WorldWideScience

Sample records for nuclear fission program

  1. Nuclear fission

    International Nuclear Information System (INIS)

    Kodama, T.

    1981-01-01

    The nuclear fission process is pedagogically reviewed from a macroscopic-microscopic point of view. The Droplet model is considered. The fission dynamics is discussed utilizing path integrals and semiclassical methods. (L.C.) [pt

  2. Nuclear fission and reactions

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The nuclear fission research programs are designed to elucidate basic features of the fission process. Specifically, (1) factors determining how nucleons of a fissioning nucleus are distributed between two fission fragments, (2) factors determining kinetic energy and excitation energies of fragments, and (3) factors controlling fission lifetimes. To these ends, fission studies are reported for several heavy elements and include investigations of spontaneous and neutron-induced fission, heavy ion reactions, and high energy proton reactions. The status of theoretical research is also discussed. (U.S.)

  3. World Energy Data System (WENDS). Volume XI. Nuclear fission program summaries

    International Nuclear Information System (INIS)

    1979-06-01

    Brief management and technical summaries of nuclear fission power programs are presented for nineteen countries. The programs include the following: fuel supply, resource recovery, enrichment, fuel fabrication, light water reactors, heavy water reactors, gas cooled reactors, breeder reactors, research and test reactors, spent fuel processing, waste management, and safety and environment

  4. World Energy Data System (WENDS). Volume XI. Nuclear fission program summaries

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    Brief management and technical summaries of nuclear fission power programs are presented for nineteen countries. The programs include the following: fuel supply, resource recovery, enrichment, fuel fabrication, light water reactors, heavy water reactors, gas cooled reactors, breeder reactors, research and test reactors, spent fuel processing, waste management, and safety and environment. (JWR)

  5. Fission 2009 4. International Workshop on Nuclear Fission and Fission Product Spectroscopy - Compilation of slides

    International Nuclear Information System (INIS)

    2009-01-01

    This conference is dedicated to the last achievements in experimental and theoretical aspects of the nuclear fission process. The topics include: mass, charge and energy distribution, dynamical aspect of the fission process, nuclear data evaluation, quasi-fission and fission lifetime in super heavy elements, fission fragment spectroscopy, cross-section and fission barrier, and neutron and gamma emission. This document gathers the program of the conference and the slides of the presentations

  6. The nuclear fission

    International Nuclear Information System (INIS)

    Fiorentino, J.

    1983-01-01

    The nuclear fission process considering initially the formation of compound nucleus and finishing with radioactive decay of fission products is studied. The process is divided in three parts which consist of the events associated to the nucleus of intermediate transitional state, the scission configuration, and the phenomenum of post scission. (M.C.K.) [pt

  7. The nuclear fission process

    International Nuclear Information System (INIS)

    Wagemans, C.

    1991-01-01

    Fifty years after its discovery, the nuclear fission phenomenon is of recurring interest. When its fundamental physics aspects are considered, fission is viewed in a very positive way, which is reflected in the great interest generated by the meetings and large conferences organized for the 50th anniversary of its discovery. From a purely scientific and practical point of view, a new book devoted to the (low energy) nuclear fission phenomenon was highly desirable considering the tremendous amount of new results obtained since the publication of the book Nuclear Fission by Vandenbosch and Huizenga in 1973 (Academic Press). These new results could be obtained thanks to the growth of technology, which enabled the construction of powerful new neutron sources, particle and heavy ion accelerators, and very performant data-acquisition and computer systems. The re-invention of the ionization chamber, the development of large fission fragment spectrometers and sophisticated multiparameter devices, and the production of exotic isotopes also contributed significantly to an improved understanding of nuclear fission. This book is written at a level to introduce graduate students to the exciting subject of nuclear fission. The very complete list of references following each chapter also makes the book very useful for scientists, especially nuclear physicists. The book has 12 chapters covering the fission barrier and the various processes leading to fission as well as the characteristics of the various fission reaction products. In order to guarantee adequate treatment of the very specialized research fields covered, several distinguished scientists actively involved in some of these fields were invited to contribute their expertise as authors or co-authors of the different chapters

  8. Nuclear fission and neutron-induced fission cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

    1981-01-01

    A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.

  9. Intermediate energy nuclear fission

    International Nuclear Information System (INIS)

    Hylten, G.

    1982-01-01

    Nuclear fission has been investigated with the double-kinetic-energy method using silicon surface barrier detectors. Fragment energy correlation measurements have been made for U, Th and Bi with bremsstrahlung of 600 MeV maximum energy. Distributions of kinetic energy as a function of fragment mass are presented. The results are compared with earlier photofission data and in the case of bismuth, with calculations based on the liquid drop model. The binary fission process in U, Yb, Tb, Ce, La, Sb, Ag and Y induced by 600 MeV protons has been investigated yielding fission cross sections, fragment kinetic energies, angular correlations and mass distributions. Fission-spallation competition calculations are used to deduce values of macroscopic fission barrier heights and nuclear level density parameter values at deformations corresponding to the saddle point shapes. We find macroscopic fission barriers lower than those predicted by macroscopic theories. No indication is found of the Businaro Gallone limit expected to occur somewhere in the mass range A = 100 to A = 140. For Ce and La asymmetric mass distributions similar to those in the actinide region are found. A method is described for the analysis of angular correlations between complementary fission products. The description is mainly concerned with fission induced by medium-energy protons but is applicable also to other projectiles and energies. It is shown that the momentum and excitation energy distributions of cascade residuals leading to fission can be extracted. (Author)

  10. Energy from nuclear fission()

    Science.gov (United States)

    Ripani, M.

    2015-08-01

    The main features of nuclear fission as physical phenomenon will be revisited, emphasizing its peculiarities with respect to other nuclear reactions. Some basic concepts underlying the operation of nuclear reactors and the main types of reactors will be illustrated, including fast reactors, showing the most important differences among them. The nuclear cycle and radioactive-nuclear-waste production will be also discussed, along with the perspectives offered by next generation nuclear assemblies being proposed. The current situation of nuclear power in the world, its role in reducing carbon emission and the available resources will be briefly illustrated.

  11. The wastes of nuclear fission

    International Nuclear Information System (INIS)

    Doubre, H.

    2005-01-01

    In this paper the author presents the problems of the radioactive wastes generated by the nuclear fission. The first part devoted to the fission phenomenon explains the incident neutron energy and the target nuclei role. The second part devoted to the nuclear wastes sources presents the production of wastes upstream of the reactors, in the reactors and why these wastes are dangerous. The third part discusses the radioactive wastes management in France (classification, laws). The last part details the associated research programs: the radionuclides separation, the disposal, the underground storage, the transmutation and the thorium cycle. (A.L.B.)

  12. 50 years of nuclear fission

    International Nuclear Information System (INIS)

    Hilscher, D.

    1989-01-01

    The article tells the story of the discovery of nuclear fission in Berlin 50 years ago by Otto Hahn and Fritz Strassmann in cooperation with Lise Meitner. 50 years later nuclear fission is still a subject of research. Some question remain unanswered. Selected new research results are used to discuss the dynamics of the collective movement of the elementary nuclear fission process. (orig.) [de

  13. Nuclear fission and fission-product spectroscopy: 3. International workshop on nuclear fission and fission-product spectroscopy

    International Nuclear Information System (INIS)

    Goutte, Heloise; Fioni, Gabriele; Faust, Herbert; Goutte, Dominique

    2005-01-01

    The present book contains the proceedings of the third workshop in a series of workshops previously held in Seyssins in 1994 and 1998. The meeting was jointly organized by different divisions of CEA and two major international laboratories. In the opening address, Prof. B. Bigot, the French High Commissioner for Atomic Energy, outlined France's energy policy for the next few decades. He emphasized the continuing progress of nuclear fission in both technical and economic terms, allowing it to contribute to the energy needs of the planet even more in the future than it does today. Such progress implies a very strong link between fundamental and applied research based on experimental and theoretical approaches. The workshop gathered the different nuclear communities studying the fission process, including topics as the following: - nuclear fission experiments, - spectroscopy of neutron rich nuclei, - fission data evaluation, - theoretical aspects of nuclear fission, - and innovative nuclear systems and new facilities. The scientific program was suggested by an International Advisory Committee. About 100 scientists from 13 different countries attended the conference in the friendly working atmosphere of the Castle of Cadarache in the heart of the Provence. The proceedings of the workshop were divided into 11 sections addressing the following subject matters: 1. Cross sections and resonances (5 papers); 2. Fission at higher energies - I (5 papers); 3. Fission: mass and charge yields (4 papers); 4. Light particles and cluster emission (4 papers); 5. Spectroscopy of neutron rich nuclei (5 papers); 6. Resonances, barriers, and fission times (5 papers); 7. Fragment excitation and neutron emission (4 papers); 8. Mass and energy distributions (4 papers); 9. Needs for nuclear data and new facilities - I (4 papers); 10. Angular momenta and fission at higher Energies - II (3 papers); 11. New facilities - II (2 papers). A poster session of 8 presentations completed the workshop

  14. Nuclear Forensics and Radiochemistry: Fission

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-07

    Radiochemistry has been used to study fission since it’ discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution.

  15. Strengthening the fission reactor nuclear science and engineering program at UCLA. Final technical report

    International Nuclear Information System (INIS)

    Okrent, D.

    1997-01-01

    This is the final report on DOE Award No. DE-FG03-92ER75838 A000, a three year matching grant program with Pacific Gas and Electric Company (PG and E) to support strengthening of the fission reactor nuclear science and engineering program at UCLA. The program began on September 30, 1992. The program has enabled UCLA to use its strong existing background to train students in technological problems which simultaneously are of interest to the industry and of specific interest to PG and E. The program included undergraduate scholarships, graduate traineeships and distinguished lecturers. Four topics were selected for research the first year, with the benefit of active collaboration with personnel from PG and E. These topics remained the same during the second year of this program. During the third year, two topics ended with the departure o the students involved (reflux cooling in a PWR during a shutdown and erosion/corrosion of carbon steel piping). Two new topics (long-term risk and fuel relocation within the reactor vessel) were added; hence, the topics during the third year award were the following: reflux condensation and the effect of non-condensable gases; erosion/corrosion of carbon steel piping; use of artificial intelligence in severe accident diagnosis for PWRs (diagnosis of plant status during a PWR station blackout scenario); the influence on risk of organization and management quality; considerations of long term risk from the disposal of hazardous wastes; and a probabilistic treatment of fuel motion and fuel relocation within the reactor vessel during a severe core damage accident

  16. Computer program FPIP-REV calculates fission product inventory for U-235 fission

    Science.gov (United States)

    Brown, W. S.; Call, D. W.

    1967-01-01

    Computer program calculates fission product inventories and source strengths associated with the operation of U-235 fueled nuclear power reactor. It utilizes a fission-product nuclide library of 254 nuclides, and calculates the time dependent behavior of the fission product nuclides formed by fissioning of U-235.

  17. Fifty years with nuclear fission

    International Nuclear Information System (INIS)

    Behrens, J.W.; Carlson, A.D.

    1989-01-01

    The news of the discovery of nuclear fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fifieth anniversary of its discovery by holding a topical meeting entitled, ''Fifty Years with Nuclear Fission,'' in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent development in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicated a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two fully days of sessions (April 27 and 28) at the main site of the NIST in Gaithersburg, Maryland. The wide range of topics covered in this Volume 1 by this topical meeting included plenary invited, and contributed sessions entitled: Preclude to the First Chain Reaction -- 1932 to 1942; Early Fission Research -- Nuclear Structure and Spontaneous Fission; 50 Years of Fission, Science, and Technology; Nuclear Reactors, Secure Energy for the Future; Reactors 1; Fission Science 1; Safeguards and Space Applications; Fission Data; Nuclear Fission -- Its Various Aspects; Theory and Experiments in Support of Theory; Reactors and Safeguards; and General Research, Instrumentation, and By-Product. The individual papers have been cataloged separately

  18. Fifty years with nuclear fission

    International Nuclear Information System (INIS)

    Behrens, J.W.; Carlson, A.D.

    1989-01-01

    The news of the discovery of nucler fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fiftieth anniversary of its discovery by holding a topical meeting entitled, ''Fifty years with nuclear fission,'' in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent developments in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicating a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two full days of sessions (April 27 and 28) at the main sites of the NIST in Gaithersburg, Maryland. The wide range of topics covered by Volume 2 of this topical meeting included plenary invited, and contributed sessions entitled, Nuclear fission -- a prospective; reactors II; fission science II; medical and industrial applications by by-products; reactors and safeguards; general research, instrumentation, and by-products; and fission data, astrophysics, and space applications. The individual papers have been cataloged separately

  19. Fission product release during MCCI. CEC nuclear safety program: MCCI project

    Energy Technology Data Exchange (ETDEWEB)

    Cenerino, G [CEA Centre d` Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Cordfunke, E H.P. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Hunterlaar, M E [Netherlands Energy Research Foundation (ECN), Petten (Netherlands)

    1995-01-01

    The assessment of the consequences of severe accidents in nuclear reactors involving molten core-concrete interactions (MCCls) requires estimates of the quantities and physicochemical forms of the radioactive species released from the melt into the cavity atmosphere. Such estimates in turn require a detailed knowledge of the complex chemical interactions which would occur between the fission products, fuel and the components of the core structural materials and the concrete. In recent years, effort has been put into the thermodynamic characterization of these processes. The results of such studies are important for predicting several aspects of MCCls, including: 1. The release of species by vaporization; 2. the extent of concrete penetration: a. The melt solidus and liquidus temperatures, which in turn affect the heat transfer processes and hence tile predictions of the melt temperature and the onset of solidification, b. the amounts of the solid and liquid phases and the respective compositions, which determines the viscosity of the melt, and c. the composition of the crust formed following the addition of water to quench the interaction. d. the distribution of fission products among metallic and oxidic phases. This SOAR is devoted to thermochemical calculations in the context of MCCI where most fission products and the metallic components of the melt are transferred into an oxidic form sooner or later. Calculations on fission product release from a molten pool without MCCI are underway in the source term project of the CEC-RCA. The following conditions have to be taken into account in order to be able to perform reliable thermodynamic calculations. (orig./HP).

  20. Fission product release during MCCI. CEC nuclear safety program: MCCI project

    International Nuclear Information System (INIS)

    Cenerino, G.; Hunterlaar, M.E.

    1995-01-01

    The assessment of the consequences of severe accidents in nuclear reactors involving molten core-concrete interactions (MCCls) requires estimates of the quantities and physicochemical forms of the radioactive species released from the melt into the cavity atmosphere. Such estimates in turn require a detailed knowledge of the complex chemical interactions which would occur between the fission products, fuel and the components of the core structural materials and the concrete. In recent years, effort has been put into the thermodynamic characterization of these processes. The results of such studies are important for predicting several aspects of MCCls, including: 1. The release of species by vaporization; 2. the extent of concrete penetration: a. The melt solidus and liquidus temperatures, which in turn affect the heat transfer processes and hence tile predictions of the melt temperature and the onset of solidification, b. the amounts of the solid and liquid phases and the respective compositions, which determines the viscosity of the melt, and c. the composition of the crust formed following the addition of water to quench the interaction. d. the distribution of fission products among metallic and oxidic phases. This SOAR is devoted to thermochemical calculations in the context of MCCI where most fission products and the metallic components of the melt are transferred into an oxidic form sooner or later. Calculations on fission product release from a molten pool without MCCI are underway in the source term project of the CEC-RCA. The following conditions have to be taken into account in order to be able to perform reliable thermodynamic calculations. (orig./HP)

  1. Low energy nuclear fission

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1982-02-01

    In these lectures we present the liquid drop model of fission and compare some of its prediction with experiment. The liquid drop analogy allows to define in a rather simple and intuitive way a number of useful concepts and possible observables. We then discuss, using the example of the oscillator model, the generality of shell effects. We show how a synthesis of the liquid drop model and of the shell model can be made using the Strutinsky shell averaging procedure. Some experimental data related to the existence of shape isomers are presented and discussed. We conclude by discussing some aspects, both experimental and theoretical, of fission dynamics

  2. Low energy nuclear fission

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1980-08-01

    In these lectures the liquid drop model of fission is presented and some of its predictions compared with experiment. The liquid drop analogy allows to define in a rather simple and intuitive way a number of useful concepts and possible observables. It is shown how a synthesis of the liquid drop model and of the shell model can be made using the Strutinsky shell averaging procedure. Some experimental data related to the existence of shape isomers are presented and discussed. We conclude by discussing some aspects, both experimental and theoretical, of fission dynamics

  3. The behavior of fission products during nuclear rocket reactor tests

    International Nuclear Information System (INIS)

    Bokor, P.C.; Kirk, W.L.; Bohl, R.J.

    1991-01-01

    Fission product release from nuclear rocket propulsion reactor fuel is an important consideration for nuclear rocket development and application. Fission product data from the last six reactors of the Rover program are collected in this paper to provide as basis for addressing development and testing issues. Fission product loss from the fuel will depend on fuel composition and reactor design and operating parameters. During ground testing, fission products can be contained downstream of the reactor. The last Rover reactor tested, the Nuclear Furnance, was mated to an effluent clean-up system that was effective in preventing the discharge of fission products into the atmosphere

  4. 40 years of nuclear fission

    International Nuclear Information System (INIS)

    Koch, H.

    1979-01-01

    On the occasion of both the 100th birthday of the discoverer of nuclear fission, Otto Hahn, and the 40th anniversary of this outstanding scientific discovery the historical development is described, which led to nuclear fission. Aspects of scientific life in Berlin and in the whole world at that time are presented, and relations between scientists are characterized by quotations. In particular, stress is laid on the life and activities of Otto Hahn as a human being and as a scientist, and his outstanding scientific achievements are appreciated. (author)

  5. Fission energy program of the US Department of Energy, FY 1981

    International Nuclear Information System (INIS)

    1980-03-01

    Information is presented concerning the National Energy Plan and fission energy policy; fission energy program management; converter reactor systems; breeder reactor systems; and special nuclear evaluations and systems

  6. Nuclear fission with inertial confinement

    CERN Document Server

    Koshkarev, D G

    2002-01-01

    The possibility of initiating the explosive fission reaction in a small quantity of fissile material through the heavy ions beam from the powerful accelerator-driver, developed for realization of the thermonuclear synthesis in the deuterium-tritium cylindrical targets with the direct ignition, is considered. The consequences of applying this method in the nuclear engineering are discussed

  7. Dynamical features of nuclear fission

    Indian Academy of Sciences (India)

    Wheeler underestimates several observables in heavy-ion-induced ... excitation energies, there may not be sufficient nuclei near the fission barrier after the .... Dissipation in nuclear dynamics in the mean-field regime accounts for the coupling of the .... barrier for different isotopes of Fr. The lines are drawn to guide the eye.

  8. 14. International workshop on nuclear fission physics. Proceedings

    International Nuclear Information System (INIS)

    2000-01-01

    The meetings on nuclear fission took place 12-15 October 1998 and was organized by Institute of Physics and Power Engineering. The aim of the workshop was to present and discuss main new both theoretical and experimental results obtained in the area of nuclear fission, dynamical feature, properties of fission fragments and complementary radiation. As usual the program of the workshop was designed to cover a wide range of physical phenomena - from low energy and spontaneous fission to fission of hot rotating nuclei and multifragmentation at intermediate and high energies. Reaction induced by slow and fast neutron, light and heavy ions were discussed [ru

  9. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1984-09-01

    This is the tenth issue of a report series on Fission Product Data, which informs us about all the activities in this field, which are planned, ongoing, or have recently been completed. The types of activities included are measurements, compilations and evaluations of: fission product yields (neutron induced and spontaneous fission), neutron reaction cross sections of fission products, data related to the radioactive decay of fission products, delayed neutron data of fission products, lumped fission product data (decay heat, absorption, etc.). There is also a section with recent references relative to fission product nuclear data

  10. Charged particle-induced nuclear fission reactions

    Indian Academy of Sciences (India)

    The nuclear fission phenomenon continues to be an enigma, even after nearly 75 years of its discovery. Considerable progress has been made towards understanding the fission process. Both light projectiles and heavy ions have been employed to investigate nuclear fission. An extensive database of the properties of ...

  11. Nuclear fission and diplomacy

    International Nuclear Information System (INIS)

    Van Splunter, J.M.

    1993-01-01

    The title study, based on archive investigations in the Netherlands, the United States and Great Britain, deals with the early phase of Dutch involvement in nuclear energy, that is up to the signing of the Euratom treaty in 1957. It concentrates upon the international aspects of Dutch activities in nuclear energy, especially upon relations with other countries active in the field. In chapter two the Dutch government policy regarding the strategic materials uranium and thorium is discussed. Attention is paid to the interest of the United States for such materials. It is explained why the Dutch government kept it a secret that they possessed a certain amount of uranium and why they negotiated the thorium reserves which were mined in the Netherlands East Indies (now Indonesia). In chapter three the Dutch policy in the United Nations regarding the so-called Baruch plan, being the USA-proposal for international control and management of the use of nuclear energy, and the counter proposal of the USSR, the Gromyko plan, in the period 1946-152 is outlined. In chapter four an overview is given of how the Dutch nuclear energy research in the first ten years after the Second World War was set up and organized. As a result of US president Eisenhower's 'Atoms for Peace' speech, held in December 1953, the Americans offered to cooperate with Western European countries, already involved in research on peaceful applications of nuclear energy. This change in the US-policy of secrecy is described in chapter five. The consequences of that speech are dealt with in chapter six. It resulted, amongst other things in the foundation of the Reactor Centre Netherlands (RCN), now Netherlands Energy Research Foundation (ECN). It is concluded that only in the last years of the period, studied in this thesis, the Netherlands reconciled itself to American supremacy, partly explained by the weakly developed political structure in the Netherlands regarding the nuclear energy policy. 17 ills., 137

  12. Theory of nuclear fission: a review

    International Nuclear Information System (INIS)

    Mosel, U.

    1976-01-01

    General properties of nuclear fission are reviewed and related to our present knowledge of fission theory. For this purpose the basic reasons for the shape of the fission barriers are discussed and their consequences compared with experimental results on barrier shapes and structures. Special emphasis is put on the asymmetry of the fission barriers and mass-distributions and its relation to the shells of the nascent fragment shells. Finally the problem of calculating fission cross sections is discussed

  13. Nuclear fission and neutron-induced fission cross-sections

    CERN Document Server

    James, G D; Michaudon, A; Michaudon, A; Cierjacks, S W; Chrien, R E

    2013-01-01

    Nuclear Fission and Neutron-Induced Fission Cross-Sections is the first volume in a series on Neutron Physics and Nuclear Data in Science and Technology. This volume serves the purpose of providing a thorough description of the many facets of neutron physics in different fields of nuclear applications. This book also attempts to bridge the communication gap between experts involved in the experimental and theoretical studies of nuclear properties and those involved in the technological applications of nuclear data. This publication will be invaluable to those interested in studying nuclear fis

  14. Future research program on prompt γ-ray emission in nuclear fission

    Science.gov (United States)

    Oberstedt, S.; Billnert, R.; Hambsch, F.-J.; Lebois, M.; Oberstedt, A.; Wilson, J. N.

    2015-12-01

    In recent years the measurement of prompt fission γ-ray spectra (PFGS) has gained renewed interest, after about forty years since the first comprehensive studies of the reactions 235U(n th , f), 239Pu(n th ,f) and 252Cf(sf). The renaissance was initiated by requests for new values especially for γ-ray multiplicity and average total energy release per fission in neutron-induced fission of 235U and 239Pu. Both isotopes are considered the most important ones with respect to the modeling of innovative cores required for the Generation-IV reactors, the majority working with fast neutrons. During the last 5 years we have conducted a systematic study of spectral data for thermal-neutron-induced fission on 235U and 241Pu as well as for the spontaneous fission of 252Cf with unprecedented accuracy. From the new data we conclude that those reactions do not considerably contribute to the observed heat excess and suspect other reactions playing a significant role. Possible contributions may originate from fast-neutron-induced reactions on 238U, which is largely present in the fuel, or from γ-induced fission from neutron capture in the construction material. A first experiment campaign on prompt γ-ray emission from fast-neutron-induced fission on 235,238U was successfully performed in order to test our assumptions. In the following we attempt to summarize, what has been done in the field to date, and to motivate future measurement campaigns exploiting dedicated neutron and photon beams as well as upcoming highly efficient detector assemblies.

  15. Future research program on prompt γ-ray emission in nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Oberstedt, S.; Hambsch, F.J. [Joint Research Centre IRMM, European Commission, Geel (Belgium); Billnert, R. [Joint Research Centre IRMM, European Commission, Geel (Belgium); Chalmers Tekniska Hoegskola, Fundamental Fysik, Goeteborg (Sweden); Lebois, M.; Wilson, J.N. [Institut de Physique Nucleaire Orsay, Orsay (France); Oberstedt, A. [Chalmers Tekniska Hoegskola, Fundamental Fysik, Goeteborg (Sweden); Ossolution Consulting, Oerebro (Sweden)

    2015-12-15

    In recent years the measurement of prompt fission γ-ray spectra (PFGS) has gained renewed interest, after about forty years since the first comprehensive studies of the reactions {sup 235}U(n{sub th}, f), {sup 239}Pu(n{sub th},f) and {sup 252}Cf(sf). The renaissance was initiated by requests for new values especially for γ-ray multiplicity and average total energy release per fission in neutron-induced fission of {sup 235}U and {sup 239}Pu. Both isotopes are considered the most important ones with respect to the modeling of innovative cores required for the Generation-IV reactors, the majority working with fast neutrons. During the last 5 years we have conducted a systematic study of spectral data for thermal-neutron-induced fission on {sup 235}U and {sup 241}Pu as well as for the spontaneous fission of {sup 252}Cf with unprecedented accuracy. From the new data we conclude that those reactions do not considerably contribute to the observed heat excess and suspect other reactions playing a significant role. Possible contributions may originate from fast-neutron-induced reactions on {sup 238}U, which is largely present in the fuel, or from γ-induced fission from neutron capture in the construction material. A first experiment campaign on prompt γ-ray emission from fast-neutron-induced fission on {sup 235,238}U was successfully performed in order to test our assumptions. In the following we attempt to summarize, what has been done in the field to date, and to motivate future measurement campaigns exploiting dedicated neutron and photon beams as well as upcoming highly efficient detector assemblies. (orig.)

  16. Geology behind nuclear fission technology

    International Nuclear Information System (INIS)

    Dhana Raju, R.

    2005-01-01

    Geology appears to have played an important role of a precursor to Nuclear Fission Technology (NFT), in the latter's both birth from the nucleus of an atom of and most important application as nuclear power extracted from Uranium (U), present in its minerals. NFT critically depends upon the availability of its basic raw material, viz., nuclear fuel as U and/ or Th, extracted from U-Th minerals of specific rock types in the earth's crust. Research and Development of the Nuclear Fuel Cycle (NFC) depends heavily on 'Geology'. In this paper, a brief review of the major branches of geology and their contributions during different stages of NFC, in the Indian scenario, is presented so as to demonstrate the important role played by 'Geology' behind the development of NFT, in general, and NFC, in particular. (author)

  17. Nuclear Dissipation from Fission Time

    International Nuclear Information System (INIS)

    Gontchar, I.; Morjean, M.; Basnary, S.

    2000-01-01

    Fission times, pre-scission neutron multiplicities and GDR pre-scission γ-ray multiplicities measured for uranium or thorium nuclei formed with temperatures T ∼ 1.8 MeV have been compared with calculations performed with CDSM2, a two-dimensional dynamical model combined with a statistical one. Among the three experimental approaches considered, fission times give access to the most precise pieces of information on nuclear dissipation at high excitation energy. For the temperature range under consideration, an agreement between the model and data is achieved if one-body dissipation is used with a strength factor k red ∼ 0.45 ± 0.10 applied to the wall term for the mononuclear configuration. (authors)

  18. Nuclear wastes: fission

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Progress is reported on investigations of transuranics in soils and plants that have demonstrated the importance of valence state, complexation, competing elements, migration down the soil profile, and weathering cycles in governing transuranic, 129 I and 99 Tc availability to plants and, in the case of Pu, to the consuming animals. In the latter case, it was demonstrated, for the first time, that ingestion of plant tissues containing Pu may result in greater transfer across the gut compared to gavaging animals with inorganic Pu solutions, underscoring the importance of detailed studies of the soil, plant, and animal factors influencing uptake by the ingestion pathway. Further evidence of the importance of the ingestion pathway was provided in studies of foliar interception of airborne transuranic elements in which it was shown that Pu in particles in the respiratory size range were effectively intercepted and retained by plants, and significant quantities of intercepted Pu were transported to roots and seeds. Similar studies on the terrestrial ingestion pathway have been initiated with other actinides including, U, Am, Cm, and Np. Radioecological field studies were directed toward establishment of pertinent ingestion pathways and exposure levels through description of habitat types, population densities, and, in several instances, dosimetry, for major insects, reptiles, birds, and mammalian species. These studies were extended to agricultural ecosystems through definition of the uptake of long-lived nuclides and digestibility in cattle of several forage species. In studies on a pond ecosystem at the nuclear fuel reprocessing plant, Pu and Am uptake rates were studied for major biotic components including organic floc, algae, fish, and ducks. The results indicated that assimilation of transuranics by the biota and export from the pond system were low compared to the total inventory

  19. Energy from nuclear fission an introduction

    CERN Document Server

    De Sanctis, Enzo; Ripani, Marco

    2016-01-01

    This book provides an overview on nuclear physics and energy production from nuclear fission. It serves as a readable and reliable source of information for anyone who wants to have a well-balanced opinion about exploitation of nuclear fission in power plants. The text is divided into two parts; the first covers the basics of nuclear forces and properties of nuclei, nuclear collisions, nuclear stability, radioactivity, and provides a detailed discussion of nuclear fission and relevant topics in its application to energy production. The second part covers the basic technical aspects of nuclear fission reactors, nuclear fuel cycle and resources, safety, safeguards, and radioactive waste management. The book also contains a discussion of the biological effects of nuclear radiation and of radiation protection, and a summary of the ten most relevant nuclear accidents. The book is suitable for undergraduates in physics, nuclear engineering and other science subjects. However, the mathematics is kept at a level that...

  20. Contribution to the study of nuclear fission

    International Nuclear Information System (INIS)

    Serot, O.

    2009-09-01

    The author proposes an overview of his research activity during the past fifteen years and more particularly that dealing with nuclear fission. The first part reports works on nucleus physics at the scission via the investigation of ternary fission (experimental procedure, influence of fission modes, influence of resonance spin, influence of excitation energy of the fissioning nucleus, emission probabilities, energy spectra of ternary alphas and tritons, emission mechanism). The second part reports measurements and assessments of neutron-induced fission cross sections. The third part reports the investigation of some properties of fission products (efficiencies, branching ratios of the main delayed neutron precursors)

  1. Nuclear fission as a macroscopic quantum tunneling

    International Nuclear Information System (INIS)

    Takigawa, N.

    1995-01-01

    We discuss nuclear fission from the point of view of a macroscopic quantum tunneling, one of whose major interests is to study the effects of environments on the tunneling rate of a macroscopic variable. We show that a vibrational excitation of the fissioning nucleus significantly enhances the fission rate. We show this effect by two different methods. The one is to treat the vibrational excitation as an environmental degree of freedom, the other treats the fission as a two dimensional quantum tunneling. (author)

  2. Nuclear Power from Fission Reactors. An Introduction.

    Science.gov (United States)

    Department of Energy, Washington, DC. Technical Information Center.

    The purpose of this booklet is to provide a basic understanding of nuclear fission energy and different fission reaction concepts. Topics discussed are: energy use and production, current uses of fuels, oil and gas consumption, alternative energy sources, fossil fuel plants, nuclear plants, boiling water and pressurized water reactors, the light…

  3. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, G.

    1976-05-01

    The purpose of this series is to inform scientists working on Fission Product Nuclear Data, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. This report consists of reproductions of essentially unaltered original contributions which the authors have sent to IAEA/NDS. The types of activities being included in this report are measurements, compilations and evaluations of: fission product yields; neutron cross-section data of fission products; data related to β-, γ-decay of fission products; delayed neutron data; and fission product decay-heat

  4. Nuclear fission and nuclear safeguards: Common technologies and challenges

    International Nuclear Information System (INIS)

    Keepin, G.R.

    1989-01-01

    Nuclear fission and nuclear safeguards have much in common, including the basic physical phenomena and technologies involved as well as the commitments and challenges posed by expanding nuclear programs in many countries around the world. The unique characteristics of the fission process -- such as prompt and delayed neutron and gamma ray emission -- not only provide the means of sustaining and controlling the fission chain reaction, but also provide unique ''signatures'' that are essential to quantitative measurement and effective safeguarding of key nuclear materials (notably 239 Pu and 235 U) against theft, loss, or diversion. In this paper, we trace briefly the historical emergence of safeguards as an essential component of the expansion of the nuclear enterprise worldwide. We then survey the major categories of passive and active nondestructive assay techniques that are currently in use or under development for rapid, accurate measurement and verification of safe-guarded nuclear materials in the many forms in which they occur throughout the nuclear fuel cycle. 23 refs., 14 figs

  5. Nuclear fission studies: from LOHENGRIN to FIPPS

    International Nuclear Information System (INIS)

    Chebboubi, Abdelaziz

    2015-01-01

    Nuclear fission consists in splitting a nucleus, in general an actinide, into smaller nuclei. Despite nuclear fission was discovered in 1939 by Hahn and Strassman, fission models cannot predict the fission observables with an acceptable accuracy for nuclear fuel cycle studies for instance. Improvement of fission models is an important issue for the knowledge of the process itself and for the applications. To reduce uncertainties of the nuclear data used in a nuclear reactor simulation, a validation of the models hypothesis is mandatory. In this work, two features of the nuclear fission were investigated in order to test the resistance of the theories. One aspect is the study of the symmetric fission fragments through the measurement of their yield and kinetic energy distribution. The other aspect is the study of the fission fragment angular momentum.Two techniques are available to assess the angular momentum of a fission fragment. The first one is to look at the properties of the prompt gamma. The new spectrometer FIPPS (Fission Product Prompt gamma-ray Spectrometer), is currently under development at the ILL and will combine a fission filter with a large array of gamma and neutron detectors in order to respond to these issues. The first part of this work is dedicated to the study of the properties of a Gas Filled Magnet (GFM) which is the type of fission filter considered for the FIPPS project.The second part of this work deals with the measurement of isomeric yields and evaluations of the angular momentum distribution of fission fragments. The study of the spherical nucleus 132 Sn shed the light on the current limits of fission models. Finally, the last part of this work is about the measurement of the yields and kinetic energy distributions of symmetric fission fragments. Since models predict the existence of fission modes, the symmetry region is a suitable choice to investigate this kind of prediction. In parallel with all these studies, an emphasis on the

  6. Nuclear fission with a Langevin equation

    International Nuclear Information System (INIS)

    Boilley, D.; Suraud, E.; Abe, Yasuhisa

    1992-01-01

    A microscopically derived Langevin equation is applied to thermally induced nuclear fission. An important memory effect is pointed out and discussed. A strong friction coefficient, estimated from microscopic quantities, tends to decrease the stationary limit of the fission rate and to increase the transient time. The calculations are performed with a collective mass depending on the collective variable and with a constant mass. Fission rates calculated at different temperatures are shown and compared with previous available results. (author) 23 refs.; 7 figs

  7. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1981-06-01

    This is the seventh issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: fission product yields (neutron induced and spontaneous fission); neutron reaction cross sections of fission products; data related to the radioactive decay of fission products; delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The sixth issue of this series has been published in June 1980 as INDC(NDS)-113/G+P. The present issue includes contributions which were received by NDS between 1 August 1980 and 25 May 1981

  8. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1982-07-01

    This is the eighth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. Therefore, the IAEA cannot be held responsible for the information contained nor for any consequences resulting from the use of this information. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); Neutron reaction cross sections of fission products; Data related to the radioactive decay of fission products; Delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The seventh issue of this series has been published in July 1981 as INDC(NDS)-116. The present issue includes contributions which were received by NDS between 1 August 1981 and 15 June 1982

  9. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1983-08-01

    This is the ninth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); Neutron reaction cross sections of fission products; Data related to the radioactive decay of fission products; Delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The eighth issue of this series has been published in July 1982 as INDC(NDS)-130. The present issue includes contributions which were received by NDS between 1 August 1982 and 25 June 1983

  10. Induced-Fission Imaging of Nuclear Material

    International Nuclear Information System (INIS)

    Hausladen, Paul; Blackston, Matthew A.; Mullens, James Allen; McConchie, Seth M.; Mihalczo, John T.; Bingham, Philip R.; Ericson, Milton Nance; Fabris, Lorenzo

    2010-01-01

    This paper presents initial results from development of the induced-fission imaging technique, which can be used for the purpose of measuring or verifying the distribution of fissionable material in an unopened container. The technique is based on stimulating fissions in nuclear material with 14 MeV neutrons from an associated-particle deuterium-tritium (D-T) generator and counting the subsequent induced fast fission neutrons with an array of fast organic scintillation detectors. For each source neutron incident on the container, the neutron creation time and initial trajectory are known from detection of the associated alpha particle of the d + t → α + n reaction. Many induced fissions will lie along (or near) the interrogating neutron path, allowing an image of the spatial distribution of prompt induced fissions, and thereby fissionable material, to be constructed. A variety of induced-fission imaging measurements have been performed at Oak Ridge National Laboratory with a portable, low-dose D-T generator, including single-view radiographic measurements and three-dimensional tomographic measurements. Results from these measurements will be presented along with the neutron transmission images that have been performed simultaneously. This new capability may have applications to a number of areas in which there may be a need to confirm the presence or configuration of nuclear materials, such as nuclear material control and accountability, quality assurance, treaty confirmation, or homeland security applications.

  11. Discovery of nuclear fission in Berlin 1938

    International Nuclear Information System (INIS)

    Hilscher, D.

    1989-01-01

    The story of the discovery of nuclear fission, one of the most exciting stories of how a scientific puzzle was finally solved and how the scientists involved were blind to many obvious indications, is described. (author). 29 refs

  12. Dynamical chaos and induced nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Bolotin, Yu L; Krivoshej, I V

    1985-01-01

    It is shown that the exponential instability of trajectories, which arises at negative curvature of the potential energy surface, leads to diffusion of the image point through the barrier and determines real time delays in induced nuclear fission.

  13. Seventy-five years of nuclear fission

    Indian Academy of Sciences (India)

    technology can play such a vital role in a nation's development subsequently motivated ... fragments with a broad mass distribution is a unique nuclear phenomenon ... low energy and spontaneous fission of actinide nuclei and how these ...

  14. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, G.

    1975-01-01

    This is the first issue of a report series on Fission Product Nuclear Data (FPND), published every six months by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). Its purpose is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The types of activities being included in this report are measurements, compilations and evaluations of: fission product yields; neutron cross-section data of fission products; data related to β-, γ-decay of fission products; delayed neutron data; and fission product decay-heat. The present issue includes contributions which were received by NDS before 1 November 1975

  15. Hybrid nuclear cycles for nuclear fission sustainability

    International Nuclear Information System (INIS)

    Piera, M.; Martinez-Val, M. M.

    2007-01-01

    Nuclear fission can play and must play an important role in paving the road to Energy Sustainability. Nuclear Fission does not produce CO 2 emissions, and it is already exploited at commercial level with the current NPP (Nuclear Power Plants). Most of them are based on LWR reactors, which have a very good safety record. It must be noted, however, that all LWR (including the advanced or evolutionary ones) have some drawbacks, particularly their very poor efficiency in exploiting the natural resources of nuclear fuels. In this paper, an analysis is presented on how to maximize the energy actually generated from the potential contents of fission natural resources. The role of fertile-to-fissile breeding is highlighted, as well as the need of attaining a very high safety performance in the reactors and other installations of the fuel cycle. The proposal presented in this paper is to use advanced and evolutionary LWR as energy producing reactors, and to use subcritical fast assemblies as breeders. The main result would be to increase by two orders of magnitude the percentage of energy effectively exploited from fission natural resources, while keeping a very high level of safety standards in the full fuel cycle. Breeders would not be intended for energy production, so that safety standards could rely on very low values of the thermal magnitudes, so allowing for very large safety margins for emergency cooling. Similarly, subcriticality would offer a very large margin for not to reach prompt criticality in any event. The main drawback of this proposal is that a sizeable fraction of the energy generated in the cycle (about 1/3, maybe a little more) would not be useful for the thermodynamic cycle to produce electricity. Besides that, a fraction of the generated electricity, between 5 and 10 %, would have to be recirculated to feed the accelerator activating the neutron source. Even so, the overall result would be very positive, because more than 50 % of the natural

  16. Analytical measurements of fission products during a severe nuclear accident

    Science.gov (United States)

    Doizi, D.; Reymond la Ruinaz, S.; Haykal, I.; Manceron, L.; Perrin, A.; Boudon, V.; Vander Auwera, J.; tchana, F. Kwabia; Faye, M.

