovski, Andrija; Kančev, Duško; Čepin, Marko

2014-01-01

Highlights: • Additional power supply for mitigation of the station blackout event in NPP is used. • A hydro power plant is considered as an off-site alternative power supply. • An upgrade of the probabilistic safety assessment from its traditional use is made. • The obtained results show improvement of nuclear power plant safety. - Abstract: A reliable power system is important for safe operation of the nuclear power plants. The station blackout event is of great importance for nuclear power plant safety. This event is caused by the loss of all alternating current power supply to the safety and non-safety buses of the nuclear power plant. In this study an independent electrical connection between a pumped-storage hydro power plant and a nuclear power plant is assumed as a standpoint for safety and reliability analysis. The pumped-storage hydro power plant is considered as an alternative power supply. The connection with conventional accumulation type of hydro power plant is analysed in addition. The objective of this paper is to investigate the improvement of nuclear power plant safety resulting from the consideration of the alternative power supplies. The safety of the nuclear power plant is analysed through the core damage frequency, a risk measure assess by the probabilistic safety assessment. The presented method upgrades the probabilistic safety assessment from its common traditional use in sense that it considers non-plant sited systems. The obtained results show significant decrease of the core damage frequency, indicating improvement of nuclear safety if hydro power plant is introduced as an alternative off-site power source

Elecnuc. Nuclear power plants in the world. 1997

International Nuclear Information System (INIS)

Maubacq, F.; Tailland, C.

1997-04-01

This small booklet provides information about all type of nuclear power plants worldwide. It is based on the data taken from the CEA/DSE/SEE Elecnuc database. The content comprises: the 1996 highlights, the main characteristics of the different type of reactors in operation or under construction, the map of the French nuclear power plant sites, the worldwide status of nuclear power plants at the end of 1996, the nuclear power plants in operation, under construction or on order (by groups of reactor-types), the power capacity evolution of power plants in operation, the net and gross capacity of the power plants on the grid, the commercial operation and grid connection forecasts, the first achieved or expected power generation supplied by a nuclear reactor for each country and the power generation from nuclear reactors, the performance indicator of the PWR units in France, the trends of the power generation indicator worldwide, the nuclear power plants in operation, under construction, on order, planned, cancelled, decommissioned and exported worldwide, the schedule of steam generator replacements, and the MOX fuel plutonium recycling programme. (J.S.)

Off-shore nuclear power plant

International Nuclear Information System (INIS)

Nakanishi, T.

1980-01-01

In order to avoid losses of energy and seawater pollution an off-shore nuclear power plant is coupled with a power plant which utilizes the temperature difference between seawater and hot reactor cooling water. According to the invention the power plant has a working media loop which is separated from the nuclear power plant. The apparative equipment and the operational characteristics of the power plant are the subject of the patent. (UWI) [de

Risks in the operation of hydroelectric power plants and nuclear power in Brazil

International Nuclear Information System (INIS)

Goldemberg, J.

1986-01-01

A comparison between the utilization of electrical energy generated by hydroelectric power plant and nuclear power plant is made. The risks from nuclear installations and the environmental effects of hydroelectric power plants and nuclear power plants are presented. (E.G.) [pt

A compact, inherently safe liquid metal reactor plant concept for terrestrial defense power applications

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Lutz, D.E.; Palmer, R.S.

1987-01-01

A compact, inherently safe, liquid metal reactor concept based on the GE PRISM innovative LMR design has been developed for terrestrial defense power applications in the 2-50 MWe range. The concept uses a small, sodium-cooled, U-5%Zr metal fueled reactor contained within two redundant steel vessels. The core is designed to operate at a low power density and temperature (925 F) and can operate 30 years without refueling. One two primary coolant loops, depending upon the plant size, transport heat from the core to sodium-to-air, double-wall heat exchangers. Power is produced by a gas turbine operated in a closed ''bottoming'' cycle that employs intercoolers between the compressor stages and a recuperator. Inherent safety is provided by passive means only; operator action is not required to ensure plant safety even for events normally considered Beyond Design Basis Accidents. In addition to normal shutdown heat removal via the sodium-to-air heat exchangers, the design utilizes an inherently passive radiant vessel auxiliary cooling system similar to that designed for PRISM. The use of an air cycle gas turbine eliminates the cost and complexity of the sodium-water reactor pressure relief system required for a steam cycle sodium-cooled reactor

Nuclear power and heating plants in the electric power system. Part I

International Nuclear Information System (INIS)

Kalincik, L.

1975-01-01

Procedures used and results obtained in the following works are described: Incorporation of the nuclear power plants in the power system in the long term perspective; physical limitations on the WWER 440 reactor power changes during fuel campaigns; evaluation of the consumption and start-up characteristics of WWER type nuclear power plants (2x440 MWe); evaluation of refuelling campaigns distribution of nuclear power plant units with regard to comprehensive control properties of nuclear power plants; the possibilities are investigated of the utilization of the WWER type reactor for heat supply in Czechoslovakia. (author)

Radiation embrittlement of Spanish nuclear reactor pressure vessel steels

International Nuclear Information System (INIS)

Bros, J.; Ballesteros, A.; Lopez, A.

1993-01-01

Commercial pressurized water reactor (PWR) and boiling water reactor (BWR) nuclear power plants contain a series of pressure vessel steel surveillance capsules as the principal means of monitoring radiation effects on the pressure vessel. Changes in fracture toughness are more severe in surveillance capsules than in reactor vessel materials because of their proximity of the reactor core. Therefore, it is possible to predict changes in fracture toughness of the reactor vessel materials. This paper describes the status of the reactor vessel surveillance program relating to Spanish nuclear power plants. To date, twelve capsules have been removed and analyzed from seven of the nine Spanish reactors in operation. The results obtained from the analysis of these capsules are compared with the predictions of the Nuclear Regulatory Commission (NRC) Regulatory Guide 1.99, Rev. 2, by means of measured and expected increase of the nil-ductility transition reference temperature (RT NDT ). The comparison is made considering the different variables normally included in the studies of radiation response of reactor pressure vessel materials, such as copper content of steel, level of neutron fluence above 1 MeV, base metal or weld metal, and so forth. The surveillance data have been used for determining the adjusted reference temperatures and upper shelf energies at any time. The results have shown that the seven pressure vessels are in excellent condition to continue operating with safety against brittle fracture beyond the design life, without the need to recuperate the degraded properties of the materials by annealing of the vessel

Operating experience in nuclear power plants

International Nuclear Information System (INIS)

Anon.

1984-01-01

The nuclear power plants in the Federal Republic of Germany kept their portion of power supply into the public grid system constant in 1983, compared to 1982. The generation had an absolute increase of 3.6% and amounts now to 65.9 TWh. Particularly mentioned should be the generation of the Grafenrheinfeld Nuclear Power Plant which is holding the 'World Record' with 9.969 TWh. The availability of the plants was generally satisfactory, as far as long-term retrofit measures with long outage periods were not necessary, as it was the case in Brunsbuettel and Wuergassen. The planned retrofit phases have been completed in all power plants. As far as safety is concerned, there was no reason to recommended a change of the present fundamental planning- and operation aspects. (orig.) [de

NUCLEAR POWER PLANT

Science.gov (United States)

Carter, J.C.; Armstrong, R.H.; Janicke, M.J.

1963-05-14

A nuclear power plant for use in an airless environment or other environment in which cooling is difficult is described. The power plant includes a boiling mercury reactor, a mercury--vapor turbine in direct cycle therewith, and a radiator for condensing mercury vapor. (AEC)

Nuclear power plants in the world - 2010 edition

International Nuclear Information System (INIS)

2010-01-01

This small booklet summarizes in tables all data relative to the nuclear power plants worldwide. These data come from the IAEA's PRIS and AREVA-CEA's GAIA databases. The following aspects are reviewed: 2009 highlights, Main characteristics of reactor types, Map of the French nuclear power plants on 2010/01/01, Worldwide status of nuclear power plants (12/31/2009), Units distributed by countries, Nuclear power plants connected to the Grid- by reactor type groups, Nuclear power plants under construction on 2009, Evolution of nuclear power plants capacities connected to the grid, First electric generations supplied by a nuclear unit in each country, Electrical generation from nuclear power plants by country at the end 2009, Performance indicator of french PWR units, Evolution of the generation indicators worldwide by type, Nuclear operator ranking according to their installed capacity, Units connected to the grid by countries at 12/31/2009, Status of licence renewal applications in USA, Nuclear power plants under construction at 12/31/2009, Shutdown reactors, Exported nuclear capacity in net MWe, Exported and national nuclear capacity connected to the grid, Exported nuclear power plants under construction, Exported and national nuclear capacity under construction, Nuclear power plants ordered at 12/31/2009, Long term shutdown units at 12/31/2009, COL applications in the USA, Recycling of Plutonium in reactors and experiences, Mox licence plants projects, Appendix - historical development, Meaning of the used acronyms, Glossary

Operating experience from Swedish nuclear power plants 2003

International Nuclear Information System (INIS)

2004-01-01

In safety terms, operations of the Swedish nuclear power plants in 2003 can be summarized as having ben good, with a few exceptions: The thermal mixer problem at Barsebaeck-2; The Highest Permissible Limit Value excursion at OKG-3, which subjected the reactor pressure vessel to a too rapid temperature change; and An INES class 1 incident at Ringhals-1. The Barsebaeck and Ringhals events were not of such seriousness as to represent a threat to reactor safety, but they both had the effect of causing the Nuclear Power Inspectorate to question safety cultures at the plants. The mixer event resulted in a considerable production loss, with the reactor being shut down twice, making a total of five months. OKG-3 was shut down for almost two months during the autumn. Despite the above, production from Swedish NPPs was much the same as during 2002. Total electricity production amounted to 65 TWh (65.2 TWh in 2002). On the average the energy availability of the eleven reactors was 79%. The PWRs at Ringhals had an average energy availability of 89%, while the BWRs reached 76%

Nuclear power plants

International Nuclear Information System (INIS)

Kiyokawa, Teruyuki; Soman, Yoshindo.

