DOCSLIB.ORG

The NIST Cold Neutron Research Facility

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The NIST Cold Neutron Research Facility Volume 98, Number 1, January-February 1993 Journal of Research of the National Institute of Standards and Technology [J. Res. Natl. Inst. Stand. Technol. 98, 1 (1993)] The NIST Cold Neutron Research Facility Volume 98 Number 1 January-February 1993 H. J. Prask, J. M. Rowe, J. J. The Cold Neutron Research Facility more details on some of the research Rush, and I. G. Schroder (CNRF) at the National Institute of opportunities that the facility will bring standards and Technology (NIST) Re- to NIST. National Institute of Standards search Reactor (NBSR) is now coming on line, with the first seven experimen- Key words: cold neutrons; guide hall; and Technology, tal stations operational, and more sta- neutron facilities; neutron guides; neu- Gaithersburg, MD 20899 tions scheduled to be installed during tron instrumentation; neutron proper- 1992. The present article provides an ties; neutrons; research reactors. introduction to the facility, and to other articles in the current issue that give Accepted: July 8, 1992 1. Introduction Since the advent of nuclear reactors with reason- • the nondestructive nature of low energy neutrons ably high fluence rates (fluxes) in the 1950s, the • the fact that neutrons with wavelengths compara- use of the thermal neutrons produced by these ble to interatomic spacings in condensed matter sources to study a wide range of problems has have energies comparable to the energies of grown rapidly. This growth has resulted from the atomic vibrations. properties of neutrons as probes, which include: The potential of this research was realized early, • absorption with subsequent radioactive decay and the Atomic Energy Commission built a succes- (used as an analytical tool) sion of research reactors with increasing fluence • high penetration as a result of the lack of an elec- rates throughout the 1950s and 1960s. trical charge This potential was also perceived by three physi- • scattering by nuclear interactions (which leads to cists at the National Bureau of Standards (NBS, a nonmonotonic variation of scattering with now NIST)-R. S. Carter, H. Landon, and C. atomic number) Muelhause—who proposed, designed, and built the • special sensitivity to hydrogen and hydrogenous 20 MW research reactor, NBSR, on the new NBS materials along with strong difference in scatter- site in Gaithersburg. The original proposal was jus- ing by hydrogen and deuterium tified on the importance of the contributions that • scattering by magnetic interactions (as a result of the NBSR would provide to the NBS mission in the magnetic dipole of the neutron) analytic chemistry, standards, solid state physics, • simple interpretation of results (as a result of the and nuclear physics, and was intended to serve weak interaction) NBS and other government agencies in the Volume 98, Number 1, January-February 1993 Journal of Research of the National Institute of Standards and Technology Washington area. The reactor design emphasized and the use of large radial penetrations into the versatility, incorporating a large number of experi- high flux regions to maximize intensity for beam mental facilities with different capabilities, rather research. than concentrating on any one specific area of re- Since the reactor first achieved continuous oper- search. The success of this philosophy can be seen ation in 1969, the use of the facilities has grown both in the increasing utilization of the reactor by steadily in both the number of researchers served NIST and other researchers, and in the changing (over 450 research participants the last year before emphasis in programs over the years. The design the CNRF was operational) and in the breadth of also included many advanced features that have the community served (the 450 participants came since been incorporated into other designs, includ- from 15 NIST divisions or offices, 25 other govern- ing a completely passive emergency cooling system, ment agencies, 50 universities and 25 industrial lab- a novel split core fuel design (recently adopted into oratories). The NBSR has gone from a local designs for the Advanced Neutron Source and the resource to a truly national facility, with re- spallation source at Los Alamos National Labora- searchers from all over the country. A diagram of tory), helium and carbon dioxide blankets around the current layout of facilities around the reactor is high flux regions to reduce radioactive emissions. shown in Fig. 1. Polarized Beam Triple-Axis Spectrometer Dlffractometer^ Single Crystal Dlffractometer Triple-Axis Spectrometer Thermal Column Radiography Facility BT-5 To Be Developed High Resolution Powder Dlffractometer Triple-Axis Spectrometer Polarized Beam I Spectrometer Fig. 1. Principal experimental facilities in the reactor hall. Volume 98, Number 1, January-February 1993 Journal of Research of the