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Sample records for ce standard reactor

  1. The ABB-CE system 80 standard plant design

    International Nuclear Information System (INIS)

    Design standardization of nuclear power plants provides more cost certainty and safer, more reliable plant performance to electric utilities. The U.S. nuclear market recognized these benefits of standardization in the mid-1970's and embarked on a program of licensing standard plant designs. ABB Combustion Engineering Nuclear Power (ABB-CE) had long before realized the many benefits of standardization and established a design approach that maximized these benefits. Standardization, however, does not mean stagnation. The System 80 design is a modern, proven pressurized water reactor (PWR) that has evolved through a process of continuous improvement. It has been in operation at the three unit station at Palo Verde in the U.S. since 1986. Subsequent System 80 plants (eight units) are either in operation, conducting initial start-up, or are under construction in the Republic of Korea. This design offers a high degree of safety as exhibited by the low core damage frequency (CDF) and many years of safe operation. As a group, the System 80 plants have maintained a high plant availability, with an average value exceeding 80 percent since 1991. Over the last three years, the System 80 plants have an average availability exceeding the EPRI ALWR Utility Requirements Document goal of 87%. The purpose of this paper is to provide descriptions and information regarding ABB-CE's System 80 Standard Plant, which is currently implemented in South Korea, and is ideally suited and being proposed for future deployment in Asia

  2. Standard Technical Specifications for Combustion Engineering Pressurized Water Reactors

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for Combustion Engineering Pressurized Water Reactors (CE-STS) is a generic document prepared by the US NRC for use in the licensing process of current Combustion Engineering Pressurized Water Reactors. The CE-STS sets forth the limits, operating conditions, and other requirements applicable to nuclear reactor facility operation as set forth by Section 50.36 of 10 CFR 50 for the protection of the health and safety of the public. The document is revised periodically to reflect current licensing requirements

  3. Standards for reactor accident cases

    International Nuclear Information System (INIS)

    The Committee on Standards for reactor accident cases in the Netherlands published its recommendations to the Minister of Health. Maximum permissible quantities of radiation and radionuclide intake are presented for adults and children as well as pregnant women. Exposure limit standards for the whole body as well as specific organs and other parts are given. Also considered is the contamination of cattle and cows' milk. The standards are compared with those of the ICRP and the English Medical Research Council

  4. New revisions of reactor physics standards

    International Nuclear Information System (INIS)

    This paper presents an overview of two of the most basic reactor physics standards, the newly revised “Steady State Neutronics Methods for Power Reactor Analysis” and its companion standard, “Nuclear Data for Reactor Design”. These two popular state-of-the-art standards provide important guidance for developing the necessary input data needed to calculate reactor lattice and core parameters such as reaction rates spatial distributions, reactivity and flux distributions in power reactors for all currently used reactor types, from fast to thermal reactors. The standards provide guidance for the selection of cross section data and libraries, the development of nuclear data sets suitable for specific applications, energy group structures and group collapsing. Key elements in the complex sequence of power reactor calculations are outlined. The effects of simplifications and approximations made in the treatment of the neutronic and geometric models and the biases and uncertainties resulting from such simplifications and assumptions are discussed. In the newly-revised standard on neutronics methods, clear distinction is made between the two important tools for assessing the reliability of the results of the calculations, verification and validation. To provide an auditable path in the verification and validation processes, the standard requires detailed documentation including methods used, selection of calculation models and experimental data and results of higher order calculations. (author)

  5. Impact of proposed research reactor standards on reactor operation

    International Nuclear Information System (INIS)

    A Standards Committee on Operation of Research Reactors, (ANS-15), sponsored by the American Nuclear Society, was organized in June 1971. Its purpose is to develop, prepare, and maintain standards for the design, construction, operation, maintenance, and decommissioning of nuclear reactors intended for research and training. Of the 15 original members, six were directly associated with operating TRIGA facilities. This committee developed a standard for the Development of Technical Specifications for Research Reactors (ANS-15.1), the revised draft of which was submitted to ANSI for review in May of 1973. The Committee then identified 10 other critical areas for standards development. Nine of these, along with ANS-15.1, are of direct interest to TRIGA owners and operators. The Committee was divided into subcommittees to work on these areas. These nine areas involve proposed standards for research reactors concerning: 1. Records and Reports (ANS-15.3) 2. Selection and Training of Personnel (ANS-15.4) 3. Effluent Monitoring (ANS-15.5) 4. Review of Experiments (ANS-15.6) 5. Siting (ANS-15.7) 6. Quality Assurance Program Guidance and Requirements (ANS-15.8) 7. Restrictions on Radioactive Effluents (ANS-15.9) 8. Decommissioning (ANS-15.10) 9. Radiological Control and Safety (ANS-15.11). The present status of each of these standards will be presented, along with their potential impact on TRIGA reactor operation. (author)

  6. Standard mirror fusion reactor design study

    International Nuclear Information System (INIS)

    This report covers the work of the Magnetic Fusion Energy Division's reactor study group during FY 1976 on the standard mirror reactor. The ''standard'' mirror reactor is characterized as a steady state, neutral beam sustained, D-T fusioning plasma confined by a Yin-Yang magnetic mirror field. The physics parameters are obtained from the same physics model that explains the 2XIIB experiment. The model assumes that the drift cyclotron loss cone mode occurs on the boundary of the plasma, and that it is stabilized by warm plasma with negligible energy investment. The result of the study was a workable mirror fusion power plant, steady-state blanket removal made relatively simple by open-ended geometry, and no impurity problem due to the positive plasma potential. The Q (fusion power/injected beam power) turns out to be only 1.1 because of loss out the ends from Coulomb collisions, i.e., classical losses. This low Q resulted in 77% of the gross electrical power being used to power the injectors, thereby causing the net power cost to be high. The low Q stimulated an intensive search for Q-enhancement concepts, resulting in the LLL reactor design effort turning to the field reversal mirror and the tandem mirror, each having Q of order 5

  7. Reactor Section standard analytical methods. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Sowden, D.

    1954-07-01

    the Standard Analytical Methods manual was prepared for the purpose of consolidating and standardizing all current analytical methods and procedures used in the Reactor Section for routine chemical analyses. All procedures are established in accordance with accepted practice and the general analytical methods specified by the Engineering Department. These procedures are specifically adapted to the requirements of the water treatment process and related operations. The methods included in this manual are organized alphabetically within the following five sections which correspond to the various phases of the analytical control program in which these analyses are to be used: water analyses, essential material analyses, cotton plug analyses boiler water analyses, and miscellaneous control analyses.

  8. Standard molar enthalpy of formation of Ce2Zr2O8

    International Nuclear Information System (INIS)

    Highlights: • Cerium zirconate (Ce2Zr2O8) has been synthesized and characterized. • The ΔHdissolution of CeO2(s), ZrO2(s), Ce2Zr2O8(s) and Ce2Zr2O8(s) (decomp) have been measured. • ΔfH°298 of Ce2Zr2O8(s) was found to be −(4344.0 ± 4.0) kJ mol−1. - Abstract: Cerium zirconate, Ce2Zr2O8(s), is an interesting material having potential applications such as matrix for immobilization of nuclear waste, component in the inert matrix fuel, oxygen storage capacitor and catalyst for chemical reactions, etc. Long term stability of the compound under reactive conditions is essential for its utilization. Thermodynamics plays an important role in predicting the stability of the material. The present paper describes determination of the standard molar enthalpy of formation (ΔfH°298) of Ce2Zr2O8(s) employing a high temperature solution calorimeter. The enthalpies of dissolution of CeO2(s), ZrO2(s), Ce2Zr2O8(s) in liquid Na2O + MoO3 solvent (3:4 M ratio) at 986 K were measured employing a Calvet Calorimeter. The standard molar enthalpy of formation of the compound at 298 K (ΔfH°298) was calculated by combining the experimentally determined values of the reaction enthalpies with the auxiliary data from the literature. The standard molar enthalpy of formation (ΔfH°298) of Ce2Zr2O8 was found to be –(4344.0 ± 4.0) kJ mol−1. Ce2Zr2O8(s) is a metastable compound, which decomposes to Ce-rich ZrO2 and Zr-rich CeO2 fluorite-type phases, when heated above 1673 K. The extent of metastability of Ce2Zr2O8 compared to its stable decomposed products has been determined

  9. IAEA role in nuclear reactor safety standardization

    International Nuclear Information System (INIS)

    In 1981 the electricity generation by nuclear power plants all over the world reached 8% of total production. It can be expected that at the turn of century up to 25% of electric power will be provided by means of nuclear fuel burning. In connection with NPP total number growth, their attraction to large population centres, widening of the atomic energy application areas, the importance of nuclearreactor safety problems can only increase. The safety measures have usually the structure of sequential barriers: for accident preventing, for protection from accidents, for accident localization. NPP safety is a complex problem having scientific, engineering, juridical, social and political aspects. Since these problems have an international importance, IAEA should actively work on their solving. Practically all the topics of nuclear power development and nuclear reactor s;fety lie within the activity area of the Department of nuclear power and safety, its sections: of nuclear safety, nuclear power, nuclear fuel cycle. In 1974 a decision was made in IAEA about initiation of work on development of an international nuclear safety standards system (NUSS Programme). These activities are divided into five major branches: a government organization for nuclear safety regulations; site selection for NPP; NPP desing; operation, start of operation and decommissioning; quality provision for NPP. The report presents a list of documents, comprising the NUSS Programme. The complection of all the works within the scope of the Programme is planned for 1985. After 1985 the start of development of fast neutron reactor and fuel cycle enterprise safety standards is planned

  10. Brief overview of American Nuclear Society's research reactor standards

    International Nuclear Information System (INIS)

    The American Nuclear Society (ANS) established the research reactor standards group in 1968. The standards group, known as ANS-15, was established for the purpose of developing, preparing, and maintaining standards for the design, construction, operation, maintenance, and decommissioning of nuclear reactors intended for research and training

  11. American Nuclear Society standards for TRIGA reactors and their use

    International Nuclear Information System (INIS)

    The American Nuclear Society established a committee (ANS-15) with the expressed charter to develop standards for research reactors. These standards were to cover all aspects of research reactor operations, maintenance and administration. Standards have been written in every area of research reactor operations that the research reactor community has deemed important. One of the uppermost goals of the Standards Committee work is to produce standards that provide guidance and help to the research reactor community in a timely manner. To make the standards meaningful requires a great deal of cooperation between all segments of the reactor community. The research reactors - whether they are private, university or government owned - have a mission to perform. At the same time, the regulatory agencies also have a mission to perform, and with a spirit of mutual respect and cooperation, both can accomplish their goals. In the last five years this spirit has been present, and a number of very good standards have resulted. These standards should be a part of every research reactor library. In particular ANS-15.16 and ANS-15.1 have been endorsed by the regulatory agencies and are being used to evaluate submittals

  12. Integrated lid unit for a nuclear reactor of standard construction

    International Nuclear Information System (INIS)

    This is an integrated lid unit for a nuclear reactor of standard construction, where many components and sub-groups of the upper reactor structure are collected into one unit, which is lifted in one lifting operation from the reactor containment vessel. The integrated lid unit includes, in particular, the pressure vessel lid, a cooling jacket, the control rod drive mechanisms, a catch plate, a lifting device, a winch and a cable connection plate. (orig.)

  13. Standard molar enthalpy of formation of Ce{sub 2}Zr{sub 2}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Phapale, S.; Shukla, R.; Mishra, R., E-mail: mishrar@barc.gov.in; Tyagi, A.K.

    2014-12-05

    Highlights: • Cerium zirconate (Ce{sub 2}Zr{sub 2}O{sub 8}) has been synthesized and characterized. • The ΔH{sub dissolution} of CeO{sub 2}(s), ZrO{sub 2}(s), Ce{sub 2}Zr{sub 2}O{sub 8}(s) and Ce{sub 2}Zr{sub 2}O{sub 8}(s) (decomp) have been measured. • Δ{sub f}H°{sub 298} of Ce{sub 2}Zr{sub 2}O{sub 8}(s) was found to be −(4344.0 ± 4.0) kJ mol{sup −1}. - Abstract: Cerium zirconate, Ce{sub 2}Zr{sub 2}O{sub 8}(s), is an interesting material having potential applications such as matrix for immobilization of nuclear waste, component in the inert matrix fuel, oxygen storage capacitor and catalyst for chemical reactions, etc. Long term stability of the compound under reactive conditions is essential for its utilization. Thermodynamics plays an important role in predicting the stability of the material. The present paper describes determination of the standard molar enthalpy of formation (Δ{sub f}H°{sub 298}) of Ce{sub 2}Zr{sub 2}O{sub 8}(s) employing a high temperature solution calorimeter. The enthalpies of dissolution of CeO{sub 2}(s), ZrO{sub 2}(s), Ce{sub 2}Zr{sub 2}O{sub 8}(s) in liquid Na{sub 2}O + MoO{sub 3} solvent (3:4 M ratio) at 986 K were measured employing a Calvet Calorimeter. The standard molar enthalpy of formation of the compound at 298 K (Δ{sub f}H°{sub 298}) was calculated by combining the experimentally determined values of the reaction enthalpies with the auxiliary data from the literature. The standard molar enthalpy of formation (Δ{sub f}H°{sub 298}) of Ce{sub 2}Zr{sub 2}O{sub 8} was found to be –(4344.0 ± 4.0) kJ mol{sup −1}. Ce{sub 2}Zr{sub 2}O{sub 8}(s) is a metastable compound, which decomposes to Ce-rich ZrO{sub 2} and Zr-rich CeO{sub 2} fluorite-type phases, when heated above 1673 K. The extent of metastability of Ce{sub 2}Zr{sub 2}O{sub 8} compared to its stable decomposed products has been determined.

  14. International standardization of nuclear reactor designs - the way forward

    International Nuclear Information System (INIS)

    The concept of 'International Standardization of Nuclear Reactor Designs' means that vendors could build their designs in every country without having to adapt it specifically to national safety requirements. Such standardization would have two main effects. It would greatly facilitate nuclear new build worldwide by giving greater efficiency and certainty to the national licensing procedures; by taking into account the fact that vendors, and nowadays also utilities, are active across borders; by helping developing countries to establish their nuclear new build programmes; and by reducing the strain on human resources on both the regulators' and the industry's side. The second valuable effect of standardization would be to further enhance safety by improving the exchange of construction and operating experience among a number of reactors belonging to fleets of the same design. The World Nuclear Association's CORDEL (Cooperation in Reactor Design Evaluation and Licensing) Group has developed a concept for implementation of international standardization of reactor designs. It has defined a number of steps to be taken by industry. At the same time, possibilities offered by national and international regulatory mechanisms would have to be fully made use of, and some changes in regulatory frameworks might be necessary. Some steps especially towards greater cooperation of regulators have already been taken; however, much still remains to be done. The concept of deploying standardized reactor designs across a number of countries supposes an alignment and, if possible, harmonization of national safety standards; a streamlining of national licensing procedures, making them more efficient and predictable; and the willingness of national regulators to take into account licensing done in other countries. In the end, this should lead to a mutual acceptance of design approvals or, in a more distant future, even to a multinational design approval process. All in all, the concept

  15. Standard Technical Specifications for Westinghouse pressurized water reactors

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for Westinghouse Pressurized Water Reactors (W-STS) is a generic document prepared by the U.S. NRC for use in the licensing process of current Westinghouse Pressurized Water Reactors. The W-STS sets forth the Limits, Operating Conditions and other requirements applicable to nuclear reactor facility operation as set forth in by Section 50.36 of 10 CFR Part 50 for the protection of the health and safety of the public. This document is revised periodically to reflect current licensing requirements

  16. Reference design for the standard mirror hybrid reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bender, D.J.; Fink, J.H.; Galloway, T.R.; Kastenberg, W.E.; Lee, J.D.; Devoto, R.S.; Neef, W.S. Jr.; Schultz, K.R.; Culver, D.W.; Rao, S.B.; Rao, S.R.

    1978-05-22

    This report describes the results of a two-year study by Lawrence Livermore Laboratory and General Atomic Co. to develop a conceptual design for the standard (minimum-B) mirror hybrid reactor. The reactor parameters have been chosen to minimize the cost of producing nuclear fuel (/sup 239/Pu) for consumption in fission power reactors (light water reactors). The deuterium-tritium plasma produces approximately 400 MW of fusion power with a plasma Q of 0.64. The fast-fission blanket, which is fueled with depleted uranium and lithium, generates sufficient tritium to run the reactor, has a blanket energy multiplication of M = 10.4, and has a net fissile breeding ratio of Pu/n = 1.51. The reactor has a net electrical output of 600 MWe, a fissile production of 2000 kg of plutonium per year (at a capacity factor of 0.74), and a net plant efficiency of 0.18. The plasma-containment field is generated by a Yin-Yang magnet using NbTi superconductor, and the neutral beam system uses positive-ion acceleration with beam direct conversion. The spherical blanket is based on gas-cooled fast reactor technology. The fusion components, blanket, and primary heat-transfer loop components are all contained within a prestressed-concrete reactor vessel, which provides magnet restraint and supports the primary heat-transfer loop and the blanket.

  17. Reference design for the standard mirror hybrid reactor

    International Nuclear Information System (INIS)

    This report describes the results of a two-year study by Lawrence Livermore Laboratory and General Atomic Co. to develop a conceptual design for the standard (minimum-B) mirror hybrid reactor. The reactor parameters have been chosen to minimize the cost of producing nuclear fuel (239Pu) for consumption in fission power reactors (light water reactors). The deuterium-tritium plasma produces approximately 400 MW of fusion power with a plasma Q of 0.64. The fast-fission blanket, which is fueled with depleted uranium and lithium, generates sufficient tritium to run the reactor, has a blanket energy multiplication of M = 10.4, and has a net fissile breeding ratio of Pu/n = 1.51. The reactor has a net electrical output of 600 MWe, a fissile production of 2000 kg of plutonium per year (at a capacity factor of 0.74), and a net plant efficiency of 0.18. The plasma-containment field is generated by a Yin-Yang magnet using NbTi superconductor, and the neutral beam system uses positive-ion acceleration with beam direct conversion. The spherical blanket is based on gas-cooled fast reactor technology. The fusion components, blanket, and primary heat-transfer loop components are all contained within a prestressed-concrete reactor vessel, which provides magnet restraint and supports the primary heat-transfer loop and the blanket

  18. Outlines of revised regulation standards for experimental research reactors

    International Nuclear Information System (INIS)

    In response to the accident of TEPCO Fukushima Daiichi Nuclear Power Station, the government took actions through the revision of regulatory standards as well as the complete separation of regulation administrative department from promotion administrative department. The Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry, which has been in charge of the regulations of commercial reactors, and the Office of Nuclear Regulations of the Ministry of Education, Culture, Sports, Science and Technology, which has been in charge of the regulations of reactors for experiment and research, were separated from both ministries, and integrated into the Nuclear Regulation Authority, which was newly established as the affiliated agency of the Ministry of the Environment. As for the revision of regulations and standards, the Nuclear Safety Commission was dismantled, and regulation enacting authority was given to the new Nuclear Regulation Authority, and the regulations that stipulated new regulatory standards were enacted. This paper outlines the contents of regulations related mainly to the reactors for experiment and research, and explains the following: (1) retroactive application of the new regulatory standards to existing reactor facilities, (2) examinations at the Nuclear Regulatory Agency, (3) procedures to confirm the compliance to the new standards, (4) seismic design classification, and (5) importance classification of safety function. (A.O.)

  19. CE Marking of Structural Timber: the European Standardization Framework and its Effects on Italian Manufacturers

    Directory of Open Access Journals (Sweden)

    Francesco Negro

    2013-03-01

    Full Text Available Structural timber has been used for centuries in construction and represents a traditional building component in many countries of the European Union. Nowadays, the interest in its use has been renewed due to several factors such as: ease of processing, relative lightness, mechanical performance, sustainability and decorative appearance. On March 2011, the European Parliament adopted the Regulation (EU No. 305/2011 (known as CPR, laying down harmonized conditions for the marketing of construction products. According to CPR’s dispositions, since January 1st 2012 CE marking of structural solid timber has been mandatory. While on one hand for the building sector enterprises this implies remarkable challenges, on the other hand it will allow a better valorisation of structural timber. In this context, the present work illustrates the European standardization framework for CE marking of structural timber, particularly with respect to the visual grading method applicable to solid wood products and to the Italian experience in adopting the new rules.

  20. Fusion reactor design studies: standard accounts for cost estimates

    International Nuclear Information System (INIS)

    The fusion reactor design studies--standard accounts for cost estimates provides a common format from which to assess the economic character of magnetically confined fusion reactor design concepts. The format will aid designers in the preparation of design concept costs estimates and also provide policymakers with a tool to assist in appraising which design concept may be economically promising. The format sets forth a categorization and accounting procedure to be used when estimating fusion reactor busbar energy cost that can be easily and consistently applied. Reasons for developing the procedure, explanations of the procedure, justifications for assumptions made in the procedure, and the applicability of the procedure are described in this document. Adherence to the format when evaluating prospective fusion reactor design concepts will result in the identification of the more promising design concepts thus enabling the fusion power alternatives with better economic potential to be quickly and efficiently developed

  1. ASTM Standards for Reactor Dosimetry and Pressure Vessel Surveillance

    International Nuclear Information System (INIS)

    The ASTM standards provide guidance and instruction on how to field and interpret reactor dosimetry. They provide a roadmap towards understanding the current ''state-of-the-art'' in reactor dosimetry, as reflected by the technical community. The consensus basis to the ASTM standards assures the user of an unbiased presentation of technical procedures and interpretations of the measurements. Some insight into the types of standards and the way in which they are organized can assist one in using them in an expeditious manner. Two example are presented to help orient new users to the breadth and interrelationship between the ASTM nuclear metrology standards. One example involves the testing of a new ''widget'' to verify the radiation hardness. The second example involves quantifying the radiation damage at a pressure vessel critical weld location through surveillance dosimetry and calculation

  2. Guidance of clearance related standards in reactor facilities

    International Nuclear Information System (INIS)

    The reactor regulation law was amended in May 2005 to provide for the clearance system. The regulatory body confirmed radioactivity concentration of material and allowed the material be classified as 'material cleared from regulatory control'. The procedure of confirmation consisted of two steps; 1) methodology and 2) results, of measurement and assessment. Clearance related standards were issued as ordinance of Ministry and NISA information notice, which specified radioactive nuclides, radioactivity concentration, evaluation unit, how to decide radioactivity concentration, radiation measurement equipment and control of object material. This report was guidance of clearance related standards in reactor facilities with explanatory notes. By applying the clearance system, material of insignificant radiation level, which was part of concrete or metals generated from decommissioning of reactor facilities, could be released from regulatory control of radioactive waste as clearance material, and recycle of such material could result in reduction of radioactive waste amount. (T. Tanaka)

  3. Effect of Co3O4 and CeO2 Infiltration on the Activity of a LSM15/GDC10 Highly Porous Electrochemical Reactor

    DEFF Research Database (Denmark)

    Ippolito, Davide; Kammer Hansen, Kent

    2014-01-01

    VOC component of Diesel engine exhausts, over a wide range of temperatures. The entire reactor was thought as a highly porous catalytic filter for a possible application in a Diesel exhausts purification system. The porous reactor was used as a backbone for the infiltration of Co3O4 and Co3O4/CeO2...

  4. Neutron standard cross sections in reactor physics - Need and status

    International Nuclear Information System (INIS)

    The design and improvement of nuclear reactors require detailed neutronics calculations. These calculations depend on comprehensive libraries of evaluated nuclear cross sections. Most of the cross sections that form the data base for these evaluations have been measured relative to neutron cross-section standards. The use of these standards can often simplify the measurement process by eliminating the need for a direct measurement of the neutron fluence. The standards are not known perfectly, however; thus the accuracy of a cross-section measurement is limited by the uncertainty in the standard cross section relative to which it is measured. Improvements in a standard cause all cross sections measured relative to that standard to be improved. This is the reason for the emphasis on improving the neutron cross-section standards. The continual process of measurement and evaluation has led to improvements in the accuracy and range of applicability of the standards. Though these improvements have been substantial, this process must continue in order to obtain the high-quality standards needed by the user community

  5. Non-Power Reactor Operator Licensing Examiner Standards. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The Non-Power Reactor Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes. As appropriate, these standards will be revised periodically to accommodate comments and reflect new information or experience.

  6. Non-Power Reactor Operator Licensing Examiner Standards. Revision 1

    International Nuclear Information System (INIS)

    The Non-Power Reactor Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes. As appropriate, these standards will be revised periodically to accommodate comments and reflect new information or experience

  7. Non-Power Reactor Operator Licensing Examiner Standards

    International Nuclear Information System (INIS)

    The Non-Power Reactor Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR Part 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes. As appropriate, this standard will be revised periodically to accommodate comments and reflect new information or experience

  8. Monitoring system for accuracy and reliability characteristics of standard temperature measurements in WWER-440 reactors

    International Nuclear Information System (INIS)

    Description of a monitoring system for accuracy and reliability characteristics of standard temperature measurements in WWER-440 reactors and benefits obtained from its use are shown in the presentation. As standard reactor temperature measurement, coolant temperature measurement at fuel assembly outlets and in loops, entered into the In-Reactor Control System , are considered. Such systems have been implemented at two V-230 reactors and are under implementation at other four V-213 reactors. (Authors)

  9. Piping benchmark problems for the ABB/CE System 80+ Standardized Plant

    International Nuclear Information System (INIS)

    To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for the ABB/Combustion Engineering System 80+ Standardized Plant, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the System 80+ standard design. It will be required that the combined license licensees demonstrate that their solution to these problems are in agreement with the benchmark problem set. The first System 80+ piping benchmark is a uniform support motion response spectrum solution for one section of the feedwater piping subjected to safe shutdown seismic loads. The second System 80+ piping benchmark is a time history solution for the feedwater piping subjected to the transient loading induced by a water hammer. The third System 80+ piping benchmark is a time history solution of the pressurizer surge line subjected to the accelerations induced by a main steam line pipe break. The System 80+ reactor is an advanced PWR type

  10. On the path to ordering standardized advanced light water reactors

    International Nuclear Information System (INIS)

    The international Advanced Light Water Reactor (ALWR) program is specifying, designing, and certifying the next generation of nuclear power plants. Begun in the mid-1980's, the program is on track to permit ordering and construction of families of standardized plants at the start of the twenty-first century. ALWRs will be constructed only if they are economically competitive with alternative forms of electricity generation and are recognized as acceptable and favorable by the public, prospective owners, and investors. This paper first gives an overview of the major building blocks ensuring safe, reliable, and economic designs and the status of those designs. Next it lays out the path the industry has charted toward adopting the ALWR option and indicates the status of three key steps -- design certification, utility requirements, and first-of-a-kind engineering. Lastly, the paper focuses on one of the most important building blocks for ensuring economic viability -- life-cycle standardization. Among the topics are the definition and scope of standardization; its advantages and disadvantages; design team standardization plans that describe the desired or optimum degree of standardization and the processes used to achieve it; and the need for an agreement among all plant owners and operators for implementing and sustaining standardization in families of ALWRs. 10 refs., 5 figs

  11. SRAC: JAERI thermal reactor standard code system for reactor design and analysis

    International Nuclear Information System (INIS)

    The SRAC (Standard Reactor Analysis Code) is a code system for nuclear reactor analysis and design. It is composed of neutron cross section libraries and auxiliary processing codes, neutron spectrum routines, a variety of transport, 1-, 2- and 3-D diffusion routines, dynamic parameters and cell burn-up routines. By making the best use of the individual code function in the SRAC system, the user can select either the exact method for an accurate estimate of reactor characteristics or the economical method aiming at a shorter computer time, depending on the purpose of study. The user can select cell or core calculation; fixed source or eigenvalue problem; transport (collision probability or Sn) theory or diffusion theory. Moreover, smearing and collapsing of macroscopic cross sections are separately done by the user's selection. And a special attention is paid for double heterogeneity. Various techniques are employed to access the data storage and to optimize the internal data transfer. Benchmark calculations using the SRAC system have been made extensively for the Keff values of various types of critical assemblies (light water, heavy water and graphite moderated systems, and fast reactor systems). The calculated results show good prediction for the experimental Keff values. (author)

  12. 76 FR 14437 - Economic Simplified Boiling Water Reactor Standard Design: GE Hitachi Nuclear Energy; Issuance of...

    Science.gov (United States)

    2011-03-16

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Economic Simplified Boiling Water Reactor Standard Design: GE Hitachi Nuclear Energy; Issuance of... GE Hitachi Nuclear Energy (GEH) for the economic simplified boiling water reactor (ESBWR)...

  13. Utilization of Research Reactors in Standard Reference Material Certification

    Energy Technology Data Exchange (ETDEWEB)

    Capannesi, G.; Rosada, A. [UTFISST-CATNUC, ENEA, R.C.-Casaccia, via Anguillarese 301, 00060 Rome (Italy); Avino, P. [DIPIA, INAIL (ex-ISPESL), via Urbana 167, 00184 Rome (Italy)

    2011-07-01

    The certification issue of Standard Reference Materials is one of the most complex analytical problems and runs over different research fields. International organization, e.g. NIST, BCR etc., organize continuously systematic intercomparison campaigns among worldwide laboratories using different analytical techniques. Samples are irradiated in nuclear research reactors and analyzed by Instrumental Neutron Activation Analysis, a technique strongly involved in this field for its significant analytical properties. This paper shows a study on Zircaloy-4. The importance of accurate measurements of minor constituents, i.d. Cr, Fe, Hf and Sn, regards its characteristics of corrosion resistance and mechanical properties. The samples were irradiated in the rotating rack of the TRIGA Mark II reactor of the R.C.-Casaccia (ENEA). The gamma spectrometry measurements were performed after 30 and 90 days of decay by means of HPGe detector. The results obtained by interlaboratory intercomparison can highlight an excellent precision for Cr, Hf and Sn, and a good precision for Fe. The reliability of the technique is confirmed by Hf determination, since the INAA is one of the few analytical techniques measuring and delivering accurate and homogeneous data. (author)

  14. Standard Master Matrix for Light-Water Reactor Pressure Vessel Surveillance Standards, E706(0)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This master matrix standard describes a series of standard practices, guides, and methods for the prediction of neutron-induced changes in light-water reactor (LWR) pressure vessel (PV) and support structure steels throughout a pressure vessel's service life (Fig. 1). Some of these are existing ASTM standards, some are ASTM standards that have been modified, and some are proposed ASTM standards. General requirements of content and consistency are discussed in Section 6 . More detailed writers' and users' information, justification, and specific requirements for the nine practices, ten guides, and three methods are provided in Sections 3-5. Referenced documents are discussed in Section 2. The summary-type information that is provided in Sections 3 and 4 is essential for establishing proper understanding and communications between the writers and users of this set of matrix standards. It was extracted from the referenced documents, Section 2 and references (1-106) for use by individual writers and users. 1...

  15. General principles of nuclear reactor instrumentation (International Electrotechnical Commission Standard Publication 60231:1967)

    International Nuclear Information System (INIS)

    This Recommendation given guidance on the provision of reactor instrumentation and recommends standards of good practice. The main body of the Recommendation is of general application and aspects applicable only to particular types of reactors are included in Appendices. Items of instrumentation are included only where they have a direct bearing on the over-all safety and effective control of the reactor

  16. Quality evaluation of the k0-standardized neutron activation analysis on Dalat research reactor

    International Nuclear Information System (INIS)

    Laboratory for neutron activation analysis (NAA) at the 500 kW Dalat Research Reactor( DRR) has been accredited following ISO/IEC 17025: 2005 (TCVN VILAS-519). Successful introduction of the k0-based NAA using Ko-Dalat software written in house at DRR has allowed to extend its applications in petroleum, archaeology and environment besides other traditional fields, i.e. geology, biomedicine, industry and materials. This study aimed to assess the quality of k0-NAA by analyzing a number of standard reference materials: SMELS, NIST-1547, NIST-2711a, IAEA-Soil-7 and IAEA-V-10. The laboratory has also participated in proficiency testing schemes organized by IAEA and FNCA. External and internal quality assessment revealed that the k0-NAA using Ko-Dalat software established at DRR has met the requirements of multi-element analysis in the intended applications. About 42 elements: Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Dy, Eu, Fe, Hf, I, In, K, La, Mg, Mn, Mo, Na, Nd, Pr, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn and Zr, were determined in the above mentioned materials. The results were evaluated and reported in this paper. (author)

  17. Radiation streaming analysis in the korean standard nuclear power plant reactor cavity

    International Nuclear Information System (INIS)

    Radiation shield plugs are provided in the reactor cavity of the KSNP (Korean Standard Nuclear Power Plant) to assure an acceptable low level of radiation streaming up through the reactor cavity. An analysis of radiation streaming in the reactor cavity was performed to evaluate the effectiveness of the reactor cavity shield plugs in meeting their design goals. The MCNP code was used for this analysis with DORT leakage flux at the reactor vessel outer surface. Based on the results of this analysis, the upper and lower shield plugs are important design features to reduce dose rates at the reactor vessel flange level and at the operating floor

  18. Postcolumn reactor using a laser-drilled capillary for light-emitting diode-induced fluorescence detection in CE.

    Science.gov (United States)

    Yamamoto, Daisuke; Kaneta, Takashi; Imasaka, Totaro

    2007-11-01

    This study investigated a novel postcolumn reactor for fluorescence detection in CE. A laser-drilled capillary, with an aperture made by laser ablation, was used for mixing derivatization reagents with the analytes separated by CZE. The derivatization reagents, o-phthaldialdehyde (OPA), and 2-mercaptoethanol, were introduced into the capillary through the aperture and reacted with the analytes after CZE separation. High voltages were applied to both the inlet reservoir and the reservoir filled with the derivatization reagents. Thus, the flow rate of the derivatization reagents was controlled by the electric potential that was applied to the reservoir of the derivatization reagents. A UV light-emitting diode was used as an excitation light source for the fluorescence detection of OPA derivatives. A commercially available tee connector was compared with the laser-drilled capillary. The results implied that the dead volume of the laser-drilled capillary was less than that of the tee connector, since the laser-drilled capillary suppressed band broadening more efficiently. The LODs for amino acids were determined to be approximately 5 microM. The method was applied to the determination of amino acids in a Japanese beverage. PMID:17948271

  19. Standard technical specifications for Westinghouse pressurized water reactors (revision issued Fall 1981). Technical report

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for Westinghouse Pressurized Water Reactors (W-STS) is a generic document prepared by the U.S. NRC for use in the licensing process of current Westinghouse Pressurized Water Reactors. The W-STS sets forth the Limits, Operating Conditions and other requirements applicable to nuclear reactor facility operation as set forth in Section 50.36 of 10 CFR Part 50 for the protection of the health and safety of the public

  20. Seismic design of the ABB-CE System 80+ Standard Plant for a site envelope

    International Nuclear Information System (INIS)

    This paper provides a summary of the design parameters used in the seismic design of the ABB Combustion Engineering System 80+ Standard Plant. The System 80+ seismic design is developed with the objective of having a standard design which would envelop the majority of sites in the world with the possible exception of sites near major active faults in areas of known high seismicity. The seismic design basis was developed based on the current state-of-the-art as well as consideration for both current and anticipated future Nuclear Regulatory guidance. The paper discusses seismic design requirements, selection of generic soil sites, selection of design control motions, soil-structure interaction analyses, and site acceptance criteria for the plant

  1. Standard interface files and procedures for reactor physics codes. Version IV

    International Nuclear Information System (INIS)

    Standards, procedures, and recommendations of the Committee on Computer Code Coordination for promoting the exchange of reactor physics codes are updated to Version IV status. Standards and procedures covering general programming, program structure, standard interface files, and file management and handling subroutines are included

  2. Standard Guide for Benchmark Testing of Light Water Reactor Calculations

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide covers general approaches for benchmarking neutron transport calculations in light water reactor systems. A companion guide (Guide E2005) covers use of benchmark fields for testing neutron transport calculations and cross sections in well controlled environments. This guide covers experimental benchmarking of neutron fluence calculations (or calculations of other exposure parameters such as dpa) in more complex geometries relevant to reactor surveillance. Particular sections of the guide discuss: the use of well-characterized benchmark neutron fields to provide an indication of the accuracy of the calculational methods and nuclear data when applied to typical cases; and the use of plant specific measurements to indicate bias in individual plant calculations. Use of these two benchmark techniques will serve to limit plant-specific calculational uncertainty, and, when combined with analytical uncertainty estimates for the calculations, will provide uncertainty estimates for reactor fluences with ...

  3. Experience of the standardization of the vibratory condition pipe line when working the reactor on powers

    International Nuclear Information System (INIS)

    Analysis of the experience of the standardization of the vibratory condition pipe line and considered approaches of the motivation of the normative requirements is organized in article to vibratory load on pipe lines when working the reactor on powers

  4. ANS shielding standards for light-water reactors

    International Nuclear Information System (INIS)

    The purpose of the American Nuclear Society Standards Subcommittee, ANS-6, Radiation Protection and Shielding, is to develop standards for radiation protection and shield design, to provide shielding information to other standards-writing groups, and to develop standard reference shielding data and test problems. A total of seven published ANS-6 standards are now current. Additional projects of the subcommittee, now composed of nine working groups, include: standard reference data for multigroup cross sections, gamma-ray absorption coefficients and buildup factors, additional benchwork problems for shielding problems and energy spectrum unfolding, power plant zoning design for normal and accident conditions, process radiation monitors, and design for postaccident radiological conditions

  5. IAEA Workshop (Training Course) on Codes and Standards for Sodium Cooled Fast Reactors. Working Material

    International Nuclear Information System (INIS)

    The training course consisted of lectures and Q&A sessions. The lectures dealt with the history of the development of Design Codes and Standards for Sodium Cooled Fast Reactors (SFRs) in the respective country, the detailed description of the current design Codes and Standards for SFRs and their application to ongoing Fast Reactor design projects, as well as the ongoing development work and plans for the future in this area. Annex 1 contains the detailed Workshop program

  6. Choosing a standard reactor: International competition and domestic politics in Chinese nuclear policy

    International Nuclear Information System (INIS)

    China has ambitious plans to expand its nuclear power capacity. One of the policy goals that high-level policymakers have desired is to base the nuclear program on a standardized reactor design. However, this has not materialized so far. By examining its nuclear reactor choices for individual projects, we argue that China’s policymaking process has been greatly influenced by international competition and domestic politics. Multiple international nuclear vendors are intent upon maintaining their respective niches in the expanding Chinese reactor market, and they have used various forms of economic and political pressure to achieve their objectives. On the other hand, China’s policymaking process is fragmented and the shifting power balances among powerful domestic actors do not allow a fixed path to be followed. Further, because of the high costs and potential profits involved, nuclear reactor choices in China have been driven not just by technical considerations but also by foreign and trade policy objectives. All of these make it unlikely that China will standardize the reactor type it constructs in the near future. -- Highlights: ► China’s nuclear power policymaking has been fragmented and without central control. ► Multiple domestic actors have pursued independent agendas. ► International nuclear vendors have intensely competed for Chinese reactor contracts. ► Economic, political and foreign policy goals have driven reactor contract decisions. ► China is unlikely to construct only a standardized reactor design.

  7. Implementation of USP antibody standard for system suitability in capillary electrophoresis sodium dodecyl sulfate (CE-SDS) for release and stability methods.

    Science.gov (United States)

    Esterman, Abbie L; Katiyar, Amit; Krishnamurthy, Girija

    2016-09-01

    Capillary electrophoresis sodium dodecyl sulfate (CE-SDS) is widely used for purity analysis of monoclonal antibody therapeutics for release and stability to demonstrate product consistency and shelf life during the manufacturing and life cycle of the product. CE-SDS method development is focused on exploring the method capability to provide the information about the product purity and product related degradants (fragmentation, aggregation etc.). In order to establish the functionality of the instrumentation, software, and sample preparation; system suitability criteria need to be defined for analytical methods using a well characterized reference standard run under the same protocol and analysis as the test articles. Typically the reference standard is produced using a manufacturing process representative of the clinical material. The qualification, control, and maintenance of in-house reference standards are established through rigorous quality and regulatory guidelines. The U.S. Pharmacopeia (USP) has developed a monoclonal IgG System Suitability Reference Standard to be utilized for assessment of system suitability in CE-SDS methods. In this communication, we evaluate the system suitability acceptance criteria performance of the USP IgG standard using two methods, the recommended USP protocol provided in monograph and a molecule specific Bristol-Myers Squibb (BMS) CE-SDS method. The results from USP IgG standard were compared with two in-house monoclonal antibody reference standards. The data suggest that the USP CE-SDS method may not be suitable for CE-SDS analysis for release and stability of monoclonal antibody therapeutics due to the high level of method induced partial reduction observed for all molecules tested. This high level of fragmentation observed utilizing the USP method will result in reporting lower purity levels, which will impact the overall quality assessment of the molecule. The system suitability criteria recommended by the USP method can be

  8. Assessement of Codes and Standards Applicable to a Hydrogen Production Plant Coupled to a Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Russell

    2006-06-01

    This is an assessment of codes and standards applicable to a hydrogen production plant to be coupled to a nuclear reactor. The result of the assessment is a list of codes and standards that are expected to be applicable to the plant during its design and construction.

  9. Modeling of a SrCe0.95Yb0.05O3-α Hollow Fibre Membrane Reactor for Methane Coupling

    Institute of Scientific and Technical Information of China (English)

    谭小耀; 杨乃涛; K.Li

    2003-01-01

    Proton-hole mixed conductor, SrCe0.95Yb0.05O3-α(SCYb), has the potential to be used as a membrane for dehydrogenation reactions such as methane coupling due to its high C2-selectivity and its simplicity for fabricating reactor systems. In addition, the mixed conducting membrane in the hollow fibre geometry is capable of providing high surface area per unit volume. In this study, mechanism of methane coupling reaction on the SCYb membrane was proposed and the kinetic parameters were obtained by regression of experimental data. A mathematical model describing the methane coupling in the SCYb hollow fibre membrane reactor was also developed.With this mathematical model, various operating conditions such as the operation mode, operation pressure and feed concentrations affecting performance of the reactor were investigated. The simulation results show that the cocurrent flow in the reactor exhibits higher conversion of methane and higher yield of ethylene compared to the countercurrent flow. In order to achieve the highest C2 yield, especially of ethylene, pure methane should be used as feed and the operating pressure be 300 kPa. Air can be used as the source of oxygen for the reaction and it soptimum feed velocity is twice of the methane feed velocity. The air pressure in the lumen side should be kept the same as or slightly lower than the vressure of shell side.

  10. Conversion and standardization of university reactor fuels using low-enrichment uranium: Plans and schedules

    Energy Technology Data Exchange (ETDEWEB)

    Young, H.H.; Brown, K.R.; Matos, J.E.

    1986-01-01

    The highly-enriched uranium (HEU) fuel used in twenty United States university reactors can be viewed as contributing to the risk of theft or diversion of weapons-useable material. To minimize this risk, the US Nuclear Regulatory Commission issued its final rule on ''Limiting the Use of Highly Enriched Uranium in Domestically Licensed Research and Test Reactors,'' in February 1986. This paper describes the plans and schedules developed by the US Department of Energy to coordinate an orderly transition from HEU to LEU fuel in most of these reactors. An important element in the planning process has been the desire to standardize the LEU fuels used in US university reactors and to enhance the performance and utilization of a number of these reactors. The program is estimated to cost about $10 million and to last about five years.

  11. Operator licensing examination standards for power reactors. Interim revision 8

    International Nuclear Information System (INIS)

    These examination standards are intended to assist NRC examiners and facility licensees to better understand the processes associated with initial and requalification examinations. The standards also ensure the equitable and consistent administration of examinations for all applicants. These standards are for guidance purposes and are not a substitute for the operator licensing regulations (i.e., 10 CFR Part 55), and they are subject to revision or other changes in internal operator licensing policy. This interim revision permits facility licensees to prepare their initial operator licensing examinations on a voluntary basis pending an amendment to 10 CFR Part 55 that will require facility participation. The NRC intends to solicit comments on this revision during the rulemaking process and to issue a final Revision 8 in conjunction with the final rule

  12. Standard Technical Specifications for General Electric Boiling Water Reactors (BWR/5)

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for General Electric Boiling Water Reactors (GE-STS) is a generic document prepared by the US NRC for use in the licensing process of current General Electric Boiling Water Reactors. The GE-STS sets forth the limits, operating conditions, and other requirements applicable to nuclear reactor facility operation as set forth by Section 50.36 of 10 CFR Part 50 for the protection of the health and safety of the public. The document is revised periodically to reflect current licensing requirements

  13. Standard technical specifications for General Electric boiling water reactors

    International Nuclear Information System (INIS)

    This Standard Technical Specification (STS) has been structured for the broadest possible use on General Electric plants currently being reviewed for an Operating License. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. This revision of the GE-STS does not typically include requirements which may be added or revised as a result of the NRC staff's further review of the Three Mile Island incident

  14. Draft of standard for graphite core components in high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    For the design of the graphite components in the High Temperature Engineering Test Reactor (HTTR), the graphite structural design code for the HTTR etc. were applied. However, general standard systems for the High Temperature Gas-cooled Reactor (HTGR) have not been established yet. The authors had studied on the technical issues which is necessary for the establishment of a general standard system for the graphite components in the HTGR. The results of the study were documented and discussed at a 'Special committee on research on preparation for codes for graphite components in HTGR' at Atomic Energy Society of Japan (AESJ). As a result, 'Draft of Standard for Graphite Core Components in High Temperature Gas-cooled Reactor.' was established. In the draft standard, the graphite components are classified three categories (A, B and C) in the standpoints of safety functions and possibility of replacement. For the components in the each class, design standard, material and product standards, and in-service inspection and maintenance standard are determined. As an appendix of the design standard, the graphical expressions of material property data of 1G-110 graphite as a function of fast neutron fluence are expressed. The graphical expressions were determined through the interpolation and extrapolation of the irradiated data. (author)

  15. Compiled reports on the applicability of selected codes and standards to advanced reactors

    International Nuclear Information System (INIS)

    The following papers were prepared for the Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission under contract DE-AC06-76RLO-1830 NRC FIN L2207. This project, Applicability of Codes and Standards to Advance Reactors, reviewed selected mechanical and electrical codes and standards to determine their applicability to the construction, qualification, and testing of advanced reactors and to develop recommendations as to where it might be useful and practical to revise them to suit the (design certification) needs of the NRC

  16. Assessment of United States industry structural codes and standards for application to advanced nuclear power reactors: Appendices. Volume 2

    International Nuclear Information System (INIS)

    Throughout its history, the USNRC has remained committed to the use of industry consensus standards for the design, construction, and licensing of commercial nuclear power facilities. The existing industry standards are based on the current class of light water reactors and as such may not adequately address design and construction features of the next generation of Advanced Light Water Reactors and other types of Advanced Reactors. As part of their on-going commitment to industry standards, the USNRC commissioned this study to evaluate US industry structural standards for application to Advanced Light Water Reactors and Advanced Reactors. The initial review effort included (1) the review and study of the relevant reactor design basis documentation for eight Advanced Light Water Reactors and Advanced Reactor Designs, (2) the review of the USNRCs design requirements for advanced reactors, (3) the review of the latest revisions of the relevant industry consensus structural standards, and (4) the identification of the need for changes to these standards. The results of these studies were used to develop recommended changes to industry consensus structural standards which will be used in the construction of Advanced Light Water Reactors and Advanced Reactors. Over seventy sets of proposed standard changes were recommended and the need for the development of four new structural standards was identified. In addition to the recommended standard changes, several other sets of information and data were extracted for use by USNRC in other on-going programs. This information included (1) detailed observations on the response of structures and distribution system supports to the recent Northridge, California (1994) and Kobe, Japan (1995) earthquakes, (2) comparison of versions of certain standards cited in the standard review plan to the most current versions, and (3) comparison of the seismic and wind design basis for all the subject reactor designs

  17. Assessment of United States industry structural codes and standards for application to advanced nuclear power reactors: Final report. Volume 1

    International Nuclear Information System (INIS)

    Throughout its history, the USNRC has remained committed to the use of industry consensus standards for the design, construction, and licensing of commercial nuclear power facilities. The existing industry standards are based on the current class of light water reactors and as such may not adequately address design and construction features of the next generation of Advanced Light Water Reactors and other types of Advanced Reactors. As part of their on-going commitment to industry standards, the USNRC commissioned this study to evaluate US industry structural standards for application to Advanced Light Water Reactors and Advanced Reactors. The initial review effort included: (1) the review and study of the relevant reactor design basis documentation for eight Advanced Light Water Reactors and Advanced Reactor Designs, (2) the review of the USNRCs design requirements for advanced reactors, (3) the review of the latest revisions of the relevant industry consensus structural standards, and (4) the identification of the need for changes to these standards. The results of these studies were used to develop recommended changes to industry consensus structural standards which will be used in the construction of Advanced Light Water Reactors and Advanced Reactors. Over seventy sets of proposed standard changes were recommended and the need for the development of four new structural standards was identified. In addition to the recommended standard changes, several other sets of information and data were extracted for use by USNRC in other ongoing programs. This information included: (1) detailed observations on the response of structures and distribution system supports to the recent Northridge, California (1994) and Kobe, Japan (1995) earthquakes, (2) comparison of versions of certain standards cited in the standard review plan to the most current versions, and (3) comparison of the seismic and wind design basis for all the subject reactor designs

  18. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    This paper provides the first comparative analysis of nuclear reactor construction costs in France and the United States. Studying the cost of nuclear power has often been a challenge, owing to the lack of reliable data sources and heterogeneity between countries, as well as the long time horizon which requires controlling for input prices and structural changes. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using expected demand variation as an instrument. We argue that benefits from nuclear reactor program standardization can arise through short term coordination gains, when the diversity of nuclear reactors' technologies under construction is low, or through long term benefits from learning spillovers from past reactor construction experience, if those spillovers are limited to similar reactors. We find that overnight construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect-Engineer (A- E). In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. (authors)

  19. Benchmark calculations by the thermal reactor standard nuclear design code system SRAC

    International Nuclear Information System (INIS)

    This report summarizes the present status of the thermal reactor standard nuclear design code system SRAC developed by the nuclear design working group of the JAERI thermal reactor standard code committee which was started on July 1978. Descriptions are given at first on the brief introduction and the process of development of the code system SRAC, and then, the several benchmark tests performed to evaluate the performance of the code system. The results show the good predictions of the experimental keff values of the critical facilities; TCA for LWR, JMTRC for JAERI MTR, DCA for the Japanese Advanced Thermal Reactor and SHE for VHTR. A trial to the IAEA benchmark calculations on the Reduction of uranium Enrichment of Research and Test Reactors yields satisfactory agreements with the results of ANL. Another test to evaluate the fast group constants was also attempted by tracing the fast reactor benchmark problems which have been used to evaluate nuclear data file in the FBR reactor physics field. (author)

  20. High Temperature Gas Reactors: Assessment of Applicable Codes and Standards

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, Bruce K.; Nickolaus, James R.; Mitchell, Mark R.; Swearingen, Gary L.; Pugh, Ray

    2011-10-31

    Current interest expressed by industry in HTGR plants, particularly modular plants with power up to about 600 MW(e) per unit, has prompted NRC to task PNNL with assessing the currently available literature related to codes and standards applicable to HTGR plants, the operating history of past and present HTGR plants, and with evaluating the proposed designs of RPV and associated piping for future plants. Considering these topics in the order they are arranged in the text, first the operational histories of five shut-down and two currently operating HTGR plants are reviewed, leading the authors to conclude that while small, simple prototype HTGR plants operated reliably, some of the larger plants, particularly Fort St. Vrain, had poor availability. Safety and radiological performance of these plants has been considerably better than LWR plants. Petroleum processing plants provide some applicable experience with materials similar to those proposed for HTGR piping and vessels. At least one currently operating plant - HTR-10 - has performed and documented a leak before break analysis that appears to be applicable to proposed future US HTGR designs. Current codes and standards cover some HTGR materials, but not all materials are covered to the high temperatures envisioned for HTGR use. Codes and standards, particularly ASME Codes, are under development for proposed future US HTGR designs. A 'roadmap' document has been prepared for ASME Code development; a new subsection to section III of the ASME Code, ASME BPVC III-5, is scheduled to be published in October 2011. The question of terminology for the cross-duct structure between the RPV and power conversion vessel is discussed, considering the differences in regulatory requirements that apply depending on whether this structure is designated as a 'vessel' or as a 'pipe'. We conclude that designing this component as a 'pipe' is the more appropriate choice, but that the ASME BPVC

  1. Standard technical specifications for Babcock and Wilcox pressurized water reactors

    International Nuclear Information System (INIS)

    The Standard Technical Specification (STS) has been structured for the broadest possible use on B and W NSSS plants currently being reviewed for an Operating License. Two separate and discrete containment specification sections are provided for each of the following containment types: Atmospheric, and Dual. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. Alternate specifications are provided in a limited number of cases to cover situations where alternate specification requirements are necessary on a generic basis because of design differences. The format of the STS addresses the categories required by 10 CFR 50 and consists of six sections covering the areas of: Definitions, Safety Limits and Limiting Safety System Settings, Limiting Conditions for Operation, Surveillance Requirements, Design Features, and Administrative Controls

  2. Standard technical specifications for Babcock and Wilcox pressurized water reactors

    International Nuclear Information System (INIS)

    This Standard Technical Specification (STS) has been structured for the broadest possible use on B and W NSSS plants currently being reviewed for an Operating License. Two separate and discrete containment specification sections are provided for each of the following containment types: Atmospheric and Dual. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. Alternate specifications are provided in a limited number of cases to cover situations where alternate specification requirements are necessary on a generic basis because of design differences. This revision of STS does not typically include requirements which may be added or revised as a result of the NRC staff's further review of the Three Mile Island incident

  3. Standard technical specifications for combustion engineering pressurized water reactors

    International Nuclear Information System (INIS)

    This Standard Technical Specification (STS) has been structured for the broadest possible use on Combustion Engineering plants currently being reviewed for an Operating License. Two separate and discrete containment specification sections are provided for each of the following containment types: Atmospheric and Dual. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. Alternate specifications are provided in a limited number of cases to cover situations where alternate specification requirements are necessary on a generic basis because of design differences. This revision of STS does not typically include requirements which may be added or revised as a result of the NRC staff's further review of the Three Mile Island incident

  4. Standard technical specifications for Westinghouse pressurized water reactors

    International Nuclear Information System (INIS)

    This Standard Technical Specification (STS) has been structured for the broadest possible use on Westinghouse plants currently being reviewed for an Operating License. Accordingly, the document contains specifications applicable to plants with (1) either 3 or 4 loops and (2) with and without loop stop valves. In addition, four separate and discrete containment specification sections are provided for each of the following containment types: Atmospheric, Ice Condenser, Sub-Atmospheric, and Dual. Optional specifications are provided for those features and systems which may be included in individual plant designs but are not generic in their scope of application. Alternate specifications are provided in a limited number of cases to cover situations where alternate specification requirements are necessary on a generic basis because of design differences. This revision of the STS does not typically include requirements which may be added or revised as a result of the NRC staff's further review of the Three Mile Island incident

  5. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    This paper provides an econometric analysis of nuclear reactor construction costs in France and the United States based on overnight costs data. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using change in expected electricity demand as instrument. We argue that the construction of nuclear reactors can benefit from standardization gains through two channels. First, short term coordination benefits can arise when the diversity of nuclear reactors' designs under construction is low. Second, long term benefits can occur due to learning spillovers from past constructions of similar reactors. We find that construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect–Engineer. In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. -- Highlights: •This paper analyses the determinants of nuclear reactors construction costs and lead-time. •We study short term (coordination gains) and long term (learning by doing) benefits of standardization in France and the US. •Results show that standardization of nuclear programs is a key factor for reducing construction costs. •We also suggest that technological progress has contributed to construction costs escalation

  6. An inspection standard of fuel for the high temperature engineering test reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Fumiaki; Shiozawa, Shusaku; Sawa, Kazuhiro; Sato, Sadao (Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment); Hayashi, Kimio; Fukuda, Kosaku; Kaneko, Mitsunobu; Sato, Tsutomu.