1985-01-01

Purpose: To constitute a heat exchanger as one unit by integrating primary and secondary coolant circuits with secondary coolant circuit and steam circuit into a single primary circuit and steam circuit. Constitution: A nuclear power plant comprises a nuclear reactor vessel, primary coolant pipeways and a leakage detection system, in which a dual-pipe type heat exchanger is connected to the primary circuit pipeway. The heat conduction tube of the heat exchanger has a dual pipe structure, in which the inside of the inner tube is connected to the primary circuit pipeway, the outside of the outer tube is connected to steam circuit pipeway and a fluid channel is disposed between the inner and outer tubes and the fluid channel is connected to the inside of an expansion tank for intermediate heat medium. The leak detection system is disposed to the intermediate heat medium expansion tank. Sodium as the intermediate heat medium is introduced from the intermediate portion (between the inner and outer tubes) by way of inermediate heat medium pipeways to the intermediate heat medium expansion tank and, further, to the intermediate portion for recycling. (Kawakami, Y.)

QA programs in nuclear power plants

International Nuclear Information System (INIS)

Ellingson, A.C.

1976-01-01

As an overview of quality assurance programs in nuclear power plants, the energy picture as it appears today is reviewed. Nuclear power plants and their operations are described and an attempt is made to place in proper perspective the alleged ''threats'' inherent in nuclear power. Finally, the quality assurance programs being used in the nuclear industry are described

Power plants 2010. Lectures

International Nuclear Information System (INIS)

2010-01-01

The proceedings include the following lectures: Facing the challenges - new structures for electricity production. Renewable energies in Europe - chances and challenges. Nuclear outlook in the UK. Sustainable energy for Europe. Requirements of the market and the grid operator at the electricity production companies. Perspectives for the future energy production. Pumped storage plants - status and perspectives. Nuclear power/renewable energies -partners or opponents? New fossil fired power stations in Europe - status and perspectives. Nuclear energy: outlook for new build and lifetime extension in Europe. Biomass in the future European energy market - experiences for dong energy. Meeting the EU 20:20 renewable energy targets: the offshore challenges. DESERTEC: sustainable electricity for Europe, Middle East and North Africa. New power plants in Europe - a challenge for project and quality management. Consideration of safely in new build activities of power plants. Challenges to an integrated development in Maasvlakte, Netherlands. Power enhancement in EnBW power plants. Operational experiences of CCS pilot plants worldwide. Two years of operational experiences with Vattenfall's oxyfuel pilot plant. Pre-conditions for CCS. Storage technologies for a volatile generation. Overview: new generation of gas turbines.

China’s Nuclear Power Plants in Operation

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

Qinshan Plant Phase I Located in Haiyan,Zhejiang Province,Qinshan Nuclear Power Plant Phase I is t he first 300-megawatt pressurized water reactor (PWR) nuclear power plant independently designed,constructed,operated and managed by China.The plant came into commercial operation in April 1994.

A study of a small nuclear power plant system for district heating

International Nuclear Information System (INIS)

Imamura, Mitsuru; Sato, Kotaro; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi

2008-01-01

We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology. 'MUTSU' had already proved its safety. And 'MUTSU' reactor was boron free reactor. It allows plant system to become more compact and simple. And load following capability by core reactivity become bigger. It means to reduce control rod movement. It leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result the core life became about 10 years. In the district heating system, there are not only district heating but also snow melting with warm water. It uses steam condenser's heat, which are only discharged now. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

The main methods of solving the problem of radioactive waste management from nuclear power stations and spent fuel reprocessing plants in the USSR

International Nuclear Information System (INIS)

1978-09-01

The main directions of solving the problem of radioactive waste management from nuclear power stations and radiochemical plants, the aspects of gaseous waste management, liquid HLW storage in vessels and the problems of heat removal during storage of vitrified HLW in surface storages are considered. The main problems arising during fine decontamination of gaseous discharges from nuclear power stations and reprocessing plants are discussed. The migration of fission products in the environment and technical aspects of their capture from gaseous discharges are also considered

Ageing management of nuclear power plant - the Tarapur experience

International Nuclear Information System (INIS)

Anilkumar, K.R.; Das, P.K.; Bhattacharjee, S.; Ramamurty, U.

2006-01-01

Tarapur Atomic Power Station, the longest serving Nuclear Power Plant in the Asian continent has completed 36 years of successful operation and generated more than 70,000 million units of electric power. Built in late sixties, with the state-of-the-art safety features prevailing then, TAPS through the process of evolution has become safer plant due to efforts of upgradation, renovation and refurbishment prompted by the station's operating experience, feed back from overseas reactors, lessons learnt from nuclear incidents, accidents and fresh review of design basis and safety analysis of the plant. All components of a Nuclear power plant experience some degradation with time. The Reactor Pressure Vessels (RPV) designed for 40 effective full power years (EFPY) of operation have operated for less than 20 EFPY and the material condition is assessed to be fit for some more years of service. The condition of the containment and main plant buildings was assessed to be satisfactory. The Ageing Management Programme (AMP) involved identification of key systems, structures and components (SSCs) that may experience degradation due to ageing, and take corrective measures through maintenance, repair and/or replacement. The identified components were classified as major critical components, important systems and other critical components. For each component mode of degradation was identified, ageing assessment was done and action plan was finalized. Replacement of some important equipment like 3 x 50 % capacity Emergency Diesel Generators (EDG) with 3 x 100 % capacity EDG, Salt Service Water (SSW) pumps, Control rod drive (CRD) pumps, Emergency Condenser tube bundles, Station battery has been done on the basis of condition monitoring and to obviate common cause failure and enhance the system reliability. Samples of Safety related cables were subjected to residual life assessment (RLA) and replacement action firmed up on the basis of the RLA findings. Condition survey of Main

Temporal neural network for the identification of nuclear power plant transients

International Nuclear Information System (INIS)

Uluyol, O.; Ragheb, M.

1993-01-01

In this paper a layered spatiotemporal neural network is proposed for the identification of nuclear power plant transients. The developed layered spatiotemporal network is inspired by the formal avalanche structure developed by S. Grossberg and offers advantages compared with the stationary pattern approach using the perceptron paradigm. Each layer in the network is trained to recognize a separate time-dependent accident scenario. Within each scenario, the temporal behavior of the relevant parameters such as pressurizer pressure, pressurizer water volume, cold and hot legs temperatures, vessel flow, and power, are considered. Numerical cases are considered where the proposed methodology is applied to two nuclear power plant anticipated transient scenarios: the Station Blackout and the Anticipated Transient without Scram transients in a pressurized water reactor . The transient signatures used were generated by modeling the accidents using RELAP5/MOD2, a best-estimate thermal-hydraulics numerical code. The ability of the proposed layered spatiotemporal network to operate at different noise levels is investigated. Its incorporation within an Insightful Algorithm and Anticipatory Systems context for identifying and in predicting the course of nuclear transients is discussed

The year 2000 power plant

International Nuclear Information System (INIS)

Roman, H.T.

1989-01-01

Every utility seeks extended service life from its existing power plants before building new ones. It is not easy to justify a new power plant. The licensing and cost of new plants have become uncertain. In response to these conditions, electric utilities are undertaking plant life-extension studies and, in some cases, reconditioning/upgrading old power plants to significantly increase useful service life. Other technologies like robotics and artificial intelligence/expert systems are also being developed to reduce operating and maintenance (O and M) expenses, to remove workers from potentially hazardous environments, and to reduce plant downtime. Together, these steps represent an interim solution, perhaps providing some relief for the next few decades. However, there are serious physical and economic limits to retrofitting new technology into existing power plants. Some old plants will simply be beyond their useful life and require retirement. In nuclear plants, for instance, retrofit may raise important and time-consuming licensing/safety issues. Based on their robotics and artificial intelligence experience, the authors of this article speculate bout the design of the year 2000 power plant - a power plant they feel will naturally incorporate liberal amounts of robotic and artificial intelligence technologies

Parametric cost analysis of a HYLIFE-II power plant

International Nuclear Information System (INIS)

Bieri, R.L.