National Institute of Standards and Technology One of the features incorporated into the design from the MeV energies typical of nuclear reactions was the large penetration for a "cold neutron down to the meV energies typical of atomic mo- source" shown in Fig. 1. From the beginning, the tions in thermal equilibrium at approximately room designers intended that this penetration would one temperature. The energy spectrum produced by day be used to provide an intense source of neu- such moderators is a Maxwellian distribution with trons with lower energies than those typical of a characteristic temperature close to that of the other ports by installation of a cryogenically cooled moderator itself—hence the name thermal neu- block of neutron moderator. A moderator for neu- trons. An example of such a spectrum is shown in trons is a material which scatters the neutrons pro- Fig. 2, with temperature chosen to represent the duced by fission so that their energy is reduced spectrum seen by the thermal beam tubes at the 10^3 B—I—I—I—r 10^2 ca 10" 0,0 Ice (40 K) 03 10»° 10» 108 107 0,0 Ice (300 K) 10« I , I , , I _, L 0.00 0.50 1.00 1.50 2.00 Wavelength (nm) ^ 15.0 —J I J I I J l— -i—I—!—;—I—I—I—I—r o o I °c, 10.0 Q \ o o 5.0 CM 1=1 as 0.0 0.00 0.50 1.00 1.50 2.00 Wavelength (nm) b Fig. 2. (a) Neutron fluxes for the cold moderator cavity filled with liquid D2O and D2O ice. (b) Flux gain, D20(ice)/D20(liquid), from the data of (a). The moderator temperature of 40 K produces a Maxwellian distribution with an "effective" tempera- ture of 60 K. Volume 98, Number 1, January-February 1993 Journal of Research of the National Institute of Standards and Technology NBSR. Cold neutrons are defined as those with en- trons lO's of meters away from the reactor into ergies less than 5 meV, corresponding to 60 K and large experimental halls (generally called guide velocities less than 1000 m/s. However, this cold halls). These guides are based on the total internal neutron port was not utilized at the beginning, and reflection of neutrons below a critical angle that is the development concentrated on the thermal neu- a function of the reflecting material and neutron tron beams and facilities. In 1985, the development energy. This reflection is exactly analogous to opti- of the cryogenic port began in earnest with funding cal reflection, and the critical angle depends on the of a cold neutron initiative (made possible by pre- deBroglie wavelength of the neutron, which is in- liminary funding from the NBS director in 1984). versely proportional to neutron velocity and equal As discussed below, events have shown that the to 0.4 nm at 1000 m/s. Thus, guides work best at large area allowed for a. cold source in the NBSR long wavelengths and therefore for cold neutrons. design and the very wide range of angular access The guides themselves consist of pipes which are (over 30°) was a key to providing a unique opportu- made of optically flat glass coated with materials of nity to create the only fully internationally competi- high scattering power (generally an isotope of tive cold neutron research capability in the United nickel) and which are evacuated in order to reduce States. losses due to air scattering. Using these devices, it The interest in applications of cold neutron tech- is possible to transport intense beams of cold neu- niques was stimulated by the success of the West- trons out of the reactor building with losses of less ern European research reactors, most notably the than 1%/m, thus opening up the possibility of cre- Institut Laue Langevin (ILL) in Grenoble, France. ating many new types of measurement capability in Among the many successes of these facilities was a large new experimental hall. the demonstration of the power of a technique Based on these considerations, NBS proposed a called Small Angle Neutron Scattering (SANS) as cold neutron facility for the FY1985 budget, and it applied to a wide variety of problems in polymers, was included in the budget submission to the De- biology, metallurgy, and other areas in which struc- partment of Commerce and 0MB for that year. tures with distance scales in the 1-100 nm range However, many proposals for new facilities were were critical. The United States was highly compet- submitted at that time from different agencies, so itive in atomic and molecular scale measurements the Office of Science and Technology Policy re- with thermal neutrons, but was far behind in uti- quested a national study to set priorities for these lization of longer wavelength neutrons, and the facilities. As a result, the National Academy of Sci- SANS technique was the area addressed first. In ences commissioned a study by a panel of the Na- 1979 one of the first competence proposals funded tional Research Council on "Major Facilities for by the NBS director was to develop a SANS spec- Materials Sciences and Related Disciplines" trometer and research program at the NBSR, chaired by Professor F.
