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Sample records for centro studi nucleari enrico fermi reactor

  1. Enrico Fermi exhibition at CERN

    CERN Multimedia

    2002-01-01

    A touring exhibition celebrating the centenary of Enrico Fermi's birth in 1901 will be on display at CERN (Main Building, Mezzanine) from 12-27 September. You are cordially invited to the opening celebration on Thursday 12 September at 16:00 (Main Building, Council Chamber), which will include speechs from: Luciano Maiani Welcome and Introduction Arnaldo Stefanini Celebrating Fermi's Centenary in Documents and Pictures Antonino Zichichi The New 'Centro Enrico Fermi' at Via Panisperna Ugo Amaldi Fermi at Via Panisperna and the birth of Nuclear Medicine Jack Steinberger Fermi in Chicago Valentin Telegdi A Close-up of Fermi and the screening of a documentary video about Fermi: Scienziati a Pisa: Enrico Fermi (Scientists at Pisa: Enrico Fermi) created by Francesco Andreotti for La Limonaia from early film, photographs and sound recordings (In Italian, with English subtitles - c. 30 mins). This will be followed by an aperitif on the Mezz...

  2. Enrico Fermi centenary exhibition seminar

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 01: Dr. Juan Antonio Rubio, Leader of the Education and Technology Transfer Division and CERN Director General, Prof. Luciano Maiani. Photo 03: Luciano Maiani, Welcome and Introduction Photo 09: Antonino Zichichi, The New 'Centro Enrico Fermi' at Via Panisperna Photos 10, 13: Ugo Amaldi, Fermi at Via Panisperna and the birth of Nuclear Medicine Photo 14: Jack Steinberger, Fermi in Chicago Photo 18: Valentin Telegdi, A close-up of Fermi Photo 21: Arnaldo Stefanini, Celebrating Fermi's Centenary in Documents and Pictures.

  3. Enrico Fermi Symposium at CERN : opening celebration

    CERN Document Server

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    You are cordially invited to the opening celebration on Thursday 12 September at 16:00 (Main Building, Council Chamber), which will include speechs from: Luciano Maiani - Welcome and Introduction Antonino Zichichi - The New 'Centro Enrico Fermi' at Via Panisperna Ugo Amaldi - Fermi at Via Panisperna and the birth of Nuclear Medicine Jack Steinberger - Fermi in Chicago Valentin Telegdi - A Close-up of Fermi Arnaldo Stefanini - Celebrating Fermi's Centenary in Documents and Pictures and the screening of a documentary video about Fermi: Scienziati a Pisa: Enrico Fermi (Scientists at Pisa: Enrico Fermi) created by Francesco Andreotti for La Limonaia from early film, photographs and sound recordings (English version - c. 30 mins).

  4. Enrico Fermi the obedient genius

    CERN Document Server

    Bruzzaniti, Giuseppe

    2016-01-01

    This biography explores the life and career of the Italian physicist Enrico Fermi, which is also the story of thirty years that transformed physics and forever changed our understanding of matter and the universe: nuclear physics and elementary particle physics were born, nuclear fission was discovered, the Manhattan Project was developed, the atomic bombs were dropped, and the era of “big science” began. It would be impossible to capture the full essence of this revolutionary period without first understanding Fermi, without whom it would not have been possible. Enrico Fermi: The Obedient Genius attempts to shed light on all aspects of Fermi’s life - his work, motivation, influences, achievements, and personal thoughts - beginning with the publication of his first paper in 1921 through his death in 1954. During this time, Fermi demonstrated that he was indeed following in the footsteps of Galileo, excelling in his work both theoretically and experimentally by deepening our understanding of the Pauli e...

  5. Enrico Fermi Fast Reactor Spent Nuclear Fuel Criticality Calculations: Degraded Mode

    International Nuclear Information System (INIS)

    The objective of this calculation is to characterize the nuclear criticality safety concerns associated with the codisposal of the Department of Energy's (DOE) Enrico Fermi (EF) Spent Nuclear Fuel (SNF) in a 5-Defense High-Level Waste (5-DHLW) Waste Package (WP) and placed in a Monitored Geologic Repository (MGR). The scope of this calculation is limited to the determination of the effective neutron multiplication factor (keff) for the degraded mode internal configurations of the codisposal WP. The results of this calculation and those of Ref. 8 will be used to evaluate criticality issues and support the analysis that will be performed to demonstrate the viability of the codisposal concept for the Monitored Geologic Repository

  6. Enrico Fermi and the Dolomites

    Science.gov (United States)

    Battimelli, Giovanni; de Angelis, Alessandro

    2014-11-01

    Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the next generations, in particular in the first half of the XX century, and the group of via Panisperna was directly connected: Edoardo Amaldi, the son of the mathematician Ugo sr., rented at least during two summers, in 1925 and in 1949, and in the winter of 1960, a house in San Vito di Cadore, and almost every year in the Dolomites; Enrico Fermi was a frequent guest. Many important steps in modern physics, in particular the development of the Fermi-Dirac statistics and the Fermi theory of beta decay, are related to scientific discussions held in the region of the Dolomites.

  7. Enrico Fermi and the Dolomites

    International Nuclear Information System (INIS)

    Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the next generations, in particular in the first half of the XX century, and the group of via Panisperna was directly connected: Edoardo Amaldi, the son of the mathematician Ugo sr., rented at least during two summers, in 1925 and in 1949, and in the winter of 1960, a house in San Vito di Cadore, and almost every year in the Dolomites; Enrico Fermi was a frequent guest. Many important steps in modern physics, in particular the development of the Fermi-Dirac statistics and the Fermi theory of beta decay, are related to scientific discussions held in the region of the Dolomites

  8. Enrico Fermi and the Dolomites

    CERN Document Server

    Battimelli, Giovanni

    2014-01-01

    Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the next generations, in particular in the first half of the XX century, and the group of via Panisperna was directly connected: Edoardo Amaldi, the son of the mathematician Ugo sr., rented at least during two summers, in 1925 and in 1949, and in the winter of 1960, a house in San Vito di Cadore, and almost every year in the Dolomites; Enrico Fermi was a frequent guest. Many important steps in modern physics, in particular the development of the Fermi-Dirac statistics and the Fermi theory of beta decay, are related to scient...

  9. Enrico Fermi and the Dolomites

    Energy Technology Data Exchange (ETDEWEB)

    Battimelli, Giovanni, E-mail: giovanni.battimelli@uniroma1.it; Angelis, Alessandro de, E-mail: alessandro.de.angelis@cern.ch

    2014-11-15

    Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the next generations, in particular in the first half of the XX century, and the group of via Panisperna was directly connected: Edoardo Amaldi, the son of the mathematician Ugo sr., rented at least during two summers, in 1925 and in 1949, and in the winter of 1960, a house in San Vito di Cadore, and almost every year in the Dolomites; Enrico Fermi was a frequent guest. Many important steps in modern physics, in particular the development of the Fermi-Dirac statistics and the Fermi theory of beta decay, are related to scientific discussions held in the region of the Dolomites.

  10. Enrico Fermi a Firenze le "Lezioni di meccanica razionale" al biennio propedeutico agli studi di ingegneria : 1924-1926

    CERN Document Server

    Frosali, Giovanni; Pelosi, Giuseppe

    2014-01-01

    Enrico Fermi, Premio Nobel per la Fisica nel 1938, ha insegnato alla Regia Università degli Studi di Firenze. La permanenza di Fermi a Firenze fu breve, solo due anni accademici (1924-25 e 1925-26); in questi anni tenne i corsi di fisica matematica e di meccanica razionale. Il presente volume è un contributo alla ricostruzione di questo periodo non molto noto della vita di Fermi, ma segnato scientificamente dalla pubblicazione della statistica che prende il suo nome, base tra l'altro della fisica dei semiconduttori e quindi dell'elettronica moderna. Vengono anche riprodotte nel testo le "Lezioni di meccanica razionale" tenute da Enrico Fermi nel periodo predetto agli studenti di scienze e del biennio propedeutico agli studi di ingegneria. I temi affrontati da Enrico Fermi nelle sue lezioni includono la cinematica e la dinamica del punto, la cinematica e la statica dei sistemi rigidi, inclusa la statica di sistemi più in generale. Infine le lezioni contengono le equazioni di "Lagrangia" e alcuni elementi di...

  11. Enrico : a Python package to simplify Fermi-LAT analysis

    CERN Document Server

    Sanchez, D A

    2013-01-01

    With the advent of the Large Array Telescope (LAT) on board the Fermi satellite, a new window on the Universe has been opened. Publicly available, the Fermi-LAT data come together with an analysis software named ScienceTools (ST, http://fermi.gsfc.nasa.gov/ssc/data/analysis/software/) which can be run through a Python interface. Nevertheless, for the user, the ST can be hard to run and imply several steps. Users already contributed with scripts for a specific task but no tool allowing a complete analysis is currently available. We present a Python package called {\\tt Enrico}, designed to facilitate the data analysis. Using only configuration files and front end tools from the command line, the user can easily perform/reproduce an entire Fermi analysis and make plots for publications. It also include new features like debug plots, pipeline execution on one or several CPUs, downloading of the Fermi data or the generation of a sky model from the Fermi catalogue. {\\tt Enrico} is an open-source project currently a...

  12. Enrico Fermi and the Old Quantum Physics

    OpenAIRE

    De Gregorio, Alberto; Sebastiani, Fabio

    2009-01-01

    We outline Fermi's early attitude towards old quantum physics. We sketch out the context from which his interest for quantum physics arose, and we deal with his work on quantum statistics. We also go through the first two courses on theoretical physics he held in Rome, and his 1928 book on atomic physics.

  13. Sobre a viagem de Enrico Fermi ao Brasil em 1934

    CERN Document Server

    Caruso, Francisco

    2014-01-01

    Enrico Fermi was one of the greater physicists of the XX century. In 1934, he gave several lectures in Brazil. Invited by Theodoro Ramos to work in S\\~ao Paulo, he preferred to stay in Rome and went to the USA in 1938. However, Fermi recommended Gleb Wataghin to come in his place. Wataghin made history in Brazil, becoming one of the first Professors of the future S\\~ao Paulo University. Besides his relevance to the History of Science, Fermi eventually leaved an indelible mark on the creation and institutionalization of national scientific research due to the indication of Wataghin. Despite this fact, very little is known about Fermi's trip to Brazil. This work tries to reconstruct the fullest possible steps of the famous Italian physicist in our lands.

  14. 178th International School of Physics "Enrico Fermi" : From the Big Bang to the Nucleosynthesis

    CERN Document Server

    Nappi, E

    2011-01-01

    Physicists have devoted much effort to reproducing the conditions of the primordial universe in laboratory conditions in their quest to work out a comprehensive theory of the appearance and evolution of nuclear matter. Whether it be trying to recreate the predicted primordial state of high-energy density matter in which quarks and gluons are effectively deconfined - the so-called Quark Gluon Plasma (QGP) - or exploring the structure and reaction properties of very unstable nuclei in experiments using radioactive beams, they have striven to understand the events which characterized the Big Bang and the various nucleosynthesis mechanisms which occur in the stars. This book contains the proceedings of the 2010 Enrico Fermi summer school held in Varenna, Italy, in July 2010, and devoted to the present understanding of the primordial universe and the origin of the elements, as achieved by studying nuclei and their constituents in extreme regimes of energy and composition. Subjects covered include: QGP formation; e...

  15. 180th International School of Physics "Enrico Fermi" : Three-dimensional Partonic Stucture of the Nucleon

    CERN Document Server

    Avakian, H; Hasch, D; Schweitzer, P

    2012-01-01

    The three-dimensional nucleon structure is central to many theoretical and experimental activities, and research in this field has seen many advances in the last two decades, addressing fundamental questions such as the orbital motion of quarks and gluons inside the nucleons, their spatial distribution, and the correlation between spin and intrinsic motion. A real three-dimensional imaging of the nucleon as a composite object, both in momentum and coordinate space, is slowly emerging. This book presents lectures and seminars from the Enrico Fermi School: Three-Dimensional Partonic Structure of the Nucleon, held in Varenna, Italy, in June and July 2011. The topics covered include: partonic distributions, fragmentation functions and factorization in QCD; theory of transverse momentum dependent partonic distributions (TMDs) and generalized partonic distributions (GPDs); experimental methods in studies of hard scattering processes; extraction of TMDs and GPDs from data; analysis tools for azimuthal asymmetries; ...

  16. Italy reactor decommissioning and safety of radioactive wastes; Proposta di piano per la disattivazione degli impianti nucleari in Italia e la messa in sicurezza dei rifiuti radioattivi

    Energy Technology Data Exchange (ETDEWEB)

    Grossi, G.; Noviello, L.; Rolandi, G. [ENEA, Rome (Italy)

    1998-07-01

    The radioactive waste disposal, fuel elements and nuclear materials is the priority country-problem in Italy. The solution at this problem is an essential condition for reactor dismantling and release of nuclear power plants place. [Italian] La sistemazione di un insieme complesso di rifiuti, elementi di combustibile e materiali nucleari costituisce oggi un problema-paese prioritario. La risoluzione di tale problema e' la condizione preliminare indispensabile per poter procedere alla disattivazione vera e propria delle centrali e degli impianti, che consenta il rilascio incondizionato dei relativi siti.

  17. Enrico : a Python package to simplify Fermi-LAT analysis

    OpenAIRE

    Sanchez, D. A.; Deil, C.

    2013-01-01

    With the advent of the Large Array Telescope (LAT) on board the Fermi satellite, a new window on the Universe has been opened. Publicly available, the Fermi-LAT data come together with an analysis software named ScienceTools (ST, http://fermi.gsfc.nasa.gov/ssc/data/analysis/software/) which can be run through a Python interface. Nevertheless, for the user, the ST can be hard to run and imply several steps. Users already contributed with scripts for a specific task but no tool allowing a compl...

  18. FINAL–REPORT NO. 2: INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE ENRICO FERMI ATOMIC POWER PLANT, UNIT 1, NEWPORT, MICHIGAN (DOCKET NO. 50 16; RFTA 10-004)

    Energy Technology Data Exchange (ETDEWEB)

    Erika Bailey

    2011-07-07

    The Enrico Fermi Atomic Power Plant, Unit 1 (Fermi 1) was a fast breeder reactor design that was cooled by sodium and operated at essentially atmospheric pressure. On May 10, 1963, the Atomic Energy Commission (AEC) granted an operating license, DPR-9, to the Power Reactor Development Company (PRDC), a consortium specifically formed to own and operate a nuclear reactor at the Fermi 1 site. The reactor was designed for a maximum capability of 430 megawatts (MW); however, the maximum reactor power with the first core loading (Core A) was 200 MW. The primary system was filled with sodium in December 1960 and criticality was achieved in August 1963.

  19. 179th International School of Physics "Enrico Fermi" : Laser-Plasma Acceleration

    CERN Document Server

    Gizzi, L A; Faccini, R

    2012-01-01

    Impressive progress has been made in the field of laser-plasma acceleration in the last decade, with outstanding achievements from both experimental and theoretical viewpoints. Closely exploiting the development of ultra-intense, ultrashort pulse lasers, laser-plasma acceleration has developed rapidly, achieving accelerating gradients of the order of tens of GeV/m, and making the prospect of miniature accelerators a more realistic possibility. This book presents the lectures delivered at the Enrico Fermi International School of Physics and summer school: "Laser-Plasma Acceleration" , held in Varenna, Italy, in June 2011. The school provided an opportunity for young scientists to experience the best from the worlds of laser-plasma and accelerator physics, with intensive training and hands-on opportunities related to key aspects of laser-plasma acceleration. Subjects covered include: the secrets of lasers; the power of numerical simulations; beam dynamics; and the elusive world of laboratory plasmas. The object...

  20. La crisi energetica nel mondo e in Italia da Enrico Fermi ed Edoardo Amaldi a oggi

    CERN Document Server

    Salvini, Giorgio

    2007-01-01

    Enrico Fermi e il suo allievo Edoardo Amaldi, grandi padri della Scuola di fisica nucleare italiana, hanno promosso l'impiego pacifico dell'energia nucleare: Fermi con il primo reattore a Chicago nel 1942, Arnaldi con i suoi contributi a tutti gli usi pacifici, dalla medicina alla produzione di energia. L'Italia, però, ha fatto eccessivo ricorso al petrolio, di cui non è produttrice. La ricerca è rimasta molto indietro rispetto a quella degli altri paesi e la politica sta dedicando pochissimi sforzi a questa gravissima situazione. Ragioni economiche, nonché ambientali, esigono ora una revisione e una ricontestualizzazione del problema. Durante un importante Convegno, tenutosi a Roma il 15 e 16 maggio 2007, alcuni tra i più noti ed esperti fisici italiani e stranieri hanno discusso proprio di questo problema. L'intento del volume, che raccoglie gli interventi del Convegno romano, è quello di fornire dati e informazioni che mettano il lettore in condizione di farsi un'idea propria, libera da pregiudizi, s...

  1. 182th International School of Physics "Enrico Fermi" : Neutrino Physics and Astrophysics

    CERN Document Server

    Ludhova, L

    2012-01-01

    This book contains chapters based on 9 of the lectures delivered at the Enrico Fermi School of Physics "Neutrino Physics and Astrophysics", held from 25 of July to 5 August 2011. The event was organized by the Italian Physical Society (SIF) jointly with the International School of Astro-particle Physics (ISAPP), a network whose aim is to build up an astro-particle community of both astrophysicists and particle physicists. Included are chapters on Neutrino oscillation physics (B. Kayser); Double-beta decay (E. Fiorini); Light neutrinos in cosmology (S. Pastor); Neutrinos and the stars (G.G. Raffelt); High energy neutrinos and cosmic rays (G. Sigl); Methods and problems in low-energy neutrino experiments (G. Ranucci); Methods and problems in neutrino observatories (M. Ribordy); New technologies in neutrino physics (L. Oberauer); and Perspectives of underground physics (A. Bettini). These are a followed by a section on the results presented in the form of posters by the Ph.D. students attending the school. The b...

  2. Development and performance evaluation of an improved standby gas treatment system for Enrico Fermi, Unit 2

    International Nuclear Information System (INIS)

    The Enrico Fermi Atomic Power Plant--Unit 2 utilizes two natural draft cooling towers. These large structures create the potential for entrainment of the stack effluent in a down wash from the leeward side of the cooling towers, thereby reducing the effectiveness of the stack. Thus, a stack of reasonable height would not be sufficient to secure compliance with 10 CFR 100 under design basis accident conditions. Detroit Edison evaluated three methods for further reducing the potential doses and hence complying with 10 CFR 100. The solution chosen by Edison was to develop a Standby Gas Treatment System of advanced design which could justifiably be credited with an iodine removal efficiency of 95 percent or higher (90 percent maximum was the AEC standard prior to the issuance of Regulatory Guide 1.52). A Standby Gas Treatment System, manufactured by the CVI Corporation, was chosen for this application. The CVI system features an all welded, submerged inlet carbon adsorber design which assures high performance by eliminating all elastomer seals and thereby, the chance for bypassing of the charcoal. In order to secure credit for higher iodine removal efficiency, system performance was demonstrated by testing a large scale system under simulated design basis accident conditions. The test program was conducted by the General Electric Co. at General Electric's Gas Technology Facility, Vallecitos Nuclear Center. The unit tested was a 400 cfm module supplied by the CVI Corporation which incorporated the same design features as the full scale unit. (U.S.)

  3. Enrico Fermi e il quaderno ritrovato 20 marzo 1934 : la vera storia della scoperta della radioattività indotta da neutroni

    CERN Document Server

    Guerra, Francesco

    2015-01-01

    La scoperta della radioattività indotta da neutroni ha aperto all'umanità nuove frontiere nel campo della conoscenza scientifica. Il ritrovamento del corrispondente quaderno di laboratorio di Enrico Fermi ha permesso una precisa ricostruzione di tale scoperta, finora basata essenzialmente su testimonianze dirette o indirette, con tutti i limiti tipici del ricordo personale.

  4. Safety Evaluation Report related to the operation of Enrico Fermi Atomic Power Plant, Unit No. 2 (Docket No. 50-341). Supplement No. 4

    International Nuclear Information System (INIS)

    Supplement No. 4 to the Safety Evaluation Report related to the operation of the Enrico Fermi Atomic Power Plant, Unit 2, provides the staff's evaluation of additional information submitted by the applicant regarding outstanding review issues identified in Supplement No. 3 to the Safety Evaluation Report, dated January 1983

  5. Safety evaluation report related to the operation of Enrico Fermi Atomic Power Plant, Unit No. 2. Docket No. 50-341

    International Nuclear Information System (INIS)

    Supplement No. 3 to the Safety Evaluation Report related to the operation of the Enrico Fermi Atomic Power Plant, Unit 2, provides the staff's evaluation of additional information submitted by the applicant regarding outstanding review issues identified in Supplement No. 2 to the Safety Evaluation Report, dated January 1982

  6. 75 FR 63867 - DTE Energy; Enrico Fermi Atomic Power Plant Unit 1, Exemption From Certain Security Requirements

    Science.gov (United States)

    2010-10-18

    .... Nuclear Regulatory Commission (NRC or the Commission) now or hereafter in effect. Fermi 1 was a fast breeder reactor power plant cooled by sodium and operated at essentially atmospheric pressure. In November... in Monroe County, Michigan. Fermi 1 is a permanently shutdown nuclear reactor facility. The...

  7. 75 FR 20867 - DTE Energy; Enrico Fermi Atomic Power Plant, Unit 1

    Science.gov (United States)

    2010-04-21

    ..., Deputy Director, Decommissioning and Uranium Recovery Licensing Directorate, Division of Waste Management... Action DTE is in the process of decommissioning Fermi-1. During the decommissioning process,...

  8. Revised FINAL–REPORT NO. 2: INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE ENRICO FERMI ATOMIC POWER PLANT, UNIT 1, NEWPORT, MICHIGAN (DOCKET NO. 50 16; RFTA 10-004) 2018-SR-02-1

    Energy Technology Data Exchange (ETDEWEB)

    Erika Bailey

    2011-10-27

    The Enrico Fermi Atomic Power Plant, Unit 1 (Fermi 1) was a fast breeder reactor design that was cooled by sodium and operated at essentially atmospheric pressure. On May 10, 1963, the Atomic Energy Commission (AEC) granted an operating license, DPR-9, to the Power Reactor Development Company (PRDC), a consortium specifically formed to own and operate a nuclear reactor at the Fermi 1 site. The reactor was designed for a maximum capability of 430 megawatts (MW); however, the maximum reactor power with the first core loading (Core A) was 200 MW. The primary system was filled with sodium in December 1960 and criticality was achieved in August 1963. The reactor was tested at low power during the first couple years of operation. Power ascension testing above 1 MW commenced in December 1965 immediately following the receipt of a high-power operating license. In October 1966 during power ascension, zirconium plates at the bottom of the reactor vessel became loose and blocked sodium coolant flow to some fuel subassemblies. Two subassemblies started to melt and the reactor was manually shut down. No abnormal releases to the environment occurred. Forty-two months later after the cause had been determined, cleanup completed, and the fuel replaced, Fermi 1 was restarted. However, in November 1972, PRDC made the decision to decommission Fermi 1 as the core was approaching its burn-up limit. The fuel and blanket subassemblies were shipped off-site in 1973. Following that, the secondary sodium system was drained and sent off-site. The radioactive primary sodium was stored on-site in storage tanks and 55 gallon (gal) drums until it was shipped off-site in 1984. The initial decommissioning of Fermi 1 was completed in 1975. Effective January 23, 1976, DPR-9 was transferred to the Detroit Edison Company (DTE) as a 'possession only' license (DTE 2010a). This report details the confirmatory activities performed during the second Oak Ridge Institute for Science and Education

  9. An interview with Enrico Coen.

    Science.gov (United States)

    Vicente, Catarina

    2016-07-15

    Enrico Coen CBE FRS is a Project Leader at the John Innes Centre in Norwich, UK, who uses a variety of approaches to study patterning and morphogenesis in plants. We met with Enrico at the Spring Meeting of the British Society for Developmental Biology, where he was awarded the Waddington Medal, to ask him more about his career and his passion for art and book-writing. PMID:27436037

  10. Fermi and Szilard

    CERN Document Server

    Byers, N

    2002-01-01

    This talk is about Enrico Fermi and Leo Szilard, their collaboration and involvement in nuclear energy development and decisions to construct and use the atomic bomb in World War II. Fermi and Szilard worked closely together at Columbia in 1939-40 to explore feasibility of a nuclear chain reaction, and then on the physics for construction of the first pile (nuclear reactor). "On matters scientific or technical there was rarely any disagreement between Fermi and myself" Szilard said. But there were sharp differences on other matters.

  11. The first reactor [40th anniversary commemorative edition

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-12-01

    This updated and revised story of the first reactor, or 'pile,' commemorates the 40th anniversary of the first controlled, self-sustaining nuclear chain reaction created by mankind. Enrico Fermi and his team of scientists initiated the reaction on December 2, 1941, underneath the West Stands of Stagg Field at the University of Chicago. Firsthand accounts of the participants as well as postwar recollections by Enrico and Laura Fermi are included.

  12. Enrico Fermi and the Dolomites

    OpenAIRE

    Battimelli, Giovanni; de Angelis, Alessandro

    2014-01-01

    Summer vacations in the Dolomites were a tradition among the professors of the Faculty of Mathematical and Physical Sciences at the University of Roma since the end of the XIX century. Beyond the academic walls, people like Tullio Levi-Civita, Federigo Enriques and Ugo Amaldi sr., together with their families, were meeting friends and colleagues in Cortina, San Vito, Dobbiaco, Vigo di Fassa and Selva, enjoying trekking together with scientific discussions. The tradition was transmitted to the...

  13. The development of breeder reactors in the US

    International Nuclear Information System (INIS)

    This article discusses the early history of breeder development in the US, the early history of the fast reactor in the US, changes during the Carter administration, and the development of LMFBR technology. Topics considered include the intermediate-energy plutonium breeder, the molten plutonium breeder, the aqueous homogeneous reactor, the molten-salt reactor, the liquid metal-fueled reactor, electronuclear breeding, the Experimental Breeder Reactor-I, the Experimental Breeder Reactor-II, the Enrico Fermi Reactor, a programmatic change to ceramic fuel, the South East Fast Oxide Reactor, the sodium void coefficient, the 1000-MWe studies of 1964, the 1000-MWe studies of 1967-1969, the FARET design, the Fast Flux Test Facility, the Clinch River Breeder Reactor (CRBR), the gas-cooled fast breeder, the light-water breeder, materials for cladding and duct walls, and reactor safety. It is pointed out that the Congress opposes the construction of the CRBR, while the Reagan administration strongly supports it

  14. The First Reactor, 40th Anniversary (rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Allardice, Corbin; Trapnell, Edward R; Fermi, Enrico; Fermi, Laura; Williams, Robert C

    1982-12-01

    This booklet, an updated version of the original booklet describing the first nuclear reactor, was written in honor of the 40th anniversary of the first reactor or "pile". It is based on firsthand accounts told to Corbin Allardice and Edward R. Trapnell, and includes recollections of Enrico and Laura Fermi.

  15. Human-factors control-room-design review draft audit report: Detroit Edison Company, Enrico Fermi Atomic Power Plant--Unit 2

    International Nuclear Information System (INIS)

    A human factors audit of the Fermi-2 control room was conducted April 27 through May 1, 1981. This report contains the audit team findings, organized according to the draft NUREG-0700 guidelines sections. The discrepancies identified during the audit are categorized according to their severity and the required schedule for their resolution

  16. Progress report on the research activities on high conversion reactors at the Centro Atomico Bariloche, Argentina

    International Nuclear Information System (INIS)

    The present progress report covers the activities performed by the High Conversion Reactors Group of the Neutrons and Reactors Division of the Centro Atomico Bariloche (CAB). This group, previously devoted mainly to neutron physics problems, started its activities in the field of this reactor concept some years ago, which were initially focused on the neutronic problems related with the design of these facilities. The main results obtained up to now and the experience acquired are reported, and they cover: description of preliminary work; implementation and validation of the calculational system; study of the sensitivity of cell calculations to geometrical treatment; evaluation of resonance self-shielding correction and heterogeneities effects; local values for the NEACRP international benchmark at zero burn-up. Moreover, the activities underway are also presented: provisions for burn-up calculations; PROTEUS Phase I and II and JAERI's FCA-HCLWR cell calculations; fuel element and whole core calculations. (author). 20 refs, figs and tabs

  17. Enrico Fermi Awards Ceremony for Dr. Mildred S. Dresselhaus and Dr. Burton Richter, May 2012 (Presentations, including remarks by Energy Secretary, Dr. Steven Chu)

    International Nuclear Information System (INIS)

    The Fermi Award is a Presidential award and is one of the oldest and most prestigious science and technology honors bestowed by the U.S. Government. On May 7, 2012 it was conferred upon two exceptional scientists: Dr. Mildred Dresselhaus, 'for her scientific leadership, her major contributions to science and energy policy, her selfless work in science education and the advancement of diversity in the scientific workplace, and her highly original and impactful research,' and Dr. Burton Richter, 'for the breadth of his influence in the multiple disciplines of accelerator physics and particle physics, his profound scientific discoveries, his visionary leadership as SLAC Director, his leadership of science, and his notable contributions in energy and public policy.' Dr. John Holder, Director of the White House Office of Science and Technology Policy, opened the ceremony, and Dr. Bill Brinkman, Director of DOE's Office of Science introduced the main speaker, Dr. Steven Chu, U.S. Energy Secretary.

  18. Sensible nuclear materials control in the European Union; Controllo dei materiali nucleari sensibili nella UE

    Energy Technology Data Exchange (ETDEWEB)

    Casarelli, Giancarlo [Politecnico Univ., Milano (Italy). Dipartimento di energetica

    2005-10-15

    In this article are reported the typology of nuclear cycle plants. Here are presented the inspection activities and results of year 2003. [Italian] I processi industriali per la produzione dei materiali fissili di base necessari per il combustibile dei reattori nucleari sono sostanzialmente gli stessi necessari per produrre esplosivi nucleari per le bombe atomiche. Il timore di una possibile proliferazione di nazioni con armamanti nucleari ha portato nel 1968 al Trattato di non proliferazione nucleare (NPT) ed alla istituzione di sistemi di controllo internazionali tramite l'IAEA, l'Euratom e le Agenzie nazionali istituite ad hoc. Nell'articolo vengono indicate le tipologie degli impianti per il ciclo del combustibile dove si concentrano nei Paesi della UE le attivita ispettive e le rispettive risultanze per l'anno 2003.

  19. The Fermi's Bayes Theorem

    CERN Document Server

    D'Agostini, G

    2005-01-01

    It is curious to learn that Enrico Fermi knew how to base probabilistic inference on Bayes theorem, and that some influential notes on statistics for physicists stem from what the author calls elsewhere, but never in these notes, {\\it the Bayes Theorem of Fermi}. The fact is curious because the large majority of living physicists, educated in the second half of last century -- a kind of middle age in the statistical reasoning -- never heard of Bayes theorem during their studies, though they have been constantly using an intuitive reasoning quite Bayesian in spirit. This paper is based on recollections and notes by Jay Orear and on Gauss' ``Theoria motus corporum coelestium'', being the {\\it Princeps mathematicorum} remembered by Orear as source of Fermi's Bayesian reasoning.

  20. Enrico Fermi / Ian Whitelaw, Julie Whitaker

    Index Scriptorium Estoniae

    Whitelaw, Ian, 1953-

    2011-01-01

    Itaalia päritolu USA teoreetiline ja eksperimentaalfüüsik, Nobeli preemia laureaat. Üks Ameerika Ühendriikide tuumaprogrammi rajajaid, esimesena juhitava aheltuumareaktsioonini jõudnud töörühma juht

  1. Fermi

    Data.gov (United States)

    National Aeronautics and Space Administration — Fermi is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is...

  2. Study of superfluid Bose-Fermi mixture

    Science.gov (United States)

    Laurent, Sebastien; Delehaye, Marion; Jin, Shuwei; Pierce, Matthieu; Yefsah, Tarik; Chevy, Frederic; Salomon, Christophe

    2016-05-01

    Using fermionic and bosonic isotopes of lithium we produce and study ultracold Bose-Fermi mixtures. First in a low temperature counterflow experiment, we measure the critical velocity of the system in the BEC-BCS crossover. Around unitarity, we observe a remarkably high superfluid critical velocity which reaches the sound velocity of the strongly interacting Fermi gas. Second, when we increase the temperature of the system slightly above the superfluid transitions we observe an unexpected phase locking of the oscillations of the clouds induced by dissipation. Finally, as suggested in, we explore the nature of the superfluid phase when we impose a spin polarization in the situation where the mean field potential created by the bosons on the fermions tends to cancel out the trapping potential of the latter.

  3. La scena nel testo: Enrico IV di Luigi Pirandello

    OpenAIRE

    De Chiara, Mariafilomena

    2009-01-01

    The starting point is the understanding of the dramatic text as literary text, thus it could be analyzed with methodologies coming from literary studies: the dramatic text is literature, creation of language and it can be read and interpreted as such. Of course I acknowledge the text’s performativity, implicit in its characteristic and functions. The analysis of Enrico IV (1921) constitutes a practical application of the proposal and the opportunity for opening the discussion to new perspecti...

  4. Raggi cosmici e telescopi a scuolatra entusiasmi e perplessità Iniziativa del Cern, del centro Enrico Fermi e dell'Infn per portare la scienza in classe. Come nel 'Codice Da Vinci'

    CERN Multimedia

    DE LUCA, Anna Maria

    2008-01-01

    Cosmic beams and telescopes between the desks. Objective: to approach science the heart of the Italian students, just those that the famous ' Pisa' relationship of the Ocse has indicated like refractory to this type of disciplines.

  5. 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.)

  6. Role of pressure in the study of the FERMI surface

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, J.E.

    1977-01-01

    Pressure studies of the Fermi surface are providing critical tests for the physical significance of model descriptions for the electron structure of metals. Work since the most recent reviews is cited. The solid and fluid He pressure techniques used in on-going studies on Gd, U and Th are described briefly and results on these materials are discussed.

  7. Teaching About Nature's Nuclear Reactors

    CERN Document Server

    Herndon, J M

    2005-01-01

    Naturally occurring nuclear reactors existed in uranium deposits on Earth long before Enrico Fermi built the first man-made nuclear reactor beneath Staggs Field in 1942. In the story of their discovery, there are important lessons to be learned about scientific inquiry and scientific discovery. Now, there is evidence to suggest that the Earth's magnetic field and Jupiter's atmospheric turbulence are driven by planetary-scale nuclear reactors. The subject of planetocentric nuclear fission reactors can be a jumping off point for stimulating classroom discussions about the nature and implications of planetary energy sources and about the geomagnetic field. But more importantly, the subject can help to bring into focus the importance of discussing, debating, and challenging current thinking in a variety of areas.

  8. [Enrico Modigliani and the Institution of maternal assistance: a study of the social factors of illegitimate motherhood during early Twentieth century].

    Science.gov (United States)

    Fano, Valeria

    2016-01-01

    Enrico Modigliani (1877-1931) was an Italian paediatrician of the early Twentieth century whose work anticipated modern concepts of maternal and child health. Convinced of the importance of creating a network of health and social care for children born out-of-wedlock, he began by providing care to single mothers and their babies at his home on Sundays. In 1918, in Rome, he established the Institution for Maternal Assistance, which aim was to provide single mothers with basic health information as well as tools to face their socioeconomic situation. The Opera encouraged breastfeeding and maternal acknowledgement of the child and promoted the establishment of lactation rooms and nurseries within factories. Moreover, women were supported to find a job which was compatible with their situation. In the first five years of activity, over 1,000 unmarried women were assisted; 95% of them acknowledged their children and 52% found a job. The infant mortality rate fell to 11%, which was much lower than the 35% observed at the time among the social classes which Modigliani called the most miserable. This article reviews Modigliani's paper, in which the paediatrician reported the first five years of activity of the Institution of Maternal Assistance and where he largely focused on the social factors surrounding illegitimate motherhood. The paper was structured like a modern scientific report, with photographic documentation and statistical data, and proposed a point of view regarding social inequality which is surprisingly up-to-date. PMID:27436257

  9. Radioactive waste treatment from experimental reactor PWR type developed to the Centro Experimental de Aramar -- Sao Paulo -- Brazil

    International Nuclear Information System (INIS)

    With the objective of getting experience on technology development to build PWR reactors in Brazil, a research center called Centro Experimental ARAMAR -- CEA was created. Taking into account all environmental factors, it had been necessary to develop a waste management program to meet this objective. This program, besides considering topics related to the safety and health of the public and worker, must consider the treatment of all radioactive waste (LLW and ILW) that will be generated, for minimizing the risks to the environment. COPESP has been developing compatible systems using technology through an extensive literature research about the state of the art in this field and practical experience from the Angra 1 Nuclear Power Plant. In this paper the authors will show some aspects related to the waste management program that have already been developed by COPESP, for instance, solids, liquids and gaseous radioactive waste management

  10. Future Multiwavelength Studies with the Fermi Large Area Telescope

    Science.gov (United States)

    Thompson, David J.

    2011-01-01

    With two and a half years of experience, Fermi LAT contributions to multiwavelength studies have become an integral part of many astrophysical research projects. Future efforts will benefit from (1) Deeper LAT exposures} resulting in more sources; (2) More high-energy, high-angular resolution photons, giving better source locations and imaging; (3) Faster analysis of variability and announcements to the community; and (4) Longer time series for studies of variable source properties in comparison to other wavelengths.

  11. Mirror reactor surface study

    International Nuclear Information System (INIS)

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included

  12. The Fermi Paradox is Neither Fermis Nor a Paradox

    OpenAIRE

    Gray, Robert H.

    2016-01-01

    The so-called Fermi paradox claims that if technological life existed anywhere else, we would see evidence of its visits to Earth-and since we do not, such life does not exist, or some special explanation is needed. Enrico Fermi, however, never published anything on this topic. On the one occasion he is known to have mentioned it, he asked 'where is everybody?'- apparently suggesting that we don't see extraterrestrials on Earth because interstellar travel may not be feasible, but not suggesti...

  13. 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.

  14. Data base for analysis of RA-1 reactor decommissioning

    International Nuclear Information System (INIS)

    Full text: The RA-1 'Enrico Fermi' reactor is located at the Constituyentes Atomic Centre near Buenos Aires city. It reached criticality for the first time on January 17th, 1958. During 45 years, major modifications were introduced. The Decommissioning of RA-1 is not foreseen in a near future, but nevertheless CNEA (legally responsible of Dismantling and Decommissioning of all relevant nuclear facilities in Argentina) has started Dismantling and Decommissioning planning activities. As a part of these activities, a historical information data base of the RA-1 reactor was performed. This report contains a set of global and specific data of the RA-1 Research Reactor prepared as a data base for a future decommissioning analysis. It describes the whole installation, and specially the core, fuel type, present configuration, shielding and the operation devices. An exhaustive listing of materials and components located in the Reactor building is given. It also reconstructs the reactor operation history based on the available information. (author)

  15. Fermi and Swift Gamma-Ray Burst Afterglow Population Studies

    Science.gov (United States)

    Racusin, Judith L.; Oates, S. R.; Schady, P.; Burrows, D. N.; dePasquale, M.; Donato, D.; Gehrels, N.; Koch, S.; McEnery, J.; Piran, T.; Roming, P.; Sakamoto, T.; Swenson, C.; Troja, E.; Vasileiou, V.; Virgili, F.; Wanderman, D.; Zhang, B.

    2011-01-01

    The new and extreme population of GRBs detected by Fermi -LAT shows several new features in high energy gamma-rays that are providing interesting and unexpected clues into GRB prompt and afterglow emission mechanisms. Over the last 6 years, it has been Swift that has provided the robust dataset of UV/optical and X-ray afterglow observations that opened many windows into components of GRB emission structure. The relationship between the LAT detected GRBs and the well studied, fainter, less energetic GRBs detected by Swift -BAT is only beginning to be explored by multi-wavelength studies. We explore the large sample of GRBs detected by BAT only, BAT and Fermi -GBM, and GBM and LAT, focusing on these samples separately in order to search for statistically significant differences between the populations, using only those GRBs with measured redshifts in order to physically characterize these objects. We disentangle which differences are instrumental selection effects versus intrinsic properties, in order to better understand the nature of the special characteristics of the LAT bursts.

  16. Reactor safety activities at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN)-Nuclebras

    International Nuclear Information System (INIS)

    This report presents the major activities developed at NUCLEBRAS in the area of Reactor Safety. The Thermohydraulics and Reactor Safety program consists of activities in the analytical and experimental area. The more recent activities under way in the analytical area are presented together with some results. They are mainly related to the development and assessment of advanced computer codes to be used in the analysis of the behavior of the plant during operational transients and postulated accidents and in thermohydraulic core design. In the experimental area, the main accomplishments and activities under way are reported they refer to steady state CHF tests in a 9-rod bundle and rewetting experiments in a tubular test section. In particular, the status of the design development of a new facility for Separate Effects LOCA tests (DTL-ES) is described. Concerning the Components Testing program, the basic characteristics of a valve test facility (CTC) are described and the present status of its construction is reported. Reference is also made to existing installations and a summary of tests already performed for Angra-2 components qualification is presented. (Author)

  17. Studies on reactor physics

    International Nuclear Information System (INIS)

    Most of the peaceful applications of atomic energy are inherently dependent on advances in the science and technology of nuclear reactors, and aspects of this development are part of a major programme of the International Atomic Energy Agency. The most useful role that the Agency can play is as a co-ordinating body or central forum where the trends can be reviewed and the results assessed. Some of the basic studies are carried out by members of the Agency's own scientific staff. The Agency also convenes groups of experts from different countries to examine a particular problem in detail and make any necessary recommendations. Some of the important subjects are discussed at international scientific meetings held by the Agency. One of the subjects covered by such studies is the physics of nuclear reactors and a specific topic recently discussed was Codes for Reactor Computations, on which a seminar was held in Vienna in April this year. Another The members of the Panel described the development of heavy water reactors, the equipment and methods of research currently used, and plans for further development in their respective countries meeting of Panel of Experts on Heavy Water Lattices was held in Vienna in August 1959

  18. Le attività del centro Altreitalie e lo sviluppo degli studi sulle migrazioni italiane nelle Americhe

    OpenAIRE

    Maddalena Tirabasi

    2015-01-01

    L’articolo presenta la storia del Centro Altreitalie, nato all’interno della Fondazione Giovanni Agnelli negli anni ottanta, e le attività di ricerca e promozione degli studi sulle migrazioni italiane oltreoceano. Particolare rilevanza viene data alle ricerche svolte in America Latina, prima area di indagine agli albori degli studi migratori italiani. Oggi il Centro Altreitalie, all’interno dell’associazione Globus et Locus, continua a sostenere e a diffondere i risultati della ricerca attrav...

  19. Optimization Studies of the FERMI at ELETTRA FEL Design

    Energy Technology Data Exchange (ETDEWEB)

    De Ninno, Giovanni; Fawley, William M.; Penn, Gregory E.; Graves,William

    2005-08-25

    The FERMI at ELETTRA project at Sincotrone Trieste involves two FEL's, each based upon the principle of seeded harmonic generation and using the existing ELETTRA injection linac at 1.2 GeV beam energy. Scheduled to be completed in 2008, FEL-1 will operate in 40-100 nm wavelength range and will involve one stage of harmonic up-conversion. The second undulator line, FEL-2, will begin operation two years later in the 10-40 nm wavelength range and use two harmonic stages operating as a cascade. The FEL design assumes continuous wavelength tunability over the full wavelength range, and polarization tunability of the output radiation including vertical or horizontal linear as well as helical polarization. The design considers focusing properties and segmentation of realizable undulators and available input seed lasers. We review the studies that have led to our current design. We present results of simulations using GENESIS and GINGER simulation codes including studies of various shot-to-shot fluctuations and undulator errors. Findings for the expected output radiation in terms of the power, transverse and longitudinal coherence are reported.

  20. Density Functional Theory Studies of Magnetically Confined Fermi Gas

    Institute of Scientific and Technical Information of China (English)

    陈宇俊; 马红孺

    2001-01-01

    A theory is developed for magnetically confined Fermi gas at a low temperature based on the density functional theory. The theory is illustrated by the numerical calculation of the density distributions of Fermi atoms 40K with parameters according to DeMarco and Jin's experiment [Science, 285(1999)1703]. Our results are in close agreement with the experiment. To check the theory, we also performed calculations using our theory at a high temperature, which compared very well to the results of the classical limit.

  1. Chernobyl reactor transient simulation study

    International Nuclear Information System (INIS)

    This paper deals with the Chernobyl nuclear power station transient simulation study. The Chernobyl (RBMK) reactor is a graphite moderated pressure tube type reactor. It is cooled by circulating light water that boils in the upper parts of vertical pressure tubes to produce steam. At equilibrium fuel irradiation, the RBMK reactor has a positive void reactivity coefficient. However, the fuel temperature coefficient is negative and the net effect of a power change depends upon the power level. Under normal operating conditions the net effect (power coefficient) is negative at full power and becomes positive under certain transient conditions. A series of dynamic performance transient analysis for RBMK reactor, pressurized water reactor (PWR) and fast breeder reactor (FBR) have been performed using digital simulator codes, the purpose of this transient study is to show that an accident of Chernobyl's severity does not occur in PWR or FBR nuclear power reactors. This appears from the study of the inherent, stability of RBMK, PWR and FBR under certain transient conditions. This inherent stability is related to the effect of the feed back reactivity. The power distribution stability in the graphite RBMK reactor is difficult to maintain throughout its entire life, so the reactor has an inherent instability. PWR has larger negative temperature coefficient of reactivity, therefore, the PWR by itself has a large amount of natural stability, so PWR is inherently safe. FBR has positive sodium expansion coefficient, therefore it has insufficient stability it has been concluded that PWR has safe operation than FBR and RBMK reactors

  2. Study and modeling of the most energetic Active Galactic Nuclei with the Fermi satellite

    International Nuclear Information System (INIS)

    The Fermi satellite was launched in June 2008. The onboard LAT detector is dedicated to the study of galactic and extra-galactic gamma sources with an energy comprised between 200 MeV and 300 GeV. 1451 sources have been detected in less than 11 months. This document is divided into 6 chapters: 1) gamma astronomy, 2) the Fermi satellite, 3) the active galactic nuclei (NAG), 4) the observation of several blazars (PKS-2155-304 and PG-1553+113) and its simulation, 5) the observation of PKS-2155-304 with both RXTE and Fermi, and 6) conclusion

  3. Monte Carlo study of thermal fluctuations and Fermi-arc formation in d-wave superconductors

    Science.gov (United States)

    Zhong, Yong-Wei; Li, Tao; Han, Qiang

    2011-07-01

    From the perspective of thermal fluctuations, we investigate the pseudogap phenomena in underdoped high-temperature curpate superconductors. We present a local update Monte Carlo procedure based on the Green’s function method to sample the fluctuating pairing field. The Chebyshev polynomial method is applied to calculate the single-particle spectral function directly and efficiently. The evolution of Fermi arcs as a function of temperature is studied by examining the spectral function at Fermi energy as well as the loss of spectral weight. Our results signify the importance of the vortexlike phase fluctuations on the formation of Fermi arcs.

  4. Studies on nuclear reactor design

    International Nuclear Information System (INIS)

    this thesis presents two studies for safety aspects in nuclear reactor design. the fission process that occurs in the reactor core is the most important process for the harmful effect of produced radiation especially neutrons with different energies and gamma radiations for their strong penetrability . so studying the criticality of the fissile materials in the reactor is one of the most important safety aspects for the reactor design, the attenuation of the neutrons and gammas using suitable shielding materials with suitable thicknesses is the second study that is discussed in this thesis

  5. Centro Polifunzionale Fiersistico

    OpenAIRE

    Claudio Zanirato

    2012-01-01

    progettazione preliminare del Centro Polifunzionale Fieristico di Olbia, con parcheggi intensivi, padiglioni espositivi, centro congressi, ristorazione, piazze, sistemazioni naturalistiche, centro universitario e scuola di navigazione

  6. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  7. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  8. Neutrino Oscillation Studies with Reactors

    CERN Document Server

    Vogel, Petr; Zhang, Chao

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  9. Fermi: a physicist in the upheaval

    International Nuclear Information System (INIS)

    This book summarizes the life, works and complex personality of the Italian physicist Enrico Fermi (1901-1954) whose myth is linked with the political upheaval of the 2. world war: the youth of an autodidact, the theorician and the quantum mechanics, his invention of a quantum statistics, the weak interaction theory, his works on artificial radioactivity, the end of the Fermi team and his exile in the USA, the secrete researches at the university of Columbia and the birth of the first atomic 'pile' (December 2, 1942), the building of Los Alamos center and the Alamogordo explosion test, the disagreements among the physicists of the Manhattan project and the position of Fermi, Fermi's contribution in the H-bomb construction, the creation of the physics school of Chicago, the Oppenheimer spying affair. (J.S.)

  10. Enrico VII e l’Italia. Un primo bilancio

    Directory of Open Access Journals (Sweden)

    Gian Maria Varanini

    2014-06-01

    Full Text Available Il testo introduce i saggi pubblicati nel fasc. 1 (2014 di “Reti Medievali - Rivista”, traccia un sintetico bilancio delle ricerche recenti sulla spedizione di Enrico VII di Lussemburgo in Italia (1310-1313 e propone alcune questioni interpretative.

  11. Study of future reactors

    International Nuclear Information System (INIS)

    Today, more than 420 large reactors with a gross output of close to 350 GWe supply 20 percent of world electricity needs, accounting for less than 5 percent of primary energy consumption. These figures are not expected to change in the near future, due to suspended reactor construction in many countries. Nevertheless, world energy needs continue to grow: the planet's population already exceeds five billion and is forecast to reach ten billion by the middle of the next century. Most less developed countries have a very low rate of energy consumption and, even though some savings can be made in industrialized countries, it will become increasingly difficult to satisfy needs using fossil fuels only. Furthermore, there has been no recent breakthrough in the energy landscape. The physical feasibility of the other great hope of nuclear energy, fusion, has yet to be proved; once this has been done, it will be necessary to solve technological problems and to assess economic viability. Although it is more ever necessary to pursue fusion programs, there is little likelihood of industrial applications being achieved in the coming decades. Coal and fission are the only ways to produce massive amounts of energy for the next century. Coal must overcome the pollution problems inherent in its use; fission nuclear power has to gain better public acceptance, which is obviously colored by safety and waste concerns. Most existing reactors were commissioned in the 1970s; reactor lifetime is a parameter that has not been clearly established. It will certainly be possible to refurbish some to extend their operation beyond the initial target of 30 or 40 years. But normal advances in technology and safety requirements will make the operation of the oldest reactors increasingly difficult. It becomes necessary to develop new generations of nuclear reactors, both to replace older ones and to revive plant construction in their countries that are not yet equipped or that have halted their

  12. Alternate-fuel reactor studies

    International Nuclear Information System (INIS)

    A number of studies related to improvements and/or greater understanding of alternate-fueled reactors is presented. These studies cover the areas of non-Maxwellian distributions, materials and lifetime analysis, a 3He-breeding blanket, tritium-rich startup effects, high field magnet support, and reactor operation spanning the range from full D-T operation to operation with no tritium breeding

  13. Helias reactor studies

    International Nuclear Information System (INIS)

    The Helias reactor is an upgraded version of the Wendelstein 7-X experiment. The magnetic field has 5 field periods and the main optimization principle is the reduction of the Pfirsch-Schlueter currents and the Shafranov shift, which has been verified by computations with the NEMEC and MFBE-codes. The modular coil system comprises 50 coils, which are constructed using NbTi-superconducting cables. The basic dimensions are: major radius 22 m, average plasma radius 1.8 m, magnetic field on axis 5 T, maximum field on the coils 10 T. Forces and stresses in the coil system have been investigated with the aid of the ANSYS code, which found maximum stress values of about 650 MPa in the coil casing. Helias configurations with 4 and 3 field periods have been constructed by starting from the 5-period case and by eliminating one or two periods while the shape of the coils is kept nearly invariant. In a first survey blanket concepts, developed for the DEMO tokamak, have been adapted to the Helias geometry, in particular, the solid breeder concept developed by FZK (Karlsruhe) has been extrapolated to the Helias geometry identifying the drawbacks and advantages of this concept. Furthermore, the liquid breeder concept using Li7-Pb83 and water-cooling is an interesting alternative for the Helias reactor. Maintenance of blanket and plasma facing components is possible through the portholes between modular coils. Numerical simulations of the start-up phase of the Helias reactor using the TOTAL-P code have confirmed the zero-dimensional modeling of the fusion plasma with the aid of empirical scaling laws. (author)

  14. The Fermi Paradox is Neither Fermis Nor a Paradox

    CERN Document Server

    Gray, Robert H

    2016-01-01

    The so-called Fermi paradox claims that if technological life existed anywhere else, we would see evidence of its visits to Earth-and since we do not, such life does not exist, or some special explanation is needed. Enrico Fermi, however, never published anything on this topic. On the one occasion he is known to have mentioned it, he asked 'where is everybody?'- apparently suggesting that we don't see extraterrestrials on Earth because interstellar travel may not be feasible, but not suggesting that intelligent extraterrestrial life does not exist, or suggesting its absence is paradoxical. The claim 'they are not here; therefore they do not exist' was first published by Michael Hart, claiming that interstellar travel and colonization of the galaxy would be inevitable if intelligent extraterrestrial life existed, and taking its absence here as proof that it does not exist anywhere. The Fermi paradox appears to originate in Hart's argument, not Fermi's question. Clarifying the origin of these ideas is important...

  15. The multi-faceted synergy between Swift and Fermi in radio-loud AGN studies

    CERN Document Server

    D'Ammando, F

    2015-01-01

    Since its launch in 2008 June, the Fermi Gamma-ray Space Telescope has opened a new era in high-energy astrophysics. The unprecedented sensitivity, angular resolution and effective area of the Large Area Telescope on board Fermi, together with the nearly continuous observation of the entire gamma-ray sky assures a formidable opportunity to study in detail gamma-ray emitting AGN of various types. In this context the Swift satellite, thanks to its broad band coverage and scheduling flexibility, creates a perfect synergy with Fermi. Swift and Fermi coordinated monitoring campaigns of radio-loud AGN allowed us to investigate correlated variability at different frequencies and to build time-resolved spectral energy distributions from optical to gamma-rays, constraining the emission mechanisms at work in these objects. The rapid Swift follow-up observations of gamma-ray flaring AGN detected by Fermi-LAT were also fundamental in firmly associating the gamma-ray sources with their low-energy counterparts. We present ...

  16. Fermi coordinates and modified Franklin transformation : A comparative study on rotational phenomena

    CERN Document Server

    Nouri-Zonoz, M

    2014-01-01

    Applying a relativistic rotational transformation to study and analyze rotational phenomena, instead of the rotational transformations based on consecutive Lorentz transformations and Fermi coordinates, leads to different predictions. In this article after a comparative study between Fermi metric of a uniformly rotating observer and the spacetime metric in a rotating frame obtained through the modified Franklin transformation, we consider rotational phenomena including transverse Doppler effect and Sagnac effect in both formalisms and compare their predictions. We also discuss length measurements in the two formalisms.

  17. Fermi coordinates and modified Franklin transformation: a comparative study on rotational phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Nouri-Zonoz, M.; Ramezani-Aval, H. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of)

    2014-10-15

    Employing a relativistic rotational transformation to study and analyze rotational phenomena, instead of the rotational transformations based on consecutive Lorentz transformations and Fermi coordinates, leads to different predictions. In this article, after a comparative study between the Fermi metric of a uniformly rotating eccentric observer and the spacetime metric in the same observer's frame obtained through the modified Franklin transformation, we consider rotational phenomena including the transverse Doppler effect and the Sagnac effect in both formalisms and compare their predictions. We also discuss length measurements in the two formalisms. (orig.)