    1992-06-01

    The High Temperature Engineering Test Reactor (HTTR) uses the fuel comprising coated fuel particles. A general inspection standard for the coated particle fuel, however, has not been established in Japan. Therefore, it has been necessary to prescribe the inspection standard of the fuel for HTTR. Under these circumstances, a fuel inspection standard of HTTR has been established under cooperation of fuel specialists both inside and outside of JAERI on referring to the inspection methods adopted in USA, Germany and Japan for HTGR fuels. Since a large number of coated fuel particle samples is needed to inspect the HTTR fuel, the sampling inspection standard has also been established considering the inspection efficiency. This report presents the inspection and the sampling standards together with an explanation of these standards. These standards will be applied to the HTTR fuel acceptance tests. (author).

  7. An inspection standard of fuel for the high temperature engineering test reactor

    International Nuclear Information System (INIS)

    The High Temperature Engineering Test Reactor (HTTR) uses the fuel comprising coated fuel particles. A general inspection standard for the coated particle fuel, however, has not been established in Japan. Therefore, it has been necessary to prescribe the inspection standard of the fuel for HTTR. Under these circumstances, a fuel inspection standard of HTTR has been established under cooperation of fuel specialists both inside and outside of JAERI on referring to the inspection methods adopted in USA, Germany and Japan for HTGR fuels. Since a large number of coated fuel particle samples is needed to inspect the HTTR fuel, the sampling inspection standard has also been established considering the inspection efficiency. This report presents the inspection and the sampling standards together with an explanation of these standards. These standards will be applied to the HTTR fuel acceptance tests. (author)

  8. Standard review plan for the review and evaluation of emergency plans for research and test reactors

    International Nuclear Information System (INIS)

    This document provides a Standard Review Plan to assure that complete and uniform reviews are made of research and test reactor radiological emergency plans. The report is organized under ten planning standards which correspond to the guidance criteria in American National Standard ANSI/ANS 15.16 - 1982 as endorsed by Revision 1 to Regulatory Guide 2.6. The applicability of the items under each planning standard is indicated by subdivisions of the steady-state thermal power levels at which the reactors are licensed to operate. Standard emergency classes and example action levels for research and test reactors which should initiate these classes are given in an Appendix. The content of the emergency plan is as follows: the emergency plan addresses the necessary provisions for coping with radiological emergencies. Activation of the emergency plan is in response to the emergency action levels. In addition to addressing those severe emergencies that will fall within one of the standard emergency classes, the plan also discusses the necessary provisions to deal with radiological emergencies of lesser severity that can occur within the operations boundary. The emergency plan allows for emergency personnel to deviate from actions described in the plan for unusual or unanticipated conditions

  9. Towards the standardization of nanoecotoxicity testing: Natural organic matter 'camouflages' the adverse effects of TiO2 and CeO2 nanoparticles on green microalgae.

    Science.gov (United States)

    Cerrillo, Cristina; Barandika, Gotzone; Igartua, Amaya; Areitioaurtena, Olatz; Mendoza, Gemma

    2016-02-01

    In the last few years, the emission of CeO2 and TiO2 nanoparticles (NPs) into the environment has been raising concerns about their potential adverse effects on wildlife and human health. Aquatic organisms constitute one of the most important pathways for the entrance of these NPs and transfer throughout the food web, but divergences exist in the experimental data published on their aquatic toxicity. The pressing need for standardization of methods to analyze their ecotoxicity requires aquatic media representing realistic environmental conditions. The present study aimed to determine the usefulness of Suwannee River natural organic matter (SR-NOM) in the assessment of the agglomeration kinetics and ecotoxicity of CeO2 and TiO2 NPs towards green microalgae Pseudokirchneriella subcapitata. SR-NOM alleviated the adverse effects of NPs on algal growth, completely in the case of TiO2 NPs and partially in the case of CeO2 NPs, suggesting a 'camouflage' of toxicity. This behavior has been observed also for other algal species and types of natural organic matter in the literature. Furthermore, SR-NOM markedly increased the stability of the NPs in algal medium, which led to a better reproducibility of the toxicity test results, and provided an electrophoretic mobility similar to that previously reported in various river and groundwaters. Thus, SR-NOM can be a representative sample of what is found in many different ecosystems, and the observed 'camouflage' of the effects of CeO2 and TiO2 NPs on algal cells might be considered as a natural interaction occurring in their standardized ecotoxicological assessment. PMID:26580731

  10. Standard Guide for Benchmark Testing of Reactor Dosimetry in Standard and Reference Neutron Fields

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    Return to Contents page 1.1 This guide covers facilities and procedures for benchmarking neutron measurements and calculations. Particular sections of the guide discuss: the use of well-characterized benchmark neutron fields to calibrate integral neutron sensors; the use of certified-neutron-fluence standards to calibrate radiometric counting equipment or to determine interlaboratory measurement consistency; development of special benchmark fields to test neutron transport calculations; use of well-known fission spectra to benchmark spectrum-averaged cross sections; and the use of benchmarked data and calculations to determine the uncertainties in derived neutron dosimetry results. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  11. The IAEA Safety Standards and Small and Medium Reactor Design Features

    International Nuclear Information System (INIS)

    The renewed interest in nuclear energy worldwide prompted the development of small and medium size reactors (SMR). These reactors are more suitable for smaller grids as well as they promise increased safety, possibly better economy, and they offer flexibility in applications (including non-power), siting and fuel cycle options. The IAEA safety standards, especially the Fundamental Safety Principles (IAEA Safety Standards series No. SF-1) provide excellent principles for design of nuclear power systems, these principles however, as such, are very generic. The IAEA safety standard Safety of Nuclear Power Plants: Design (SSR-2/1) provides specific requirements for the design of nuclear power plants, yet these requirements were developed based on best practices related to the design of current generation of reactors. On other hand, the SMRs currently under design incorporate features that are innovative but with which there is no operational experience, therefore the current standards and design requirement might not be directly applicable to the new SMR designs. This paper examines four most advanced in their development designs (NuScale, mPower, SMART, CAREM) with respect to design safety requirements of the IAEA. These designs were selected because all of them are pressurized water reactors and among SMRs they are closest relatives to the current designs currently Being offered to the market. Therefore, the existing safety standards should be potentially applicable. Since these SMR designs are under development and most of the detailed information is not available this paper utilizes only information that is public domain. This limits the depth of the evaluation and mainly principal technical requirements and some general design requirements are addressed. Focus is on issues such as defence in depth, design principles (single failure criterion, fail safe design, etc.), design extension conditions, external hazards. (author)

  12. Standardization of specifications and inspection procedures for LEU plate-type research reactor fuels

    International Nuclear Information System (INIS)

    With the transition to high density uranium LEU fuel, fabrication costs of research reactor fuel elements have a tendency to increase because of two reasons. First, the amount of the powder of the uranium compound required increases by more than a factor of five. Second, fabrication requirements are in many cases nearer the fabrication limits. Therefore, it is important that measures be undertaken to eliminate or reduce unnecessary requirements in the specification or inspection procedures of research reactor fuel elements utilizing LEU. An additional stimulus for standardizing specifications and inspection procedures at this time is provided by the fact that most LEU conversions will occur within a short time span, and that nearly all of them will require preparation of new specifications and inspection procedures. In this sense, the LEU conversions offer an opportunity for improving the rationality and efficiency of the fuel fabrication and inspection processes. This report focuses on the standardization of specifications and inspection processes of high uranium density LEU fuels for research reactors. However, in many cases the results can also be extended directly to other research reactor fuels. 15 refs, 1 fig., 3 tabs

  13. Shifts of neutrino oscillation parameters in reactor antineutrino experiments with non-standard interactions

    CERN Document Server

    Li, Yu-Feng

    2014-01-01

    We discuss reactor antineutrino oscillations with non-standard interactions (NSIs) at the neutrino production and detection processes. The neutrino oscillation probability is calculated with a parametrization of the NSI parameters by splitting them into the averages and differences of the production and detection processes respectively. The average parts induce constant shifts of the neutrino mixing angles from their true values, and the difference parts can generate the energy (and baseline) dependent corrections to the initial mass-squared differences. We stress that only the shifts of mass-squared differences are measurable in reactor antineutrino experiments. Taking Jiangmen Underground Neutrino Observatory (JUNO) as an example, we analyze how NSIs influence the standard neutrino measurements and to what extent we can constrain the NSI parameters.

  14. Shifts of neutrino oscillation parameters in reactor antineutrino experiments with non-standard interactions

    International Nuclear Information System (INIS)

    We discuss reactor antineutrino oscillations with non-standard interactions (NSIs) at the neutrino production and detection processes. The neutrino oscillation probability is calculated with a parametrization of the NSI parameters by splitting them into the averages and differences of the production and detection processes respectively. The average parts induce constant shifts of the neutrino mixing angles from their true values, and the difference parts can generate the energy (and baseline) dependent corrections to the initial mass-squared differences. We stress that only the shifts of mass-squared differences are measurable in reactor antineutrino experiments. Taking Jiangmen Underground Neutrino Observatory (JUNO) as an example, we analyze how NSIs influence the standard neutrino measurements and to what extent we can constrain the NSI parameters

  15. High flux materials testing reactor HFR Petten. Characteristics of facilities and standard irradiation devices

    International Nuclear Information System (INIS)

    For the materials testing reactor HFR some characteristic information is presented. Besides the nuclear data for the experiment positions short descriptions are given of the most important standard facilities for material irradiation and radionuclide production. One paragraph deals with the experimental set-ups for solid state and nuclear structure investigations. The information in this report refers to a core type, which is operational since March 1977. The numerical data compiled have been up-dated to June 1978

  16. Synthesis of nano-Ce0.5Zr0.5O2 by absorption of ammonia into water-in-oil microemulsion in a rotor–stator reactor

    International Nuclear Information System (INIS)

    A gas-microemulsion reaction precipitation method was employed to prepare nano-Ce0.5Zr0.5O2 by absorption of NH3 into water-in-oil (W/O) microemulsion in a rotor–stator reactor . The effects of different operating conditions including final pH of the microemulsion, reaction temperature, initial Ce3+ and Zr4+ concentration, rotation speed, and gas–liquid volumetric ratio were investigated. Nano-Ce0.5Zr0.5O2 with an average diameter of about 5.5 nm, a specific surface area of 215.6 m2/g and a size distribution of 4–8 nm was obtained under the optimum operating conditions. The as-prepared nano-Ce0.5Zr0.5O2 was loaded with Au to prepare nano-Au/Ce0.5Zr0.5O2 catalyst which was subsequently used for CO oxidation test. CO conversion rate reached 100 % at room temperature, indicating high catalytic activity of the nano-Au/Ce0.5Zr0.5O2 catalyst

  17. Synthesis of nano-Ce{sub 0.5}Zr{sub 0.5}O{sub 2} by absorption of ammonia into water-in-oil microemulsion in a rotor–stator reactor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingwen; Wang, Hongrun; Arowo, Moses; Sun, Baochang, E-mail: sunbc@mail.buct.edu.cn; Chen, Jianfeng; Shao, Lei, E-mail: shaol@mail.buct.edu.cn [Beijing University of Chemical Technology, State Key Laboratory of Organic–Inorganic Composites (China)

    2015-01-15

    A gas-microemulsion reaction precipitation method was employed to prepare nano-Ce{sub 0.5}Zr{sub 0.5}O{sub 2} by absorption of NH{sub 3} into water-in-oil (W/O) microemulsion in a rotor–stator reactor . The effects of different operating conditions including final pH of the microemulsion, reaction temperature, initial Ce{sup 3+} and Zr{sup 4+} concentration, rotation speed, and gas–liquid volumetric ratio were investigated. Nano-Ce{sub 0.5}Zr{sub 0.5}O{sub 2} with an average diameter of about 5.5 nm, a specific surface area of 215.6 m{sup 2}/g and a size distribution of 4–8 nm was obtained under the optimum operating conditions. The as-prepared nano-Ce{sub 0.5}Zr{sub 0.5}O{sub 2} was loaded with Au to prepare nano-Au/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} catalyst which was subsequently used for CO oxidation test. CO conversion rate reached 100 % at room temperature, indicating high catalytic activity of the nano-Au/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} catalyst.

  18. Standardization of gamma sources using NaI (Tl) and LaBr3 (Ce) detectors: measurements and simulations

    International Nuclear Information System (INIS)

    In the present work, we made detailed studies on activity of a single gamma emitter 137Cs for different values of source-detector separation. The studies were made using NaI (Tl) and LaBr3 (Ce) detectors. Monte Carlo techniques were employed to estimate the intrinsic photo-peak efficiencies corresponding to 662 keV gamma rays. We have also made activity measurements on a double gamma emitter 60Co using sum-peak method. In both cases, calibrated sources were used and the measured results were compared with the activities certified by the manufacturer (Board of Radiation and Isotope Technology, Govt. of India)

  19. Three-dimensional flow field analysis of the standard fuel assembly for China advanced research reactor

    International Nuclear Information System (INIS)

    Numerical simulation of the flow field of the standard fuel assembly in China Advanced Research Reactor is carried out by using computational fluid dynamics software CFX4.4 and CFX5.5. The flow distribution and pressure difference of different coolant channels in the standard fuel assembly at rated operating condition are reached. Based on the computational pressure drop results of different flow rate, the resistance characteristic curve is given and compared with experimental results. The two results are in good agreement. (authors)

  20. Standardization of the SLOWPOKE-2 reactor in Jamaica for routine NAA

    International Nuclear Information System (INIS)

    The International Centre for Environmental and Nuclear Sciences (ICENS) has been involved in conducting multipurpose geochemical surveys, the results of which were published in 'A Geochemical Atlas of Jamaican Soils'. The primary analytical tool for these studies was neutron activation analysis (NAA) using the SLOWPOKE-2 reactor at the Centre. The neutron flux of the SLOWPOKE-2 reactor is extremely stable, thus allowing a semi-absolute method for quantitative NAA. This has several advantages, but requires preparation and measurement of the single- or multi-element standards for each gamma-spectroscopy system (GSS). The NAA laboratory at ICENS operates three GSSs. The primary ('master') GSS was standardized using single element standards for over 50 elements, naturally occurring in most geological and biological materials. The standardization of the secondary GSS's was achieved by transferring of the elemental sensitivities of the master GSS using an instrumentation-free standardization approach. Implementation of this methodology and its utilization in the routine analytical work is described. (author)

  1. Selective methods for the maintainability and standardization of the engineering of a research reactor

    International Nuclear Information System (INIS)

    the same function in each specialty. These diversities bring about conflicts and confusion between the maintenance and operation crew, besides modifying dangerously the fail rate and thus the overall reliability of the reactor. The maintainability is the capacity of being maintained an equipment/system has, serving as a design parameter. A system must be designed in a way in which it is maintained without a great investment of time and with low costs, minimum environmental impact and the least resources possible. Standardization is the action of normalizing the engineering of all systems/equipments of the reactor from its design, in all the disciplines, (mechanical, electrical, electronic, chemical, etc.) taking into consideration the facility of its maintenance and conserving or increasing the reliability of the system. The intention of this Program of Maintainability and Standardization in Research Reactors is based on procedures and calculations to improve the reliability of the equipments/systems according to pre-established criterion. (author)

  2. Corrosion experiment on non standard austenitic steel A1, in reactor coolant water

    International Nuclear Information System (INIS)

    Experimental corrosion studies on non standard austenitic SS, A1, have been carried out. The samples were immersed in reactor coolant water medium with pH variation of 5.95, 6.0, 6.1, and 6.31. The experiments were carried out using a type of M-273 EG&G potentiostate/galvanometer test instrument. The post-corrosion samples' microstructure were analyzed with the aid of EDS (energy dispersive spectroscopy) equipped SEM instrument to detect the presence of any viable corrosion products. For further verification x-ray diffraction method was also used to detect any possible emerging corrosion products type on the samples' surfaces. Experimental results confirm that non standard austenitic SS immersed in reactor coolant water corrosion medium with a variation of concentration experience very little or almost no corrosion, and that according to the so-called Fontana's criteria these test-materials turn out to have an excellent resistance toward reactor coolant water corrosion medium. This is also evidenced by the very low corrosion rate value measured in this study. EDS study and X-ray diffraction results indicate that the possible ensuing corrosion by products are chrome oxides and iron oxides. (author)

  3. Standard Guide for Application of Neutron Transport Methods for Reactor Vessel Surveillance, E706 (IID)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 Need for Neutronics Calculations—An accurate calculation of the neutron fluence and fluence rate at several locations is essential for the analysis of integral dosimetry measurements and for predicting irradiation damage exposure parameter values in the pressure vessel. Exposure parameter values may be obtained directly from calculations or indirectly from calculations that are adjusted with dosimetry measurements; Guide E944 and Practice E853 define appropriate computational procedures. 1.2 Methodology—Neutronics calculations for application to reactor vessel surveillance encompass three essential areas: (1) validation of methods by comparison of calculations with dosimetry measurements in a benchmark experiment, (2) determination of the neutron source distribution in the reactor core, and (3) calculation of neutron fluence rate at the surveillance position and in the pressure vessel. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is th...

  4. Development of standards and investigation of safety examination items for advancement of safety regulation of fast breeder reactor

    International Nuclear Information System (INIS)

    The purposes of this study are to prepare the fuel technical standard and the structure and materials standard of fast breeder reactors (FBRs), and to develop the requirements in a reactor establishment permission. The objects of this study are mainly the Monju high performance core and a demonstration FBR. In JFY 2012, the following results were obtained. As for the fuel technical standard, the fuel technical standard adapting the examination of integrity of the FBR fuels was prepared based on the information and data obtained in this study. As for the structure and material standard, the investigation of the revised parts of the standard was carried out. And as for the examination of the safety requirements, safety evaluation items for the future FBR plant and the fission products to be considered in a reactor establishment permission were investigated and examined. (author)

  5. Comparison of Standard Light Water Reactor Cross-Section Libraries using the United States Nuclear Regulatory Commission Pressurized Water Reactor Standard Core Loading Benchmark Problem

    Science.gov (United States)

    Arzu Alpan, F.; Kulesza, Joel A.

    2016-02-01

    This paper compares contemporary and historical light water reactor shielding and pressure vessel dosimetry cross-section libraries for a pressurized water reactor calculational benchmark problem with a standard out-in core loading. The calculational benchmark problem was developed at Brookhaven National Laboratory by the request of the U. S. Nuclear Regulatory Commission and used the Oak Ridge National Laboratory two-dimensional discrete ordinates code DORT and the BUGLE-93 cross-section library for the calculations. In this paper, a Westinghouse three-dimensional discrete ordinates code with parallel processing, the RAPTOR-M3G code was used. A variety of cross section libraries were used with RAPTOR-M3G including the BUGLE-93, BUGLE-96, and BUGLE-B7 cross-section libraries developed at Oak Ridge National Laboratory, and the broad-group ALPAN-VII.0 cross-section library developed at Westinghouse. In comparing the calculation-to-calculation reaction rates using the BUGLE-93 cross-section library at the thermal shield, pressure vessel, and cavity capsules, for eleven dosimetry reaction rates, a maximum relative difference of 5% was observed, with the exception of 65Cu(n,2n) in the pressure vessel capsule that had a 90% relative difference with respect to the reference results. It is thought that the 65Cu(n,2n) reaction rate reported in the reference for the pressure vessel capsule is not correct. In considering the libraries developed after BUGLE-93, a maximum relative difference of 12% was observed in reaction rates, with respect to the reference results, for 237Np(n,f) in the cavity capsule using BUGLE-B7.

  6. Implementation of k0-standardization method of the INAA at ETRR-2 research reactor

    International Nuclear Information System (INIS)

    The k0-method of INAA standardization has been implemented using the irradiation facilities of the fast pneumatic rabbit and some selected manually loaded irradiation positions, which designated for short and long irradiation, respectively, at Egypt second research reactor. The neutron flux parameters (f and α) in each site have been determined using Zr-Au sets as neutron flux monitors. The reference materials coal NIST 1632c and IAEA-Soil 7 were analyzed for data validation and good agreement between the experimental values and the certified values was obtained. (author)

  7. Standard technical specifications for Babcock and Wilcox pressurized water reactors. Revision 4. Technical report

    International Nuclear Information System (INIS)

    The Standard Technical Specifications for Babcock and Wilcox Pressurized Water Reactors (BandW-STS) is a generic document prepared by the U.S. NRC for use in the licensing process. The BandW-STS provide applicants with model specifications to be used in formulation plant-specific technical specifications required by 10 CFR Part 50, Section 50.36, which set forth the specific characteristics of the facility and the conditions for its operation that are required to provide adequate protection to the health and safety of the public. This document is revised periodically to reflect current licensing requirements

  8. Study on Kο-standardization method of neutron activation analysis in HANARO research reactor

    International Nuclear Information System (INIS)

    The neutron activation analysis based on kο-standardization method (kο-NAA) has been known as one of the remarkable developments of NAA in recent with advantages of experimental simplicity, high accuracy, excellent flexibility with respect to irradiation and counting conditions, and suitability for computerization. This work has carried out to consider the application of kο-NAA on NAA 1 of HANARO research reactor such as the calibration of gamma-ray spectrometry and irradiation facility. α and f-values related to the reactor neutron spectrum parameters as main factor of irradiation quality are measured and some SRMs are analyzed to compare the accuracy of the measured results. The analytical results with the deviation mostly less than ±15% and all Z-score lower 1.5 in comparison between the experiment value and that value certified of some SRMs has shown a promising capability in application of kο-NAA on the HANARO research reactor

  9. Application of NAA standardization methods using a low power research reactor

    International Nuclear Information System (INIS)

    Two widely used neutron activation analysis (NAA) standardization methods (relative and k0) have been validated at the Ghana Research Reactor-1 (GHARR-1) Centre using environmental and biological standard reference materials (SRMs). The samples were IAEA Soil-7 as an environmental sample, and NIST Orchard Leaves 1571 as a biological sample. The qualitative and quantitative analyses were done using a high resolution Canberra N-type high purity germanium (HPGe) detector. The accuracy and precision were evaluated for the elements analysed. The concentrations of most of the elements were found to be within 10% of the certified values. Precision was calculated from six replicate measurements and was found to be within 15%. (author)

  10. Standard review plan for the review and evaluation of emergency plans for research and test reactors. Technical report

    International Nuclear Information System (INIS)

    This document provides a Standard Review Plan for the guidance of the NRC staff to assure that complete and uniform reviews are made of research and test reactor emergency plans. The report is organized under ten planning standards which correspond to the guidance criteria in Draft II of ANSI/ANS 15.16 as endorsed by Revision 1 to Regulatory Guide 2.6. The applicability of the items under each planning standard is indicated by subdivisions of the steady state thermal power levels at which the reactors are licensed to operate. Standard emergency classes and example action levels for research and test reactors which should initiate these classes are given in an Appendix

  11. Standard Molar Enthalpies of Formation of Ce ( TCA)3·3H2O (s) and Ce(TCA) (C9H6NO)2(S)

    Institute of Scientific and Technical Information of China (English)

    李强国; 叶丽娟; 首梦娟

    2003-01-01

    The standard molar reaction enthalpies of two reactions, CeCl3·7H2O(s)+3CCl3COOH(s)=Ce(TCA)3·3H2O(s)+3HCl(g)+4H2O(I) (1) and Ce (TCA)3·3H2O(s)+2C9H7NO (s) =Ce(TCA) (C9H6NO)2(s)+2CCl3COOH(s) + 3H2O(I) (2),were investigated by classical solution calorimetry and an isoperibol calorimeter at 298.15 K. The standard molar enthalpies △sHm- of solution of CeCl3·7H2O(s), 3CCl3COOH(s),Ce(TCA)3·3H2O(s), Ce(TCA)3·3H2O(s), 2C9H7NO(s), Ce(TCA) (C9H6NO)2(s) and 2CCl3COOH(s) were determined to be (50.615±0.028), (23.431±0.027), (94.206±0.010),(54.151±0.020), (27.485±0.045), (106.392±0.060) and -(14.893±0.026) kJ/mol, respectively. The reaction enthalpies △rHm- of reactions (1) and (2) were obtained to be (204.279±0.023) and -(9.863±0.041) kJ/mol, respectively. According to the above results and the data given in literature, through Hess'' law, the standard molar enthalpies △fHm- of formation of Ce(TCA)3·3H2O(s) and Ce(TCA)(C9H6NO)2(s) were estimated to be -(3060.0±0.087) and -(1369.0±0.292) kJ/mol, respectively.

  12. Guidelines for estimating present and forecasting future population distributions surrounding power reactor sites. (Draft of a standard)

    International Nuclear Information System (INIS)

    This report presents demographic procedures for estimating and forecasting population totals and distributions within a 50-mile radius of a proposed power plant site. Procedures such as those described are needed to comply with the license application procedure for a proposed power reactor site. The report includes a draft for a prospective American National Standard to estimate present and forecast future population distributions surrounding proposed reactor sites

  13. Catalogue and classification of technical safety standards, rules and regulations for nuclear power reactors and nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    The present report is an up-dated version of the report 'Catalogue and Classification of Technical Safety Rules for Light-water Reactors and Reprocessing Plants' edited under code No EUR 5362e, August 1975. Like the first version of the report, it constitutes a catalogue and classification of standards, rules and regulations on land-based nuclear power reactors and fuel cycle facilities. The reasons for the classification system used are given and discussed

  14. Performance testing of irradiation facility rabbit system pneumatic reactor RSG-GAS using standard reference material

    International Nuclear Information System (INIS)

    The irradiation facility function test of rabbit system pneumatic (RS-5) has been done using standard reference material SRM 1633 Coal Fly ash through the sending station. Long irradiation of about 4-5 seconds. The results of qualitative analysis showed that the dominant elements listed in the certificate can be detected are Al, Ca, Mg, Si, Na, Ti, V, Mn. But only an element of Mn and Na which has a relative refractive values below 10%. And the other elements have a value relative refractive index 25% - 60%. The significant difference of value was not influenced by the position of irradiation in the reactor facility but due to the influence of the time difference between the sample and the standard count, and the half-life nuclide itself. Overall it can be said that the performance of the irradiation facility pneumatic rabbit system is good, but needs to be tested again by using different standard reference materials, in order to obtain the test results of analysis that can be trusted. (author)

  15. Standardization of advanced light water reactors and progress on achieving utility requirements

    International Nuclear Information System (INIS)

    This paper reports that for a number of years, the U.S. utilities had led an industry-wide effort to establish a technical foundation for the design of the next generation of light water reactors in the United States. Since 1985, this utility initiative has been effected through a major technical program managed by the Electric Power Research Institute (EPRI); the U.S. Advanced Light Water Reactor (ALWR) Program. In addition to the U.S. utility leadership and sponsorship, the ALWR Program also has the participation and sponsorship of a number of international utility companies and close cooperation with the U.S. Department of Energy (DOE). The NPOC Strategic Plan for Building New Nuclear Plants creates a framework within which new standardized nuclear plants may be built. The Strategic Plan is an expression of the nuclear energy industry's serious intent to create the necessary conditions for new plant construction and operation. The industry has assembled a comprehensive, integrated list of actions that must be taken before new plants will be built and assigns responsibility for managing the various issues and sets time-tables and milestones against which we must measure progress

  16. Reliability study: digital reactor protection system of Korean standard nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H. G.; Jang, S. C.; Eom, H. S.; Jeong, H. S

    2003-02-01

    Digital safety-critical systems which are now installed in Korean Standard Nuclear Power Plants (KSNPP) would be quantitatively evaluated in order to prove the safety. In this study, we quantify the safety of the digital reactor protection system in KSNPPs using PSA technology. This study also includes the detailed investigation of the target system operation. The Fault Tree (FT) models were constructed for 15 reactor trip parameters. For digital parts, because the operation data for the same type PWR was unavailable, we used the data provided by vendors. On the other hand, for the conventional analog/mechanical parts, we used experience data presented in KAERI/TR-2164/2002.The result of quantification shows that the system unavailability varies from 4.36E-5 to 8.96E-4 according to the trip parameter. Main contributor to the difference from the conventional analysis would be the difference in human failure probability estimation. Generally, the system unavailability depends on several important factors: Human failure probability, software failure probability, watchdog timer coverage, and common cause failure estimation.

  17. Standard- and extended-burnup PWR [pressurized-water reactor] and BWR [boiling-water reactor] reactor models for the ORIGEN2 computer code

    International Nuclear Information System (INIS)

    The purpose of this report is to describe an updated set of reactor models for pressurized-water reactors (PWRs) and boiling-water reactors (BWRs) operating on uranium fuel cycles and the methods used to generate the information for these models. Since new fuel cycle schemes and reactor core designs are introduced from time to time by reactor manufacturers and fuel vendors, an effort has been made to update these reactor models periodically and to expand the data bases used by the ORIGEN2 computer code. In addition, more sophisticated computational techniques than previously available were used to calculate the resulting reactor model cross-section libraries. The PWR models were based on a Westinghouse design, while the BWR models were based on a General Electric BWR/6 design. The specific reactor types considered in this report are as follows (see Glossary for the definition of these and other terms): (1) PWR-US, (2) PWR-UE, (3) BWR-US, (4) BWR-USO, and (5) BWR-UE. Each reactor model includes a unique data library that may be used to simulate the buildup and deletion of isotopes in nuclear materials using the ORIGEN2 computer code. 33 refs., 44 tabs

  18. Self absorption and geometric correction factors for reactor off-gas samples relative to NBS standards

    International Nuclear Information System (INIS)

    Although they can be counted in identical bottles using identical counting systems, real gas samples differ from the NBS solution standards (e.g., mock reactor off-gas) in two respects--geometry and self absorption. Because both detector and source are real and finite, the simple ''narrow beam'' linear attenuation coefficient approximations currently used in the industry are quite inadequate for correction. Accordingly, the well-tested, complete-analog program, BIM 130, was used to compute the fraction of photons, and the photon energy spectra, reaching typical detectors used in the industry. Using this method, it was possible to correct the given NBS standard activity to its effective activity relative to a gas sample in an identical bottle. Factors were much closer to unity than predictions based on ''narrow beam'' linear attenuation coefficient approximations. At 80 keV, for example, such approximations gave 0.76, whereas the factor proved to be 1.03 for a 3'' x 3'' NaI(Tl) crystal and a 3 cm distance. Results are presented for various gamma energies of interest from 80 keV to 1,830 keV, and for the commonly used industrial distances of 3, 10, and 30 cm from the bottom of the sample bottle to the top of the detector container. Complete spectra for photons entering the detectors, as well as factors derived from these for typical NaI(Tl) and Ge(Li) detector resolutions, are given

  19. Standard Test Method for Application and Analysis of Helium Accumulation Fluence Monitors for Reactor Vessel Surveillance, E706 (IIIC)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method describes the concept and use of helium accumulation for neutron fluence dosimetry for reactor vessel surveillance. Although this test method is directed toward applications in vessel surveillance, the concepts and techniques are equally applicable to the general field of neutron dosimetry. The various applications of this test method for reactor vessel surveillance are as follows: 1.1.1 Helium accumulation fluence monitor (HAFM) capsules, 1.1.2 Unencapsulated, or cadmium or gadolinium covered, radiometric monitors (RM) and HAFM wires for helium analysis, 1.1.3 Charpy test block samples for helium accumulation, and 1.1.4 Reactor vessel (RV) wall samples for helium accumulation. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  20. 76 FR 23630 - Office of New Reactors; Proposed Revision 2 to Standard Review Plan, Section 1.0 on Introduction...

    Science.gov (United States)

    2011-04-27

    ... COMMISSION Office of New Reactors; Proposed Revision 2 to Standard Review Plan, Section 1.0 on Introduction...), Section 1.0, ``Introduction and Interfaces'' (Agencywide Documents Access and Management System (ADAMS...: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch (RADB), Office of Administration,...

  1. 75 FR 68009 - Office of New Reactors; Notice of Availability of the Final Staff Guidance Standard Review Plan...

    Science.gov (United States)

    2010-11-04

    ... COMMISSION Office of New Reactors; Notice of Availability of the Final Staff Guidance Standard Review Plan Section 13.6.2, Revision 1 on Physical Security--Design Certification AGENCY: Nuclear Regulatory Commission (NRC). ACTION: Notice of Availability. SUMMARY: The NRC is issuing its Final Revision 1 to...

  2. Characterization and catalytic performance of CeO2-Co/SiO2 catalyst for Fischer-Tropsch synthesis using nitrogen-diluted synthesis gas over a laboratory scale fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Dai; Changchun Yu

    2008-01-01

    The surface species of CO hydrogenation on CeO2-Co/SiO2 catalyst were investigated using the techniques of temperature programmed reaction and transient response method. The results indicated that the formation of H2O and CO2 was the competitive reaction for the surface oxygen species, CH4 was produced via the hydrogenation of carbon species step by step, and C2 products were formed by the polymerization of surface-active carbon species (-CH2-). Hydrogen assisted the dissociation of CO. The hydrogenation of surface carbon species was the rate-limiting step in the hydrogenation of CO over CeO2-Co/SiO2 catalyst. The investigation of total pressure, gas hourly space velocity (GHSV), and product distribution using nitrogen-rich synthesis gas as feedstock over a laboratory scale fixed-bed reactor indicated that total pressure and GHSV had a significant effect on the catalytic performance of CeO2-Co/SiO2 catalyst. The removal of heat and control of the reaction temperature were extremely critical steps, which required lower GHSV and appropriate CO conversion to avoid the deactivation of the catalyst. The feedstock of nitrogen-rich synthesis gas was favorable to increase the conversion of CO, but there was a shift of product distribution toward the light hydrocarbon. The nitrogen-rich synthesis gas was feasible for F-T synthesis for the utilization of remote natural gas.

  3. DOE plutonium disposition study: Analysis of existing ABB-CE Light Water Reactors for the disposition of weapons-grade plutonium

    International Nuclear Information System (INIS)

    Core reactivity and basic fuel management calculations were conducted on the selected reactors (with emphasis on the System 80 units as being the most desirable choice). Methods used were identical to those reported in the Evolutionary Reactor Report. From these calculations, the basic mission capability was assessed. The selected reactors were studied for modification, such as the addition of control rod nozzles to increase rod worth, and internals and control system modifications that might also be needed. Other system modifications studied included the use of enriched boric acid as soluble poison, and examination of the fuel pool capacities. The basic geometry and mechanical characteristics, materials and fabrication techniques of the fuel assemblies for the selected existing reactors are the same as for System 80+. There will be some differences in plutonium loading, according to the ability of the reactors to load MOX fuel. These differences are not expected to affect licensability or EPA requirements. Therefore, the fuel technology and fuel qualification sections provided in the Evolutionary Reactor Report apply to the existing reactors. An additional factor, in that the existing reactor availability presupposes the use of that reactor for the irradiation of Lead Test Assemblies, is discussed. The reactor operating and facility licenses for the operating plants were reviewed. Licensing strategies for each selected reactor were identified. The spent fuel pool for the selected reactors (Palo Verde) was reviewed for capacity and upgrade requirements. Reactor waste streams were identified and assessed in comparison to uranium fuel operations. Cost assessments and schedules for converting to plutonium disposition were estimated for some of the major modification items. Economic factors (incremental costs associated with using weapons plutonium) were listed and where possible under the scope of work, estimates were made

  4. 用于甲烷偶联的SrCe0.95Yb0.05O3-α中空纤维膜反应器建模%Modeling of a SrCe0.95Yb0.05O3-α Hollow Fibre Membrane Reactor for Methane Coupling

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Proton-hole mixed conductor, SrCe0.95Yb0.05O3-α(SCYb), has the potential to be used as a mem-brane for dehydrogenation reactions such as methane coupling due to its high C2-selectivity and its simplicity forfabricating reactor systems. In addition, the mixed conducting membrane in the hollow fibre geometry is capable ofproviding high surface area per unit volume. In this study, mechanism of methane coupling reaction on the SCYbmembrane was proposed and the kinetic parameters were obtained by regression of experimental data. A math-ematical model describing the methane coupling in the SCYb hollow fibre membrane reactor was also developed.With this mathematical model, various operating conditions such as the operation mode, operation pressure andfeed concentrations affecting performance of the reactor were investigated. The simulation results show that thecocurrent flow in the reactor exhibits higher conversion of methane and higher yield of ethylene compared to thecountercurrent flow. In order to achieve the highest C2 yield, especially of ethylene, pure methane should be usedas feed and the operating pressure be 300kPa. Air can be used as the source of oxygen for the reaction and itsoptimum feed velocity is twice of the methane feed velocity. The air pressure in the lumen side should be kept thesame as or slightly lower than the pressure of shell side.

  5. Standard B presentation vs. contrast-enhanced ultrasound (US-CE). A comparison of usefulness of different ultrasonographic techniques in the evaluation of the echo structure and size of haematomas inpost-renal transplant patients: A preliminary report

    International Nuclear Information System (INIS)

    During routine ultrasonographic examination in B presentation, performed as a standard diagnostic procedure during the early post-operative period, the most important problem with the interpretation of the images of perirenal haematoma is their ability to change in time. The aim of this work was to assess the echogenicity and the size of perirenal haematomas in patients after kidney transplant during routine examinations in B presentation and during examinations enhanced with a contrast medium (CE-US). Thirty-seven patients after kidney transplant were examined using standard examination in B presentation. Sixteen patients (7 women and 9 men) with isoechogenic and hypoechogenic areas visualized within the renal parenchyma, who were suspected of perirenal haematoma, underwent a CE-US examination after intravenous administration of sculpture hexafluoride (dose: 2.4 ml/examination). Using time-intensity curves (TIC), changes in the values were analysed for two areas of interest (ROI): in the renal parenchyma and in the areas identified during standard US as haematomas. Identical examination protocols and dynamic data loops allowed the acquisition of identical kidney cross-sections and enabled measuring the echogenicity and thickness of the abnormalities at the same location. During the routine B presentation examination, the average difference between haematoma and the renal cortex was 5 dB. When performing US-CE examination, a significantly greater difference in echogenicity was observed and reached 31 dB. In six patients, the size of haematomas was comparable using both techniques, whereas in ten patients lesions visualized in B presentation were smaller than in the US-CE examination. The US-CE examination demonstrated a greater, statistically significant, difference in the echogenicity of perirenal haematomas compared to the routine examination in B presentation. This method enabled a more detailed assessment of the size of haematomas in the perirenal space that

  6. The Advanced Candu reactor annunciation system - Compliance with IEC standard and US NRC guidelines

    International Nuclear Information System (INIS)

    Annunciation is a key plant information system that alerts Operations staff to important changes in plant processes and systems. Operational experience at nuclear stations worldwide has shown that many annunciation implementations do not provide the support needed by Operations staff in all plant situations. To address utility needs for annunciation improvement in Candu plants, AECL in partnership with Canadian Candu utilities, undertook an annunciation improvement program in the early nineties. The outcome of the research and engineering development program was the development and simulator validation of alarm processing, display, and information presentation techniques that provide practical and effective solutions to key operational deficiencies with earlier annunciation implementations. The improved annunciation capabilities consist of a series of detection, information processing and presentation functions called the Candu Annunciation Message List System (CAMLS). The CAMLS concepts embody alarm processing, presentation and interaction techniques, and strategies and methods for annunciation system configuration to ensure improved annunciation support for all plant situations, especially in upset situations where the alarm generation rate is high. The Advanced Candu Reactor (ACR) project will employ the CAMLS annunciation concepts as the basis for primary annunciation implementations. The primary annunciation systems will be implemented from CAMLS applications hosted on AECL Advanced Control Centre Information System (ACCIS) computing technology. The ACR project has also chosen to implement main control room annunciation aspects in conformance with the following international standard and regulatory review guide for control room annunciation practice: International Electrotechnical Commission (IEC) 62241 - Main Control Room, Alarm Function and Presentation (International standard) US NRC NUREG-0700 - Human-System Interface Design Review Guidelines, Section 4

  7. A probabilistic safety assessment of the standard French 900MWe pressurized water reactor. Main report

    International Nuclear Information System (INIS)

    To situate the probabilistic safety assessment of standardized 900 MWe units made by the Institute for Nuclear Safety and Protection (IPSN), it is necessary to consider the importance and possible utilization of a study of this type. At the present time, the safety of nuclear installations essentially depends on the application of the defence in-depth approach. The design arrangements adopted are justified by the operating organization on the basis of deterministic studies of a limited number of conventional situations with corresponding safety margins. These conventional situations are grouped in categories by frequency, it being accepted that the greater the consequences the lesser the frequency must be. However in the framework of the analysis performed under the control of the French safety authority, the importance was rapidly recognized of setting an overall reference objective. By 1977, on the occasion of appraisal of the fundamental safety options of the standardized 1300 MWe units, the Central Service for the Safety of Nuclear Installations (SCSIN) set the following global probabilistic objective: 'Generally speaking, the design of installations including a pressurized water nuclear reactor must be such that the global probability of the nuclear unit being the origin of unacceptable consequences does not exceed 10-6 per year...' Probabilistic analyses making reference to this global objective gradually began to supplement the deterministic approach, both for examining external hazards to be considered in the design basis and for examining the possible need for additional means of countering the failure of doubled systems in application of the deterministic single-failure criterion. A new step has been taken in France by carrying out two level 1 probabilistic safety assessments (calculation of the annual probability of core meltdown), one for the 900 MWe series by the IPSN and the other for the 1300 MWe series by Electricite de France. The objective of

  8. Reactors

    International Nuclear Information System (INIS)

    Purpose: To provide a spray cooling structure wherein the steam phase in a bwr reactor vessel can sufficiently be cooled and the upper cap and flanges in the vessel can be cooled rapidly which kept from direct contaction with cold water. Constitution: An apertured shielding is provided in parallel spaced apart from the inner wall surface at the upper portion of a reactor vessel equipped with a spray nozzle, and the lower end of the shielding and the inner wall of the vessel are closed to each other so as to store the cooling water. Upon spray cooling, cooling water jetting out from the nozzle cools the vapor phase in the vessel and then hits against the shielding. Then the cooling water mostly falls as it is, while partially enters through the apertures to the back of the shielding plate, abuts against stoppers and falls down. The stoppers are formed in an inverted L shape so that the spray water may not in direct contaction with the inner wall of the vessel. (Horiuchi, T.)

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

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

  10. Standard Guide for In-Service Annealing of Light-Water Moderated Nuclear Reactor Vessels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This guide covers the general procedures to be considered for conducting an in-service thermal anneal of a light-water moderated nuclear reactor vessel and demonstrating the effectiveness of the procedure. The purpose of this in-service annealing (heat treatment) is to improve the mechanical properties, especially fracture toughness, of the reactor vessel materials previously degraded by neutron embrittlement. The improvement in mechanical properties generally is assessed using Charpy V-notch impact test results, or alternatively, fracture toughness test results or inferred toughness property changes from tensile, hardness, indentation, or other miniature specimen testing (1). 1.2 This guide is designed to accommodate the variable response of reactor-vessel materials in post-irradiation annealing at various temperatures and different time periods. Certain inherent limiting factors must be considered in developing an annealing procedure. These factors include system-design limitations; physical constrain...

  11. The French Fast Reactor Programme: Innovations in Support of Higher Standards

    International Nuclear Information System (INIS)

    Deriving from the feedback of experience of former sodium cooled fast reactors, very high levels of requirements have been set for the ASTRID reactor (Advanced Sodium Technological Reactor for Industrial Demonstration). Innovations are needed to further enhance safety, reduce capital cost and improve efficiency, reliability and operability, making the Generation IV SFR an attractive option for electricity production. This puts great pressure not only on the R&D and design teams at CEA but also on the CEA’s R&D and industrial partners. During the first phase of the ASTRID conceptual design (2010–2012), promising innovative options have been identified. They will be further developed in the next phases of ASTRID design studies, keeping a strong interaction between design and R&D. (author)

  12. Computer-assisted reactor NAA of geological and other reference materials, using the ksub(o)-standardization method

    International Nuclear Information System (INIS)

    USGS BCR-1 and G-2, NBS 1633a Coal Fly-Ash and a 7-element synthetic standard for biological materials were analyzed by reactor NAA, using the ksub(o)-standardization method. The analyses were performed independently in the analytical laboratories of the Institute for Nuclear Sciences (INW), Gent, and the Central Research Institute for Physics (KFKI), Budapest. This procedure allowed not only a comparison with the specified data or with other published values, but enabled a check of the consistency of our own results obtained in largely different experimental conditions. As concluded, the ksub(o)-standardization method combines general versatility (with respect to irradiation and counting conditions) with good accuracy, while the experimental work remains as simple as possible. Since the ksub(o) method is a computer-oriented technique, a FORTRAN IV program was designed and applied on a VAX 11/780 machine. (author)

  13. Study of reactor characteristics for the adaptation of the monoelement standard method in activation analysis. Application to impurity determination in silicon

    International Nuclear Information System (INIS)

    Nuclear reactions by irradiation in a nuclear reactor are reviewed. Quantitative analysis by comparison with multielement standard is treated. Comparison methods using a monoelement standard, easier to use they require a previous study of neutronic characteristics of irradiation channels of reactors (thermal and epithermal flux ratio and eventual deviations fo epithermal neutron energy spectra from the 1/E relationship). Then analysis fo silicon polycrystals by both methods is studied and interfering reactions during irradiation are examined

  14. Application of coupled code technique to a safety analysis of a standard MTR research reactor

    International Nuclear Information System (INIS)

    Accident analyses in nuclear research reactors have been performed, up to now, using simple computational tools based on conservative physical models. These codes, developed to focus on specific phenomena in the reactor, were widely used for licensing purposes. Nowadays, the advances in computer technology make it possible to switch to a new generation of computational tools that provides more realistic description of the phenomena occurring in a nuclear research reactor. Recent International Atomic Energy Agency (IAEA) activities have emphasized the maturity in using Best Estimate (BE) Codes in the analysis of accidents in research reactors. Indeed, some assessments have already been performed using BE thermal-hydraulic system codes such as RELAP5/Mod3. The challenge today is oriented to the application of coupled code techniques for research reactors safety analyses. Within the framework of the current study, a Three-Dimensional Neutron Kinetics Thermal-Hydraulic Model (3D-NKTH) based on coupled PARCS and RELAP5/Mod3.3 codes has been developed for the IAEA High Enriched Uranium (HEU) benchmark core. The results of the steady state calculations are sketched by comparison to tabulated results issued from the IAEA TECDOC 643. These data were obtained using conventional diffusion codes as well as Monte Carlo codes. On the other hand, the transient analysis was assessed with conventional coupled point kinetics-thermal-hydraulic channel codes such as RELAP5 stand alone, RETRAC-PC, and PARET codes. Through this study, the applicability of the coupled code technique is emphasized with an outline of some remaining challenges.

  15. Application of coupled code technique to a safety analysis of a standard MTR research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hamidouche, Tewfik [Division de l' Environnement, de la Surete et des Dechets Radioactifs, Centre de Recherche Nucleaire d' Alger (CRNA), Alger (Algeria); Laboratoire de Mecanique des Fluides Theorique et Appliquee, Faculte de Physique, Universite Des Sciences et de la Technologie Houari Boumediene, (USTHB), Bab-Ezzouar, Alger (Algeria)], E-mail: t.hamidouche@crna.dz; Bousbia-Salah, Anis [Dipartimento di Ingegneria Meccanica, Nucleari e della Produzione-Facolta di Ingegneria, Universita di Pisa, Pisa (Italy)], E-mail: b.salah@ing.unipi.it; Si-Ahmed, El Khider [Laboratoire de Mecanique des Fluides Theorique et Appliquee, Faculte de Physique, Universite Des Sciences et de la Technologie Houari Boumediene, (USTHB), Bab-Ezzouar, Alger (Algeria)], E-mail: esi-ahmed@usthb.dz; Mokeddem, Mohamed Yazid [Division de la Physique et des Applications Nucleaires, Centre de Recherche Nucleaire de Draria (CRND) (Algeria); D' Auria, Franscesco [Dipartimento di Ingegneria Meccanica, Nucleari e della Produzione-Facolta di Ingegneria, Universita di Pisa, Pisa (Italy)

    2009-10-15

    Accident analyses in nuclear research reactors have been performed, up to now, using simple computational tools based on conservative physical models. These codes, developed to focus on specific phenomena in the reactor, were widely used for licensing purposes. Nowadays, the advances in computer technology make it possible to switch to a new generation of computational tools that provides more realistic description of the phenomena occurring in a nuclear research reactor. Recent International Atomic Energy Agency (IAEA) activities have emphasized the maturity in using Best Estimate (BE) Codes in the analysis of accidents in research reactors. Indeed, some assessments have already been performed using BE thermal-hydraulic system codes such as RELAP5/Mod3. The challenge today is oriented to the application of coupled code techniques for research reactors safety analyses. Within the framework of the current study, a Three-Dimensional Neutron Kinetics Thermal-Hydraulic Model (3D-NKTH) based on coupled PARCS and RELAP5/Mod3.3 codes has been developed for the IAEA High Enriched Uranium (HEU) benchmark core. The results of the steady state calculations are sketched by comparison to tabulated results issued from the IAEA TECDOC 643. These data were obtained using conventional diffusion codes as well as Monte Carlo codes. On the other hand, the transient analysis was assessed with conventional coupled point kinetics-thermal-hydraulic channel codes such as RELAP5 stand alone, RETRAC-PC, and PARET codes. Through this study, the applicability of the coupled code technique is emphasized with an outline of some remaining challenges.

  16. Safety-evaluation report related to the license renewal and power increase for the National Bureau of Standards Reactor (Docket No. 50-184)

    International Nuclear Information System (INIS)

    This Safety Evaluation Report for the application filed by the National Bureau of Standards (NBS) for an increase in power from 10 MWt to 20 MWt and for a renewal of the Operating License TR-5 to continue to operate the test reactor has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. The facility is located in Gaithersburg, Maryland, on the site of the National Bureau of Standards, which is a bureau of the Department of Commerce. The staff concludes that the NBS reactor can operate at the 20 MWt power level without endangering the health and safety of the public

  17. CFD Simulation of Hydrodynamic Characteristics in Stirred Reactors Equipped with Standard Rushton or 45°-Upward PBT Impeller

    Institute of Scientific and Technical Information of China (English)

    未作君; 徐世民; 元英进; 许松林

    2003-01-01

    The hydrodynamic characteristics generated by the standard Rushton or 45°-upward pitched-blade-turbine (PBT) impellers in a baffled reactor are numerically simulated for different off-bottom clearances (C= 1/3H and 1/2H) and agitator speeds (100, 150, 200, 250 and 300r·min-1) by using FLUENT code (Version 5.4). The results are compared with the experimental and simulated data in the published papers and good agreement is observed. The shapes of the profile of mean velocities seem independent to the speed of agitators under the experimental conditions (100-300r·min-1).

  18. A comprehensive study on the thermal movement of the reactor coolant system for Korea Standard Nuclear Power Plant

    International Nuclear Information System (INIS)

    The specific thermal pattern of each component of the reactor coolant system (RCS) is a basic design parameter for the establishment of the RCS arrangement and support system. Development of an effective method to analyze the global behavior of thermal movement of the RCS is required for design process. In this paper a fundamental but reliable and comprehensive method of obtaining thermal movement of the Korea Standard Nuclear Power Plant (KSNPP) is presented. Experimental results are included to illustrate the validity of the analyses

  19. Design of standardized WWER-1000 reactor power plant allowing industrialization of production

    International Nuclear Information System (INIS)

    The improvement consists in the siting of the individual units which allows streamlined construction, the assembly of power units and improved quality of construction work. To protect it against vibrations the reactor building is designed as a symmetric box-shaped reinforced concrete structure. The heaviest equipment is placed in the lowest parts, which increases stability and facilitates the solution of the problem of the interaction of foundations and structure proper. The cylindrical part of the sealed envelope of the reactor part may be assembled of large units up to 100 t in weight and another design of the envelope copula allows the assembly of basic equipment to be started 3 to 4 months earlier. These and other improvements make it possible to shorten construction time by 35 to 40%, to reduce material consumption and to increase productivity. (E.S.)

