International Nuclear Information System (INIS)

In Tarapur Atomic Power Station unit-3 and 4, which is 540 MWe pressurized heavy water reactor, tritium is produced in primary heat transport system and moderator system. Tritium is a major contributor to the internal dose. Internal dose contributes about 30% of the collective dose. Internal dose monitoring and its control are important to control the collective dose. Estimation of internal dose is done by analysis of bioassay samples of radiation workers. In a month, about 7000 bioassay samples are analysed for the internal dose assessment during normal operation, and about 12000 during the biennial shut down of the reactor. To enhance the sample preparation and counting performance, minimize the entry errors and reduce the processing time, barcode based label generation system was developed for the ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)

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... thermal power plants thermal reactors water cooled reactors WATER

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Recommended nuclear decay data for specific actinides are important in fuel-cycle studies for thermal and fast reactors and inventory studies for safeguards. Therefore, a programme of work was initiated in 2005 to improve the actinide decay data library of the International Atomic Energy Agency through the efforts of a Coordinated Research Project (CRP). The proposed contents of the new database are described, including the agreement to include additional actinides and a significant number of natural decay chain radionuclides. This work is on-going, and is estimated for completion in 2009/10.

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The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion ...

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English Sep 2008 p. 56-57 International Atomic Energy Agency (IAEA)

International Nuclear Information System (INIS)

Aug 2010 p. 31-35 Japan Kishioka, Kazuhiko Japan Atomic Industrial Forum,

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This project of law concerns an additional protocol to the agreement of warranties signed on September 22, 1998 between France, the European atomic energy community and the IAEA. This agreement concerns the declaration of all information relative to the R and D activities linked with the fuel cycle and involving the cooperation with a foreign country non endowed with nuclear weapons. These information include the trade and processing of nuclear and non-nuclear materials and equipments devoted to nuclear reactors (pressure vessels, fuel loading/unloading systems, control rods, force and zirconium tubes, primary coolant pumps, deuterium and heavy water, nuclear-grade graphite), to fuel reprocessing plants, to isotope separation plants (gaseous diffusion, laser enrichment, plasma separation, electromagnetic enrichment), to heavy water and deuterium production plants, and to uranium conversion plants. (J.S.)

International Nuclear Information System (INIS)

An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs.

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

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Based on the enhanced cooperation between Republic of Korea (ROK) and International Atomic Energy Agency (IAEA), IAEA installed new safeguards equipment (Unattended Monitoring System, UMS) at Wolsung unit 2 on January, 2005. The UMS was utilized in parallel with traditional human surveillance during the transfer campaign of Wolsung unit 2 (7 March - 22 July). Installation of UMS at all Wolsung units will be decided on the basis of the result of this test. The transfer campaign with UMS at Wolsung units 2 and 4 was started from September 1, 2006 at the same time. Implementation of UMS to the transfer campaign in Wolsung site will be considerably reduced the IAEA's inspection effort and burden of operator.

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Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions.

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The development of detailed chemical kinetic reaction mechanisms for oxidation of n-octane and iso-octane is described, with emphasis on the factors which are specific to many large hydrocarbon fuel molecules. Elements which are of particular importance are found to include site-specific abstraction of H atoms, radical isomerization of alkyl radicals by internal H atom abstraction, and rapid ..beta..-scission of the alkyl radicals. These features, combined with distinctions in the types of intermediate olefin species produced, are used to explain the significant differences in the rate of oxidation between n-octane and iso-octane. Experimental results from the turbulent flow reactor and low pressure laminar flames, using both n-octane and iso-octane as fuels, are used to test the reaction mechanisms and indicate those parts of the total mechanisms which are in greatest need of further development and ...

International Nuclear Information System (INIS)

The CO laser is superior in the absorption characteristic to materials to the CO2 laser due to its shorter wavelength. In consideration of this characteristic Nuclear Power Engineering Corporation is studying this applicability sponsored by the Ministry of International Trade Industry of Japan to cutting of reactor core internals of commercial nuclear power plant. In decommissioning of reactor core internals it is necessary to cut stainless steel plates of 305 mm thick. The authors cut stainless steel plates of up to 310mm thick in air and those of up to 150 mm thick underwater with a 20kW class laser. Further, models simulating key structural elements of PWR core internals were cut and secondary products to clarify the applicability of the CO laser cutting to reactor core internals were evaluated. (author)

CERN Document Server

Atomic pioneers

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Division of Remote Handling and Robotics (DRHR) at Bhabha Atomic Research Centre (BARC) has been working on design and development of Reactivity Control Mechanisms for Nuclear Research Reactors (Dhruva, KAMINI and recently Critical Facility of Advanced Heavy Water Reactor (AHWR)) as well as Power Reactors in India (Pressurized Heavy Water Reactors of 220 MWe at Narora and recently India's first 540 MWe PHWR Unit -1 and 2 at Tarapur). This paper gives a brief account of evolution of reactivity control mechanisms for nuclear research and power reactors in India. (author)

Science.gov (United States)

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main to...

Science.gov (United States)

(accumulates & stores brine for disposal). Separator. (separates water from purge gases). ? Purge pump periodically vent ... Reactor Health. Sensor. ( verifies reactor is operating w/n limits) ... Waste and Hygiene Compartment ...

International Nuclear Information System (INIS)

As an integral part of the Fast Test Reactor Vibration Program for Reactor Internals, the flow-induced vibrational characteristics of scaled Fast Test Reactor core internal and peripheral components were assessed under scaled and simulated prototype flow conditions in the Hydraulic Core Mockup. The Hydraulic Core Mockup, a 0.285 geometric scale model, was designed to model the vibrational and hydraulic characteristics of the Fast Test Reactor. Model component vibrational characteristics were measured and determined over a range of 36 percent to 111 percent of the scaled prototype design flow. Selected model and prototype components were shaker tested to establish modal characteristics. The dynamic response of the Hydraulic Core Mockup components exhibited no anomalous flow-rate dependent or modal characteristics, and prototype response predictions were adjudged ...

International Nuclear Information System (INIS)

It was agreed that both of the Republic Of Korea (ROK) and the International Atomic Energy Agency (IAEA) cooperate with the new approach using the Unattended Monitoring Systems (UMS), the mailbox declaration and the short notice inspections, which can decrease the agency inspection efforts and operator' s burden. As a result of the positive cooperation of ROK for applying new approach, the IAEA could accomplish a successful implementation of new safeguards approach during last transfer campaigns at Wolsung site. As of the end of Feb. 2007, the IAEA installed the UMS at Wolsung units 2, 3 and 4. The transfer campaigns at Wolsung units 2 and 4 are performing from April, 2007. The IAEA will install the UMS at Wolsung unit 1 by the end of 2007. Then agency will inspect all of transfer campaign at Wolsung units by using new approach with UMS, mailbox declaration and SNI. It is based on the SSAC full cooperation with IAEA to meet agency safeguards ...

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This volume presents the main address, the lectures and the discussions of the symposium. The papers presented to the symposium were the following: the Draft Convention on the Law of the Sea and problems of the international deep seabed regime; developments in science and technology, as a challenge to international law; modern fishery engineering and its impact on international law; the EEC agricultural market - a case study of European Law; problems of international law in connection with a new system of the world economy; the GATT and a new world economic system; the Third World and UNCTAD; international disaster relief and mutual assistance in case of accidents, especially with a view to Atomic Energy Law; organisation, scope and limits of international co-operation in the peaceful use of nuclear energy.

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This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core.

Science.gov (United States)

The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser ...

International Nuclear Information System (INIS)

Iron is one of the main constituents of stainless steel which is used as a structural material in nuclear reactors. In fast and conceptual fusion and fusion-fission hybrid systems the primary energy range of neutron interaction lies between 1 and 20 MeV which opens up several reaction channels. The reaction cross-sections in this energy range are important for dosimetry, radiation damage, neutronics and safety studies of nuclear reactors. Keeping this in view Nuclear Data Section of the International Atomic Energy Agency has sponsored a Research Co-ordination Programme on Methods for the Calculation of Fast Neutron Nuclear Data for Structural Elements. Under this programme we propose to study (n,n'), (n,2n), (n,3n), (n,p), (n,np), (n,pn), (n,#alpha#), (n,n#alpha#), (n,#alpha#n) and (n,#gamma#) reaction cross-sections. Besides these, total, elastic and discrete level inelastic scattering cross-sections, ...

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The integrity of the RPV head and reactor internals was assessed by means of fluid-structural analyses using a coupled method to evaluate the water hammer phenomenon arising from high burnup fuel failure under RIA conditions. The fluid viscosity effect on the water column burst as well as the complex three-dimensional flow paths caused by a core shroud and standpipes were considered in this study. The three analysis scenarios were designed to investigate the above mentioned influential factors separately. In the first scenario, a two-dimensional axisymmetric reactor vessel model without any reactor internals was modeled to assess the influence of the fluid dynamics in the NSC RIA regulatory evaluation. This model has an actual RPV geometry and can be simply separated from other influential factors in order to concentrate only on investigation of the fluid viscosity effect. In the ...

International Nuclear Information System (INIS)

The aim of the report is to describe the state and prospects of the experimental and stand base (ESB) for fundamental investigations in the RF Ministry for Atomic Energy. The ESB includes the following scientific directions: high energy physics, nuclear physics, solid state physics (including superconductivity), plasma physics and controlled thermonuclear synthesis, nuclear reactors and reactor materials testing, lasers, energy conversion and others. Main economical, scientific and technical data on the ESB as a whole and on its most large scientific centers are presented

International Nuclear Information System (INIS)

This paper explores the current trends in development of technology-neutral safety requirements to be used in the regulation of future nuclear power reactors and the role of the quantitative safety goals in the design of reactor safety systems. Establishing the requirements concerning the reliability of safety functions rather than on particular systems employed to achieve the functions, as well as the use of the recommendations of the International Commission on Radiological Protection (ICRP) on protection against potential exposure could form the basis of a technology-neutral framework for safety requirements on new reactor designs. Also it could contribute to international harmonisation of nuclear safety assessment practices as part of the licensing processes for future nuclear power plants. (author)

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The Fast Flux Test Facility (FFTF) is a 400 Mw(t), loop-type, sodium-cooled, fast neutron reactor. It is operated by the Westinghouse Hanford Company for the United States Department of Energy at Richland, Washington. The FFTF is a multipurpose test reactor used to irradiate fuels and materials for programs such as Liquid Metal Reactor (LMR) research, fusion research, space power systems, isotope production and international research. FFTF is also used for testing concepts to be used in Advanced Reactors which will be designed to maximize passive safety features and not require complex shutdown systems to assure safe shutdown and heat removal. The FFTF also provides experience in the operation and maintenance of a reactor having prototypic components and systems typical of large LMR (LMFBR) power plants. The 5 year operational performance of the FFTF ...

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This thesis is devoted to studies which prepared the construction of an atom Mach-Zehnder interferometer. In such an interferometer, the propagating waves are spatially separated, and the internal state of the atom is not modified. The beam-splitters are diffraction gratings, consisting of standing optical waves near-resonant with an atomic transition. We use the Bloch functions to define the atom wave inside the standing wave grating and thus explain the diffraction process in different cases. We developed a nearly all-analytical model for the propagation of an atom wave inside a Mach-Zehnder interferometer. The contrast of the signal is studied for many cases: phase or amplitude gratings, effects of extra paths, effects of the main mismatches, monochromatic or lightly polychromatic sources. Finally, we discuss three interferometric measurements we think very ...

Science.gov (United States)

The Cordoba and Wolsung projects mark the entry into the international sales arena of the standardized Canadian 600 MWe CANDU-PHW reactor design. The Cordoba station experienced a setback in the early stages when severe inflation in Argentina led to a ren...

International Nuclear Information System (INIS)

SMART (System-Integrated Modular Advanced Reactor) is a first-of-the-kind integral reactor with 330 MW thermal power under active development by Korea Atomic Energy Research Institute (KAERI) for power generation and seawater desalination. SMART employs various design features that are not typically found in other nuclear power plants. Examples include a unique passive residual heat removal system (PRHRS), and enclosure of a pressurizer, eight helical steam generators, and eight canned reactor coolant pumps inside the reactor pressure vessel. This paper presents risk insights on the SMART reactor gained during the development of a regulatory PSA model by Korea Institute of Nuclear Safety (KINS)

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Two of the working sessions of the meeting were devoted to aspects of international atomic energy law; the international character of the meeting was also reflected by the home countries of the members of the panel discussion concluding the working sessions. There was substantial reason to put emphasis on the international dimension of the topics discussed. In June 1994, the Nuclear Safety Convention had been signed in Vienna by diplomatic representatives of the signatory countries, and this Convention marks a signpost in the history of international atomic energy law. At the time the meeting was held, negotiations for improving the international nuclear lability law, which had been dragging on since 1989, had come to a stalemate. The meeting offered a suitable forum for taking a scientific approach to tackle the complex problems involved in ...