1991-01-01

The SAFIRE (Systems Analysis for ICF Reactor Economics) code was adapted to model a power plant using a HYLIFE-2 reactor chamber. The code was then used to examine the dependence of the plant capital costs and the busbar cost of electricity (COE) on a variety of design parameters (type of driver, chamber repetition rate, and net electric power). The results show the most attractive operating space for each set of driver/target assumptions and quantify the benefits of improvements in key design parameters. The base-case plant was a 1000-MW(e) plant containing a reactor vessel driven by an induction linac heavy-ion accelerator, run at 8 Hz with a driver energy of 6.73 MJ and a target yield of 350 MJ. The total direct cost for this plant was $2.6 billion. (All costs in this paper are given in equivalent 1988 dollars.) The COE was 8.5 cents/(kWh). The COE and total capital costs for a 1000-MW(e) base plant are nearly independent of the chosen combination of repetition rate and driver energy for a driver operating between 4 and 10 Hz. For comparison, the COE for a coal or future fission plant would be 4.5--5.5 cents/(kWh). The COE for a 1000-MW(e) plant could be reduced to 7.5 cents/(kWh) by using advanced targets and could be cut to 6.5 cents/(kWh) with conventional targets, if the driver cost could be cut in half. There is a large economy of scale with heavy-ion-driven inertial confinement fusion (ICF) plants. A 2000-MW(e) plant with a heavy-ion driver and a HYLIFE-2 chamber would have a COE of only 5.8 cents/(kWh)

Technical report on dc power supplies in nuclear power plants

International Nuclear Information System (INIS)

1977-06-01

Emergency electrical power supplies, both a.c. and d.c. for nuclear power plants are important to safety. For this reason, the electric power systems for operating nuclear plants and those plants under licensing review have been required to provide a high degree of reliability. It is this high reliability that provides confidence that sufficient safety margin exists against loss of all d.c. power for extended periods of time to allow an orderly examination of safety issues, such as this. However, because of the importance of the a.c. and d.c. power systems, the staff has been expending effort to review the reliability of these systems and shall continue to do so in the future

Estimation of environmental external costs between coal fired power plant and nuclear power plant

International Nuclear Information System (INIS)

Moon, G. H.; Kim, S. S.

2000-01-01

First of all, this study evaluated the impacts on the health and the environment of air pollutants emitted from coal power plant and nuclear power pant, two major electric power generating options in Korea. Then, the environmental external costs of those two options were estimated by transforming the health and environment impact into monetary values. To do this, AIRPACTS and Impacts of Atmospheric Release model developed by IAEA were used. The environmental external cost of Samcheonpo coal power plant was estimated about 25 times as much as that of Younggwang nuclear power plant. This result implies that nuclear power plant is a clean technology compared with coal power plant. This study suggests that the external cost should be reflected in the electric system expansion plan in order to allocate energy resources efficiently and to reduce economic impact stemming from the environmental regulation emerged recently on a global level

Safstor decommissioning of the Humboldt Bay Power Plant Unit No. 3

International Nuclear Information System (INIS)

Nelson, R.T.

1985-01-01

The Humboldt Bay Power Plant is located near Eureka, California, about 265 miles north of San Francisco. The plant consists of two fossil fueled units, two mobil gas turbine peaking units, and a nuclear unit - Unit No. 3. Unit No. 3, which utilized a boiling water reactor, was constructed between 1960 and 1963. The unit began commercial operation in August 1963 and operated until July 2, 1976 when it was shutdown for refueling, seismic modifications, and additional seismic and geologic studies. During the years Unit 3 operated it had one of the best operating records of any nuclear power plant in the United States. For its operating lifetime Unit 3 had an overall capacity factor of 63.0% and an availability factor of 85.9%. The unit included certain design features which made it unique among nuclear power plants of its era. Some of these unique features included natural circulation recirculation flow which eliminated the need for costly recirculation pumps, utilization of a pressure suppression containment system which had been developed jointly by PG and E and the General Electric Company, and the fact that the reactor vessel and the containment system were constructed in a caisson below ground level. These design features reduced the overall construction cost of the unit and improved its inherent safety

Technology and costs for decommissioning the Swedish nuclear power plants

International Nuclear Information System (INIS)

1986-05-01

The study shows that, from the viewpoint of radiological safety, a nuclear power plant can be dismantled immediately after it has been shut down and the fuel has been removed, which is estimated to take about one year. Most of the equipment that will be used in decommissioning is already available and is used routinely in maintenance and rebuilding work at the nuclear power plants. Special equipment need only be developed for dismantlement of the reactor vessel and for demolishing of heavy concrete structures. The dismantling of a nuclear power plant can be accomplished in about five years, with an average labour force of about 200 men. The maximum labour force required for Ringhals 1 has been estimated at about 500 men during the first years, when active systems are being dismantled in a number of fronts in the plant. During the last years when the buildings are being demolished, approximately 50 men are required. In order to limit the labour requirement and the dose burden to the personnel, the material is taken out in as large pieces as possible. The cost of decommissioning a boiling water reactor (BWR) of the size of Ringhals 1 has been estimated to be about MSEK 540 in January 1986 prices, and for a pressurized water reactor (PWR, Ringhals 2) about MSEK 460. The cost for the other Swedish nuclear power plants lie in the range of MSEK 410-760. These are the direct cost for the decommissioning work, to which must be added the costs of transportation and disposal of the decommissioning waste, about 100 000 m/sup3/. These costs have been estimated to be about MSEK 600 for the 12 Swedish reactors. (author)

Standard Practice for Design of Surveillance Programs for Light-Water Moderated Nuclear Power Reactor Vessels

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice covers procedures for designing a surveillance program for monitoring the radiation-induced changes in the mechanical properties of ferritic materials in light-water moderated nuclear power reactor vessels. This practice includes the minimum requirements for the design of a surveillance program, selection of vessel material to be included, and the initial schedule for evaluation of materials. 1.2 This practice was developed for all light-water moderated nuclear power reactor vessels for which the predicted maximum fast neutron fluence (E > 1 MeV) at the end of license (EOL) exceeds 1 × 1021 neutrons/m2 (1 × 1017 n/cm2) at the inside surface of the reactor vessel. 1.3 This practice applies only to the planning and design of surveillance programs for reactor vessels designed and built after the effective date of this practice. Previous versions of Practice E185 apply to earlier reactor vessels. 1.4 This practice does not provide specific procedures for monitoring the radiation induced cha...

Wind power plant system services

DEFF Research Database (Denmark)

Basit, Abdul; Altin, Müfit

Traditionally, conventional power plants have the task to support the power system, by supplying power balancing services. These services are required by the power system operators in order to secure a safe and reliable operation of the power system. However, as in the future the wind power...... is going more and more to replace conventional power plants, the sources of conventional reserve available to the system will be reduced and fewer conventional plants will be available on-line to share the regulation burden. The reliable operation of highly wind power integrated power system might...... then beat risk unless the wind power plants (WPPs) are able to support and participate in power balancing services. The objective of this PhD project is to develop and analyse control strategies which can increase the WPPs capability to provide system services, such as active power balancing control...

Safety analysis of Oi nuclear power plant

International Nuclear Information System (INIS)

1979-01-01

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

A powerful methodology for reactor vessel pressurized thermal shock analysis

International Nuclear Information System (INIS)

Boucau, J.; Mager, T.

1994-01-01

The recent operating experience of the Pressurized Water Reactor (PWR) Industry has focused increasing attention on the issue of reactor vessel pressurized thermal shock (PTS). More specifically, the review of the old WWER-type of reactors (WWER 440/230) has indicated a sensitive behaviour to neutron embrittlement. This led already to some remedial actions including safety injection water preheating or vessel annealing. Such measures are usually taken based on the analysis of a selected number of conservative PTS events. Consideration of all postulated cooldown events would draw attention to the impact of operator action and control system effects on reactor vessel PTS. Westinghouse has developed a methodology which couples event sequence analysis with probabilistic fracture mechanics analyses, to identify those events that are of primary concern for reactor vessel integrity. Operating experience is utilized to aid in defining the appropriate event sequences and event frequencies of occurrence for the evaluation. Once the event sequences of concern are identified, detailed deterministic thermal-hydraulic and structural evaluations can be performed to determine the conditions required to minimize the extension of postulated flaws or enhance flaw arrest in the reactor vessel. The results of these analyses can then be used to better define further modifications in vessel and plant system design and to operating procedures. The purpose of the present paper will be to describe this methodology and to show its benefits for decision making. (author). 1 ref., 3 figs

Human factors in nuclear power plants

International Nuclear Information System (INIS)

Swain, A.D.