  20. The French Fast Reactor Program - Innovations in Support to Higher Standards

    International Nuclear Information System (INIS)

    • From the experience of ASTRID first phase of conceptual design studies (2010-2012), two remarks can be made: → Higher requirements in safety and operability lead to higher costs that cannot be fully recovered by advances in technology. This puts additional pressure on the next phases of the design to optimize the design and to keep the costs to the minimum. → There is a clear link between the level of safety that can be achieved and the maturity of the technology, i.e. the experience accumulated in R&D, design, construction, operation and decommissioning of past reactors. In the field of fast neutron reactors, this gives a strong advantage to the sodium technology, because strengths and weaknesses are well mastered. • Meeting the high requirements set for ASTRID and serving R&D needs of innovative options will require increased industrial and international collaboration

  1. The application and development of k0-standardization method of neutron activation analysis at Dalat research reactor

    International Nuclear Information System (INIS)

    In recent years the k0-NAA method has been applied and developed at the 500 kW Dalat research reactor, which includes the establishment of a PC database of k0-NAA-related nuclear parameters, e.g., radionuclide produced, half-lives, k0-factors, Q0, E-barr Eγ, etc; the access to the database is able by a k0-NAA software or by manual; the detection efficiency calibration of gamma spectrometers used in k0-NAA, the determination of reactor neutron spectrum parameters such as α and f factors and neutron fluxes in the irradiation channels, and the validation of the developed k0-NAA procedure by analysing some SRMs, namely Coal Fly Ash (NIST-1633b), Bovine Liver (NIST-1577b) and IAEA-Soil7. The analytical results showed the deviations between experimental and certified values were mostly less than 15% with most Z-scores lower than 2. The k0-NAA procedure established at the Dalat research reactor has been regarded as a reliable standardization method of NAA and as available for practical applications, in particularly for airborne particulate and crude oil samples. (author)

  2. Development and implementation of k0-INAA standardization at 10 MW Pakistan research reactor-1

    International Nuclear Information System (INIS)

    The k0-method has been developed for 10 MW Pakistan Research Reactor (PARR-1). It involved the full energy peak efficiency calibration of HPGe detector for different counting geometries and characterization of neutron flux at three irradiation channels. Neutron flux was characterized for thermal to epithermal flux ratio, epithermal flux shape factor, modified spectral index. Westcott's g-factor and fast flux. The method was validated by analyzing IAEA-SL1 (lake sediment) and NIST-SRM-1572 (citrus leaves). All calculations were performed in Excel. The results revealed most of the elements with good accuracy. (orig.)

  3. 78 FR 59981 - Proposed Revision to Physical Security-Standard Design Certification and Operating Reactors

    Science.gov (United States)

    2013-09-30

    ..., incorporate licensing experience from previous design certification application reviews, and to inform... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY... AGENCY: Nuclear Regulatory Commission. ACTION: Standard review plan-draft section revision; request...

  4. Final Environmental Statement related to license renewal and power increase for the National Bureau of Standards Reactor: Docket No. 50-184

    International Nuclear Information System (INIS)

    This Final Environmental Statement contains an assessment of the environmental impact associated with renewal of Operating License No. TR-5 for the National Bureau of Standards (NBS) reactor for a period of 20 years at a power level of 20 MW. This reactor is located on the 576-acre NBS site near Gaithersburg in Montgomery County, Maryland, about 20 mi northwest of the center of Washington, DC. The reactor is a high-flux heavy-water-moderated, cooled and reflected test reactor, which first went critical on December 7, 1967. Though the reactor was originally designed for 20-MW operation, it has been operating for 14 years at a maximum authorized power level to 10 MW. Program demand is now great enough to warrant operation at a power level of 20 MW. No additional major changes to the physical plant are required to operate at 20 MW

  5. The studies for application of Ko-standardization method of neutron activation analysis on Dalat reactor

    International Nuclear Information System (INIS)

    The studies for application of the Ko-NAA method have been carried out in order to aim at creating a concrete procedure of the method, which is able to apply for practical samples. The results of the calibration of neutron spectrum parameters at cell 7-1, 13-2 and rotary rack on Dalat reactor, the calibration of detection efficiency of gamma spectrometers, the application and development of computer software for processing of gamma-ray spectra and for calculating of related problems (i.e. detector efficiency, neutron spectrum parameters, elemental concentration, etc.) and the quality control/assessment (QC/QA) with the analysis of the reference material IAEA-Soil7 have been presented as well as the application of the ko-NAA for practical samples in geological, archaeological, bio-medical and environmental objects has also been shown. (author)

  6. Offsite dose calculation manual guidance: Standard radiological effluent controls for boiling water reactors

    International Nuclear Information System (INIS)

    This report contains guidance which may be voluntarily used by licensees who choose to implement the provision of Generic Letter 89-- 01, which allows Radiological Effluent Technical Specifications (RETS) to be removed from the main body of the Technical Specifications and placed in the Offsite Dose Calculation Manual (ODCM). Guidance is provided for Standard Effluent Controls definitions, Controls for effluent monitoring instrumentation, Controls for effluent releases, Controls for radiological environmental monitoring, and the basis for Controls. Guidance on the formulation of RETS has been available in draft form for a number of years; the current effort simply recasts those RETS into Standard Radiological Effluent Controls for application to the ODCM. 11 tabs

  7. Exit reactor Thetis/Ghent (1967-2003). A recollection of its significant contribution to NAA and its leading role in the development of the k0-standardization

    International Nuclear Information System (INIS)

    After 36 years of operation, reactor Thetis at the Institute for Nuclear Sciences (Ghent University) was decommissioned in December 2003. On this occasion, a survey is presented of the characteristics and features of Thetis, which were opening the way to its significant contribution to NAA and its leading role in the development of the k0-standardization. A summary is given, including a few specific examples, of fundamental analytical developments and practical applications based on irradiations in the reactor Thetis. (author)

  8. Safety evaluation report related to the license renewal and power increase for the National Bureau of Standards reactor (Docket No. 50-184)

    International Nuclear Information System (INIS)

    Supplement 1 to the Safety Evaluation Report (SER) related to the renewal of the operating license and for a power increase (10 MWt to 20 MWt) for the research reactor at the National Bureau of Standards (NBS) facility has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. This supplement reports on the review of the licensee's emergency plan, which had not been reviewed at the time the Safety Evaluation Report (NUREG-1007) was published, and the review of the NBS application by the Advisory Committee on Reactor Safeguards, which was completed subsequent to the publication of the SER

  9. The reference neutron field - a standard neutron source for neutron measurements at the research reactor IRT-2000 in Sofia

    International Nuclear Information System (INIS)

    A reference neutron field (RFN) is used as a standard neutron source (SNS) that is influenced by the changes in the reactor core due to recharging or other causes. A whole range of measurements is carried out in a full scope, to specify its characteristics precisely. The SNS comprises: 1) the RNF certificated to the neutron energy spectrum, its location in the reactor field, being a reference measure of the differential energy distribution in the neutron flux; 2) exposure monitoring tools (detectors revealing the certified physical characteristics); 3) functional measurement apparatus (revealing the spectral characteristics). The following basic metrological characteristics are given: differential neutron energy spectrum, described by F(E) [1/cm2.s.MeV], normalized by 1 in the range 3-19 MeV and the measurement error; the conventional neutron flux density and its error. The methodology of measuring the neutron flux integral density comprises the following six steps: 1) assessment of the influence of the changes in the core configuration on the stability of the RNF (estimated in six energy ranges); 2) demonstration of RNF application in reactor physics studies; 3) irradiation of two sets of activation detectors (Au, Sc and Au, Sc, S in Al and Cd shields); 4) measurement of the detector activities by calibrated gamma- and beta- spectrometric apparatus; 5) determination of the neutron field characteristics at a certain point of the RNF by the method of activating ratios; 6) the result accuracy assessment and probabilistic error limits determination with 95% upper bound frequency. The RNF neutron energy range have been measured 6 times for a period of two years. 6 refs., 8 figs. (M.A.)

  10. Different magnetic behaviour of the Kondo compounds Al3Ce and Al11Ce3

    International Nuclear Information System (INIS)

    Neutron diffraction experiments on the Al3Ce and Al11Ce3 compounds have been performed on the multidetector of the I.L.L. high flux reactor. No magnetic structure has been detected on the Al3Ce compound down to 20 mK. This confirms the non magnetic ground state of Al3Ce. For Al11Ce3, two magnetic structures have been observed: a ferromagnetic one at 4.2 K and an antiferromagnetic one at 2 K. The antiferromagnetic structure, which corresponds to a propagation vector (0,0,1/3), implies a strong reduction of the magnetic moment of determined sites; this reflects the Kondo character of the compounds

  11. Simulation of primary to secondary break in a VVER-type reactor: Results of the IAEA's Third Standard Problem Exercise

    International Nuclear Information System (INIS)

    Seeking to enlarge the experimental data base for code assessment, the International Atomic Energy Agency (IAEA), in collaboration with the Central Research Institute for Physics of the Hungarian Academy of Sciences, has organized the Third Standard Problem Exercise (SPE-3) involving the simulation of a break from primary to secondary in the steam generator of the PMK-NVH experimental facility. The facility is a scaled-down model of a VVER-type reactor, and the experiment addresses the possibility of a break developing in the steam generator collector of the actual plant. This paper presents a brief description of the experimental facility and the experiment. Results of a comparison of pretest and posttest calculations performed by some of the 24 participants in the exercise are also presented. The complete report of the exercise has been published as an IAEA technical document

  12. Evaluation and standardization of neutron activation analysis according to the K0 method in the RP-10 reactor

    International Nuclear Information System (INIS)

    It has been characterized and standardized an irradiation of the RP-10 Research Nuclear Reactor for use of the K0 method of neutron activation analysis using the Hoegdahl convention; also it has been evaluate the behaviour of such method in regard to the accuracy and precision of the results obtained in the quantitative multi elemental analysis of several certified materials of reference. In order to prove that the analytical method is totally under statistical control, it has been used the Heydorn method. It has been verified that the method is exact, precise and reliable to determine the aluminium, antimuonium, arsenic, bromine, calcium, chloride, copper, magnesium, manganese, sodium, titanium, vanadium, zinc and other elements. Also, they are discussed, in regard to the use of K0 constants, the different formalisms employed to calculate the integral of the reaction rate by nucleus in the activation. (author). 58 refs., 18 tabs., 6 figs

  13. Standard for prevention of gas entrainment phenomena in fast reactors. (2) Proposal of gas entrainment evaluation method

    International Nuclear Information System (INIS)

    For the stable operation of fast breeder reactors (FBRs), the occurrences of gas entrainment (GE) phenomena should be suppressed below an allowance level. Therefore, a reliable evaluation method for the GE phenomena is necessary to determine the operating conditions of FBRs. However, such a method has not yet been established, especially for the vortex-type GE. In this paper, the authors propose a GE evaluation method in which free surface vortices are identified from velocity fields by using the second invariant of the velocity gradient tensor, and GE evaluation parameters, e.g., gas core length, are calculated by using the Burgers vortex model. In addition, the standard method for the prevention of three kinds of vortex-type GE is shown by considering experimental data, evaluation results obtained by the proposed method and comparison results. Finally, it is confirmed that the onset conditions of the vortex-type GE can be evaluated by the proposed method. (author)

  14. Offsite dose calculation manual guidance: Standard radiological effluent controls for pressurized water reactors

    International Nuclear Information System (INIS)

    This report contains guidance which may be voluntarily used by licensees who choose to implement the provision of Generic Letter 89-01, which allows Radiological Effect Technical Specifications (RETS) to be removed from the main body of the Technical Specifications and placed in the Offsite Dose Calculation Manual (ODCM). Guidance is provided for Standard Effluent Controls definitions, Controls for effluent monitoring instrumentation, Controls for effluent releases, Controls for radiological environmental monitoring, and the basis for Controls. Guidance on the formulation of RETS has been available in draft from (NUREG-0471 and -0473) for a number of years; the current effort simply recasts those RETS into Standard Radiological Effluent Controls for application to the ODCM. Also included for completeness are: (1) radiological environmental monitoring program guidance previously which had been available as a Branch Technical Position (Rev. 1, November 1979); (2) existing ODCM guidance; and (3) a reproduction of generic Letter 89-01

  15. Standard reference material certification: contribution of NAA with a TRIGA reactor

    International Nuclear Information System (INIS)

    Pavia has cooperative links with the major international agencies devoted to the certification of SRMs or CRMs as the Bureau Communautaire de Reference (BCR), the European Institute for Reference Materials and Measurement (IRMM), the USA National Institute of Standards and Technology (NIST) and the International Atomic Energy Agency (IAEA). During these cooperative works, a large amount of analytical data obtained with NAA has been compared, and meaningful methodological information achieved with respect to accuracy and precision in the analysis of several elements at different concentrations in various matrices. Analytical data on As, Cd, Cr, Co, Cu, Cs, Fe, Zn, K, Sc, U, Th, Al, Sb, Mn, V, Hg, Sr, Rb, Se,Pt, all the Rare Earths and halogens Br, Cl, I, have been obtained and contributed for the final certification

  16. Electro-regeneration of Ce(IV) in real spent Cr-etching solutions.

    Science.gov (United States)

    Chen, Te-San; Huang, Kuo-Lin

    2013-11-15

    This paper presents the electro-regeneration of Ce(IV) in real (hazardous) spent thin-film transistor liquid-crystal display (TFT-LCD) Cr-etching solutions. In addition to Ce(III)>Ce(IV) in diffusivity, a quasi-reversible behavior of Ce(III)/Ce(IV) was observed at both boron-doped diamond (BDD) and Pt disk electrodes. The Ce(IV) yield on Pt increased with increasing current density, and the best current efficiency (CE) was obtained at 2A/2.25 cm(2). The performance in terms of Ce(IV) yield and CE of tested anodes was in order BDD>Pt>dimensional stable anode (DSA). At 2A/2.25 cm(2) on Pt and 40 °C for 90 min, the Ce(IV) yield, CE and apparent rate constant (k) for Ce(III) oxidation were 81.4%, 21.8% and 3.17 × 10(-4) s(-1), respectively. With the increase of temperature, the Ce(IV) yield, CE, and k increased (activation energy = 10.7 kJ/mol), but the specific electricity consumption decreased. The Neosepta CMX membrane was more suitable than Nafion-117 and Nafion-212 to be used as the separator of the Ce(IV) regeneration process. The obtained parameters are useful to design divided batch reactors for the Ce(IV) electro-regeneration in real spent Cr-etching solutions. PMID:24140527

  17. ABB CE's turboTM fuel design-proven more robust relative to fretting

    International Nuclear Information System (INIS)

    ABB CE has established an excellent track record of reliability for its current fuel designs and has developed the TurboTM fuel design to continue to maintain this excellent performance. The heart of the TurboTM fuel design is an advanced Zircaloy spacer grid with rod support features that make the grid more robust relative to grid-to-rod fretting. The author describes the dual bundle endurance test of the TurboTM design co resident with a standard design assembly. This endurance test was run in ABB CE's Test Facility 2 (TF-2) at reactor operating pressure and temperature, and mechanical design flow. The test results demonstrate the superior performance of the TurboTM design, indicating at least a factor of 14 reduction in the potential for grid-to-rod fretting

  18. Improving CE with PDM

    NARCIS (Netherlands)

    Wognum, P.M. (Nel); Bondarouk, T.V. (Tanya); Weber, F.; Pawar, K.S.; Thoben, K.D.

    2003-01-01

    The concept of Concurrent Engineering (CE) centers around the management of information so that the right information will be at the right place at the right time and in the right format. Product Data Management (PDM) aims to support a CE way of working in product development processes. In specific

  19. Comparison of Standard Light Water Reactor Cross-Section Libraries using the United States Nuclear Regulatory Commission Boiling Water Reactor Benchmark Problem

    Directory of Open Access Journals (Sweden)

    Kulesza Joel A.

    2016-01-01

    Full Text Available This paper describes a comparison of contemporary and historical light water reactor shielding and pressure vessel dosimetry cross-section libraries for a boiling water reactor calculational benchmark problem. The calculational benchmark problem was developed at Brookhaven National Laboratory by the request of the U. S. Nuclear Regulatory Commission. The benchmark problem was originally evaluated by Brookhaven National Laboratory using the Oak Ridge National Laboratory discrete ordinates code DORT and the BUGLE-93 cross-section library. In this paper, the Westinghouse RAPTOR-M3G three-dimensional discrete ordinates code was used. A variety of cross-section libraries were used with RAPTOR-M3G including the BUGLE93, BUGLE-96, and BUGLE-B7 cross-section libraries developed at Oak Ridge National Laboratory and ALPAN-VII.0 developed at Westinghouse. In comparing the calculated fast reaction rates using the four aforementioned cross-section libraries in the pressure vessel capsule, for six dosimetry reaction rates, a maximum relative difference of 8% was observed. As such, it is concluded that the results calculated by RAPTOR-M3G are consistent with the benchmark and further that the different vintage BUGLE cross-section libraries investigated are largely self-consistent.

  20. Comparison of Standard Light Water Reactor Cross-Section Libraries using the United States Nuclear Regulatory Commission Boiling Water Reactor Benchmark Problem

    Science.gov (United States)

    Kulesza, Joel A.; Arzu Alpan, F.

    2016-02-01

    This paper describes a comparison of contemporary and historical light water reactor shielding and pressure vessel dosimetry cross-section libraries for a boiling water reactor calculational benchmark problem. The calculational benchmark problem was developed at Brookhaven National Laboratory by the request of the U. S. Nuclear Regulatory Commission. The benchmark problem was originally evaluated by Brookhaven National Laboratory using the Oak Ridge National Laboratory discrete ordinates code DORT and the BUGLE-93 cross-section library. In this paper, the Westinghouse RAPTOR-M3G three-dimensional discrete ordinates code was used. A variety of cross-section libraries were used with RAPTOR-M3G including the BUGLE93, BUGLE-96, and BUGLE-B7 cross-section libraries developed at Oak Ridge National Laboratory and ALPAN-VII.0 developed at Westinghouse. In comparing the calculated fast reaction rates using the four aforementioned cross-section libraries in the pressure vessel capsule, for six dosimetry reaction rates, a maximum relative difference of 8% was observed. As such, it is concluded that the results calculated by RAPTOR-M3G are consistent with the benchmark and further that the different vintage BUGLE cross-section libraries investigated are largely self-consistent.

  1. Validation of standardized computer analyses for licensing evaluation/TRITON two-dimensional and three-dimensional models for light water reactor fuel

    International Nuclear Information System (INIS)

    The isotopic depletion capabilities of the new Standardized Computer Analyses for Licensing Evaluation control module TRITON, coupled with ORIGEN-S, were evaluated using spent fuel assays from several commercial light water reactors with both standard and mixed-oxide fuel assemblies. Calculations were performed using the functional modules NEWT and KENO-VI. NEWT is a two-dimensional, arbitrary-geometry, discrete-ordinates transport code, and KENO-VI is a three-dimensional Monte Carlo transport code capable of handling complex three-dimensional geometries. To validate the codes and data used in depletion calculations, numerical predictions were compared with experimental measurements for a total of 29 samples taken from the Calvert Cliffs, Obrigheim, and San Onofre pressurized water reactors and the Gundremmingen boiling water reactor. Similar comparisons have previously been performed at the Oak Ridge National Laboratory for the one-dimensional SAS2H control module. The SAS2H, TRITON/KENO-VI, and TRITON/NEWT results were compared for corresponding samples. All analyses showed that TRITON/KENO-VI and TRITON/NEWT produced typically similar or better results than SAS2H. The calculations performed in this validation study demonstrate that the depletion capabilities of TRITON accurately model spent fuel depletion and decay. (authors)

  2. A study of the Ce3+/Ce4+ redox couple in sulfamic acid for redox battery application

    International Nuclear Information System (INIS)

    Highlights: ► SA served as media electrolyte for Ce3+/Ce4+ was reported. ► A Zn–Ce redox battery was assembled and it showed impressive charge–discharge performance. ► The performance of Zn–Ce battery was improved by adding carbonate such as NH4HCO3. Its energy efficiency reached up to 53%. -- Abstract: The present paper reports a cerium sulfamate electrolyte for use in redox battery. The electrochemical behavior of Ce3+/Ce4+ in sulfamic acid (SA) media has been investigated using linear-sweep voltammetry and cyclic voltammetry. The formal potential of the Ce3+/Ce4+ redox couple in SA is approximately 1.52 V vs. NHE. The exchange current density and standard rate constant of the Ce3+/Ce4+ redox reaction on platinum electrode in SA are determined as 5.95 × 10−4 A cm−2 and 4.95 × 10−5 cm s−1 respectively. The diffusion coefficient of Ce3+ in SA is 5.93 × 10−6 cm2 s−1. The conductivity of cerium(III) sulfamate solution is improved significantly by adding NH4+. A zinc–cerium test cell with Ce3+/Ce4+ sulfamate solution as the positive electrolyte is constructed and the charge-discharge performance is evaluated. The coulombic efficiency of the Zn–Ce cell is calculated to be 90%. The preliminary exploration shows that the cerium sulfamate electrolyte is promising for redox battery application and is worthy of further study.

  3. Determination of silicon in Japanese iron reference standard materials by reactor fast neutron activation analysis combined with a simple pre-concentration

    International Nuclear Information System (INIS)

    A reactor fast neutron activation analysis was used in combination with a simple pre-concentration procedure for determining silicon in some iron reference standard materials of Japan Iron and Steel Federation. The samples were dissolved with aqua regia and digested with perchloric or sulfuric acid. The precipitated silica was collected on a filter paper and irradiated in a cadmium case with reactor fast neutrons. Silicon can be determined in tool steel SKD6, low-alloy steel Nos 2 and 4 and silico-manganese samples by a present method measuring 1,273.4 keV γ-rays from 6.63-minute 29Al produced by 29Si(n,p)29Al reaction. (author)

  4. A simple modeling study of the Ce(IV) regeneration in sulfuric acid solutions

    International Nuclear Information System (INIS)

    Highlights: → The simple model of electrochemical regeneration of Ce(IV) in sulfuric acid solutions at PbO2 anode has been developed. → The study showed that Ce(SO4)2- is the kinetically active species and the decomposition of surface complex of Ce(IV) at the anode surface is the rate determining step. → There is no relation between current density and concentrations of ions participating in the anodic reaction. - Abstract: The electrochemical regeneration of Ce(IV) for mediated electrochemical oxidation in sulfuric acid media was investigated in an electrolytic membrane reactor. A simple kinetic model was developed to analyze and simulate the regeneration of Ce(IV) in the electrolysis process. The model was based on the Faraday's law and the mass balance of components in the reactor. The key operating conditions of the initial electrolyte concentration and the regeneration time were analyzed. It was found that the simulating model agreed well with the experimental data for regeneration of Ce(IV). Experimental results showed that Ce(SO4)2- is the active species. The decomposition of surface complex of Ce(IV) at the anode surface is the rate determining step. Constant-current electrolysis shows that the high proton and Ce(III) concentrations are electrochemically favorable for the regeneration of Ce(IV). The current efficiency for regeneration of Ce(IV) decrease obviously with the increase of SO42- concentration from 0.8 to 2.4 mol/L.

  5. Thermodynamic stabilities of SrCeO3 and Sr2CeO4 using the fluoride EMF technique

    International Nuclear Information System (INIS)

    The standard Gibbs energies of formation of SrCeO3 and Sr2CeO4 were measured by the EMF method using CaF2 as a solid electrolyte. Three fluoride galvanic cells (I-III) were constructed in order to determine ΔfG deg. of SrCeO3. The ΔfG deg. of Sr2CeO4 was determined using galvanic cell (IV). The cells used were Pt,O2(g)(1bar),SrO(s),SrF2(s) vertical bar CaF2 vertical bar SrF2(s),CeO2(s),SrCeO3(s),O2(g) (1bar) (I); Pt,O2(g)(1bar),SrO(s),SrF2(s) vertical bar SrF2 vertical bar SrF2(s),CeO2(s),SrCeO3(s), O2(g)(1bar) (II); Pt,O2(g)(1bar),SrF2(s),CeO2(s),SrCeO3(s) vertical bar CaF2 vertical bar CaF2(s), CaO(s),O2(1bar) (III); Pt,O2(g)(1bar),SrO(s),SrF2(s) vertical bar CaF2 vertical bar SrF2(s),SrCeO3(s),Sr2CeO4(s),O2(1bar),Pt (IV). The standard Gibbs energy of formation of SrCeO3, derived from the mean of the EMFs of the above galvanic cells (I to III), is given by the following expression:ΔfG deg. (SrCeO3)+/-17(kJmol-1)=-1703+0.327T(K)(788-1142K) By combining this expression with the EMF measured using Cell IV, the following expression was obtained for the temperature dependence of the standard Gibbs energy of formation of Sr2CeO4ΔfG deg. (Sr2CeO4)+/-21(kJmol-1)=-2307+0.4400T(K)(805-1066K)

  6. Method of realization and exploitation of monitoring system for accuracy and reliability characteristics of standard temperature measurements in WWER-440 reactors at NPP Bohunice V1

    International Nuclear Information System (INIS)

    The sequences in development of computer equipment s and the sequences in development of measurement tools and procedures are listed in submitted presentation - from start-up the power plant in operation until present days. Present status of integration of a monitoring system for accuracy and reliability characteristics of standard temperature measurements in WWER-440 reactors in NPP V1 is presented here. The ways of data acquisition, storing of results and their evaluation are described in this presentation. In conclusion some practical possibilities of using a a monitoring system for accuracy and reliability are listed. (Authors)

  7. Instrumental neutron activation analysis of Malaysian off-shore carbonate samples irradiated in a nuclear reactor

    International Nuclear Information System (INIS)

    The elemental abudances of the USGS standard rock AGV-1 and two Malaysian off-shore drill core carbonate samples (off Sarawak) are studied by the method of Neutron Activation Analysis. One major element (Fe) and 23 trace elements (Sc, Cr, Co, Rb, Sr, Zr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Ho, Yb, Lu, Hf, Ta, Au, Th and U) have been determined using reactor irradiations and high-resolution gamma-ray spectrometry. (author)

  8. Development and implementation of k{sub 0}-INAA standardization at 10 MW Pakistan research reactor-1

    Energy Technology Data Exchange (ETDEWEB)

    Wasim, M.; Arif, M.; Zaidi, J.H.; Anwar, Y. [Chemistry Div., Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan)

    2009-07-01

    The k{sub 0}-method has been developed for 10 MW Pakistan Research Reactor (PARR-1). It involved the full energy peak efficiency calibration of HPGe detector for different counting geometries and characterization of neutron flux at three irradiation channels. Neutron flux was characterized for thermal to epithermal flux ratio, epithermal flux shape factor, modified spectral index. Westcott's g-factor and fast flux. The method was validated by analyzing IAEA-SL1 (lake sediment) and NIST-SRM-1572 (citrus leaves). All calculations were performed in Excel. The results revealed most of the elements with good accuracy. (orig.)

  9. Compact Reactor

    International Nuclear Information System (INIS)

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date

  10. Standard Test Method for Application and Analysis of Solid State Track Recorder (SSTR) Monitors for Reactor Surveillance, E706(IIIB)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This test method describes the use of solid-state track recorders (SSTRs) for neutron dosimetry in light-water reactor (LWR) applications. These applications extend from low neutron fluence to high neutron fluence, including high power pressure vessel surveillance and test reactor irradiations as well as low power benchmark field measurement. (1) This test method replaces Method E 418. This test method is more detailed and special attention is given to the use of state-of-the-art manual and automated track counting methods to attain high absolute accuracies. In-situ dosimetry in actual high fluence-high temperature LWR applications is emphasized. 1.2 This test method includes SSTR analysis by both manual and automated methods. To attain a desired accuracy, the track scanning method selected places limits on the allowable track density. Typically good results are obtained in the range of 5 to 800 000 tracks/cm2 and accurate results at higher track densities have been demonstrated for some cases. (2) Trac...

  11. CE APPROVAL IN ELECTRICAL HOUSEHOLD APPLIANCES AND A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Nazmi EKREN

    2009-01-01

    Full Text Available Due to the reason for rapidly developing technology, increasing competition medium, and awareness of the consumers, nowadays, the exigency of production with good quality has gained more and more significance. Certification of the quality and safety of the products to the consumers is compulsory in terms of producers. There are some documents to certify safety of the products. One of them is CE certificate. In this paper, basic information about CE mark is given and CE standards and tests required for electrical household appliances are mentioned. As an application, one of an electrical household appliance, toaster grill is treated and examined. To obtain CE certificate for toaster grill, required tests are made according to EN60335-2-9 and CE certificate is obtained.

  12. Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials, E706 (IIF)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This guide presents a method for predicting reference transition temperature adjustments for irradiated light-water cooled power reactor pressure vessel materials based on Charpy V-notch 30-ftlbf (41-J) data. Radiation damage calculative procedures have been developed from a statistical analysis of an irradiated material database that was available as of May 2000. The embrittlement correlation used in this guide was developed using the following variables: copper and nickel contents, irradiation temperature, and neutron fluence. The form of the model was based on current understanding for two mechanisms of embrittlement: stable matrix damage (SMD) and copper-rich precipitation (CRP); saturation of copper effects (for different weld materials) was included. This guide is applicable for the following specific materials, copper, nickel, and phosphorus contents, range of irradiation temperature, and neutron fluence based on the overall database: 1.1.1 MaterialsA 533 Type B Class 1 and 2, A302 Grade B, A302 G...

  13. Inconsistencies of neutron flux parameters for k0 standardization in neutron activation analysis determined with the use of Au+Zr and Au+Mo+Cr monitor sets at the LVR-15 reactor in Rez

    International Nuclear Information System (INIS)

    Multipurpose research reactors require monitoring of neutron flux parameters (α, f, Fc or Φth ) during every irradiation of samples when k0 standardization in neutron activation analysis is to be used, because the above parameters may change quite frequently and unpredictably. We tested two monitor sets consisting of Au+Zr and Au+Mo+Cr for determination of the neutron flux parameters in k0-NAA at the LVR-15 reactor in Rez. Based on analysis of several reference materials, we found the use of the Au+Zr monitor set superior over the Au+Mo+Cr monitor set in the specific conditions of the LVR-15 reactor. (author)

  14. CE-BEMS

    DEFF Research Database (Denmark)

    Mohamed, Nader; Lazarova-Molnar, Sanja; Al-Jaroodi, Jameela

    2016-01-01

    costs savings in smart buildings significantly depend on the monitoring and control methods used in the installed BEMS. This paper proposes a Cloud-Enabled BEMS (CE-BEMS) for Smart Buildings. This system can utilize cloud computing to provide enhanced management mechanisms and features for energy...... savings in smart buildings. This system is connected to the cloud to have access to a number of advanced cloud-based services to enhance energy management in smart buildings. In this paper, we discuss the current limitations of BEMS, the conceptual design of the proposed system, and the advantages...

  15. Comparison between MAAP and ECART predictions of radionuclide transport throughout a French standard PWR reactor coolant system

    International Nuclear Information System (INIS)

    In the framework of a collaboration agreement between EDF and ENEL, the MAAP (Modular Accident Analysis Program) and ECART (ENEL Code for Analysis of radionuclide Transport) predictions about the fission product retention inside the reactor cooling system of a French PWR 1300 MW during a small Loss of Coolant Accident were compared. The volatile fission products CsI, CsOH, TeO2 and the structural materials, all of them released early by the core, are more retained in MAAP than in ECART. On the other hand, the non-volatile fission products, released later, are more retained in ECART than in MAAP, because MAAP does not take into account diffusion-phoresis: in fact, this deposition phenomenon is very significant when the molten core vaporizes the water of the vessel lower plenum. Centrifugal deposition in bends, that can be modeled only with ECART, slightly increases the whole retention in the circuit if it is accounted for. (authors). 18 refs., figs., tabs

  16. INCA-CE project: status and results

    Science.gov (United States)

    Strauss, Franziska; Meirold-Mautner, Ingo; Bica, Benedikt; Kann, Alexander; Wang, Yong

    2013-04-01

    Every year, Central Europe (CE) is affected by weather extremes challenging civil protection authorities, hydrologists and road maintenance services to timely warnings. Within the INCA-CE project (Integrated Nowcasting through Comprehensive Analysis in Central Europe; http://www.inca-ce.eu) which is supported by the European Regional Development Fund a deepened transnational cooperation between meteorological/hydrological services and three application areas is established. This guarantees for both enhancements of meteorological products in the sense of end-user friendliness, and standardized information exchange across borders. At present, INCA-CE is the only project throughout the world which connects cooperation to such an extent with respect to its transnational and multidisciplinary framework (in the meanwhile it has been chosen as World Weather Research Programme/Forecast Demonstration Project by the World Meteorological Organization). Key partners from eight countries (from national meteorological/hydrological services and the three different application areas) accept the challenge to work on standardization and harmonization tools. Therefore, the INCA nowcasting system - developed at the Austrian weather service (ZAMG) in the 1990ies - has been implemented at all CE meteorological/hydrological services and is advanced and refined to the specific user needs to (i) provide high quality nowcasting products which are standardized and harmonized across borders, (ii) improve information chains from models to warnings and protection measures in case of disaster, and (iii) make the public and stakeholders more familiar with meteorological products. However, the potential to achieve these listed improvements is only possible through the intense transnational and multidisciplinary cooperation, because for one institution and one country alone it would be impossible to cope with all the necessary tasks. In this presentation the status and results of the INCA-CE

  17. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  18. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Conceptual design studies were made of fusion reactors based on the three current mirror-confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fuel for fission reactors. We have designed a large commercial hybrid and a small pilot-plant hybrid based on standard mirror confinement. Tandem mirror designs include a commercial 1000-MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single-cell pilot plant

  19. Neutron flux characterization of the Moroccan Triga Mark II research reactor and validation of the k0 standardization method of NAA using k0-IAEA program

    International Nuclear Information System (INIS)

    The aim of this work was to implement and to validate the k0 standardization method in neutron activation analysis (k0-NAA) at the Moroccan TRIGA Mark II research reactor. This technique was used in order to determine, the calibration of several HPGe detectors and calibration of neutron flux parameters in the typical irradiation channels [rotary specimen rack (RSR) and the pneumatic tube system (PTS) facilities]. Calibrations and calculations of k0-NAA results were carried out using the k0-IAEA program. The two parameters of neutron flux in the selected irradiation channels used for elemental concentration calculation, f (thermal-to-epithermal ratio) and α (deviation from the 1/E distribution), have been determined as well in the PTS as in the RSR facilities using the zirconium bare triple method. Results obtained for f and α in two irradiation channels show that f parameter determined in this way is different in the RSR and the PTS facilities. This can be explained by the fact that the RSR channel is situated in a graphite reflector and is relatively far from the reactor core, while the PTS is in the core. Five reference materials of different origin obtained from USGS (basalt BE-N, bauxite BX-N, biotite mica-Fe, granite GS-N) and IAEA (Soil-7) were used to evaluate the validity of this method in our laboratory by analyzing the elemental concentrations with respect to the certified values. In general, good agreement was obtained between results of this work and values in certificates of the individual reference materials, thus proving the accuracy of our results and successful implementation of the method for analysis of real samples. (author)

  20. Nioboaeschynite-(Ce, Ce(NbTiO6

    Directory of Open Access Journals (Sweden)

    Shaunna M. Morrison

    2012-08-01

    Full Text Available Nioboaeschynite-(Ce, ideally Ce(NbTiO6 [cerium(III niobium(V titanium(IV hexaoxide; refined formula of the natural sample is Ca0.25Ce0.79(Nb1.14Ti0.86O6], belongs to the aeschynite mineral group which is characterized by the general formula AB2(O,OH6, where eight-coordinated A is a rare earth element, Ca, Th or Fe, and six-coordinated B is Ti, Nb, Ta or W. The general structural feature of nioboaeschynite-(Ce resembles that of the other members of the aeschynite group. It is characterized by edge-sharing dimers of [(Nb,TiO6] octahedra which share corners to form a three-dimensional framework, with the A sites located in channels parallel to the b axis. The average A—O and B—O bond lengths in nioboaeschynite-(Ce are 2.471 and 1.993 Å, respectively. Moreover, another eight-coordinated site, designated as the C site, is also located in the channels and is partially occupied by A-type cations. Additionally, the refinement revealed a splitting of the A site, with Ca displaced slightly from Ce (0.266 Å apart, presumably resulting from the crystal-chemical differences between the Ce3+ and Ca2+ cations.

  1. TRX and UO2 criticality benchmarks with SAM-CE

    International Nuclear Information System (INIS)

    A set of thermal reactor benchmark calculations with SAM-CE which have been conducted at both MAGI and at BNL are described. Their purpose was both validation of the SAM-CE reactor eigenvalue capability developed by MAGI and a substantial contribution to the data testing of both ENDF/B-IV and ENDF/B-V libraries. This experience also resulted in increased calculational efficiency of the code and an example is given. The benchmark analysis included the TRX-1 infinite cell using both ENDF/B-IV and ENDF/B-V cross section sets and calculations using ENDF/B-IV of the TRX-1 full core and TRX-2 cell. BAPL-UO2-1 calculations were conducted for the cell using both ENDF/B-IV and ENDF/B-V and for the full core with ENDF/B-V

  2. Ce que soigner veut dire

    OpenAIRE

    Mol, Annemarie

    2013-01-01

    Qu'est-ce que bien soigner? Dans ce livre provoquant et original, Annemarie Mol montre que ce n'est pas, comme on l'a beaucoup dit, laisser les patients choisir. À partir de l'exemple des personnes atteintes de diabète, l'auteur propose une nouvelle manière de prendre soin des personnes, qui ne les transforme pas en citoyens ou en consommateurs, mais qui les reconnaît comme corps et âmes souffrants, comme individus investis dans leur propre prise en charge, comme membres de collectifs multipl...

  3. The CeDRES data portal

    Science.gov (United States)

    Albert-Aguilar, Alexandre; Delmotte, Pauline; André, François; Brissebrat, Guillaume; Canonici, Jean-Christophe; Piguet, Bruno

    2016-04-01

    SAFIRE is the French facility dedicated to airborne measurement for environmental research. The SAFIRE steering committee decided that access to its archives should be improved. If certain data, including recent campaigns, are available online, access to them is difficult for users because these data are dispersed in as many data portals as campaigns. Most of projects are not able to keep medium to long term online access to their database. Therefore, many airborne data, particularly the oldest, are not available online, stored on media whose sustainability is not guaranteed. SAFIRE also decided to identify old data stored in Meudon (France) on paper and hard media and to rescue with the help of an archivist. At the same time, the development of a centralized digital archive - containing data collected with the Fokker - 27 " ARAT " and Merlin IV aircraft - associated to a web portal was given to SEDOO. The first part of the project consisted in modelling the database. The second part, still in progess, was the development of the CeDRES (Centre de Données aéRoportées & SAFIRE) portal (http://cedres.sedoo.fr) which is responsive and bilingual (French and English) ; and metadata standardization (iso 19115). The main objectives of this project are data preservation and open data access. A first test version of CeDRES portal will be release in mid-February 2016. And operational version is planned for summer 2016. In the future, CeDRES portal will be able to receive and to distribute metadata and data of aircraft currently in service (FALCON-20, ATR-42 and PiperAztec-23). The interoperability implementation and data homogenization are planned in the medium term. The CeDRES portal is part of the French atmospheric chemistry data center AERIS (http://www.aeris-data.fr). Every scientist is invited to browse the catalog and use CEDRES data. Feel free to contact cedres-contact@sedoo.fr for any question.

  4. Regulations for RA reactor operation

    International Nuclear Information System (INIS)

    Regulations for RA reactor operation are written in accordance with the legal regulations defined by the Law about radiation protection and related legal acts, as well as technical standards according to the IAEA recommendations. The contents of this book include: fundamental data about the reactor; legal regulations for reactor operation; organizational scheme for reactor operation; general and detailed instructions for operation, behaviour in the reactor building, performing experiments; operating rules for operation under steady state and accidental conditions

  5. Signature splitting in 129Ce

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; WU Xiao-Guang; ZHU Li-Hua; LI Guang-Sheng; HE Chuang-Ye; LI Xue-Qin; PAN Bo; HAO Xin; LI Li-Hua; WANG Zhi-Min; LI Zhong-Yu; XU Qiang

    2009-01-01

    The high spin states of 129Ce have been populated via heavy-ion fusion evaporation reaction 96Mo (37C1, 1p3n) 129Ce. The γ-γ coincidence and intensity balance used to measure the B(M1; I→I-1)/B(E2; I→I-2) (the probability ratio of the dipole and quadrupole transition) in v7/2[523] rotational band of 129Ce. And the energy splitting (Δe') has been got through the experimental Routhians. The lifetimes and quadrupole moments Qt have been extracted from the lineshape analyses using DSAM. The deformation of the v7/2[523] rotational band of 129Ce was extracted from the Qt and moment of inertia JRR.

  6. Thermal Dihydrogen Activation by a Closed-Shell AuCeO2(+) Cluster.

    Science.gov (United States)

    Meng, Jing-Heng; He, Sheng-Gui

    2014-11-01

    Laser-ablation-generated AuCeO2(+) and CeO2(+) oxide clusters were mass-selected using a quadrupole mass filter and reacted with H2 in an ion trap reactor at ambient conditions. The reactions were characterized by mass spectrometry and density functional theory calculations. The gold-cerium bimetallic oxide cluster AuCeO2(+) is more reactive in H2 activation than the pure cerium oxide cluster CeO2(+). The gold atom is the active adsorption site and facilitates the heterolytic cleavage of H2 in collaboration with the separated O(2-) ion of the CeO2 support. To the best of our knowledge, this is the first example of thermal H2 activation by a closed-shell atomic cluster, which provides molecular-level insights into the single gold atom catalysis over metal oxide supports. PMID:26278765

  7. CeO2 nanoparticles for high performance supercapacitor electrode

    International Nuclear Information System (INIS)

    Cerium Oxide plays a vital role in rising technologies for energy-related applications. In this study, CeO2 nanoparticles have been successfully synthesized by microwave irradiation method and its capacitance performance is further investigated. Prepared nanoparticles were analysed by X-Ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). X-ray diffraction analysis confirms that CeO2 Nanoparticles in cubic phase and the grain size was calculated to be 15 nm using Debye-Scherrer formula. The FTIR spectrum of the CeO2 exhibits the stretching vibration of Ce-O at about 601 cm-1. The SEM analysis shows the irregular spherical morphology with some of the particles agglomerated. Electrochemical characterization of the sample was performed using a standard three electrode cell configuration. Cyclic Voltammogram (CV) and galvanostatic (GV) charge-discharge measurements demonstrated that the CeO2 electrode exhibited superior capacitive properties in 1 M Na2SO4 aqueous solution within the potential range -0.2V to 1.5V The discharge curves are linear in the total range of potential with constant slopes at a constant current of 0.9 A/g showing perfect capacitive behavior. These findings can open up new opportunities for CeO2 nanoparticles in constructing the high-performance electrochemical supercapacitors as well as other energy storage devices. (author)

  8. Influence of the Zr and Ce on the structure of experimental hot-work tool steel

    OpenAIRE

    L.A. Dobrzański; J. Mazurkiewicz; E. Hajduczek

    2006-01-01

    Purpose: of this paper was to examine of the influence of the Zr i Ce on the structure of the newly developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1.Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoWVTiCeZr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X...

  9. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  10. Lattice dynamics of γ--Ce

    International Nuclear Information System (INIS)

    The phonon and magnetic measurements described in the thesis produced the following significant results concerning the lattice dynamical and magnetic properties of γ-Ce. The phonon spectrum is relatively soft, which is consistent with results obtained for CeSn3. The L [110] and T [111] branches of the dispersion curve are anomalous. The C11 and C44 elastic constants are quite close in value. No discrete magnetic excitations were observed. The magnetic scattering is qualitatively similar to the results from Ce0.74Th0.26, however, GAMMA/sub Ce/ less than GAMMA/sub Ce-Th/. The various lattice dynamical and magnetic similarities among γ-Ce, CeSn3, and Ce0.74Th0.26 are mixed valence compounds. Therefore, a complete theoretical description of the observed properties of Ce and its compounds may provide a basis for understanding a whole class of mixed valence materials

  11. Measure of the efficiency of a long counter of Hanson's type and use of this counter for the survey of the slow neutrons coming from the reactor of Chatillon; Mesure de l'efficacite d'un long compteur du type Hanson et utilisation de ce compteur a l'etude des neutrons lents sortant de la pile de Chatillon

    Energy Technology Data Exchange (ETDEWEB)

    Barloutaud, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-07-01

    A detection device of fast neutrons of efficiency almost independent of the energy of the neutrons has been achieved. It efficiency has been measured in absolute value for groups of neutrons of different energies. This device allowed to get some indications on the energy composition of the neutrons leaving from the reactor of Chatillon. (author) [French] Un dispositif de detection de neutrons rapides d'efficacite pratiquement independante de l'energie des neutrons a ete realise. Son efficacite a ete mesuree en valeur absolue pour des groupes de neutrons de diverses energies. Ce dispositif a permis obtenir quelques indications sur la composition energetique des neutrons sortant de la pile de Chatillon. (auteur)

  12. Electrochemical aspects of Ce+3 / Ce system in Flinak

    International Nuclear Information System (INIS)

    The voltammetric electrodeposition of cerium has been studied on three types of substrates - Ag, W and vitreous Carbon with the aim of know the mechanisms of the process. The Flinak - Ce F3 melt was used, with temperature range of 500-850O C. No alkaline metals co deposition was observed. (author)

  13. Space-time reactor kinetics for heterogeneous reactor structure

    International Nuclear Information System (INIS)

    An attempt is made to formulate time dependent diffusion equation based on Feinberg-Galanin theory in the from analogue to the classical reactor kinetic equation. Parameters of these equations could be calculated using the existing codes for static reactor calculation based on the heterogeneous reactor theory. The obtained kinetic equation could be analogues in form to the nodal kinetic equation. Space-time distribution of neutron flux in the reactor can be obtained by solving these equations using standard methods

  14. TRIGA reactor main systems

    International Nuclear Information System (INIS)

    This module describes the main systems of low power (<2 MW) and higher power (≥2 MW) TRIGA reactors. The most significant difference between the two is that forced reactor cooling and an emergency core cooling system are generally required for the higher power TRIGA reactors. However, those TRIGA reactors that are designed to be operated above 3 MW also use a TRIGA fuel that is specifically designed for those higher power outputs (3 to 14 MW). Typical values are given for the respective systems although each TRIGA facility will have unique characteristics that may only be determined by the experienced facility operators. Due to the inherent wide scope of these research reactor facilities construction and missions, this training module covers those systems found at most operating TRIGA reactor facilities but may also discuss non-standard equipment that was found to be operationally useful although not necessarily required. (author)

  15. Design and fabrication of an automated temperature programmed reaction system to evaluate 3-way catalysts Ce1--(La/Y)PtO2-

    Indian Academy of Sciences (India)

    Arup Gayen; Tinku Baidya; G S Ramesh; R Sriharia; M S Hegde

    2006-01-01

    A completely automated temperature-programmed reaction (TPR) system for carrying out gas-solid catalytic reactions under atmospheric flow conditions is fabricated to study CO and hydrocarbon oxidation, and NO reduction. The system consists of an all-stainless steel UHV system, quadrupole mass spectrometer SX200 (VG Scientific), a tubular furnace and micro-reactor, a temperature controller, a versatile gas handling system, and a data acquisition and analysis system. The performance of the system has been tested under standard experimental conditions for CO oxidation over well-characterized Ce1--Pt(La/Y)O2- catalysts. Testing of 3-way catalysis with CO, NO and C2H2 to convert to CO2, N2 and H2O is done with this catalyst which shows complete removal of pollutants below 325°C. Fixed oxide-ion defects in Pt substituted Ce1-(La/Y)O2-/2 show higher catalytic activity than Pt ion-substituted CeO2.

  16. Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

    Energy Technology Data Exchange (ETDEWEB)

    Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.; Piro, Nicholas A.; Carroll, Patrick J.; Booth, Corwin H.; Schelter, Eric J.

    2014-06-25

    Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.

  17. Examination of fast-reactor fuels and FBR analytical quality-assurance standards and methods. Progress report, October 1-December 31, 1980

    International Nuclear Information System (INIS)

    This project is directed toward the examination and comparison of the effects of neutron irradiation on Liquid Metal Fast Breeder Reactor (LMFBR) Program fuel materials. Unirradiated and irradiated materials will be examined as requested by the Reference Fuels System Branch of the Division of Reactor Research and Technology (DRRT). Capabilities have been established and are being expanded for providing conventional preirradiation and postirradiation examinations. Nondestructive tests will be conducted in a hot-cell facility specifically modified for examining irradiated prototype fuel pins at a rate commensurate with schedules established by DRRT

  18. Effect of Ce(3+) on soluble microbial products production in anaerobic granular sludge digestion.

    Science.gov (United States)

    Fu, Bo; Liang, Rui; Xia, Qing; Ding, Lili; Xu, Ke; Ren, Hongqiang

    2011-01-01

    Upflow anaerobic sludge bed reactors fed on glucose were used to investigate the effects of Ce(3+) on soluble microbial products (SMP) production, which is the majority of the residual chemical oxygen demand present in the effluent. It was found that Ce(3+) concentration of 0.05 mg/L had no significant effect on the amount of SMP production, whereas that of 1 mg/L led to the increase in SMP production. The molecular-weight distribution and carbohydrate analysis indicated that an increase in SMP production may be partly attributed to the release of extracellular polymeric substances (EPS) into the bulk solution resulted from cerium toxicity, and the nucleic acids analysis suggested that increased cell lysis also contributed to SMP accumulation in the presence of Ce(3+). The increase in SMP production in the presence of Ce(3+) is possibly a consequence of the release of EPS and increased cell lysis due to cerium toxicity. PMID:22179643

  19. Standard Technical Specifications, Combustion Engineering plants

    International Nuclear Information System (INIS)

    This NUREG contains improved Standard Technical Specifications (STS) for Combustion Engineering (CE) Plants and documents the positions of the Nuclear Regulatory Commission based on the CE Owners Group's proposed STS. This document is the result of extensive technical meetings and discussions among the NRC staff, the Nuclear Steam Supply System (NSSS) Owners Groups, the NSSS vendors, and the Nuclear Management and Resources Council (NUMARC). The improved STS were developed based on the criteria in the interim Commission Policy Statement on Technical Specification Improvements for Nuclear Power Reactors, dated February 6, 1987. The improved STS will be used as the basis for individual nuclear power plant licensees to develop improved plant-specific technical specifications. This report contains three volumes. Volume 1 contains the Specifications for all chapters and sections of the improved SM. Volume 2 contains the Bases for Chapters 2.0 and 3.0, and Sections 3.1--3.3 of the improved STS. This document Volume 3 contains the Bases for Sections 3.4--3.9 of the improved M

  20. Guidelines for preparing and reviewing applications for the licensing of non-power reactors: Standard review plan and acceptance criteria. NUREG - 1537, Part 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    NUREG - 1537, Part 2 gives guidance on the conduct of licensing action reviews to NRC staff who review non-power reactor licensing applications. These licensing actions include construction permits and initial operating licenses, license renewals, amendments, conversions from highly enriched uranium to low-enriched uranium, decommissioning, and license termination.

  1. Guidelines for preparing and reviewing applications for the licensing of non-power reactors: Standard review plan and acceptance criteria. NUREG - 1537, Part 2

    International Nuclear Information System (INIS)

    NUREG - 1537, Part 2 gives guidance on the conduct of licensing action reviews to NRC staff who review non-power reactor licensing applications. These licensing actions include construction permits and initial operating licenses, license renewals, amendments, conversions from highly enriched uranium to low-enriched uranium, decommissioning, and license termination

  2. N Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The last of Hanfordqaodmasdkwaspemas7ajkqlsmdqpakldnzsdflss nine plutonium production reactors to be built was the N Reactor.This reactor was called a dual purpose...

  3. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining licensees and applicants for reactor operator and senior reactor operator licenses at power reactor facilities pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). The Examiner Standards are intended to assist NRC examiners and facility licensees to better understand the initial and requalification examination processes and to ensure the equitable and consistent administration of examinations to all applicants. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator licensing policy changes

  4. Standard integrated head package

    International Nuclear Information System (INIS)

    An integrated head package for a standard-type nuclear reactor is described which consolidates many components and subassemblies of the upper reactor structure into a single unit which may be removed from the reactor vessel in a single lift. Included among the consolidated elements are a pressure vessel head, a cooling shroud, control rod drive mechanisms, a missile shield, a lifting rig, a hoist assembly, and a cable tray assembly. (author)

  5. Collective excitations in 132Ce

    International Nuclear Information System (INIS)

    The structure of normally deformed states (β2∼0.2) in 132Ce has been investigated using EUROGAM2. Eight ΔI=2 bands and three ΔI=1 bands have been identified up to spin 40. The results are interpreted with the aid of Woods-Saxon cranking calculations which suggest a variety of triaxial shapes stabilized by specific active quasiparticle orbitals. (authors)

  6. Identification of levels in neutron-rich 145Ce and 147Ce nuclei

    International Nuclear Information System (INIS)

    High-spin structures in the neutron-rich nuclei 145Ce and 147Ce produced in the spontaneous fission of 252Cf have been investigated by prompt γ-ray spectroscopy. A collective band structure in 145Ce is identified. Several sidebands along with the new high-spin states in 147Ce are also identified. Particle-plus-rotor model calculations indicate that the yrast bands in 145Ce and 147Ce most probably originate from coupling of the νi13/2 orbital to the ground states of 144Ce and 146Ce. The ground state configurations of 145,147Ce are (νh9/2+νf7/2) and νh9/2, respectively. (c) 1999 The American Physical Society

  7. Energy levels of the Ce activator relative to the YAP(Ce) scintillator host

    International Nuclear Information System (INIS)

    The electronic structure of the cerium-activated yttrium aluminum perovskite [YAP(Ce)] scintillator has been studied by core level x-ray spectroscopy and first-principles calculations. X-ray absorption and emission spectra at the oxygen K-edge of YAP(Ce) and CeO2 have been measured and compared with the calculated partial density of states. With the known band gap of CeO2, the measured oxygen K-edge absorption and emission spectra are used to construct a fixed relation between the valence and conduction bands of YAP and CeO2. This allows us to determine the fundamental band gap of YAP to be 8.1 ± 0.3 eV. A comparison between the cerium M4,5-edges x-ray absorption spectra of the YAP(Ce) and Ce model compounds (CeO2, CeF3, and Ce foils) then shows that the Ce activator is in the desired Ce3+, with a small fraction of Ce4+ due to oxidization at the surface. Finally, we determine that the ground state 4f1 energy level of the Ce3+ activator lies 1.8 ± 0.5 eV above the top of the valence band of the host YAP. (paper)

  8. Information System through ANIS at CeSAM

    Science.gov (United States)

    Moreau, C.; Agneray, F.; Gimenez, S.