    2018-01-01

    The Fukushima accident emphasized the fact that ways to monitor in real time the evolution of a nuclear reactor during a severe accident remain to be developed. No fission products were monitored during twelve days; only dose rates were measured, which is not sufficient to carry out an online diagnosis of the event. The first measurements were announced with little reliability for low volatile fission products. In order to improve the safety of nuclear plants and minimize the industrial, ecological and health consequences of a severe accident, it is necessary to develop new reliable measurement systems, operating at the earliest and closest to the emission source of fission products. Through the French program ANR « Projet d'Investissement d'Avenir », the aim of the DECA-PF project (diagnosis of core degradation from fission products measurements) is to monitor in real time the release of the major fission products (krypton, xenon, gaseous forms of iodine and ruthenium) outside the nuclear reactor containment. These products are released at different times during a nuclear accident and at different states of the nuclear core degradation. Thus, monitoring these fission products gives information on the situation inside the containment and helps to apply the Severe Accident Management procedures. Analytical techniques have been proposed and evaluated. The results are discussed here.

  17. Analytical measurements of fission products during a severe nuclear accident

    Directory of Open Access Journals (Sweden)

    Doizi D.

    2018-01-01

    Full Text Available The Fukushima accident emphasized the fact that ways to monitor in real time the evolution of a nuclear reactor during a severe accident remain to be developed. No fission products were monitored during twelve days; only dose rates were measured, which is not sufficient to carry out an online diagnosis of the event. The first measurements were announced with little reliability for low volatile fission products. In order to improve the safety of nuclear plants and minimize the industrial, ecological and health consequences of a severe accident, it is necessary to develop new reliable measurement systems, operating at the earliest and closest to the emission source of fission products. Through the French program ANR « Projet d’Investissement d’Avenir », the aim of the DECA-PF project (diagnosis of core degradation from fission products measurements is to monitor in real time the release of the major fission products (krypton, xenon, gaseous forms of iodine and ruthenium outside the nuclear reactor containment. These products are released at different times during a nuclear accident and at different states of the nuclear core degradation. Thus, monitoring these fission products gives information on the situation inside the containment and helps to apply the Severe Accident Management procedures. Analytical techniques have been proposed and evaluated. The results are discussed here.

  18. Bimodality in macroscopic dynamics of nuclear fission

    International Nuclear Information System (INIS)

    Bastrukov, S.I.; Salamatin, V.S.; Strteltsova, O.I.; Molodtsova, I.V.; Podgainy, D.V.; )

    2000-01-01

    The elastodynamic collective model of nuclear fission is outlined whose underlying idea is that the stiff structure of nuclear shells imparts to nucleus properties typical of a small piece of an elastic solid. Emphasis is placed on the macroscopic dynamics of nuclear deformations resulting in fission by two energetically different modes. The low-energy S-mode is the fission due to disruption of elongated quadrupole spheroidal shape. The characteristic features of the high-energy T-mode of division by means of torsional shear deformations is the compact scission configuration. Analytic and numerical estimates for the macroscopic fission-barrier heights are presented, followed by discussion of fingerprints of the above dynamical bimodality in the available data [ru

  19. Energy partition in nuclear fission

    International Nuclear Information System (INIS)

    Ruben, A.; Maerten, H.; Seeliger, D.

    1990-01-01

    A scission point model (two spheroid model TSM) including semi-empirical temperature-dependent shell correction energies for deformed fragments at scission is presented. It has been used to describe the mass-asymmetry-dependent partition of the total energy release on both fragments from spontaneous and induced fission. Characteristic trends of experimental fragment energy and neutron multiplicity data as function of incidence energy in the Th-Cf region of fissioning nuclei are well reproduced. Based on model applications, information on the energy dissipated during the descent from second saddle of fission barrier to scission point have been deduced. (author). 39 refs, 13 figs

  20. The wastes of nuclear fission; Les dechets de la fission nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Doubre, H. [Paris-11 Univ., Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, IN2P3/CNRS, 91 - Orsay (France)

    2005-07-01

    In this paper the author presents the problems of the radioactive wastes generated by the nuclear fission. The first part devoted to the fission phenomenon explains the incident neutron energy and the target nuclei role. The second part devoted to the nuclear wastes sources presents the production of wastes upstream of the reactors, in the reactors and why these wastes are dangerous. The third part discusses the radioactive wastes management in France (classification, laws). The last part details the associated research programs: the radionuclides separation, the disposal, the underground storage, the transmutation and the thorium cycle. (A.L.B.)

  1. Hyperfission - a new mode of nuclear fission

    International Nuclear Information System (INIS)

    Ion, D.B.; Ivascu, M.; Ion-Mihai, R.

    1988-02-01

    In this paper the nuclear hyperfission as a new mode of fission, possible for heavy elements with Z > 92, is investigated. The Q-systematics, hyperfissibility parameters, hyperfission barrier as well as the essential hindrance factors are presented. The hyperfission hindrance factor relative to that of fission is found to be in the interval 1.0x10 -17 - 3.4x10 -16 for the parent nuclei with Z = 92-108. (orig.)

  2. JNDC nuclear data library of fission products

    International Nuclear Information System (INIS)

    Tasaka, Kanji; Ihara, Hitoshi; Akiyama, Masatsugu; Yoshida, Tadashi; Matumoto, Zyun-itiro; Nakasima, Ryuzo

    1983-10-01

    The JNDC (Japanese Nuclear Data Committee) FP (Fission Product) nuclear data library for 1172 fission products is described in this report. The gross theory of beta decay has been used extensively for estimating unknown decay data and also some of known decay data with poor accuracy. The calculated decay powers of fission products using the present library show excellent agreement with the latest measurements at ORNL (Oak Ridge National Laboratory), LANL (Los Alamos National Laboratory) and UTT (University of Tokyo, Tokai) for cooling times shorter than 10 3 s after irradiation. The calculated decay powers by the existing libraries showed systematic deviations at short cooling times; the calculated beta and gamma decay powers after burst fission were smaller than the experimental results for cooling times shorter than 10 s, and in the cooling time range 10 to 10 3 s the beta-decay power was larger than the measured values and the gamma decay power smaller than the measured results. The present JNDC FP nuclear data library resolved these discrepancies in the short cooling time ranges. The decay power of fission products has been calculated for ten fission types and the results have been fitted by an analytical function with 31 exponentials. This permits the easy application of the present results of decay power calculations to a LOCA (Loss-of-Coolant Accident) analysis of a light water reactor and so on. (author)

  3. Fifty years of nuclear fission: Nuclear data and measurements series

    International Nuclear Information System (INIS)

    Lynn, J.E.

    1989-06-01

    This report is the written version of a colloquium first presented at Argonne National Laboratory in January 1989. The paper begins with an historical preamble about the events leading to the discovery of nuclear fission. This leads naturally to an account of early results and understanding of the fission phenomena. Some of the key concepts in the development of fission theory are then discussed. The main theme of this discussion is the topography of the fission barrier, in which the interplay of the liquid-drop model and nucleon shell effects lead to a wide range of fascinating phenomena encompassing metastable isomers, intermediate-structure effects in fission cross-sections, and large changes in fission product properties. It is shown how study of these changing effects and theoretical calculations of the potential energy of the deformed nucleus have led to broad qualitative understanding of the nature of the fission process. 54 refs., 35 figs

  4. Chemical immobilization of fission products reactive with nuclear reactor components

    International Nuclear Information System (INIS)

    Grossman, L.N.; Kaznoff, A.I.; Clukey, H.V.

    1975-01-01

    This invention teaches a method of immobilizing deleterious fission products produced in nuclear fuel materials during nuclear fission chain reactions through the use of additives. The additives are disposed with the nuclear fuel materials in controlled quantities to form new compositions preventing attack of reactor components, especially nuclear fuel cld, by the deleterious fission products. (Patent Office Record)

  5. Nuclear fission induced by heavy ions

    International Nuclear Information System (INIS)

    Newton, J.O.

    1988-09-01

    Because the accelerators of the 50's and 60's mostly provided beams of light ions, well suited for studying individual quantum states of low angular momentum or reactions involving the transfer of one or two nucleons, the study of fission, being an example of large-scale collective motion, has until recently been outside of the mainstream of nuclear research. This situation has changed in recent years, due to the new generation of accelerators capable of producing beams of heavy ions with energies high enough to overcome the Coulomb barriers of all stable nuclei. These have made possible the study of new examples of large-scale collective motions, involving major rearrangements of nuclear matter, such as deep-inelastic collisions and heavy-ion fusion. Perhaps the most exciting development in the past few years is the discovery that dissipative effects (nuclear viscosity) play an important role in fission induced by heavy ions, contrary to earlier assumptions that the viscosity involved in fission was very weak and played only a minor role. This review will be mainly concerned with developments in heavy-ion induced fission during the last few years and have an emphasis on the very recent results on dissipative effects. Since heavy-ion bombardment usually results in compound systems with high excitation energies and angular momenta, shell effects might be expected to be small, and the subject of low energy fission, where they are important, will not be addressed. 285 refs., 58 figs

  6. Rupture of the neck in nuclear fission

    International Nuclear Information System (INIS)

    Davies, K.T.R.; Managan, R.A.; Nix, J.R.; Sierk, A.J.

    1977-01-01

    We introduce a degree of freedom to describe the rupture of the neck in nuclear fission and calculate the point at which the neck ruptures as the nucleus descends dynamically from its fission saddle point. This is done by mentally slicing the system into two portions at its minimum neck radius and calculating the force required to separate the two portions while keeping their shapes fixed. This force is obtained by differentiating with respect to separation the sum of the Coulomb and nuclear interaction energies between the two portions. For nuclei throughout the Periodic Table we calculate this force along dynamical paths leading from the fission saddle point. The force is initially attractive but becomes repulsive when the neck reaches a critical size. For actinide nuclei the neck radius at which rupture occurs is about 2 fm. This increases the calculated translational kinetic energy of the fission fragments at infinity relative to that calculated for scission occurring at zero neck radius. With the effect of neck rupture taken into account, we calculate and compare with experimental results fission-fragment kinetic energies for two types of nuclear dissipation: ordinary two-body viscosity and one-body dissipation

  7. The MCEF code for nuclear evaporation and fission calculations

    International Nuclear Information System (INIS)

    Deppman, A.; Pina, S.R. de; Likhachev, V.P.; Mesa, J.; Arruda-Neto, J.D.T.; Rodriguez, O.; Goncalves, M.

    2001-11-01

    We present an object oriented algorithm, written in the Java programming language, which performs a Monte Carlo calculation of the evaporation-fission process taking place inside an excited nucleus. We show that this nuclear physics problem is very suited for the object oriented programming by constructing two simple objects: one that handles all nuclear properties and another that takes care of the nuclear reaction. The MCEF code was used to calculate important results for nuclear reactions, and here we show examples of possible uses for this code. (author)

  8. Otto Hahn (1944). Discovery of nuclear fission

    International Nuclear Information System (INIS)

    2003-01-01

    Otto Hahn (Frankfurt-on-Main, 1879-Gotinga, 1968) is the discoverer of nuclear fission, which awarded him the Nobel Prize for Chemistry in 1944. After leaving Germany during the Second World War to settle in the United Kingdom, he returned to this country as a renown figure

  9. Otto Hahn (1944). Discovery of nuclear fission

    CERN Document Server

    Hahn, Otto

    2003-01-01

    Otto Hahn (Frankfurt-on-Main, 1879-Gotinga, 1968) is the discoverer of nuclear fission, which awarded him the Nobel Prize for Chemistry in 1944. After leaving Germany during the Second World War to settle in the United Kingdom, he returned to this country as a renown figure.

  10. 60 years controlled nuclear fission: CP-1

    International Nuclear Information System (INIS)

    Anon.

    2002-01-01

    On December 2, 1942, the Chicago Pile 1 (CP-1) went critical for the first time. In this way, the scientists and engineers involved in the project under the leadership of Enrico Fermi succeeded in demonstrating that a self-sustaining nuclear reaction with nuclear fission processes was technically feasible. Only four years after the discovery and proof of nuclear fission by Otto Hahn, Fritz Strassmann, and Lise Meitner, the experiment consisting of graphite blocks as the moderator and uranium dioxide pellets as the fuel, as well as instrumentation and control devices, had been set up in the former squash court of the field and track stadium of the University of Chicago. Precisely at 3.36 a.m. Chicago time, after control rods had been withdrawn, the instruments showed the chain reaction by the neutron flux they indicated. An important cornerstone in the use of nuclear power had thus been laid. (orig.)

  11. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 2: Power from nuclear fission

    Science.gov (United States)

    Clement, J. D.

    1973-01-01

    Different types of nuclear fission reactors and fissionable materials are compared. Special emphasis is placed upon the environmental impact of such reactors. Graphs and charts comparing reactor facilities in the U. S. are presented.

  12. Thirty years of nuclear fission in Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Pesic, M; Stefanovic, D [Boris Kidric Institute of Nuclear Sciences VINCA, Belgrade (Yugoslavia)

    1989-07-01

    Experimental nuclear reactor 'RB' in Boris Kidric Institute in Vinca is the first nuclear facility built in Yugoslavia in which the first Yugoslav controlled nuclear fission was achieved thirty years ago on April 26, 1958. Designed by Yugoslav scientist as a bare, natural uranium-heavy water critical assembly, the 'RB' reactor has survived a series of modifications trying to follow directions of contemporary nuclear research. The actual 'RB' reactor technical characteristics and experimental possibilities are described. The modifications are underlined, the experience gained and plans for future are presented. A brief review of reactor operation and experiments performed is shown. (author)

  13. Outlook for nuclear fission energy

    International Nuclear Information System (INIS)

    Anderson, T.D.

    1978-01-01

    The electric utility industry has made a substantial commitment to nuclear power. The industrial capability to produce nuclear plants is large and well established. Nevertheless, nuclear energy in the United States is at the crossroad, and the direction it will take is not at all assured. The postponements, cancellations, and lack of orders for new plants over the past three years raise some serious questions about the future. The present problems of nuclear energy are primarily nontechnical in nature. If the nontechnical issues can be resolved, the future for nuclear looks bright indeed. The LWR and other converters could provide strong competition for coal and other electric power options for a half century or more. If development goals are met, the nuclear breeder offers the prospect of a very large supply of energy at stabilized prices over a time span of centuries

  14. Some aspects of the nuclear fission process

    International Nuclear Information System (INIS)

    Netter, F.

    1961-01-01

    In the following report one can find first a short general view on the present situation of our knowledge concerning the nuclear fission process, namely on the nucleus going through the saddle-point. Then there are some aspects connected with the excitation energy of the fissioning nucleus. The measurements made at Saclay on the fast neutron fission cross-section of U 233 , U 235 , Pu 239 , U 238 are described at the beginning of this work. It appears that for U 233 there is some characteristic shape modulation of the cross-section curve, in relation with the collective excited state of the deformed nucleus at the saddle-point. Good evidence of this is also given by the study of the relative fission rate with emission of long-range particles; it appears also that this ternary fission rate does not change substantially for neutron between thermal energy and 2 MeV, but that is very lower for the compound nucleus U 239 than for even-even compound nuclei. At the end there are some experiments on the strong 4,5 MeV gamma-ray originated by slow neutron absorption in U 235 . Time-of-flight device is used to establish that this 4,5 MeV gamma-ray seems mostly connected with radiative capture. (author) [fr

  15. Microscopic theory of nuclear fission: a review

    Science.gov (United States)

    Schunck, N.; Robledo, L. M.

    2016-11-01

    This article reviews how nuclear fission is described within nuclear density functional theory. A distinction should be made between spontaneous fission, where half-lives are the main observables and quantum tunnelling the essential concept, and induced fission, where the focus is on fragment properties and explicitly time-dependent approaches are often invoked. Overall, the cornerstone of the density functional theory approach to fission is the energy density functional formalism. The basic tenets of this method, including some well-known tools such as the Hartree-Fock-Bogoliubov (HFB) theory, effective two-body nuclear potentials such as the Skyrme and Gogny force, finite-temperature extensions and beyond mean-field corrections, are presented succinctly. The energy density functional approach is often combined with the hypothesis that the time-scale of the large amplitude collective motion driving the system to fission is slow compared to typical time-scales of nucleons inside the nucleus. In practice, this hypothesis of adiabaticity is implemented by introducing (a few) collective variables and mapping out the many-body Schrödinger equation into a collective Schrödinger-like equation for the nuclear wave-packet. The region of the collective space where the system transitions from one nucleus to two (or more) fragments defines what are called the scission configurations. The inertia tensor that enters the kinetic energy term of the collective Schrödinger-like equation is one of the most essential ingredients of the theory, since it includes the response of the system to small changes in the collective variables. For this reason, the two main approximations used to compute this inertia tensor, the adiabatic time-dependent HFB and the generator coordinate method, are presented in detail, both in their general formulation and in their most common approximations. The collective inertia tensor enters also the Wentzel-Kramers-Brillouin (WKB) formula used to extract

  16. Nuclear fission, chain reaction and criticality

    International Nuclear Information System (INIS)

    Reuss, Paul

    2016-01-01

    Criticality is, notably for nuclear reactors, the status which separates the case of a fission chain reaction which inexorably decays, from that of a reaction which grows faster and faster until a counter-reaction occurs. If this status is an objective in nuclear reactors, it must not be reached or exceeded in any case in other types of installations in which fissile materials are handled (fabrication, transports, nuclear fuel processing). The author proposes an insight into this notion of criticality, discusses elements of neutron science which allow the multiplication factor to be assessed, analyses accidental scenarios which may happen, and presents associated experiments and computation codes

  17. Proceedings of the Conference on 75 years of Nuclear Fission

    Indian Academy of Sciences (India)

    Proceedings of the Conference on 75 years of Nuclear Fission: Present Status and Future Perspectives (Fission75) - Part I. pp 187-188. Organizing Committee · More Details Fulltext PDF. pp 189-190. Foreword · D C Biswas K Mahata V M Datar · More Details Fulltext PDF. pp 191-198. Seventy-five years of nuclear fission.

  18. Modification of the fission product inventory program FISPIN

    International Nuclear Information System (INIS)

    Thomas, R.B.

    1977-05-01

    The fission product inventory program FISPIN calculates inventories of fission products, actinides and activation products, during and after irradiation in a nuclear reactor, estimates also being given for heat output and radioactive activity of the isotopes. The program has been developed further by making provision for the simulation of fuel reprocessing and in providing subroutines to make the program compatible with nuclear data in a slightly modified ENDF/B4 format. Continuous development of FISPIN over the years has however involved many program alterations and additions, and this has resulted in a generally untidy and cumbersome program. An attempt has therefore been made to improve the basic structure of the program. The subject is dealt with under the following headings: modularisation, direct access data, override facility, selective output, flowcharts, summary. (U.K.)

  19. Nuclear materials for fission reactors

    International Nuclear Information System (INIS)

    Matzke, H.; Schumacher, G.

    1992-01-01

    This volume brings together 47 papers from scientists involved in the fabrication of new nuclear fuels, in basic research of nuclear materials, their application and technology as well as in computer codes and modelling of fuel behaviour. The main emphasis is on progress in the development of non -oxide fuels besides reporting advances in the more conventional oxide fuels. The two currently performed large reactor safety programmes CORA and PHEBUS-FP are described in invited lectures. The contributions review basic property measurements, as well as the present state of fuel performance modelling. The performance of today's nuclear fuel, hence UO 2 , at high burnup is also reviewed with particular emphasis on the recently observed phenomenon of grain subdivision in the cold part of the oxide fuel at high burnup, the so-called 'rim' effect. Similar phenomena can be simulated by ion implantation in order to better elucidate the underlying mechanism and reviews on high resolution electron microscopy provide further information. The papers will provide a useful treatise of views, ideas and new results for all those scientists and engineers involved in the specific questions of current nuclear waste management

  20. Fission hindrance and nuclear viscosity

    Indian Academy of Sciences (India)

    is in exact conformity with all the previous measurements [7,10–13]. The CASCADE calculations (solid lines in figure 1) used in this first level of analysis do not include any viscosity or temperature-dependent nuclear level density parameter a. The γ and particle decay are calculated using the standard prescriptions as ...

  1. From nuclear fission to nuclear energy

    International Nuclear Information System (INIS)

    Pocock, R.F.

    1988-01-01

    Otto Hahn, a German chemist, demonstrated the fission of the uranium nucleus in December 1938. Ten months later, basic physical theory had been modified to account for this phenomenon. It is suggested here that this great advance in radio-chemistry and physics was influenced considerably by political considerations. By the outbreak of the European War in September 1939, all the major scientific principles involved in the production of atomic weapons were well-known and were available in all industrial countries. (author)

  2. National nuclear scientific program

    International Nuclear Information System (INIS)

    Plecas, I.; Matausek, M.V.; Neskovic, N.

    2001-01-01

    National scientific program of the Vinca Institute Nuclear Reactors And Radioactive Waste comprises research and development in the following fields: application of energy of nuclear fission, application of neutron beams, analyses of nuclear safety and radiation protection. In the first phase preparatory activities, conceptual design and design of certain processes and facilities should be accomplished. In the second phase realization of the projects is expected. (author)

  3. Nuclear. Areva, a French fission

    International Nuclear Information System (INIS)

    Dupin, Ludovic

    2015-01-01

    This article comments the difficulties and problems faced by Areva for its activity of nuclear reactor construction, and which leaded to the transfer of this activity from Areva to EDF while Areva will keep its uranium providing and fuel enrichment activities. These difficulties and problems concern the Flamanville EPR (the construction is 5 years late, vessel defects have just been identified, cost overruns), the Finnish EPR (7 years late, a 5 billions cost overrun), the Jules Horowitz research reactor (5 years late, cost overrun), and strategic choices (notably with respect to the post-Fukushima context). The article also outlines that other activities (mining, enrichment, reactor maintenance) are still doing well, and then briefly discusses the future of Areva NP

  4. Hybrid fission-fusion nuclear reactors

    International Nuclear Information System (INIS)

    Zucchetti, Massimo

    2011-01-01

    A fusion-fission hybrid could contribute to all components of nuclear power - fuel supply, electricity production, and waste management. The idea of the fusion-fission hybrid is many decades old. Several ideas, both new and revisited, have been investigated by hybrid proponents. These ideas appear to have attractive features, but they require various levels of advances in plasma science and fusion and nuclear technology. As a first step towards the development of hybrid reactors, fusion neutron sources can be considered as an option. Compact high-field tokamaks can be a candidate for being the neutron source in a fission-fusion hybrid, essentially due to their design characteristics, such as compact dimensions, high magnetic field, flexibility of operation. This study presents the development of a tokamak neutron source for a material testing facility using an Ignitor-based concept. The computed values show the potential of this neutron-rich device for fusion materials testing. Some full-power months of operation are sufficient to obtain relevant radiation damage values in terms of dpa. (Author)

  5. Safety device for nuclear fission reactors

    International Nuclear Information System (INIS)

    Brownlee, M.L.

    1982-01-01

    A plurality of radially arranged and neutron absorbing baffles are stacked in vertical sets under the fuel core assemblies, and the whole enclosed in a bottle shaped containment vessel. The radially arranged baffles of each set extend vertically, and each set has double the number of baffles as the set above it in the stack. A melt-down of a fuel core assembly drops the fissioning nuclear fuel into the stacked sets of baffles, there, as it passes through, to be progressively divided, redivided and dispersed in smaller and smaller masses between the doubling number of baffles in safe fuel pellet size. Neutron absorbing containment prevents contamination of the environment and together with cooling means stops fissioning of fuel

  6. IAEA CRP on Fission Yield Data and activity of WG in Japanese Nuclear Data Committee

    International Nuclear Information System (INIS)

    Katakura, Junichi; Fukahori, Tokio

    1999-01-01

    The outline of the coordinate research program on fission yield data organized by International Atomic Energy Agency and the working group on the subject newly organized in Japanese Nuclear Data Committee are presented. (author)

  7. Mass and Inertia Parameters for Nuclear Fission

    International Nuclear Information System (INIS)

    Damgaard, J.; Pauli, H.C.; Strutinsky, V.M.; Wong, C.Y.; Brack, M.; Stenholm-Jensen, A.

    1969-01-01

    The effective mass parameter and the moments of inertia for a deformed nucleus are evaluated using the cranking-model formalism. Special attention is paid to the dependence of these quantities on the intrinsic structure, which may arise due to shells in deformed nuclei. It is found that these inertial parameters are very much influenced by the shells present. The effective-mass parameter, which appears in an important way in the theory of spontaneous fission, fluctuates in the same manner as the shell-energy corrections. Its values at the fission barrier are up to two or three times larger than those at the equilibrium minima. This correlation comes about because for the effective mass the change in the local density of single-particle states is very important, much more so than the change in the pairing correlation. The moments of inertia which enter in the theory of angular anisotropy of fission fragments, also fluctuate as a function of the deformation. At low temperatures, the fluctuation is large and shows a distinct but more complicated correlation with the shells. At high temperatures, the moments of inertia fluctuate with a smaller amplitude about the rigid-body value in correlation with the energy-shell corrections. For the first-and second barriers, the rigid-body values are essentially reached at a nuclear temperature of 0.8 to 1.0 MeV. (author)

  8. Progress in fission product nuclear data. No. 14

    International Nuclear Information System (INIS)

    Lammer, M.

    1994-06-01

    This is the 14th issue of a report series on Fission Product Nuclear Data published by the Nuclear Data Section of the IAEA. The types of activities included are measurements, compilations and evaluations of fission product yields, neutron reaction cross sections of fission products, data related to the radioactive decay of fission products, delayed neutron data from neutron induced and spontaneous fission, lumped fission product data. The first part of the report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The second part contains some recent references relative to fission product nuclear data, which were not covered by the contributions submitted, and selected papers from conferences. The third part contains requirements for further measurements

  9. Nuclear fission discovered fifty years ago

    International Nuclear Information System (INIS)

    Weis, M.

    1988-01-01

    Fifty years ago, Otto Hahn, Lise Meitner and Fritz Strassmann discovered the process of nuclear fission which, more than other scientific discoveries to date, profoundly has changed the world and continues to influence our life significantly: This discovery made the up to then incontestable physicists' view of the atom as an inseparable whole suddenly shatter to pieces. It has brought about the invaluable advantages of a peaceful utilization of nuclear energy, and at the same time put scientists in the position to build the most terrible weapon ever, threatening mankind and earth with complete destruction. All this certainly is reason enough to recall the scientists, their work and the spirit of the time. (orig.) [de

  10. Nuclear fission and the transuranium elements

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1989-02-01

    Many of the transuranium elements are produced and isolated in large quantities through the use of neutrons furnished by nuclear fission reactions: plutonium (atomic number 94) in ton quantities; neptunium (93), americium (95), and curium (96) in kilogram quantities; berkelium (97) in 100 milligram quantities; californium (98) in gram quantities; and einsteinium (99) in milligram quantities. Transuranium isotopes have found many practical applications---as nuclear fuel for the large-scale generation of electricity, as compact, long-lived power sources for use in space exploration, as means for diagnosis and treatment in the medical area, and as tools in numerous industrial processes. Of particular interest is the unusual chemistry and impact of these heaviest elements on the periodic table. This account will feature these aspects. 9 refs., 5 figs

  11. Nuclear fission and the transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Seaborg, G.T.

    1989-02-01

    Many of the transuranium elements are produced and isolated in large quantities through the use of neutrons furnished by nuclear fission reactions: plutonium (atomic number 94) in ton quantities; neptunium (93), americium (95), and curium (96) in kilogram quantities; berkelium (97) in 100 milligram quantities; californium (98) in gram quantities; and einsteinium (99) in milligram quantities. Transuranium isotopes have found many practical applications---as nuclear fuel for the large-scale generation of electricity, as compact, long-lived power sources for use in space exploration, as means for diagnosis and treatment in the medical area, and as tools in numerous industrial processes. Of particular interest is the unusual chemistry and impact of these heaviest elements on the periodic table. This account will feature these aspects. 9 refs., 5 figs.

  12. ISOLDE experiment explores new territory in nuclear fission

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    An international collaboration led by the University of Leuven, Belgium, exploiting ISOLDE’s radioactive beams, has recently discovered an unexpected new type of asymmetric nuclear fission, which challenges current theories. The surprising result opens the way for new nuclear structure models and further theories to elucidate the question.   Resonance Ionization Laser Ion Source (RILIS) in action at ISOLDE. RILIS was instrumental in providing the pure beam necessary for the successful nuclear fission experiment. In nuclear fission, the nucleus splits into two fragments (daughter nuclei), releasing a huge amount of energy. Nuclear fission is exploited in power plants to produce energy. From the fundamental research point of view, fission is not yet fully understood decades after its discovery and its properties can still surprise nuclear physicists. The way the process occurs can tell us a lot about the internal structure of the nucleus and the interactions taking place inside the com...

  13. Progress in fission product nuclear data. No. 13

    International Nuclear Information System (INIS)

    Lammer, M.

    1990-11-01

    This is the 13th issue of a report series published by the Nuclear Data Section of the IAEA. The types of activities included are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission), neutron reaction cross-sections of fission products, data related to the radioactive decay of fission products, delayed neutron data of fission products and bumped fission product data (decay heat, absorption, etc.). The first part of the report consists of unaltered original data which the authors have sent to IAEA/NDS. The second part contains some recent references relative to fission product nuclear data, which were not covered by the contributions submitted, and selected papers from conferences. Part 3 contains requirements for further measurements

  14. Nuclear data for structural materials of fission and fusion reactors

    International Nuclear Information System (INIS)

    Goulo, V.

    1989-06-01

    The document presents the status of nuclear reaction theory concerning optical model development, level density models and pre-equilibrium and direct processes used in calculation of neutron nuclear data for structural materials of fission and fusion reactors. 6 refs

  15. Nuclear data in the problem of fission reactor decommissioning

    International Nuclear Information System (INIS)

    Manokhin, V.N.; Kulagin, N.T.

    1993-01-01

    This report presents a review of the works published in Russia during last several years and devoted to the problem of nuclear data and calculations of nuclear facilities activation for fission reactor decommissioning. 6 refs

  16. Dynamics of process at the final stage of nuclear fission

    International Nuclear Information System (INIS)

    Koljari, I.G.; Mavlitov, N.D.

    2005-01-01

    Numerous experimental data show, that the final stage of nuclear fission near to a scission point plays an essential role at formation of characteristics of fission products. At the description of a final stage of fission there is a number of problems: Definition of the form of the nuclear near the scission point and definition forms of a fission fragments; The account of dynamic processes in compound nuclear directly before of fission. The condition of the quasistatic al adiabatic process - dS/dt=0 - is applied in a point of transition from the uniform compound nuclei to several forms for definition of generalized coordinates and speeds. Calculation of dependence of post neutrons from nuclear mass of fission fragments for reactions is α+ 83 Bi 209 → 85 At 213 (E lab = 45 MeV); α+ 92 U 242 → 94 Pu 242 (E lab = 45 MeV); 8 O 18 + 79 Au 197 → 97 Fr 215 (E lab = 159 MeV). System of equations, which describes behaviour of system in a point of nuclear fission-transition from the uniform form to system of a two (and, probably more) fission fragments is given. The system of the equations allows in a fission point to define the generalized coordinates, and the generalized speeds for each of the generalized coordinates of collective deformation variables

  17. Detector for gaseous nuclear fission products

    International Nuclear Information System (INIS)

    Kobayashi, Yoshihiro; Kubo, Katsumi.

    1979-01-01

    Purpose: To facilitate the fabrication of a precipitator type detector, as well as improve the reliability. Constitution: Gas to be measured flown in an anode is stored in a gas processing system. By applying a voltage between the anode and the cathode, if positively charged Rb or Cs which is the daughter products of gaseous fission products are present in the gas to be measured, the daughter products are successively deposited electrostatically to the cathode. The daughter products issue beta-rays and gamma-rays to ionize the argon gas at the anode, whereby ionizing current flows between both of the electrodes. Pulses are generated from the ionizing current, and presence or absence, as well as the amount of the gaseous fission products are determined by the value recorded for the number of the pulses to thereby detect failures in the nuclear fuel elements. After the completion of the detection, the inside of the anode is evacuated and the cathode is heated to evaporate and discharge the daughter products externally. This eliminates the effects of the former detection to the succeeding detection. (Moriyama, K.)

  18. Sommerfeld-Watson transformation for nuclear fission

    International Nuclear Information System (INIS)

    Alexandru, G.

    1978-01-01

    It is proved that the fission matrix element can be written like a Sommerfeld-Watson relation. This leads to a dispersion relation for the fission process in which the substraction term is uniquely determined. (author)

  19. Separation of fission strontium from nuclear fuels by ammonium molybdatophosphate

    International Nuclear Information System (INIS)

    Hermann, A.

    1984-01-01

    The separation of fission strontium from solutions of prolonged cooled nuclear fuel has been performed using ammoniummolybdatophosphate (AMP) columns. The sorption mechanism of bivalent ions of AMP has been investigated by column and batch experiments. A pure ion exchange of Sr 2+ for two H + or NH 4 + ions has been established. Conditions for the sepasorption and elution of fission strontium and other fission products on AMP columns are described. (author)

  20. The role of the dinuclear system in the processes of nuclear fusion, quasi-fission, fission and cluster formation

    International Nuclear Information System (INIS)

    Volkov, V.V.

    1999-01-01

    The nuclear fusion, quasi-fission, fission and cluster formation in an excited nucleus are considered as the processes of the formation and evolution of the dinuclear system. This approach allows one to reveal new aspects of nuclear fusion, to show that quasi-fission plays an important role in nuclear reactions used to synthesise superheavy elements. A qualitative picture is given of the fission process of an excited nucleus and an important role of cluster formation in this process is shown

  1. Research and Development on nuclear fission

    International Nuclear Information System (INIS)

    2007-01-01

    Research and development activities on advanced and innovative reactors are performed within a domestic programme and international initiatives. The ongoing New Nuclear Fission National Programme is synergic and complementary to the International Nuclear Energy Initiative (INERI) and EURATOM framework programmes and is managed by ENEA through a specific agreement signed in June 2007 by the Italian Ministry for Economic Development (MSE). The activities concern an integral advanced pressurised light-water-cooled reactor (IRIS nuclear power plant [NPP]) and several Generation-4. fast reactors: lead-cooled, very high temperature and sodium-cooled. A summary of the main results achieved in 2007 follows. In the framework of the INERI programme ENEA and other Italian organisations are involved in the design of the International Reactor Innovative and Secure (IRIS NPP), particularly in the design certification. An appropriate integral testing programme will be performed in the SPES-3 facility to be built at the SIET laboratories in Piacenza. The facility will be located inside the building of the decommissioned Emilia oil-fired power plant. Once erected, the facility will simulate IRIS at full height, full pressure and temperature, and with volumes and power scaled by factors of 1:100 and 1:150, respectively. The activity will be carried out in a collaboration with Oak Ridge National Laboratory (ORNL), USA under an international initiative concerning cooperation in the field of nuclear-related technologies of mutual interest. In 2007 activities were mainly devoted to the conceptual design of the SPES-3 facility, the development of SPES-3 nodalization and the seismic isolation analysis of the IRIS auxiliary building

  2. Influence of nuclear dissipation on fission dynamics of the excited ...

    Indian Academy of Sciences (India)

    A stochastic approach to fission dynamics based on two-dimensional Langevin equations was applied to calculate the anisotropy of the fission fragments angular distribution and average pre-scission neutron multiplicities for the compound nucleus 248Cf formed in the $${16}$O+$^{232}$Th reactions. Postsaddle nuclear ...

  3. United States Nuclear Regulatory Commission research program on core debris/concrete interactions and ex-vessel fission-product release

    International Nuclear Information System (INIS)

    Burson, S.B.

    1987-01-01

    The study of core debris/concrete interaction phenomena has been a significant element of the NRC's Severe Accident Research Program for a number of years. The CORCON and VANESA codes used to predict the consequences of high-temperature debris attack on concrete and fission-product aerosol release are state-of-the-art computational tools. The major thrust of current NRC sponsored research focuses on the refinement, verification, and validation of these codes. An overview of the analytical and experimental aspects of the NRC research program is presented

  4. Nuclear data for neutron emission in the fission process

    International Nuclear Information System (INIS)

    Ganesan, S.

    1991-11-01

    This document contains the proceedings of the IAEA Consultants' Meeting on Nuclear Data for Neutron Emission in the Fission Process, Vienna, 22 - 24 October 1990. Included are the conclusions and recommendations reached at the meeting and the papers presented by the meeting participants. These papers provide a review of the status of experimental and theoretical data on neutron emission in spontaneous and neutron induced fission with reference to the data needs for reactor applications oriented towards actinide burner studies. The specific topics covered are the following: experimental measurements and theoretical predictions and evaluations of fission neutron energy spectra, average prompt fission neutron multiplicity, correlation in neutron emission from complementary fragments, neutron emission during acceleration of fission fragments, statistical properties of neutron rich nuclei by study of emission spectra of neutrons from the excited fission fragments, integral qualification of nu-bar for the major fissile isotopes, nu-bar total of 239 Pu and 235 U, and related problems. Refs figs and tabs

  5. Charged particle-induced nuclear fission reactions – Progress and ...

    Indian Academy of Sciences (India)

    attracting the attention of the investigators right from the beginning of nuclear fis- ... the change from mass asymmetric division to symmetric division as A and N/Z values .... (a) Schematic of the fissioning nucleus showing the decision making.

  6. Nuclear dynamics in heavy ion induced fusion-fission reactions

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    1992-01-01

    Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

  7. Nuclear fission: What have we learned in 50 years?

    International Nuclear Information System (INIS)

    Vandenbosch, R.

    1989-01-01

    Nuclear fission has captured the imagination of chemists and physicists for half a century now. There are several reasons for this. One of course is that it represents the most drastic rearrangement of nuclear matter known, challenged only recently by collisions induced by very heavy ions. Another is that both statistical and dynamical features come into play. Perhaps one of the most compelling reasons is its never-ending capacity to surprise us: asymmetric mass distributions, the sawtooth dependence of neutron yields in fragment mass, spontaneously fissioning isomers and intermediate structure resonances. Finally, and perhaps most importantly, fission is a rich laboratory within which one can explore the delicate interplay between the macroscopic aspects of bulk nuclear matter and the quantal effects of a finite number of Fermions. It will of course be impossible for me to cover all aspects of fission. I have chosen a limited number of topics to cover, with particular topics being chosen either because the have been associated with persistent puzzles in fission or because they have, or hopefully will, tell us something special about how nuclei behave. After a brief historical note, I organize these topics sequentially according to the various stages of the fission process, starting first with the probability for fission to occur and ending with scission phenomena. 56 refs., 11 figs

  8. Sustainable and safe nuclear fission energy technology and safety of fast and thermal nuclear reactors

    CERN Document Server

    Kessler, Günter

    2012-01-01

    Unlike existing books of nuclear reactor physics, nuclear engineering and nuclear chemical engineering this book covers a complete description and evaluation of nuclear fission power generation. It covers the whole nuclear fuel cycle, from the extraction of natural uranium from ore mines, uranium conversion and enrichment up to the fabrication of fuel elements for the cores of various types of fission reactors. This is followed by the description of the different fuel cycle options and the final storage in nuclear waste repositories. In addition the release of radioactivity under normal and possible accidental conditions is given for all parts of the nuclear fuel cycle and especially for the different fission reactor types.

  9. Balanced program plan. Volume XI. Fission analysis for biomedical and environmental research

    International Nuclear Information System (INIS)

    Foster, R.F.