  18. Angle-resolved photoemission spectroscopy study on the Fermi surface topology of NaxCoO2

    International Nuclear Information System (INIS)

    We report a systematic study on NaxCoO2 (0.3≤x≤0.72) using angle-resolved photoemission spectroscopy (ARPES), with a focus on the Fermi surface topology of the metallic samples. Within this doping range, we observed only one large hexagonal Fermi surface around the Γ-point, which comes from the a1g band. Contrary to most band calculations, our results show that the eg' bands never cross the Fermi level to form small Fermi surface pockets near the K-point. The enclosed area of the a1g Fermi surface is found to be consistent with the Luttinger theorem within the doping range in this study. We also found that, at x = 1/3, the Fermi surface coincides with the zone boundary of the √3x√3 commensurate ordering, indicating the importance of charge fluctuations in this material

  19. Enrico Chiaveri, new Head of the Human Resources Department

    CERN Multimedia

    2005-01-01

    Enrico Chiaveri has been appointed Head of the Human Resources Department of with effect from 1st April 2005. A senior physicist, Dr Chiaveri joined CERN in 1973. During his career, he has performed various management roles, including that of Deputy Leader of the SPS/LEP Division, and has acquired extensive experience in human resources matters. Over the transition period up to 1st August 2005 he will gradually relinquish his current functions as Group Leader within the AB Department.

  20. Civilian nuclear power on the drawing board: the development of Experimental Breeder Reactor-II

    International Nuclear Information System (INIS)

    On September 28, 2001 a symposium was held at Argonne National Laboratory as part of the festivities to mark the 100th birthday of Enrico Fermi. The symposium celebrated Fermi's ''contribution to the development of nuclear power'' and focused on one particular ''line of development'' resulting from Fermi's interest in power reactors: Argonne's fast reactor program. Symposium participants made many references to the ways in which the program was linked to Fermi, who led the team which created the world's first self-sustaining nuclear chain reaction. For example, one presentation featured an April, 1944 memo that described a meeting attended by Fermi and others. The memo came from the time when research on plutonium and the nuclear chain reaction at Chicago's WWII Metallurgical Laboratory was nearing its end. Even as other parts of the Manhattan Engineering Project were building on this effort to create the bombs that would end the war, Fermi and his colleagues were taking the first steps to plan the use of nuclear energy in the postwar era. After noting that Fermi ''viewed the use of [nuclear] power for the heating of cities with sympathy,'' the group outlined several power reactor designs. In the course of discussion, Fermi and his colleagues took the first steps in conjuring the vision that would later be brought to life with Experimental Breeder Reactor I (EBR-I) and Experimental Breeder Reactor II (EBR-II), the celebrated achievements of the Argonne fast reactor program. Group members considered various schemes for a breeder reactor in which the relatively abundant U-238 would be placed near a core of fissionable material. The reactor would be a fast reactor; that is, neutrons would not be moderated, as were most wartime reactors. Thus, the large number of neutrons emitted in fast neutron fission would hit the U-238 and create ''extra'' fissionable material, that is, more than ''invested,'' and at the same time produce power. The group identified the problem of

  1. Civilian nuclear power on the drawing board: the development of Experimental Breeder Reactor-II.

    Energy Technology Data Exchange (ETDEWEB)

    Westfall, C.

    2003-02-20

    On September 28, 2001 a symposium was held at Argonne National Laboratory as part of the festivities to mark the 100th birthday of Enrico Fermi. The symposium celebrated Fermi's ''contribution to the development of nuclear power'' and focused on one particular ''line of development'' resulting from Fermi's interest in power reactors: Argonne's fast reactor program. Symposium participants made many references to the ways in which the program was linked to Fermi, who led the team which created the world's first self-sustaining nuclear chain reaction. For example, one presentation featured an April, 1944 memo that described a meeting attended by Fermi and others. The memo came from the time when research on plutonium and the nuclear chain reaction at Chicago's WWII Metallurgical Laboratory was nearing its end. Even as other parts of the Manhattan Engineering Project were building on this effort to create the bombs that would end the war, Fermi and his colleagues were taking the first steps to plan the use of nuclear energy in the postwar era. After noting that Fermi ''viewed the use of [nuclear] power for the heating of cities with sympathy,'' the group outlined several power reactor designs. In the course of discussion, Fermi and his colleagues took the first steps in conjuring the vision that would later be brought to life with Experimental Breeder Reactor I (EBR-I) and Experimental Breeder Reactor II (EBR-II), the celebrated achievements of the Argonne fast reactor program. Group members considered various schemes for a breeder reactor in which the relatively abundant U-238 would be placed near a core of fissionable material. The reactor would be a fast reactor; that is, neutrons would not be moderated, as were most wartime reactors. Thus, the large number of neutrons emitted in fast neutron fission would hit the U-238 and create ''extra'' fissionable material

  2. History and evolution of the breeder reactor

    International Nuclear Information System (INIS)

    The concept of the breeder reactor is almost as old as the idea of the nuclear reactor itself. From the very first years following the discovery of nuclear fission, scientists and technicians tried to turn mankind's eternal dream into reality; that is, enjoy an abundant source of energy without using up our raw material reserves. Nuclear energy offered several solutions to realize this dream. One of them, fusion, seemed out of our grasp in the near future. But fission of 235U was possible, and the Manhattan Project soon furnished ample proof of this theory. However, everyone working in this field was conscious of the fact that thermal neutron reactors make very inefficient use of the energy potential contained in natural uranium. The solution was to use in a core sufficiently rich in fissile matter, the excess neutrons to convert the 238U, so poorly used by other types of reactors, into fissile 239Pu. Regeneration, or 'breeding' of fuel, can multiply the energy drawn from a ton of uranium by a factor of 50 to 100. This would enable us to ward off the specter of an energy shortage and the rapid depletion of uranium mines. As early as 1945 in Los Alamos, Enrico Fermi stated: 'The country which first develops a breeder reactor will have a great competitive edge in atomic energy.' The development of the breeder reactor in the USA and around the world is discussed

  3. Fermi variability study of the candidate pulsar binary 2FGL J0523.3−2530

    OpenAIRE

    Xing, Y.; Wang, ZX; Ng, SCY

    2014-01-01

    The Fermi source 2FGL~J0523.3$-$2530 has recently been identified as a candidate millisecond pulsar binary with an orbital period of 16.5 hrs. We have carried out detailed studies of the source's emission properties by analyzing data taken with the Fermi Large Area Telescope in the 0.2--300 GeV energy range. Long-term, yearly variability from the source has been found, with a factor of 4 flux variations in 1--300 GeV. From spectral analysis, we find an extra spectral component at 2--3 GeV tha...

  4. Nordic study on reactor waste

    International Nuclear Information System (INIS)

    In 1981, 14 nuclear power reactors are in operation and 2 under construction in the Nordic countries. So far, the reactor waste originating from day-to-day operation of these plants has been stored in solidified form at the reactor sites. Within a few years a satisfactory disposal procedure needs to be established. While the main R and D effects in the waste field have earlier been devoted to the question of irradiated fuel and waste from reprocessing, there is therefore now an increased interest in reactor waste with its much lower radioactivity but somewhat larger volumes. Since 1977, efforts have been made in a joint Nordic study to examine which facts need to be known in order to perform a comprehensive safety assessment of a reactor waste management system. In the present study a Reference system related to the waste generated over 30 years from six 500 MW-reactors is examined. The dominating radionuclides during storage and transportation accident scenarios are Cs-134, Cs-137 and Co-60. For most of the release scenarios from repositories Cs-137 and Sr-90 are dominating. Some scenarios are, however, dominated by the very longlived nuclides I-129 and C-14. A closer examination of the concentration in the waste of these nuclides and of their leaching properties indicates that their small - but significant - influence, as calculated, is probably grossly overestimated. The mechanical stability obtained in routine solidification processes of reactor waste products in conjunction with the outer container (steel drum, transport container, etc.) turns out to be sufficient. Difficulties were encountered in applying ICRP methodology and available dose calculation methods to calculation of population doses due to small activity releases, and effects extending into the far future. (EG)

  5. Tokamak experimental power reactor studies

    International Nuclear Information System (INIS)

    The principal results of a scoping and project definition study for the Tokamak Experimental Power Reactor are presented. Objectives are discussed; a preliminary conceptual design is described; detailed parametric, survey and sensitivity studies are presented; and research and development requirements are outlined. (U.S.)

  6. US reactor safety study reviewed

    International Nuclear Information System (INIS)

    The policy statement issued by the United States Nuclear Regulatory Commission concerning its views of the Reactor Safety Study (WASH-1400) in the light of criticisms of the study made by a special review group headed by Dr Harold Lewis, is discussed. Dr Lewis appeared before a Congressional sub-committee to discuss the findings of the review group and his testimony is reproduced here. This is considered under the four headings; safety - what is it, WASH-1400 and RARG - what was found, risk assessment methodology -where do we go from here, and are reactors safe. (UK)

  7. Study of nuclear giant resonances using a Fermi-liquid method

    CERN Document Server

    Sun, Bao-Xi

    2012-01-01

    The nuclear giant resonances are studied by using a Fermi-liquid method, and the nuclear collective excitation energies of different values of $l$ are obtained, which are fitted with the centroid energies of the giant resonances of spherical nuclei, respectively. In addition, the relation between the isovector giant resonance and the corresponding isoscalar giant resonance is discussed.

  8. Le attività del centro Altreitalie e lo svilupo degli studi sulle migrazioni italiane nelle Americhe

    Directory of Open Access Journals (Sweden)

    Maddalena Tirabasi

    2015-01-01

    Full Text Available L’articolo presenta la storia del Centro Altreitalie, nato all’interno della Fondazione Giovanni Agnelli negli anni ottanta, e le attività di ricerca e promozione degli studi sulle migrazioni italiane oltreoceano. Particolare rilevanza viene data alle ricerche svolte in America Latina, prima area di indagine agli albori degli studi migratori italiani. Oggi il Centro Altreitalie, all’interno dell’associazione Globus et Locus, continua a sostenere e a diffondere i risultati della ricerca attraverso la rivista Altreitalie e indagini mirate su tematiche emergenti. Tra le più recenti la pubblicazione di un volume sul voto italiano all’estero, uno sull’emigrazione delle donne piemontesi in Argentina e infine il libro sulle nuove mobilità italiane.  

  9. The ARIES tokamak reactor study

    International Nuclear Information System (INIS)

    The ARIES study is a community effort to develop several visions of tokamaks as fusion power reactors. The aims are to determine the potential economics, safety, and environmental features of a range of possible tokamak reactors, and to identify physics and technology areas with the highest leverage for achieving the best tokamak reactor. Three ARIES visions are planned, each having a different degree of extrapolation from the present data base in physics and technology. The ARIES-I design assumes a minimum extrapolation from current tokamak physics (e.g., 1st stability) and incorporates technological advances that can be available in the next 20 to 30 years. ARIES-II is a DT-burning tokamak which would operate at a higher beta in the 2nd MHD stability regime. It employs both potential advances in the physics and expected advances in technology and engineering. ARIES-II will examine the potential of the tokamak and the D3He fuel cycle. This report is a collection of 14 papers on the results of the ARIES study which were presented at the IEEE 13th Symposium on Fusion Engineering (October 2-6, 1989, Knoxville, TN). This collection describes the ARIES research effort, with emphasis on the ARIES-I design, summarizing the major results, the key technical issues, and the central conclusions

  10. The ARIES tokamak reactor study

    Energy Technology Data Exchange (ETDEWEB)

    1989-10-01

    The ARIES study is a community effort to develop several visions of tokamaks as fusion power reactors. The aims are to determine the potential economics, safety, and environmental features of a range of possible tokamak reactors, and to identify physics and technology areas with the highest leverage for achieving the best tokamak reactor. Three ARIES visions are planned, each having a different degree of extrapolation from the present data base in physics and technology. The ARIES-I design assumes a minimum extrapolation from current tokamak physics (e.g., 1st stability) and incorporates technological advances that can be available in the next 20 to 30 years. ARIES-II is a DT-burning tokamak which would operate at a higher beta in the 2nd MHD stability regime. It employs both potential advances in the physics and expected advances in technology and engineering. ARIES-II will examine the potential of the tokamak and the D{sup 3}He fuel cycle. This report is a collection of 14 papers on the results of the ARIES study which were presented at the IEEE 13th Symposium on Fusion Engineering (October 2-6, 1989, Knoxville, TN). This collection describes the ARIES research effort, with emphasis on the ARIES-I design, summarizing the major results, the key technical issues, and the central conclusions.

  11. Health effects of low dose exposure to fission products from Chernobyl and the Fermi nuclear reactor in the population of the Detroit metropolitan area

    International Nuclear Information System (INIS)

    The present paper describes the results of the exposure of a very large population in the Detroit, Michigan, area to fallout from Chernobyl measured in 1986, followed by the reported releases from the start-up of the Fermi-II nuclear plant in 1988 located 20 miles from the city that receives its drinking water from Lake St. Clair downwind to the north-east of the plant. Due to the prior existence of a local cancer registry for a total population of about 4 million, and the availability of reliable public-heath statistics by age, race and sex, combined with the absence of an accident known to produce population movement and stress, highly significant rises and declines of the incidence of early childhood leukemia and other cancers could be related both geographically and temporally to the observed rises and declines of fission products in the milk as well as releases from the reactor. Furthermore, surprisingly rapid rises in the incidence of breast cancer also took place in Monroe County where the reactor is located and in Macomb County downwind on Lake St. Clair to the northeast, presumably due to weakening of the immune defenses by the mix of fission products not seen so rapidly after exposure in the case of external X-rays or gamma rays. For Michigan as a whole, for which incidence of thyroid cancer at all ages combined became available after 1985, rapid rises were observed after Chernobyl and the start of the Fermi plant, using as rapidly as in the case of Belarus and Connecticut. Additionally, highly significant synchronous rises in low birth weight, infant mortality, fetal deaths, asthma and infectious disease mortality were also observed consistent with the known action of bone-seeking fission products on the immune system, following reported nuclear tests, nuclear accidents and the start-up of the Fermi plant. (orig.)

  12. The multi-product nature of the firm in the arts sector: A case study on ‘Centro Zo’

    OpenAIRE

    Cellini, Roberto; Martorana, Marco Ferdinando; Platania, Felicita

    2014-01-01

    This article studies the relevance of the multi-product nature of a firm whose core-business rests in the performing arts sector. A specific case study is presented, concerning ‘Centro Zo’, a firm which was born in Catania (Italy) about 15 years ago, to supply performing arts pieces. Now it is a multi-product firm, offering different goods and services. The multi-product choice is investigated from the firm’s perspective, and from the consumers’ standpoint. Fresh data, collected in 2013, ar...

  13. Study on equation of state based on Thomas-Fermi-Kirzhnits mo del%基于Thomas-Fermi-Kirzhnits模型的物态方程研究∗

    Institute of Scientific and Technical Information of China (English)

    王坤; 史宗谦; 石元杰; 吴坚; 贾申利; 邱爱慈

    2015-01-01

    本文针对丝阵Z箍缩等高能量密度物理实验的数值模拟研究,建立了一种适用温度、密度范围宽的三项式半经验物态方程。三项式半经验物态方程包括零温自由能项,电子热贡献项和离子热贡献项。零温自由能项采用多项式拟合的方法确定。多项式系数通过多项式计算的结果与高压缩比区域和压缩比为1时零温Thomas-Fermi-Kirzhnits模型计算的结果对应相等得到。离子对物态方程的热贡献采用一种准谐振模型,此谐振模型可以描述离子在固态相中的行为,并且在高温度、低密度区域趋近于理想气体物态方程。电子对物态方程的热贡献采用含温Thomas-Fermi-Kirzhnits模型计算。利用所建立的三项式半经验物态方程计算了铝的等温压缩曲线,并与实验数据做了对比。给出了很宽温度、密度范围内铝的压强,其数据与相应的SESAME数据库数据做了对比。%A wide-range semi-empirical equation of state is constructed for numerical simulation of high-energy density experi-ments, such as, wire-array Z-pinch etc. The equation of state consists of zero-temperature free energy term, and thermal contributions of electron and ion. Thomas-Fermi model, which was firstly put forward by Thomas and Fermi, is initially developed to study the electron distribution of multi-electron atoms. Since its advent, this model has been widely used in solid-state physics, atomic physics, astrophysics and equation of state computations. It is a particularly important model to describe the behavior of matter under extreme conditions of high temperature and high density. This model provides reasonably accurate results that are validated experimentally for some thermodynamic quantities, such as the pressure. However, the Thomas-Fermi model yields a pressure of a few GPa under normal density even at very low tem-perature, and the pressure is always positive, indicating an obvious

  14. Reliability studies in research reactors

    International Nuclear Information System (INIS)

    Fault trees and event trees are widely used in industry to model and to evaluate the reliability of safety systems. Detailed analyzes in nuclear installations require the combination of these two techniques. This study uses the methods of FT (Fault Tree) and ET (Event Tree) to accomplish the PSA (Probabilistic Safety Assessment) in research reactors. According to IAEA (lnternational Atomic Energy Agency), the PSA is divided into Level 1, Level 2 and Level 3. At the Level 1, conceptually, the security systems perform to prevent the occurrence of accidents, At the Level 2, once accidents happened, this Level seeks to minimize consequences, known as stage management of accident, and at Level 3 accident impacts are determined. This study focuses on analyzing the Level 1, and searching through the acquisition of knowledge, the consolidation of methodologies for future reliability studies. The Greek Research Reactor, GRR-1, is a case example. The LOCA (Loss of Coolant Accident) was chosen as the initiating event and from it, using ET, possible accidental sequences were developed, which could lead damage to the core. Moreover, for each of affected systems, probabilities of each event top of FT were developed and evaluated in possible accidental sequences. Also, the estimates of importance measures for basic events are presented in this work. The studies of this research were conducted using a commercial computational tool SAPHIRE. Additionally, achieved results thus were considered satisfactory for the performance or the failure of analyzed systems. (author)

  15. Progress in Helias reactor studies

    International Nuclear Information System (INIS)

    The Helias reactor is an upgraded version of the Wendelstein 7-X experiment, which is under construction in the city of Greifswald. The modular coil system comprises 50 coils, which are constructed using NbTi-superconducting cables. The basic dimensions are: major radius 22 m, average plasma radius 1.8 m, magnetic field on axis 5 T, maximum field on coils 10 T. Over the past year progress toward better understanding of the fusion plasma has been made. In particular, the following issues have been addressed: Plasma equilibrium and MHD-stability; Neoclassical transport in the Helias configuration; Start-up scenarios and steady state burn; Alpha-particle orbits and alpha-particle losses; Drift waves in Helias configurations; Modelling the fusion plasma using empirical scaling laws Technical studies have been focussed on the optimization of the coil system with respect to magnetic field distribution, forces and stresses. In this context the ANSYS-code has been found useful for optimising the support system. In a first survey several blanket concepts, developed for the DEMO tokamak, have been adapted to the Helias geometry. Presently a water-cooled LiPb-blanket is favored in comparison with ceramic breeders, since safety properties and maintenance procedure seem to be more advantageous within this concept. Maintenance and replacement of blanket segments through portholes have also been studied with respect to their geometric compatibility. Finally parameter studies of low aspect ratio Helias reactors will be discussed. (orig.)

  16. 132nd International School of Physics "Enrico Fermi" : Course on Dark Matter in the Universe

    CERN Document Server

    Primack, Joel R; Provenzale, A; International School of Physics "Enrico Fermi" : Course on Dark Matter in the Universe; Scuola Internazionale di Fisica "Enrico Fermi"

    1996-01-01

    Physics and astrophysics came to dark matter through many different routes, finally accepting it, but often with some distaste. It has been noticed that the existence of dark matter is yet another displacement of humans from the centre of the Universe: not only do our planet and our sun have no central position in the Universe, not only are humans just animals (although with a 'specialized' central nervous system), but even the material of which we are made is only a marginal component of the cosmic substance! If this is the right attitude to take, scientists feeling distaste for dark matter are much like Galileo Galilei's colleagues who refused to look through the telescope to watch the Medici planets. Nevertheless, astronomers, when required to take a ballot in favour of some cosmological model, often still vote for 'pure baryonic' with substantial majorities, although most cosmologists assume that a 'cold' component of dark matter plays a role in producing the world as we observe it. Among the many subject...

  17. 138th International School of Physics "Enrico Fermi" : Unfolding the Matter of Nuclei

    CERN Document Server

    Ricci, R A

    1998-01-01

    The nucleus and its constituents are a challenging problem. The lectures collected in this book present a broad and comprehensive review of the current knowledge about nuclei.They cover topics such as searching for signatures of the quarks in nuclei with electromagnetic probes and, at much higher energies, for signatures of the quark-gluon plasma in ultrarelativistic nuclear collisions. The attempts to obtain new nuclei in the laboratory are also discussed, as well as the central role played by nuclear physics in the development of weak interactions. Progress in all these areas rests on a deeper theoretical handling of the nuclear and nucleon’s structure. The latter can also be addressed by relying on numerical solutions of QCD on a discrete space-time lattice. The advancement of computational capabilities has spurred a growing interest in this approach. Finally, the book deals with different paths toward solving non-perturbative QCD.

  18. 175th International School of Physics "Enrico Fermi" : Radiation and Particle Detectors

    CERN Document Server

    Bottigli, U; Oliva, P

    2010-01-01

    High energy physics (HEP) has a crucial role in the context of fundamental physics. HEP experiments make use of a massive array of sophisticated detectors to analyze the particles produced in high-energy scattering events. This book contains the papers from the workshop 'Radiation and Particle Detectors', organized by the International School of Physics, and held in Varenna in July 2009. Its subject is the use of detectors for research in fundamental physics, astro-particle physics and applied physics. Subjects covered include the measurement of: the position and length of ionization trails, time of flight velocity, radius of curvature after bending the paths of charged particles with magnetic fields, coherent transition radiation, synchrotron radiation, electro-magnetic showers produced by calorimetric methods and nuclear cascades produced by hadrons in massive steel detectors using calorimetry. Detecting muons and the detection of Cherenkov radiation are also covered, as is the detection of neutrinos by ste...

  19. First detections of nebula with the Fermi-Large Area Telescope and study of their pulsars

    International Nuclear Information System (INIS)

    The Fermi Gamma-ray Space Telescope was launched on 2008 June 11, carrying the Large Area Telescope (LAT), sensitive to gamma-rays in the 20 MeV - 300 GeV energy range. The Crab Nebula had been detected and studied in the 70 MeV - 30 GeV band using the CGRO-EGRET experiment, but no pulsar wind nebula (PWN) had ever been firmly identified in the high energy gamma-ray domain. PWNe are powered by the constant injection of a relativistic wind of electrons and positrons from their central pulsars. These charged particles are accelerated at the shock front forming the PWN and emit photons which can be observed along the entire electromagnetic spectrum, including the high energy gamma-ray domain. Data provided by the Fermi-LAT during the first two years of the mission have allowed the detection and the identification of three PWNe and their associated pulsars (Crab Nebula, Vela X and MSH 15-52) as well as the PWN HESS J1825-137 discovered by ground-based experiments sensitive to very high energy gamma-rays. Results of temporal, spectral and morphological analyses of the pulsar/PWN systems detected by Fermi- LAT, as well as results of systematic studies performed first around every gamma-ray pulsar detected by the LAT and secondly around every very high energy source identified as a PWN or a PWN candidate are presented in this dissertation. These studies bring new insights and constraints on the physical properties of the sources as well as on emitting processes in pulsar magnetospheres and in PWNe. (author)

  20. D-D tokamak reactor studies

    International Nuclear Information System (INIS)

    A tokamak D-D reactor design, utilizing the advantages of a deuterium-fueled reactor but with parameters not unnecessarily extended from existing D-T designs, is presented. Studies leading to the choice of a design and initial studies of the design are described. The studies are in the areas of plasma engineering, first-wall/blanket/shield design, magnet design, and tritium/fuel/vacuum requirements. Conclusions concerning D-D tokamak reactors are stated

  1. Experimental studies of spin-imbalanced Fermi gases in 2D geometries

    Science.gov (United States)

    Thomas, John

    We study the thermodynamics of a quasi-two-dimensional Fermi gas, which is not quite two-dimensional (2D), but far from three dimensional (3D). This system offers opportunities to test predictions that cross interdisciplinary boundaries, such as enhanced superfluid transition temperatures in spin-imbalanced quasi-2D superconductors, and provides important benchmarks for calculations of the phase diagrams. In the experiments, an ultra-cold Fermi gas is confined in an infrared CO2 laser standing-wave, which produces periodic pancake-shaped potential wells, separated by 5.3 μm. To study the thermodynamics, we load an ultra-cold mixture of N1 = 800 spin 1/2 -up and N2 measured properties are in disagreement with 2D-BCS theory, but can be fit by a 2D-polaron gas model, where each atom is surrounded by a cloud of particle-hole pairs of the opposite spin. However, this model fails to predict a transition to a spin-balanced central region as N2/N1is increased. Supported by the physics divisions of ARO, AFOSR, and NSF and by the Division of Materials Science and Engineering, the Office of Basic Energy Sciences, DOE.

  2. Study of isotopic exchange reactors (1961)

    International Nuclear Information System (INIS)

    A study is made of the general case of the theory of first-order isotopic chemical exchange between a gaseous and a liquid phase in a reactor, starting from fundamental reaction kinetics data, and without making any limiting hypothesis concerning the value of the separation factor. The cases of counter-current reactors and of co-current reactors are considered successively. The general deuterium conservation equation requires the definition of the quotient of the reactor; the performances of this reactor are characterised by its overall efficiency. The idea of the ratio is introduced because it represents a convenient intermediary in the calculations. The search for an additive value for reactors in series leads logically to the defining of an exchange capacity, and a total efficiency, or number of theoretical reactors. This method of expressing the performances of a reactor is more general than the efficiency due to Murphee which only has a physical significance in the particular case of homogeneous liquid reactors. The relationships between these various quantities are established, and the representation due to Mc Cabe and Thiele is generalized. The reactor performances are linked to the first - order reaction kinetics by the transfer number. The relationships are given for a certain number of concrete cases. Finally the application of these calculations is given, together with the approximations necessary in the case where, because of the presence of several components in each phase, the exchange reaction no longer obeys a single kinetic law. (authors)

  3. Extrap conceptual fusion reactor design study

    International Nuclear Information System (INIS)

    A study has recently been initiated to asses the fusion reactor potential of the Extrap concept. A reactor model is defined that fulfills certain economic and environmental criteria. This model is applied to Extrap and a reference reactor is outlined. The design is optimized by varying parameters subject to both physics and engineering constraints. Several design options are examined and key engineering issues are identified and addressed. Some preliminary results and conclusions of this work are summarized. (authors)

  4. Electronic transitions and fermi edge singularity in polar heterostructures studied by absorption and emission spectroscopy

    Science.gov (United States)

    Pandey, S.; Cavalcoli, D.; Minj, A.; Fraboni, B.; Cavallini, A.; Gamarra, P.; Poisson, M. A.

    2012-12-01

    Optically induced electronic transitions in nitride based polar heterostructures have been investigated by absorption and emission spectroscopy. Surface photovoltage (SPV), photocurrent (PC), and photo luminescence spectroscopy have been applied to high quality InAlN/AlN/GaN structures to study the optical properties of two dimensional electron gas. Energy levels within the two dimensional electron gas (2DEG) well at the interface between the GaN and AlN have been directly observed by SPV and PC. Moreover, a strong enhancement of the photoluminescence intensity due to holes recombining with electrons at the Fermi Energy, known as fermi energy singularity, has been observed. These analyses have been carried out on InAlN/AlN/GaN heterojunctions with the InAlN barrier layer having different In content, a parameter which affects the energy levels within the 2DEG well as well as the optical signal intensity. The measured energy values are in a very good agreement with the ones obtained by Schrödinger-Poisson simulations.

  5. Parametric studies of tandem mirror reactors

    International Nuclear Information System (INIS)

    This report, along with its companion, An Improved Tandem Mirror Reactor, discusses the recent progress and present status of our tandem mirror reactor studies. This report presents the detailed results of parametric studies up to, but not including, the very new ideas involving thermal barriers

  6. CARNSORE: Hypothetical reactor accident study

    International Nuclear Information System (INIS)

    Two types of design-basis accident and a series of hypothetical core-melt accidents to a 600 MWe reactor are described and their consequences assessed. The PLUCON 2 model was used to calculate the consequences which are presented in terms of individual and collective doses, as well as early and late health consequences. The site proposed for the nucelar power station is Carnsore Point, County Wexford, south-east Ireland. The release fractions for the accidents described are those given in WASH-1400. The analyses are based on the resident population as given in the 1979 census and on 20 years of data from the meteorological stations at Rosslare Harbour, 8.5 km north of the site. The consequences of one of the hypothetical core-melt accidents are described in detail in a meteorological parametric study. Likewise the consequences of the worst conceivable combination of situations are described. Finally, the release fraction in one accident is varied and the consequences of a proposed, more probable ''Class 9 accident'' are presented. (author)

  7. Enrico Chiaveri: The dialogue in the HR Strategy

    CERN Multimedia

    2009-01-01

    Enrico Chiaveri has been Head of the Human Resources Department since 2005. A core part of his department’s mission with the new Management is to develop and implement a strategic HR approach for our forward-looking Organization. He explained key aspects of the HR strategy to the Bulletin. For the first time in CERN’s history, a head of the HR Department and his deputy - Anne-Sylvie Catherin - invited the staff to a general information meeting on 23 February 2009. The scope of the meeting was to present the status of a number of current initiatives that will improve and tailor CERN’s HR strategy to the needs of the Organization and its staff, and also open up dialogue. Presented for the first time in an integrated way, the initiatives include contract policy, MARS, a staff survey, CERN’s values, a performance model, recruitment & outreach, learning & development, internal mobility and the development of a code of condu...

  8. On fast reactor kinetics studies

    Energy Technology Data Exchange (ETDEWEB)

    Seleznev, E. F.; Belov, A. A. [Nuclear Safety Inst. of the Russian Academy of Sciences IBRAE (Russian Federation); Matveenko, I. P.; Zhukov, A. M.; Raskach, K. F. [Inst. for Physics and Power Engineering IPPE (Russian Federation)

    2012-07-01

    The results and the program of fast reactor core time and space kinetics experiments performed and planned to be performed at the IPPE critical facility is presented. The TIMER code was taken as computation support of the experimental work, which allows transient equations to be solved in 3-D geometry with multi-group diffusion approximation. The number of delayed neutron groups varies from 6 to 8. The code implements the solution of both transient neutron transfer problems: a direct one, where neutron flux density and its derivatives, such as reactor power, etc, are determined at each time step, and an inverse one for the point kinetics equation form, where such a parameter as reactivity is determined with a well-known reactor power time variation function. (authors)

  9. Elastic constants and Fermi surface topology change in Calaverite AuTe{sub 2}: A density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Gudelli, Vijay Kumar, E-mail: kanchana@iith.ac.in; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh (India)

    2014-04-24

    Structural, elastic, electronic and Fermi surface studies of AuTe{sub 2} have been carried out by means of first principles calculations based on density functional theory. The calculated ground state properties agree well with the experiment. Fermi surface and elastic constants are predicted for the first time and from the calculated elastic constants we find the compound to be mechanically stable satisfying the stability criteria of monoclinic structure. In addition, we also find the c-axis to be more compressible than the other two which is also speculated from the present work. The metallic behaviour of this compound is confirmed from the electronic band structure calculation as we find the bands to cross the Fermi level (E{sub F}). In addition, we also observe a FS topology change under pressure which is also explained in the present work.

  10. Fermi surface study of ScAu2(Al, In) and ScPd2(Sn, Pb) compounds

    International Nuclear Information System (INIS)

    A detailed study on the electronic structure and Fermi surface (FS) of superconducting Heusler compounds ScAu2(Al, In) and ScPd2(Sn, Pb) has been carried out using first principles electronic structure calculations. The spin orbit coupling is found to play a major role in understanding the band structure and FS. Analysis of the data shows the importance of spin orbit coupling effect in the above compounds. The bands which cross Fermi level (EF) are found to be dominated by the Sc dt2g-states. The calculated total density of states are in good agreement with the experimentally reported value for ScPd2Sn. Under compression we find a change in the Fermi surface topology of ScPd2Sn at V/V0 = 0.95 (pressure of≈15 GPa), which is explained using the band structure calculations

  11. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    Science.gov (United States)

    Thompson, David J.; Baldini, L.; Uchiyama, Y.

    2012-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TeV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  12. Study of power reactor dynamics by stochastic reactor oscillator method

    International Nuclear Information System (INIS)

    Stochastic reactor oscillator and cross correlation method were used for determining reactor dynamics characteristics. Experimental equipment, fast reactor oscillator (BOR-1) was activated by random pulses from the GBS-16 generator. Tape recorder AMPEX-SF-300 and data acquisition tool registered reactor response to perturbations having different frequencies. Reactor response and activation signals were cross correlated by digital computer for different positions of stochastic oscillator and ionization chamber

  13. Neutronic study of fusion reactor blanket

    International Nuclear Information System (INIS)

    The problem of effective regeneration is a crucial issue for the fusion reactor, specially for the power reactor because of the conflicting requirements of heat removal and tritium breeding. For that, calculations are performed to evaluate blanket materials. Precise techniques are herein developed to improve the accuracy of the tritium production and the neutron and gamma transport calculations. Many configurations are studied with realistic breeder, structure, and coolant proportions. Accuracy of the results are evaluated from the sensitivity theory and uncertainty study using covariance matricies. At the end of this work, we presented the needs of nuclear data for fusion reactors and we give some advices for improving our knowledge of these data

  14. Neutronic study of fusion reactor blanket

    International Nuclear Information System (INIS)

    The problem of effective regeneration is a crucial issue for the fusion reactor, specially for the power reactor because of the conflicting requirements of heat removal and tritium breeding. For that, calculations are performed to evaluate blanket materials. Precise techniques are herein developed to improve the accuracy of the tritium production and the neutron and gamma transport calculations. Many configurations are studied with realistic breeder, structure, and coolant proportions. Accuracy of the results are evaluated from the sensitivity theory and uncertainty study using covariance matrices. At the end of this work, we presented the needs of nuclear data for fusion reactors and we give some advices for improving our knowledge of these data

  15. The ARIES-I tokamak reactor study

    International Nuclear Information System (INIS)

    This report discusses the following topics on the Aries-I Tokamak: Design description; systems studies and economics; reactor plasma physics; magnet engineering; fusion-power-ore engineering; and environmental and safety features

  16. Studies of the Fermi surface of tantalum by 2D ACAR measurements

    International Nuclear Information System (INIS)

    Two dimensional angular correlation of annihilation radiation measurements for two crystallographic orientations of a tantalum single crystal are presented. An analysis by reciprocal lattice convolution gives a surprisingly good fit to a calculation based on Fermi surface dimensions. (Auth.)

  17. The Illness and Death of Enrico Caruso (1873-1921): A Medical Chorus Out of Tune?

    Science.gov (United States)

    Cascella, Marco

    2016-02-01

    The Italian opera singer Enrico Caruso is considered by many people the most famous opera singer of all time or "The Matchless Singer" for his unique and suggestive vocal timber. Although a man of humble origins, he managed to rise from poverty, thanks to his extraordinary intelligence and determination. From his debut in 1895 in Naples, until December 24, 1920, the tenor had a brilliant career with many performances and over 500 songs in his repertoire. This intense lifestyle went on until 1919, when the fortune that had always accompanied him began to fade and he entered a fast "descending parable." In this study, we analyze Caruso's medical history during his last year of life: Through the study of the newspapers from the period and the statements reported on the tenor's many biographies, we tried to offer a detailed evaluation of the complex pathogenic chain of events that led to his death, impeding him from keeping to alleviate the heart-breaking nostalgia of many emigrants that felt in his singing the warmth of a too distant land. PMID:25877665

  18. Fusion reactor safety studies, FY 1977

    International Nuclear Information System (INIS)

    This report reviews the technical progress in the fusion reactor safety studies performed during FY 1977 in the Fusion Power Program at the Argonne National Laboratory. The subjects reported on include safety considerations of the vacuum vessel and first-wall design for the ANL/EPR, the thermal responses of a tokamak reactor first wall, the vacuum wall electrical resistive requirements in relationship to magnet safety, and a major effort is reported on considerations and experiments on air detritiation

  19. TARA tandem mirror reactor design study

    International Nuclear Information System (INIS)

    A point design is presented for a tandem mirror reactor based upon a TARA plug configuration in which a potential plug for center cell ions is created in an axisymmetric cell adjacent to the center cell. We will incorporate the same center cell as the MARS design, allowing a direct comparison of the different plug configurations. The study will include a magnet design that satisfied the reactor criteria for circular flux surfaces at the center cell plasma edge, stability against ballooning, trapped particle and interchange modes, and zero net parallel currents. We will also present a self-consistent power balance of the reactor, and compare the reactor's energy amplification factor Q and technological requirements with the MARS design

  20. Antineutrino reactor safeguards - a case study

    CERN Document Server

    Christensen, Eric; Jaffke, Patrick

    2013-01-01

    Antineutrinos have been proposed as a means of reactor safeguards for more than 30 years and there has been impressive experimental progress in neutrino detection. In this paper we conduct, for the first time, a case study of the application of antineutrino safeguards to a real-world scenario - the North Korean nuclear crisis in 1994. We derive detection limits to a partial or full core discharge in 1989 based on actual IAEA safeguards access and find that two independent methods would have yielded positive evidence for a second core with very high confidence. To generalize our results, we provide detailed estimates for the sensitivity to the plutonium content of various types of reactors, including most types of plutonium production reactors, based on detailed reactor simulations. A key finding of this study is that a wide class of reactors with a thermal power of less than 0.1-1 GWth can be safeguarded achieving IAEA goals for quantitative sensitivity and timeliness with detectors right outside the reactor ...

  1. Afterglow Population Studies from Swift Follow-Up Observations of Fermi LAT GRBs

    Science.gov (United States)

    Racusin, Judith L.; Oates, S. R.; McEnery, J.; Vasileiou, V.; Troja, E.; Gehrels, N.

    2010-01-01

    The small population of Fermi LAT detected GRBs discovered over the last year has been providing interesting and unexpected clues into GRB prompt and afterglow emission mechanisms. Over the last 5 years, it has been Swift that has provided the robust data set of UV/optical and X-ray afterglow observations that opened many windows into other components of GRB emission structure. We explore the new ability to utilize both of these observatories to study the same GRBs over 10 orders of magnitude in energy, although not always concurrently. Almost all LAT GRBs that have been followed-up by Swift within 1-day have been clearly detected and carefully observed. We will present the context of the lower-energy afterglows of this special subset of GRBs that has > 100 MeV emission compared to the hundreds in the Swift database that may or may not have been observed by LAT, and theorize upon the relationship between these properties and the origin of the high energy gamma-ray emission.

  2. Fermi questions

    Science.gov (United States)

    Bouffard, Karen

    1999-05-01

    This column contains problems and solutions for the general category of questions known as "Fermi" questions. Forcing the students to use their ability to estimate, giving answers in terms of order-of-magnitude, is not only a challenge for a competition, but a teaching strategy to use in the classroom to develop self-confidence and the ability to analyze answers as to whether or not they make sense, as opposed to relying on the "precision" of a calculator value.

  3. Study of reactivity of fluidized bed nuclear reactor

    International Nuclear Information System (INIS)

    The reactor physics calculations of a 19 module Fluidized Bed Nuclear Reactor using Leopard and Odog codes are performed. The behaviour of the reactor was studied by calculating the reactivity of the reactor as a function of the parameters governing the operational and accidental conditions of the reactor. The effects of temperature, pressure, and vapor generation in the core on the reactivity are calculated. Also the start up behaviour of the reactor is analyzed. For the purpose of the study of a prototype research reactor, the calculations on a one module reactor have been performed. (Author)

  4. Mirror Advanced Reactor Study interim design report

    International Nuclear Information System (INIS)

    The status of the design of a tenth-of-a-kind commercial tandem-mirror fusion reactor is described at the midpoint of a two-year study. When completed, the design is to serve as a strategic goal for the mirror fusion program. The main objectives of the Mirror Advanced Reactor Study (MARS) are: (1) to design an attractive tandem-mirror fusion reactor producing electricity and synfuels (in alternate versions), (2) to identify key development and technology needs, and (3) to exploit the potential of fusion for safety, low activation, and simple disposal of radioactive waste. In the first year we have emphasized physics and engineering of the central cell and physics of the end cell. Design optimization and trade studies are continuing, and we expect additional modifications in the end cells to further improve the performance of the final design

  5. L-Reactor Habitat Mitigation Study

    International Nuclear Information System (INIS)

    The L-Reactor Fish and Wildlife Resource Mitigation Study was conducted to quantify the effects on habitat of the L-Reactor restart and to identify the appropriate mitigation for these impacts. The completed project evaluated in this study includes construction of a 1000 acre reactor cooling reservoir formed by damming Steel Creek. Habitat impacts identified include a loss of approximately 3,700 average annual habitat units. This report presents a mitigation plan, Plan A, to offset these habitat losses. Plan A will offset losses for all species studied, except whitetailed deer. The South Carolina Wildlife and Marine Resources Department strongly recommends creation of a game management area to provide realistic mitigation for loss of deer habitats. 10 refs., 5 figs., 3 tabs

  6. Mirror Advanced Reactor Study interim design report

    Energy Technology Data Exchange (ETDEWEB)

    1983-04-01

    The status of the design of a tenth-of-a-kind commercial tandem-mirror fusion reactor is described at the midpoint of a two-year study. When completed, the design is to serve as a strategic goal for the mirror fusion program. The main objectives of the Mirror Advanced Reactor Study (MARS) are: (1) to design an attractive tandem-mirror fusion reactor producing electricity and synfuels (in alternate versions), (2) to identify key development and technology needs, and (3) to exploit the potential of fusion for safety, low activation, and simple disposal of radioactive waste. In the first year we have emphasized physics and engineering of the central cell and physics of the end cell. Design optimization and trade studies are continuing, and we expect additional modifications in the end cells to further improve the performance of the final design.

  7. The ARIES-I tokamak reactor study

    International Nuclear Information System (INIS)

    This report contains an overview of the Aries-I tokamak reactor study. The following topics are discussed on this tokamak: Systems studies; equilibrium, stability, and transport; summary and conclusions; current drive; impurity control system; tritium systems; magnet engineering; fusion-power-core engineering; power conversion; Aries-I safety design and analysis; design layout and maintenance; and start-up and operations

  8. Fusion reactor blanket: neutronic studies in France

    International Nuclear Information System (INIS)

    The problem of effective tritium regeneration is a crucial issue for the fusion reactor, especially for the power reactor because of the conflicting requirements of heat removal and tritium breeding. For that, calculations are performed to evaluate blanket materials. Precise techniques are herein developed to improve the accuracy of the tritium production and the neutron and gamma transport calculations. Many configurations are studied with realistic breeder, structure, and coolant proportions. Accuracy of the results are evaluated from the sensitivity theory and uncertainty analysis. The results of these studies permit us to conclude that it is possible to expect an adequate tritium breeding ratio

  9. The First Reactor, Understanding the Atom Series.

    Science.gov (United States)

    Allardice, Corbin; And Others

    This booklet is one of the "Understanding the Atom" Series. Consisting of three sections, it is an account of the development of the first nuclear reactor by a team of scientists led by Enrico Farmi. The first section briefly reviews the early work on nuclear fission and neutron emission, the impact of Einstein's letter to President Roosevelt, the…

  10. Fermi surface study of YBa2Cu3O7 by 2D-ACAR

    International Nuclear Information System (INIS)

    We present recent angular correlation of positron annihilation radiation (2D-ACAR) measurements, performed on metallic twinned and untwinned single crystals of YBa2Cu3O7. Both in extended and reduced momentum space, the structures are compatible with the one dimensional Fermi surface of the Cu-O chains predicted by band structure calculations

  11. Detection, localization and study of spectral properties of high energy gamma bursts observed in the Fermi experiment

    International Nuclear Information System (INIS)

    Gamma-Ray Bursts (GRB) are among the brightest gamma-ray sources in the sky. The current standard framework associates their prompt gamma-ray emission to charged particles accelerated in relativistic jets issued by newly-formed stellar-mass black holes. The radio to X-ray afterglow emission is due to the interaction between these jets and the interstellar medium. The LAT, pair-creation instrument onboard Fermi gamma-ray space telescope, performs unprecedented observation of the gamma-ray sky at energies of 20 MeV to over 300 GeV since its launch in june 2008. Fermi's transient sources detector (GBM) observed prompt emissions of about 450 GRB between 8 keV and 40 MeV. 18 of these GRB were also studied up to GeV energies with the LAT. Accurate GRB localizations and Fermi's synergy with other observatories allows the study of GRB afterglows, and therefore a better interpretation of these observations. The analyses of GRB emissions between 8 keV to GeV energies is presented here. Localizations based on LAT data and their biases are studied. Spectral analyses of combined GBM and LAT data are shown, and their theoretical interpretations explained. An alternative analysis based on a relaxed selection of LAT data is presented and fully characterized. It allows to recover and use low-energy LAT statistics in temporal and spectral analyses of GRB prompt emission. Searches for long-lived high-energy emission from GRB are presented. The analysis of GRB 090510 afterglow emission from eV to GeV energies is described. Finally, Fermi bright GRB prompt emissions are compared to an internal shock model developed at IAP. (author)

  12. Charge density wave formation, superconductivity and Fermi surface determination in NbSe3: a pressure study

    International Nuclear Information System (INIS)

    The resistance of single crystals of NbSe3 under pressure, between 1.2 and 70 K has been measured in magnetic fields up to 180 kG. The CDW which appears at ambient pressures at 59 K, is totally suppressed for pressures greater than 5.5 kbar. At this pressure NbSe3 is fully superconducting as shown by a total Meissner effect. Fermi surface studies by Shubnikov-de Haas oscillations show that the Fermi surface is strongly affected by the CDW formation. At ambient pressure, when H is parallel to the plane (b,c), one frequency (0.3 MG) is detected, but when the pressure has suppressed the CDW, at least eight frequencies (up to 7 MG) were detected. The experiments are consistent with the model of different types of chains in NbSe3 on which the two CDW form. (author)

  13. Design study on the Advanced Recycling Reactor

    International Nuclear Information System (INIS)

    Full text: The design study on the Advanced Recycling Reactor (ARR) has been conducted. This paper presents the pre-conceptual design of the ARR that is a loop-typed sodium cooled reactor with MOX fuel. International Nuclear Recycling Alliance (INRA) takes advantage of international experience and uses the design based on Japan Sodium-cooled Fast Reactor (JSFR) as reference for FOA studies of US DOE, because Japan has conducted R and Ds for the JSFR incorporating thirteen technology enhancements expected to improve safety, enhance economics, and increase reactor reliability. The targets of the ARR are to generate electricity while consuming fuel containing transuranics and to attain cost competitiveness with the similar sized LWRs. INRA proposes 3 evolutions of the ARR; ARR1, a 500 MWe demonstration plant, online in 2025; ARR2, a 1,000 MWe commercial plant, online in 2035; ARR3, a 1,500 MWe full-scale commercial plant, online in 2050. INRA believes the scale-up factor of two is acceptable increase from manufacturing and licensing points of view. Major features of the ARR1 are the following: The reactor core is 70cm high and the volume fraction of fuel is approximately 32%. The conversion ratio of fissile is set up less than 0.6 and the amount of burned TRU is 45-51 kg/TWeh.Decay heat can be removed by natural circulation to improve safety. The primary cooling system consists of two-loop arrangement and the integrated IHX/Pump to improve economics. The steam generator with the straight double-walled tube is used to improve reliability. The ARR1 is co-located with a recycling facility. The overall plant facility arrangement is planned assuming to be constructed and installed in an inland area. The plant consists of a reactor building (including reactor auxiliary facilities and electrical/control systems), a turbine building, and a recycling building. The volume of the reactor building will be approximately 180,000 m3. The capital cost for the ARR1 and the ARR2 are

  14. Hybrid Molten Salt Reactor (HMSR) System Study

    Energy Technology Data Exchange (ETDEWEB)

    Woolley, Robert D [PPPL; Miller, Laurence F [PPPL

    2014-04-01

    Can the hybrid system combination of (1) a critical fission Molten Salt Reactor (MSR) having a thermal spectrum and a high Conversion Ratio (CR) with (2) an external source of high energy neutrons provide an attractive solution to the world's expanding demand for energy? The present study indicates the answer is an emphatic yes.

  15. Phase Separation in Bose-Fermi-Fermi Mixtures as a Probe of Fermi Superfluidity

    OpenAIRE

    Bhongale, S. G.; Pu, Han

    2008-01-01

    We study the phase diagram of a mixture of Bose-Einstein condensate and a two-component Fermi gas. In particular, we identify the regime where the homogeneous system becomes unstable against phase separation. We show that, under proper conditions, the phase separation phenomenon can be exploited as a robust probe of Fermi superfluid.

  16. Technical Design and Optimization Study for the FERMI at Elettra FEL Photoinjector

    International Nuclear Information System (INIS)

    The FERMI (at) Elettra FEL project will provide a novel, x-ray free electron laser user facility at Sincrotrone Trieste based on seeded and cascade FEL techniques. The electron beam source and injector systems play a crucial role in the success of the facility by providing the highest quality electron beams to the linac and FEL undulators. This Technical Note examines the critical technology components that make up the injector system, and demonstrates optimum beam dynamics solutions to achieve the required high quality electron beams. Section 2 provides an overview of the various systems and subsystems that comprise the photoinjector. The different operating modes of the injector are described as they pertain to the different linac configurations driven by the FEL and experimental design. For each mode, the required electron beam parameters are given. Sections 3 and 4 describe the critical beamline elements in the injector complex: the photocathode and drive laser, and the RF gun. The required drive laser parameters are given at the end of Section 3. Additional details on the design of the photoinjector drive laser systems are presented in a separate Technical Note. Design considerations for the RF gun are extensively presented in Section 4. There, we describe the variation of the cavity geometry to optimize the efficiency of the energy transfer to the electron beam. A study of the power coupling into the various cavity modes that interact within the bandwidth of the RF drive pulse is presented, followed by a study of the transient cavity response under several models and, finally, the effects on extracted beam quality. Section 5 describes the initial design for the low energy, off-axis diagnostic beamline. Beam dynamics simulations using ASTRA, elegant, and MAD are presented. Section 6 presents the optimization studies for the beam dynamics in the various operating modes. The optimized baseline configurations for the beamline and incident drive laser pulse are

  17. 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

  18. Reversed field pinch reactor study 3

    International Nuclear Information System (INIS)

    This report, the third of a series on the Reversed Field Pinch Reactor, describes a preliminary concept of the engineering design and layout of this pulsed toroidal reactor, which uses the stable plasma behaviour first observed in ZETA. The basic parameters of the 600 MW(e) reactor are taken from a companion study by Hancox and Spears. The plasma volume is 1.75m minor radius and 16m major radius surrounded by a 1.8m blanket-shield region - with the blanket divided into 14 removable segments for servicing. The magnetic confinement system consists of 28 toroidal field coils situated just outside the blanket and inside the poloidal and vertical field coils and all coils have normal copper conductors. The requirement to incorporate a conducting shell at the front of the blanket to provide a short-time plasma stability has a marked effect on the design. It sets the size of the blanket segment and the scale of the servicing operations, limits the breeding gain and complicates the blanket cooling and its integration with the heat engine. An extensive study will be required to confirm the overall reactor potential of the concept. (author)

  19. Design Study on the Advanced Recycling Reactor

    International Nuclear Information System (INIS)

    The design study on the Advanced Recycling Reactor (ARR) has been conducted. This paper presents the pre-conceptual design of the ARR that is a loop-typed sodium cooled reactor with MOX fuel. International Nuclear Recycling Alliance (INRA) takes advantage of international experience and uses the design based on Japan Sodium-cooled Fast Reactor (JSFR) as reference for FOA studies of DOE in the U.S., because Japan has conducted R and Ds for the JSFR incorporating thirteen technology enhancements expected to improve safety, enhance economics, and increase reactor reliability. ARR's goal is to generate electricity while consuming fuel containing transuranics and to be cost-competitive with LWRs of similar size. INRA proposes 3 evolutions of the ARR; ARR1, a 500 MWe demonstration plant, online in 2025; ARR2, a 1,000 MWe commercial plant, online in 2035; ARR3, a 1,500 MWe full-scale commercial plant, online in 2050. INRA believes the scale-up factor of two is acceptable increase from manufacturing and licensing points of view. Major features of the ARR1 are the following: The reactor core of 70 cm high is working for a burner of TRU. The conversion ratio of fissile is set up less than 0.6 and the amount of burned TRU is 45-51 kg/TWeh. Decay heat can be removed by natural circulation to improve safety. The primary cooling system consists of two-loop arrangement and the integrated IHX/Pump to improve economics. The steam generator with the straight doublewalled tube is used to improve reliability. The capital cost, the construction schedule and regulatory and licensing schedule are estimated. Furthermore, the technology readiness level and the technology development roadmap are studied and identified to be ready for commercial deployment. (author)

  20. Reprint of : Regular and singular Fermi liquid in triple quantum dots: Coherent transport studies

    Science.gov (United States)

    Tooski, S. B.; Ramšak, A.; Bułka, B. R.

    2016-08-01

    A system of three coupled quantum dots in a triangular geometry (TQD) with electron-electron interaction and symmetrically coupled to two leads is analyzed with respect to the electron transport by means of the numerical renormalization group. Varying gate potentials this system exhibits extremely rich range of regimes with different many-electron states with various local spin orderings. It is demonstrated how the Luttinger phase changes in a controlled manner which then via the Friedel sum rule formula exactly reproduces the conductance through the TQD system. The analysis of the uncoupled TQD molecule from the leads gives a reliable qualitative understanding of various relevant regimes and an insight into the phase diagram with the regular Fermi liquid and singular-Fermi liquid phases.

  1. A Multi-wavelength Study of Unidentified Objects in the Second Fermi Gamma-Ray Catalogue

    OpenAIRE

    Paiano, Simona

    2014-01-01

    The research field of the gamma-ray astronomy is new and rapidly grown, providing remarkable and promising scientific results. In the last decades, the development of new gamma-ray detectors on board satellites as the AGILE and the Fermi observatories, or groud-based instruments as the Imaging Atmospheric Cherenkov Technique telescope MAGIC, lead up to a big increase in the number of discovered gamma-ray emitters. Different types of astrophysical sources have been identified as gamma-r...

  2. Studies of the Fermi surface of V3Si by 2D ACAR measurements

    International Nuclear Information System (INIS)

    A report is presented on two-dimensional angular correlation of annihilation radiation (2D ACAR) measurements using positrons in single crystals of V3Si. Anisotropic structure commensurate with the reciprocal lattice is observed and attributed to the complex Fermi surface (FS). A simple geometrical model for the FS is developed and compared with folded ACAR distributions. The results of a 3D reconstruction are compared with recent band calculations. (U.K.)

  3. A velocity map imaging apparatus for gas phase studies at FERMI-Elettra

    International Nuclear Information System (INIS)

    The design and evaluation of a velocity map imaging spectrometer specifically optimised for experiments at the FERMI free electron laser source are described. Optimisation of the set-up for the detection of high energy electrons (experimentally calibrated up to 45 eV), reduction of scattered light and characterisation of the pulsed gas source are outlined. The instrument has been tested using synchrotron light at the GasPhase beamline at Elettra, the Italian synchrotron source, and the results are presented.