1981-01-01

This report describes some of the human factors problems in nuclear power plants and the technology that can be employed to reduce those problems. Many of the changes to improve the human factors in existing plants are inexpensive, and the expected gain in human reliability is substantial. The human factors technology is well-established and there are practitioners in most countries that have nuclear power plants. (orig.) [de

Power plant conceptual studies in Europe

International Nuclear Information System (INIS)

Maisonnier, D.; Campbell, D.; Cook, I.; Pace, L. Di; Giancarli, L.; Hayward, J.; Puma, A. Li; Medrano, M.; Norajitra, P.; Roccella, M.; Sardain, P.; Tran, M.Q.; Ward, D.

2007-01-01

The European fusion programme is 'reactor oriented' and it is aimed at the successive demonstration of the scientific, the technological and the economic feasibility of fusion power. The European Power Plant Conceptual Study (PPCS) has been a study of conceptual designs of five commercial fusion power plants and the main emphasis was on system integration. It focused on five power plant models which are illustrative of a wider spectrum of possibilities. They are all based on the tokamak concept and they have approximately the same net electrical power output, 1500 MWe. These span a range from relatively near-term, based on limited technology and plasma physics extrapolations, to an advanced conception. The PPCS allows one to clarify the concept of DEMO, the device that will bridge the gap between ITER and the first-of-a-kind fusion power plant. An assessment of the PPCS models with limited extrapolations highlighted a number of issues that must be addressed to establish the DEMO physics and technological basis

Organization patterns of PWR power plants

International Nuclear Information System (INIS)

Leicman, J.

1980-01-01

Organization patterns are shown for the St. Lucia 1, North Anna, Sequoyah, and Beaver Valley nuclear power plants, for a typical PWR power plant in the USA, for the Biblis/RWE-KWU nuclear power plants and for a four-unit nuclear power plant operated by Electricite de France as well as for the Loviisa power plant. Organization patterns are also shown for relatively independent and non-independent nuclear power plants according to IAEA recommendations. (J.P.)

Design of Hemispherical Downward-Facing Vessel for Critical Heat Flux Experiment

International Nuclear Information System (INIS)

Hwang, J. S.; Suh, K. Y.

2009-01-01

The in-vessel retention (IVR) is one of major severe accident management strategies adopted by some operating nuclear power plants during a severe accident. The recent Shin-Gori Units 3 and 4 of the Advanced Power Reactor 1400 MWe (APR1400) have adopted the external reactor vessel cooling (ERVC) by reactor cavity flooding as major severe accident management strategy. The ERVC in the APR1400 design resorts to active flooding system using thermal insulator. The Corium Attack Stopper Apparatus Spherical Channel (CASA SC) tests are conducted to measure the critical power and critical heat flux (CHF) on a downward hemispherical vessel scaled down from the APR1400 lower head by 1/10 on a linear scale. CASA is designed through scaling and thermal analysis to simulate the APR1400 vessel and thermal insulator. The heated vessel of CASA SC represents the external surface of a hemisphere submerged vessel in water. The heated vessel plays an important role in the ERVC experiment depending on the configuration of oxide pool and metallic layer. Hand calculation and computational analysis are performed to produce high heat flux from the downward facing hemisphere in excess of 1 MW/m 2

Images of nuclear power plants

International Nuclear Information System (INIS)

Hashiguchi, Katsuhisa; Misumi, Jyuji; Yamada, Akira; Sakurai, Yukihiro; Seki, Fumiyasu; Shinohara, Hirofumi; Misumi, Emiko; Kinjou, Akira; Kubo, Tomonori.

1995-01-01

This study was conducted to check and see, using Hayashi's quantification method III, whether or not the respondents differed in their images of a nuclear power plant, depending on their demographic variables particularly occupations. In our simple tabulation, we compared subject groups of nuclear power plant employees with general citizens, nurses and students in terms of their images of a nuclear power plant. The results were that while the nuclear power plant employees were high in their evaluations of facts about a nuclear power plant and in their positive images of a nuclear power plant, general citizens, nurses and students were overwhelmingly high in their negative images of a nuclear power plant. In our analysis on category score by means of the quantification method III, the first correlation axis was the dimension of 'safety'-'danger' and the second correlation axis was the dimension of 'subjectivity'-'objectivity', and that the first quadrant was the area of 'safety-subjectivity', the second quadrant was the area of 'danger-subjectivity', the third quadrant as the area of 'danger-objectivity', and the forth quadrant was the area of 'safety-objectivity'. In our analysis of sample score, 16 occupation groups was compared. As a result, it was found that the 16 occupation groups' images of a nuclear power plant were, in the order of favorableness, (1) section chiefs in charge, maintenance subsection chiefs, maintenance foremen, (2) field leaders from subcontractors, (3) maintenance section members, operation section members, (4) employees of those subcontractors, (5) general citizens, nurses and students. On the 'safety-danger' dimension, nuclear power plant workers on the one hand and general citizens, nurses and students on the other were clearly divided in terms of their images of a nuclear power plant. Nuclear power plant workers were concentrated in the area of 'safety' and general citizens, nurses and students in the area of 'danger'. (J.P.N.)

Tasks of a power engineer in future thermal power plants

International Nuclear Information System (INIS)

Freymeyer, P.; Scherschmidt, F.

1982-01-01

Today already the power plants provide plenty of tasks and problems to the electrical engineer in the fields of power and conductive engineering. A completely new orientation of power engineering leads to larger, more complex system and even to systems unknown so far. In conductive engineering entirely new solutions have come in view. There are a lot of interesting topics for the electrical engineer in the rearrangement and advance into virgin territory of thermal power plants. (orig.) [de

Optimal control systems in hydro power plants

International Nuclear Information System (INIS)

Babunski, Darko L.

2012-01-01

The aim of the research done in this work is focused on obtaining the optimal models of hydro turbine including auxiliary equipment, analysis of governors for hydro power plants and analysis and design of optimal control laws that can be easily applicable in real hydro power plants. The methodology of the research and realization of the set goals consist of the following steps: scope of the models of hydro turbine, and their modification using experimental data; verification of analyzed models and comparison of advantages and disadvantages of analyzed models, with proposal of turbine model for design of control low; analysis of proportional-integral-derivative control with fixed parameters and gain scheduling and nonlinear control; analysis of dynamic characteristics of turbine model including control and comparison of parameters of simulated system with experimental data; design of optimal control of hydro power plant considering proposed cost function and verification of optimal control law with load rejection measured data. The hydro power plant models, including model of power grid are simulated in case of island ing and restoration after breakup and load rejection with consideration of real loading and unloading of hydro power plant. Finally, simulations provide optimal values of control parameters, stability boundaries and results easily applicable to real hydro power plants. (author)

Working in a virtual power plant

International Nuclear Information System (INIS)

Thibault, G.; Smadja, S.

1999-01-01

Graphical simulations on computer providing a virtual and reversible experience can now be used for maintenance in nuclear power plants allowing operations to be tested and tools to be optimised. Eventually, operatives will be trained to work in virtual nuclear power plants in complete safety. (authors)

Reactor Pressure Vessel (RPV) Acquisition Strategy

Energy Technology Data Exchange (ETDEWEB)

Mizia, Ronald Eugene [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2008-04-01

The Department of Energy has selected the High Temperature Gas-cooled Reactor design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, TRISO-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. The purpose of this report is to address the acquisition strategy for the NGNP Reactor Pressure Vessel (RPV). This component will be larger than any nuclear reactor pressure vessel presently in service in the United States. The RPV will be taller, larger in diameter, thicker walled, heavier and most likely fabricated at the Idaho National Laboratory (INL) site of multiple subcomponent pieces. The pressure vessel steel can either be a conventional materials already used in the nuclear industry such as listed within ASME A508/A533 specifications or it will be fabricated from newer pressure vessel materials never before used for a nuclear reactor in the US. Each of these characteristics will present a

Use of Reactor Pressure Vessel Surveillance Materials for Extended Life Evaluations Using Power and Test Reactor Irradiations

International Nuclear Information System (INIS)

Server, W.L.; Nanstad, R.K.; Odette, G.R.