    1976-06-01

    Factors involved in the formulation of an ERDA-sponsored program for health and environmental research in connection with the fission fuel cycle are discussed under the following section headings: major issues associated with the use of nuclear power; fission fuel cycle technology: milling, UF 6 production, uranium enrichment, plutonium fuel fabrication, power production (reactors), fuel reprocessing, waste management, fuel and waste transportation; problem definition: characterization, measurement and monitoring, transport processes, health effects, ecological processes and effects, and integrated assessment; budget; characterization, measuring and monitoring program units; transport processes program units; health effects program units; ecological processes and effects program units; and integrated assessment program units

  10. Chemistry of fission product iodine under nuclear reactor accident conditions

    International Nuclear Information System (INIS)

    Malinauskas, A.P.; Bell, J.T.

    1986-01-01

    The radioisotopes of iodine are generally acknowledged to be the species whose release into the biosphere as a result of a nuclear reactor accident is of the greatest concern. In the course of its release, the fission product is subjected to differing chemical environments; these can alter the physicochemical form of the fission product and thus modify the manner and extent to which release occurs. Both the chemical environments which are characteristic of reactor accidents and their effect in determining physical and chemical form of fission product iodine have been studied extensively, and are reviewed in this report. 76 refs

  11. Progress in fission product nuclear data. Issue no. 6

    International Nuclear Information System (INIS)

    Lammer, G.; Lammer, M.

    1980-06-01

    This is the sixth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed

  12. Applications of nuclear data on short-lived fission products

    International Nuclear Information System (INIS)

    Rudstam, G.; Aagaard, P.; Aleklett, K.; Lund, E.

    1981-01-01

    The study of short-lived fission products gives information about the nuclear structure on the neutron-rich side of stability. The data are also of interest for various applications both to basic science and to nuclear technology. Some of these applications, taken up by the OSIRIS group at Studsvik, are described in the present contribution. (orig.)

  13. Insights into nuclear structure and the fission process from spontaneous fission

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.H.; Butler-Moore, K.; Ramayya, A.V. [Vanderbilt Univ., Nashville, TN (United States)] [and others

    1993-12-31

    The {gamma}-rays emitted following spontaneous and induced fission are rich sources of information about the structure of neutron-rich nuclei and about the fission process itself. The study of spontaneous fissioning isotopes with large Ge detector arrays are providing a wealth of such information as seen, for example, in recent reports. In this paper we present some of our most recent results on nuclear structure studies and conclusions on the fission process itself. In our work, we have employed in spontaneous fission, a triple gamma coincidence study for the first time and a high resolution, X-ray detector-{gamma}-coincidence study. These data provide powerful ways of separating the gamma rays which belong to a particular nucleus. The triple coincidence technique was used to uniquely identify the levels in {sup 136}Te and higher spin states in its N=84 isotones, {sup 138}Xe and {sup 140}Ba{sup 171}. Some other examples of the level structures observed in the low and high mass partners are presented, including a detailed analysis of the backbending of the moment of inertia in {sup 112,114,116}Pd. Finally, we present the first examples of how our analysis allows one to extract a detailed picture of the dependence of the angular momentum on the mass and atomic numbers of the fission fragments and of the long-sought neutron multiplicity distribution from zero-n to ten-n as a function of the charge and mass asymmetry.

  14. An application program for fission product decay heat calculations

    International Nuclear Information System (INIS)

    Pham, Ngoc Son; Katakura, Jun-ichi

    2007-10-01

    The precise knowledge of decay heat is one of the most important factors in safety design and operation of nuclear power facilities. Furthermore, decay heat data also play an important role in design of fuel discharges, fuel storage and transport flasks, and in spent fuel management and processing. In this study, a new application program, called DHP (Decay Heat Power program), has been developed for exact decay heat summation calculations, uncertainty analysis, and for determination of the individual contribution of each fission product. The analytical methods were applied in the program without any simplification or approximation, in which all of linear and non-linear decay chains, and 12 decay modes, including ground state and meta-stable states, are automatically identified, and processed by using a decay data library and a fission yield data file, both in ENDF/B-VI format. The window interface of the program is designed with optional properties which is very easy for users to run the code. (author)

  15. Nuclear Technology Programs

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1990-10-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1988. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with examining the feasibility of substituting low-enriched for high-enriched uranium in the production of fission-product 99 Mo. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories

  16. Nuclear Technology Programs

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, J.E. (ed.)

    1990-10-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1988. These programs involve R D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with examining the feasibility of substituting low-enriched for high-enriched uranium in the production of fission-product {sup 99}Mo. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories.

  17. Status update on the NIFFTE high precision fission cross section measurement program

    International Nuclear Information System (INIS)

    Laptev, Alexander B.; Tovesson, Fredrik; Burgett, Eric; Greife, Uwe; Grimes, Steven; Heffner, Michael D.; Hertel, Nolan E.; Hill, Tony; Isenhower, Donald; Klay, Jennifer L.; Kornilov, Nickolay; Kudo, Ryuho; Loveland, Walter; Massey, Thomas; McGrath, Chris; Pickle, Nathan; Qu, Hai; Sharma, Sarvagya; Snyder, Lucas; Thornton, Tyler; Towell, Rusty S.; Watson, Shon

    2010-01-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) program has been underway for nearly two years. The program's mission is to measure fission cross sections of the primary fissionable and fissile materials ( 235 U, 239 Pu, 238 U) as well as the minor actinides across energies from approximately 50 keV up to 20 MeV with an absolute uncertainty of less than one percent while investigating energy ranges from below an eV to 600 MeV. This basic nuclear physics data is being reinvestigated to support the next generation power plants and a fast burner reactor program. Uncertainties in the fast, resolved and unresolved resonance regions in plutonium and other transuranics are extremely large, dominating safety margins in the next generation nuclear power plants and power plants of today. This basic nuclear data can be used to support all aspects of the nuciear renaissance. The measurement campaign is utilizing a Time Projection Chamber or TPC as the tool to measure these cross sections to these unprecedented levels. Unlike traditional fission cross section measurements using time-of-flight and a multiple fission foil configurations in which fission cross sections in relation to that of 235 U are performed, the TPC project uses time-of-flight and hydrogen as the benchmark cross section. Using the switch to hydrogen, a simple, smooth cross section that can be used which removes the uncertainties associated with the resolved and unresolved resonances in 235 U.

  18. Nuclearization of ionic chromatography system for fission products analysis

    International Nuclear Information System (INIS)

    Dimeglio, Remi

    1996-06-01

    The accident at Tchernobyl in 1986 had entailed the release in the atmosphere of different products coming from the splitting of the fuel. It is to better understand, and also to warn this type of catastrophe that the CEA (Commissariat a L'Energie Atomique) develops many programs of researches, aiming to characterize these fission products and to study their mechanisms of relaxation. Thus, the LESC (Laboratoire d'Etude de la Surete du Combustible) takes part, since several years, in many nuclear safety experiences, and in particular to the project PHEBUS PF, that is a reconstitution, in reduced scale, of an accident entailing the fusion of the reactor core. The aim of the researches that have been led during this training period was to the nuclearization of an HPIC (High Performance Ion Chromatography) system, dedicated to the analysis of the PHEBUS PF fission products analysis. The first step was to develop HPIC lines already settled, so as to reduce the quantity of wastes. Indeed, those one are very difficult to process in a radioactive area. For this purpose, we have implanted a column cationic more effective, so as to decrease analysis times, and, by there even, the quantity of sewage generated. We have equally replaced, on lines cationic and anionic, the system of suppression of the eluent conductivity, to make it thriftier in fluid. But the radioactive products characterization necessitates that all analyses are led within a special box with gloves. The second step of the project was therefore to adapt the system to this type of cell, and to its automation. It has been necessary to modify the system of sample injection, the system of detection, and to put in place a supplementary box with gloves, connected by sieve to the first, for the active products dilution. (author) [fr

  19. Elise: a new facility for unprecedented experimental nuclear fission studies

    International Nuclear Information System (INIS)

    Taieb, J.; Belier, G.; Chatillon, A.; Granier, T.; Kelic, A.; Ricciardi, V.; Schmidt, K.H.; Voss, B.; Coste-Delclaux, M.; Diop, C.; Jouanne, C.; Schmitt, C.; Aiche, M.; Czajkowski, S.; Jurado, B.; Audouin, L.; Peyre, J.; Rosier, P.; Tassan-Got, L.; Bertoumieux, E.; Dore, D.; Dupont, E.; Letourneau, A.; Panebianco, S.

    2009-01-01

    A novel experimental program aiming to study the properties of fragments and neutrons emitted in the fission process has been initiated. The experiment will be held at the ELISe electron-ion collider to be constructed at GSI, Darmstadt in the framework of the FAIR extension of the facility. The experiment will take advantage of the inverse kinematics allowing, in particular, a total mass and charge resolution for all fission fragments. (authors)

  20. Nuclear structure in cold rearrangement processes in fission and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, P.

    1998-11-01

    In fission and fusion of heavy nuclei large numbers of nucleons are rearranged at a scale of excitation energy very small compared to the binding energy of the nuclei. The energies involved are less than 40 MeV at nuclear temperatures below 1.5 MeV. The shapes of the configurations in the rearrangement of a binary system into a monosystem in fusion, or vice versa in fission, change their elongations by as much as 8 fm, the radius of the monosystem. The dynamics of the reactions macroscopically described by a potential energy surface, inertia parameters, dissipation, and a collision energy is strongly modified by the nuclear structure of the participating nuclei. Experiments showing nuclear structure effects in fusion and fission of the heaviest nuclei are reviewed. The reaction kinematics and the multitude of isotopes involved are investigated by detector techniques and by recoil spectrometers. The advancement of the latter allows to find very small reaction branches in the range of 10{sup -5} to 10{sup -10}. The experiments reveal nuclear structure effects in all stages of the rearrangement processes. These are discussed pointing to analogies in fusion and fission on the microscopic scale, notwithstanding that both processes macroscopically are irreversible. Heavy clusters, as 132Sn, 208Pb, nuclei with closed shell configurations N=82,126, Z=50,82 survive in large parts of the nuclear rearrangement. They determine the asymmetry in the mass distribution of low energy fission, and they allow to synthesise superheavy elements, until now up to element 112. Experiments on the cold rearrangement in fission and fusion are presented. Here, in the range of excitation energies below 12 MeV the phenomena are observed most convincingly. (orig.)

  1. Nuclear data requirements for fission reactor neutronics calculations

    International Nuclear Information System (INIS)

    Finck, P.

    1998-01-01

    The paper discusses current European nuclear data measurement and evaluation requirements for fission reactor technology applications and problems involved in meeting the requirements. Reference is made to the NEA High Priority Nuclear Data Request List and to the production of the new JEFF-3 library of evaluated nuclear data. There are requirements for both differential (or basic) nuclear data measurements and for different types of integral measurement critical facility measurements and isotopic sample irradiation measurements. Cross-section adjustment procedures are being used to take into account the simpler types of integral measurement, and to define accuracy needs for evaluated nuclear data

  2. Nuclear fission - the great discovery of the nuclear chemistry 50 years ago

    International Nuclear Information System (INIS)

    Eichler, B.

    1988-01-01

    A scientific discovery only seldom in that extent has influenced the scientific-technical progress and the historical development of mankind as the discovery of nuclear fission. The investigation of the reactions at irradiation of the uranium with neutrons was historically the order of the day. In 1938, the radiochemical proof of the nuclear fission succeeded by coprecipitation, fractional crystallization and application of the tracer method. To be master of these methods as well as their profound physico-chemical insight enabled O. Hahn and F. Strassmann to give reliable evidence of fission by identifying the fission product barium. (author)

  3. Sustainable, Full-Scope Nuclear Fission Energy at Planetary Scale

    OpenAIRE

    Robert Petroski; Lowell Wood

    2012-01-01

    A nuclear fission-based energy system is described that is capable of supplying the energy needs of all of human civilization for a full range of human energy use scenarios, including both very high rates of energy use and strikingly-large amounts of total energy-utilized. To achieve such “planetary scale sustainability”, this nuclear energy system integrates three nascent technologies: uranium extraction from seawater, manifestly safe breeder reactors, and deep borehole d...

  4. Fission product chemistry in severe nuclear reactor accidents

    International Nuclear Information System (INIS)

    Nichols, A.L.

    1990-09-01

    A specialist's meeting was held at JRC-Ispra from 15 to 17 January 1990 to review the current understanding of fission-product chemistry during severe accidents in light water reactors. Discussions focussed on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. Recommendations for future chemistry work were made covering the following areas: (a) fuel degradation and fission-product release, (b) transport and attenuation processes in the reactor coolant system, (c) containment chemistry (iodine behaviour and core-concrete interactions)

  5. A brief history of the ''Delayed'' discovery of nuclear fission

    International Nuclear Information System (INIS)

    Holden, N.E.

    1989-08-01

    This year marks the Fiftieth Anniversary of the discovery of Nuclear Fission. In the early 1930's, the neutron was discovered, followed by the discovery of artificial radioactivity and then the use of the neutron to produce artificial radioactivity. The first experiments resulting in the fission of uranium took place in 1934. A paper which speculated on fission as an explanation was almost immediately published, yet no one took it seriously not even the author herself. Why did it take an additional five years before anyone realized what had occurred? This is an abnormally long time in a period when discoveries, particularly in nuclear physics, seemed to be almost a daily occurrence. The events which led up to the discovery are recounted, with an attempt made to put them into their historical perspective. The role played by Mendeleev's Periodic Table, the role of the natural radioactive decay chain of uranium, the discovery of protactinium, the apparent discovery of masurium (technetium) and a speculation on the reason why Irene Curie may have missed the discovery of nuclear fission will all be discussed. 43 refs

  6. Fission energy program of the U.S. Department of Energy. FY 1980

    International Nuclear Information System (INIS)

    1979-04-01

    This document presents the baseline implementation program plan as of January 1979 and is derived from the National Energy Plan and other major policy documents. The document discusses civilian nuclear power development, the policy for which has been established by the National Energy Plan of April 1977 and the National Energy Act of 1978. It derives the fission energy policy and program objectives from the National Energy Plan and Act, describes the overall program strategy, and presents the overall budget. The approach used in managing the program, including the program structure and methods used for program control, is explained. The civilian fission power development implementation programs are described in detail. Other considerations affecting civilian nuclear power development are also discussed

  7. High-energy nuclear reaction mechanisms - fission, fragmentation and spallation

    International Nuclear Information System (INIS)

    Kaufman, S.B.

    1987-01-01

    Measurements of the correlations in kinetic energy, mass, charge, and angle of coincident fragments formed in high-energy nuclear reactions have helped to characterize the processes of fission, fragmentation and spallation. For example, fission or fission-like two-body breakup mechanisms result in a strong angular correlation between two heavy fragments; in addition, the momentum transfer in the reaction can be deduced from the correlation. Another example is the multiplicity of light charged particles associated with a given heavy fragment, which is a measure of the violence of the collision, thus distinguishing between central and peripheral collisions. A summary of what has been learned about these processes from such studies will be given, along with some suggestions for further experiments

  8. R and D in Ciemat Nuclear Fission Department

    International Nuclear Information System (INIS)

    Diaz, J. L.; Diaz Arocas, P.; Gomez Briceno, D.; Gonzalez de la Huebra Gordo, A.; Gonzalez Romero, E.; Herranz Puebla, L. E.; Sola Farre, R.

    2000-01-01

    The technologically developed countries count on nuclear fission as a durable energy resource to produce electricity, facing the future by establishing research programmes to enhance the safety and extend the lifetime of the current power plants and to achieve the adequate management of radioactive waste. At the same time, the progress in the development of a new generation of reactors based in innovative safety concepts. The Nuclear fission Department has the ultimate objective of providing technical support to the Spanish nuclear reactors through applied research and development focused on improving the safety and performance of the operating power plants, and cooperating in the activities related to radioactive waste. In this context, the Departament has been organised in four R and D project covering the areas of Safety, Materials, Radioactive. (Author)

  9. Dynamics of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1979-01-01

    Large-amplitude collective motion in fission and heavy-ion reactions is studied by solving classical equations of motion for the time evolution of the nuclear shape. In the nuclear potential energy of deformation, the generalized surface energy was calculated by means of a double volume integral of a Yukawa-plus-exponential function, which was obtained by requiring that two semi-infinite slabs of constant-density nuclear matter have minimum energy at zero separation. The collective kinetic energy is calculated for nuclear flow that is a superposition of incompressible, nearly irrotational collective-shape motion and rigid-body rotation. Nuclear dissipation is included by means of the Rayleigh dissipation function, which depends upon the physical mechanism that converts collective energy into internal energy. For both ordinary two-body viscosity and a combined wall and window one-body dissipation, fission-fragment kinetic energies are calculated for the fission of nuclei throughout the periodic table and compare with experimental results. Finally, the one-body dynamics of nucleons inside a cylinder colliding with a moving piston is explicitly studied by solving exactly the collisionless Boltzmann equation for the distribution function. By examining the relative phases of the pressure at the piston and the piston's velocity, a dissipative force and an elastic restoring force can be separately identified. 9 references

  10. Design of containment system of nuclear fuel attacked by corrosion with leaking fission products

    International Nuclear Information System (INIS)

    Poblete Maturana, Tomas

    2015-01-01

    The following report presents the design of an innovative confinement system for the nuclear fuel attacked by corrosion, with leakage of fission products to be used in the RECH-1 nuclear experimental reactor of the Chilean Nuclear Energy Commission, is currently within the framework of the international nuclear waste management program developed by the member countries of the IAEA, including Chile. The main objective of this project is the development of a system that is capable of containing, in the smallest possible volume, the fission products that are released to the reactor coolant medium from the nuclear fuel that are attacked by corrosion. Among the tasks carried out for the development of the project are: the compilation of the necessary bibliography for the selection of the most suitable technology for the retention of the fission products, the calculation of the most important parameters to ensure that the system will operate within ranges that do not compromise the radiological safety, and the design of the hydraulic circuit of the system. The results obtained from the calculations showed that the fuel element confinement system is stable from a thermal point of view since the refrigerant does not under any circumstances reach the saturation temperature and, in addition, from a hydraulic point of view, since the rate at which the refrigerant flows through the hydraulic circuit is low enough so that the deformation of the fuel plates forming the nuclear fuel does not occur. The most appropriate technology for the extraction of fission products according to the literature consulted is by ion exchange. The calculations developed showed that with a very small volume of resins, it is possible to capture all of the non-volatile fission products of a nuclear fuel

  11. Nuclear data requirements for fission reactor decommissioning

    International Nuclear Information System (INIS)

    Kocherov, N.P.

    1993-01-01

    The meeting was attended by 13 participants from 8 Member States and 2 International Organizations who reviewed the status of the nuclear data libraries and computer codes used to calculate the radioactive inventory in the reactor unit components for the decommissioning purposes. Nuclides and nuclear reactions important for determination of the radiation fields during decommissioning and for the final disposal of radioactive waste from the decommissioned units were identified. Accuracy requirements for the relevant nuclear data were considered. The present publication contains the text of the reports by the participants and their recommendations to the Nuclear Data Section of the IAEA. A separate abstract was prepared for each of these reports. Refs, figs and tabs

  12. Characteristic relation for the mass and energy distribution of the nuclear fission products

    International Nuclear Information System (INIS)

    Alexandru, G.

    1977-01-01

    The dispersion relation for nuclear fission is written in the two part fragmentation approach which allows to obtain the characteristic relation for the mass and energy distribution of the nuclear fission products. One explains the resonance approximation in the mass distribution of the fission products taking into account the high order resonances too. (author)

  13. Some aspects of the nuclear fission process; Quelques aspects du processus de fission nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    In the following report one can find first a short general view on the present situation of our knowledge concerning the nuclear fission process, namely on the nucleus going through the saddle-point. Then there are some aspects connected with the excitation energy of the fissioning nucleus. The measurements made at Saclay on the fast neutron fission cross-section of U{sup 233}, U{sup 235}, Pu{sup 239}, U{sup 238} are described at the beginning of this work. It appears that for U{sup 233} there is some characteristic shape modulation of the cross-section curve, in relation with the collective excited state of the deformed nucleus at the saddle-point. Good evidence of this is also given by the study of the relative fission rate with emission of long-range particles; it appears also that this ternary fission rate does not change substantially for neutron between thermal energy and 2 MeV, but that is very lower for the compound nucleus U{sup 239} than for even-even compound nuclei. At the end there are some experiments on the strong 4,5 MeV gamma-ray originated by slow neutron absorption in U{sup 235}. Time-of-flight device is used to establish that this 4,5 MeV gamma-ray seems mostly connected with radiative capture. (author) [French] Le present travail debute par un apercu de l'etat actuel de nos connaissances sur le processus de fission nucleaire, notamment sur le passage par le point-seuil. Puis sont evoques des aspects lies au niveau d'energie d'excitation auquel est porte le noyau qui subit la fission. Les mesures de sections efficaces de fission induite dans {sup 233}U, {sup 235}U, {sup 239}Pu et {sup 238}U par des neutrons rapides effectuees a Saclay sont decrites en premier lieu; elles font apparaitre pour {sup 233}U une ondulation caracteristique du role des etats collectifs d'excitation du noyau deforme au point-seuil. Des experiences sur la fission avec emission de particules de long parcours confirment cet aspect tout en demontrant que la frequence

  14. Theoretical nuclear fission: The evolution of the first fifty years

    International Nuclear Information System (INIS)

    Griffin, J.J.

    1989-01-01

    The evolution of the dynamical theory of nuclear fission is reviewed through four recognizable major phases. Its conceptual structure was from the outset shaped by the Bohr-Wheeler idea of the nucleus as a liquid drop. On the other hand, today's nuclear drop is a system which has under study repeatedly revealed remarkable and unexpected properties, especially with respect to the dependence of its energy upon its shape. Although some of these special properties arise from quantal effects, the theory of fission is still expressed largely in terms of classical dynamics. This situation leaves open the question whether our theoretical success flows entirely from physical truth or in part from the great phenomenological flexibility of the drop model. It leads one also to wonder whether in the next phase connections with the quantal many-body dynamics might finally find a firm place in the theory, and tie its predictions quantitatively to the deeper microscopic reality

  15. Nuclear fission: the tarnished star of our energy future

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The use of fission nuclear energy to fuel commercial electricity-generating facilities, once considered the answer to the world's energy dilemma, is facing serious financial problems and reduced demand. Although the technology to handle the necessary functions exists, construction errors and delays, extensive cost overruns, equipment malfunctions, operator errors, continual regulation and design changes, and concern about long-term wastes and their effects on the environment and human health are plaguing the industry. Research and development efforts continue worldwide to improve the technology in the areas of use and waste handling. Many people express the belief that nuclear fission is necessary to fill the void being created by the decline in availability of fossil fuels. This may be true without extensive efforts in conservation and the use of other energy forms. 26 references, 13 figures

  16. Legal and Regulatroy Obstacles to Nuclear Fission Technology in Space

    Science.gov (United States)

    Force, Melissa K.

    2013-09-01

    In forecasting the prospective use of small nuclear reactors for spacecraft and space-based power stations, the U.S. Air Force describes space as "the ultimate high ground," providing access to every part of the globe. But is it? A report titled "Energy Horizons: United States Air Force Energy Science &Technology Vision 2011-2026," focuses on core Air Force missions in space energy generation, operations and propulsion and recognizes that investments into small modular nuclear fission reactors can be leveraged for space-based systems. However, the report mentions, as an aside, that "potential catastrophic outcomes" are an element to be weighed and provides no insight into the monumental political and legal will required to overcome the mere stigma of nuclear energy, even when referring only to the most benign nuclear power generation systems - RTGs. On the heels of that report, a joint Department of Energy and NASA team published positive results from the demonstration of a uranium- powered fission reactor. The experiment was perhaps most notable for exemplifying just how effective the powerful anti-nuclear lobby has been in the United States: It was the first such demonstration of its kind in nearly fifty years. Space visionaries must anticipate a difficult war, consisting of multiple battles that must be waged in order to obtain a license to fly any but the feeblest of nuclear power sources in space. This paper aims to guide the reader through the obstacles to be overcome before nuclear fission technology can be put to use in space.

  17. A constrained approximation for nuclear barrier penetration and fission

    International Nuclear Information System (INIS)

    Tang, H.H.K.; Negele, J.W.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge

    1983-01-01

    An approximation to the time-dependent mean-field theory for barrier penetration by a nucleus is obtained in terms of constrained Hartree-Fock wave functions and a coherent velocity field. A discrete approximation to the continuum theory suitable for practical numerical calculations is presented and applied to three illustrative models. Potential application of the theory to the study of nuclear fission is discussed. (orig.)

  18. Calculation of fission gases internal pressure in nuclear fuel rods

    International Nuclear Information System (INIS)

    Vasconcelos Santana, M. de.

    1981-12-01

    Models concerning the principal phenomena, particularly thermal expansion, fuel swelling, densification, reestructuring, relocation, mechanical strain, fission gas production and release, direct or indirectly important to calculate the internal pressure in nuclear fuel rods were analysed and selected. Through these analyses a computer code was developed to calculate fuel pin internal pressure evolution. Three different models were utilized to calculate the internal pressure in order to select the best and the most conservative estimate. (Author) [pt

  19. Biological effects induced by low amounts of nuclear fission products

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.; Shishkin, V.F.; Khudyakova, N.V.

    1991-01-01

    The review deals with the problem of biological hazard of low radiation doses for animals and human beings taking into the danger of internal and external irradiation by nuclear fission products under conditions of enhancing anthropogenic radiation contamination of biosphere. An attention is paid to the estimation of life span carcinogenesis, genetic and delayed effects. A conclusion is made on a necessity of multiaspect investigation of biological importance of low radiation doses taking into account modifying effects of other environmental factors

  20. Nuclear inertia for fission in a generalized cranking model

    International Nuclear Information System (INIS)

    Kunz, J.; Nix, J.R.

    1984-01-01

    A time dependent formalism which is appropriate for β vibrations and fission is developed for a generalized cranking model. The formalism leads to additional terms in the density matrix which affect the nuclear inertia. The case of a harmonic oscillator potential is used to demonstrate the contribution of the pairing gap term on the β vibrational inertia for Pu 240. The inertia remains finite and close to the limiting irrotational value

  1. Nuclear technology programs

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1992-01-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period October 1989--March 1990. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned water waste stream generated in production of 2,4,6-trinitrotoluene. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories

  2. Progress in fission product nuclear data. Information about activities in the field of measurements and compilations/evaluations of fission product nuclear data (FPND)

    International Nuclear Information System (INIS)

    Lammer, G.

    1978-07-01

    This is the fourth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); neutron reaction cross sections of fission products; data related to the radioactive decay of fission products; delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.)

  3. Nuclear inertia for fission in a generalized cranking model

    International Nuclear Information System (INIS)

    Kunz, J.; Nix, J.R.

    1984-01-01

    The Inglis cranking model has been widely used to calculate the nuclear inertia associated with collective degrees of freedom. After the inclusion of pairing correlations, theoretical results obtained with the cranking model for nuclear rotations and γ-vibrations were in relatively good agreement with experimental data. Calculations of β-vibrational inertias were also performed in the cranking model for fission deformations. Theoretical results were several times the irrotational values and gave reasonable agreement with experimental spontaneous-fission lifetimes, although in one study a renormalization factor of 0.8 was required. However, as pointed out by many authors, the Inglis cranking model possesses two serious deficiencies. First, problems arise when the single-particle potential contains momentum-dependence terms. Second, in the limit of large pairing strength the inertia approaches zero instead of a finite (irrotational) limit. Alternative approaches to the cranking model which did not lead to such unacceptable results were developed by Migdal, Belyaev and Thouless and Valatin. They showed that these deficiencies of the cranking model are due to a lack of self-consistency, since the reaction of the mean field to the collective motion is neglected in the Inglis model. Previously we used their arguments and developed a generalized cranking model for stationary collective motion. Here it is shown how to develop a time-dependent formalism appropriate to β-vibrations and fission. 10 references

  4. Evaluation of fission product worth margins in PWR spent nuclear fuel burnup credit calculations

    International Nuclear Information System (INIS)

    Blomquist, R.N.; Finck, P.J.; Jammes, C.; Stenberg, C.G.

    1999-01-01

    Current criticality safety calculations for the transportation of irradiated LWR fuel make the very conservative assumption that the fuel is fresh. This results in a very substantial overprediction of the actual k eff of the transportation casks; in certain cases, this decreases the amount of spent fuel which can be loaded in a cask, and increases the cost of transporting the spent fuel to the repository. Accounting for the change of reactivity due to fuel depletion is usually referred to as ''burnup credit.'' The US DOE is currently funding a program aimed at establishing an actinide only burnup credit methodology (in this case, the calculated reactivity takes into account the buildup or depletion of a limited number of actinides). This work is undergoing NRC review. While this methodology is being validated on a significant experimental basis, it implicitly relies on additional margins: in particular, the absorption of neutrons by certain actinides and by all fission products is not taken into account. This provides an important additional margin and helps guarantee that the methodology is conservative provided these neglected absorption are known with reasonable accuracy. This report establishes the accuracy of fission product absorption rate calculations: (1) the analysis of European fission product worth experiments demonstrates that fission product cross-sections available in the US provide very good predictions of fission product worth; (2) this is confirmed by a direct comparison of European and US cross section evaluations; (3) accuracy of Spent Nuclear Fuel (SNF) fission product content predictions is established in a recent ORNL report where several SNF isotopic assays are analyzed; and (4) these data are then combined to establish in a conservative manner the fraction of the predicted total fission product absorption which can be guaranteed based on available experimental data

  5. Recoil release of fission products from nuclear fuel

    International Nuclear Information System (INIS)

    Wise, C.

    1985-01-01

    An analytical approximation is developed for calculating recoil release from nuclear fuel into gas filled interspaces. This expression is evaluated for a number of interspace geometries and shown to be generally accurate to within about 10% by comparison with numerical calculations. The results are applied to situations of physical interest and it is demonstrated that recoil can be important when modelling fission product release from low temperature CAGR pin failures. Furthermore, recoil can contribute significantly in experiments on low temperature fission product release, particularly where oxidation enhancement of this release is measured by exposing the fuel to CO 2 . The calculations presented here are one way of allowing for this, other methods are suggested. (orig.)

  6. Mitochondrial fission proteins regulate programmed cell death in yeast.

    Science.gov (United States)

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J; Qi, Bing; Pevsner, Jonathan; McCaffery, J Michael; Hill, R Blake; Basañez, Gorka; Hardwick, J Marie

    2004-11-15

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we found that the Saccharomyces cerevisiae homolog of human Drp1, Dnm1, promotes mitochondrial fragmentation/degradation and cell death following treatment with several death stimuli. Two Dnm1-interacting factors also regulate yeast cell death. The WD40 repeat protein Mdv1/Net2 promotes cell death, consistent with its role in mitochondrial fission. In contrast to its fission function in healthy cells, Fis1 unexpectedly inhibits Dnm1-mediated mitochondrial fission and cysteine protease-dependent cell death in yeast. Furthermore, the ability of yeast Fis1 to inhibit mitochondrial fission and cell death can be functionally replaced by human Bcl-2 and Bcl-xL. Together, these findings indicate that yeast and mammalian cells have a conserved programmed death pathway regulated by a common molecular component, Drp1/Dnm1, that is inhibited by a Bcl-2-like function.

  7. International conference on fifty years research in nuclear fission

    International Nuclear Information System (INIS)

    1989-02-01

    These proceedings contain extended abstracts of the papers presented at the named conference. They deal with static properties of fission, instrumentation for fission studies, fission in compound-nucleus reactions, fission dynamics, fission-like heavy ion reactions, and fusion reactions. See hints under the relevant topics. (HSI)

  8. Main orientations of the JRC nuclear fission programme

    International Nuclear Information System (INIS)

    Haas, Didier

    2009-01-01

    Full text: The European Union has taken the lead in responding to climate change, announcing far-reaching initiatives from promoting energy efficient light bulbs and cars to new building codes, carbon trading schemes, the development of low carbon technologies and greater competition in energy markets. Nuclear energy remains central to the energy debate in Europe. One third of EU electricity is produced via nuclear fission, and eight new reactors are under construction. Traditionally non-nuclear countries are manifesting an interest in building nuclear power plants while the clock is ticking down on Belgium, Germany and the UK's decision to renew or close existing nuclear infrastructures. Sustainability in nuclear energy production is ensured in the medium term due to the large and diverse uranium resources available in politically stable countries around the world. The quantities available with high probability ensure more than hundred year of nuclear energy production. This extrapolation depends however on the forecast for the future nuclear energy production. The use of fast neutron breeder reactors would lead to a much more efficient utilisation of the uranium, extending the sustainable energy production to several thousands of years. The presentation will outline the fast reactors of the new generation currently being developed within the 'Generation IV' initiative. Broad conclusions of the presentation will be that: -There is a growing nuclear renaissance in Europe for good reason; - Nuclear energy is a green and sustainable option for Europe and indeed the world's energy needs; - Nuclear energy is a competitive energy that makes economic sense; - Nuclear fission reactors have a safety and environmental track record that is second to none, yet public misperceptions persist and must be tackled; - Waste management solutions exist while new developments hold great promise; - The evolution and promise of nuclear technologies must also be examined against the

  9. Dynamical calculations of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1984-01-01

    With the goal of determining the magnitude and mechanism of nuclear dissipation from comparisons of predictions with experimental data, we describe recent calculations in a unified macroscopic-microscopic approach to large-amplitude collective nuclear motion such as occurs in fission and heavy-ion reactions. We describe the time dependence of the distribution function in phase space of collective coordinates and momenta by a generalized Fokker-Planck equation. The nuclear potential energy of deformation is calculated as the sum of repulsive Coulomb and centrifugal energies and an attractive Yukawa-plus-exponential potential, the inertia tensor is calculated for a superposition of rigid-body rotation and incompressible, nearly irrotational flow by use of the Werner-Wheeler method, and the dissipation ensor that describes the conversion of collective energy into single-particle excitation energy is calculated for two prototype mechanisms that represent opposite extremes of large and small dissipation. We solve the generalized Hamilton equations of motion for the first moments of the distribution function to obtain the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as dynamical thresholds, capture cross sections, and ternary events in heavy-ion reactions. 33 references

  10. Reprocessing free nuclear fuel production via fusion fission hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Kotschenreuther, Mike, E-mail: mtk@mail.utexas.edu [Intitute for Fusion Studies, University of Texas at Austin (United States); Valanju, Prashant; Mahajan, Swadesh [Intitute for Fusion Studies, University of Texas at Austin (United States)

    2012-05-15

    Fusion fission hybrids, driven by a copious source of fusion neutrons can open qualitatively 'new' cycles for transmuting nuclear fertile material into fissile fuel. A totally reprocessing-free (ReFree) Th{sup 232}-U{sup 233} conversion fuel cycle is presented. Virgin fertile fuel rods are exposed to neutrons in the hybrid, and burned in a traditional light water reactor, without ever violating the integrity of the fuel rods. Throughout this cycle (during breeding in the hybrid, transport, as well as burning of the fissile fuel in a water reactor) the fissile fuel remains a part of a bulky, countable, ThO{sub 2} matrix in cladding, protected by the radiation field of all fission products. This highly proliferation-resistant mode of fuel production, as distinct from a reprocessing dominated path via fast breeder reactors (FBR), can bring great acceptability to the enterprise of nuclear fuel production, and insure that scarcity of naturally available U{sup 235} fuel does not throttle expansion of nuclear energy. It also provides a reprocessing free path to energy security for many countries. Ideas and innovations responsible for the creation of a high intensity neutron source are also presented.

  11. Reprocessing free nuclear fuel production via fusion fission hybrids

    International Nuclear Information System (INIS)

    Kotschenreuther, Mike; Valanju, Prashant; Mahajan, Swadesh

    2012-01-01

    Fusion fission hybrids, driven by a copious source of fusion neutrons can open qualitatively “new” cycles for transmuting nuclear fertile material into fissile fuel. A totally reprocessing-free (ReFree) Th 232 –U 233 conversion fuel cycle is presented. Virgin fertile fuel rods are exposed to neutrons in the hybrid, and burned in a traditional light water reactor, without ever violating the integrity of the fuel rods. Throughout this cycle (during breeding in the hybrid, transport, as well as burning of the fissile fuel in a water reactor) the fissile fuel remains a part of a bulky, countable, ThO 2 matrix in cladding, protected by the radiation field of all fission products. This highly proliferation-resistant mode of fuel production, as distinct from a reprocessing dominated path via fast breeder reactors (FBR), can bring great acceptability to the enterprise of nuclear fuel production, and insure that scarcity of naturally available U 235 fuel does not throttle expansion of nuclear energy. It also provides a reprocessing free path to energy security for many countries. Ideas and innovations responsible for the creation of a high intensity neutron source are also presented.

  12. Behavior of Nb fission product during nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Gue, J.P.

    1977-02-01

    Investigations on niobium fission product behavior in nitric acid and tributyl phosphate media have been carried out in order to explain the difficulties encountered in separating this element from fissile materials during spent nuclear fuel reprocessing. The studies have shown that in nitric acid solution, pentavalent niobium has a colloidal hydroxide form. The so-obtained sols were characterized by light scattering, electronic microscopy, electrophoresis and ultracentrifugation methods. In heterogeneous extracting media containing tributyl phosphate and dibutyl phosphoric acid the niobium hydroxide sols could be flocculated by low dibutyl phosphoric acid concentration or extracted into the organic phase containing an excess of dibutyl phosphoric acid [fr

  13. Nuclear fission: reaction to the discovery in 1939

    International Nuclear Information System (INIS)

    Badash, L.; Hodes, E.; Tiddens, A.

    1985-01-01

    Historical aspects of the behavior of scientists in the aftermath of the discovery of nuclear fission are presented. An extensive background section is given which documents the worldwide discussion of atomic energy over the preceding four decades. A second section briefly surveys the research highlights of 1939. The third section examines the reactions of scientists, primarily in the United States, and includes coverage by newspapers, magazines and radio. The final section includes a number of themes to explain why there was little acknowledgment of the potential of the bomb to affect personal morality, the scientific community and international relations

  14. Development of nuclear microfilters using the fission tracks registration technique

    International Nuclear Information System (INIS)

    Yamasaki, I.M.; Geraldo, L.P.

    1990-10-01

    Nuclear microfilters with mean pores diameter in the range from 1.9 to 10.6 μm have been produced using the fission tracks registration technique in Makrofol KG (8 μm thickness). Fluctuations around 11% and 10% were obtained respectively for the pores size and pores uniformity in the analysis of a typical sample of microfilter. The essential features of the microfilters were similar to those ones, commercially known as Nuclepore and thus they may be routinely employed in the several applications areas of the Industry and Biology. (author)

  15. Sustainable, Full-Scope Nuclear Fission Energy at Planetary Scale

    Directory of Open Access Journals (Sweden)

    Robert Petroski

    2012-11-01

    Full Text Available A nuclear fission-based energy system is described that is capable of supplying the energy needs of all of human civilization for a full range of human energy use scenarios, including both very high rates of energy use and strikingly-large amounts of total energy-utilized. To achieve such “planetary scale sustainability”, this nuclear energy system integrates three nascent technologies: uranium extraction from seawater, manifestly safe breeder reactors, and deep borehole disposal of nuclear waste. In addition to these technological components, it also possesses the sociopolitical quality of manifest safety, which involves engineering to a very high degree of safety in a straightforward manner, while concurrently making the safety characteristics of the resulting nuclear systems continually manifest to society as a whole. Near-term aspects of this nuclear system are outlined, and representative parameters given for a system of global scale capable of supplying energy to a planetary population of 10 billion people at a per capita level enjoyed by contemporary Americans, i.e., of a type which might be seen a half-century hence. In addition to being sustainable from a resource standpoint, the described nuclear system is also sustainable with respect to environmental and human health impacts, including those resulting from severe accidents.

  16. Mitochondrial fission proteins regulate programmed cell death in yeast

    OpenAIRE

    Fannjiang, Yihru; Cheng, Wen-Chih; Lee, Sarah J.; Qi, Bing; Pevsner, Jonathan; McCaffery, J. Michael; Hill, R. Blake; Basañez, Gorka; Hardwick, J. Marie

    2004-01-01

    The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we fo...

  17. Sequential character of low-energy ternary and quaternary nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Bulychev, A. O. [Voronezh State University (Russian Federation)

    2016-09-15

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  18. Sequential character of low-energy ternary and quaternary nuclear fission

    International Nuclear Information System (INIS)

    Kadmensky, S. G.; Bulychev, A. O.