  4. Power reactor noise studies and applications

    International Nuclear Information System (INIS)

    The present thesis deals with the neutron noise arising in power reactor systems. Generally, it can be divided into two major parts: first, neutron noise diagnostics, or more specifically, novel methods and algorithms to monitor nuclear industrial reactors; and second, contributions to neutron noise theory as applied to power reactor systems. Neutron noise diagnostics is presented by two topics. The first one is a theoretical study on the possibility to use a newly proposed current-flux (C/F) detector in Pressurised Water Reactors (PWR) for the localisation of anomalies. The second topic concerns various methods to detect guide tube impacting in Boiling Water Reactors (BWR). The significance of these problems comes from the operational experience. The thesis describes a novel method to localise vibrating control rods in a PWR by using only one C/F detector. Another novel method, based on wavelet analysis, is put forward to detect impacting guide tubes in a BWR. Neutron noise theory is developed for both Accelerator Driven Systems (ADS) and traditional reactors. By design the accelerator-driven systems would operate in a subcritical mode with a strong external source. This calls for a revision of many concepts and methods that have been developed for traditional reactors and also it poses a number of new problems. As for the latter, the thesis investigates the space-dependent neutron noise caused by a fluctuating source. It is shown that the frequency-dependent spatial behaviour exhibits some new properties that are different from those known in traditional critical systems. On the other hand, various reactor physics approximations (point kinetic, adiabatic etc.) have not been defined yet for the subcritical systems. In this respect the thesis presents a systematic formulation of the above mentioned approximations as well as investigations of their properties. Another important problem in neutron noise theory is the treatment of moving boundaries. In this case one

  5. Power reactor noise studies and applications

    Energy Technology Data Exchange (ETDEWEB)

    Arzhanov, V

    2002-03-01

    The present thesis deals with the neutron noise arising in power reactor systems. Generally, it can be divided into two major parts: first, neutron noise diagnostics, or more specifically, novel methods and algorithms to monitor nuclear industrial reactors; and second, contributions to neutron noise theory as applied to power reactor systems. Neutron noise diagnostics is presented by two topics. The first one is a theoretical study on the possibility to use a newly proposed current-flux (C/F) detector in Pressurised Water Reactors (PWR) for the localisation of anomalies. The second topic concerns various methods to detect guide tube impacting in Boiling Water Reactors (BWR). The significance of these problems comes from the operational experience. The thesis describes a novel method to localise vibrating control rods in a PWR by using only one C/F detector. Another novel method, based on wavelet analysis, is put forward to detect impacting guide tubes in a BWR. Neutron noise theory is developed for both Accelerator Driven Systems (ADS) and traditional reactors. By design the accelerator-driven systems would operate in a subcritical mode with a strong external source. This calls for a revision of many concepts and methods that have been developed for traditional reactors and also it poses a number of new problems. As for the latter, the thesis investigates the space-dependent neutron noise caused by a fluctuating source. It is shown that the frequency-dependent spatial behaviour exhibits some new properties that are different from those known in traditional critical systems. On the other hand, various reactor physics approximations (point kinetic, adiabatic etc.) have not been defined yet for the subcritical systems. In this respect the thesis presents a systematic formulation of the above mentioned approximations as well as investigations of their properties. Another important problem in neutron noise theory is the treatment of moving boundaries. In this case one

  6. Angle resolved photoemission study of Fermi surfaces and single-particle excitations of quasi-low dimensional materials

    Science.gov (United States)

    Gweon, Gey-Hong

    Using angle resolved photoemission spectroscopy (ARPES) as the main experimental tool and the single particle Green's function as the main theoretical tool, materials of various degrees of low dimensionality and different ground states are studied. The underlying theme of this thesis is that of one dimensional physics, which includes charge density waves (CDW's) and the Luttinger liquid (LL). The LL is the prime example of a lattice non-Fermi liquid (non-FL) and CDW fluctuations also give non-FL behaviors. Non-FL physics is an emerging paradigm of condensed matter physics. It is thought by some researchers that one dimensional LL behavior is a key element in solving the high temperature superconductivity problem. TiTe2 is a quasi-2 dimensional (quasi-2D) Fermi liquid (FL) material very well suited for ARPES lineshape studies. I report ARPES spectra at 300 K which show an unusual behavior of a peak moving through the Fermi energy (EF). I also report a good fit of the ARPES spectra at 25 K obtained by using a causal Green's function proposed by K. Matho. SmTe3 is a quasi-2D CDW material. The near EF ARPES spectra and intensity map reveal rich details of an anisotropic gap and imperfectly nested Fermi surface (FS) for a high temperature CDW. A simple model of imperfect nesting can be constructed from these data and predicts a CDW wavevector in very good agreement with the value known from electron diffraction. NaMo6O17 and KMo 6O17 are also quasi-2D CDW materials. The "hidden nesting" or "hidden 1 dimensionality" picture for the CDW is confirmed very well by our direct image of the FS. K0.3MoO3, the so-called "blue bronze," is a quasi-1 dimensional (quasi-1D) CDW material. Even in its metallic phase above the CDW transition temperature, its photoemission spectra show an anomalously weak intensity at EF and no clear metallic Fermi edge. I compare predictions of an LL model and a CDW fluctuation model regarding these aspects, and find that the LL scenario explains them

  7. Design study of marine reactor core

    International Nuclear Information System (INIS)

    JAERI have carried out four core designs for three different type Reactor of Trial design in FY 1983 ∼ 1986 and one core (the optimum core) and three survey cores for conceptual design Reactor in 1987. Based on these cores study results, we are now studying to design MRX CORE. On the other side, we started design study of super-miniaturized 2 MWt core concept for deep-sea submersible. This report describes the results of comparison and studies of the core specification, specific characteristics etc of these cores, and we study that more thick fuel outer diameter (9.5 mm) core was possible or not as for the MRX CORE that has now thin fuel outer diameter (7.0 mm) in consideration of rapid power change etc especially with marine reactor. As the results, it was found that 9.5 mm diameter fuel core was possible and some methods were found, therefore it will be necessary to study the 9.5 mm diameter fuel core in detail continuously. (author)

  8. Thermal hydraulic studies of high temperature reactors

    International Nuclear Information System (INIS)

    The development of High Temperature Nuclear Reactors capable of supplying process heat at a temperature around 1273 K, is in Progress at BARC. These nuclear reactors are being developed with the objective of providing energy to facilitate combined production of hydrogen, electricity, and drinking water. The reject and waste heat in the overall energy scheme are utilised for electricity generation and desalination, respectively. Presently, technology development for a small power (100 kWth) Compact High Temperature Reactor (CHTR) capable of supplying high temperature process heat at 1273 K is being carried out. In addition conceptual details of a 10 MWth reactor supplying heat at 1273 K for commercial hydrogen production, are also being worked out. 3D CFD analysis of the CHTR reactor core has been carried out to estimate the core heat removal capability by natural circulation during normal operating conditions. PHOENICS, a generalized CFD code is used for the analysis. The full-scale core, including fuel tube, coolant channel, plenums, down comer, heat sink, moderator and reflector has been modeled and analysed in PHOENICS. Steady state analysis is carried out to find flow distribution in the coolant circuit and temperature distribution in the whole core. Analyses have also been carried out to simulate various operational transients and accidental conditions of the reactor. This paper deals with the detailed CFD analysis. The details on the selection of the appropriate turbulence model, turbulent Prandtl number and mesh distribution for the CFD analysis are described in the paper. The results of the steady state and transient analyses are also presented in the paper. Paper shows one of the results of 3D CFD analysis for CHTR core. This paper also deals with the core thermal hydraulic analysis of the conceptual design of the 10MWth High Temperature Pebble Bed Reactor. Preliminary thermal hydraulic analysis is carried out with FLiBe as the primary coolants. The

  9. Laser fusion hybrid reactor systems study

    International Nuclear Information System (INIS)

    The work was performed in three phases. The first phase included a review of the many possible laser-reactor-blanket combinations and resulted in the selection of a ''demonstration size'' 500 MWe plant for further study. A number of fast fission blankets using uranium metal, uranium-molybdenum alloy, and uranium carbide as fuel were investigated. The second phase included design of the reactor vessel and internals, heat transfer system, tritium processing system, and the balance of plant, excluding the laser building and equipment. A fuel management scheme was developed, safety considerations were reviewed, and capital and operating costs were estimated. Costs developed during the second phase were unexpectedly high, and a thorough review indicated considerable unit cost savings could be obtained by scaling the plant to a larger size. Accordingly, a third phase was added to the original scope, encompassing the redesign and scaling of the plant from 500 MWe to 1200 MWe

  10. Fermi-LAT Gamma-Ray Variability Study of Misaligned AGN

    OpenAIRE

    De Grandi P; Torresi E.; De Rosa A.; Rainó S.; Malaguti G.

    2013-01-01

    We review the gamma-ray variability properties of AGN with a jet not directly pointing at the observer, i.e. Misaligned AGN. This class is mainly populated by nearby low power radio galaxies (i.e. FRIs). The high power radio sources (i.e. FRIIs) are indeed rare in the GeV sky. Our Fermi-LAT inspection of 4 years of data reveals different temporal behaviors, supporting the idea that beaming/jet structural differences could characterize the FRI-FRII jets. The case of 3C111 (FRII) and NGC6251 (F...

  11. Studies of the Fermi surface of V3Si by 2d acar measurements

    International Nuclear Information System (INIS)

    Using a two-dimensional angular correlation of annihilation radiation apparatus, projections of the electronic momentum distribution of V3Si (sampled by a thermalized positron) have been obtained. The three dimensional momentum distribution is reconstructed, and a zone-folding technique yields the density in the reduced zone p(k), which reflects the gross features of the Fermi surface. Nested cylindrical hole surfaces along the edges of the zone that join at the corner points R are observed, and also additional electron density on the zone faces centered about X. Comparisons are made to recent APW calculations

  12. A positron study of the Fermi surface of TmGa{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Biasini, M.; Monge, M. [ENEA, Bologna (Italy); Czopnik, A.; Jura, A.; Kontrym-Sznajd, G. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych

    2001-07-01

    For a single crystal of TmGa{sub 3}, two-dimensional angular correlation of positron annihilation radiation spectra were measured and subjected to a deconvolution algorithm based on the Van Citter iterative method. The three-dimensional electron-positron momentum density was reconstructed both via the Cormack and a modified Fourier-transform-based method. After the 3D LCW transformation, the resulting k-space density was in fair agreement with band structure LMTO calculations. In particular, the use of deconvoluted data helped to reveal small details of the Fermi surface in the 6{sup th} band. (orig.)

  13. Detection, localization and study of spectral properties of high energy gamma bursts observed in the Fermi experiment; Detection, localisation et etude des proprietes spectrales de sursauts gamma observes a haute energie avec l'experience Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Pelassa, V.

    2010-12-13

    Gamma-Ray Bursts (GRB) are among the brightest gamma-ray sources in the sky. The current standard framework associates their prompt gamma-ray emission to charged particles accelerated in relativistic jets issued by newly-formed stellar-mass black holes. The radio to X-ray afterglow emission is due to the interaction between these jets and the interstellar medium. The LAT, pair-creation instrument onboard Fermi gamma-ray space telescope, performs unprecedented observation of the gamma-ray sky at energies of 20 MeV to over 300 GeV since its launch in june 2008. Fermi's transient sources detector (GBM) observed prompt emissions of about 450 GRB between 8 keV and 40 MeV. 18 of these GRB were also studied up to GeV energies with the LAT. Accurate GRB localizations and Fermi's synergy with other observatories allows the study of GRB afterglows, and therefore a better interpretation of these observations. The analyses of GRB emissions between 8 keV to GeV energies is presented here. Localizations based on LAT data and their biases are studied. Spectral analyses of combined GBM and LAT data are shown, and their theoretical interpretations explained. An alternative analysis based on a relaxed selection of LAT data is presented and fully characterized. It allows to recover and use low-energy LAT statistics in temporal and spectral analyses of GRB prompt emission. Searches for long-lived high-energy emission from GRB are presented. The analysis of GRB 090510 afterglow emission from eV to GeV energies is described. Finally, Fermi bright GRB prompt emissions are compared to an internal shock model developed at IAP. (author)

  14. The TITAN reversed-field-pinch fusion reactor study

    International Nuclear Information System (INIS)

    This paper on titan plasma engineering contains papers on the following topics: reversed-field pinch as a fusion reactor; parametric systems studies; magnetics; burning-plasma simulations; plasma transient operations; current drive; and physics issues for compact RFP reactors

  15. Diffusion Monte Carlo study of strongly interacting two-dimensional Fermi gases

    Science.gov (United States)

    Galea, Alexander; Dawkins, Hillary; Gandolfi, Stefano; Gezerlis, Alexandros

    2016-02-01

    Ultracold atomic Fermi gases have been a popular topic of research, with attention being paid recently to two-dimensional (2D) gases. In this work, we perform T =0 ab initio diffusion Monte Carlo calculations for a strongly interacting two-component Fermi gas confined to two dimensions. We first go over finite-size systems and the connection to the thermodynamic limit. After that, we illustrate pertinent 2D scattering physics and properties of the wave function. We then show energy results for the strong-coupling crossover, in between the Bose-Einstein condensation (BEC) and Bardeen-Cooper-Schrieffer (BCS) regimes. Our energy results for the BEC-BCS crossover are parametrized to produce an equation of state, which is used to determine Tan's contact. We carry out a detailed comparison with other microscopic results. Finally, we calculate the pairing gap for a range of interaction strengths in the strong coupling regime, following from variationally optimized many-body wave functions.

  16. Deep morphological and spectral study of the SNR RCW 86 with Fermi-LAT

    CERN Document Server

    Dubner, G; Giacani, E; Green, D; Jung-Richardt, I; Vink, J

    2016-01-01

    RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier \\textit{Fermi} Large Area Telescope results reported the detection of $\\gamma$-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the poor statistics. Thanks to 6.5 years of data acquired by the \\textit{Fermi}-LAT and the new event reconstruction Pass 8, we report the significant detection of spatially extended emission coming from RCW 86. The spectrum is described by a power-law function with a very hard photon index ($\\Gamma = 1.42 \\pm 0.1_{\\rm stat} \\pm 0.06_{\\rm syst}$) in the 0.1--500 GeV range and an energy flux above 100 MeV of ($2.91$ $\\pm$ $0.8_{\\rm stat}$ $\\pm$ $0.12_{\\rm syst}$) $\\times$ $10^{-11}$ erg cm$^{-2}$ s$^{-1}$. Gathering all the available multiwavelength (MWL) data, we perform a broadband modeling of the nonthermal emission of RCW 86 to constrain parameters of t...

  17. FERMI LARGE AREA TELESCOPE STUDY OF COSMIC RAYS AND THE INTERSTELLAR MEDIUM IN NEARBY MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L.; Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [CNRS, IRAP, F-31028 Toulouse cedex 4 (France); Brigida, M. [Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P., E-mail: hayashi@hep01.hepl.hiroshima-u.ac.jp, E-mail: mizuno@hep01.hepl.hiroshima-u.ac.jp [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); and others

    2012-08-10

    We report an analysis of the interstellar {gamma}-ray emission from the Chamaeleon, R Coronae Australis (R CrA), and Cepheus and Polaris flare regions with the Fermi Large Area Telescope. They are among the nearest molecular cloud complexes, within {approx}300 pc from the solar system. The {gamma}-ray emission produced by interactions of cosmic rays (CRs) and interstellar gas in those molecular clouds is useful to study the CR densities and distributions of molecular gas close to the solar system. The obtained {gamma}-ray emissivities above 250 MeV are (5.9 {+-} 0.1{sub stat}{sup +0.9}{sub -1.0sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1}, (10.2 {+-} 0.4{sub stat}{sup +1.2}{sub -1.7sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1}, and (9.1 {+-} 0.3{sub stat}{sup +1.5}{sub -0.6sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1} for the Chamaeleon, R CrA, and Cepheus and Polaris flare regions, respectively. Whereas the energy dependences of the emissivities agree well with that predicted from direct CR observations at the Earth, the measured emissivities from 250 MeV to 10 GeV indicate a variation of the CR density by {approx}20% in the neighborhood of the solar system, even if we consider systematic uncertainties. The molecular mass calibrating ratio, X{sub CO} = N(H{sub 2})/W{sub CO}, is found to be (0.96 {+-} 0.06{sub stat}{sup +0.15}{sub -0.12sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1}, (0.99 {+-} 0.08{sub stat}{sup +0.18}{sub -0.10sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1}, and (0.63 {+-} 0.02{sub stat}{sup +0.09}{sub -0.07sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1} for the Chamaeleon, R CrA, and Cepheus and Polaris flare regions, respectively, suggesting a variation of X{sub CO} in the vicinity of the solar system. From the

  18. Fermi-LAT Gamma-Ray Variability Study of Misaligned AGN

    Directory of Open Access Journals (Sweden)

    Grandi P.

    2013-12-01

    Full Text Available We review the gamma-ray variability properties of AGN with a jet not directly pointing at the observer, i.e. Misaligned AGN. This class is mainly populated by nearby low power radio galaxies (i.e. FRIs. The high power radio sources (i.e. FRIIs are indeed rare in the GeV sky. Our Fermi-LAT inspection of 4 years of data reveals different temporal behaviors, supporting the idea that beaming/jet structural differences could characterize the FRI-FRII jets. The case of 3C111 (FRII and NGC6251 (FRI are treated in detail. New insights into the location and dimension of the gamma-ray dissipation regions are provided for galaxies with different radio morphologies.

  19. Time-resolved Spectral Study Of Fermi GRBs Having Single Pulses

    CERN Document Server

    Basak, Rupal

    2014-01-01

    We analyze gamma-ray bursts (GRBs) detected by \\textit{Fermi}/Gamma-Ray Burst Monitor (GBM) and having single pulse. We fit the light curves with a model having exponential rise and decay parts. We perform a detailed time-resolved spectroscopy using four models: Band, blackbody with a power-law (BBPL), multicolour blackbody with a power-law (mBBPL) and two blackbodies with a power-law (2BBPL). We find that models other than the BBPL give better $\\chi_{red}^2$ for the "hard-to-soft" (HTS) pulses, while for the "intensity tracking" (IT) pulses, the BBPL model is statistically as good as the other models. Interestingly, the energy at the peak of the spectrum resulting from the BBPL model ($\\sim3kT$), is always lower than that of the $\

  20. The F-GAMMA program: multi-wavelength AGN studies in the Fermi-GST era

    CERN Document Server

    Angelakis, E; Nestoras, I; Zensus, J A; Marchili, N; Pavlidou, V; Krichbaum, T P

    2010-01-01

    The F -GAMMA program is a coordinated effort of several observing facilities to understand the AGN/blazar phenomenon via a multi-frequency monitoring approach, especially in the era of Fermi-GST. Some 60 prominent sources are monitored monthly with the Effelsberg 100-m telescope, the IRAM 30-m telescope and more frequently but in a less uniform fashion at the APEX 12-m telescope, covering from 2.64 to 345 GHz. The program has been running since January 2007 and here some of its findings are summarized. (a) There are two major variability patterns that the spectra of sources follow, one spectral-evolution-dominated and one achromatic. (b) The FSRQs show higher brightness temperatures indicative of larger Doppler factors at play and (c) a statistically significant radio-gamma-ray correlation has been found with a method recently suggested by Pavlidou et al. (in prep.).

  1. Deep Morphological and Spectral Study of the SNR RCW 86 with Fermi-LAT

    Science.gov (United States)

    Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Cavazzuti, E.; Charles, E.; Chekhtman, A.; Ciprini, S.; Cohen-Tanugi, J.; Condon, B.; Costanza, F.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Drell, P. S.; Dubner, G.; Dumora, D.; Duvidovich, L.; Favuzzi, C.; Focke, W. B.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giacani, E.; Giglietto, N.; Glanzman, T.; Green, D. A.; Grenier, I. A.; Guiriec, S.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Jung-Richardt, I.; Kensei, S.; Kuss, M.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Schmid, J.; Schulz, A.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Vink, J.; Wood, K. S.; Yassine, M.

    2016-03-01

    RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier Fermi Large Area Telescope results reported the detection of γ-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the poor statistics. Thanks to 6.5 years of data acquired by the Fermi-LAT and the new event reconstruction Pass 8, we report the significant detection of spatially extended emission coming from RCW 86. The spectrum is described by a power-law function with a very hard photon index ({{Γ }}=1.42+/- {0.1}{{stat}}+/- {0.06}{{syst}}) in the 0.1-500 GeV range and an energy flux above 100 MeV of (2.91+/- {0.8}{{stat}}+/- {0.12}{{syst}}) × {10}-11 erg cm-2 s-1. Gathering all the available multiwavelength (MWL) data, we perform a broadband modeling of the nonthermal emission of RCW 86 to constrain parameters of the nearby medium and bring new hints about the origin of the γ-ray emission. For the whole SNR, the modeling favors a leptonic scenario in the framework of a two-zone model with an average magnetic field of 10.2 ± 0.7 μG and a limit on the maximum energy injected into protons of 2 × 1049 erg for a density of 1 cm-3. In addition, parameter values are derived for the north-east and south-west (SW) regions of RCW 86, providing the first indication of a higher magnetic field in the SW region.

  2. Study of space reactors for exploration missions

    Energy Technology Data Exchange (ETDEWEB)

    Cliquet, Elisa; Ruault, Jean-Marc; Masson, Frederic, E-mail: elisa.cliquet@cnes.fr, E-mail: frederic.masson@cnes.fr [Centre National d' Etudes Spatiales (CNES), Paris (France); Roux, Jean-Pierre; Paris, Nicolas; Cazale, Brice; Manifacier, Laurent, E-mail: jean-pierre.roux@areva.com [AREVA TA, Aix en Provence, (France); Poinot-Salanon, Christine, E-mail: christine.poinot@cea.fr [Comissariado a l' Energie Atomique et Aux Energies alternatives (CEA), Paris (France)

    2013-07-01

    Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences - SNAP10 in the 60's or Buk/Topaz in the 60-80's - no high power reactor has been developed: investment cost, long term time frame, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10kWe, 100kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA], and Europe, have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. (author)

  3. Study of space reactors for exploration missions

    International Nuclear Information System (INIS)

    Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences - SNAP10 in the 60's or Buk/Topaz in the 60-80's - no high power reactor has been developed: investment cost, long term time frame, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10kWe, 100kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA], and Europe, have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. (author)

  4. Reactor structural materials study by PGNAA

    International Nuclear Information System (INIS)

    Prompt gamma neutron activation analysis (PGNAA) facility at Pakistan Research Reactor (PARR-I) has been used for the study of different kinds of materials. High efficiency, high-resolution gamma spectrometer based on high purity germanium detector is being employed. The cadmium ratio of the incident neutron beam is about 60 and the thermal neutron flux at the target positron is ∼2·106 n/cm2/s. The system is usually operated in Compton suppression mode to identify lower intensity gamma ray peaks in the lower energy region. The detection system is calibrated with standard radioactive sources from up to 1.5 MeV. In the higher energy region (up to 10 MeV), the energy calibration is done with prompt gamma rays from thermal neutron capture in chlorine and nitrogen. The aim of present study is to determine the quantity of boron in reactor grade steels as well as in some other materials containing boron because it is difficult to measure the concentration of boron by other analytical techniques. The results of boron assessment in SS-304L and ribbon will also be presented

  5. Fusion reactor blanket/shield design study

    International Nuclear Information System (INIS)

    A joint study of tokamak reactor first-wall/blanket/shield technology was conducted by Argonne National Laboratory (ANL) and McDonnell Douglas Astronautics Company (MDAC). The objectives of this program were the identification of key technological limitations for various tritium-breeding-blanket design concepts, establishment of a basis for assessment and comparison of the design features of each concept, and development of optimized blanket designs. The approach used involved a review of previously proposed blanket designs, analysis of critical technological problems and design features associated with each of the blanket concepts, and a detailed evaluation of the most tractable design concepts. Tritium-breeding-blanket concepts were evaluated according to the proposed coolant. The ANL effort concentrated on evaluation of lithium- and water-cooled blanket designs while the MDAC effort focused on helium- and molten salt-cooled designs. A joint effort was undertaken to provide a consistent set of materials property data used for analysis of all blanket concepts. Generalized nuclear analysis of the tritium breeding performance, an analysis of tritium breeding requirements, and a first-wall stress analysis were conducted as part of the study. The impact of coolant selection on the mechanical design of a tokamak reactor was evaluated. Reference blanket designs utilizing the four candidate coolants are presented

  6. Thorium fuel-cycle studies for CANDU reactors

    International Nuclear Information System (INIS)

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

  7. Feasibility study for fast reactor and related fuel cycle. Preliminary studies in 1998

    International Nuclear Information System (INIS)

    Prior to the feasibility study for fast reactors (FRs) starting from the 1999 fiscal year, planned in the medium and long-term program of JNC, preliminarily studies were performed on 'FR systems except sodium cooled MOX fueled reactors'. Small scale or module type reactors, heavy metal (Pb or Pb-Bi) cooled reactors, gas cooled reactors, light water cooled reactors, and molten salt reactors were studied on the basis of literature. They were evaluated from the viewpoint of the technical possibility (the structure integrity, earthquake resistance, safety, productivity, operability, maintenance repair, difficulty of the development), the long-term targets (market competitiveness as an energy system, utilization of uranium resources, reduction of radioactive waste, security of the non-proliferation), and developmental risk. As the result, the following concepts should be studied for future commercialized FRs. Small scale and module type reactor: Middle-sized reactor with an excellent economical efficiency. Small power reactor with a multipurpose design concept. Gas cooled reactor: CO2 gas cooled reactor, He gas cooled reactor. Heavy metal cooled reactor: Russian type lead cooled reactor. Light water cooled reactor: Light water cooled high converter reactor and super critical pressure light water cooled reactor. Molten salt reactor: Trichloride molten salt reactor which matches the U-Pu cycle. (author)

  8. Estimation of total effective dose equivalent (TEDE) following a hypothetical nuclear power release of radionuclides from a 4- loop Pressurized Water Reactor (PWR)

    International Nuclear Information System (INIS)

    Safety is an essential aspect in design and analysis of nuclear reactors to keep the system in a safe condition in case of accidents. One vital issue in safety assessment is the management of radiological accident and dispersion of released radionuclides during nuclear accident. With the increase in interest of nuclear energy and its introduction in the overall national energy mix, a corresponding environmental impact and radiological assessment is imperative. Modeling atmospheric dispersion is the first step of such assessments using versatile computer codes. Atmospheric dispersion modeling and radiological safety analysis have been performed for a postulated accident scenario of the genetic Enrico Fermi 4-loop PWR NPP in Trino, a kind of nuclear reactor type to be introduced in Ghana’s energy mix. The postulated procedure considered would be applied Ghana in selecting a suitable site for its nuclear power program as a requirement by licensee. The source term was generated from an inventory of peak radioisotope activities released by using the isotope generation code ORIGEN2. The MACCS2 and RASCAL 3.0.5 code were employed to perform the atmospheric transport and dispersion modeling. The idea is to select the best method that can better predict the radiological assessment in terms of radionuclide concentration and released doses from a nuclear facility. The codes were used to estimate the Total Effective Dose Equivalent (TEDE) and investigate how the release would be distributed to human organs as a function of distance. The adopted methodology was the use of predominant site-specific meteorological data and dispersion modeling. The study considered calculation of release dose of three selected radionuclide (Cs-137, 1-131 and Sr-90) due to their health implication on the environment during accident conditions. The results indicate that the maximum TEDE value of 1.2E-09Sv and 3.8E-80 were estimated from RASCAL and MACCS2 code respectively at a distance of 50km

  9. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  10. Enrico Morselli's Psychology and "Spiritism": psychiatry, psychology and psychical research in Italy in the decades around 1900.

    Science.gov (United States)

    Brancaccio, Maria Teresa

    2014-12-01

    This paper traces Enrico Morselli's intellectual trajectory from the 1870s to the early 1900s. His interest in phenomena of physical mediumship is considered against the backdrop of the theoretical developments in Italian psychiatry and psychology. A leading positivist psychiatrist and a prolific academic, Morselli was actively involved in the making of Italian experimental psychology. Initially sceptical of psychical research and opposed to its association with the 'new psychology', Morselli subsequently conducted a study of the physical phenomena produced by the medium Eusapia Palladino. He concluded that her phenomena were genuine and represented them as the effects of an unknown bio-psychic force present in all human beings. By contextualizing Morselli's study of physical mediumship within contemporary theoretical and disciplinary discourse, this study elaborates shifts in the interpretations of 'supernormal' phenomena put forward by leading Italian psychiatrists and physiologists. It demonstrates that Morselli's interest in psychical research stems from his efforts to comprehend the determinants of complex psychological phenomena at a time when the dynamic theory of matter in physics, and the emergence of neo-vitalist theories influenced the theoretical debates in psychiatry, psychology and physiology. PMID:25218119

  11. Electron momentum distribution and Fermi surface of vanadium studied by positron annihilation

    International Nuclear Information System (INIS)

    Two-dimensional (2D) angular correlation of positron annihilation radiation (ACPAR) N(psub(y),psub(z)) has been measured for four orientations [100], [110], [111] and [112] in vanadium. Theoretical band-structure calculations of N(psub(y),psub(z)) in V are performed in the independent-particle model by taking into account the positron wavefunctions but leaving out e+-e- many-body correlations. A detailed analysis of the experimental and theoretical results is carried out using different approaches. Although the agreement between experiment and theory is good in general, some discrepancies of the e+-e- many-body correlations which appear to be anisotropic and energy-dependent in nature. Effects of the Fermi surface (FS) of vanadium on the ACPAR curves are observed in the p and k space and the results allow a determination of the dimensions of the FS. The possibility of a neck (along GAMMAN) connecting the n-centred ellipsoid and multiply connected 'jungle-gym' arms in the FS of vanadium is examined and it is concluded that the present experimental data do not support the existence of such a neck. (author)

  12. Microstructural Study of High Irradiated Reactor Steels

    OpenAIRE

    SLUGEN Vladimir; PETRISKA Martin; SOJAK Stanislav; VETERNIKOVA Jana

    2009-01-01

    Positron Annihilation Spectroscopy (PAS) techniques in combination with other techniques were effectively used in the testing and selection process of optimal reactor steels for use in Generation III and IV reactors or thermonuclear fusion facilities. Conventional PAS lifetime technique and pulsed low energy positron system were applied on wide spectrum of reactor steels together with other techniques viz., Transmission Electron Microscopy and Mossbauer Spectroscopy focused on the role of Nic...

  13. Mirror Advanced Reactor Study engineering overview

    International Nuclear Information System (INIS)

    The Mirror Advanced Reactor Study (MARS) was the first comprehensive conceptual design of a commercial tandem mirror reactor with thermal barriers. The design exploited the inherent attractive features of a tandem mirror: steady state operation, linear central cell, simple high performance blankets, low first wall heat fluxes, natural impurity diversion by the halo plasma, no driven plasma currents or associated disruptions, and direct conversion of the charged particle power lost out the ends. The study introduced new design concepts in high field magnets, neutral beams, ECRH systems, drift pumping, direct conversion, lithium-lead blankets and plant safety. The MARS design would produce 1200 MWsub(e) net and more than 1500 MWsub(e) gross from only 2600 MW of fusion power. This high efficiency is achieved through a combination of blanket design and direct conversion. Special emphasis was placed on fusion's potential for inherent safety, lower activation and simpler disposal of radioactive waste as compared with fission. The blanket has a very low tritium inventory, cannot melt in loss-of-coolant and/or loss-of-flow accidents and can be disposed of as low level waste subject to near-surface burial. MARS would produce busbar electricity at about 7 cents per kilowatthour (constant 1983 dollars). This value is near the upper end of the cost range for new generation capability being installed in the late 1980's. Significant cost reductions can be gained by further improvements in the engineering designs combined with a simplified end cell. The largest cost reductions from engineering can be attained through redesigned magnets, heat transport system and electrical system. The combination of engineering and physics improvements are projected to lower the cost of electricity by about 40% without sacrificing the environmental, safety and maintainability attributes of MARS. This work is now being pursued in the MINIMARS study. (orig.)

  14. Acceptable risk in reactor safety studies

    International Nuclear Information System (INIS)

    Acceptable risk is defined in terms of its five basic parameters: the hazard or problem; the probability of occurrence; the consequence; the possible alternative actions; and the value system of the community or the society. The problem of consistency in design at a site and between differing sites is discussed and solutions are suggested. Techniques for consistent deterministic and probabilistic setting limits and design standards are illustrated using data from AEC Reactor Safety Study, WASH-1400. The influence of level of consequence is discussed and a general methodology for decision analysis in resource allocation problem is briefly introduced and illustrated. The concept of acceptable risk is put in a quantitative format that can be used by engineers and planners. Bayesian statistical methods are introduced to develop the methodologies

  15. Neutronic study of the two french heavy water reactors

    International Nuclear Information System (INIS)

    The two french reactors - the reactor of Chatillon, named Zoe, and the reactor of Saclay - P2 - were the object of detailed neutronic studies which the main ideas are exposed in this report. These studies were mostly done by the Department of the Reactor Studies (D.E.P.). We have thus studied the distribution of neutronic fluxes; the factors influencing reactivity; the link between reactivity and divergence with the formula of Nordheim; the mean time life of neutrons; neutron spectra s of P2; the xenon effect; or the effect of the different adjustments of the plates and controls bar. (M.B.)

  16. A Spectral Variability Study Using the Entire FERMI Data from the Blazar 3C 454.3

    Science.gov (United States)

    Nandikotkur, Giridhar; Gomez, Daniel; Dovale, Johanna; Clarke, Daniel; Komstead, Kaitlyn; Shah, Raj; Aboasu, Stephen

    2016-06-01

    3C454.3 is one of most active and bright blazars that have been observed by the LAT instrument on board the gamma-ray satellite FERMI. The data show multiple large flares where the flux in the energy interval of 100MeV-300000MeV has exceeded 1 x 10^(-5) photons/cm^2/s. We are analyzing the entire LAT-data from 3C454.3 spanning ~7.5 years, and conducting spectral and temporal variability studies. We have divided the entire energy interval into 14 sub-intervals (three per decade) and examining the spectrum for deviations from power-law. We are also looking at the hardness ratios between a smaller set of energy intervals to gain insight into the relative importance of the various inverse-Compton mechanisms that contribute to gamma-ray emission at these energies.

  17. An Approach to the Study of Organizational Culture Educational Centers Una Aproximación al Estudio de la Cultura Organizacional en Centros Educativos

    Directory of Open Access Journals (Sweden)

    Marcos R. Sarasola

    2004-10-01

    Full Text Available The main goal of this research is to approach to the school’s culture and subcultures knowledge. Teachers, as learning communities’ members, should be conscious of their basic assumptions in order to accomplish effective change. Culture, as a socio-critical metaphor, includes organizational clime and goes over artefacts and values. It refers to the organizational deeper level of the unconscious assumptions constructed and shared by it members. The quantitative research uses two instruments. A cultural model including six elements (Teacher Efficacy, Teachers as Learners, Collegiality, Mutual Empowerment/Collaboration, Shared visions/School-wide Planning and Transformational Leadership and proposes that the prevailing culture is the result of the level of development of each individual element. It assumes that in different cultures or at different times in the same culture, there would be a variation in these levels of development. The second scale help to reach two organisational constructs: ‘Transformational leadership culture’ and ‘Transactional leadership culture’. This phase of the investigation centred upon the development and administration of a survey instrument in twenty-five schools and almost eight hundred teachers. That phase of the study is followed by case studies of two schools in which there is a combination of quantitative and qualitative research strategies. Finally, main guidelines are featuring in order to orientate change and innovation for both schools. El principal objetivo de esta investigación es aproximarse al conocimiento de la cultura y subcultura en centros educativos. El profesorado, en tanto miembro de una comunidad que aprende, ha de ser consciente de sus supuestos básicos en orden de implementar cambios. La cultura, como metáfora socio-crítica, incluye el clima organizacional y trasciende el nivel de artefactos y valores. Refiere el nivel más profundo de la vida organizacional: el nivel de los

  18. Study of electronic structure, charge density, Fermi energy and optical properties of Cs2KTbCl6 and Cs2KEuCl6

    International Nuclear Information System (INIS)

    Through the assist of the full-potential linear augmented plane wave (FPLAPW) method, the calculations of the electronic band structure, density of states, charge density, Fermi energy and regularity dependent dielectric functions of Cs2KTbCl6 and Cs2KEuCl6 are reported. This study shows that the nature of both these compounds is metallic. The generalized gradient approximations (GGA) exchange correlation potential was applied. The densities of states around Fermi level are frequently subjugated by Eu/Tb-f and DOS below Fermi level are subjugated by Eu/Tb-s/d, Cs-s, Cl-s and K-s/p. The value of the DOS at Fermi level N(EF) is 17.02 and 4.86 (states per unit cell per eV) for Cs2KEuCl6 and Cs2KTbCl6. The bare electronic specific heat coefficient, is found to be 2.95 and 0.84 mJ/mol K2 for Cs2KEuCl6 and Cs2KTbCl6, respectively. Three bands crossing the Fermi level along the Γ−A direction of Brillion zone of Cs2KTbCl6 compound and one band crossing along the Γ−A direction of Brillion zone of Cs2KEuCl6 compounds, to form the Fermi surface. There exists a strong hybridization between Tb/Eu-K-p and Cl-s K-s and at −5.0 and −4.0 eV

  19. Studies on transferring the safety features of the module reactor to a large power reactor

    International Nuclear Information System (INIS)

    The German industries and research institutions have developed the HTR module reactor, which is strongly characterized by inherent safety features. The power output is limited to about 200 MWth because of its core configuration. It has been investigated in this work, whether the safety features of the module reactor can be transferred to larger power reactors. For this purpose the conceptual design of a ring core pebble bed reactor has been made with a thermal power output of 3000 MW. By means of computer calculations, the principal physical, thermohydraulical and safety features of the ring reactor have been studied. It has been shown that the 3000-MWth ring reactor basically possesses the same safety characteristics as the small module reactor. At reactivity disturbances, the reactor is shut down passively by the strongly negative temperature coefficient. The decay heat removal is also realized based on the passive priniciple. In the case of a total loss of coolant, the maximum fuel element temperature remains below 1600deg C; and consequently the retention of fission products in the fuel elements is fully attained. The control of xenon oscillations takes place inherently due to the mutual coupling between the local power production and the fuel temperature. (orig.)

  20. Power calibration study at the Musashi reactor

    International Nuclear Information System (INIS)

    The Musashi reactor (TRIGA-II,100 kW) initially went critical in January of 1963. The reactor had been used for training, isotope production and medical irradiation for boron neutron capture therapy (1). The initial power calibration was based on the use of a calibrated electrical heater in a calorimetric procedure where the rate of rise of the bulk pit water temperature was measured using 2 kW heaters x 6 pieces. The rate of rise of water temperature was determined to be 0.0474 C/kWh. The reactor was then operated to give the same rate of rise of water temperature. Thus the reactor power was established at the value produced by the electrical heaters. A stirrer for tank water mixing was not used. Recent communications (2)(3) indicated that power calibrations using a stirrer provided a much more uniform mixing, and heating in the reactor tank water which was essential for an accurate calibration. In this paper, the effect of mixing using a stirrer was investigated considering the physical factors such as room temperature, humidity, tank water temperature and it's distributions. The room temperature and humidity around the reactor varies 6-30 and 30-80 %, respectively, depending on four seasons. The heat flow through the surface of the pool was also evaluated because the reactor usually operates without cover on the surface of the pool. (orig.)

  1. Design study of cooling system for tokamak fusion reactor

    International Nuclear Information System (INIS)

    Design study of the reactor cooling system for a tokamak fusion reactor has been carried out. In the cooling system of an experimental 150 MWt fusion reactor, to grasp the plant concept and clarify the R and D items the main cooling system and the tritium recovery system were designed and the auxiliary system was examined. In the cooling system of a commercial 2000 MWt fusion reactor, to study the plant and environment safety the main cooling system and the tritium recovery system were designed, including the evaluation of water leakage and tritium penetration in the steam generators. (auth.)

  2. Design study on small CANDLE reactor

    International Nuclear Information System (INIS)

    A new reactor burnup strategy CANDLE was proposed, where shapes of neutron flux, nuclide densities and power density distributions remain constant but move to an axial direction. Here important points are that the solid fuel is fixed at each position and that any movable burnup reactivity control mechanisms such as control rods are not required. This burnup strategy can derive many merits. The change of excess reactivity along burnup is theoretically zero, and shim rods will not be required for this reactor. The reactor becomes free from accidents induced by unexpected control rods withdrawal. The core characteristics, such as power feedback coefficients and power peaking factor, are not changed along burnup. Therefore, the operation of the reactor becomes much easier than the conventional reactors especially for high burnup reactors. The transportation and storage of replacing fuels become easy and safe, since they are free from criticality accidents. In our previous works it is appeared that application of this burnup strategy to neutron rich fast reactors makes excellent performances. Only natural or depleted uranium is required for the replacing fuels. The average burnup of the spent fuel is about 40% that is equivalent to 40% utilization of the natural uranium without the reprocessing and enrichment. This reactor can be realized for large reactor, since the neutron leakage becomes small and its neutron economy becomes improved. In the present paper we try to design small CANDLE reactor whose performance is similar to the large reactor by increasing its fuel volume ration of the core, since its performance is strongly required for local area usage. Small long life reactor is required for some local areas. Such a characteristic that only natural uranium is required after second core is also strong merit for this case. The core with 1.0 m radius, 2.0 m length can realize CANDLE burn-up with nitride (enriched N-15) natural uranium as fresh fuel. Lead-Bismuth is

  3. A study of reactor vessel integrity assessment

    International Nuclear Information System (INIS)

    The fast neutron fluence at the Reactor Pressure Vessel(RPV) of KNGR designed for 60 years lifetime was calculated by full-scope Monte Carlo simulation for reactor vessel integrity assessment. KNGR core geometry was modeled on a three-dimensional representation of the one-sixteenth of the reactor in-vessel component. Each fuel assemblies were modeled explicitly, and each fuel pins were axially divided into 5 segments. The maximum flux of 4.3 x 1010 neutrons/cm2. sec at the RPV was obtained by tallying neutrons crossing the beltline of inner surface of the RPV

  4. Conceptual design study of small sodium cooled reactors

    International Nuclear Information System (INIS)

    A conceptual design of various small metal fuel sodium cooled reactors has been studied in the feasibility study on commercialized fast breeder reactor cycle system. In FY2004 study, a 50 MWe power plant for remote places with a long life core without refueling and a 300 MWe modular reactor which pursues standardization for learning effect and reduction of capital risks. In the small reactor with a long life core, the reactor vessel is minimized without a permanent fuel handling system and the cooling system is simplified adopting 1 loop. The total mass of the reactor vessel and the cooling system is dramatically reduced and the concept has a potential to be an attractive power source for remote places. In the 300 MWe modular reactor, the cooling system adopts 1 loop and the ex-vessel fuel storage tank for spent fuels is eliminated adapting the in-vessel storage (IVS) which has a capacity for a 4 year storage. The reactor building is minimized without the ex-vessel storage. This concept has a potential to be an power source for key grids with modular constructions and a first plant with a small fuel cycle facility can demonstrate the metal fuel fast reactor cycle. (author)

  5. Fermi-surface topology of YBa2Cu3Ox with varied oxygen stoichiometry: A photoemission study

    International Nuclear Information System (INIS)

    High-resolution angle-resolved photoemission measurements are reported for YBa2Cu3Ox when oxygen stoichiometry x was varied between 6.3 and 6.9. Fermi surfaces were measured and their dependence on oxygen stoichiometry was monitored by observing the dispersing behavior of spectral features, scanning the entire first Brillouin zone. For x=6.9, measured Fermi surfaces correspond very well with the plane-related Fermi surfaces calculated from band theory. Relatively small changes in Fermi surfaces were observed when oxygen stoiochiometry was varied in the range 6.5≤x≤6.9, where the material is metallic. However, significant changes in the spectral behavior were observed when the material becomes insulating

  6. Calibration Analyses and Efficiency Studies for the Anti Coincidence Detector on the Fermi Gamma Ray Space Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Kachulis, Chris; /Yale U. /SLAC

    2011-06-22

    The Anti Coincidence Detector (ACD) on the Fermi Gamma Ray Space Telescope provides charged particle rejection for the Large Area Telescope (LAT). We use two calibrations used by the ACD to conduct three studies on the performance of the ACD. We examine the trending of the calibrations to search for damage and find a timescale over which the calibrations can be considered reliable. We also calculated the number of photoelectrons counted by a PMT on the ACD from a normal proton. Third, we calculated the veto efficiencies of the ACD for two different veto settings. The trends of the calibrations exhibited no signs of damage, and indicated timescales of reliability for the calibrations of one to two years. The number of photoelectrons calculated ranged from 5 to 25. Large errors in the effect of the energy spectrum of the charged particles caused these values to have very large errors of around 60 percent. Finally, the veto efficiencies were found to be very high at both veto values, both for charged particles and for the lower energy backsplash spectrum. The Anti Coincidence Detector (ACD) on the Fermi Gamma Ray Space Telescope is a detector system built around the silicon strip tracker on the Large Area Telescope (LAT). The purpose of the ACD is to provide charged particle rejection for the LAT. To do this, the ACD must be calibrated correctly in flight, and must be able to efficiently veto charged particle events while minimizing false vetoes due to 'backsplash' from photons in the calorimeter. There are eleven calibrations used by the ACD. In this paper, we discuss the use of two of these calibrations to preform three studies on the performance of the ACD. The first study examines trending of the calibrations to check for possible hardware degradation. The second study uses the calibrations to explore the efficiency of an on-board hardware veto. The third study uses the calibrations to calculate the number of photoelectrons seen by each PMT when a

  7. A photochemical reactor for studies of atmospheric chemistry

    DEFF Research Database (Denmark)

    Nilsson, Elna Johanna Kristina; Eskebjerg, Carsten; Johnson, Matthew Stanley

    2009-01-01

    A photochemical reactor for studies of atmospheric kinetics and spectroscopy has been built at the Copenhagen Center for Atmospheric Research. The reactor consists of a vacuum FTIR spectrometer coupled to a 100 L quartz cylinder by multipass optics mounted on electropolished stainless steel end...

  8. Conceptual Design Study of JSFR (2) - Reactor System

    International Nuclear Information System (INIS)

    Several innovative technologies are adopted in the JSFR design to meet the high level requirements for economic competitiveness in the design requirements. The cost-down approaches for JSFR are as follows. In order to reduce the amount of structural materials, the diameter of the reactor vessel shall be minimized and the reactor internal structures shall be simplified. The reduction of the reactor vessel diameter is achieved by adopting a advanced refueling system and the hot reactor vessel with high temperature wall. The flow velocity in the reactor upper plenum increases because the diameter of the reactor vessel is decreased. As the result, the coolant flow field in reactor upper plenum is severe. The optimization of the coolant flow field in the reactor upper plenum was carried out for prevention the cover gas entrainment and the vortex cavitations at the hot leg intake. In addition, structural integrities for seismic loadings and thermal loadings were evaluated because the design seismic loading was highly increased and the vessel wall is directly exposed to the thermal transients of the upper plenum. This paper describes the characteristics and the results of the design study of the reactor system. (author)

  9. Study on effects of development of reactor constant in fast reactor analysis

    International Nuclear Information System (INIS)

    Evaluation was carried out about an effect of development of the new generation reactor constant system that substitutes for the JFS library in fast reactor analysis. Analyzed cores were ZPPR in JUPITER critical experiment and several power reactor cores that were designed in the feasibility study. In the JUPITER analysis, large effects, over 10%, were observed in sodium void reactivity and sample Doppler reactivity. The former resulted from several factors, while the latter was due to an accurate of a resonance interaction effect between Doppler sample and core fuel. In the previous study, the effect had been evaluated in power reactor cores. The effect included an effect of corrosion of weighting spectrum because JFS-3-J3.2, which had been made with the incorrect weighting spectrum, was used in the evaluation. In the present study, JFS-3-J3.2R, which had been made with the correct weighting spectrum, was used. It was confirmed that the effect of development of reactor constant in power reactor was not as large as that in critical assembly. (author)

  10. Using deterministic methods for research reactor studies

    International Nuclear Information System (INIS)

    As an alternative to prohibitive Monte Carlo simulations, deterministic methods can be used to simulate research reactors. Using various microscopic cross section libraries currently available in Canada, flux distributions were obtained from DRAGON cell and supercell transport calculations. Then, homogenization/condensation is done to produce few-group nuclear properties, and diffusion calculations were performed using DONJON core models. In this paper, the multigroup modular environment of the code DONJON is presented, and the various steps required in the modelling of SLOWPOKE hexagonal cores are described. Numerical simulations are also compared with experimental data available for the EPM Slowpoke reactor. (author)

  11. Thorium fuel studies for CANDU reactors

    International Nuclear Information System (INIS)

    Applying the once-through Thorium (OTT) cycle in existing and advanced CANDU reactors might be seen as an evolved concept for the sustainable development both from the economic and waste management points of view. Using the Canadian proposed scheme - loading mixed ThO2-SEU CANFLEX bundles in CANDU 6 reactors - simulated at lattice cell level led to promising conclusions on higher burnup, lesser actinide inventory and proliferation resistance. The calculations were performed using the lattice codes WIMS and DRAGON (together with the corresponding nuclear data library based on ENDF/B-VII). (authors)

  12. Study on statistical analysis of nonlinear and nonstationary reactor noises

    International Nuclear Information System (INIS)

    For the purpose of identification of nonlinear mechanism and diagnosis of nuclear reactor systems, analysis methods for nonlinear reactor noise have been studied. By adding newly developed approximate response function to GMDH, a conventional nonlinear identification method, a useful method for nonlinear spectral analysis and identification of nonlinear mechanism has been established. Measurement experiment and analysis were performed on the reactor power oscillation observed in the NSRR installed at the JAERI and the cause of the instability was clarified. Furthermore, the analysis and data recording methods for nonstationary noise have been studied. By improving the time resolution of instantaneous autoregressive spectrum, a method for monitoring and diagnosis of operational status of nuclear reactor has been established. A preprocessing system for recording of nonstationary reactor noise was developed and its usability was demonstrated through a measurement experiment. (author) 139 refs

  13. Study on secondary shutdown systems in Tehran research reactor

    International Nuclear Information System (INIS)

    Highlights: • A study was undertaken to summarize the techniques for secondary shutdown systems (SSS). • Neutronic calculation performed for proposed systems as SSS. • Dumping the heavy water stored in the reflector vessel is capable to shut down reactor. • Neutronic and transient calculation was done for validating the selected SSS. • All calculation shown that this system has advantages in safety and neutron economy. - Abstract: One important safety aspect of any research reactor is the ability to shut down the reactor. Usually, research reactors, currently in operation, have a single shutdown system based on the simultaneous insertion of the all control rods into the reactor core through gravity. Nevertheless, the International Atomic Energy Agency currently recommends use of two shutdown systems which are fully independent from each other to guarantee secure shutdown when one of them fails. This work presents an investigative study into secondary shutdown systems, which will be an important safety component in the research reactor and will provide another alternative way to shut down the reactor emergently. As part of this project, a study was undertaken to summarize the techniques that are currently used at world-wide research reactors for recognizing available techniques to consider in research reactors. Removal of the reflector, removal of the fuels, change in critical shape of reactor core and insertion of neutron absorber between the core and reflector are selected as possible techniques in mentioned function. In the next step, a comparison is performed for these methods from neutronic aspects. Then, chosen method is studied from the transient behavior point of view. Tehran research reactor which is a 5 MW open-pool reactor selected as a case study and all calculations are carried out for it. It has 5 control rods which serve the purpose of both reactivity control and shutdown of reactor under abnormal condition. Results indicated that heavy

  14. Study on secondary shutdown systems in Tehran research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jalali, H.R.; Fadaei, A.H., E-mail: Fadaei_amir@aut.ac.ir; Gharib, M.

    2015-09-15

    Highlights: • A study was undertaken to summarize the techniques for secondary shutdown systems (SSS). • Neutronic calculation performed for proposed systems as SSS. • Dumping the heavy water stored in the reflector vessel is capable to shut down reactor. • Neutronic and transient calculation was done for validating the selected SSS. • All calculation shown that this system has advantages in safety and neutron economy. - Abstract: One important safety aspect of any research reactor is the ability to shut down the reactor. Usually, research reactors, currently in operation, have a single shutdown system based on the simultaneous insertion of the all control rods into the reactor core through gravity. Nevertheless, the International Atomic Energy Agency currently recommends use of two shutdown systems which are fully independent from each other to guarantee secure shutdown when one of them fails. This work presents an investigative study into secondary shutdown systems, which will be an important safety component in the research reactor and will provide another alternative way to shut down the reactor emergently. As part of this project, a study was undertaken to summarize the techniques that are currently used at world-wide research reactors for recognizing available techniques to consider in research reactors. Removal of the reflector, removal of the fuels, change in critical shape of reactor core and insertion of neutron absorber between the core and reflector are selected as possible techniques in mentioned function. In the next step, a comparison is performed for these methods from neutronic aspects. Then, chosen method is studied from the transient behavior point of view. Tehran research reactor which is a 5 MW open-pool reactor selected as a case study and all calculations are carried out for it. It has 5 control rods which serve the purpose of both reactivity control and shutdown of reactor under abnormal condition. Results indicated that heavy

  15. Poloidal field distribution studies in tokamak reactor

    International Nuclear Information System (INIS)

    On the design studies with the INTOR plasma equilibrium and poloidal field coil configuration (PFCC) from the Phase I to the Phase II A have been obtained the following main results. Three optimized PFCCs have been obtained: the INTOR-J ''Universal'' with the optimized PFCC for the divertor configuration, the optimized PFCC for the pump limiter, and the INTOR ''Universal'' with the PFCC defined as the INTOR reference. These PFCCs satisfy with the requirements for the porthole size for the remote assembly and maintenance of the device, and the maximum flux swing and current densities of the solenoidal coils. The INTOR-J ''Universal'' will be almost the same as the INTOR ''Universal'' in the reactor size. But the optimized PFCC for the pump limiter will be a little larger than the above two configuration because of being in need of slightly larger radii on the two large coils if the plasma with 1.5 in elongation is unconditionally necessary. The total sum of absolute currents with PFCC, which is used as a parameter for its figure of merit, is found to be given in a range of 80 -- 90 MAT at high beta for the divertor configuration for both of the INTOR-J ''Universal'' and the INTOR ''Universal''. The optimized PFCC for pump limiter has 70 -- 80 MAT in its range. The INTOR-J ''Universal'' and the INTOR ''Universal'' for the pump limiter will have its larger sum than one optimized for pump limiter by several MAT. The ''EF only'' method, where the flux, psi sub(P), necessary for maintaining the plasma current on high beta is provided only by EF coils, seems to give the total sum a little less than the ''EF + OH'' method using EF and OH coils for psi sub(P). (J.P.N.)

  16. Studies on the transient operation and stability of fast reactors

    International Nuclear Information System (INIS)

    These studies form part of the general programme of perfecting calculation methods for fast reactors. The basic formulae are given for the layouts used, i.e. the classic kinetic and thermal exchange equations, etc. A description is then given of the digital computer methods employed for studying the stable functioning of the reactor and of the methods used for transient operation studies. Finally, some examples of application are discussed and a comparison is made with parallel studies on the same subject. (author)

  17. Enrico Biasin - Giovanna Maina - Federico Zecca (Eds., Porn After Porn. Contemporary Alternative Pornographies

    Directory of Open Access Journals (Sweden)

    Mirko Lino

    2015-05-01

    Full Text Available Dopo Il Porno Espanso, recensito a suo tempo su Between, il nuovo libro a cura di Enrico Biasin, Giovanna Maina e Federico Zecca, Porn After Porn, è il primo tassello di un'interessante collana, “Mapping Pornographies: Histories, Geographies, Cultures”, che ha l'obiettivo di fornire materiali e strumenti metodologici al dibattito scientifico sulla pornografia contemporanea.I contributi che compongono il volume, dai saggi prettamente accademici alle testimonianze di artisti, produttori e registi del porno, creano tra loro fitte geometrie tematiche che illustrano i corpi, gli usi dei new media, gli sguardi e i consumi delle pornografie alternative, dalla loro proliferazione in Rete alla democratizzazione dell'accesso ai piaceri visivi inscritti nella fruizione di contenuti hard-core a pubblici non esclusivamente maschili ed eterosessuali.

  18. Steady-state spheromak reactor studies

    International Nuclear Information System (INIS)

    After summarizing the essential elements of a gun-sustained spheromak, the potential for a steady-state is explored by means of a comprehensive physics/engineering/costing model. A range of cost-optimized reactor design points is presented, and the sensitivity of cost to key physics, engineering, and operational variables is reported

  19. NGNP Reactor Coolant Chemistry Control Study

    Energy Technology Data Exchange (ETDEWEB)

    Brian Castle

    2010-11-01

    The main focus of this paper is to identify the most desirable ranges of impurity levels in the primary coolant to optimize component life in the primary circuit of the Next Generation Nuclear Plant (NGNP), which will either be a prismatic block or pebble bed reactor.

  20. A stochastic study of coupled reactor systems

    International Nuclear Information System (INIS)

    The neutronic behaviour of a system of two loosely coupled reactor cores is investigated on the basis of a stochastic formulation, by the development of a four points model. The mathematical development is explained. Both real and imaginary parts of the core-to-core neutron cross sepctral density show good agreement with those reported for expermental noise. (U.K.)