2012-01-01

The most important component in assuring safety of the nuclear power plant is the reactor pressure (RPV). Surveillance programs have been designed to cover the licensed life of operating nuclear RPVs. The original surveillance programs were designed when the licensed life was 40 years. More than one-half of the operating nuclear plants in the USA have an extended license out to 60 years, and there are plans to continue to operate many plants out to 80 years. Therefore, the surveillance programs have had to be adjusted or enhanced to generate key data for 60 years, and now consideration must be given for 80 or more years. To generate the necessary data to assure safe operation out to these extended license lives, test reactor irradiations have been initiated with key RPV and model alloy steels, which include several steels irradiated in the current power reactor surveillance programs out to relatively high fluence levels. These data are crucial in understanding the radiation embrittlement mechanisms and to enable extrapolation of the irradiation effects on mechanical properties for these extended time periods. This paper describes the potential radiation embrittlement mechanisms and effects when assessing much longer operating times and higher neutron fluence levels. Potential methods for adjusting higher neutron flux test reactor data for use in predicting power reactor vessel conditions are discussed. (author)

Current developments in mechanized non-destructive testing in nuclear power plants; Aktuelle Entwicklungen bei mechanisierten, zerstoerungsfreien Pruefungen in Kernkraftwerken

Energy Technology Data Exchange (ETDEWEB)

Zeilinger, R. [intelligeNDT System und Services GmbH und Co. KG, Erlangen (Germany)

2008-01-15

Nuclear power plants require frequent in-service activities to be carried out conscientiously in areas potentially hazardous to human operators (because of the associated radiation exposure), such as non-destructive testing of pressurized components of the steam system. Locations to be inspected in this way include the reactor pressure vessel, core internals, steam generators, pressurizers, and pipes. The codes to be used as a basis of these inspections demand high absolute positioning and repeating accuracy. These requirements can be met by mechanized test procedures. Accordingly, many new applications of, mostly mobile, robots have been developed over the past few years. The innovative control and sensor systems for stationary and mobile robots now on the market offer a potential for economic application in a large number of new areas in inspection, maintenance and service in nuclear power plants. More progress in this area is expected for the near future. Areva NP founded the new NDT Center, NETEC (Non-destructive Examination Technical Center), as a global technical center for non-destructive materials testing. NETEC is to advance research and development of all basic NDT technologies, robotics included. For many years, intelligeNDT has offered solutions and products for a variety of inspection and testing purposes and locations in nuclear power plants and is involved in continuous further development of the experience collected in nuclear power plants on the spot. (orig.)

Severe Accident Mitigation by using Core Catcher applicable for Korea standard nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Park, Hae Kyun; Kim, Sang Nyung [Kyung Hee Univ., Yongin (Korea, Republic of)

2013-10-15

Nuclear power plants have been designed and operated in order to prevent severe accident because of their risk that contains tremendous radioactive materials that are potentially hazardous. Moreover, the government requested the nuclear industry to implement a severe accident management strategy for existing reactors to mitigate the risk of potential severe accidents. However, Korea standard nuclear power plant(APR-1400 and OPR-1000) are much more vulnerable for severe accident management than that of developed countries. Due to the design feature of reactor cavity in Korea standard nuclear power plant, inequable and serious Molten Core-Concrete Interaction(MCCI) may cause considerable safety problem to the reactor containment liner. At worst, it brings the release of radioactive materials to the environment. This accident applies to the fourth level of defense in depth(IAEA 1996), 'severe accident'. This study proposes and designs the 'slope' to secure reactor containment liner integrity when the corium spreads out from the destroyed reactor vessel to the reactor cavity due to the core melting accident. For this, make the initial corium distribution evenly exploit the 'slope' on the basis of the study of Ex-vessel corium behavior to prevent inequable and serious MCCI, in order to mitigate severe accident. The viscosity has a dominant position in the calculation. According to the result, the spread out distance on the slope is 10.7146841m, considering the rough surface of the concrete(slope) and margin of reactor cavity end(under 11m). Easy to design, production and economic feasibility are the advantage of the designed slope in this study. However, the slope design may unsuitable when the sequences of the accidents did not satisfy the assumptions as mentioned. Despite of those disadvantages, the slope will show a great performance to mitigate the severe accident. As mentioned in assumption, the corium releasing time property was

Severe Accident Mitigation by using Core Catcher applicable for Korea standard nuclear power plant

International Nuclear Information System (INIS)

Park, Hae Kyun; Kim, Sang Nyung

2013-01-01

Nuclear power plants have been designed and operated in order to prevent severe accident because of their risk that contains tremendous radioactive materials that are potentially hazardous. Moreover, the government requested the nuclear industry to implement a severe accident management strategy for existing reactors to mitigate the risk of potential severe accidents. However, Korea standard nuclear power plant(APR-1400 and OPR-1000) are much more vulnerable for severe accident management than that of developed countries. Due to the design feature of reactor cavity in Korea standard nuclear power plant, inequable and serious Molten Core-Concrete Interaction(MCCI) may cause considerable safety problem to the reactor containment liner. At worst, it brings the release of radioactive materials to the environment. This accident applies to the fourth level of defense in depth(IAEA 1996), 'severe accident'. This study proposes and designs the 'slope' to secure reactor containment liner integrity when the corium spreads out from the destroyed reactor vessel to the reactor cavity due to the core melting accident. For this, make the initial corium distribution evenly exploit the 'slope' on the basis of the study of Ex-vessel corium behavior to prevent inequable and serious MCCI, in order to mitigate severe accident. The viscosity has a dominant position in the calculation. According to the result, the spread out distance on the slope is 10.7146841m, considering the rough surface of the concrete(slope) and margin of reactor cavity end(under 11m). Easy to design, production and economic feasibility are the advantage of the designed slope in this study. However, the slope design may unsuitable when the sequences of the accidents did not satisfy the assumptions as mentioned. Despite of those disadvantages, the slope will show a great performance to mitigate the severe accident. As mentioned in assumption, the corium releasing time property was conservatively calculated

Nuclear power plant prestressed concrete containment vessel structure monitoring during integrated leakage rate test using three kinds of fiber optic sensors

Science.gov (United States)

Liao, Kaixing; Li, Jinke; Kong, Xianglong; Sun, Changsen; Zhao, Xuefeng

2017-04-01

After years of operation, the safety of the prestressed concrete containment vessel (PCCV) structure of Nuclear Power Plant (NPP) is an important aspect. In order to detect the strength degradation and the structure deformation, several sensors such as vibrating wire strain gauge, invar wires and pendulums were installed in PCCV. However, the amounts of sensors above are limited due to the cost. Due to the well durability of fiber optic sensors, three kinds of fiber optic sensors were chosen to install on the surface of PCCV to monitor the deformation during Integrated Leakage Rate Test (ILRT). The three kinds of fiber optic sensors which had their own advantages and disadvantages are Fiber Bragg Grating (FBG), white light interferometry (WLI) and Brillouin Optical Time Domain Analysis (BOTDA). According to the measuring data, the three fiber optic sensors worked well during the ILRT. After the ILRT, the monitoring strain was recoverable thus the PCCV was still in the elastic stage. If these three kinds of fiber optic sensors are widely used in the PCCV, the unusual deformations are easier to detect. As a consequence, the three fiber optic sensors have good potential in the structure health monitoring of PCCV.

Fire scenarios in nuclear power plant

International Nuclear Information System (INIS)

Asp, I.B.; MacDougall, E.A.; Hall, R.E.

1978-01-01

This report defines a Design Base Fire and looks at 3 major areas of a hypothetical model for a Nuclear Power Plant. In each of these areas a Design Base Fire was developed and explained. In addition, guidance is given for comparing fire conditions of a given Nuclear Power Plant with the model plant described. Since there is such a wide variation in nuclear plant layouts, model areas were chosen for simplicity. The areas were not patterned after any existing plant area; rather several plant layouts were reviewed and a simplified model developed. The developed models considered several types of fires. The fire selected was considered to be the dominant one for the case in point. In general, the dominant fire selected is time dependent and starts at a specific location. After these models were developed, a comparison was drawn between the model and an operating plant for items such as area, cable numbers and weight, tray sizes and lengths. The heat loads of the model plant are summarized by area and compared with those of an actual operating plant. This document is intended to be used as a guide in the evaluation of fire hazards in nuclear power stations and a summarization of one acceptable analytical methodology to accomplish this

Occupational dose control in Nuclear Power Plants

International Nuclear Information System (INIS)

Viktorsson, C.; Lochard, J.; Benedittini, M.; Baum, J.; Khan, T.A.

1990-01-01

Reduction in occupational exposure at nuclear power plants is desirable not only in the interest of the health and safety of plant personnel, but also because it enhances the safety and reliability of the plants. This report summarises the current trends of doses to workers at nuclear power plants and the achievements and developments regarding methods for their reduction

Seismic proving test of PWR reactor containment vessel

International Nuclear Information System (INIS)

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

1987-01-01

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

PWSCC issues and material aging management for nuclear power plants in Korea

Energy Technology Data Exchange (ETDEWEB)

Hwang, Seong Sik; Lim, Yun Soo; Kim, Dong Jin; Kim, Sung Woo; Kim, Hong Pyo [Nuclear Materials Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-10-15

The primary water stress corrosion cracking (PWSCC) of alloy 600 in a PWR has been reported in the control rod drive mechanism (CRDM). Beginning in the mid-seventies, the pressurized water reactor (PWR) plants suffered from a sequence of SCC events mostly confined to S/G tubes, initially ODSCC, and then PWSCC. PWSCC was first reported in Bugey 3 vessel head penetration made of forged alloy 600 materials in September 1991. Other PWRs experienced cracking attributed to the PWSCC of the major primary side weld area made from alloy 182 at the end of the year 2000. Examples of dissimilar metal butt welds between the main austenitic stainless steel primary circuit piping and the outlet pressure vessel nozzles are the cracking of Ringhals 4, V. C. Summer and some J-groove welds of the CRDM of the RVH at Oconee 1. In addition to the Reactor Vessel Head (RVH), the PWSCC of alloy 182/82 has been reported at bottom mounted instrumentation (BMI) nozzle J-welds, steam generator(SG) J-weld drain nozzle, and SG tube sheet cladding. Two cases of boric acid precipitation were reported at the bottom head surface of a SG in Korea. Cracking was found in the cold leg drain nozzles made of alloy 600 in two units, hot side nozzles were fabricated with alloy 690 from the beginning. The cracking of steam generator tubings made of alloy 600 is another concern in Korea, because some plants still have alloy 600 HTMA tubings. The flow accelerated corrosion of secondary pipings is another type of corrosion problems, though it has not been treated as a severe problem in Korea. To properly manage the corrosion issues and seek out research items for maintaining the integrity of nuclear plants, the PRIMA-Net (Proactive Research and Innovative Material Aging Network) was organized in 2007. The research and development expert group consists of a National research laboratory (KAERI), regulatory body (KINS), utility (KHNP), engineering and design company (KEPCO EC), manufacturer (Doosan Heavy

The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

International Nuclear Information System (INIS)

Barney, G.S.; Cooper, T.D.