    2016-01-01

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  19. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalick, S.; Jansen, P.; Kessler, G.; Klumpp, P.

    1980-08-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  20. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalik, S.I.

    1980-01-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrides are coupled to the breeders. The results also indicate that from a resource standpaint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  1. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalik, S.I.; Jansen, P.; Kessler, G.; Klumpp, P.

    1981-01-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  2. Nuclear fission - the unexpected discovery seventy years ago

    International Nuclear Information System (INIS)

    Weis, Michael

    2008-01-01

    Seventy years ago, on December 17, 1938, Otto Hahn, Lise Meitner, and Fritz Strassmann discovered nuclear fission. It was a serendipitous discovery resulting from the consistent pursuit, for many years, of occasionally unexpected radiochemical experimental findings. Hardly any other scientific discovery has had such direct bearing on our life, changing our view of the world. It over-threw the tenet of physics, believed to be incontestable, that the atom was indivisible. The use of nuclear power it has made possible has given rise to immense benefits, but it has also allowed mankind's most dreadful weapon so far to be developed. All this is ample reason seventy years later to recall the discovery, the discoverers and their times. It will also be shown what later generations have made of this discovery, and what economic and ecological prospects it continues to hold. (orig.)

  3. Improving the safety of future nuclear fission power plants

    International Nuclear Information System (INIS)

    Frisch, W.; Gros, G.

    2001-01-01

    The main objectives and principles in nuclear fission reactor safety are presented, e.g. the defence in depth strategy and technical principles such as redundancy, diversity and physical separation. After a brief historical review of the continuous development of safety improvement, the most recent international discussion is presented. This includes mainly the international activities within IAEA and its International Nuclear Safety Advisory Group (INSAG). The safety improvement, presented in recommendations of IAEA and INSAG is expressed as an improvement of all elements and all levels of the defence in depth concept. Special emphasis is put on improvement of the highest level, which requires the implementation of means to mitigate consequences of accidents with severe core damage. The different future concepts are briefly characterised. Some examples from the French-German safety approach are taken to demonstrate how requirements for safety improvement by means of an enhancement of the defence in depth principle are developed

  4. Table of superdeformed nuclear bands and fission isomers

    International Nuclear Information System (INIS)

    Firestone, R.B.; Singh, B.

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in 152 Dy was predicted for β 2 -0.65. Subsequently, a discrete set of γ-ray transitions in 152 DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of γ-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra

  5. Table of superdeformed nuclear bands and fission isomers

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B. [Lawrence Berkeley Lab., CA (United States); Singh, B. [McMaster Univ., Hamilton, ON (Canada)

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

  6. Fission Product Release from Spent Nuclear Fuel During Melting

    International Nuclear Information System (INIS)

    Howell, J.P.; Zino, J.F.

    1998-09-01

    The Melt-Dilute process consolidates aluminum-clad spent nuclear fuel by melting the fuel assemblies and diluting the 235U content with depleted uranium to lower the enrichment. During the process, radioactive fission products whose boiling points are near the proposed 850 degrees C melting temperature can be released. This paper presents a review of fission product release data from uranium-aluminum alloy fuel developed from Severe Accident studies. In addition, scoping calculations using the ORIGEN-S computer code were made to estimate the radioactive inventories in typical research reactor fuel as a function of burnup, initial enrichment, and reactor operating history and shutdown time.Ten elements were identified from the inventory with boiling points below or near the 850 degrees C reference melting temperature. The isotopes 137Cs and 85Kr were considered most important. This review serves as basic data to the design and development of a furnace off-gas system for containment of the volatile species

  7. Fission gas release in LWR fuel measured during nuclear operation

    International Nuclear Information System (INIS)

    Appelhans, A.D.; Skattum, E.; Osetek, D.J.

    1980-01-01

    A series of fuel behavior experiments are being conducted in the Heavy Boiling Water Reactor in Halden, Norway, to measure the release of Xe, Kr, and I fission products from typical light water reactor design fuel pellets. Helium gas is used to sweep the Xe and Kr fission gases out of two of the Instrumented Fuel Assembly 430 fuel rods and to a gamma spectrometer. The measurements of Xe and Kr are made during nuclear operation at steady state power, and for 135 I following reactor scram. The first experiments were conducted at a burnup of 3000 MWd/t UO 2 , at bulk average fuel temperatures of approx. 850 K and approx. 23 kW/m rod power. The measured release-to-birth ratios (R/B) of Xe and Kr are of the same magnitude as those observed in small UO 2 specimen experiments, when normalized to the estimated fuel surface-to-volume ratio. Preliminary analysis indicates that the release-to-birth ratios can be calculated, using diffusion coefficients determined from small specimen data, to within a factor of approx. 2 for the IFA-430 fuel. The release rate of 135 I is shown to be approximately equal to that of 135 Xe

  8. Nuclear terrorism - an unavoidable companion of nuclear fission?

    International Nuclear Information System (INIS)

    Mueller, H.

    1989-01-01

    Comparing the security measures provided for with regard to nuclear weapons or to the nuclear inventory of the civilian fuel cycle, it is shown that there are significantly lower standards applied to the storage, processing, and transport of the radioactive fuel material. The difference becomes most obvious when looking at the planning horizons of those responsible for the security measures. The NATO institutions establish their system of security measures on the basis of a dynamical 'threat analysis' reaching far into the future. In the civilian sector, risk analyses and the deduced security measures are well lagging behind the development of realistic risk scenarios. This makes life easier for the operators of nuclear fuel cycle facilities, who otherwise would be obliged to continuously backfit their installations. The cost advantage on the operator's part, however, is obtained at the expense of security. (orig./HSCH) [de

  9. Tables and figures from JNDC Nuclear Data Library of fission products, version 2

    International Nuclear Information System (INIS)

    Ihara, Hitoshi

    1989-11-01

    The content of JNDC (Japanese Nuclear Data Committee) FP (Fission Product) Nuclear Data Library version 2 for 1227 fission products is presented in the form of tables and figures. The library is inclusive of evaluated decay data such as decay constant, Q-value, average energies of beta, gamma and internal conversion electron, spin-parity, branching ratio of each decay mode and fission yield. The neutron capture cross-sections are also contained for 166 nuclides. The mass number of the fission product nuclides ranges from A = 66 to A = 172. (author)

  10. Determination of shell energies. Nuclear deformations and fission barriers

    International Nuclear Information System (INIS)

    Koura, Hiroyuki; Tachibana, Takahiro; Uno, Masahiro; Yamada, Masami.

    1996-01-01

    We have been studying a method of determining nuclear shell energies and incorporating them into a mass formula. The main feature of this method lies in estimating shell energies of deformed nuclei from spherical shell energies. We adopt three assumptions, from which the shell energy of a deformed nucleus is deduced to be a weighted sum of spherical shell energies of its neighboring nuclei. This shell energy should be called intrinsic shell energy since the average deformation energy also acts as an effective shell energy. The ground-state shell energy of a deformed nucleus and its equilibrium shape can be obtained by minimizing the sum of these two energies with respect to variation of deformation parameters. In addition, we investigate the existence of fission isomers for heavy nuclei with use of the obtained shell energies. (author)

  11. Semiclassical shell structure and nuclear double-humped fission barriers

    Directory of Open Access Journals (Sweden)

    A. G. Magner

    2010-09-01

    Full Text Available We derived the semiclassical trace formulas for the level density as sums over periodic-orbit families and isolated orbits within the improved stationary phase method. Averaged level-density shell corrections and shell-structure energies are continuous through all symmetry-breaking (bifurcation points with the correct asymptotics of the standard stationary phase approach accounting for continuous symmetries. We found enhancement of the nuclear shell structure near bifurcations in the superdeformed region. Our semiclassical results for the averaged level densities with the gross-shell and more thin-shell structures and the energy shell corrections for critical deformations are in good agreement with the quantum calculations for several single-particle Hamiltonians, in particular for the potentials with a sharp spheroidal shape. Enhancement of the shell structure owing to bifurcations of the shortest 3-dimensional orbits from equatorial orbits is responsible for the second well of fission barrier in a superdeformation region.

  12. Exclusion of nuclear forces in heavy-ion Coulomb excitation and Coulomb fission experiments

    International Nuclear Information System (INIS)

    Neese, R.E.; Guidry, M.W.

    1982-01-01

    A simple prescription for estimating the energy at which nuclear forces begin to play a role in heavy-ion Coulomb excitation and Coulomb fission experiments is presented. The method differs from most commonly used recipes in accounting for projectile and target nucleus deformation effects. Using a single adjustable parameter the formula reproduces the energy for the onset of Coulomb-nuclear interference effects for a broad range of heavy-ion systems. It is suggested that most Coulomb fission experiments which have been done involve both Coulomb and nuclear excitation processes and should more properly be termed Coulomb-nuclear fission experiments

  13. Separation of transuranic elements and some fission products in irradiated spent fuels. Program 2005; Separacion de elementos transuranicos y algunos productos de fision presentes en los combustibles nucleares irradiados Programa 2005

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, C.; Espartero, A. G.; Cordoba, G. de; Gascon, J. L.; Pina, G.; Martinez-Esparza, A.; Uriarte, A.

    2006-07-01

    This technical publication of ENRESA refers to Partitioning of some chemical elements containing longlived radionuclides (actinides and fission products), from spent nuclear fuels. The Partitioning includes the different processes developed or on R and D way, from the middle of the past century to the present. These processes are of two types, wet (hydro-metallurgical) and dry (pyro-metallurgical). Among the hydro-metallurgical processes the most important is the PUREX process, developed in the U.S.A. at the middle of the past century, used for the separation of uranium and plutonium from spent nuclear fuels, previous dissolution with nitric acid of the irradiated fuels. Later other hydrometallurgical processes have been developed for the separation of some TRUs and long-lived fission products from the high activity liquid (HLW) coming from PUREX reprocessing. Among the most important countries and institutions that are developing new hydrometallurgical processes are USA, Japan, China, Russia and the European Union, fundamentally France, the Czech Republic, United Kingdom, Italy, Belgium, Holland, Germany, Spain and the JRC-ITU. In the case of Spain it is possible to remark the works of synthesis of new extractants, developed by the group of the Prof. Javier de Mendoza of the Dept. of Organic Chemistry of the Universidad Autonoma de Madrid and by the group of Prof. Teixidor of the Instituto de Ciencias de Materiales de Barcelona (ICMAB) of the Consejo Superior de Investigaciones Cientificas (CSIC) and the activities carried out by the CIEMAT from 1999, based fundamentally on a collaboration agreement with ENRESA, that are related to the characterization and tests of the new extractants synthesized in Spain and also abroad, mainly by the CEA (France). All these activities are included in the Projects PARTNEW and EUROPART of the European Union. About Pyro-metallurgical Processes, they started in the ANL (Argonne National Laboratory, USA) by the 60' is of the

  14. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  15. Nuclear fission: a review of experimental advances and phenomenology

    Science.gov (United States)

    Andreyev, A. N.; Nishio, K.; Schmidt, K.-H.

    2018-01-01

    In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies. This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams. The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and γ-ray emission will also be reviewed. A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as β-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion–fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around {\\hspace{0pt}}180 Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined. The unprecedented high-quality data for fission fragments, completely identified in Z and A, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions

  16. Advantages of Production of New Fissionable Nuclides for the Nuclear Power Industry in Hybrid Fusion-Fission Reactors

    Science.gov (United States)

    Tsibulskiy, V. F.; Andrianova, E. A.; Davidenko, V. D.; Rodionova, E. V.; Tsibulskiy, S. V.

    2017-12-01

    A concept of a large-scale nuclear power engineering system equipped with fusion and fission reactors is presented. The reactors have a joint fuel cycle, which imposes the lowest risk of the radiation impact on the environment. The formation of such a system is considered within the framework of the evolution of the current nuclear power industry with the dominance of thermal reactors, gradual transition to the thorium fuel cycle, and integration into the system of the hybrid fusion-fission reactors for breeding nuclear fuel for fission reactors. Such evolution of the nuclear power engineering system will allow preservation of the existing structure with the dominance of thermal reactors, enable the reprocessing of the spent nuclear fuel (SNF) with low burnup, and prevent the dangerous accumulation of minor actinides. The proposed structure of the nuclear power engineering system minimizes the risk of radioactive contamination of the environment and the SNF reprocessing facilities, decreasing it by more than one order of magnitude in comparison with the proposed scheme of closing the uranium-plutonium fuel cycle based on the reprocessing of SNF with high burnup from fast reactors.

  17. Fission decay properties of nuclear giant multipole resonances

    International Nuclear Information System (INIS)

    Dias, H.; Arruda Neto, J.D.T.; Hussein, M.S.; Carlson, B.V.

    1986-05-01

    The statistical fission decay properties of the giant dipole, quadrupole and monopole resonances in 236 U are investigated with the aid of the Hauser-Feshbach model. It is found, contrary to several recent claims, that the GQR fission decay probability is as large as that of the GDR, at energies higher than the fission barrier. At energies close to the f.b., the GQR fission probability is found to be appreciably larger than that of the GDR. The GMR fission probability follows closely that of the GQR. (Author) [pt

  18. Metrology for New Generation Nuclear Power Plants - MetroFission

    International Nuclear Information System (INIS)

    Johansson, Lena; Dinsdale, Alan; Keightley, John; Filtz, Jean-Remy; Hay, Bruno; DeFelice, Pierino; Sadli, Mohamed; Plompen, Arjan; Heyse, Jan; Pomme, Stefaan; Cassette, Philippe

    2013-06-01

    MetroFission project has been looking at solving metrological problems related to a new generation of NPPs. The proposed Gen. IV NPPs are designed to run safely, make efficient use of natural resources, minimize the waste and maintain proliferation resistance. In order to reach these goals, the reactor operation involves higher temperatures, high-energy neutron fluence, different types of fuel where the minor actinides are included etc. The work has focused on improved temperature measurements, investigation of thermal properties of advanced materials, determination of new and relevant nuclear data and development of measurement techniques for radionuclides suitable for Gen. IV NPPs. The improved temperature measurement for nuclear power plant applications includes the development of a new Fe-C fixed point. Robust, repeatable and versatile cells have been constructed and compared with success among the project participants and their melting temperatures have been determined. Methodology of self-validating thermocouples has proven efficient at several fixed point temperatures using different designs. A practical acoustic thermometer has been tested at 1000 deg. C with success thanks to the use of innovative signal processing methods. Mo/Nb thermocouples have been obtained with different sheath materials and tested with the aim to achieve for the first time a reference function determined with the best possible uncertainties. Following reviews of designs and technology proposed for fourth generation nuclear plants effort within this project, with regards to thermal properties of advanced materials for nuclear design, has concentrated on provision of thermodynamic data to support the development of the sodium cooled fast reactor. Data has been critically assessed to represent the potential interaction between the Na coolant and the nuclear fuel taken to be based on (U, Pu)O 2 but incorporating minor actinides such as Np and Am. Data for the fission products and

  19. Source driven breeding fission power reactors and the nuclear energy strategy

    International Nuclear Information System (INIS)

    Greenspan, E.

    The nuclear energy economy is facing severe difficulties associated with low utilization of uranium resources, safety, non-proliferation and environmental issues. Energy policy makers face the dilemma: commercialize LMFBRs immediately with the risk of negative economical, proliferation or other consequences, or continue with R and D programs that will provide the information needed for sounder decisions, but now taking the risk of running out of economically exploitable uranium ore resources. The development of hybrid reactors can provide an assurance against the latter risk and offers many interesting new options for the nuclear energy strategy. Being based on the technology of LWRs and HWRs, Light Water Hybrid Reactors (LWHR) provide a most natural link between the fission reactor technology of the present and the fusion power technology of the future. The investment in their development in excess of that required for the development of fusion power reactors is expected to be relatively small, thus making the development of LWHRs potentially a high benefit-to-cost ratio program. It is recommended that the fission and fusion communities will cooperate in hybrids R and D programs aimed at assessing the technological and economical viability of hybrid reactors as reliably and soon as possible. (author)

  20. Disposal of fissionable material from dismantled nuclear weapons

    International Nuclear Information System (INIS)

    Taylor, J.J.

    1991-01-01

    The reduction in tensions between the United States and the Soviet Union has improved the prospects for nuclear disarmament, making it more likely that significant numbers of nuclear warheads will be dismantled by the United States and USSR in the foreseeable future. Thus, the question becomes more urgent as to the disposition of the weapons materials, highly enriched uranium and plutonium. It is timely, therefore, to develop specific plans for such disposal. The overall process for disposal of weapons materials by the burnup option involves the following steps: (1) removing the weapons material from the warheads, (2) converting the material to a fuel form suitable for power reactors, (3) burning it up as a power reactor fuel, and (4) removing the spent fuel and placing it in a permanent repository. This paper examines these four steps with the purpose of answering the following questions. What facilities would be appropriate for the disposal process? Do they need to be dedicated facilities, or could industrial facilities be used? What is the present projection of the economics of the burnup process, both the capital investment and the operating costs? How does one assure that fissionable materials will not be diverted to military use during the disposal process? Is the spent fuel remaining from the burnup process proliferation resistant? Would the disposal of spent fuel add an additional burden to the spent fuel permanent repository? The suggested answers are those of the author and do not represent a position by the Electric Power Research Institute

  1. Nuclear fission fragment excitation of electronic transition laser media

    International Nuclear Information System (INIS)

    Lorents, D.C.; McCusker, M.V.; Rhodes, C.K.

    1976-01-01

    The properties of high energy electronic transition lasers excited by fission fragments are expanded. Specific characteristics of the media including density, excitation rates, wavelength, kinetics, fissile material, scale size, and medium uniformity are assessed. The use of epithermal neutrons, homogeneously mixed fissile material, and special high cross section nuclear isotopes to optimize coupling of the energy to the medium are shown to be important considerations maximizing the scale size, energy deposition, and medium uniformity. A performance limit point of approximately 1000 J/l in approximately 100 μs pulses is established for a large class of systems operating in the near ultraviolet and visible spectral regions. It is demonstrated that e-beam excitation can be used to simulate nuclear pumping conditions to facilitate the search for candidate media. Experimental data for the kinetics of a XeF* laser operating in Ar/Xe/F 2 /UF 6 mixtures are given. These reactor-pumped systems are suitable for scaling to volumes on the order of (meters) 3

  2. Influence of the bud neck on nuclear envelope fission in Saccharomyces cerevisiae.

    Science.gov (United States)

    Melloy, Patricia G; Rose, Mark D

    2017-09-15

    Studies have shown that nuclear envelope fission (karyokinesis) in budding yeast depends on cytokinesis, but not distinguished whether this was a direct requirement, indirect, because of cell cycle arrest, or due to bud neck-localized proteins impacting both processes. To determine the requirements for karyokinesis, we examined mutants conditionally defective for bud emergence and/or nuclear migration. The common mutant phenotype was completion of the nuclear division cycle within the mother cell, but karyokinesis did not occur. In the cdc24 swe1 mutant, at the non-permissive temperature, multiple nuclei accumulated within the unbudded cell, with connected nuclear envelopes. Upon return to the permissive temperature, the cdc24 swe1 mutant initiated bud emergence, but only the nucleus spanning the neck underwent fission suggesting that the bud neck region is important for fission initiation. The neck may be critical for either mechanical reasons, as the contractile ring might facilitate fission, or for regulatory reasons, as the site of a protein network regulating nuclear envelope fission, mitotic exit, and cytokinesis. We also found that 77-85% of pairs of septin mutant nuclei completed nuclear envelope fission. In addition, 27% of myo1Δ mutant nuclei completed karyokinesis. These data suggested that fission is not dependent on mechanical contraction at the bud neck, but was instead controlled by regulatory proteins there. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Energy distribution of antineutrinos originating from the decay of fission products in a nuclear reactor

    International Nuclear Information System (INIS)

    Rudstam, G.; Aleklett, K.

    1979-01-01

    The energy spectrum of antineutrinos around a nuclear reactor has been derived by summing contributions from individual fission products. The resulting spectrum is weaker at energies above approx. 8 MeV than earlier published antineutrino spectra. The reason may be connected to the strong feeding of high-lying daughter states in the beta decay of fission products with high disintegration energies

  4. Environmental life cycle assessment of high temperature nuclear fission and fusion biomass gasification plants

    International Nuclear Information System (INIS)

    Takeda, Shutaro; Sakurai, Shigeki; Kasada, Ryuta; Konishi, Satoshi

    2017-01-01

    The authors propose nuclear biomass gasification plant as an advancement of conventional gasification plants. Environmental impacts of both fission and fusion plants were assessed through life cycle assessment. The result suggested the reduction of green-house gas emissions would be as large as 85.9% from conventional plants, showing a potential for the sustainable future for both fission and fusion plants. (author)

  5. Comparative energetics of three fusion-fission symbiotic nuclear reactor systems

    International Nuclear Information System (INIS)

    Gordon, C.W.; Harms, A.A.

    1975-01-01

    The energetics of three symbiotic fusion-fission nuclear reactor concepts are investigated. The fuel and power balances are considered for various values of systems parameters. The results from this analysis suggest that symbiotic fusion-fission systems are advantageous from the standpoint of economy and resource utilization. (Auth.)

  6. Research activities in fission chamber modeling in support of the nuclear energy industry

    Energy Technology Data Exchange (ETDEWEB)

    Jammes, C.; Filliatre, P.; Geslot, B.; Oriol, L.; Berhouet, F.; Villard, J. F. [Commissariat a l' Energie Atomique, DEN/SPEX/LDCI, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium)

    2009-07-01

    Fission chambers are widely used in the nuclear industry. As an example, they play a major role in the control of any fission reactor and are thus regarded as a key component for ensuring their safety. They are also employed in the material testing reactors for monitoring irradiations. We have recently started a research program, the objective of which is to improve the performance of those neutron detectors in terms of lifetime, calibration and online diagnosis. In this paper, we present several studies carried out in order to model the signal delivered by a fission chamber. First, the simulation of the deposit evolution allowed us to select the most appropriate fissile material for a given spectrum and fluence. Second, we studied the impact of the bias voltage and filling gas characteristics on the charge collection time. Finally, the simulation of a pulse signal prior to amplification showed how it is important to have a satisfactory knowledge of the energy for creating ion pairs to accurately assess the signal in current or Campbelling mode. (authors)

  7. Research activities in fission chamber modeling in support of the nuclear energy industry

    International Nuclear Information System (INIS)

    Jammes, C.; Filliatre, P.; Geslot, B.; Oriol, L.; Berhouet, F.; Villard, J. F.; Vermeeren, L.

    2009-01-01

    Fission chambers are widely used in the nuclear industry. As an example, they play a major role in the control of any fission reactor and are thus regarded as a key component for ensuring their safety. They are also employed in the material testing reactors for monitoring irradiations. We have recently started a research program, the objective of which is to improve the performance of those neutron detectors in terms of lifetime, calibration and online diagnosis. In this paper, we present several studies carried out in order to model the signal delivered by a fission chamber. First, the simulation of the deposit evolution allowed us to select the most appropriate fissile material for a given spectrum and fluence. Second, we studied the impact of the bias voltage and filling gas characteristics on the charge collection time. Finally, the simulation of a pulse signal prior to amplification showed how it is important to have a satisfactory knowledge of the energy for creating ion pairs to accurately assess the signal in current or Campbelling mode. (authors)

  8. Fission Product Experimental Program: Validation and Computational Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Leclaire, N.; Ivanova, T.; Letang, E. [Inst Radioprotect and Surete Nucl, F-92262 Fontenay Aux Roses (France); Girault, E. [CEA Valduc, Serv Rech Neutron and Critcite, 21 - Is-sur-Tille (France); Thro, J. F. [AREVA NC, F-78000 Versailles (France)

    2009-02-15

    From 1998 to 2004, a series of critical experiments referred to as the fission product (FP) experimental program was performed at the Commissariat a l'Energie Atomique Valduc research facility. The experiments were designed by Institut de Radioprotection et de Surete Nucleaire (IRSN) and funded by AREVA NC and IRSN within the French program supporting development of a technical basis for burnup credit validation. The experiments were performed with the following six key fission products encountered in solution either individually or as mixtures: {sup 103}Rh, {sup 133}Cs, {sup nat}Nd, {sup 149}Sm, {sup 152}Sm, and {sup 155}Gd. The program aimed at compensating for the lack of information on critical experiments involving FPs and at establishing a basis for FPs credit validation. One hundred forty-five critical experiments were performed, evaluated, and analyzed with the French CRISTAL criticality safety package and the American SCALE5. 1 code system employing different cross-section libraries. The aim of the paper is to show the experimental data potential to improve the ability to perform validation of full burnup credit calculation. The paper describes three Phases of the experimental program; the results of preliminary evaluation, the calculation, and the sensitivity/uncertainty study of the FP experiments used to validate the APOLLO2-MORET 4 route in the CRISTAL criticality package for burnup credit applications. (authors)

  9. Measurement of fission track of uranium particle by solid state nuclear track detector

    International Nuclear Information System (INIS)

    Son, S. C.; Pyo, H. W.; Ji, K. Y.; Kim, W. H.

    2002-01-01

    In this study, we discussed results of the measurement of fission tracks for the uranium containing particles by solid state nuclear track detector. Uranium containing silica and uranium oxide particles were prepared by uranium sorption onto silica powder in weak acidic medium and laser ablation on uranium pellet, respectively. Fission tracks for the uranium containing silica and uranium oxide particles were detected on Lexan plastic detector. It was found that the fission track size and shapes depend on the particle size uranium content in particles. Correlation of uranium particle diameter with fission track radius was also discussed

  10. Prompt muon-induced fission: A probe for nuclear friction in large-amplitude collective motion

    International Nuclear Information System (INIS)

    Oberacker, V.E.; Umar, A.S.; Wells, J.C.; Strayer, M.R.; Maruhn, J.A.; Reinhard, P.G.

    1998-01-01

    Excited muonic atoms in the actinide region may induce prompt fission by inverse internal conversion, i.e. the excitation energy of the muonic atom is transferred to the nucleus. The authors solve the time dependent Dirac equation for the muonic spinor wave function in the Coulomb field of the fissioning nucleus on a 3-dimensional lattice and demonstrate that the muon attachment probability to the light fission fragment is a measure of the nuclear energy dissipation between the outer fission barrier and the scission point

  11. Nuclear molecules in low energy fission of actinides?

    International Nuclear Information System (INIS)

    Pyatkov, Yu.V.; Pashkevich, V.V.; Tishchenko, V.G.; Unzhakova, A.V.; )

    2000-01-01

    A comparison is presented of the fine structure (FS) of the both energy-mass and energy-charge distributions of the fission fragments of thermal neutron induced fission of uranium in the data obtained at different spectrometers. Some peculiarities of the FS observed can be treated as a manifestation of two different types of collective vibrations of the fissioning system on its way to scission [ru

  12. Low-energy nuclear fission and our understanding of the nucleus

    International Nuclear Information System (INIS)

    Hall, H.L.; Hoffman, D.C.

    1990-01-01

    The interactions between experimental discoveries in low-energy nuclear fission and the theoretical understanding of the structure of the nucleus are reviewed. The history of this synergistic relationship begins with the discovery of fission, the development of the liquid-drop model and the experimental evidence for magic numbers, continues through the development of the shell model, the experimental discovery of shape isomerism, the double-humped fission barrier the spontaneous fission half-life disaster, the discovery of symmetric mass division in spontaneous fission and theoretical treatments based on different paths to scission. It concludes with a brief review of current experimental and theoretical understanding of low-energy fission and the prospects for future developments. (author) 150 refs.; 5 figs.; 1 tab

  13. Fission energy program of the U. S. Department of Energy

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-01

    The document describes programs managed by the Program Director for Nuclear Energy, Department of Energy, and under the cognizance of the Committee on Science and Technology, United States House of Representatives. The major portion of the document is concerned with civilian nuclear power development, the policy for which has been established by the National Energy Plan of April 1977, but it also includes descriptions of the space applications and naval reactor programs.

  14. Ontario Hydro's nuclear program

    International Nuclear Information System (INIS)

    McCredie, J.

    1984-01-01

    This report briefly describes Ontario Hydro's nuclear program, examining the design and construction status, and the future from Ontario Hydro's perspective. Ontario Hydro relies heavily on nuclear power. Nuclear fuel was responsible for approximately 34% of Ontario Hydro's energy production in 1983. The nuclear proportion was supplied by twelve operating units located: NPD, Douglas Point, Pickering A and B. It is expected that by approximately 1992, 65% of the total energy needs will be generated through nuclear power

  15. Compilation and evaluation of fission yield nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1991-09-01

    The task of this meeting was to review the progress made since the previous meeting on fission yield evaluation and to define the tasks for an IAEA Co-ordinated Research Programme in detail. Improvements have been noted in measured data, model calculations and the situation of fission yield evaluation. Tabs

  16. Fission yield correlation generation and impact on nuclear problems - 15570

    International Nuclear Information System (INIS)

    Fiorito, L.; Stankovskiy, A.; Van den Eynde, G.

    2015-01-01

    In our work we defined a scheme to update fission yields and their covariance matrices. We implemented a Generalised Linear Least Square (GLLS) updating procedure to produce inter-isotope fission yield correlations. At each update, a constraining equation was selected and the related set of observables calculated using the prior knowledge of the fission yield data and uncertainties. Then, available extra information on each observable was introduced into the system - e.g. a data set of direct measurements or uncertainties. Our GLLS-based updating tool calculates best-estimate posterior fission yields and covariance matrices which merge both the extra and prior data. The major result of the update is the generation of fission yield correlations. We created complete updated covariance matrices for 6 nuclides (Th 232 , U 233 , U 235 , U 238 , Pu 239 and Pu 241 ) and a total of 14 fissioning systems using the JEFF-3.1.1 files. The fission yield covariance matrices were tested against the criticality and nuclide inventory calculations of the REBUS single pin benchmark after one irradiation cycle. It appears that fission yield correlations reduce the uncertainties to a very great extent, which in many cases are 4 times smaller than those obtained with uncorrelated data

  17. IAEA nuclear security program

    Energy Technology Data Exchange (ETDEWEB)

    Ek, D. [International Atomic Energy Agency, Vienna (Austria)

    2006-07-01

    Although nuclear security is a State responsibility, it is nevertheless an international concern, as the consequences of a nuclear security incident would have worldwide impact. These concerns have resulted in the development of numerous international instruments on nuclear security since the terrorist events in the USA on September 11, 2001. The IAEA Office of Nuclear Security has been charged to assist Member States to improvement their nuclear security and to meet the intent of these international obligations in order to ensure a cohesive thread of nuclear security protects the global community. The programs underway and planned by the Office of Nuclear Security will be discussed in this paper. (author)

  18. IAEA nuclear security program

    International Nuclear Information System (INIS)

    Ek, D.

    2006-01-01

    Although nuclear security is a State responsibility, it is nevertheless an international concern, as the consequences of a nuclear security incident would have worldwide impact. These concerns have resulted in the development of numerous international instruments on nuclear security since the terrorist events in the USA on September 11, 2001. The IAEA Office of Nuclear Security has been charged to assist Member States to improvement their nuclear security and to meet the intent of these international obligations in order to ensure a cohesive thread of nuclear security protects the global community. The programs underway and planned by the Office of Nuclear Security will be discussed in this paper. (author)

  19. 50 years with nuclear fission, April 25-28, 1989. A prelude to fission: France

    International Nuclear Information System (INIS)

    Savic, P.

    1989-01-01

    A personal account of the events leading to the 1938 discovery, by Irene Joliot-Curie and the author, of the unidentified element R 3.5h will be presented, as well as the experimental methods proving the R 3.5h had chemical properties similar to lanthanum which in turn led Hahn and Strassmann to the discovery of fission in 1939. The author points out that Irene Curie's intuition indicated the path towards the solution of the problem of uranium irradiated by neutrons, which made possible the discovery of fission by Hahn and Strassmann. Further applications of fission became possible by tremendous efforts and excellent contributions of scientists in the USA

  20. Journey from discovery of nuclear fission to accelerator-driven sub-critical reactor systems (ADS)

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    2005-01-01

    The epoch making discovery of nuclear fission in 1939, which resulted purely from the curiosity driven basic research to understand the atomic and nuclear structure has changed the world forever with the onset of a new era in the history of human civilization. The basic nuclear physics research pursued after the discovery of fission has also been of much relevance in the harnessing of nuclear energy. In the recent years, there is considerable interest towards developing accelerator driven sub-critical reactor systems (ADS) for the incineration of the long-lived spent fuel radioactive waste and for the utilization of thorium fuel for nuclear power generation. In this talk, we discuss important milestones in the journey from discovery of nuclear fission to ADS. (author)

  1. Isotopic Determination of Nuclear Materials Using Nuclear Fission Track Registration Technique and Thermal Ionization Mass Spectrometric Technique

    International Nuclear Information System (INIS)

    Jeon, Young Sin; Pyo, Hyeong Yeol; Park, Yong Joon; Song, Kyu Seok; Kim, Won Ho; Jee, Kwang Yong

    2007-05-01

    It is very important to develope the technology for the determination of isotopic ratios of hot particles( 234 U, 235 U, 236 U etc.) detected from swipe samples of various nuclear facilities. This technology is highly competitive internationally and has to be established independently as long as our government maintains atomic energy and treats nuclear materials. In this text, sample pretreatment procedure, gamma-ray counting, alpha or fission track techniques, isotopic analysis of U and Pu, background problems and detection limits for mass determination, and their application to the real swipe sample were described with detailed procedure. This technology would contribute to the Korean economy's high growth rate as well as to superiority of government's leading research and development programs if successfully established

  2. Transfer-induced fission in inverse kinematics: Impact on experimental and evaluated nuclear data bases

    Energy Technology Data Exchange (ETDEWEB)

    Farget, F.; Schmidt, K.H.; Clement, E.; Delaune, O.; Derkx, X.; Dijon, A.; Golabek, C.; Lemasson, A.; Roger, T.; Schmitt, C. [CEA/DSM-CNRS/IN2P3, GANIL, Caen (France); Caamano, M.; Ramos, D.; Benlliure, J.; Cortina, D.; Fernandez-Dominguez, B.; Paradela, C. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Rodriguez-Tajes, C. [CEA/DSM-CNRS/IN2P3, GANIL, Caen (France); Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Audouin, L. [Universite Paris-Sud 11, CNRS/IN2P3, Institut de Physique Nucleaire, Orsay (France); Casarejos, E. [Universidade de Vigo, Vigo (Spain); Dore, D.; Salsac, M.D. [Centre de Saclay, CEA, Irfu, Gif-sur-Yvette (France); Gaudefroy, L. [CEA DAM Ile-de-France, BP 12, Bruyeres-le-Chatel (France); Heinz, A. [Chalmers Tekniska Hoegskola, Fundamental Fysik, Goeteborg (Sweden); Jurado, B. [Universite Bordeaux, CENBG, UMR 5797 CNRS/IN2P3, Gradignan (France)

    2015-12-15

    Inverse kinematics is a new tool to study nuclear fission. Its main advantage is the possibility to measure with an unmatched resolution the atomic number of fission fragments, leading to new observables in the properties of fission-fragment distributions. In addition to the resolution improvement, the study of fission based on nuclear collisions in inverse kinematics beneficiates from a larger view with respect to the neutron-induced fission, as in a single experiment the number of fissioning systems and the excitation energy range are widden. With the use of spectrometers, mass and kinetic-energy distributions may now be investigated as a function of the proton and neutron number sharing. The production of fissioning nuclei in transfer reactions allows studying the isotopic yields of fission fragments as a function of the excitation energy. The higher excitation energy resulting in the fusion reaction leading to the compound nucleus {sup 250}Cf at an excitation energy of 45MeV is also presented. With the use of inverse kinematics, the charge polarisation of fragments at scission is now revealed with high precision, and it is shown that it cannot be neglected, even at higher excitation energies. In addition, the kinematical properties of the fragments inform on the deformation configuration at scission. (orig.)

  3. Vinca nuclear decommissioning program

    International Nuclear Information System (INIS)

    Pesic, M.; Subotic, K.; Sotic, O.; Plecas, I.; Ljubenov, V.; Peric, A.

    2002-01-01

    In this paper a preliminary program for the nuclear decommissioning in The Vinca Institute of Nuclear Sciences is presented. Proposed Projects and Activities, planned to be done in the next 10 years within the frames of the Program, should improve nuclear and radiation safety and should solve the main problems that have arisen in the previous period. Project of removal of irradiated spent nuclear fuel from the RA reactor, as a first step in all possible decommissioning strategies and the main activity in the first two-three years of the Program realization, is considered in more details. (author)

  4. FISPRO: a simplified computer program for general fission product formation and decay calculations

    International Nuclear Information System (INIS)

    Jiacoletti, R.J.; Bailey, P.G.

    1979-08-01

    This report describes a computer program that solves a general form of the fission product formation and decay equations over given time steps for arbitrary decay chains composed of up to three nuclides. All fission product data and operational history data are input through user-defined input files. The program is very useful in the calculation of fission product activities of specific nuclides for various reactor operational histories and accident consequence calculations

  5. Considerations for a sustainable nuclear fission energy in Europe

    International Nuclear Information System (INIS)

    Cognet, G.; Ledermann, P.; Cacuci, D.

    2005-01-01

    Presented is the global energy perspectives and and sustainable development fission vision scenario. Described are the innovative concepts with technological breakthroughs concerning the fuel cycle and evolution of the spent fuel radiotoxic contents

  6. Laser Intertial Fusion Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Kevin James [Univ. of California, Berkeley, CA (United States)

    2010-04-08

    having a packing fraction of 20% in 2 cm diameter fuel pebbles. The fission blanket is cooled by the same radial flibe flow that travels through perforated ODS walls to the reflector blanket. This reflector blanket is 75 cm thick comprised of 2 cm diameter graphite pebbles cooled by flibe. The flibe extraction plenum surrounds the reflector bed. Detailed neutronics designs studies are performed to arrive at the described design. The LFFH engine thermal power is controlled using a technique of adjusting the 6Li/7Li enrichment in the primary and secondary coolants. The enrichment adjusts system thermal power in the design by increasing tritium production while reducing fission. To perform the simulations and design of the LFFH engine, a new software program named LFFH Nuclear Control (LNC) was developed in C++ to extend the functionality of existing neutron transport and depletion software programs. Neutron transport calculations are performed with MCNP5. Depletion calculations are performed using Monteburns 2.0, which utilizes ORIGEN 2.0 and MCNP5 to perform a burnup calculation. LNC supports many design parameters and is capable of performing a full 3D system simulation from initial startup to full burnup. It is able to iteratively search for coolant 6Li enrichments and resulting material compositions that meet user defined performance criteria. LNC is utilized throughout this study for time dependent simulation of the LFFH engine. Two additional methods were developed to improve the computation efficiency of LNC calculations. These methods, termed adaptive time stepping and adaptive mesh refinement were incorporated into a separate stand alone C++ library name the Adaptive Burnup Library (ABL). The ABL allows for other client codes to call and utilize its functionality. Adaptive time stepping is useful for automatically maximizing the size of the depletion time step while maintaining a desired level of accuracy. Adaptive meshing allows for analysis

  7. Determination of the fission coefficients in thermal nuclear reactors for antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Lenilson M. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Cabral, Ronaldo G., E-mail: rgcabral@ime.eb.b [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Anjos, Joao C.C. dos, E-mail: janjos@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Dept. GLN - G

    2011-07-01

    The nuclear reactors in operation periodically need to change their fuel. It is during this process that these reactors are more vulnerable to occurring of several situations of fuel diversion, thus the monitoring of the nuclear installations is indispensable to avoid events of this nature. Considering this fact, the most promissory technique to be used for the nuclear safeguard for the nonproliferation of nuclear weapons, it is based on the detection and spectroscopy of antineutrino from fissions that occur in the nuclear reactors. The detection and spectroscopy of antineutrino, they both depend on the single contribution for the total number of fission of each actinide in the core reactor, these contributions receive the name of fission coefficients. The goal of this research is to show the computational and mathematical modeling used to determinate these coefficients for PWR reactors. (author)

  8. Implementation of a Thermodynamic Solver within a Computer Program for Calculating Fission-Product Release Fractions

    Science.gov (United States)

    Barber, Duncan Henry

    During some postulated accidents at nuclear power stations, fuel cooling may be impaired. In such cases, the fuel heats up and the subsequent increased fission-gas release from the fuel to the gap may result in fuel sheath failure. After fuel sheath failure, the barrier between the coolant and the fuel pellets is lost or impaired, gases and vapours from the fuel-to-sheath gap and other open voids in the fuel pellets can be vented. Gases and steam from the coolant can enter the broken fuel sheath and interact with the fuel pellet surfaces and the fission-product inclusion on the fuel surface (including material at the surface of the fuel matrix). The chemistry of this interaction is an important mechanism to model in order to assess fission-product releases from fuel. Starting in 1995, the computer program SOURCE 2.0 was developed by the Canadian nuclear industry to model fission-product release from fuel during such accidents. SOURCE 2.0 has employed an early thermochemical model of irradiated uranium dioxide fuel developed at the Royal Military College of Canada. To overcome the limitations of computers of that time, the implementation of the RMC model employed lookup tables to pre-calculated equilibrium conditions. In the intervening years, the RMC model has been improved, the power of computers has increased significantly, and thermodynamic subroutine libraries have become available. This thesis is the result of extensive work based on these three factors. A prototype computer program (referred to as SC11) has been developed that uses a thermodynamic subroutine library to calculate thermodynamic equilibria using Gibbs energy minimization. The Gibbs energy minimization requires the system temperature (T) and pressure (P), and the inventory of chemical elements (n) in the system. In order to calculate the inventory of chemical elements in the fuel, the list of nuclides and nuclear isomers modelled in SC11 had to be expanded from the list used by SOURCE 2.0. A

  9. Theoretical analysis of knock-out release of fission products from nuclear fuels

    International Nuclear Information System (INIS)

    Yamagishi, S.