    2015-09-01

    ANIS (AstroNomical Information System) is a web generic tool developed at CeSAM to facilitate and standardize the implementation of astronomical data of various kinds through private and/or public dedicated Information Systems. The architecture of ANIS is composed of a database server which contains the project data, a web user interface template which provides high level services (search, extract and display imaging and spectroscopic data using a combination of criteria, an object list, a sql query module or a cone search interfaces), a framework composed of several packages, and a metadata database managed by a web administration entity. The process to implement a new ANIS instance at CeSAM is easy and fast : the scientific project has to submit data or a data secure access, the CeSAM team installs the new instance (web interface template and the metadata database), and the project administrator can configure the instance with the web ANIS-administration entity. Currently, the CeSAM offers through ANIS a web access to VO compliant Information Systems for different projects (HeDaM, HST-COSMOS, CFHTLS-ZPhots, ExoDAT,...).

  9. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  10. Evaluation of production samples of the scintillators LaBr3:Ce and LaCl3:Ce

    International Nuclear Information System (INIS)

    We report on the evaluation of the performance of two recently developed scintillator materials, LaCl3:Ce and LaBr3:Ce, at the task of gamma ray spectroscopy. Their performance is compared to a standard scintillator used for gamma ray spectroscopy--a 25 mm diameter 25 mm tall cylinder of NaI:Tl. We measure the pulse height, energy resolution, and full-energy efficiency of production LaBr3:Ce and LaCl3:Ce scintillation crystals of different sizes and geometries for a variety of gamma-ray energies. Using production rather than specially selected crystals will establish whether immediate large-scale use is feasible. The crystal is excited by gamma rays from one of six isotopic sources (125I, 241Am, 57Co, 22Na, 137Cs, and 60Co) placed 15 cm away from the scintillator. Our measurements show that both LaCl3 and LaBr3 outperform NaI:Tl in almost all cases. They outperform NaI:Tl at all energies for the photopeak fraction and counting rate measurements, and for energy resolution at higher energies (above 200 keV for LaCl3 and 75 keV for LaBr3). The performance of production crystals is excellent and these scintillators should be considered for immediate use in systems where stopping power and energy resolution are crucial

  11. A photoemission study of the interaction of Ga with CeO2(1 1 1) thin films

    International Nuclear Information System (INIS)

    The interaction of gallium with CeO2(1 1 1) layers was studied using standard and resonant photoelectron spectroscopy, by means of both a laboratory X-ray source and tunable synchrotron light. Firstly a 1.5-nm thick CeO2 film was grown on a Cu(1 1 1) substrate. Secondly Ga was deposited in six steps up to a thickness of 0.35 nm, at room temperature. The interaction of gallium with the oxide layer induced partial CeO2 reduction, and gallium oxidation. The photoemission data suggest that a mixed Ga-Ce-O oxide was established similarly to the Sn-Ce-O case for Sn deposited on cerium oxide layers. As a consequence, gallium-induced weakening of Ce-O bonds provides a higher number of active sites on the surface that play a major role in its catalytic behaviour

  12. Synthesis and characterization of CNT/Ce-TiO2 nanocomposite for phenol degradation

    Institute of Scientific and Technical Information of China (English)

    Shaari N; Tan S H; Mohamed A R

    2012-01-01

    An innovative photocatalyst,Carbon nanotube (CNT) supported Ce-TiO2 nanocomposite was successfully synthesized via modified sol gel method and investigated in a batch reactor for abolition of phenol under UV light spectrum.Characterization of catalyst microstructure and internal properties were done by means of X-ray diffraction (XRD),Brunauer-Emmett-Teller (BET),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectra (DRS).Ce doping can inhibit phase transformation from anatase to rutile and eliminate the recombination of electron-hole pairs in the catalyst.The presence of CNT in TiO2 composite can both increase the photoactivity under UV and change surface properties to achieve sensitivity to visible light.The optimum mass ratio of CNT support and cerium (Ce) dopant in TiO2 was the prominent factor to harvest CNT/Ce-TiO2 photocatalyst nanocomposite.The results demonstrated that optimum mass ratio of CNT:TiO2:Ce was 0.02:1.0:0.06,which resulted in the great performance of the photocatalyst to degrade about 94% of phenol in a 50 mg/L solution in only 3 h.In this paper,dissimilar role of CNT support and Ce dopant in the TiO2 photocatalysis of phenol was also discussed.

  13. Reactor Physics

    International Nuclear Information System (INIS)

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised

  14. Reactor Physics

    International Nuclear Information System (INIS)

    SCK-CEN's Reactor Physics and MYRRHA Department offers expertise in various areas of reactor physics, in particular in neutron and gamma calculations, reactor dosimetry, reactor operation and control, reactor code benchmarking and reactor safety calculations. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 materials testing reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2001 are summarised

  15. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  16. Design guide for category V reactors transient reactors

    International Nuclear Information System (INIS)

    The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirements of Category V reactor structures, components, and systems

  17. Training and Certification of Research Reactor Personnel

    International Nuclear Information System (INIS)

    The safe operation of a research reactor requires that reactor personnel be fully trained and certified by the relevant authorities. Reactor operators at PUSPATI TRIGA Reactor underwent extensive training and are certified, ever since the reactor first started its operation in 1982. With the emphasis on enhancing reactor safety in recent years, reactor operator training and certification have also evolved. This paper discusses the changes that have to be implemented and the challenges encountered in developing a new training programme to be in line with the national standards. (author)

  18. CuO/CeO2 catalysts prepared with different cerium supports for CO oxidation at low temperature

    International Nuclear Information System (INIS)

    The activity of a catalyst depends on the nature of its support, its active site, and its preparation method. This study aimed to employ various types of CeO2 supports such as commercial CeO2 and self-prepared CeO2 for the preparation of copper catalysts. The CuO/CeO2 catalysts were prepared using the polyol process and impregnation method. The catalysts were characterized using Brunauer–Emmett–Teller analysis, scanning electron microscopy, and X-ray analysis, and their catalytic activity for CO removal was evaluated in a microcatalytic reactor. The experimental results showed that the catalytic activity of the CuO/CeO2 catalysts with different calcination temperatures decreased in the following order: 500 °C > 300 °C > 700 °C. Compared to the impregnation method, the polyol process generated well-dispersed metal particles over the support and showed higher CO removal efficiency with low activation energy. Compared to CuO/CeO2 catalysts with commercial CeO2, those with CeO2 that was self-prepared by pyrolysis had a large pore volume and good crystal structure of CeO2 and showed good performance. The catalytic activity for CO removal was in the following order: CuO/CeO2-P (pyrolysis) > CuO/CeO2-C (commercial) > CuO/CeO2-D (deposition precipitation). CuO/CeO2-P catalysts showed good activity even at low temperature. The CuO/CeO2-P(300)-P-120 min catalyst was found to possess the good CO removal rate when the oxygen content was 6%, CO concentration was 500 ppm, catalyst weighed 1.0 g, pollutant gas velocity was 500 mL min−1, SV was 3.7 × 104 h−1, and reaction temperature was 150 °C. - Highlights: • CuO/CeO2 catalysts were prepared using polyol and impregnation methods. • The supports of catalyst were self-prepared cerium oxide and commercial cerium oxide. • Pyrolysis and deposition precipitation methods were used for cerium preparation. • Catalytic activity of CuO/CeO2 catalysts were evaluated by the removal of CO

  19. CuO/CeO{sub 2} catalysts prepared with different cerium supports for CO oxidation at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chi-Yuan [School of Public Health, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Chang, Wen-Chi [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Wey, Ming-Yen, E-mail: mywey@dragon.nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China)

    2013-08-15

    The activity of a catalyst depends on the nature of its support, its active site, and its preparation method. This study aimed to employ various types of CeO{sub 2} supports such as commercial CeO{sub 2} and self-prepared CeO{sub 2} for the preparation of copper catalysts. The CuO/CeO{sub 2} catalysts were prepared using the polyol process and impregnation method. The catalysts were characterized using Brunauer–Emmett–Teller analysis, scanning electron microscopy, and X-ray analysis, and their catalytic activity for CO removal was evaluated in a microcatalytic reactor. The experimental results showed that the catalytic activity of the CuO/CeO{sub 2} catalysts with different calcination temperatures decreased in the following order: 500 °C > 300 °C > 700 °C. Compared to the impregnation method, the polyol process generated well-dispersed metal particles over the support and showed higher CO removal efficiency with low activation energy. Compared to CuO/CeO{sub 2} catalysts with commercial CeO{sub 2}, those with CeO{sub 2} that was self-prepared by pyrolysis had a large pore volume and good crystal structure of CeO{sub 2} and showed good performance. The catalytic activity for CO removal was in the following order: CuO/CeO{sub 2}-P (pyrolysis) > CuO/CeO{sub 2}-C (commercial) > CuO/CeO{sub 2}-D (deposition precipitation). CuO/CeO{sub 2}-P catalysts showed good activity even at low temperature. The CuO/CeO{sub 2}-P(300)-P-120 min catalyst was found to possess the good CO removal rate when the oxygen content was 6%, CO concentration was 500 ppm, catalyst weighed 1.0 g, pollutant gas velocity was 500 mL min{sup −1}, SV was 3.7 × 10{sup 4} h{sup −1}, and reaction temperature was 150 °C. - Highlights: • CuO/CeO{sub 2} catalysts were prepared using polyol and impregnation methods. • The supports of catalyst were self-prepared cerium oxide and commercial cerium oxide. • Pyrolysis and deposition precipitation methods were used for cerium preparation.

  20. Towards standardization of the dissemination measures and tritium solubility in materials of fusion reactors; Hacia la estandarizacion de las medidas de difusion y solubilidad de tritio en materiales de reactores de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Alberto, G.; Penalva, I.; Aranburu, I.; Sarrionandia-Ibarra, A.; Legarda, F.; Martinez, P. M.; Sedano, L.; Moral, N.

    2011-07-01

    The standardization of the measurements of hydrogen isotope interaction with different materials is a challenge and goal of fusion technology programs worldwide. For decades the programs have promoted the need for a reference laboratory for measurements of hydrogen transport to the evolution of fusion technology, but that goal is still pending, in contrast to the situation in other goals I+D.

  1. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  2. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  3. Radon gamma-ray spectrometry with YAP:Ce scintillator

    CERN Document Server

    Plastino, W; De Notaristefani, F

    2002-01-01

    The detection properties of a YAP:Ce scintillator (YAlO sub 3 :Ce crystal) optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocathode have been analyzed. In particular, the application to radon and radon-daughters gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg.C and in acids solutions such as HCl (37%), H sub 2 SO sub 4 (48%) and HNO sub 3 (65%) have been performed. The measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA) have emphasized the non-hygroscopic properties of the scintillator and a small dependence of the light yield on temperature and HNO sub 3. The data collected in this first step of our research have pointed out that the YAP:Ce scintillator can allow high response stability for rad...

  4. Photoelectron spectra of CeO{sup −} and Ce(OH){sub 2}{sup −}

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Manisha; Felton, Jeremy A.; Kafader, Jared O.; Topolski, Josey E.; Jarrold, Caroline Chick, E-mail: cjarrold@indiana.edu [Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405 (United States)

    2015-02-14

    The photoelectron spectrum of CeO{sup −} exhibits what appears to be a single predominant electronic transition over an energy range in which numerous close-lying electronic states of CeO neutral are well known. The photoelectron spectrum of Ce(OH){sub 2}{sup −}, a molecule in which the Ce atom shares the same formal oxidation state as the Ce atom in CeO{sup −}, also exhibits what appears to be a single transition. From the spectra, the adiabatic electron affinities of CeO and Ce(OH){sub 2} are determined to be 0.936 ± 0.007 eV and 0.69 ± 0.03 eV, respectively. From the electron affinity of CeO, the CeO{sup −} bond dissociation energy was determined to be 7.7 eV, 0.5 eV lower than the neutral bond dissociation energy. The ground state orbital occupancies of both CeO{sup −} and Ce(OH){sub 2}{sup −} are calculated to have 4f 6s{sup 2} Ce{sup +} superconfigurations, with open-shell states having 4f5d6s superconfiguration predicted to be over 1 eV higher in energy. Low-intensity transitions observed at higher electron binding energies in the spectrum of CeO{sup −} are tentatively assigned to the {sup 1}Σ{sup +} (Ω = 0) state of CeO with the Ce{sup +2}⍰6s{sup 2} superconfiguration.

  5. Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Frederick H. [Argonne National Laboratory; Jacobson, Norman H.

    1968-09-01

    This booklet discusses research reactors - reactors designed to provide a source of neutrons and/or gamma radiation for research, or to aid in the investigation of the effects of radiation on any type of material.

  6. Identification and Quality Assessment of Chrysanthemum Buds by CE Fingerprinting

    Directory of Open Access Journals (Sweden)

    Xiaoping Xing

    2015-01-01

    Full Text Available A simple and efficient fingerprinting method for chrysanthemum buds was developed with the aim of establishing a quality control protocol based on biochemical makeup. Chrysanthemum bud samples were successively extracted by water and alcohol. The fingerprints of the chrysanthemum buds samples were obtained using capillary electrophoresis and electrochemical detection (CE-ED employing copper and carbon working electrodes to capture all of the chemical information. 10 batches of chrysanthemum buds were collected from different regions and various factories to establish the baseline fingerprint. The experimental data of 10 batches electropherogram buds by CE were analyzed by correlation coefficient and the included angle cosine methods. A standard chrysanthemum bud fingerprint including 24 common peaks was established, 12 from each electrode, which was successfully applied to identify and distinguish between chrysanthemum buds from 2 other chrysanthemum species. These results demonstrate that fingerprint analysis can be used as an important criterion for chrysanthemum buds quality control.

  7. Water Cooled FBNR Nuclear Reactor

    International Nuclear Information System (INIS)

    A new era of nuclear energy is emerging through innovative nuclear reactors that are to satisfy the new philosophies and criteria that are developed by the INPRO program of the International Atomic Energy Agency (IAEA). The IAEA is establishing a new paradigm in relation to nuclear energy. The future reactors should meet the new standards in respect to safety, economy, non-proliferation, nuclear waste, and environmental impact. The Fixed Bed Nuclear Reactor (FBNR) is a small (70 MWe) nuclear reactor that meets all the established requirements. It is an inherently safe and passively cooled reactor that is fool proof against nuclear proliferation. It is simple in design and economic. It can serve as a dual purpose plant to produce simultaneously both electricity and desalinated water thus making it especially suitable to the needs of most of developing countries. FBNR is developed with the support of the IAEA under its program of Small Reactors Without On-Site Refuelling (SRWOSR). The FBNR reactor uses the pressurized water reactor (PWR) technology. It fulfills the objectives of design simplicity, inherent and passive safety, economy, standardization, shop fabrication, easy transportability and high availability. The inherent safety characteristic of the reactor dispenses with the need for containment; however, a simple underground containment is envisaged for the reactor in order to reduce any adverse visual impact. (author)

  8. Lifetimes of Excited Levels in 131Ce

    Institute of Scientific and Technical Information of China (English)

    LI Guang-Sheng; LI Xian-Feng; WEN Li-Jun; ZHENG Yong-Nan; ZHENG Yong; LIU Yun-Zuo; YUAN Guan-Jun; YANG Chun-Xiang; MENG Rui; ZHU Li-Hua; ZHANG Zhen-Long; WANG Yue; WANG Zhi-Min; WEN Shu-Xian; LU Jing-Bin; ZHAO Guang-Yi

    2004-01-01

    @@ The fusion-evaporation reaction 116Sn (1gF, p3n) 131 Ce at projectile energy of 95 MeV is used to populate high spin states in 131 Ce. The de-exciting γ-rays are detected in γ-γ coincidence measurement with Compton-suppressed BGO-HPGe detectors. Level lifetimes of 131 Ce were determined by using the Doppler shift attenuation method.The experimental results indicate that collectivity of 131 Ce is reduced relative to that of 130 Ce and it follows that deformation decreases with increase of the neutron number on the basis of systematic comparison of transition quadrupole moments for the light cerium isotopes.

  9. Research reactors

    International Nuclear Information System (INIS)

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  10. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  11. Exotic clustering in Ce and Nd isotopes

    CERN Document Server

    Buck, B; Pérez, S M

    1999-01-01

    We propose exotic binary cluster models for the intermediate mass nuclei sup 1 sup 4 sup 6 sup , sup 1 sup 4 sup 8 sup , sup 1 sup 5 sup 0 Ce and sup 1 sup 4 sup 8 sup , sup 1 sup 5 sup 0 sup , sup 1 sup 5 sup 2 sup , sup 1 sup 5 sup 4 Nd. The optimum choice of cluster and core is determined by joint consideration of the penetrability for exotic cluster emission, the deviations of cluster and core binding energies from underlying liquid drop values and the Q-values for breakup. It is noticeable that the core neutron number selected in this way is at or near the N = 82 shell closure. We use a standard form of the cluster-core potential to calculate the energies and wave functions of states in the ground 0 sup + , 2 sup + , 4 sup + , ... and lowest lying negative parity 1 sup - , 3 sup - , 5 sup - , ... bands. The theoretical spectra and electromagnetic properties are compared with measurements, and their general trends are reproduced satisfactorily.

  12. Research reactors

    International Nuclear Information System (INIS)

    There are currently 284 research reactors in operation, and 12 under construction around the world. Of the operating reactors, nearly two-thirds are used exclusively for research, and the rest for a variety of purposes, including training, testing, and critical assembly. For more than 50 years, research reactor programs have contributed greatly to the scientific and educational communities. Today, six of the world's research reactors are being shut down, three of which are in the USA. With government budget constraints and the growing proliferation concerns surrounding the use of highly enriched uranium in some of these reactors, the future of nuclear research could be impacted

  13. Reactor container

    International Nuclear Information System (INIS)

    Object: To provide a jet and missile protective wall of a configuration being inflated toward the center of a reactor container on the inside of a body of the reactor container disposed within a biological shield wall to thereby increase safety of the reactor container. Structure: A jet and missile protective wall comprised of curved surfaces internally formed with a plurality of arch inflations filled with concrete between inner and outer iron plates and shape steel beam is provided between a reactor container surrounded by a biological shield wall and a thermal shield wall surrounding the reactor pressure vessel, and an adiabatic heat insulating material is filled in space therebetween. (Yoshino, Y.)

  14. Design guide for category IV reactors: liquid metal reactors

    International Nuclear Information System (INIS)

    The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirements of liquid metal cooled fast reactor (Category IV reactor) structures, components, and systems

  15. Stress corrosion (Astm G30-90 standard) in 08x18H10T stainless steel of nuclear fuel storage pool in WWER reactors

    International Nuclear Information System (INIS)

    At the water storage of the irradiated nuclear fuel has been an important factor in its management. The actual pools have its walls covered with inoxidable steel and heat exchangers to dissipate the residual heat from fuel. It is essential to control the water purity to eliminate those conditions which aid to the corrosion process in fuel and at related components. The steel used in this research was obtained from an austenitic inoxidizable steel standardized with titanium 08x18H10T (Type 321) similar to one of the two steel coatings used to cover walls and the pools floor. the test consisted in the specimen deformation through an U ply according to the Astm G30-90 standard. The exposition of the deformed specimen it was realized in simulated conditions to the chemical regime used in pools. (Author)

  16. Temperature dependence of the scintillation properties of Ce:GSO and Ce:GSOZ

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Shunsuke, E-mail: kurosawa@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Sugiyama, Makoto [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yanagida, Takayuki [New Industry Creation Hatchery Center (NICHe), 6-6-10 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Yokota, Yuui [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yoshikawa, Akira [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe), 6-6-10 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2012-10-21

    The light output and decay times of Ce:GSO and Ce:GSOZ scintillators depend on Ce concentration and temperature. We investigated the temperature dependence of the light output and the decay time for Ce:GSO and Ce:GSOZ doped with 0.3 (only GSO), 0.5, 1.0, and 1.5 mol% Ce. These samples were measured with a ruggedized photomultiplier (PMT) (Hamamatsu R6877A) at 175 Degree-Sign C (in the thermostat chamber). Up to 100 Degree-Sign C, the relative light output of all of the samples remained within 10% after correcting the PMT gain, which depends on the temperature. The decay times of the GSO and GSOZ samples with the identical Ce concentrations were equal. Moreover, the quenching energy values for all the samples were equivalent.

  17. Temperature dependence of the scintillation properties of Ce:GSO and Ce:GSOZ

    International Nuclear Information System (INIS)

    The light output and decay times of Ce:GSO and Ce:GSOZ scintillators depend on Ce concentration and temperature. We investigated the temperature dependence of the light output and the decay time for Ce:GSO and Ce:GSOZ doped with 0.3 (only GSO), 0.5, 1.0, and 1.5 mol% Ce. These samples were measured with a ruggedized photomultiplier (PMT) (Hamamatsu R6877A) at 175 °C (in the thermostat chamber). Up to 100 °C, the relative light output of all of the samples remained within 10% after correcting the PMT gain, which depends on the temperature. The decay times of the GSO and GSOZ samples with the identical Ce concentrations were equal. Moreover, the quenching energy values for all the samples were equivalent.

  18. Safety of research reactors

    International Nuclear Information System (INIS)

    review of the research reactor facility and to verify compliance with the IAEA' Safety Standards. This issue paper discusses the concerns generated by an analysis of the results of INSARR missions and those expressed by INSAG. The topic is timely and important because a large number of research reactors currently face not only these concerns but also the problem of spent fuel disposal following completion of the current US takeback programme and the Russian take-back programme, which is expected to commence in the near future. Many countries will need to make decisions soon on the future of their reactors to take advantage of these spent fuel options

  19. Licensed reactor nuclear safety criteria applicable to DOE reactors

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC [Nuclear Regulatory Commission] licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor

  20. Licensed reactor nuclear safety criteria applicable to DOE reactors

    International Nuclear Information System (INIS)

    This document is a compilation and source list of nuclear safety criteria that the Nuclear Regulatory Commission (NRC) applies to licensed reactors; it can be used by DOE and DOE contractors to identify NRC criteria to be evaluated for application to the DOE reactors under their cognizance. The criteria listed are those that are applied to the areas of nuclear safety addressed in the safety analysis report of a licensed reactor. They are derived from federal regulations, USNRC regulatory guides, Standard Review Plan (SRP) branch technical positions and appendices, and industry codes and standards

  1. Photocatalytic degradation of gaseous benzene over TiO2/Sr2CeO4: Preparation and photocatalytic behavior of TiO2/Sr2CeO4

    International Nuclear Information System (INIS)

    The paper demonstrates that the photocatalytic activity of TiO2 towards the decomposition of gaseous benzene in a batch reactor can be greatly improved by loading TiO2 on the surface of Sr2CeO4. The research investigates the optimum loading amount of TiO2 on Sr2CeO4 in enhancing the photocatalytic activity of TiO2. The prepared photocatalyst was characterized by XRD, UV-vis diffuse reflectance and XPS analyses. TiO2 is loaded on Sr2CeO4 at 773 K. TiO2/Sr2CeO4 absorbs much more visible light than TiO2. The XPS spectrum shows that there are Ti, O, C, Sr elements on the surface of the TiO2/Sr2CeO4, and that the binding energy value of Ti2p transfers to a lower value. TiO2/Sr2CeO4 demonstrates 2.0 times the photocatalytic activity of pure TiO2. Based upon these observations, the mechanistic role of Sr2CeO4 in the photocatalytic oxidation reaction has been suggested

  2. Characterization of low power research reactor neutrons for the validation of k0-INAA standardization based on k0-IAEA software

    International Nuclear Information System (INIS)

    Channel Bsite2 of Ghana research reactor-1 has been characterized for k0-INAA application. Cadmium ratio and bare multi-monitor were used to determine flux parameters using 0.1%Au–Al, Fe, and Zr wire as flux monitors. The parameters determined were 18.36±1.91, 0.0479±0.012, 5.12×1011±0.42×1011 ncm−2 s−1, 2.74×1010±0.14×1010 ncm−2 s−1, 7.73×1010±0.16×1010 ncm−2 s−1 and 16.75±1.58, −0.034±0.0028, 4.28×1011±1.71×1011 ncm−2 s−1, 2.55×1010±0.15×1010 ncm−2 s−1 respectively for thermal-to-epithermal flux ratio, alpha, thermal neutron, epithermal neutron and fast neutron flux using cadmium ratio and multi-monitor method accordingly. The k0-INAA performance assessment based on z-score distributions showed most results within |z|0-INAA application. • Both bare and Cd-ratio method were used for the characterization. • α, f and thermal, epithermal and fast neutron flux values were found to agree largely with earlier reports. • We developed an irradiation method to detect and quantify up to 32 elements in plants, rock and lake sediment matrices. • The z-score analysis showed 90% of the data points within the range of |z|<2

  3. Standard for prevention of gas entrainment phenomena in fast reactors. (1) Validations of CFD methods for reproducibilities of gas entrainment phenomena

    International Nuclear Information System (INIS)

    It is of importance for stable operations of sodium-cooled fast reactors (SFRs) to prevent gas entrainment (GE) phenomena due to free surface vortices. The entrained gas flow rate should be below an allowance level. However, theoretical determination of universal onset conditions of GE is difficult due to nonlinear characteristics of GE phenomena. Therefore, the authors have been developing an evaluation method for GE based on computational fluid dynamics (CFD) methods. In this study, we determine a suitable CFD method for GE phenomena from several candidates through some numerical benchmarks. As a result, we obtain the following guideline for the vortex-induced gas entrainment. The free vortex flow around the vortex core can be correctly evaluated by using appropriate numerical models, such as sufficient mesh resolution, suitable advection solver, suitable turbulence and free surface modeling. From the geometrical viewpoint, the jagged description of the curved boundary using a rectangular mesh is not suitable since it damps rotating flow. As for turbulence modeling, which is especially investigated in this paper, direct numerical simulation (DNS) without any turbulent model is strongly recommended, but RNG k-ε and LES are acceptable. Lastly, we apply the recommended methods to the numerical analysis of a large-scale (>1/2) test experiment. The numerical results show good agreement with the onset condition of the GE observed in the experiments. This fact indicates that our recommended CFD methods are applicable to the GE phenomena in SFRs. In the next paper, a GE evaluation method is developed, which can calculate GE occurrences based on the results of numerical simulations performed in accordance with the simulation guideline proposed in this paper. (author)

  4. Unstable magnetic moments in Ce compounds

    International Nuclear Information System (INIS)

    The problems which are connected with the appearance or disappearance of local moments in metals are well reflected in the magnetic behaviour of Ce intermetallic compounds. This work describes experiments on two Ce compounds which are typical examples of unstable moment systems. The first of these is CeAl2 which at low temperatures, shows coexistence of antiferromagnetic order and the Kondo effect. Measurements are presented of the magnetization and the susceptibility in different magnetic field and temperature regions. An analysis of these measurements, using a model for the crystal field effects, shows the agreement between the measurements and the calculations to be reasonably good for CeAl2, but this agreement becomes worse upon decreasing Ce concentration. A phenomenological description of the observations is given. The second compound reported on is CeCu2Si2, the first 'heavy-fermion' superconductor to be investigated. The superconducting state is possibly formed by the quasi-particles of a non-magnetic many body singlet state, and not simply by the (sd) conduction electrons. This being a novel phenomenon, a number of experiments were performed to test this picture and to obtain a detailed description of the behaviour of CeCu2Si2. Measurements of the Meissner volume, confirmed the superconductivity to be intrinsic. (Auth.)

  5. Optical properties of CeO2 thin films

    Indian Academy of Sciences (India)

    S Debnath; M R Islam; M S R Khan

    2007-08-01

    Cerium oxide (CeO2) thin films have been prepared by electron beam evaporation technique onto glass substrate at a pressure of about 6 × 10-6 Torr. The thickness of CeO2 films ranges from 140–180 nm. The optical properties of cerium oxide films are studied in the wavelength range of 200–850 nm. The film is highly transparent in the visible region. It is also observed that the film has low reflectance in the ultra-violet region. The optical band gap of the film is determined and is found to decrease with the increase of film thickness. The values of absorption coefficient, extinction coefficient, refractive index, dielectric constant, phase angle and loss angle have been calculated from the optical measurements. The X-ray diffraction of the film showed that the film is crystalline in nature. The crystallite size of CeO2 films have been evaluated and found to be small. The experimental -values of the film agreed closely with the standard values.

  6. Advanced Light Water Reactor Plants System 80+trademark Design Certification Program

    International Nuclear Information System (INIS)

    The purpose of this report is to provide a status of the progress that was made towards Design Certification of System 80+trademark during the US government's 1993 fiscal year. The System 80+ Advanced Light Water Reactor (ALWR) is a 3931 MWt (1350 MWe) Pressurized Water Reactor (PWR). The design consists of an essentially complete plant. It is based on evolutionary improvements to the Standardized System 80 nuclear steam supply system in operation at Palo Verde Units 1, 2, and 3, and the Duke Power Company P-81 balance-of-plant (BOP) that was designed and partially constructed at the Cherokee plant site. The System 80/P-81 original design has been substantially enhanced to increase conformance with the EPRI ALWR Utility Requirements Document (URD). Some design enhancements incorporated in the System 80+ design are included in the four units currently under construction in the Republic of Korea. These units form the basis of the Korean standardization program. The full System 80+ standard design has been offered to the Republic of China, in response to their recent bid specification. The ABB-CE Standard Safety Analysis Report (CESSAR-DC) was submitted to the NRC and a Draft Safety Evaluation Report was issued by the NRC in October 1992. CESSAR-DC contains the technical basis for compliance with the EPRI URD for simplified emergency planning. The Nuclear Steam Supply System (NSSS) is the standard ABB-Combustion Engineering two-loop arrangement with two steam generators, two hot legs and four cold legs each with a reactor coolant pump. The System 80+ standard plant includes a sperical steel containment vessel which is enclosed in a concrete shield building, thus providing the safety advantages of a dual containment

  7. An Update on Improvements to NiCE Support for PROTEUS

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McCaskey, Alexander J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    The Department of Energy Office of Nuclear Energy s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has supported the development of the NEAMS Integrated Computational Environment (NiCE), a modeling and simulation workflow environment that provides services and plugins to facilitate tasks such as code execution, model input construction, visualization, and data analysis. This report details the developement of workflows for the reactor core neutronics application, PROTEUS. This advanced neutronics application (primarily developed at Argonne National Laboratory) aims to improve nuclear reactor design and analysis by providing an extensible and massively parallel, finite-element solver for current and advanced reactor fuel neutronics modeling. The integration of PROTEUS-specific tools into NiCE is intended to make the advanced capabilities that PROTEUS provides more accessible to the nuclear energy research and development community. This report will detail the work done to improve existing PROTEUS workflow support in NiCE. We will demonstrate and discuss these improvements, including the development of flexible IO services, an improved interface for input generation, and the addition of advanced Fortran development tools natively in the platform.

  8. Cost objective PLM and CE

    CERN Document Server

    Perry, Nicolas

    2010-01-01

    Concurrent engineering taking into account product life-cycle factors seems to be one of the industrial challenges of the next years. Cost estimation and management are two main strategic tasks that imply the possibility of managing costs at the earliest stages of product development. This is why it is indispensable to let people from economics and from industrial engineering collaborates in order to find the best solution for enterprise progress for economical factors mastering. The objective of this paper is to present who we try to adapt costing methods in a PLM and CE point of view to the new industrial context and configuration in order to give pertinent decision aid for product and process choices. A very important factor is related to cost management problems when developing new products. A case study is introduced that presents how product development actors have referenced elements to product life-cycle costs and impacts, how they have an idea bout economical indicators when taking decisions during t...

  9. New fission reactor designs

    International Nuclear Information System (INIS)

    A number of critical challenges to the expanded or continued use of nuclear power have developed. These can be categorized as: regulatory restrictions and complications; negative public attitudes; plant complexity; plant life, operations, and maintenance; uncertain load growth, financing; waste management. Solutions to these challenges through advanced reactor design centre around four key technical responses. Passive safety systems are being introduced which use the laws of physics to provide emergency reactor coding, control and shutdown thus eliminating the possibility of human error. Modular construction promises cuts in costs and construction time by shifting the major part of component manufacture from the site to the factory. Standardization also cuts capital costs and in addition operations and repair costs and expedites reactor licensing. Improvements to the fuel cycle include improved fuel types, designs and fabrication, and the reprocessing of and recycling spent fuel back into energy production, thus extending uranium resources and offering a partial solution to the problem of waste disposal. Examples of evolutionary and advanced water-cooled reactors, modular high temperature gas-cooled reactors, and advanced liquid metal cooled fast breeder reactors which are being developed round the world are presented. (author)

  10. Backfitting of the FRG reactors

    International Nuclear Information System (INIS)

    The FRG-research reactors The GKSS-research centre is operating two research reactors of the pool type fueled with MTR-type type fuel elements. The research reactors FRG-1 and FRG-2 having power levels of 5 MW and 15 MW are in operation for 31 year and 27 years respectively. They are comparably old like other research reactors. The reactors are operating at present at approximately 180 days (FRG-1) and between 210 and 250 days (FRG-2) per year. Both reactors are located in the same reactor hall in a connecting pool system. Backfitting measures are needed for our and other research reactors to ensure a high level of safety and availability. The main backfitting activities during last ten years were concerned with: comparison of the existing design with today demands (criteria, guidelines, standards etc.); and probability approach for events from outside like aeroplane crashes and earthquakes; the main accidents were rediscussed like startup from low and full power, loss of coolant flow, loss of heat sink, loss of coolant and fuel plate melting; a new reactor protection system had to be installed, following today's demands; a new crane has been installed in the reactor hall. A cold neutron source has been installed to increase the flux of cold neutrons by a factor of 14. The FRG-l is being converted from 93% enriched U with Alx fuel to 20% enriched U with U3Si2 fuel. Both cooling towers were repaired. Replacement of instrumentation is planned

  11. Reactor building

    International Nuclear Information System (INIS)

    The whole reactor building is accommodated in a shaft and is sealed level with the earth's surface by a building ceiling, which provides protection against penetration due to external effects. The building ceiling is supported on walls of the reactor building, which line the shaft and transfer the vertical components of forces to the foundations. The thickness of the walls is designed to withstand horizontal pressure waves in the floor. The building ceiling has an opening above the reactor, which must be closed by cover plates. Operating equipment for the reactor can be situated above the building ceiling. (orig./HP)

  12. Heterogeneous reactors

    International Nuclear Information System (INIS)

    The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author)

  13. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  14. Hydrogenation of the intermediate valence ternary stannides CeRhSn and CeIrSn

    OpenAIRE

    Chevalier, Bernard; Sebastian, C. P.; Pöttgen, Rainer

    2006-01-01

    CeRhSn and CeIrSn were synthesized from the elements via arc-melting. A single crystal from the CeIrSn sample was investigated on the basis of X-ray diffractometer data: ZrNiAl type, P2m, a=743.8(2), c=407.58(7) pm, wR2=0.0308, 352 F2 values and 14 variable parameters. An important structural feature of CeIrSn are relatively short Cesingle bondIr distances (4×303 and 1×308 pm). Hydrogenation of these ternary stannides leads to the formation of the new hydrides CeRhSnH0.8 and CeIrSnH0.7 which ...

  15. Radiation streaming with SAM-CE

    International Nuclear Information System (INIS)

    The SAM-CE Monte Carlo code has been employed to calculate doses, due to neutron streaming, on the operating floor and other locations of the Millstone Unit II Nuclear Power Facility. Calculated results were compared against measured doses

  16. Inherently safe light water reactors

    International Nuclear Information System (INIS)

    Today's large nuclear power reactors of world-wise use have been designed based on the philosophy. It seems that recent less electricity demand rates, higher capital cost and the TMI accident let us acknowledge relative small and simplified nuclear plants with safer features, and that Chernobyl accident in 1983 underlines the needs of intrinsic and passive safety characteristics. In such background, several inherently safe reactor concepts have been presented abroad and domestically. First describing 'Can inherently safe reactors be designed,' then I introduce representative reactor concepts of inherently safe LWRs advocated abroad so far. All of these innovative reactors employ intrinsic and passive features in their design, as follows: (1) PIUS, an acronym for Process Inherent Ultimate Safety, or an integral PWR with passive heat sink and passive shutdown mechanism, advocated by ASEA-ATOM of Sweden. (2) MAP(Minimum Attention Plant), or a self-pressurized, natural circulation integral PWR, promoted by CE Inc. of the U.S. (3) TPS(TRIGA Power System), or a compact PWR with passive heat sink and inherent fuel characteristics of large prompt temperature coefficient, prompted by GA Technologies Inc. of the U.S. (4) PIUS-BWR, or an inherently safe BWR employing passively actuated fluid valves, in competition with PIUS, prompted by ORNL of the U.S. Then, I will describe the domestic trends in Japan and the innovative inherently safe LWRs presented domestically so far. (author)

  17. Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO 2

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Duane D.; Siriwardane, Ranjani

    2013-08-15

    Chemical looping combustion (CLC) is a promising technology for fossil fuel combustion that produces sequestration-ready CO{sub 2} stream, reducing the energy penalty of CO{sub 2} separation from flue gases. An effective oxygen carrier for CLC will readily react with the fuel gas and will be reoxidized upon contact with oxygen. This study investigated the development of a CeO{sub 2}-promoted Fe{sub 2}O{sub 3}-hematite oxygen carrier suitable for the methane CLC process. Composition of CeO{sub 2} is between 5 and 25 wt % and is lower than what is generally used for supports in Fe{sub 2}O{sub 3} carrier preparations. The incorporation of CeO{sub 2} to the natural ore hematite strongly modifies the reduction behavior in comparison to that of CeO{sub 2} and hematite alone. Temperature-programmed reaction studies revealed that the addition of even 5 wt % CeO{sub 2} enhances the reaction capacity of the Fe{sub 2}O{sub 3} oxygen carrier by promoting the decomposition and partial oxidation of methane. Fixed-bed reactor data showed that the 5 wt % cerium oxides with 95 wt % iron oxide produce 2 times as much carbon dioxide in comparison to the sum of carbon dioxide produced when the oxides were tested separately. This effect is likely due to the reaction of CeO{sub 2} with methane forming intermediates, which are reactive for extracting oxygen from Fe{sub 2}O{sub 3} at a considerably faster rate than the rate of the direct reaction of Fe{sub 2}O{sub 3} with methane. These studies reveal that 5 wt % CeO{sub 2}/Fe{sub 2}O{sub 3} gives stable conversions over 15 reduction/oxidation cycles. Lab-scale reactor studies (pulsed mode) suggest the methane reacts initially with CeO{sub 2} lattice oxygen to form partial oxidation products (CO + H{sub 2}), which continue to react with oxygen from neighboring Fe{sub 2}O{sub 3}, leading to its complete oxidation to form CO{sub 2}. The reduced cerium oxide promotes the methane decomposition reaction to form C + H{sub 2}, which continue to

  18. Reactor neutron activation analysis on reference materials from intercomparison runs

    International Nuclear Information System (INIS)

    A review of using the Instrumental Neutron Activation Analysis (INAA) technique in our laboratory to determine major, minor and trace elements in mineral and biological samples from international intercomparison runs organised by IAEA Vienna, IAEA-MEL Monaco, 'pb-anal' Kosice, INCT Warszawa and IPNT Krakow is presented. Neutron irradiation was carried out at WWR-S reactor in Bucharest (short and long irradiation) during 1982-1997 and at TRIGA reactor in Pitesti (long irradiation) during the later period. The following type of materials were analysed: soils, marine sediments, uranium phosphate ore, water sludge, copper flue dust, whey powder, yeast, cereal flour (rye and wheat), marine animal tissue (mussel, garfish and tuna fish), as well as vegetal tissue (seaweed, cabbage, spinach, alfalfa, algae, tea leaves and herbs). The following elements could be, in general, determined: Ag, As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, K, La, Lu, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, U, W, Yb and Zn of long-lived radionuclides, as well as Al, Ca, Cl, Cu, Mg, Mn, and Ti of short-lived radionuclides. Data obtained in our laboratory for various matrix samples presented and compared with the intercomparison certified values. The intercomparison exercises offer to the participating laboratories the opportunity to test the accuracy of their analytical methods as well as to acquire valuable Reference Materials/ standards for future analytical applications. (authors)

  19. Synthesis, structure, optical, and electric properties of Ce-doped CuInTe2 compound

    International Nuclear Information System (INIS)

    Ce-doped CuInTe2 (CICT) semiconducting compounds are successfully synthesized. The phase structures, optical, and electric properties are investigated using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectrometer (XPS), Raman spectrometer, ultraviolet and visible spectrophotometer (UV-Vis), and a standard four-probe method. CuIn1−xCexTe2 crystallizes into a tetragonal structure with predominant orientation along the [112] direction. The lattice parameters are a = 6.190(6) Å–6.193(0) Å and c = 12.406(5) Å–12.409(5) Å. Ce prefers to occupy the 4b crystal position. According to the analysis of XPS spectra, Ce shows the mixture of valences 4+ and 3+. Raman spectra reveal that the photon vibrating model in the CICT follows A1 mode in a wavenumber range of 123 cm−1–128 cm−1. UV-Vis spectra show that the band gap Eg values before and after 0.1 mole Ce doped into CuInTe2 are 1.28 eV and 1.16 eV, respectively. It might be due to the mixture of valences for Ce. Ce doped into CuInTe2 still shows the semiconductor characteristics. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. Structural and magnetic properties of Ce/Fe and Ce/FeCoV multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mannix, D.; Stirling, W.G. [Liverpool Univ. (United Kingdom); Lander, G.H.

    1997-09-01

    Ce/Fe and Ce/FeCoV multilayers have been grown by magnetron sputtering. The interfaces are well defined and the layers are crystalline down to an individual layer thickness of 20 A. Ce/FeCoV multilayers show sharper interfaces than Ce/Fe but some loss of crystallinity is observed. Hysteresis loops obtained by SQUID show different behaviour of the bulk magnetisation as a function of the layer thickness. Fe moments are found by Moessbauer spectroscopy to be perpendicular to the interfaces for multilayers with small periodicity. (author) 2 figs., 2 refs.

  1. Magnetic and transport properties of CePdAs and CePdSb

    International Nuclear Information System (INIS)

    The results of measurements of electrical resistivity ρ, magnetic susceptibility χ, magnetization M and specific heat C are reported on single-crystalline samples of CePdAs and CePdSb. As for CePdAs, ρ(T) perpendicular to the c-axis behaves like a metal and a sharp drop appears around 4 K corresponding to the magnetic transition. But ρ(T) parallel to the c-axis shows a maximum at about 10 K and semiconducting behavior at high temperature. ρ(T) perpendicular to the c-axis on CePdSb shows the same metallic behavior as in the case of CePdAs. The strong aniosotropy in ρ(T) suggests that CePdAs and CePdSb are better characterized as quasi-two-dimensional electrical conductors. This anisotropy is also manifested in χ and M. χ(T) and M(H) along the c-axis of CePdAs and CePdSb exhibits antiferromagnetic ordering at 4 and 17 K, respectively. But χ(T) along the a-axis increases, with decreasing temperature following Curie-Weiss-like behavior of a ferromagnet. (orig.)

  2. Preparation and stability of a new compound SrCe0.9Lu0.1O2.95

    International Nuclear Information System (INIS)

    Highlights: • The phase SrCe0.9Lu0.1O2.95 was synthesized. • The formation enthalpy of SrCe0.9Lu0.1O2.95 was measured by solution calorimetry. • The phase is thermodynamically stable with respect to decomposition into binary oxides. • The adding of Lu leads to increasing the stability of SrCeO3. - Abstract: The preparation of SrCeO3 doped by lutetium oxide (SrCe0.9Lu0.1O2.95) has been carried out by the solid-state reaction of SrCO3, CeO2 and Lu2O3. The X-ray measurements have shown that SrCe0.9Lu0.1O2.95 has an orthorhombic structure (space group Pnma). For the first time the standard molar enthalpy of SrCe0.9Lu0.1O2.95 formation has been determined by solution calorimetry in combination with standard molar dissolution enthalpies of SrCe0.9Lu0.1O2.95 and SrCl2 + 0.9CeCl3 + 0.1LuCl3 mixture in 1 M HCl with 0.1 M KI at 298.15 K and other thermochemical data. It has been found out that the mixed oxide mentioned above is thermodynamically more stable than the component oxides at room temperature. It has been also shown that SrCe0.9Lu0.1O2.95 is thermodynamically more favored than 0.9SrCeO3 + 0.1SrO + 0.05Lu2O3 mixture. We have established that Lu adding increases SrCeO3 thermodynamic stability

  3. Study of magnetic excitations in CeCu{sub 2} with inelastic neutron scattering; Untersuchung von magnetischen Anregungen in CeCu{sub 2} mit inelastischer Neutronenstreuung

    Energy Technology Data Exchange (ETDEWEB)

    Schedler, R.

    2006-07-01

    In this thesis, the electronic and magnetic properties of the heavy-fermion system CeCu{sub 2} are investigated. For that purpose, measurements of susceptibility, magnetisation and specific heat from literature are compared with each other and are compared with neutron-scattering experiments performed for the present work. One part of the thesis is addressed to the design of the new triple-axis spectrometer PANDA, which is situated at the research reactor FRM2 in Munich. Extensive simulations were performed with the ray-tracing simulation package McStas in order to model this neutron scattering instrument and to optimise its neutron optic elements. The second part of this work deals with measurements and calculations of the magnetic phase diagram of CeCu{sub 2}. The experiments include the macroscopic magnetisation (VSM) and elastic neutron-scattering measurements (D23, ILL Grenoble). The McPhase calculations are in a good agreement with the experiments. The next part presents elastic and inelastic neutron-scattering experiments (IN12 and IN20, ILL Grenoble) at CeCu{sub 2} single crystals. These measurements investigate the static (phase diagram) as well as dynamic properties (excitations) of this compound. Especially, the experiments are concentrated on the investigation of the dispersion relation of magnons in magnetic fields up to {mu}{sub 0}H=12 T. For these measurements, a new sample holder suitable for use in high magnetic fields was designed, which fixes the sample in a hermetically sealed containment. In the experiments an unexpected dispersionless excitation was observed, which does not fit the standard magnon model. With increasing magnetic field the energy of this excitation increases with a slope of twice the value expected for regular magnons. A neutron-induced {pi}/2 spin-flop process is proposed to explain this excitation. In another measurement with polarised neutrons the first excited crystal-field level at 9 meV, which has not been directly

  4. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor... reactor batch process vent located at a new affected source shall control organic HAP emissions...

  5. Photoluminescent properties of Sr2CeO4 : Eu3+ and Sr2CeO4 : Eu2+ phosphors suitable for near ultraviolet excitation

    Indian Academy of Sciences (India)

    K Suresh; N V Poornachandra Rao; K V R Murthy

    2014-10-01

    Powder phosphors of 1 mol% Eu3+- and Eu2+-doped strontium cerium oxide (Sr2CeO4) were synthesized by standard solid-state reaction method. Eu3+- and Eu2+-doped Sr2CeO4 phosphors fired at 1100 °C for 2 h were analysed by X-ray diffraction (XRD) and photoluminescence (PL) techniques. The XRD patterns confirm that the obtained phosphors are a single phase of Sr2CeO4 composed of orthorhombic structure. Room temperature PL excitation spectrum of air-heated Sr2CeO4 : Eu phosphor has exhibited bands at 260, 280 and 350 nm. Whereas the excitation spectrum of Sr2CeO4 : Eu phosphor heated under reducing (carbon) atmosphere exhibited single broadband range from 260 to 390 nm. The (PL) emission peaks of both the phosphors at 467 (blue), 537 (green) and 616 nm (red) generate white light under 260, 280 and 350 nm excitation wavelengths. The Commission International de l’Eclairage (CIE) colour coordinates conforms that these phosphors emitting white light. The results reveal that these phosphors are multifunctional phosphors which emit white light under these excitations that they could be used as white components for display and lamp devices and as well as possible good light-conversion phosphor LEDs under near-ultraviolet (nUV) chip.

  6. Plasma reactor

    OpenAIRE

    Molina Mansilla, Ricardo; Erra Serrabasa, Pilar; Bertrán Serra, Enric

    2008-01-01

    [EN] A plasma reactor that can operate in a wide pressure range, from vacuum and low pressures to atmospheric pressure and higher pressures. The plasma reactor is also able to regulate other important settings and can be used for processing a wide range of different samples, such as relatively large samples or samples with rough surfaces.

  7. Reactor physics

    International Nuclear Information System (INIS)

    Progress in research on reactor physics in 1997 at the Belgian Nuclear Research Centre SCK/CEN is described. Activities in the following four domains are discussed: core physics, ex-core neutron transport, experiments in Materials Testing Reactors, international benchmarks

  8. Survey of light-water-reactor designs to be offered in the United States

    International Nuclear Information System (INIS)

    ORNL has conducted a Nuclear Power Options Viability Study for the Department of Energy. That study is primarily concerned with new technology which could be developed for initial operation in the 2000 to 2010 time frame. Such technology would have to compete not only with coal options but with incrementally improved commercial light-water-reactors. This survey reported here was undertaken to gain an understanding of the nuclear commercial technology likely to be offered in the late 1980s and perhaps beyond. The three US vendors actively marketing NSSSs are each developing a product for the future which they expect to be more reliable, more maintainable, more economical, and safer than the present plants. These are all essentially 3800-MW(t) designs, although all are studying smaller plants. They apparently will be off offered as standard prelicensed designs with much larger scope than earlier NSSS offerings, with the possibility of firm prices. Westinghouse with Mitsubishi Heavy Industries is developing a completely new design (APWR) to be built initially in Japan, hopefully for operation by the mid-1990s. Westinghouse is making a strong effort to have the APWR licensed in the US as a standard plant. Combustion Engineering (C-E) is evaluating potential improvements to the System-80 standard design (CESSAR) that has already received final design approval by the NRC. General Electric (GE), with Hitachi and Toshiba, is developing a new design (ABWR) that incorporates advanced features which have been proven by the worldwide BWR suppliers. The ABWR is to be built initially in Japan, but the design could be adapted to the United States. Westinghouse, C-E, and GE have done some conceptual evaluation of reactors in the 600-MW(e) class. The Westinghouse concept is a two-loop plant intended for factory assembly in a shipyard and delivery to a site by barge. The GE concept is a modification of the ABWR with some additional passive safety features. 16 figs

  9. Design guide for Category III reactors: pool type reactors

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) in the ERDA Manual requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirement of Category III reactor structures, components, and systems

  10. Integral test of JENDL-3.3 for fast reactors

    International Nuclear Information System (INIS)

    An integral test of JENDL-3.3 was performed for fast reactors. Various types of fast reactors were analyzed. Calculation values of the nuclear characteristics were greatly especially affected by the revisions of the cross sections of U-235 capture and elastic scattering reactions. The C/E values were improved for ZPPR cross where plutonium is mainly fueled, but not for BFS cores where uranium is mainly fueled. (author)

  11. China experimental fast reactor

    International Nuclear Information System (INIS)

    The Chinese experimental fast reactor (CEFR) is a pool-type sodium-cooled fast reactor whose short term purposes are: -) the validation of computer codes, -) the check of the relevance of standards, and -) the gathering of experimental data on fast reactors. On the long term the expectations will focus on: -) gaining experience in fast reactor operations, -) the testing of nuclear fuels and materials, and -) the study of sodium compounds. The main technical features of CEFR are: -) thermal power output: 65 MW (electrical power output: 20 MW), -) size of the core: height: 45 cm, diameter: 60 cm, -) maximal linear output: 430 W/cm, -) neutron flux: 3.7*1015 n/cm2/s, -) input/output sodium temperature: 360 / 530 Celsius degrees, -) 2 loops for the primary system and 2 loops for the secondary system. The temperature coefficient and the power coefficient are settled to stay negative for any change in the values of the core parameters. The installation of the reactor vessel will be completed by mid 2007. The first criticality of CEFR is expected during the first semester of 2010. (A.C.)