  1. Studies of Neutrino Oscillations at Reactors

    OpenAIRE

    Boehm, Felix

    2000-01-01

    Experiments with reactor neutrinos continue to shed light on our understanding of neutrino oscillations. We review some of the early decisive experiments. We then turn to the recent long baseline oscillation experiments at Palo Verde and Chooz which are leading to the conclusion that the atmospheric neutrino anomaly if attributed to oscillations does not involve an appreciable mixing with the $\\bar\

  2. Design study of high breeding fast reactor

    International Nuclear Information System (INIS)

    Aiming to increase fuel breeding capability as the most essential feature of fast breeders, an idea of the FP gas purge/tube-in-shell type metallic fuel assembly is proposed. It makes volume fraction of fuel high as more than 50% and realizes a very hard neutron spectrum in the core. The structure of the fuel assembly, its fabrication and the FP gas purging mechanism were assessed and it is clarified that the new concept of the fuel assembly is engineeringly feasible. FP gas purging does not affect shielding structure and can be managed by a small scale cover-gas treatment system because of good trapping characteristics of bonding sodium in the assembly as expected. The fuel handling system without forced cooling is possible. Other reactor components such as IHX were also evaluated. Thus, a concept of the total reactor system of a fast breeding reactor of 670 MWe with the ultra-high breeding ratio of 1.84 and the short reactor doubling time of 6.7 years was obtained. (author)

  3. Study of the boron homogenizing process employing an experimental low-pressure bench simulating the IRIS reactor pressurizer – Part II

    International Nuclear Information System (INIS)

    Highlights: • Experimental bench with test section made of transparent acrylic, simulating the pressurizer reactor IRIS. • Workbench used to study the process of homogenization of boron in the pressurizer IRIS nuclear reactor. • Results were obtained through videos and digital photos of the test section. - Abstract: The reactivity control of a nuclear reactor to pressurized water is made by means of controlling bars or by boron dilution in the water from the coolant of a primary circuit. The control with boron dilution has great importance, despite inserting small variations in the reactivity in the reactor, as it does not significantly affect the distribution of the neutron flux. A simplified experimental bench with a test section manufactured in transparent acrylic, was built in reduced scale as to be used in a boron homogenizing process, simulating an IRIS reactor pressurizer (International Reactor Innovative and Secure). The bench was assembled in the Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), an entity linked to the Comissão Nacional de Energia Nuclear (CNEN), Recife–PE

  4. Study of the boron homogenizing process employing an experimental low-pressure bench simulating the IRIS reactor pressurizer – Part I

    International Nuclear Information System (INIS)

    Highlights: ► Experimental bench with test section made of transparent acrylic, simulating the pressurizer reactor IRIS. ► Workbench used to study the process of homogenization of boron in the pressurizer IRIS nuclear reactor. ► Results were obtained through videos and digital photos of the test section. - Abstract: The reactivity control of a nuclear reactor to pressurized water is made by means of controlling bars or by boron dilution in the water from the coolant of a primary circuit. The control with boron dilution has great importance, despite inserting small variations in the reactivity in the reactor, as it does not significantly affect the distribution of the neutron flux. A simplified experimental bench with a test section manufactured in transparent acrylic, was built in reduced scale as to be used in a boron homogenizing process, simulating an IRIS reactor pressurizer (International Reactor Innovative and Secure). The bench was assembled in the Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), an entity linked to the Comissão Nacional de Energia Nuclear (CNEN), Recife – PE

  5. Descriptive study of breast and cervix cancer, in patients treated with linear accelerator, at the Centro Medico de Radioterapia Irazu, between 2000 and 2001, and proposed a database

    International Nuclear Information System (INIS)

    A descriptive study of breast and cervix cancer was performed in patients who have received treatment linear accelerator, during the period 2000 - 2001 in the Centro Medico de Radioterapia Irazu. The survival of the patients was assessed to five years (2006). One proposal called database is the product of analysis performed and consistent with the objectives set. The idea to develop the database of these features in the medical center, arises because the Centre was at that time with the only linear accelerator in the country and also all the necessary information of patients was easily accessible. A population of 438 records, with a common pathology was analyzed under the following variables: type of cancer, identification of anatomic region, province, age, sex, type of radiation, number of sessions, referral hospital, physician, physician referral. This work is relevant, because breast and cervical cancers have been a major cause of mortality, ranked among the five most common malignancies in women. From there to have adequate information systems, has led policy makers and health professionals to have a better outlook for their level of management. (author)

  6. Design study on sodium-cooled large-scale reactor

    International Nuclear Information System (INIS)

    In Phase 1 of the 'Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)', an advanced loop type reactor has been selected as a promising concept of sodium-cooled large-scale reactor, which has a possibility to fulfill the design requirements of the F/S. In Phase 2 of the F/S, it is planed to precede a preliminary conceptual design of a sodium-cooled large-scale reactor based on the design of the advanced loop type reactor. Through the design study, it is intended to construct such a plant concept that can show its attraction and competitiveness as a commercialized reactor. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2001, which is the first year of Phase 2. In the JFY2001 design study, a plant concept has been constructed based on the design of the advanced loop type reactor, and fundamental specifications of main systems and components have been set. Furthermore, critical subjects related to safety, structural integrity, thermal hydraulics, operability, maintainability and economy have been examined and evaluated. As a result of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowing down candidate concepts at the end of Phase 2. (author)

  7. Advanced Burner Reactor Preliminary NEPA Data Study

    International Nuclear Information System (INIS)

    The Global Nuclear Energy Partnership (GNEP) is a new nuclear fuel cycle paradigm with the goals of expanding the use of nuclear power both domestically and internationally, addressing nuclear waste management concerns, and promoting nonproliferation. A key aspect of this program is fast reactor transmutation, in which transuranics recovered from light water reactor spent fuel are to be recycled to create fast reactor transmutation fuels. The benefits of these fuels are to be demonstrated in an Advanced Burner Reactor (ABR), which will provide a representative environment for recycle fuel testing, safety testing, and modern fast reactor design and safeguard features. Because the GNEP programs will require facilities which may have an impact upon the environment within the meaning of the National Environmental Policy Act of 1969 (NEPA), preparation of a Programmatic Environmental Impact Statement (PEIS) for GNEP is being undertaken by Tetra Tech, Inc. The PEIS will include a section on the ABR. In support of the PEIS, the Nuclear Engineering Division of Argonne National Laboratory has been asked to provide a description of the ABR alternative, including graphics, plus estimates of construction and operations data for an ABR plant. The compilation of this information is presented in the remainder of this report. Currently, DOE has started the process of engaging industry on the design of an Advanced Burner Reactor. Therefore, there is no specific, current, vendor-produced ABR design that could be used for this PEIS datacall package. In addition, candidate sites for the ABR vary widely as to available water, geography, etc. Therefore, ANL has based its estimates for construction and operations data largely on generalization of available information from existing plants and from the environmental report assembled for the Clinch River Breeder Reactor Plant (CRBRP) design [CRBRP, 1977]. The CRBRP environmental report was chosen as a resource because it thoroughly

  8. Advanced Burner Reactor Preliminary NEPA Data Study.

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, L. L.; Cahalan, J. E.; Deitrich, L. W.; Fanning, T. H.; Grandy, C.; Kellogg, R.; Kim, T. K.; Yang, W. S.; Nuclear Engineering Division

    2007-10-15

    The Global Nuclear Energy Partnership (GNEP) is a new nuclear fuel cycle paradigm with the goals of expanding the use of nuclear power both domestically and internationally, addressing nuclear waste management concerns, and promoting nonproliferation. A key aspect of this program is fast reactor transmutation, in which transuranics recovered from light water reactor spent fuel are to be recycled to create fast reactor transmutation fuels. The benefits of these fuels are to be demonstrated in an Advanced Burner Reactor (ABR), which will provide a representative environment for recycle fuel testing, safety testing, and modern fast reactor design and safeguard features. Because the GNEP programs will require facilities which may have an impact upon the environment within the meaning of the National Environmental Policy Act of 1969 (NEPA), preparation of a Programmatic Environmental Impact Statement (PEIS) for GNEP is being undertaken by Tetra Tech, Inc. The PEIS will include a section on the ABR. In support of the PEIS, the Nuclear Engineering Division of Argonne National Laboratory has been asked to provide a description of the ABR alternative, including graphics, plus estimates of construction and operations data for an ABR plant. The compilation of this information is presented in the remainder of this report. Currently, DOE has started the process of engaging industry on the design of an Advanced Burner Reactor. Therefore, there is no specific, current, vendor-produced ABR design that could be used for this PEIS datacall package. In addition, candidate sites for the ABR vary widely as to available water, geography, etc. Therefore, ANL has based its estimates for construction and operations data largely on generalization of available information from existing plants and from the environmental report assembled for the Clinch River Breeder Reactor Plant (CRBRP) design [CRBRP, 1977]. The CRBRP environmental report was chosen as a resource because it thoroughly

  9. Ultracold Fermi-Fermi Mixtures of Lithium and Potassium

    International Nuclear Information System (INIS)

    Ultracold atomic Fermi gases are a unique experimental tool for simulating and studying many-body systems. Since they are very well controllable and clean systems with tunable interactions, they can serve as quantum simulators for effects that occur in solid states and usually arise from the quantum nature of the Fermi gas of electrons. Different phenomena such as high-temperature superconductivity, Josephson junctions and ferromagnetism can be explored using degenerate Fermi gases. Even in the context of particle physics, Fermi gases can be used to simulate the behavior of quarks inside a nucleus. In the past decade, experiments with a single fermionic (either 6Li or 40K) species have led to ground breaking results. In the past five years, several experiments have been set up that combine the two fermionic alkali species. Additionally to the capabilities offered by a single-species experiment (such as tuning of interaction strength, spin polarization, trap parameters), the two-species mixtures open up control of new parameters - the most obvious being the mass ratio. Due to the mass-imbalance, the Fermi-spheres would no longer overlap, and thus exotic quantum phases emerge. So far experimentally unobserved effects include superfluidity, phase separation, crystalline phases, exotic pairing mechanisms and long-lived trimers. More practically, a mixture would allow to species-selectively apply optical trapping potentials. This thesis presents the experimental efforts from creating an ultracold Fermi- Fermi mixture of 6Li and 40K to the creation of heteronuclear molecules. Three published articles are contained in this thesis. In the first article we report on the observation of Feshbach resonances in an ultracold mixture of two fermionic species, 6Li and 40K. The experimental data are interpreted using a simple asymptotic bound state model and full coupled channels calculations. This unambiguously assigns the observed resonances in terms of various s- and p

  10. A design study on the recycle reactor

    International Nuclear Information System (INIS)

    PNC is promoting R and D on advanced nuclear-fuel recycling which reduces the environmental load and supports nuclear non-proliferation while fully securing economic efficiency and safety. This report describes the fast breeder reactor core which is suitable for constituting this system. This core consists of large-sized opening type fuel assemblies each carrying a control rod and employing mixed nitride fuel pins with sodium bonded to maintain passive safety. (author)

  11. A Study of Reactor Neutrino Monitoring at Experimental Fast Reactor JOYO

    CERN Document Server

    Furuta, H; Hara, T; Haruna, T; Ishihara, N; Ishitsuka, M; Ito, C; Katsumata, M; Kawasaki, T; Konno, T; Kuze, M; Maeda, J; Matsubara, T; Miyata, H; Nagasaka, Y; Nitta, K; Sakamoto, Y; Suekane, F; Sumiyoshi, T; Tabata, H; Takamatsu, M; Tamura, N

    2011-01-01

    We carried out a study of neutrino detection at the experimental fast reactor JOYO using a 0.76 tons gadolinium loaded liquid scintillator detector. The detector was set up on the ground level at 24.3m from the JOYO reactor core of 140MW thermal power. The measured neutrino event rate from reactor on-off comparison was 1.11\\pm1.24(stat.)\\pm0.46(syst.)events/day. Although the statistical significance of the measurement was not enough, the background in such a compact detector at the ground level was studied in detail and MC simulation was found to describe the data well. A study for improvement of the detector for future such experiments is also shown.

  12. Some data on operational, in-construction, projected or studied nuclear reactors - 6. edition

    International Nuclear Information System (INIS)

    This directory contains brief presentations of various types of nuclear reactors or piles. It indicates their location, main characteristics and status (operational, in construction, projected, studied). Several types are addressed: natural uranium-fueled reactors moderated with graphite or with heavy water (research piles, power reactors), enriched uranium-fueled reactors moderated with ordinary water or with other products (research piles and power reactors), homogeneous thermal reactors (research piles, power reactors), fast breeder reactors (research piles, power reactors), and non classified reactors (supposed research piles and power reactors). An analytic list indicates the moderator, fuel-type (either natural or enriched), nationality, location, status (operational, in construction, projected, studied or dismantled), reactor name or names. An alphabetic index of each reactor name, location and constructor is provided. Tables give some limited information which enable comparison between reactors in terms of types and fuel elements

  13. Determining the Appropriate Package and Transportation Methodology for the Detroit Edison, Fermi II Msrs and Associated Components

    International Nuclear Information System (INIS)

    During the spring of 2005, Detroit Edison, Enrico Fermi II Nuclear Power Station (Fermi) decided to disposition two MSRs and associated components scheduled for replacement in the spring of 2006 during the MSR Replacement Outage. Of concern to Fermi was the proper packaging and transportation methodology when dis-positioning a component measuring approximately 110' in length and 13' in diameter and weighing over 300 tons. Upon removal from the Turbine Deck the retired MSRs and associated components were turned over to the Rad Waste Group for packaging and final disposition. Fermi requested quotations from vendors to package, transport, and disposition the MSRs and associated components. However, multiple Vendors informed Fermi that the size and weight of the MSRs were questionable in passing permitting requirements and would require segmentation and volume reduction on site or at a waste processor. Fermi contracted with MHF Logistical Solutions (MHF-LS) based on their ability to receive clearances for shipping the MSRs in one piece via two heavy haul rail conveyances acting as a bolstered load with professionally engineered blocking and bracing configured to support the retired MSRs. (authors)

  14. Study of the dynamic behaviour of the reactor Rapsodie

    International Nuclear Information System (INIS)

    It is known that fast neutron breeder reactors pose new problems in the fields of mechanics and heat technology, as well as in respect to their dynamic behaviour and safety. The reactor RAPSODIE has been the object of numerous dynamic studies on analogue and digital computers for two types of fuel (metal and oxide). After elaborating the mathematical models representing the whole of the installation (reactor block and cooling circuit) from the point of view of neutrons as well as thermodynamics, the analogue diagrams and digital codes required for simulating incidents, control and stability of the reactor were established. Considerable effort was made to obtain a greater precision than in the usual methods, either by using smaller intervals, or by the use of formulations closer to the real system, or even analytically soluble. The study of incidents was carried out on analog computer for the whole system, and digital computer for the reactor block alone or the installation functioning with a single thermal circuit. A special complementary programme - which so far as we know, was used for the first time here for sodium reactors - which takes into account the behaviour of the reactor beyond the boiling point of sodium was refined on the basis of some simplifying assumptions. The investigation of incidents has served to determine: - The intrinsic safety of the reactor, i.e. its behaviour-under accident conditions without the intervention of the safety systems; - The behaviour of the installation under normal accident conditions, i.e. with the safety systems functioning, and the definition and organisation of the latter ; - the comparison of the two versions investigated (metal or oxide fuel) for the choice of the first loading of the reactor; - the determination of thermal shocks (amplitudes and gradients suffered by the structures during probable incidents) to be used in the test on the full-scale model of the reactor. The stability tests were carried out digitally

  15. Study of an hypothetical reactor meltdown accident for a 50 MW sub(th) fast reactor

    International Nuclear Information System (INIS)

    A melhodology for determining the energy released in hypothetical reactor meltdown accidents is presented. A numerical code was developed based upon the Nicholson method for a uniform and homogeneous reactor with spherical geometry. A comparative study with other know programs in the literature which use better approximations for small energy released, shows that the methodology used were compatible with those under comparison. Besides the influence of some parameters on the energy released, such as the initial power level and the prompt neutron lifetime was studied under this metodology and its result exhibitted. The Doppler effect was also analyzed and its influence on the energy released has been emphasized. (Author)

  16. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    V. Ravi; Young Sun Mok; B. S. Rajanikanth; Ho-Chul Kang

    2003-01-01

    An electric discharge plasma reactor combined with a catalytic reactor was studied for removing nitrogen oxides. To understand the combined process thoroughly, discharge plasma and catalytic process were separately studied first, and then the two processes were combined for the study. The plasma reactor was able to oxidize NO to NO2 well although the oxidation rate decreased with temperature. The plasma reactor alone did not reduce the NOx (NO+NO2)level effectively, but the increase in the ratio of NO2 to NO as a result of plasma discharge led to the enhancement of NOx removal efficiency even at lower temperatures over the catalyst surface (V2O5-WOa/TiO2). At a gas temperature of 100℃, the NOx removal efficiency obtained using the combined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/1.

  17. Hydrodynamic study of an internal airlift reactor for microalgae culture.

    Science.gov (United States)

    Rengel, Ana; Zoughaib, Assaad; Dron, Dominique; Clodic, Denis

    2012-01-01

    Internal airlift reactors are closed systems considered today for microalgae cultivation. Several works have studied their hydrodynamics but based on important solid concentrations, not with biomass concentrations usually found in microalgae cultures. In this study, an internal airlift reactor has been built and tested in order to clarify the hydrodynamics of this system, based on microalgae typical concentrations. A model is proposed taking into account the variation of air bubble velocity according to volumetric air flow rate injected into the system. A relationship between riser and downcomer gas holdups is established, which varied slightly with solids concentrations. The repartition of solids along the reactor resulted to be homogenous for the range of concentrations and volumetric air flow rate studied here. Liquid velocities increase with volumetric air flow rate, and they vary slightly when solids are added to the system. Finally, liquid circulation time found in each section of the reactor is in concordance with those employed in microalgae culture. PMID:21710261

  18. New light on R.E.G. Pichi Sermolli’s plants from the Lake Tana expedition in 1937 – an important collection from Ethiopia at the Centro Studi Erbario Tropicale (FT)

    DEFF Research Database (Denmark)

    Friis, Ib

    2015-01-01

    At the age of 24, R.E.G. Pichi Sermolli (1912–2005) travelled to Ethiopia as botanist on the Missione di Studio al Lago Tana, staying in Eritrea and Ethiopia from early January to late April 1937. The expedition was organized by the Centro Studi per l’Africa Orientale Italiana under the Reale Acc...... Erbario Tropicale, from an Italian colonial herbarium towards a tropical herbarium with international orientation....

  19. Transient behaviour study program of research reactors fuel elements at the Hydra Pulse Reactor

    International Nuclear Information System (INIS)

    Program on behavior study of research reactor Fuel Elements (FE) under transient regimes initiated by excessive reactivity insertion is being presented. Program would be realized at HYDRA pulse reactor at Russian Research Center 'Kurchatov Institute' (RRC 'K1'). HYDRA uses aqueous solution of uranyl sulfate (UO2SO4) as a fuel. Up to 30 MJ of energy can be released inside the core during the single pulse, effective power pulse width varying from 2 to 10 ms. Reactor facility allows to investigate behaviour of FE consisting of different types of fuel composition, being developed according to Russian RERTR. First part of program is aimed at transient behaviour studying of FE MR, IRT-3M, WWR-M5 types containing meats based on dioxide uranium in aluminum matrix. Mentioned FEs use 90% and 36% enriched uranium. (author)

  20. Parametric study of the Tormac fusion reactor concept

    International Nuclear Information System (INIS)

    A preliminary but comprehensive power balance for the D-T Tormac magnetic fusion reactor concept is examined parametrically in order to establish general scaling relationships, tradeoffs, and constraints. The results are based on the simplifying assumptions of steady-state operation, a homogeneous plasma, and ideal thin-sheath, mirror-like confinement. Crucial physics uncertainties requiring further theoretical and experimental research attention are identified. Representative reactor physics operating points are generated to illustrate anticipated Tormac reactor embodiments. This study should be considered preliminary to a more detailed physics and technology modeling effort and is intended only to scope and identify possible operating points, parametric sensitivities, and potential physics/technological problems

  1. Methods for studying fuel management in advanced gas cooled reactors

    International Nuclear Information System (INIS)

    The methods used for studying fuel and absorber management problems in AGRs are described. The basis of the method is the use of ARGOSY lattice data in reactor calculations performed at successive time steps. These reactor calculations may be quite crude but for advanced design calculations a detailed channel-by-channel representation of the whole core is required. The main emphasis of the paper is in describing such an advanced approach - the ODYSSEUS-6 code. This code evaluates reactor power distributions as a function of time and uses the information to select refuelling moves and determine controller positions. (author)

  2. Study of heavy ion collisions at Fermi energy: is the methodology orientating our understanding of physics?

    International Nuclear Information System (INIS)

    The analysis of the reaction products in the case of a multi-fragmentation reaction requires an efficient sorting of the experimental data. A collision, detected in a 4π detector generates about 100 parameters that are measured. Experimental data have to be reduced to the part most meaningful of the studied event. A model of the reaction is necessary to discard or value variables on which the sorting could be based. The selection of experimental data implies almost always the introduction of a bias that is necessary to know in order to continue a thorough analysis of the experimental results. A theoretical work is then necessary not only in the view of the comparison between results and predictions but also to validate the assumptions that have been made to sort out the experimental data. This method is applied to the study of the nuclear reaction: Gd + U at 36 MeV/U. (A.C.)

  3. Feasibility study of self sustaining capability on water cooled thorium reactors for different power reactors

    International Nuclear Information System (INIS)

    Thorium fuel cycle can maintain the sustainable system of the reactor for self sustaining system for future sustainable development in the world. Some characteristics of thorium cycle show some advantages in relation to higher breeding capability, higher performance of burn-up and more proliferation resistant. Several investigations was performed to improve the breeding capability which is essential for maintaining the fissile sustainability during reactor operation in thermal reactor such as Shippingport reactor and molten salt breeder reactor (MSBR) project. The preliminary study of breeding capability on water cooled thorium reactor has been investigated for various power output. The iterative calculation system is employed by coupling the equilibrium fuel cycle burn-up calculation and cell calculation of PIJ module of SRAC2000. In this calculation, 1238 fission products and 129 heavy nuclides are employed. In the cell calculation, 26 heavy metals and 66 fission products and 1 pseudo FP are employed. The employed nuclear data library was JENDL 3.2. The reactor is fueled by 233U-Th Oxide and it has used the light water coolant as moderator. Some characteristics such as conversion ratio and void reactivity coefficient performances are evaluated for the systems. The moderator to fuel ratio (MFR) values and average burnups are studied for survey parameter. The parametric survey for different power outputs are employed from 10 MWt to 3000 MWt for evaluating the some characteristics of core size and leakage effects to the spectra profile, required enrichment, breeding capability, fissile inventory condition, and void reactivity coefficient. Different power outputs are employed in order to evaluate its effect to the required enrichment for criticality, breeding capability, void reactivity and fissile inventory accumulation. The obtained value of the conversion ratios is evaluated by using the equilibrium atom composition. The conversion ratio is employed based on the

  4. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    This report describes the results of the reactor configuration/structure design for the fusion experimental reactor (FER) performed in FY 1986. The design was intended to meet the physical and engineering mission of the next step device which was decided by the subcommittee on the next step device of the nuclear fusion council. The objectives of the design study in FY 1986 are to advance and optimize the design concept of the last year because the recommendation of the subcommittee was basically the same as the design philosophy of the last year. Six candidate reactor configurations which correspond to options C ∼ D presented by the subcommittee were extensively examined. Consequently, ACS reactor (Advanced Option-C with Single Null Divertor) was selected as the reference configuration from viewpoints of technical risks and cost performance. Regarding the reactor structure, the following items were investigated intensively: minimization of reactor size, protection of first wall against plasma disruption, simplification of shield structure, reactor configuration which enables optimum arrangement of poloidal field coils. (author)

  5. Plasma nitriding monitoring reactor: A model reactor for studying plasma nitriding processes using an active screen

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, S., E-mail: hamann@inp-greifswald.de; Röpcke, J. [INP-Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Börner, K.; Burlacov, I.; Spies, H.-J. [TU Bergakademie Freiberg, Institute of Materials Engineering, Gustav-Zeuner-Str. 5, 09599 Freiberg (Germany); Strämke, M.; Strämke, S. [ELTRO GmbH, Arnold-Sommerfeld-Ring 3, 52499 Baesweiler (Germany)

    2015-12-15

    A laboratory scale plasma nitriding monitoring reactor (PLANIMOR) has been designed to study the basics of active screen plasma nitriding (ASPN) processes. PLANIMOR consists of a tube reactor vessel, made of borosilicate glass, enabling optical emission spectroscopy (OES) and infrared absorption spectroscopy. The linear setup of the electrode system of the reactor has the advantages to apply the diagnostic approaches on each part of the plasma process, separately. Furthermore, possible changes of the electrical field and of the heat generation, as they could appear in down-scaled cylindrical ASPN reactors, are avoided. PLANIMOR has been used for the nitriding of steel samples, achieving similar results as in an industrial scale ASPN reactor. A compact spectrometer using an external cavity quantum cascade laser combined with an optical multi-pass cell has been applied for the detection of molecular reaction products. This allowed the determination of the concentrations of four stable molecular species (CH{sub 4}, C{sub 2}H{sub 2}, HCN, and NH{sub 3}). With the help of OES, the rotational temperature of the screen plasma could be determined.

  6. Plasma nitriding monitoring reactor: A model reactor for studying plasma nitriding processes using an active screen.

    Science.gov (United States)

    Hamann, S; Börner, K; Burlacov, I; Spies, H-J; Strämke, M; Strämke, S; Röpcke, J

    2015-12-01

    A laboratory scale plasma nitriding monitoring reactor (PLANIMOR) has been designed to study the basics of active screen plasma nitriding (ASPN) processes. PLANIMOR consists of a tube reactor vessel, made of borosilicate glass, enabling optical emission spectroscopy (OES) and infrared absorption spectroscopy. The linear setup of the electrode system of the reactor has the advantages to apply the diagnostic approaches on each part of the plasma process, separately. Furthermore, possible changes of the electrical field and of the heat generation, as they could appear in down-scaled cylindrical ASPN reactors, are avoided. PLANIMOR has been used for the nitriding of steel samples, achieving similar results as in an industrial scale ASPN reactor. A compact spectrometer using an external cavity quantum cascade laser combined with an optical multi-pass cell has been applied for the detection of molecular reaction products. This allowed the determination of the concentrations of four stable molecular species (CH4, C2H2, HCN, and NH3). With the help of OES, the rotational temperature of the screen plasma could be determined. PMID:26724023

  7. Plasma nitriding monitoring reactor: A model reactor for studying plasma nitriding processes using an active screen

    International Nuclear Information System (INIS)

    A laboratory scale plasma nitriding monitoring reactor (PLANIMOR) has been designed to study the basics of active screen plasma nitriding (ASPN) processes. PLANIMOR consists of a tube reactor vessel, made of borosilicate glass, enabling optical emission spectroscopy (OES) and infrared absorption spectroscopy. The linear setup of the electrode system of the reactor has the advantages to apply the diagnostic approaches on each part of the plasma process, separately. Furthermore, possible changes of the electrical field and of the heat generation, as they could appear in down-scaled cylindrical ASPN reactors, are avoided. PLANIMOR has been used for the nitriding of steel samples, achieving similar results as in an industrial scale ASPN reactor. A compact spectrometer using an external cavity quantum cascade laser combined with an optical multi-pass cell has been applied for the detection of molecular reaction products. This allowed the determination of the concentrations of four stable molecular species (CH4, C2H2, HCN, and NH3). With the help of OES, the rotational temperature of the screen plasma could be determined

  8. Plasma nitriding monitoring reactor: A model reactor for studying plasma nitriding processes using an active screen

    Science.gov (United States)

    Hamann, S.; Börner, K.; Burlacov, I.; Spies, H.-J.; Strämke, M.; Strämke, S.; Röpcke, J.

    2015-12-01

    A laboratory scale plasma nitriding monitoring reactor (PLANIMOR) has been designed to study the basics of active screen plasma nitriding (ASPN) processes. PLANIMOR consists of a tube reactor vessel, made of borosilicate glass, enabling optical emission spectroscopy (OES) and infrared absorption spectroscopy. The linear setup of the electrode system of the reactor has the advantages to apply the diagnostic approaches on each part of the plasma process, separately. Furthermore, possible changes of the electrical field and of the heat generation, as they could appear in down-scaled cylindrical ASPN reactors, are avoided. PLANIMOR has been used for the nitriding of steel samples, achieving similar results as in an industrial scale ASPN reactor. A compact spectrometer using an external cavity quantum cascade laser combined with an optical multi-pass cell has been applied for the detection of molecular reaction products. This allowed the determination of the concentrations of four stable molecular species (CH4, C2H2, HCN, and NH3). With the help of OES, the rotational temperature of the screen plasma could be determined.

  9. Feasibility study of potential LEU fuels for generic MNSR reactor

    International Nuclear Information System (INIS)

    A feasibility study was performed for a generic Miniature Source Reactor (MNSR) reactor to identify potential LEU fuels that could be used for conversion of these reactors. The model that was used and analysis results obtained with the current HEU fuel are first described. Potential LEU fuels are then listed. The study results were used to identify fuels that may be suitable for use in MNSR conversions, the qualification status of these fuels, and potential manufacturers. Five LEU fuels and core designs were identified that match the excess reactivity of the HEU core. Conversion of MNSR reactors to these fuels would be technically feasible if all safety requirements are shown to be satisfied, the fuels are qualified and licensed, and manufacturers are available to fabricate the fuels at a reasonable price. (author)

  10. Comparative study of cost models for tokamak DEMO fusion reactors

    International Nuclear Information System (INIS)

    Cost evaluation analysis of the tokamak-type demonstration reactor DEMO using the PEC (physics-engineering-cost) system code is underway to establish a cost evaluation model for the DEMO reactor design. As a reference case, a DEMO reactor with reference to the SSTR (steady state tokamak reactor) was designed using PEC code. The calculated total capital cost was in the same order of that proposed previously in cost evaluation studies for the SSTR. Design parameter scanning analysis and multi regression analysis illustrated the effect of parameters on the total capital cost. The capital cost was predicted to be inside the range of several thousands of M$s in this study. (author)

  11. Landau theory of relativistic Fermi liquids

    International Nuclear Information System (INIS)

    A relativistic extension of the Landau Fermi liquid theory, applicable to the study of high density matter, is developed. Consequences of Lorentz invariance in the theory are explored. The formalism is illustrated by a study of relativistic Fermi systems weakly interacting via scalar and vector meson exchange. Second order exchange energies for both massless scalar and massless vector interactions are calculated in terms of Landau parameters on the Fermi surface. Zero sound and 'color-plasma oscillations' are studied in quark matter with SU(3) color gluon coupling. (Auth.)

  12. Study of enzymatic reactors with microencapsulated lipase. Doctoral thesis. Estudo de reactores enzimaticos com lipase microencapsulada

    Energy Technology Data Exchange (ETDEWEB)

    de Franca Teixeira dos Prazeres, D.M.

    1992-10-01

    The work reports the development of a membrane reactor for the hydrolysis of triglycerides catalyzed by lipase B from Chromobacterium viscosum in AOT/isooctane reversed miceller system. In a preliminary phase the potential of the organic system was evaluated with comparative studies on the activity and stability of lipase B in aqueous media (emulsion) and in the alternative miceller media. A tubular ceramic membrane reactor with recirculation was selected for the olive oil hydrolysis in a reversed miceller system. The influence of the hydration degree, recirculation rate, AOT, olive oil and lipase concentration in the operation of the reactor were investigated in a batch mode. The hydration degree was identified as a critical parameter due to its influence in the separation process and in the kinetics of the reaction.

  13. Calculation of fundamental parameters for the dynamical study of TRIGA-3-Salazar reactor (Mixed reactor core)

    International Nuclear Information System (INIS)

    Kinetic parameters for dynamic study of two different configurations, 8 and 9, both with standard fuel, 20% enrichment and Flip (Fuel Life Improvement Program with 70% enrichment) fuel, for TRIGA Mark-III reactor from Mexico Nuclear Center, are obtained. A calculation method using both WIMS-D4 and DTF-IV and DAC1 was established, to decide which of those two configurations has the best safety and operational conditions. Validation of this methodology is done by calculate those parameters for a reactor core with new standard fuel. Configuration 9 is recommended to be use. (Author)

  14. Studies of aged cast stainless steel from the Shippingport reactor

    International Nuclear Information System (INIS)

    The cast stainless steels used for primary coolant piping in many pressurized water reactors and for valve bodies, fittings, and coolant pump casings in most light water reactors are subject to embrittlement after extended service at reactor operating temperatures. Most studies pertaining to embrittlement of cast stainless steels involve simulation of end-of-life reactor conditions by accelerated aging at ≥400 degrees C since the time period for operation of a power plant is far longer than can generally be considered for laboratory studies. Thus, an assessment of the end-of-life mechanical properties is almost always based on an extrapolation of the accelerated test data. Because the embrittlement mechanisms and kinetics are complex, microstructural studies and mechanical testing of actual component materials that have completed long in-reactor service are needed to ensure that the mechanisms observed in accelerated aging experiments are the same as those occurring in reactor. Cast stainless steel materials from the decommissioned Shippingport reactor offered a unique opportunity to validate and benchmark the laboratory studies. Cast stainless steel materials were obtained from four primary coolant system check valves, two manual hot-leg isolation valves, and two pump volutes. Microstructural examination of the cast materials indicates that the primary mechanism of thermal embrittlement is the same as that of laboratory-aged materials, i.e., spinodal decomposition of the ferrite to form chromium-rich α' phase. Other phases, such as nickel- and silicon-rich G phase precipitated in the ferrite, and the presence of carbides at the austenite/ferrite phase boundary also contribute to embrittlement. Charpy-impact, tensile, and J-R curve tests were conducted on several cast stainless steels from the Shippingport reactor

  15. Detailed photoluminescence studies of thin film Cu2S for determination of quasi-Fermi level splitting and defect levels

    International Nuclear Information System (INIS)

    We have studied chalcocite (Cu2S) layers prepared by physical vapor deposition with varying deposition parameters by calibrated spectral photoluminescence (PL) and by confocal PL with lateral resolution of Δ x≈0.9 μm. Calibrated PL experiments as a function of temperature T and excitation fluxes were performed to obtain the absolute PL-yield and to calculate the splitting of the quasi-Fermi levels (QFLs) μ=Ef,n−Ef,p at an excitation flux equivalent to the AM 1.5 spectrum and the absorption coefficient α(ℏω), both in the temperature range of 20 K≤T≤400 K. The PL-spectra reveal two peaks at E#1=1.17 eV and E#2=1.3 eV. The samples show a QFL-splitting of μ>700 meV associated with a pseudo band gap of Eg=1.25 eV. The high-energy peak shows an unexpected temperature behavior, namely, an increase of PL-yield with rising temperature at variance with the behavior of QFL-splitting that decreases with rising T. Our observations indicate that, contrary to common believe, it is not the PL-yield, but rather the QFL-splitting that is the comprehensive indicator of the quality of the excited state in an illuminated semiconductor. A further examination of the lateral variation of opto-electronic properties by confocal PL and the surface contour shows no detectable correlation between Cu2S grains/grain boundaries and the PL-yield or QFL-splitting

  16. Study on neutronic safety parameters of BAEC TRIGA research reactor

    International Nuclear Information System (INIS)

    Highlights: • The control rod worth is measured using the positive period method. • Core excess reactivities are measured at different power levels. • Shut down margin of the reactor has been determined. • Fuel and water temperatures are measured at different power levels. • All the safety parameters are compared with the safety analysis report of the reactor. - Abstract: Measurement and validation of safety parameters of a nuclear reactor are required for reactor start up, normal power operation, experimental research and shutdown. The reactivity of the control rod is one of the important parameters for management of reactor operations, and is used for the prediction of control rod position at startup and the estimation of the core excess reactivity during the reactor operation. In this study, some reactor safety parameters such as control rod worth, core excess reactivity, shutdown margin, reactivity changes by fuel and control rods, and temperature effect on reactivity has been measured using digital instrumentation & control (I&C) system of the BAEC TRIGA Research Reactor (BTRR). All of these safety parameters have significant effects on the reactor control system. The measured total worth of all control rods of BTRR are 14.888 $, 14.672 $, 14.348 $ for 1.5 folding time, doubling time, 5 folding time, respectively. The measured reactivity has also been compared with the previously measured reactivity. The core excess reactivity and shutdown margin were found to be 6.38 $ and 5.20 $, respectively. The measured values were found to be within the safety limit as mentioned in the Safety Analysis Report (SAR) of the BTRR

  17. A multiwavelength phenomenological study of Fermi-LAT blazars: acceleration mechanisms and emission models (SSC vs. EC), in a leptonic scenario

    International Nuclear Information System (INIS)

    Full text: We present a phenomenological study of blazars observed by Fermi. We study both acceleration mechanisms and emission models, in the framework of a leptonic scenario. We use broad-band multiwavelength data of Fermi blazars to investigate trends between observational features, such as peak energy and peak fluxes. We compare these phenomenological results with accurate Montecarlo simulations, to test predictions from Synchrotron Self-Compton (SSC) and External Compton (EC) scenarios. We can make a partition of the parameter space that allows us to disentangle the SSC from the EC scenario, and to frame different classes of objects in different emission models. We find an interesting transition from SSC to EC for BL Lac objects with the synchrotron peak energy below 1014 Hz. As second topic, we focus on the relation between spectral properties observed in the X-rays and hard X-rays of Femi blazars, that we cross check with those observed by Fermi-LAT in the gamma-rays. By comparing observational trends with Montecarlo results we investigate the acceleration mechanisms, and we constrain the minimum energy of the accelerated particle, and the spectral index in the low-energy branch of their energy distribution. (author)

  18. SOLASE conceptual laser fusion reactor study

    International Nuclear Information System (INIS)

    A conceptual laser fusion reactor for electric power, SOLASE, has been designed. The SOLASE design utilizes a 1 MJ, 6.7% efficient laser to implode 20 fusion targets per second. The target gain is 150 and produces a net electrical power of 1000 MW. The reactor cavity is spherical with a 6 m radius. The first wall is graphite and has a neutron wall loading of 5 MW/m2. It is protected from the target debris by low pressure xenon gas that is introduced into the cavity. The blanket structure is a honeycombed graphite composite. The tritium breeding and heat transport medium is Li2O in the form of pellets that flow through the blanket. The tritium breeding ration is 1.34. Temperature decoupling of the graphite structure and the Li2O coolant enables the structure to operate at temperatures that minimize radiation damage effects. The graphite blanket is replaced every year but exhibits low levels of radioactivity so that limited hands on maintenance is possible two weeks after shutdown, thus facilitating rapid replacement

  19. Enrico Biasin - Giovanna Maina - Federico Zecca (Eds.), Porn After Porn. Contemporary Alternative Pornographies

    OpenAIRE

    Mirko Lino

    2015-01-01

    Dopo Il Porno Espanso, recensito a suo tempo su Between, il nuovo libro a cura di Enrico Biasin, Giovanna Maina e Federico Zecca, Porn After Porn, è il primo tassello di un'interessante collana, “Mapping Pornographies: Histories, Geographies, Cultures”, che ha l'obiettivo di fornire materiali e strumenti metodologici al dibattito scientifico sulla pornografia contemporanea.I contributi che compongono il volume, dai saggi prettamente accademici alle testimonianze di artisti, produttori e regis...

  20. Estudio sobre la influencia de género en la incorporación de las TIC a los centros educativos Study on the influence of gender in the introduction of ICT to schools

    Directory of Open Access Journals (Sweden)

    Enrique SÁNCHEZ RIVAS

    2011-07-01

    Full Text Available La investigación planteada en este proyecto busca ampliar el conocimiento de la influencia ejercida por la variable de género sobre la incorporación de las TIC a los ámbitos curriculares y organizativos de los centros educativos públicos de Educación Primaria y Secundaria de la provincia de Málaga. A través de un estudio de casos múltiples se recaba la valoración que realiza el profesorado sobre el grado de incidencia de los proyectos para la incorporación de las TIC en sus centros. Y mediante técnicas de triangulación se precisa el nivel de implementación de las TIC en centros cuyos procesos han sido dirigidos por hombres y centros en los que esta responsabilidad se ha depositado en mujeres. Esta doble perspectiva ha permitido concretar en qué medida es importante el género de la persona que coordina el proyecto para la implementación educativa de las TIC en nuestro contexto.The research presented in this project seeks to increase awareness of the influence of the gender variable on the integration of ICT into the curriculum and organizational areas of public schools Elementary and Secondary Education in the province of Malaga. Through a multiple case study collects the assessment made by the teachers on the degree of impact of projects for the integration of ICT in their schools. And through triangulation techniques specifying the level of implementation of ICT in schools whose processes have been led by men and places in which this responsibility has been placed on women. This dual perspective has allowed to realize how important is the gender of the person who coordinates the project for the educational implementation of ICT in our context.

  1. Research reactor records in the INIS Database - A bibliometric study

    International Nuclear Information System (INIS)

    This report presents a statistical analysis of more than 13,000 records of publications concerned with research and technology in the field of research and/or experimental reactors which are included in the INIS Bibliographic Database for the period from 1970 to 2002. The main objectives of this bibliometric study were: to make an inventory of research reactor related records in the INIS Database; to provide statistics and scientific indicators for the INIS users, namely science managers, researchers, engineers, operators, scientific editors and publishers, decision-makers in the field of research reactors related subjects; to extract other useful information from the INIS Bibliographic Database about articles published in research reactors research and technology. Special attention is devoted to publications related to fuel management and RERTR issues. The quantitative data in this report are obtained for various properties of relevant INIS records such as year of publication, secondary subject categories, countries of publication, language, publication types, literary types, etc. (author)

  2. 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

  3. Reactor Physics Scoping and Characterization Study on Implementation of TRIGA Fuel in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jennifer Lyons; Wade R. Marcum; Mark D. DeHart; Sean R. Morrell

    2014-01-01

    The Advanced Test Reactor (ATR), under the Reduced Enrichment for Research and Test Reactors (RERTR) Program and the Global Threat Reduction Initiative (GTRI), is conducting feasibility studies for the conversion of its fuel from a highly enriched uranium (HEU) composition to a low enriched uranium (LEU) composition. These studies have considered a wide variety of LEU plate-type fuels to replace the current HEU fuel. Continuing to investigate potential alternatives to the present HEU fuel form, this study presents a preliminary analysis of TRIGA® fuel within the current ATR fuel envelopes and compares it to the functional requirements delineated by the Naval Reactors Program, which includes: greater than 4.8E+14 fissions/s/g of 235U, a fast to thermal neutron flux ratio that is less than 5% deviation of its current value, a constant cycle power within the corner lobes, and an operational cycle length of 56 days at 120 MW. Other parameters outside those put forth by the Naval Reactors Program which are investigated herein include axial and radial power profiles, effective delayed neutron fraction, and mean neutron generation time.

  4. Reactor Physics Scoping and Characterization Study on Implementation of TRIGA Fuel in the Advanced Test Reactor

    International Nuclear Information System (INIS)

    The Advanced Test Reactor (ATR), under the Reduced Enrichment for Research and Test Reactors (RERTR) Program and the Global Threat Reduction Initiative (GTRI), is conducting feasibility studies for the conversion of its fuel from a highly enriched uranium (HEU) composition to a low enriched uranium (LEU) composition. These studies have considered a wide variety of LEU plate-type fuels to replace the current HEU fuel. Continuing to investigate potential alternatives to the present HEU fuel form, this study presents a preliminary analysis of TRIGA® fuel within the current ATR fuel envelopes and compares it to the functional requirements delineated by the Naval Reactors Program, which includes: greater than 4.8E+14 fissions/s/g of 235U, a fast to thermal neutron flux ratio that is less than 5% deviation of its current value, a constant cycle power within the corner lobes, and an operational cycle length of 56 days at 120 MW. Other parameters outside those put forth by the Naval Reactors Program which are investigated herein include axial and radial power profiles, effective delayed neutron fraction, and mean neutron generation time.

  5. Fermi comes to CERN

    CERN Multimedia

    NASA

    2009-01-01

    1. This view from NASA's Fermi Gamma-ray Space Telescope is the deepest and best-resolved portrait of the gamma-ray sky to date. The image shows how the sky appears at energies more than 150 million times greater than that of visible light. Among the signatures of bright pulsars and active galaxies is something familiar -- a faint path traced by the sun. (Credit: NASA/DOE/Fermi LAT Collaboration) 2. The Large Area Telescope (LAT) on Fermi detects gamma-rays through matter (electrons) and antimatter (positrons) they produce after striking layers of tungsten. (Credit: NASA/Goddard Space Flight Center Conceptual Image Lab)

  6. Design study on gas turbine high temperature reactor (GTHTR300)

    International Nuclear Information System (INIS)

    Japan Atomic Energy Research Institute (JAERI) has been conducting the design study of an original design concept of gas turbine high temperature reactor, the GTHTR300 (Gas Turbine High Temperature Reactor 300). The GTHTR300 is a greatly simplified HTGR-GT plant that leads to substantially reduced technical and cost requirements for earlier technology deployment. Also, it is expected to be an efficient and economically competitive reactor in 2010s due to newly proposed design features such as core design with two-year refueling interval, conventional steel material usage for a reactor pressure vessel, innovative plant flow scheme and horizontally installed gas turbine unit. This paper describes the original design features focusing on reactor core design, fuel design, in-core structure design and reactor pressure vessel design. In addition, a preliminary cost evaluation proved that the capital cost of the GTHTR300 is less than a target cost of 200 thousands Yen/kWe. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  7. Preliminary design studies on the Broad Application Test Reactor

    International Nuclear Information System (INIS)

    This report describes progress made at the Idaho National Engineering Laboratory during the first three quarters of Fiscal Year (FY) 1992 on the Laboratory-Directed Research and Development (LDRD) project to perform preliminary design studies on the Broad Application Test Reactor (BATR). This work builds on the FY-92 BATR studies, which identified anticipated mission and safety requirements for BATR and assessed a variety of reactor concepts for their potential capability to meet those requirements. The main accomplishment of the FY-92 BATR program is the development of baseline reactor configurations for the two conventional conceptual test reactors recommended in the FY-91 report. Much of the present report consists of descriptions and neutronics and thermohydraulics analyses of these baseline configurations. In addition, we considered reactor safety issues, compared the consequences of steam explosions for alternative conventional fuel types, explored a Molten Chloride Fast Reactor concept as an alternate BATR design, and examined strategies for the reduction of operating costs. Work planned for the last quarter of FY-92 is discussed, and recommendations for future work are also presented

  8. Oregon State TRIGA reactor power calibration study

    International Nuclear Information System (INIS)

    As a result of a recent review of the Oregon State TRIGA Reactor (OSTR) power calibration procedure, an investigation was performed on the origin and correctness of the OSTR tank factor and the calibration method. It was determined that there was no clear basis for the tank factor which was being used (0.0525 deg. C/kwh) and therefore a new value was calculated (0.0493 deg. C/kwh). The calculational method and likely errors are presented in the paper. In addition, a series of experimental tests were conducted to decide if the power calibration was best performed with or without a mixer, at 100 KW or at 1 MW. The results of these tests along with the final recommendation are presented. (author)

  9. Preliminary Study of Potential Market for Small Reactors

    International Nuclear Information System (INIS)

    Small reactors are an energy supply for a specific purpose and oriented for a different market than large reactors. Small reactors will provide a local solution for developed and developing countries, such as, in remote areas, on small grids, or for non-electricity applications such as, district heating, seawater desalination and process heat. Single or medium sized power stations with small reactors should be compared with single fissile or renewable energy source and not be compared with large reactors. CRIEPI and LLNL have studied the business opportunities for small reactors. The small reactor concept is planned for initial use in small remote communities and in developing countries with small power distribution grid. Rapid installation and simple operation of the small plants is intended to support use in these communities without requiring development of a substantial nuclear technology infrastructure. In this study, two approaches were used in the assessment of the potential market. The first approach took a global look at the need for small nuclear plants. Then selected countries and sites were identified based on countries expressing interest in small reactors to the IAEA and consideration of sites in the US and Japan. (1) Tunisia, Mexico, Indonesia, Uruguay, Egypt and Argentina have demonstrated interest in nuclear power. Selecting one of these is dependent on political and socioeconomic factors, some of which have been identified, that require direct interaction with the countries to establish if they represent real opportunities. (2) The states of Hawaii and Alaska in the United States have high power cost and remote or island communities that may benefit from small nuclear plants. Alaska has shown greater interest in power alternatives including small than Hawaii and there is clearly less public resistance to nuclear power in Alaska. (3) The countries in Central America are actively expanding their power grids but have not demonstrated great interest

  10. Relación Familia-Centro

    OpenAIRE

    Martínez Segura, María José

    2009-01-01

    Contenidos: La participación de las Familias en los Centros Educativos. Procesos de facilitación en la relación y comunicación la Familia en el Centro Educativo. Habilidades sociales en la relación Familia-Centro. Habilidades a de la familia para incidir positivamente en el desarrollo de la educación.

  11. De Haas-van Alphen study of niobium: Fermi surface, cyclotron effective masses, and magnetic breakdown effects

    International Nuclear Information System (INIS)

    The Fermi surface of niobium has been investigated using the de Haas--van Alphen effect. Data were taken at temperatures as low as 0.3 K and in fields as high as 130 kG. An on-line minicomputer was used to Fourier-transform the digitized signals. Many new extremal area data have been obtained, including oscillations associated with the previously unobserved GAMMA-centered hole octahedron and GAMMA and N-centered orbits on the so-called jungle gym. An additional set of signals has been observed near [100], which are thought to be a result of magnetic breakdown between the second zone octahedron result of magnetic breakdown between the second zone octahedron and third zone jungle gym. A separate low-frequency signal was observed and is believed to be a result of magnetic-breakdown-induced quantum interference oscillations. Anisotropies of the cyclotron effective mass have been determined for many orbits on all three of the Fermi surface sheets. Finally, the area data have been used to parametrize the Fermi surface in terms of scattering phase shifts in a Korringa--Kohn--Rostoker band structure formalism

  12. Fermi GBM Trigger Catalog

    Data.gov (United States)

    National Aeronautics and Space Administration — Fermi is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is...

  13. Fermi LAT GRBs

    Data.gov (United States)

    National Aeronautics and Space Administration — All analysis results presented here are preliminary and are not intended as an official catalog of Fermi-LAT detected GRBs. Please consult the table's caveat page...

  14. Fermi-Segre formula

    International Nuclear Information System (INIS)

    The Fermi-Segre normalization expression is rederived for arbitrary orbital angular momentum l within the context of a generalized WKB method. Results from the approximation are compared with calculations employing Hartree-Slater atomic potentials

  15. Fermi surface of yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Kontrym-Sznajd, G. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych; Sormann, H. [Technische Univ., Graz (Austria). Inst. fuer Theoretische Physik; West, R.N. [Texas Univ., Arlington, TX (United States). Dept. of Physics

    2001-07-01

    Electron-positron momentum densities in Y, reconstructed from two-dimensional angular correlation of annihilation radiation spectra, are compared with the theoretical predictions of fully-relativistic augmented plane-wave calculations. Knowledge of the theoretical densities and of the effects on them of certain symmetry selection rules has allowed us to separate two hole Fermi surfaces in the third and fourth bands and to establish some Fermi momenta for each of them. (orig.)

  16. A study of passive safety conditions for fast reactor core

    International Nuclear Information System (INIS)

    A study has been made for passive safety conditions of fast reactor cores. Objective of the study is to develop a concept of a core with passive safety as well as a simple safety philosophy. A simple safety philosophy, which is wore easy to explain to the public, is needed to enhance the public acceptance for nuclear reactors. The present paper describes a conceptual plan of the study including the definition of the problem a method of approach and identification of tasks to be solved

  17. Recent high-pressure Fermi-surface studies on (TMTSF)/sub 2/PF/sub 6/ and ReO/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, J.E.

    1981-01-01

    Hydrostatic pressure coupled with temperatures near absolute zero has proven to be an extremely important environment in the study of the Fermi surface and electronic structure of metals. This environment allows critical testing of theoretical models for the electronic structure and allows access to regions of the phase diagram of the material where interesting and desirable properties may be isolated and studied. Two recent examples of the latter type of study are reviewed involving the compressibility collapse transition in ReO/sub 3/ and quantum oscillatory behavior at high-magnetic fields in (TMTSF)/sub 2/PF/sub 6/. 11 figures.

  18. Feasibility study on the thorium fueled boiling water breeder reactor

    International Nuclear Information System (INIS)

    The feasibility of (Th,U)O 2 fueled, boiling water breeder reactor based on conventional BWR technology has been studied. In order to determine the potential use of water cooled thorium reactor as a competitive breeder, this study evaluated criticality, breeding and void reactivity coefficient in response to changes made in MFR and fissile enrichments. The result of the study shows that while using light water as moderator, low moderator to fuel volume ratio (MFR=0.5), it was possible to breed fissile fuel in negative void reactivity condition. However the burnup value was lower than the value of the current LWR. On the other hand, heavy water cooled reactor shows relatively wider feasible breeding region, which lead into possibility of designing a core having better neutronic and economic performance than light water with negative void reactivity coefficient. (authors)

  19. Thermodynamics of ultracold Fermi gases

    International Nuclear Information System (INIS)

    Complex Hamiltonians from condensed matter, such as the Fermi-Hubbard model, can be experimentally studied using ultracold gases. This thesis describes a new method for determining the equation of state of an ultracold gas, making the comparison with many-body theories straightforward. It is based on the measurement of the local pressure inside a trapped gas from the analysis of its in situ image. We first apply this method to the study of a Fermi gas with resonant interactions, a weakly-interacting 7Li gas acting as a thermometer. Surprisingly, none of the existing many-body theories of the unitary gas accounts for the equation of state deduced from our study over its full range. The virial expansion extracted from the high-temperature data agrees with the resolution of the three-body problem. At low temperature, we observe, contrary to some previous studies, that the normal phase behaves as a Fermi liquid. Finally we obtain the critical temperature for superfluidity from a clear signature on the equation of state. We also measure the pressure of the ground state as a function of spin imbalance and interaction strength - measure directly relevant to describe the crust of neutron stars. Our data validate Monte-Carlo simulations and quantify the Lee-Huang-Yang corrections to mean-field interactions in low-density fermionic or bosonic superfluids. We show that, in most cases, the partially polarized normal phase can be described as a Fermi liquid of polarons. The polaron effective mass extracted from the equation of state is in agreement with a study of collective modes. (author)

  20. 变换溶液浓度方法研究费米共振%Study of Fermi Resonance by Means of Solution Concentration Variation

    Institute of Scientific and Technical Information of China (English)

    蒋秀兰; 李东飞; 陈元正; 周密; 孙成林; 杨光; 里佐威; 高淑琴

    2011-01-01

    The values of Raman scattering coefficients of some molecules in which Fermi resonance occurs vary with solution concentration variation. We measured the Raman spectra of some solvents such as CCl4, CS2, C6 H6, etc by changing the concentration of the solutions ranging from 10% to 100% in volume. As a result, the authors obtained the general law of Fermi resonance. We found some weak Fermi resonance phenomena as well that the two bands of Raman spectrum shift asymmetrically and that the fundamental of overtone is tuned by Fermi resonance and moves towards the same direction with the overtone simultaneously, which is same as the results Bier K. D. obtained by means of high-pressure technique. By means of this method, the authors demonstrated the conclusion that only the fundamental in combinations which has the same symmetry as the fundamental involved in Fermi resonance directly can its intensity variation influence the Fermi resonance. In this article, the authors present a new method to study Fermi resonance. This method is valuable in the identification and the assignment of spectral lines of solutions, the determination of molecular configuration of enzyme, the discrimination of isomer, as well as the influences on the molecular structures and properties caused by hydrogen bond.%一些分子的拉曼散射系数随其在溶液中的浓度而变化.通过改变样品的浓度测量了CCl4,CS2和C6H6等几种溶剂的拉曼光谱并获得了费米共振的普遍规律,发现了两费米峰不对称移动、倍频峰的基频被费米共振调制并向同方向移动等弱费米共振的一些规律.这与Bier利用高压方法获得的结果相同.文章还验证了以下结论:参与费米共振的和频中的基频只有其振动对称性与直接参与费米共振的基频的振动对称性相同时其光谱强度变化对费米共振有影响,含则无影响.实验证明了通过改变溶液浓度方法可以获得费米共振的有关规律,这对溶液

  1. Conceptual design study of Fusion Experimental Reactor (FY87FER)

    International Nuclear Information System (INIS)

    This report describes the results of the design coordination and the conceptual design study on plant systems which have been carried out as a part of the design work for the Fusion Experimental Reactor (FY87 FER). The former contains the selection of the reference concept for FY87 FER and giving it flexibility, directions for study and assessment of low physics risk reactors, and the revision of system integration, while the latter mainly describes the design philosophies, construction of systems, and the results of designs and analyses of processes and systems. (author)

  2. Utilization of the experimental reactor Osiris for the study and the development of fuels of the fast neutron reactor type

    International Nuclear Information System (INIS)

    Nuclear fuel tests for the fast neutron reactor type have been carried out at the Osiris reactor: thermal study of (U,Pu)O2 oxide by measurement with thermocouples in the core of the fuel pellet; study of the effects of power cycling on nuclear fuel; study of the mechanical interactions between oxide and cladding by measurement of the cladding deformation during irradiation

  3. Experimental studies of irradiated and hydrogen implantation damaged reactor steels

    Science.gov (United States)

    Slugeň, Vladimír; Pecko, Stanislav; Sojak, Stanislav

    2016-01-01

    Radiation degradation of nuclear materials can be experimentally simulated via ion implantation. In our case, German reactor pressure vessel (RPV) steels were studied by positron annihilation lifetime spectroscopy (PALS). This unique non-destructive method can be effectively applied for the evaluation of microstructural changes and for the analysis of degradation of reactor steels due to neutron irradiation and proton implantation. Studied specimens of German reactor pressure vessel steels are originally from CARINA/CARISMA program. Eight specimens were measured in as-received state and two specimens were irradiated by neutrons in German experimental reactor VAK (Versuchsatomkraftwerk Kahl) in the 1980s. One of the specimens which was in as-received and neutron irradiated condition was also used for simulation of neutron damage by hydrogen nuclei implantation. Defects with the size of about 1-2 vacancies with relatively small contribution (with intensity on the level of 20-40 %) were observed in "as-received" steels. A significant increase in the size of the induced defects due to neutron damage was observed in the irradiated specimens resulting in 2-3 vacancies. The size and intensity of defects reached a similar level as in the specimens irradiated in the nuclear reactor due to the implantation of hydrogen ions with energies of 100 keV (up to the depth <500 nm).