    1975-01-01

    The knock-out release of fission products is studied theoretically. The general equations of knock-out release are derived, assuming that a fission fragment passing through the surface of nuclear fuels knocks out a local region of the surface with an effective thickness and an effective cross-sectional area. Using these equations, the knock-out release of fission gases is calculated for various cases. The conditions under which the knock-out coefficients (the average number of uranium atoms knocked out by one fission fragment) is obtainable are clarified by experiments on the knock-out release of fission gases. A method of determining the effective thickness and the effective cross-sectional area of a knock-out region is proposed. (Auth.)

  10. Compilation and evaluation of fission yield nuclear data. Final report of a co-ordinated research project 1991-1996

    International Nuclear Information System (INIS)

    2000-12-01

    Fission product yields are required at several stages of the nuclear fuel cycle and are therefore included in all large international data files for reactor calculations and related applications. Such files are maintained and disseminated by the Nuclear Data Section of the IAEA as a member of an international data centres network. Users of these data are from the fields of reactor design and operation, waste management and nuclear materials safeguards, all of which are essential parts of the IAEA programme. In the 1980s, the number of measured fission yields increased so drastically that the manpower available for evaluating them to meet specific user needs was insufficient. To cope with this task, it was concluded in several meetings on fission product nuclear data, some of them convened by the IAEA, that international co-operation was required, and an IAEA co-ordinated research project (CRP) was recommended. This recommendation was endorsed by the International Nuclear Data Committee, an advisory body for the nuclear data programme of the IAEA. As a consequence, the CRP on the Compilation and Evaluation of Fission Yield Nuclear Data was initiated in 1991, after its scope, objectives and tasks had been defined by a preparatory meeting. The different tasks, such as special evaluations and development of improved methods, were distributed among participants. The results of the research work were discussed and approved by all participants in research co-ordination meetings. For a successful development of theoretical and empirical models, experiments had to be recommended and their results to be awaited, which made necessary an extension of the CRP by two years. This TECDOC is the result of a joint effort of all participants in this CRP. The individual sections represent CRP tasks and were prepared by the participants responsible for doing the research, some of which comprise significant new scientific developments. The appendices to this book contain voluminous

  11. Argonne Nuclear Data Program

    Energy Technology Data Exchange (ETDEWEB)

    Kondev, F. [US Nuclear Data Program, U.S. DOE/SC (United States)

    2013-08-15

    Nuclear Data Compilations and Evaluations: - Nuclear structure and decay data compilations and evaluations for the International NSDD network (ENSDF and XUNDL); - AME12 and NuBase12 - in collaboration with G. Audi and M. MacCormick, CSNSM (Orsay), M. Wang, IMP (Lanzhou) and B. Pfeiffer, GSI (Darmstadt) - presentation by M. Wang; - DDEP coordinator - completed; - Horizontal nuclear data evaluation activities -IAEA CRP's, Isomers, Medical Isotopes; Complementary ND research Activities: - CARIBU, FRIB and other RIB facilities, Gretina, IAEA-CRP - emphasis on nuclear structure physics and astrophysics, and their intersection with applied nuclear physics programs.

  12. Nuclear structure via isomer tagging of fission fragments

    Science.gov (United States)

    Wu, C. Y.; Cline, D.; Simon, M. W.; Stoyer, M. A.

    1997-10-01

    The high efficiency for detecting high-fold γ rays by large Ge arrays makes it possible to study the detailed spectroscopy of many neutron-rich nuclei produced by fission. Major progress has been made using sealed spontaneous fission sources. Considerable improvement in selectivity is provided, with an open source, both by gating on isomers and by detection of both fission fragments in coincidence with the deexcitation γ rays (see the preceding contribution). The reconstructed kinematics allows a measure of fragment mass and the Doppler shift correction of γ rays. In a recent experiment, fission fragments were detected using half of the CHICO array and an annular PPAC in coincidence with deexcitation γ rays detected by the Rochester array of eight Compton-suppressed Ge detectors. The annular PPAC was located only 1.0" from a 3.7 μCi ^252Cf source for efficient isomer tagging. The correlation was studied between delayed, within a time window between 150 ns and 10 μs after a fission occurring, and prompt γ rays. Several prominent feeding patterns to isomers in the mass region around 100 and 130 are identified by such correlation study. Experimental details and results will be presented.

  13. Review of the book: Vasilenko, I.Ya. Toxicology of nuclear fission products

    International Nuclear Information System (INIS)

    Gordeev, K.I.

    2001-01-01

    Review on monograph of Vasilenko, I.Ya. Toxicology of nuclear fission (Moscow, Medicine, 1999) is presented. Data of longevity full-scale investigations during nuclear explosions on the Semipalatinsk test site are given. Classified, complex investigations into the effect of nuclear fission products mixtures on different kinds of laboratory animals are described, transfer of radiobiological researches to organism of man is scientific valid. The most complicate radiobiological problem of low dose is analyzed. The being investigated monograph contains unique scientific information and makes a heavy contribution in radiobiology [ru

  14. Coupling of mass and charge distributions for low excited nuclear fission

    International Nuclear Information System (INIS)

    Salamatin, V.S.; )

    2000-01-01

    The simple model for calculation of charge distributions of fission fragments for low exited nuclear fission from experimental mass distributions is offered. The model contains two parameters, determining amplitude of even-odd effect of charge distributions and its dependence on excitation energy. Results for reactions 233 U(n th ,f), 235 U(n th ,f), 229 Th(n th ,f), 249 Cf(n th ,f) are spent [ru

  15. Lise meitner and her contribution to the discovery of nuclear fission

    International Nuclear Information System (INIS)

    Dai Hongyi; Wang Shangwu

    1999-01-01

    Lise Meitner, a famous nuclear physicist in both theory and experiment, played a unique role and made outstanding contributions in the course of the discovery of nuclear fission reviewed. However, due to a variety of reasons, her great contributions were not recognized during her time

  16. On-line nuclear half life and spectroscopic measurements on mass-separated fission product nuclei

    International Nuclear Information System (INIS)

    McDonald, J.; Fogelberg, B.; Baecklin, A.

    1979-01-01

    A description is given of the methods and equipment employed for nuclear spectroscopy studies of short lived fission product nuclei at the OSIRIS ISOL facility in Studsvik, Sweden. Furthermore a table of new nuclear half-lives measured with this equipment is presented. (author)

  17. Effects of nuclear structure on quasi-fission

    International Nuclear Information System (INIS)

    Simenel, Cedric; Wakhle, Aditya; Hinde, D.J.; Rietz, R. du; Dasgupta, M.; Evers, M.; Lin, C.J.; Luong, D.H.; Avez, B.

    2012-01-01

    The quasi-fission mechanism hinders fusion of heavy systems because of a mass flow between the reactants, leading to a re-separation of more symmetric fragments in the exit channel. A good understanding of the competition between fusion and quasi-fission mechanisms is expected to be of great help to optimize the formation and study of heavy and superheavy nuclei. Quantum microscopic models, such as the time-dependent Hartree-Fock approach, allow for a treatment of all degrees of freedom associated to the dynamics of each nucleon. This provides a description of the complex reaction mechanisms, such as quasi-fission, with no parameter adjusted on reaction mechanisms. In particular, the role of the deformation and orientation of a heavy target, as well as the entrance channel magicity and isospin are investigated with theoretical and experimental approaches. (authors)

  18. Estimates of fission yields in nuclear criticality excursions

    International Nuclear Information System (INIS)

    Choi, J.S.; Thompson, J.W.; Reed, R.

    1995-06-01

    There is a need for computer simulation of hypothetical criticality excursions involving significant quantities of fissionable materials, especially in fissile aqueous system. The need arises due to the requirements for the emergency planning of facilities where the fissionable materials are handled, processed, or stored; and the regulatory requirements associated with facility operation or conversion. It is proposed here that a data base of fission yeilds for critical experiments and known accidents (both aqueous and solid) should be generated by using existing or new computer codes. The success in compiling this data base would provide useful source-terms for criticality excursions, realistic estimates of emergency-response boundary, as well as a replacement for the ''rule-of-thumb'' or ''bounding'' method. 10 refs

  19. Argentine nuclear program

    International Nuclear Information System (INIS)

    Leibovich, H.; Takacs, E.A.

    1983-01-01

    The paper describes Argentina's nuclear program, detailing its objectives, the schedule of construction of nuclear plants and local production of required equipment. The technologies adopted so far, the local industrial and engineering participation, the preliminary study for the construction of the next power station and Argentina's nonproliferation nuclear policy are analyzed. Argentina's point of view on Canadian nonproliferation policy and CANDU reactor export is discussed

  20. Studies on the reaction mechanism of the muon induced nuclear fission

    International Nuclear Information System (INIS)

    Mutius, R. von.

    1985-01-01

    The mass and energy distribution of the fission fragments after muon induced nuclear fission allows the determination of the mean excitation energy of the fissioning nucleus after muon capture. By the systematic comparison with a mass distribution of a corresponding reaction for the first time for this an accuracy of about 1 MeV could be reached. Theoretical calculations on the excitation probability in the muon capture allow in connection with the fission probability an estimating calculation of this energy. The experimental result represents by this a test criterium for the valuation of the theoretical calculation. The measured probabilities for the occurrence of radiationless transitions in the muonic γ cascade of 237 Np permit an indirect experimental determination of the barrier enhancement which causes the muon present during the fission process. The value found for this extends to 0.75+-0.1 MeV. A change of the mass distribution by the muon cannot be detected in the nuclides 235 U, 237 Np, and 242 Pu studied here. Only the mean total kinetic energy of the fission products is reduced in these three nuclides in the prompt μ - induced fission by 1 to 2 MeV. For this result the incomplete screening of the nuclear charge during the fission process is made responsible. A mass dependence of this reduction has not been stated. Because the muon has appearently no influence on the mass splitting it can be valied as nearly ideal particle in order to study the hitherto little studied dynamics of the fission process. (orig.) [de

  1. Nuclear physics program plan

    International Nuclear Information System (INIS)

    1985-11-01

    The nuclear physics program objectives, resources, applications and implications of scientific opportunities are presented. The scope of projected research is discussed in conjunction with accelerator facilities and manpower. 25 figs., 2 tabs

  2. Iran's Nuclear Program: Status

    National Research Council Canada - National Science Library

    Kerr, Paul K

    2008-01-01

    .... Indeed, the UN Security Council has responded to Iran's refusal to suspend work on its uranium enrichment and heavy-water nuclear reactor programs by adopting several resolutions, most recently...

  3. Iran's Nuclear Program: Status

    National Research Council Canada - National Science Library

    Kerr, Paul K

    2008-01-01

    .... Indeed, the UN Security Council has responded to Iran's refusal to suspend work on its uranium enrichment and heavy-water nuclear reactor programs by adopting several resolutions which imposed sanctions on Tehran...

  4. Heavy cluster in cold nuclear rearrangements in fusion and fission

    International Nuclear Information System (INIS)

    Armbruster, P.

    1997-01-01

    The experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangements processes, as fusion and fission, is presented. Clusters in the sense as used in the following are strongly bound, doubly magic neutron rich nuclei as 48 Ca 28 , 78 Ni 50 , 132 Sn 82 , and 208 Pb 126 , the spherical nuclei Z=114 - 126 and N=184, and nuclei with closed shells N=28, 50, 82, and 126, and Z=28, 50, and 82. As with increasing nucleon numbers, the absolute shell corrections to the binding energies increase, the strongest effects are to be observed for the higher shells. The 132 cluster manifests itself in low energy fission (Faissner, H. and Wildermuth, K. Nucl. Phys., 58 (1964) 177). The 208 Pb cluster gave the new radioactivity (Rose, M.J. and Jones G.A., Nature, 307 (1984) 245) and the first superheavy elements (SHE) (Armbruster P., Ann. Rev. Nucl. Part. Sci., 35 (1985) 135-94; Munzenberg, G. Rep. Progr. Phys., 51 (1988) 57). The paper discuss experiments concerning the stability of clusters to intrinsic excitation energy in fusion and fission (Armbruster, P. Lect. Notes Phys., 158 (1982) 1). and the manifestation of clusters in the fusion entrance channel (Armbruster, P., J. Phys. Soc. Jpn., 58 (1989) 232). The importance of compactness of the clustering system seems to be equally decisive in fission and fusion. Finally, it s covered the importance of clusters for the production of SHEs)

  5. The discovery of nuclear fission and the responsibility of the scientist

    International Nuclear Information System (INIS)

    Staab, H.A.

    1989-01-01

    The history of the discovery of nuclear fission is placed in historical context and the responsibility of the scientists involved for the subsequent military uses is discussed. It is explained that the deep things in science are not found because they are useful; they are found because it is possible to find them. If Otto Hahn and his co-workers had not discovered nuclear fission someone else in the late 1930s or early 1940s would have done so. It was decisions outside science which set the course for the nuclear fission research once the basic principle had been understood. The question how far does the scientists responsibility extend for unknown and unintended consequences of research and for misuses of his findings by others is discussed. Scientists have a duty to understand the applications of their work and to warn of misuse or hazards, as did Otto Hahn. (UK)

  6. An alternative nuclear program

    International Nuclear Information System (INIS)

    Goldemberg, J.

    1981-01-01

    An analysis of the development of nuclear energy in Brazil is made since its beginning, showing the fundamental policy changes introduced in the end of the 60's with the purchase of the Angra dos Reis I reactor. This decision discouraged the existing efforts of an autonomous development in nuclear energy. The reaction to this policy led to the Nuclear Deal with Germany, which although incorporating some positive aspects is nor capable to lead to nuclear independence. The presently existing options are discussed, as well as the transformation of the Nuclear Program in a R and D Program based only in the reactors I, II and III, located in Angra dos Reis. (Author) [pt

  7. Alternative Nuclear Program

    International Nuclear Information System (INIS)

    Goldemberg, J.

    1982-01-01

    An analysis of the development of nuclear energy in Brazil is made since its beginning, showing the fundamental policy changes introduced in the end of the 60's with the purchase of the Angra dos Reis I reactor. This decision discouraged the existing efforts of an autonomous development in nuclear energy. The reaction to this policy led to the Nuclear Deal with Germany, which although incorporating some positive aspects is not capable to lead to nuclear independence. The presently existing options are discussed, as well as the transformation of the Nuclear Program in a R and D Program based only in the reactors I, II and III, located in Angra dos Reis. (Author) [pt

  8. The Commission's research action programme on the development of nuclear fission energy

    International Nuclear Information System (INIS)

    1984-01-01

    For its 'Framework Programme 1984-1987' the Commission has defined the major goals for a European Scientific and Technical Strategy. One of the means to reduce the energy dependence of the Community, which is an important objective, is to favour the development of nuclear fission energy. As electricity production by nuclear reactors has reached industrial maturity, the Community activities are directed mainly to safety aspects, in order to ensure the protection of workers and the general public, against hazards linked to operations in the nuclear fuel cycle. A description of the main features of the five sub-programmes on nuclear fission energy is given below; these programmes are: reactor safety; nuclear fuels and actinides research; management of radioactive waste; safeguarding and management of fissile materials; decommissioning of nuclear installations. The research and development work is carried out either by the Commission's Joint Research Center or by organizations and companies of the Member Countries, with the Commission's financial support. (author)

  9. Fission nuclear power prospects and its role in meeting global energy needs

    International Nuclear Information System (INIS)

    Golan, S.

    1992-01-01

    Nuclear power currently makes an important contribution to world's energy requirements providing 17% of its electricity. But as global warming becomes of greater concern, many ask whether nuclear power can and should contribute more. The author, who is involved in the nuclear power enterprise for 35 years, tries to answer this question affirmative. He holds the view that: a) nuclear fission power is essential to meeting world's energy needs without unduly impairing the global environment; b) by possessing the required attributes discussed in this paper, nuclear fission power can be made societally acceptable; c) the industrialized world should accelerate LMFR deployment while fostering more convenient energy alternatives for the developing world; and d) the HTGR is unique in its ability to augment non-electricity energy needs and could become the technology choice of developing countries for nuclear electricity production. (author). 5 refs., 5 figs., 4 tabs

  10. Preparation of a primary target for the production of fission products in a nuclear reactor

    International Nuclear Information System (INIS)

    Arino, H.; Cosolito, F.J.; George, K.D.; Thornton, A.K.

    1976-01-01

    A primary target for the production of fission products in a nuclear reactor, such as uranium or plutonium fission products, is comprised of an enclosed, cylindrical vessel, preferably comprised of stainless steel, having a thin, continuous, uniform layer of fissionable material, integrally bonded to its inner walls and a port permitting access to the interior of the vessel. A process is also provided for depositing uranium material on to the inner walls of the vessel. Upon irradiation of the target with neutrons from a nuclear reactor, radioactive fission products, such as molybdenum-99, are formed, and thereafter separated from the target by the introduction of an acidic solution through the port to dissolve the irradiated inner layer. The irradiation and dissolution are thus effected in the same vessel without the necessity of transferring the fissionable material and fission products to a separate chemical reactor. Subsequently, the desired isotopes are extracted and purified. Molybdenum-99 decays to technetium-99m which is a valuable medical diagnostic radioisotope. 3 claims, 1 drawing figure

  11. Qualitative and quantitative characteristics of fission products in spent nuclear fuel from RBMK-type reactor

    International Nuclear Information System (INIS)

    Adlys, G.; Adliene, D.

    2002-01-01

    Well-known empirical models or experimental instruments and methods for the estimation of fission product yields do not allow prediction of the behavior and evaluation of the time-dependent qualitative and quantitative characteristics of all fission products in spent nuclear fuel during long-term storage. Several computer codes were developed in different countries to solve this problem. French codes APOLLO1 and PEPIN were used in this work for modeling the characteristics of spent nuclear fuel in the RBMK reactor. The modeling results of qualitative and quantitative characteristics of long-lived fission products for different cooling periods of spent nuclear fuel, including 50-year cooling period, are presented in this paper. The 50-year cooling period conforms to the foreseen time of storage of spent nuclear fuel in CONSTOR and CASTOR casks at the Ignalina NPP. These results correlate well with evaluated quantities for the well-known yields of the nuclides and could be used for the compilation of the database for long-lived fission products in spent nuclear fuel from the RBMK-type reactor. They allow one to predict and to solve effectively safety problems concerning with long-term spent nuclear fuel storage in casks. (author)

  12. Nuclear fission energy: the international scene and the outlook for Italy

    International Nuclear Information System (INIS)

    Monti, S.

    2008-01-01

    Because of concerns about the environment, energy security and energy costs, fission nuclear energy is gaining ground again around the world. In Italy, the research community can help relaunch the national nuclear programmes by providing advanced training, recruiting young engineers and researchers for RD activities, and furthering an immediate cooperation of the Italian system in the principal European and international projects on sustainable nuclear energy [it

  13. BTC the UK focus for nuclear fission R and D in the post NDA era

    International Nuclear Information System (INIS)

    Rice, T.G.; Carpenter, J.C.; Williamson, R.

    2005-01-01

    The BNFL Technology Centre at Sellafield, UK, will provide the focal point for nuclear fission R and D in the UK for the 21th Century. The facility provides a range of non-active, trace active, plutonium active and high active facilities enabling NSTS to support the Nuclear Decommissioning Authority's remit to manage the UK's nuclear legacy and other requirements The facilities also provide an environment for academic research and foster the development of University Research Alliances. (Author)

  14. Detection of fission fragments using thick samples in contact with solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Lima, D.A. de; Martins, J.B.; Tavares, O.A.P.

    1987-01-01

    Whenever use is made of thick samples in contact with solid state nuclear track detectors for determining fission yields, one of the fundamental problems is the evaluation of the effective number of target nuclei which contributes to the fraction of the number of fission events that will be recorded. The evaluation of the effective number of target nuclei which contributes to recorded events is based on the effective thickness of the sample. A method for evaluating effective thickness of thick samples for binary fission modes, is presented. A cross section equation which takes into account all the necessary corrections due to fragment attenuation effects by a thick target for calculation induced fission yields, was obtained. (Author) [pt

  15. An Inconvenient History: the Nuclear-Fission Display in the Deutsches Museum

    Science.gov (United States)

    Sime, Ruth Lewin

    2010-06-01

    One of the longstanding attractions of the Deutsches Museum in Munich, Germany, has been its display of the apparatus associated with the discovery of nuclear fission. Although the discovery involved three scientists, Otto Hahn, Lise Meitner, and Fritz Strassmann, the fission display was designated for over 30 years as the Arbeitstisch von Otto Hahn (Otto Hahn’s Worktable), with Strassmann mentioned peripherally and Meitner not at all, and it was not until the early 1990s that the display was revised to include all three codiscoverers more equitably. I examine the creation of the fission display in the context of the postwar German culture of silencing the National Socialist past, and trace the eventual transformation of the display into a contemporary exhibit that more accurately represents the scientific history of the fission discovery.

  16. India's nuclear program

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    India made an early commitment to being as self-sufficient as possible in nuclear energy and has largely achieved that goal. The country operates eight nuclear reactors with a total capacity of 1,304 MWe, and it remains committed to an aggressive growth plan for its nuclear industry, with six reactors currently under construction, and as many as twelve more planned. India also operates several heavy water production facilities, fabrication facilities, reprocessing works, and uranium mines and mills. Due to India's decision not to sign the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the country has had to develop nearly all of its nuclear industry and infrastructure domestically. Overall, India's nuclear power program is self-contained and well integrated, with plans to expand to provide up to ten percent of the country's electrical generating capacity

  17. Transfer parameters of fission and activation products present in effluents of nuclear power reactors

    International Nuclear Information System (INIS)

    Cancio, D.; Menossi, C.A.; Ciallella, N.R.

    1978-01-01

    The paper presents results of research carried out in Argentina on transfer parameters of fission and activation products which may be present in the effluents of nuclear power reactors. For some nuclides, as Sr-90, Co-137 and I-131, the parameters were obtained by studies of the fallout, from measurements of integrated levels in the environment and in the food chains. Other values are concentration factors derived from laboratory and field experiments. They refer to fish, molluscs, crustaces and fresh water plants, for several fission and activation nuclides. Transfer parameters obtained have been of significant importance for environmental assessments, relating to nuclear installations in Argentina. (author)

  18. Romanian nuclear fuel program

    International Nuclear Information System (INIS)

    Budan, O.

    1999-01-01

    The paper presents and comments the policy adopted in Romania for the production of CANDU-6 nuclear fuel before and after 1990. The CANDU-6 nuclear fuel manufacturing started in Romania in December 1983. Neither AECL nor any Canadian nuclear fuel manufacturer were involved in the Romanian industrial nuclear fuel production before 1990. After January 1990, the new created Romanian Electricity Authority (RENEL) assumed the responsibility for the Romanian Nuclear Power Program. It was RENEL's decision to stop, in June 1990, the nuclear fuel production at the Institute for Nuclear Power Reactors (IRNE) Pitesti. This decision was justified by the Canadian specialists team findings, revealed during a general, but well enough technically founded analysis performed at IRNE in the spring of 1990. All fuel manufactured before June 1990 was quarantined as it was considered of suspect quality. By that time more than 31,000 fuel bundles had already been manufactured. This fuel was stored for subsequent assessment. The paper explains the reasons which provoked this decision. The paper also presents the strategy adopted by RENEL after 1990 regarding the Romanian Nuclear Fuel Program. After a complex program done by Romanian and Canadian partners, in November 1994, AECL issued a temporary certification for the Romanian nuclear fuel plant. During the demonstration manufacturing run, as an essential milestone for the qualification of the Romanian fuel supplier for CANDU-6 reactors, 202 fuel bundles were produced. Of these fuel bundles, 66 were part of the Cernavoda NGS Unit 1 first fuel load (the balance was supplied by Zircatec Precision Industries Inc. ZPI). The industrial nuclear fuel fabrication re-started in Romania in January 1995 under AECL's periodical monitoring. In December 1995, AECL issued a permanent certificate, stating the Romanian nuclear fuel plant as a qualified and authorised CANDU-6 fuel supplier. The re-loading of the Cernavoda NGS Unit 1 started in the middle

  19. Nuclear criticality safety basics for personnel working with nuclear fissionable materials. Phase I

    International Nuclear Information System (INIS)

    Vausher, A.L.

    1984-10-01

    DOE order 5480.1A, Chapter V, ''Safety of Nuclear Facilities,'' establishes safety procedures and requirements for DOE nuclear facilities. The ''Nuclear Criticality Safety Basic Program - Phase I'' is documented in this report. The revised program has been developed to clearly illustrate the concept of nuclear safety and to help the individual employee incorporate safe behavior in his daily work performance. Because of this, the subject of safety has been approached through its three fundamentals: scientific basis, engineering criteria, and administrative controls. Only basics of these three elements were presented. 5 refs

  20. Role of deformed shell effects on the mass asymmetry in nuclear fission of mercury isotopes

    International Nuclear Information System (INIS)

    Panebianco, Stefano; Sida, Jean-Luc; Goutte, Heloise; Lemaitre, Jean-Francois; Dubray, Noel; Hilaire, Stephane

    2012-01-01

    Until now, the mass asymmetry in the nuclear fission process has been understood in terms of the strong influence of the nuclear structure of the nascent fragments. Recently, a surprising asymmetric fission has been discovered in the light mercury region and has been interpreted as the result of the influence of the nuclear structure of the parent nucleus, totally discarding the influence of the fragments' structure. To assess the role of the fragment shell effects in the mass asymmetry in this particular region, a scission-point model, based on a full energy balance between the two nascent fragments, has been developed using one of the best theoretical descriptions of microscopic nuclear structure. As for actinides, this approach shows that the asymmetric splitting of the Hg-180 nucleus and the symmetric one of Hg-198 can be understood on the basis of only the microscopic nuclear structure of the fragments at scission. (authors)

  1. Microscopic Theory of Fission

    International Nuclear Information System (INIS)

    Younes, W; Gogny, D

    2008-01-01

    In recent years, the microscopic method has been applied to the notoriously difficult problem of nuclear fission with unprecedented success. In this paper, we discuss some of the achievements and promise of the microscopic method, as embodied in the Hartree-Fock method using the Gogny finite-range effective interaction, and beyond-mean-field extensions to the theory. The nascent program to describe induced fission observables using this approach at the Lawrence Livermore National Laboratory is presented

  2. Fission yeast cells undergo nuclear division in the absence of spindle microtubules.

    Directory of Open Access Journals (Sweden)

    Stefania Castagnetti

    2010-10-01

    Full Text Available Mitosis in eukaryotic cells employs spindle microtubules to drive accurate chromosome segregation at cell division. Cells lacking spindle microtubules arrest in mitosis due to a spindle checkpoint that delays mitotic progression until all chromosomes have achieved stable bipolar attachment to spindle microtubules. In fission yeast, mitosis occurs within an intact nuclear membrane with the mitotic spindle elongating between the spindle pole bodies. We show here that in fission yeast interference with mitotic spindle formation delays mitosis only briefly and cells proceed to an unusual nuclear division process we term nuclear fission, during which cells perform some chromosome segregation and efficiently enter S-phase of the next cell cycle. Nuclear fission is blocked if spindle pole body maturation or sister chromatid separation cannot take place or if actin polymerization is inhibited. We suggest that this process exhibits vestiges of a primitive nuclear division process independent of spindle microtubules, possibly reflecting an evolutionary intermediate state between bacterial and Archeal chromosome segregation where the nucleoid divides without a spindle and a microtubule spindle-based eukaryotic mitosis.

  3. Mechanism of nuclear dissipation in fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1986-01-01

    Recent advances in the theoretical understanding of nuclear dissipation at intermediate excitation energies are reviewed, with particular emphasis on a new surface-plus-window mechanism that involves interactions of either one or two nucleons with the moving nuclear surface and also, for dumbbell-like shapes encountered in fission and heavy-ion reactions, the transfer of nucleons through the window separating the two portions of the system. This novel dissipation mechanism provides a unified macroscopic description of such diverse phenomena as widths of isoscalar giant quadrupole and giant octupole resonances, mean fission-fragment kinetic energies and excitation energies, dynamical thresholds for compound-nucleus formation, enhancement in neutron emission prior to fission, and widths of mass and charge distributions in deep-inelastic heavy-ion reactions. 41 refs., 8 figs

  4. Fission product yield data for the transmutation of minor actinide nuclear waste

    International Nuclear Information System (INIS)

    2008-04-01

    A report issued by an international study group for the transmutation of nuclear waste using accelerator driven systems has highlighted the need for specific sets of nuclear data. These authoritative requirements include fission product yields at an intermediate incident neutron energy of up to 150 MeV. Before the start of the present CRP on fission product yield data for the transmutation of nuclear waste, only four types of evaluated fission yield data sets existed, namely for spontaneous fission, and for fission induced by thermal, fast (or fission) spectrum, and by 'high energy' (14-15 MeV) neutrons. A new type of evaluation for energy dependent neutron induced fission yields was required for this project. In view of the scarcity of experimental data, such an evaluation has to be based on systematics and theoretical model calculations. Unlike fission cross-sections, where nuclear models are being used successfully for the calculation of unmeasured cross-section ranges, such models or theories existed only for low energy fission yields. Hence the CRP participants entered a completely new field of research for which the progress and outcome were unpredictable. Clearly the ultimate goal of such an effort, namely an evaluation of energy dependent fission yields, could not be realized within the perceived lifetime of a CRP. The main emphasis of the CRP was on the development of adequate systematics and models for the calculation of energy dependent fission yields up to 150 MeV incident neutron energy. Several problems had to be solved, such as the correct choice of model parameters and multiplicity distributions of emitted neutrons, and the effect of multi-chance fission. Models and systematics have been tested for lower energy yields, but they failed to reproduce recent experimental data, particularly at higher energies, and the parameters had to be modified. Other models have been developed from the analysis of experimental data in order to derive systematic

  5. The Chinese nuclear program

    International Nuclear Information System (INIS)

    Prenez, J.C.; Bettoun, G.

    2009-01-01

    This series of slides presents the organization of the Chinese nuclear industry and its perspectives for the 2 next decades. The presentation is divided into 5 parts. Part one: the energy sector in China. Due to the economic development of the country this sector is flourishing and reaches an average growth rate of 9% per year. More than fifty per cent of the power plants being built in the world, are located in China. The electricity production stems by far from fossil energies (>80%) but this part is expected to decrease to reach 70% in 2020. Part 2: the Chinese nuclear program. This program is dual: the massive deployment of chinese improved reactors of second generation (the construction of 6 CPR1000 reactors will be launched each year) and the import and assimilation of reactors of the third generation: 4 AP1000 and 2 EPR are being built. Part 3: the organization of the Chinese nuclear sector. The main actors are CNNC (China National Nuclear Corporation), CGNPC (China Guangdong Nuclear Power Corporation), CPI (China Power Investment Corporation), SNPTC (State Nuclear Power Technology Corporation). The main 5 Chinese suppliers are also presented. Part 4: The role of EDF. Today's EDF role is multiple: to be active in the Chinese nuclear program, to go beyond technical assistance to reach partnership, to invest in Chinese power plants, to promote cooperation between French and Chinese actors of the nuclear industry. A lot of joint ventures have been created. Part 5: the Taishan project. Taishan is a coastal site near Macao in the Guangdong province in which 2 EPR are being built, the first concrete was cast in october 2009, 52 months of construction are scheduled and the first unit will be commissioned in end 2013 while the second commissioning is planned for end 2014. (A.C.)

  6. Fission product inventory calculation by a CASMO/ORIGEN coupling program

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Heon; Kim, Jong Kyung [Hanyang University, Seoul (Korea, Republic of); Choi, Hang Bok; Roh, Gyu Hong; Jung, In Ha [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    A CASMO/ORIGEN coupling utility program was developed to predict the composition of all the fission products in spent PWR fuels. The coupling program reads the CASMO output file, modifies the ORIGEN cross section library and reconstructs the ORIGEN input file at each depletion step. In ORIGEN, the burnup equation is solved for actinides and fission products based on the fission reaction rates and depletion flux of CASMO. A sample calculation has been performed using a 14 x 14 PWR fuel assembly and the results are given in this paper. 3 refs., 1 fig., 1 tab. (Author)

  7. Fission product inventory calculation by a CASMO/ORIGEN coupling program

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Heon; Kim, Jong Kyung [Hanyang University, Seoul (Korea, Republic of); Choi, Hang Bok; Roh, Gyu Hong; Jung, In Ha [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A CASMO/ORIGEN coupling utility program was developed to predict the composition of all the fission products in spent PWR fuels. The coupling program reads the CASMO output file, modifies the ORIGEN cross section library and reconstructs the ORIGEN input file at each depletion step. In ORIGEN, the burnup equation is solved for actinides and fission products based on the fission reaction rates and depletion flux of CASMO. A sample calculation has been performed using a 14 x 14 PWR fuel assembly and the results are given in this paper. 3 refs., 1 fig., 1 tab. (Author)

  8. Uncertainty of decay heat calculations originating from errors in the nuclear data and the yields of individual fission products

    International Nuclear Information System (INIS)

    Rudstam, G.

    1979-01-01

    The calculation of the abundance pattern of the fission products with due account taken of feeding from the fission of 235 U, 238 U, and 239 Pu, from the decay of parent nuclei, from neutron capture, and from delayed-neutron emission is described. By means of the abundances and the average beta and gamma energies the decay heat in nuclear fuel is evaluated along with its error derived from the uncertainties of fission yields and nuclear properties of the inddividual fission products. (author)

  9. Spread of fission products after a nuclear melt-down accident

    International Nuclear Information System (INIS)

    Andriesse, C.D.; Tanke, R.H.J.

    1987-01-01

    In this article experimental investigation is described into the spread of fission products within a nuclear power plant, which after an accident involving melting of the nucleus, will be possible in spite of prohibiting constructions for the case of severe unbalancing of generated and carried-off energy. 6 refs.; 4 figs

  10. Nuclear data project in Korea and resonance parameter evaluation of fission products

    International Nuclear Information System (INIS)

    Chang, Jonghwa; Oh, Soo-Youl

    2000-01-01

    Nuclear data activities in the fields of evaluation, processing, measurement, and service in Korea are presented in this paper. As one of the current activities, the neutron resonance parameters for stable or long-lived nineteen fission products have been evaluated and the results are presented here. (author)

  11. Properties of neutron-rich nuclei studied by fission product nuclear chemistry

    International Nuclear Information System (INIS)

    Meyer, R.A.; Henry, E.A.; Griffin, H.C.; Lien, O.G. III; Lane, S.M.; Stevenson, P.C.; Yaffe, R.P.; Skarnemark, G.

    1979-09-01

    A review is given of the properties of neutron-rich nuclei studied by fission product nuclear chemistry and includes the techniques used in elemental isolation and current research on the structure of nuclei near 132 Sn, particle emission, and coexisting structure in both neutron-poor and neutron-rich nuclei. 35 references

  12. On the fissionable materials management system in the process of nuclear disarmament

    International Nuclear Information System (INIS)

    Vikharev, S.S.; Mikijchuk, N.B.; Pinaev, V.S.; Sudarushkin, I.S.; Yuferev, V.I.

    1994-01-01

    Various scenarios of nuclear weapons proliferation and goals of fissionable material accounting and control system (FMACS) are considered. Ways of improving FMACS in Russia under a complicated social situation are discussed. This improvement should follow two directions: introduction of non-destructive control methods and accounting and control process automation

  13. Nuclear program review

    International Nuclear Information System (INIS)

    Brito, S.; Rosa, L.P.; Carvalho, Joaquim de; Simon, D.N.

    1985-01-01

    A review of the Brazilian Nuclear Program based in Brazilian energy perspectives, in world-wide technology evolution and in international and national economic context is done. The objetive is look for subsidies for new decisions related to the future of program, taking in account the acquired experience and new data created by evolution of internal and external political and technological conjuncture. (M.C.K.) [pt

  14. Ontario Hydro's nuclear program

    International Nuclear Information System (INIS)

    Jackson, H.A.

    1982-06-01

    In 1981 Ontario Hydro generated over 100 billion KWh of electrical energy. Approximately one third of this was from nuclear units. There are ten CANDU units (5 250 MW) currently in operation, and another twelve (8 600 MW) are under construction. The presently committed nuclear expansion program is estimated to involve expenditures of 16 billion dollars over the next 10 years. About 10 000 people are employed in the nuclear design and construction program. All projects are generally on schedule, with the stations coming into service during the following time periods: Pickering B, 1983-85; Bruce B, 1984-87; Darlington, 1988-90. The status of each project is reviewed. Planning is underway for some retubing projects, as early as 1985 for Pickering A

  15. Japanese list of requests for neutron nuclear data for fission reactors

    International Nuclear Information System (INIS)

    Igarasi, Sin-iti; Asami, Tetsuo

    1977-05-01

    Requests for neutron nuclear data for fission reactors are presented. These are screened by a WRENDA Working Group of Japanese Nuclear Data Committee and submitted to WRENDA 76/77. This report includes 163 requests of which 55 requests are newly registered in the WRENDA. Three requests of the previous list are withdrawn. This activity is a part of the international cooperation with CCDN, NEANDC and INDC. (auth.)

  16. Nuclear isomerism in fission fragments produced by the spontaneous fission of {sup 252}Cf; Isomerisme nucleaire dans les fragments de fission produits dans la fission spontanee du {sup 252}Cf

    Energy Technology Data Exchange (ETDEWEB)

    Gautherin, C

    1997-09-01

    This thesis is devoted to the study of the nuclear structure of neutron-rich nuclei, via the search of isomeric nuclear states. Neutron-rich nuclei were produced in the spontaneous fission of {sup 252}Cf. The experimental study of isomeric states in these nuclei was performed with the {gamma}-array EUROGAM II, coupled to an additional and original fission fragment detector composed by photovoltaic cells, SAPhIR. The photovoltaic cells are well adapted to detect low energy heavy ions and have good energy and time resolutions to obtain a good fission fragment detection. This experiment led to the discovery of new isomeric states in {sup 135}Xe, {sup 104}Mo, {sup 146,147,148}Ce and {sup 152,154,156}Nd, with lifetimes between 60 ns and 2 {mu}s. Level schemes of these nuclei have been completed. An interpretation of the isomeric states in the nuclei {sup 154,156}Nd and {sup 156,158}Sm was performed by Hartree-Fock-Bogolyubov calculations using the DIS Gogny force with two quasi-particles excitations. The confrontation with the experimental results led to an interpretation of these isomeric states as K-isomers. (author)

  17. Scission-point model of nuclear fission based on deformed-shell effects

    International Nuclear Information System (INIS)

    Wilkins, B.D.; Steinberg, E.P.; Chasman, R.R.