International Nuclear Information System (INIS)

Interaction of the internal states of an atom with spatially dependent standing-wave cavity field can impart position information of the atom passing through it leading to subwavelength atom localization. We recently demonstrated a different regime of atom localization [Phys. Rev. A 72, 013820 (2005)], namely sub-half-wavelength localization through phase control of electromagnetically induced transparency. This regime corresponds to extreme localization of atoms within a chosen half-wavelength region of the standing-wave cavity field. Here we present further investigation of the simplified model considered earlier and show interesting features of the proposal. We show how the model can be used to simulate a variety of energy-level schemes. Furthermore, the dressed-state analysis is employed to explain the emergence and suppression of the localization peaks, and ...

International Nuclear Information System (INIS)

The deliveration by the Nuclear Safety Commission was commenced on the alteration in reactor installation, as it had been inquired by the Ministry of International Trade and Industry. The alteration is the additional installation of the reactor No. 2 in the Sendai Nuclear Power Station, Kyushu Electric Power Co., Inc. It is a PWR power plant with thermal output of about 2,660 MW (electric output of 890 MW), to be installed, adjoining to the reactor No. 1 of the same type and capacity under construction. In the examination by MITI, it was confirmed that the technological capabilities for its construction and operation and the radiation protection measures in power generation are both sufficient. The contents of the examination include the siting conditions, the location and construction of reactor facilities, etc. (J.P.N.).

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Tritium dose management is an important aspect of the radiation protection program at CANDU type reactor sites. This paper describes the bioassay and dosimetry of tritium at CANDU reactor sites, especially for Wolsung Nuclear Power Plant. It presents a compilation of information drawn from published papers, technical reports, international and national guidelines as well as practical experience both in Korean and Canadian CANDU Nuclear Power Plants. The implementation of this program would provide a technical basis for calculations and records should be of acceptable quality and should meet overall radiation protection program objectives.

Science.gov (United States)

Among KEPCO's 9 nuclear power units, Korea Nuclear Unit No. 3, the Wolsung Nuclear Power Plant is the only CANDU-PHWR Unit, while the rest of 8 others are PWR units. The unit was designed by Atomic Energy of Canada, Ltd. of Canada, who also performed overall project management for the plant construction under the provisions and arrangement of the relevant contracts. The gross electrical output of the plant is 678.7 MWe and thermal output of the reactor is 2061 MWth. While these figures lead to lower plant efficiency than LWR counterparts, unit energy cost for fuel is more favorable than LWRs because natural uranium is utilized for the fuel bundles, some of which are already being fabricated domestically. Annual capacity factors for 1983 and 1984 could have been improved, if two major planned outages for the modification works on steam generator internals and one major forced outage from the heavy water spill ...

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The Nuclear Renaissance is stumbling at the very same time it should speed up in order to help control the climate change and meet a fast growing energy need in a large part of the world. Rising costs of projects, uncertainties about their completion, rocketing safety requirements, and financial constraints are key factors which slow down the Nuclear Renaissance. Furthermore, the legal infrastructure required from any country to enter a commercial nuclear programme (safety authorities, fuel cycle, and waste disposal) is a major hurdle s which impedes consideration for small to mid size reactors, well suited for many countries. The paper prepared and presented by Alain Bugat (Chairman of NucAdvisor and former Head of the French Atomic Energy Commission), Dominique Vignon (CEO of NucAdvisor and former President and CEO of AREVA NP) and Michel Lecomte (Co-founder NucAdvisor) reviews the present status of the Nuclear Renaissance. Based on an ...

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Starting from the Molten Salt Breeder Reactor project of Oak-Ridge, we have performed parametric studies in terms of safety coefficients, reprocessing requirements and breeding capabilities. In the frame of this major re-evaluation of the molten salt reactor (MSR), we have developed a new concept called Molten Salt Fast Reactor or MSFR, based on the Thorium fuel cycle and a fast neutron spectrum. This concept has been selected for further studies by the MSR steering committee of the Generation IV International Forum in 2009. Our reactor's studies of the MSFR concept rely on numerical simulations making use of the MCNP neutron transport code coupled with a code for materials evolution which resolves the Bateman's equations giving the population of each nucleus inside each part of the reactor at each moment. Because of MSR's fundamental characteristics compared to ...

International Nuclear Information System (INIS)

SMART (System integrated Modular Advanced ReacTor) , is under development at the Korea Atomic Energy Research Institute (KAERI). SMART is an integral type pressurized water reactor which contains a pressurizer, 4 reactor coolant pumps (RCPs), and 8 steam generator cassettes(S/Gs) in a single reactor vessel. This reactor has substantially enhanced its safety with an integral layout of its major components, 4 trains of safety injection system (SIS), and an adoption of 4 trains of passive residual heat removal system (PRHRS) instead of an active auxiliary feedwater system . The thermal power is 330 MWth. During the conceptual design stage, a preliminary PSA was performed. PSA results identified that a steam generator tube rupture (SGTR) is one of the most important initiating events which results in a high core damage frequency. Clear understanding of accident ...

International Nuclear Information System (INIS)

About 210 abstracts by Ukrainian and foreign authors submitted to the 11-th International Conference on Plasma Physics and Controlled Fusion and 2-nd Alushta International Workshop on the Role of Electric Fields in Plasma Confinement in Stellarators and Tokamaks have been considered by Conference Program Committee members. All the abstracts have been divided into 9 groups: Magnetic confinement systems (stellarators, tokamaks, alternative conceptions); plasma heating and current drive; ITER and fusion reactor aspects; basic plasma physics; space plasma; plasma dynamics and plasma-wall interaction; plasma electronics; low temperature plasma and plasma technologies; plasma diagnostics.

International Nuclear Information System (INIS)

This document comprises the final technical report for atomic collisions research supported by DOE grant No. DE-FG02-87ER13778 from September 1, 2001 through August 31, 2004. The research involved the experimental investigation of excitation and charge-changing processes occurring in ion-atom and ion-molecule collisions. Major emphases of the study were: (1) interference effects resulting from coherent electron emission in H2, (2) production of doubly vacant K-shell (hollow ion) states due to electron correlation, and (3) formation of long-lived metastable states in electron transfer processes. During the period of the grant, this research resulted in 23 publications, 12 invited presentations, and 39 contributed presentations at national and international meetings and other institutions. Brief summaries of the completed research are presented below.

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This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from February 16, 1990 through February 15, 1993. This work involves the experimental investigation of atomic interactions in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron-correlation effects. The processes studied are of interest both from fundamental and applied points of view. In the latter case, results are obtained which are relevant to the understanding of laboratory and astrophysical plasmas, highly-excited (Rydberg) and continuum states of atoms and ions, atomic structure effects, the interaction of ions with surfaces, and the development of heavy-ion storage-rings. The results obtained have provided the basis for several M.A. thesis projects at Western Michigan and several ...

International Nuclear Information System (INIS)

The activation aspects of pure fusion and hybrid fusion technology is studied to assess the radioactive safety of various fusion concepts including tokamak pure fusion, fissile fuel producing hybrid and radio waste transmuting hybrid. The activation properties of breeding, coolant and structural materials in fusion reactors might be quite different from those in fission reactors because of the high energy D-T fusion neutrons from the fusion cores. A study on the involved activation reactions and the uncertainties of the associated nuclear cross-sections is carried. The activation properties of various first wall concepts and blanket concepts are discussed. The radioactive inventory during the operation lifetime and the potential hazard of the radioactive nuclides with respect to near term (reprocessing) and long term (waste disposal) aspects are calculated, with reference to ITER/NET (International Thermonuclear Experiment ...

International Nuclear Information System (INIS)

Full text: Korea Atomic Energy Research Institute (KAERI) has many R and D facilities in operation. including HANARO research reactor, radioactive waste treatment facility (RWTF), post-irradiation examination facility (PIEF) and irradiated material test facility (IMEF). Recently. nation-wide interest is focused on the safety and security of major industrial facilities. Safe operation of nuclear facilities is imperative because of the consequence of public disaster by radiological release/contamination, in case of an accident. Recently, Ministry of Science and Technology (MOST) of the Korean government announced amendments of Atomic Energy laws to enforce requirements of the physical protection and radiological emergency. All provisions on nuclear safety regulation and radiation protection are entrusted to the Atomic Energy Act(AEA). The Act is enacted as the main law concerning the safety regulation of ...

International Nuclear Information System (INIS)

Korea Atomic Energy Research Institute (KAERI) has many R and D facilities in operation, including HANARO research reactor, radioactive waste treatment facility (RWTF), post-irradiation examination facility (PIEF) and irradiated material test facility (IMEF). Recently, nation-wide interest is focused on the safety and security of major industrial facilities. Safe operation of nuclear facilities is imperative because of the consequence of public disaster by radiological release/ contamination, in case of an accident. Recently, Ministry of Science and Technology (MOST) of the Korean government announced amendments of Atomic Energy laws to enforce requirements of the physical protection and radiological emergency. In this paper, the context of amended Atomic Energy laws were reviewed to confirm quality assurance measures and identify additional QA activities, if any, that is required by the amendment

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The present report concerns a research for the tritium and for the carbon 14 in lichens in a spirit of bio-indication: the first results appear in Daillant and al (2004 ) and additional results were presented to the congress B.I.O.M.A.P. in Slovenia, organized collectively by the institute Josef Stefan from Ljubljana and the international atomic energy agency from Vienna (Daillant and al 2003). (N.C.)

Science.gov (United States)

... 52.891 69.782 2002 004 19 06 06 48 000 7.6065 -3.2645 1.9299 -42.260 17.293 52.842 69.837 2002 004 19 06 06 54 000 7.6054 -3.2635 1.9312 -42.433 17.274 ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station Unit-3 and 4 (TAPS -3 and 4) are the 540 MWe reactors. Unit-4 attained first criticality on 06th March 2005 and operated for about 230 effective full power days (EFPD). Unit-3 attained first criticality on 21st May 2006 and operated for about 20 EFPD. With the reactor operation radiation field increases on the Primary Heat Transport system equipments, Moderator system equipments and auxiliary system equipments due to deposition of fission products and activation products in different reactor systems. These dose rates significantly contributes to the external exposure and stations collective dose during reactor operation, refueling operation and maintenance activities. A study was undertaken at TAPS 3 and 4 to identify the system equipments showing the significant dose rates and identify the radionuclides present in the primary heat transport system, ...

International Nuclear Information System (INIS)

Korea Atomic Energy Research Institute(KAERI) launched a project to develop an integral reactor in 1996. The reactor called as System Integrated Modular Advanced Reactor(SMART) which is a kind of small modular reactors (SMRs). Since the early 1990s, there has been renewed interest in the development and application of small and medium sized integral reactors. 2009 assessment by the IAEA under its Innovative Nuclear Power Reactor and Fuel Cycle (INPRO) program concluded that there could be 96 SMRs in operation around the world by 2030 in its 'high' case, and 43 units in the 'low' case, none of them in the USA. The reason of the increased demand mostly comes from the fact that SMRs are thought to be more suitable for developing countries with small electrical grid capacity, insufficient infrastructure and limited investment capability than ...

Energy Technology Data Exchange (ETDEWEB)

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

International Nuclear Information System (INIS)

This study describes the mechanical compatibility of the direct use of spent pressurized water reactor (PWR) fuel in Canada deuterium uranium (CANDU) reactors (DUPIC) fuel, when it is loaded into a CANDU reactor. The mechanical compatibility can be assessed for the fuel management, primary heat transport system, fuel channel, and the fuel handling system in the reactor core by both the experimental and analytic methods. Because the physical dimensions of the DUPIC fuel bundle adopt the CANDU flexible (CANFLEX) fuel bundle design which has already been demonstrated for a commercial use in CANDU reactors, the experimental compatibility analyses focused on the generation of material property data and the irradiation tests of the DUPIC fuel, which are used for the computational analysis. The intermediate results of the mechanical compatibility analysis have shown that the integrity of ...

Science.gov (United States)

Americium 242m and americium 242 were prepared by reactor irradiation of americium 241 as its diphthalocyanine complex. The product atoms were extracted from the parent isotope at an enrichment factor of 10. A Dowex 50 chromatographic column raised the factor to 24.6.

International Nuclear Information System (INIS)

Active Process Water (APW) System, provided as unitized closed loop system in Tarapur Atomic Power Project Units-3 and 4, serves to remove heat from various heat exchangers. One of the important loads served by APW system is shutdown cooling heat exchangers and if APW shutdown is taken then reactor cannot be maintained in cold shutdown condition. It is estimated that after 7 days of reactor shutdown, if about 20% of the normal cooling flow to shutdown cooling heat exchangers is provided then along with keeping PHT in cold shutdown state, reactor components, moderator, end shield water, calandria vault water and calandria vault concrete temperature can be maintained within technical specification limits for extended duration. (author)

Energy Technology Data Exchange (ETDEWEB)

Forced vibration experiment has been conducted for the reactor building of Sendai Unit 1 nuclear power plant. The beam vibrational behaviors of the outer shielding building and the internal concrete structure have been observed by using a 50 tf vibration for low frequency region, and a 10 tf vibration for high frequency region, respectively. The outline of the experimental methods, the data handling system and the major results of experiment are described. The experimental results were simulated by an analytical model. The proper vibrational frequency and the vibration modes obtained by the analysis were compared with those obtained by the experiment. By these comparisons, the adequacy of the analytical method employed for the design was confirmed.