Load more

Recommended publications
  • The Jules Horowitz Reactor Project, a Driver for Revival of the Research Reactor Community
    THE JULES HOROWITZ REACTOR PROJECT, A DRIVER FOR REVIVAL OF THE RESEARCH REACTOR COMMUNITY P. PERE, C. CAVAILLER, C. PASCAL AREVA TA CEA Cadarache - Etablissement d'AREVA TA - Chantier RJH - MOE - BV2 - BP n° 9 – 13115 Saint Paul lez Durance - France CS 50497 - 1100, rue JR Gauthier de la Lauzière, 13593 Aix en Provence cedex 3 – France ABSTRACT The first concrete of the nuclear island for the Jules Horowitz Reactor (JHR) was poured at the end of July 2009 and construction is ongoing. The JHR is the largest new platform for irradiation experiments supporting Generation II and III reactors, Generation IV technologies, and radioisotope production. This facility, composed of a unique grouping of workshops, hot cells and hot laboratories together with a first -rate MTR research reactor, will ensure that the process, from preparations for irradiation experiments through post-irradiation non-destructive examination, is completed expediently, efficiently and, of course, safely. In addition to the performance requirements to be met in terms of neutron fluxes on the samples (5x1014 n.cm-2/sec-1 E> 1 MeV in core and 3,6x1014 n.cm-2/sec-1 E<0.625 eV in the reflector) and the JHR’s considerable irradiation capabilities (more than 20 experiments and one-tenth of irradiation area for simultaneous radioisotope production), the JHR is the first MTR to be built since the end of the 1960s, making this an especially challenging project. The presentation will provide an overview of the reactor, hot cells and laboratories and an outline of the key milestones in the project schedule, including initial criticality in early 2014 and radioisotope production in 2015.
    [Show full text]
  • Decommissioning of Nuclear Facilities in Switzerland – Lessons Learned
    WIR SCHAFFEN WISSEN – HEUTE FÜR MORGEN Fritz Leibundgut :: Decommissioning Officer :: Paul Scherrer Institut Decommissioning of Nuclear Facilities in Switzerland – Lessons learned HRP/IAEA/NEA Decommissioning workshop – February 7, 2017 Overview Basel Germany Aarau/Bern Zürich material sciences nanotechnology radio chemistry hotlab radio pharmacy biology PSI east solar concentrator energy research SwissFEL particle physics proton accelerator neutron source muon source proton therapy PSI west synchrotron light source Page 2 Nuclear installations on the PSI area • (ZWILAG) • AERA with VVA* • Hotlabor • DIORIT* • SAPHIR* • PROTEUS* *Post-operation phase/ Decomm./Dismantling Page 3 SAPHIR: 1957-1993 First reactor in Switzerland; used for isotope production, reactor training, neutron source for various experiments 1955 USA exposed a reactor at the “Atoms for Peace” conference in Geneva 1956 Laying of the cornerstone in Würenlingen 1957 First criticality 1960 Approval by Swiss government 1985 Approval for 10 MW 1993 Final shutdown 2000 Decommissioning ordinance 2008 Dismantling of the pool completed 2015 Cleanout of the KBL (“Kernbrennstofflager”) Page 4 SAPHIR: Status 2016 ENSI-Inspection at 7. of April, 2016 Page 5 DIORIT: 1960-1977 Proprietary Swiss development. Goal was the construction of industrial applicable reactors for material testings and experiments. 1960 Operation with natural uranium and D2O as coolant and moderator. 1966 Uprating from 20 MW to 30 MW. 1972 (after modification): Operation with LEU. 1977 Final shutdown. 1982 Partial dismantling; continued 1988-1993. 1994 Approval of dismantling the reactor. 2005 Asbestos was found interruption until 2009. 2013 Dismantling of biological shielding 2016 Cutting of the „Arbeitsboden“ (22 t activated Fe) 2019 (?) 2. Decommissioning ordinance for greenfield Page 6 DIORIT PSI, 23.10.2016 Page 7 Biol.