    1976-01-01

    A static model of nuclear fission is proposed based on the assumption of statistical equilibrium among collective degrees of freedom at the scission point. The relative probabilities of formation of complementary fission fragment pairs are determined from the relative potential energies of a system of two nearly touching, coaxial spheroids with quadrupole deformations. The total potential energy of the system at the scission point is calculated as the sum of liquid-drop and shell- and pairing-correction terms for each spheroid, and Coulomb and nuclear potential terms describing the interaction between them. The fissioning system at the scission point is characterized by three parameters: the distance between the tips of the spheroids (d), the intrinsic excitation energy of the fragments (tau/sub int/), and a collective temperature (T/sub coll/). No attempt is made to adjust these parameters to give optimum fits to experimental data, but rather, a single choice of values for d, tau/sub int/, and T/sub coll/ is used in the calculations for all fissioning systems. The general trends of the distributions of mass, nuclear charge, and kinetic energy in the fission of a wide range of nuclides from Po to Fm are well reproduced in the calculations. The major influence of the deformed-shell corrections for neutrons is indicated and provides a convenient framework for the interpretation of observed trends in the data and for the prediction of new results. The scission-point configurations derived from the model provide an interpretation of the ''saw-tooth'' neutron emission curve as well as previously unexplained observations on the variation of TKE for isotopes of U, Pu, Cm, and Cf; structure in the width of total kinetic energy release as a function of fragment mass ratio; and a difference in threshold energies for symmetric and asymmetric mass splits in the fission of Ra and Ac isotopes

  18. New paths for nuclear fission; De nouvelles pistes pour la fission

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, B. [CEA Saclay, 91 - Gif sur Yvette (France)

    2007-01-15

    Future nuclear power plants will be different from present day ones because uranium resources are limited and not efficiently used by today's reactors. Several new reactor concepts have been examined by international experts in the framework of the generation 4 international forum. Five among the six reactor concepts retained concern FBR-type reactors which allow to efficiently convert {sup 238}U into plutonium which is continuously consumed and regenerated. One challenge concerns the development of high temperature and radiation resistant materials for reactors operating at higher temperature (> 600 deg. C) and offering new industrial applications of nuclear energy like hydrogen generation and seawater desalination. Another priority concerns the management of wastes, in particular the chemical separation of all actinides, including plutonium. A prototype of reactor of 4. generation is expected for 2020 before its industrial implementation by 2040. Short paper. (J.S.)

  19. The Fukushima nuclear disaster and its effects on media framing of fission and fusion energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Luisa; Horta, Ana; Pereira, Sergio; Delicado, Ana [Institute of Social Sciences of the University of Lisbon, Av. Prof. Anibal de Bettencourt, 9 1600-189 Lisbon (Portugal)

    2015-07-01

    This paper presents results of a comparison of media coverage of fusion and fission energy technologies in three countries (Germany, Spain and Portugal) and in the English language international print media addressing transnational elite, from 2008 to 2012. The analysis showed that the accident in Fukushima in March 2010 did not have significant impact on media framing of nuclear fusion in the major part of print media under investigation. In fact, fusion is clearly dissociated from traditional nuclear (fission) energy and from nuclear accidents. It tends to be portrayed as a safe, clean and unlimited source of energy, although less credited when confronted with research costs, technological feasibility and the possibility to be achieved in a reasonable period of time. On the contrary, fission is portrayed as a hazardous source of energy, expensive when compared to research costs of renewables, hardly a long-term energy option, susceptible to contribute to the proliferation of nuclear weapons or rogue military use. Fukushima accident was consistently discussed in the context of safety problems of nuclear power plants and in many cases appeared not as an isolated event but rather as a reminder of previous nuclear disasters such as Three Miles Island and Chernobyl. (authors)

  20. The Fukushima nuclear disaster and its effects on media framing of fission and fusion energy technologies

    International Nuclear Information System (INIS)

    Schmidt, Luisa; Horta, Ana; Pereira, Sergio; Delicado, Ana

    2015-01-01

    This paper presents results of a comparison of media coverage of fusion and fission energy technologies in three countries (Germany, Spain and Portugal) and in the English language international print media addressing transnational elite, from 2008 to 2012. The analysis showed that the accident in Fukushima in March 2010 did not have significant impact on media framing of nuclear fusion in the major part of print media under investigation. In fact, fusion is clearly dissociated from traditional nuclear (fission) energy and from nuclear accidents. It tends to be portrayed as a safe, clean and unlimited source of energy, although less credited when confronted with research costs, technological feasibility and the possibility to be achieved in a reasonable period of time. On the contrary, fission is portrayed as a hazardous source of energy, expensive when compared to research costs of renewables, hardly a long-term energy option, susceptible to contribute to the proliferation of nuclear weapons or rogue military use. Fukushima accident was consistently discussed in the context of safety problems of nuclear power plants and in many cases appeared not as an isolated event but rather as a reminder of previous nuclear disasters such as Three Miles Island and Chernobyl. (authors)

  1. TMI-2 [Three Mile Island] fission product inventory program: FY-85 status report

    International Nuclear Information System (INIS)

    Langer, S.; Croney, S.T.; Akers, D.W.; Russell, M.L.

    1986-11-01

    This report presents the status of the TMI-2 fission product inventory program through May 1985. The fission product inventory program is an assessment of the location of fission products distributed in the plant as a result of the TMI-2 accident. Included in this report are principal results of samples from the reactor building where most of the mobile fission products (i.e., radiocesium and iodine) are expected to be found. The data are now complete enough for most reactor components; therefore, it is possible to direct the balance of the examination and sampling program to areas and components where it is likely to be most productive. Those areas are the reactor core and the reactor building basement, with emphasis on the currently unsampled portions of the core

  2. Proceedings of the specialists' meeting on interdisciplinary approach to nuclear fission 1998

    International Nuclear Information System (INIS)

    Nakagome, Yoshihiro

    1999-02-01

    One of the prominent features of nuclear fission phenomena distinguished from other reactions consists in its many-facet nature. This includes interesting problems in nuclear physics like stability and properties of transactinide and superheavy nuclei, macroscopic and microscopic effects in large-amplitude deformation process, partition of mass and energy at scission, formation of neutron-rich nuclei, neutron- and gamma-ray emission from highly excited states and so on. These aspects are intriguing not only from scientific point of view but also from technological one, because knowledge and understanding of the essential features of the phenomena forms the basis of application of nuclear energy. Physicists expect to obtain a deeper insight into fundamental problems in subjects such as relation between fission process and fusion of heavy-ions, statistical and dynamical processes in nuclear reactions, level structure and decay modes of highly-excited nuclei. On the other hand, there are still continued requests from scientists in nuclear engineering for more accurate data for transuranium nuclei and fission products, as well as for fundamental constants, like fission cross sections, multiplicity and spectra of prompt and delayed neutrons, and other physical quantities that are important in reactor physics. Studies on properties of neutron-rich nuclei are conducted under double interests: one from nucleosynthesis in the universe, another from nuclear incineration of fission products. We considered that these many-facet nature of the fission phenomena should be the central idea of the Specialists' Meeting itself. This implies that we intended to devise a common place where people from different fields encounter, discuss together, exchange ideas and hopefully find good suggestions for pursuing further studies. We are sure that such a meeting, really rare and unique in academic communities in our country, should serve to vitalize research activities relevant to fission

  3. Measurement of delayed neutron-emitting fission products in nuclear reactor coolant water during reactor operation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The method covers the detection and measurement of delayed neutron-emitting fission products contained in nuclear reactor coolant water while the reactor is operating. The method is limited to the measurement of the delayed neutron-emitting bromine isotope of mass 87 and the delayed neutron-emitting iodine isotope of mass 137. The other delayed neutron-emitting fission products cannot be accurately distinguished from nitrogen 17, which is formed under some reactor conditions by neutron irradiation of the coolant water molecules. The method includes a description of significance, measurement variables, interferences, apparatus, sampling, calibration, standardization, sample measurement procedures, system efficiency determination, calculations, and precision

  4. Nuclear dissipation effects on fission and evaporation in systems of intermediate fissility

    Directory of Open Access Journals (Sweden)

    Gelli N.

    2010-03-01

    Full Text Available The systems of intermediate fissility 132Ce and 158Er have been studied experimentally and theoretically in order to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation residues channels together with charged particles multiplicities in both channels, their spectra, angular correlations and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using multi-dimensional stochastic approach with realistic treatment of particle evaporation. The results of analysis show that full one-body or unusually strong two-body dissipation allows to reproduce experimental data. No temperature dependent dissipation was needed.

  5. A brief history of the Delayed'' discovery of nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Holden, N.E.

    1989-08-01

    This year marks the Fiftieth Anniversary of the discovery of Nuclear Fission. In the early 1930's, the neutron was discovered, followed by the discovery of artificial radioactivity and then the use of the neutron to produce artificial radioactivity. The first experiments resulting in the fission of uranium took place in 1934. A paper which speculated on fission as an explanation was almost immediately published, yet no one took it seriously not even the author herself. Why did it take an additional five years before anyone realized what had occurred This is an abnormally long time in a period when discoveries, particularly in nuclear physics, seemed to be almost a daily occurrence. The events which led up to the discovery are recounted, with an attempt made to put them into their historical perspective. The role played by Mendeleev's Periodic Table, the role of the natural radioactive decay chain of uranium, the discovery of protactinium, the apparent discovery of masurium (technetium) and a speculation on the reason why Irene Curie may have missed the discovery of nuclear fission will all be discussed. 43 refs.

  6. Distribution of nuclear charge in the proton-induced fission of Th-232

    Energy Technology Data Exchange (ETDEWEB)

    Pate, B D [Brookhaven National Laboratory, Upton, New York (United States); Foster, J S; Yaffe, L [McGill Univ., Montreal, Quebec (Canada)

    1958-09-15

    A great deal of work has been done on the distribution of nuclear mass in the fission process. About the nuclear charge distribution less is known. Data exist on the distribution from the fission of U-235 with thermal neutrons and with 14 Mev neutrons. Data also exist for the fission of uranium by 170 Mev protons, of bismuth by 190 Mev deuterons, and of uranium, thorium and bismuth by 480 Mev protons, and there is fragmentary information from other systems. The present work was undertaken to investigate the changes that occur in the charge distribution from proton-induced fission of Th-232 as the bombarding energy is raised from 8 to 90 Mev, the maximum proton energy of the McGill synchrocyclotron. This energy range is of interest in view of the substantial changes observed in the mass distribution. Also in this interval a change presumably begins in the nature of the initial step in nuclear reactions, from simple compound-nucleus formation, to a mechanism of direct interaction with individual nucleons. Thus at the lower energies studied, excitation of the nuclei at the end of the first step of the reaction will be essentially monochromatic whereas at the higher end of the bombarding-energy range, a broad spectrum of excitation energies will be produced, with corresponding complexity of the reaction products observed. (author)

  7. Applications: fission, nuclear reactors. Fission: the various ways for reactors and cycles

    International Nuclear Information System (INIS)

    Bacher, P.

    1997-01-01

    A historical review is presented concerning the various nuclear reactor systems developed in France by the CEA: the UNGG (graphite-gas) system with higher CO 2 pressures, bigger fuel assemblies and powers higher than 500 MW e, allowed by studies on reactor physics, cladding material developments and reactor optimization; the fast neutron reactor system, following the graphite-gas development, led to the Superphenix reactor and important progress in simulation based on experiment and return of experience; and the PWR system, based on the american license, which has been successfully accommodated to the french industry and generates up to 75% of the electric power in France

  8. Non Nuclear Testing of Reactor Systems In The Early Flight Fission Test Facilities (EFF-TF)

    International Nuclear Information System (INIS)

    Van Dyke, Melissa; Martin, James

    2004-01-01

    The Early Flight Fission-Test Facility (EFF-TF) can assist in the design and development of systems through highly effective non-nuclear testing of nuclear systems when technical issues associated with near-term space fission systems are 'non-nuclear' in nature (e.g. system's nuclear operations are understood). For many systems, thermal simulators can be used to closely mimic fission heat deposition. Axial power profile, radial power profile, and fuel pin thermal conductivity can be matched. In addition to component and subsystem testing, operational and lifetime issues associated with the steady state and transient performance of the integrated reactor module can be investigated. Instrumentation at the EFF-TF allows accurate measurement of temperature, pressure, strain, and bulk core deformation (useful for accurately simulating nuclear behavior). Ongoing research at the EFF-TF is geared towards facilitating research, development, system integration, and system utilization via cooperative efforts with DOE laboratories, industry, universities, and other Nasa centers. This paper describes the current efforts for the latter portion of 2003 and beginning of 2004. (authors)

  9. Fission product release from nuclear fuel I. Physical modelling in the ASTEC code

    International Nuclear Information System (INIS)

    Brillant, G.; Marchetto, C.; Plumecocq, W.

    2013-01-01

    Highlights: • Physical modeling of FP and SM release in ASTEC is presented. • The release is described as solid state diffusion within fuel for high volatile FP. • The release is described as FP vaporisation for semi volatile FP. • The release is described as fuel vaporisation for low volatile FP. • ASTEC validation is presented in the second paper. - Abstract: This article is the first of a series of two articles dedicated to the mechanisms of fission product release from a degraded core as they are modelled in the ASTEC code. The ASTEC code aims at simulating severe accidents in nuclear reactors from the initiating event up to the radiological consequences on the environment. This code is used for several applications such as nuclear plant safety evaluation including probabilistic studies and emergency preparedness. To cope with the requirements of robustness and low calculation time, the code is based on a semi-empirical approach and only the main limiting phenomena that govern the release from intact rods and from debris beds are considered. For solid fuel, fission products are classified into three groups, depending on their degree of volatility. The kinetics of volatile fission products release depend on the rate-limiting process of solid-state diffusion through fuel grains. For semi-volatile fission products, the release from the open fuel porosities is assumed to be governed by vaporisation and mass transfer processes. The key phenomenon for the release of low volatile fission products is supposed to be fuel volatilisation. A similar approach is used for the release of fission products from a rubble bed. An in-depth validation of the code including both analytical and integral experiments is the subject of the second article

  10. Reference and standard benchmark field consensus fission yields for U.S. reactor dosimetry programs

    International Nuclear Information System (INIS)

    Gilliam, D.M.; Helmer, R.G.; Greenwood, R.C.; Rogers, J.W.; Heinrich, R.R.; Popek, R.J.; Kellogg, L.S.; Lippincott, E.P.; Hansen, G.E.; Zimmer, W.H.

    1977-01-01

    Measured fission product yields are reported for three benchmark neutron fields--the BIG-10 fast critical assembly at Los Alamos, the CFRMF fast neutron cavity at INEL, and the thermal column of the NBS Research Reactor. These measurements were carried out by participants in the Interlaboratory LMFBR Reaction Rates (ILRR) program. Fission product generation rates were determined by post-irradiation analysis of gamma-ray emission from fission activation foils. The gamma counting was performed by Ge(Li) spectrometry at INEL, ANL, and HEDL; the sample sent to INEL was also analyzed by NaI(Tl) spectrometry for Ba-140 content. The fission rates were determined by means of the NBS Double Fission Ionization Chamber using thin deposits of each of the fissionable isotopes. Four fissionable isotopes were included in the fast neutron field measurements; these were U-235, U-238, Pu-239, and Np-237. Only U-235 was included in the thermal neutron yield measurements. For the fast neutron fields, consensus yields were determined for three fission product isotopes--Zr-95, Ru-103, and Ba-140. For these fission product isotopes, a separately activated foil was analyzed by each of the three gamma counting laboratories. The experimental standard deviation of the three independent results was typically +- 1.5%. For the thermal neutron field, a consensus value for the Cs-137 yield was also obtained. Subsidiary fission yields are also reported for other isotopes which were studied less intensively (usually by only one of the participating laboratories). Comparisons with EBR-II fast reactor yields from destructive analysis and with ENDF/B recommended values are given

  11. Disposition of plutonium from dismantled nuclear weapons: Fission options and comparisons

    International Nuclear Information System (INIS)

    Omberg, R.P.; Walter, C.E.

    1993-01-01

    Over the next decade, the United States expects to recover about 50 Mg of excess weapon plutonium and the Republic of Russia expects to recover a similar amount. Ensuring that these large quantities of high-grade material are not reused in nuclear weapons has drawn considerable attention. In response to this problem, the US Department of Energy (DOE) chartered the Plutonium Disposition Task Force (PDTF), in the summer of 1992, to assess a range of practical means for disposition of excess US plutonium. This report summarizes and compares the ''Fission Options'' provided to the Fission Working Group Review Committee (the committee) of the PDTF. The review by the committee was based on preliminary information received as of December 4, 1992, and as such the results summarized in this report should also be considered preliminary. The committee concluded that irradiation of excess weapon plutonium in fission reactors in conjunction with the generation of electricity and storing the spent fuel is a fast, cost-effective, and environmentally acceptable method of addressing the safeguards (diversion) issue. When applied appropriately, this method is consistent with current nonproliferation policy. The principal effect of implementing the fission options is at most a moderate addition of plutonium to that existing in commercial spent fuel. The amount of plutonium in commercial spent fuel by the year 2000 is estimated to be 300 Mg. The addition of 50 Mg of excess weapon plutonium, in this context, is not a determining factor, moreover, several of the fission options achieve substantial annihilation of plutonium

  12. A View on the Future of Nuclear Fission Energy

    International Nuclear Information System (INIS)

    Knapp, Vladimir; Pevec, Dubravko

    2014-01-01

    Recent publications discussing the role of nuclear energy in contributing to carbon emission reduction take different approaches and reach very different conclusions. For the pessimistic approach the nuclear contribution in the year 2050 would be on the unimportant level of 8 EJ/year, whilst the optimistic approach with early introduction of fast breeders sees the nuclear contribution in 2060 on the level 144 EJ/year with massive build-up of breeder reactors in the years 2030-2060, reaching the nuclear capacity of 5372 GW in the year 2060. We do not find the optimistic strategy acceptable from political, safety and technical grounds. We show instead that a technologically more conservative nuclear build-up in the years 2025-2065 with proven conventional reactors using once through fuel cycle without fuel reprocessing could reach 3300 GW on the uranium resources as known in 2008. With this concept nuclear contribution of 94 EJ/year would be reached by 2065, many times more than the pessimistic estimate, while integral CO2 emission savings would be about 500 GtCO2. This shows that essential nuclear contributions is possible without the use of plutonium and fast breeders, technology not ready for climate-critical next 50 years and not acceptable in present political environment. (author)

  13. Fission and nuclear fragmentation of silver and bromine nuclei by photons of 1-6 GeV

    International Nuclear Information System (INIS)

    Pinheiro Filho, J.D.

    1983-01-01

    The studies of fission and fragmentation of silver and bromine nuclei by Bremsstrahlung photons of 1.6 GeV energy range are presented. The Il ford-KO nuclear emulsion submitted to Bremsstrahlung beams in Deutsches Elektronen Synchrotron (DESY) with total doses of 10'' equivalent photons, was used for nuclear fragment detection. The discrimination of fission and fragmentation events was done analysing angular distribution, range and angles between fragments. The results of fragment range distributions, angular distributions, distributions of angles between fragments, distributions of ratio between range, velocity distributions forward/backward ratio, cross sections of fission and fragmentation, nuclear fissionability and ternary fission frequency are presented and discussed. (M.C.K.)

  14. Fission yeast mating-type switching: programmed damage and repair

    DEFF Research Database (Denmark)

    Egel, Richard

    2005-01-01

    Mating-type switching in fission yeast follows similar rules as in budding yeast, but the underlying mechanisms are entirely different. Whilst the initiating double-strand cut in Saccharomyces cerevisiae requires recombinational repair for survival, the initial damage in Schizosaccharomyces pombe...

  15. 1: the atom. 2: radioactivity. 3: man and radiations. 4: the energy. 5: nuclear energy: fusion and fission. 6: the operation of a nuclear reactor. 7: the nuclear fuel cycle

    International Nuclear Information System (INIS)

    2002-01-01

    This series of 7 digest booklets present the bases of the nuclear physics and of the nuclear energy: 1 - the atom (structure of matter, chemical elements and isotopes, the four fundamental interactions, nuclear physics); 2 - radioactivity (definition, origins of radioelements, applications of radioactivity); 3 - man and radiations (radiations diversity, biological effects, radioprotection, examples of radiation applications); 4 - energy (energy states, different forms of energy, characteristics); 5 - nuclear energy: fusion and fission (nuclear energy release, thermonuclear fusion, nuclear fission and chain reaction); 6 - operation of a nuclear reactor (nuclear fission, reactor components, reactor types); 7 - nuclear fuel cycle (nuclear fuel preparation, fuel consumption, reprocessing, wastes management). (J.S.)

  16. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    Science.gov (United States)

    Norman, Eric B [Oakland, CA; Prussin, Stanley G [Kensington, CA

    2009-01-27

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  17. Overview of beneficial uses of nuclear fission products

    International Nuclear Information System (INIS)

    Sivinski, J.S.

    1980-01-01

    Recoverable or reprocessed nuclear wastes as conservable resources with significant potential benefits for use as heat sources, or as radiation sources for industrial, agricultural, and medical applications are reviewed

  18. Highlighted requests of neutron nuclear data measurements for fission reactors

    International Nuclear Information System (INIS)

    1977-01-01

    Highlighted requests were selected from lists of requests for neutron nuclear Data measurements. This work was made by WRENDA Working Group of Japanese Nuclear Data Committee in response to an action of the NEANDC. This will be submitted to a NEA meeting on request lists. Compiled requests in this note correspond finally to the parts of the WRENDA 76/77 with some modifications and additional comments. (auth.)

  19. Transport and release of fission products during nuclear reactor accident

    International Nuclear Information System (INIS)

    Lee, K.W.; Kuhlman, M.R.; Gieseke, J.A.

    1984-01-01

    This study represents the identification and formulation of a systematic, mechanistic approach to estimating source terms and the implementation of this approach through calculations of fission products release to the environment for a large PWR reactor under a selected set of accident conditions. The development and improvement of calculational procedures is an evolutionary process and in the long term must be verified through experimental studies. It is anticipated that as additional information is obtained the accuracy of predictions can be improved and uncertainties reduced. Transport and deposition of radionuclides were found to be quite dependent on the accident sequences and the corresponding thremal hydraulic conditions. Reduced temperatures led to increased deposition of vapor species, and reduced flow rates to increased aerosol deposition. It is to be recognized that the estimates of release fractions are subject to uncertainties in the data and computer models employed in the calculations and are expected to have been influenced by assumptions regarding plant geometry, thermal hydraulics, deposition mechanisms, and sequence events. The effects of these assumptions will be investigated as this study continues. (Author)

  20. New prompt fission gamma-ray spectral data from 239Pu(nth, f in response to a high priority request from OECD Nuclear Energy Agency

    Directory of Open Access Journals (Sweden)

    Gatera Angélique

    2017-01-01

    Full Text Available Benchmark reactor calculations have revealed an underestimation of γ-heat following fission of up to 28%. To improve the modelling of new nuclear reactors, the OECD/NEA initiated a nuclear data High Priority Request List (HPRL entry for the major isotopes (235U, 239Pu. In response to that HPRL entry, we executed a dedicated measurement program on prompt fission γ-rays employing state-of-the-art lanthanum bromide (LaBr3 detectors with superior timing and good energy resolution. Our new results from 252Cf(sf, 235U(nth,f and 241Pu(nth,f provide prompt fission γ-ray spectra characteristics : average number of photons per fission, average total energy per fission and mean photon energy; all within 2% of uncertainty. We present preliminary results on 239Pu(nth,f, recently measured at the Budapest Neutron Centre and supported by the CHANDA Trans-national Access Activity, as well as discussing our different published results in comparison to the historical data and what it says about the discrepancy observed in the benchmark calculations.

  1. Nuclear energy: fusion and fission - From the atomic nucleus to energy

    International Nuclear Information System (INIS)

    2002-09-01

    Matter is made up of atoms. In 1912, the English physicist Ernest Rutherford (who had shown that the atom had a nucleus), and the Danish physicist Niels Bohr developed a model in which the atom was made up of a positively charged nucleus surrounded by a cloud of electrons. In 1913, Rutherford discovered the proton, and in 1932, the English physicist Chadwick discovered the neutron. In 1938, Hahn and Strassmann discovered spontaneous fission and the French physicist Frederic Joliot-Curie, assisted by Lew Kowarski and Hans Von Halban, showed in 1939 that splitting uranium nuclei caused an intense release of heat. The discovery of the chain reaction would enable the exploitation of nuclear energy. 'It was the Second World War leaders who, by encouraging research for military purposes, contributed to the development of nuclear energy'. During the Second World War, from 1939 to 1945, studies of fission continued in the United States, with the participation of emigre physicists. The Manhattan project was launched, the aim of which was to provide the country with a nuclear weapon (used at Hiroshima and Nagasaki in 1945). After the war ended, research into energy production by the nuclear fission reaction continued for civil purposes. CEA (the French Atomic Energy Commission) was set up in France in 1945 under the impetus of General de Gaulle. This public research body is responsible for giving France mastery of the atom in the research, health, energy, industrial, safety and defense sectors. (authors)

  2. The Korean nuclear power program

    International Nuclear Information System (INIS)

    Choi, Chang Tong

    1996-01-01

    Although the world nuclear power industry may appear to be in decline, continued nuclear power demand in Korea indicates future opportunities for growth and prosperity in this country. Korea has one of the world's most vigorous nuclear power programs. Korea has been an active promoter of nuclear power generation since 1978, when the country introduced nuclear power as a source of electricity. Korea now takes pride in the outstanding performance of its nuclear power plants, and has established a grand nuclear power scheme. This paper is aimed at introducing the nuclear power program of Korea, including technological development, international cooperation, and CANDU status in Korea. (author). 2 tabs

  3. National nuclear program

    International Nuclear Information System (INIS)

    Costa A, D.

    1980-01-01

    The basic concepts of the Nuclear program that Mexico plans are presented, to develop pointing out that it constitutes an outstanding event within the history of the country, that will result in an equilibrated profit of the resources of oil exploitation consolidating each step of its technical evolution; all of this represents a challenge since it establishes a qualitative transformation in the very roots of the National economy. Being certain that oil is a non renovable natural resource, the author points out that Mexican Government has emphasized the promotion of the research of alternate resource of energy in the future. According to this panorama, the quidelines that Mexico must undertake regarding production, distribution and consumption of nuclear energy, will point primarily to a global program, which will avoid the imports of equipment and technicians, to achieve maximum advantages for the Country. It stresses the fact that this program cannot start from zero; since first, Mexico, has to import foreign technology, which once assimilated, will give to the Mexican technicians the starting point to establish the proper solution to the foreseen objectives. Therefore, any kind of International cooperation must tend to accelerate the nuclear development and to obtain the transference to technology, within a frame of respect to Mexican sovereignity. The conclusion is that the task at which Mexico aims must be based on the existing human potentiality and on the one that will be prepared in the future, and also on the knowledge and adequate exploitation of the uranium reserves, having the ININ a prominent role of creating the necessary human infrastructure, the development of a Mexican nuclear energy can be achieved in a medium term. (author)

  4. Experimental examination of ternary fission in nuclear track emulsion

    Czech Academy of Sciences Publication Activity Database

    Mamatkulov, K. Z.; Ambrožová, Iva; Artemenkov, D. A.; Bradnova, V.; Firu, E.; Haiduc, M.; Kákona, Martin; Kattabekov, R. R.; Marey, A.; Neagu, A.; Ploc, Ondřej; Rusakova, V. V.; Stanoeva, R.; Turek, Karel; Zaitsev, A. A.; Zarubin, P. I.; Zarubina, I. G.

    2017-01-01

    Roč. 48, č. 6 (2017), s. 910-913 ISSN 1063-7796 Institutional support: RVO:61389005 Keywords : angular correlation * nuclear track emulsion Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 0.681, year: 2016

  5. Mobile fission and activation products in nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Umeki, H; Evans, N; Czervinski, K; Bruggeman, Ch; Poineau, F; Breynaert, A; Reiler, P; Pablo, J de; Pipon, Y; Molnar, M; Nishimura, T; Kienzler, B; Van Iseghem, P; Crovisier, J L; Wieland, E; Mace, N; Pablo, J de; Spahiu, K; Cui, D; Lida, Y; Charlet, L; Liu, X; Sato, H; Goutelard, F; Savoye, S; Glaus, M; Poinssot, C; Seby, F; Sato, H; Tournassat, Ch; Montavon, G; Rotenberg, B; Spahiu, K; Smith, G; Marivoet, J; Landais, P; Bruno, J; Johnson, H; Umeki, L; Geckeis, H; Giffaut, E; Grambow, B; Dierckx, A

    2007-07-01

    This document gathers 33 oral presentations that were made at this workshop dedicated to the mobility of some radionuclides in nuclear waste disposal. The workshop was organized into 6 sessions: 1) performance assessment, 2) speciation/interaction in aqueous media, 3) radioactive wastes, 4) redox processes at interfaces, 5) diffusion processes, and 6) retention processes.

  6. Health Consequences of Nuclear Fission Products | Ajlouni | Journal ...

    African Journals Online (AJOL)

    effects of these radionuclides enter the human body, a large number of fatalities, malignancies, thyroid cancer, born (genic) defects, etc. Nevertheless, the actual data after Chernobyl and TMI accidents, and nuclear detonations, were not consistent with these models. Deep Atomic Binding Hypothesis (DAB)), interprets the ...

  7. Mobile fission and activation products in nuclear waste disposal

    International Nuclear Information System (INIS)

    Umeki, H.; Evans, N.; Czervinski, K.; Bruggeman, Ch.; Poineau, F.; Breynaert, A.; Reiler, P.; Pablo, J. de; Pipon, Y.; Molnar, M.; Nishimura, T.; Kienzler, B.; Van Iseghem, P.; Crovisier, J.L.; Wieland, E.; Mace, N.; Pablo, J. de; Spahiu, K.; Cui, D.; Lida, Y.; Charlet, L.; Liu, X.; Sato, H.; Goutelard, F.; Savoye, S.; Glaus, M.; Poinssot, C.; Seby, F.; Sato, H.; Tournassat, Ch.; Montavon, G.; Rotenberg, B.; Spahiu, K.; Smith, G.; Marivoet, J.; Landais, P.; Bruno, J.; Johnson, H.; Umeki, L.; Geckeis, H.; Giffaut, E.; Grambow, B.; Dierckx, A.

    2007-01-01

    This document gathers 33 oral presentations that were made at this workshop dedicated to the mobility of some radionuclides in nuclear waste disposal. The workshop was organized into 6 sessions: 1) performance assessment, 2) speciation/interaction in aqueous media, 3) radioactive wastes, 4) redox processes at interfaces, 5) diffusion processes, and 6) retention processes

  8. Nuclear-charge polarization at scission in fission from moderately excited light-actinide nuclei

    International Nuclear Information System (INIS)

    Nishinaka, Ichiro

    2009-01-01

    Fragment mass yields and the average neutron multiplicity in the proton-induced fission of 232 Th and 238 U were measured by a double time-of-flight method. The most probable charges of secondary fragments were evaluated from the fragment mass yields measured by the double time-of-flight method and the fractional cumulative and independent yields reported in literature. The nuclear-charge polarization of primary fragments at scission was obtained by correcting the most probable charge of secondary fragments for neutron evaporation. The results show that the nuclear-charge polarization at scission is associated with the liquid-drop properties of nuclei and the proton shell effect with Z = 50 of heavy fragments and that it is practically insensitive to mass and excitation energy of the fissioning nucleus in the region of light-actinide nuclei. (author)

  9. Using New Fission Data with the Multi-detector Analysis System for Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    A. V. Ramayya; A.V. Daniel (Joint Institute for Nuclear Research); C. J. Beyer (Vanderbilt Univ.); E. L. Reber; G. M. Ter-Akopian; G.S. Popeko; J. D. Cole; J. H. Hamilton; J. K. Jewell (INEEL); M. W. Drigert; R. Aryaeinejad; Ts.Yu. Oganessian

    1998-11-01

    New experiments using an array of high purity germanium detectors and fast liquid scintillation detectors has been performed to observe the radiation emitted from the induced fission of 235U with a beam of thermal neutrons. The experiment was performed at the Argonne National Laboratory Intense Pulsed Neutron Source. Preliminary observations of the data are presented. A nondestructive analysis system for the characterization of DOE spent nuclear fuel based on these new data is presented.

  10. Using New Fission Data with the Multi-detector Analysis System for Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Jerald Donald

    1998-11-01

    New experiments using an array of high purity germanium detectors and fast liquid scintillation detectors has been performed to observe the radiation emitted from the induced fission of 235U with a beam of thermal neutrons. The experiment was performed at the Argonne National Laboratory Intense Pulsed Neutron Source. Preliminary observations of the data are presented. A nondestructive analysis system for the characterization of DOE spent nuclear fuel based on these new data is presented.

  11. Fission product release from defected nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Lewis, B.J.

    1983-01-01

    The release of gaseous (krypton and xenon) and iodine radioactive fission products from defective fuel elements is described with a semi-empirical model. The model assumes precursor-corrected 'Booth diffusional release' in the UO 2 and subsequent holdup in the fuel-to-sheath gap. Transport in the gap is separately modelled with a phenomenological rate constant (assuming release from the gap is a first order rate process), and a diffusivity constant (assuming transport in the gap is dominated by a diffusional process). Measured release data from possessing various states of defection are use in this analysis. One element (irradiated in an earlier experiment by MacDonald) was defected with a small drilled hole. A second element was machined with 23 slits while a third element (fabricated with a porous end plug) displayed through-wall sheath hydriding. Comparison of measured release data with calculated values from the model yields estimates of empirical diffusion coefficients for the radioactive species in the UO 2 (1.56 x 10 -10 to 7.30 x 10 -9 s -1 ), as well as escape rate constants (7.85 x 10 -7 to 3.44 x 10 -5 s -1 ) and diffusion coefficients (3.39 x 10 -5 to 4.88 x 10 -2 cm 2 /s) for these in the fuel-to-sheath gap. Analyses also enable identification of the various rate-controlling processes operative in each element. For the noble gas and iodine species, the rate-determining process in the multi-slit element is 'Booth diffusion'; however, for the hydrided element an additional delay results from diffusional transport in the fuel-to-heath gap. Furthermore, the iodine species exhibit an additional holdup in the drilled element because of significant trapping on the fuel and/or sheath surfaces. Using experimental release data and applying the theoretical results of this work, a systematic procedure is proposed to characterize fuel failures in commercial power reactors (i.e., the number of fuel failures and average leak size)

  12. FPFPspace2: A code for following airborne fission products in generic nuclear plant flow paths

    International Nuclear Information System (INIS)

    Owcarski, P.C.; Burk, K.W.; Ramsdell, J.V.; Yasuda, D.D.

    1991-03-01

    In order to assure that a nuclear power plant control room remains habitable during certain types of postulated accidents, Pacific Northwest Laboratory (PNL) has undertaken a special study for the US Nuclear Regulatory Commission. This purpose of this study is to develop software that can aid in the analyses of control room habitability during accidents in which airborne fission products could challenge internal air pathways to the control room. PNL has completed an initial version (FPFP) and final version (FPFP 2) of a software package that can estimate the unsteady-state invasion of quantities of fission products into the control room or any other destination within the nuclear plant via generic internal flow paths. This report consists of three parts: Section 2.0, Technical Bases, describes the flow path components and mechanisms of natural fission product deposition; Section 3.0, FPFP 2 Code Description, describes code organization and the functions of the subroutines; and Section 4.0, Code Operation, discusses details of input requirements, code output, and a sample case demonstration. The appendices consist of an FPFP 2 Fortran code listing, a listing of a code for building input files, forms for building input files, and the sample case input and output files. 7 refs., 3 figs

  13. Geochemical properties and nuclear chemical characteristics of Oklo natural fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Hiroshi [Hiroshima Univ., Higashi-Hiroshima (Japan). Faculty of Science

    1997-07-01

    There are six uranium deposits in the Gabonese Republic in the cnetral Africa. `Fission reactor zone`, the fission chain reactions generated about 200 billion years ago, was existed in a part of them. CEA begun geochemical researches of Oklo deposits etc. in 1991. The geochemical and nuclear chemical properties of Oklo were reviewed from the results of researches. Oklo deposits is consisted of main five sedimentary faces such as sandstone (FA), Black Shale formation (FB), mudstone (FC), tuff (FD) and volcaniclastic sandstone (FE) from the bottom on the base rock of granite in the Precambrian era. Uranium is enriched in the upper part of FA layer and the under part of FB layer. {sup 235}U/{sup 238}U, U content, fission proportion, duration time, neutron fluence, temperature, restitution factor of {sup 235}U and epithermal index ({gamma}) were investigated and compared. The geochemical properties of Oklo are as followed: large enrich of uranium, the abundance ratio of {sup 235}U as same as that of enriched uranium, interaction of natural water and small rear earth elements. These factors made casually Oklo fission reactor. (S.Y.)

  14. The Brazilian Nuclear Energy Program

    International Nuclear Information System (INIS)

    Carvalho, H.G. de

    1980-01-01

    A survey is initially of the international-and national situation regarding energetic resources. The Brazilian Nuclear Energy Policy and the Brazilian Nuclear Program are dealt with, as well as the Nuclear Cooperation agreement signed with the Federal Republic of Germany. The situation of Brazil regarding Uranium and the main activities of the Brazilian Nuclear Energy Commission are also discussed [pt

  15. Role and use of nuclear theories and models in practical evaluation of neutron nuclear data needed for fission and fusion reactor design and other nuclear applications

    International Nuclear Information System (INIS)

    Prince, A.

    1975-01-01

    A review of the various nuclear models used in the evaluation of neutron nuclear data for fission and fusion reactors is presented. Computer codes embodying the principles of the relevant nuclear models are compared with each other and with experimental data. The regions of validity and limitations of the conceptual formalisms are also included, along with the effects of the numerical procedures used in the codes themselves. Conclusions and recommendations for future demands are outlined.15 tables, 15 figures, 90 references

  16. The role and use of nuclear theories and models in practical evaluation of neutron nuclear data needed for fission and fusion reactor design and other nuclear applications

    International Nuclear Information System (INIS)

    Prince, A.

    1976-01-01

    A review of the various nuclear models used in the evaluation of neutron nuclear data for fission and fusion reactors is presented. Computer codes embodying the principles of the relevant nuclear models are compared with each other and with experimental data. The regions of validity and limitations of the conceptual formalisms are also included, along with the effects of the numerical procedures used in the codes themselves. Conclusions and recommendations for future demands are outlined. (author)

  17. Nuclear fission technology in Spain: History and social concerns.

    Science.gov (United States)

    Aliende Urtasun, Ana; Luquin, Asunción; Garrido, Julián J

    2017-04-01

    This research examines the evolution of nuclear technology in Spain from the early years of the Franco dictatorship to the global financial crisis and technology's influence on Spanish culture. To this end, we take a sociological perspective, with science culture and social perceptions of risk in knowledge societies serving as the two elements of focus in this work. In this sense, this article analyses the transformation of social relationships in light of technological changes. We propose technology as a strategic place to observe the institutional and organisational dynamics of technologic-scientific risks, the expert role and Spain's science culture. In addition, more specifically, within the language of co-production, we 'follow the actor' and favour new forms of citizen participation that promote ethics to discuss technological issues.

  18. Radiochemical studies on fission

    Energy Technology Data Exchange (ETDEWEB)

    None

    1973-07-01

    Research progress is reported on nuclear chemistry; topics considered include: recoil range and kinetic energy distribution in the thermal neutron ftssion of /sup 245/Cm; mass distribution and recoil range measurements in the reactor neutron-induced fission of /sup 232/U; fission yields in the thermal neutron fission of /sup 241/PU highly asymmetric binary fission of uranium induced by reactor neutrons; and nuclear charge distribution in low energy fission. ( DHM)

  19. Measurement of fission cross-section of actinides at n_TOF for advanced nuclear reactors

    CERN Document Server

    Calviani, Marco; Montagnoli, G; Mastinu, P

    2009-01-01

    The subject of this thesis is the determination of high accuracy neutron-induced fission cross-sections of various isotopes - all of which radioactive - of interest for emerging nuclear technologies. The measurements had been performed at the CERN neutron time-of-flight facility n TOF. In particular, in this work, fission cross-sections on 233U, the main fissile isotope of the Th/U fuel cycle, and on the minor actinides 241Am, 243Am and 245Cm have been analyzed. Data on these isotopes are requested for the feasibility study of innovative nuclear systems (ADS and Generation IV reactors) currently being considered for energy production and radioactive waste transmutation. The measurements have been performed with a high performance Fast Ionization Chamber (FIC), in conjunction with an innovative data acquisition system based on Flash-ADCs. The first step in the analysis has been the reconstruction of the digitized signals, in order to extract the information required for the discrimination between fission fragm...