  4. Study on (super) small FBRs. Space and deep sea reactors

    International Nuclear Information System (INIS)

    The Japan Nuclear Cycle Development Institute (JNC) has also carried out conceptual investigation on deep sea fast reactors (DSFRs) mainly used at deep sea by considering on independent demand in Japan, one of oceanic nations in addition to reactors for space use as the (super) small reactors. On DSFRs, JNC carried out a summary on past investigations on JNC TN4420 2001-001, the 'DSFRs required for oceanic studies' on June, 2001 Then, in this report, was intended to carry out similar summary on space reactors (SRs). Its concrete contents were determined for their worldwide trends and SRs for lunar surface installed reactors. On the other hand, on DSFRs, under response to extreme development in oceanic studies after last summary, some theme to newly be examined at their standpoints, to determine to describe here as a form of its additional report. Its concrete contents contain newly developed no-man sea bottom station installed by autonomous underwater vehicles with automatically charging function in the sea, and so on. (G.K.)

  5. The Entrance of Quantum Mechanics in Italy:. from Garbasso to Fermi

    Science.gov (United States)

    Leone, Matteo; Robotti, Nadia

    2006-06-01

    The first steps of quantum mechanics in Italy will be here discussed, through the use of the available archives and printed sources. As it will be shown, this development was closely linked with a spectroscopy tradition of research, whose major protagonists were three physicists working in Tuscany during the first two decades of the century, namely Antonio Garbasso, who worked in Arcetri (Florence) on the theoretical basis of the recently discovered Stark Effect (1913-14); Rita Brunetti, in Arcetri as well, who made use of the quantum theory in order to explain the X-rays emission (1918-20); and, finally, the young Enrico Fermi, who paid attention to the quantum theory since his days at the Scuola Normale Superiore in Pisa (1918-22).

  6. Conceptual design study of Fusion Experimental Reactor (FY87FER)

    International Nuclear Information System (INIS)

    The design study of Fusion Experimental Reactor(FER) which has been proposed to be the next step fusion device has been conducted by JAERI Reactor System Laboratory since 1982 and by FER design team since 1984. This is the final report of the FER design team program and describes the results obtained in FY1987 (partially in FY1986) activities. The contents of this report consist of the reference design which is based on the guideline in FY1986 by the Subcomitees set up in Nuclear Fusion Council of Atomic Energy Commission of Japan, the Low-Physics-Risk reactor design for achieving physics mission more reliably and the system study of FER design candidates including above two designs. (author)

  7. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    This report describes the results of conceptual design study on plant systems for the Fusion Experimental Reactor (FY86 FER). Design studies for FER plant systems have been continued from FY85, especially for design modifications made in accordance with revisions of plasma scaling parameters and system improvements. This report describes 1) system construction, 2) site and reactor building plan, 3) repaire and maintenance system, 4) tritium circulation system, 5) heating, ventilation and air conditioning system, 6) tritium clean-up system, 7) cooling and baking system, 8) waste treatment and storage system, 9) control system, 10) electric power system, 11) site factory plan, all of which are a part of FY86 design work. The plant systems described in this report generally have been based on the FY86 FER (ACS Reactor) which is an one of the six candidates for FER. (author)

  8. ELMO Bumpy Torus Reactor and power plant: conceptual design study

    International Nuclear Information System (INIS)

    A complete power plant design of a 1200-MWe ELMO Bumpy Torus Reactor (EBTR) is presented. An emphasis is placed on those features that are unique to the EBT confinement concept, with subsystems and balance-of-plant items that are more generic to magnetic fusion being adapted from past, more extensive tokamak reactor designs. Similar to the latter tokamak studies, this conceptual EBTR design also emphasizes the use of conventional or near state-of-the-art engineering technology and materials. An emphasis is also placed on system accessibility, reliability, and maintainability, as these crucial and desirable characteristics relate to the unique high-aspect-ratio configuration of EBTs. Equal and strong emphasis is given to physics, engineering/technology, and costing/economics components of this design effort. Parametric optimizations and sensitivity studies, using cost-of-electricity as an object function, are reported. Based on these results, the direction for future improvement on an already attractive reactor design is identified

  9. Studies of a modular advanced stellarator reactor ASRA6C

    International Nuclear Information System (INIS)

    This study is directed towards the clarification of critical issues of advanced modular stellerator reactors exploiting the inherent potential of steady state operation, and is not a point design study of a reactor. Critical technology issues arise from the three-dimensional magnetic field structure. The first wall, blanket and shield are more complex than those of axi-symmetric systems, but this is eased at moderate to large aspect ratio typical of stellarators. Several blanket options have been studied and a thin blanket (21 cm) was the first choice for the design. Superconducting modular coils were investigated with respect to the conductor and mechanical supports. From the analysis of forces and stresses caused by the electromagnetic loads the coils are considered to be feasible, although shear stresses might pose a critical issue. Demountable intermagnetic support elements were designed for use at separation areas between the cryostat modules. A scheme for remote reactor maintenance was also developed. The plasma physics issues of different configurations were studied using extrapolations of transport behaviour and equilibrium from theory and present experiments. These studies indicate that the confinement and equilibrium behaviour is adequate for ignited operation at an average value of 5% beta. Impurities may pose a critical issue. Several impurity control operations were investigated; a pumped limiter configuration utilizing the 'ergodic layer' at the plasma edge was chosen for edge plasma and impurity control. A general conclusion of the study is that the modular stellerator configuration offers interesting prospects regarding the development towards steady-state reactors. (orig.)

  10. Studies of a modular advanced stellarator reactor ASRA6C

    International Nuclear Information System (INIS)

    This study is directed towards the clarification of critical issues of advanced modular stellerator reactors exploiting the inherent potential of steady state operation, and is not a point design study of a reactor. Critical technology issues arise from the three-dimensional magnetic field structure. The first wall, blanket and shield are more complex than those of axi-symmetric systems, but this is eased at moderate to large aspect ratio typical of stellerators. Several blanket options have been studied and a thin blanket (21 cm) was the first choice for the design. Superconducting modular coils were investigated with respect to the conductor and mechanical supports. From the analysis of forces and stresses caused by the electromagnetic loads the coils are considered to be feasible, although shear stresses might pose a critical issue. Demountable intermagnetic support elements were designed for use at separation areas between the cryostat modules. A scheme for remote reactor maintenance was also developed. The plasma physics issues of different configurations were studied using extrapolations of transort behaviour and equilibrium from theory and present experiments. These studies indicate that the confinement and equilibrium behaviour is adequate for ignited operation at an average value of 5% beta. Impurities may pose a critical issue. Several impurity control operations were investigated; a pumped limiter configuration utilizing the 'ergodic layer' at the plasma edge was chosen for edge plasma and impurity control. A general conclusion of the study is that the modular stellerator configuration offers interesting prospects regarding the development towards steady-state reactors. (orig.)

  11. The Statistical Fermi Paradox

    Science.gov (United States)

    Maccone, C.

    2008. 4. A practical example is then given of how the SEH works numerically. Each of the ten random variables is uniformly distributed around its own mean value as given by Dole (1964) and a standard deviation of 10% is assumed. The conclusion is that the average number of habitable planets in the Galaxy should be around 100 million ±200 million, and the average distance in between any two nearby habitable planets should be about 88 light years ±40 light years. 5. The SEH results are matched against the results of the Statistical Drake Equation from reference 4. As expected, the number of currently communicating ET civilizations in the Galaxy turns out to be much smaller than the number of habitable planets (about 10,000 against 100 million, i.e. one ET civilization out of 10,000 habitable planets). The average distance between any two nearby habitable planets is much smaller that the average distance between any two neighbouring ET civilizations: 88 light years vs. 2000 light years, respectively. This means an ET average distance about 20 times higher than the average distance between any pair of adjacent habitable planets. 6. Finally, a statistical model of the Fermi Paradox is derived by applying the above results to the coral expansion model of Galactic colonization. The symbolic manipulator "Macsyma" is used to solve these difficult equations. A new random variable Tcol, representing the time needed to colonize a new planet is introduced, which follows the lognormal distribution, Then the new quotient random variable Tcol/D is studied and its probability density function is derived by Macsyma. Finally a linear transformation of random variables yields the overall time TGalaxy needed to colonize the whole Galaxy. We believe that our mathematical work in deriving this STATISTICAL Fermi Paradox is highly innovative and fruitful for the future.

  12. Control rod studies in small and medium sized fast reactors

    International Nuclear Information System (INIS)

    Control rods are the primary safety mechanism in the operation of fast reactors. Neutronic parameters associated with the control rods have to be evaluated precisely for studying the behaviour of the reactor under various operating conditions. Control rods are strong neutron absorbers discretely distributed in the reactor core. Accurate estimation of control rod parameters demand, in principle transport theory solutions in exact geometry. But computer codes for such evaluations usually consume exorbitantly large computer time and memory for even a single parameter evaluation. During the design of reactors, evaluation of these parameters will be required for many configurations of control rods. In this paper, the method used at Indira Gandhi Centre for Atomic Research for estimating the parameters associated with control rods is presented. Diffusion theory solutions were used for computations. A scheme using three dimensional geometry represented by triangular meshes and diffusion theory solutions in few energy groups for control rod parameter evaluation is presented. This scheme was employed in estimating the control rod parameters in a 500 Mw(e) fast reactor. Error due to group collapsing is estimated by comparing with 25 group calculations in three dimensions for typical cases. (author). 5 refs, 4 figs, 3 tabs

  13. Isotopic studies relative to the Oklo natural fission reactors

    International Nuclear Information System (INIS)

    It has been clearly demonstrated that natural fission reactors operated about 2 109 years ago, in rich uranium one deposits of the Oklo mine in the Republique of Gabon. Six reactions zones have been identified in which approximately six tons of 235U were consumed and the same amount of fission products deposited in the ground. These fission products, their filiation isotopes and nuclei formed from neutron captures are precious tracers, which now can be analysed on well localized samples, to obtain informations on the stability in soil of such elements and data on the nuclear parameters and characteristics of the nuclear reactors. The studies which have been developed at Saclay concern several aspects of this phenomenon: the migrations of fission products, the age of the nuclear reaction, the date of the uranium deposit and the temperature of the reaction zones during the operation of the reactors

  14. Mirror Advanced Reactor Study (MARS) final report summary

    International Nuclear Information System (INIS)

    The Mirror Advanced Reactor Study (MARS) has resulted in an overview of a first-generation tandem mirror reactor. The central cell fusion plasma is self-sustained by alpha heating (ignition), while electron-cyclotron resonance heating and negative ion beams maintain the electrostatic confining potentials in the end plugs. Plug injection power is reduced by the use of high-field choke coils and thermal barriers, concepts to be tested in the Tandem Mirror Experiment-Upgrade (TMX-U) and Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory

  15. A study on the decommissioning of research reactor

    International Nuclear Information System (INIS)

    As the result of study on decommissioning, discussion has made and data have been collected about experiences, plannings, and techniques for decommissioning through visit to GA and JAERI. GA supplied our Research Reactor No. 1 and No. 2, and JAERI made a memorial museum after dicommissioning of JRR-1 and is dismentling JPDR now. Also many kinds of documents are collected and arranged such as documents related to TRIGA reactor dicommissioning, 30 kinds of documents including decommissioning plan, technical criteria and related regulatory, and 1,200 kinds of facility description data. (Author)

  16. The TITAN Reversed-Field Pinch fusion reactor study

    International Nuclear Information System (INIS)

    The TITAN Reversed-Field Pinch (RFP) fusion reactor study is a multi-institutional research effort to determine the technical feasibility and key developmental issues of an RFP fusion reactor, especially at high power density, and to determine the potential economics, operations, safety, and environmental features of high-mass-power-density fusion systems. The TITAN conceptual designs are DT burning, 1000 MWe power reactors based on the RFP confinement concept. The designs are compact, have a high neutron wall loading of 18 MW/m2 and a mass power density of 700 kWe/tonne. The inherent characteristics of the RFP confinement concept make fusion reactors with such a high mass power density possible. Two different detailed designs have emerged: the TITAN-I lithium-vanadium design, incorporating the integrated-blanket-coil concept; and the TITAN-II aqueous loop-in-pool design with ferritic steel structure. This report contains a collection of 16 papers on the results of the TITAN study which were presented at the International Symposium on Fusion Nuclear Technology. This collection describes the TITAN research effort, and specifically the TITAN-I and TITAN-II designs, summarizing the major results, the key technical issues, and the central conclusions and recommendations. Overall, the basic conclusions are that high-mass power-density fusion reactors appear to be technically feasible even with neutron wall loadings up to 20 MW/m2; that single-piece maintenance of the FPC is possible and advantageous; that the economics of the reactor is enhanced by its compactness; and the safety and environmental features need not to be sacrificed in high-power-density designs. The fact that two design approaches have emerged, and others may also be possible, in some sense indicates the robustness of the general findings

  17. Estudo sobre a percepção do clima organizacional do centro cirúrgico de um hospital especializado Estudio sobre la percepción del clima organizacional del centro quirúrgico de un hospital especializado Study on the perception of the organization climate of the surgical center in a specialized hospital

    Directory of Open Access Journals (Sweden)

    Wilza Carla Spiri

    1998-01-01

    Full Text Available O presente estudo tem o objetivo de identificar como o grupo de funcionários recém-admitidos no centro cirúrgico de um hospital especializado, percebe o clima organizacional existente, utilizando uma abordagem qualitativa. Como referencial teórico para interpretar o clima organizacional utilizamos os conceitos de CHIAVENATO, que define clima organizacional como meio interno de uma organização e que através de sua experienciação pelos participantes influencia o comportamento dos mesmos, podendo ser favorável, desfavorável e neutro. Os discursos reiteram um clima organizacional favorável, considerando o referencial teórico adotado.El presente estudio tiene el objetivo de identificar cómo el grupo de funcionarios recién admitidos en el centro quirúrgico denota el clima organizacional existente, utilizando un abordaje cualitative. Como referencial teórico para interpretar el clima organizacional utilizamos los conceptos de CHIAVENATO, que define clima organizacional como el medio interno de una organización y que a través de su experiencia los participantes influéncian el comportamiento de los mismos, pudiendo ser favorable, desfavorable y neutro. Los discursos revelaron un clima organizacional favorable, considerándo el referencial teórico adoptado.The aim of this study is to identify how a new team of the surgical center staff in a specialized hospital perceive the organization climate. A qualitative approach was utilized. As a theoretical reference to measure the organization climate, we have used CHIAVENATO, that defines organization climate as the interior of an organization that influences its members´ behavior. The organization climate could be favourable, unfavourable or neutral. The speechs showed a favourable organization climate considering the adopted methodology.

  18. Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Korecka, Lucie [Department of Analytical Chemistry, University of Pardubice, Namesti Cs. Legii 565, 532 10 Pardubice (Czech Republic)]. E-mail: lucie.korecka@upce.cz; Jezova, Jana [Department of Analytical Chemistry, University of Pardubice, Namesti Cs. Legii 565, 532 10 Pardubice (Czech Republic); Bilkova, Zuzana [Department of Biological and Biochemical Sciences, University of Pardubice, Namesti Cs. Legii 565, 532 10 Pardubice (Czech Republic); Benes, Milan [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho Namesti 2, 162 06 Prague (Czech Republic); Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovskeho Namesti 2, 162 06 Prague (Czech Republic); Hradcova, Olga [Department of Biological and Biochemical Sciences, University of Pardubice, Namesti Cs. Legii 565, 532 10 Pardubice (Czech Republic); Slovakova, Marcela [Department of Biological and Biochemical Sciences, University of Pardubice, Namesti Cs. Legii 565, 532 10 Pardubice (Czech Republic); Laboratoire Physicochimie Curie, UMR 168 CNRS/Institute Curie, Paris Cedex 05 (France); Viovy, Jean-Louis [Laboratoire Physicochimie Curie, UMR 168 CNRS/Institute Curie, Paris Cedex 05 (France)

    2005-05-15

    The newly developed magnetic micro- and nanoparticles with defined hydrophobicity and porosity were used for the preparation of magnetic enzyme reactors. Magnetic particles with immobilized proteolytic enzymes trypsin, chymotrypsin and papain and with enzyme neuraminidase were used to study the structure of heterogeneous glycoproteins. Factors such as the type of carrier, immobilization procedure, operational and storage stability, and experimental conditions were optimized.

  19. Kartini Research Reactor prospective studies for neutron scattering application

    Energy Technology Data Exchange (ETDEWEB)

    Widarto [Yogyakarta Nuclear Research Center, BATAN (Indonesia)

    1999-10-01

    The Kartini Research Reactor (KRR) is located in Yogyakarta Nuclear Research Center, Yogyakarta - Indonesia. The reactor is operated for 100 kW thermal power used for research, experiments and training of nuclear technology. There are 4 beam ports and 1 column thermal are available at the reactor. Those beam ports have thermal neutron flux around 10{sup 7} n/cm{sup 2}s each other and used for sub critical assembly, neutron radiography studies and Neutron Activation Analysis (NAA). Design of neutron collimator has been done for piercing radial beam port and the calculation result of collimated neutron flux is around 10{sup 9} n/cm{sup 2}s. This paper describes experiment facilities and parameters of the Kartini research reactor, and further more the prospective studies for neutron scattering application. The purpose of this paper is to optimize in utilization of the beam ports facilities and enhance the manpower specialty. The special characteristic of the beam ports and preliminary studies, pre activities regarding with neutron scattering studies for KKR is presented. (author)

  20. A comparative study of fuel management in PWR reactors

    International Nuclear Information System (INIS)

    A study about fuel management in PWR reactors, where not only the conventional uranium cycle is considered, but also the thorium cycle as an alternative is presented. The final results are presented in terms of U3O8 demand and SWU and the approximate costs of the principal stages of the fuel cycle, comparing with the stardand cycle without recycling. (E.G.)

  1. Theoretical study of a solar fixed bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bizarro, P.; Le Palec, G.; Daguenet, M. (Laboratoire de Thermodynamique et Energetique, Universite de Perpignan (France))

    1984-01-01

    The authors calculate numerically the temperature and concentration profiles in a catalytic packed bed reactor submitted to concentrated solar radiation. They examine the co-current case (gas circulates in the direction of heat flow) as well as the counter-current case (gas circulates in the opposite direction) and study the influence of various parameters on the chemical reaction rate.

  2. Framatome studies on high conversion water reactor concept

    International Nuclear Information System (INIS)

    This paper presents Framatome studies concerning the optimization of water power reactors. Three fuel models have been taken into account: fuel with grid and stainless steel cladding; fuel with grid and zircaloy cladding; and, fuel with grid, zircaloy cladding and spectral shift

  3. Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

    Science.gov (United States)

    Korecká, Lucie; Ježová, Jana; Bílková, Zuzana; Beneš, Milan; Horák, Daniel; Hradcová, Olga; Slováková, Marcela; Viovy, Jean-Louis

    2005-05-01

    The newly developed magnetic micro- and nanoparticles with defined hydrophobicity and porosity were used for the preparation of magnetic enzyme reactors. Magnetic particles with immobilized proteolytic enzymes trypsin, chymotrypsin and papain and with enzyme neuraminidase were used to study the structure of heterogeneous glycoproteins. Factors such as the type of carrier, immobilization procedure, operational and storage stability, and experimental conditions were optimized.

  4. Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

    International Nuclear Information System (INIS)

    The newly developed magnetic micro- and nanoparticles with defined hydrophobicity and porosity were used for the preparation of magnetic enzyme reactors. Magnetic particles with immobilized proteolytic enzymes trypsin, chymotrypsin and papain and with enzyme neuraminidase were used to study the structure of heterogeneous glycoproteins. Factors such as the type of carrier, immobilization procedure, operational and storage stability, and experimental conditions were optimized

  5. GRB physics with Fermi

    CERN Document Server

    Medvedev, Mikhail V

    2009-01-01

    Radiation from GRBs in the prompt phase, flares and an afterglow is thought to be produced by accelerated electrons in magnetic fields. Such emission may be produced at collisionless shocks of baryonic outflows or at reconnection sites (at least for the prompt and flares) of the magnetically dominated (Poynting flux driven) outflows, where no shocks presumably form at all. An astonishing recent discovery is that during reconnection strong small-scale magnetic fields are produced via the Weibel instability, very much like they are produced at relativistic shocks. The relevant physics has been successfully and extensively studied with the PIC simulations in 2D and, to some extent, in 3D for the past few years. We discuss how these simulations predict the existence of MeV-range synchrotron/jitter emission in some GRBs, which can be observed with Fermi. Recent results on modeling of the spectral variability and spectral correlations of the GRB prompt emission in the Weibel-jitter paradigm applicable to both baryo...

  6. A de Haas-van Alphen study of the field dependence of the Fermi surface in ZrZn2

    International Nuclear Information System (INIS)

    Pulsed field de Haas-van Alphen measurements of the GAMMA centred part of the Fermi surface in ZrZ2 are presented for fields up to 35 T. The spin-split Fermi surface was found to be field dependent. It is argued that the observed de Haas-van Alphen frequency is different from the frequency defined by the Onsager relation. An expression is derived based on the Stoner-Wohlfarth model which describes the difference in spin-up and spin-down frequencies as a function of field strength. The observed difference in the effective mass for the two spin directions can also be explained by this model and it compares well with band structure calculations. An anomalous behaviour of the second harmonic of the majority surface de Haas-van Alphen frequency was observed. A search for other frequencies was carried out but in spite of the high sensitivity, in terms of m*Tsub(D), no other orbits were seen. (author)

  7. Fermi comes to CERN

    CERN Multimedia

    2009-01-01

    In only 10 months of scientific activity, the Fermi space observatory has already collected an unprecedented wealth of information on some of the most amazing objects in the sky. In a recent talk at CERN, Luca Latronico, a member of the Fermi collaboration, explained some of their findings and emphasized the strong links between High Energy Physics (HEP) and High Energy Astrophysics (HEA). The Fermi gamma-ray telescope was launched by NASA in June 2008. After about two months of commissioning it started sending significant data back to the Earth. Since then, it has made observations that are changing our view of the sky: from discovering a whole new set of pulsars, the greatest total energy gamma-ray burst ever, to detecting an unexplained abundance of high-energy electrons that could be a signature of dark matter, to producing a uniquely rich and high definition sky map in gamma-rays. The high performance of the instrument comes as ...

  8. Fermi coordinates and Penrose limits

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Matthias; Frank, Denis; Weiss, Sebastian [Institut de Physique, Universite de Neuchatel Rue Breguet 1, CH-2000 Neuchatel (Switzerland)

    2006-06-07

    We propose a formulation of the Penrose plane wave limit in terms of null Fermi coordinates. This provides a physically intuitive (Fermi coordinates are direct measures of geodesic distance in spacetime) and manifestly covariant description of the expansion around the plane wave metric in terms of components of the curvature tensor of the original metric, and generalizes the covariant description of the lowest order Penrose limit metric itself, obtained in Blau et al (2004 Class. Quantum Grav. 21 L43-9). We describe in some detail the construction of null Fermi coordinates and the corresponding expansion of the metric, and then study various aspects of the higher order corrections to the Penrose limit. In particular, we observe that in general the first-order corrected metric is such that it admits a light-cone gauge description in string theory. We also establish a formal analogue of the Weyl tensor peeling theorem for the Penrose limit expansion in any dimension, and we give a simple derivation of the leading (quadratic) corrections to the Penrose limit of AdS{sub 5} x S{sup 5}.

  9. Safety benefits from CANDU reactor replacement. A case study

    International Nuclear Information System (INIS)

    Both total core replacement and core retubing have been used in the CANDU industry. For future plant refurbishments, based on experience both in new construction and in recent refurbishments, the concept of total core replacement has been revisited. This builds on practices for replacement of other large plant equipment like boilers. The Bruce CANDU reactors, with their local shield tanks built around the Calandria and containment closely located around that Calandria Shield Tank Assembly (CSTA), are believed to be good candidates for core replacement. A structured process was used to design a replacement CSTA suitable for Bruce A use. The work started with a study of opportunities for safety enhancements in the core. This progressed into design studies and related design assist safety analysis on the reactor. A key element of the work involved consideration of how verified features from later CANDU designs, and from our new reactor design work, could be tailored to fit this replacement core. The replacement reactor core brings in structural improvements in both calandria and end shield, and safety improvements like the natural circulation enhancing moderator cooling layout and further optimized reactivity layouts to improve shutdown system performance. Bruce Power are currently studying the business implications of this and retube techniques as part of preparation for future refurbishments. The work explained in this paper is in the context of the safety related changes and the work to choose and quantify them. (author)

  10. Safety benefits from CANDU reactor replacement - a case study

    International Nuclear Information System (INIS)

    Both total core replacement and core retubing have been used in the CANDU industry. For future plant refurbishments, based on experience both in new construction and in recent refurbishments, the concept of total core replacement has been revisited. This builds on practices for replacement of other large plant equipment like boilers. The Bruce CANDU reactors, with their local shield tanks built around the Calandria and containment closely located around that Calandria Shield Tank Assembly (CSTA), are believed to be good candidates for core replacement. A structured process was used to design a replacement CSTA suitable for Bruce A use. The work started with a study of opportunities for safety enhancements in the core. This progressed into design studies and related design assist safety analysis on the reactor. A key element of the work involved consideration of how verified features from later CANDU designs, and from our new reactor design work, could be tailored to fit this replacement core. The replacement reactor core brings in structural improvements in both calandria and end shield, and safety improvements like the natural circulation enhancing moderator cooling layout and further optimized reactivity layouts to improve shutdown system performance. Bruce Power are currently studying the business implications of this and retube techniques as part of preparation for future refurbishments. The work explained in this paper is in the context of the safety related changes and the work to choose and quantify them. (author)

  11. Study of the thorium cycle in pressurized water reactors

    International Nuclear Information System (INIS)

    We have been led to consider the PWRs with the present characteristics (reference Bugey 2), an introduction of Th 232-Pu fuel with a view to producing the U 233 in strictly non modified reactors and starting this introduction in 1990 only. Likewise, the Th 232-U 233 cycle in the water reactors would not be launched until the year 2000. The recommended solution consist in starting up the reactor with a Th 232-Pu cycle as from the first core, the plutonium being that which comes from the present PWRs at 33 GWd/t and to abandon during the following cycles the draughtboard loading plans in favour of crown recharging plans. The burnable poisons are no longer necessary and the breakdown of the assembly into several areas with different plutonium levels become pointless. The reactors require much plutonium and only restitute plutonium which is hardly of any worth save in fast reactors. Also, the conversion factor is relatively low; it was retained as such because its improvement would have involved very extensive modifications in the characteristics of the core. Nevertheless this first part of the study showed that there was at least one type of solution to the Th-Pu cycle which complies with the constraints ion the power peak, temperature coefficients, etc. The thorny point concerning the behaviour of the fuel is the temperature coefficient of the moderator. The solution chosen is that which leads to an acceptable temperature coefficient whilst at the same time improving the conversion factor, that is to say the operation in spectrum shift control of the reactor. Having shown the Th 232-Pu and Th 232-U cycles to be feasible, this strategy remained to be compared with other strategies in terms of uranium consumptions

  12. 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.)

  13. FermiGrid

    Energy Technology Data Exchange (ETDEWEB)

    Yocum, D.R.; Berman, E.; Canal, P.; Chadwick, K.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Sharma, N.; Timm, S.; /Fermilab

    2007-05-01

    As one of the founding members of the Open Science Grid Consortium (OSG), Fermilab enables coherent access to its production resources through the Grid infrastructure system called FermiGrid. This system successfully provides for centrally managed grid services, opportunistic resource access, development of OSG Interfaces for Fermilab, and an interface to the Fermilab dCache system. FermiGrid supports virtual organizations (VOs) including high energy physics experiments (USCMS, MINOS, D0, CDF, ILC), astrophysics experiments (SDSS, Auger, DES), biology experiments (GADU, Nanohub) and educational activities.

  14. A reactor study on a belt-shaped screw pinch

    International Nuclear Information System (INIS)

    A previous study on a screw-pinch reactor with circular cross section (ECN-16 (1977) or Rijnhuizen report 77-101) has been extended to a belt configuration which allows to raise β to 0.5. The present study starts from the main assumptions and principal constraints of the previous work, but some technical aspects are treated more realistically. More attention has been paid to the modular construction, the non-uniform distribution of the wall loading, the thermo-hydraulics, the design of and the losses in the coil systems, and the energy storage and electric transmission systems. A potential use of the first wall of the blanket as part of the implosion coil system is suggested. Finally, a conceptual design of a reactor, with a cost estimate is given. Numerical results are given of parameter variations around the values for the reference reactor. The belt screw-pinch reactor with resistive coils turns out to be uneconomical because of its low net efficiency and its high capital costs. The application of superconducting coils to reduce the ohmic losses turns out to be a non-viable alternative. A more promising way to improve the energy balance seems to be the alternative scheme of fuel injection during the burn

  15. Reactor physics studies for a pressure tube supercritical water reactor (PT-SCWR)

    International Nuclear Information System (INIS)

    Preliminary lattice physics and full core neutronic analysis have been performed for the pressure-tube supercritical water reactor (PT-SCWR). Current CANDU reactor physics codes (WIMS-AECL and RFSP) were used for modeling this reactor. A key challenge in the physics design of this reactor is the optimization of lattice parameters to achieve the appropriate balance between coolant void reactivity (CVR) and fuel utilization. A vertically-oriented, batch-fuelled reactor is considered, with an insulated pressure tube to accommodate the high coolant temperatures and pressures. The analysis shows the reactor physics conceptual feasibility of the design, although further optimization is required. (author)

  16. Feasibility study of a pilot scale molten salt reactor demonstration

    International Nuclear Information System (INIS)

    Energy Process Developments Ltd. was awarded a grant by Innovate UK in July 2014 to undertake a year-long project to determine the feasibility of developing a pilot scale molten salt reactor in the UK. The study looked at six current available proposed MSR configurations and proposed the immediate next steps for design and build of a chosen demonstrator reactor project. Tremendous knowledge growth in the 60 years of the first nuclear era has not seen substantial advances in nuclear fission technology much beyond the Pressurised Water Reactor, initially a hastily adopted device for military and civil applications, and essentially comprising water cooling of solid fuel elements. The imminent second nuclear era requires introduction of inherently more efficient, safer, cheaper, nuclear power obtainable with liquid-fuelled - namely Molten Salt Reactor (MSR) technology - the best out of the six Gen IV options. This Gen IV option, when considered in 2002, was believed to be decades away from readiness. This study reviews more recent work. The evidence is that the MSR is ready now. In the immediate urgency of the present, this liquid-fuelled reactor technology can be seen as highly innovative, necessary and rewarding. It is ready to form a key part of any affordable policy proposals for the UK energy supply. This feasibility study is seen as the first step towards full scale implementation of the technology. MSRs are passively safe, operate at atmospheric pressure, at higher efficiencies than PWRs and can be load following. Thorium is the ultimate fuel of choice which can provide the world with a near limitless supply of energy. A demonstration reactor will show the media, public and investors that this technology exists as a clean source of cheap sustainable power. The project reviewed the status of all MSR activity internationally, the regulatory regime in the UK and potential sites. Nuclear insurers were consulted on their insurability and the outlook of an energy

  17. Entrained Flow Reactor Study of KCl Capture by Solid Additives

    OpenAIRE

    Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao; Jappe Frandsen, Flemming; Bøjer, M.; Glarborg, Peter

    2016-01-01

    An option for abating deposition and corrosion caused byalkali species during biomass combustion, is the introduction of additivesinto boilers for transforming harmful gaseous alkali compounds (e.g. KCl,KOH) into less corrosive ash species with a higher melting point. Kaolin andcoal fly ash have been proved to be very promising additives and havereceived extensive studies during the past decades. However, mostprevious studies were carried out in fixed-bed reactors where the reaction condition...

  18. Comparative end-plug study for tandem mirror reactors

    International Nuclear Information System (INIS)

    A comparative evaluation was made of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axicell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axicell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability

  19. Design study of blanket structure for tokamak experimental fusion reactor

    International Nuclear Information System (INIS)

    Design study of the blanket structure for JAERI Experimental Fusion Reactor (JXFR) has been carried out. Studied here were fabrication and testing of the blanket structure (blanket cells, blanket rings, piping and blanket modules), assembly and disassembly of the blanket module, and monitering and testing technique. Problems in design and fabrication of the blanket structure could be revealed. Research and development problems for the future were also disclosed. (author)

  20. Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Heeger, Karsten M. [Yale Univ., New Haven, CT (United States)

    2014-09-13

    This report presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta_{13}$. Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

  1. Conceptual design study of fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    Since 1980 the design study has been conducted at JAERI for the Fusion Experimental Reactor (FER) which has been proposed to be the next machine to JT-60 in the Japanese long term program of fusion reactor development. During two years from 1984 to 1985 FER concept was reviewed and redesigned. This report is the summary of the results obtained in the review and redesign activities in 1984 and 85. In the first year FER concept was discussed again and its frame work was reestablished. According to the new frame work the major reactor components of FER were designed. In the second year the whole plant system design including plant layout plan was conducted as well as the more detailed design analysis of the reactor conponents. The newly established frame for FER design is as follows: 1) Plasma : Self-ignition. 2) Operation scenario : Quasi-steady state operation with long burn pulse. 3) Neutron fluence on the first wall : 0.3 MWY/M2. 4) Blanket : Non-tritium breeding blanket with test modules for breeding blanket development. 5) Magnets : Superconducting Magnets. (author)

  2. More Fermi questions

    Science.gov (United States)

    Bouffard, Karen

    1999-09-01

    "Fermi" questions are a popular component of most Physics Olympics meets. Asking students to make a reasonable assumption about a problem and give answers in terms of order of magnitude is not only a great challenge for a competition, but is also a valued teaching strategy in the classroom.

  3. Fermi Bubbles with HAWC

    CERN Document Server

    Solares, H A Ayala; Hüntemeyer, P

    2015-01-01

    The Fermi Bubbles, which comprise two large and homogeneous regions of spectrally hard gamma-ray emission extending up to $55^{o}$ above and below the Galactic Center, were first noticed in GeV gamma-ray data from the Fermi Telescope in 2010. The mechanism or mechanisms which produce the observed hard spectrum are not understood. Although both hadronic and lep- tonic models can describe the spectrum of the bubbles, the leptonic model can also explain similar structures observed in microwave data from the WMAP and Planck satellites. Recent publications show that the spectrum of the Fermi Bubbles is well described by a power law with an exponential cutoff in the energy range of 100MeV to 500GeV. Observing the Fermi Bubbles at higher gamma-ray energies will help constrain the origin of the bubbles. A steeper cutoff will favor a leptonic model. The High Altitude Water Cherenkov (HAWC) Observatory, located 4100m above sea level in Mexico, is designed to measure high-energy gamma rays between 100GeV to 100TeV. With...

  4. Pressurized water reactor thorium fuel cycle studies

    International Nuclear Information System (INIS)

    The use of a thorium fuel cycle in a PWR is studied. The thorium has no fissile isotope and a fissile nuclide must be added to the thorium fuel. This nuclide can be uranium 235, plutonium 239 or uranium 233. In this work we have kept the fuel assembly geometry and the control rod system of an usual PWR. Cell calculations showed that the moderation ratio of an usual PWR can be used with uranium 235 and plutonium 239 fuels. But this moderation ratio must be decreased and accordingly the pumping power must be increased in the case of a uranium 233 fuel. The three fuels can be controlled with soluble boron. The power distribution inside an assembly agrees with the safety rules and the worth of the control rods is sufficient. To be interesting the thorium fuels must be recycled. Because the activity and the residual power are higher for a thorium fuel than for a uranium fuel the shielding of the shipping casks and storage pools must be increased. The Uranium 235-Thorium fuel is the best even if it needs expensive enrichment work. With this type of fuel more natural uranium is saved. The thorium fuel would become very interesting if we observe again in the future an increase of the uranium cost

  5. Seismic study on high temperature gas-cooled reactor core

    International Nuclear Information System (INIS)

    The resistance against earthquakes of a high temperature gas-cooled reactor (HTGR) core with block-type fuel is not yet fully ascertained. Seismic studies must be made if such a reactor plant is to be installed in the areas with frequent earthquakes. The experimental and analytical studies for the seismic response of the HTGR core were carried out. First, the fundamental behavior, such as the softening characteristic of a single stacked column (which is piled up with blocks) and the hardening characteristic with the block impact were clarified from the seismic experiments. Second, the displacement and the impact characteristics of the two-dimensional vertical core and the two-dimensional horizontal core were studied from the seismic experiments. Finally, analytical methods and computer programs for the seismic response of HTGR cores were developed. (author) 57 refs

  6. Study of luminosity and spin-up relation in X-ray binary pulsars with long-term monitoring by MAXI/GSC and Fermi/GBM

    CERN Document Server

    Sugizaki, Mutsumi; Nakajima, Motoki; Yamaoka, Kazutaka

    2015-01-01

    We study the relation between luminosity and spin-period change in X-ray binary pulsars using long-term light curve obtained by the MAXI/GSC all-sky survey and pulse period data from the Fermi/GBM pulsar project. X-ray binaries, consisting of a highly magnetized neutron star and a stellar companion, originate X-ray emission according to the energy of the accretion matter onto the neutron star. The accretion matter also transfers the angular momentum at the Alfven radius, and then spin up the neutron star. Therefore, the X-ray luminosity and the spin-up rate are supposed to be well correlated. We analyzed the luminosity and period-change relation using the data taken by continuous monitoring of MAXI/GSC and Fermi/GBM for Be/X-ray binaries, GX 304$-$1, A 0535$+$26, GRO J1008$-$57, KS 1947$+$300, and 2S 1417$-$624, which occurred large outbursts in the last four years. We discuss the results comparing the obtained observed relation with that of the theoretical model by Ghosh \\& Lamb (1979).

  7. Fermi surface of MoO2 studied by angle-resolved photoemission spectroscopy, de Haas-van Alphen measurements, and electronic structure calculations

    Science.gov (United States)

    Moosburger-Will, Judith; Kündel, Jörg; Klemm, Matthias; Horn, Siegfried; Hofmann, Philip; Schwingenschlögl, Udo; Eyert, Volker

    2009-03-01

    A comprehensive study of the electronic properties of monoclinic MoO2 from both an experimental and a theoretical point of view is presented. We focus on the investigation of the Fermi body and the band structure using angle-resolved photoemission spectroscopy, de Haas-van Alphen measurements, and electronic structure calculations. For the latter, the full-potential augmented spherical wave method has been applied. Very good agreement between the experimental and theoretical results is found. In particular, all Fermi surface sheets are correctly identified by all three approaches. Previous controversies concerning additional holelike surfaces centered around the Z and B points could be resolved; these surfaces were artifacts of the atomic-sphere approximation used in the old calculations. Our results underline the importance of electronic structure calculations for the understanding of MoO2 and the neighboring rutile-type early transition-metal dioxides. This includes the low-temperature insulating phases of VO2 and NbO2 , which have crystal structures very similar to that of molybdenum dioxide and display the well-known prominent metal-insulator transitions.

  8. Reactor core conversion studies of Ghana: Research Reactor-1 and proposal for addition of safety rod

    International Nuclear Information System (INIS)

    The inclusion of an additional safety rod in conjunction with a core conversion study of Ghana Research Reactor-1 (GHARR-1) was carried out using neutronics, thermal hydraulics and burnup codes. The study is based on a recommendation by Integrated Safety Assessment for Research Reactors (INSARP) mission to incorporate a safety rod to the reactor safety system as well as the need to replace the reactor fuel with LEU. Conversion from one fuel type to another requires a complete re-evaluation of the safety analysis. Changes to the reactivity worth, shutdown margin, power density and material properties must be taken into account, and appropriate modifications made. Neutronics analysis including burnup was studied followed by thermal hydraulics analyses which comprise steady state and transients. Four computer codes were used for the analysis; MCNP, REBUS, PLTEP and PARET. The neutronics analysis revealed that the LEU core must be operated at 34 Kw in order to attain the flux of 1.0E12 n/cm2.s as the nominal flux of the HEU core. The auxiliary safety rod placed at a modified irradiation site gives a better worth than the cadmium capsules. For core excess reactivity of 4 mk, 348 fuel pins would be appropriate for the GHARR-1 LEU core. Results indicate that flux level of 1.0E12 n/cm2.s in the inner irradiation channel will not be compromised, if the power of the LEU core is increased to 34 kW. The GHARR-1 core using LEU-U02-12.5% fuel can be operated for 23 shim cycles, with cycles length 2.5 years, for over 57 years at the 17 kW power level. All 23 LEU cycles meet the ∼ 4.0 mk excess reactivity required at the beginning of cycle . For comparison, the MNSR HEU reference core can also be operated for 23 shim cycles, but with a cycle length of 2.0 years for just over 46 years at 15.0kW power level. It is observed that the GHARR-1 core with LEU UO2 fuel enriched to 12.5% and a power level of 34 kW can be operated ∼25% longer than the current HEU core operated at 30 k

  9. Fish distribution studies near N Reactor, Summer 1983

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Page, T.L.

    1984-06-01

    This report summarizes field studies that were initiated in July 1983 to provide estimates of the relative distribution of late-summer outmigrant juvenile salmonids and juvenile resident fish upstream of the N Reactor 009 Outfall. Chinook salmon are among the fish species most sensitive to thermal effects, and impacts to the juvenile outmigrant populations are of particular concern to state and federal regulatory and fisheries management agencies. Therefore, the distribution studies were conducted from late July through September, a period when high ambient river temperatures and low river flows make these salmonid populations most susceptible to thermal effects. In addition, data were not available on the spatial distribution of outmigrant juvenile chinook salmon in late summer. Information on the relative distribution of resident fish populations was also gathered. Previous studies of midstream distribution of juvenile resident fish were limited to a description of ichthyoplankton populations (Beak Consultants, Inc. 1980 Page et al. 1982), and no data were available on vertical or horizontal distribution of juvenile resident fish species near N Reactor. Relative densities and spatial distribution estimates of juvenile salmonid and resident fish species will be used in conjunction with laboratory thermal effects studies (Neitzel et al. 1984) and with plume characterization studies (Ecker et al. 1983) to assess potential impacts of thermal discharge on fish populations near N Reactor.

  10. Studies on fuel failure detection in Rikkyo Research Reactor

    International Nuclear Information System (INIS)

    Rikkyo Research Reactor, TRIGA Mark II, the maximum power output of which is 100 kW, has been operated since December 1961 and has experienced the integral output of 2,028.469 kWh (85.5 MWD) as of the end of January 1988. The cylindrical-shaped fuel elements are made of a UZrH alloy using 8 percent by weight (wt-%) uranium (20% enriched), 91 wt-% zirconium, and 1 wt-% hydrogen, and they are cladded with aluminum of 0.76 mm thickness. The total inventory of 235U in the core is ca. 2.3 kg, and the number of fuel elements inserted in the core at present is 67. Almost all of these fuel elements have been in the pure water as the primary coolant (the volume is ca. 20 tons) in the reactor tank for these 26 years, and none of them have been taken out as spent fuel from the reactor tank. Thus the total burn-up degree is about 3.7%, in other words, the average burn-up degree per one fuel element is about 1.3 MWD. Considering the fact that the fuel failure in TRIGA reactors occurred almost only for pulsing reactors while our reactor has experienced no pulse operation and the average burn-up degree per fuel element is still low, we do not have so much fear that a serious trouble for our fuel elements might happen in very near future. However, in order to keep the wholesomeness of this reactor as long as possible, it seems quite pertinent to have a good supervision on the status of the possible leakage of FP from our fuel elements. In one sense, our aluminum-clad fuel elements which have been used in water as long as more than 26 years may be a useful tool for establishing an effective method of detecting the leakage of FP and rapidly finding the location of the defective fuel. Thus we have recently begun to undertake this studies in various approaches. In this paper is stated mainly the recent data since a preliminary report was made in November 1986. (author)

  11. Treatment Method for Fermi Barrel Sodium Metal Residues

    International Nuclear Information System (INIS)

    Fermi barrels are 55-gallon drums that once contained bulk sodium metal from the shutdown Fermi 1 breeder reactor facility, and now contain residual sodium metal and other sodium/air reaction products. This report provides a residual sodium treatment method and proposed quality assurance steps that will ensure that all residual sodium is deactivated and removed from the Fermi barrels before disposal. The treatment method is the application of humidified carbon dioxide to the residual sodium followed by a water wash. The experimental application of the treatment method to six Fermi barrels is discussed, and recommendations are provided for further testing and evaluation of the method. Though more testing would allow for a greater refinement of the treatment technique, enough data has been gathered from the tests already performed to prove that 100% compliance with stated waste criteria can be achieved

  12. Neutronic study regarding transmutation fuel research at Jules Horowitz Reactor

    International Nuclear Information System (INIS)

    In order to estimate the possibilities for transmutation experiments at the Jules Horowitz Reactor several ideas for neutronic and fuel behaviour studies are investigated at CEA Cadarache. Naturally an exact replication of the burning of minor actinides in fast reactors, as expected in most transmutation scenarios, is impossible, but some key transmutation parameters can be investigated in a MTR neutron spectrum. In this paper a parametric study regarding fuel damage by He and fission products in AmUO2 is presented. By varying flux level, uranium enrichment and americium content of the sample in the JHR reflector a He production to fission ratio comparable to reference samples in the core of a SFR can be achieved. The calculations were done with the depletion code DARWIN2.2 using JEF2.2 data and spectra from a TRIPOLI model of JHR and an ERANOS model for the SFR respectively. (author)

  13. Fast-mixed spectrum reactor interim report initial feasibility study

    International Nuclear Information System (INIS)

    The report summarizes the results of an initial four-month feasibility study of the Fast-Mixed Spectrum Reactor (FMSR). Reactor physics, fuel cycle, and thermal-hydraulic analyses were performed on a reference design. These results when coupled to a fuel and materials evaluation performed in cooperation with the Argonne National Laboratory indicate that the FMSR is feasible provided the fuels, cladding, and subassembly ducts can survive a peak fuel burnup of 15 to 20 atom percent heavy metal and peak fluences of 8 x 1023 (nvt > 0.1 MeV). The results of this short study have also provided a basis for exploring alternative designs requiring significantly lower peak burnup and fluences for their operation

  14. Test reactor studies of the shadow corrosion phenomenon

    International Nuclear Information System (INIS)

    The shadow effect, resulting in enhanced corrosion on zirconium-base alloys in proximity to other metal, has been observed since the 1960's. In 1997, hot-cell examinations revealed thick oxide layers on fuel cladding surfaces that during irradiation had been located in the shadow of Inconel spacer grids. The acronym ESSC (Enhanced spacer shadow corrosion) was used to describe the phenomenon. Following the observation of ESSC, several investigations were initiated to develop an explanation of the shadow corrosion phenomenon. In this paper, results are presented and compared from in-reactor experiments performed in three different test reactors, the R2 reactor in Studsvik, the MITR-II reactor at MIT, and the Halden test reactor. The first study, performed in Studsvik, was initiated to assess the feasibility of studying the shadow corrosion phenomenon during relatively short irradiation periods in a test reactor. The results clearly showed that a shadow was formed on Zircaloy cladding in contact with Inconel within 34 days of exposure in the center of the core, while no shadow was observed on specimens situated outside and upstream from the core. The test at MIT was initiated to identify the basic mechanisms of the shadow effect. The MIT research reactor MITR-II was used to simulate BWR core coolant conditions. A sample train included Zircaloy-2 claddings with different counter materials surrounding each clad specimen. The counter materials were intended to serve as the materials tentatively producing shadow corrosion. when located in close proximity to the clad specimens. The counter materials chosen were strong or weak beta emitters, platinum, inert material (zirconia), Inconel X-750, coated Inconel X-750, and Zircaloy-2 at various separation distances. The results showed that beta radiation from the counter material is not the main mechanism for the shadow effect, that a coating on the counter material inhibits the formation of shadow corrosion, and that shadow

  15. Test reactor studies of the shadow corrosion phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, B.; Limback, M. [Westinghouse Atom AB, Vasteras (Sweden); Wikmark, G. [Advanced Nuclear Technology Swede AB, Uppsala (Sweden); Hauso, E.; Johnsen, T. [Institut fur Energiteknikk, Halden (Norway); Ballinger, R.G. [Massachusetts Institute of Technology, Cambridge, Ma (United States); Nystrand, A.C. [Studsvik Nuclear AB, Nykiping (Sweden)

    2002-07-01

    The shadow effect, resulting in enhanced corrosion on zirconium-base alloys in proximity to other metal, has been observed since the 1960's. In 1997, hot-cell examinations revealed thick oxide layers on fuel cladding surfaces that during irradiation had been located in the shadow of Inconel spacer grids. The acronym ESSC (Enhanced spacer shadow corrosion) was used to describe the phenomenon. Following the observation of ESSC, several investigations were initiated to develop an explanation of the shadow corrosion phenomenon. In this paper, results are presented and compared from in-reactor experiments performed in three different test reactors, the R2 reactor in Studsvik, the MITR-II reactor at MIT, and the Halden test reactor. The first study, performed in Studsvik, was initiated to assess the feasibility of studying the shadow corrosion phenomenon during relatively short irradiation periods in a test reactor. The results clearly showed that a shadow was formed on Zircaloy cladding in contact with Inconel within 34 days of exposure in the center of the core, while no shadow was observed on specimens situated outside and upstream from the core. The test at MIT was initiated to identify the basic mechanisms of the shadow effect. The MIT research reactor MITR-II was used to simulate BWR core coolant conditions. A sample train included Zircaloy-2 claddings with different counter materials surrounding each clad specimen. The counter materials were intended to serve as the materials tentatively producing shadow corrosion. when located in close proximity to the clad specimens. The counter materials chosen were strong or weak beta emitters, platinum, inert material (zirconia), Inconel X-750, coated Inconel X-750, and Zircaloy-2 at various separation distances. The results showed that beta radiation from the counter material is not the main mechanism for the shadow effect, that a coating on the counter material inhibits the formation of shadow corrosion, and that

  16. Numerical study of the effects of lamp configuration and reactor wall roughness in an open channel water disinfection UV reactor.

    Science.gov (United States)

    Sultan, Tipu

    2016-07-01

    This article describes the assessment of a numerical procedure used to determine the UV lamp configuration and surface roughness effects on an open channel water disinfection UV reactor. The performance of the open channel water disinfection UV reactor was numerically analyzed on the basis of the performance indictor reduction equivalent dose (RED). The RED values were calculated as a function of the Reynolds number to monitor the performance. The flow through the open channel UV reactor was modelled using a k-ε model with scalable wall function, a discrete ordinate (DO) model for fluence rate calculation, a volume of fluid (VOF) model to locate the unknown free surface, a discrete phase model (DPM) to track the pathogen transport, and a modified law of the wall to incorporate the reactor wall roughness effects. The performance analysis was carried out using commercial CFD software (ANSYS Fluent 15.0). Four case studies were analyzed based on open channel UV reactor type (horizontal and vertical) and lamp configuration (parallel and staggered). The results show that lamp configuration can play an important role in the performance of an open channel water disinfection UV reactor. The effects of the reactor wall roughness were Reynolds number dependent. The proposed methodology is useful for performance optimization of an open channel water disinfection UV reactor. PMID:27108375

  17. Experimental study of the IPR-R1 TRIGA reactor power channels responses

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Henrique F.A.; Ferreira, Andrea V., E-mail: hfam@cdtn.br, E-mail: avf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    The IPR-R1 nuclear reactor installed at Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil, is a Mark I TRIGA reactor (Training, Research, Isotopes, General Atomics) and became operational on November of 1960. The reactor has four irradiation devices: a rotary specimen rack with 40 irradiation channels, the central tube, and two pneumatic transfer tubes. The nuclear reactor is operated in a power range between zero and 100 kW. The instrumentation for IPR-R1 operation is mainly composed of four neutronic channels for power measurements. The aim of this work is to investigate the responses of neutronic channels of IPR-R1, Linear, Log N and Percent Power channels, and to check their linearity. Gold foils were activated at low powers (0.125-1.000 kW), and cobalt foils were activated at high powers (10-100kW). For each sample irradiated at rotary specimen rack, another one was irradiated at the same time at the pneumatic transfer tube-2. The obtained results allowed evaluating the linearity of the neutronic channels responses. (author)

  18. Centro de Estudos e Pesquisa em Enfermagem (CEPEn: uma trajetória de 36 anos Centro de Estudios y Investigación en Enfermería (CEPn: una trayectoria de 36 años Center of Studies and Research in Nursing (CEPEn: a trajectory of 36 years

    Directory of Open Access Journals (Sweden)

    Josete Luzia Leite

    2007-12-01

    Full Text Available O presente estudo trata dos destaques da trajetória do Centro de Estudos e Pesquisa em Enfermagem (CEPEn da Associação Brasileira de Enfermagem no recorte temporal de 1971 a 2007. Estudo de cunho histórico social no qual utilizou-se o Catálogo Informações sobre Pesquisas e Pesquisadores em Enfermagem e os Relatórios dos Seminários Nacionais de Pesquisa em Enfermagem (SENPE. Os objetivos foram resgatar a trajetória do CEPEn e apresentar um dos eventos de maior importância para a Enfermagem Brasileira. A preocupação com o futuro e a necessidade de fortalecimento e enriquecimento, tanto dos docentes quanto dos profissionais do campo assistencial, é uma marca dos dias atuais e se coloca como desafio a ser enfrentado no presente.El presente estudio trata de los realces de la trayectoria del Centro de Estudios y Investigación en Enfermería (CEPEn de la Asociación Brasileña de Enfermería en el periodo de 1971 al 2007. Es un estudio histórico el lo cual se utilizó el Catalogo de Informaciones sobre Investigaciones y Investigadores y los reportes de los Seminarios Nacionales de Investigación en Enfermería. Los objetivos fueran rescatar la trayectoria del CEPEn y presentar uno de los eventos de más importancia para la Enfermería Brasileña. La preocupación con el futuro y la necesidad de fortalecimiento y enriquecimiento, tanto de los profesores como de los profesionales del campo asistencial es una marca de los días actuales y se pone como un desafío a ser enfrentado en la actualidad.The study presents some trajectory highlights of the Center of Studies and Research in Nursing of the Brazilian Nursing Association, considering the period from 1971 to 2007. This is a historical study based on the Information Catalog of Research and Researchers in Nursing and the reports of the National Seminars of Nursing Research. The objectives were to rescue the contribution of CEPEn and to present one of the most important events for

  19. Conceptual design study of fusion experimental reactor (FY86FER)

    International Nuclear Information System (INIS)

    This report describes the results of applicability studies for the negative ion-based neutral beam injector to the Fusion Experimental Reactor (FER). The operation scenario of FER has been proposed to adopt the neutral injection method as one of candidates, which has three functions of heating, current drive and profile control. One of the fundamental requirements is the tangential injection of the neutral beam. For neutral beam injectors, three port sections are available. Supposing to adopt the beam line with the straight long neutralizer which has been designed in JAERI, the geometrical arrangement was determined so as to avoid any trouble to the reactor structure. The conceptual study for major components which compose the beam line system was carried out including the estimation of the neutron streaming. The power supply system was studied also and the work was concentrated on the acceleration power supply which requires the output voltage of 500 kV and fast cut-off time. A basic concept, in which a inverter with a AC switch is used and the frequency of the supplied AC line is increased was proposed. In these works, the configuration of the neutral beam injection system was detailed and it was shown that the beam line seems to be well implemented with the geometrical constraints related to the reactor configuration. (author)

  20. Experimental studies on catalytic hydrogen recombiners for light water reactors

    International Nuclear Information System (INIS)

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  1. Synthetic study of reactor irradiation for medical use

    International Nuclear Information System (INIS)

    This report is described on the results of the study on the reactor irradiation for medical use shared by the Nuclear Engineering Research Laboratory, Faculty of Engineering, University of Tokyo, and other seventeen facilities. Boron neutron-capturing therapy developed in Japan is extremely significant treating method for tumors by destroying tumor cells of encephaloma, etc. selectively. This is the synthetic study for promoting the above therapeutic method. Two existing reactors were reconstructed into the thermal neutron reactors for boron neutron-capturing therapy. The various preparatory and physical researches were made with the reconstruction, and the therapy was tried on eleven cases. Further experiments were made on the following points: (1) To promote treatment on encephaloma by boron neutron-capturing therapy. (2) To develop its application to malignant tumors other than encephaloma. (3) Animal irradiation experiments. (4) The basic experiments on the cellular level. (5) The study of remote controlled anesthesia. (6) To control irradiated dose. (7) To improve boron compounds. (8) To condense radioisotopes. (Kobatake, H.)