  12. CeRh3B2: A ferromagnet with anomalously large Ce 5d spin and orbital magnetic moments

    International Nuclear Information System (INIS)

    We report a high-energy magnetic-Compton-scattering study performed on the ferromagnet CeRh3B2. This technique solely measures the electron spin magnetic moments. In contrast to a number of Ce intermetallics with nonmagnetic elements, the Ce 5d spin moment is found to be large and parallel to the Ce 4f spin moment. Therefore the Kondo effect does not play a key role for CeRh3B2. The inferred large Ce 5d orbital magnetic moment is a signature of the strong spin-orbit interaction for the Ce 5d band. copyright 1998 The American Physical Society

  13. The new sun-sky-lunar Cimel CE318-T multiband photometer - a comprehensive performance evaluation

    Science.gov (United States)

    Barreto, África; Cuevas, Emilio; Granados-Muñoz, María-José; Alados-Arboledas, Lucas; Romero, Pedro M.; Gröbner, Julian; Kouremeti, Natalia; Almansa, Antonio F.; Stone, Tom; Toledano, Carlos; Román, Roberto; Sorokin, Mikhail; Holben, Brent; Canini, Marius; Yela, Margarita

    2016-02-01

    This paper presents the new photometer CE318-T, able to perform daytime and night-time photometric measurements using the sun and the moon as light source. Therefore, this new device permits a complete cycle of diurnal aerosol and water vapour measurements valuable to enhance atmospheric monitoring to be extracted. In this study we have found significantly higher precision of triplets when comparing the CE318-T master instrument and the Cimel AErosol RObotic NETwork (AERONET) master (CE318-AERONET) triplets as a result of the new CE318-T tracking system. Regarding the instrument calibration, two new methodologies to transfer the calibration from a reference instrument using only daytime measurements (Sun Ratio and Sun-Moon gain factor techniques) are presented and discussed. These methods allow the reduction of the previous complexities inherent to nocturnal calibration. A quantitative estimation of CE318-T AOD uncertainty by means of error propagation theory during daytime revealed AOD uncertainties (uDAOD) for Langley-calibrated instruments similar to the expected values for other reference instruments (0.002-0.009). We have also found uDAOD values similar to the values reported in sun photometry for field instruments ( ˜ 0.015). In the case of the night-time period, the CE318-T-estimated standard combined uncertainty (uNAOD) is dependent not only on the calibration technique but also on illumination conditions and the instrumental noise. These values range from 0.011-0.018 for Lunar Langley-calibrated instruments to 0.012-0.021 for instruments calibrated using the Sun Ratio technique. In the case of moon-calibrated instruments using the Sun-Moon gain factor method and sun-calibrated using the Langley technique, we found uNAOD ranging from 0.016 to 0.017 (up to 0.019 in 440 nm channel), not dependent on any lunar irradiance model.A subsequent performance evaluation including CE318-T and collocated measurements from independent reference instruments has served to

  14. Hydrogen and syngas production from two-step steam reforming of methane using CeO2 as oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    Xing Zhu; Hua Wang; Yonggang Wei; Kongzhai Li; Xianming Cheng

    2011-01-01

    CeO2 oxygen carrier was prepared by precipitation method and tested by two-step steam reforming of methane (SRM).Two-step SRM for hydrogen and syngas generation is investigated in a fixed-bed reactor.Methane is directly converted to syngas at a H2/CO ratio close to 2∶ 1 at a high temperature (above 750 ℃) by the lattice oxygen of CeO2; methane cracking is found when the reduction degree of CeO2 was above 5.0% at 850 ℃ in methane isothermal reaction.CeO2-δ obtained from methane isothermal reaction can split water to generate CO-free hydrogen and renew its lattice oxygen at 700 ℃; simultaneously, deposited carbon is selectively oxidized to CO2 by steam following the reaction (C+2H2O→CO2+2H2).Slight deactivation in terms of amounts of desired products (syngas and hydrogen) is observed in ten repetitive two-step SRM process due to the carbon deposition on CeO2 surface as well as sintering of CeO2.

  15. University Reactor Conversion Lessons Learned Workshop for Purdue University Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Eric C. Woolstenhulme; Dana M. Hewit

    2008-09-01

    The Department of Energy’s Idaho National Laboratory, under its programmatic responsibility for managing the University Research Reactor Conversions, has completed the conversion of the reactor at Purdue University Reactor. With this work completed and in anticipation of other impending conversion projects, the INL convened and engaged the project participants in a structured discussion to capture the lessons learned. The lessons learned process has allowed us to capture gaps, opportunities, and good practices, drawing from the project team’s experiences. These lessons will be used to raise the standard of excellence, effectiveness, and efficiency in all future conversion projects.

  16. NEUTRONIC REACTOR

    Science.gov (United States)

    Anderson, H.L.

    1960-09-20

    A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

  17. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  18. Nuclear reactors

    International Nuclear Information System (INIS)

    This draft chart contains graphical symbols from which the type of (nuclear) reactor can be seen. They will serve as illustrations for graphical sketches. Important features of the individual reactor types are marked out graphically. The user can combine these symbols to characterize a specific reactor type. The basic graphical symbol is a square with a point in the centre. Functional groups can be depicted for closer specification. If two functional groups are not clearly separated, this is symbolized by a dotted line or a channel. Supply and discharge lines for coolant, moderator and fuel are specified in accordance with DIN 2481 and can be further specified by additional symbols if necessary. The examples in the paper show several different reactor types. (orig./AK)

  19. Influence of the Zr and Ce on the structure of experimental hot-work tool steel

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2006-04-01

    Full Text Available Purpose: of this paper was to examine of the influence of the Zr i Ce on the structure of the newly developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1.Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoWVTiCeZr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X40CrMoV5-1. Both investigated steels were melted in a vacuum electric furnace. Specimens made from the investigated steels were heat treated with austenitizing in salt bath furnaces for 30 minutes in the temperature range of 970-1180°C with gradation of 30°C. Next, the specimens were tempered twice in the temperature range of 450-660°C for 2 hours.Findings: The 47CrMoWVTiCeZr16-26-8 steel quenched from the temperature of 1120°C has the martensitic structure with the small portion of the retained austenite and alloy carbides partially dissolved during austenitizing (about 3.5%, including the MC type carbides (based on ZrC, TiC, (Ti,VC and VC, with differing chemical compositions and crystallographic lattice parameter and of the M2C3 type (based on Ce2C3.Research limitations/implications: Basing on the investigations of the newly developed 47CrMoWVTiCeZr16-26-8 steel and the standard X40CrMoV5-1 steel, the most advantageous heat treatment conditions were determined to obtain thesis most advantageous structure and mechanical properties: for the 47CrMoWVTiCeZr16-26-8 steel quenching at the temperature of 1120°C and tempering at the temperature of 540°C, and for the X40CrMoV5-1 one quenching at the temperature of 1060°C and tempering at the temperature of 510°C.Originality/value: The newly developed hot-work tool steel include Zr and Ce characterizations good structure and can be used to hot work small-size tools which requires higher strength properties

  20. Multifunctional reactors

    OpenAIRE

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much emphasis in research in the last decade. A survey is given of modern developments and the first successful applications on a large scale. It is explained why their application in many instances is ...

  1. NUCLEAR REACTOR

    Science.gov (United States)

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  2. Nuclear reactor

    International Nuclear Information System (INIS)

    In order to reduce neutron embrittlement of the pressue vessel of an LWR, blanked off elements are fitted at the edge of the reactor core, with the same dimensions as the fuel elements. They are parallel to each other, and to the edge of the reactor taking the place of fuel rods, and are plates of neutron-absorbing material (stainless steel, boron steel, borated Al). (HP)

  3. Breeder reactors

    International Nuclear Information System (INIS)

    The reasons for the development of fast reactors are briefly reviewed (a propitious neutron balance oriented towards a maximum uranium burnup) and its special requirements (cooling, fissile material density and reprocessing) discussed. The three stages in the French program of fast reactor development are outlined with Rapsodie at Cadarache, Phenix at Marcoule, and Super Phenix at Creys-Malville. The more specific features of the program of research and development are emphasized: kinetics and the core, the fuel and the components

  4. Experience with reactor power cutback system at Palo Verde nuclear generating station

    International Nuclear Information System (INIS)

    Palo Verde Nuclear Generating Station (PVNGS) is a three unit site which illustrates System 80 nuclear steam supply system (NSSS) design. The System 80 NSSS is the Combustion Engineering (C-E) standard design rated at 3817 Mwth. PVNGS Units 1 and 2 achieved commercial operation on February 13, 1986 and September 22, 1986, respectively, while Unit 3 has a forecast date for commercial operation in the third quarter of 1987. The System 80 design incorporates a reactor power cutback system (RPCS) feature which reduces plant trips caused by two common initiating events: loss of load/turbine trip (LOL) and loss of one main feedwater pump (LOMFWP). The key design objective of the RPCS is to improve overall plant availability and performance, while minimizing challenges to the plant safety system

  5. Calorimetric dosimetry of reactor radiation

    International Nuclear Information System (INIS)

    Calorimetric dosimetry of reactor radiation is relatively new reactor dosimetry method and the number of relevant papers is rather small. Some difficulties in applying standard methods (chemical dosemeters, ionization chambers) exist because of the complexity of radiation. In general application of calorimetric dosemeters for measuring absorbed doses is most precise. In addition to adequate choice of calorimetric bodies there is a possibility of determining the yields of each component of the radiation mixture in the total absorbed dose. This paper contains a short review of the basic calorimetry methods and some results of measurements at the RA reactor in Vinca performed by isothermal calorimeter

  6. Ageing management for research reactors

    International Nuclear Information System (INIS)

    During the past several years, ageing of research reactor facilities continues to be an important safety issue. Despite the efforts exerted by operating organizations and regulatory authorities worldwide to address this issue, the need for an improved strategy as well as the need for establishing and implementing a systematic approach to ageing management at research reactors was identified. This paper discusses, on the basis of the IAEA Safety Standards, the effect of ageing on the safety of research reactors and presents a proactive strategy for ageing management. A systematic approach for ageing management is developed and presented together with its key elements, along with practical examples for their application. (author)

  7. Oxygen potential and lattice parameter measurements in (U,Ce)Osub(2-x)

    International Nuclear Information System (INIS)

    Studies have been carried out on (U, Ce)Osub(2-x) to assist the understanding of oxygen behaviour in the fast reactor fuel (U, Pu)Osub(2-x). Oxygen potentials at 1123 K and lattice parameters after rapid cooling to room temperature have been determined as functions of O/M ratio for (Ce/U+Ce) ratios of 0.148 and 0.282. The results show some similarities between the two mixed oxides, but also important differences. The Markin-McIver rule, that oxygen potential at a given temperature is a function only of the supposed plutonium valence, does not apply with cerium. Simple cluster models are basically inconsistent with experimental data and a complex cluster model requires further development before it can account for the oxygen potential behaviour of (U, Ce)Osub(2-x). The ratio of lattice parameter change to O/M ratio change in Usub(1-y)Cesub(y)Osub(2-x) is not strongly dependent on y and averages 0.30 A, slightly greater than the corresponding value for Usub(1-y)Pusub(y)Osub(2-x). A transition to a room-temperature two-phase structure occurs at an O/M ratio of about 1.985 for γ = 0.282. (orig.)

  8. On-line 60Co monitor for reactor recirculation system piping in primary containment vessel during reactor operation

    International Nuclear Information System (INIS)

    Highlights: • We developed an on-line 60Co monitor for reactor recirculation system piping during reactor operation. • Energy resolution at 1.4 × 106 cps is 33 keV at 1332 keV using a pulse integral method. • A coincidence method is applied to reduce an effect of background gamma rays. • The coincidence counting of 60Co cascade gamma rays could be detected for a background dose rate of 4.8 mSv/h. - Abstract: Water chemistry control during reactor operation and installation of temporary radiation shielding prior to scheduled outages are carried out in order to reduce workers’ dose exposure caused by 60Co which is the main radiation source during scheduled outages of boiling water reactor (BWR) power plants. It is necessary to monitor the deposited 60Co on inner surfaces of reactor recirculation system (RRS) piping to evaluate effects of water chemistry control. We have developed an on-line 60Co monitor (OLCM) for this purpose. The OLCM applies a pulse integral method as a new method to measure gamma-ray counts of more than 1.0 × 106 counts per second (cps) and a coincidence counting method to reduce an effect of background gamma rays caused by 16N in the measurement of 60Co cascade gamma rays. Energy resolution at 1.4 × 106 cps is 33 keV using the pulse integral method and single LaBr3:Ce scintillation detector. The energy resolutions of this detector using the fast response photo multiplier tube (PMT) are 50 keV at 1.5 × 106 cps and 59 keV at 2.1 × 106 cps. Furthermore, we measured the energy spectra using the pulse integral method, the coincidence counting method and two LaBr3:Ce scintillation detectors and examined the transition of coincidence counting for 60Co detection under high dose rate during reactor operation at the Kyoto University Research Reactor (KUR). The coincidence counting of 60Co cascade gamma rays could be detected, and the result was average values of 47.9 counts per 40 min and standard deviations of 34%, 58.3 counts per 60 min

  9. Superconductivity in CeCo2 nanoparticles

    International Nuclear Information System (INIS)

    Both Ce and Co are essentially nonmagnetic in Pauli-paramagnetic CeCo2, which undergoes a superconducting transition near 1K. When made into 58-A nanoparticles, the compound becomes paramagnetic. Meanwhile, based on heat capacity measurements, the nanoparticles remain to be nonsuperconducting down to 0.4K but exhibit a low-temperature Kondo anomaly with C/T∼ 350mJ/molK2 at 0.4K. Such intriguing effects are consequences of the competition between superconducting gap and electronic spectrum's mean level spacing

  10. Laser altimeter of CE-1 payloads system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The design and operation of the Laser Altimeter of CE-1 Payloads System are presented in this paper.The paper includes the design of the system and spacecraft-level laser,the description of the emitting-system and receiving system,and the testing of the laser altimeter.The CE-1 laser altimeter is the first Chinese deep-space probe using a laser.It has one beam and operates at 1 Hz,with a nominal accuracy of 5 m.The laser altimeter has operated successfully in lunar orbit since November 28,2007.It has obtained 9120 thousand data values about the lunar altitude.

  11. Metamagnetism in Ce(Ga,Al)2

    Indian Academy of Sciences (India)

    K G Suresh; S Radha; A K Nigam

    2002-05-01

    Effect of Al substitution on the magnetic properties of Ce(Ga1-Al)2 ( = 0, 0.1 and 0.5) system has been studied. The magnetic state of CeGa2 is found to be FM with a C of 8 K, whereas the compounds with =0.1 and 0.5 are AFM and possess N of about 9 K. These two compounds undergo metamagnetic transition and the critical fields are about 1.2 T and 0.5 T, respectively at 2 K. These variations are explained on the basis of helical spin structure in these compounds.

  12. NDE standards for materials of fast reactors

    International Nuclear Information System (INIS)

    Primary objective of this paper is to bring out the salient features of the specifications followed for the procurement of various materials such as 316LN plates, tube sheets and 9Cr-1Mo tube sheets, 2.25Cr-1Mo dished ends and chrome-moly tubes and the difficulties encountered in procurement. 4 figs

  13. Neutron scattering from -Ce at epithermal neutron energies

    Indian Academy of Sciences (India)

    A P Murani

    2008-10-01

    Neutron scattering data, using neutrons of incident energies as high as 2 eV, on -Ce and -Ce-like systems such as CeRh2, CeNi2, CeFe24, CeRu2, and many others that point clearly to the substantially localized 4f electronic state in these systems are reviewed. The present interpretation is contrary to the widely held view that the 4f electrons in these systems form a narrow itinerant electron 4f band.

  14. CeO2-stabilized tetragonal ZrO2 polycrystals (Ce-TZP ceramics)

    International Nuclear Information System (INIS)

    This work presents the development and the characterization of CeO2-stabilized tetragonal ZrO2 polycrystals (Ce-TZP ceramics), since it is considered candidate material for applications as structural high performance ceramics. Sintered ceramics were fabricated from mixtures of powders containing different CeO2 content prepared by conventional and nonconventional techniques. These powders and their resultant sintered ceramics were specified by chemical and physical characterization, compactation state and mechanical properties. The chemical characteristics were determined by chemical analysis and the physical characteristics were evaluated by phase content, particle and agglomerate size and aspect, and powder porosity. (author)

  15. Research reactors - an overview

    Energy Technology Data Exchange (ETDEWEB)

    West, C.D.

    1997-03-01

    A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

  16. Study of preferential oxidation reaction of CO on CuO/CeO2-TiO2 system

    International Nuclear Information System (INIS)

    Cu catalysts supported on CeO2, TiO2 and CeO2/TiO2 were prepared by precipitation method and used for preferential oxidation of carbon monoxide contained in a hydrogen flow generated by methane steam reforming. The samples were characterized by XRD, BET and TPR techniques. The catalytic properties were studied in the 50-330 deg C range by using a quartz micro-reactor vertically positioned on an electrical furnace. The results showed that the small copper particles generated with the lower metal content are the most easily reducible and give the best catalytic performance. In respect of support effect, the strong metal-support interaction and the redox characteristics of the CuOx-CeO2 series resulted in the best catalytic results, especially with the sample with 1% copper content. (author)

  17. Seebeck coefficient of CePd3

    International Nuclear Information System (INIS)

    Rare earth compounds have potential applications in thermoelectric devices due to their large value conductivity and Seebeck coefficient. CePd3 has the highest reported Seebeck coefficient (S ∼ 125 μV/K), when doped appropriately, among all rare-earth compounds. This high value is explained as a result of the placement of the cerium f1 level. (author)

  18. Simplifying instrumentation for CE-MS analysis

    Czech Academy of Sciences Publication Activity Database

    Týčová, Anna; Foret, František

    Vienna, 2015. s. 37-37. [MassSpec-Forum-Vienna-2015. 17.02.2015-18.02.2015, Vienna] R&D Projects: GA ČR(CZ) GBP206/12/G014; GA ČR(CZ) GA15-15479S Institutional support: RVO:68081715 Keywords : interface * CE-MS * sheathless Subject RIV: CB - Analytical Chemistry, Separation

  19. The Doniach diagram and hydrogenation of the ternary compounds CePdIn and CePdSn

    OpenAIRE

    Chevalier, Bernard; Wattiaux, Alain; Bobet, Jean-Louis

    2006-01-01

    The process of hydrogenation of the antiferromagnetic compounds CePdIn and CePdSn has been studied. Investigation of the new hydrides CePdInH and CePdSnH by means of x-ray powder diffraction reveals that they adopt the same crystal symmetry as the original intermetallic but the unit cell volume increases during the hydrogenation. Magnetization, electrical resistivity, thermoelectric power and 119Sn Mössbauer spectroscopy measurements reveal that CePdInH and CePdSnH order antiferromagnetically...

  20. Mass spectrometric studies on Ce-Cd system

    International Nuclear Information System (INIS)

    Molten salt electrorefining process, which is a pyrochemical reprocessing method, is ideally suited for reprocessing of metallic fuels. Separation of fuel material and fission products is carried out by electrorefining of spent fuel by using solid mandrel and liquid cadmium as cathodes for the electrodeposition of uranium and transuranium elements, respectively. Due to the standard electrode potentials of rare earths being close to that of transuranium elements, some amount of rare-earths are accompanied during the electrodeposition of Pu and minor actinides at liquid cadmium cathode. Therefore the investigation of thermodynamic properties of rare earth-cadmium system is essential. As part of this, vaporization studies on Ce-Cd system with the initial composition of 63.3 at % Cd (corresponding to Cd2Ce+CdCe phase region) has been investigated by Knudsen effusion mass spectrometry. This paper reports the preliminary studies carried out on this system. High purity cadmium (99.99%, M/s. Johnson Matthey Chemical Ltd, England) and cerium (99.8%, M/s. Alfa Aesar) were used for the preparation. The sample was prepared by isopiestic method by equilibrating Cd vapours over the Ce samples in a vacuum sealed quartz set up kept in a gradient furnace. The quartz set up was subsequently quenched and opened inside an argon atmosphere glove box to retrieve the sample. The phase characterization was carried out by XRD. A VG Micromass 30 BK mass spectrometer was employed for the vaporisation studies. The sample was taken in an alumina Knudsen cell (Sample loading carried out inside an argon atmosphere glovebox) and this was placed inside a molybdenum outer cup and a tungsten lid. The cell was heated by electron bombardment and the vapour effusing from Knudsen cell was ionized by electron impact, the ions produced were mass analysed by a 90° sector magnetic analyser and detected by a secondary electron multiplier. Cd+ was the ion detected in the mass spectra of the equilibrium

  1. Reactor utilization

    International Nuclear Information System (INIS)

    In 1962, the RA reactor was operated almost three times more than in 1961, producing total of 25 555 MWh. Diagram containing comparative data about reactor operation for 1960, 1961, and 1962, percent of fuel used and U-235 burnup shows increase in reactor operation. Number of samples irradiated was 659, number of experiments done was 16. mean powered level was 5.93 MW. Fuel was added into the core twice during the reporting year. In fact the core was increased from 56 to 68 fuel channels and later to 84 fuel channels. Fuel was added to the core when the reactivity worth decreased to the minimum operation level due to burnup. In addition to this 5 central fuel channels were exchanged with fresh fuel in february for the purpose of irradiation in the VISA-2 channel

  2. Reactor Neutrinos

    CERN Document Server

    Lasserre, T; Lasserre, Thierry; Sobel, Henry W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrino oscillation physics in the last years. It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the last undetermined neutrino mixing angle theta13. We conclude by opening on possible use of neutrinos for Society: NonProliferation of Nuclear materials and Geophysics.

  3. The AP1000 reactor

    International Nuclear Information System (INIS)

    The design of the AP1000 reactor began 20 years ago when Westinghouse launched the AP600 reactor project. In fact by re-assessing AP600's safety margins Westinghouse realized that the its power output could be raised without putting at risk its safety standard. The AP1000 was born, it yields 1100 MWe. The main AP1000's design features is its passive safety (particularly after the Fukushima accident) and its modularity. The passive safety of the AP1000 implies: -) no humane intervention needed for 72 hours at least after the incident; -) no necessity for redundant complex safety systems. The modularity means that the plant, the reactor and other buildings are constructed from a choice of 300 modular units. These units can be built off-site and fit together on site. The modularity allows more construction activities to be led simultaneously and more chances to cope with the construction schedule. The NRC has approved the operation license for 30 years of the first AP1000 being built in the Usa (Vogtle plant in Georgia). 4 AP1000 are being built in China (Sanmen and Haiyang sites) and 6 others are planned in the Usa. Westinghouse is convinced that the AP1000's passive safety makes it more attractive. Let us not forget that Westinghouse was at the origin of the concept of pressurized water reactors, an idea adopted for half the nuclear power stations in the world and for all the plants now active in France. (A.C.)

  4. Elements of reactor system design

    International Nuclear Information System (INIS)

    When the first commercial nuclear power plants were designed, each plant was treated as a new design problem. However, it became apparent that the full design effort was far too lengthy and costly to be undertaken for each order. The reactor system vendors have therefore developed a series of essentially standard reactor designs. A utility customer is offered that standard design which most closely meets his requirements. Only minor modification are made in order to meet particular local requirements. The reactor design effort for such a plant is generally limited to (a) a verification that the standard system proposed will meet the required specifications and (b) a revision of the safety analysis to take into consideration the features of the particular site. Standard system designs are usually revised on a regular basis to take advantage of new developments and operational experience. It has become customary to refer to the reactor core and entire primary system as the ''nuclear steam supply system''. In the United States, when a reactor vendor supplies a system to a public utility, it is generally only the ''nuclear steam supply system'' and specific auxiliaries which are supplied. The reactor vendor will specify the general requirements of the steam cycle, vapor container and auxiliary systems and safety systems which are not vendor supplied. The detailed design of these systems, as well as the complete structural and electrical design, is normally handled by the utility or an architect-engineer engaged by the utility. The safety analysis is usually conducted by the reactor vendor. As more experience with nuclear systems is gained, it is likely that the larger utilities will assume an expanded role in the design process

  5. Some regularities of Ce(3) and Ce(4) stabilization in their compounds with β-diketones

    International Nuclear Information System (INIS)

    Adduct formation of cerium (3) and cerium (4) β-diketonates (acetylacetonate, benzoylacetonate, dibenzoylmethanate and thenoyltrifluoroacetonate) with oxygen- and nitrogen-donor ligands (Q-α, α'-dipyridyl, o-phenanthroline, trioctylphosphine oxide and triphenylphosphine oxide) is studied. The compounds obtained as a results of the reactions are studied by means of IR-spectroscopic, derivatographic and X-ray phase methods. It is concluded that composition and thermodynamic stability of adducts of Ce(3) tris-β-diketonates are determined by correlation of donor properties of the basis and additional ligand and stability of adducts to oxidation - as well as by their solubility. Introduction of the additional ligand to the system Ce(4)-β-diketones even in the presence of air oxygen stabilizes Ce(3) and destabilizes Ce(4)

  6. Proton induced activation of LaBr3:Ce and LaCl3:Ce

    International Nuclear Information System (INIS)

    In the framework of an assessment of lanthanum halide scintillators, such as LaBr3:Ce and LaCl3:Ce on their suitability for space based gamma-ray spectroscopy, proton induced activation of the materials has been studied. One inch scintillators were subjected to proton irradiations in the range of 60-184 MeV, where after the activation was measured. The activation was analyzed by identifying the decaying isotopes by means of gamma-ray spectroscopy and lifetime measurements using both a germanium detector and the activated scintillator itself. It was found that the dominant source of activation in the scintillators originates from the lighter elements in the materials: bromide and chloride, respectively. The activation of LaBr3:Ce manifest itself through gamma-decay, which partly leaves the volume. Activation of LaCl3:Ce originates mainly from beta decay, which is confined to the volume itself

  7. Nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor has a large prompt negative temperature coefficient of reactivity. A reactor core assembly of a plurality of fluid-tight fuel elements is located within a water-filled tank. Each fuel element contains a solid homogeneous mixture of 50-79 w/o zirconium hydride, 20-50 w/o uranium and 0.5-1.5 W erbium. The uranium is not more than 20 percent enriched, and the ratio of hydrogen atoms to zirconium atoms is between 1.5:1 and 7:1. The core has a long lifetime, E.G., at least about 1200 days

  8. Nuclear reactors

    International Nuclear Information System (INIS)

    In a liquid cooled nuclear reactor, the combination is described for a single-walled vessel containing liquid coolant in which the reactor core is submerged, and a containment structure, primarily of material for shielding against radioactivity, surrounding at least the liquid-containing part of the vessel with clearance therebetween and having that surface thereof which faces the vessel make compatible with the liquid, thereby providing a leak jacket for the vessel. The structure is preferably a metal-lined concrete vault, and cooling means are provided for protecting the concrete against reaching a temperature at which damage would occur. (U.S.)

  9. Fabrication of W–Cu/CeO2 composites with excellent electric conductivity and high strength prepared from copper-coated tungsten and Ceria powders

    International Nuclear Information System (INIS)

    W–Cu/CeO2 composites with excellent electric conductivity and high strength have been prepared from Cu-coated W and CeO2 composite powders. The phase and morphology of W–Cu/CeO2 composite powders and W–Cu/CeO2 composites are characterized by x-ray diffraction, field-emission scanning electron microscopy and energy-dispersive spectroscopy. The relative density, microhardness, electrical conductivity, and bending strength of the sintered samples are also examined. Results show that the addition of Cu-coated CeO2 composite powders significantly affect the microstructure and properties of W–Cu composite materials. The low content of CeO2 (0, 0.25 wt%, 0.5 wt%) have made an inconspicuous impression on bending strength and microhardness. While the composites still exhibit a best bending strength of 1102.7 MPa, which is higher than the national standard (W–Cu) of 39.28%. When the addition of CeO2 reached 0.25 wt%, the composites show the best electric conductivity of 69.41% IACS, which is higher than the national standard (W–Cu) of 65.26%. However, with further addition of CeO2 to 1 wt% and 2 wt%, the composites show numerous pores and aggregated particles, which is prone to damage the properties of the alloys

  10. Russian-American venture designs new reactor

    International Nuclear Information System (INIS)

    Russian and American nuclear energy experts have completed a joint design study of a small, low-cost and demonstrably accident-proof reactor that they say could revolutionize the way conventional reactors are designed, marketed and operated. The joint design is helium-cooled and graphite-moderated and has a power density of 3 MWt/cubic meter, which is significantly less than the standard American reactor. A prototype of this design should be operating in Chelyabinsk by June 1996

  11. Physics and kinetics of TRIGA reactor

    International Nuclear Information System (INIS)

    This training module is written as an introduction to reactor physics for reactor operators. It assumes the reader has a basic, fundamental knowledge of physics, materials and mathematics. The objective is to provide enough reactor theory knowledge to safely operate a typical research reactor. At this level, it does not necessarily provide enough information to evaluate the safety aspects of experiment or non-standard operation reviews. The material provides a survey of basic reactor physics and kinetics of TRIGA type reactors. Subjects such as the multiplication factor, reactivity, temperature coefficients, poisoning, delayed neutrons and criticality are discussed in such a manner that even someone not familiar with reactor physics and kinetics can easily follow. A minimum of equations are used and several tables and graphs illustrate the text. (author)

  12. Pneumatic transport systems for TRIGA reactors

    International Nuclear Information System (INIS)

    Main parameters and advantages of pneumatically operated systems, primarily those operated by gas pressure are discussed. The special irradiation ends for the TRIGA reactor are described. To give some idea of the complexity of some modern systems, the author presents the large system currently operating at the National Bureau of Standards in Washington. In this system, 13 stations are located throughout the radiochemistry laboratories and three irradiation ends are located in the reactor, which is a 14-megawatt unit. The system incorporates practically every fail-safe device possible, including ball valves located on all capsule lines entering the reactor area, designed to close automatically in the event of a reactor scram, and at that time capsules within the reactor would be diverted by means of switches located on the inside of the reactor wall. The whole system is under final control of a permission control panel located in the reactor control room. Many other safety accessories of the system are described

  13. CeO2 catalysed soot oxidation. The role of active oxygen to accelerate the oxidation conversion

    International Nuclear Information System (INIS)

    The influence of CeO2 in the acceleration of NOx-assisted soot oxidation has been studied in flow-reactor equipment by comparing two catalyst configurations, namely: (1) Pt upstream of soot and (2) Pt upstream of CeO2-soot. The role of CeO2 has been elucidated by means of DRIFT spectroscopy coupled with mass spectrometry and TAP reactor experiments. It was found that CeO2 has the potential to accelerate the oxidation rate of soot due to its active oxygen storage. The formation of active oxygen is initiated by NO2 in the gas phase. A synergetic effect is observed as a result of surface nitrate decomposition, which results in gas phase NO2 and desorption of active oxygen. Stored oxygen is postulated to exist in the form of surface peroxide or super oxide. Active oxygen is likely to play a role on the acceleration of soot oxidation and to contribute more than desorbed NO2 or NO2 from surface nitrate decomposition

  14. Applications of Research Reactors

    International Nuclear Information System (INIS)

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world.' One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property'. The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The purpose of the earlier publication, The Application of Research Reactors, IAEA-TECDOC-1234, was to present descriptions of the typical forms of research reactor use. The necessary criteria to enable an application to be performed were outlined for each one, and, in many cases, the minimum as well as the desirable requirements were given. This revision of the publication over a decade later maintains the original purpose and now specifically takes into account the changes in service requirements demanded by the relevant stakeholders. In particular, the significant improvements in

  15. cDNA library Table: ce-- [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available ce-- NA ce-- C202 x J201 compound eyes mixture of fifth instar larval stage to pupa...l stage mixed pBluescript SK- EcoR1 for 5' Xho1for 3' sequenced from T3 primer (5' -> 3') BP117205-BP118782 ce--[number] ...

  16. Nuclear reactor

    International Nuclear Information System (INIS)

    In an improved reactor core for a high conversion BWR reactor, Pu-breeding type BWR type reactor, Pu-breeding type BWR type rector, FEBR type reactor, etc., two types of fuel assemblies are loaded such that fuel assemblies using a channel box of a smaller irradiation deformation ratio are loaded in a high conversion region, while other fuel assemblies are loaded in a burner region. This enables to suppress the irradiation deformation within an allowable limit in the high conversion region where the fast neutron flux is high and the load weight from the inside of the channel box due to the pressure loss is large. At the same time, the irradiation deformation can be restricted within an allowable limit without deteriorating the neutron economy in the burner region in which fast neutron flux is low and the load weight from the inside of the channel box is small since a channel box with smaller neutron absorption cross section or reduced wall thickness is charged. As a result, it is possible to prevent structural deformations such as swelling of the channel box, bending of the entire assemblies, bending of fuel rods, etc. (K.M.)

  17. Neutronic models for the HIFAR reactor

    International Nuclear Information System (INIS)

    Standard neutronic models have been developed for the AAEC's materials testing reactor HIFAR, and are available as members of a partitioned data set. The models have been used to calculate reactor physics parameters related to operation and safety. Results from the calculations are presented

  18. Selecting reactor operator trainees

    International Nuclear Information System (INIS)

    Reactor operator trainee selection tends to be more effective if tailored to a utility's unique needs, and offers the organization a better chance for compliance with Federal regulations than if selection methods are adopted without benefit of local research. The costs of operator training range from $50,000 to $100,000. The test validity relative to a variety of training grades and performance measures is reviewed. Of interest is the degree to which tests differentiate reactor operators with respect to simulator training grades and performance in simulator operation; forms of evaluation which have become fairly standard throughout the power industry. The tests administered to each individual were selected because of their presumed relevance to training grades, and the aptitude measures are intended to assess an individual's potential to benefit from training. Tests, availability, form, the abilities they measure, and the time limit are described. (MCW)

  19. OILY WASTEWATER TREATMENT FOR CATALYTIC OXIDATION WITH K-MNO2/CeO2

    OpenAIRE

    JERÔNIMO, Carlos Enrique de Medeiros; FERNANDES, Hermano Gomes; SOUSA, João Fernandes

    2012-01-01

    The search for alternatives for the treatment of industrial effluents, especially high toxicity is one of the main difficulties of the industrial treatment systems. This work aims to use potassium as a promoter of electrons for the oxidation to the catalyst by impregnating it MnO2/CeO2 to degrade the effluent coming from the processing of cashew nuts in the presence of oxygen. The experiments were performed in a slurry bed reactor. In the experiments were kept constant initial concentratio...

  20. Effect of La,Ce,Tb Concentration on Luminescence Properties of (La,Ce,Tb)BO3%La,Ce,Tb含量对(La,Ce,Tb)BO3发光性能的影响

    Institute of Scientific and Technical Information of China (English)

    王林生; 黄可龙; 周智; 文小强; 周健; 赖华生

    2012-01-01

    采用高温固相法合成(La,Ce,Tb)BO3荧光粉,并对该荧光粉进行XRD和SEM分析.结果表明:(La,Ce,Tb)BO3的晶体结构和LaBO3相同,Ce3+,Tb3+的掺入没有改变晶体的结构,发光粉颗粒大小均匀,形貌规则,粒度在5 μm左右.研究了(La,Ce,Tb)BO3的光谱性质,在(La,Ce,Tb)BO3的发射和激发光谱中除了有Tb3+的特征发射和激发峰外,还有Ce3+的特征发射和激发峰.%The phosphors of (La,Ce,Tb)BO3 were synthesized by high temperature solid state reaction. X-ray diffractometry (XRD) patterns indicate that the crystal structures of (La,Ce,Tb)BO3 and LaBO3 are the same. The crystal structure has not been changed by Ce3+ and Tb3+ doping. Emission scanning electron microscopy (SEM) images show that the particle sizes of phosphors are more uniform, the morphology is more regular, and the granularity is about 5 μm. The content of TbBO3 phase in (La,Ce,Tb)BO3 increases with increasing of Tb content in (La,Ce,Tb)BO3. When Tb concentration reaches 15% and above, the content of TbBO3 phase in (La,Ce,Tb)BO3 increases more rapidly. The luminescence properties of (La,Ce,Tb)BO3 and the sensitization of Ce to Tb were studied. In the excitation spectrum of Ce there are three peaks at 244, 268 and 330 nm, respectively. And in the emission spectrum of Ce , there are two peaks at 365 and 380 nm, respectively. All of them have the large overlap. The Maximum emission wavelength of Tb3+ is 541 nm, and its excitation peaks is 230 nm. Both the Tb characteristic emission and excitation peaks and the Ce characteristic emission and excitation peaks were observed in the emission and excitation spectrum of (La,Ce,Tb)BO3. Comparing the excitation spectrum of (La,Ce)BO3 with the emission spectrum of (La,Tb)BO3, it is found that they have the large overlap. It is indicated that there is a remarkable energy transfer from Ce to Tb in (La,Ce,Tb)BO3. When the concentration of Ce or Tb in (La,Ce,Tb)BO3 is fixed, because of concentration self

  1. Sodium fast neutron reactors. Status and perspective of development

    International Nuclear Information System (INIS)

    This report reveals data on development history of domestic fast neutron reactors cooled with sodium (BN reactors). It also shows BN reactors' unique role in expanding source of nuclear power raw materials and in solving ecological problems relating to radioactive wastes. There is brief information on characteristics and operation experience of research reactors BR-10, BOR-60, pilot-industrial reactors BN-350 and BN-600. As well there is data on BN-800 reactor designing that obtained a license for building. There are considered BN reactor peculiarities in regard of safety and design decisions on safety provision at the level meeting standard document requirements. BN reactor technical and economic indices and the ways of their improvement are evaluated. There is brief information on alternative perspective technologies of fast reactors, in particular regarding 'BREST-300' reactor cooled with lead coolant

  2. The cerium ground state in the intermetallic compounds Al2Ce, Al3Ce at very low temperature

    International Nuclear Information System (INIS)

    Nuclear orientation experiments show the different behaviour between the Al2Ce and Al3Ce compounds. Despite the occurrence of a Kondo coupling, the first compound is well ordered down to 5 mK. No long range ordering seems to exist in Al3Ce but crystal field effects can partly mask the ordering. (author)

  3. Cerium intermetallics CeTX. Review III

    International Nuclear Information System (INIS)

    The structure-property relationships of CeTX intermetallics with structures other than the ZrNiAl and TiNiSi type are systematically reviewed. These CeTX phases form with electron-poor and electron-rich transition metals (T) and X = Mg, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, Sb, and Bi. The review focusses on the crystal chemistry, the chemical bonding peculiarities, and the magnetic and transport properties. Furthermore 119Sn Moessbauer spectroscopic data, high-pressure studies, hydrogenation reactions and the formation of solid solutions are reviewed. This paper is the third of a series of four reviews on equiatomic intermetallic cerium compound [Part I: R. Poettgen, B. Chevalier, Z. Naturforsch. 2015, 70b, 289; Part II: R. Poettgen, B. Chevalier, Z. Naturforsch. 2015, 70b, 695].

  4. Maanhonka hirsitalot CE-merkintä

    OpenAIRE

    Nieminen, Ville

    2012-01-01

    Tämän insinöörityön tarkoitus oli saada päivitettyä Maanhonka hirsitalojen ETA, joka oli mennyt vanhaksi marraskuussa 2010. ETA-hyväksynnän ja vaatimuksen-mukaisuustodistuksen myötä on tarkoitus hakea yritykselle CE-merkintäoikeus. CE-merkintä tulee pakolliseksi talotehtaille ja kaikille rakennustuotteille 1.7.2013 alkaen. Prosessi kestää yrityksestä riippuen vähintään puolesta vuodesta vuoteen. Riippuen siitä, mitä ETAan sisällytetään ja mitä testejä yrityksellä on jo ennestään tehtynä. VTT:...

  5. Cerium intermetallics CeTX. Review III

    Energy Technology Data Exchange (ETDEWEB)

    Poettgen, Rainer; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Chevalier, Bernard [Bordeaux Univ., Pessac (France). Inst. de Chimie de la Matiere Condensee de Bordeaux

    2016-05-01

    The structure-property relationships of CeTX intermetallics with structures other than the ZrNiAl and TiNiSi type are systematically reviewed. These CeTX phases form with electron-poor and electron-rich transition metals (T) and X = Mg, Zn, Cd, Hg, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, Sb, and Bi. The review focusses on the crystal chemistry, the chemical bonding peculiarities, and the magnetic and transport properties. Furthermore {sup 119}Sn Moessbauer spectroscopic data, high-pressure studies, hydrogenation reactions and the formation of solid solutions are reviewed. This paper is the third of a series of four reviews on equiatomic intermetallic cerium compound [Part I: R. Poettgen, B. Chevalier, Z. Naturforsch. 2015, 70b, 289; Part II: R. Poettgen, B. Chevalier, Z. Naturforsch. 2015, 70b, 695].

  6. Efficiency Calibration of LaBr3(Ce) γ Spectroscopy in Analyzing Radionucles in Reactor Loop Water

    Institute of Scientific and Technical Information of China (English)

    CHEN; Xi-lin; QIN; Guo-xiu; GUO; Xiao-qing; CHEN; Yong-yong; MENG; Jun

    2013-01-01

    Monitoring the occurring and radioactivity concentration of fission products in nuclear reactor loop water is important for the nuclear reactor safe running evaluation,prevention of accidence and safe protection of working personnel.Study on the efficiency calibration for a LaBr3(Ce)detector experimental

  7. Low flow electrospray interfacing CE/MS

    Czech Academy of Sciences Publication Activity Database

    Foret, František; Týčová, Anna; Křenková, Jana; Klepárník, Karel

    2015. L-10. ISBN N. [International Symposium on Electro- and Liquid Phase-Separation Techniques (ITP2015) /22./ and the Nordic Separation Science (NoSSS) symposium /8./. 30.08.2015-03.09.2015, Helsinki] R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : electrospray * CE/MS * GAP20612G014 Subject RIV: CB - Analytical Chemistry, Separation

  8. Thermoemission of Ce+ ions and its fluctuations

    Science.gov (United States)

    Gladyszewski, Longin

    1994-12-01

    The surface ionization of cerium on tungsten and its fluctuatins (noises) have been studied using a single filament ion source in a 90° magnetic mass spectrometer. The statistical behaviour of the spectral density and autocorrelation functions for Ce+ ion thermoemission noise were investigated by means of a special stochastic analyser. These noises are generated as a result of adsorbate density fluctuations. The method used made it possible to determine the atom desorption and migration energy for cerium from tungsten.

  9. Radiometric analysis of the spent fuel pool water and reactor coolant of ET-RR.1

    International Nuclear Information System (INIS)

    This work aims at analysis of radioactivity levels in the water of spent fuel pool and reactor core of the Egyptian 2MW research reactor (ET-RR.1 at Inshas). Gamma spectrometric and laser fluorimetric analysis have been used for carrying out this study. The fission product 137Cs and activation product 60Co are found with very high concentration in the spent fuel storage pool water. Thirteen isotopes; La-140, Cr-51, Ba-140, I-131, Cs-137, Ce-144, Nb-95, Ce-141, Zr-95, Ru-103, Cs-134, Nd-147 and Zn-65 are identified in the reactor core water. However no radiological hazard resulted because the fission products are contained within the shielded reactor pool. The radioactivity released into the reactor coolant water is mainly controlled by the diffusion mechanism. (orig.)

  10. Convenient synthesis of CeO2 nanotubes

    International Nuclear Information System (INIS)

    A simple and facile route was used in the fabrication of CeO2 nanotubes within anodic alumina membrane. A piece of membrane was first immersed into Ce(NO3)3 aqueous solution under ambient conditions. After dried at 50 deg. C and thermally calcined at 150 deg. C and 550 deg. C, CeO2 nanotubes can be easily synthesized. The characterization with electron microscopy and X-ray diffraction indicated that CeO2 nanotubes were composed of tiny well-crystalline CeO2 nanoparticles

  11. YAP (Ce) as focal plane detectors

    International Nuclear Information System (INIS)

    YAP (Ce) has been known to be one of the commercially available new scintillators that can be used for several applications. It has a good timing response and a very high value for the radiation hardness, compared to other known inorganic scintillators. Several studies have been reported on the properties of the scintillator, viz., light yield, decay time constant, gamma and charged particle response, pulse shape discrimination and timing characteristics. The YAP(Ce) crystals has a very good response to the energetic heavy ions and attempts have been made to employ it as a viable alternative to the Si detectors for the detection of heavy ions. As a part of the experimental facilities, being developed for the upcoming Superconducting cyclotron at VECC, the possibility is being explored for using the YAP(Ce) as an E detector, preceded by a position sensitive MWPCs as αE counterpart, at the focal plane of the proposed superconducting solenoid spectrometer. The selection of Photo Multiplier Tubes (PMT) has been very crucial in such cases in order to have good timing response and energy resolution for energetic heavy ions. The responses have been tested for different bias voltages of the tube and the best values have been reported here

  12. Nuclear reactor fissile isotopes antineutrino spectra

    OpenAIRE

    Sinev, V.

    2012-01-01

    Positron spectrum from inverse beta decay reaction on proton was measured in 1988-1990 as a result of neutrino exploration experiment. The measured spectrum has the largest statistics and lowest energy threshold between other neutrino experiments made that time at nuclear reactors. On base of the positron spectrum the standard antineutrino spectrum for typical reactor fuel composition was restored. In presented analysis the partial spectra forming this standard spectrum were extracted using s...

  13. Ce(III)/Ce(IV) in methanesulfonic acid as the positive half cell of a redox flow battery

    International Nuclear Information System (INIS)

    The characteristics of the Ce(III)/Ce(IV) redox couple in methanesulfonic acid were studied at a platinum disk electrode (0.125 cm2) over a wide range of electrolyte compositions and temperatures: cerium (III) methanesulfonate (0.1-1.2 mol dm-3), methanesulfonic acid (0.1-5.0 mol dm-3) and electrolyte temperatures (295-333 K). The cyclic voltammetry experiments indicated that the diffusion coefficient of Ce(III) ions was 0.5 x 10-6 cm2 s-1 and that the electrochemical kinetics for the oxidation of Ce(III) and the reduction of Ce(IV) was slow. The reversibility of the redox reaction depended on the electrolyte composition and improved at higher electrolyte temperatures. At higher methanesulfonic acid concentrations, the degree of oxygen evolution decreased by up to 50% when the acid concentration increased from 2 to 5 mol dm-3. The oxidation of Ce(III) and reduction of Ce(IV) were also investigated during a constant current batch electrolysis in a parallel plate zinc-cerium flow cell with a 3-dimensional platinised titanium mesh electrode. The current efficiencies over 4.5 h of the process Ce(III) to Ce(IV) and 3.3 h electrolysis of the reverse reaction Ce(IV) to Ce(III) were 94.0 and 97.6%, respectively. With a 2-dimensional, planar platinised titanium electrode (9 cm2 area), the redox reaction of the Ce(III)/Ce(IV) system was under mass-transport control, while the reaction on the 3-dimensional mesh electrode was initially under charge-transfer control but became mass-transport controlled after 2.5-3 h of electrolysis. The effect of the side reactions (hydrogen and oxygen evolution) on the current efficiencies and the conversion of Ce(III) and Ce(IV) are discussed.

  14. Moessbauer studies of nano phase Ce-Fe oxide composites

    International Nuclear Information System (INIS)

    Chemical co-precipitation method was used to synthesize nano-structured α-Fe2O3-CeO2 composite by calcination of the goethite-cerium hydroxide precursor. It was observed that the precursor contained goethite matrix doped with cerium. Calcination of the precursor at 400oC showed the formation of nanosize hematite. Moessbauer spectra show the presence of a paramagnetic component in the precursor but not in the samples calcined at 400oC to 800oC temperatures. Our study shows that Ce precipitated as CeO2 and stuck on the surface of hematite particles. The precipitation of Ce as CeO2 is independent of the concentration of Ce in the Ce-Fe-O composite.

  15. High Temperature Gas-Cooled Test Reactor Options Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bayless, Paul David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    Preliminary scoping calculations are being performed for a 100 MWt gas-cooled test reactor. The initial design uses standard prismatic blocks and 15.5% enriched UCO fuel. Reactor physics and thermal-hydraulics simulations have been performed to identify some reactor design features to investigate further. Current status of the effort is described.

  16. Reactor container

    International Nuclear Information System (INIS)

    A reactor container has a suppression chamber partitioned by concrete side walls, a reactor pedestal and a diaphragm floor. A plurality of partitioning walls are disposed in circumferential direction each at an interval inside the suppression chamber, so that independent chambers in a state being divided into plurality are formed inside the suppression chamber. The partition walls are formed from the bottom portion of the suppression chamber up to the diaphragm floor to isolate pool water in a divided state. Operation platforms are formed above the suppression chamber and connected to an access port. Upon conducting maintenance, inspection or repairing, a pump is disposed in the independent chamber to transfer pool water therein to one or a plurality of other independent chambers to make it vacant. (I.N.)

  17. Reactor building

    International Nuclear Information System (INIS)

    The present invention concerns a structure of ABWR-type reactor buildings, which can increase the capacity of a spent fuel storage area at a low cost and improved earthquake proofness. In the reactor building, the floor of a spent fuel pool is made flat, and a depth of the pool water satisfying requirement for shielding is ensured. In addition, a depth of pool water is also maintained for a equipment provisionally storing pool for storing spent fuels, and a capacity for a spent fuel storage area is increased by utilizing surplus space of the equipment provisionally storing pool. Since the flattened floor of the spent fuel pool is flushed with the floor of the equipment provisionally storing pool, transfer of horizontal loads applied to the building upon occurrence of earthquakes is made smooth, to improve earthquake proofness of the building. (T.M.)

  18. Nuclear reactors

    International Nuclear Information System (INIS)

    Disclosed is a nuclear reactor cooled by a freezable liquid has a vessel for containing said liquid and comprising a structure shaped as a container, and cooling means in the region of the surface of said structure for effecting freezing of said liquid coolant at and for a finite distance from said surface for providing a layer of frozen coolant on and supported by said surface for containing said liquid coolant. In a specific example, where the reactor is sodium-cooled, the said structure is a metal-lined concrete vault, cooling is effected by closed cooling loops containing NaK, the loops extending over the lined surface of the concrete vault with outward and reverse pipe runs of each loop separated by thermal insulation, and air is flowed through cooling pipes embedded in the concrete behind the metal lining. 7 claims, 3 figures

  19. Radon test measurements with Ce-doped yttrium aluminum oxide perovskite scintillator

    Directory of Open Access Journals (Sweden)

    F. de Notaristefani

    2002-04-01

    Full Text Available Scintillation properties of a Ce-doped yttrium aluminium oxide perovskite monocrystal optically coupled to a Hamamatsu H5784 photomultiplier are analyzed with a standard bialkali photocathode for radon and radon daughters gamma-ray spectrometry. Tests in water up to 100°C and in acidic solutions of HCl (37%, H2SO4 (48% and HNO3 (65% were performed to simulate environments of geophysical interest, such as geothermal and volcanic areas. Comparative measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA confirm the non-hygroscopic properties of the scintillator and small dependence of the light yield on temperature and HNO3.The Ce-doped yttrium aluminum oxide perovskite monocrystal shows high response stability for radon gamma-ray spectrometry in environments with large temperature gradients and high acid concentrations.

  20. NEUTRONIC REACTORS

    Science.gov (United States)

    Anderson, J.B.

    1960-01-01

    A reactor is described which comprises a tank, a plurality of coaxial steel sleeves in the tank, a mass of water in the tank, and wire grids in abutting relationship within a plurality of elongated parallel channels within the steel sleeves, the wire being provided with a plurality of bends in the same plane forming adjacent parallel sections between bends, and the sections of adjacent grids being normally disposed relative to each other.

  1. Nuclear reactor

    International Nuclear Information System (INIS)

    The liquid metal (sodium) cooled fast breeder reactor has got fuel subassemblies which are bundled and enclosed by a common can. In order to reduce bending of the sides of the can because of the load caused by the coolant pressure the can has got a dodecagon-shaped crosssection. The surfaces of the can may be of equal width. One out of two surfaces may also be convex towards the center. (RW)

  2. Nuclear reactor

    International Nuclear Information System (INIS)

    A detector having high sensitivity to fast neutrons and having low sensitivity to thermal neutrons is disposed for reducing influences of neutron detector signals on detection values of neutron fluxes when the upper end of control rod pass in the vicinity of the neutron flux detector. Namely, the change of the neutron fluxes is greater in the thermal neutron energy region while it is smaller in the fast neutron energy region. This is because the neutron absorbing cross section of B-10 used as neutron absorbers of control rods is greater in the thermal neutron region and it is smaller in the fast neutron region. As a result, increase of the neutron detection signals along with the local neutron flux change can be reduced, and detection signals corresponding to the reactor power can be obtained. Even when gang withdrawal of operating a plurality of control rods at the same time is performed, the reactor operation cycle can be measured accurately, thereby enabling to shorten the reactor startup time. (N.H.)

  3. The System 80+ standard plant design reduces operations and maintenance costs

    International Nuclear Information System (INIS)

    To be cost-competitive, nuclear power plants must maximize plant availability and minimize operations and maintenance (O and M) costs. A plant whose design supports these goals will generate more power at less cost and thereby have a lower unit generating cost. The ABB Combustion Engineering Nuclear Systems (ABB-CE) System 80+ Standard Nuclear Power Plant, rated at 1400 megawatts electric (MWe), is designed for high availability at reduced cost. To demonstrate that the duration of refueling outages, the major contributor to plant unavailability, can be shortened, ABB-CE developed a detailed plan that shows a System 80+ plant can safely perform a refueling and maintenance outage in 18 days. This is a significant reduction from the average current U.S. plant outages of 45 days, and is possible due to a two-part outage strategy: use System 80+ advanced system design features and relaxed technical specification (TS) time limits to shift some maintenance from outages to operating periods: and, use System 80+ structural, system, and component features, such as the larger operating floor, permanent pool seal, integral reactor head area cable tray system and missile shield, and longer life reactor coolant pump seals, to reduce the scope and duration of outage maintenance activities. Plant staffing level is the major variable, or controllable contributor to operations costs. ABB-CE worked with the Institute of Nuclear Power Operations (INPO) to perform detailed staffing analyses that show a System 80+ plant can be operated reliably with 30 percent less staff than currently operating nuclear plants of similar size. Safety was not sacrificed when ABB-CE developed the System 80+ refueling outage plan and staffing level. The outage plan was developed utilizing a defense-in-depth concept for shutdown safety. The defense in-depth concept is implemented via systematic control of outage risk evaluation (SCORE) cards. The SCORE cards identify primary and alternate means of

  4. Effect of oxygen vacancy on half metallicity in Ni-doped CeO{sub 2} diluted magnetic semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Hardev S., E-mail: hardevdft@gmail.com; Saini, G. S. S. [Department of Physics, Panjab University, Chandigarh-160014 INDIA (India); Singh, Mukhtiyar [Department of Physics, Dayanand National P.G. College, Hisar-125001 (Haryana) INDIA (India); Kashyap, Manish K. [Department of Physics, Kurukshetra University, Kurukshetra-136119 (Haryana) INDIA (India)

    2015-05-15

    The electronic and magnetic properties of Ni-doped CeO{sub 2} diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (V{sub o}) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO{sub 2} compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without V{sub O} and realized that the ferromagnetism in CeO{sub 2} remarkably depends on the V{sub o} concentrations. The presence of V{sub o}, in Ni-doped CeO{sub 2}, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in V{sub o}. The HMF characteristics of Ni-doped CeO{sub 2} including V{sub o} makes it an ideal material for spintronic devices.