Energy Technology Data Exchange (ETDEWEB)

Many nations and international agencies are working to develop improved technology and industrial capability for neuclear fuel cycle and waste management operations. The effort in some countries is limited to research in university laboratories on treating low-level waste from reactor plant operations. In other countries, national nuclear research institutes are engaged in major programs in all phases of the fuel cycle and waste management, and there is a national effort to commercialize fuel cycle operations. Since late 1976, staff members of Pacific Northwest Laboratory have been working under US Department of Energy sponsorship to assemble and consolidate openly available information on foreign and international nuclear waste management programs and technology. This report summarizes the information collected on the status of fuel cycle and waste management programs in selected countries making major efforts in these ...

International Nuclear Information System (INIS)

During the last ten years, the U.S. Nuclear Regulatory Commission and the U.S. nuclear utilities have been developing methods and requirements for risk-informed applications making use of probabilistic risk assessments (PRA) of nuclear power plants. Early in this process, it became clear that the existing PRAs were done with different objectives and methodologies by different analysts. For uniformity and consistency in future risk-informed applications, industry consensus standards on probabilistic risk assessments were deemed to be essential. Currently, the following standards have been published or under preparation: - ASME RA-S-2002: 'Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications', Addendum C, March 2005. - ANSI/ANS-58.21-2003 'External-Events PRA Methodology' March 2003. - ANS-58.22 'Low Power and Shutdown PRA Standard'. - ANS-58.23 'Fire PRA Methodology Standard'. - ANS Level 2 and Level 3 PRA Standards. The ASME Standard specifies the ...

Energy Technology Data Exchange (ETDEWEB)

The Fixed Bed Nuclear Reactor (FBNR) is a small 40 MWe reactor based on the Pressurized Water Reactor (PWR) technology. FBNR is an integrated primary circuit and simple in design. It has the characteristics of being small, modular, proliferation resistant, inherently safe and passively cooled reactor with reduced adverse environmental impact. It utilizes the fuel designed for high temperature reactors operating in a relatively low temperature of PWR environment The 15 mm diameter spherical fuel elements are made of TRISO type microspheres embedded in graphite and cladded by SiC. The coolant flow transfers them from the fuel chamber into the core and become fixed forming a suspended core. Any accident signal will cut off the power to the coolant pump causing a stop in the flow. This results in making the fuel elements fall out of the reactor core by the force of ...

International Nuclear Information System (INIS)

Full text: The transmutation of nuclear waste to reduce the burden on a geological repository is a relevant topic within the Program of Nuclear Safety Research of the Research Centre Karlsruhe. Several studies have confirmed that a high efficiency of transmutation of actinides is reached in fast neutron spectrum reactor system. Therefore, an important effort is dedicated to the study of transmutation strategies with different fast reactors and their associated technologies. Moreover, in international contexts as Generation IV International Forum (GIF) and Sustainable Nuclear Energy Technology Platform (SNETP), fast reactors are considered in the frame of sustainable development of nuclear energy and reduction of waste. The systems that are currently under investigation, in the frame of the different fuel cycle scenarios, are liquid metal cooled and gas cooled fast ...

International Nuclear Information System (INIS)

The objective was to find out whether international research has now provided sufficiently reliable models to assess the corrosion behavior of spent fuel in groundwater and by this to contribute to answering the question whether the highly radioactive used fuel from nuclear reactors can be disposed of safely in a geological repository. Principal project results are described in the paper

International Nuclear Information System (INIS)

Technical developments in the construction of high power accelerators have created new research activities on accelerator-driven transmutation technologies (ADTT) with main applications for energy production and nuclear waste transmutation. The on-going research was reported and discussed at the conference. The studies of energy production based on ADTT indicate possible important advantages compared to the present nuclear power reactors. Natural Uranium or Thorium is burned in a subcritical reactor with or without simultaneous incineration and transmutation of nuclear waste. High level radioactive wastes and weapons Plutonium constitute an environmental and proliferation problem. Studies were reported on the possibilities to use ADTT to considerably shorten the life-time and reduce the amount of long-lived radioactive waste in order to decrease the volumes needed for long-term geologic deposition. A panel discussed the ADTT impact on nuclear ...

British Library Electronic Table of Contents (United Kingdom)

This paper is dedicated to the treatment of sludge occurring in frame of the Egyptian produced from oil and gas production. The activity levels of three radium isotopes: Ra-226 (of U-series), Ra-228 and Ra-224 (of Th-series) in the solid TENORM waste (sludge) were first evaluated and followed by a sequential treatment for all radium species (fractions) presented in TENORM. The sequential treatment was carried out based on two approaches `A' and `B' using different chemical solutions. The results obtained indicate that the activity levels of all radium isotopes (Ra-226, Ra-228 and Ra-224) of the environmental interest in the TENORM waste sludge were elevated with regard to exemption levels established by IAEA [International Atomic Energy Agency (IAEA), International basic safety standards f...

International Nuclear Information System (INIS)

The CAMDU 6 reactor has an international reputation as one of the world's best performing and safe reactors. CANDU 6 reactors are consistently ranked in the world's top 10 for annual and lifetime performance. Six CANDU 6 units are currently in operation in four continents; in Quebec, New Brunswick, South Korea, Argentina and Romania. There are another two CANDU 6 units currently under construction at wolsong, in Korea which ore scheduled to go into service in 1998 and 1999 respectively. A second CANDU 6 unit is currently being considered for Romania. The construction of two CANDU 6 units at Qinshan, in China, is now underway. The performance of the four first-generation CANDU 6 plants, which have now been in service for 15 years, continue to show very good performance, with capacity factors on average since in-service of over 85%. The annual capacity factor of 10.21% during 1997 has been achieved by the ...

Energy Technology Data Exchange (ETDEWEB)

Elemental analysis of some medicinal plants used in the Indian Ayurvedic system was performed by employing instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS) techniques. The samples were irradiated with thermal neutrons in a nuclear reactor and the induced activity was counted by gamma ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector. Most of the medicinal plants were found to be rich in one or more of the elements under study. The variation in elemental concentration in same medicinal plants samples collected in summer, winter and rainy seasons was studied and the biological effects of these elements on human beings are discussed. (orig.)

International Nuclear Information System (INIS)

Novel and unprecedented ion exchange resin cleaning system, for use in BWR plants and featuring a vibration separator and basic design factors of Radiological Solutions, Inc., had been delivered to Tokai No. 2 Power Station, Japan Atomic Power Company, in October 2005. This compactly-designed system effectively separates crud and resin fines from ion exchange resins, with no clogging of separation screens. It generates minimized waste liquid and has a specially designed over-pack cleaning tank. The system has been in operation for about 2 years and half now and favorable operational data, such as crud and sulfate concentration decrease in feed water and reactor water respectively, and evaluation results have been reported from Japan Atomic Power Company and so on. (author)

Energy Technology Data Exchange (ETDEWEB)

The U.S. Support Program to International Atomic Energy Agency (IAEA) Safeguards (USSP) was established in 1977 to transfer US technology and expertise to assist the IAEA Department of Safeguards because its limited budget and scope would not allow for R&D activities and the procurement of specialized or customized equipment. Over the years, the USSP and the Department of Safeguards have worked together continuously to develop and improve processes for requesting, selecting, and managing projects that support the Safeguards verification mission. This paper will discuss the main USSP processes for accepting and processing Safeguards requests, and managing and reporting task progress.

International Nuclear Information System (INIS)

This Publications Catalogue lists all sales publications of the IAEA published in 2004, 2005 and forthcoming in 2006. Most IAEA publications are issued in English, some are also available in Arabic, Chinese, French, Russian or Spanish. This is indicated at the bottom of the book entry. A complete listing of all IAEA priced publications is available on the IAEA's web site: http://www.iaea.org/books

International Nuclear Information System (INIS)

Understanding of the thermal hydraulic phenomena is now the key issue in solving the severe accident problems of light water reactors. The Atomic Energy Society of Japan has organized a special committee on the evaluation of the thermal hydraulic phenomena in severe accident. The committee has continued the investigation of present status of thermal hydraulics in severe accident. Industries have completed the detailed implementation of the accident management measures, and industries have established also a self-regulatory document mainly on phase II accident management for the containment design of the future reactors. Present paper reviews the current status of evaluation activity referring to severe accident research in Japan. The phenomena included in this paper are (1) molten core behavior in lower plenum of pressure vessel, (2) fuel-coolant interaction, (3) molten core-concrete interaction, (4) direct containment ...

International Nuclear Information System (INIS)

... power reactors pressure tube reactors reactors THERMAL REACTORS.

Energy Technology Data Exchange (ETDEWEB)

The subjects, principles and purpose of the atomic energy law and the radiation protection law are set out, and criminal offences under atomic energy law are outlined explaining the legal terminology applied. The peaceful uses of nuclear energy and radioactive materials are briefly discussed, primarily looking at the hazards involved and the protective role of criminal law principles that have been developed in connection with the atomic energy law and its application in practice. The draft version of the 16th criminal law amendment act - Act to combat environmental delinquency - is discussed, which aims at adoption of all criminal offences under atomic energy law by the Criminal Code. The book furthermore presents considerations about basic features of delinquency under atomic energy and radiation protection law, revealing elements and facts of offences defined, and particular ...

Energy Technology Data Exchange (ETDEWEB)

The radiation control carried out in Atomic Energy Research Institute, Kinki University, for the reactor installation and the tracer/accelerator facilities from April, 1981, to March, 1982, is described. The reactor was operated for total 1057.1 hours at the maximum heat output of 1 W. The persons subject to radiation protection as of April, 1981, were 126 persons in all, including 23 in radiation work and 11 in X-ray work, etc. The contents of this report are as follows: personnel monitoring (health examination, the control of individual exposure dose); laboratory monitoring (the measurement of area dose rate, radioactive concentration in air and water, and surface contamination density); field monitoring (environmental ..gamma..-ray dose rate, radioactive concentration in environmental samples); the use of unsealed radioisotopes, etc.

CERN Document Server

A new methane cold neutron source has been tested at the IBR-2 pulsed reactor at the Frank Laboratory of Neutron Physics. In a paper the results of experiments at neutron diffractometers HRFD and DN-2 which are placed at the IBR-2 from the methane moderator side are given. A comparison with the results obtained with the conventional water comb-like moderator is performed. The perspectives of the cold source for various kinds of neutron diffraction experiments, including atomic and magnetic structural analysis and real time experiments are discussed. It is shown, that for a huge number of the experiments which are performing at both HRFD and DN-2 the methane cold neutron source provides the better conditions than water comb-like moderator.

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) Carlsbad Field Office (CBFO) administers and operates the Waste Isolation Pilot Plant (WIPP) site, which hosts a deep geologic repository for safe disposal of U.S. defense-related TRU waste and is located 42 kilometers (km) east of Carlsbad, New Mexico. CBFO also manages the National Transuranic Waste Program (NTP), which oversees TRU waste management from generation to disposal. The WIPP began receiving waste in March 1999. In some areas of broad international interest, the CBFO has developed a leading expertise through its 25-year WIPP repository and TRU waste characterization activities. In addition to participating in relevant and beneficial experiments, the CBFO will provide the international community convenient access to this information by sponsoring and hosting symposia and workshops on relevant topics and by participation in international waste management organizations and ...

International Nuclear Information System (INIS)

In General Electric's design of the Simplified Boiling Water Reactor (SBWR), The depressurization valves (DPV) are installed in the reactor pressure boundary: four are connected to the reactor vessel by means of nozzles, and two more are located on the main steam pipes (one DPV for each line), which act during particular transients and/or loss of coolant accidents (LOCA), consequently providing the reactor vessel with a safe quick depressurization system. Once the vessel is de pressurised, the passive gravity-driven cooling system (GDCS) starts to operate, permitting the injection of water required for continuous core cooling. DPVs are leak tight, with welded flaps, actuated by a [striker[hammer***] which is activated by an explosive mixture. The dynamic loads that open these valves include, in addition to those produced by steam (typical in any thermodynamic transient with open/close valves), other ...

Science.gov (United States)

The Advanced Coal Liquefaction Research and Development Facility in Wilsonville, Alabama, is funded by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), and Amoco Corporation. On behalf of these organizations, Southern Company Services manages and Southern Clean Fuels Division of Southern Electric International operates the Wilsonville facility. Oak Ridge National Laboratory (ORNL) receives funding from DOE to provide materials technical support to the Wilsonville operators. For the period July 1987 through November 1990 the plant was operated with two reactors a thermal reactor and a catalytic reactor in a close-coupled integrated two-stage liquefaction mode. Coal processed was obtained from several seams including Ohio No. 6, Illinois No. 6, and Pittsburgh No. 8, as well as Texas lignite and several subbituminous coals. Corrosion samples which were removed for ...