  2. Lagrangian Approach to Study Catalytic Fluidized Bed Reactors

    Science.gov (United States)

    Madi, Hossein; Hossein Madi Team; Marcelo Kaufman Rechulski Collaboration; Christian Ludwig Collaboration; Tilman Schildhauer Collaboration

    2013-03-01

    Lagrangian approach of fluidized bed reactors is a method, which simulates the movement of catalyst particles (caused by the fluidization) by changing the gas composition around them. Application of such an investigation is in the analysis of the state of catalysts and surface reactions under quasi-operando conditions. The hydrodynamics of catalyst particles within a fluidized bed reactor was studied to improve a Lagrangian approach. A fluidized bed methanation employed in the production of Synthetic Natural Gas from wood was chosen as the case study. The Lagrangian perspective was modified and improved to include different particle circulation patterns, which were investigated through this study. Experiments were designed to evaluate the concepts of the model. The results indicate that the setup is able to perform the designed experiments and a good agreement between the simulation and the experimental results were observed. It has been shown that fluidized bed reactors, as opposed to fixed beds, can be used to avoid the deactivation of the methanation catalyst due to carbon deposits. Carbon deposition on the catalysts tested with the Lagrangian approach was investigated by temperature programmed oxidation (TPO) analysis of ex-situ catalyst samples. This investigation was done to identify the effects of particles velocity and their circulation patterns on the amount and type of deposited carbon on the catalyst surface. Ecole Polytechnique Federale de Lausanne(EPFL), Paul Scherrer Institute (PSI)

  3. Inertial Fusion Energy reactor design studies: Prometheus-L, Prometheus-H

    International Nuclear Information System (INIS)

    This report contains a review of design studies for inertial confinement reactors. The first of three volumes briefly discusses the following: Introduction; Key objectives, requirements, and assumptions; Systems modeling and trade studies; Prometheus-L reactor plant design overview; Prometheus-H reactor plant design overview; Key technical issues and R ampersand D requirements; Comparison of IFE designs; and study conclusions

  4. Inertial Fusion Energy reactor design studies: Prometheus-L, Prometheus-H. Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Waganer, L.M.; Driemeyer, D.E.; Lee, V.D.

    1992-03-01

    This report contains a review of design studies for inertial confinement reactors. The first of three volumes briefly discusses the following: Introduction; Key objectives, requirements, and assumptions; Systems modeling and trade studies; Prometheus-L reactor plant design overview; Prometheus-H reactor plant design overview; Key technical issues and R&D requirements; Comparison of IFE designs; and study conclusions.

  5. Feasibility study on commercialized fast reactor cycle systems technical study report of phase II. (1) Fast reactor plant systems

    International Nuclear Information System (INIS)

    A joint project team of Japan Atomic Energy Agency and the Japan Atomic Power Company (as the representative of the electric utilities) has started the feasibility study on commercialized fast reactor cycle systems (F/S) in July 1999 in cooperation with Central Research Institute of Electric Power Industry, vendors and universities. On the major premise of safety assurance, F/S aims to present an appropriate picture of commercialization of fast reactor (FR) cycle system which has economic competitiveness with light water reactor cycle systems and other electricity base load systems, and to establish FR cycle technologies for the future major energy supply. In the period from Japanese fiscal year (JFY) 1999 to 2000, the phase-I of F/S was carried out to screen out representative FR, reprocessing and fuel fabrication technologies. In the phase-II (JFY 2001-2005), the design study of FR cycle concepts, the development of significant technologies necessary for the feasibility evaluation, and the confirmation of key technical issues were performed to clarify the promising candidate concepts toward the commercialization. In this final phase-II report clarified the most promising concept, the R and D plan until around 2015, and the key issues for the commercialization. The summary of results are as follows; Sodium cooled reactor is evaluated as most compatible to the F/S design requirement. In the conceptual design study, several innovative technologies are proposed in order to increase safety, economic performance, and integrity. Researches and developments on these technologies are also carried out and technical feasibilities are indicated. Alternative technologies are also prepared to decrease the development risk of innovative technologies. Sodium cooled reactor is generally most promising concept for the commercialization of FR cycle. Lead-bismuth-cooled FBR is evaluated to have a potential compatible to the F/S design requirement. But it is indicated that a

  6. Experimental study of fluidic mixing in a cylindrical reactor

    Energy Technology Data Exchange (ETDEWEB)

    Orfaniotis, A.; Fonade, C.; Lalane, M.; Doubrovine, N. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)

    1996-04-01

    Fluidic mixing in a cylindrical reactor was studied in an effort to determine the effect of jet disposition and the viscosity of the liquid. The tests were carried out in a a tank using conductimetric probes to measure the mixing time. Results indicated that relative jet positions leading to an impinging flow structure were less efficient than shear flow configurations. When these results were compared with results of earlier work by Simon and Fonade (1993) it was found that they were consistent with the exponent 2/3 obtained by them in experiments with turbulent jets. It was pointed out that these mixing times apply only to mixing in cylindrical reactors. With different geometries, such as basins and lagoons with small liquid depths, a new choice of the reference length included in the expression of the reference time will be needed. 10 refs., 3 tabs., 16 figs.

  7. Study on core design for reduced-moderation water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, Tsutomu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-12-01

    The Reduced-Moderation Water Reactor (RMWR) is a water-cooled reactor with the harder neutron spectrum comparing with the LWR, resulting from low neutron moderation due to reduced water volume fraction. Based on the difference from the spectrum from the LWR, the conversion from U-238 to Pu-239 is promoted and the new cores preferable to effective utilization of uranium resource can be possible Design study of the RMWR core started in 1997 and new four core concepts (three BWR cores and one PWR core) are recently evaluated in terms of control rod worths, plutonium multiple recycle, high burnup and void coefficient. Comparative evaluations show needed incorporation of control rod programming and simplified PUREX process as well as development of new fuel cans for high burnup of 100 GW-d/t. Final choice of design specifications will be made at the next step aiming at realization of the RMWR. (T. Tanaka)

  8. Physics-magnetics trade studies for tandem mirror reactors

    International Nuclear Information System (INIS)

    We describe and present results obtained from the optimization package of the Tandem Mirror Reactor Systems Code. We have found it to be very useful in searching through multidimensional parameter space, and have applied it here to study the effect of choke coil field strength and net electric power on cost of electricity (COE) and mass utilization factor (MUF) for MINIMARS type reactors. We have found that a broad optimum occurs at B/sub choke/ = 26 T for both COE and MUF. The COE economy of scale approaches saturation at quite low powers, around 600 MW(e). The saturation is mainly due to longer construction times for large plants, and the associated time related costs. The MUF economy of scale does not saturate, at least for powers up to 2400 MW(e)

  9. Systems study of tokamak fusion--fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Tenney, F.H.; Bathke, C.G.; Price, W.G. Jr.; Bohlke, W.H.; Mills, R.G.; Johnson, E.F.; Todd, A.M.M.; Buchanan, C.H.; Gralnick, S.L.

    1978-11-01

    This publication reports the results of a two to three year effort at a systematic analysis of a wide variety of tokamak-driven fissioning blanket reactors, i.e., fusion--fission hybrids. It addresses the quantitative problems of determining the economically most desirable mix of the two products: electric power and fissionable fuel and shows how the price of electric power can be minimized when subject to a variety of constraints. An attempt has been made to avoid restricting assumptions, and the result is an optimizing algorithm that operates in a six-dimensional parameter space. Comparisons are made on sets of as many as 100,000 distinct machine models, and the principal results of the study have been derived from the examination of several hundred thousand possible reactor configurations.

  10. A 600 MW(e) reversed field pinch reactor study

    International Nuclear Information System (INIS)

    The Reversed Field Pinch is an axisymmetric toroidal magnetic system in which the stable confinement of high β plasma has already been demonstrated experimentally. This study has reviewed the plasma physics relevant to a reactor based on the Reversed Field Pinch, defined a possible set of reactor parameters and undertaken a preliminary consideration of the mechanical and electrical engineering problems of this system. The design assumes pulsed operation without refuelling during the burn, ignition by ohmic heating alone, and the use of normal (i.e. not superconducting) magnetic field windings. For the chosen net output of 600 MW(e) and mean neutron wall loading of 1.5MW/m2 the plasma minor and major radii are 1.75m and 16m respectively. The energy multiplication factor Q of the system is 5.9. (author)

  11. Systems study of tokamak fusion--fission reactors

    International Nuclear Information System (INIS)

    This publication reports the results of a two to three year effort at a systematic analysis of a wide variety of tokamak-driven fissioning blanket reactors, i.e., fusion--fission hybrids. It addresses the quantitative problems of determining the economically most desirable mix of the two products: electric power and fissionable fuel and shows how the price of electric power can be minimized when subject to a variety of constraints. An attempt has been made to avoid restricting assumptions, and the result is an optimizing algorithm that operates in a six-dimensional parameter space. Comparisons are made on sets of as many as 100,000 distinct machine models, and the principal results of the study have been derived from the examination of several hundred thousand possible reactor configurations

  12. Rebuilding the Brookhaven high flux beam reactor: A feasibility study

    International Nuclear Information System (INIS)

    After nearly thirty years of operation, Brookhaven's High Flux Beam Reactor (HFBR) is still one of the world's premier steady-state neutron sources. A major center for condensed matter studies, it currently supports fifteen separate beamlines conducting research in fields as diverse as crystallography, solid-state, nuclear and surface physics, polymer physics and structural biology and will very likely be able to do so for perhaps another decade. But beyond that point the HFBR will be running on borrowed time. Unless appropriate remedial action is taken, progressive radiation-induced embrittlement problems will eventually shut it down. Recognizing the HFBR's value as a national scientific resource, members of the Laboratory's scientific and reactor operations staffs began earlier this year to consider what could be done both to extend its useful life and to assure that it continues to provide state-of-the-art research facilities for the scientific community. This report summarizes the findings of that study. It addresses two basic issues: (i) identification and replacement of lifetime-limiting components and (ii) modifications and additions that could expand and enhance the reactor's research capabilities

  13. Exposure mode study to xenon-133 in a reactor building

    International Nuclear Information System (INIS)

    The work described in this thesis focuses on the external and internal dose assessment to xenon-133. During the nuclear reactor operation, fission products and radioactive inert gases, as 133Xe, are generated and might be responsible for the exposure of workers in case of clad defect. Particle Monte Carlo transport code is adapted in radioprotection to quantify dosimetric quantities. The study of exposure to xenon-133 is conducted by using Monte-Carlo simulations based on GEANT4, an anthropomorphic phantom, a realistic geometry of the reactor building, and compartmental models. The external exposure inside a reactor building is conducted with a realistic and conservative exposure scenario. The effective dose rate and the eye lens equivalent dose rate are determined by Monte-Carlo simulations. Due to the particular emission spectrum of xenon-133, the equivalent dose rate to the lens of eyes is discussed in the light of expected new eye dose limits. The internal exposure occurs while xenon-133 is inhaled. The lungs are firstly exposed by inhalation, and their equivalent dose rate is obtained by Monte-Carlo simulations. A biokinetic model is used to evaluate the internal exposure to xenon-133. This thesis gives us a better understanding to the dosimetric quantities related to external and internal exposure to xenon-133. Moreover the impacts of the dosimetric changes are studied on the current and future dosimetric limits. The dosimetric quantities are lower than the current and future dosimetric limits. (author)

  14. Study of trans-uranian incineration in molten salt reactor

    International Nuclear Information System (INIS)

    With the emergence of new options for nuclear power, molten salt reactors are envisaged for waste management. The aim of this thesis is to show how molten salt reactors can help to solve the transuranics issue. Their high versatility regarding to isotopic vector allows to accommodate large fractions of minor actinides as compared to solid fuel system. In this thesis, a neutronics study of molten salt reactors, MSR, has been conducted. For this purpose, two reference systems were considered, TIER1 and AMSTER. In the case of TIER1, an optimisation was made to reach an equilibrium. The analysis of both systems showed the main characteristics of MSR: their link to chemistry and on line reprocessing. In this work, several methods to drive the system to a state of equilibrium have been implemented and compared. During this process the isotopic composition and neutron spectrum, thus the nuclear reaction cross sections, vary tremendously. It is essential to take these evolutions into account in order to accurately estimate the equilibrium state. This has been accomplished inside the multi-recycling procedure we set with ERANOS. A dedicated calculation schema has been realized to simulate superthermal systems with this computation code. These results were checked through a benchmark against other computer codes. Then, with multi-recycling method, several molten salt systems have been compared in order to define the optimal reactor for transuranics incineration. Nevertheless, a final choice can not only be done using only neutronics characteristics since chemistry and thermal-hydraulics constraints are really important for MSR. Moreover, a complete safety study would be required. (author)

  15. Studying the SGR 1806-20/Cl* 1806-20 region using the \\emph{Fermi} Large Area Telescope

    CERN Document Server

    Yeung, Paul K H; Tam, P H Thomas; Lin, Lupin C C; Hui, C Y; Hu, Chin-Ping; Cheng, K S

    2016-01-01

    The region around SGR 1806-20 and its host stellar cluster Cl* 1806-20 is a potentially important site of particle acceleration. The soft $\\gamma-$ray repeater and Cl* 1806-20, which also contains several very massive stars including a luminous blue variable hypergiant LBV 1806-20, are capable of depositing a large amount of energy to the surroundings. Using the data taken with the \\emph{Fermi} Large Area Telescope (LAT), we identified an extended LAT source to the south-west of Cl* 1806-20. The centroid of the 1-50~GeV emission is consistent with that of HESS J1808-204 (until now unidentified). The LAT spectrum is best-fit by a broken power-law with the break energy $E_\\mathrm{b}=297\\pm15$ MeV. The index above $E_\\mathrm{b}$ is $2.60\\pm0.04$, and is consistent with the flux and spectral index above 100 GeV for HESS J1808-204, suggesting an association between the two sources. Meanwhile, the interacting supernova remnant SNR G9.7-0.0 is also a potential contributor to the LAT flux. A tentative flux enhancemen...

  16. Conformal Fermi Coordinates

    CERN Document Server

    Dai, Liang; Schmidt, Fabian

    2015-01-01

    Fermi Normal Coordinates (FNC) are a useful frame for isolating the locally observable, physical effects of a long-wavelength spacetime perturbation. Their cosmological application, however, is hampered by the fact that they are only valid on scales much smaller than the horizon. We introduce a generalization that we call Conformal Fermi Coordinates (CFC). CFC preserve all the advantages of FNC, but in addition are valid outside the horizon. They allow us to calculate the coupling of long- and short-wavelength modes on all scales larger than the sound horizon of the cosmological fluid, starting from the epoch of inflation until today, by removing the complications of the second order Einstein equations to a large extent, and eliminating all gauge ambiguities. As an application, we present a calculation of the effect of long-wavelength tensor modes on small scale density fluctuations. We recover previous results, but clarify the physical content of the individual contributions in terms of locally measurable ef...

  17. Leaky Fermi accelerators

    CERN Document Server

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  18. The study meeting report on the undermoderated spectrum reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Nobuya; Ochiai, Masaaki [eds.

    1998-09-01

    The interest to the high converter or in the breeder is rising as the research and the development of the light water-type nuclear reactor in future. A study session about the undermoderated spectrum reactor of the Japan Atomic Energy Research Institute (JAERI) sponsorship was held in March, 1998 4, on the 5th. This report is the contents of the study session. The study session began with the basis lecture to entitle to be `The expectations to the undermoderated core study` almost. Next, the review of the high conversion-type core study about PWR and BWR was reported. As the undermoderated spectrum MOX core study, the latest situation of (1) the development of the supercritical pressure water reactor, (2) the development of RBWR, (3) the development of the advanced fuel cycle by BWR and (4) the development of the pressurized water-type breeder were reported from the university and the maker. As also the study present situation and the plan in future in JAERI, there was an explanation about the design study of the undermoderated spectrum core and the actinide research facility. The panel discussion lastly, to entitle to be `Undermoderated MOX core research and development of the future and the technical issues` was done. There was an opinion about the way of carrying forward concerned research and development, the acceptability of the society, the view of the future, the cooperation of the electric power or the desire to JAERI and there was wide inquiry replying. The 9 of the presented papers are indexed individually. (J.P.N.)

  19. Numerical study of the effects of surface roughness on water disinfection UV reactor.

    Science.gov (United States)

    Sultan, Tipu; Ahmad, Sarfraz; Cho, Jinsoo

    2016-04-01

    UV reactors are an emerging choice as a big barrier against the pathogens present in drinking water. However, the precise role of reactor's wall roughness for cross flow ultraviolet (CF-UV) and axial flow ultraviolet (AF-UV) water disinfection reactors are unknown. In this paper, the influences of reactor's wall roughness were investigated with a view to identify their role on the performance factors namely dose distribution and reduction equivalent dose (RED). Herein, the relative effects of reactor's wall roughness on the performance of CF-UV and AF-UV reactors were also highlighted. This numerical study is a first step towards the comprehensive analysis of the effects of reactor's wall roughness for UV reactor. A numerical analysis was performed using ANSYS Fluent 15 academic version. The reactor's wall roughness has a significant effect on the RED. We found that the increase in RED is Reynolds number dependent (at lower value of turbulent Reynolds number the effects are remarkable). The effects of reactor's roughness were more pronounced for AF-UV reactor. The simulation results suggest that the study of reactor's wall roughness provides valuable insight to fully understand the effects of reactor's wall roughness and its impact on the flow behavior and other features of CF-UV and AF-UV water disinfection reactors. PMID:26802269

  20. Fermi surface of niobium

    International Nuclear Information System (INIS)

    The Fermi surface of niobium has been investigated using the de Haas-van Alphen effect. Data were taken at temperatures as low as .3 K and in fields as high as 130 kG. An on-line minicomputer was used to Fourier transform the digitized signals. Many new extremal area data have been obtained including oscillations associated with the previously unobserved Gamma-centered hole octahedron and Gamma and N centered orbits on the so called jungle gym. An additional set of signals has been observed near [100] which are thought to be a result of magnetic breakdown between the second zone octahedron and third zone jungle gym. A separate low frequency signal was observed and is believed to be a result of magnetic breakdown induced quantum interference oscillations. Anisotropies of the cyclotron effective mass have been determined for many orbits on all three of the Fermi surface sheets. Finally, the area data has been used to parametrize the Fermi surface in terms of scattering phase shifts in a KKR band structure formalism

  1. Neutronics Study of the KANUTER Space Propulsion Reactor

    International Nuclear Information System (INIS)

    The Korea Advanced Nuclear Thermal Engine Rocket (KANUTER) has been developed at the Korea Advanced Institute of Science and Technology (KAIST). This space propulsion system is unique in that it implements a HEU fuel with a thermal spectrum system. This allows the system to be designed with a minimal amount of fissile material and an incredibly small and light system. This then allows the implementation of the system in a cluster format which enables redundancy and easy scalability for different mission requirements. This combination of low fissile content, compact size, and thermalized spectrum contribute to an interesting and novel behavior of the reactor system. The two codes were both used for the burn up calculations in order to verify their validity while the static calculations and characterization of the core were done principally with MCNPX. The KANUTER space propulsion reactor is in the process of being characterized and improved. Its basic neutronic characteristics have been studied, and its behavior over time has been identified. It has been shown that this reactor will have difficulty operating as hoped in a bimodal configuration where it is able to provide both propulsion and power throughout mission to Mars. The reason for this has been identified as Xe135, and it is believed that a possible solution to this issue does exist, either in the form of an appropriately designed neutron spectrum or the building in of sufficient excess reactivity

  2. Neutronics Study of the KANUTER Space Propulsion Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Venneri, Paolo; Nam, Seung Hyun; Kim, Yonghee [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea Advanced Nuclear Thermal Engine Rocket (KANUTER) has been developed at the Korea Advanced Institute of Science and Technology (KAIST). This space propulsion system is unique in that it implements a HEU fuel with a thermal spectrum system. This allows the system to be designed with a minimal amount of fissile material and an incredibly small and light system. This then allows the implementation of the system in a cluster format which enables redundancy and easy scalability for different mission requirements. This combination of low fissile content, compact size, and thermalized spectrum contribute to an interesting and novel behavior of the reactor system. The two codes were both used for the burn up calculations in order to verify their validity while the static calculations and characterization of the core were done principally with MCNPX. The KANUTER space propulsion reactor is in the process of being characterized and improved. Its basic neutronic characteristics have been studied, and its behavior over time has been identified. It has been shown that this reactor will have difficulty operating as hoped in a bimodal configuration where it is able to provide both propulsion and power throughout mission to Mars. The reason for this has been identified as Xe{sup 135}, and it is believed that a possible solution to this issue does exist, either in the form of an appropriately designed neutron spectrum or the building in of sufficient excess reactivity.

  3. Conceptual study of a straight field line mirror hybrid reactor

    International Nuclear Information System (INIS)

    A hybrid reactor based on the straight field line mirror (SFLM) with magnetic expanders at the ends is proposed as a compact device for transmutation of nuclear waste and power production. Compared to a fusion reactor, plasma confinement demands can be relaxed if there is a strong energy multiplication by the fission reactions, i.e. Qr=Pfission/Pfusion>>1. The values of Qr is primarily restricted by fission reactor safety requirements. For the SFLM, computations suggest that values of Qr ranging up to 150 are consistent with reactor safety. In a mirror hybrid device with Qr >100, the lower bound on the electron temperature for power production can then be estimated to be around 400 eV, which may be achievable for a mirror machine. The SFLM with its quadrupolar stabilizing fields does not rely on plasma flow into the expanders for MHD stability, and a scenario with plasma density depletion in the expanders is a possibility to increase the electron temperature. Efficient power production is predicted with a fusion Q = 0.15 and an electron temperature around 500 eV. A fusion power of 10 MW could then be amplified to 1.5 GW fission power in a compact 25 m long hybrid mirror machine. Beneficial features are that all sensitive equipment can be located outside the neutron rich region and a steady state power production seems possible. Self circulation of the lead coolant, which is useful for heat removal if coolant pumps cease to operate, could be arranged by orienting the magnetic axis vertically. Results from studies on plasma equilibrium and stability, coil designing, RF heating and neutron computations are presented.

  4. A preliminary conceptual design study for Korean fusion DEMO reactor

    International Nuclear Information System (INIS)

    Highlights: ► Perform a preliminary conceptual study for a steady-state Korean DEMO reactor. ► Present design guidelines and requirements of Korean DEMO reactor. ► Present a preliminary design of TF (toroidal field) and CS (central solenoid) magnet. ► Present a preliminary result of the radial build scheme of Korean DEMO reactor. -- Abstract: As the ITER is being constructed, there is a growing anticipation for an earlier realization of fusion energy, so called fast-track approach. Korean strategy for fusion energy can be regarded as a fast-track approach and one special concept discussed in this paper is a two-stage development plan. At first, a steady-state Korean DEMO Reactor (K-DEMO) is designed not only to demonstrate a net electricity generation and a self-sustained tritium cycle, but also to be used as a component test facility. Then, at its second stage, a major upgrade is carried out by replacing in-vessel components in order to show a net electric generation on the order of 300 MWe and the competitiveness in cost of electricity (COE). The major radius is designed to be just below 6.5 m, considering practical engineering feasibilities. By using high performance Nb3Sn-based superconducting cable currently available, high magnetic field at the plasma center above 8 T can be achieved. A design concept for TF magnets and radial builds for the K-DEMO considering a vertical maintenance scheme, are presented together with preliminary design parameters

  5. Study on spent fuel rejuvenation in PROMETHEUS fusion reactor

    International Nuclear Information System (INIS)

    This study presents the spent fuel rejuvenation potential of the PROMETHEUS-H fusion reactor. For this purpose, three different spent fuels were selected, i.e. (1) CANDU (2) PWR-UO2 and (3) PWR-MOX spent fuels. The spent fuel (volume fraction of 60%), spherically prepared and cladded with SiC (volume fraction of 10%), was located in the fuel zone (FZ) in the blanket of the modified PROMETHEUS-H fusion reactor. The FZ was cooled with high pressure helium gas (volume fraction of 30%) for the nuclear heat transfer. The neutronic calculations were performed by solving the Boltzmann transport equation with the help of the neutron transport code XSDRNPM-S/SCALE 4.3. The calculations of the time dependent atomic densities of the isotopes were performed for an operation period (OP) of up to 4 years with a 75% plant factor (η) under a first wall neutron load (P) of 4.7 MW/m2. The temporal variations of the atomic densities of the isotopes in the spent fuel composition and other physical parameters were calculated for a discrete time interval (Δt) of 1/12 year (one month) by using the interface program (code). In all investigated spent fuel cases, the tritium self sufficiency is maintained for the DT fusion driver along the OP. The CANDU spent fuel becomes usable in a conventional CANDU reactor after a regeneration time of ∼5.5 months. The CFFE value approaches 3.5% in the blanket fuelled with the PWR-UO2 and PWR-MOX spent fuels after 41 and 35 months, respectively. The plutonium component can never reach a nuclear weapon grade quality during the spent fuel rejuvenation. Consequently, the modified PROMETHEUS-H fusion reactor has high neutronic performance for the rejuvenation of the spent fuels

  6. Evolution of electron Fermi surface with doping in cobaltates.

    Science.gov (United States)

    Ma, Xixiao; Lan, Yu; Qin, Ling; Kuang, Lülin; Feng, Shiping

    2016-08-24

    The notion of the electron Fermi surface is one of the characteristic concepts in the field of condensed matter physics, and it plays a crucial role in the understanding of the physical properties of doped Mott insulators. Based on the t-J model, we study the nature of the electron Fermi surface in the cobaltates, and qualitatively reproduce the essential feature of the evolution of the electron Fermi surface with doping. It is shown that the underlying hexagonal electron Fermi surface obeys Luttinger's theorem. The theory also predicts a Fermi-arc phenomenon at the low-doped regime, where the region of the hexagonal electron Fermi surface along the [Formula: see text]-K direction is suppressed by the electron self-energy, and then six disconnected Fermi arcs located at the region of the hexagonal electron Fermi surface along the [Formula: see text]-M direction emerge. However, this Fermi-arc phenomenon at the low-doped regime weakens with the increase of doping. PMID:27351111

  7. Evolution of electron Fermi surface with doping in cobaltates

    Science.gov (United States)

    Ma, Xixiao; Lan, Yu; Qin, Ling; Kuang, Lülin; Feng, Shiping

    2016-08-01

    The notion of the electron Fermi surface is one of the characteristic concepts in the field of condensed matter physics, and it plays a crucial role in the understanding of the physical properties of doped Mott insulators. Based on the t-J model, we study the nature of the electron Fermi surface in the cobaltates, and qualitatively reproduce the essential feature of the evolution of the electron Fermi surface with doping. It is shown that the underlying hexagonal electron Fermi surface obeys Luttinger’s theorem. The theory also predicts a Fermi-arc phenomenon at the low-doped regime, where the region of the hexagonal electron Fermi surface along the Γ -K direction is suppressed by the electron self-energy, and then six disconnected Fermi arcs located at the region of the hexagonal electron Fermi surface along the Γ -M direction emerge. However, this Fermi-arc phenomenon at the low-doped regime weakens with the increase of doping.

  8. Renormalization group flow for noncommutative Fermi liquids

    International Nuclear Information System (INIS)

    Some recent studies of the AdS/CFT correspondence for condensed matter systems involve the Fermi liquid theory as a boundary field theory. Adding B-flux to the boundary D-branes leads in a certain limit to the noncommutative Fermi liquid, which calls for a field theory description of its critical behavior. As a preliminary step to more general consideration, the modification of the Landau's Fermi liquid theory due to noncommutativity of spatial coordinates is studied in this paper. We carry out the renormalization of interactions at tree level and one loop in a weakly coupled fermion system in two spatial dimensions. Channels ZS, ZS' and BCS are discussed in detail. It is shown that while the Gaussian fixed-point remains unchanged, the BCS instability is modified due to the space noncommutativity.

  9. System analysis study for Korean fusion DEMO reactor

    International Nuclear Information System (INIS)

    Highlights: ► A conceptual design study for a steady-state K-DEMO has been initiated. ► The major radius is designed to be below 6.5 m, considering engineering feasibilities. ► Magnetic field at the plasma center around 8 T is achieved by using Nb3Sn technology. ► Feasibility of near-future DEMO reactor is studied with a system analysis code. ► A net electric generation on the order of 300 MWe can be achieved below the βN of 5. -- Abstract: A conceptual design study for a steady-state Korean fusion DEMO reactor (K-DEMO) has been initiated. Two peculiar features need to be noted. First, the major radius is designed to be just below 6.5 m, considering practical engineering feasibilities. But still, high magnetic field at the plasma center around 8 T is expected to be achieved by using current state-of-the-art high performance Nb3Sn strand technology. Second, a two-stage development plan is being considered. In the first stage, K-DEMO will demonstrate a net electricity generation but will also act as a component test facility. Then, after a major upgrade, K-DEMO is expected to show a net electric generation on the order of 300 MWe and the competitiveness in cost of electricity (COE). Feasibility of such a practical, near-future demonstration reactor is studied in this paper, based on a zero dimensional system analysis code study. It was shown that a net electric generation on the order of 300 MWe can be achieved below the optimistic βN limit of 5. The elongation of K-DEMO is around 1.8 with single null configuration. Detailed optimization process and the resultant various plasma parameters are described

  10. Relativistic Thermodynamics of Magnetized Fermi Electron Gas

    CERN Document Server

    Tsintsadze, Nodar L

    2012-01-01

    To study the relativistic thermodynamic properties of a Fermi gas in a strong magnetic field, we construct the relativistic thermodynamic potential by the relativistic Fermi distribution function taking into account that the motion of particles in a plane perpendicular to the magnetic field is quantized. With this general potential at hand, we investigate all the thermodynamic quantities as a function of densities, temperatures and the magnetic field. We obtain a novel set of adiabatic equations. Having the expression of the pressure and adiabatic state equations, we determine the sound velocity for several cases revealing a new type of sound velocity. Finally, we disclose the magnetic cooling in the quantized electron Fermi gas, which is based on an adiabatic magnetization in contrast to the known adiabatic demagnetization.

  11. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids

    Directory of Open Access Journals (Sweden)

    Ajay Bansal

    2010-10-01

    Full Text Available Hydrodynamic studies of trickle bed reactors (TBRs are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic liquid saturation are greatly affected by the physical properties of the liquids. In the present study experiments have been carried out in a concurrent downflow air - liquid trickle bed reactor to investigate the dynamic liquid saturation and pressure drop for the water (non-foaming and 3% polyethylene glycol and 4% polyethylene glycol foaming liquids in the gas continuous regime (GCF and foaming pulsing regime (FP. In the GCF regime the dynamic liquid saturation was found to increase with increase in liquid flow rate for non-foaming and foaming liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP regime. The decrease in dynamic liquid saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic liquid saturation was observed. The pressure drop for foaming liquids is observed to be manifolds higher compared to non-foaming liquid in the GCF regime. ©2010 BCREC UNDIP. All rights reserved(Received: 16th January 2010, Revised: 10th February 2010, Accepted: 21st Feberuary 2010[How to Cite: R. Gupta, A. Bansal. (2010. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids. Bulletin of Chemical Reaction Engineering & Catalysis, 5 (1: 31-37. doi:10.9767/bcrec.5.1.775.31-37][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.775.31-37 ][Cited by: Scopus 1 |

  12. Don't Just Stand There--Teach Fermi Problems!

    Science.gov (United States)

    Robinson, A. W.

    2008-01-01

    Fermi problems, or order of magnitude estimates, are often used in introductory physics courses. In this paper I will show that first year students studying physics at university do not arrive with the skill set to solve these problems, and they have to be actively taught how to solve them. Once they have been shown how to solve Fermi problems,…

  13. Fermi-Dirac statistics and the number theory

    CERN Document Server

    Kubasiak, A; Zakrzewski, J; Lewenstein, M

    2005-01-01

    We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantum statistical physics we derive analytic expressions for cumulants of the probability distribution of the number of different partitions.

  14. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    This report describes the results of a conceptual study on the RF system in the typical candidates for the Fusion Experimental Reactor (FER), which were picked out through the '86FER scoping studies. According to the FER operation scenario, three RF systems, that is, ICRF (heating), LHRF (current drive and heating), ECRF (auxiliary heating) were studied. Main concern in these RF systems is the launcher, which may be so designed that required power match the geometrical constraints of the reactor. Then studies were concentrated on the launcher configuration. A prug-in concept of the launcher was adopted in each system and vacancies except transmission space were filled with water. The ICRF launcher had the 2 x 2 loop arrays antenna and the faraday shield area of 1.5 m x 1 m to provide a power of 20 MW. The LHRF launcher had the grillantenna with 28 x 8 open waveguides, and included multi junction-type power splitters which were connected to 56 transmission wave guides. The grild was designed to have two functions of current drive and heating, and provide a power of 20 MW each. The ECRF launcher had a boundle of open wave guides which a reflection mirror each, and three plain mirrors. Assuming a oscillator unit size of 200 kW, it had 40 oversized wave guides to provide a power of 3 MW. (author)

  15. Conceptual design study of a scyllac fusion test reactor

    International Nuclear Information System (INIS)

    The report describes a conceptual design study of a fusion test reactor based on the Scyllac toroidal theta-pinch approach to fusion. It is not the first attempt to describe the physics and technology required for demonstrating scientific feasibility of the approach, but it is the most complete design in the sense that the physics necessary to achieve the device goals is extrapolated from experimentally tested MHD theories of toroidal systems,and it uses technological systems whose engineering performance has been carefully calculated to ensure that they meet the machine requirements

  16. Conceptual design study of a scyllac fusion test reactor

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, K.I. (comp.)

    1975-07-01

    The report describes a conceptual design study of a fusion test reactor based on the Scyllac toroidal theta-pinch approach to fusion. It is not the first attempt to describe the physics and technology required for demonstrating scientific feasibility of the approach, but it is the most complete design in the sense that the physics necessary to achieve the device goals is extrapolated from experimentally tested MHD theories of toroidal systems,and it uses technological systems whose engineering performance has been carefully calculated to ensure that they meet the machine requirements.

  17. Transverse flow reactor studies of the dynamics of radical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, R.G. [Argonne National Laboratory, IL (United States)

    1993-12-01

    Radical reactions are in important in combustion chemistry; however, little state-specific information is available for these reactions. A new apparatus has been constructed to measure the dynamics of radical reactions. The unique feature of this apparatus is a transverse flow reactor in which an atom or radical of known concentration will be produced by pulsed laser photolysis of an appropriate precursor molecule. The time dependence of individual quantum states or products and/or reactants will be followed by rapid infrared laser absorption spectroscopy. The reaction H + O{sub 2} {yields} OH + O will be studied.

  18. Electronic structure near the Fermi level in the ferromagnetic semiconductor GaMnAs studied by ultrafast time-resolved light-induced reflectivity measurements

    Science.gov (United States)

    Ishii, Tomoaki; Kawazoe, Tadashi; Hashimoto, Yusuke; Terada, Hiroshi; Muneta, Iriya; Ohtsu, Motoichi; Tanaka, Masaaki; Ohya, Shinobu

    2016-06-01

    Clarification of the electronic structure near the Fermi level is important in understanding the origin of ferromagnetism in the prototypical ferromagnetic semiconductor GaMnAs. Here, we perform ultrafast transient reflectivity spectra measurement, which is a powerful tool for selective detection of absorption edges in GaMnAs. The results show that the Fermi level of GaMnAs exists in the band gap. By using the Kramers-Kronig relation, we find the Mn-induced electronic states around the Fermi level, confirming that the ferromagnetism is stabilized by spin-polarized impurity-band holes.

  19. Study of a multi-beam accelerator driven thorium reactor

    International Nuclear Information System (INIS)

    The primary advantages that accelerator driven systems have over critical reactors are: (1) Greater flexibility regarding the composition and placement of fissile, fertile, or fission product waste within the blanket surrounding the target, and (2) Potentially enhanced safety brought about by operating at a sufficiently low value of the multiplication factor to preclude reactivity induced events. The control of the power production can be achieved by vary the accelerator beam current. Furthermore, once the beam is shut off the system shuts down. The primary difference between the operation of an accelerator driven system and a critical system is the issue of beam interruptions of the accelerator. These beam interruptions impose thermo-mechanical loads on the fuel and mechanical components not found in critical systems. Studies have been performed to estimate an acceptable number of trips, and the value is significantly less stringent than had been previously estimated. The number of acceptable beam interruptions is a function of the length of the interruption and the mission of the system. Thus, for demonstration type systems and interruption durations of 1sec 5mins 2500/yr and 50/yr are deemed acceptable. However, for industrial scale power generation without energy storage type systems and interruption durations of t 5mins, the acceptable number of interruptions are 25000, 2500, 250, and 3 respectively. However, it has also been concluded that further development is required to reduce the number of trips. It is with this in mind that the following study was undertaken. The primary focus of this study will be the merit of a multi-beam target system, which allows for multiple spallation sources within the target/blanket assembly. In this manner it is possible to ameliorate the effects of sudden accelerator beam interruption on the surrounding reactor, since the remaining beams will still be supplying source neutrons. The proton beam will be assumed to have an

  20. Langmuir probe diagnostic studies of pulsed hydrogen plasmas in planar microwave reactors

    OpenAIRE

    A. Rousseau(MSSL, Surrey, United Kingdom); Teboul, E.; Lang, N.; M. Hannemann; Röpcke, J.

    2002-01-01

    Langmuir probe techniques have been used to study time and spatially resolved electron densities and electron temperatures in pulse-modulated hydrogen discharges in two different planar microwave reactors (fmicrowave= 2.45 GHz, tpulse= 1 ms). The reactors are (i) a standing-wave radiative slotted waveguide reactor and (ii) a modified travelling-wave radiative slotted waveguide reactor, which generate relatively large plasmas over areas from about 350 cm^2 to 500 cm^2. The plasma properties of...

  1. Fermi liquids near Pomeranchuk instabilities

    Science.gov (United States)

    Reidy, Kelly Elizabeth

    We explore features of a Fermi liquid near generalized Pomeranchuk instabilities (PIs) starting from both ordered and disordered phases. These PIs can be viewed as quantum critical points in parameter space, and thus provide an alternate viewpoint on quantum criticality. We employ the tractable crossing symmetric equation method, which is a non-perturbative diagrammatic many-particle method used to calculate the Fermi liquid interaction functions and scattering amplitudes. We consider both repulsive and attractive underlying interactions of arbitrary strength. Starting from a ferromagnetically ordered ground state, we find that upon approach to an s-wave instability in one critical channel, the system simultaneously approaches instabilities in non-critical channels. We study origins and implications of this "quantum multicriticality". We also find that a nematic (non-s-wave) instability precedes and is driven by Pomeranchuk instabilities in both the s-wave spin and density channels. Finally, we discuss potential applications of our results to physical systems, such as ferromagnetic superconductors.

  2. Development of studies on helium cooled fast reactors

    International Nuclear Information System (INIS)

    A necessity is shown of developing breeders with high reproductive properties. Helium cooled fast reactor is considered. The reactor performances, heating circuit with the use of a steam turbine unit in the secondary circuit is outlined. The reactor design and fuel assemblies are described

  3. The FERMI (at) Elettra Technical Optimization Study: General Layout and Parameters and Physics Studies of Longitudinal Space Charge, the Spreader, the Injector, and Preliminary FEL Performance

    International Nuclear Information System (INIS)

    The FERMI (at) Elettra facility will make use of the existing GeV linac at Sincrotrone Elettra, which will become available for dedicated FEL applications following the completion of construction of a new injector booster complex for the storage ring. With a new rf photocathode injector, and some additional accelerating sections, this linac will be capable of providing high brightness bunches at 1.2 GeV and up to 50 Hz repetition rates

  4. The FERMI @ Elettra Technical Optimization Study: General Layoutand Parameters and Physics Studies of Longitudinal Space Charge, theSpreader, the Injector, and Preliminary FEL Performance

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox,Russell; Wurtele, Jonathan; Zholents, Alexander

    2005-09-01

    The FERMI {at} Elettra facility will make use of the existing GeV linac at Sincrotrone Elettra, which will become available for dedicated FEL applications following the completion of construction of a new injector booster complex for the storage ring. With a new rf photocathode injector, and some additional accelerating sections, this linac will be capable of providing high brightness bunches at 1.2 GeV and up to 50 Hz repetition rates.

  5. Feasibility study on small modular reactors for modern microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Islam, R.; Gabbar, H.A., E-mail: hossam.gabbar@uoit.ca [Univ. of Ontario Inst. of Technology, Faculty of Energy Systems and Nuclear Science, Oshawa, Ontario (Canada)

    2013-07-01

    Microgrid is a solution of conventional power grid problem and offer sustainable decentralized power system. Microgrid with modern distributed energy resources (DER) could play an important role to alleviate dependency on the main electricity grid. Distributed energy resource comprises wind turbine, solar photovoltaic, diesel generator, gas engine, micro turbine, fuel cells, etc.Due to the gap between typical loads and supply within microgrid, larger scale energy generation could provide a possible solution to balance power demand and supply. Feasibility study of Small Nuclear Power Plant, such as Small Modular reactor (SMR), within microgrids could be achieved via different cases. To achieve the target, a comprehensive feasibility study is conducted on microgrid with SMR through electricity generation profiles, geographical and environmental assessment, as well as cost analysis using simulation practices and data analysis.Also potency of SMRs is analyzed. Parameters and Key Performance Indicators (KPIs) could be analyzed to achieve feasible solution of microgrids with small modular reactor (SMR) to improve the overall microgrid performance.The study shows that SMR could be a feasible solution if microgrid parameters are selected properly. (author)

  6. Feasibility study on small modular reactors for modern microgrids

    International Nuclear Information System (INIS)

    Microgrid is a solution of conventional power grid problem and offer sustainable decentralized power system. Microgrid with modern distributed energy resources (DER) could play an important role to alleviate dependency on the main electricity grid. Distributed energy resource comprises wind turbine, solar photovoltaic, diesel generator, gas engine, micro turbine, fuel cells, etc.Due to the gap between typical loads and supply within microgrid, larger scale energy generation could provide a possible solution to balance power demand and supply. Feasibility study of Small Nuclear Power Plant, such as Small Modular reactor (SMR), within microgrids could be achieved via different cases. To achieve the target, a comprehensive feasibility study is conducted on microgrid with SMR through electricity generation profiles, geographical and environmental assessment, as well as cost analysis using simulation practices and data analysis.Also potency of SMRs is analyzed. Parameters and Key Performance Indicators (KPIs) could be analyzed to achieve feasible solution of microgrids with small modular reactor (SMR) to improve the overall microgrid performance.The study shows that SMR could be a feasible solution if microgrid parameters are selected properly. (author)

  7. Aging study of boiling water reactor high pressure injection systems

    International Nuclear Information System (INIS)

    The purpose of high pressure injection systems is to maintain an adequate coolant level in reactor pressure vessels, so that the fuel cladding temperature does not exceed 1,200 degrees C (2,200 degrees F), and to permit plant shutdown during a variety of design basis loss-of-coolant accidents. This report presents the results of a study on aging performed for high pressure injection systems of boiling water reactor plants in the United States. The purpose of the study was to identify and evaluate the effects of aging and the effectiveness of testing and maintenance in detecting and mitigating aging degradation. Guidelines from the United States Nuclear Regulatory Commission's Nuclear Plant Aging Research Program were used in performing the aging study. Review and analysis of the failures reported in databases such as Nuclear Power Experience, Licensee Event Reports, and the Nuclear Plant Reliability Data System, along with plant-specific maintenance records databases, are included in this report to provide the information required to identify aging stressors, failure modes, and failure causes. Several probabilistic risk assessments were reviewed to identify risk-significant components in high pressure injection systems. Testing, maintenance, specific safety issues, and codes and standards are also discussed

  8. Nordic study on reactor waste. Technical part 1 and 2

    International Nuclear Information System (INIS)

    An important part of the Nordic studies on system- and safety analysis of the management of low and medium level radioactive waste from nuclear power plants, is the safety analysis of a Reference System. This reference system was established within the study and is described in this Technical Part 1. The reference system covers waste management Schemes that are potential possibilities in either one of the four participating Nordic countries. The reference system is based on: a power reactor system consisting of 6 BWR's of 500 MWe each, operated simultaneously over the same 30 year period, and deep bed granular ion exchange resin wastes from the Reactor Water Clean-Up System (RWCS and powdered ion exchange resin from the Spent Fuel Pool Cleanup System (SFPCS)). Both waste types are supposed to be solidified by mixing with cement and bitumen. Two basic types of containers are considered. Standard 200 liter steel drums and specially made cubicreinforced concrete moulds with a net volume of 1 m3. The Nordic study assumes temporary storage of the solidified waste for a maximum of 50 years before the waste is transferred to the disposal site. Transportation of the waste from the storage facilitiy to the disposal site will be by road or sea. Three different disposal facilities are considered: Shallow land burial, near surface concrete bunker, and rock cavern with about 30 m granite cover. (EG)

  9. Berry Fermi Liquid Theory

    CERN Document Server

    Chen, Jing-Yuan

    2016-01-01

    We develop an extension of the Landau Fermi liquid theory to systems of interacting fermions with non-trivial Berry curvature. We propose a kinetic equation and a constitutive relation for the electromagnetic current that together encode the linear response of such systems to external electromagnetic perturbations, to leading and next-to-leading orders in the expansion over the frequency and wave number of the perturbations. We analyze the Feynman diagrams in a large class of interacting quantum field theories and show that, after summing up all orders in perturbation theory, the current-current correlator exactly matches with the result obtained from the kinetic theory.

  10. La experiencia del lugar. Ernesto Nathan Rogers, Enrico Tedeschi, José Antonio Coderch y Lina Bo Bardi

    Directory of Open Access Journals (Sweden)

    Josep Maria Montaner

    2011-10-01

    Full Text Available

    The concept of place becomes a central element in the conceptualization of a postwar architecture, which strives to surpass the coordinates of the Modern Movement. It is a concept used by Christian Norberg-Schulz, as a means of overcoming the concepts of his master Siegfried Giedion. From the general idea of a universal space we have evolved into the specific idea of a place. But the complexity of the concept of place lies in that it is neither generic nor universal; its essence lies rather in learning and getting used to the context and its process.
    We start out from two hypotheses. The first is that the idea of place that develops in Latin and Latin American cultures has Mediterranean roots, from which the Modern archetypes are capable of incorporating contributions from specific places.
    The second and complementary hypothesis would be that the experience of a place develops in contemporary authors of the 1950's such as Ernesto Nathan Rogers, Enrico Tedeschi, José Antonio Coderch y Lina Bo Bardi, members of what could be called the second modern generation. The text will analyze the ideas found in the writings of these four authors, as well as a milestone work by each one of them in relationship to its site. Of these, two will be public, and two will be private: the refurbishment of the castello Sforzesco in Milan by BBPR, the Mendoza Faculty of Architecture by Enrico Tedeschi, the Casa Ugalde by Coderch and the Casa de Cristal in Sao Paulo by Lina Bo Bardi.

  11. A design study of reactor core optimization for direct nuclear heat-to-electricity conversion in a space power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Hidekazu; Takahashi, Makoto; Shimoda, Hiroshi; Takeoka, Satoshi [Kyoto Univ. (Japan); Nakagawa, Masayuki; Kugo, Teruhiko

    1998-01-01

    To propose a new design concept of a nuclear reactor used in the space, research has been conducted on the conceptual design of a new nuclear reactor on the basis of the following three main concepts: (1) Thermionic generation by thermionic fuel elements (TFE), (2) reactivity control by rotary reflector, and (3) reactor cooling by liquid metal. The outcomes of the research are: (1) A calculation algorithm was derived for obtaining convergent conditions by repeating nuclear characteristic calculation and thermal flow characteristic calculation for the space nuclear reactor. (2) Use of this algorithm and the parametric study established that a space nuclear reactor using 97% enriched uranium nitride as the fuel and lithium as the coolant and having a core with a radius of about 25 cm, a height of about 50 cm and a generation efficiency of about 7% can probably be operated continuously for at least more than ten years at 100 kW only by reactivity control by rotary reflector. (3) A new CAD/CAE system was developed to assist design work to optimize the core characteristics of the space nuclear reactor comprehensively. It is composed of the integrated design support system VINDS using virtual reality and the distributed system WINDS to collaboratively support design work using Internet. (N.H.)

  12. Summary of conceptual design study of fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    Since 1980 the design study has been conducted at JAERI for the Fusion Experimental Reactor (FER) which has been proposed to be the next machine to JT-60 in the Japanese long term program of fusion reactor development. Starting from 1984 FER design is now being reviewed and redesigned. This report is the summary of the report which describes the results obtained in the review and redesign activities in 1984. The following three steps are followed in those activities ; critical issues study step in which FER critical issues were reviewed and the frame of FER design was revised, torus structure selection step in which a few options within the frame for FER were examined and design step in which major components of the torus structure were designed. The newly established frame for FER design is as follows : 1) Plasma : Self-ignition, 2) Operation scenario : Quasi-steady state operation with long burn pulse, 3) Neutron fluence on the first wall : 0.3 MWY/m2, 4) Blanket : Non-tritium breeding blanket with test modules for breeding blanket development, 5) Magnets : Superconducting Magnets. (author)

  13. Conceptual design study of the fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    A conceptual design study of the Fusion Experimental Reactor (FER) is presented. FER is planned, on the basis of a domestic programme, as a device to explore reasonable minimum physics and technological issues necessary to proceed to DEMO. Among various concepts, including the improvement of ITER-like design, the reference design of FER is chosen as size-minimum and a detailed design study is performed. LHCD assist and a single null divertor configuration are employed to reduce the device size. Simplification and the resultant reliability are attained by the appropriate choice of the fluence, 0.3 MW·a·m-2. A variety of new ideas are explored to develop the FER concept. A layered structure of the divertor for a reliable maintenance scheme and a uniform vacuum vessel with a thin double wall structure for providing structural simplicity and tritium double containment are typical examples. R and D programmes for these key reactor components are now actively being promoted in conjunction with this design activity. (author). 4 refs, 2 figs, 1 tab

  14. Study meeting on 'criteria for materials of nuclear fusion reactors'

    International Nuclear Information System (INIS)

    This study meeting was held on March 1 and 2, 1984, at the Institute of Plasma Physics, Nagoya University. Recently, the problems required for the materials of nuclear fusion reactors have become considerably clear. The problem of the high concentration damage due to 14 MeV neutrons and the problem of surface materials have been well known from the beginning, but moreover, the radioactivation of materials, the problem of safety, and the feasibility of remote operation related to it have become urgent problems. Besides, the plan of large scale facilities as the means of promoting research is one of the important themes. The research on materials must take part in the whole technological problems which enable the construction of actual nuclear fusion devices. This study meeting was held as a part of the R project of the Institute of Plasma Physics, Nagoya University, but it aimed at grasping the present status and discussing the future perspective of the materials of nuclear fusion reactors, and examining the criteria for nuclear fusion materials. The gists of 23 lectures presented at the meeting are collected in this report. (Kako, I.)