    [Show full text]
  • German Research Reactor
    German Research Reactor Back-end Provisions RERTR 2002 San Carlos de Bariloche, Argentina Nov-3/8 Authors: Siegfried Koester/German Federal Ministry of Economics and Technology Gerhard Gruber/RWE NUKEM GmbH On behalf of the German Working Group Back-end for Research Reactors Fuel Cycle History of Half a Century US 'Atoms for Peace Program', President Eisenhower 1953 HEU for peaceful research and development (R&D) First RR built in Germany in the late 1950s US supplied fuel on a lease basis until 1974 Until 1987 fuel sale with option to return spent HEU + LEU fuel 1987-Dec-31: DOE's policy for receipt of FRR SNF expires without prior notice German RR Back-end History 1960s: US Reprocessing, no return of waste 1960/70s: UK Reprocessing, no return of waste 1970s: Belgium + France Reprocessing, no return of waste 1980s: US Reprocessing, no return of waste 1990s: UK Reprocessing, mandatory waste return Current German Back-end Solution 1996 - 2006: Return SNF to US under 'FRR SNF Return Policy' (US-origin) Non-Proliferation: Return of all HEU to the US 2 Promote RR conversion to LEU 10 yrs to provide for national Back-end solutions Establish int. Back-end solutions (e.g. IAEA promotion) German Spent RR Fuel Output Current Reactors (operation time): 'BER-II' (2015), 'FRG-1' (> 2010), 'FRJ-2' (2005?), 'TRIGA-MZ' (>2010), 8 'SUR’ Future Reactors: 'FRM-II' (2003-2033), 'NN' (possibly needed > 2010) Fuels: U-Al, U-Si, U-ZrH, U-PE, U-Mo in future US- and RUS-origin RUS-origin: 'FRM-II' + 'RFR' (shut down) with 1,000 FE leftover
    [Show full text]
  • Institute for Nuclear Research and Nuclear Energy Bulgarian Academy of Sciences
    Institute for Nuclear Research and Nuclear Energy Bulgarian Academy of Sciences 20102010 Present State Future Prospects Short History The Physical Institute of the Bulgarian Academy of Sciences (BAS) was established on 1 July 1946 by academician Georgi Nadjakov who became its first director. JINR, Dubna, was established on 26 March 1956 Acad. G. Nadjakov was signing the Protocol together with 10 representatives of other countries. In the autumn of 1955 the Bulgarian government took a decision to build a research nuclear reactor. In 1962 the Physical Institute of BAS was renamed as the Physical Institute with a Nuclear Experimental Facility. In 1972 it was splited into Institute for Nuclear Research and Nuclear Energy (INRNE) and Institute of Solid State Physics. Mission The Institute for Nuclear Research and Nuclear Energy (INRNE) of the Bulgarian Academy of Sciences is the biggest leading complex centre in Bulgaria for scientific research and applications of the nuclear science and technologies and studies of their interactions with the environment. Vision INRNE guarantees a high quality performance of research and innovation activities, addressed to support important national programs, keeping abreast with the modern scientific achievements. With its long standing experience and active collaboration with leading European and International institutions, INRNE contributes to the progress of the physical science. Since 2003/2004 INRNE BAS is certificated ISO 9001:2000 №3312/0 according to ISO 14001:2004 №357/0 Staff and Budget 14 74 126
    [Show full text]
  • Treatment of Spent Fuels from Research Reactors and Reactor Development Programs in Germany
    TREATMENT OF SPENT FUELS FROM RESEARCH REACTORS AND REACTOR DEVELOPMENT PROGRAMS IN GERMANY K.D. CLOSS XA9949808 Forschungszentrum Karlsruhe, Karlsruhe, Germany Abstract Quite a great number of different types of spent fuel from research reactors and development programs exists in Germany. The general policy is to send back to the USA as long as possible fuel from MTRs and TRIG As of USA origin. An option is reprocessing in Great Britain or France. This option is pursued as long as reprocessing and reuse of the recovered material is economically justifiable. For those fuels which cannot be returned to the USA or which will not be reprocessed, a domestic back-up solution of spent fuel management has been developed in Germany, compatible with the management of spent fuel from power reactors. It consists in dry storage in special casks and, later on, direct disposal. Preliminary results from experimental R&D inves- tigations with research reactor fuel and experience from LWR fuel lead to the conclusion that the direct dis- posal option even for research reactor fuel or exotic fuel does not impose major technical difficulties for the German waste management and disposal concept. 1. RESEARCH AND EXPERIMENTAL REACTORS IN GERMANY At the end of 1997, six research reactors with a power > 100 kW were operating in Germany. These comprise two TRIGA-type reactors, three swimming-pool reactors and one DIDO-type reactor. Moreover, one new research reactor is under construction, the operational start-up of which is expected in 2001. More details of these reactors are given in Table I. In addition to these reactors, there are eight research reactors permanently shut down, some of which have already been dismantled.