Energy Technology Data Exchange (ETDEWEB)

The nuclear data activity at AERE, Savar is briefly presented in this paper. Major thrust is on the customization of cross section libraries for general purpose reactor and shielding calculations. The processing codes that are available are NJOY91.91, some AMPX-Modules and the modules in SCALE-PC. Recent measurements on cross section data over the energy range 13-15 MeV at the Institute of Nuclear science and Technology have been reviewed. Measurements and calculations are based on the determination of excitation functions of neutron induced reactions on the elements and isotopes of FRT-relevant structural materials. (author).

Energy Technology Data Exchange (ETDEWEB)

In the study a preliminary mid-term analysis of the BARCOM test model is presented. The BARCOM test model is a 1:4 scale of an existing pressurized heavy water reactor (PHWR) pre-stressed concrete inner containment of 540 MW Tarapur Atomic Power Station 3 and 4 units in India. The goal of this midterm analysis is to illustrate the modeling approach and achieve a prediction of the failure mode. The analysis was carried out using ABAQUS/CAE and ABAQUS/EXPLICIT version 6.7-EF1 software

International Nuclear Information System (INIS)

Taking into consideration India's limited reserves of natural and vast reserves of thorium, the fast reactor route holds a great promise for India's energy supply in future. The fast reactor fueled with "2"3"9Pu/"2"3"8U (unused or depleted) produces (breeds) more fissionable fuel material "2"3"9Pu than it consumes. Calculations show that a fast breeder reactor (FBR) increases energy potential of natural uranium by about 60 times. As the fast reactor can also convert "2"3"2Th into "2"3"3U which is a fissionable material, it can make India's thorium reserves a source of almost inexhaustible energy supply for a long time to come. Significant advantage of FBR plants cooled by sodium and their world-wide operating experience are reviewed. There are two main safety issues of FBR, one nuclear and the other non-nuclear. The nuclear issue concerns core disruptive accident and the non-nuclear one concerns the ...

Energy Technology Data Exchange (ETDEWEB)

Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of internal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atomic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, as well as certain differences in others. A number of structural features are common to both metal and oxide grain boundaries, as well as certain heterophase boundaries. Of particular ...

Energy Technology Data Exchange (ETDEWEB)

The most important aim of the title program is to investigate the possibility to convert long-lived actinides and mobile fission products in short-lived and stable isotopes by means of nuclear transmutation and recycling. First, an overview is given of the present situation regarding fission material waste, the origin of such waste in light water reactors and the options for interim and ultimate storage. Next, attention is paid to the aim of the the RAS program, the working method and the results so far of national and international research on the transmutation of actinides and fission products. Speculative expectations for the future are briefly outlined. The report also contains four appendices with technical aspects of the title subject: the RAS program of ECN, chemical aspects of reprocessing fission material, transmutation in fission reactors and in accelerators. 12 figs., 7 tabs., 4 appendices, 57 refs.

Energy Technology Data Exchange (ETDEWEB)

The Riskaudit 7 report has been made by a group of independent experts from Western European countries representing technical organizations specialized in the support of regulatory bodies of those countries. It represents a preliminary estimation of the Ukrainian WWER B 213 and B 320 reactors, based on the example of Rovno NPP, analysed with a Western practice. The first part of the document covers the following aspects of the report: core design and fuel management; pressurized components; electrical supply; instrumentation and control; containment; internal events; site conditions and external events.

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and lndustry (MITI) of Japan. The nuclear reactor buildings are partially embedded due to conditions for the construction or building arrangement in Japan. It is necessary to verify the partial embedment effects by experiments and analytical studies in order to incorporate the effects in the seismic design. Forced vibration tests, therefore, were performed using a model with several types of embedment. Correlated simulation analyses were also performed and the characteristics of partial embedment effects on soil-structure interaction were evaluated. (author)

Energy Technology Data Exchange (ETDEWEB)

A project is underway at Oak Ridge National Laboratory (ORNL) to design, test, and install a cold neutron source facility in the High Flux Isotope Reactor (HFIR). This new cold source employs supercritical hydrogen at cryogenic temperatures both as the medium for neutron moderation and as the working fluid for removal of internally-generated nuclear heating. The competing design goals of minimizing moderator vessel mass and providing adequate structural integrity for the vessel motivated the requirement of detailed multidimensional thermal-hydraulic analyses of the moderator vessel as a critical design subtask. This paper provides a summary review of the HFIR cold source moderator vessel design and a description of the thermal-hydraulic studies that were carried out to support the vessel development.

International Nuclear Information System (INIS)

Alloy 800 was developed in 1949 by The International Nickel Company, Inc. The basic composition, nominally 32wt.%Ni, 20.5wt.%Cr and 46wt.%Fe, was designed to provide a stable, fully austenitic structure and to impart high strength combined with resistance to oxidation, carburization and corrosion in a wide variety of aggressive industrial environments at elevated temperatures. In the short span of twenty-five years, alloy 800 has earned a unique position in the family of heat- and corrosion-resistant materials. Established uses include a wide range of applications in the industrial heating field, in the petro-chemical industry, in domestic appliances and in food processing equipment. The good performance of alloy 800 in these applications has led to its use as boiler tube material both in fossil-fired plants and in HTGR and PWR nuclear power systems. Recently, it was specified for a PHW CANDU reactor and it is now being considered as heat ...

International Nuclear Information System (INIS)

The pressurized Heavy Water Reactor (PHWR) consists of horizontal calandria vessel containing a large number of pressure tubes (fuel channels) connected to the reactor inlet and outlet headers by individual feeders. Coolant flow distribution among the pressure tubes play a vital role in extraction of thermal power. For these reactors one of the design objectives is to achieve uniform coolant outlet temperatures by providing coolant flows according to the channel power. This is achieved by the design process known as feeder sizing. This basically consists of accounting for the individual channel power and centre line geometry of individual feeder and iteratively adjusting the feeder hydraulic resistances within the design constraints such as limiting flow velocities, channel flows. Recently, the first unit of 540 MWe i.e Tarapur Atomic Power Project (unit 4) has been commissioned. This paper discusses ...

International Nuclear Information System (INIS)

A method for converting organic iodides to elemental iodine would be advantageous in improving the performance of charcoal filters for the removal of radio iodines from reactor off gases. A photochemical method has been developed. The HAVCHM code was used to establish the relevant process time scales on a complete set of rate equations describing the primary and secondary reactions occurring in a plug-flow reactor containing low levels of elemental iodine and methyl iodide in air, which is irradiated by intense u.v. light. These simulations were used to justify the contraction of the complete set of reactions to the most significant elementary processes. The contracted set of rate equations are then solved analytically to render the concentration-time profiles of methyl iodide, total inorganic iodine and total oxidized organics, consistent with the achievement of a desirable radioiodine decontamination factor. For the short contact times ...

International Nuclear Information System (INIS)

Alloy HT-9 is being used for both duct and cladding applications in advanced liquid-metal reactor (LMR) experiments. This tempered martensitic steel was selected for use as an LMR core component material primarily because of its excellent resistance to radiation-induced swelling. Experiments conducted in the Fast Flux Test Facility (FFTF) at 410 degree C and exposures in the range of 150 to 175 displacements per atom (dpa) have shown that Ht-9 exhibits only a 0.2 to 0.3% increase in volume. Cold-worked austenitic steels exhibit volumetric increases of 20 to 30% at 410 degree C, Alloy HT-9 is being used for a series of fuel pin experiments in the FFTF, and these tests have achieved a burnup of 175 MWd/kg metal and a fluence of 25 x 10"2"2 n/cm"2 (E > 0.1 MeV) without fuel pin breach. The high confidence placed in HT-9 is based on a wide series of in- and ex-reactor experiments. Test results for these experiments are ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear energy related research in Switzerland is concentrated at PSI's Nuclear Energy and Safety Research Department (NES). The activities of the department are concentrated on three main domains of: Safety and related problems of operating plants; safety features of future reactor and fuel cycles; waste management. Comprehensive assessments of energy systems are carried out in cooperation with PSI's General Energy Research Department. Many of the programs are part of collaborations with universities, industry, or international organisations. Progress in 2000 in these topical areas is described in this report. A list of scientific publications in 2000 is also provided.

International Nuclear Information System (INIS)

Corrosion is increasingly becoming an important factor reducing the reliability of many nuclear power plant components. The significance is evaluated of corrosion phenomena with respect to the reliability of primary circuit components of LWR's, viz., the reactor pressure vessel, primary piping, steam generator, and fuel elements. The mechanism of corrosion phenomena is explained and methods of minimizing their effects are presented. An analysis is made of the needs to solve the corrosion problems of nuclear power plants from the point of view of Czechoslovak producers and research and development activities. International cooperation is reviewed and main problems are formulated on which the solution of corrosion problems of structural materials used in WWER type nuclear power plants should be focussed. (author).

International Nuclear Information System (INIS)

Development and deployment of small-scale nuclear power reactors and their maintenance, monitoring, and control are part of the mission under the Small Modular Reactor (SMR) program. The objectives of this NERI-consortium research project are to investigate, develop, and validate advanced methods for sensing, controlling, monitoring, diagnosis, and prognosis of these reactors, and to demonstrate the methods with application to one of the proposed integral pressurized water reactors (IPWR). For this project, the IPWR design by Westinghouse, the International Reactor Secure and Innovative (IRIS), has been used to demonstrate the techniques developed under this project. The research focuses on three topical areas with the following objectives. Objective 1 - Develop and apply simulation capabilities and sensitivity/uncertainty analysis methods to address sensor ...

International Nuclear Information System (INIS)

Total quality management strategy and the worldwide introduction of the DIN/ISO 9000 (EN 29 000) series of standards have given new impetus to traditional quality assurance. The most important change must surely be seen in the holistic approach of total quality management and its strict orientation towards customer requirements and satisfaction. International codes and standards for the nuclear industry will also have to be brought into line as part of the process of harmonizing quality assurance system standards. One possible approach is simply to specify a supplementary 'delta' of nuclear-specific requirements to be appended to the broad range of conventional requirements. It is a particular feature of quality-assured procedures in Germany that product and/or component related quality requirements and quality verifications are defined in the specifications of the architect engineer so that full implementation of the requirements from the design phase through to ...

International Nuclear Information System (INIS)

Standardization enhances: international cooperation; development of new nuclear techniques and technologies; characterization and checking procedures of equipment; sharing a common terminology. A historical sketch is given focussing: inception of standardization in electro-techniques at international scale; organization of the International Electrotechnical Commission, IEC; - current aspects of nuclear equipment standardization; activity of seven working groups devoted to nuclear reactor equipment; activity of seven groups working on radioprotection equipment; activity of four groups working on nuclear equipment. ISO organization and present issues concerning the nuclear technology development in Romania. It is presented the activity in the frame of CENELEC, CLC/TC45, for endorsing the IEC/TC45B standards. In 2007 a CENELEC/ BTT 127-1 working commission was formed to enhance assimilation of IEC /TC45 A ...

Science.gov (United States)

The Heavy Water Reactor Facility (HWRF), as part of the defense-in-depth philosophy to mitigate the effect of design-basis and severe accidents, is equipped with a passive containment cooling system (PCCS). The function of the PCCS is to provide a safety-grade path to the ultimate heat sink for the removal of the reactor coolant system sensible heat and core decay heat. Ambient air enters an annular space between the steel containment shell and the surrounding concrete shield building through inlets in the shield building wall, is heated via natural convection, rises, and exits the building through a chimney located above the containment dome. A test program is in place to access parameters important to the effective operation of the PCCS. This paper focuses on the large-scale tests (LSTs). The objectives of these tests are as follows: (1) demonstrate natural circulation cooling with more prototypic cylinder and dome surface area ratios than ...

Energy Technology Data Exchange (ETDEWEB)

The newly developed techniques by the Hot Laboratory (JMTR HL) have provided for us the key information on behavior of specimens due to mechanical / physical / chemical / synergistic effects of radiation, stress and water for fission and fusion reactor environment. These techniques are focused on several topics as follows; (1) miniaturized specimen test for the development of fusion reactor materials, (2) slow strain rate tensile testing (SSRT) and crack propagation measuring tests for the study of Irradiation Assisted Stress Corrosion Cracking (IASCC) of core internals of LWR, (3) handling technique on specimens including tritium for the research and development of tritium breeders and neutron multiplier as fusion blanket materials, (4) joining method using the Tungsten Inert Gas (TIG) welding technique for re-assembling of capsule and re-fabrication of specimen and (5) nondestructive evaluation using ultrasonic wave and ...

CERN Document Server

A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector ...