  15. Nuclear reactor system study for NASA/JPL. Final report

    International Nuclear Information System (INIS)

    Reactor shielding and safety studies and heat pipe development work undertaken for the Jet Propulsion Laboratory during the period March 1, 1981 to October 30, 1981 are described. Monte Carlo calculations of gamma and neutron shield configurations show that substantial weight penalties are incurred if exposures at 25 m to neutrons and gammas must be limited to 1012 nvt and 106 rad, instead of the 1013 nvt and 107 rad values used earlier. For a 1.6 MW/sub t/ reactor, the required shield weight increases from 400 to 815 kg. Water immersion criticality calculations have been extended to study the effect of water in fuel void spaces as well as in the core heat pipes. These show that the insertion into the core of eight blades of B4C with a mass totaling 2.5 kg will guarantee subcriticality. The design, fabrication procedure, and testing of a 4-m-long molybdenum/lithium heat pipe are described. It appears that an excess of oxygen in the wick prevented the attainment of expected performance capability

  16. Studies on air ingress for pebble bed reactors

    International Nuclear Information System (INIS)

    A loss-of-coolant accident (LOCA) has been considered a critical event for helium-cooled pebbled bed reactors. Following helium depressurization, it is anticipated that unless countermeasures are taken air will enter the core through the break and then by molecular diffusion and ultimately by natural convection leading to oxidation of the in-core graphite structure and graphite pebbles. Thus, without any mitigating features a LOCA will lead to an air ingress event. The INEEL is studying such an event with two well-respected light water reactor transient response codes: RELAP5/ATHENA and MELCOR. To study the degree of graphite oxidation occurring due to an air ingress event, a MELCOR model of a reference pebble bed design was constructed. A modified version of MELCOR developed at INEEL, which includes graphite oxidation capabilities, and molecular diffusion of air into helium was used for these calculations. Results show that the lower reflector graphite consumes all of the oxygen before reaching the core. The results also show a long time delay between the time that the depressurization phase of the accident is over and the time that natural circulation air through the core occurs. (author)

  17. Event Investigation at Research Reactor: Case Study at PUSPATI TRIGA Reactor

    International Nuclear Information System (INIS)

    Any events or incidents at research reactors have to be investigated thoroughly to determine the direct and root causes so that corrective or preventive actions could be taken to minimise or eliminate such events or incidents from occurring in the future. These events or incidents should then be reported to the Incident Reporting System for Research Reactors (IRSRR) managed by the International Atomic Energy Agency IAEA) as lessons learnt for the research reactor community. This paper will present methodology for event investigation and several events at the PUSPATI TRIGA Reactor (RTP) that has been reported to the national regulator. However, no nuclear safety related event or incident has occurred since RTP first reached criticality in June 1982. (author)

  18. Study on the absenteeism of nursing professionals in a psychiatric center in Manaus, Brazil Estudio sobre ausentismo en profesionales de enfermería del centro psiquiátrico de Manaus, Brasil Estudo do absenteísmo dos profissionais de enfermagem de um centro psiquiátrico em Manaus, Brasil

    Directory of Open Access Journals (Sweden)

    Sandra Greice Becker

    2008-02-01

    Full Text Available This quantitative study was performed to research the rate of absenteeism of nursing professionals in a psychiatric center in Manaus, from January/2004 to January/2005, in the Human Resources sector of the institution. In this period, the records of workers who were absent from their professional activities for at least one day were checked. Results showed that there were 415 absence reports in the nursing team during the studied period, by 74.29% of nursing professionals. The average rate of absenteeism is 2.79. The main reason reported for absenteeism was illness. These data suggest further studies are needed in order to improve professionals' health, allowing for better quality of life, and, consequently, for providing better health care to Single Health System users.Con el objetivo de investigar sobre el índice de ausentismo en trabajadores de enfermería del Centro Psiquiátrico de Manaus, se realizó una investigación cuantitativa durante el periodo de enero de 2004 a enero del 2005 en el sector de recursos humanos de la institución en mención. Durante este periodo se buscó a través de consulta documental, registros de los trabajadores que tuvieron faltas de por lo menos 1 día en sus actividades laborales. Los resultados mostraron que durante el periodo de la investigación, hubo 415 registros de faltas por parte del equipo de enfermería, totalizando 74,29%. El índice del ausentismo profesional fue en promedio 2.79. Se observó que el principal motivo del ausentismo fue por enfermedad. Este hecho resalta la necesidad de mejorar la salud del trabajador, favoreciendo a una mejor calidad de vida en el trabajo y en consecuencia una mejor atención a la salud del usuario a través del SUS.Com o objetivo de investigar o índice de absenteísmo dos trabalhadores de enfermagem de um Centro Psiquiátrico em Manaus, realizou-se esta pesquisa quantitativa, no período de janeiro de 2004 a janeiro de 2005, no setor de recursos humanos da

  19. Numerical study on seismic response of the reactor coolant pump in Advanced Passive Pressurized Water Reactor

    International Nuclear Information System (INIS)

    Highlights: • An artificial accelerogram of the specified SSE is generated. • A dynamic FE model of the RCP in AP1000 (with gyroscopic and FSI effects) is developed. • The displacement, force, moment and stress in the RCP during the earthquake are summarized. - Abstract: The reactor coolant pump in the Advanced Passive Pressurized Water Reactor is a kind of nuclear canned-motor pump. The pump is classified as Seismic Category I, which must function normally during the Safe Shutdown Earthquake. When the nuclear power plant is located in seismically active region, the seismic response of the reactor coolant pump may become very important for the safety assessment of the whole nuclear power plant. In this article, an artificial accelerogram is generated. The response spectrum of the artificial accelerogram fits well with the design acceleration spectrum of the Safe Shutdown Earthquake. By applying the finite element modeling method, the dynamic finite element models of the rotor and stator in the reactor coolant pump are created separately. The rotor and stator are coupled by the journal bearings and the annular flow between the rotor and stator. Then the whole dynamic model of the reactor coolant pump is developed. Time domain analysis which uses the improved state-space Newmark method of a direct time integration scheme is carried out to investigate the response of the reactor coolant pump under the horizontal seismic load. The results show that the reactor coolant pump responds differently in the direction of the seismic load and in the perpendicular direction. During the Safe Shutdown Earthquake, the displacement response, the shear force, the moment and the journal bearing reaction forces in the reactor coolant pump are analyzed

  20. Numerical study on seismic response of the reactor coolant pump in Advanced Passive Pressurized Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    De, Cheng, E-mail: 0100209064@sjtu.edu.cn; Zhen-Qiang, Yao, E-mail: zqyaosjtu@gmail.com; Ya-bo, Xue; Hong, Shen

    2014-10-15

    Highlights: • An artificial accelerogram of the specified SSE is generated. • A dynamic FE model of the RCP in AP1000 (with gyroscopic and FSI effects) is developed. • The displacement, force, moment and stress in the RCP during the earthquake are summarized. - Abstract: The reactor coolant pump in the Advanced Passive Pressurized Water Reactor is a kind of nuclear canned-motor pump. The pump is classified as Seismic Category I, which must function normally during the Safe Shutdown Earthquake. When the nuclear power plant is located in seismically active region, the seismic response of the reactor coolant pump may become very important for the safety assessment of the whole nuclear power plant. In this article, an artificial accelerogram is generated. The response spectrum of the artificial accelerogram fits well with the design acceleration spectrum of the Safe Shutdown Earthquake. By applying the finite element modeling method, the dynamic finite element models of the rotor and stator in the reactor coolant pump are created separately. The rotor and stator are coupled by the journal bearings and the annular flow between the rotor and stator. Then the whole dynamic model of the reactor coolant pump is developed. Time domain analysis which uses the improved state-space Newmark method of a direct time integration scheme is carried out to investigate the response of the reactor coolant pump under the horizontal seismic load. The results show that the reactor coolant pump responds differently in the direction of the seismic load and in the perpendicular direction. During the Safe Shutdown Earthquake, the displacement response, the shear force, the moment and the journal bearing reaction forces in the reactor coolant pump are analyzed.

  1. On Thursday 14 September 2006, members of CERN Management welcomed recently-recruited staff members and fellows at the trimester session of the Induction Programme (photographed here with Enrico CHIAVERI, Department HR).

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    On Thursday 14 September 2006, members of CERN Management welcomed recently-recruited staff members and fellows at the trimester session of the Induction Programme (photographed here with Enrico CHIAVERI, Department HR).

  2. A phylogenetic study of canine parvovirus type 2c in midwestern Brazil Estudo filogenético do parvovírus canino tipo 2c no Centro-Oeste do Brasil

    Directory of Open Access Journals (Sweden)

    Danúbia S. Fontana

    2013-02-01

    Full Text Available Since the late 1970s, canine parvovirus type 2 (CPV-2 has emerged as a causative agent of fatal severe acute hemorrhagic enteritis in dogs. To date, three antigenic types of CPV-2 were described worldwide (CPV-2a/b/c. This study was conducted to determine the variants of CPV-2 circulating in dogs from the Cuiabá Municipality in Midwestern Brazil. Out of 50 fecal samples, collected between 2009 and 2011, 27 tested positive for CPV-2. A 583 bp fragment of the VP2 gene was amplified by PCR, 13 representative samples were analyzed further by DNA sequencing. All strains were characterized as CPV-2c, displayed a low genetic variability although observed several amino acid substitution. These findings indicated that CPV-2c has been circulating in dogs from the Cuiabá Municipality in Midwestern Brazil.Desde o final dos anos de 1970, o parvovírus canino tipo 2 (CPV-2 tem emergido como agente de severa e fatal enterite hemorrágica, principalmente em cães com idade inferior a seis meses. Três variantes antigênicas de CPV-2 foram descritas mundialmente (CPV-2a/b/c. O objetivo do estudo foi determinar a presença do CPV-2 e suas variantes circulantes em cães no Município de Cuiabá, Centro-oeste, Brasil. Das 50 amostras fecais, coletadas entre 2009 e 2011, 27 foram positivas para CPV-2 na PCR, sendo 13 analisadas pelo sequenciamento de um fragmento de 583 pares de base do gene VP2. Todas as cepas foram caracterizadas como CPV-2c e apresentaram baixa variabilidade genética. Estes achados indicaram que o CPV-2c está circulando na população canina do Município de Cuiabá, Região Centro-Oeste do Brasil.

  3. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    This report describes the study on safety for FER(Fusion Experimental Reactor) which has been designed as a next step machine to the JT-60. Though the final purpose of this study is to have an image of design base accident, maximum credible accident and to assess their risk or probability, etc., as FER plant system, the emphasis of this years study is placed on fuel-gas circulation system where the tritium inventory is maximum. This report consists of two chapters. The first chapter of this report summaries the FER system and describes FMEA(Failure Mode and Effect Analysis) and related accident progression sequence for FER plant system as a whole. The second chapter of this report is focused on fuel-gas circulation system including the purification, isotope separation system and storage system. Here, probability of risk is assessed by the probabilistic risk analysis (PRA) procedure based on FMEA, ETA and FTA. (author)

  4. Joint KAERI/VAEC pre-possibility study on a new research reactor for Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol; Lee, B. C.; Chae, H. T.; Kim, H.; Lee, C. S.; Choi, C. O.; Jun, B. J. [KAERI, Taejon (Korea, Republic of); Vien, Luong Ba; Dien, Nguyen Nhi [Vietnam Atomic Energy Commission, Hanoi (Viet Nam)

    2004-05-01

    Based on the agreement on the technical cooperation for nuclear technology between Korea and Vietnam, a KAERI/VAEC joint study on the pre-possibility of a new research reactor for Vietnam has been carried out in the research reactor area from Nov. 2003 to May 2004. In this report, the results of the pre-possibility study on a new research reactor are described. The report presents the necessity of a new research reactor in Vietnam, and the desired performance requirements of the new research reactor if necessary. The major design characteristics of some existing research reactors and those under planning were also reviewed and the main characteristics which should be considered in selecting a new multipurpose research reactor for Vietnam were drawn. Some recommendations on the considerations for the next step of the feasibility study such as the project formulation, manpower requirements and international co-operation were also briefly touched upon.

  5. A feasibility study of a linear laser heated solenoid fusion reactor. Final report

    International Nuclear Information System (INIS)

    This report examines the feasibility of a laser heated solenoid as a fusion or fusion-fission reactor system. The objective of this study, was an assessment of the laser heated solenoid reactor concept in terms of its plasma physics, engineering design, and commercial feasibility. Within the study many pertinent reactor aspects were treated including: physics of the laser-plasma interaction; thermonuclear behavior of a slender plasma column; end-losses under reactor conditions; design of a modular first wall, a hybrid (both superconducting and normal) magnet, a large CO2 laser system; reactor blanket; electrical storage elements; neutronics; radiation damage, and tritium processing. Self-consistent reactor configurations were developed for both pure fusion and fusion-fission designs, with the latter designed both to produce power and/or fissile fuels for conventional fission reactors. Appendix A is a bibliography with commentary of theoretical and experimental studies that have been directed at the laser heated solenoid

  6. Joint KAERI/VAEC pre-possibility study on a new research reactor for Vietnam

    International Nuclear Information System (INIS)

    Based on the agreement on the technical cooperation for nuclear technology between Korea and Vietnam, a KAERI/VAEC joint study on the pre-possibility of a new research reactor for Vietnam has been carried out in the research reactor area from Nov. 2003 to May 2004. In this report, the results of the pre-possibility study on a new research reactor are described. The report presents the necessity of a new research reactor in Vietnam, and the desired performance requirements of the new research reactor if necessary. The major design characteristics of some existing research reactors and those under planning were also reviewed and the main characteristics which should be considered in selecting a new multipurpose research reactor for Vietnam were drawn. Some recommendations on the considerations for the next step of the feasibility study such as the project formulation, manpower requirements and international co-operation were also briefly touched upon

  7. Study of the high energy gamma-ray emission from the crab pulsar with the MAGIC telescope and Fermi-LAT

    International Nuclear Information System (INIS)

    My thesis deals with a fundamental question of high energy gamma-ray astronomy. Namely, I studied the cut-off shape of the Crab pulsar spectrum to distinguish between the leading scenarios for the pulsar models. Pulsars are celestial objects, which emit periodic pulsed electromagnetic radiation (pulsation) from radio to high energy gamma-rays. Two major scenarios evolved in past 40 years to explain the pulsation mechanism: the inner magnetosphere scenario and the outer magnetosphere scenario. Both scenarios predict a high energy cut-off in the gamma-ray energy spectrum, but with different cut-off sharpness. An exponential cut-off is expected for the outer magnetosphere scenario while a super-exponential cut-off is predicted for the inner magnetosphere scenario. Therefore, one of the best ways to confirm or refute these scenarios is to measure the energy spectrum of a pulsar at around the cut-off energy, i.e., at energies between a few GeV and a few tens of GeV. All past attempts to measure pulsar spectra with ground-based instruments have failed while satellite-borne detectors had a too small area to study detailed spectra in the GeV domain. In this thesis, the gamma-ray emission at around the cut-off energy from the Crab pulsar is studied with the MAGIC telescope. The public data of the satellite-borne gamma-ray detector, Fermi-LAT, are also analyzed in order to discuss the MAGIC observation results in comparison with the adjacent energy band. In late 2007, a new trigger system (SUM trigger system) allowed to reduce the threshold energy of the MAGIC telescope from 50 GeV to 25 GeV and the Crab pulsar was successfully detected during observations from October 2007 and January 2009. My analysis reveals that the energy spectrum is consistent with a simple power law between 25 GeV to 100 GeV. The extension of the energy spectrum up to 100 GeV rules out the inner magnetosphere scenario. Fermi-LAT started operation in August 2008. The Fermi-LAT data reveal that a power

  8. Study of the high energy gamma-ray emission from the crab pulsar with the MAGIC telescope and Fermi-LAT

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Takayuki

    2010-12-06

    My thesis deals with a fundamental question of high energy gamma-ray astronomy. Namely, I studied the cut-off shape of the Crab pulsar spectrum to distinguish between the leading scenarios for the pulsar models. Pulsars are celestial objects, which emit periodic pulsed electromagnetic radiation (pulsation) from radio to high energy gamma-rays. Two major scenarios evolved in past 40 years to explain the pulsation mechanism: the inner magnetosphere scenario and the outer magnetosphere scenario. Both scenarios predict a high energy cut-off in the gamma-ray energy spectrum, but with different cut-off sharpness. An exponential cut-off is expected for the outer magnetosphere scenario while a super-exponential cut-off is predicted for the inner magnetosphere scenario. Therefore, one of the best ways to confirm or refute these scenarios is to measure the energy spectrum of a pulsar at around the cut-off energy, i.e., at energies between a few GeV and a few tens of GeV. All past attempts to measure pulsar spectra with ground-based instruments have failed while satellite-borne detectors had a too small area to study detailed spectra in the GeV domain. In this thesis, the gamma-ray emission at around the cut-off energy from the Crab pulsar is studied with the MAGIC telescope. The public data of the satellite-borne gamma-ray detector, Fermi-LAT, are also analyzed in order to discuss the MAGIC observation results in comparison with the adjacent energy band. In late 2007, a new trigger system (SUM trigger system) allowed to reduce the threshold energy of the MAGIC telescope from 50 GeV to 25 GeV and the Crab pulsar was successfully detected during observations from October 2007 and January 2009. My analysis reveals that the energy spectrum is consistent with a simple power law between 25 GeV to 100 GeV. The extension of the energy spectrum up to 100 GeV rules out the inner magnetosphere scenario. Fermi-LAT started operation in August 2008. The Fermi-LAT data reveal that a power

  9. Safe and Effective Deactivation of Metallic Sodium Filled Scrap and Cold Traps From Sodium-cooled Nuclear Reactor D and D - 12176

    International Nuclear Information System (INIS)

    As part of the Plateau Remediation Project at US Department of Energy's Hanford, Washington site, CH2M Hill Plateau Remediation Company (CHPRC) contracted with IMPACT Services, LLC to receive and deactivate approximately 28 cubic meters of sodium metal contaminated debris from two sodium-cooled research reactors (Enrico Fermi Unit 1 and the Fast Flux Test Facility) which had been stored at Hanford for over 25 years. CHPRC found an off-site team composed of IMPACT Services and Commodore Advanced Sciences, Inc., with the facilities and technological capabilities to safely and effectively perform deactivation of this sodium metal contaminated debris. IMPACT Services provided the licensed fixed facility and the logistical support required to receive, store, and manage the waste materials before treatment, and the characterization, manifesting, and return shipping of the cleaned material after treatment. They also provided a recycle outlet for the liquid sodium hydroxide byproduct resulting from removal of the sodium from reactor parts. Commodore Advanced Sciences, Inc. mobilized their patented AMANDA unit to the IMPACT Services site and operated the unit to perform the sodium removal process. Approximately 816 Kg of metallic sodium were removed and converted to sodium hydroxide, and the project was accomplished in 107 days, from receipt of the first shipment at the IMPACT Services facility to the last outgoing shipment of deactivated scrap metal. There were no safety incidents of any kind during the performance of this project. The AMANDA process has been demonstrated in this project to be both safe and effective for deactivation of sodium and NaK. It has also been used in other venues to treat other highly reactive alkali metals, such as lithium (Li), potassium (K), NaK and Cesium (Cs). (authors)

  10. Pressurized-water reactor internals aging degradation study

    International Nuclear Information System (INIS)

    This report documents the results of a Phase I study on the effects of aging degradations on pr internals. Primary stressers for internals an generated by the primary coolant flow in the they include unsteady hydrodynamic forces and pump-generated pressure pulsations. Other stressors are applied loads, manufacturing processes, impurities in the coolant and exposures to fast neutron fluxes. A survey of reported aging-related failure information indicates that fatigue, stress corrosion cracking (SCC) and mechanical wear are the three major aging-related degradation mechanisms for PWR internals. Significant reported failures include thermal shield flow-induced vibration problems, SCC in guide tube support pins and core support structure bolts, fatigue-induced core baffle water-jet impingement problems and excess wear in flux thimbles. Many of the reported problems have been resolved by accepted engineering practices. Uncertainties remain in the assessment of long-term neutron irradiation effects and environmental factors in high-cycle fatigue failures. Reactor internals are examined by visual inspections and the technique is access limited. Improved inspection methods, especially one with an early failure detection capability, can enhance the safety and efficiency of reactor operations

  11. Operators of nuclear reactors. A study about their professional identity

    International Nuclear Information System (INIS)

    This research studies the process of identity formation/transformation in a group of workers at a Research Institute, which deals with nuclear energy for peaceful uses. It had as a referential the work developed by Antonio da Costa Ciampa (1995). This approach conceives identity as metamorphosis and it is empirically expressed by characters. The research was candied out at the IPEN-CNEN/SP with the oldest reactor operators at work, with open interviews mainly. At the end of the analysis, it was observed that the team, in spite of its grievance and complaints, is still united and operates the reactor with great responsibility. This fact can be proved since no accidents have happened in the last forty years. Nevertheless, the group misses the community recognition for the importance of its work. This was interpreted as the search for an emancipatory feeling towards the development of a collective identity. The lack of this feeling tends to produce an identity with a mere instrumental rationality, suggesting that the organization identity policy must be reviewed. (author)

  12. Boiling-Water Reactor internals aging degradation study

    International Nuclear Information System (INIS)

    This report documents the results of an aging assessment study for boiling water reactor (BWR) internals. Major stressors for BWR internals are related to unsteady hydrodynamic forces generated by the primary coolant flow in the reactor vessel. Welding and cold-working, dissolved oxygen and impurities in the coolant, applied loads and exposures to fast neutron fluxes are other important stressors. Based on results of a component failure information survey, stress corrosion cracking (SCC) and fatigue are identified as the two major aging-related degradation mechanisms for BWR internals. Significant reported failures include SCC in jet-pump holddown beams, in-core neutron flux monitor dry tubes and core spray spargers. Fatigue failures were detected in feedwater spargers. The implementation of a plant Hydrogen Water Chemistry (HWC) program is considered as a promising method for controlling SCC problems in BWR. More operating data are needed to evaluate its effectiveness for internal components. Long-term fast neutron irradiation effects and high-cycle fatigue in a corrosive environment are uncertainty factors in the aging assessment process. BWR internals are examined by visual inspections and the method is access limited. The presence of a large water gap and an absence of ex-core neutron flux monitors may handicap the use of advanced inspection methods, such as neutron noise vibration measurements, for BWR

  13. A comparative study of fuel management in PWR reactors

    International Nuclear Information System (INIS)

    A comparitive study of fuel recycling in Pressurized Water Reactors was developed, considering not only the conventional uranium cycle, but also the use of thorium as an alternative. The use of thorium was done by varying its conoentration in the homogeneous mixture with uranium in the fuel from 30% up to 90%. The U-233 produced is incorporated within the isotopic composition of irradiated uranium. Various fractions of irradiated recycled fuel to be reprocessed and recycled was considered. Various alternatives of recycling were outlined and a final comparison in the tests done, is furnished in terms of U3O8 and UTS requirements and approximated costs of fuel cycle stages involved. The recycled fuel is considered to be uniformly distributed in the fuel element rods introduced in the nucleus. The influence of the utilization of thorium was also considered for the development of an optimum fuel cycle, regarding the safeguards against nuclear proliferation when utilizing plutonium. A zero-dimensional cellular model was adopted to represent the reactor and the calculus of microscopic cross-sections for the homogenized cell was done by the computer code LEOPARD. A digital computer program was develped for neutronic and fuel depletion calculus and to simulate the refueling of various cycles. (Author)

  14. Application of the Thomas-Fermi statistical model to the thermodynamics of high density matter

    International Nuclear Information System (INIS)

    The Thomas-Fermi statistical model, from the N-body point of view is used in order to have systematic corrections to the T-Fermis equation. Approximate calculus methods are found from analytic study of the T-Fermis equation for non zero temperature. T-Fermis equation is solved with the code GOLEM written in FORTRAN V (UNIVAC). It also provides the thermodynamical quantities and a new method to calculate several isothermal tables. (Author) 24 refs

  15. A brief history of design studies on innovative nuclear reactors

    International Nuclear Information System (INIS)

    In a short period after the success of CP1, many types of nuclear reactors were proposed and investigated. However, soon only a small number of reactors were selected for practical use. Around 1970, only LWRs with small number of CANDUs were operated in the western world, and FBRs were under development. It was about the time when Apollo moon landing was accomplished. However, at the same time, the future of human being was widely considered pessimistic and Limits to Growth was published. In the end of 1970’s the TMI accident occurred and many nuclear reactor contracts were cancelled in USA and any more contracts had not been concluded until recent years. From the reflection of this accident, many Inherent Safe Reactors (ISRs) were proposed, though none of them were constructed. A common idea of ISRs is smallness of their size. Tokyo Institute of Technology (TokyoTech) held a symposium on small reactors, SR/TIT, in 1991, where many types of small ISRs were presented. Recently small reactors attract interest again. The most ideas employed in these reactors were the same discussed in SR/TIT. In 1980’s the radioactive wastes from fuel cycle became a severe problem around the world. In TokyoTech, this issue was discussed mainly from the viewpoint of nuclear transmutations. The neutron economy became inevitable for these innovative nuclear reactors especially small long-life reactors and transmutation reactors

  16. A brief history of design studies on innovative nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sekimoto, Hiroshi, E-mail: hsekimot@gmail.com [Emeritus Professor, Tokyo Institute of Technology (Japan)

    2014-09-30

    In a short period after the success of CP1, many types of nuclear reactors were proposed and investigated. However, soon only a small number of reactors were selected for practical use. Around 1970, only LWRs with small number of CANDUs were operated in the western world, and FBRs were under development. It was about the time when Apollo moon landing was accomplished. However, at the same time, the future of human being was widely considered pessimistic and Limits to Growth was published. In the end of 1970’s the TMI accident occurred and many nuclear reactor contracts were cancelled in USA and any more contracts had not been concluded until recent years. From the reflection of this accident, many Inherent Safe Reactors (ISRs) were proposed, though none of them were constructed. A common idea of ISRs is smallness of their size. Tokyo Institute of Technology (TokyoTech) held a symposium on small reactors, SR/TIT, in 1991, where many types of small ISRs were presented. Recently small reactors attract interest again. The most ideas employed in these reactors were the same discussed in SR/TIT. In 1980’s the radioactive wastes from fuel cycle became a severe problem around the world. In TokyoTech, this issue was discussed mainly from the viewpoint of nuclear transmutations. The neutron economy became inevitable for these innovative nuclear reactors especially small long-life reactors and transmutation reactors.

  17. The Fermi-Pasta-Ulam problem: Simulation and modern dynamics

    International Nuclear Information System (INIS)

    In 1952, Enrico Fermi, John Pasta and Stanislaw Ulam (FPU) simulated the loaded string model, perturbed with small, nonlinear interaction terms. Because Poincare's theorem guarantees the non-existence of a complete set of integrals for three-body problem, they expected to see the diffusion of energy from its single-mode initial condition to all other modes of the string. But for every combination of initial conditions, the energy remained bounded within the lowest few modes. No theoretical explanation existed for this failure of the underlying hypothesis that erogidicity follows from the lack of a complete set of integrals of the motion in a Hamiltonian model. The author traces the history of this problem from the FPU simulation to the point that a consensus was reached concerning its solution twenty years later. During this period, the simulation of nonlinearly-perturbed integral models became the methodology for a new era in dynamics. Through the use of simulation, dynamicists discovered deterministic chaos, in which the exponential separation of pair orbits generate randomness in deterministic macroscopic systems, and a new kind of structure-related to the KAM theorem-that provides limited order in the absence of analytic integrals of the motions. The author maps the set of conceptually-related journal articles into a chronological inference topology that tracks the understanding of this problem of dynamics. Simulating non-integrable models on a digital computer requires the discretization of time and space. These approximations affect what the simulation can reveal about the model, and the model about reality. Simulations play the role of experiments on mathematical models. A discussion is presented of the issues that emerge with the use of simulation as a heuristic device and the groundwork is laid for an epistemology of simulation

  18. FERMI multi-chip module

    CERN Multimedia

    This FERMI multi-chip module contains five million transistors. 25 000 of these modules will handle the flood of information through parts of the ATLAS and CMS detectors at the LHC. To select interesting events for recording, crucial decisions are taken before the data leaves the detector. FERMI modules are being developed at CERN in partnership with European industry.

  19. Fermi Communications and Public Outreach

    CERN Document Server

    Cominsky, L

    2015-01-01

    The Sonoma State University (SSU) Education and Public Outreach (E/PO) group participates in the planning and execution of press conferences that feature noteworthy Fermi discoveries, as well as supporting social media and outreach websites. We have also created many scientific illustrations for the media, tools for amateur astronomers for use at star parties, and have given numerous public talks about Fermi discoveries.

  20. Light water reactor materials and water chemistry studies at Halden

    International Nuclear Information System (INIS)

    The OECD Halden Reactor Project is undertaking several studies aimed at evaluating the effects of coolant chemistry on LWR materials corrosion performance by means of in-pile tests performed in facilities simulating both PWR and BWR environments. A PWR facility has been used to determine the effects of high pH (4-4.5ppm Li) on the corrosion behaviour of Zircaloy-4 cladding material and the results of this investigation are presented. A BWR test facility, dedicated to exploring the effects of environmental variables on the Irradiation Assisted Stress Corrosion Cracking behaviour of stainless steels and nickel-based alloys commonly found in BWRs, is described. The water chemistry monitoring capabilities at Halden are addressed and plans for future studies are discussed. (author)

  1. Neutronic study of a nuclear reactor of fused salts; Estudio neutronico de un reactor nuclear de sales fundidas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia B, F. B.; Francois L, J. L., E-mail: faviolabelen@gmail.com [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-10-15

    The reactors of fused salts called Molten Salt Reactor have presented a resurgence of interest in the last decade, due to they have a versatility in particular to operate, either with a thermal or fast neutrons spectrum. The most active development was by the middle of 1950 and principles of 1970 in the Oak Ridge National Laboratory. In this work some developed models are presented particularly and studied with the help of the MCNPX code, for the development of the neutronic study of this reactor, starting of proposed models and from a simple and homogeneous geometry until other more complex models and approximate to more real cases. In particular the geometry conditions and criticality of each model were analyzed, the isotopic balance, as well as the concentrations of the salts and different assigned fuel types. (Author)

  2. ISO 9001: Quality management systems. The experience of the centre for hydro graphic studies (CEDEX); ISO 9001: Sistemas de gestion de la calidad. La experiencia del Centro de Estudios Hidrograficos del CEDEX

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Garcia, A. M.; Aviles Garcia, J.; Gonzalez Ramos, M. E.; Diago Sanchez, I.

    2010-07-01

    The Spanish government is developing several plans and programmes in order to introduce the quality culture and instruments in the various institutions, looking for efficient and committed public organizations, providers of quality services. To achieve the commitment to improve and modernize the Administration, the Centro de Estudios y Experimentacion de Obras Publicas (CEDEX) has decided the implementation and certification of a Quality Management System according to ISO 9001: standard at the Centro de Estudios Hidrograficos as pilot experience. (Author) 5 refs.

  3. Thomas-Fermi-Dirac-Weizsäcker Density Functional Formalism Applied to the Study of Many-electron Atom Confinement by Open and Closed Boundaries

    Science.gov (United States)

    Cruz, Salvador A.

    An assessment of the use of statistical atomic models for the study of many-electron atom confinement is presented. The Thomas-Fermi-Dirac-[lambda]-Weizsäcker TFD[lambda]W functional formalism based on known properties of the orbital electron density is shown to be an appropriate tool for the description of the ground-state energy evolution of many-electron atoms spatially limited by closed and open boundaries. A brief review of the strategy followed in the TFD[lambda]W method for the study of atoms enclosed in hard and soft spherical cavities is presented along with more refined quantitative calculations as compared with previous results. Also, detailed quantitative results are shown-for the first time-in the case of confinement by a hard prolate spheroidal box for nuclear positions located at one of the foci and for an atom located at a distance D from a hard plane. A discussion is presented on the physical consequences of different confinement geometries and the adequacy of the TFD[lambda]W formalism to explore many-electron atom confinement by open and closed boundaries.

  4. Siting study for small platform-mounted industrial energy reactors

    International Nuclear Information System (INIS)

    Utilizing an existing 313 MW(t) ship propulsion reactor design, a concept has been formulated for a floating platform-mounted nuclear plant and an evaluation has been made to determine reductions in construction time and cost achievable by repetitive platform construction in a shipyard. Concepts and estimates are presented for siting platform-mounted nuclear plants at the location of industrial facilities where the nuclear plants would furnish industrial process heat and/or electrical power. The representative industrial site designated for this study is considered typical of sites that might be used along the extensive network of navigable canals adjacent to the ocean and is similar to potential sites along the inland waterways of the United States

  5. Blanket design study for a Commercial Tokamak Hybrid Reactor (CTHR)

    International Nuclear Information System (INIS)

    The results are presented of a study on two blanket design concepts for application in a Commercial Tokamak Hybrid Reactor (CTHR). Both blankets operate on the U-Pu cycle and are designed to achieve tritium self-sufficiency while maximizing the fissile fuel production within thermal and mechanical design constraints. The two blanket concepts that were evaluated were: (1) a UC fueled, stainless steel clad and structure, helium cooled blanket; and (2) a UO2 fueled, zircaloy clad, stainless steel structure, boiling water cooled blanket. Two different tritium breeding media, Li2O and LiH, were evaluated for use in both blanket concepts. The use of lead as a neutron multiplier or reflector and graphite as a reflector was also considered for both blankets

  6. Study on plasma ignition of JAERI experimental fusion reactor

    International Nuclear Information System (INIS)

    Heating the plasma in JAERI Experimental Fusion Reactor up to the equilibrium operating state has been studied with a time dependent zero-dimensional model. The neoclassical or pseudoclassical scaling-law plays a leading part of the plasma diffusion in the low temperature region below several keV and the trapped-ion scaling-law does so in the higher region. The plasma temperature is raised to 1 keV by 10 sec Joule-heating. The plasma is heated up to the equilibrium operating state of plasma temperature 7 keV and electron density 1.1 x 1020 m-3 by 10 sec neutral beam injection heating with injection power 28 MW and fueling rate 3 x 1019 m-3s-1. (auth.)

  7. A Parameter Study of Large Fast Reactor Nuclear Explosion Accidents

    International Nuclear Information System (INIS)

    An IBM-code EEM (Explosive Excursion Model) has been developed for calculating the energy releases associated with the explosive disassembly of a large fast reactor following a superprompt critical condition. The assumed failure chain of events and the possible core collapse following a fuel meltdown give the input data and initial conditions, the most important of which is the reactivity insertion rate at the moment of the explosive core disassembly. The dependence of the energy releases on the reactivity insertion rate, the Doppler reactivity feedback, the power form factor and the core size have been studied. The model enables a quick estimation of conservative values of the destructive mechanical energy releases following a nuclear explosion and gives suggestions as to how to reduce or even avoid such excursions

  8. Studies of fragileness in steels of vessels of BWR reactors; Estudios de fragilizacion en aceros de vasija de reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Robles, E.F.; Balcazar, M.; Alpizar, A.M.; Calderon, B.E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    The structural materials with those that are manufactured the pressure vessels of the BWR reactors, suffer degradation in its mechanical properties mainly to the damage taken place by the fast neutrons (E > 1 MeV) coming from the reactor core. Its are experimentally studied those mechanisms of neutron damage in this material type, by means of the irradiation of steel vessel in experimental reactors to age them quickly. Alternatively it is simulated the neutron damage by means of irradiation of steel with heavy ions. In this work those are shown first results of the damage induced by irradiation from a similar steel to the vessel of a BWR reactor. The irradiation was carried out with fast neutrons (E > 1 MeV, fluence of 1.45 x 10{sup 18} n/cm{sup 2}) in the TRIGA MARK lll reactor and separately with Ni{sup +3} ions in a Tandetrom accelerator, E = 4.8 MeV and range of the ionic flow of 0.1 to 53 iones/A{sup 2}. (Author)

  9. Study for improvement of performance of the test and research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Fumio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Current utilization needs for the test and research reactors become more advanced and diversified along with the advance of nuclear science and technology. Besides, the requested safety for the research and test reactors grows strictly every year as well as a case of the power reactors. Under this circumstance, every effort to improve reactor performance including its safety is necessary to be sustained for allowing more effective utilization of the test and research reactors as experimental apparatus for advanced researches. In this study, the following three themes i.e., JMTR high-performance fuel element, evaluation method of fast neutron irradiation dose in the JMTR, evaluation method of performance of siphon break valve as core covering system for water-cooled test and research reactors, were investigated respectively from the views of improvement of core performance as a neutron source, utilization performance as an experimental apparatus, and safety as a reactor plant. (author)

  10. Physics and feasibility study of the Fast-Mixed Spectrum Reactor concept

    International Nuclear Information System (INIS)

    Reactor physics and fuel cycle studies, coordinated with heat transfer and material science and structural analysis work has indicated the feasibility potential of the coupled Fast-Mixed Spectrum Reactor (FMSR) concept. This concept employs what are considered reasonable extrapolations of present fast breeder reactor technology to achieve a once-through-and-store reactor fuel cycle. Since the fuel cycle for this reactor is intended to use only natural or depleted uranium for its equilibrium feed, the resultant reactor would have excellent anti-proliferation characteristics. It would also extend utilization of natural uranium resources by a factor of about 15 relative to LWR reactors when on its equilibrium fuel cycle; startup requirements would of course reduce this factor

  11. Magnetic Fustion Reactor Design Studies Program final report, 1 July 1986--30 September 1986

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-09-30

    This report presents progress reported during the period, 7/1/86 - 9/30/86 for the Technical Support Services (TSS) for the Magnetic Fusion Reactor Design Studies Program. Tasks reported include: systems studies work plan, normalization of reactor design studies, interpretation of design study activities, research and development plan, conference support, and reports generated.

  12. Experimental studies of fission properties utilized in reactor design

    International Nuclear Information System (INIS)

    Experimental studies of fission properties utilized in reactor design. A programme of experimental studies of fission parameters useful in reactor design is described including the following: (a) The periods and yields of delayed-neutron groups emitted following the neutron-induced fission of Pu241 are measured. Evidence for systematic isotopic dependence of delayed-neutron yields is presented. An experimental investigation of the relation between the time behaviour of delayed-neutron emission and the energy of the incident neutron inducing fission is described. (b) The cross-section for the inducing, of fission in Am243, Pu242 and Pu241 with neutrons in the energy range 0.030 to 1.8 MeV is measured. Emphasis is placed upon the detailed dependence of the fission cross-section on the incident-neutron energy. The absolute values of the cross-sections are given to a precision of ∼25%. (c) Detailed results of a measurement of the Pu241 fission-neutron spectrum are given, including the spectral shape and average fission-neutron energy. Techniques and methods of measuring prompt-fission-neutron spectra are described. (d) The dependence of #-v# (the average number of neutrons emitted per fission) of U235 on the incident neutron energy is measured from 100 keV to 1.6 MeV. #-v# of U238 and other fissile isotopes is compared to #-v# of U235 (thermal). The relative precision of the measurements is #>approx#1.2%. (author)

  13. Elusiveness of revenge and impossibility of tragedy: Shakespeare’s Hamelt and Pirandello’s Enrico IV Elusiveness of revenge and impossibility of tragedy: Shakespeare’s Hamelt and Pirandello’s Enrico IV

    Directory of Open Access Journals (Sweden)

    Carla Dente

    2008-04-01

    Full Text Available The objective dimension of the relationship between Shakespeare and Pirandello, if one means to restrict it to explicit quotations and allusions, is very limited and would seem to make the link somewhat tenuous between the two dramatists so far apart in time; however, an indirect link—so far not spelled out—does exist, and I intend to reaffirm it here in all its strength. It is a question of a link that is to be found mainly in two plays: Shakespeare’s Hamlet and Pirandello’s Enrico IV (1921, which present on stage basic thematic analogies already articulated and argued in various words by the Italian writer, especially in the novel Il fu Mattia Pascal (1904 and the essay L’umorismo (1908. This is an element that shows the homogeneity, the continuity of the author’s thinking as well as the appearance of the same themes in the different literary forms Pirandello uses. I would like to emphasize in particular, with regard to this, the contiguity between the works of the imagination and these essays, of theory or practice. The objective dimension of the relationship between Shakespeare and Pirandello, if one means to restrict it to explicit quotations and allusions, is very limited and would seem to make the link somewhat tenuous between the two dramatists so far apart in time; however, an indirect link—so far not spelled out—does exist, and I intend to reaffirm it here in all its strength. It is a question of a link that is to be found mainly in two plays: Shakespeare’s Hamlet and Pirandello’s Enrico IV (1921, which present on stage basic thematic analogies already articulated and argued in various words by the Italian writer, especially in the novel Il fu Mattia Pascal (1904 and the essay L’umorismo (1908. This is an element that shows the homogeneity, the continuity of the author’s thinking as well as the appearance of the same themes in the different literary forms Pirandello uses. I would like to emphasize in

  14. Study of plutonium recycling physics in light water reactors

    International Nuclear Information System (INIS)

    A stock of plutonium from the reprocessing of thermal neutron reactor fuel is likely to appear in the next few years. The use of this plutonium as fuel replacing 235U in thermal reactors is probably more interesting than simple stock-piling storage: immobilization of a capital which moreover would deteriorate by radioactive decay of isotope 241 also fissile and present to an appreciable extend in plutonium from reprocessing (half-life 15 years); recycling, on the other hand, will supply energy without complete degradation of the stock for fast neutron reactor loads, the burned matter having been partially renewed by conversion; furthermore the use of plutonium will meet the needs created by a temporary pressure on the naturel and/or enriched uranium market. For these two reasons the recycling of plutonium in thermal neutron reactors is being considered seriously today. The present work is confined to neutronic aspects and centres mainly on pressurized water-moderated reactors, the most highly developed at present in France. Four aspects of the problem are examined: 1. the physics of a plutonium-recycling reactor special features of neutronic phenomena with respect to the 'conventional' scheme of the 235U burning reactor; 2. calculation of a plutonium-recycling reactor: adaptation of standard methods; 3. qualification of these calculations from the viewpoint of both data and inevitable approximations; 4. the fuel cycle and particularly the equivalence of fissile matters

  15. Shuffling strategy study of breeding-burning integrated fast reactor

    International Nuclear Information System (INIS)

    The breeding-burning integrated fast reactor uses burning assemblies to generate thermal power, meanwhile, converts 238U into 239Pu in the fertile assemblies. With periodical shuffling of assemblies, the reactor can maintain criticality for decades of years. To maintain long-term stability of the core reactivity, the core layout and shuffling strategy should balance the burning and the breeding of the assemblies. The scattered core layout and shuffling strategy ensures fast breeding of the fertile assemblies, and keeps stable core power distribution in whole life of the reactor. Moreover, at the end of the reactor life, the discharge burnups of different fuel assemblies are close to each other, which are about 250300 GW · d/t. This is important for breeding-burning integrated fast reactor to achieve very efficient utilization of uranium resource without reprocessing. (authors)

  16. Band structure, Fermi surface, elastic, thermodynamic, and optical properties of AlZr 3 , AlCu 3 , and AlCu 2 Zr: First-principles study

    Science.gov (United States)

    Parvin, R.; Parvin, F.; Ali, M. S.; Islam, A. K. M. A.

    2016-08-01

    The electronic properties (Fermi surface, band structure, and density of states (DOS)) of Al-based alloys AlM 3 (M = Zr and Cu) and AlCu2Zr are investigated using the first-principles pseudopotential plane wave method within the generalized gradient approximation (GGA). The structural parameters and elastic constants are evaluated and compared with other available data. Also, the pressure dependences of mechanical properties of the compounds are studied. The temperature dependence of adiabatic bulk modulus, Debye temperature, specific heat, thermal expansion coefficient, entropy, and internal energy are all obtained for the first time through quasi-harmonic Debye model with phononic effects for T = 0 K–100 K. The parameters of optical properties (dielectric functions, refractive index, extinction coefficient, absorption spectrum, conductivity, energy-loss spectrum, and reflectivity) of the compounds are calculated and discussed for the first time. The reflectivities of the materials are quite high in the IR–visible–UV region up to ∼ 15 eV, showing that they promise to be good coating materials to avoid solar heating. Some of the properties are also compared with those of the Al-based Ni3Al compound.

  17. Variation of the Fermi level in n-type microcrystalline silicon by electron bombardment and successive annealing: ESR and conductivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Astakhov, Oleksandr [IEF-5, Forschungszentrum Juelich (Germany); CYCLORTON research facility, NSC KIPT, Kharkov (Ukraine); Carius, Reinhard; Finger, Friedhelm [IEF-5, Forschungszentrum Juelich (Germany); Petrusenko, Yuri; Borysenko, Valeriy; Barankov, Dmytro [CYCLORTON research facility, NSC KIPT, Kharkov (Ukraine)

    2010-04-15

    ESR and conductivity studies have been preformed on {mu}c-Si:H exposed to 2 MeV electron bombardment and successive annealing in order to investigate the influence of the defect density on the electronic properties of n-type {mu}c-Si:H. With this approach one can vary the defect density in one and the same sample and directly deduce its influence on the electronic properties. The defect density is varied by 2 orders of magnitude with strong influence on the dark conductivity and electron spin resonance (ESR) properties. The relationship of ESR and conductivity data obtained over the whole defect density range is in agreement with the data obtained on the sets of samples deposited with different doping level. The results indicate that the Fermi level position in {mu}c-Si:H is defined by a balance of defect and donor states densities regardless of which of these quantities is varied. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Fermi Study of 5-300 GeV emission from the high-mass pulsar binary PSR B1259-63/LS 2883

    CERN Document Server

    Xing, Yi; Takata, Jumpei

    2016-01-01

    We report the results from our detailed analysis of the Fermi Large Area Telescope (LAT) data for the pulsar binary PSR B1259-63/LS 2883. During the GeV flares that occurred when the pulsar was in the periastron passages, we have detected a 5--300 GeV component at $\\simeq 5\\sigma$ in emission from the binary. The detection verifies the presence of the component that has been marginally found in the previous studies of the binary. Furthermore, we have discovered that this component was present even in the quiescent state of the binary, specifically the mean anomaly phase 0.7--0.9. The component can be described by a power law with photon index $\\Gamma\\sim 1.4$, and the flux in the flares is approximately one order of magnitude higher than that in quiescence. We discuss the origin of this component. It likely arises from the inverse-Compton process: high-energy particles from the shock, due to the interaction between the winds from the pulsar and massive companion, scatter the seed photons from the companion to...

  19. Electronic structure near the Fermi level in the ferromagnetic semiconductor GaMnAs studied by ultrafast time-resolved light-induced reflectivity measurements

    Science.gov (United States)

    Ishii, Tomoaki; Kawazoe, Tadashi; Hashimoto, Yusuke; Terada, Hiroshi; Muneta, Iriya; Ohtsu, Motoichi; Tanaka, Masaaki; Ohya, Shinobu

    The determination of the Fermi level (EF) position is important to understand the origin of the ferromagnetism in ferromagnetic semiconductor GaMnAs. The recent transient reflectivity (TR) spectroscopy measurement, which is potentially sensitive to the absorption edges, indicated that the EF exists in the valence band. However, the pump fluence in this study is rather high, and the accumulation of photo-carriers can shift the absorption edges. Thus, the definition of both the band gap and EF is obscure. Here, we have performed TR spectroscopy measurements on GaMnAs films with the pump fluence carefully controlled to suppress the accumulation of photo-carriers. The energy resolution of the TR spectrum was improved to 0.5 meV. The data shows light-induced change in the reflectivity spectra which is attributed to the band-gap renormalization and band filling. We have reproduced the observed TR spectra using the Kramers-Kronig relation and found the Mn-induced electronic states near the EF in the band gap. This work was partially supported by Grants-in-Aids for Scientific Research including Specially Promoted Research and Project for Developing Innovation Systems of MEXT.

  20. What can we learn from high energy flares in the Fermi sample of FSRQs : from a case study to dozens of objects

    Directory of Open Access Journals (Sweden)

    Pacciani Luigi

    2013-12-01

    Full Text Available In 2008 the flat spectrum radio quasar GB6 J1239+0443 (z=1.762, underwent an high activity period at all wavelengths. In particular, at optical-uv wavelengths, the source underwent a flux enhancement of a factor 15–30 in 6 years, and >10 in half a year, showing a transition from accretion disk to synchrotron jet dominated emission. During the flare, Fermi observed a flat gamma-ray spectrum, extended up to 15 GeV, with no statistically-significant absorption from the broad line region (BLR, suggesting that the blazar-zone is located beyond it. We obtained the same findings from the modeling of the broad-band spectral energy distribution for the flaring activity periods, which is well constrained by the multiwavelength data collected, and from the accretion disk luminosity and black hole mass that we estimated from the archival data. Other authors suggested that 4C +21.35, PMN J2345-1555, and 3C 279 underwent high energy flares originating from outside or just beyond the BLR.We report here the first results obtained in our study, while we will report the results on the complete sample in a forthcoming paper where we will show the multiwavelength spectra on a dozen of FSRQ which we propose radiate gamma-rays far from the central SMBH, and we will discuss the scenarios originating from this result.

  1. Study of the pyrochemical treatment-recycling process of the Molten Salt Reactor fuel

    International Nuclear Information System (INIS)

    The Separation Processes Studies Laboratory (Commissariat a l'energie Atomique) has made a preliminary assessment of the reprocessing system associated with Molten Salt Fast Reactor (MSFR). The scheme studied in this paper is based on the principle of reductive extraction and metal transfer that constituted the core process designed for the Molten Salt Breeder Reactor (MSBR), although the flow diagram has been adapted to the current needs of the Molten Salt Reactor Fast (MSFR).

  2. Tokamak power systems studies: A second stability power reactor

    International Nuclear Information System (INIS)

    A number of innovative physics and engineering features have been studied which promise to greatly improve the reactor prospects of tokamaks relative to STARFIRE. A reference design point has been developed with the following features: large aspect ratio (A = 6); high beta (β ≅ 0.20), with only mild shaping and no indentation, which brings the maximum toroidal field down to 7 T; low toroidal current (I ≅ 5MA), which reduces the cost of the current drive and EF coil system; and steady-state operation with combined fast wave and lower hybrid wave current drive. The key to high beta operation with low toroidal current lies in utilizing second stability regime equilibria with control of the current achieved by the appropriate choice of wave frequencies and spectra. By selecting an axial safety factor q(o) = 2.0, MHD stability has been found above β ≅ 0.20. Additional features include: impurity control with self-pumped limiters which bury helium on continuously deposited metal surfaces; liquid Li-cooled blanket which provides good performance with low pressure operation; vanadium alloy blanket structure for higher thermal efficiency (eta = 0.42), longer lifetime and reduced activation; and reduced reactor mass (higher power density) due to smaller TF coil, less shielding, fewer blanket penetrations, and higher wall loading. At low neutron wall loads this device represents a minimum capital cost unit. However, economies of scale are strong, and eventually higher wall loads (W ≅ 8 MW/m2, P/sub net/ = 1400 MW) may prove most attractive. Preliminary investigations show inherently safe operation is likely at W ≥ 5 MW/m2. 15 refs., 3 figs., 1 tab

  3. Experimental study of neutrino oscillations at a fission reactor

    International Nuclear Information System (INIS)

    The energy spectrum of neutrinos from a fission reactor was studied with the aim of gaining information on neutrino oscillations. The well shielded detector was set up at a fixed position of 8.76 m from the point-like core of the Laue-Langevin reactor in an antineutrino flux of 9.8 x 1011cm-2s-1. The target protons in the reaction antiνsub(e)p → e+n were provided by liquid scintillation counters (total volume of 377l) which also served as positron detectors. The product neutrons moderated in the scintillator were detected by 3He wire chambers. A coincidence signature was required between the prompt positron and the delayed neutron events. The positron energy resolution was 18% FWHM at 0.91 MeV. The signal-to-background ratio was better than one to one between 2 MeV and 6 MeV positron energy. At a counting rate of 1.58 counts per hour, 4890+-180 neutrino induced events were detected. The shape of the measured positron spectrum was analyzed in terms of the parameters Δ2 and sin2 2theta for two-neutrino oscillations. The experimental data are consistent with no oscillations. An upper limit of 0.15 eV2 (90% c.l.) for the mass-squared differences Δ2 of the neutrinos was obtained, assuming maximum mixing of the two neutrino states. The ratio of the measured to the expected integral yield of positrons assuming no oscillations was determined to be ∫Ysub(exp)/∫Ysub(th) = 0.955+-0.035 (statistical)+-0.110 (systematic)

  4. Optimal design study of cylindrical finned reactor for solar adsorption cooling machine

    Energy Technology Data Exchange (ETDEWEB)

    Allouache, N. [Univ. des Sciences et de la Technologie Houari Boumediene, Bab Ezzouar (Algeria). Faculte de Genie Mecanique et de Genie des Procedes; Al Mers, A. [Moulay Ismail Univ., Meknes (Morocco). Ecole National Superieure d' Art et Metiers

    2010-07-01

    Solid adsorption cooling machines use medium temperature industrial waste heat together with a renewable energy source, such as solar energy. The adsorption cooling machine consists of an evaporator, a condenser and a reactor containing a solid adsorbent. In this study, a model was developed for thermodynamic performance analysis and optimization of a cylindrical finned solar reactor in an adsorption refrigerator working with activated carbon-ammonia. The heat and mass transfer in the adsorption cooling machine was determined. The model was validated using experimental results. The study investigated the sensitivity of the machine performance versus the geometrical configuration of the reactor. The study showed that for an optimized reactor, a higher fin number significantly reduces the heat losses of the reactor. It was concluded that the solar coefficient of performance (COP) of an optimized reactor can reach 45 per cent when the number of fins varies between 5 and 6. 10 refs., 4 figs.

  5. The Kerr-Fermi Sea

    CERN Document Server

    Hartman, Thomas; Strominger, Andrew

    2009-01-01

    The presence of a massive scalar field near a Kerr black hole is known to produce instabilities associated with bound superradiant modes. In this paper we show that for massive fermions, rather than inducing an instability, the bound superradiant modes condense and form a Fermi sea which extends well outside the ergosphere. The shape of this Fermi sea in phase space and various other properties are analytically computed in the semiclassical WKB approximation. The low energy effective theory near the black hole is described by ripples in the Fermi surface. Expressions are derived for their dispersion relation and the effective force on particles which venture into the sea.

  6. Active orogeny of the south-central Andes studied with GPS geodesy Orogenia activa de los Andes centro-australes estudiada mediante geodesia de GPS

    Directory of Open Access Journals (Sweden)

    E. Kendrick

    2006-12-01

    Full Text Available We present GPS measurements of the crustal velocity field in the southern Central Andes between the Santa Cruz corner and the Malargüe fold and thrust belt, and model this interseismic velocity field as the combination of an ephemeral, elastic signal associated with locking of the main plate boundary, and a steady and non-reversing component of displacement associated with localized backarc convergence and growth of the mountain belt. We find that this second component, i.e. the ongoing and permanent displacement of the forearc and the high Andes relative to the craton, can be modeled very well as a steady clockwise rotation of an Andean microplate about a pole located in southern Argentina. Near the Malargüe Basin, this microplate (or block is moving nearly parallel to the strike of the orogen, transporting material towards the bend in the central Andes. Farther north, in the southern limb of the Central Andes, the motion of this same crustal block is directed nearly perpendicular to the strike of the mountain belt. Our results suggest that permanent deformation rates in the backarc range from a maximum of ~ 6-7 mm/yr in the Bolivian Subandes to less than ~ 3 mm/yr in the Argentine Precordillera and Malargue fold and thrust belt. It is likely that most active backarc deformation is accruing in a narrow zone (~ 50 km wide associated with the backarc boundary (usually defined as the thrust front though at this stage it is impossible to distinguish whether specific backarc structures are actively accruing strain.Se presentan mediciones GPS del campo de velocidad en los Andes centro-australes entre el extremo norte de Santa Cruz y la faja plegada de Malargüe. Se modela el campo de velocidad intersísmico como la combinación de una señal elástico/efímera asociada con el anclaje del límite principal de placas, y una componente constante, no reversible de desplazamiento asociada con una convergencia localizada en el retroarco y crecimiento del

  7. Strongly correlated Fermi-systems: Non-Fermi liquid behavior, quasiparticle effective mass and their interplay

    International Nuclear Information System (INIS)

    Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc., gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh2Si2.

  8. Conceptual Study on Dismantling of CANDU Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

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

  9. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Christopher; Erickson, Anna [Georgia Institute of Technology, Nuclear and Radiological Engineering, G. W. Woodruff School of Mechanical Engineering, 770 State St. NW, Atlanta, Georgia 30332 (United States)

    2015-10-28

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0–6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  10. Study of organic waste for production of hydrogen in reactor

    International Nuclear Information System (INIS)

    Biological processes have long been used for the treatment of organic waste makes, especially our study is based on the anaerobic process in reactors, using residual organic industry. Without excluding other non-industrial we have studied. Fundamental objectives treating organic waste is to reduce the pollutant load to the environment, another aim is to recover the waste recovering the energy contained in it. In this context, the biological hydrogen production from organic waste is an interesting alternative because it has low operating costs and raw material is being used as a residue in any way should be treated before final disposal. Hydrogen can be produced sustainable by anaerobic bacteria that grow in the dark with rich carbohydrate substrates giving as final products H2, CO2 and volatile fatty acids. The whey byproduct from cheese production, has great potential to be used for the generation of hydrogen as it has a high carbohydrate content and a high organic load. The main advantages of using anaerobic processes in biological treatment of organic waste, are the low operating costs, low power consumption, the ability to degrade high organic loads, resistance biomass to stay long in the absence of substrate, without lose their metabolic activity, and low nutritional requirements and increase the performance of 0.9 mol H2 / mol lactose. (full text)Biological processes have long been used for the treatment of organic waste makes, especially our study is based on the anaerobic process in reactors, using residual organic industry. Without excluding other non-industrial we have studied. Fundamental objectives treating organic waste is to reduce the pollutant load to the environment, another aim is to recover the waste recovering the energy contained in it. In this context, the biological hydrogen production from organic waste is an interesting alternative because it has low operating costs and raw material is being used as a residue in any way should be treated

  11. Study on the fuel balance of a DT reactor

    International Nuclear Information System (INIS)

    The tritium balance in a DT fusion reactor is discussed in this paper. It is pointed out in this discussion that tritium balance in a fusion reactor is largely influenced by such uncertainties as plasma vessel effect, module effect and recovery efficiency of bred tritium required to estimate the overall tritium recovery efficiency and such uncertainties as overall burning efficiency of tritium in the plasma vessel, tritium trapping ratio at the first wall, loss due to β-decay of tritium inventory and designated reactor base tritium breeding ratio required to decide (β)overall to decide tritium balance.

  12. Study on transient of fluidized bed nuclear reactor

    International Nuclear Information System (INIS)

    The point kinetic equations for a Fluidized-Bed Nuclear Reactor are solved by the method of Hansen. Due to the time varying nature of the reactor volume, the equations have a non-conventional formulation (moving boundary problem), but the method of solution preserves its asymptotic convergence and efficiency characteristics under this formulation. A one dimensional and linearized thermal hydraulics feedback model was coupled to the point kinetic equations in order to obtain a more realistic representation of the reactor power. The resulting equations are solved by the Euler explicit method. (author)

  13. Study on reactor building structure using ultrahigh strength materials, 5

    International Nuclear Information System (INIS)

    Reinforced concrete (RC) shear walls are the main members of a reactor building for the aseismatic design. The characteristics of nonlinear behavior have been clarified by a number of experimental studies, and the reliability of the nonlinear analysis of RC structures by FEM has been improved by the studies on the constitutive equation for concrete and the simulation analysis of test results. However, the characteristics of the RC shear walls made of ultrahigh strength materials have not been sufficiently studied. In this paper, the nonlinear analysis of the RC shear walls made of ultrahigh strength materials is discussed. Based on the results of a series of the material test and pure shear test on ultrahigh strength materials, the simulation analysis of bending shear test was performed by three-dimensional nonlinear FEM. The specimens used for the bending shear test were single story, single span model shear walls. The analytical method, the modeling of concrete and reinforcing bars, the properties of the materials used and the results of analysis on the effects of concrete strength and the quantity and grade of bars are reported. (K.I.)