    [Show full text]
  • Neutrons for the Nation Discovery and Applications While Minimizing the Risk of Nuclear Proliferation
    Neutrons for the Nation Discovery and Applications while Minimizing the Risk of Nuclear Proliferation A Report by the APS Panel on Public Affairs July 2018 ABOUT APS & POPA AUTHORSHIP Founded in 1899 to advance and diffuse the knowledge of The American Physical Society has sole responsibility for physics, the American Physical Society (APS) is now the nation’s the contents of this report, and the questions, findings, and leading organization of physicists with approximately 55,000 recommendations within. members in academia, national laboratories and industry. APS has long played an active role in the federal government; its members serve in Congress and have held positions such as Science Advisor to the President of the United States, Director ACKNOWLEDGEMENTS of the CIA, Director of the National Science Foundation and We thank Frank Bates, Bill Buyers, David Dean, Alex Glaser, Secretary of Energy. Geoff Greene, Jenny Heimberg, Mark Johnson, John Katsaras, Julia Kornfield, Patrick Lemoine, Dan Neumann, Sean O’Kelly, This report was overseen by the APS Panel on Public Affairs Ray Orbach, Winfried Petry, Roger Pynn, Kate Ross, and (POPA). POPA routinely produces reports on timely topics J. Michael Rowe for their contributions to this report. being debated in government so as to inform the debate with the perspectives of physicists working in the relevant issue areas. PUBLICATION DATE: JULY 2018 REPORT COMMITTEE American Physical Society James Wells, Co-Chair, University of Michigan Physics This report is available under the terms of a Creative Commons Department Attribution 4.0 International License. Sharing and adapting the material for any purpose, even commercial, does not require Julia Phillips, Co-Chair, Sandia National Laboratory prior written permission.
    [Show full text]
  • Assessment of Missions and Requirements for a New U.S. Test Reactor
    Nuclear Energy Advisory Committee Assessment of Missions and Requirements for a New U.S. Test Reactor Draft Report December 2016 i Table of Contents ii Acronyms ANL Argonne National Laboratory ANSTO Australian Nuclear Science and Technology Organisation ATR Advanced Test Reactor BARC Bhabha Atomic Research Centre CAEA China Atomic Energy Authority CEA Commissariat à l’Energie Atomique et aux Energies Alternatives CNEA National Atomic Energy Commission DOD Department of Defense DOE Department of Energy DOE-NE Department of Energy -Office of Nuclear Energy dpa displacements per atom ESAAB Energy Systems Acquisition Advisory Board EBR-II Experimental Breeder Reactor-II GCR Gas-Cooled Reactor GIF Generation IV International Forum FFTF Fast Flux Test Facility FHR Fluoride Salt-Cooled High Temperature Reactor HFIR High Flux Isotope Reactor HTGR High Temperature Gas-cooled reactors HTR-PM High Temperature gas-cooled Reactor Pebble-bed Module IFE Institute for Energy Technology IGCAR Indira Gandhi Centre for Atomic Research IKET Institute for Nuclear and Energy Technologies ININ Instituto Nacional de Investigaciones Nucleare INL Idaho National Laboratory JAEA Japan Atomic Energy Agency (JAEA) KAERI Korea Atomic Energy Research Institute KIT Karlsruhe Institute of Technology LANL Los Alamos National Laboratory LWR Light Water Reactor iii LFR Lead Fast Reactor MITR Massachusetts Institute of Technology Research Reactor MOST Ministry of Science and Technology MSR Molten Salt Reactor MTR Material Test Reactor NAS National Academy of Science NBSR National Bureau of Standards Reactor NEAC Nuclear Energy Advisory Committee NEI Nuclear Energy Institute NRT SC Nuclear Reactor Technology Subcommittee NASA National Aeronautics and Space Administration NNSA National Nuclear Security Administration NRC U.S.