1994-01-01

Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125 degrees C and 250 degrees C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110 degrees C to 270 degrees C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252 degrees C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant

The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

Energy Technology Data Exchange (ETDEWEB)

Barney, G.S.; Cooper, T.D.

1994-06-01

Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125{degrees}C and 250{degrees}C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110{degrees}C to 270{degrees}C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252{degrees}C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant.

Human factors in atomic power plant

International Nuclear Information System (INIS)

Kawano, Ryutaro

1997-01-01

To ensure safety should have priority over all other things in atomic power plants. In Chernobyl accident, however, various human factors including the systems for bulb check after inspection and communication, troubles in the interface between hardwares such as warning speakers and instruments, and their operators, those in education and training for operators and those in the general management of the plant have been pointed out. Therefore, the principles and the practical measures from the aspect of human factors in atomic power plants were discussed here. The word, ''human factor'' was given a definition in terms of the direct cause and the intellectual system. An explanatory model for human factors, model SHEL constructed by The Tokyo Electric Power Co., Ltd., Inc. was presented; the four letter mean software(S), hardware(H), environment(E) and liveware(L). In the plants of the company, systemic measures for human error factors are taken now in all steps not only for design, operation and repairing but also the step for safety culture. Further, the level required for the safety against atomic power is higher in the company than those in other fields. Thus, the central principle in atomic power plants is changing from the previous views that technology is paid greater importance to a view regarding human as most importance. (M.N.)

Small hydroelectric power plants

International Nuclear Information System (INIS)

Helgesen, Boerre

2002-01-01

Small hydroelectric power plants are power plants of 1 - 10 MW. For a supplier, this is an unnatural limit. A more natural limit involves compact engine design and simplified control system. The article discusses most of the engine and electrotechnical aspects in the development, construction and operation of such a plant

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

Directory of Open Access Journals (Sweden)

Petersen Pia Damm

2012-11-01

Full Text Available Abstract Background Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production. Results Xylan is the major non-cellulosic polysaccharide in secondary cell walls, and the xylan deficient irregular xylem (irx mutants irx7, irx8 and irx9 exhibit severe dwarf growth phenotypes. The main reason for the growth phenotype appears to be xylem vessel collapse and the resulting impaired transport of water and nutrients. We developed a xylan-engineering approach to reintroduce xylan biosynthesis specifically into the xylem vessels in the Arabidopsis irx7, irx8 and irx9 mutant backgrounds by driving the expression of the respective glycosyltransferases with the vessel-specific promoters of the VND6 and VND7 transcription factor genes. The growth phenotype, stem breaking strength, and irx morphology was recovered to varying degrees. Some of the plants even exhibited increased stem strength compared to the wild type. We obtained Arabidopsis plants with up to 23% reduction in xylose levels and 18% reduction in lignin content compared to wild-type plants, while exhibiting wild-type growth patterns and morphology, as well as normal xylem vessels. These plants showed a 42% increase in saccharification yield after hot water pretreatment. The VND7 promoter yielded a more complete complementation of the irx phenotype than the VND6 promoter. Conclusions Spatial and temporal deposition of xylan in the secondary cell wall of

Buckling of steel containment shells. Task 1b. Buckling of Washington Public Power Supply Systems' plant No. 2 containment vessel. Final report, 25 August 1980-30 September 1982

International Nuclear Information System (INIS)

Meller, E.; Bushnell, D.

1982-12-01

Static buckling analyses of the steel containment vessel of the Washington Public Power Supply Systems' (WPPSS) plant No. 2 were conducted with use of several computer programs developed at the Lockheed Missiles and Space Company (LMSC). These analyses were conducted as part of Task 1, Evaluation of Two Steel Containment Designs. The report is divided into two main sections. The first gives results from analyses of the containment as if it were axisymmetric (computerized models with use of BOSOR4, BOSOR5, and PANDA), and the second gives results from a STAGSC-1 model in which the largest penetration is included. Good agreement is obtained from analyses with BOSOR5 and STAGSC-1 for a case in which both of these computer programs were applied to the same configuration and loading. It is important to include nonlinear material behavior (plasticity) in the computerized models for collapse. Predictions of collapse from STAGSC-1 indicate that the largest penetration of the WPPSS-2 containment vessel is reinforced such that there is no decrease in load carrying capability below that indicated from models in which this penetration is neglected

Realistic thermal transient margin analysis of 'MONJU' based on plant performance measurements. Reactor vessel outlet nozzle and evaporator feed water inlet tube sheet of the manual reactor plant trip

International Nuclear Information System (INIS)

Yamada, Fumiaki; Mori, Takero

2005-01-01

In order to develop technologies and achieve safe and stable operation of Monju' as well as realize optimized design and construction of safe and economically competitive fast breeder reactors, the authors are evaluating design approach applied to 'Monju' based on actually measured behavioral data during plant operations. This report uses actual measured characteristic data of 'Monju' during a plant trip test obtained at a commissioning stage with up to 40% power output and introduces plant thermal hydraulic behavior analysis in a representative thermal transient event, i.e. a manual plant trip. Thermal transient driven loads incurred by the reactor vessel outlet nozzle and by the evaporator feed water inlet tube sheet were further derived by structural analyses and were compared with the previously derived values in the design stage and with the limit values. Though the reactor vessel outlet nozzle was exposed to larger temperature change in the trip test than the analytical prediction, the newly calculated mechanical load was about 50% of the previous evaluation in the design stage. Also, the newly analyzed mechanical load incurred by the evaporator feed water inlet tube sheet in this event had a large margin against the limit value of cumulative damage cycle fraction, although the observed temperature disturbance in a steam blow test was wilder than the analytical prediction. Thus we concluded that the Monju' plant has an assured safety margin against thermal transient in plant trip events. (author)

Ventilation-air conditioner system in nuclear power plant

International Nuclear Information System (INIS)

Kubota, Ryuji; Sugisaki, Toshihiko.

1989-01-01

This invention concerns a ventilation-air conditioner system which enables, upon occurrence of accidents in a nuclear power plant, continuous operation for other adjacent nuclear power plants with no effect of accidents. Air supply system and exhaust system are operated during usual operaiton. If loss of coolants accidents should occur in an adjacent nuclear power plants, operation is switched from ventilation operaiton to the operation of re-cycling system based on an AND logic of three signals, that is, a pressure HIGH signal for the reactor container, a water level LOW signal for the reactor and a radioactivity signal of the ventilation-air conditioner sytem on the side of air supply in the nuclear power plant. Thus, nuclear reactor buildings of the nuclear power plant are from the external atmosphere. Therefore, the radioactivity HIGH signal for switching to the emergency air conditioner system of the nuclear power plant is not actuated due to the loss of coolant accidents in the adjacent nuclear power plant. In addition, since the atmospheric temperature in the nuclear reactor building can be maintained by a cooling device disposed to the recycling system, reactor shutdown can be prevented. (I.S.)

Neutron dosimetry in EDF experimental surveillance programme for VVER-440 nuclear power plants

International Nuclear Information System (INIS)

Brumovsky, M.; Erben, O.; Novosad, P.; Zerola, L.; Hogel, J.; Trollat, C.