  20. Fission rates measured using high-energy gamma-rays from short half-life fission products in fresh and spent nuclear fuel

    International Nuclear Information System (INIS)

    Kroehnert, H.

    2011-02-01

    In recent years, higher discharge burn-ups and initial fuel enrichments have led to more and more heterogeneous core configurations in light water reactors (LWRs), especially at the beginning of cycle when fresh fuel assemblies are loaded next to highly burnt ones. As this trend is expected to continue in the future, the Paul Scherrer Institute has, in collaboration with the Swiss Association of Nuclear Utilities, swissnuclear, launched the experimental programme LIFE(at)PROTEUS. The LIFE(at)PROTEUS programme aims to better characterise interfaces between burnt and fresh UO 2 fuel assemblies in modern LWRs. Thereby, a novel experimental database is to be made available for enabling the validation of neutronics calculations of strongly heterogeneous LWR core configurations. During the programme, mixed fresh and highly burnt UO 2 fuel lattices will be investigated in the zero-power research reactor PROTEUS. One of the main types of investigations will be to irradiate the fuel in PROTEUS and measure the resulting fission rate distributions across the interface between fresh and burnt fuel zones. The measurement of fission rates in burnt fuel re-irradiated in a zero-power reactor requires, however, the development of new experimental techniques which are able to discriminate against the high intrinsic activity of the fuel. The principal goal of the present research work has been to develop such a new measurement technique. The selected approach is based on the detection of high-energy gamma-ray lines above the intrinsic background (i.e. above 2200 keV), which are emitted by short-lived fission products freshly created in the fuel. The fission products 88 Kr, 142 La, 138 Cs, 84 Br, 89 Rb, 95 Y, 90m Rb and 90 Rb, with half-lives between 2.6 min and 2.8 h, have been identified as potential candidates. During the present research work, the gamma-ray activity of short-lived fission products has, for the first time, been measured and quantitatively evaluated for re

  1. Fission rates measured using high-energy gamma-rays from short half-life fission products in fresh and spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kroehnert, H.

    2011-02-15

    In recent years, higher discharge burn-ups and initial fuel enrichments have led to more and more heterogeneous core configurations in light water reactors (LWRs), especially at the beginning of cycle when fresh fuel assemblies are loaded next to highly burnt ones. As this trend is expected to continue in the future, the Paul Scherrer Institute has, in collaboration with the Swiss Association of Nuclear Utilities, swissnuclear, launched the experimental programme LIFE(at)PROTEUS. The LIFE(at)PROTEUS programme aims to better characterise interfaces between burnt and fresh UO{sub 2} fuel assemblies in modern LWRs. Thereby, a novel experimental database is to be made available for enabling the validation of neutronics calculations of strongly heterogeneous LWR core configurations. During the programme, mixed fresh and highly burnt UO{sub 2} fuel lattices will be investigated in the zero-power research reactor PROTEUS. One of the main types of investigations will be to irradiate the fuel in PROTEUS and measure the resulting fission rate distributions across the interface between fresh and burnt fuel zones. The measurement of fission rates in burnt fuel re-irradiated in a zero-power reactor requires, however, the development of new experimental techniques which are able to discriminate against the high intrinsic activity of the fuel. The principal goal of the present research work has been to develop such a new measurement technique. The selected approach is based on the detection of high-energy gamma-ray lines above the intrinsic background (i.e. above 2200 keV), which are emitted by short-lived fission products freshly created in the fuel. The fission products {sup 88}Kr, {sup 142}La, {sup 138}Cs, {sup 84}Br, {sup 89}Rb, {sup 95}Y, {sup 90m}Rb and {sup 90}Rb, with half-lives between 2.6 min and 2.8 h, have been identified as potential candidates. During the present research work, the gamma-ray activity of short-lived fission products has, for the first time, been

  2. Design related aspects in advanced nuclear fission plants

    International Nuclear Information System (INIS)

    Hoffelner, Wolfgang

    2011-01-01

    Important issues to be considered for design of future reactors are: extrapolation of stress rupture data, creep-fatigue, negligible creep, damage monitoring. The paper highlights some new developments taking examples from a martensitic steel (mod 9% Cr), oxide dispersion strengthened (ODS) steels and nickel-base superalloys. Traditional approaches to extrapolation of (thermal) stress rupture data like Larson-Miller Parameter or Monkman-Grant rule seem to be valid concepts also for advanced reactors. However, a significant influence of cyclic softening on creep rates and stress rupture data can be expected as shown for grade 91. This is particularly true for creep-fatigue interactions. Based on cyclic stress-strain behaviour it is also possible to get very good life-time predictions under creep-fatigue with a strain range separation (inelastic fatigue and creep ranges) technique which could replace the currently used linear life fraction rule. Results from in-beam irradiation creep reveal no significant influence of dispersoid size. It can be assumed that irradiation creep is a matrix property. Finally it is shown that micro-sample testing of exposed material could be used as an advanced method for damage assessment in future nuclear power plants.

  3. China's nuclear programs and policies

    International Nuclear Information System (INIS)

    Wang, C.

    1983-01-01

    Economics and the futility of arms competition with the US and USSR has forced China to shift its nuclear effort to peaceful uses, although its current nuclear-deterrent warrants including China in arms negotiations. China's nuclear program began during the 1950s with an emphasis on weaponry and some development in space technology. Proponents of nuclear power now appear to have refuted the earlier arguments that nuclear-plant construction would be too slow, too dangerous and polluting, and too expensive and the idea that hydro resources would be adequate. The current leadership supports a serious nuclear-power-plant construction program. 6 references

  4. High-power proton linac for transmuting the long-lived fission products in nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.P.

    1991-01-01

    High power proton linacs are being considered at Los Alamos as drivers for high-flux spallation neutron sources that can be used to transmute the troublesome long-lived fission products in defense nuclear waste. The transmutation scheme being studied provides a high flux (> 10{sup 16}/cm{sup 2}{minus}s) of thermal neutrons, which efficiently converts fission products to stable or short-lived isotopes. A medium-energy proton linac with an average beam power of about 110 MW can burn the accumulated Tc99 and I129 inventory at the DOE's Hanford Site within 30 years. Preliminary concepts for this machine are described. 3 refs., 5 figs., 2 tabs.

  5. Nuclear structure effects in multi-nucleon transfer and sequential fission reactions

    International Nuclear Information System (INIS)

    Biswas, D.C.

    2001-01-01

    The role of the nuclear structure in multi-nucleon transfer and sequential fission reactions has been discussed. The recent results on multi-nucleon transfer and transfer induced fission reaction, have brought out many interesting features in understanding the reaction mechanism and collective dynamics of heavy ion reactions. The structure of the projectile nucleus has strong influence on the transfer of multi-nucleons and/or clusters from the projectile to the target. The mechanism of multi-nucleon transfer between two heavy nuclei is a complex process which has a strong dependence on the ground state Q-value of the reaction as well as on the number of transferred nucleons

  6. Nuclear irradiation parameters of beryllium under fusion, fission and IFMIF irradiation conditions

    International Nuclear Information System (INIS)

    Fischer, U.; Chen, Y.; Leichtle, D.; Simakov, S.; Moeslang, A.; Vladimirov, P.

    2004-01-01

    A computational analysis is presented of the nuclear irradiation parameters for Beryllium under irradiation in typical neutron environments of fission and fusion reactors, and of the presently designed intense fusion neutron source IFMIF. The analysis shows that dpa and Tritium production rates at fusion relevant levels can be achieved with existing high flux fission reactors while the achievable Helium production is too low. The resulting He-Tritium and He/dpa ratios do not meet typical fusion irradiation conditions. Irradiation simulations in the medium flux test modules of the IFMIF neutron source facility were shown to be more suitable to match fusion typical irradiation conditions. To achieve sufficiently high production rates it is suggested to remove the creep-fatigue testing machine together with the W spectra shifter plate and move the tritium release module upstream towards the high flux test module. (author)

  7. Measuring head for determining the pressure of fission gases released inside bars of nuclear fuel

    International Nuclear Information System (INIS)

    Granata, S.

    1984-01-01

    A measuring head suitable for determining the pressure of fission gases released inside non-instrumented bars of nuclear fuel (which have reached high irradiation levels), and for connection to said bars by a method which allows no escape of said active gases and does not cause appreciable disturbance either to the fuel or to the released fission gases, is disclosed. The head consists of a tubular casing adapted to be welded at one end to the bar, and having a metal bellows at its other end. A pointed metal bar is used to penetrate the bar by a blow to a pin, whereupon pressure variations within the casing are measured by a pressure measuring device having an iron core, the movement of the core, due to such pressure variations, being recorded by a differential transformer. (author)

  8. The LANL/LLNL Program to Measure Prompt Fission Neutron Spectra at LANSCE

    Science.gov (United States)

    Haight, Robert; Wu, Ching Yen; Lee, Hye Young; Taddeucci, Terry; Mosby, Shea; O'Donnell, John; Fotiades, Nikolaos; Devlin, Mattew; Ullmann, John; Nelson, Ronald; Wender, Stephen; White, Morgan; Solomon, Clell; Neudecker, Denise; Talou, Patrick; Rising, Michael; Bucher, Brian; Buckner, Matthew; Henderson, Roger

    2015-10-01

    Accurate data on the spectrum of neutrons emitted in neutron-induced fission are needed for applications and for a better understanding of the fission process. At LANSCE we have made important progress in understanding systematic uncertainties and in obtaining data for 235U on the low-energy part of the prompt fission neutron spectra (PFNS), a particularly difficult region because down-scattered neutrons go in this direction. We use a double time-of-flight technique to determine energies of incoming and outgoing neutrons. With data acquisition via waveform digitizers, accidental coincidences between fission chamber and neutron detector are measured to high statistical accuracy and then subtracted from measured events. Monte Carlo simulations with high performance computers have proven to be essential in the design to minimize neutron scattering and in calculating detector response. Results from one of three approaches to analyzing the data will be presented. This work is funded by the US Department of Energy, National Nuclear Security Administration and Office of Nuclear Physics.

  9. Introducing Knowledge Management in Study Program of Nuclear Engineering

    International Nuclear Information System (INIS)

    Pleslic, S.

    2012-01-01

    Nuclear engineering is the branch of engineering concerning application of the fission as well as the fusion of atomic nuclei, and the application of other sub-atomic physics, based on the principles of nuclear physics. In the sub-field of nuclear fission there are many investigations of interactions and maintaining of systems and components like nuclear reactors and nuclear power plants. The field also includes the study of different applications of ionizing radiation (medicine, agriculture...), nuclear safety, the problems of thermodynamics transport, nuclear materials and nuclear fuels, and other related technologies like radioactive waste management. In the area of nuclear science and engineering a big amount of knowledge has been accumulated over the last decades. Different levels of nuclear knowledge were considered in different ways and they were taught to different parts of population as a general human culture and as a general scientific-technical-technological culture (high schools, nuclear information centres, training centres, universities...). An advanced level of nuclear knowledge has been accumulated by many experienced workers, specialists and experts in all nuclear and nuclear-related fields and applications. In the last 20 years knowledge management has established itself as a discipline of enabling individuals, teams and whole organizations to create, share and apply knowledge collectively and systematically, with goal to better achieve their objectives. Also, knowledge management became key strategic approach for management of intellectual assets and knowledge that can improve safety, efficiency and innovation, and lead to preserve and enhance current knowledge. Knowledge management could be applied in education, training, networking, human resource development and capacity building, sharing, pooling and transferring knowledge form centres of knowledge to centres of growth. Considering the critical importance of nuclear knowledge it is important

  10. The Sustainable Nuclear Future: Fission and Fusion E.M. Campbell Logos Technologies

    Science.gov (United States)

    Campbell, E. Michael

    2010-02-01

    Global industrialization, the concern over rising CO2 levels in the atmosphere and other negative environmental effects due to the burning of hydrocarbon fuels and the need to insulate the cost of energy from fuel price volatility have led to a renewed interest in nuclear power. Many of the plants under construction are similar to the existing light water reactors but incorporate modern engineering and enhanced safety features. These reactors, while mature, safe and reliable sources of electrical power have limited efficiency in converting fission power to useful work, require significant amounts of water, and must deal with the issues of nuclear waste (spent fuel), safety, and weapons proliferation. If nuclear power is to sustain its present share of the world's growing energy needs let alone displace carbon based fuels, more than 1000 reactors will be needed by mid century. For this to occur new reactors that are more efficient, versatile in their energy markets, require minimal or no water, produce less waste and more robust waste forms, are inherently safe and minimize proliferation concerns will be necessary. Graphite moderated, ceramic coated fuel, and He cooled designs are reactors that can satisfy these requirements. Along with other generation IV fast reactors that can further reduce the amounts of spent fuel and extend fuel resources, such a nuclear expansion is possible. Furthermore, facilities either in early operations or under construction should demonstrate the next step in fusion energy development in which energy gain is produced. This demonstration will catalyze fusion energy development and lead to the ultimate development of the next generation of nuclear reactors. In this presentation the role of advanced fission reactors and future fusion reactors in the expansion of nuclear power will be discussed including synergies with the existing worldwide nuclear fleet. )

  11. Measurement of Fission Product Yields from Fast-Neutron Fission

    Science.gov (United States)

    Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Henderson, R.; Kenneally, J.; Macri, R.; McNabb, D.; Ryan, C.; Sheets, S.; Stoyer, M. A.; Tonchev, A. P.; Bhatia, C.; Bhike, M.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.

    2014-09-01

    One of the aims of the Stockpile Stewardship Program is a reduction of the uncertainties on fission data used for analyzing nuclear test data [1,2]. Fission products such as 147Nd are convenient for determining fission yields because of their relatively high yield per fission (about 2%) and long half-life (10.98 days). A scientific program for measuring fission product yields from 235U,238U and 239Pu targets as a function of bombarding neutron energy (0.1 to 15 MeV) is currently underway using monoenergetic neutron beams produced at the 10 MV Tandem Accelerator at TUNL. Dual-fission chambers are used to determine the rate of fission in targets during activation. Activated targets are counted in highly shielded HPGe detectors over a period of several weeks to identify decaying fission products. To date, data have been collected at neutron bombarding energies 4.6, 9.0, 14.5 and 14.8 MeV. Experimental methods and data reduction techniques are discussed, and some preliminary results are presented.

  12. 'Masurium' and the 'early transuranium elements' or how discovery of nuclear fission was not clearly seen

    International Nuclear Information System (INIS)

    Keller, C.

    1988-01-01

    Fifty years after the discovery of fission, the scientific community is aware that this type of nuclear reaction could have been discovered more than a decade earlier. Noddack, Tacke and Berg announced in 1925 the discovery of elements Z = 43 (masurium) and rhenium (Z = 75), the first one could be detected only in U-bearing minerals. A recent re-examination by P.H.M. von Assche of the published data clearly showed that the original claim for element Z = 43 of the authors in 1925 was correct and, therefore, they detected not only element Z = 43 but also the first fission product. Because this discovery of element Z = 43 could not be repeated by other authors as that time, the scientific credibility of Noddack-Tacke was very low in order to give credit to her proposal that the 'early' transuranium elements by Enrico Fermi might also be fragments of known (lighter) elements. Enrico Fermi in 1934 obtained these 'early' (and as we today know: wrong) transuranium isotopes by irradiation of uranium with neutrons. A 'wrong' periodic system in the thirties which placed Th, Pa and U as 6d-elements and not as 5f-actinides chemically helped to consider these fission products as transuranium elements Z = 93/94. In 1937/38 I. Curie and P. Savitch discovered an 'actinium-nuclide' with 3,5 h half-life which, however, had properties similar to lanthanium and not to actinium, as they stated. (orig.) [de

  13. Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

    Science.gov (United States)

    Abrecht, David G; Schwantes, Jon M

    2015-03-03

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores.

  14. Nuclear Fission Reactor Safety Research in FP7 and future perspectives

    CERN Document Server

    Garbil, Roger

    2014-01-01

    The European Union (ЕU) has defined in the Europe 2020 strategy and 2050 Energy Roadmap its long-term vision for establishing a secure, sustainable and competitive energy system and setting up legally binding targets by 2020 for reducing greenhouse emissions, by increasing energy efficiency and the share of renewable energy sources while including a significant share from nuclear fission. Nuclear energy can enable the further reduction in harmful emissions and can contribute to the EU’s competitive energy system, security of supply and independence from fossil fuels. Nuclear fission is a valuable option for those 14 EU countries that promote its use as part of their national energy mix. The European Group on Ethics in Science and New Technologies (EGE) adopted its Opinion No.27 ‘An ethical framework for assessing research, production and use of energy’ and proposed an integrated ethics approach for the research, production and use of energy in the EU, seeking equilibrium among four criteria – access ...

  15. The Potential Of Fission Nuclear Energy In Resolving Global Climate Change

    International Nuclear Information System (INIS)

    Pevec, D.

    2015-01-01

    There is an international consensus on the need of drastic reduction of carbon emission if very serious global climate changes are to be avoided. At present target is to limit global temperature increase to 2 Degrees of C and to keep CO 2 concentration below 450 ppm, though some recent request by climatologists argue for lower limit of 1.5 Degrees of C. The carbon emission reduction has to be done in the next few decades, as climate effects are essentially determined by integral emission. The integral emissions should not exceed 1000 Gt CO 2 to keep the probability of exceeding global temperature by 2 Degrees of C below 25 percent. Consequently, when we consider energy sources that could produce carbon free energy we have to concentrate on the period not later than 2060-2065. The sources that can take the burden of reduction in the years up to 2065 are Renewable Energy Sources (RES) and nuclear fission energy. The potential of RES has been estimated by many organizations and individuals. Their predictions indicate that RES are not likely to be sufficient to replace carbon emitters and fulfill the 2 Degrees of C limit requirements. The nuclear fission energy can give a very serious and hopefully timely (unlike nuclear fusion) contribution to reduction of emission. Even with proven conventional reactors using once through fuel cycle without fuel reprocessing the nuclear build-up in the years 2025-2065 could reach 3330 GW. With this concept nuclear contribution of 94.5 EJ/y would be reached by 2065, while integral CO 2 emission savings would be about 500 Gt CO 2 by 2065. This shows that essential nuclear contribution is possible without the use of plutonium and fast breeders, technology not ready for climate-critical next 50 years and not acceptable in present political environment. This nuclear fission energy contribution along with contributions from renewable sources, energy saving, and increased efficiency in energy use can solve the climate problems. (author).

  16. A Monte Carlo method for nuclear evaporation and fission at intermediate energies

    International Nuclear Information System (INIS)

    Deppman, A.; Likhachev, V.P.; Mesa, J.; Pina, S.R. de; Arruda-Neto, J.D.T.; Goncalves, M.; Rodriguez, O.

    2003-04-01

    We describe a Monte Carlo method to calculate the characteristics of the competition between particle evaporation and nuclear fission processes taking place in the compound nucleus formed after the intranuclear cascade following the absorption of intermediate energy photons by the nucleus. In this version we include not only neutrons, but also protons and alphas as possible evaporating particles. However, this method allows an ease inclusion of other evaporating particles, as deuteron or heavier clusters. Some results for 237 Np, 238 U, and 232 Th are shown. (author)

  17. A Monte Carlo method for nuclear evaporation and fission at intermediate energies

    International Nuclear Information System (INIS)

    Deppman, A.; Tavares, O.A.P.; Duarte, S.B.; Arruda-Neto, J.D.T.; Goncalves, M.; Likhachev, V.P.; Mesa, J.; Oliveira, E.C. de; Pina, S.R. de; Rodriguez, O.

    2003-01-01

    We describe a Monte Carlo method to calculate the characteristics of the competition between particle evaporation and nuclear fission processes taking place in the compound nucleus formed after the intranuclear cascade following the absorption of intermediate energy photons by the nucleus. In this version we include not only neutrons, but also protons and alphas as possible evaporating particles. The present method allows the easy inclusion of other evaporating particles, such as deuteron or heavier clusters. Some fissility results are discussed for the target nuclei 237 Np, 238 U and 232 Th

  18. Preliminary design and analysis on nuclear fuel cycle for fission-fusion hybrid spent fuel burner

    International Nuclear Information System (INIS)

    Chen Yan; Wang Minghuang; Jiang Jieqiong

    2012-01-01

    A wet-processing-based fuel cycle and a dry-processing were designed for a fission-fusion hybrid spent fuel burner (FDS-SFB). Mass flow of SFB was preliminarily analyzed. The feasibility analysis of initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing were preliminarily evaluated. The results of mass flow of FDS-SFB demonstrated that the initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing of nuclear fuel cycle of FDS-SFB is preliminarily feasible. (authors)

  19. Nuclear fission today and tomorrow: from renaissance to technological breakthrough (Generation IV)

    International Nuclear Information System (INIS)

    Van Goethem, G.

    2010-01-01

    This paper describes briefly the major scientific and technological challenges related to the very innovative nuclear fission reactor systems to be deployed at the horizon 2040 (called Generation IV). The paper focuses on the benefits of the Generation IV systems, according to criteria or technology goals established at the international level (Generation IV International Forum (GIF)). This goals are drastic improvements on four areas: sustainable development, industrial competitiveness, safety and reliability and proliferation resistance. The focus is on the design objectives and associated research issues that have been agreed upon internationally to meet these four ambitious goals. (author)

  20. Online ICPMS detection of the thermal release of fission products from nuclear fuel samples

    International Nuclear Information System (INIS)

    Guenther-Leopold, I.; Svedkauskaite-Le Gore, J.; Kivel, N.

    2009-01-01

    Full text: The release of volatile and semi-volatile fission products (like Cs, Tc, Mo etc.) from spent nuclear fuel by thermal and thermochemical treatment (oxidative or reductive conditions) as a head-end step for advanced reprocessing scenarios is studied in the Hot Laboratory of the Paul Scherrer Institut. For this purpose, a heated sampling cell online connected to an ICPMS (Element 2, Thermo Fisher Scientific) was designed and tested on simulated fuel samples up to 650 o C. The results of this study as well as technical perspectives for heating experiments up to 2000 o C will be presented. (author)

  1. Nuclear Reactor Sharing Program

    International Nuclear Information System (INIS)

    1994-01-01

    The Ohio State University Research Reactor (OSURR) is licensed to operate at a maximum power level of 500 kW. A pool-type reactor using flat-plate, low enriched fuel elements, the OSURR provides several experimental facilities including two 6-inch i.d. beam ports, a graphite thermal column, several graphite-isotope-irradiation elements, a pneumatic transfer system (Rabbit), various dry tubes, and a Central Irradiation Facility (CIF). The core arrangement and accessibility facilitates research programs involving material activation or core parameter studies. The OSURR control room is large enough to accommodate laboratory groups which can use control instrumentation for monitoring of experiments. The control instrumentation is relatively simple, without a large amount of duplication. This facilitates opportunities for hands-on experience in reactor operation by nuclear engineering students making reactor parameter measurements. For neutron activation analysis and analyses of natural environmental radioactivity, the NRL maintains the gamma ray spectroscopy system (GRSS). It is comprised of two PC-based 8192-channel multichannel analyzers (MCAs) with all the required software for quantitative analysis. A 3 double-prime x 3 double-prime NaI(Tl), a 14 percent Ge(Li), and a High Purity Germanium detector are currently available for use with the spectroscopy system

  2. Measurements of fission yields

    International Nuclear Information System (INIS)

    Denschlag, H.O.

    2000-01-01

    After some historical introductory remarks on the discovery of nuclear fission and early fission yield determinations, the present status of knowledge on fission yields is briefly reviewed. Practical and fundamental reasons motivating the pursuit of fission yield measurements in the coming century are pointed out. Recent results and novel techniques are described that promise to provide new interesting insights into the fission process during the next century. (author)

  3. Effects of hyperstoichiometry and fission products on the electrochemical reactivity of UO2 nuclear fuel

    International Nuclear Information System (INIS)

    Betteridge, J.S.; Scott, N.A.M.; Shoesmith, D.W.; Bahen, L.E.; Hocking, W.H.; Lucuta, P.G.

    1997-03-01

    The effects of hyperstoichiometry and fission products on the electrochemical reactivity Of UO 2 nuclear fuel have been systematically investigated using cyclic voltammetry and the O 2 reduction reaction. Significant constraints are placed on the active-site model for O 2 reduction by the modest impact of bulk hyperstoichiometry. Formation of the U 4 O 9 derivative phase was associated with a marked increase in transient surface oxidation/reduction processes, which probably involve localized attack and might be fostered by tensile stresses induced during oxidation. Electrocatalytic reduction Of O 2 on simulated nuclear fuel (SIMFUEL) has been determined to increase progressively with nominal burnup and pronounced enhancement of H 2 O reduction has been observed as well. Substitution of uranium by lower-valence (simulated) fission products, which was formerly considered the probable cause for this behaviour, has now been shown to merely provide good electrical conductivity. Instead, the enhanced reduction kinetics for O 2 and H 2 O on SIMFUEL can be fully accounted for by noble metals, which segregate to the UO 2 grain boundaries as micron-sized particles, despite their low effective surface area. Apparent convergence of the electrochemical properties Of UO 2 and SIMFUEL through natural corrosion likely reflects evolution toward a common active surface. (author)

  4. The programme 'fission product deposition' at the IRB of Juelich nuclear research centre

    International Nuclear Information System (INIS)

    Gottaut, H.; Iniotakis, N.; Malinowski, J.; Muenchow, K.H.; Sackmann, B.

    1976-01-01

    The transport and deposition behaviour of the non-gaseous fission and activation products in the primary circuit of HTR-type reactors determines the possibility of inspection and maintenance of single components of the primary circuit as well as the safety of the reactor in normal operation and during accidents. For the investigation of these problems, the programme 'fission product deposition' was started at Juelich nuclear research centre in 1969 in cooperation with a number of industrial firms. The programme covers in-pile and out-of-pile experiments, in which the HTR conditions are simulated as realistically as possible, as well as various laboratory experiments and extensive theoretical studies. It is the objective of this work to establish a realistic physical model and computer programme with which the transport and deposition of nuclides in the primary circuit of HTR reactors can be calculated in advance. A report is given on the experimental and theoretical studies carried out at the IRB of Juelich nuclear research centre. (orig./AK) [de

  5. Nuclear structure and shapes from prompt gamma ray spectroscopy of fission products

    International Nuclear Information System (INIS)

    Ahmad, I.; Morss, L.R.; Durell, J.L.

    1996-01-01

    Many nuclear shape phenomena are predicted to occur in neutron-rich nuclei. The best source for the production of these nuclides is the spontaneous fission which produces practically hundreds of nuclides with yields of greater than 0.1 % per decay. Measurements of coincident gamma rays with large Ge arrays have recently been made to obtain information on nuclear structures and shapes of these neutron- rich nuclei. Among the important results that have been obtained from such measurements are octupole correlations in Ba isotopes, triaxial shapes in Ru nuclei, two-phonon vibrations in 106 Mo and level lifetimes and quadrupole moments in Nd isotopes and A=100 nuclei. These data have been used to test theoretical models

  6. Euratom innovation in nuclear fission: Community research in reactor systems and fuel cycles

    International Nuclear Information System (INIS)

    Goethem, G. van; Hugon, M.; Bhatnagar, V.; Manolatos, P.; Deffrennes, M.

    2007-01-01

    The following questions are naturally at the heart of the current Euratom research and training framework programme:(1)What are the challenges facing the European Union nuclear fission research community in the short (today), medium (2010) and long term (2040)? (2)What kind of research and technological development (RTD) does Euratom offer to respond to these challenges, in particular in the area of reactor systems and fuel cycles? In the general debate about energy supply technologies there are challenges of both a scientific and technological (S/T) as well as an economic and political (E/P) nature. Though the Community research programme acts mainly on the former, there is nevertheless important links with Community policy. These not only exist in the specific area of nuclear policy, but also more generally as is depicted in the following figure. It is shown in the particular area of nuclear fission, to what extent Euratom research, education and innovation ('Knowledge Triangle' in above figure) respond to the following long-term criteria: (1) sustainability, (2) economics, (3) safety, and (4) proliferation resistance. Research and innovation in nuclear fission technology has broad and extended geographical, disciplinary and time horizons:- the community involved extends to all 25 EU Member States and beyond; - the research assembles a large variety of scientific disciplines; - three generations of nuclear power technologies (called II, III and IV) are involved, with the timescales extending from now to around the year 2040. To each of these three generations, a couple of challenges are associated (six in total):- Generation II (1970-2000, today): security of supply+environmental compatibility; - Generation III (around 2010): enhanced safety and competitiveness (economics); - Generation IV (around 2040): cogeneration of heat and power, and full recycling. At the European Commission (EC), the research related to nuclear reactor systems and fuel cycles is

  7. Ternary fission

    International Nuclear Information System (INIS)

    Wagemans, C.

    1991-01-01

    Since its discovery in 1946, light (charged) particle accompanied fission (ternary fission) has been extensively studied, for spontaneous as well as for induced fission reactions. The reason for this interest was twofold: the ternary particles being emitted in space and time close to the scission point were expected to supply information on the scission point configuration and the ternary fission process was an important source of helium, tritium, and hydrogen production in nuclear reactors, for which data were requested by the nuclear industry. Significant experimental progress has been realized with the advent of high-resolution detectors, powerful multiparameter data acquisition systems, and intense neutron and photon beams. As far as theory is concerned, the trajectory calculations (in which scission point parameters are deduced from the experimental observations) have been very much improved. An attempt was made to explain ternary particle emission in terms of a Plateau-Rayleigh hydrodynamical instability of a relatively long cylindrical neck or cylindrical nucleus. New results have also been obtained on the so-called open-quotes trueclose quotes ternary fission (fission in three about-equal fragments). The spontaneous emission of charged particles has also clearly been demonstrated in recent years. This chapter discusses the main characteristics of ternary fission, theoretical models, light particle emission probabilities, the dependence of the emission probabilities on experimental variables, light particle energy distributions, light particle angular distributions, correlations between light particle accompanied fission observables, open-quotes trueclose quotes ternary fission, and spontaneous emission of heavy ions. 143 refs., 18 figs., 8 tabs

  8. Study of the stability of the stationary wave of nuclear fission

    International Nuclear Information System (INIS)

    Khotyanintsev, V.N.; Aksenov, A.V.; Khotyanintseva, E.N.; Pavlovich, V.N.

    2014-01-01

    Stability of the stationary wave of nuclear burning in fast reactor with uranium-plutonium fuel chain is investigated. The reactor model including 1-D diffusion equation in one-group approximation for neutron flux density and kinetic equations for nuclear densities describes slow evolution of nuclear densities followed by neutron flux. New analytical approach was proposed, which is based on the approximation of small wave velocity of the stationary wave. We obtain so-called wave velocity characteristic of the reactor which is the dependence of wave velocity to the effective absorber concentration. We show that due to instability of long-living 241 Pu a turning point and lower branch of stationary solutions appear. Numerical solution of the time dependent problem proves that the solutions of the lower branch are unstable. Thus, the turning point of the velocity characteristic corresponds to the lower margin of possible wave velocities of nuclear fission waves of the steady shape. At the same time the solutions of the upper branch are stable with respect to slow evolution of nuclear densities

  9. Nuclear data for fission reactor core design and safety analysis: Requirements and status of accuracy of nuclear data

    International Nuclear Information System (INIS)

    Rowlands, J.L.

    1984-01-01

    The types of nuclear data required for fission reactor design and safety analysis, and the ways in which the data are represented and approximated for use in reactor calculations, are summarised first. The relative importance of different items of nuclear data in the prediction of reactor parameters is described and ways of investigating the accuracy of these data by evaluating related integral measurements are discussed. The use of sensitivity analysis, together with estimates of the uncertainties in nuclear data and relevant integral measurements, in assessing the accuracy of prediction of reactor parameters is described. The inverse procedure for deciding nuclear data requirements from the target accuracies for prediction of reactor parameters follows on from this. The need for assessments of the uncertainties in nuclear data evaluations and the form of the uncertainty information is discussed. The status of the accuracies of predictions and nuclear data requirements are then summarised. The reactor parameters considered include: (a) Criticality conditions, conversion and burn-up effects. (b) Energy production and deposition, decay heating, irradiation damage, dosimetry and induced radioactivity. (c) Kinetics characteristics and control, including temperature, power and coolant density coefficients, delayed neutrons and control absorbers. (author)

  10. Computer program system for evaluation of FP nuclear data for JENDL. Smooth part

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Watanabe, Takashi; Iijima, Shungo

    1997-12-01

    This report describes computer programs used to evaluate nuclear data of fission product (FP) nuclides stored in an evaluated nuclear data library JENDL, especially in the smooth part above the resonance region. Many programs were used for determination of nuclear model parameters, calculation of nuclear data, handling of experimental and/or calculated data, and so on. Among them, reported here are programs for determination of level density parameters (ENSDFRET, LVLPLOT, LEVDES), for making sets of JCL and input data for the theoretical calculation program CASTHY (JOBSETTER, INDES/CASTHY), and for conversion of format of CASTHY output files to the ENDF format (CTOB2). (author). 51 refs.

  11. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    Science.gov (United States)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  12. High priority nuclear data request list. The data for long-lived fission products, minor actinides and the thorium cycle

    Energy Technology Data Exchange (ETDEWEB)

    Rowlands, J. [Organisation for Economic Co-Operation and Development, Nuclear Energy Agency, 75 - Paris (France)

    2002-07-01

    This workshop is organised by the Research Group GEDEON together with CERN, OECD-NEA and the CFDN (French Committee for Nuclear Data). It is the continuation of the one at CERN on September 21 and 22, 1998, jointly organised with EC, GEDEON and OCDE-NEA. This last one is centred on the CERN proposal of a facility for neutron production up to 250 MeV, devoted to neutron data measurements. The first aim of the Paris workshop is to identify the present status of specific nuclear data relevant to innovative options (accelerator driven system - ADS and thorium) in the nuclear fuel cycle, beyond what has been gathered for standard reactors (PWR, FBR) and for the associated fuel cycles based on uranium and plutonium. The following topics were presented and discussed: 1. extension of present evaluated nuclear data files beyond 20 MeV needed to correctly describe the high energy part (up to approximately 200 MeV) of the spallation process used to generate the external neutrons needed for the sub-critical assemblies; 2. differential and integral cross section data in relation with the use of a thorium based; 3. the same for minor actinides and some long-lived fission residues likely to be destroyed in reactors; 4. the same for new type of materials such as lead or lead-bismuth, to be used as spallation target or as cooling, in relation with corrosion and irradiation effects. Beyond these specific issues, ADS will also take advantage of better known nuclear data coming from the existing reactors in operation. Very recent results related to spallation target physics such as neutron and residues production from heavy targets were also presented at this workshop. One very important aim of this workshop is also to bring physicists from different origin, especially from CERN, to cooperate in a program on nuclear data in relation with innovative options. This document brings together two articles entitled ''high priority nuclear data request list. The data for long lived

  13. Two billion year old natural analogs for nuclear waste disposal: the natural nuclear fission reactors in Gabon (Africa)

    International Nuclear Information System (INIS)

    Gauthier-Lafaye, F.

    2002-01-01

    Two billion years ago, the increase of oxygen in atmosphere and the high 235 U/ 238 U uranium ratio (> 3%) made possible the occurrence of natural nuclear reactors on Earth. These reactors are considered to be a good natural analogue for nuclear waste disposal. Their preservation during such a long period of time is mainly due to the geological stability of the site, the occurrence of clays surrounding the reactors and acting as an impermeable shield, and the occurrence of organic matter that maintained the environment in reducing conditions, favourable for the stability of uraninite. Hydrogeochemical studies and modelling have shown the complexity of the geochemical system at Oklo and Bangombe (Gabon) and the lack of precise data about uranium and fission products retention and migration mechanisms in geological environments. (author)

  14. Nuclear power plant with improved arrangements for the removal of post fission and emergency heating

    International Nuclear Information System (INIS)

    Buescher, E.; Vinzens, K.

    1977-01-01

    This is concerned with additional equipment for emergency heat removal in a sodium cooled reactor, which operates on failure of the post fission heat removal system. The space for pressure relieving spaces and concrete masses as heat sinks within the reactor cell is no longer required. In this nuclear power plant, a heat exchanger chain transmits heat and power: There is a first sodium circuit between pressure vessel and the first heat exchanger, a second one between the first and second heat excahngers, and a third (Steam) circuit with turbine, condenser and return pump. A fourth circuit connects the secondary side of the condenser with a cooling tower. There is a threee component heat excahgner in the primary circuit after the first heat exchanger, which is built around the first heat exchanger, and is sealed into an unloading space. This space is situated next to the reactor cell and is above the operating level of the sodium in the pressure vessel. It is connected to the cell by an upper duct, normally closed by a bursting disc, and by a lower duct. In the three comopnent heat exchanger, a liquid lead-bismuth eutectic mixture transmits the heat from sodium pipes to water pipes. In normal operation it is used for steam superheating or feedwater preheating. The three component heat exchanger bridges the first and second heat exchangers as an emergency heat exchanger. If in such a case the post fission heat removal has failed, the sodium evaporating in the pressure vessel flows into the unloading space and condenses on the ribs of the emergency heat exchanger. The post fission heat is fed by the water secondary medium directly into the tertiary circuit. The sodium condensate flows back from the unloading space via the lower duct into the reactor cell and maintains the emergency level there. (RW) 891 RW [de

  15. Fission products collecting devices

    International Nuclear Information System (INIS)

    Matsumoto, Hiroshi

    1979-01-01

    Purpose: To enable fission products trap with no contamination to coolants and cover gas by the provision of a fission products trap above the upper part of a nuclear power plant. Constitution: Upon fuel failures in a reactor core, nuclear fission products leak into coolants and move along the flow of the coolants to the coolants above the reactor core. The fission products are collected in a trap container and guided along a pipeline into fission products detector. The fission products detector monitors the concentration of the fission products and opens the downstream valve of the detector when a predetermined concentration of the fission products is detected to introduce the fission products into a waste gas processing device and release them through the exhaust pipe. (Seki, T.)

  16. The study of two, three and four dimensional nonlinear dynamics of nuclear fission reactors and effective parameters on its behaviour

    International Nuclear Information System (INIS)

    Tajik, M.; Ghasemizad, A.

    2008-01-01

    In this research, new physical fission reactor parameters which have very sensitive effects on the qualitative behavior of a reactor, are introduced. Therefore, the two, the nonlinear dynamics of two, three and four dimensional, considering almost the effective parameters are formulated for describing nuclear fission reactor systems. Using both analytical and numerical methods, the stability and instability of the given dynamical equations and the conditions of stability are studied in these systems. We have shown that the two parameters of the mean energy residence time in fuel and coolant and also their ratios have the most qualitative effects on the dynamical behaviour of a typical nuclear fission reactor. Increasing or decreasing of these parameters from a captain limit can lead to stability or un stability in a given system

  17. New ceramics for nuclear industry. Case of fission and fusion reactors

    International Nuclear Information System (INIS)

    Yvars, M.

    1979-10-01

    The ceramics used in the nuclear field are described as is their behaviour under radiation. 1) Power reactors - nuclear fission. Ceramics enter into the fabrication of nuclear fuels: oxides, carbides, uranium or plutonium nitrides or oxy-nitrides. Silicon carbide SiC is used for preparing the fuels of helium cooled high temperature reactors. Its use is foreseen in the design of gas high temperature gas thermal exchangers, as is silicon nitride (Si 3 N 4 ). In the materials for safety or control rods, the intense neutron flows induce nuclear reactions which increase the temperature of the neutron absorbing material. Boron carbide B 4 C, rare earth oxides Ln 2 O 3 , or B 4 C-Cu or B 4 C-Al cermets are employed. Burnable poison materials are formed of Al 2 O 3 -B 4 C or Al 2 O 3 -Ln 2 O 3 cermets. The moderators of thermal neutron reactors are in high purety polycrystalline graphite. For the thermal insulation of reactor vessels and jackets, honeycomb ceramics are used as well as ceramic fibres on an increasing scale (kaolin, alumina and other fibres). 2) fusion reactors (Tokomak). These require refractory materials with a low atomic number. Carbon fibres, boron carbide, some borons (Al B 12 ), silicon nitrides and oxy-nitrides and high density alumina are the substances considered [fr

  18. Determination of burnup in irradiated nuclear fuels by the method of stable 148Nd fission products

    International Nuclear Information System (INIS)

    Souza Sarkis, J.E. de.