  5. A comparison between Ce(III) and Ce(IV) ions in photocatalytic degradation of organic pollutants

    Institute of Scientific and Technical Information of China (English)

    程强; 施薇; 段炼; 孙彬哲; 李晓霞; 徐爱华

    2015-01-01

    Nano cerium oxides are efficient photocatalysts for pollutants degradation with highly dispersed Ce(III) ions as the sug-gested active species to promote the reaction, while Ce(IV) species do not behave as a catalyst. In this paper, to understand the mechanism of Ce-based photocatalysts, we studied the comparison of simple cerium ions, Ce(III) and Ce(IV) in aqueous solution for organic pollutants degradation under UV irradiation. Orange II (AOII), methyl orange, andp-nitrophenol were selected as the target pollutants. The formation and contribution of reactive oxygen species, the kinetics of Ce(IV) photoreduction and Ce(III) photooxida-tion, and the influence of solution pH were investigated in detail. It was found that at low pH Ce(IV) ions showed a higher activity for hydroxyl radicals production and AOII degradation than Ce(III) ions, which could be attributed to its fast reduction rate to Ce(III). However, its activity dramatically decreased when solution pH increased, and was also strongly influenced by the type of pollutants; while Ce(III) exhibited high degradation efficiency of all the tested pollutants over a wide pH range.

  6. Standard interface file handbook

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, A.; Huria, H.C. [Cincinnati Univ., OH (United States)

    1992-10-01

    This handbook documents many of the standard interface file formats that have been adopted by the US Department of Energy to facilitate communications between and portability of, various large reactor physics and radiation transport software packages. The emphasis is on those files needed for use of the VENTURE/PC diffusion-depletion code system. File structures, contents and some practical advice on use of the various files are provided.

  7. Standard interface file handbook

    International Nuclear Information System (INIS)

    This handbook documents many of the standard interface file formats that have been adopted by the US Department of Energy to facilitate communications between and portability of, various large reactor physics and radiation transport software packages. The emphasis is on those files needed for use of the VENTURE/PC diffusion-depletion code system. File structures, contents and some practical advice on use of the various files are provided

  8. Grèce antique et Grèce moderne

    OpenAIRE

    Baud-Bovy, Samuel

    2015-01-01

    Alors que les savants grecs du siècle dernier, que ce soit pour faire plaisir aux philhellènes ou pour combattre la théorie de Fallermayer sur la slavisation de la Grèce au Moyen Age, mettaient tout en œuvre pour prouver que les Grecs modernes étaient les descendants directs des Grecs anciens, les générations suivantes se lassèrent de ce culte exclusif voué aux ancêtres. Il arrivait même à Palamas, le poète national du XXe siècle naissant, de s’insurger contre cette mentalité : Les tombes, mê...

  9. Equilibrium and kinetic modeling of adsorptive sulfur removal from gasoline by synthesized Ce-Y zeolite

    International Nuclear Information System (INIS)

    In this research, the adsorption of a model sulfur compound, thiophene, from a simulated gasoline onto Ce-Y zeolite in pellet and powder forms was investigated. For this purpose, zeolite Na-Y was synthesized, and Ce-Y zeolite was prepared via solid-state ion-exchanged (SSIE) method. Adsorptive desulfurization of model gasoline was conducted in a batch reactor at ambient conditions to evaluate the equilibrium and kinetics of thiophene adsorption onto Ce-Y zeolite. The equilibrium data were fitted to Langmuire and Toth models. Pseudo-n-order and modified n-order models, LDF-base model, and intra-particle diffusion model were evaluated to fit the kinetic of the adsorption process and to determine the mechanism of it. The corresponding parameters and/or correlation coefficients of each model were reported. The LDF-base model was used also to fit the mass transfer coefficient for both powder and pellet forms of the adsorbent. The best fit estimates for the mass transfer coefficient were obtained 4 x 10-11 m/s and k = 3.1 x 10-12[exp( - t/τ) + 1/(t + 10-4)], for powder and pellet form adsorbents, respectively.

  10. Effects of Cr on the interdiffusion between Ce and Fe-Cr alloys

    Science.gov (United States)

    Lo, Wei-Yang; Silva, Nicolas; Wu, Yuedong; Winmann-Smith, Robert; Yang, Yong

    2015-03-01

    Fuel cladding chemical interaction (FCCI) has been a long-standing issue for the metallic fuel with a steel cladding in a sodium-cooled fast reactor, particularly for a high burnup fuel. Although the FCCI has been largely improved by alloying the fuels with Zr or Pd elements, applying a physical diffusion barrier between fuel and cladding, and employing advanced ferritic/martensitic (F/M) claddings, there is a scientific knowledge gap in understanding the behavior of chromium and its effects on the interdiffusion between lanthanides and advanced F/M steels that contain 9-12 wt.% Cr. In this paper, we systematically studied the interdiffusion between cerium and Fe-Cr model alloys with Cr contents of 6, 9 and 12 wt.%. Following the thermal annealing at 560 °C for up to 100 h, detailed microstructural characterizations were performed to determine the interdiffusion microstructures, compositional distributions, diffusion kinetics, and phase structures in the interdiffusion zone. This study unambiguously disclosed that, as the Ce diffuses into Fe-Cr model alloys, Cr segregates and precipitates into Cr-rich σ phase consisted of Fe and Cr instead of forming a ternary phase together with Fe and Ce. The precipitation of those nano-sized σ phase particles at the Ce diffusion front would effectively slow down the interdiffusion.

  11. Equilibrium and kinetic modeling of adsorptive sulfur removal from gasoline by synthesized Ce-Y zeolite

    Science.gov (United States)

    Montazerolghaem, Maryam; Rahimi, Amir; Seyedeyn-Azad, Fakhry

    2010-11-01

    In this research, the adsorption of a model sulfur compound, thiophene, from a simulated gasoline onto Ce-Y zeolite in pellet and powder forms was investigated. For this purpose, zeolite Na-Y was synthesized, and Ce-Y zeolite was prepared via solid-state ion-exchanged (SSIE) method. Adsorptive desulfurization of model gasoline was conducted in a batch reactor at ambient conditions to evaluate the equilibrium and kinetics of thiophene adsorption onto Ce-Y zeolite. The equilibrium data were fitted to Langmuire and Toth models. Pseudo-n-order and modified n-order models, LDF-base model, and intra-particle diffusion model were evaluated to fit the kinetic of the adsorption process and to determine the mechanism of it. The corresponding parameters and/or correlation coefficients of each model were reported. The LDF-base model was used also to fit the mass transfer coefficient for both powder and pellet forms of the adsorbent. The best fit estimates for the mass transfer coefficient were obtained 4 × 10-11 m/s and k = 3.1 × 10-12[exp( - t/τ) + 1/(t + 10-4)], for powder and pellet form adsorbents, respectively.

  12. Sorption of Cd(II) on CeO2 Resin and Its Solvent-Elution Pattern

    International Nuclear Information System (INIS)

    Capability of CeO2 resin as chemical separator component and its immobilization potential to cadmium can be exploited for utilization of the resin in the separation of Cd-In matrices. The separation of Cd-In matrices is important for improving and mastering production technology of 111/115m In using high-enriched 112/114 Cd targets. The phenomena on the sorption of Cd(11) on CeO2 resin and its solvent elution pattern were studied using CeO2 synthesized from reaction between Ce(SO4)2 and NH4OH. A series of Cd(11) standard solution was treated with the activated resin in the both static and dynamic systems. The Cd(11) content of the solution after the treatment was the determined by UV-spectrophotometry for measuring Cd (11)-sorption capacity. The solvent elution pattern was observed by fractional elution from CeO2 column followed by UV-spectrophotometric determination to the fractions giving positive test for Cd(11). It was found that the treatment of the resin with 10% NH4OH solution increases the Cd(11)-sorption capacity of the resin compared to the treatment with water or 1M HCI solution. A sharp elution patter with quantitative yield of Cd(11) recovery (more than 94%) was found by elution using 5, 10 or 20% NH4OH solution. Key words : CeO2 resin, hydrous cerium oxide, radioisotope 111/115m In, separation of Cd-In matrices, sorption of Cd(11) on CeO2 resin , elution profile of Cd(11) on CeO2 resin, Cd(11) measurement by means of UV spectrophotometry

  13. Simplified numerical simulation of hot channel in sodium cooled reactor

    International Nuclear Information System (INIS)

    The thermal-hydraulic parameter values that restrict the operation of a liquid sodium cooled reactor are not established by the average conditions of the coolant in the reactor core but by the extreme conditions of the hot channel. The present work was developed to analysis of hot channel of a sodium cooled reactor, adapting to this reactor an existent simplified model for hot channel of pressurized water reactor. The model was applied for a standard sodium reactor and the results are considered satisfatory. (author)

  14. Reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    In a BWR type nuclear reactor, the number of first fuel assemblies (uranium) loaded in a reactor core is smaller than that of second fuel assemblies (mixed oxide), the average burnup degree upon take-out of the first fuel assemblies is reduced to less than that of the second fuel assemblies, and the number of the kinds of the fuel rods constituting the first fuel assemblies is made smaller than that of the fuel rods constituting the second fuel assemblies. As a result, the variety of the plutonium enrichment degree is reduced to make the distribution of the axial enrichment degree uniform, thereby enabling to simplify the distribution of the enrichment degree. Then the number of molding fabrication steps for MOX fuel assemblies can be reduced, thereby enabling to reduce the cost for molding and fabrication. (N.H.)

  15. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining licensees and applicants for reactor operator and senior reactor operator licenses at power reactor facilities pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). The Examiner Standards are intended to assist NRC examiners and facility licensees to better understand the initial and requalification examination processes and to ensure the equitable and consistent administration of examinations to all applicants. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator licensing policy changes. Revision 7 was published in January 1993 and became effective in August 1993. Supplement 1 is being issued primarily to implement administrative changes to the requalification examination program resulting from the amendment to 10 CFR 55 that eliminated the requirement for every licensed operator to pass an NRC-conducted requalification examination as a condition for license renewal. The supplement does not substantially alter either the initial or requalification examination processes and will become effective 30 days after its publication is noticed in the Federal Register. The corporate notification letters issued after the effective date will provide facility licensees with at least 90 days notice that the examinations will be administered in accordance with the revised procedures

  16. Role of the Ce valence in the coexistence of superconductivity and ferromagnetism of CeO$_{1-x}$F$_{x}$BiS$_{2}$ revealed by Ce $L_3$-edge x-ray absorption spectroscopy

    OpenAIRE

    Sugimoto, Takuya; Joseph, Boby; Paris, Eugenio; Iadecola, Antenolla; Mizokawa, Takashi; Demura, Satoshi; Mizuguchi, Yoshikazu; Takano, Yoshihiko; Saini, Naurang L.

    2014-01-01

    We have performed Ce $L_3$-edge x-ray absorption spectroscopy (XAS) measurements on CeO$_{1-x}$F$_x$BiS$_2$, in which the superconductivity of the BiS$_2$ layer and the ferromagnetism of the CeO$_{1-x}$F$_x$ layer are induced by the F-doping, in order to investigate the impact of the F-doping on the local electronic and lattice structures. The Ce $L_3$-edge XAS spectrum of CeOBiS$_2$ exhibits coexistence of $4f^1$ (Ce$^{3+}$) and $4f^0$ (Ce$^{4+}$) state transitions revealing Ce mixed valency...

  17. Study of Ce-modified antibacterial 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Yuan Junping

    2012-11-01

    Full Text Available 316L stainless steel is widely used for fashion jewelry, but it can carry a large number of bacteria and bring the risk of infection since the steel has no antimicrobial performance. In this paper, the effects of Ce on the antibacterial property, corrosion resistance and processability of 316L were studied by microscopic observation, thin-film adhering quantitative bacteriostasis, and electrochemical and mechanical tests. The results show that a trace of Ce can distribute uniformly in the matrix of 316L and slightly improve its corrosion resistance in artificial sweat. With an increase in Ce content, the Ce is prone to form clustering, which degrades the corrosion resistance and the processability. The Ce-containing 316L exhibits Hormesis effect against S. aureus. A small Ce addition stimulates the growth of S. aureus. As the Ce content increases, the modified 316L exhibits an improved antibacterial efficacy. The more Ce is added, the better antibacterial capability is achieved. Overall, if the 316L is modified with Ce alone, it is difficult to obtain the optimal combination of corrosion resistance, antibacterial performance and processability. In spite of that, 0.15 wt.%-0.20 wt.% Ce around is inferred to be the best trade-off.

  18. Low temperature magnetic behavior of Ce7Ni3

    International Nuclear Information System (INIS)

    Low-temperature specific heat (CP) (70 mK7Ni3 (under applied magnetic fields up to B=6 T) are presented. The maxima in CP (at 1.55 K) and in χ (at 1.85 K) are related to an antiferromagnetic (AF) type transition. The experimental results are interpreted in terms of three Ce sublattices (1CeI, 3CeII and 3CeIII atoms per formula unit) of the Th7Ni3-type structure. These sublattices correspond to the three different Ce local environments. According to the entropy gain the AF order is related to the CeI sublattice and the CeII atoms behave as heavy fermions, with γLT∼2.7 J/CeII-at.K2 and a characteristic temperature of TK∼4 K. The CeIII atoms are responsible for an intermediate valence behavior with γHT∼0.3 J/CeIII-at.K2 and a characteristic temperature of T0∼70 K, which is confirmed by the ln T dependence of the electrical resistivity. ((orig.))

  19. A review of the Italian fast reactor programme

    International Nuclear Information System (INIS)

    In the frame of Italian nuclear program, this report deals with the current activities related to PEC reactor delay in construction and start-up, activities within the joint venture between Novatome, France and NIRA, Italy related to components for Super Phenix reactor, participation of NIRA in the Super Phenix studies covering technology of reactor components, reactor core, fuel, safety, fuel cycle technical and economical aspects, codes and standards

  20. Types of Nuclear Reactors

    International Nuclear Information System (INIS)

    The presentation is based on the following areas: Types of Nuclear Reactors, coolant, moderator, neutron spectrum, fuel type, pressurized water reactor (PWR), boiling water reactor (BWR) reactor pressurized heavy water (PHWR), gas-cooled reactor, RBMK , Nuclear Electricity Generation,Challenges in Nuclear Technology Deployment,EPR, APR1400, A P 1000, A PWR, ATMEA 1, VVER-1000, A PWR, VVER 1200, Boiling Water Reactor, A BWR, A BWR -II, ESBUR, Ke ren, AREVA, Heavy Water Reactor, Candu 6, Acr-1000, HWR, Bw, Iris, CAREM NuCcale, Smart, KLT-HOS, Westinghouse small modular Reactor, Gas Cooled Reactors, PBMR.

  1. Nuclear reactor

    International Nuclear Information System (INIS)

    A nuclear reactor is described in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assemblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters in the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters in the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance

  2. Safety analysis for non-power reactors

    International Nuclear Information System (INIS)

    Non-power reactors have been operating in Canada since 1945, with NRU (National Research Universal, 1957) being the oldest operating non-power reactor. Presently, there are five generic 'types' of non-power reactors: NRU, ZED-2, SLOWPOKE, MNR and MAPLE, the latter undergoing commissioning as the MDS Medical Isotope Reactor. These reactors range in thermal power from 200 Watts to more than 100 MW. Other non-power reactors are likely to be built for new applications and to replace older reactors. The uniqueness of each reactor, the wide range of power levels and the evolution of safety philosophy over time have lead to non-uniform practices for safety analysis. This non-uniformity may be a problem for the preparation by the licensee and review by the regulator of the safety analysis report required for licensing of the reactor facility. Clearly, there is no universally applicable practice, while at the same time, expectations for safety analyses have evolved in order to demonstrate higher levels of overall safety. This paper examines a new 'graded approach' to preparing the safety analysis report for reactors of diverse features but with a common standard of safety. It discusses necessary content, methods and the training and qualification of the safety analyst. (author)

  3. Nuclear research reactors

    International Nuclear Information System (INIS)

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.)

  4. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  5. System 80+trademark standard design incorporates radiation protection lessons learned

    International Nuclear Information System (INIS)

    Many lessons have been learned from the current generation of nuclear plants in the area of radiation protection. The following paper will outline how the lessons learned have been incorporated into the design and operational philosophy of the System 80+trademark Standard Design currently under development by ABB Combustion Engineering (ABB-CE) with support from Duke Engineering and Services, Inc. and Stone and Webster Engineering Corporation in the Balance-of-Plant design. The System 80+trademark Standard Design is a complete nuclear power plant for national and international markets, designed in direct response to utility needs for the 1990's, and scheduled for Nuclear Regulatory Commission (NRC) Design Certification under the new standardization rule (10 CFR Part 52). System 80+trademark is a natural extension of System 80R technology, an evolutionary change based on proven Nuclear Steam Supply System (NSSS) in operation at Palo Verde in Arizona and under construction at Yonggwang in the Republic of Korea. The System 80+trademark Containment and much of the Balance of Plant design is based upon Duke Power Company's Cherokee Plant, which was partially constructed in the late 1970's, but, was later canceled (due to rapid declined in electrical load growth). The System 80+trademark Standard Design meets the requirements given in the Electric Power Research Institute (EPRI) Advanced Light Water Reactor (ALWR) Requirements Document. One of these requirements is to limit the occupational exposure to 100 person-rem/yr. This paper illustrates how this goal can be achieved through the incorporation of lessons learned, innovative design, and the implementation of a common sense approach to operation and maintenances practices

  6. Electrical resistivity of CeFe2

    International Nuclear Information System (INIS)

    Electrical and magneitc properties of CeFe2 were investigated from the temperature dependence of electrical resistivity in the range of 1,5 to 3000K. The critical temperature, determined from the maximum of dp/dT, gives T sub(c) = 2200K and the temperature independent magnetic resistivity is 87μωcm. This value is compared with the corresponding in YFe2. At low temperature the resistivity shows a fairly large variation proportional to AT2 up to about 320K with A = 1,2x10-2 μωcm/0K2. (Author)

  7. Internal bremsstrahlung spectrum of 139Ce

    International Nuclear Information System (INIS)

    The internal bremsstrahlung spectrum which accompanies the electron capture decay of 139Ce to the first excited state of 139La has been measured in coincidence with the nuclear gamma ray which deexcites that state. The measured intensity above 42 keV is found to be (1.070±0.024) times that predicted by the recent calculations of Suriacute c et al. The QEC value is found to be 264.6±2.0 keV. copyright 1996 The American Physical Society

  8. Crystal structure and solution species of Ce(III) and Ce(IV) formates: from mononuclear to hexanuclear complexes.

    Science.gov (United States)

    Hennig, Christoph; Ikeda-Ohno, Atsushi; Kraus, Werner; Weiss, Stephan; Pattison, Philip; Emerich, Hermann; Abdala, Paula M; Scheinost, Andreas C

    2013-10-21

    Cerium(III) and cerium(IV) both form formate complexes. However, their species in aqueous solution and the solid-state structures are surprisingly different. The species in aqueous solutions were investigated with Ce K-edge EXAFS spectroscopy. Ce(III) formate shows only mononuclear complexes, which is in agreement with the predicted mononuclear species of Ce(HCOO)(2+) and Ce(HCOO)2(+). In contrast, Ce(IV) formate forms in aqueous solution a stable hexanuclear complex of [Ce6(μ3-O)4(μ3-OH)4(HCOO)x(NO3)y](12-x-y). The structural differences reflect the different influence of hydrolysis, which is weak for Ce(III) and strong for Ce(IV). Hydrolysis of Ce(IV) ions causes initial polymerization while complexation through HCOO(-) results in 12 chelate rings stabilizing the hexanuclear Ce(IV) complex. Crystals were grown from the above-mentioned solutions. Two crystal structures of Ce(IV) formate were determined. Both form a hexanuclear complex with a [Ce6(μ3-O)4(μ3-OH)4](12+) core in aqueous HNO3/HCOOH solution. The pH titration with NaOH resulted in a structure with the composition [Ce6(μ3-O)4(μ3-OH)4(HCOO)10(NO3)2(H2O)3]·(H2O)9.5, while the pH adjustment with NH3 resulted in [Ce6(μ3-O)4(μ3-OH)4(HCOO)10(NO3)4]·(NO3)3(NH4)5(H2O)5. Furthermore, the crystal structure of Ce(III) formate, Ce(HCOO)3, was determined. The coordination polyhedron is a tricapped trigonal prism which is formed exclusively by nine HCOO(-) ligands. The hexanuclear Ce(IV) formate species from aqueous solution is widely preserved in the crystal structure, whereas the mononuclear solution species of Ce(III) formate undergoes a polymerization during the crystallization process. PMID:24090406

  9. Bismuth flux growth of CeRh6Ge4 and CeRh2Ge2 single crystals

    International Nuclear Information System (INIS)

    Single crystals of the germanides CeRh6Ge4 and CeRh2Ge2 were synthesized from the elements in bismuth fluxes. Polycrystalline samples are available by arc-melting. The structures were refined on the basis of single-crystal X-ray diffractometer data. CeRh6Ge4: LiCo6P4 type, P anti 6m2, a = 715.4(2), c = 385.5(1) pm, wR2 = 0.0554, 273 F2 values, 19 variables; CeRh2Ge2: ThCr2Si2 type, I4/mmm, a = 415.69(6), c = 1048.5(2) pm, wR2 = 0.0391, 131 F2 values, 9 variables. The rhodium and germanium atoms build three-dimensional, covalently bonded [Rh6Ge4] and [Rh2Ge2] networks with Rh-Ge distances ranging from 246 to 255 pm. The cerium atoms are located in larger cavities within these networks: Ce rate at Ge6Rh12 in CeRh6Ge4 and Ce rate at Ge8Rh8 in CeRh2Ge2. Temperature-dependent magnetic susceptibility data of CeRh6Ge4 show Curie-Weiss behavior above 70 K with an experimental magnetic moment of 2.35(1) μB per Ce atom. Low-field measurements are indicative of magnetic ordering below 2.5 K. (orig.)

  10. Comparative Study of Various Preparation Methods of CuO–CeO2 Catalysts for Oxidation of n–Hexane and iso–Octane

    OpenAIRE

    Ashutosh Mishra; B.D. Tripathi; A. K. Rai; Ram Prasad

    2013-01-01

    The complete oxidation of n-Hexane and iso-Octane was studied individually in a fixed bed tubular flow reactor over CuO-CeO2 catalysts synthesized via four different methods namely urea-nitrate combustion method, urea gelation/co-precipitation method, citric acid sol-gel method and co-impregnation method. Laser diffraction was employed in catalysts characterization. The results obtained from the complete conversion of n-Hexane and iso-Octane revealed that the CuO-CeO2 catalysts prepared by ur...

  11. A pressure study of CePt{sub 3}B

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Daniela; Suellow, Stefan [Institute of Condensed Matter Physics, University of Technology Braunschweig, Braunschweig (Germany); Hartwig, Steffen [Institute of Condensed Matter Physics, University of Technology Braunschweig, Braunschweig (Germany); BENSC, Helmholtz Zentrum Berlin, Berlin (Germany); Hidaka, Hiroyuki; Yamazaki, Seigo; Amitsuka, Hiroshi [Department of Physics, Hokkaido University, Sapporo (Japan); Bauer, Ernst [Institute of Solid State Physics, Vienna University of Technology, Vienna (Austria)

    2013-07-01

    CePt{sub 3}B is isostructural to the non-centro symmetric heavy-fermion superconductor CePt{sub 3}Si. In contrast to the latter system, CePt{sub 3}B exhibits a complex magnetically ordered state at low temperatures, with an antiferromagnetic phase below T{sub N}=7.8 K and a weakly ferromagnetic transition below T{sub C}∼5 K. CePt{sub 3}B can be understand as a low pressure variant of CePt{sub 3}Si. Here we report a study of CePt{sub 3}B by means of high pressure magnetization measurements, this way in particular accessing the pressure evolution of the ferromagnetic transition temperature T{sub C}. From our investigation up to about 40 kbar we observe an almost constant transition temperature T{sub C} with pressure. This behavior we discuss in the context of alloying studies on this material.

  12. Facile hydrothermal synthesis of CeO2 nanopebbles

    Indian Academy of Sciences (India)

    N Sabari Arul; D Mangalaraj; Jeong In Han

    2015-09-01

    Cerium oxide (CeO2) nanopebbles have been synthesized using a facile hydrothermal method. X-ray diffraction pattern (XRD) and transmission electron microscopy analyses confirm the presence of CeO2 nanopebbles. XRD shows the formation of cubic fluorite CeO2 and the average particle size estimated from the Scherrer formula was found to be 6.69 nm. X-ray absorption spectrum of CeO2 nanopebbles exhibits two main sharp white lines at 880 and 898 eV due to the spin orbital splitting of 4 and 5. Optical absorption for the synthesized CeO2 nanopebbles exhibited a blue shift (g = 3.35 eV) with respect to the bulk CeO2 (g = 3.19 eV), indicating the existence of quantum confinement effects.

  13. Valence state of Ce and the magnetism in CeRh3B2

    International Nuclear Information System (INIS)

    The compound CeRh3B2 orders magnetically with a high Curie temperature (T/sub C/) of 115 K but with a low moment of only 0.4 μ/sub B/. L/sub III/ absorption-edge measurements show a dominant absorption peak at the energy corresponding to trivalent cerium. Magnetic studies on the compounds Ce(Rh/sub 1-x/T/sub x/)3B2 with T = Ru and Os reveal that the magnetic state is very rapidly broken up with the replacement of Rh by Ru and Os. These results, along with the observation of a high T/sub C/ in CeRh3B2, suggest that magnetism in this compound arises from a strong hybridization of nearly localized or slightly delocalized Ce 4f electrons with conduction electrons. The small moment may be due to a Kondo-type interaction coupled with crystal-field effects. 14 references, 4 figures

  14. Nuclear reactor

    International Nuclear Information System (INIS)

    Cover gas spaces for primary coolant vessel, such as a reactor container, a pump vessel and an intermediate heat exchanger vessel are in communication with each other by an inverted U-shaped pressure conduit. A transmitter and a receiver are disposed to the pressure conduit at appropriate positions. If vibration frequencies (pressure vibration) from low frequency to high frequency are generated continuously from the transmitter to the inside of the communication pipe, a resonance phenomenon (air-column resonance oscillation) is caused by the inherent frequency or the like of the communication pipe. The frequency of the air-column resonance oscillation is changed by the inner diameter and the clogged state of the pipelines. Accordingly, by detecting the change of the air-column oscillation characteristics by the receiver, the clogged state of the flow channels in the pipelines can be detected even during the reactor operation. With such procedures, steams of coolants flowing entrained by the cover gases can be prevented from condensation and coagulation at a low temperature portion of the pipelines, otherwise it would lead clogging in the pipelines. (I.N.)

  15. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  16. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  17. Preparation and stability of a new compound SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95}

    Energy Technology Data Exchange (ETDEWEB)

    Matskevich, N.I., E-mail: nata@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Karlsruhe Institute of Technology, Institute of Solid State Physics, Karlsruhe D-76334 (Germany); Wolf, Th. [Karlsruhe Institute of Technology, Institute of Solid State Physics, Karlsruhe D-76334 (Germany); Vyazovkin, I.V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Adelmann, P. [Karlsruhe Institute of Technology, Institute of Solid State Physics, Karlsruhe D-76334 (Germany)

    2015-04-15

    Highlights: • The phase SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} was synthesized. • The formation enthalpy of SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} was measured by solution calorimetry. • The phase is thermodynamically stable with respect to decomposition into binary oxides. • The adding of Lu leads to increasing the stability of SrCeO{sub 3}. - Abstract: The preparation of SrCeO{sub 3} doped by lutetium oxide (SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95}) has been carried out by the solid-state reaction of SrCO{sub 3}, CeO{sub 2} and Lu{sub 2}O{sub 3}. The X-ray measurements have shown that SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} has an orthorhombic structure (space group Pnma). For the first time the standard molar enthalpy of SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} formation has been determined by solution calorimetry in combination with standard molar dissolution enthalpies of SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} and SrCl{sub 2} + 0.9CeCl{sub 3} + 0.1LuCl{sub 3} mixture in 1 M HCl with 0.1 M KI at 298.15 K and other thermochemical data. It has been found out that the mixed oxide mentioned above is thermodynamically more stable than the component oxides at room temperature. It has been also shown that SrCe{sub 0.9}Lu{sub 0.1}O{sub 2.95} is thermodynamically more favored than 0.9SrCeO{sub 3} + 0.1SrO + 0.05Lu{sub 2}O{sub 3} mixture. We have established that Lu adding increases SrCeO{sub 3} thermodynamic stability.

  18. Enhancement of photocatalytic properties of TiO{sub 2} nanoparticles doped with CeO{sub 2} and supported on SiO{sub 2} for phenol degradation

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Chunjing [School of Environment Science and Spatial Informatics, CUMT, Xuzhou, Jiangsu 221116 (China); State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jing; Zhang, Zailei [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Ji, Yongjun, E-mail: jiyongjun1981@126.com [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhan, Hanhui, E-mail: zhanhhh@263.net [School of Environment Science and Spatial Informatics, CUMT, Xuzhou, Jiangsu 221116 (China); Xiao, Fangxing [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Wang, Dan [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Bin [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore (Singapore); Su, Fabing, E-mail: fbsu@ipe.ac.cn [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-03-15

    Highlights: • CeO{sub 2}-TiO{sub 2}/SiO{sub 2} composites were prepared via a facile co-precipitation method. • Introduction of SiO{sub 2} support increases the dispersion of CeO{sub 2}-TiO{sub 2}. • CeO{sub 2}-TiO{sub 2}/SiO{sub 2} exhibits an enhanced photocatalytic efficiency for phenol degradation. • Ce{sup 3+}/Ce{sup 4+} pair coexisting in CeO{sub 2} improves electron–hole pairs separation efficiency. - Abstract: A series of CeO{sub 2}-TiO{sub 2} and CeO{sub 2}-TiO{sub 2}/SiO{sub 2} composites were prepared with TiCl{sub 4} and Ce (NO{sub 3}){sub 3}·6H{sub 2}O as precursors via a facile co-precipitation method. The obtained samples were characterized by various techniques such as X-ray diffraction (XRD), nitrogen adsorption (N{sub 2}-BET), Fourier transformation infrared spectrum (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis spectroscopy measurements. The results indicated that TiO{sub 2} doped with CeO{sub 2} and supported on SiO{sub 2} could reduce the crystallite size, inhibit the phase transformation, enhance the thermal stability, and effectively extend the spectral response from UV to visible range. When applied to the phenol photodegradation on a homemade batch reactor with an external cooling jacket, the CeO{sub 2}-TiO{sub 2}/SiO{sub 2} catalysts exhibited significantly enhanced photodegradation efficiency in comparison with commercial Degussa P25 and CeO{sub 2}-TiO{sub 2}. The unique catalytic properties of CeO{sub 2}-TiO{sub 2}/SiO{sub 2} were ascribed to improved electron–hole pairs separation efficiency and formation of more reactive oxygen species owing to the presence of Ce{sup 3+}/Ce{sup 4+}, as well as high dispersion of active component of CeO{sub 2}-TiO{sub 2} as a result of the introduction of SiO{sub 2} support. Furthermore, the catalysts can be easily recovered from the reaction solution by centrifugation and reused for four cycles without significant loss of activity.

  19. Thermodynamic assessment of Al-Ce-Cu system

    International Nuclear Information System (INIS)

    The Ce-Cu binary system has been thermodynamically reassessed by CALPHAD approach based on experimental data and thermodynamic properties of phase diagram. Incorporating the thermodynamic evaluations of Al-Ce and Al-Cu systems from literature, the Al-Ce-Cu ternary system has been assessed using CALPHAD approach. The solution phases including liquid, Fcc and Bcc were treated as substitutional solution phases and the Redlich-Kister polynomial was used to describe their excess Gibbs energies. All binary and ternary intermetallic compounds were treated as stoichiometric phases and their Gibbs energies of formation were optimized. The calculated Al-Ce-Cu phase diagram agreed well with available experimental data.

  20. Complex charge ordering in CeRuSn

    Energy Technology Data Exchange (ETDEWEB)

    Feyerherm, Ralf; Dudzik, Esther; Valencia, Sergio [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, 12489 Berlin (Germany); Mydosh, John A. [MPI-CPFS, 01187 Dresden (Germany); Kamerlingh Onnes Laboratory, Leiden University, 2300RA Leiden (Netherlands); Hermes, Wilfried; Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster, 48149 Muenster (Germany)

    2012-07-01

    At room temperature (RT), CeRuSn exhibits coexistence of trivalent Ce{sup 3+} and intermediate valent Ce{sup (4-{delta})+} in a metallic environment. Charge ordering produces a doubling of the unit cell along the c-axis with respect to the basic CeCoAl type structure. Below RT, a phase transition with broad hysteresis has been observed in various bulk properties. The present X-ray diffraction results show that at low temperatures the doubling of the CeCoAl type structure is replaced by an ill-defined modulated ground state in which at least three modulation periods compete. The dominant mode is close to a tripling of the basic cell. XANES data suggest that the average Ce valence remains constant. We propose a qualitative structure model with modified stacking sequences of Ce{sup 3+} and Ce{sup (4-{delta})+} layers in the various modulated phases. Surprisingly, far below 100 K the modulated state is sensitive to synchrotron X-ray irradiation. With a photon flux {approx} 10{sup 12} s{sup -1}, the modulated ground state is destroyed on a timescale of minutes and the doubling of the CeCoAl cell observed at room temperature is recovered. The final state is metastable at 10 K. Heating the sample above 60 K again leads to a recovery of the modulated state.

  1. Synthesis and thermochemistry of new phase BaCe0.7Nd0.2In0.1O2.85

    International Nuclear Information System (INIS)

    Highlights: •We synthesized new phase BaCe0.7Nd0.2In0.1O2.85. •We measured formation enthalpy of BaCe0.7Nd0.2In0.1O2.85. •The phase is thermodynamically stable with respect to decomposition into binary oxides. -- Abstract: The BaCe0.7Nd0.2In0.1O2.85 phase has been prepared from BaCO3, CeO2, Nd2O3 and In2O3. X-ray measurements have showed that BaCe0.7Nd0.2In0.1O2.85 has an orthorhombic structure (Pmcn space group). The standard formation enthalpy of BaCe0.7Nd0.2In0.1O2.85 has been determined by solution calorimetry combining solution enthalpies of BaCe0.7Nd0.2In0.1O2.85, BaCl2 + 0.7CeCl3 + 0.2NdCl3 + 0.1InCl3 mixture in 1 M HCl with KI and literature data. We determined the thermodynamic stability of Nd(In)-doped barium cerate with respect to mixtures of binary oxides. On the basis of the data we established that above-mentioned mixed oxide is thermodynamically stable with respect to their decomposition into binary oxides at room temperatures. We also established that BaCe0.7Nd0.2In0.1O2.85 is thermodynamically favored than BaCe0.8Nd0.2O2.9

  2. An Analysis of Problematic C-E Translations of Signs in Light of Nida ’s Functional Equivalence Theory

    Institute of Scientific and Technical Information of China (English)

    TANG Fang

    2015-01-01

    Based on Nida’s Functional Equivalence theory, this article makes an analysis of the problems in C-E translations of signs in China. The author will discuss respectively the problematic C-E translations from two respects: 1) not being equivalent to source-language message, and 2) not being natural for target language. If translators work hard with the help of Nida’s functional equivalence theory, the defects and imperfections will be discovered, and standard signs in English will be read more and more in public places.

  3. Thermogravimetric studies of (U0.72Ce0.28)O2.00 under different oxygen partial pressures

    International Nuclear Information System (INIS)

    (U, Pu)O2 mixed oxide fuels with different percent of plutonium have been developed and used all over the world in commercial and research reactors. (U0.72Pu0.28)O2.00 is used as a nuclear fuel in Prototype Fast Breeder Reactor (PFBR) at Kalpakkam. CeO2 has been used as a surrogate for PuO2 because of similarity in their thermophysical and thermochemical properties. In addition, cerium is one of the high yield fission products formed during burn up and dissolves in UO2 matrix to form (U, Ce)O2. It is reported that the oxidation and phase behavior of (U1-yCey)O2±x system are quite comparable to (U1-yPuy)O2±x system in hyper-stoichiometric (2+x) region than in hypo-stoichiometric (2-x) region. (U0.72Ce0.28)O2 was prepared by gel combustion route followed by sintering at 1400°C for 10 h in Ar/8%H2 atmosphere

  4. Status of conversion of NE standards to national consensus standards

    International Nuclear Information System (INIS)

    One major goal of the Nuclear Standards Program is to convert existing NE standards into national consensus standards (where possible). This means that an NE standard in the same subject area using the national consensus process. This report is a summary of the activities that have evolved to effect conversion of NE standards to national consensus standards, and the status of current conversion activities. In some cases, all requirements in an NE standard will not be incorporated into the published national consensus standard because these requirements may be considered too restrictive or too specific for broader application by the nuclear industry. If these requirements are considered necessary for nuclear reactor program applications, the program standard will be revised and issued as a supplement to the national consensus standard. The supplemental program standard will contain only those necessary requirements not reflected by the national consensus standard. Therefore, while complete conversion of program standards may not always be realized, the standards policy has been fully supported in attempting to make maximum use of the national consensus standard. 1 tab

  5. TRIGA Reactor Power Upgrading Analysis

    International Nuclear Information System (INIS)

    Reactor physics safety analysis supporting the power upgrading from 1MW to 2MW of a typical TRIGA Mark II reactor is presented for steady state and pulse operation. The analysis is performed for mixed core configuration consisting of two types of fuel elements: standard 8,5% or 12% stainless-steel clad fuel elements and LEU fuel elements (20% uranium concentration). The following reactor physics codes are applied: WIMS, TRIGAC, EXTERMINATOR, PULSTRI and TRISTAN. Results of the calculations are compared to experiments for steady state operation at 1 MW. The analysis shows that besides technical modifications of the core (installation of an additional control rod) also some strict administrative limitations have to be imposed on operational parameters (excess reactivity, pulse reactivity, core composition) to assure safe operation within design limits. (author)

  6. Business Opportunities for Small Reactors

    International Nuclear Information System (INIS)

    This report assesses the market potential and identifies a number of potential paths for developing the small nuclear reactor business. There are several potential opportunities identified and evaluated. Selecting a specific approach for the business development requires additional information related to a specific market and sources of capital to support the investment. If and how a market for small nuclear plants may develop is difficult to predict because of the complexity of the economic and institutional factors that will influence such development. Key factors are; economics, safety, proliferation resistance and investment risk. The economic and political interest of any of the identified markets is also dependent on successful demonstration of the safety and reliability of small nuclear reactor. Obtaining a US-NRC Standard Design approval would be an important development step toward establishing a market for small reactors. (authors)

  7. Catalytic oxidation with Al-Ce-Fe-PILC as a post-treatment system for coffee wet processing wastewater.

    Science.gov (United States)

    Sanabria, Nancy R; Peralta, Yury M; Montañez, Mardelly K; Rodríguez-Valencia, Nelson; Molina, Rafael; Moreno, Sonia

    2012-01-01

    The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al-Ce-Fe-PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al-Ce-Fe-PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO(2) (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce-Fe-PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al-Ce-Fe-PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater. PMID:22907449

  8. Preparation of catalysts based on Ce-Mn mixed oxide by coprecipitation for combustion of n-hexane

    International Nuclear Information System (INIS)

    Catalysts based on Ce-Mn mixed with different Ce/Mn molar ratios ranging from 0,5 to 2 have been prepared by coprecipitation at pH constant with ageing times of 4, 18 and 24 h for combustion of n-hexane. XRD patterns of the mixed oxides showed the majority presence of fluorite phase. Specific BET surface areas of mixed oxides were always higher than their single counterparts and their adsorption isotherm depicted a mesoporous surface of Type IV. TPR thermograms confirmed the presence of mixed oxide phase, whose profile shifted to smaller temperatures with increasing content of ceria. Catalytic tests were performed with 2000 ppm of n-hexane and WHSV of 80 h-1 in a fixed-bed reactor. For all samples, only CO2 and water were observed at total conversion and no partial combustion products were obtained. Ce-Mn mixed oxides were more active than simple oxide samples no matter the aging time. Mixed samples presented thermal stability in contrast with simple ones. Mixed sample with Ce/Mn molar ratio of 2 depicted the highest activity probably due to higher surface area and better reducibility ability of mixed phase. (author)

  9. Reactor container

    International Nuclear Information System (INIS)

    Purpose: To prevent shocks exerted on a vent head due to pool-swell caused within a pressure suppression chamber (disposed in a torus configuration around the dry well) upon loss of coolant accident in BWR type reactors. Constitution: The following relationship is established between the volume V (m3) of a dry well and the ruptured opening area A (m2) at the boundary expected upon loss of coolant accident: V >= 30340 (m) x A Then, the volume of the dry well is made larger than the ruptured open area, that is, the steam flow rate of leaking coolants upon loss of coolant accident to decrease the pressure rise in the dry well at the initial state where loss of coolant accident is resulted. Accordingly, the pressure of non-compressive gases jetted out from the lower end of the downcomer to the pool water is decreased to suppress the pool-swell. (Ikeda, J.)

  10. Material test reactor fuel research at the BR2 reactor

    International Nuclear Information System (INIS)

    The construction of new, high performance material test reactor or the conversion of such reactors' core from high enriched uranium (HEU) to low enriched uranium (LEU) based fuel requires several fuel qualification steps. For the conversion of high performance reactors, high density dispersion or monolithic fuel types are being developed. The Uranium-Molybdenum fuel system has been selected as reference system for the qualification of LEU fuels. For reactors with lower performance characteristics, or as medium enriched fuel for high performance reactors, uranium silicide dispersion fuel is applied. However, on the longer term, the U-Mo based fuel types may offer a more efficient fuel alternative and-or an easier back-end solution with respect to the silicide based fuels. At the BR2 reactor of the Belgian nuclear research center, SCK-CEN in Mol, several types of fuel testing opportunities are present to contribute to such qualification process. A generic validation test for a selected fuel system is the irradiation of flat plates with representative dimensions for a fuel element. By flexible positioning and core loading, bounding irradiation conditions for fuel elements can be performed in a standard device in the BR2. For fuel element designs with curved plates, the element fabrication method compatibility of the fuel type can be addressed by incorporating a set of prototype fuel plates in a mixed driver fuel element of the BR2 reactor. These generic types of tests are performed directly in the primary coolant flow conditions of the BR2 reactor. The experiment control and interpretation is supported by detailed neutronic and thermal-hydraulic modeling of the experiments. Finally, the BR2 reactor offers the flexibility for irradiation of full size prototype fuel elements, as 200mm diameter irradiation channels are available. These channels allow the accommodation of various types of prototype fuel elements, eventually using a dedicated cooling loop to provide the

  11. Preparation,Characterization of CuO/CeO2 and Cu/CeO2 Catalysts and Their Applications in Low-Temperature CO Oxidation

    Institute of Scientific and Technical Information of China (English)

    Zheng Xiucheng; Han Dongzhan; Wang Shuping; Zhang Shoumin; Wang Shurong; Huang Weiping; Wu Shihua

    2005-01-01

    CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were examined by means of a microreactor-GC system, HRTEM, XRD, TPR and XPS techniques. The results show that CuO has not catalytic activity and the activity of CeO2 is quite low for CO oxidation. However, the catalytic activity of CuO/CeO2 and Cu/CeO2 catalysts increases significantly. Furthermore, the activity of CuO/CeO2 is higher than that of Cu/CeO2 catalysts.

  12. β-Cyclodextrin-assisted preparation of hierarchical walnut-like CeOHCO3 and CeO2 mesocrystals

    International Nuclear Information System (INIS)

    The hierarchical walnut-like CeOHCO3 mesocrystals were prepared by a facile hydrothermal method under low temperature with β-cyclodextrin (β-CD) as assistant agent. The hierarchical walnut-like CeO2 mesocrystals were obtained by thermal decomposition of CeOHCO3 mesocrystals. The crystal phase, morphology, and structure of CeOHCO3 and CeO2 mesocrystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The time-dependent experimental results indicated that the morphology transformation from shuttle-like to walnut-like and the crystal phase transformation from orthorhombic to hexagonal simultaneously occurred in the formation processes of CeOHCO3 mesocrystals. On the basis of the morphological and crystal phase evolution processes, the formation mechanism of hierarchical walnut-like CeOHCO3 mesocrystals, including dissolution-recrystallization processes, was discussed. β-CD was believed to play an important role in the formation of the hierarchical walnut-like CeOHCO3 mesocrystals. The effects of reaction temperature, β-CD amount, and concentration of reactants on the morphologies of the products were systematically studied. CeO2 mesocrystals exhibited the distinct red-shift phenomenon in UV-vis absorption spectra.

  13. Ce and T magnetism in CeTPO compounds (T = Os, Ru, Fe, Co) - large variety of ground states

    International Nuclear Information System (INIS)

    In the last years we have started a detailed investigation of the CeTPO compounds (T = Os, Ru, Fe, Co). These materials correspond to the family of LnTPnO systems, crystallizing in the tetragonal ZrCuSiAs structure-type, which attracts a lot of attention due the observation of high temperature superconductivity (SC) in the doped LnFeAsO compounds. Whereas the 3d-magnetism of the Fe is essentially for the occurrence of SC in LnFeAsO, the magnetism in CeTPO is dominated by the 4f-electrons of Ce3+. In this contribution, we summarize our results on the single crystal growth of the CeTPO materials together with a thorough physical characterization, including magnetization, susceptibility, resistivity, specific heat, and thermopower. These measurements reveal four different magnetic ground states: (1) CeRuPO is a rare example of a ferromagnetically ordered Kondo-lattice system with TC=15 K and a Kondo scale of TK∝10 K; (2) CeOsPO orders antiferromagnetically at TN=4.5 K; (3) CeFePO is a heavy-fermion system on the non-magnetic side of a ferromagnetic instability; (4) CeCoPO present ferromagnetic order of the Co-ions at TC=75 K and Ce-moments close to magnetism. Therefore, these new materials present a nice playground to study in detail the phenomena of strongly correlated electron systems.

  14. Training courses at VR-1 reactor

    International Nuclear Information System (INIS)

    This paper describes one of the main purposes of the VR-1 training reactor utilization - i.e. extensive educational program. The educational program is intended for the training of university students and selected nuclear power plant personnel. The training courses provide them experience in reactor and neutron physics, dosimetry, nuclear safety and operation of nuclear facilities. At present, the training course participants can go through more than 20 standard experimental exercises; particular exercises for special training can be prepared. Approximately 200 university students become familiar with the reactor (lectures, experiments, experimental and diploma works, etc.) every year. About 12 different faculties from Czech universities use the reactor. International co-operation with European universities in Germany, Hungary, Austria, Slovakia, Holland and UK is frequent. The VR-1 reactor takes also part in Eugene Wigner Course on Reactor Physics Experiments in the framework of European Nuclear Educational Network (ENEN) association. Recently, training courses for Bulgarian research reactor specialists supported by IAEA were carried out. An attractive program including demonstration of reactor operation is prepared also for high school students. Every year, more than 1500 high school students come to visit the reactor, as do many foreigner visitors. (author)

  15. System assessment of helical reactors in comparison with tokamaks

    International Nuclear Information System (INIS)

    A comparative assessment of tokamak and helical reactors has been performed using equivalent physics/engineering model and common costing model. Higher-temperature plasma operation is required in tokamak reactors to increase bootstrap current fraction and to reduce current-drive (CD) power. In helical systems, lower-temperature operation is feasible and desirable to reduce helical ripple transport. The capital cost of helical reactor is rather high, however, the cost of electricity (COE) is almost same as that of tokamak reactor because of smaller re-circulation power (no CD power) and less-frequent blanket replacement (lower neutron wall loading). The standard LHD-type helical reactor with 5% beta value is economically equivalent to the standard tokamak with 3% beta. The COE of lower-aspect ratio helical reactor is on the same level of high-βN tokamak reactors. (author)

  16. A Novel Assembly Line Scheduling Algorithm Based on CE-PSO

    Directory of Open Access Journals (Sweden)

    Xiaomei Hu

    2015-01-01

    Full Text Available With the widespread application of assembly line in enterprises, assembly line scheduling is an important problem in the production since it directly affects the productivity of the whole manufacturing system. The mathematical model of assembly line scheduling problem is put forward and key data are confirmed. A double objective optimization model based on equipment utilization and delivery time loss is built, and optimization solution strategy is described. Based on the idea of solution strategy, assembly line scheduling algorithm based on CE-PSO is proposed to overcome the shortcomings of the standard PSO. Through the simulation experiments of two examples, the validity of the assembly line scheduling algorithm based on CE-PSO is proved.

  17. Sn-CeO2 thin films prepared by rf magnetron sputtering: XPS and SIMS study

    International Nuclear Information System (INIS)

    Sn addition in the CeO2 thin film by simultaneous Sn metal and cerium oxide magnetron sputtering causes growth of Ce3+ rich films whilst pure cerium oxide sputtering provides stoichiometric CeO2 layers. Ce4+ → Ce3+ conversion is explained by a charge transfer from Sn atoms to unoccupied orbital Ce 4f0 of cerium oxide by forming Ce 4f1 state. XPS and SIMS revealed a formation of a new chemical Ce(Sn)+ state, which belongs to SnCeO2 species.

  18. TRIGA mark-II,III reactor safety re-evaluation

    International Nuclear Information System (INIS)

    For two years of 1990 and 1991, the safety of TRIGA Mk-II and III reactor has been re-evaluated. For this, domestic rules on research reactors has been reviewed, and as it was judged that standards on research reactors in USA is applicable to our ones it was evaluated whether TRIGA Mk-II and III reactors satisfy these standards. The site parameters and the environmental impacts during normal operation and hypothetical accident conditions have been analysed, and those parts for reactor facility and structure have been rewritten to fit SAR standard format based on the review of old SAR and maintenance manuals reflecting changes after the construction. Based on this re-evaluation, SAR, Technical Specifications, Radiation Emergency Plan, Environment Report, various procedures,etc. will be amended by the reactor management project. (Author)

  19. Economic analysis of nuclear reactors

    International Nuclear Information System (INIS)

    The report presents several methods for estimating the power costs of nuclear reactors. When based on a consistent set of economic assumptions, total power costs may be useful in comparing reactor alternatives. The principal items contributing to the total power costs of a nuclear power plant are: (1) capital costs, (2) fuel cycle costs, (3) operation and maintenance costs, and (4) income taxes and fixed charges. There is a large variation in capital costs and fuel expenses among different reactor types. For example, the standard once-through LWR has relatively low capital costs; however, the fuel costs may be very high if U3O8 is expensive. In contrast, the FBR has relatively high capital costs but low fuel expenses. Thus, the distribution of expenses varies significantly between these two reactors. In order to compare power costs, expenses and revenues associated with each reactor may be spread over the lifetime of the plant. A single annual cost, often called a levelized cost, may be obtained by the methods described. Levelized power costs may then be used as a basis for economic comparisons. The paper discusses each of the power cost components. An exact expression for total levelized power costs is derived. Approximate techniques of estimating power costs will be presented

  20. Pressurized water reactor inspection procedures

    International Nuclear Information System (INIS)

    Inspections of the reactor pressure vessels of pressurized water reactors (PWR) so far used to be carried out with different central mast manipulators. For technical reasons, parallel inspections of two manipulators alongside work on the refueling cavity, so as to reduce the time spent on the critical path in a revision outage, are not possible. Efforts made to minimize the inspection time required with one manipulator have been successful, but their effects are limited. Major reductions in inspection time can be achieved only if inspections are run with two manipulators in parallel. The decentralized manipulator built by GEC Alsthom Energie and so far emmployed in boiling water reactors in the USA, Spain, Switzerland and Japan allows two systems to be used in parallel, thus reducing the time required for standard inspection of a pressure vessel from some six days to three days. These savings of approximately three days are made possible without any compromises in terms of positioning by rail-bound systems. During inspection, the reactor refueling cavity is available for other revision work without any restrictions. The manipulator can be used equally well for inspecting standard PWR, PWR with a thermal shield, for inspecting the land between in-core instrumentation nozzles, BWR with and without jet pumps (complementary inspection), and for inspecting core support shrouds. (orig.)

  1. The Constrained Exceptional Supersymmetric Standard Model

    CERN Document Server

    Athron, P; Miller, D J; Moretti, S; Nevzorov, R

    2009-01-01

    We propose and study a constrained version of the Exceptional Supersymmetric Standard Model (E6SSM), which we call the cE6SSM, based on a universal high energy scalar mass m_0, trilinear scalar coupling A_0 and gaugino mass M_{1/2}. We derive the Renormalisation Group (RG) Equations for the cE6SSM, including the extra U(1)_{N} gauge factor and the low energy matter content involving three 27 representations of E6. We perform a numerical RG analysis for the cE6SSM, imposing the usual low energy experimental constraints and successful Electro-Weak Symmetry Breaking (EWSB). Our analysis reveals that the sparticle spectrum of the cE6SSM involves a light gluino, two light neutralinos and a light chargino. Furthermore, although the squarks, sleptons and Z' boson are typically heavy, the exotic quarks and squarks can also be relatively light. We finally specify a set of benchmark points which correspond to particle spectra, production modes and decay patterns peculiar to the cE6SSM, altogether leading to spectacular...