2001-01-01

Fourteen chains containing experimental surveillance material specimens of the VVER 440/213 nuclear power reactor pressure vessels were irradiated in the surveillance channels of the Nuclear Power Plant Dukovany in the Czech Republic. The irradiation periods were one, two or three cycles. The chains contained different number and types of containers, the omitted ones were replaced by chain elements. All of the containers were instrumented with wire neutron fluence detectors, some of the containers in the chain had spectrometric sets of neutron fluence monitors. For the absolute fluence values evaluation it was taken into account time history of the reactor power and local changes of the neutron flux along the reactor core height, correction factors due to the orientation of monitors with respect to the reactor core centre. Unfolding programs SAND-II or BASA-CF were used. The relative axial fluence distribution was obtained from the O-wire measurements. Neutron fluence values above 0.5 MeV energy and above 1.0 MeV energy in the container axis on the axial positions of the sample centres and fluence values in the geometric centre of the samples was calculated making use the exponential attenuation model of the incident neutron beam. Received fast neutron fluence values can be used as reference values to all VVER-440 type 213 nuclear power plant reactors. (author)

Quality assurance in nuclear power plant

International Nuclear Information System (INIS)

Magalhaes, M.T. de

1981-01-01

The factors related to the licensing procedures of a nuclear power plant (quality assurance and safety analysis) are presented and discussed. The consequences of inadequate attitudes towards these factors are shown and suggestions to assure the safety of nuclear power plants in Brazil are presented. (E.G.) [pt

Dukovany nuclear power plant in 1993

International Nuclear Information System (INIS)

1994-01-01

Data on the power generation, nuclear safety, and gaseous and liquid releases into the environment were extracted from the 1993 annual report of the Dukovany nuclear power plant. Operation of the plant was safe and reliable in 1993. Three events were classed as INES category 1. The plant's Failure Commission dealt with 100 events which brought about a total electricity generation loss of 217,624 MWh, corresponding to about 22 reactor-days. Out of this, 26.8 % was due to human error. Three fires occurred at the power plant site. Releases of radioactive aerosols, tritium, noble gases and radioiodine into air and of tritium, corrosion products, and fission products into the aquatic environment were below annual limits. The collective dose equivalent was 1.78 manSv in 1993. (Z.S.). 2 tabs., 11 figs

Securing the Safety of Nuclear Power Plants against Oil Spill Accidents at Sea

International Nuclear Information System (INIS)

Hyun, Seung Gyu; Choi, Ho Seon; Kim, Sang Yun

2008-01-01

As of 2008, 20 nuclear power plants are under operation and six plants are under construction in Korea. NPPs account for approximately 38% of Korea's electric power production; however, it is expected that the share of power produced by NPPs will be further increased to reduce the level of CO 2 emissions, taking into account the concern over global warming. All of NPPs in Korea are located on the coast to facilitate the supply of cooling water sources. Thus, tar and other floating matters from vessels following oil spill accidents at sea may affect intake systems, and consequently interrupt the supply of cooling water. This study will review cases of response measures taken by NPPs against large-scale crude oil spill accidents that had occurred off the coast of Korea, including such accidents as the Sea Prince (July 23, 1995) and the Hebei Sprit(December 7, 2007), and relevant regulatory requirements at home and abroad

The Kuroshio power plant

CERN Document Server

Chen, Falin

2013-01-01

By outlining a new design or the Kuroshio power plant, new approaches to turbine design, anchorage system planning, deep sea marine engineering and power plant operations and maintenance are explored and suggested. The impact on the local environment, particularly in the face of natural disasters, is also considered to provide a well rounded introduction to plan and build a 30MW pilot power plant. Following a literature review, the six chapters of this book propose a conceptual design by focusing on the plant's core technologies and establish the separate analysis logics for turbine design and

Economics of hybrid photovoltaic power plants

Energy Technology Data Exchange (ETDEWEB)

Breyer, Christian

2012-08-16

The global power supply stability is faced to several severe and fundamental threats, in particular steadily increasing power demand, diminishing and degrading fossil and nuclear energy resources, very harmful greenhouse gas emissions, significant energy injustice and a structurally misbalanced ecological footprint. Photovoltaic (PV) power systems are analysed in various aspects focusing on economic and technical considerations of supplemental and substitutional power supply to the constraint conventional power system. To infer the most relevant system approach for PV power plants several solar resources available for PV systems are compared. By combining the different solar resources and respective economics, two major PV systems are identified to be very competitive in almost all regions in the world. The experience curve concept is used as a key technique for the development of scenario assumptions on economic projections for the decade of the 2010s. Main drivers for cost reductions in PV systems are learning and production growth rate, thus several relevant aspects are discussed such as research and development investments, technical PV market potential, different PV technologies and the energetic sustainability of PV. Three major market segments for PV systems are identified: off-grid PV solutions, decentralised small scale on-grid PV systems (several kWp) and large scale PV power plants (tens of MWp). Mainly by application of 'grid-parity' and 'fuel-parity' concepts per country, local market and conventional power plant basis, the global economic market potential for all major PV system segments is derived. PV power plant hybridization potential of all relevant power technologies and the global power plant structure are analyzed regarding technical, economical and geographical feasibility. Key success criteria for hybrid PV power plants are discussed and comprehensively analysed for all adequate power plant technologies, i.e. oil, gas and coal fired power

Economics of hybrid photovoltaic power plants

Energy Technology Data Exchange (ETDEWEB)

Breyer, Christian

2012-08-16

The global power supply stability is faced to several severe and fundamental threats, in particular steadily increasing power demand, diminishing and degrading fossil and nuclear energy resources, very harmful greenhouse gas emissions, significant energy injustice and a structurally misbalanced ecological footprint. Photovoltaic (PV) power systems are analysed in various aspects focusing on economic and technical considerations of supplemental and substitutional power supply to the constraint conventional power system. To infer the most relevant system approach for PV power plants several solar resources available for PV systems are compared. By combining the different solar resources and respective economics, two major PV systems are identified to be very competitive in almost all regions in the world. The experience curve concept is used as a key technique for the development of scenario assumptions on economic projections for the decade of the 2010s. Main drivers for cost reductions in PV systems are learning and production growth rate, thus several relevant aspects are discussed such as research and development investments, technical PV market potential, different PV technologies and the energetic sustainability of PV. Three major market segments for PV systems are identified: off-grid PV solutions, decentralised small scale on-grid PV systems (several kWp) and large scale PV power plants (tens of MWp). Mainly by application of 'grid-parity' and 'fuel-parity' concepts per country, local market and conventional power plant basis, the global economic market potential for all major PV system segments is derived. PV power plant hybridization potential of all relevant power technologies and the global power plant structure are analyzed regarding technical, economical and geographical feasibility. Key success criteria for hybrid PV power plants are discussed and comprehensively analysed for all adequate power plant technologies, i.e. oil, gas and

Report of the Federal Ministry for the Environment, Nature Conservation, Buildings and Nuclear Safety (BMUB) on the topical peer review aging management in nuclear power plants and research reactors

International Nuclear Information System (INIS)

2017-01-01

The report of the Federal Environmental Ministry (BMUB) on the topical peer review aging management in nuclear power plants and research reactors covers the following issues: comprehensive requirements for aging management and its implementation, electric cables, non accessible pipes, reactor pressure vessel, calandria/pressure tubes (CANDU), concrete containment, pre-stressed concrete reactor pressure vessel (AGR).

Plant life management optimized utilization of existing nuclear power plants

International Nuclear Information System (INIS)

Watzinger, H.; Erve, M.

1999-01-01

For safe, reliable and economical nuclear power generation it is of central importance to understand, analyze and manage aging-related phenomena and to apply this information in the systematic utilization and as-necessary extension of the service life of components and systems. An operator's overall approach to aging and plant life management which also improves performance characteristics can help to optimize plant operating economy. In view of the deregulation of the power generation industry with its increased competition, nuclear power plants must today also increasingly provide for or maintain a high level of plant availability and low power generating costs. This is a difficult challenge even for the newest, most modern plants, and as plants age they can only remain competitive if a plant operator adopts a strategic approach which takes into account the various aging-related effects on a plant-wide basis. The significance of aging and plant life management for nuclear power plants becomes apparent when looking at their age: By the year 2000 roughly fifty of the world's 434 commercial nuclear power plants will have been in operation for thirty years or more. According to the International Atomic Energy Agency, as many as 110 plants will have reached the thirty-year service mark by the year 2005. In many countries human society does not push the construction of new nuclear power plants and presumably will not change mind within the next ten years. New construction licenses cannot be expected so that for economical and ecological reasons existing plants have to be operated unchallengeably. On the other hand the deregulation of the power production market is asking just now for analysis of plant life time to operate the plants at a high technical and economical level until new nuclear power plants can be licensed and constructed. (author)

Current production costs in various power plant systems

Energy Technology Data Exchange (ETDEWEB)

Weible, H.

1977-01-01

The costs of producing electric power were evaluated for flowing water power plants, storage and pumped storage power plants, bituminous coal power plants, heating oil power plants (fired with heavy heating oil), natural gas-fired power plants, gas turbines, pressurized water reactors, and boiling water reactors. The calculational methods used for evaluating costs and the input data for methods used for the KOSKON and KOSKERN computer programs are described. It is emphasized that the calculations are examples to indicate the possible effects of the cost program and are only as valid as the input data. (JSR)

Safety culture in nuclear power plants

International Nuclear Information System (INIS)

Weihe, G. von; Pamme, H.

2003-01-01

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

Nuclear power. Volume 1. Nuclear power plant design

International Nuclear Information System (INIS)

Pedersen, E.S.