International Nuclear Information System (INIS)

... fast reactors fbr type reactors fuels liquid metal cooled reactors materials nuclear

Energy Technology Data Exchange (ETDEWEB)

Since June 1997 the standards/specifications and inspection/certification of various products in Japan have been reviewed by Ministries and Agencies, with the aim of reducing direct government intervention to a necessary minimum and creating a free and fair socio-economic system that is fully opened to the international community and based on the rules of self-responsibility and market principles. Reflecting this policy the administrative regulations which prescribe technical standards as specific requirements have been revised by degrees into performance prescriptions. Detailed provisions in ordinances and notices have been abolished gradually to utilize voluntary standards and rules. In the nuclear energy field voluntary standards are being developed to make up statutory performance requirements by the Atomic Energy Society of Japan (AESJ) and the Japan Society of Mechanical Engineers (JSME) together with other organizations such as the Japan ...

International Nuclear Information System (INIS)

Classification and ranking of the solid solution on their reaction to the irradiation is suggested on the basis of binary system structure controlled by mixing enthalpy sign, melting temperatures relation of components and solidus curves slope. Several combinations of these characteristics permit to pick out three groups of substitutional elements capable of forming the vacancy-solute atom complexes either low-mobile or fast-mobile ones as compared to monovacancies migration. The radiation hardening (and embrittlement) of binary alloys should be intensified respectively either due to heterogeneous point defect clusters nucleation on solute traps or due to solute atom clusters/ precipitate formation. A local cohesion decrease may also occur especially if low-melting elements (characterized by low surface energy) are segregating on internal sinks or grain boundaries. The predicted specifics of different alloy group under ...

Science.gov (United States)

In order to model transport of dissolved ions in subsurface environments, one should understand how these ions interact with solid phase adsorbents. Our primary goal has been investigating the reaction mechanisms which affect microcontaminant partitioning between aqueous solutions and solid phase adsorbents, using goethite ({alpha}-FeOOH) as a model adsorbent. Cylindrical internal reflection -- Fourier transform infrared (CIR-FTIR) spectroscopy has been developed as the primary technique for this study. Wet chemical adsorption studies, acoustophoresis and electrophoretic mobility have been used to obtain supporting information as needed. Phenol and o-nitrophenol did not adsorb to goethite. Benzoate, phthalate and p-hydroxybenzoate all adsorbed via a bidentate mechanism to two adjacent iron atoms, while salicylate and 2,4-dihydroxybenzoate formed a chelate complex to single iron atoms. Phosphate adsorption was predominately ...

International Nuclear Information System (INIS)

New values of the factors required to convert the reading of a radiation dosemeter calibrated in terms of air kerma (or exposure) into absorbed dose to water for medium-energy x-radiation were given in a code of practice published by the International Atomic Energy Agency in 1987. These are not considered to possess sufficient support from other sources. It is therefore recommended that the F-factors given or codes of practice should continue to be used. Values of backscatter factors for low-energy x-radiation (below 140 kV) in Supplement 17 of the British Journal of Radiology appear to be inaccurate. New values based on Monte Carlo calculations, and supported by new experimental data, are given for use in radiotherapy. (author).

Energy Technology Data Exchange (ETDEWEB)

One of the countermeasures for exhaust emissions from a diesel engine, especially, DI diesel engine, is the use of a super high pressure injection system with a small hole diameter. However, the system needs greater driving force than that with normal injection pressure,and its demerit is an increase in NO{sub x}, although soot decreases. The authors propose a new concept, the simultaneous reduction of NO{sub x} and soot. The concept is that the utilization of flash boiling phenomenon in a diesel engine. The phenomenon can be realized by use of the injection of fuel oil with CO{sub 2} gas dissolved. Flash boiling facilities the distinguished atomization of fuel oil and CO{sub 2} gas contributes to the internal EGR (Exhaust Gas Recirculation) during combustion. Fundamental information on the characteristics of a flash boiling spray of n-tridecane with CO{sub 2} gas dissolved is described in this paper, as a first step.

International Nuclear Information System (INIS)

The demand of nuclear energy is sharply increasing to solve the energy and environment problems all over the world. The interest and support on the field of nuclear energy in Korea are enlarging as the acceptance of ordering nuclear power plant of UAE. The attention of safeguards is needed to maintain peaceful use of nuclear material and the nuclear nonproliferation as the increasing demand of nuclear energy. The International Atomic Energy Agency (IAEA) invests more in research and development to achieve the effective and efficient implementation of safeguards. Research and development (R and D) in safeguards approaches, procedures and techniques is essential to meeting the safeguards challenges of the future. The IAEA has conducted the R and D program through member state support program (MSSP) since 1977. The objective of this paper is to introduce the MSSP and policy of Korea on MSSP

British Library Electronic Table of Contents (United Kingdom)

Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hosp...

Energy Technology Data Exchange (ETDEWEB)

The International Atomic Energy Agency (IAEA) plans to use the Common Criteria, as the tool for developing graded and measurable evaluation criteria for information technology (IT) in safeguards systems in facilities subject to IAEA inspection. In their draft paper [ITSECSES] the IAEA defines a three-tiered Vulnerability Assessment Level (VAL) scheme. Each increased VAL level (1-3) defines additional and more stringent security and security-related requirements for the system developer, the system evaluator (assessor or authenticator), and for the IAEA. When all parties meet all requirements for a particular VAL level, IAEA has a measurable degree of confidence in the secure and proper operation of an IT system.

International Nuclear Information System (INIS)

The Atomic Energy Control Board (AECB), Canada's nuclear regulatory authority, is preparing new regulations based on ICRP-60. The proposed regulations have some features which are different from ICRP-60, e.g., the limit for pregnant workers was set at a higher level than that proposed in ICRP-60. The AECB, through its consultative process, received many responses from female staff in nuclear medicine. The concern was that it would be very difficult to prove compliance with such low doses, particularly for internal doses. There was an additional concern that hospital administrators would respond to the reduction of the current pregnant worker limit from 10 mSv to the ICRP-60 recommended value of 2 mSv by discriminating against hiring women. A new proposal for the dose limit for pregnant workers has been made which will limit the dose to the mother by means of a combining formula that will take both external and internal ...

Science.gov (United States)

... 4 Joint Committee on Atomic Energy as a Model . . . . . ... Joint Committee on Atomic Energy as a Model ...

British Library Electronic Table of Contents (United Kingdom)

Abstract A next generation material for surface passivation of crystalline Si is Al2O3. It has been shown that both thermal and plasma-assisted (PA) atomic layer deposition (ALD) Al2O3 provide an adequate level of surface passivation for both p- and n-type Si substrates. However, conventional time-resolved ALD is limited by its low deposition rate. Therefore, an experimental high-deposition-rate prototype ALD reactor based on the spatially separated ALD principle has been developed and Al2O3 deposition rates up to 1.2-nm/s have been demonstrated. In this work, the passivation quality and uniformity of the experimental spatially separated ALD Al2O3 films are evaluated and compared to conventional temporal ALD Al2O3, by use of quasi-steady-state photo-conductance (QSSPC) and carrier density ...

International Nuclear Information System (INIS)

Displacements per atom (DPA) is a widely used damage unit for displacement damage in nuclear materials. Calculating the DPA for SiC irradiated in a particular facility requires a knowledge of the neutron spectrum as well as specific information about displacement damage in that material. In recent years significant improvements in displacement damage information for SiC have been generated, especially the energy required to displace an atom in an irradiation event and the models used to describe electronic and nuclear stopping. Using this information, numerical solutions for the displacement functions in SiC have been determined from coupled integro-differential equations for displacements in polyatomic materials and applied in calculations of spectral-averaged displacement cross sections for SiC. This procedure has been used to generate spectrally averaged displacement cross sections for SiC in a number of reactors used ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station Unit-4 was made critical on 6th March 2005. Since radiation field builds up with the power level due to formation of fission products and activation products in different systems. Radiation dose rates were recorded from different areas using Area Radiation Monitors (ARMs) installed at different areas. These monitors are connected to Radiation Data Acquisition System (RADAS). The trend of radiation field build-up was also analyzed by making survey of different plant areas at various power levels and comparison was made with RADAS readings. The results obtained were compared with 220 MWe dose rates. This study discusses about the dose rates observed at accessible area, shut down accessible area and hotspots observed during the early stage of operation of the reactor. The attempt was also made to find the contributing factors of the high dose rates. It was found that the finding of the study was utilized for the ...

Science.gov (United States)

This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and ...

International Nuclear Information System (INIS)

In Japan, the development of next-generation Light Water Reactor has been launched since April 2008. The development program will be completed in 2015. The purpose of development is to cope with the replacement for existing nuclear power plants after 2030 in Japan and the expanding demand for nuclear power in the world; 'Nuclear Renaissance.' The reactor also aims to be global standard at around 2030. The requirements for global standard and domestic users have been investigated through the feasibility study of past 2 years, 2006-2007, and six innovative features or 'Core-Concepts' were established as follows. A) Reactor core system with uranium enrichment above 5% for significant decrease of spent fuel discharge and prominent higher availability B) Long-life materials and innovative water chemistry technologies for 80 years plant lifetime and significant reduction of occupational dose C) Seismic isolation technologies to ...

Energy Technology Data Exchange (ETDEWEB)

The core bypass flow in a prismatic very high temperature gas-cooled reactor (VHTR) is one of the important design considerations which impacts considerably on the integrity of reactor core internals including operating fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) will be affected by the bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to understand better the bypass flow phenomenon and establish the ...

Energy Technology Data Exchange (ETDEWEB)

Severe accident analysis has been performed for the Wolsung nuclear power= plants in Korea to investigate severe accident phenomena of CANDU-600 reactors as a part of Level II PSA study. The accident sequence analyzed in this paper is loss of active heat sinks (LOAH) which is caused by loss of off-site power, diesel generators, and DC power. ISAAC (Integrated Severe Accident Analysis Code) computer code developed by KAERI (Korea Atomic Energy Research Institute) was used in this analysis. This paper describes the important thermal-hydraulics and source term behaviors in the primary system and inside containment, and the failure mechanisms of calandria vessel and containment. In addition, some insights for accident management program (AMP) are also given. (Author) 5 refs., 1 tab., 12 figs.

International Nuclear Information System (INIS)

This study started with a comprehensive and critical review of the published information of relevance to the different methods to produce uranium dioxide from raw materials. we have chosen this method 'flame denitration' or flame process to produce Uo_2. from its compounds, uranyl nitrate Uo_2 ( NO_3) _2 .6H_2o) prepared from raw uranium 'yellow cake'. This method in short produces uranium dioxide from aqueous uranyl nitrate by contacting the atomized liquid which has 40 #mu# in diameter with hot reducing gases (butane and oxygen mixture) till we obtain a suitable and yellow red colour light for the flame and this is a prof that there is carbon monoxide and hydrogen, the temperature of the reactor at is least 950 degree C.

International Nuclear Information System (INIS)

In Korea, a manufacturing process for the fabrication of CANDU 37-element fuel bundles was successfully developed between 1981 and 1986. At Korea Atomic Energy Research Institute (KAERI), more than 20,000 fuel bundles were produced up to May 1992, for use in Wolsung-1 power reactor. At the time of the conference, about 15,000 of these fuel bundles had been irradiated in Wolsung-1, and almost all of them had performed well. From 1995, the commercial fuel production program will be transferred to Korea Nuclear Fuel Company, which is building a plant with a capacity of 400 tons of uranium per year. So-called CANFLEX fuel, more appropriate to advanced fuel cycles, is being developed jointly by AECL and KAERI. The paper includes a listing of the current status of the Republic of Korea's nuclear power plants, with planning projections up to the year 2006. 2 tabs.

International Nuclear Information System (INIS)

Thermal hydraulics of a liquid metal is important to design the blanket of a magnetic confined fusion reactor. Since a liquid metal has high thermal and electrical conductivity, the flow characteristics are often different from those of an ordinary liquid like water especially in thermal convection and under a magnetic field. It is difficult to simulate such flows in a liquid metal cooled blanket by water. Flow visualization is a popular method to study thermal hydraulics. Since most of metals are visible by neutron rays, neutron radiography is available to the flow visualization of a liquid metal. The purpose of this study is to develop a visualization technique of the flow in a liquid metal by real-time neutron radiography using the tracer and the dye injection methods. A real-time thermal neutron radiography system of JRR-3M in Japan Atomic Energy Research Institute was used for the visualization test.

Indian Academy of Sciences (India)

- technology moving forward with new developments ...

Energy Technology Data Exchange (ETDEWEB)

Hydrogen injection into the reactor water has been applied to many BWR power stations. Since hydrogen injected accelerates recombination of oxidant generated by water radiolysis, oxidant concentration, such as dissolved oxygen concentration in reactor water can be reduced. As the result of the reduction of oxidant concentration, Electrochemical Corrosion Potential (ECP) at the surface of structural material can be lowered. Lowered ECP moderates Stress Corrosion Cracking (SCC) sensitivity of structural materials, such as stainless steels. As usual, hydrogen injection system begins to work after the plant start-up is finished, when the condition of normal operation is established. Accordingly, Hydrogen Water Chemistry (HWC) does not cover all the period of plant operation. As far as SCC crack growth is considered, loss of HWC during plant start-up does not result in significant crack growth, because of duration of plant start-up is much shorter ...