  14. Conceptual design study of fusion experimental reactor (FY86FER)

    International Nuclear Information System (INIS)

    This report describes the results of the capacity estimation for the electrical power system on the typical two candidates for the FER (Fusion Experimental Reactor) which were picked out through the process of '86 FER scoping studies. Main concern in the electrical systems is coil power supplies which have a capacity of about 1 GW, and this is dominated by poloidal coil power supplies. Then, studies to reduce the converter capacity are concentrated on the poloidal coil power system in relation to the sypplying poloidal flux at the initial phase of plasma ramp-up. A quench protection circuit was proposed on the toroidal coil power supply. On the position control power supply, a circuit with reasonable functions was proposed. Under these system studies, general specifications were determined and the capacity of each power supply unit was estimated. On the poloidal coil power supply system, the accumulated capacity of converters amounted to 885 MW for the one candidate and 782 MW for another. (author)

  15. Small and medium power reactors: project initiation study, Phase 1

    International Nuclear Information System (INIS)

    In conformity with the Agency's promotional role in the peaceful uses of nuclear energy, IAEA has provided, over the past 20 years, assistance to Member States, particularly developing countries, in planning for the introduction of nuclear power plants in the Small and Medium range (SMPR). However these efforts did not produce any significant results in the market introduction of these reactors, due to various factors. In 1983 the Agency launched a new SMPR Project Initiation Study with the objective of surveying the available designs, examining the major factors influencing the decision-making processes in Developing Countries and thereby arriving at an estimate of the potential market. Two questionnaires were used to obtain information from possible suppliers and prospective buyers. The Nuclear Energy Agency of OECD assisted in making a study of the potential market in industrialized countries. The information gained during the study and discussed during a Technical Committee Meeting on SMPRs held in Vienna in March 1985, along with the contribution by OECD-NEA is embodied in the present report

  16. analysis and implementation of reactor protection system circuits - case study Egypt's 2 nd research reactor-

    International Nuclear Information System (INIS)

    this work presents a way to design and implement the trip unit of a reactor protection system (RPS) using a field programmable gate arrays (FPGA). instead of the traditional embedded microprocessor based interface design method, a proposed tailor made FPGA based circuit is built to substitute the trip unit (TU), which is used in Egypt's 2 nd research reactor ETRR-2. the existing embedded system is built around the STD32 field computer bus which is used in industrial and process control applications. it is modular, rugged, reliable, and easy-to-use and is able to support a large mix of I/O cards and to easily change its configuration in the future. therefore, the same bus is still used in the proposed design. the state machine of this bus is designed based around its timing diagrams and implemented in VHDL to interface the designed TU circuit

  17. Phenomenological study of in-reactor corrosion of Zircaloy-4 in pressurized water reactors

    International Nuclear Information System (INIS)

    Uniform in-reactor corrosion has been examined on pressurized water reactor (PWR) Zircaloy-4 fuel cladding that were irradiated up to four cycles in the KORI Unit 1. The oxide layer that was formed on the Zircaloy-4 fuel claddings changes from a uniform black oxide into the nonuniform white granular oxides when the oxide layer reaches about 5 to 10 μm. With irradiation exposure, enough of the white granular oxides have nucleated above the black oxide layer to entirely cover the fuel cladding, resulting in a gray or white cladding surface. The change in the oxide layer growth pattern from the uniform black oxide layer into the nonuniform granular oxides resulted in the formation of macro-pores or cracks in the oxide layer, causing the corrosion rate to change into a linear rate from the cubic rate, especially at the beginning of fuel rod life. Consequently, the nucleation of white granular oxides is a phenomenological indicator of the transition of the in-reactor corrosion rate. To explain the effect of hydride precipitates on the in-reactor corrosion, the corrosion behavior for a defective fuel rod with a through-hole and in intact fuel rod adjacent to it (both were irradiated for two cycles in the KORI Unit 1) has been investigated. Even through both of them were found to have almost identical operating power histories, their corrosion behavior was quite different: the maximum oxide layer thickness for the intact fuel rod was less than 10 μm, while the defective fuel rod had an abnormally thick oxide of 50 μm, especially at an elevation where a large extent of hydrides (corresponding to 1,295 to 1,520 ppm hydrogen) were precipitated at the cladding outer surface

  18. Preliminary Study for Conceptual Design of Advanced Long Life Small Modular Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tak, Taewoo; Choe, Jiwon; Jeong, Yongjin; Lee, Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, T. K. [Argonne National Laboratory, Argonne (United States)

    2015-05-15

    As one of the non-water coolant Small-Modular Reactor (SMR) core concepts for use in the mid- to long-term, ANL has proposed a 100 MWe Advanced sodium-cooled Fast Reactor core concept (AFR-100) targeting a small grid, transportable from pre-licensed factories to the remote plant site for affordable supply. Various breed-and-burn core concepts have been proposed to extend the reactor cycle length, which includes CANDLE with a cigar-type depletion strategy, TerraPower reactors with fuel shuffling for effective breeding, et al. UNIST has also proposed an ultra-long cycle fast reactor (UCFR) core concept having the power rating of 1000 MWe. By adopting the breed-and-burn strategies, the UCFR core can maintain criticality for a targeting reactor lifetime of 60 years without refueling. The objective of this project is to develop an advanced long-life SMR core concept by adopting both the small modular design features of the AFR-100 and the long-life breed-and-burn concept of the UCFR. A conceptual design of long life small modular fast reactor is under development by adopting both the small modular design features of the AFR-100 and the long-life breed-and-burn concept of the UCFR. The feasibility of the long-life fast reactor concepts was reviewed to obtain the core design guidelines and the reactor design requirements of long life small modular fast reactor were proposed in this study.

  19. Preliminary Study for Conceptual Design of Advanced Long Life Small Modular Fast Reactor

    International Nuclear Information System (INIS)

    As one of the non-water coolant Small-Modular Reactor (SMR) core concepts for use in the mid- to long-term, ANL has proposed a 100 MWe Advanced sodium-cooled Fast Reactor core concept (AFR-100) targeting a small grid, transportable from pre-licensed factories to the remote plant site for affordable supply. Various breed-and-burn core concepts have been proposed to extend the reactor cycle length, which includes CANDLE with a cigar-type depletion strategy, TerraPower reactors with fuel shuffling for effective breeding, et al. UNIST has also proposed an ultra-long cycle fast reactor (UCFR) core concept having the power rating of 1000 MWe. By adopting the breed-and-burn strategies, the UCFR core can maintain criticality for a targeting reactor lifetime of 60 years without refueling. The objective of this project is to develop an advanced long-life SMR core concept by adopting both the small modular design features of the AFR-100 and the long-life breed-and-burn concept of the UCFR. A conceptual design of long life small modular fast reactor is under development by adopting both the small modular design features of the AFR-100 and the long-life breed-and-burn concept of the UCFR. The feasibility of the long-life fast reactor concepts was reviewed to obtain the core design guidelines and the reactor design requirements of long life small modular fast reactor were proposed in this study

  20. Fermi LAT View of a Sample of Flaring -Ray AGNs

    Indian Academy of Sciences (India)

    S. Buson; D. Bastieri; F. D’Ammando; G. Tosti

    2014-09-01

    In the first 3.5 years of operations, Fermi detected several sources whose flaring activity brought them to exceed daily fluxes brighter than ( > 100MeV) > 10-6 ph cm-2 s-1. These episodes were promptly reported to the scientific community by the Fermi collaboration by means of astronomer telegrams (ATels). We focus our attention on the sample composed by these flaring sources, most of which are blazars, known to be extremely variable over the whole electromagnetic spectrum, from radio to -ray energies. We study properties of the selected sample and compare them to general characteristics of the Fermi source catalogue.

  1. The Fermi-GBM X-ray burst monitor

    Science.gov (United States)

    Linares, M.; Fermi GBM X-ray Burst Collaboration

    2010-12-01

    We discuss the first results of the Fermi-GBM all-sky search for X-ray bursts. The very large field of view and X-ray response of the Fermi-GBM make it a unique instrument to study rare, bright and short-lived X-ray bursts. We are performing a systematic search that exploits such capabilities. We present results on long/intermediate type I X-ray bursts, an unusual kind of thermonuclear bursts from accreting neutron stars, and show how Fermi-GBM is giving for the first time robust measurements of their recurrence time.

  2. Electronic structure modification and Fermi level shifting in niobium-doped anatase titanium dioxide thin films: a comparative study of NEXAFS, work function and stiffening of phonons.

    Science.gov (United States)

    Gautam, Subodh K; Das, Arkaprava; Ojha, S; Shukla, D K; Phase, D M; Singh, Fouran

    2016-02-01

    The electronic structure and tuning of work function (WF) by electronic excitations (EEs) induced by swift heavy ions (SHIs) in anatase niobium-doped titanium dioxide (NTO) thin films is reported. The densities of EEs were varied using 80 MeV O, 130 MeV Ni and 120 MeV Ag ions for irradiation. The EE-induced modifications in electronic structure were studied by O K-edge and Ti L3,2 edge absorption spectra using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The reduction of hybridized O 2p and Ti 3d unoccupied states in the conduction band with a decrease in energy of the crystal field strength of ∼ 480 meV and the correlated effect on the decrease in the WF value of ∼ 520 meV upon increasing the total energy deposition in the lattice are evident from the study of NEXAFS and scanning Kelvin probe microscopy (SKPM), respectively. The observed stiffening in the low frequency Raman mode (LFRM) of ∼ 9 cm(-1) further validates the electronic structure modification under the influence of EE-induced strain in TiO6 octahedra. The reduction of hybridized valence states, stiffening behavior of LFRM and decrease in WF by nano-crystallization followed by amorphization and defects in NTO lattice are explained in terms of continuous, discontinuous amorphous ion tracks containing intestinally created defects and non-stoichiometry in the lattice. These studies are very appropriate for better insights of electronic structure modification during phase transformation and controlled Fermi level shifting, which plays a crucial role in controlling the charge carrier injection efficiency in opto-electronic applications and also provides a deeper understanding of the involved physical processes. PMID:26752253

  3. Introduction to the study of boiling in water reactors

    International Nuclear Information System (INIS)

    In order to plot the low and high power transfer function for a reactor using its background, a conventional method is proposed here for estimating the efficiency of a CC5 chamber associated to a direct current detection system. (author)

  4. Reactor physics studies for assessment of tramp uranium methods

    International Nuclear Information System (INIS)

    This paper presents calculation studies towards validation of a methodology for estimations of the tramp uranium mass from water chemistry measurements. Particular emphasis is given to verify, from a reactor physics point of view, the justification basis for the so-called 'Pu-based model' versus the 'U-based model' as a key assumption for the methodology. The computational studies are carried out for a typical BWR fuel assembly with CASMO-5M and MCNPX. By approximating the evolution of fissile nuclides and the fraction of 235U fissions to total fissions in different zones of a fuel rod, including tramp uranium on the clad surface, it is found that Pu gives the dominant contribution to fissions for tramp uranium after an irradiation on the outer clad surface of at least one cycle in a BWR. Thus, the use of the so-called Pu model for the determination of the tramp uranium mass (this means in particular using the yields for 239Pu fission) appears justified in the cases considered. On that basis, replacing the older U model by a Pu model is recommended. (authors)

  5. Reactor physics studies for assessment of tramp uranium methods

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, P.; Vasiliev, A.; Wieselquist, W.; Ferroukhi, H. [Paul Scherrer Institut, CH 5232 Villigen (Switzerland); Ledergerber, G. [Kernkraftwerk Leibstadt AG, CH 5325 Leibstadt (Switzerland)

    2012-07-01

    This paper presents calculation studies towards validation of a methodology for estimations of the tramp uranium mass from water chemistry measurements. Particular emphasis is given to verify, from a reactor physics point of view, the justification basis for the so-called 'Pu-based model' versus the 'U-based model' as a key assumption for the methodology. The computational studies are carried out for a typical BWR fuel assembly with CASMO-5M and MCNPX. By approximating the evolution of fissile nuclides and the fraction of {sup 235}U fissions to total fissions in different zones of a fuel rod, including tramp uranium on the clad surface, it is found that Pu gives the dominant contribution to fissions for tramp uranium after an irradiation on the outer clad surface of at least one cycle in a BWR. Thus, the use of the so-called Pu model for the determination of the tramp uranium mass (this means in particular using the yields for {sup 239}Pu fission) appears justified in the cases considered. On that basis, replacing the older U model by a Pu model is recommended. (authors)

  6. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    This report summarizes the FER magnet design which was conducted last year (1986). Main objective of the new FER design is to have better cost performance of the machine. The physics assumptions are reviewed to reduce risks. Optimization of the physics design and improvements of the engineering design have been done without changing missions of the device. After a preliminary investigation for the optimization and improvements, six FER concepts have been developed to establish the improved design point, and have been studied in more detail. In the magnet design, the improvements of superconducting magnet design were mainly investigated to reduce the reactor size. A normal conductor was studied as an alternative option for appling to the special poloidal field coils that were located on the interior to the toroidal field coils. Some improvements were made on the superconducting magnet design. Based on the preliminary investigation, the magnet design specifications have been modified somewhat. The conceptual design of the magnet system components have been done for the candidate FER concepts. (author)

  7. Software to study the control strategy of pressurized water reactor

    International Nuclear Information System (INIS)

    The computational program, result of this work, is a tool developed for the study of the control of Pressurized Water Reactors (PWR) constituted by only one coolant loop. The implementation of a user friendly interface for input/output data, makes the program also suitable for training and teaching applications. As design premise, it was considered enough just the modeling of the primary circuit, using as interface with the secondary circuit, a simplified differential equation of the temperature associated with the secondary power. All the incorporated dynamic equations to the model were developed using basic laws of conservation, boundary conditions and hypotheses appropriated to the control study. To arrive to the final model, core thermal and hydraulic characteristics and design data were obtained from of the available bibliography and adapted for a conceptual peculiar design of a small PWR. The whole program and all input/output interfaces were developed using the software Matlab, version 5.L Sub-routines of numeric integration based on the Runge-Kutta 4 method were applied, to solve the set of ordinary differential equations. (author)

  8. Study and Analysis on Naphtha Catalytic Reforming Reactor Simulation

    Institute of Scientific and Technical Information of China (English)

    Liang Ke min; Song Yongji; Pan Shiwei

    2004-01-01

    A naphtha catalytic reforming unit with four reactors connected in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reaction characteristics based on idealizing the complex naphtha mixture to represent the paraffin, naphthene, and aromatic groups with individual compounds. The simulation results based on above models agree very well with actual operating data of process unit.

  9. Reactor Technology Options Study for Near-Term Deployment of GNEP Grid-Appropriate Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ingersoll, Daniel T [ORNL; Poore III, Willis P [ORNL

    2007-09-01

    World energy demand is projected to significantly increase over the coming decades. The International Energy Agency projects that electricity demand will increase 50% by 2015 and double by 2030, with most of the increase coming in developing countries as they experience double-digit rates of economic growth and seek to improve their standards of living. Energy is the necessary driver for human development, and the demand for energy in these countries will be met using whatever production technologies are available. Recognizing this inevitable energy demand and its implications for the United States, the U.S. National Security Strategy has proposed the Global Nuclear Energy Partnership (GNEP) to work with other nations to develop and deploy advanced nuclear recycling and reactor technologies. This initiative will help provide reliable, emission-free energy with less of the waste burden of older technologies and without making available separated plutonium that could be used by rogue states or terrorists for nuclear weapons. These new technologies will make possible a dramatic expansion of safe, clean nuclear energy to help meet the growing global energy demand. In other words, GNEP seeks to create an international regime to support large-scale growth in the worldwide use of nuclear energy without increasing the risk of nuclear weapon proliferation. This global expansion of nuclear power is strategically important to the United States for several reasons, including the following: (1) National security, by reducing the competition and potential for conflict over increasingly scarce fossil energy resources; (2) Economic security, by helping maintain stable prices for nonrenewable resources such as oil, gas, and coal; (3) Environmental security, by replacing or off-setting large-scale burning of greenhouse gas-emitting fuels for electricity production; and (4) Regaining technical leadership, through deployment of innovative U.S. technology-based reactors. Fully meeting

  10. Reactor Technology Options Study for Near-Term Deployment of GNEP Grid-Appropriate Reactors

    International Nuclear Information System (INIS)

    World energy demand is projected to significantly increase over the coming decades. The International Energy Agency projects that electricity demand will increase 50% by 2015 and double by 2030, with most of the increase coming in developing countries as they experience double-digit rates of economic growth and seek to improve their standards of living. Energy is the necessary driver for human development, and the demand for energy in these countries will be met using whatever production technologies are available. Recognizing this inevitable energy demand and its implications for the United States, the U.S. National Security Strategy has proposed the Global Nuclear Energy Partnership (GNEP) to work with other nations to develop and deploy advanced nuclear recycling and reactor technologies. This initiative will help provide reliable, emission-free energy with less of the waste burden of older technologies and without making available separated plutonium that could be used by rogue states or terrorists for nuclear weapons. These new technologies will make possible a dramatic expansion of safe, clean nuclear energy to help meet the growing global energy demand. In other words, GNEP seeks to create an international regime to support large-scale growth in the worldwide use of nuclear energy without increasing the risk of nuclear weapon proliferation. This global expansion of nuclear power is strategically important to the United States for several reasons, including the following: (1) National security, by reducing the competition and potential for conflict over increasingly scarce fossil energy resources; (2) Economic security, by helping maintain stable prices for nonrenewable resources such as oil, gas, and coal; (3) Environmental security, by replacing or off-setting large-scale burning of greenhouse gas-emitting fuels for electricity production; and (4) Regaining technical leadership, through deployment of innovative U.S. technology-based reactors. Fully meeting

  11. Study of the characteristics of methanol synthesis in a recirculation slurry reactor - a novel three-phase synthesis reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.H.; Wang, X.J.; Yu, G.S.; Wang, F.C.; Yu, Z.H. [Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237 (China)

    2008-01-15

    A process feasibility analysis on the liquid phase methanol synthesis (LPMeOH trademark) process was performed in a recirculation slurry reactor (RSR). In the three-phase RSR system, a fine catalyst is slurried in the paraffin and this catalyst slurry is continuously recirculated through the nozzle from the slurry sector to the entrained sector by a pump. The syngas is fed concurrently with the downward flow of slurry to form the methanol product. A laboratory scale mini-pilot plant version of a recirculation slurry reactor system was successfully designed and built to carry out process engineering research, and in addition, an identical cold model was built to measure the mass transfer coefficient in the recirculation slurry reactor. The effects of operating conditions, including temperature, pressure, gas flow rate and catalyst slurry recirculation flow rate on the productivity of methanol were studied. This experimental data helps the scale-up and commercialization of the methanol synthesis process in recirculation slurry reactors. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  12. Design study of plant system for the fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    This report describes design study results of the FER plant system. The purpose of this study is to have an image of the FER plant system as a whole by designing major auxiliary systems, reactor building and maintenance and radwaste desposal systems. The major auxiliary systems include tritium, cooling, evacuation and fueling systems. For these each systems, flowdiagrams are studied and designs of devices and pipings are conducted. In the reactor building design, layout of the above auxiliary systems in the building is studied with careful zoning concept by the radiation level. Structural integrity of the reactor building is also studied including seismic analysis. In the design of the maintenance and radwaste system flowdiagram of failed reactor components is developed and transfer vehicles and buildings are designed. Finally assuming JAERI Naka site as the reactor site layout of the whole FER plant system is developed. (author)

  13. A neutronic feasibility study on a small LEU fueled reactor for space applications

    International Nuclear Information System (INIS)

    Highlights: • The minimum critical reactor mass with a simple homogeneous core was investigated. • The minimum mass of 133.8 kg was achieved with LEU-ZrH1.5 core and Be reflector. • The reactor mass can be reduced by introducing heterogeneous core configuration. • Three space reactor designs with a control rod system were presented. • The neutronic performance and the safety behavior of the reactors were investigated. - Abstract: In this paper, a neutronic feasibility study on a small space reactor with LEU fuel is presented. The minimum critical reactor mass of a simple homogeneous core model was investigated for the variety of fuel types, moderator materials, and reflector materials. Lithium hydride (LiH) with 99.99% enriched 7Li showed a very good performance in terms of reactor mass. However, further study should be conducted to resolve the problems that could rise from the poor thermal properties of LiH such as a low melting point, low thermal conductivity, and high thermal expansion coefficient. The combination of uranium metal fuel and zirconium hydride (ZrH1.5) moderator with a Be reflector showed a good performance as well. Uranium hydride (UH3) is a very attractive fuel from a neutronic point of view. However, it requires hydrogen pressurization for high temperature operation due to its low hydrogen decomposition temperature. It was also shown that the core reactivity can be maximized or the critical reactor mass can be further reduced by adopting a heterogeneous core configuration through stacking fuel and moderator plates. Three small space reactors with a control rod system and NaK coolant pipes have been designed and the neutronic performance of these reactors during their life time as well as their safety behavior during various accident scenarios have also been investigated. All the three reactors showed similar neutronic performance during their life time, nevertheless, the smallest reactor mass was achieved in case of a reactor with

  14. El futuro de las asociaciones sin centros

    OpenAIRE

    Azúa, Paulino

    1991-01-01

    El de unas asociaciones sin centros ¿puede ser interpretado como un feliz horizonte, la "tercera etapa de Wolfensberger", resultado del trabajo reivindicativo y de mentalízación social, en el que, finalmente, podrán permitirse la opción de dedicarse a sus auténticas funciones asociativas? La gestión de servicios ¿sirve para cohesionar a los padres para dar vida a las asociaciones, y, en consecuencia, carecer de centros significa languidecer? Paulino Azúa, director gerente de la FEAPS, intr...

  15. Investigation and evaluation of water cooled fast reactor in the feasibility study on commercialized fast reactor cycle systems. Technical investigation

    International Nuclear Information System (INIS)

    The reduced-moderation water reactor (RMWR) aims at effective utilization of uranium resource, multiple recycling of plutonium and high burn-up and long operation cycle. Since the concept of RMWR will require high neutron energy spectrum comparable with that of FBR and keep conversion ratio grater than one, the RMWR can be regarded as one of the FBR and the investigation and evaluation has started in the feasibility study on commercialized fast reactor cycle systems. Study aims at investigation and evaluation of FBR design requirement's attainability, operation and maintenance, and technical feasibility of the candidate system. The study requests reprocessing technology of MOX spent fuels with low decontamination to mitigate environmental load and improve effective utilization of resources, while the RWMR program has deployed the one with high decontamination. (T. Tanaka)

  16. Study on the transient behaviours of MNSR reactor for control rod withdrawal

    International Nuclear Information System (INIS)

    The transient behaviours of Miniature Neutron Source Reactor MNSR are analyzed and calculated with the reactor thermohydraulics RETRAN-02 program and the reactor physics MARIA program. The obtained event sequence and consequence from the calculation are compared with the experiments. The effective resonance integral for study on Doppler effect is taken into account. The reactivity temperature coefficient weighting factors are computed. The transient parameters related to reactor power peaking, coolant inlet temperatures, outlet temperatures and coolant mass flow, etc. are computed and compared with the experimental results. (6 refs., 2 figs., 5 tabs.)

  17. Conceptual design study of quasi-steady state fusion experimental reactor (FEQ-Q), part 1

    International Nuclear Information System (INIS)

    Since 1980 the design study has been conducted at JAERI for the Fusion Experimental Reactor (FER) which has been proposed to be the next machine to JT-60 in the Japanese long term program of fusion reactor development. Starting from 1984 JER design is being reviewed and redesigned. This report is a part of the interim report which describes the results obtained in the review and redesign activities in FY 1984. The results of the following design items are included; core plasma, reactor structure, reactor core components, magnets. (author)

  18. Study of reactor parameters of on critical systems, Phase I: Safety report for RB zero power reactor

    International Nuclear Information System (INIS)

    In addition to the safety analysis for the zero power RB reactor, this report contains a general description of the reactor, reactor components, auxiliary equipment and the reactor building. Reactor Rb has been reconstructed during 1961-1962 and supplied with new safety-control system as well as with a complete dosimetry instrumentation. Since RB reactor was constructed without shielding special attention is devoted to safety and protection of the staff performing experiments. Due to changed circumstances in the Institute ( start-up of the RA 7 MW power reactor) the role of the RB reactor was redefined

  19. High temperature gas-cooled reactor: gas turbine application study

    International Nuclear Information System (INIS)

    The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project

  20. Comparison study on cell calculation method of fast reactor

    International Nuclear Information System (INIS)

    Effective cross sections obtained by cell calculations are used in core calculations in current deterministic methods. Therefore, it is important to calculate the effective cross sections accurately and several methods have been proposed. In this study, some of the methods are compared to each other using a continuous energy Monte Carlo method as a reference. The result shows that the table look-up method used in Japan Nuclear Cycle Development Institute (JNC) sometimes has a difference over 10% in effective microscopic cross sections and be inferior to the sub-group method. The problem was overcome by introducing a new nuclear constant system developed in JNC, in which the ultra free energy group library is used. The system can also deal with resonance interaction effects between nuclides which are not able to be considered by other methods. In addition, a new method was proposed to calculate effective cross section accurately for power reactor fuel subassembly where the new nuclear constant system cannot be applied. This method uses the sub-group method and the ultra fine energy group collision probability method. The microscopic effective cross sections obtained by this method agree with the reference values within 5% difference. (author)

  1. Design study of toroidal magnets for tokamak experimental power reactors

    International Nuclear Information System (INIS)

    This report contains the results of a six-month study of superconducting toroidal field coils for a Tokamak Experimental Power Reactor to be built in the late 1980s. The designs are for 8 T and 12 T maximum magnetic field at the superconducting winding. At each field level two main concepts were generated; one in which each of the 16 coils comprising the system has an individual vacuum vessel and the other in which all the coils are contained in a single vacuum vessel. The coils have a D shape and have openings of 11.25 m x 7.5 m for the 8 T coils and 10.2 m x 6.8 m for the 12 T coils. All the designs utilize rectangular cabled conductor made from copper stabilized Niobium Titanium composite which operates at 4.2 K for the 8 T design and at 2.5 K for the 12 T design. Manufacturing procedures, processes and schedule estimates are also discussed

  2. Engineering study hard coal gasification with pressurized water reactor

    International Nuclear Information System (INIS)

    Work has been concentrated on the design of the power plant and the interface between reactor and gasification unit. First of all, the combination of a PWR with a Lurgi pressure gasification was investigated. This first phase of the study has been completed. To meet the Lurgi pressure gasification characteristics, the saturated PWR-steam is brought to the required higher stage of pressure by steam compressors and superheated by fossil fired steam boilers. To obtain the higher availability of process steam for the hard coal gasification coal fired quick start stand-by boilers are provided. To judge the economic prospectives, the costs for supply of process steam and electric energy have been determined. The results are showing that hard coal gasification with a PWR is more economic than autothermal processes and that it is expedient and promising to continue the work on combined gasification processes in order to improve the efficiency of the overall plant. By request of the public authorities the RAG/Ruhrgas work on advanced gasification processes to be coupled with a PWR has been stopped temporary. (orig.)

  3. Reactor physics studies in the GCFR Phase III critical assembly

    International Nuclear Information System (INIS)

    The third phase of the gas cooled fast reactor (GCFR) program, ZPR-9 Assembly 30, is based on a multi-zoned core of PuO2-UO2 with radial and axial blankets of UO2. Studies performed in this assembly will be compared to the previous phases of the GCFR program and will help to define parameters in this power-flattened demonstration plant-type core. Measurements in the Phase III program included small sample reactivity worths of various materials, central reaction rates and reaction rate distributions, absorption-to-fission ratios and the central point conversion ratio and the worth of steam entry into a small central zone. The reactivity change associated with the construction of a central pin zone in the core and axial blanket was measured. Reaction rate and steam entry measurements were repeated in the pin environment. Standard analysis methods using ENDF/B-IV data are described and the results are compared to measurements performed during the program

  4. High temperature gas-cooled reactor: gas turbine application study

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project.

  5. A study of reactor-neutron-induced reactions

    International Nuclear Information System (INIS)

    Cross sections of the second neutron capture in the double-neutron-capture process were studied in the irradiation of 26Mg, 64Ni, 93Nb, and 164Dy with reactor neutrons. Weak radioactivities produced were determined with sufficient accuracy by taking advantage of high resolution Ge(Li) detectors. The neutron spectrum at the irradiating site was defined with Westcott's epithermal index determined by the use of the cadmium ratio method. The isomer cross-section ratio was obtained with the 94Nb target. The statistical theory was found to be applicable to such an unstable or odd-odd nuclide as 94Nb. Cross sections of isomers of 165Dy were determined. The capture cross section of the ground state nuclei was found greater than that of the metastable state nuclei in this case. This differs from the other four isomers observed so far. Cross sections of 28Al(n, p)28Mg and 58Ni(n, 2n)57Ni reactions with fission neutrons were also measured. A simple formula was proposed for the systematics of (n, 2n) reaction cross sections, which enabled prediction of the cross section more accurately than the previously proposed formulae. (author)

  6. Reduced enrichment neutronic study on high power research reactor

    International Nuclear Information System (INIS)

    The FG2DB two dimensional two group diffusion/burnup code and the CELL few group cell parameter code with 69 groups neutron cross section database have been used for reduced enrichment neutronic study on high power research reactor with LEU fuel elements of uranium density 3.6-7.2 g/cm3 and cladding thickness 0.38-0.56 mm. Results show the equivalence of fuel meat uranium density on the thickness changing. Control rod worth and other operation safety parameters of core are acceptable. Parts of the results have been fitted to linear or quadratic expression for easy application. The minimum critical value, excess reactivity, cycle length, fast and thermal fluxes and integrated fluxes, etc. are given. Analysis of these parameters shows that with the U-235 content increased by 20% or more, the LEU core main physical characteristics are similar to those of the HEU core; reduced enrichment almost has no influence on the fast neutron flux; the decreasing rate of the thermal neutron fluxes proportional approximately to the increasing rate of the U-235 content in fuel element; because of the cycle length prolonging, common radioisotope production and fuel element irradiation testing are apparently not influenced. (author)

  7. Feasibility studies on commercialized fast breeder reactor cycle system

    International Nuclear Information System (INIS)

    JNC (Japan Nuclear Cycle Development Institute) and the electric utilities in Japan have established a new organization to develop a commercialized fast breeder reactor (FBR) cycle system since July 1, 1999, feasibility studies (F/S) have been undertaken in order to determine the promising concepts and to define the necessary R and D tasks. In the first two-year phase, a number of candidate concepts will be selected from various options, featuring innovative technologies. In the F/S, the options are evaluated and conceptual designs are examined considering the attainable perspectives for following: 1) ensuring safety, 2) economic competitiveness to future LWRs, 3) efficient utilization of resources, 4) reduction of environmental burden and 5) enhancement of nuclear non-proliferation. The F/S should also guide the necessary R and D to commercialize FBR cycle system. In particular enhanced technologies should be integrated in order to ensure nuclear non-proliferation. In the second five-year phase of the F/S, scaled engineering tests will be conducted. Based on the test data, a comprehensive evaluation will be conducted to confirm the technical attainability of candidate concepts. A few proposals for the commercialization of the FBR cycle system will be proposed. (author)

  8. Uses of reactor neutrons for studying the microcomposition of materials

    International Nuclear Information System (INIS)

    Reactor neutrons constitute excellents 'probes' for exploring and measuring a wide range both of minor and trace constituents in solids and liquids with high sensitivity because of their transparency in materials. Nondestructive neutron prompt-gamma analysis (PGA) utilizing either cold or thermal neutrons, such as at JRR-3M, is compared and contrasted to the more common (delayed) instrumental neutron activation analysis (INAA) and epithermal NAA. Clearly PGA offers high sensitivity for selected elements: B, H, Cd and REE's in suitable matrices, and is therefore, complementary to INAA which is not as useful for them, or for Ni, Sn, Fe, C or N. Recent INAA applications in our laboratory that demonstrate some of the uniqueness of neutron methods include use of epithermal neutrons for small biological specimens to measure Cd, K, As, Zn and, multielemental INAA for environmental pollution studies. The latter involves large data sets of multielemental concentrations which are subjected to statistical multivariant factor analysis to reveal unknown or unsuspected quantitative relationships among groups of trace constituents. These patterns, or 'factors' are shown to be uniquely related to pollution sources and can be utilized to compute the relative source contributions at a given receptor site. (author)

  9. Studies of aged cast stainless steel from the Shippingport reactor

    International Nuclear Information System (INIS)

    Charpy-impact and tensile tests were conducted on several cast stainless steel materials from the Shippingport reactor. Baseline mechanical properties for unaged material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 degree C and water-quenched, or material from the cooler region of the component. The materials indicate relatively modest decreases in impact energy. The results show good agreement with estimations based on accelerated laboratory-aging studies. Correlations for estimating thermal-aging degradation of cast stainless steels indicate that the degree of embrittlement of the Shippingport materials is low. The minimum room-temperature impact energies that would ever be achieved after long-term aging are >75 J/cm2 (>45 ft·lb) for all materials. The estimated activation energies for embrittlement range from 150 to 230 kJ/mole. The estimated fracture toughness J-R curves for the materials are also presented. 14 refs., 16 figs

  10. Estudo sobre a percepção do clima organizacional do centro cirúrgico de um hospital especializado Estudio sobre la percepción del clima organizacional del centro quirúrgico de un hospital especializado Study on the perception of the organization climate of the surgical center in a specialized hospital

    OpenAIRE

    Wilza Carla Spiri

    1998-01-01

    O presente estudo tem o objetivo de identificar como o grupo de funcionários recém-admitidos no centro cirúrgico de um hospital especializado, percebe o clima organizacional existente, utilizando uma abordagem qualitativa. Como referencial teórico para interpretar o clima organizacional utilizamos os conceitos de CHIAVENATO, que define clima organizacional como meio interno de uma organização e que através de sua experienciação pelos participantes influencia o comportamento dos mesmos, podend...

  11. Design review and hazop studies for stable salt reactor

    International Nuclear Information System (INIS)

    Atkins has been assisting Moltex Energy in carrying out a review of their Stable Salt Reactor (SSR) (formerly the Simple Molten Salt Reactor (SMSR)), which they believe has many benefits over other nuclear reactor systems. Their current design is for a 2.5 GW thermal output reactor, supplying a superheated steam turbine that could provide an electrical output of 1GW. Our first task was to carry out an assessment of the SSR concept against relevant UK Regulatory Requirements, using data and information that was provided by Moltex Energy. Moltex Energy updated their design using the output from this review. The next activity was to carry out a Hazard and Operability (HAZOP) review to identify issues that may not have been apparent in the original design and the UK Regulatory Requirements assessment. For the HAZOP, we brought together a Process Engineer, Fuel Route and Mechanical Handling Specialist, Safety Case Engineer, Reactor Chemist, Decommissioning and Waste Management Specialist. The HAZOP review gave rise to the generation of a list of key Structures, Systems and Components (SSCs) that would be necessary in a fully designed reactor system, which were discussed and described in a report. This report provided the scope and assumptions that were used as the basis for the costing estimate, using expertise provided in-house by Faithful and Gould. Our paper will discuss the processes used in more detail, identify how these processes increased the knowledge and design concepts to ascertain the SSCs in more detail. Discuss the costing approach and the use of a three-point capital cost estimate, modelled using Monte Carlo simulation, to provide a cost/uncertainty distribution profile. Discussion on how Atkins can assist with the Indian reactor programme using a similar approach detailed above

  12. Blazards variability detected by the spatial Fermi-LAT telescope. Study of 3C454.3 and development of an optimised light curves generation method

    International Nuclear Information System (INIS)

    The Fermi Gamma-ray Space Telescope was launched on 2008 June 11, carrying the Large Area Telescope (LAT), sensitive to gamma-rays in the 20 MeV - 300 GeV energy range. The data collected since then allowed to multiply by a factor of 10 the number of Active Galactic Nuclei (AGN) detected in the GeV range. Gamma-rays observed in AGNs come from energetic precesses bringing into play very high energy charged particles. These particles are confined in a magnetized plasma jet rising in a region close to the supermassive black hole in the center of the host galaxy. This jet moves away with velocities as high as 0.9999 c, forming in many cases radio lobes on kilo-parsec or even mega-parsec scales. Among the AGNs, those whose jet inclination angle to the line of sight is small are called blazars. The combination of this small inclination angle with relativistic ejection speeds led to relativistic effects: apparent superluminal motions, amplification of the luminosity and modification of the time scales. Blazars are characterized by extreme variability at all wavelengths, on time scales from a few minutes to several months. A temporal and spectral study of the most luminous of those detected by the LAT, 3C 454.3, was done so as to constrain emission models. A new method for generating adaptive-binning light curves is also suggested in this thesis. It allows to extract the maximum of information from the LAT data whatever the flux state of the source. (author)

  13. Fermi liquid theory of resonant spin pumping

    OpenAIRE

    Moca, C. P.; Alex, A.; Shnirman, A.; Zarand, G.

    2013-01-01

    We study resonant all-electric adiabatic spin pumping through a quantum dot with two nearby levels by using a Fermi liquid approach in the strongly interacting regime, combined with a projective numerical renormalization group (NRG) theory. Due to spin-orbit coupling, a strong spin pumping resonance emerges at every charging transition, which allows for the transfer of a spin $~ \\hbar/2$ through the device in a single pumping cycle. Depending on the precise geometry of the device, controlled ...

  14. "Permanence" - An Adaptationist Solution to Fermi's Paradox?

    OpenAIRE

    Cirkovic, Milan M.

    2004-01-01

    A new solution of Fermi's paradox sketched by SF writer Karl Schroeder in his 2002. novel "Permanence" is critically investigated. It is argued that this solution is tightly connected with adaptationism - a widely discussed working hypothesis in evolutionary biology. Schroeder's hypothesis has important ramifications for astrobiology, SETI projects, and future studies. Its weaknesses should be explored without succumbing to the emotional reactions often accompanying adaptationist explanations.

  15. Generalized Seniority Description of Cold Fermi Gases

    OpenAIRE

    G. E. Brown; Gelman, B. A.; Kuo, T. T. S.

    2004-01-01

    We suggest that the extension of the Racah seniority description of strongly interacting fermions in the nuclear shell model is directly generalizable to describe pairing of atoms in cold Fermi systems. We illustrate this by the fermionic pairing in the much studied cold two-component gas of Li atoms. Our pairing interaction is two orders of magnitude stronger than that used in the usual BCS approach. We also explain why the Racah scheme is less applicable to nuclei, and discuss the similarit...

  16. A Study on Dismantling of Westinghouse Type Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

    KHNP started a research project this year to develop a methodology to dismantle nuclear reactors and internals. In this paper, we reviewed 3D design model of the reactor and suggested feasible cutting scheme.. Using 3-D CAD model of Westinghouse type nuclear reactor and its internals, we reviewed possible options for disposal. Among various options of dismantling the nuclear reactor, plasma cutting was selected to be the best feasible and economical method. The upper internals could be segmented by using a band saw. It is relatively fast, and easily maintained. For cutting the lower internals, plasma torch was chosen to be the best efficient tool. Disassembling the baffle and the former plate by removing the baffle former bolts was also recommended for minimizing storage volume. When using plasma torch for cutting the reactor vessel and its internal, installation of a ventilation system for preventing pollution of atmosphere was recommended. For minimizing radiation exposure during the cutting operation, remotely controlled robotic tool was recommended to be used.

  17. Some results of studying of spatial kinetics in fast reactors

    International Nuclear Information System (INIS)

    The paper presents an analysis of the solution to the spatial non-stationary equation of neutron transport the example of a fast reactor. To solve the spatial kinetics equation in three-dimensional geometry in diffusion approximation a calculated code TIME was created. In a direct problem the neutron flux density and its derivatives (for example, reactor power) are determinate at each time step. Solution of a direct problem allows to investigate a deformation of a steady neutron field form which is one of the main reasons of spatial effects occurrence in a reactor. Such deformations affect spatial distribution of delayed-neutrons that is reflected in behavior of reactivity and in related with it results of experiments. The paper also considers some questions of reducing of spatial effects through a choice of a point of reactivity input or detector location. In the inverse problem the reactor reactivity is calculated using the known dependence of reactor power on time. The paper describes some problems of solving the inverse problem taking into account spatial effects. (author)

  18. A fuel management study and cycle nuclear design for PW reactors

    International Nuclear Information System (INIS)

    A reference reactor was chosen to do a general study involving Fuel Management Evaluations of several cycles, and Design Calculations of cycles already performed, according to a calculation scheme set up in the Reactor Technology Division of the J.E.N., using some computer codes acquired to foreign sources and other ones developed in the J.E.N. (Author) 5 refs

  19. Reactor oscillator project - Theoretical study; operation problems; choice of the ionization chamber

    International Nuclear Information System (INIS)

    Theoretical study of the reactor operator covers methods of the danger coefficient and the method based on measuring the phase angle. Operation with the reactor oscillator describes measurement of the cross section and resonance integral, measurement of the fissionable materials properties, measurement of impurities in the graphite sample. A separate chapter is devoted to the choice of the appropriate ionization chamber

  20. Study of advanced fission power reactor development for the United States. Volume II

    International Nuclear Information System (INIS)

    This report presents the results of a multi-phase research study which had as its objective the comparative study of various advanced fission reactors and evaluation of alternate strategies for their development in the USA through the year 2020. By direction from NSF, ''advanced'' reactors were defined as those which met the dual requirements of (1) offering a significant improvement in fissile fuel utilization as compared to light-water reactors and (2) currently receiving U.S. Government funding. (A detailed study of the LMFBR was specifically excluded, but cursory baseline data were obtained from ERDA sources.) Included initially were the High-Temperature Gas-Cooled Reactor (HTGR), Gas-Cooled Fast Reactor (GCFR), Molten Salt Reactor (MSR), and Light-Water Breeder Reactor (LWBR). Subsequently, the CANDU Heavy Water Reactor (HWR) was included for comparison due to increased interest in its potential. This volume presents the reasoning process and analytical methods utilized to arrive at the conclusions for the overall study

  1. A conceptual design study on various types of HLMC fast reactor plant

    International Nuclear Information System (INIS)

    To seek for a promising concept of a heavy liquid metal coolant (HLMC) fast reactor plant, Japan Nuclear Cycle Development Institute (JNC) and the electric utilities conducted conceptual design study on various types of plant concepts and compared these concepts based on technical feasibility and economical perspective. Finally, Pb-Bi cooled medium tank type reactor was selected as a most promising concept. (author)

  2. Conceptual design studies on various types of HLMC fast reactor plants

    International Nuclear Information System (INIS)

    To seek for a promising concept of a heavy liquid metal coolant (HLMC) fast reactor plant, Japan Nuclear Cycle Development Institute (JNC) and the electric utilities conducted conceptual design studies on various types of plant concepts and compared these concepts based on technical feasibility and economical perspective. Finally, Pb-Bi cooled medium tank type reactor was selected as the most promising concept. (author)

  3. Reactor-accelerator coupled experiments (RACE): A feasibility study at TAMU

    International Nuclear Information System (INIS)

    A series of accelerator driven system (ADS) experiments are being planned to conduct demonstration and benchmark studies involving a nuclear reactor in a subcritical condition coupled to an accelerator driven neutron source. These experiments are being planned to use various levels of criticality and various power levels allowing for kinetics evaluation with and without temperature feedback. The reactor fuel to be used in these experiments is TRIGA reactor fuel. These reactor fuels are inherently safe and the reactor systems involved have large coolant capacities to ensure safe operation. The cores to be considered will be fully-instrumented and will allow for detailed and accurate data on core power levels, temperatures, and neutron fluxes during the experiments. A feasibility study is currently in progress at Texas A and M Univ. (TAMU) to determine the viability and capability of these experiments. Preliminary results of this feasibility study are given. (authors)

  4. Estudio sobre la influencia de género en la incorporación de las TIC a los centros educativos Study on the influence of gender in the introduction of ICT to schools

    OpenAIRE

    Enrique SÁNCHEZ RIVAS; José SÁNCHEZ RODÍGUEZ; Ruiz Palmero, Julio

    2011-01-01

    La investigación planteada en este proyecto busca ampliar el conocimiento de la influencia ejercida por la variable de género sobre la incorporación de las TIC a los ámbitos curriculares y organizativos de los centros educativos públicos de Educación Primaria y Secundaria de la provincia de Málaga. A través de un estudio de casos múltiples se recaba la valoración que realiza el profesorado sobre el grado de incidencia de los proyectos para la incorporación de las TIC en sus centros. Y mediant...

  5. Comparison of pool/loop configurations in the JAEA fast reactor feasibility study

    International Nuclear Information System (INIS)

    JAEA conducted a feasibility study on commercialized fast breeder reactor cycle systems from 1999 to 2006 (FS). In the FS, various fast reactor concepts with various power levels, coolant materials and plant configurations were proposed and competed. In the large-scale sodium cooled reactor region, four nuclear industry vendors proposed each original advanced sodium cooled reactor concept in 1999. One was a loop concept which was named 'JSFR' later and the other three were pool concepts. The first competition among the four concepts showed that the economical competitiveness of JSFR is better than pool concepts. Therefore, in the 2000 study, one pool concept was selected and the selected pool concept was refined to compete with JSFR. In this appendix, the selected FS pool concept is described and the pool/loop comparative study in the FS is briefly summarized. Schematic illustration of the reactor vessel of the FS pool is shown. Relation of reactor vessel diameters and electric output of various sodium-cooled reactor concepts are compared. The comparison shows that the FS pool concept has a smaller reactor vessel than recent conceptual large reactors such as SPX-2, SNR-2, EFR and BN-1600. The material amount comparison shows that the reactor vessel and primary system material amount of the FS pool concept is heavier than that of the FS loop concept (JSFR) by approximately 250ton. Because the reactor vessel diameter comparison of various concepts shows that the FS pool concept is one of the most compact pool configurations, the FS pool/loop competition is thought to provide comparative information between the most economical loop and pool concepts

  6. Coulomb sum rules in the relativistic Fermi gas model

    International Nuclear Information System (INIS)

    Coulomb sum rules are studied in the framework of the Fermi gas model. A distinction is made between mathematical and observable sum rules. Differences between non-relativistic and relativistic Fermi gas predictions are stressed. A method to deduce a Coulomb response function from the longitudinal response is proposed and tested numerically. This method is applied to the 40Ca data to obtain the experimental Coulomb sum rule as a function of momentum transfer

  7. Correlation Analysis of Multi-Wavelength Luminosity of Fermi Blazars

    Indian Academy of Sciences (India)

    Xiongwei Bi; Wanquan He; Jiajin Tian; Zhimei Ding; Shuping Ge

    2014-09-01

    We have studied the correlations between luminosities (R, O, X, ) in radio, optical, X-ray and -ray wave bands for Fermi blazars, and found that there are significant correlations between R and , X and and O and for blazars, BL Lacs and FSRQs, but no correlation between and O for BL Lacs. These results suggest that for Fermi blazars, the high energy -ray emission can be related with radio, X-ray and optical emissions.

  8. Probing ultracold Fermi gases with light-induced gauge potentials

    International Nuclear Information System (INIS)

    We theoretically investigate the response of a two-component Fermi gas to vector potentials that couple separately to the two spin components. Such vector potentials may be implemented in ultracold atomic gases using optically dressed states. Our study indicates that light-induced gauge potentials may be used to probe the properties of the interacting ultracold Fermi gas, providing, among other things, ways to measure the superfluid density and the strength of pairing.

  9. A study on future nuclear reactor technology and development strategy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. Y.; Kim, S. H.; Sohn, D. S.; Suk, S. D.; Zee, S. K.; Yang, M. H.; Kim, H. J.; Park, W. S

    2000-12-01

    Development of nuclear reactor and fuel cycle technology for future is essential to meet the current issues such as enhancement of nuclear power reactor safety, economically competitive with gas turbine power generation, less production of radioactive waste, proliferation resistant fuel cycle, and public acceptance in consideration of lack of energy resources in the nuclear countries worldwide as well as in Korea. This report deals with as follows, 1) Review the world energy demand and supply perspective and analyse nature of energy and sustainable development to set-up nuclear policy in Korea 2) Recaptitulate the current long term nuclear R and D activities 3) Review nuclear R and D activities and programs of USA, Japan, France, Russia, international organizations such as IAEA, OECD/NEA 4) Recommend development directions of nuclear reactors and fuels.

  10. Preliminary study or RSG-GAS reactor fuel element integrity

    International Nuclear Information System (INIS)

    After 8 years of operation, RSG-GAS was able to reach 15 cycles of reactor operation with 116 irradiated fuels, whereas 49 fuels were produced by NUKEM; and the other 67 were produced by PEBN-BATAN. At the 15Th cycles, it have been used 40 standard fuels and 8 control fuels (Forty standard fuels and eight control fuels have been used in the 15th core cycles). Several activities have been performed in the reactor, to investigate the fuel integrity, among of them are: .fuel visual test with under water camera, which the results were recorder in the video cassette, primary water quality test during, reactor operation, fuel failure detector system examination and compared the PIE results in the Radiometallurgy Installation (RMI). The results showed that the fuel integrity, before and after irradiation, have still good performance and the fission products have not been released yet

  11. Study of the applicability of CFD calculation for HTTR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Nobumasa, E-mail: tsuji-nobumasa@fujielectric.co.jp [Fuji Electric Co. Ltd., 1-1 Tanabeshinden, Kawasaki-ku, Kawasaki city 210-9530 (Japan); Nakano, Masaaki; Takada, Eiji; Tokuhara, Kazumi; Ohashi, Kazutaka; Okamoto, Futoshi [Fuji Electric Co. Ltd., 1-1 Tanabeshinden, Kawasaki-ku, Kawasaki city 210-9530 (Japan); Tazawa, Yujiro; Inaba, Yoshitomo; Tachibana, Yukio [Japan Atomic Energy Agency, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken 311-1393 (Japan)

    2014-05-01

    Passive heat removal performance of the reactor vessel cavity cooling system (RCCS) is of primary concern for enhanced inherent safety of HTGR. In a loss of forced cooling accident, decay heat must be removed by radiation and natural convection of RCCS. Thus thermal hydraulic analysis of reactor internals and RCCS is powerful means for evaluation of the heat removal performance of RCCS. The thermal hydraulic analyses using CFD computation tools are conducted for normal operation of the high temperature engineering test reactor (HTTR) and are compared to the temperature distribution of measured data. The calculated temperatures on outer faces of the permanent side reflector (PSR) blocks are in fair agreement with measured data. The transient analysis for decay heat removal mode in HTTR is also conducted.

  12. Study on the Export Strategies for Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Oh, S. K.; Lee, Y. J.; Ham, T. K.; Hong, S. T.; Kim, J. H. [Ajou University, Suwon (Korea, Republic of)

    2008-12-15

    Key strategic considerations taken into account should be based on understanding in the forecasts of demand and supply balance as well as the missions of research reactor for customers. For timely arrival at the competition, it may be advantageous to categorize the potential customers into 3 groups, the developed, the developing and the underdeveloped countries in respect of nuclear technology, and to be ready for the group-wise reference designs of the key reactor systems. Customizing the design to specific owner's requirements can advance from one of these reference designs when competition starts. To mobilize this approach effectively, it is useful to establish an integral project and technology management system earlier. This system will function as an important success factor for international research reactor business, because it makes easy to accommodate customer requirements and to achieve the design-to-cost.

  13. Study, design and evaluation of nuclear reactor computer control system

    International Nuclear Information System (INIS)

    Nuclear reactor control is a complex process that varies with each reactor and there is no universal agreement as to the best type of control system. After the use of conventional systems for a long time, attention turned towards digital techniques in the reactor control system. This interest emerged because of the difficulties faced in the data manipulation, mainly for post-incident analysis. However, it is not sufficient to insert a computer in a system to solve all the data-handling problems and also the insertion of a computer in a real-time system is not without any effect on the overall system. The scope of this thesis is to show the important parameters that have to be taken into account when choosing and evaluate the performances of the selected system

  14. Study on the Export Strategies for Research Reactors

    International Nuclear Information System (INIS)

    Key strategic considerations taken into account should be based on understanding in the forecasts of demand and supply balance as well as the missions of research reactor for customers. For timely arrival at the competition, it may be advantageous to categorize the potential customers into 3 groups, the developed, the developing and the underdeveloped countries in respect of nuclear technology, and to be ready for the group-wise reference designs of the key reactor systems. Customizing the design to specific owner's requirements can advance from one of these reference designs when competition starts. To mobilize this approach effectively, it is useful to establish an integral project and technology management system earlier. This system will function as an important success factor for international research reactor business, because it makes easy to accommodate customer requirements and to achieve the design-to-cost.

  15. Background Studies for the MINER Coherent Neutrino Scattering Reactor Experiment

    CERN Document Server

    Agnolet, G; Barker, D; Beck, R; Carroll, T J; Cesar, J; Cushman, P; Dent, J B; De Rijck, S; Dutta, B; Flanagan, W; Fritts, M; Gao, Y; Harris, H R; Hays, C C; Iyer, V; Jastram, A; Kadribasic, F; Kennedy, A; Kubik, A; Ogawa, I; Lang, K; Mahapatra, R; Mandic, V; Martin, R D; Mast, N; McDeavitt, S; Mirabolfathi, N; Mohanty, B; Nakajima, K; Newhouse, J; Newstead, J L; Phan, D; Proga, M; Roberts, A; Rogachev, G; Salazar, R; Sander, J; Senapati, K; Shimada, M; Strigari, L; Tamagawa, Y; Teizer, W; Vermaak, J I C; Villano, A N; Walker, J; Webb, B; Wetzel, Z; Yadavalli, S A

    2016-01-01

    The proposed Mitchell Institute Neutrino Experiment at Reactor (MINER) experiment at the Nuclear Science Center at Texas A&M University will search for coherent elastic neutrino-nucleus scattering within close proximity (about 2 meters) of a 1 MW TRIGA nuclear reactor core using low threshold, cryogenic germanium and silicon detectors. Given the Standard Model cross section of the scattering process and the proposed experimental proximity to the reactor, as many as 5 to 20 events/kg/day are expected. We discuss the status of preliminary measurements to characterize the main backgrounds for the proposed experiment. Both in situ measurements at the experimental site and simulations using the MCNP and GEANT4 codes are described. A strategy for monitoring backgrounds during data taking is briefly discussed.

  16. Compact reactor for spatial application

    International Nuclear Information System (INIS)

    A project to develop nucleo electric space power systems, sub project RESPA, is in progress since 1987 at the Instituto de Estudos Avancados of the Centro Tecnico Aeroespacial, with a view to a possible future application in the Brazilian Space Program. This paper describes the selected system, special aspects of the reactor compared to terrestrial power reactors, and current and planned activities of RESPA. (author)

  17. System Study: Reactor Core Isolation Cooling 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-01-31

    This report presents an unreliability evaluation of the reactor core isolation cooling (RCIC) system at 31 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RCIC results.

  18. ELMO Bumpy Torus fusion-reactor design study

    International Nuclear Information System (INIS)

    A complete power plant design of a 1200-MWe ELMO Bumpy Torus Reactor (EBTR) is described. Those features that are unique to the EBT confinement concept are emphasized, with subsystems and balance-of-plant items that are generic to magnetic fusion being adopted from past, more extensive tokamak reactor designs. This overview paper stresses the design philosophy and asumptions that led to an economic, 35-m major-radius design that at 1.4 MW/m2 wall loading generates 4000 MWt with a 15% recirculating power fraction

  19. Conceptual design study of fusion experimental reactor (FY 86 FER)

    International Nuclear Information System (INIS)

    This report describes the results of the investigation on critical issues of FY 86 FER reactor configuration/structure design. Accuracy evaluation of shielding calculation and crack growth prediction of first wall and divertor based on the elastic-plastic fracture mechanics were performed. Further, optimization of shield configuration, graphite first wall armor and flexifility of reactor were investigated to support future design work. Feasibilities of innovative ideas were also examined, such as the ripple insert effect and the application of shape memory alloys. (author)

  20. System Study: Reactor Core Isolation Cooling 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-12-01

    This report presents an unreliability evaluation of the reactor core isolation cooling (RCIC) system at 31 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RCIC results.