    [Show full text]
  • A National Strategy for Materials Research with Neutron Beams
    DRAFT FOR CONSULTATION A National Strategy for Materials Research with Neutron Beams A discussion paper for the Roundtable Meeting, “Canadian Neutron Initiative: Towards a National Neutron Strategy” To be held as a virtual event, December 15–16, 2020 Updated Dec 10, 2020 1 DRAFT FOR CONSULTATION This Canadian Neutron Initiative (CNI) discussion paper and associated Roundtable Meeting are produced in partnership with CIFAR. We also thank the following sponsors: 2 DRAFT FOR CONSULTATION Contents 1 Executive summary and overview of a national strategy ..................................................................... 5 2 Consultation on the strategy ................................................................................................................ 9 3 The present: A strong foundation for continued excellence .............................................................. 12 3.1 The Canadian neutron beam user community ........................................................................... 12 3.2 McMaster University ................................................................................................................... 16 3.3 Other neutron beam capabilities and interests .......................................................................... 17 4 Forging foreign partnerships ............................................................................................................... 19 4.1 Global renewal of advanced neutron sources ...........................................................................
    [Show full text]
  • The Research Reactor Irt-Sofia: 50 Years After First Criticality
    E4 THE RESEARCH REACTOR IRT-SOFIA: 50 YEARS AFTER FIRST CRITICALITY K. KREZHOV International Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria Abstract The design features of the research reactor IRT-2000 in Sofia and accumulated experience in the past prior to the partial dismantling of obsolete reactor systems are outlined. The present status of the ongoing refurbishment to a low power reactor IRT-200 and its planned utilization are briefly described. 1. INTRODUCTION Since early 1956, the Bulgarian government has officially favored the use of nuclear power. In 1957 Bulgaria ratified the Statute of the IAEA and became one of the IAEA states- founders. In June 1957 the Committee for Peaceful Use of Atomic Energy (CPUAE) within the Council of Ministers was established as the specialized state body to promote the nuclear research and applications as well as to control and coordinate the related activities in industry, agriculture, medicine and science. In support to this program the research reactor (RR) IRT- Sofia was contracted. The initial construction of a reactor of the same WWR type as in Poland, Czechoslovakia, Hungary and Rumania that started in 1956 was adapted for the IRT- type of reactor designed and constructed from 1957 to 1961 by the Kurchatov Institute, Moscow. The first chain reaction was accomplished at 20:15 h on September 18, 1961. The official inauguration took place on November 9, 1961. The Reactor underwent several upgrades from initial 500 kW: 1000 kW (1962), 1500 kW (1965) and 2000 kW (IRT-2000) in 1970. The reactor was operated safely with a mixed (LEU-HEU) core for 28 years at power levels agreed upon user demands up to 2000 kW.