Energy Technology Data Exchange (ETDEWEB)

The Japan Atomic Energy Research Institute has conducted a piping reliability test program to demonstrate the safety and reliability of light water reactor primary piping. In this program, pipe fatigue test, leak-before-break (LBB) verification test and pipe rupture test were carried out to examine the integrity of piping, to verify the LBB and to demonstrate the effectiveness of protective measures against jet impingement and pipe whip loads under a pipe rupture event.In the pipe fatigue test, a procedure to predict the fatigue crack growth was developed, and the integrity of piping during the plant service life was evaluated. In the LBB verification test, the pipe fracture test and the leak rate test were performed to verify the LBB in the primary piping.In the pipe rupture test, the influence of jet impingement on the target disk and the deformation behavior of whipping pipe and restraint were investigated. Using the test results, the jet ...

Energy Technology Data Exchange (ETDEWEB)

Upon request by the Science and Technology Agency of Japanese Government, the Japan Atomic Energy Research Institute has conducted Piping Reliability Test Program to demonstrate the safety and reliability of light water reactor primary pipings. In this report, the results of the program are summarized. In the test program, pipe fatigue tests, Leak-Before-Break (LBB) verification tests and pipe rupture tests were carried out to examine the integrity of pipings, to verify the LBB concept and to demonstrate the effectiveness of the protective measures against jet impingement and pipe whip under pipe rupture event, respectively. In the pipe fatigue tests, a procedure to predict the fatigue crack growth was developed and the integrity of piping during plant service life was demonstrated. In the LBB verification tests, pipe fracture tests and leak rate tests were performed using cracked pipes. Based on the test results, LBB in the primary pipings was ...

International Nuclear Information System (INIS)

Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM ...

International Nuclear Information System (INIS)

The heavy dependence on nuclear power eventually raise the issues of an efficient utilization of uranium resources, which Korea presently imports from abroad, end of a spent fuel storage. From the viewpoint that sodium-cooled fast Reactors (SFRs) have the potential of an enhanced safety by utilizing inherent safety characteristics, trans-uranics (TRU) reduction and resolving the spent fuel storage problems through a proliferation-resistant actinide recycling. SFRs are sure to be most promising nuclear power operation. The Korea Atomic Energy Research Institute (KAERI) has been developing SFR design technologies since 1997. And nowadays, the preliminary heat balance of the demonstration SFR is calculated. However, in order to verify design condition of the NSSS, it is necessary to set the heat balance and the conceptual design for BOP of the SFR as a part of the SFR design technique development business. Moreover, in order to confirm whether the ...

International Nuclear Information System (INIS)

To obtain reactor physics parameters for high-moderation mixed-oxide (MOX) cores, Nuclear Power Engineering Corporation (NPEC), the French Atomic Commission (CEA), and their industrial partners have conducted a MOX core physics experimental program called MISTRAL with the EOLE critical facility of the Cadarache research center. This program consists of four high-moderation cores and was successfully completed in July 2000. This paper describes the analysis results of MISTRAL-3 that is a homogeneous full MOX cylindrical core (H/HM = 6.2) with an 80-cm height and a 59-cm diameter consisting of 1388 standard pressurized water reactor-type MOX fuel rods of 7.0 wt% plutonium-enrichment in a square pitch of 1.39 cm. NPEC has been analyzing the experimental results by using the SRAC and MVP code systems. SRAC and MVP calculate the nuclear core characteristics correctly for the high-moderation MOX core MISTRAL-3. No apparent trend ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station Unit-4 is first 540 MWe pressurized heavy water reactor in India. It achieved criticality on 06th March 2005 and then operated at full power i.e 500 MWe. Radiation workers during the normal operation and reactor shutdown are exposed to radiation field. The control of dose rates and the collective dose of the radiation workers is most important for the best performance of the reactor. Experience gained during the operation of the 220 MWe reactors has shown that the Moderator system, primary heat transport system, annulus gas system and moderator cover gas system are the main systems contributing to the dose rate and collective dose. In order to identify the radio nuclides contributing to the radiation field, study was undertaken at TAPS Unit-4. Various samples from the Moderator, primary heat transport system, annulus gas system and moderator cover gas ...

Energy Technology Data Exchange (ETDEWEB)

As for Wolsung NPP unit 1, radiation shielding analysis was performed by using neutron diffusion codes, one-dimensional discrete ordinates code ANISN, and analytical methods. But for Wolsung NPP unit 2, 3, and 4, two-dimensional discrete ordinates code DOT substituted for neutron diffusion codes. In other words, the method of analysis and computer codes used for radiation shielding of CANDU 6 type reactor have been improved. Recently Monte Carlo MCNP code has been widely utilized in the field of radiation physics and other radiation related areas because it can describe an object sophisticately by use of three-dimensional modelling and can adopt continuous energy cross-section library. Nowadays Monte Carlo method has been reported to be competitive to discrete ordinate method in the field of radiation shielding and the former has been known to be superior to the latter for complex geometry problem. However, Monte Carlo method had not been used for radiation ...

International Nuclear Information System (INIS)

This paper summarizes the progress to date by CH2M HILL and the UKAEA in development of a parametric modelling capability for estimating the costs of large nuclear decommissioning projects in the United Kingdom (UK) and Europe. The ability to successfully apply parametric cost estimating techniques will be a key factor to commercial success in the UK and European multi-billion dollar waste management, decommissioning and environmental restoration markets. The most useful parametric models will be those that incorporate individual components representing major elements of work: reactor decommissioning, fuel cycle facility decommissioning, waste management facility decommissioning and environmental restoration. Models must be sufficiently robust to estimate indirect costs and overheads, permit pricing analysis and adjustment, and accommodate the intricacies of international monetary exchange, currency fluctuations and contingency. The development ...

International Nuclear Information System (INIS)

In the frame of the European Technology R and D programme for International thermonuclear experimental reactor (ITER) and in the area of high heat flux plasma facing components (HHFC), representative small-scale mock-ups were manufactured and tested to compare different concepts and joining technologies (i.e. active brazing, hot isostatic pressing (HIPping), diffusion bonding, etc.). On the basis of the results obtained by thermal fatigue tests, the monoblock concept resulted to be the most robust one, particularly when the HIPping manufacturing technology is used. Within this programme, ENEA developed an alternative technique for manufacturing plasma-facing components with a monoblock geometry of the ITER machine. The basic idea of this technique, named hot radial pressing (HRP), is to perform a radial diffusion bonding between the cooling tube and the armour tile by pressurising the internal tube only and by keeping the ...

Energy Technology Data Exchange (ETDEWEB)

The fourth in a series of international Leak-Before-Break (LBB) Seminars supported in part by the US Nuclear Regulatory Commission was held at the National Central Library in Taipei, Taiwan on May 11 and 12, 1989. The seminar updated the international polices and supporting research on LBB. Attendees included representatives from regulatory agencies, electric utilities, nuclear power plant fabricators, research organizations, and academic institutions. Regulatory policy was the subject of presentations by Mr. G. Arlotto (US NRC, USA) Dr. B. Jarman (AECB, Canada), Dr.P. Milella (ENEA-DISP, Italy), Dr. C. Faidy (EDF/Septen, France ), and Dr. K. Takumi (NUPEC, Japan). A paper by Mr. K. Wichman and Mr. A. Lee of the US NRC Office of Nuclear Reactor Regulation is included as background material to these proceedings; it discusses the history and status of LBB applications in US nuclear power plants. In addition, several papers on ...

Energy Technology Data Exchange (ETDEWEB)

A meeting was held on October 15, 16, 17, 1990 to discuss the state of tritium safety and environmental effects. The meeting was organized with the help of the International Energy Agency planning committee consisting of K. Steinmetz, Y. Seki, G. Nardella, and G. Vivian. Representative of tritium production facilities and heavy water reactor power production were also involved. The meeting was organized to address seven topics in tritium safety that were thought to require further work. The topics were: (1) materials science, (2) environmental models, (3) environmental model validation, (4) tritiated organic compounds, (5) human dosimetry, (6) tritium sampling and measurement, and (7) long-term environmental databases.

Energy Technology Data Exchange (ETDEWEB)

Recognizing that a high percentage of transmission-line faults are single-phase to earth and temporary in nature, provides the impetus for considering single-pole switching as a means to enhance the reliability of EHV transmission systems. The effectiveness of single-pole switching schemes is largely determined by the speed with which the secondary arcs extinguish, and hence allow system restoration. Simulation techniques that enable better prediction of the faulted-system response are of obvious importance to the design and assessment of the various single-pole switching scheme applications. In this thesis, digital methods are developed to enable the faulted response of EHV systems to be simulated for a variety of different single-pole switching schemes. These include conventional single-pole switching, the hybrid method of autoreclosure, the neutral switched reactor, and the High Speed Grounding Switch implementations. The work is of importance to system ...

International Nuclear Information System (INIS)

Through an international collaborative effort, a special version of the CONTAIN code is being developed for integrated mechanistic analysis of the conditions in liquid metal reactor (LMR) containments during severe accidents. The capabilities of the most recent code version, CONTAIN LMR/1B-Mod.1, are discussed. These include new models for the treatment of two condensables, sodium condensation on aerosols, chemical reactions, hygroscopic aerosols, and concrete outgassing. This code version also incorporates all of the previously released LMR model enhancements. The results of an integral demonstration calculation of a sever core-melt accident scenario are given to illustrate the features of this code version. 11 refs., 7 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

A study, based on a literature review was made to examine currently recommended meteorological measurement programs and diffusion prediction methods for nuclear power plants to determine their adequacy for plants located in coastal zones. Although procedures for handling the near-worst case (stable, light-wind situation) were judged adequately conservative, deficiencies in guidelines and procedures were found with respect to the following: failure to consider the role of coastal internal boundary layers; specifications for tower locations and instrument heights; methods of classifying atmospheric stability; methods of allowing credit for plume meander, and models specified for diffusion calculations. Recommendations were made for changes in the guidelines applicable to these topics. Areas in which additional research is needed were identified.

Energy Technology Data Exchange (ETDEWEB)

A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%. (author)

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. Sinusoidal forced vibration tests were carried out on three types of large-scale models to study the embedment effect on dynamic soil-structure interaction. The differences in the resonance curves and the impedance functions were discussed in relation to the vibration characteristics of the respective structures. The embedment effects on the structural responses vary according to the stiffness of the structure. The responses of the structures can be evaluated by the Axisymmetric FEM analyses. (author)

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.

Science.gov (United States)

We report on recent progress and improvements in the metal-organic chemical vapor deposition (MOCVD) growth of mid-infrared lasers and using a high speed rotating disk reactor (RDR). The devices contain AlAsSb active regions. These lasers have multi-stage, type I InAsSb/InAsP quantum well active regions. A semi-metal GaAsSb/InAs layer acts as an internal electron source for the multi-stage injection lasers and AlAsSb is an electron confinement layer. These structures are the first MOCVD multi-stage devices. Growth in an RDR was necessary to avoid the previously observed Al memory effects found in conventional horizontal reactors. A single stage, optically pumped laser yielded improved power (greater than 650 mW/facet) at 80K and 3.8um. A multi-stage 3.8-3.9um laser structure operated up to T=170K. At 80K, peak power greater than 100mW and a high slope- efficiency were observed in gain guided lasers.

Energy Technology Data Exchange (ETDEWEB)

High-burnup mixed oxide fuel pins from the Fast-Flux Test Facility (FFTF) reactor were sheared in a single-pin shear, dissolved in nitric acid, and then used in solvent extraction tests to assist in establishing operating parameters for fuel recycle facilities. The fuel burnups were 2, 36, 55, and 90 MWd/kg for initial cooling times of 2.5, 1.3, 1, and 1 year, respectively. These tests include the first experiments using fuel of approximately the reference burnup (80-MWd/kg peak burnup) irradiated under reference conditions. The FFTF is a sodium-cooled reactor with stainless steel-clad fuel; the oxide fuel, which is of two compositions, has Pu/(U + Pu) ratios of approx.0.225 and 0.275. The peak fuel center temperature was about 1640/sup 0/C, the peak internal cladding temperature was approx.530/sup 0/C, the peak heat rating was approx.300 W/cm, and the peak fluence (E > 0.1 MeV) was approx.15.7 x 10/sup 22/ ...

International Nuclear Information System (INIS)

The Department of Nuclear Engineering and Fluid Mechanics in the University of the Basque Country (UPV-EHU), has done calculations for the proposed benchmark problem, in the frame of the 11th international meeting of the IAHR working group on advanced nuclear reactors thermal-hydraulics (Obninsk-Russian Federation, 5-9 July 2004). The purpose of the benchmark is to compare experimental and analytical results of some experiments carried out in the State Scientific Center of Russian Federation 'Institute of Physics and Power Engineering' (SSC RF IPPE). These experiments were held to research the cooling of pin bundles by liquid metals in reference to the core of Nuclear Reactors such as BREST. The analytical results have been done with the Computational Fluid Dynamics (CFD) code FLUENT. Temperature and velocity fields are the main variables considered for the comparison, and some assumptions has been made in order to simplify ...