  2. Electrochemical properties of Atomic layer deposition processed CeO2 as a protective layer for the molten carbonate fuel cell cathode

    International Nuclear Information System (INIS)

    Highlights: • Nano-structured CeO2-coated Ni by Atomic Layer Deposition, crystalline as-deposited. • Progressive transformation into a complex surface stable in molten carbonates. • Lower Ni solubility with CeO2 protective coating. • Feasibility of CeO2 coating in Molten Carbonate Fuel Cell cathode conditions. - Abstract: In order to increase the lifetime and performance of the molten carbonate fuel cell, it is compulsory to control the corrosion and dissolution of the state of the art porous nickel oxide cathode. A protective coating constituted by more stable oxides appears to be the best approach. Previous research on CeO2 coatings obtained by DC reactive magnetron sputtering to protect the Molten carbonate fuel cell cathode gave promising results but it was necessary to improve the coating adhesion. In this paper Atomic Layer Deposition, producing high quality, homogeneous and conformal layers, was used to obtain thin layers of CeO2 (20 nm and 120 nm) deposited over porous nickel. CeO2-Ni coated samples were tested as cathodes in Li2CO3-K2CO3 (62-38 mol %) eutectic mixture under standard cathode atmosphere (CO2/air 30:70 vol. %). Structural and morphological characterizations of the nickel coated cathode before and after electrochemical tests in the molten carbonate melt are reported together with the Open Circuit Potential evolution all over 230 h for both the bare porous nickel and the CeO2-coated samples

  3. Oxidación Húmeda de Fenoles con Catalizadores Fe-CeO2, K-MnO2/ CeO2/Paligorsquita y Fe/ Paligorsquita Wet Oxidation of Phenols using Fe-CeO2, K-MnO2/ CeO2/Paligorskite and Fe/ Palygorskite Catalysts

    Directory of Open Access Journals (Sweden)

    Santiago A. F Junior

    2011-01-01

    Full Text Available Se ha evaluado el funcionamiento de catalizadores Fe-MnO2/CeO2, K-MnO2/CeO2/Paligorsquita y Fe/Paligorsquita en la degradación oxidativa húmeda del fenol en un reactor de mezcla. Los experimentos se ejecutaron a: temperatura de 130º C, presión de 20.4 atm., concentración másica del catalizador de 5 g/L y concentración inicial del fenol de 0,5 g/L Los parámetros evaluados fueron: contenido de hierro impregnado (0, 3; 7 y 10%, m/m y el pH inicial del medio reactivo (3.1; 6.8 y 8.7. Las curvas de degradación del fenol indican que el catalizador Fe+2/Paligorsquita tiene un papel preponderante en la conversión de carbono orgánico total comparado con los demás catalizadores. Se encontró también que la disminución de la alcalinidad del medio reactivo favorece la conversión de fenol y que el soporte paligorsquita parece ser más resistente a la acción de los compuestos ácidos formados durante la reacción.The performance of Fe-MnO2/CeO2, K-MnO2/CeO2/ Palygorskite and Fe/ Palygorskite catalysts during the wet oxidative degradation of phenol in a stirred reactor has been evaluated. The experiments were run at 130°C, 20.4 atm., and with an initial phenol and catalyst mass concentration of 0.5 g/L and 5 g/L, respectively. The influence of iron loaded on the support (0, 3; 7 and 10%, m/m and the initial pH of the reactant medium (3.1; 6.8; 8.7 were studied. The phenol degradation curves showed that the Fe+2//Palygorskite catalyst had the best performance toward the organic carbon conversion compared to the other catalysts. It was also found that by lowering the alkalinity of the reacting media favoured the phenol conversion and that the Palygorskite support showed higher resistance to the actions of the acids formed during the reaction.

  4. Provádění zkoušek stálosti u rentgenových přístrojů a spolupráce na vypracování místních radiologických standardů

    OpenAIRE

    ŠIMKOVÁ, Veronika

    2010-01-01

    The objective of the paper is to examine correct fiction of X-ray apparatuses at the Radiodiagnostic Station of the Hospital i Jihlava. I tis to estabilish if the chase in conditions that may occur (such as temperature, power failures ETA.) may affect the results of the operational stability tests. The subjekt of this paper is to develop local radiology standards for particular apparatuses based on the ordinances of the State Nuclear Safety Institute. The results shall be processed statistica...

  5. Synthesis and structural characterization of Ce-doped bismuth titanate

    International Nuclear Information System (INIS)

    Ce-modified bismuth titanate nanopowders Bi4-xCexTi3O12 (x ≤ 1) have been synthesized using a coprecipitation method. DTA/TG, FTIR, XRD, SEM/EDS and BET methods were used in order to investigate the effect of Ce-substitution on the structure, morphology and sinterability of the obtained powders. The phase structure investigation revealed that after calcinations at 600 deg. C powder without Ce addition exhibited pure bismuth titanate phase; however, powders with Ce (x = 0.25, 0.5 and 0.75) had bismuth titanate pyrochlore phase as the second phase. The strongest effect of Ce addition on the structure was noted for the powder with the highest amount of Ce (x = 1) having a cubic pyrochlore structure. The presence of pure pyrochlore phase was explained by its stabilization due to the incorporation of cerium ions in titanate structure. Ce-modified bismuth titanate ceramic had a density over 95% of theoretical density and the fracture in transgranular manner most probably due to preferable distribution of Ce in boundary region

  6. Biofunctionalization of CeF(3):Tb(3+) nanoparticles.

    Science.gov (United States)

    Kong, D Y; Wang, Z L; Lin, C K; Quan, Z W; Li, Y Y; Li, C X; Lin, J

    2007-02-21

    CeF(3):Tb(3+) nanoparticles (short pillar-like morphology with an average length and width of 11 and 5 nm, respectively) were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with a SiO(2)-NH(2) layer, these CeF(3):Tb(3+) nanoparticles can be conjugated with biotin molecules (activated by thionyl chloride) and further with avidin. The as-formed CeF(3):Tb(3+) nanoparticles, CeF(3):Tb(3+) nanoparticles functionalized with amino groups, biotin conjugated amino-functionalized CeF(3):Tb(3+) nanoparticles and biotinylated CeF(3):Tb(3+) nanoparticles bonded with avidin were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), UV/vis absorption spectra and luminescence spectra, respectively. The biofunctionalization of the CeF(3):Tb(3+) nanoparticles has less effect on their luminescence properties, i.e. they still show strong green emission (from Tb(3+), with (5)D(4)-(7)F(5) at 543 nm as the most prominent group), indicative of the great potential for these CeF(3):Tb(3+) nanoparticles to be used as biological fluorescence probes. PMID:21730503

  7. Biofunctionalization of CeF3:Tb3+ nanoparticles

    Science.gov (United States)

    Kong, D. Y.; Wang, Z. L.; Lin, C. K.; Quan, Z. W.; Li, Y. Y.; Li, C. X.; Lin, J.

    2007-02-01

    CeF3:Tb3+ nanoparticles (short pillar-like morphology with an average length and width of 11 and 5 nm, respectively) were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with a SiO2-NH2 layer, these CeF3:Tb3+ nanoparticles can be conjugated with biotin molecules (activated by thionyl chloride) and further with avidin. The as-formed CeF3:Tb3+ nanoparticles, CeF3:Tb3+ nanoparticles functionalized with amino groups, biotin conjugated amino-functionalized CeF3:Tb3+ nanoparticles and biotinylated CeF3:Tb3+ nanoparticles bonded with avidin were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), UV/vis absorption spectra and luminescence spectra, respectively. The biofunctionalization of the CeF3:Tb3+ nanoparticles has less effect on their luminescence properties, i.e. they still show strong green emission (from Tb3+, with 5D4-7F5 at 543 nm as the most prominent group), indicative of the great potential for these CeF3:Tb3+ nanoparticles to be used as biological fluorescence probes.

  8. A benchmark for investigating the radial dependence of C/E for control rod worths in large decoupled cores

    International Nuclear Information System (INIS)

    The first physics measurements of a heterogeneous core on the critical assembly ZPPR-7 at ANL showed that the C/E ratios with ENDF/B data for the worths of the control rods in the outer bank were several percent higher than those at the inner bank positions. This radial variation in the C/E for the rod worths was further confirmed in the analysis of the large conventional core ZPPR-10, and again in the analysis of the large heterogeneous core series ZPPR-13. In the design of a power reactor, the number of control rods, and their disposition, are determined by calculations. Misprediction of the worth of the control rods can lead to serious economic penalties by restricting the operation of the core. Retrofitting a core to accommodate more worth will be costly and is likely to lead to a non-optimized core. This document provides a discussion of these calculations. 7 refs., 7 figs., 12 tabs

  9. ['Gold standard', not 'golden standard'

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2005-01-01

    In medical literature, both 'gold standard' and 'golden standard' are employed to describe a reference test used for comparison with a novel method. The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In the same w

  10. Investigation of thermal neutron capture in 23Na, 138Ba, 140Ce and 142Ce

    International Nuclear Information System (INIS)

    A measurement of the angular correlation of γ-rays emitted in the capture of thermal neutrons in 23Na has been used to determine the multipole mixing ratio delta for seventeen transitions in 24Na, of which seven are primary transitions. For these primary transitions also the capture state spin admixture α has been derived. The neutron capture reaction proceeds predominantly through the Jsup(π)=1+ channel, as expected from previous cross-section measurements. A measurement of the circular polarization of γ-rays resulting from the capture of polarized thermal neutrons in 138Ba, 140Ce and 142Ce has yielded spin assignments for p-states in the final nuclei. Excitation energies and reaction Q-values have been obtained from the analysis of singles spectra taken with unpolarized neutrons. (Auth.)

  11. Developments in the regulation of research reactors

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has data on over 670 research reactors in the world. Fewer than half of them are operational and a significant number are in a shutdown but not decommissioned state. The International Nuclear Safety Advisory Group (INSAG) has expressed concerns about the safety of many research reactors and this has resulted in a process to draw up an international Code of Conduct on the Safety of Research Reactors. The IAEA is also reviewing its safety standards applying to research reactors. On the home front, regulation of the construction of the Replacement Research Reactor continues. During the construction phase, regulation has centred around the consideration of Requests for Approval (RFA) for the manufacture and installation of systems, structures and components important for safety. Quality control of construction of systems, structures and components is the central issue. The process for regulation of commissioning is under consideration

  12. Influences of doping Cr/Fe/Ta on the performance of Ni/CeO2 catalyst under microwave irradiation in dry reforming of CH4

    Science.gov (United States)

    Odedairo, Taiwo; Ma, Jun; Chen, Jiuling; Wang, Shaobin; Zhu, Zhonghua

    2016-01-01

    The structure of Ni/CeO2 catalyst with doping of Cr, Fe and Ta was investigated with XRD, N2 physisorption, XPS and HRTEM and the catalytic activity of the catalysts under microwave irradiation in dry reforming of methane was tested in a microwave reactor. The results show that the introduction of Cr and Ta to Ni/CeO2 can enhance the interaction between Ni and the support/promoter and inhibit the enlargement of NiO particles during the synthesis. The CH4 conversions in dry reforming on the catalysts follow the order: Ni/CeO2<2Fe-Ni<2Ta-Ni<2Cr-Ni. The superior performance of 2Ta-Ni and 2Cr-Ni may be attributed to the locally-heated Ni particles caused by the strong microwave absorption of the in-situ grown graphene attached on them under microwave irradiation.

  13. Collective excitations in {sup 132}Ce; Excitations collectives de {sup 132}Ce

    Energy Technology Data Exchange (ETDEWEB)

    Paul, E.S.; Boston, A.J.; Zoss, D.T.; Nolan, P.J.; Sampson, J.A.; Semple, A.T. [Oliver Lodge Laboratory, University of Livepool, Liverpool (United Kingdom); Farget, F.; Gizon, A.; Gizon, J.; Santos, D. [Inst. des Sciences Nucleaires, Grenoble-1 Univ., 38 (France); Nyako, B.M. [Institute of Nuclear Research, Debrecen (Hungary); O`Brien, N.J.; Parry, C.M.; Wadsworth, W. [Department of Physics, University of York, Helsington, York (United Kingdom)

    1997-12-31

    The structure of normally deformed states ({beta}{sub 2}{approx}0.2) in {sup 132}Ce has been investigated using EUROGAM2. Eight {Delta}I=2 bands and three {Delta}I=1 bands have been identified up to spin 40. The results are interpreted with the aid of Woods-Saxon cranking calculations which suggest a variety of triaxial shapes stabilized by specific active quasiparticle orbitals. (authors)

  14. Valence fluctuation in CeMo2Si2C

    International Nuclear Information System (INIS)

    Highlights: •Evidence for valence fluctuation of Ce ions. •XAS provides average formal LIII valence of Ce. •Kadowaki Woods ratio and Sommerfeld Wilson ratio indicate Fermi-liquid behavior. •DFT calculations reveal strong hybridization between Ce 4f and Mo 4d states. -- Abstract: We report on the valence fluctuation of Ce in CeMo2Si2C as studied by means of magnetic susceptibility χ(T), specific heat C(T), electrical resistivity ρ(T) and X-ray absorption spectroscopy. Powder X-ray diffraction revealed that CeMo2Si2C crystallizes in CeCr2Si2C-type layered tetragonal crystal structure (space group P4/mmm). The unit cell volume of CeMo2Si2C deviates from the expected lanthanide contraction, indicating non-trivalent state of Ce ions in this compound. The observed weak temperature dependence of the magnetic susceptibility and its low value indicate that Ce ions are in valence fluctuating state. The formal LIII Ce valence in CeMo2Si2C〈ν∼〉=3.14 as determined from X-ray absorption spectroscopy measurement is well below the value 〈ν∼〉≃3.4 in tetravalent Ce compound CeO2. The temperature dependence of specific heat does not show any anomaly down to 1.8 K which rules out any magnetic ordering in the system. The Sommerfeld coefficient obtained from the specific heat data is γ = 23.4 mJ/mol K2. The electrical resistivity follows the T2 behavior in the low temperature range below 35 K confirming a Fermi liquid behavior. Accordingly both the Kadowaki Woods ratio A/γ2 and the Sommerfeld Wilson ratio χ(0)/γ are in the range expected for Fermi-liquid systems. In order to get some information on the electronic states, we calculated the band structure within the density functional theory, eventhough this approach is not able to treat 4f electrons accurately. The non-f electron states crossing the Fermi level have mostly Mo 4d character. They provide the states with which the 4f sates are strongly hybridized, leading to the intermediate valent state

  15. Properties of LuAP: CE scintillator containing intentional impurities

    CERN Document Server

    Petrosyan, A G; Ovanesyan, K; Lecoq, Paul; Auffray, Etiennette; Trummer, Julia; Kronberger, Matthias; Pédrini, C; Dujardin, C; Anfre, P

    2007-01-01

    Single crystals of LuAP:Ce and LuYAP(Lu*70%):Ce co-doped with tetravalent (Hf and Zr) and pentavalent (Ta) ions were grown from melts by the Bridgman process. Underlying absorption, slope of the optical edge and transmission in the range of emission were compared to those of LuAP:Ce crystals. Absorption coefficients at 260 nm less than 2 cm−1 have been recorded in LuAP:Ce crystals containing tetravalent ions that are lower than the corresponding figures (5–6 cm−1) measured in undoped LuAP. At high concentrations of added impurities, despite of suppression of the parasitic underlying absorption below 300 nm, the slope of the optical edge and transmission in the range of emission are seriously damaged. Scintillation parameters of crystals with added impurities are compared to those of LuAP:Ce.

  16. Moment dilution in the heavy fermion compound Ce2Bi

    International Nuclear Information System (INIS)

    The heavy fermion compound Ce2Bi has two inequivalent Ce-sites. La was doped on these sites to study the influence of the antiferromagnetic order on the high electronic contribution of the specific heat (γHT(T>TN)∼340mJ/Ce-molK2). The slightly larger La atom replaces the Ce2 site first and then subsequently the Ce1 site in the La2Sb structure. Lattice parameters, magnetic susceptibility and specific heat are used to elucidate the magnetic nature of the two different cerium sites. We find a somewhat enhanced γHT, a decrease in TN and furthermore a metamagnetic transition at 2.2T (2K), which is closely related to the long-range antiferromagnetic order. ((orig.))

  17. Photodynamic Processes in Fluoride Crystals Doped with Ce3+

    Directory of Open Access Journals (Sweden)

    Pavlov V.V.

    2015-01-01

    Full Text Available Integrated studies of photoelectric phenomena and their associated photodynamic processes in LiCaAlF6, LiLuF4, LiYF4, LiY0,5Lu0,5F4, SrAlF5 crystals doped with Ce3+ ions have been carried out using the combination of the methods of optical and dielectric spectroscopy. The numerical values of the basic parameters of photodynamic processes and their spectral dependence in 240 – 310 nm spectral range are evaluated. It has been shown that the most probable process, which leads to the photoionization of Ce3+ ions in LiYxLu1-xF4:Ce3+ (x=0; 0,5; 1 and LiCaAlF6:Ce3+ crystals, is excited-state absorption to the states of mixed configurations of Ce3+ ions localized near/in the conduction band of crystal.

  18. Decommissioning standards

    International Nuclear Information System (INIS)

    EPA has agreed to establish a series of environmental standards for the safe disposal of radioactive waste through participation in the Interagency Review Group on Nuclear Waste Management (IRG). One of the standards required under the IRG is the standard for decommissioning of radioactive contaminated sites, facilities, and materials. This standard is to be proposed by December 1980 and promulgated by December 1981. Several considerations are important in establishing these standards. This study includes discussions of some of these considerations and attempts to evaluate their relative importance. Items covered include: the form of the standards, timing for decommissioning, occupational radiation protection, costs and financial provisions. 4 refs

  19. Survey of research reactors

    International Nuclear Information System (INIS)

    A survey of reasearch reactors based on the IAEA Nuclear Research Reactor Data Base (RRDB) was done. This database includes information on 273 operating research reactors ranging in power from zero to several hundred MW. From these 273 operating research reactors 205 reactors have a power level below 5 MW, the remaining 68 reactors range from 5 MW up to several 100 MW thermal power. The major reactor types with common design are: Siemens Unterrichtsreaktors, 1.2 Argonaut reactors, Slowpoke reactors, the miniature neutron source reactors, TRIGA reactors, material testing reactors and high flux reactors. Technical data such as: power, fuel material, fuel type, enrichment, maximum neutron flux density and experimental facilities for each reactor type as well as a description of their utilization in physics and chemistry, medicine and biology, academic research and teaching, training purposes (students and physicists, operating personnel), industrial application (neutron radiography, silicon neutron transmutation doping facilities) are provided. The geographically distribution of these reactors is also shown. As conclusions the author discussed the advantages (low capital cost, low operating cost, low burn up, simple to operate, safe, less restrictive containment and sitting requirements, versatility) and disadvantages (lower sensitivity for NAA, limited radioisotope production, limited use of neutron beams, limited access to the core, licensing) of low power research reactors. 24 figs., refs. 15, Tab. 1 (nevyjel)

  20. Department of reactor technology

    International Nuclear Information System (INIS)

    The activities of the Department of Reactor Technology at Risoe during 1979 are described. The work is presented in five chapters: Reactor Engineering, Reactor Physics and Dynamics, Heat Transfer and Hydraulics, The DR 1 Reactor, and Non-Nuclear Activities. A list of the staff and of publications is included. (author)

  1. RB reactor noise analysis

    International Nuclear Information System (INIS)

    Statistical fluctuations of reactivity represent reactor noise. Analysis of reactor noise enables determining a series of reactor kinetic parameters. Fluctuations of power was measured by ionization chamber placed next to the tank of the RB reactor. The signal was digitized by an analog-digital converter. After calculation of the mean power, 3000 data obtained by sampling were analysed

  2. Basis for Interim Operation for the K-Reactor in Cold Standby

    Energy Technology Data Exchange (ETDEWEB)

    Shedrow, B.

    1998-10-19

    The Basis for Interim Operation (BIO) document for K Reactor in Cold Standby and the L- and P-Reactor Disassembly Basins was prepared in accordance with the draft DOE standard for BIO preparation (dated October 26, 1993).

  3. Basis for Interim Operation for the K-Reactor in Cold Standby

    International Nuclear Information System (INIS)

    The Basis for Interim Operation (BIO) document for K Reactor in Cold Standby and the L- and P-Reactor Disassembly Basins was prepared in accordance with the draft DOE standard for BIO preparation (dated October 26, 1993)

  4. The WWR-SM-20 research reactor

    International Nuclear Information System (INIS)

    In this paper the design features and experimental capabilities of the WWR-SM-20 research reactor are described. The reactor uses fuel assemblies consisting of six coaxial fuel tubes with a square cross-section. IRT-3M fuel assemblies can be used with both 90% enriched and 36% enriched uranium. The main characteristics of the IRT-3M fuel assemblies are given, as are the technical and physical parameters of the WWR-SM-20 reactor. The core can hold up to ten ampoule-type channels with a diameter of up to 68 mm. For irradiation purposes, up to 22 26-mm-diameter channels in the fuel assemblies, and up to 48 42-mm-diameter channels in the beryllium blocks of the reflector can be used. In the graphite blanket between the horizontal channels, channels with a diameter of up to 130 mm can be used. The thermal neutron flux density has a maximum value of 1.5 X 1018 m-2 · s-1 in the core and 2.3 X 1018 m-2 · s-1 in the reflector, and the fast neutron flux density (cE > 0.821 MeV) a maximum of 1.9 X 1018 m-2 · s-1. A number of design features have been incorporated in the WWR-SM-20 reactor to make it effectively safe

  5. Ordering of CeIII/CeIV and interstitial oxygens in CeTaO4+x (x ∼ 0.17) superstructure

    International Nuclear Information System (INIS)

    A structural model for CeTaO4+x (x ∼ 0.17) or alternately Ce4IIICe2IVTa6O25 (monoclinic, P21, a = 7.616(2), b = 16.459(5), c = 7.704(2) angstrom, β = 102.48(2)degree, Z = 2) is derived from X-ray powder diffraction data. The starting model was a 3 x b superstructure of CeTaO4+x (x = 0.0) with excess oxygen atoms occupying interstices between the Ce atom layers consistent with the electron diffraction determined space group symmetry P21. Unexpectedly, the four Ce atoms surrounding the interstitial oxygen are not oxidized. During the refinement the model was forced to be chemically plausible by restraining bond valence sums, bond lengths, and O-O distances. This was necessary due to the very weak scattering contribution to the XRD profile by oxygen atoms. The mechanism for oxidation of the subject phase from CeTaO4+x (x = 0.0) is discussed and a reason for the limiting composition for this phase is proposed

  6. Novelties in design and construction of the advanced reactors

    International Nuclear Information System (INIS)

    The advanced pressurized water reactors (APWR), advanced boiling water reactors (ABWR), advanced liquid metal reactors (ALMR), and modular high temperature gas-cooled reactors (MHTGR), as well as heavy water reactors (AHWR), are analyzed taking into account those characteristics which make them less complex, but safer than their current homologous ones. This fact simplifies their construction which reduces completion periods and costs, increasing safety and protection of the plants. It is demonstrated how the accumulated operational experience allows to find more standardized designs with some enhancement in the material and component technology and thus achieve also a better use of computerized systems

  7. Enthalpies of mixing in binary Fe-Sb, Ce-Fe and ternary Ce-Fe-Sb liquid alloys

    Energy Technology Data Exchange (ETDEWEB)

    Usenko, Natalia; Kotova, Natalia [Taras Shevchenko National Univ., Kyiv (Ukraine). Dept. of Chemistry; Ivanov, Michael; Berezutski, Vadim [National Academy of Sciences, Kyiv (Ukraine). I. Frantsevich Institute for Problems of Materials Science

    2016-01-15

    The enthalpies of mixing in liquid alloys in the binary Fe-Sb, Ce-Fe and ternary Ce-Fe-Sb systems were determined over a wide range of composition by means of isoperibolic calorimetry in the temperature range 1600-1830 K. The minimum values of the integral enthalpy of mixing (ΔH{sub min}) were determined to be (-2.32 ± 0.22) kJ . mol{sup -1} at x{sub Sb} = 0.5 in the Fe-Sb system, and (-0.97 ± 0.19) kJ . mol{sup -1} at x{sub Ce} = 0.35 in the Ce-Fe system. The enthalpies of mixing in liquid ternary Ce-Fe-Sb alloys were found to increase smoothly from the binary boundary systems Ce-Fe and Fe-Sb towards the Ce-Sb system, reaching the minimum value of (-107.5 ± 3.6) kJ . mol{sup -1} in the vicinity of the phase CeSb.

  8. Structural and electronic properties of Ce overlayers and low-dimensional Pt-Ce alloys on Pt{111}

    International Nuclear Information System (INIS)

    The structural, thermal, chemisorptive, and electronic properties of Ce on Pt{111} are studied by photoemission, Auger spectroscopy, scanning tunnel microscope (STM), and low-energy electron diffraction (LEED). Stranski-Krastanov-like growth of low-density Ce layers is accompanied by substantial valence charge transfer from Ce to Pt: in line with this, the measured dipole moment and polarizability of adsorbed Ce at low coverages are 7.2x10-30Cm and ∼1.3x10-29m3, respectively. Pt-Ce intermixing commences at ∼400K and with increasing temperature a sequence of five different ordered surface alloys evolves. The symmetry, periodicities, and rotational epitaxy observed by LEED are in good accord with the STM data which reveal the true complexity of the system. The various bimetallic surface phases are based on growth of crystalline Pt5Ce, a hexagonal layer structure consisting of alternating layers of Pt2Ce and Kagomacute e nets of Pt atoms. This characteristic ABAB layered arrangement of the surface alloys is clearly imaged, and chemisorption data permit a distinction to be made between the more reactive Pt2Ce layer and the less reactive Pt Kagomacute e net. Either type of layer can appear at the surface as the terminating structure, thicker films exhibiting unit mesh parameters characteristic of the bulk alloy. copyright 1997 The American Physical Society

  9. Ce4+/Ce3+-V2+/V3+氧化还原流动电池的可行性研究(Ⅱ)--旋转圆盘(RDE)与旋转环盘(RRDE)法对Ce4+/Ce3+氧化还原体系的研究%Studies on Feasibility of Ce4+/Ce3+ - V2+/V3+ Redox Flow Cell ( Ⅱ ) --Investigation of Ce4 +/Ce3 + Redox System by RDE and RRDE

    Institute of Scientific and Technical Information of China (English)

    夏熙; 刘洋; 刘洪涛

    2001-01-01

    用RDE与REDE法研究了Ce4+/Ce3+-V2+/V3+氧化还原流动电池中Ce4+/Ce3+体系的电化学动力学参数,以说明组成该新型氧化还原流动电池的可能性.用RDE法得出在铂电极表面与玻碳电极上均会生成一层氧化膜,对Ce3+的氧化反应产生阻碍作用.但在铂上的氧化膜对Ce4+的还原反应却有催化作用.用Rrde法得出Ce3+在玻碳电极上的氧化与析氧之间存在着竞争,为得到较高的Ce3+氧化效率,应控制氧化电流在2~8 mA@cm-2之间.

  10. Monte Carlo interpretation of the AMMON/REF experiment in EOLE for the JHR reactor neutron calculations

    International Nuclear Information System (INIS)

    A new experimental program, named AMMON, was performed between late 2010 and early 2013 in the EOLE zero-power experimental reactor at CEA Cadarache. It is dedicated to the analysis of the neutron and photon physics of the Jules Horowitz Reactor (JHR), the next international materials testing reactor under construction in France. The objective of the program is to provide measurement data for the experimental validation of the calculation tools developed for the JHR design and safety studies. The first core configuration, the so-called reference configuration, was loaded in 2012; it consisted of an experimental zone of seven JHR assemblies with U3Si2-Al, 27% 235U enriched fuel curved plates surrounded by a driver zone with 622 standard pressurized water reactor uranium oxide fuel pins. It has been instrumented and studied throughout the first year of the experimental program. The final analysis of the AMMON/REF neutron measurements is presented in this paper. It is based on calculations performed with the three-dimensional reference Monte Carlo TRIPOLI-4.7 code and the JEFF3.1.1 European library. The comparison between calculation and experiment makes it possible to calibrate the bias due to nuclear data on the calculated neutron parameters. It highlights good agreement between calculation and experiment concerning reactivity, power distribution in the experimental zone, fuel plate conversion ratios, and core kinetics parameters. The reactivity prediction is very satisfactory, despite the presence of a large aluminum quantity in the core: calculation-to-experiment comparison (C-E=)365 ± 334 pcm (1σ). For the other neutron parameters (assembly power distribution, plate conversion ratios, and kinetics parameters), the (C-E)/E discrepancies are within the experimental uncertainty (2σ). (authors)

  11. Accounting standards

    NARCIS (Netherlands)

    B. Stellinga

    2014-01-01

    The European and global regulation of accounting standards have witnessed remarkable changes over the past twenty years. In the early 1990s, EU accounting practices were fragmented along national lines and US accounting standards were the de facto global standards. Since 2005, all EU listed companie

  12. International Standards.

    Science.gov (United States)

    Havard-Williams, Peter

    1982-01-01

    Discussion of standardization on an international scale for resource sharing--cooperation, coordination, interlibrary loans, cooperative acquisition and cataloging--focuses on a definition of standards; the development of standards for cataloging; public, school, and university libraries; and library education. A 60-item bibliography is included.…

  13. C-E setpoint methodology. C-E local power density and DNB LSSS and LCO setpoint methodology for analog protection systems. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-04-01

    A description is presented of the methodology presently in use by Combustion Engineering to calculate Limiting Safety System Setting (LSSS) for the Local Power Density and Thermal Margin Trip Systems and Limiting Conditions for Operation (LCO) to assure that the specified acceptable fuel design limits are not exceeded during the design basis anticipated operational occurrences. The C-E Nuclear Steam Supply Systems for which the report is applicable are those incorporating the analog reactor protection system and licensed under the requirements of 10CFR50, Appendix A. The design basis events to be accommodated by the subject LSSS and LCO are discussed, and the methods to assure the required protection system response and initial required margin are described. The calculational techniques used to represent the specified acceptable fuel design limits in terms of monitored reactor parameters are provided. Using the resultant limits as a base, the methodology to synthesize the subject LSSS and LCO in terms of the parameters processed by the protection and monitoring systems is described.

  14. C-E setpoint methodology. C-E local power density and DNB LSSS and LCO setpoint methodology for analog protection systems

    International Nuclear Information System (INIS)

    A description is presented of the methodology presently in use by Combustion Engineering to calculate Limiting Safety System Setting (LSSS) for the Local Power Density and Thermal Margin Trip Systems and Limiting Conditions for Operation (LCO) to assure that the specified acceptable fuel design limits are not exceeded during the design basis anticipated operational occurrences. The C-E Nuclear Steam Supply Systems for which the report is applicable are those incorporating the analog reactor protection system and licensed under the requirements of 10CFR50, Appendix A. The design basis events to be accommodated by the subject LSSS and LCO are discussed, and the methods to assure the required protection system response and initial required margin are described. The calculational techniques used to represent the specified acceptable fuel design limits in terms of monitored reactor parameters are provided. Using the resultant limits as a base, the methodology to synthesize the subject LSSS and LCO in terms of the parameters processed by the protection and monitoring systems is described

  15. Research Nuclear Reactors

    International Nuclear Information System (INIS)

    Published in English and in French, this large report first proposes an overview of the use and history of research nuclear reactors. It discusses their definition, and presents the various types of research reactors which can be either related to nuclear power (critical mock-ups, material test reactors, safety test reactors, training reactors, prototypes), or to research (basic research, industry, health), or to specific particle physics phenomena (neutron diffraction, isotope production, neutron activation, neutron radiography, semiconductor doping). It reports the history of the French research reactors by distinguishing the first atomic pile (ZOE), and the activities and achievements during the fifties, the sixties and the seventies. It also addresses the development of instrumentation for research reactors (neutron, thermal, mechanical and fission gas release measurements). The other parts of the report concern the validation of neutronics calculations for different reactors (the EOLE water critical mock-up, the MASURCA air critical mock-up dedicated to fast neutron reactor study, the MINERVE water critical mock-up, the CALIBAN pulsed research reactor), the testing of materials under irradiation (OSIRIS reactor, laboratories associated with research reactors, the Jules Horowitz reactor and its experimental programs and related devices, irradiation of materials with ion beams), the investigation of accident situations (on the CABRI, Phebus, Silene and Jules Horowitz reactors). The last part proposes a worldwide overview of research reactors

  16. Commission of the European Communities review of fast reactor activities, March 1981

    International Nuclear Information System (INIS)

    The Commission of the European Communities continued its activities in the field of fast reactors development essentially in the frame of the Fast Reactor Coordinating Committee (FRCC) and by execution of a Reactor Programme at its Joint Research Center (JRC). The study was concerned with introducing fast reactors into European Community, elaboration of preliminary safety criteria and guidelines for typical fast reactor accidents; codes and standards; LMFBR safety, fuel, fuel cycle safety

  17. The formation of intermetallic compounds during interdiffusion of Mg–Al/Mg–Ce diffusion couples

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jiahong [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Jiang, Bin, E-mail: jiangbinrong@cqu.edu.cn [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Li, Xin [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Yang, Qingshan [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Dong, Hanwu [Chongqing Academy of Science and Technology, Chongqing 401123 (China); Xia, Xiangsheng [No. 59 Institute of China Ordnance Industry, Chongqing 400039 (China); Pan, Fusheng [College of Materials Science and Engineering, National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China)

    2015-01-15

    Graphical abstract: Al–Ce intermetallic compounds (IMCs) formed in Mg–Al/Mg–Ce diffusion couples. During the whole diffusion process, Al was the dominant diffusing species, and it substituted for Mg atoms of the Mg–Ce substrate. Five Al–Ce IMCs of Al{sub 4}Ce, Al{sub 11}Ce{sub 3}, Al{sub 3}Ce, Al{sub 2}Ce, and AlCe were formed via the reaction of Al and Ce. - Highlights: • Al–Ce IMCs formation in the Mg–Al/Mg–Ce diffusion couples was studied. • Formation of Al{sub 4}Ce as the first phase was rationalized using the Gibbs free energy. • The activation energy for the growth of the diffusion reaction zones was 36.6 kJ/mol. - Abstract: The formation of Al–Ce intermetallic compounds (IMCs) during interdiffusion of Mg–Al/Mg–Ce diffusion couples prepared by solid–liquid contact method was investigated at 623 K, 648 K and 673 K for 24 h, 48 h and 72 h, respectively. During the whole diffusion process, Al was the dominant diffusing species, and it substituted for Mg of the Mg–Ce substrate. Five Al–Ce IMCs of Al{sub 4}Ce, Al{sub 11}Ce{sub 3}, Al{sub 3}Ce, Al{sub 2}Ce and AlCe were formed via the reaction of Al and Ce. The formation of Al{sub 4}Ce as the first kind of IMC was rationalized on the basis of an effective Gibbs free energy model. The activation energy for the growth of the total diffusion reaction layer was 36.6 kJ/mol.

  18. Safety of Ghana Research Reactor (GHARR-1)

    International Nuclear Information System (INIS)

    The Ghana Research Reactor, GHARR-1 is a low power research rector with maximum thermal power lever of 30kW. The reactor is inherently safe and uses highly enriched uranium (HEU) as fuel, light water as moderator and beryllium as a reflector. The construction, commissioning and operation of this reactor have been subjected to the system of authorization and inspection developed by the Regulatory Authority, the Radiation Protection Board (RPB) with the assistance of the International Atomic Energy Agency. The reactor has been regulated by the preparation of an Interim Safety Analysis Report (SAR) based upon International Atomic Energy Agency standards. An International Safety Assessment peer review and safe inspections have confirmed a high level of operational safety of the reactor since it started operation in 1994. Since its operation there has been no significant reported incident/accidents. Several studies have validated the inherent safety of the reactor. The reactor has been used for neutron activation analysis of various samples, research and teaching. About 1000 samples are analysed annually. The final Safety Analysis Report (SAR) was submitted (after five years of extensive research on the operational reactor) to the Regulatory Authority for review in June 2000. (author)

  19. Reactor Physics Training

    International Nuclear Information System (INIS)

    University courses in nuclear reactor physics at the universities consist of a theoretical description of the physics and technology of nuclear reactors. In order to demonstrate the basic concepts in reactor physics, training exercises in nuclear reactor installations are also desirable. Since the number of reactor facilities is however strongly decreasing in Europe, it becomes difficult to offer to students a means for demonstrating the basic concepts in reactor physics by performing training exercises in nuclear installations. Universities do not generally possess the capabilities for performing training exercises. Therefore, SCK-CEN offers universities the possibility to perform (on a commercial basis) training exercises at its infrastructure consisting of two research reactors (BR1 and VENUS). Besides the organisation of training exercises in the framework of university courses, SCK-CEN also organizes theoretical courses in reactor physics for the education and training of nuclear reactor operators. It is indeed a very important subject to guarantee the safe operation of present and future nuclear reactors. In this framework, an understanding of the fundamental principles of nuclear reactor physics is also necessary for reactor operators. Therefore, the organisation of a basic Nuclear reactor physics course at the level of reactor operators in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The objectives this activity are: (1) to provide training and education activities in reactor physics for university students and (2) to organise courses in nuclear reactor physics for reactor operators

  20. Introduction of Nuclear Reactor Engineering

    International Nuclear Information System (INIS)

    This book introduces development, status, supply and demand and resource of nuclear reactor. It deals with basic knowledge of nuclear reactor, which are reactor system, heat recovery in reactor core, structural feature in reactor, materials of structure in reactor, shielding of gamma ray, shielding of reactor, safety and environmental problem of nuclear power plant, nuclear fuel and economical efficiency of nuclear energy.

  1. Research Reactors: Decommissioning of a Small Reactor (BR3 Reactor, Belgium). Appendix III

    International Nuclear Information System (INIS)

    Research reactors are nuclear reactors that serve primarily as source of neutrons. They are less complex than power reactors and operate at lower temperatures. Research reactors need far less fuel, and far less fission products build up as the fuel is used. On the other hand, their fuel requires more highly enriched uranium, typically up to 20% 235U. More than 650 research reactors worldwide have been built or are under construction or in a planning phase; of which more than 350 have been shut down and partly or wholly decommissioned. Experience has shown that decommissioning can be undertaken in line with safety standards aimed at protecting human beings or the environment from harm, provided that decommissioning activities are undertaken in accordance with a properly formulated plan. The potential or actual radiological hazards associated with reactors may require the application of special techniques and procedures during decommissioning. The decommissioning of the BR3 reactor in Mol, Belgium, Belgian nuclear research centre SCK•CEN, provides an example of current good practice in decommissioning research reactors.13 Since 1991, the organization’s statutory mission gives priority to research on problems of societal concern such as the safety of nuclear installations, radiation protection, safe treatment and disposal of radioactive waste, fighting against uncontrolled proliferation of fissile materials, and education and training. BR3 was the first European pressurized water reactor (PWR) power plant and was put into service in 1962. It was in that industrial context that the BR3 has played its role as a demonstration unit for the development and improvement of decommissioning related techniques. While the BR3 power level was low (40 MW(th), 10.5 MW(e) net), it contains all the features of commercial PWR power plants. The reactor was used at the beginning of its lifetime as a training facility for future nuclear power plant operators. Later, it was also used

  2. Morphology and Spectral Properties Study of LaCeF 3 ∶Tb Microcrystalline%LaCeF3∶Tb微晶的合成及光谱性质研究

    Institute of Scientific and Technical Information of China (English)

    姜浩; 白晓菲; 闫景辉; 邹明强

    2015-01-01

    LaCeF3 ∶Tb microcrystalline was synthesized by microemulsion method ,oleic acid-assisted solvothermal method ,ul-trasonic-assisted solvothermal method separately .LaCeF3 ∶ Tb microcrystalline synthesized by ultrasonic-assisted solvothermal method is rarely reported .Using X-ray diffraction (XRD) ,scanning electron microscope (SEM ) ,fluorescence spectroscopy (PL) method such as the crystal phase ,morphology and luminescence properties of the samples have been characterized .XRD results show that the crystallization product is good ,microcrystalline and standard card PDF# 38-0452 (the six-party LaCeF3 ) is corresponding ,SEM images showing the product has uniform size and morphology ,under 250 nm excitation nanoparticles shows strong green light ,the main emission peaks respectively belonged to 5 D4 → 7 F6 (489 nm) ,5 D4 → 7 F5 (545 nm) ,5 D4 → 7 F4 (585 nm)and 5 D4 → 7 F3 (621 nm) transition of Tb3+ .Through LaCeF3 and LaCeF3 ∶Tb spectral studies prove the existence of the Ce-Tb energy transfer .Calculated the critical doping concentration of Tb in LaCeF3 microcrystalline synthesized by different methods .%采用微乳液法、油酸辅助溶剂热法、超声波辅助溶剂热法分别合成了LaCeF3∶T b微晶。使用超声波辅助溶剂热法合成LaCeF3∶Tb微晶鲜有报道。利用X射线衍射(XRD)、扫描电子显微镜(SEM )、荧光光谱(PL )等方法对样品的晶相、形貌和发光性能进行了表征。XRD结果表明产物结晶良好,微晶与标准卡片PDF#38-0452(六方相LaCeF3)对应;SEM图像显示产物形貌、尺寸均一;在250 nm光的激发下,纳米粒子发出强绿色光,主要发射峰分别归属于Tb3+的5D4→7F6(489nm),5D4→7F5(543nm),5D4→7F4(585nm)和5 D4→7 F3(621 nm)跃迁。通过对LaCeF3和LaCeF3∶Tb光谱的研究证明了Ce→Tb能量传递的存在。计算了Tb在不同方法合成的LaCeF3微晶中的临界掺杂浓度。

  3. Proton induced reactions on 159Tb and 139La for producing 159Dy and 139Ce

    International Nuclear Information System (INIS)

    The radionuclides 159Dy (T1/2 =144 d) and 139Ce (T1/2=137.64 d) are potentially important for medical purposes. The first radioisotope is important for transmission imaging and bone mineral analysis. The other one is convenient as a standard source. In the present work the possibility of their production at M GC-20 cyclotron was investigated through the (p,n) reactions on natTb and natLa. Excitation functions were measured from the respective threshold of 159Tb(p,n)159Dy and 139La(p,n)139Ce reactions up to 18 MeV and 14.7 MeV, respectively, using the stacked-foil technique. Radioactivity of the produced radionuclides was measured using high resolution gamma ray spectrometer. Natural copper foils were used as monitors. Nuclear model calculations were performed using ALICE-91, ALICE-IPPE and EMPIRE-2.19 codes. The experimental results were compared with the theoretical calculations as well as with the previously reported data. Integral yields for the produced 159Dy and 139Ce were also calculated

  4. Reactor calculations for improving utilization of TRIGA reactor

    International Nuclear Information System (INIS)

    A brief review of our work on reactor calculations of 250 kW TRIGA with mixed core (standard + FLIP fuel) will be presented. The following aspects will be treated: - development of computer programs; - optimization of in-core fuel management with respect to fuel costs and irradiation channels utilization. TRIGAP programme package will be presented as an example of computer programs. It is based on 2-group 1-D diffusion approximation and besides calculations offers possibilities for operational data logging and fuel inventory book-keeping as well. It is developed primarily for the research reactor operators as a tool for analysing reactor operation and fuel management. For this reason it is arranged for a small (PC) computer. Second part will be devoted to reactor physics properties of the mixed cores. Results of depletion calculations will be presented together with measured data to confirm some general guidelines for optimal mixed core fuel management. As the results are obtained using TRIGAP program package results can be also considered as an illustration and qualification for its application. (author)

  5. Characterizations of electrodeposited Ni–CeO2 nanocomposite coatings

    International Nuclear Information System (INIS)

    The expansion of current machinery requires metallic materials with better surface properties. In the present investigation, CeO2 reinforced nickel nanocomposite coatings were deposited on mild steel substrate by direct current electrodeposition process employing nickel acetate bath. The effect of incorporation of CeO2 particles in the Ni nanocomposite coatings on the micro hardness and corrosion behaviour has been evaluated. Smooth and compact nanocomposite deposits containing well-distributed cerium oxide particles were obtained. The crystallite structure was fcc for electrodeposited nickel and Ni–CeO2 nanocomposite coatings. It has been observed that, the presence of CeO2 nanoparticles favours the [111] and [200] texture of nickel matrix. The co-deposition of CeO2 nanoparticles with nickel was found to be favoured at applied current density of 8 A dm−2. The micro hardness values of the nickel nanocomposite coatings (725 HV) was higher than that of pure nickel (265 HV).The decrease in Icorr values and increase in Constant Phase Element values were investigated in 3.5% NaCl solution which showed the higher corrosion resistant nature of Ni–CeO2 coatings. - Highlights: • Ni–CeO2 composite coatings have electrodeposited from eco-friendly acetate bath. • Inclusion of CeO2 in the composite coating has refined the crystallite size. • Micro hardness values have increased with CeO2 content in the composite coatings. • The negative shift of Ecorr confirming cathodic protective nature of coatings

  6. Nitrate conversion and supercritical fluid extraction of UO2-CeO2 solid solution prepared by an electrolytic reduction-coprecipitation method

    International Nuclear Information System (INIS)

    A low-waste technology for the reprocessing of spent nuclear fuel (SNF) has been developed recently, which involves the conversion of actinide and lanthanide oxides with liquid N2O4 into their nitrates followed by supercritical fluid extraction of the nitrates. The possibility of the reprocessing of SNF from high-temperature gas-cooled reactors (HTGRs) with nitrate conversion and supercritical fluid extraction is a current area of research in China. Here, a UO2-CeO2 solid solution was prepared as a surrogate for a UO2-PuO2 solid solution, and the recovery of U and Ce from the UO2-CeO2 solid solution with liquid N2O4 and supercritical CO2 containing tri-n-butyl phosphate (TBP) was investigated. The UO2-CeO2 solid solution prepared by electrolytic reduction-coprecipitation method had square plate microstructures. The solid solution after heat treatment was completely converted into nitrates with liquid N2O4. The XRD pattern of the nitrates was similar to that of UO2(NO3)2 . 3H2O. After 120 min of online extraction at 25 MPa and 50 , 99.98% of the U and 98.74% of the Ce were recovered from the nitrates with supercritical CO2 containing TBP. The results suggest a promising potential technology for the reprocessing of SNF from HTGRs. (orig.)

  7. Safeguarding research reactors

    International Nuclear Information System (INIS)

    The report is organized in four sections, including the introduction. The second section contains a discussion of the characteristics and attributes of research reactors important to safeguards. In this section, research reactors are described according to their power level, if greater than 25 thermal megawatts, or according to each fuel type. This descriptive discussion includes both reactor and reactor fuel information of a generic nature, according to the following categories. 1. Research reactors with more than 25 megawatts thermal power, 2. Plate fuelled reactors, 3. Assembly fuelled reactors. 4. Research reactors fuelled with individual rods. 5. Disk fuelled reactors, and 6. Research reactors fuelled with aqueous homogeneous fuel. The third section consists of a brief discussion of general IAEA safeguards as they apply to research reactors. This section is based on IAEA safeguards implementation documents and technical reports that are used to establish Agency-State agreements and facility attachments. The fourth and last section describes inspection activities at research reactors necessary to meet Agency objectives. The scope of the activities extends to both pre and post inspection as well as the on-site inspection and includes the examination of records and reports relative to reactor operation and to receipts, shipments and certain internal transfers, periodic verification of fresh fuel, spent fuel and core fuel, activities related to containment and surveillance, and other selected activities, depending on the reactor

  8. Research nuclear reactors

    International Nuclear Information System (INIS)

    Since the divergence of the first nuclear reactor in 1942, about 600 research or test reactors have been built throughout the world. Today 255 research reactors are operating in 57 countries and about 70% are over 25 years old. Whereas there are very few reactor types for power plants because of rationalization and standardisation, there is a great diversity of research reactors. We can divide them into 2 groups: heavy water cooled reactors and light water moderated reactors. Heavy water cooled reactors are dedicated to the production of high flux of thermal neutrons which are extracted from the core by means of neutronic channels. Light water moderated reactors involved pool reactors and slightly pressurized closed reactors, they are polyvalent but their main purposes are material testing, technological irradiations, radionuclide production and neutron radiography. At the moment 8 research reactors are being built in Canada, Germany, Iran, Japan, Kazakhstan, Morocco, Russia and Slovakia and 8 others are planned in 7 countries (France, Indonesia, Nigeria, Russia, Slovakia, Thailand and Tunisia. Different research reactors are described: Phebus, Masurca, Phenix and Petten HFR. The general principles of nuclear safety applied to test reactors are presented. (A.C.)

  9. CE-merkityn murskeen tuottaminen rakennusurakan sivutuottena - kannattavuusselvitys

    OpenAIRE

    Komulainen, Ville

    2014-01-01

    Työssä tutkittiin murskatun kiviaineksen CE-merkintäperusteita sekä mitä tuotannollisia sekä laadullisia vaatimuksia kiviainestuotannolle CE-merkintä edellyttää. Lisäksi tutkittiin, onko mahdollista saada CE-merkityn kiviaineksen tuotanto ISO 9001 -standardin sisältävän laadunhallintajärjestelmän alle ja voiko tuotanto olla osa kyseistä laadunhallintajärjestelmää. Työ tehdään Graniittirakennus Kallio Oy:lle. Tuotannon kannattavuusselvityksen osalta tutkittiin eri tuotantomalleja, mikä on ...

  10. Template electrosynthesis of CeO2 nanotubes

    International Nuclear Information System (INIS)

    Nanotube arrays of CeO2 were produced in a single step by potentiostatic electrochemical deposition from a non-aqueous electrolyte, using anodic alumina membrane templates. The CeO2 nanotubes showed a polycrystalline structure, and they were assembled in the membrane nanochannels. The nanotubes had somewhat uniform diameters, with an average external value of about 210 nm, and a maximum length of about 60 μm; the latter parameter was controlled by the electrodeposition time. Each single nanotube was found to consist of crystalline grains having a size of about 3 nm. Raman analysis shows that these CeO2 nanotubes are suitable for catalytic applications

  11. Non-Fermi Liquid Scaling in CeRhSn

    International Nuclear Information System (INIS)

    We have recently shown that CeRhSn exhibits non-Fermi liquid temperature dependences in its low-temperature physical properties. Here we suggest that the non-Fermi liquid behavior observed in CeRhSn may be due to the existence of a Griffiths phase in the vicinity of a quantum critical point, based on electrical resistivity, magnetic susceptibility , and specific heat measurements. For CeRhSn, the low-temperature scaling of bulk properties (C/T ∝ χ ∝ T-1+λ, where λ<1) is masked by an anomaly at about 6 K, which is of magnetic origin. (author)

  12. Growth of LGSO: Ce crystals by the Czochralski method

    International Nuclear Information System (INIS)

    Single crystals of Lu2xGd2-2xSiO5: Ce (0 1/c to C2/c in the course of substitution of lutetium for gadolinium occurs at the ratio Lu/(Lu + Gd) = 0.1. The lattice thus formed with symmetry C2/c in the structure of Lu2xGd2-2xSiO5: Ce crystals favors the maximum possible incorporation of Ce3+ ions into the sevenfold-coordinated position with respect to oxygen. This explains the substantial improvement of the scintillation characteristics of the grown crystals.

  13. Properties and practical application of thin CeOx films

    Directory of Open Access Journals (Sweden)

    Maksimchuk N. V.

    2010-10-01

    Full Text Available The properties of CeOx films produced by various methods have been investigated. According to the comparative analisys “metallic mirror oxidation” method allows to produce films with significantly better characteristics than the «explosive evaporation» method. Though the latter method yields higher photosensitivity of CeOx films and structures on their base. In the process the optimal value of the substrate temperature was determined. Obtained data expand the CeOx application potential in microelectronic sensor sphere.

  14. Catalytic wet peroxide oxidation of phenol solutions over CuO/CeO2 systems

    International Nuclear Information System (INIS)

    Three 5% CuO/CeO2 catalysts were synthesized by sol-gel, precipitation and combustion methods, followed by incipient wetness impregnation with copper nitrate. The samples were characterized by XRD, TPR, BET and tested for the catalytic wet peroxide oxidation of a phenol solution (5 g/L). The reaction took place in a batch reactor at atmospheric pressure, in a temperature range of 60-80°C , during 4 h. Phenol conversion, H2O2 consumption, pH and chemical oxygen demand were determined. The reaction temperature and the catalyst loading did improve the phenol and the H2O2 conversions. The effect on the selectivity towards complete mineralization was less marked, with levels among 60-70%. Stepwise addition of H2O2 was also tested.

  15. Preparation of 14Ce-TZP ceramic powder by co-precipitation method

    International Nuclear Information System (INIS)

    There are several methods to prepare the above powder, but precipitation and co-precipitation methods are usually used to manufacture high performance ceramics in electronic applications and uranium dioxide in the nuclear material technology. Based on the rule that stipulates requirements of major physico-chemical characteristics of the ceramic powder and feasibility of practice development, operating conditions for preparing 14Ce-TZP ceramic powder are calculated and verified by using continuous stirred tank reactor in continuous operation mode. The obtained ceramic powder has typical physical behaviors such as filterability, compressibility, sinterability, average particle size (APS), specific surface area (SSA) and distribution form of particle size similar to that of UO2 powder used in the nuclear material production. The density of final ceramics made of the powder is in the range of 5.82 - 5.88, equivalent to 97 - 98% TD. (author)

  16. A unique CE16 acetyl esterase from Podospora anserina active on polymeric xylan.

    Science.gov (United States)

    Puchart, Vladimír; Berrin, Jean-Guy; Haon, Mireille; Biely, Peter

    2015-12-01

    The genome of the coprophilous fungus Podospora anserina displays an impressive array of genes encoding hemicellulolytic enzymes. In this study, we focused on a putative carbohydrate esterase (CE) from family 16 (CE16) that bears a carbohydrate-binding module from family CBM1. The protein was heterologously expressed in Pichia pastoris and purified to electrophoretic homogeneity. The P. anserina CE16 enzyme (PaCE16A) exhibited different catalytic properties than so far known CE16 esterases represented by the Trichoderma reesei CE16 acetyl esterase (TrCE16). A common property of both CE16 esterases is their exodeacetylase activity, i.e., deesterification at positions 3 and 4 of monomeric xylosides and the nonreducing end xylopyranosyl (Xylp) residue of oligomeric homologues. However, the PaCE16A showed lower positional specificity than TrCE16 and efficiently deacetylated also position 2. The major difference observed between PaCE16A and TrCE16 was found on polymeric substrate, acetylglucuronoxylan. While TrCE16 does not attack internal acetyl groups, PaCE16A deacetylated singly and doubly acetylated Xylp residues in the polymer to such an extent that it resulted in the polymer precipitation. Similarly as typical acetylxylan esterases belonging to CE1, CE4, CE5, and CE6 families, PaCE16A did not attack 3-O-acetyl group of xylopyranosyl residues carrying 4-O-methyl-D-glucuronic acid at position 2. PaCE16A thus represents a CE16 member displaying unique catalytic properties, which are intermediate between the TrCE16 exodeacetylase and acetylxylan esterases designed to deacetylate polymeric substrate. The catalytic versatility of PaCE16A makes the enzyme an important candidate for biotechnological applications. PMID:26329850

  17. Nuclear reactor building

    International Nuclear Information System (INIS)

    Purpose: To prevent seismic vibrations of external buildings from transmitting to the side walls of a reactor container in a tank type FBR reactor building. Constitution: The reactor building is structured such that the base mat for a reactor container chamber and a reactor container is separated from the base mat for the walls of building, and gas-tight material such as silicon rubber is filled in the gap therebetween. With such a constitution, even if the crane-supporting wall vibrates violently upon occurrence of earthqualkes, the seismic vibrations do not transmit toward the reactor container chamber. (Horiuchi, T.)