    [Show full text]
  • IAEA Nuclear Energy Series Applications of Research Reactors No
    IAEA Nuclear Energy Series IAEA Nuclear No. NP-T-5.3 No. IAEA Nuclear Energy Series Applications of Research Reactors No. NP-T-5.3 Basic Applications of Principles Research Reactors Objectives Guides Technical Reports INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA ISBN 978–92–0–145010–4 ISSN 1995–7807 13-49091_PUB1627_cover_A4.indd 1,3 2014-02-27 08:47:02 IAEA NUCLEAR ENERGY SERIES PUBLICATIONS STRUCTURE OF THE IAEA NUCLEAR ENERGY SERIES Under the terms of Articles III.A and VIII.C of its Statute, the IAEA is authorized to foster the exchange of scientific and technical information on the peaceful uses of atomic energy. The publications in the IAEA Nuclear Energy Series provide information in the areas of nuclear power, nuclear fuel cycle, radioactive waste management and decommissioning, and on general issues that are relevant to all of the above mentioned areas. The structure of the IAEA Nuclear Energy Series comprises three levels: 1 — Basic Principles and Objectives; 2 — Guides; and 3 — Technical Reports. The Nuclear Energy Basic Principles publication describes the rationale and vision for the peaceful uses of nuclear energy. Nuclear Energy Series Objectives publications explain the expectations to be met in various areas at different stages of implementation. Nuclear Energy Series Guides provide high level guidance on how to achieve the objectives related to the various topics and areas involving the peaceful uses of nuclear energy. Nuclear Energy Series Technical Reports provide additional, more detailed information on activities related to the various areas dealt with in the IAEA Nuclear Energy Series. The IAEA Nuclear Energy Series publications are coded as follows: NG — general; NP — nuclear power; NF — nuclear fuel; NW — radioactive waste management and decommissioning.
    [Show full text]
  • Supplement Analysis for the Foreign Research Reactor Spent Nuclear Fuel Acceptance Program
    DOE/EIS-0218-SA-8 SUPPLEMENT ANALYSIS FOR THE FOREIGN RESEARCH REACTOR SPENT NUCLEAR FUEL ACCEPTANCE PROGRAM APRIL 2019 \?f1l ~ : ~ National Nuclear Security Administration U.S. Department of Energy National Nuclear Security Administration Washington, DC Supplement Analysis for the Foreign Research Reactor Spent Nuclear Fuel Acceptance Program TABLE OF CONTENTS Page 1.0 INTRODUCTION AND BACKGROUND ........................................................................................... 1 1.1 Policy on Exemptions ..... ................................................ .... .................................................... 2 1.2 Statement of Intent Between the United States and Japan .................. .. .................... ......... 3 1.3 HEU Shipments ..... .. ............................................................................................................... 3 1.4 Training Research Isotope General Atomics (TRIGA) Fuel .................................... ................ 4 2.0 PURPOSE AND NEED, AND PROPOSED ACTION ............................................................................ 4 2.1 Purpose and Need .................................................... ...................... ....................................... 4 2.2 Proposed Action ............ .. ...................... ....................................................................... .. .... ... 4 2.3 Description of Activities ......................................................................................................... 4 3.0 AFFECTED
    [Show full text]
  • Low Dimensional Neutron Moderators for Enhanced Source Brightness
    Low dimensional neutron moderators for enhanced source brightness Ferenc Mezei 1,2 , Luca Zanini 1, Alan Takibayev 1, Konstantin Batkov 1, Esben Klinkby 1,3 , Eric Pitcher 1 and Troels Sch önfeldt 1,3 1European Spallation Source, ESS AB, PO BOX 176, 22100 Lund, Sweden 2Hungarian Academy of Sciences, Wigner RCF, 1525 Budapest, Pf. 49, Hungary 3DTU Nutech, Technical University of Denmark, DTU Risø Campus, 4000 Roskilde, Denmark Corresponding Author: F. Mezei, European Spallation Source ESS AB, PO BOX 176, 22100 Lund, Sweden, e-mail: [email protected] , Tel:+46 72 179 2039 Abstract In a recent numerical optimization study we have found that liquid para-hydrogen coupled cold neutron moderators deliver 3 – 5 times higher cold neutron brightness at a spallation neutron source if they take the form of a flat, quasi 2-dimensional disc, in contrast to the conventional more voluminous shapes used by now. In the present paper we describe a simple theoretical explanation of this unexpected behavior, which is based on the large difference in para-hydrogen between the values of the scattering mean free path for thermal neutrons (in the range of 1 cm) and its much larger equivalent for cold neutrons. This model leads to the conclusions that the optimal shape for high brightness para- hydrogen neutron moderators is the quasi 1-dimensional tube and these low dimensional moderators can also deliver much enhanced cold neutron brightness in fission reactor neutron sources, compared to much more voluminous liquid D 2 or H 2 moderators currently used. Neutronic simulation calculations confirm both of these theoretical conclusions.
    [Show full text]