1978-01-01

NUCLEAR POWER PLANT DESIGN is intended to be used as a working reference book for management, engineers and designers, and as a graduate-level text for engineering students. The book is designed to combine theory with practical nuclear power engineering and design experience, and to give the reader an up-to-date view of the status of nuclear power and a basic understanding of how nuclear power plants function. Volume 1 contains the following chapters; (1) nuclear reactor theory; (2) nuclear reactor design; (3) types of nuclear power plants; (4) licensing requirements; (5) shielding and personnel exposure; (6) containment and structural design; (7) main steam and turbine cycles; (8) plant electrical system; (9) plant instrumentation and control systems; (10) radioactive waste disposal (waste management) and (11) conclusion

Design of PCCV for Tsuruga No.2 plant of Japan Atomic Power Co

International Nuclear Information System (INIS)

Toda, Shiro; Yamada, Yasushi; Kuno, Toshio.

1987-01-01

The reactor containment vessel for Tsuruga No.2 plant is a prestressed concrete structure, the design of which was carried out in USA for three years from August, 1977. The research on PCCVs has been carried out for more than ten years in Japan, but this is the first case adopting it for an actual plant, so the design was advanced by the close cooperation between both Japanese and USA sides so as to conform to Japanese laws and tradition, and the check and review of the design results were jointly carried out. In reactor containment vessels, the internal pressure and temperature rise occurring at the time of LOCA become the main design load. The features of PCCVs as prestressed concrete structures are the utilization of prestress for large scale membrane structures, the vessels are subjected to thermal stress since those contain nuclear reactors, and the sufficient safety to the severe aseismatic condition peculiar to nuclear power stations. The prestressed concrete structure achieves the function of pressure vessels, the steel liner achieves the function of leak prevention, and the concrete achieves the function of radiation shield, and these are combined in one body as PCCVs. A PCCV is composed of a prestressed concrete upper shell and a reinforced concrete foundation. The structure, the standards to be applied, the allowable values of load and materials, the stress analysis, the cross section design and the design reinforcement are reported. (Kako, I.)

Hybrid combined cycle power plant

International Nuclear Information System (INIS)

Veszely, K.

2002-01-01

In case of re-powering the existing pressurised water nuclear power plants by the proposed HCCPP solution, we can increase the electricity output and efficiency significantly. If we convert a traditional nuclear power plant unit to a HCCPP solution, we can achieve a 3.2-5.5 times increase in electricity output and the achievable gross efficiency falls between 46.8-52% and above, depending on the applied solution. These figures emphasise that we should rethink our power plant technologies and we have to explore a great variety of HCCPP solutions. This may give a new direction in the development of nuclear reactors and power plants as well.(author)

Seismic isolation of nuclear power plants - EDF's philosophy

International Nuclear Information System (INIS)

Coladant, C.

1989-01-01

The elastomer bearing pads used since 1963 as supports for prestressed concrete pressure vessels (PCPVs) was quickly chosen by Electricite de France (ED) to improve the capability of nuclear power plants (NPPs) to withstand strong earthquakes and to reduce the seismic loads on structures and equipment. The standardized units for 900 and 1,300 MW(e) pressurized water reactor (PWR) plants have moderate seismic design loads of 0.2 and 0.15 g, respectively. These design loads were exceeded by the site dependent spectra of Cruas (France) and Koeberg (South Africa). To keep the plant design unchanged and to take the advantages of standardization, these units were put on laminated bearings with or without sliding plates. For the future French 1,500 MW(e) fast breeder reactors (FBRs), which are more sensitive to seismic loads, the base isolation is considered by EDF at the beginning of the design, even for low ground motions of 0.1 g. The buildings are placed on laminated bearings while the reactor block is supported by springs and dampers. The isolated plant has identical costs as a conventional design such as SPX1 at Creys-Malville

Offshore atomic power plants

International Nuclear Information System (INIS)

Anon.

1975-01-01

Various merits of offshore atomic power plants are illustrated, and their systems are assessed. The planning of the offshore atomic power plants in USA is reviewed, and the construction costs of the offshore plant in Japan were estimated. Air pollution problem may be solved by the offshore atomic power plants remarkably. Deep water at low temperature may be advantageously used as cooling water for condensers. Marine resources may be bred by building artificial habitats and by providing spring-up equipments. In the case of floating plants, the plant design can be standardized so that the construction costs may be reduced. The offshore plants can be classified into three systems, namely artificial island system, floating system and sea bottom-based system. The island system may be realized with the present level of civil engineering, but requires the development of technology for the resistance of base against earthquake and its calculation means. The floating system may be constructed with conventional power plant engineering and shipbuilding engineering, but the aseismatic stability of breakwater may be a problem to be solved. Deep water floating system and deep water submerging system are conceivable, but its realization may be difficult. The sea bottom-based system with large caissons can be realized by the present civil engineering, but the construction of the caissons, stability against earthquake and resistance to waves may be problems to be solved. The technical prediction and assessment of new plant sites for nuclear power plants have been reported by Science and Technology Agency in 1974. The construction costs of an offshore plant has been estimated by the Ministry of International Trade and Industry to be yen71,026/kW as of 1985. (Iwakiri, K.)

Demonstration of an automated electromanometer for measurement of solution in accountability vessels in the Tokai Reprocessing Plant (part II)

International Nuclear Information System (INIS)

Yamonouchi, T.; Fukuari, Y.; Hayashi, M.; Komatsu, M.; Suyama, N.; Uchida, T.

1982-01-01

This report describes the results of an operational field test of the automated electromanometer system installed at the input accountability vessel (251V10) and the plutonium product accountability vessel (266V23) in the Tokai Reprocessing Plant. This system has been in use since September 1979 when it was installed in the PNC plant by BNL as part of Task-E, one of the thirteen tasks, in the Tokai Advanced Safeguards Technology Exercise (TASTEX) program. The first report on the progress of this task was published by S. Suda, et al., in the Proceedings of the INMM 22nd Annual Meeting. In this paper, further results of measurement and data analysis are shown. Also, the reliability and applicability of this instrument for accountability, safeguards, and process control purposes are investigated using the data of 106 batches for 251V10 and 40 batches for 266V23 obtained during two campaigns in 1981. There were small but significant differences relative to the plant's measurements for both vessels of 251V10 and 266V23; however, the difference for 251V10 was slightly decreased in the latest vessel calibration. Initially, there were many spurious signals originating with the raw data caused by a software error in the system. However, almost normal conditions were obtained after corrections of the program were made

ELECNUC Nuclear power plants in the world - 2013 edition

International Nuclear Information System (INIS)

2013-01-01

This small booklet summarizes in a series of tables the figures relative to the nuclear power plants worldwide. Data come from the IAEA's PRIS database and from specific I-tese studies. The following aspects are reviewed: 2012 highlights; Main characteristics of reactor types; Map of the French nuclear power plants on 2012/01/01; Worldwide status of nuclear power plants (12/31/2012); Units distributed by countries; Nuclear power plants connected to the Grid- by reactor type groups; Nuclear power plants under construction on 2012; Evolution of nuclear power plants capacities connected to the grid; First electric generations supplied by a nuclear unit in each country; Electrical generation from nuclear power plants by country at the end 2012; Performance indicator of french PWR units; Evolution of the generation indicators worldwide by type; Nuclear operator ranking according to their installed capacity; Units connected to the grid by countries at 12/31/2012; Status of licence renewal applications in USA; Nuclear power plants under construction at 12/31/2012; Shutdown reactors; Exported nuclear capacity in net MWe; Exported and national nuclear capacity connected to the grid; Exported nuclear power plants under construction; Exported and national nuclear capacity under construction; Nuclear power plants ordered at 12/31/2012; Long term shutdown units at 12/31/2012; COL (Combined Licence) applications in the USA; Recycling of Plutonium in reactors and experiences; Mox licence plants projects; Appendix - historical development; Meaning of the used acronyms; Glossary

Human factors in nuclear power plants

International Nuclear Information System (INIS)

Hennig, J.; Bohr, E.

1976-04-01

This annotated bibliography is a first attempt to give a survey of the kind of literature which is relevant for the ergonomic working conditions in nuclear power plants. Such a survey seems to be useful in view of the fact that the 'factor human being' comes recently more and more to the fore in nuclear power plants. In this context, the necessity is often pointed out to systematically include our knowledge of the performance capacity and limits of human beings when designing the working conditions for the personnel of nuclear power plants. For this reason, the bibliography is so much intended for the ergonomics experts as for the experts of nuclear engineering. (orig./LN) [de

Reliability analysis techniques in power plant design

International Nuclear Information System (INIS)

Chang, N.E.

1981-01-01

An overview of reliability analysis techniques is presented as applied to power plant design. The key terms, power plant performance, reliability, availability and maintainability are defined. Reliability modeling, methods of analysis and component reliability data are briefly reviewed. Application of reliability analysis techniques from a design engineering approach to improving power plant productivity is discussed. (author)