Science.gov (United States)

Deforestation in Mato Grosso, Brazil. atom_author. atom_name, Jesse Allen. atom_link. kml_href, http://earthobservatory.nasa.gov/Feeds/GoogleEarth/ ...

International Nuclear Information System (INIS)

In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a ...

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Li{sub 2}TiO{sub 3} is regarded as one of the most suitable candidates for the solid tritium breeder material of D-T fusion reactors. It is known that, in an operating fusion reactor, the radiation damage in Li{sub 2}TiO{sub 3} will be caused by fast neutrons, energetic tritons and helium ions generated in {sup 6}Li(n,{alpha}){sup 3}H reaction. The irradiation damage caused by such radiation may result in the microstructural changes, and the changes may affect the characteristics of Li{sub 2}TiO{sub 3} such as tritium release behavior. Thus the study of irradiation defects and microstructural changes caused by irradiation in Li{sub 2}TiO{sub 3} is essential to evaluate its irradiation performance. Simulation of the fusion reactor environment and hence the study of a synergistic effect of atomic displacement damage in Li{sub 2}TiO{sub 3} are approached by a simultaneous ...

CERN Document Server

Individual laser cooled atoms are delivered on demand from a single atom magneto-optic trap to a high-finesse optical cavity using an atom conveyor. Strong coupling of the atom with the cavity field allows simultaneous cooling and detection of individual atoms for time scales exceeding 15 s. The single atom scatter rate is studied as a function of probe-cavity detuning and probe Rabi frequency, and the experimental results are in good agreement with theoretical predictions. We demonstrate the ability to manipulate the position of a single atom relative to the cavity mode with excellent control and reproducibility.

International Nuclear Information System (INIS)

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 (16N) and Oxygen-19 (19O) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of 19O and 16N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high ambient radiation level even though sensitivity is appreciably good. For detector position in RB in the accessible areas and out side the ...

International Nuclear Information System (INIS)

The world's fleet of nuclear power plants is, on average, more than 20 years old. Even though the design life of a nuclear power plant is typically 30-40 years, it is quite feasible that many plants will be able to operate in excess of their design lives, provided that nuclear power plant engineers demonstrate by analysis, trending, equipment and system upgrades, increased vigilance, testing and ageing management that the plant will operate safely. In the operation of nuclear power plants, safety should be always the prime consideration. Plant operators and regulators must always ensure that plant safety is maintained, and where possible enhanced, during a plant's operating lifetime. Nuclear power plant life management (PLiM) has gained increased attention over the past decade, and effective ageing management of systems, structures and components (SSCs) is a key element in PLiM for the safe and reliable long term operation of nuclear power plants. A PLiM programme is an effective tool ...

Energy Technology Data Exchange (ETDEWEB)

This Conference is a key technology transfer activity supported by the ongoing Combustion Equipment Technology (Oil-Heat R and D) program at BNL, and is aimed at providing a forum for the exchange of information among international researchers, engineers, manufacturers, and marketers of oil-fired space-conditioning equipment. The objectives of the Conference were to: identify and evaluate the state-of-the-art and recommend new initiatives for higher efficiency, a cleaner environment, and to satisfy consumer needs cost-effectively, reliably, and safely; and foster cooperation among federal and industrial representatives with the common goal of sustained national economic growth and energy security via energy conservation. The 1996 Oil Technology Conference comprised: (a) fourteen technical papers, and (b) four workshops which focused on mainstream issues in oil-heating technology, namely: oilheat research agenda forum; fan atomized burner ...

Energy Technology Data Exchange (ETDEWEB)

Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub ..cap alpha..//K/sub ..beta../ X-ray intensity ratio was found to be an indicator of the nearest neighbour ...

Energy Technology Data Exchange (ETDEWEB)

Most of the tissue banks in the Asia Pacific region have been using ionising radiation at 25 kGy to sterilise human tissues for save clinical usage. Under tissue banking quality system, any dose employed for sterilisation has to be validated and the validation exercise has to be a part of quality document. Tissue grafts, unlike medical items, are not produced in large number per each processing batch and tissues relatively have a different microbial population. A Code of Practice established by the International Atomic Energy Agency (IAEA) in 2004 offers several validation methods using smaller number of samples compared to ISO 11137 (1995), which is meant for medical products. The methods emphasise on bioburden determination, followed by sterility test on samples after they were exposed to verification dose for attaining of sterility assurance level (SAL) of 10{sup -1}. This paper describes our experience in using the IAEA Code of Practice in ...

International Nuclear Information System (INIS)

Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican ...

CERN Document Server

Safe operation of research reactors and critical assemblies

International Science & Technology Center (ISTC)

Development of Methods and Apparatus for Processes Diagnostics in Plasma Reactors at the Neutralization of Chemical Herbiside and Pestiside

International Nuclear Information System (INIS)

The first Advanced Boiling Water Reactor (ABWR) started commercial operation as Tokyo Electric Power Company's (TEPCO) Kashiwazaki-Kariwa Nuclear Power Station Unit No.6 (K-6) in November 1996 and its sister Unit No.7 (K-7) in July 1997. The ABWR was developed to achieve higher reliability and safety margin while improving overall operability and economics. To achieve these goals, the optimal Boiling Water Reactor (BWR) technologies had been studied, tested and were finally adopted into the ABWR design. These technologies were called 'First of a Kind' and include the Reactor Internal Pump (RIP), Fine Motion Control Rod Drive (FMCRD), Reinforced Concrete Containment Vessel (RCCV), and integrated digital Instrumentation and Control System (I and C). Intensive development study, confirmation tests and verification tests were conducted by the plant equipment suppliers, electric utilities, and government ...

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. Reactor buildings in Japan are partially embedded in general. Therefore, it is important to know how partial embedment affects the vibration characteristics of reactor buildings relating to seismic safety. Laboratory tests were conducted using a ground model made of silicone rubber (Young's modulus 2.3x10"6 Pa, Poisson's ratio 0.484, Density 1.24x 10"3 kg/m3 , Damping ratio 0.01) and a foundation model made of aluminum shown to study the effects of embedment on soil-structure interaction with different backfill types. The ground model is a cylinder, 70 cm high and 300 cm in diameter, with pit where the parallelepiped foundation model with square plan of 30 cm x 30 cm and 18 cm ...

Energy Technology Data Exchange (ETDEWEB)

The first of three scheduled poolside fuel examinations at the Oyster Creek reactor conducted during February/March 1980, was directed at one of the four symmetrically loaded ENC 8 x 8 lead assemblies that had achieved a burnup of approx. 25,000 MWd/MTU. Forty-five of the fuel rods in assembly UD3-109 were removed and examined. In general, the individual fuel rods were in excellent condition. The average fuel rod diameter continued to decrease during the last cycle was assembly burnup increased from 19,500 to 25,700 MWd/MTU. The creepdown since the beginning of life (BOL) in the center of the fuel rods is about 0.003 in. The fuel rods bore no indication of cladding ridging. Fuel rod growth continued at a linear rate of about 0.02% per GWd/MTU burnup since BOL. Preliminary eddy current test data showed that the cladding was free of significant defects. Visual examination of fuel rods, spacers, and tie plate revealed no unusual conditions. An average assembly burnup ...

Energy Technology Data Exchange (ETDEWEB)

Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with ...

Energy Technology Data Exchange (ETDEWEB)

We have been developing an innovative Steam Generator concept of Fast Breeder Reactors by using liquid-liquid direct contact heat transfer. In this concept, the SG shell is filled with a molten alloys, which is heated by primary sodium. Water is fed into the high temperature molten alloy, and evaporates by direct contact heating. In order to obtain the fundamental information to discuss the heat transfer mechanisms of the direct contact between the water and the alloy, this phenomenon was visualized by real-time neutron radiography. JRR-3M real-time thermal neutron radiography in Japan Atomic Energy Research Institute was used. Followings are main results. (1) The vigorous evaporation occurs in the molten alloy. This phenomena is different from the known phenomenon such as the evaporation of refrigerant R-113 in the water. (2) The evaporation in the bubble has finished in a moment due to high heat transfer performance between the liquid and ...

International Nuclear Information System (INIS)

France has a wide variety of experimental spent fuels different from LWR spent fuel discharged from commercial reactors. Reprocessing such fuels would thus require the development and construction of special facilities. The French Atomic Energy Commission (CEA) has consequently opted for long-term interim storage of these spent fuels over a period of 50 years. Comparative studies of different storage concepts have been conducted on the basis of safety (mainly containment barriers and cooling), economic, modular design and operating flexibility criteria. These studies have shown that dry storage in a concrete vault cooled by natural convection is the best solution. A research and development program including theoretical investigations and mock-up tests confirmed the feasibility of cooling by natural convection and the validity of design rules applied for fuel storage. A facility called CASCAD was built at the CEA's Cadarache Nuclear Research ...

International Nuclear Information System (INIS)

The report presents the results of the study carried out to estimate the accident risk involved in the transport of spent fuel from Rajasthan Atomic Power Station near Kota to the fuel reprocessing plant at Tarapur. The technique of probabilistic safety analysis is used. The fuel considered is the Indian pressurised heavy water reactor fuel with a minimum cooling period of 485 days. The spent fuel is transported in a cuboidal, naturally-cooled shipping cask over a distance of 822 km by rail. The Indian rail accident statistics are used to estimate the basic rail accident frequency. The possible ways in which a release of radioactive material can occur from the spent fuel cask are identified by the fault tree analysis technique. The release sequences identified are classified into eight accident severity categories, and release fractions are assigned to each. The consequences resulting from the release are estimated by the computer code RADTRAN ...

Energy Technology Data Exchange (ETDEWEB)

The development and evaluation of a post-column reaction detector sensitive to platinum(II) complexes is presented in which sodium bisulfite is used as the derivatizing agent with potassium dichromate as an activating agent. The influences of mobile phase changes (i.e., pH, organic modifiers, electrolytes), oxygen, metal ions, and order of reagent addition on reaction kinetics and product yield are defined and used in optimization of detector response. Detection at lambda/sub max/ 290 nm results in an on-line post-column sensitivity of 40-60 ng/mL for selected cis-dichloroplatinum complexes and a sensitivity of 300-1200 ng/mL for four (substituted)-malonato-platinum complexes. The reaction detector is used to monitor the kinetics of aquation of cisplatin (CDDP) and to quantitate CDDP degradation in plasma. As the sensitivity for CDDP in plasma is comparable to that achieved from high pressure liquid chromatography (HPLC) effluent fractionation/off-line flameless ...

International Nuclear Information System (INIS)

Tensile properties of reduced-activation 10Cr-30Mn austenitic steels with carbon levels from 0.003 to 0.55% were investigated over the temperature range from room temperature to 873 K after neutron irradiation in the Japan Materials Testing Reactor at 573 K to 8.5x10"2"2 n/m"2. Irradiation-induced increase in yield stress increased significantly with carbon concentration up to about 0.1% and it was constant above 0.1% carbon. A high density of dislocation loops with small (below 10 nm) and large (20-30 nm) sizes formed during irradiation. The high density, small loops caused a large irradiation hardening, while the large loops contributed only slightly to irradiation hardening. It was considered that carbon atoms formed the small loops together with irradiation defects. The deformation channeling was observed in the irradiated high carbon steels, 0.11 and 0.55% carbon, but not in the very low carbon steel, 0.003% carbon, after deformation near ...

International Nuclear Information System (INIS)

Further to a cost-benefit analysis of the various medium-term and long-term and H.L.W. storage possibilities, C.E.A. (French Atomic Energy Commission) and S.G.N. decided to develop an original dry storage process with natural convection cooling that offers many advantages: cut in the total investment and operating costs; high operating safety; natural convection cooling; existence of two containment barriers irrespective of the assumed clad conditions; flexible, modular and compact design. The process was first implemented in the so-called CASCAD Cadarache Facility (vault-type facility) constructed in Cadarache mainly to store fuel from Brennilis heavy water reactor. For the purpose, a large program was set up to develop and validate computer codes, in particular with the use of mockups. On the request of many clients, and owing to the outstanding operating results of the CASCAD Cadarache Facility, SGN was brought to adapt the process to the ...

Energy Technology Data Exchange (ETDEWEB)

A p[sup +]-Al[sub 0.3]Ga[sub 0.7]As/n[sup +]-GaAs heterojunction tunnel diode was fabricated using Atomic Layer Epitaxy (ALE) growth technique. Background carbon doping of [similar to]10[sup 20] cm[sup [minus]3] was achieved in the p-side of the diode by optimizing growth conditions such as V/III ratio, exposure times to reactant gases, and growth temperature. In the n-side of the diode GaAs was doped with silane and doping concentrations as high as 7[times]10[sup 18] cm[sup [minus]3] were also achieved. The dopants are chosen to satisfy the high levels and low diffusion requirements. The diode can be used to interconnect the high and low band-gap cells in the AlGaAs/GaAs cascade solar cell structure. The reactor used in this investigation is a commercial MOCVD system which has been specially modified for dual operation of ALE and MOCVD growth modes.