  18. Study on characteristics of bias caused by FI-CE split flow electrokinetic injection

    Institute of Scientific and Technical Information of China (English)

    Luo Jinwen; Zhu Hailin; Li Huilin

    2006-01-01

    The characteristics of bias caused by split-flow electrokinetic injection(SEKI),a new type of sample injection method used in coupled flow injection-capillary electrophoresis system(FI-CE),was investigated using pseudoephedrine hydrochloride,a basic drug,and ibuprofen,an acidic drug,as model analytes.It was found that bias imposed by SEKI under the condition of continuous sample matrix/running buffer was similar to that done by electrokinetic injection(EKI).The linearity of calibration curve provided by SEKI was similar to that offered by non-bias hydrodynamic injection(HDI)but significantly better than that obtained by EKI.These features were exploited to improve analytical performances in simultaneous determination of the minor ingredient of pseudoephedrine hydrochloride and the major ingredient of ibuprofen in a pharmaceutical preparation.Detectability of 0.7 mg/l for pseudoephedrine hydrochloride was achieved at a sample throughput rate of 24 times per hour,which is 30%lower than that obtained by HDI-based conventional CE.Relative standard deviations(RSDs)of 2.8%for the minor ingredient and 1.2%for the major ingredient were produced in 11 runs of a test solution containing 13.1 mg/l pseudoephedrine hydrochloride and 81.4 mg/l ibuprofen.This is an improvement compared to that obtained by HDI-based conventional CE.Analytical results for two batches of compound ibuprofen tablets by the SEKI-based FI-CE approach were in good agreement with that obtained by a conventional high performance liquid chromatographic method.

  19. Sensitive CE-MS analysis of potentially genotoxic alkylation compounds using derivatization and electrokinetic injection.

    Science.gov (United States)

    van Wijk, A M; Niederländer, H A G; van Ogten, M D; de Jong, G J

    2015-05-18

    A CE-MS method has been developed to detect trace levels of potentially genotoxic alkyl halides. After derivatization of the target components with 4-dimethylaminopyridine (DMAP) or butyl 1-(pyridinyl-4yl) piperidine 4-carboxylate (BPPC), the natively positively charged derivatives are pre-concentrated by applying electrokinetic injection and separated by a highly efficient CZE method using a background electrolyte (BGE) consisting of 100mM of TRIS adjusted to pH 2.5 with phosphoric acid. Using a sheath liquid interface, subsequent MS detection allows highly specific and sensitive analysis of alkyl halides. Conditions for electrokinetic injection were optimized to allow selective and effective injection. Injection of samples with low water content at 10 kV for 150 s using a high concentration of buffer in the BGE resulted in optimum sample stacking during injection and a highly efficient CE separation. At the sample pH applied, neutral and negatively charged components are shown to be selectively discarded, resulting in injection of positively charged ions only. The sample matrix influences the efficiency of the injection, but when using an internal standard, reproducibilities better than 10% RSD are obtained. Relative recoveries of the derivatives spiked to different types of model API between 85 and 115% demonstrate that the method can be applied for quantitative analysis. Detection limits of lower than 1 mg kg(-1) for the tested alkyl halides obtained in CE-MS at least equal the sensitivity obtained in LC-MS. The CE-MS method is a valuable alternative for the LC-MS method used for analysis of alkylation compounds. PMID:25910449

  20. Radon alpha and gamma-ray spectrometry with YAP:Ce-scintillator

    International Nuclear Information System (INIS)

    Full text: The detection properties of a YAP:Ce scintillator (YAlO 3:Ce crystal) for radon and radon daughters alpha and gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg C and in acids solutions such as HCl (37%), H2SO4 (48%) and HNO3 (65%) have been performed. The experimental array consisted of a bare cylindrical crystal of YAP:Ce optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocatode. The crystal size was 8 mm diameter and 30 mm height. The crystal was positioned at the geometrical center of a 6 l stainless steel light- and gas-tight vessel equipped with gas input/output and a pass-through electrical connectors. Output signals were integrated with a charge preamplifier, shaped with a spectroscopy amplifier (ORTEC-450) and processed by a multichannel analyzer card (ORTEC-Trump). The collected pulse-height spectrum was managed by a suitable MCA emulation software (ORTEC-Maestro32). The device was serially connected to the radon Reference Measurement System (RMS) developed at the National Institute for Metrology of Ionizing Radiations (INMRI-ENEA). The RMS is routinely used for calibration and testing of radon measuring instruments and it provided the reference radon- in-air activity concentration needed for efficiency calibration of the YAP:Ce radon spectrometer. The RMS is based on a cylindrical electrostatic cell with a Si detector. It is used for the alpha spectrometry of the electrostatically collected polonium ions produced in the decay of radon. The radioactive source section consisted in a 35 cm3 glass bulb filled with about 15 kBq radon in air. The internal volume of the whole circuit was about 10 l. The energy calibration curves of the device were obtained irradiating the crystal by means of a set of

  1. HumanViCe: Host ceRNA network in virus infected cells in human

    Directory of Open Access Journals (Sweden)

    Suman eGhosal

    2014-07-01

    Full Text Available Host-virus interaction via host cellular components has been an important field of research in recent times. RNA interference mediated by short interfering RNAs and microRNAs (miRNA, is a widespread anti-viral defence strategy. Importantly, viruses also encode their own miRNAs. In recent times miRNAs were identified as key players in host-virus interaction. Furthermore, viruses were shown to exploit the host miRNA networks to suite their own need. The complex cross-talk between host and viral miRNAs and their cellular and viral targets forms the environment for viral pathogenesis. Apart from protein-coding mRNAs, non-coding RNAs may also be targeted by host or viral miRNAs in virus infected cells, and viruses can exploit the host miRNA mediated gene regulatory network via the competing endogenous RNA effect. A recent report showed that viral U-rich non-coding RNAs called HSUR, expressed in primate virus herpesvirus saimiri (HVS infected T cells, were able to bind to three host miRNAs, causing significant alteration in cellular level for one of the miRNAs. We have predicted protein coding and non protein-coding targets for viral and human miRNAs in virus infected cells. We identified viral miRNA targets within host non-coding RNA loci from AGO interacting regions in three different virus infected cells. Gene ontology (GO and pathway enrichment analysis of the genes comprising the ceRNA networks in the virus infected cells revealed enrichment of key cellular signalling pathways related to cell fate decisions and gene transcription, like Notch and Wnt signalling pathways, as well as pathways related to viral entry, replication and virulence. We identified a vast number of non-coding transcripts playing as potential ceRNAs to the immune response associated genes; e.g. APOBEC family genes, in some virus infected cells. All these information are compiled in HumanViCe, a comprehensive database that provides the potential ceRNA networks in virus

  2. GE's advanced nuclear reactor designs

    International Nuclear Information System (INIS)

    The excess of US electrical generating capacity which has existed for the past 15 years is coming to an end as we enter the 1990s. Environmental and energy security issues associated with fossil fuels are kindling renewed interest in the nuclear option. The importance of these issues are underscored by the National Energy Strategy (NES) which calls for actions which open-quotes are designed to ensure that the nuclear power option is available to utilities.close quotes Utilities, utility associations, and nuclear suppliers, under the leadership of the Nuclear Power Oversight Committee (NPOC), have jointly developed a 14-point strategic plan aimed at establishing a predictable regulatory environment, standardized and pre-licensed Advanced Light Water Reactor (ALWR) nuclear plants, resolving the long-term waste management issue, and other open-quotes enabling conditions.close quotes GE is participating in this national effort and GE's family of advanced nuclear power plants feature two reactor designs, developed on a common technology base, aimed at providing a new generation of nuclear plants to provide safe, clean, economical electricity to the world's utilities in the 1990s and beyond. Together, the large-size (1300 MWe) Advanced Boiling Water Reactor (ABWR) and the small-size (600 MWe) Simplified Boiling Water Reactor (SBWR) are innovative, near-term candidates for expanding electrical generating capacity in the US and worldwide. Both possess the features necessary to do so safety, reliably, and economically

  3. SP-100 Reactor Subsystem Development

    Science.gov (United States)

    Demuth, Scott F.

    1994-07-01

    The SP-100 reactor subsystem consists of the pressure vessel, vessel internals, and fuel elements. Type A (standard) Nb-1Zr and rhenium materials development efforts related to fabrication of the vessel, vessel internals, and fuel cladding/liner have been completed. Type A and Type C (PWC-11) Nb-1Zr loop fabrication has been successfully demonstrated by prototypic testing with flowing lithium at 1350 K for 1500 hr. Development of UN fuel has been completed, and the performance validated by irradiation testing to the full life (7 yr. full power) burnup of 6 atom %. Neutronic and hydraulic core performance have been validated by engineering mockup critical experiments in the Zero Power Physics Reactor at Argonne National Laboratory, and detailed core hydraulic flow testing with water. Essentially all feasibility issues have been settled for the full life SP-100 reactor subsystem. Remaining SP-100 reactor subsystem development efforts are focused on further reducing mass by the use of Type C (PWC-11) Nb-1Zr rather than Type A, and demonstrating fuel life for beyond full life to perhaps 9 atom % burnup.

  4. Analysis of large and non-standard geometry samples of ancient potteries by internal monostandard neutron activation analysis using in situ detection efficiency

    International Nuclear Information System (INIS)

    The k0-based internal monostandard neutron activation analysis (IM-NAA) method was used for the analysis of 30 large and non-standard geometry ancient pottery samples obtained from Buddhist sites of Andhra Pradesh, India. One freshly finished pottery and a sun-drenched pottery were also analyzed for comparison. Samples were irradiated in thermal column facility of Apsara reactor and also in graphite reflector position of critical facility of Bhabha Atomic Research Centre. Radioactive assay was carried out using a 40% relative efficiency HPGe detector coupled to MCA. Concentration ratios of 15 elements with respect to Sc were determined. The La/Ce values as well as statistical cluster analysis utilizing concentration ratios of elements were used for grouping/provenance of the potteries. (author)

  5. Communications standards

    CERN Document Server

    Stokes, A V

    1986-01-01

    Communications Standards deals with the standardization of computer communication networks. This book examines the types of local area networks (LANs) that have been developed and looks at some of the relevant protocols in more detail. The work of Project 802 is briefly discussed, along with a protocol which has developed from one of the LAN standards and is now a de facto standard in one particular area, namely the Manufacturing Automation Protocol (MAP). Factors that affect the usage of networks, such as network management and security, are also considered. This book is divided into three se

  6. Reactor Physics Programme

    International Nuclear Information System (INIS)

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies

  7. Review of ANS-19 standards and activities

    International Nuclear Information System (INIS)

    The standards subcommittee ANS-19, 'Physics of Reactor Design' sponsored by the ANS Reactor Physics Division, has been in existence since 1972. Five standards have been produced, two data review groups have been established, and a working group has reviewed reactor physics terms for inclusion in the N 1.1 American National Standard Glossary of Terms in Nuclear Science and Technology. Much to the disappointment of those of us involved in their development, these standards have for the most part been uniformly ignored by all segments of the nuclear industry. Nevertheless, there is still great interest in revising the standards to make them more useful. It is hoped that the changes now under consideration as well as possible new standards areas of physics inputs to safety and transient calculations and operational power reactor measurements for license compliance will help to bring this about. There is a general feeling that within the large and diverse nuclear industry there is real benefit to be gained both technically and in public perception by the introduction of increasing standardization of good engineering practices. Such standardization to have maximum benefit must come from the technical experts within the industry, rather than being imposed by the regulators. (orig.)

  8. Optical properties of CeNi{sub 5} and CeNi{sub 4}M (M = Al, Cu) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Yu. V., E-mail: knyazev@imp.uran.ru [Institute of Metal Physics, Ural Division, RAS, 18 Kovalevskaya St., 620990 Ekaterinburg (Russian Federation); Kuz' min, Yu. I.; Kuchin, A.G. [Institute of Metal Physics, Ural Division, RAS, 18 Kovalevskaya St., 620990 Ekaterinburg (Russian Federation)

    2011-01-21

    The experimental study of the optical properties of CeNi{sub 5}, CeNi{sub 4}Cu and CeNi{sub 4}Al compounds was carried out in the 0.083-5.64 eV energy range using the ellipsometry method. The optical constants, dielectric functions and electronic parameters (plasma and relaxation frequencies) were determined. The energy dependencies of the optical interband conductivities are discussed by using the available information on the electronic band structure of these compounds. In the ternary alloys the optical spectra show the presence of peculiarities related to effect of Cu or Al substitution at Ni sites.

  9. Optical properties of CeNi5 and CeNi4M (M = Al, Cu) compounds

    International Nuclear Information System (INIS)

    The experimental study of the optical properties of CeNi5, CeNi4Cu and CeNi4Al compounds was carried out in the 0.083-5.64 eV energy range using the ellipsometry method. The optical constants, dielectric functions and electronic parameters (plasma and relaxation frequencies) were determined. The energy dependencies of the optical interband conductivities are discussed by using the available information on the electronic band structure of these compounds. In the ternary alloys the optical spectra show the presence of peculiarities related to effect of Cu or Al substitution at Ni sites.

  10. Highly Enhanced Concentration and Stability of Reactive Ce^3+ on Doped CeO_2 Surface Revealed In Operando

    OpenAIRE

    Chueh, William C.; McDaniel, Anthony H.; Grass, Michael E.; Hao, Yong; Jabeen, Naila; Liu, Zhi; Haile, Sossina M.; McCarty, Kevin F.; Bluhm, Hendrik; El Gabaly, Farid

    2012-01-01

    Trivalent cerium ions in CeO_2 are the key active species in a wide range of catalytic and electro-catalytic reactions. We employed ambient pressure X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy to quantify simultaneously the concentration of the reactive Ce^3+ species on the surface and in the bulk of Sm-doped CeO_2(100) in hundreds of millitorr of H2–H2O gas mixtures. Under relatively oxidizing conditions, when the bulk cerium is almost entirely in the 4+ oxida...

  11. Risk management activities at the DOE Class A reactor facilities

    International Nuclear Information System (INIS)

    The probabilistic risk assessment (PRA) and risk management group of the Association for Excellence in Reactor Operation (AERO) develops risk management initiatives and standards to improve operation and increase safety of the DOE Class A reactor facilities. Principal risk management applications that have been implemented at each facility are reviewed. The status of a program to develop guidelines for risk management programs at reactor facilities is presented

  12. N Reactor Lessons Learned workshop

    International Nuclear Information System (INIS)

    This report describes a workshop designed to introduce participants to a process, or model, for adapting LWR Safety Standards and Analysis Methods for use on rector designs significantly different than LWR. The focus of the workshop is on the ''Lessons Learned'' from the multi-year experience in the operation of N Reactor and the efforts to adapt the safety standards developed for commercial light water reactors to a graphite moderated, water cooled, channel type reactor. It must be recognized that the objective of the workshop is to introduce the participants to the operation of a non-LWR in a LWR regulatory world. The total scope of this topic would take weeks to provide a through overview. The objective of this workshop is to provide an introduction and hopefully establish a means to develop a longer term dialogue for technical exchange. This report provides outline of the workshop, a proposed schedule of the workshop, and a description of the tasks will be required to achieve successful completion of the project

  13. Inconsistencies of neutron flux parameters for k(0) standardization in neutron activation analysis determined with the use of Au+Zr and Au+Mo+Cr monitor sets at the LVR-15 reactor in Rez

    Czech Academy of Sciences Publication Activity Database

    Kubešová, Marie; Kučera, Jan

    2012-01-01

    Roč. 293, č. 2 (2012), s. 665-674. ISSN 0236-5731 R&D Projects: GA ČR GA202/09/0363 Institutional support: RVO:61389005 Keywords : Neutron activation analysis * K(0) standardization * Neutron flux parameters Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.467, year: 2012

  14. Three-Dimensional Structure of CeO2 Nanocrystals

    DEFF Research Database (Denmark)

    Tan, Joyce Pei Ying; Tan, Hui Ru; Boothroyd, Chris;

    2011-01-01

    Visualization of three-dimensional (3D) structures of materials at the nanometer scale can shed important information on the performance of their applications and provide insight into the growth mechanism of shape-controlled nanomaterials. In this paper, the 3D structures and growth pathway of CeO2...... samples synthesized under different conditions. The homogeneous growth environment in solution with polyvinylpyrrolidone (PVP) molecules led to the formation of regular octahedral CeO2 nanocrystals with small {001} facet truncations. When the PVP surfactant was removed, the aggregation of regular...... truncated octahedral CeO2 particles through a lattice matched interface generated irregular compressed truncated octahedral CeO2 nanoparticles. The formation of this irregular shape is attributed to the lower surface diffusion and slow incorporation of atoms on surfaces by step attachment of the fused...

  15. Performance evaluation of LaBr3: Ce scintillator

    International Nuclear Information System (INIS)

    The cerium doped lanthanum bromide crystal (LaBr3: Ce) is a new kind of scintillator with many advantages such as good energy resolution, high light output, short decay time, good proportionality response. These properties make the LaBr3: Ce attractive substantial interest to use in the radiation detection. The energy resolution were investigated with Φ25 × 25 mm LaBr3: Ce coupled to a Hamamatsu R8900 photomultiplier tube. Energy resolution of 3.6% (FWHM) have been achieved for 511 keV photons (18F source) at room temperature. Decay time constant of 20 ns have been acquired with a Hamamatsu fast-time-response R9800 photomultiplier tube. The results approve the excellent characterizations of LaBr3: Ce and imply its enormous potentiality in the radiation detectors of gamma-ray spectroscopy and PET. (authors)

  16. O- centers in LuAG:Ce,Mg ceramics

    International Nuclear Information System (INIS)

    Electron traps are known to a have great influence on the carriers transport process in Ce based scintillators. On the other hand, the role of hole traps in the scintillation process has been less considered. By means of electron spin resonance (ESR), we detected hole traps in highly Ce-doped LuAG:Ce,Mg ceramics in the form of σ-type O- centers. The g -tensor components turn out to be g perpendicular to = 2.0103, and g parallel = 2.0023, revealing the axial symmetry of these defects. Mg-perturbed variants of O- centers are proposed to exist in LuAG:Ce,Mg. Their occurrence is related to an elongated Mg-O bond as evidenced by DFT calculations. Finally, the multiple role of O- centers in the scintillation process is discussed. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Nuclear structure of 130-136Ce in IBM-1

    International Nuclear Information System (INIS)

    The level structure of Ce isotopes with N < 82 has been studied in recent experiments, yielding increasing information on the non yrast bands. The Interacting Boson Model (IBM-1) offers a useful tool for such phenomenological study

  18. Thermoelectric Properties of Nanostructured CeAl3

    Science.gov (United States)

    Pokharel, Mani; Dahal, Tulashi; Ren, Zhifeng; Opeil, Cyril; Opeil Group Team; Ren Group Team

    2014-03-01

    Past investigations into the heavy fermion compound CeAl3 reveal a complex low-temperature physics resulting from the strong hybridization of localized 4f states with delocalized conduction electrons. This phenomenon gives rise to unusual electronic, thermal, and magnetic properties. We investigate the low-temperature thermoelectric properties of this strongly correlated system for its potential application as a p-type Peltier cooling element. In our work, nanostructured samples of CeAl3 have been prepared using dc hot-press method and evaluated for their thermoelectric properties. Effects of different hot-pressing temperatures on the nanostructure and the thermoelectric properties will be discussed. Our results on CeAl3 will be compared with our previous work on CeCu6. Funding for this work was provided by the DOD, USAF-OSR, MURI Program under Contract FA9550-10-1-0533.

  19. Ship propulsion reactors technology

    International Nuclear Information System (INIS)

    This paper takes the state of the art on ship propulsion reactors technology. The french research programs with the corresponding technological stakes, the reactors specifications and advantages are detailed. (A.L.B.)

  20. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  1. Process heat reactors

    International Nuclear Information System (INIS)

    The consumption of heat, for industrial and domestic needs, takes up half of the national energy supply; direct utilization of the heat produced by nuclear reactors could therefore contribute to reduce the deficit in the energetic results. The restraints proper to heat consumption (dispersal and variety of consumers, irregular demand) involve the development of the heat transport system structures and adequate nuclear reactors. With this in view, the Commissariat a l'Energie Atomique and Technicatome are developing the CAS reactor series, pressurized water reactors (PWR), (CAS 3G reactor with a power of 420 MW.th.), and the Thermos reactor (100 MW.th.), directly conceived to produce heat at 1200C and whose technology derives from the experimental pool reactors type. In order to prove the value of the Thermos design, an experimental reactor should soon be constructed in the Saclay nuclear research centre

  2. Reactor System Design

    International Nuclear Information System (INIS)

    SMART NPP(Nuclear Power Plant) has been developed for duel purpose, electricity generation and energy supply for seawater desalination. The objective of this project IS to design the reactor system of SMART pilot plant(SMART-P) which will be built and operated for the integrated technology verification of SMART. SMART-P is an integral reactor in which primary components of reactor coolant system are enclosed in single pressure vessel without connecting pipes. The major components installed within a vessel includes a core, twelve steam generator cassettes, a low-temperature self pressurizer, twelve control rod drives, and two main coolant pumps. SMART-P reactor system design was categorized to the reactor coe design, fluid system design, reactor mechanical design, major component design and MMIS design. Reactor safety -analysis and performance analysis were performed for developed SMART=P reactor system. Also, the preparation of safety analysis report, and the technical support for licensing acquisition are performed

  3. Analyzing input/output subsystem security in Windows CE

    OpenAIRE

    Pereira, Barbara A.

    2001-01-01

    In the past few years, mobile handheld devices have emerged as an exciting new tool for accomplishing everyday tasks. Devices with the Windows CE operating system provide flexibility for the designer in the form of customizable modules and components. With wireless capabilities and a familiar user interface, Windows CE devices are becoming popular for such tasks as inventory control and information retrieval. By enhancing the self-protection of the operating system, handheld devices could be ...

  4. Design guide for category II reactors light and heavy water cooled reactors

    International Nuclear Information System (INIS)

    The Department of Energy (DOE), in the ERDA Manual, requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification operation, maintainance, and decommissioning of DOW-owned reactors be in accordance with generally uniform standards, guide and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirements of Category II reactor structure, components, and systems

  5. Design guide for Category III reactors: pool type reactors. [US DOE

    Energy Technology Data Exchange (ETDEWEB)

    Brynda, W J; Lobner, P R; Powell, R W; Straker, E A

    1978-11-01

    The Department of Energy (DOE) in the ERDA Manual requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirement of Category III reactor structures, components, and systems.

  6. Design guide for category II reactors light and heavy water cooled reactors. [US DOE

    Energy Technology Data Exchange (ETDEWEB)

    Brynda, W J; Lobner, P R; Powell, R W; Straker, E A

    1978-05-01

    The Department of Energy (DOE), in the ERDA Manual, requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification operation, maintainance, and decommissioning of DOW-owned reactors be in accordance with generally uniform standards, guide and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirements of Category II reactor structure, components, and systems.

  7. Nuclear Reactor RA Safety Report, Vol. 11, Reactor operation

    International Nuclear Information System (INIS)

    This volume includes the following chapters describing: Organisation of reactor operation (including operational safety, fuel management, and regulatory rules for RA reactor operation); Control and maintenance of reactor components (reactor core, nuclear fuel, heavy water and cover gas systems, mechanical structures, electric power supply system, reactor instrumentation); Quality assurance and Training of the reactor personnel

  8. Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Marc D.; Booth, Corwin H.; Lukens, Wayne W.; Andersen, Richard A.

    2009-02-02

    New synthetic procedures for the preparation of Ce(cot)2, cerocene, from [Li(thf)4][Ce(cot)2], and Ce2(cot)3 in high yield and purity are reported. Heating solid Ce(cot)2 yields Ce2(cot)3 and COT while heating Ce2(cot)3 with an excess of COT in C6D6 to 65oC over four months yields Ce(cot)2. The solid state magnetic susceptibility of these three organocerium compounds shows that Ce(cot)2 behaves as a TIP (temperature independent paramagnet) over the temperature range of 5-300 K, while that of Ce2(cot)3 shows that the spin carriers are antiferromagnetically coupled below 10 K; above 10 K, the individual spins are uncorrelated, and [Ce(cot)2]- behaves as an isolated f1 paramagnet. The EPR at 1.5K for Ce2(cot)3 and [Ce(cot)2]- have ground state of MJ= +- 1/2. The LIII edge XANES of Ce(cot)2 (Booth, C.H.; Walter, M.D.; Daniel, M.; Lukens, W.W., Andersen, R.A., Phys. Rev. Lett. 2005, 95, 267202) and 2Ce2(cot)3 over 30-500 K are reported; the Ce(cot)2 XANES spectra show Ce(III) and Ce(IV) signatures up to a temperature of approximately 500 K, whereupon the Ce(IV) signature disappears, consistent with the thermal behavior observed in the melting experiment. The EXAFS of Ce(cot)2 and Ce2(cot)3 are reported at 30 K; the agreement between the molecular parameters for Ce(cot)2 derived from EXAFS and single crystal X-ray diffraction data are excellent. In the case of Ce2(cot)3 no X-ray diffraction data are known to exist, but the EXAFS are consistent with a"triple-decker" sandwich structure. A molecular rationalization is presented for the electronic structure of cerocene having a multiconfiguration ground state that is an admixture of the two configurations Ce(III, 4f1)(cot1.5-)2 and Ce(IV, 4f0)(cot2-)2; the multiconfigurational ground state has profound effects on the magnetic properties and on the nature of the chemical bond in cerocene and, perhaps, other molecules.

  9. Fabrication of Ni-5 at. %W Long Tapes with CeO2 Buffer Layer by Reel-to-Reel Method

    DEFF Research Database (Denmark)

    Ma, Lin; Tian, Hui; Yue, Zhao;

    2015-01-01

    A 10-m-long homemade textured Ni-5at.%W (Ni5W) long tape with a CeO2 buffer layer has been prepared successfully by means of rolling-assisted biaxially textured substrate (RABiTS) route followed by a chemical solution deposition method in a reel-to-reel manner. Globally, the Ni5W substrate and CeO2...... film exhibit high homogeneity in terms of biaxial texture over the tape. The average values of full width at half maximum of in-plane and out-of-plane texture are 7.2° and 6.1° in Ni5W substrate, 7.6° and 6.1° in CeO2 buffer layer, respectively, all of those with a small standard deviation. On a...... microlevel, the CeO2 film epitaxially grows well on top of the Ni5W tape. A continuous, smooth, and crack-free morphology was observed on the CeO2 film and the fraction of low-angle grain boundaries (≤ 10°) is about 98 %. This process is a potential possibility for producing long-length textured CeO2/Ni5W...

  10. Passive gamma analysis of the boiling-water-reactor assemblies

    Science.gov (United States)

    Vo, D.; Favalli, A.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S.; Trellue, H.; Vaccaro, S.

    2016-09-01

    This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden's Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative-Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in the count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: 137Cs, 154Eu, 134Cs, and to a lesser extent, 106Ru and 144Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.

  11. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2016-01-01

    International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  12. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2014-01-01

    International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  13. Training Standardization

    International Nuclear Information System (INIS)

    The article describes the benefits of and required process and recommendations for implementing the standardization of training in the nuclear power industry in the United States and abroad. Current Information and Communication Technologies (ICT) enable training standardization in the nuclear power industry. The delivery of training through the Internet, Intranet and video over IP will facilitate this standardization and bring multiple benefits to the nuclear power industry worldwide. As the amount of available qualified and experienced professionals decreases because of retirements and fewer nuclear engineering institutions, standardized training will help increase the number of available professionals in the industry. Technology will make it possible to use the experience of retired professionals who may be interested in working part-time from a remote location. Well-planned standardized training will prevent a fragmented approach among utilities, and it will save the industry considerable resources in the long run. It will also ensure cost-effective and safe nuclear power plant operation

  14. The Chernobylsk reactor accident

    International Nuclear Information System (INIS)

    The construction, the safety philosophy, the major reactor physical parameters of RBMK-1000 type reactor units and the detailed description of the Chernobylsk-4 reactor accident, its causes and conclusions, the efforts to reduce the consequences on the reactor site and in the surroundings are discussed based on different types of Soviet documents including the report presented to the IAEA by the Soviet Atomic Energy Agency in August 1986. (V.N.)

  15. Zero energy reactor 'RB'

    International Nuclear Information System (INIS)

    In 1958 the zero energy reactor RB was built with the purpose of enabling critical experiments with various reactor systems to be carried out. The first core assembly built in this reactor consists of heavy water as moderator and natural uranium metal as fuel. In order to be able to obtain very accurate results when measuring the main characteristics of the assembly the reactor was built as a completely bare system. (author)

  16. Sr2+ and Cs+ ion exchange properties of KLn(PO3)4: Ln = Ce and Eu

    International Nuclear Information System (INIS)

    With the aim to study the potential of layered phosphates as ion exchangers two stoichiometric compositions as KLn(PO3)4 with Ln = Ce and Eu were prepared by solid state reaction and characterized by powder X-ray diffraction method. The Cs+ and Sr2+ exchange properties of both materials were investigated using standard solutions of Sr2+ or Cs+ in low acidic aqueous medium

  17. Thermal stratification of sodium in the BN 600 reactor

    International Nuclear Information System (INIS)

    The signs of thermal stratification of sodium in the BN 600 reactor upper plenum revealed by the analysis of standard temperature sensors' readings are defined. The initial conditions for existence of different temperature sodium layers are given. Two approaches for realizing on a computer of equations describing sodium motion in the upper plenum of the reactor are presented. (author)

  18. High solids fermentation reactor

    Science.gov (United States)

    Wyman, Charles E.; Grohmann, Karel; Himmel, Michael E.; Richard, Christopher J.

    1993-01-01

    A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

  19. Fossil nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Maurette, M.

    1976-01-01

    The discussion of fossil nuclear reactors (the Oklo phenomenon) covers the earth science background, neutron-induced isotopes and reactor operating conditions, radiation-damage studies, and reactor modeling. In conclusion possible future studies are suggested and the significance of the data obtained in past studies is summarized. (JSR)

  20. Fusion reactor studies

    International Nuclear Information System (INIS)

    A review is given of fusion reactor systems studies, the objectives of these studies are outlined and some recent conceptual reactor designs are described. The need for further studies in greater depth is indicated so that progress towards a commercial fusion reactor may be consolidated. (U.K.)

  1. Reactor power measuring device

    International Nuclear Information System (INIS)

    The present invention provides a self-powered long detector having a sensitivity over the entire length of a reactor core as an entire control rod withdrawal range of a BWR type reactor, and a reactor power measuring device using a gamma ray thermometer which scarcely causes sensitivity degradation. That is, a hollow protection pipe is disposed passing through the reactor core from the outside of a reactor pressure vessel. The self-powered long detectors and the gamma ray thermometers are inserted and installed in the protection pipe. An average reactor power in an axial direction of the reactor relative to a certain position in the horizontal cross section of the reactor core is determined based on the power of the self-powered long detector over the entire length of the reactor core. Since the response of the self-powered detector relative to a local power change is rapid, the output is used as an input signal to a safety protection device of the reactor core. Further, a gamma ray thermometer secured in the reactor and having scarce sensitivity degradation is used instead of an incore travelling neutron monitor used for relative calibration of an existent neutron monitor secured in the reactor. (I.S.)

  2. Design guide for category VI reactors: air-cooled graphite reactors

    International Nuclear Information System (INIS)

    The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned air-cooled graphite reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission

  3. Development of Reactor Protection System (RPS) in Reactor Digital Instrumentation and Control System (ReDICS)

    International Nuclear Information System (INIS)

    RTP Research Reactor are in the process upgraded from analogue control console system to a digital control console system . Upgrade process requires a statistical study to improve safety during reactor operation. RPS was developed to meet the needs of operational safety and at the same time comply with the guidelines set by the IAEA. RPS is in analog and hardware with industry standard interfaced with digital DAC (Data Acquisition and Control) and OWS (Operator Work Station). (author)

  4. Structural and optical study of Ce segregation in Ce-doped SiO{sub 1.5} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Beainy, G.; Castro, C.; Pareige, P.; Talbot, E., E-mail: etienne.talbot@univ-rouen.fr [Groupe de Physique des Matériaux, Université et INSA de Rouen, UMR CNRS 6634, Normandie Université, Avenue de l' Université, BP 12, 76801 St Etienne du Rouvray (France); Weimmerskirch-Aubatin, J.; Stoffel, M.; Vergnat, M.; Rinnert, H. [Université de Lorraine, UMR CNRS 7198, Institut Jean Lamour, BP 70239, 54506 Vandoeuvre-lès-Nancy (France)

    2015-12-21

    Cerium doped SiO{sub 1.5} thin films fabricated by evaporation and containing silicon nanocrystals were investigated by atom probe tomography. The effect of post-growth annealing treatment has been systematically studied to correlate the structural properties obtained by atom probe tomography to the optical properties measured by photoluminescence spectroscopy. The atom probe results demonstrated the formation of Ce-Si rich clusters upon annealing at 900 °C which leads to a drastic decrease of the Ce-related luminescence. At 1100 °C, pure Si nanocrystals and optically active cerium silicate compounds are formed. Consequently, the Ce-related luminescence is found to re-appear at this temperature while no Si-nanocrystal related luminescence is observed for films containing more than 3% Ce.

  5. Optical properties of LaF3:Ce and LaF3:Ce, Tb embedded polymer nanocomposites

    International Nuclear Information System (INIS)

    Colloidal solutions containing LaF3:Ce and LaF3:Ce,Tb nanoparticles were synthesized and embedded in polyacrylamide through a simple procedure. Very fine colloidal nanoparticle suspension in dm-water was synthesized by adopting co-precipitation technique in acidic environment. Nanoparticles were characterized for their crystal structure, particle size, UV-ViS absorption and photoluminescence behavior using X-ray diffraction, DLS, and photoluminescence spectroscopy techniques respectively. Size of nano-crystals was estimated using the Scherer formula. The life time measurements of the colloidal solutions were done. The transparent polymer nano composites containing LaF3:Ce and LaF3:Ce, Tb exhibited emissions at 304 and 490, 543, 585, 622 nm respectively. The colloidal route for polymer nanocomposite synthesis seems to be an easy and effective way to fabricate optically transparent photo-luminescent composite materials in variety of sizes and shapes. (author)

  6. PWR standardization: The French experience

    International Nuclear Information System (INIS)

    After a short historical review of the French PWR programme with 45000 MWe in operation and 15000 MWe under construction, the paper first develops the objectives and limits of the standardizatoin policy. Implementation of standardization is described through successive reactor series and feedback of experience, together with its impact on safety and on codes and standards. Present benefits of standardization range from low engineering costs to low backfitting costs, via higher quality, reduction in construction times and start-up schedules and improved training of operators. The future of the French programme into the 1990's is again with an advanced standardized series, the N4-1400 MW plant. There is no doubt that the very positive experience with standardization is relevant to any country trying to achieve self-reliance in the nuclear power field. (author)

  7. Designing a reactor for the next generation

    International Nuclear Information System (INIS)

    The Modular High-Temperature Gas-Cooled Reactor (MHTGR) is an advanced reactor concept being developed under a cooperative program involving the U.S. Government, the utilities and the nuclear industry. The design utilizes basic High-Temperature Gas-Cooled Reactor (HTGR) features of ceramic fuel, helium coolant, and a graphite moderator. The specific size and configuration is selected to utilize the inherent materials characteristics associated with these standard features to develop a passively safe design which provides a higher margin of safety and investment protection than current generation reactors. The MHTGR which is now into the preliminary design phase meets regulatory and new, more challenging user requirements. This paper outlines the requirements, describes the design and the current status, shows how the design meets the requirements, and looks at potential future deployment from the vendor's perspective

  8. Comparison between MAAP and ECART predictions of radionuclide transport throughout a French standard PWR reactor coolant system; Transport des radionucleides dans le circuit primaire d`un REP: comparaison des codes MAAP et ECART

    Energy Technology Data Exchange (ETDEWEB)

    Hervouet, C.; Ranval, W. [Electricite de France (EDF), 92 - Clamart (France); Parozzi, F.; Eusebi, M. [Ente Nazionale per l`Energia Elettrica, Rome (Italy)

    1996-04-01

    In the framework of a collaboration agreement between EDF and ENEL, the MAAP (Modular Accident Analysis Program) and ECART (ENEL Code for Analysis of radionuclide Transport) predictions about the fission product retention inside the reactor cooling system of a French PWR 1300 MW during a small Loss of Coolant Accident were compared. The volatile fission products CsI, CsOH, TeO{sub 2} and the structural materials, all of them released early by the core, are more retained in MAAP than in ECART. On the other hand, the non-volatile fission products, released later, are more retained in ECART than in MAAP, because MAAP does not take into account diffusion-phoresis: in fact, this deposition phenomenon is very significant when the molten core vaporizes the water of the vessel lower plenum. Centrifugal deposition in bends, that can be modeled only with ECART, slightly increases the whole retention in the circuit if it is accounted for. (authors). 18 refs., figs., tabs.

  9. Ce substitution for Gd in Gd1-xCexBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Full text: It has been found that REBa2Cu3O7-δ compounds with RE=rare earths elements, except Ce, Pr, Pm and Tb, have the same crystal structure, normal state properties, and transition temperature near 92K. RE compounds with RE=Ce and Tb due to their tendency toward tetravalence or mixed valence behavior do not form in the 123 orthorhombic structure. Moreover, both Ce and Tb form double oxides BaCeO3 and BaTbO3, respectively, which lead to formation of multiphase samples. In regards to the ionic radius, it has been demonstrated that the effective ionic radius of the trivalence element is important for the formation of 123 phase. Related to the RE radius, Nd123 has the stable structure; since Ce and Nd have approximately the same radius, the instability of Ce123 phase cannot be related to its radius. We have substituted Ce for Gd in Gd1-xCexBa2Cu3O7-δ compounds. We have prepared Gd1-xCexBa2Cu3O7-δ compounds with x=0.0, 0.03, 0.05, 0.09, 0.1, 0.12, 0.15, 0.3, 0.325, 0.35, 0.4, 0.5, 0.6 by the standard solid-state reaction technique. The resistivity has been measured under an applied magnetic field in the range 0 to 15KOe in the temperature range 10K to 300K. X-ray diffraction experiments are performed and its results are refined by the Rietveld method. X-ray diffraction analysis shows a predominantly single phase perovskite structure with few impurity phases, but in the compound with x=0.4 a pure single phase is formed. Magnetic properties are measured via a vibrating sample magnetometer at 77K in magnetic field up to 15KOe. Our resistivity results show that by increasing Ce content, Tc decreases, but the transition width increases, and in the normal state a metal-insulator transition occurs. The normal state resistivity does not change with applying the magnetic field, but the transition width changes distinctively after the branching point. In these samples, the onset transition temperature increases slowly with applying magnetic field, which is interesting and

  10. Role of combined DWIBS/3D-CE-T1w whole-body MRI in tumor staging: Comparison with PET-CT

    International Nuclear Information System (INIS)

    Objectives: To assess the diagnostic performance of whole-body magnetic resonance imaging (WB-MRI) by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) in malignant tumor detection and the potential diagnostic advantages in generating fused DWIBS/3D-contrast enhanced T1w (3D-CE-T1w) images. Methods: 45 cancer patients underwent 18F-FDG PET-CT and WB-MRI for staging purpose. Fused DWIBS/3D-CE T1w images were generated off-line. 3D-CE-T1w, DWIBS images alone and fused with 3D-CE T1w were compared by two readers groups for detection of primary diseases and local/distant metastases. Diagnostic performance between the three WB-MRI data sets was assessed using receiver operating characteristic (ROC) curve analysis. Imaging exams and histopathological results were used as standard of references. Results: Areas under the ROC curves of DWIBS vs. 3D-CE-T1w vs. both sequences in fused fashion were 0.97, 0.978, and 1.00, respectively. The diagnostic performance in tumor detection of fused DWIBS/3D-CE-T1w images were statistically superior to DWIBS (p < 0.001) and 3D-CE-T1w (p ≤ 0.002); while the difference between DWIBS and 3D-CE-T1w did not show statistical significance difference. Detection rates of malignancy did not differ between WB-MRI with DWIBS and 18F-FDG PET-CT. Conclusion: WB-MRI with DWIBS is to be considered as alternative tool to conventional whole-body methods for tumor staging and during follow-up in cancer patients.

  11. Role of combined DWIBS/3D-CE-T1w whole-body MRI in tumor staging: Comparison with PET-CT

    Energy Technology Data Exchange (ETDEWEB)

    Manenti, Guglielmo, E-mail: guggi@tiscali.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Ciccio, Carmelo, E-mail: carmeciccio@libero.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Squillaci, Ettore, E-mail: ettoresquillaci@tiscali.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Strigari, Lidia, E-mail: strigari@ifo.it [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome (Italy); Calabria, Ferdinando, E-mail: ferdinandocalabria@hotmail.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Danieli, Roberta, E-mail: roberta.danieli@ptvonline.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); and others

    2012-08-15

    Objectives: To assess the diagnostic performance of whole-body magnetic resonance imaging (WB-MRI) by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) in malignant tumor detection and the potential diagnostic advantages in generating fused DWIBS/3D-contrast enhanced T1w (3D-CE-T1w) images. Methods: 45 cancer patients underwent 18F-FDG PET-CT and WB-MRI for staging purpose. Fused DWIBS/3D-CE T1w images were generated off-line. 3D-CE-T1w, DWIBS images alone and fused with 3D-CE T1w were compared by two readers groups for detection of primary diseases and local/distant metastases. Diagnostic performance between the three WB-MRI data sets was assessed using receiver operating characteristic (ROC) curve analysis. Imaging exams and histopathological results were used as standard of references. Results: Areas under the ROC curves of DWIBS vs. 3D-CE-T1w vs. both sequences in fused fashion were 0.97, 0.978, and 1.00, respectively. The diagnostic performance in tumor detection of fused DWIBS/3D-CE-T1w images were statistically superior to DWIBS (p < 0.001) and 3D-CE-T1w (p {<=} 0.002); while the difference between DWIBS and 3D-CE-T1w did not show statistical significance difference. Detection rates of malignancy did not differ between WB-MRI with DWIBS and 18F-FDG PET-CT. Conclusion: WB-MRI with DWIBS is to be considered as alternative tool to conventional whole-body methods for tumor staging and during follow-up in cancer patients.

  12. Non-Stoichiometry of UO2-CeO2: The System UO2-CeO2-CeO1.5 at 900 to 1200°C

    International Nuclear Information System (INIS)

    This investigation covers the substoichiometric fluorite (UO2-CeO2) phase, that is, the behaviour of the system U1-yCe1-yO2+x. Though UO2 and CeO2 are completely miscible, and in the CeO2-CeO1-5 system the fluorite phase extends to CeO1.72 , the UO2-CeO2-CeO1.5 system is characterized by a large two-phase region, where two fluorite- type structures, one CeO2-rich, the other UO2-rich, coexist. Only in the UO2-rich corner of the ternary system is a noticeable single-phase region present. This is in contrast to the CeO2-UO2-UO267 system where a large single-phase region exists. The oxygen activity as a function of composition x was measured in U1-yCe1-yO2+x (y = 0.15 and 0.35) at 900°C, using H2/H2O and metal/metal oxide equilibria. In all cases the oxygen activity increases extremely rapidly with decreasing x; the behaviour of the system resembles that of dilute solutions of UO2+X in ThO2. Both systems can be explained by assuming defect complexes: a vacancy bound to two Ce3+, an interstitial oxygen bound to two U5+. (author)

  13. C-E Nuclear Power Businesses Quality Management of Manufacturing and Design and its impact on Reliability of C-E Supplied Components

    International Nuclear Information System (INIS)

    To attain and sustain this objective, Nuclear Power Businesses has established a quality system for design and manufacturing of Nuclear Steam Supply System components, nuclear fuel and operating plant systems and services. Today's quality system has been designed, developed and refined over the past forty (40) years. This system is a dynamic one, based on solid quality principles, accepted industry standards and practices, complies with the ASME Code and 10 CFRP 50, Appendix B, but within the bounds of mandated requirements is adaptable to unique client needs. Nuclear Power Businesses is successfully implementing its quality philosophy through management and organizational commitment, strong leadership, teamwork and use of modern quality techniques. The quality system at C-E Nuclear Power Businesses has been developed in response to changing requirements over the past forty years. It is still changing today. The effectiveness of the system is evidenced by the superior performance of C-E Nuclear Power Businesses supplied Ness's. The system includes management involvement and awareness involvement and awareness and ensures that all employees are aware of Nuclear Power Businesses' quality goals. The system has a strong quality organization that establishes uniform policies and assures compliance. In addition, the system promotes open communication and prompt, permanent corrective action. Although we believe our system, as they exist today, meet or exceed client requirements, they are continuously reviewed and adjusted to improve their usefulness to make them more cost effective

  14. The CE3R Network: current status and future perspectives

    Science.gov (United States)

    Lenhardt, Wolfgang; Pesaresi, Damiano; Živčić, Mladen; Costa, Giovanni; Kuk, Kresimir; Bondár, István; Duni, Llambro; Spacek, Petr

    2016-04-01

    In order to improve the monitoring of seismic activities in the border regions and to enhance the collaboration between countries and seismological institutions in Central Europe, the Environment Agency of the Slovenian Republic (ARSO), the Italian National Institute for Oceanography and Experimental Geophysics (OGS), the University of Trieste (UniTS) and the Austrian Central Institute for Meteorology and Geodynamics (ZAMG) established in 2001 the "South Eastern Alps Transfrontier Seismological Network". In May 2014 ARSO, OGS, UniTS and ZAMG agreed to formalize the transfrontier network, to name it "Central and East European Earthquake Research Network", (CE3RN or CE3R Network) in order to locate it geographically since cross-border networks can be established in other areas of the world and to expand their cooperation, including institutions in other countries. The University of Zagreb (UniZG) joined CE3RN in October 2014. The Kövesligethy Radó Seismological Observatory (KRSZO) of the Hungarian Academy of Sciences joined CE3RN in October 2015. The Institute of Geosciences, Energy, Water and Environment (IGEWE) of the Polytechnic University of Tirana joined CE3RN in November 2015. The Institute of Physics of the Earth (IPE) of the Masaryk University in Brno joined CE3RN in November 2015. CE3RN Parties intend to formalize and possibly extend their ongoing cooperation in the field of seismological data acquisition, exchange and use for seismological and earthquake engineering and civil protection purposes. The purpose of this cooperation is to retain and expand the existing cross-border network, specify the rules of conduct in the network management, improvements, extensions and enlargements, enhance seismological research in the region, and support civil protection activities. Since the formal establishment of CE3RN, several common projects have been completed, like the SeismoSAT project for the seismic data center connection over satellite funded by the Interreg

  15. Electroless ternary NiCeP coatings: Preparation and characterisation

    International Nuclear Information System (INIS)

    Highlights: ► Rare earth element (Ce) has been successfully codeposited in NiP matrix. ► Surface analysis carried out by XPS showed that the Ce is present in +3 and +4 oxidation state. ► Palladium stability test indicated that the Ce salts in electroless nickel bath has reduced the stability. ► Cerium codeposition in NiP matrix has increased the microhardness both in as-plated and annealed conditions. ► Higher thermal stability has been obtained by Ce incorporation. - Abstract: Electroless ternary NiCeP deposits were prepared from alkaline citrate bath containing nickel sulphate, cerium chloride and sodium hypophosphite. Concentration of rare earth cerium was varied from 1 to 2 g/L to obtain ternary deposits containing variable Ce and P contents. The influence of cerium on the deposit properties was analysed. The deposit exhibited a maximum cerium content of 6.2 ± 0.1 wt.% when the cerium chloride concentration was 2 g/L. The result of the Pd stability test showed that the stability of the bath was reduced due to Ce salt addition. The microhardness measurements made on both as-plated and heat treated samples exhibited a peak hardness of 1006 ± 11 VHN for cerium concentration of 1.5 g/L. The concept of kinetic strength analysis was proved to be applicable only for binary and not for ternary alloys due to multistep deposition mechanism with different kinetic energies. X-ray diffraction (XRD) patterns of as-plated and heat treated samples revealed peaks corresponding to Ni (1 1 1) and nickel phosphide (Ni3P). Higher amount of Ce incorporation in NiP matrix increased the crystallisation temperature of the deposit which could be due to the suppression of nickel crystallisation prior to Ni3P compound formation and thus increasing the activation energy for the formation of stable phases. Surface compositional analysis using X-ray photoelectron spectroscopy (XPS) carried out on as-plated NiCeP-2 deposit showed a prominent peak of P existing in +1 oxidation

  16. Electroless ternary NiCeP coatings: Preparation and characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Balaraju, J.N., E-mail: jnbalraj@nal.res.in [Surface Engineering Division, CSIR National Aerospace Laboratories, Post Bag No. 1779 Bangalore 560017, Karnataka (India); Chembath, Manju [Surface Engineering Division, CSIR National Aerospace Laboratories, Post Bag No. 1779 Bangalore 560017, Karnataka (India)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Rare earth element (Ce) has been successfully codeposited in NiP matrix. Black-Right-Pointing-Pointer Surface analysis carried out by XPS showed that the Ce is present in +3 and +4 oxidation state. Black-Right-Pointing-Pointer Palladium stability test indicated that the Ce salts in electroless nickel bath has reduced the stability. Black-Right-Pointing-Pointer Cerium codeposition in NiP matrix has increased the microhardness both in as-plated and annealed conditions. Black-Right-Pointing-Pointer Higher thermal stability has been obtained by Ce incorporation. - Abstract: Electroless ternary NiCeP deposits were prepared from alkaline citrate bath containing nickel sulphate, cerium chloride and sodium hypophosphite. Concentration of rare earth cerium was varied from 1 to 2 g/L to obtain ternary deposits containing variable Ce and P contents. The influence of cerium on the deposit properties was analysed. The deposit exhibited a maximum cerium content of 6.2 {+-} 0.1 wt.% when the cerium chloride concentration was 2 g/L. The result of the Pd stability test showed that the stability of the bath was reduced due to Ce salt addition. The microhardness measurements made on both as-plated and heat treated samples exhibited a peak hardness of 1006 {+-} 11 VHN for cerium concentration of 1.5 g/L. The concept of kinetic strength analysis was proved to be applicable only for binary and not for ternary alloys due to multistep deposition mechanism with different kinetic energies. X-ray diffraction (XRD) patterns of as-plated and heat treated samples revealed peaks corresponding to Ni (1 1 1) and nickel phosphide (Ni{sub 3}P). Higher amount of Ce incorporation in NiP matrix increased the crystallisation temperature of the deposit which could be due to the suppression of nickel crystallisation prior to Ni{sub 3}P compound formation and thus increasing the activation energy for the formation of stable phases. Surface compositional analysis

  17. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  18. Reactor Physics Modeling Of Spent Nuclear Research Reactor Fuel For SNM Attribution And Nuclear Forensics

    International Nuclear Information System (INIS)

    Nuclear research reactors are the least safeguarded type of reactor; in some cases this may be attributed to low risk and in most cases it is due to difficulty from dynamic operation. Research reactors vary greatly in size, fuel type, enrichment, power and burnup providing a significant challenge to any standardized safeguard system. If a whole fuel assembly was interdicted, based on geometry and other traditional forensics work, one could identify the material's origin fairly accurately. If the material has been dispersed or reprocessed, in-depth reactor physics models may be used to help with the identification. Should there be a need to attribute research reactor fuel material, the Savannah River National Laboratory would perform radiochemical analysis of samples of the material as well as other non-destructive measurements. In depth reactor physics modeling would then be performed to compare to these measured results in an attempt to associate the measured results with various reactor parameters. Several reactor physics codes are being used and considered for this purpose, including: MONTEBURNS/ORIGEN/MCNP5, CINDER/MCNPX and WIMS. In attempt to identify reactor characteristics, such as time since shutdown, burnup, or power, various isotopes are used. Complexities arise when the inherent assumptions embedded in different reactor physics codes handle the isotopes differently and may quantify them to different levels of accuracy. A technical approach to modeling spent research reactor fuel begins at the assembly level upon acquiring detailed information of the reactor to be modeled. A single assembly is run using periodic boundary conditions to simulate an infinite lattice which may be repeatedly burned to produce input fuel isotopic vectors of various burnups for a core level model. A core level model will then be constructed using the assembly level results as inputs for the specific fuel shuffling pattern in an attempt to establish an equilibrium cycle. The

  19. Field-induced coupled superconductivity and spin density wave order in the heavy fermion compound CeCoIn5

    International Nuclear Information System (INIS)

    In strong magnetic fields the Heavy Fermion superconductor CeCoIn5 shows a first order transition from the normal state into the SC phase. Several modulated SC phases are suggested at high magnetic fields in CeCoIn5, e.g., the spin singlet FFLO and mixed singlet/triplet phases (Q-phase). We have carried out transverse field muSR measurements between 2 T and 5 T (H parallel c-axis) on single crystalline CeCoIn5 in a temperature range between 25 mK and 7 K. In addition to the standard modulation perpendicular to the applied field due to the vortex lattice, a longitudinal modulation is expected. For the modulated high field phases in a local probe experiment an additional line or a static line broadening should occur. Our data clearly evidence the field-driven change from second to first order transition at an applied field of 4.8 T. Temperature and field dependence of the muon spin relaxation rate support the formation of a mode-coupled SC and AFM ordered phase in CeCoIn5 for fields directed parallel to the c-axis.

  20. Management system requirements for small reactors

    International Nuclear Information System (INIS)

    This abstract identifies the management system requirements for the life cycle of small reactors from initial conception through completion of decommissioning. For small reactors, the requirements for management systems remain the same as those for 'large' reactors regardless of the licensee' business model and objectives. The CSA N-Series of standards provides an interlinked set of requirements for the management of nuclear facilities. CSA N286 provides overall direction to management to develop and implement sound management practices and controls, while other CSA nuclear standards provide technical requirements and guidance that support the management system. CSA N286 is based on a set of principles. The principles are then supported by generic requirements that are applicable to the life cycle of nuclear facilities. CNSC regulatory documents provide further technical requirements and guidance. (author)