Science.gov (United States)

This paper is dedicated to the treatment of sludge occurring in frame of the Egyptian produced from oil and gas production. The activity levels of three radium isotopes: Ra-226 (of U-series), Ra-228 and Ra-224 (of Th-series) in the solid TENORM waste (sludge) were first evaluated and followed by a sequential treatment for all radium species (fractions) presented in TENORM. The sequential treatment was carried out based on two approaches 'A' and 'B' using different chemical solutions. The results obtained indicate that the activity levels of all radium isotopes (Ra-226, Ra-228 and Ra-224) of the environmental interest in the TENORM waste sludge were elevated with regard to exemption levels established by IAEA [International Atomic Energy Agency (IAEA), International basic safety standards for the protection against ionizing radiation and for the safety of radiation sources. GOV/2715/Vienna, 1994]. Each approach of the ...

International Nuclear Information System (INIS)

The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m"2 of floor area, the irradiator design is ...

CSIR Research Space (South Africa)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Indian Institute of Science Theses & Dissertations (India)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The major part of the chapter 'Physical Properties' in concerned with, in addition to nuclear and atomic properties, the properties of the metal molybdenum. Due to the huge number of relevant papers, the present volume comprises only the first part of the metal properties, i.e. the crystallographic properties, the electronic structure, the lattice dynamics, and subsequently the mechanical and thermal properties. There are two small sections where the properties of the molecules, primarily Mo/sub 2/ and Mo/sub 6/, and of the vapor are described. The strength and some other mechanical properties have been frequently investigated to establish the change due to neutron irradiation, because this affects the durability of the fuel containers in nuclear reactors. For that purpose, changes in structure, texture, etc., due to irradiation had to be determined; the structural properties of nonirradiated samples also had to be studied in ...

International Nuclear Information System (INIS)

The total radiation rate, angular distribution of the emitted energy and photon correlations of the cooperative spontaneous radiation from two atoms with different resonance frequencies and spontaneous decay rates are calculated. Contrary to the case of two identical atoms oscillations appear in the total radiation rate and the spatial distribution of the total number of emitted photons differs from the single-atom radiation pattern. The effect of the dipole-dipole near-field interaction on the time evolution of the atomic system is discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

An essential issue in gallium (Ga)-stabilized fcc-phase plutonium ({delta}-Pu) is the formation of helium (He) voids and bubbles emanating from the radiolytic decay of the Pu. The rate of formation of He voids and bubbles is related to the He-defect formation energies and their associated migration barriers. The size and shape distributions of the bubbles are coupled to these critical migration processes. The values of the defect formation energies, internal pressure, and migration barriers can be estimated from atomistic calculations. Complicating this picture is the destruction of He-filled voids and bubbles by subsequent radiolytic decay events. The present study concerns the construction of the necessary potential energy surfaces for the Pu-He and He-He interactions within the modified embedded atom method (MEAM). Once fully tested, the potentials will be used to estimate the He-defect formation energies and barriers to the migration of ...

International Nuclear Information System (INIS)

To clarify the effects of the principal factors that govern the thermal fragmentation of a molten metallic fuel jet in the course of fuel-coolant interaction, which is important in evaluating the sequence of core disruptive accidents (CDAs) for metallic fuel fast reactors, basic experiments were carried out using molten metallic fuel simulants (copper and silver) and a sodium pool.Fragmentation of a molten metal jet with a solid crust was caused by internal pressure produced by the boiling of sodium, which is locally entrapped inside the jet due to hydrodynamic motion between the jet and the coolant. The superheating and the latent heat of fusion of the jet are the principal factors governing this type of thermal fragmentation. On the other hand, the effect of the initial sodium temperature is regarded as negligible in the case of thermal conditions expected to result in CDAs for practical metallic fuel cores. Based on the fragmentation data ...

Energy Technology Data Exchange (ETDEWEB)

Microstructural analyses by several advanced metallographic techniques were conducted on austenitic stainless steel mockup and core shroud welds that had cracked in boiling water reactors. Contrary to previous beliefs, heat-affected zones of the cracked Type 304L, as well as 304 SS core shroud welds and mockup shielded-metal-arc welds, were free of grain-boundary carbides, which shows that core shroud failure cannot be explained by classical intergranular stress corrosion cracking. Neither martensite nor delta-ferrite films were present on the grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the core shroud welds were significantly contaminated by oxygen and fluorine, which migrate to grain boundaries. Significant oxygen contamination seems to promote fluorine contamination and suppress thermal sensitization. Results of slow-strain-rate tensile tests also indicate that fluorine exacerbates the susceptibility of ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear energy related research in Switzerland is concentrated at PSI`s Nuclear Energy and Safety Research Department (NES). The total effort invested in nuclear energy research in 1998 amounted to about 195 py/a and 4.5 millions CHF of investment and maintenance costs. Approximately half of the salary, investment and maintenance costs are externally funded, primarily by the Swiss Utilities, the national co-operative for the disposal of nuclear waste (NAGRA), the Federal Office of Energy (BFE) through the nuclear safety inspectorate (HSK) and the Federal Office for Science and Education (BBW) in connection with the EC Framework Programmes; an increasing part of external funding is coming from domestic and foreign industry (nuclear component and fuel suppliers). The activities of the department are concentrated on three main domains of: Safety and related problems of operating plants; safety features of future reactor and fuel cycles; waste management. 4 % of the ...

International Nuclear Information System (INIS)

Steam generators of four VVER-440 units at nuclear power plants V-1 and V-2 in Jaslovske Bohunice (Slovakia) were gradually changed by new original 'Bohunice' design in period 1994-1998. Corrosion processes before and after these design and material changes in Bohunice secondary circuit were studied using Moessbauer spectroscopy during last 25 years. Innovations in the feed water pipeline design as well as material composition improvements were evaluated positively. Moessbauer spectroscopy studies of phase composition of corrosion products were performed on real specimens scrapped from water pipelines or in form of filter deposits. The corrosion of new feed water pipelines system (from austenitic steel) in combination to innovated operation regimes goes dominantly to magnetite. The hematite presence is mostly on the internal surface of steam generator body and its concentration increases towards the top of the body. In the results interpretation it is necessary to ...

Energy Technology Data Exchange (ETDEWEB)

Westinghouse is currently conducting the pre-application licensing of the International Reactor Innovative and Secure (IRIS). One of the key aspects of the IRIS design is its safety-by-designTM philosophy and within this framework the PRA is being used as an integral part of the design process. The most ambitious risk-related goal for IRIS is to reduce the Emergency Planning Zone (EPZ) to within the exclusion area by demonstrating that the off-site doses are consistent with the US Protective Action Guidelines (PAGs) for initiation of emergency response so that the required protective actions would be limited to the exclusion area. As a first step, a model has been developed to provide a first order approximation of the Large Early Release Frequency (LERF) as a surrogate predictor of the off-site doses. A key-aspect of the LERF model development is the characterization of the possible paths of release. Four main categories have been historically ...

International Nuclear Information System (INIS)

A laminated material composed of glass cloth/polyimide film/epoxy resin will be used as an insulating material for superconducting coil of International Thermonuclear Experimental Reactor (ITER). In order to keep safe and stable operation of the superconducting coil system, it is indispensable to evaluate radiation resistance of the material, because the material is exposed to severe environments such as high radiation field and low temperature of 4 K. Especially, it is important to estimate the amount of gases evolved from the insulating material by irradiation, because the gases affect on the purifying system of liquid helium in the superconducting coil system. In this work, the gas evolution from the laminated material by gamma ray irradiation at liquid nitrogen temperature (77 K) was investigated, and the difference of gas evolution behavior due to difference of composition in the epoxy resin was discussed. It was found that the main gases ...

Energy Technology Data Exchange (ETDEWEB)

Cementitious materials have physical and chemical properties that are well suited for the requirements of radioactive waste management. Namely, the materials have low permeability and durability that is consistent with the time frame required for short-lived radionuclides to decay. Furthermore, cementitious materials can provide a long-term chemical environment that substantially reduces the mobility of some long-lived radionuclides of concern for decommissioning (e.g., C-14, Ni-63, Ni-59). Because of these properties, cementitious materials are common in low-level radioactive waste disposal facilities throughout the world and are an attractive option for entombment of nuclear facilities. This paper describes design considerations for cementitious barriers in the context of performance over time frames of a few hundreds of years (directed toward short-lived radionuclides) and time frames of thousands of years (directed towards longer-lived radionuclides). The emphasis is on providing a ...

Energy Technology Data Exchange (ETDEWEB)

Technologies producing high power negative ion beams have been highly developed in these years at JAERI for use in neutral beam injectors for heating the thermonuclear fusion plasmas. At present, it is possible to produce multi-ampere H-/D- ion beams quasi-continuously at energies more than a few hundred keV with a good beam optics of beamlet divergence of a few milli-radian. Based on these technologies, two R and D projects have been initiated; one is to develop a 22A/500keV/10s D- ion source for the neutral beam injector for JT-60U, and the other is to develop a 1A/1MeV/60s H- ion source to demonstrate high current negative ion acceleration up to the energy of 1MeV, the energy required for the neutral beam injector for International Thermonuclear Experimental Reactor (ITER). (author).

Energy Technology Data Exchange (ETDEWEB)

Recently, the capabilities of the CORMLT code, which was designed to predict heatup, degradation, and meltdown of core and Reactor Pressure VEssel (RPV) internals during postulated severe accidents, were enhanced to enable tracking of individual fission product species during core meltdown. In addition, a mechanistic treatment of the release and flow of molten materials was developed to replace the engineering models developed earlier. In the present paper, the improved models are described and predictions of melt progression for a postullated accident sequence (TMLB') are discussed. A key issue in the new modeling is the mechanical behavior of fuel pellet stacks during run-off of molten cladding. One view is that capillary forces result in ''welding'' of porous fuel, thereby promoting free-standing pellet stacks; another is that rubblization and slumping of fuel take place. Results are reported for ...

Energy Technology Data Exchange (ETDEWEB)

The present paper is concerned with development and application of a so-called Effective Convection Model (ECM), which aims to provide a detailed, mechanistic description of heat transfer processes in a BWR lower plenum. The ECM is a Computational Fluid Dynamics (CFD)-like tool which employs a simpler and more effective approach to compute heat transfer by solving only energy conservation equation instead of solving the full set of Navier-Stokes and energy equations by a CFD code. We implement the ECM in a CFD code (Fluent), with detailed description of the ECM development, implementation and validation. A dual approach is used to validate the ECM, namely validation against experimental data and against heat transfer results obtained by CFD predictions in the same geometries and conditions. Insights gained from CFD simulations are also used to improve ECM. The ECM capability as an effective tool to simulate heat transfer of an internally heated volume in ...

Energy Technology Data Exchange (ETDEWEB)

Positron annihilation experiments on Fe-Cu model dilute alloys of nuclear reactor pressure vessel (RPV) steels have been performed after neutron irradiation in JMTR. Nanovoids whose inner surfaces were covered by Cu atoms were clearly observed. The nanovoids transformed to ultrafine Cu precipitates by dissociating their vacancies after annealing at around 400degC. The nanovoids and the ultrafine Cu precipitates are strongly suggested to be responsible for irradiation-induced embrittlement of RPV steels. Effects of Ni, Mn and P addition on the nanovoid and Cu precipitate formations were also studied. The nanovoid formation was enhanced by Ni and P, but suppressed by Mn. The Cu precipitates after annealing around 400degC were almost free from these doping elements and hence were pure Cu in the chemical composition. Furthermore the Fermi surface of the 'embedded' Cu precipitates with a body centered cubic crystal structure was ...

International Nuclear Information System (INIS)

As a part of the compatibility analysis of DUPIC fuel in CANDU reactors, the radiation physics calculations have been performed for the CANDU primary shielding system, thermal shield, radiation damage, transportation cask and storage. At first, the primary shield system was assessed for the DUPIC fuel core, which has shown that the dose rates and heat deposition rates through the primary shield of the DUPIC fuel core are not much different from those of natural uranium core because the power levels on the core periphery are similar for both cores. Secondly, the radiation effects on the critical components and the themal shields were assessed when the DUPIC fuel is loaded in CANDU reactors. Compared with the displacement per atom (DPA) of the critical component for natural uranium core, that for the DUPIC fuel core was increased by -30% for the innermost groove and the weld points and by -10% for the corner of the calandria ...

International Nuclear Information System (INIS)

The problem of fast wave plasma heating in reactor-torsatron at the ICRF range in scenarios, optimal for fusion reactor, is numerically studied.

International Nuclear Information System (INIS)

... californium 252 fftf reactor mockup power density reactor cores reactor noise