    1982-01-01

    A method is described for the isotopic analysis and determination of burnup in irradiated nuclear fuel by mass spectrometric technique. The burnup is calculed from the determination of the concentration of uranium, plutonium and the fission product 148 Nd in the samples of UO 2 irradiated fuel from a P.W.R. type reactor. The method involves the separation of fractions of uranium, plutonium and neodimium from the dissolved irradiated fuel by ion exchange technique. The determination of uranium, plutonium and the fission product 148 Nd is carried out by isotope diluition mass spectrometry technique using as isotope tracers the nuclides 233 U, 242 Pu and 150 Nd. For the chemical processing and handling of the irradiated sample a Hot Chemistry Laboratory was mounted. It consists of glove boxes and equipments for radiation monitoring and protection. The results obtained indicate an atom percent burnup of 2.181 + - 0.035% wich corresponds an 20.937 + - 0.739 Gwd/ton of thermal energy produced. (Author) [pt

  19. Development of fission micro-chambers for nuclear waste incineration studies

    CERN Document Server

    Fadil, M; Christophe, S; Deruelle, O; Fioni, G; Marie, F; Mounier, C; Ridikas, D; Trapp, J P

    2002-01-01

    The Incineration by Accelerator (INCA) project of the Directorate for Science of Matter of the French Atomic Energy Authority (CEA/DSM) aims to outline the ideal physical conditions to transmute minor actinides in a high intensity neutron flux obtained either by hybrid systems or innovative critical reactors. To measure on-line the incineration rates of minor actinides, we are developing an innovative Double Deposit Fission Chamber (DDFC) working in current mode. Our method is based on a comparison between the isotope under study and a reference material whose nuclear parameters are well known, as sup 2 sup 3 sup 5 U and sup 2 sup 3 sup 9 Pu. This new fission chamber will be used in the High Flux Reactor in Grenoble/France in a neutron flux of 1.2x10 sup 1 sup 5 n cm sup - sup 2 s sup - sup 1 for 50 days, the operating cycle of the reactor. These specific experimental conditions require substantial modifications of the existing chambers. The first experiment will be carried out in fall 2000.

  20. Thermochemical Study on the Sulfurization of Fission Products in Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Lee, Jung Won; Yang, M. S.; Park, G. I.; Kim, W. K.; Lee, J. W.

    2005-11-01

    The thermodynamic behavior of the sulfurization of Nd, and Eu element, which are contained in spent nuclear fuel as fission products was investigated through collection and properties analysis of thermodynamic data in sulfurization of uranium oxides, thermodynamic properties analysis for the oxidation and reduction of fission products, and test and analysis for sulfurization characteristics of Nd and Eu oxide. And also, analysis on thermodynamic data, such as M-O-S phase stability diagram and changes of Gibbs free energy for sulfurization of uranium and Nd 2 O 3 and Eu 2 O 3 were carried out. Nd 2 O 3 and Eu 2 O 3 are sulfurized into Nd 2 O 2 S and Eu 2 O 2 S or NdySx and EuySx at a range of 400 to 450 .deg. C, while uranium oxides, such as UO 2 and U 3 O 8 remain unreacted up to 450 .deg. C Formation of UOS at 500 .deg. C is initiated by sulfurization of uranium oxides. Hence, reaction temperature for the sulfurization of the Nd 2 O 3 and Eu 2 O 3 was selected as a 450 .deg. C

  1. The surrogate-reaction method and excitation-energy sorting in nuclear fission

    International Nuclear Information System (INIS)

    Jurado, Beatriz

    2015-01-01

    This manuscript summarises the main activities that I have carried out during the last ten years of research at the Centre d'etudes Nucleaires de Bordeaux-Gradignan (CENBG). It is, to a great extent, a synthesis of nine articles. They can be consulted by the reader that would like to have more detailed information. These articles are denoted as Article I, II.. all along the manuscript. The manuscript is intended to be accessible to PhD students not familiar with the topic. Chapter 1 recalls some of the basic ideas of statistical mechanics and discusses the applicability of its concepts to nuclei. Some of these concepts, in particular the concept of statistical equilibrium, are essential for the topics covered by chapters 2 and 3. Chapter 2 summarises the studies performed by the CENBG collaboration on the surrogate-reaction method in the last ten years. Chapter 3 summarises part of the work done on the modelling of nuclear fission in collaboration with Karl-Heinz Schmidt, it considers the partition of excitation energy and unpaired nucleons in fission on the basis of statistical mechanics. Chapters 2 and 3 contain the bulk of my work, each of them has its own introduction and conclusion sections. Chapter 4 presents the medium and long-term experimental perspectives for the topics described in chapters 2 and 3. (author)

  2. US nuclear power programs

    International Nuclear Information System (INIS)

    McGolf, D.J.

    1994-01-01

    In the United States, coal provided 56 percent of the electricity generated in 1992. Nuclear energy was the next largest contributor, supplying 22 percent. Natural gas provided 9 percent, while hydro-electric and renewables together supplied another 9 percent. Currently, the 109 nuclear power plants in the U.S. have an overall generating capacity of 99,000 MWe. To improve efficiency, safety, and performance, the lessons of 30 years of experience with nuclear powerplants are being incorporated into design criteria for the next generation of U.S. plants. The new Advanced Light Water Reactor plants will feature simpler designs, which will enable more cost-effective construction and maintenance. To enhance safety, design margins are being increased, and human factors are being considered and incorporated into the designs

  3. US nuclear power programs

    Energy Technology Data Exchange (ETDEWEB)

    McGolf, D J

    1994-12-31

    In the United States, coal provided 56 percent of the electricity generated in 1992. Nuclear energy was the next largest contributor, supplying 22 percent. Natural gas provided 9 percent, while hydro-electric and renewables together supplied another 9 percent. Currently, the 109 nuclear power plants in the U.S. have an overall generating capacity of 99,000 MWe. To improve efficiency, safety, and performance, the lessons of 30 years of experience with nuclear powerplants are being incorporated into design criteria for the next generation of U.S. plants. The new Advanced Light Water Reactor plants will feature simpler designs, which will enable more cost-effective construction and maintenance. To enhance safety, design margins are being increased, and human factors are being considered and incorporated into the designs.

  4. Arctic Nuclear Waste Assessment Program

    International Nuclear Information System (INIS)

    Edson, R.

    1995-01-01

    The Arctic Nuclear Waste Assessment Program (ANWAP) was initiated in 1993 as a result of US congressional concern over the disposal of nuclear materials by the former Soviet Union into the Arctic marine environment. The program is comprised of appr. 70 different projects. To date appr. ten percent of the funds has gone to Russian institutions for research and logistical support. The collaboration also include the IAEA International Arctic Seas Assessment Program. The major conclusion from the research to date is that the largest signals for region-wide radionuclide contamination in the Arctic marine environment appear to arise from the following: 1) atmospheric testing of nuclear weapons, a practice that has been discontinued; 2) nuclear fuel reprocessing wastes carried in the Arctic from reprocessing facilities in Western Europe, and 3) accidents such as Chernobyl and the 1957 explosion at Chelyabinsk-65

  5. Thai Nuclear Power Program

    International Nuclear Information System (INIS)

    Namwong, Ratanachai

    2011-01-01

    The Electricity Generating Authority of Thailand (EGAT), the main power producer in Thailand, was first interested in nuclear power as an electricity option in 1967 when the electricity demand increased considerably for the first time as a result of the economic and industrial growth. Its viability had been assessed several times during the early seventies in relation to the changing factors. Finally in the late 1970s, the proceeding with nuclear option was suspended for a variety of reasons, for instance, public opposition, economic repercussion and the uncovering of the indigenous petroleum resources. Nonetheless, EGAT continued to maintain a core of nuclear expertise. During 1980s, faced with dwindling indigenous fossil fuel resources and restrictions on the use of further hydro as an energy source, EGAT had essentially reconsidered introducing nuclear power plants to provide a significant fraction to the long term future electricity demand. The studies on feasibility, siting and environmental impacts were conducted. However, the project was never implemented due to economics crisis in 1999 and strong opposition by environmentalists and activists groups. The 1986 Chernobyl disaster was an important cause. After a long dormant period, the nuclear power is now reviewed as one part of the solution for future energy supply in the country. Thailand currently relies on natural gas for 70 percent of its electricity, with the rest coming from oil, coal and hydro-power. One-third of the natural gas consumed in Thailand is imported, mainly from neighbouring Myanmar. According to Power Development Plan (PDP) 2007 rev.2, the total installed electricity capacity will increase from 28,530.3 MW in 2007 to 44,281 MW by the end of plan in 2021. Significantly increasing energy demand, concerns over climate change and dependence on overseas supplies of fossil fuels, all turn out in a favor of nuclear power. Under the current PDP (as revised in 2009), two 1,000- megawatt nuclear

  6. JEFF 3.1.2 - Joint evaluated nuclear data library for fission and fusion applications - February 2012 (DVD)

    International Nuclear Information System (INIS)

    2012-02-01

    The Joint Evaluated Fission and Fusion File (JEFF) project is a collaboration between NEA Data Bank member countries. The JEFF library combines the efforts of the JEFF and EFF/EAF Working Groups to produce a common sets of evaluated nuclear data, mainly for fission and fusion applications. The JEFF-3.1.2 version, released in February 2012, contains a number of different data types, including neutron and proton interaction data, radioactive decay data, fission yields, and thermal scattering law data. Currently, JEFF-3.1.2 data are available in ENDF-6 format (neutron library) from the Web. This new release is an update from JEFF-3.1.1 which concerns 115 material files from the general purpose incident neutron library which have been modified since JEFF-3.1.1. Modifications include: Hf isotopes: 6 new Hf evaluations have replaced previous ones; Gamma production data from neutron capture (MF=6 MT=102) has been added to 89 fission products (FP) evaluations; 47 of these FP have been replaced by ENDF-B/VII.0 evaluations, with gamma data added in this release. Corrections from JEFF-Beta feedback have been incorporated for 15 materials. Corrections that solve NJOY covariance processing problems and JANIS warnings have been made to 6 files. This DVD contains: - General purpose incident neutron data in ENDF-6 and ACE formats; - Activation data; - Thermal scattering data; - Incident proton data; - Radioactive decay data; - Neutron-induced fission yields data; - Spontaneous fission yields data

  7. 4π-spectrometer technique for measurements of secondary neutron average number in nuclear fission by 252Cf neutrons

    International Nuclear Information System (INIS)

    Vasil'ev, Yu.A.; Barashkov, Yu.A.; Golovanov, O.A.; Sidorov, L.V.

    1977-01-01

    A method for determining the average number of secondary neutrons anti ν produced in nuclear fission by the neutrons of the 252 Cf fission spectra by means of a 4π time-of-flight spectrometer is described. Layers of 252 Cf and an isotope studied are placed close to each other; if the isotope layer density is 1 mg/cm 2 probability of its fission is about 10 -5 per one spontaneous fission of californium. Fission fragments of 252 Cf and the isotope investigated have been detected by two surface-barrier counters with an efficiency close to 100%. The layers and the counters are situated in a measuring chamber placed in the center of the 4π time-of-flight spectrometer. The latter is utilized as a neutron counter because of its fast response. The method has been verified by carrying out measurements for 235 U and 239 Pu. A comparison of the experimental and calculated results shows that the method suggested can apply to determine the number of secondary neutrons in fission of isotopes that have not been investigated yet

  8. Method to separate fission noble gases from gaseous wastes of a reprocessing plant for nuclear fuel material

    International Nuclear Information System (INIS)

    Schnez, H.

    1977-01-01

    In order to avoid the high cost expenditure in the separation of fission noble gases from waste gas of the head end, the following economical method is suggested: The fission noble gases released in the solvent - after grinding and burn-up of the nuclear fuel elements and dissolving in HNO 3 - are purified in a known method and collected in an equalizing tank. From here, the fission noble gas quantity necessary as washing gas is recycled into the solvent, so that a part of the fission noble gas quantity flows in a circuit. The quantity of fission noble gas not required for the above is separated from the circuit, compressed and put into a storage container from where it can be put into gas flashs or be recycled in the gas circuit where necessary. Furthermore, the method involves that to separate krypton, the filtered fission noble gas is compressed, cooled and rectified, whereby the krypton mixture taken from the rectification column is stored under high pressure and the gas part containing xenon, occuring as liquid, is at least partly fed back to the solvent. (HPH) [de

  9. Theoretical Description of the Fission Process

    International Nuclear Information System (INIS)

    Nazarewicz, Witold

    2009-01-01

    Advanced theoretical methods and high-performance computers may finally unlock the secrets of nuclear fission, a fundamental nuclear decay that is of great relevance to society. In this work, we studied the phenomenon of spontaneous fission using the symmetry-unrestricted nuclear density functional theory (DFT). Our results show that many observed properties of fissioning nuclei can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. From the calculated collective potential and collective mass, we estimated spontaneous fission half-lives, and good agreement with experimental data was found. We also predicted a new phenomenon of trimodal spontaneous fission for some transfermium isotopes. Our calculations demonstrate that fission barriers of excited superheavy nuclei vary rapidly with particle number, pointing to the importance of shell effects even at large excitation energies. The results are consistent with recent experiments where superheavy elements were created by bombarding an actinide target with 48-calcium; yet even at high excitation energies, sizable fission barriers remained. Not only does this reveal clues about the conditions for creating new elements, it also provides a wider context for understanding other types of fission. Understanding of the fission process is crucial for many areas of science and technology. Fission governs existence of many transuranium elements, including the predicted long-lived superheavy species. In nuclear astrophysics, fission influences the formation of heavy elements on the final stages of the r-process in a very high neutron density environment. Fission applications are numerous. Improved understanding of the fission process will enable scientists to enhance the safety and reliability of the nation's nuclear stockpile and nuclear reactors. The deployment of a fleet of safe and efficient advanced reactors, which will also minimize radiotoxic

  10. LASL analytical chemistry program for fissionable materials safeguards

    International Nuclear Information System (INIS)

    Jackson, D.D.; Marsh, S.F.

    1979-01-01

    Gas-solid reactions at elevated temperature, used previously to convert uranium in refractory forms to species readily soluble in acid, are being applied to thorium materials. A microgram-sensitive spectrophotometric method was developed for determining uranium and the LASL Automated Spectrophotometer has been modified to use it. The instrument now is functional for determining milligram amounts of plutonium, and milligram and microgram amounts of uranium. Construction of an automated controlled-potential-coulometric analyzer has been completed. It is giving design performance of 0.1% relative standard deviation for the determination of plutonium using a method developed especially for the instrument. A method has been developed for the microcomplexometric titration of uranium in its stable (VI) oxidation state. A color probe analyzer assembled for this titration also has been used for microcomplexometric titration of thorium. The present status of reference materials prepared for NBS and for the SALE program, as well as examples of working reference materials prepared for use with nondestructive analyzers, is given. The interlaboratory measured value of the 239 Pu half-life is 24,119 y. Just completed measurement of the half life of 241 Pu is 14.38 y. Measurement of the 240 Pu half life is in progress

  11. Research problems of fission product behaviour in fuels of nuclear power plants and ways of their solution

    International Nuclear Information System (INIS)

    Sulaberidze, V.Sh.

    1988-01-01

    The most important problems of studying behaviour of fission products in fuel elements of maneouvrable nuclear power plants units are formulated. In-pile and out-of-pile investigation methods solving these problems are characterized in brief. 12 refs.; 2 figs

  12. Needs and accuracy requirements for fission product nuclear data in the physics design of power reactor cores

    International Nuclear Information System (INIS)

    Rowlands, J.L.

    1978-01-01

    The fission product nuclear data accuracy requirements for fast and thermal reactor core performance predictions were reviewed by Tyror at the Bologna FPND Meeting. The status of the data was assessed at the Meeting and it was concluded that the requirements of thermal reactors were largely met, and the yield data requirements of fast reactors, but not the cross section requirements, were met. However, the World Request List for Nuclear Data (WRENDA) contains a number of requests for fission product capture cross sections in the energy range of interest for thermal reactors. Recent reports indicate that the fast reactor reactivity requirements might have been met by integral measurements made in zero power critical assemblies. However, there are requests for the differential cross sections of the individual isotopes to be determined in addition to the integral data requirements. The fast reactor requirements are reviewed, taking into account some more recent studies of the effects of fission products. The sodium void reactivity effect depends on the fission product cross sections in a different way to the fission product reactivity effect in a normal core. This requirement might call for different types of measurement. There is currently an interest in high burnup fuel cycles and alternative fuel cycles. These might require more accurate fission product data, data for individual isotopes and data for capture products. Recent calculations of the time dependence of fission product reactivity effects show that this is dependent upon the data set used and there are significant uncertainties. Some recent thermal reactor studies on approximations in the treatment of decay chains and the importance of xenon and samarium poisoning are also summarized. (author)

  13. Accreditation of nuclear engineering programs

    International Nuclear Information System (INIS)

    Williamson, T.G.

    1989-01-01

    The American Nuclear Society (ANS) Professional Development and Accreditation Committee (PDAC) has the responsibility for accreditation of engineering and technology programs for nuclear and similarly named programs. This committee provides society liaison with the Accreditation Board for Engineering and Technology (ABET), is responsible for the appointment and training of accreditation visitors, nomination of members for the ABET Board and Accreditation Commissions, and review of the criteria for accreditation of nuclear-related programs. The committee is composed of 21 members representing academia and industry. The ABET consists of 19 participating bodies, primarily professional societies, and 4 affiliate bodies. Representation on ABET is determined by the size of the professional society and the number of programs accredited. The ANS, as a participating body, has one member on the ABET board, two members on the Engineering Accreditation Commission, and one on the Technology Accreditation Commission. The ABET board sets ABET policy and the commissions are responsible for accreditation visits

  14. On the combination of delayed neutron and delayed gamma techniques for fission rate measurement in nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Perret, G.; Jordan, K. A. [Paul Scherrer Institut, Villigen, 5232 (Switzerland)

    2011-07-01

    Novel techniques to measure newly induced fissions in spent fuel after re-irradiation at low power have been developed and tested at the Proteus zero-power research reactor. The two techniques are based on the detection of high energy gamma-rays emitted by short-lived fission products and delayed neutrons. The two techniques relate the measured signals to the total fission rate, the isotopic composition of the fuel, and nuclear data. They can be combined to derive better estimates on each of these parameters. This has potential for improvement in many areas. Spent fuel characterisation and safeguard applications can benefit from these techniques for non-destructive assay of plutonium content. Another application of choice is the reduction of uncertainties on nuclear data. As a first application of the combination of the delayed neutron and gamma measurement techniques, this paper shows how to reduce the uncertainties on the relative abundances of the longest delayed neutron group for thermal fissions in {sup 235}U, {sup 239}Pu and fast fissions in {sup 238}U. The proposed experiments are easily achievable in zero-power research reactors using fresh UO{sub 2} and MOX fuel and do not require fast extraction systems. The relative uncertainties (1{sigma}) on the relative abundances are expected to be reduced from 13% to 4%, 16% to 5%, and 38% to 12% for {sup 235}U, {sup 238}U and {sup 239}Pu, respectively. (authors)

  15. Fusion-Fission Transmutation Scheme-Efficient destruction of nuclear waste

    International Nuclear Information System (INIS)

    Kotschenreuther, M.; Valanju, P.M.; Mahajan, S.M.; Schneider, E.A.

    2009-01-01

    A fusion-assisted transmutation system for the destruction of transuranic nuclear waste is developed by combining a subcritical fusion-fission hybrid assembly uniquely equipped to burn the worst thermal nonfissile transuranic isotopes with a new fuel cycle that uses cheaper light water reactors for most of the transmutation. The center piece of this fuel cycle, the high power density compact fusion neutron source (100 MW, outer radius <3 m), is made possible by a new divertor with a heat-handling capacity five times that of the standard alternative. The number of hybrids needed to destroy a given amount of waste is an order of magnitude below the corresponding number of critical fast-spectrum reactors (FRs) as the latter cannot fully exploit the new fuel cycle. Also, the time needed for 99% transuranic waste destruction reduces from centuries (with FR) to decades

  16. Monitoring and diagnostic system of fission product transport and release in nuclear power plants

    International Nuclear Information System (INIS)

    Kodaira, H.; Kondo, S.; Togo, Y.

    1983-01-01

    A monitoring and diagnostic system (MADS) of fission product (FP) transport and release in nuclear power plants (NPPs) is proposed and the conceptual design for MADS is studied. A MADS can be described in the most general way as a computer-based information processing system which takes in plant data, processes it and displays the results to the NPP's operating crew. A major concern for MADS is, however, not to evaluate general plant dynamics, but to monitor the distribution of whole radioactive materials such as FP, and to diagnose the plant state in the view of FP transport during the NPP's lifetime. Several functions demanded of MADS are: (a) during normal operation, to certify the fuel integrity and the effectiveness of the purification systems, (b) in an unusual event, to identify the event and to monitor the amount of FP release with accuracy, and (c) in case of a rare occurrence, to estimate the maximum potential release

  17. Continuous radiochemical analysis of fission products in a nuclear reactor water coolant

    International Nuclear Information System (INIS)

    Moskvin, L.N.; Zakharov, L.K.; Leont'ev, G.G.; Mel'nikov, V.A.; Orlenkov, I.S.; Slutskij, G.K.

    1975-01-01

    Method for continuous radiochemical analysis of I, Cs, Ba, Sr and Ce isotopes in a reactor water heat-transfer agent was developed. A continuous two-dimensional chromatographic process of complex mixtures separation of substances proved to be feasible on several parallel sorbent layers, which moved at constant velocities and separated by stationary intermediate collectors. Tests on model solutions containing I, Ce, Cs and Ba isotopes and on heat-carrier samples showed quantitative separation of elements. The results were indicative of a basic possibility of using multisorbent chromatographs for continuous control of multicomponent mixtures, particularly for control of radioactive fission product compositions in water heat-transfer agents in nuclear power plants. A diagram is shown for a two-dimensional chromatographic separation of a multicomponent mixture. Also shown is a flow chart of an installation for continuous control of iodine and cesium isotope activities

  18. Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

    International Nuclear Information System (INIS)

    McDeavitt, Sean; Shao, Lin; Tsvetkov, Pavel; Wirth, Brian; Kennedy, Rory

    2014-01-01

    Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

  19. Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean [Texas A & M Univ., College Station, TX (United States); Shao, Lin [Texas A & M Univ., College Station, TX (United States); Tsvetkov, Pavel [Texas A & M Univ., College Station, TX (United States); Wirth, Brian [Univ. of Tennessee, Knoxville, TN (United States); Kennedy, Rory [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-04-07

    Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

  20. Programs for nuclear data analysis

    International Nuclear Information System (INIS)

    Bell, R.A.I.

    1975-01-01

    The following report details a number of programs and subroutines which are useful for analysis of data from nuclear physics experiments. Most of them are available from pool pack 005 on the IBM1800 computer. All of these programs are stored there as core loads, and the subroutines and functions in relocatable format. The nature and location of other programs are specified as appropriate. (author)

  1. 1: the atom. 2: radioactivity. 3: man and radiations. 4: the energy. 5: nuclear energy: fusion and fission. 6: the operation of a nuclear reactor. 7: the nuclear fuel cycle; 1: l'atome. 2: la radioactivite. 3: l'homme et les rayonnements. 4: l'energie. 5: l'energie nucleaire: fusion et fission. 6: le fonctionnement d'un reacteur nucleaire. 7: le cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This series of 7 digest booklets present the bases of the nuclear physics and of the nuclear energy: 1 - the atom (structure of matter, chemical elements and isotopes, the four fundamental interactions, nuclear physics); 2 - radioactivity (definition, origins of radioelements, applications of radioactivity); 3 - man and radiations (radiations diversity, biological effects, radioprotection, examples of radiation applications); 4 - energy (energy states, different forms of energy, characteristics); 5 - nuclear energy: fusion and fission (nuclear energy release, thermonuclear fusion, nuclear fission and chain reaction); 6 - operation of a nuclear reactor (nuclear fission, reactor components, reactor types); 7 - nuclear fuel cycle (nuclear fuel preparation, fuel consumption, reprocessing, wastes management). (J.S.)

  2. Nuclear wastes: research programs

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    The management of long-living and high level radioactive wastes in France belongs to the framework of the December 30, 1991 law which defines three ways of research: the separation and transmutation of radionuclides, their reversible storage or disposal in deep geologic formations, and their processing and surface storage during long duration. Research works are done in partnership between public research and industrial organizations in many French and foreign laboratories. Twelve years after its enforcement, the impact of this law has overstepped the simple research framework and has led to a deep reflection of the society about the use of nuclear energy. This short paper presents the main results obtained so far in the three research ways, the general energy policy of the French government, the industrial progresses made in the framework of the 1991 law and the international context of the management of nuclear wastes. (J.S.)

  3. 75 years of the discovery of nuclear fission. A timeline; 75 Jahre Entdeckung der Kernspaltung. Eine Zeitlinie

    Energy Technology Data Exchange (ETDEWEB)

    Reinartz, Jerome [atw-Redaktion, Hattingen (Germany)

    2013-12-15

    The discovery of nuclear fission and the possibility of a self- sustaining chain reaction begins with modern atomic and nuclear physics at the end of the 19{sup th} century. Further key discoveries resulted as of 1900 with the fundamentals on the structure of matter. In 1938 Otto Hahn, Fritz Strassmann and Lise Meitner came to realise that neutrons were able to split uranium nuclei. Important milestones until 1938 and beyond are summarized. (orig.)

  4. On-line mass spectrometry measurement of fission gas release from nuclear fuel submitted to thermal transients

    International Nuclear Information System (INIS)

    Guigues, E.; Janulyte, A.; Zerega, Y.; Pontillon, Y.

    2013-06-01

    The work presented in this paper has been performed in the framework of a joint research program between Aix-Marseille University and CEA Cadarache. The aim is to develop a mass spectrometer (MS) device for the MERARG facility. MERARG is devoted to the study of fission gas release measurement, from nuclear fuels submitted to annealing tests in high activity laboratory such as LECA-STAR, thanks to gamma spectrometry. The mass spectrometer will then extend the measurement capability from the γ-emitters gases to all the gases involved in the release in order to have a better understanding of the fission gas release dynamics from fuel during thermal transients. Furthermore, the mass spectrometer instrument combines the capabilities and performances of both on-line (for release kinetic) and off-line implementations (for delayed accurate analysis of capacities containing total release gas). The paper deals with two main axes: (1) the modelling of gas sampling inlet device and its performance and (2) the first MS qualification/calibration results. The inlet device samples the gas and also adapts the pressure between MERARG sweeping line at 1.2 bar and mass spectrometer chamber at high vacuum. It is a two-stage device comprising a capillary at inlet, an intermediate vacuum chamber, a molecular leak inlet and a two-stage pumping device. Pressure drops, conductance and throughputs are estimated both for mass spectrometer operation and for exhaust gas recovery. Possible gas segregation is also estimated and device modification is proposed to attain a more accurate calibration. First experimental results obtained from a standard gas bottle show that the quantitative analysis at a few ppm level can be achieved for all isotopes of Kr and Xe, as well as masses 2 and 4 u. (authors)

  5. Fabrication and Testing of a Modular Micro-Pocket Fission Detector Instrumentation System for Test Nuclear Reactors

    Science.gov (United States)

    Reichenberger, Michael A.; Nichols, Daniel M.; Stevenson, Sarah R.; Swope, Tanner M.; Hilger, Caden W.; Roberts, Jeremy A.; Unruh, Troy C.; McGregor, Douglas S.

    2018-01-01

    Advancements in nuclear reactor core modeling and computational capability have encouraged further development of in-core neutron sensors. Measurement of the neutron-flux distribution within the reactor core provides a more complete understanding of the operating conditions in the reactor than typical ex-core sensors. Micro-Pocket Fission Detectors have been developed and tested previously but have been limited to single-node operation and have utilized highly specialized designs. The development of a widely deployable, multi-node Micro-Pocket Fission Detector assembly will enhance nuclear research capabilities. A modular, four-node Micro-Pocket Fission Detector array was designed, fabricated, and tested at Kansas State University. The array was constructed from materials that do not significantly perturb the neutron flux in the reactor core. All four sensor nodes were equally spaced axially in the array to span the fuel-region of the reactor core. The array was filled with neon gas, serving as an ionization medium in the small cavities of the Micro-Pocket Fission Detectors. The modular design of the instrument facilitates the testing and deployment of numerous sensor arrays. The unified design drastically improved device ruggedness and simplified construction from previous designs. Five 8-mm penetrations in the upper grid plate of the Kansas State University TRIGA Mk. II research nuclear reactor were utilized to deploy the array between fuel elements in the core. The Micro-Pocket Fission Detector array was coupled to an electronic support system which has been specially developed to support pulse-mode operation. The Micro-Pocket Fission Detector array composed of four sensors was used to monitor local neutron flux at a constant reactor power of 100 kWth at different axial locations simultaneously. The array was positioned at five different radial locations within the core to emulate the deployment of multiple arrays and develop a 2-dimensional measurement of

  6. Determination of fission gas release of spent nuclear fuel in puncturing test and in leaching experiments under anoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    González-Robles, E., E-mail: ernesto.gonzalez-robles@kit.edu [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany); Metz, V. [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany); Wegen, D.H. [European Commission, Joint Research Centre, Institute for Transuranium Elements (JRC-ITU), P.O. Box 2340, 76125, Karlsruhe (Germany); Herm, M. [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany); Papaioannou, D. [European Commission, Joint Research Centre, Institute for Transuranium Elements (JRC-ITU), P.O. Box 2340, 76125, Karlsruhe (Germany); Bohnert, E. [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany); Gretter, R. [European Commission, Joint Research Centre, Institute for Transuranium Elements (JRC-ITU), P.O. Box 2340, 76125, Karlsruhe (Germany); Müller, N. [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany); Nasyrow, R.; Weerd, W. de; Wiss, T. [European Commission, Joint Research Centre, Institute for Transuranium Elements (JRC-ITU), P.O. Box 2340, 76125, Karlsruhe (Germany); Kienzler, B. [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), P.O. Box 3640, D-76021, Karlsruhe (Germany)

    2016-10-15

    During reactor operation the fission gases Kr and Xe are formed within the UO{sub 2} matrix of nuclear fuel. Their quantification is important to evaluate their impact on critical parameters regarding the fuel behaviour during irradiation and (long-term) interim storage, such as internal pressure of the fuel rod and fuel swelling. Moreover the content of Kr and Xe in the plenum of a fuel rod and their content in the UO{sub 2} fuel itself are widely used as indicators for the release properties of {sup 129}I, {sup 137}Cs, and other safety relevant radionuclides with respect to final disposal of spent nuclear fuel. The present study deals with the fission gas release from spent nuclear fuel exposed to simulated groundwater in comparison with the fission gas previously released to the fuel rod plenum during irradiation in reactor. In a unique approach we determined both the Kr and Xe inventories in the plenum by means of a puncturing test and in leaching experiments with a cladded fuel pellet and fuel fragments in bicarbonate water under 3.2 bar H{sub 2} overpressure. The fractional inventory of the fission gases released during irradiation into the plenum was (8.3 ± 0.9) %. The fraction of inventory of fission gases released during the leaching experiments was (17 ± 2) % after 333 days of leaching of the cladded pellet and (25 ± 2) % after 447 days of leaching of the fuel fragments, respectively. The relatively high release of fission gases in the experiment with fuel fragments was caused by the increased accessibility of water to the Kr and Xe occluded in the fuel.

  7. Sloan foundation nuclear education program

    International Nuclear Information System (INIS)

    Kursunoglu, B.N.

    1992-01-01

    The Alfred P. Sloan Foundation realized the time had come for a real and significant contribution to the enlightenment of university students concerning nuclear matters. The Sloan Foundation chose to educate the youth of four-year colleges and universities with a curriculum established with the resource information sieved from three workshops for professors in these institutions. The three workshops were organized by groups at Harvard-MIT (two-week Summer Program on Nuclear Weapons and Arms Control), the University of California, San Diego (two-week Summer Seminar on Global Security and Arms Control), and the University of Miami (one-week Winter Workshop on Enlightenment: The Best Security in a Nuclear-Armed World). In this report the author focuses on a unified presentation of the basic facts, aims, and results of the Sloan Foundation Nuclear Education Program based on three workshops directed by Jack Ruina (MIT), Herbert York (USCD), and Behram Kursunoglu (UM) and offered from 1983-1990

  8. Fission product chemistry in severe nuclear reactor accidents, specialists' meeting at JRC-Ispra, 15-17 January 1990

    International Nuclear Information System (INIS)

    Nichols, A.L.

    1990-05-01

    A specialists' meeting was held at JRC-Ispra from 15 to 17 January 1990 to review the current understanding of fission-product chemistry during severe accidents in light water reactors. Discussions focussed on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. Recommendations for future chemistry work were made covering the following areas: (a) fuel degradation and fission-product release, (b) transport and attenuation processes in the reactor coolant system, (c) containment chemistry (iodine behaviour and core-concrete interactions). (author)

  9. The Oklo natural nuclear reactors: neutron parameters, age and duration of the reactions, uranium and fission products migrations

    International Nuclear Information System (INIS)

    Ruffenach, J.-C.

    1979-09-01

    Mass spectrometry and isotopic dilution technique are used in order to carry out, on various samples from the fossil nuclear reactors at Oklo, Gabon, isotopic and chemical analyses of some particular elements involved in the nuclear reactions: uranium, lead, bismuth, thorium, rare gases (krypton, xenon), rare earths (neodymium, samarium, europium, gadolinium, dysprosium), ruthenium and palladium. Interpretations of these analyses lead to the determination of many neutron parameters such as the neutron fluence received by the samples, the spectrum index, the conversion coefficient, and also the percentages of fissions due to uranium-238 and plutonium-239 and the total number of fissions relative to uranium. All these results make it possible to determine the age of the nuclear reactions by measuring the amounts of fission rare earths formed, i.e. 1.97 billion years. This study brings some informations to the general problem of radioactive wastes storage in deep geological formations, the storage of uranium, plutonium and many fission products having been carried out naturally, and for about two billion years [fr

  10. Soviet Union's Nuclear Power Program

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Glasnost has dramatically increased the availability of information about the Soviet Union's nuclear industry. In the future, even more information is likely to become known as Soviet participation in international forums increases. Not only is much more general information now available, but up-to-date details are regularly provided, including information such as the Soviet nuclear industry's strategic direction and goals, recent reactor design changes, safety inspection results, and reports of public opposition and protest. This article summarizes the current status of the Soviet nuclear power program, reconciling the often conflicting reports from various public sources

  11. A Research Program for Fission Product/Dust Transport in HTGR's

    International Nuclear Information System (INIS)

    Loyalka, Sudarshan

    2016-01-01

    High and Very High Temperatures Gas Reactors (HTGRs/VHTRs) have five barriers to fission product (FP) release: the TRISO fuel coating, the fuel elements, the core graphite, the primary coolant system, and the reactor building. This project focused on measurements and computations of FP diffusion in graphite, FP adsorption on graphite and FP interactions with dust particles of arbitrary shape. Diffusion Coefficients of Cs and Iodine in two nuclear graphite were obtained by the release method and use of Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) and Instrumented Neutron Activation Analysis (INAA). A new mathematical model for fission gas release from nuclear fuel was also developed. Several techniques were explored to measure adsorption isotherms, notably a Knudsen Effusion Mass Spectrometer (KEMS) and Instrumented Neutron Activation Analysis (INAA). Some of these measurements are still in progress. The results will be reported in a supplemental report later. Studies of FP interactions with dust and shape factors for both chain-like particles and agglomerates over a wide size range were obtained through solutions of the diffusion and transport equations. The Green's Function Method for diffusion and Monte Carlo technique for transport were used, and it was found that the shape factors are sensitive to the particle arrangements, and that diffusion and transport of FPs can be hindered. Several journal articles relating to the above work have been published, and more are in submission and preparation.

  12. A Research Program for Fission Product/Dust Transport in HTGR’s

    Energy Technology Data Exchange (ETDEWEB)

    Loyalka, Sudarshan [Univ. of Missouri, Columbia, MO (United States)

    2016-02-01

    High and Very High Temperatures Gas Reactors (HTGRs/VHTRs) have five barriers to fission product (FP) release: the TRISO fuel coating, the fuel elements, the core graphite, the primary coolant system, and the reactor building. This project focused on measurements and computations of FP diffusion in graphite, FP adsorption on graphite and FP interactions with dust particles of arbitrary shape. Diffusion Coefficients of Cs and Iodine in two nuclear graphite were obtained by the release method and use of Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) and Instrumented Neutron Activation Analysis (INAA). A new mathematical model for fission gas release from nuclear fuel was also developed. Several techniques were explored to measure adsorption isotherms, notably a Knudsen Effusion Mass Spectrometer (KEMS) and Instrumented Neutron Activation Analysis (INAA). Some of these measurements are still in progress. The results will be reported in a supplemental report later. Studies of FP interactions with dust and shape factors for both chain-like particles and agglomerates over a wide size range were obtained through solutions of the diffusion and transport equations. The Green's Function Method for diffusion and Monte Carlo technique for transport were used, and it was found that the shape factors are sensitive to the particle arrangements, and that diffusion and transport of FPs can be hindered. Several journal articles relating to the above work have been published, and more are in submission and preparation.

  13. Characterization of the ptr5+ gene involved in nuclear mRNA export in fission yeast

    International Nuclear Information System (INIS)

    Watanabe, Nobuyoshi; Ikeda, Terumasa; Mizuki, Fumitaka; Tani, Tokio

    2012-01-01

    Highlights: ► We cloned the ptr5 + gene involved in nuclear mRNA export in fission yeast. ► The ptr5 + gene was found to encode nucleoporin 85 (Nup85). ► Seh1p and Mlo3p are multi-copy suppressors for the ptr5 mutation. ► Ptr5p/Nup85p functions in nuclear mRNA export through the mRNA export factor Rae1p. ► Ptr5p/Nup85p interacts genetically with pre-mRNA splicing factors. -- Abstract: To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A) + RNA transport] 1 to 11, which accumulate poly(A) + RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5–1 mutant shows dots- or a ring-like accumulation of poly(A) + RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5 + gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5–1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5–1 mutation. In addition, we found that the ptr5–1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5–1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.

  14. Study of the adequacy of personnel for the US nuclear program

    International Nuclear Information System (INIS)

    1981-11-01

    The report will emphasize fission topics relative to fusion because of the relative number of personnel involved. However, the commonality of types of personnel and their required educational background are such that the health of the fission educational infrastructure will affect the future supply of fusion technologists. Alternatively, the attractive aspects of some closely related fusion research in universities can help attract the high quality personnel needed in the fission field. The report's recommendations are therefore based on the needs of both programs. A separate study of the detailed requirements for fusion scientific and engineering personnel has been prepared by the Office of Fusion Energy. In this report, the present status of nuclear power, historic personnel requirements, future requirements, and constraints on future supply are analyzed. The intent of this report is to provide a context for conclusions and recommendation of Government actions leading to an adequate supply of nuclear manpower both for the industrial and Government components of the nuclear enterprise

  15. Fission products in the spent nuclear fuel from czech nuclear power plants

    International Nuclear Information System (INIS)

    Lelek, V.; Mikisek, M.; Marek, T.

    1999-01-01

    The nuclear power is expected to become a supply able to cover a significant part of the world energetic demand in future. But its big disadvantage, the risk of the spent nuclear fuel, has to be solved. The aim of this paper is to make simple estimates of the upper limits of amounts of the most dangerous spent fuel components and their compounds produced in Czech Republic until 2040. Our estimates are independent on particular type reactor (only on its power) and so they can be carried out for any nuclear fuel cycle. (Authors)

  16. Selective separation of long-lived fission products in nuclear spent fuel

    International Nuclear Information System (INIS)

    Ozawa, Masaki; Ikegami, Tetsuo; Asakura, Toshihide; Morita, Yasuji

    2003-01-01

    A catalytic electrolytic extraction (CEE) method has been studied to separate rare metal fission products (Pd, Ru, Rh, Tc, Te and Se). Some of them are long-lived radioactive, but are potentially strategic materials. In CEE process, Pd 2+ cation itself would not only be easily deposited from various nitric acid solutions but also enhance the deposition of RuNO 3+ and ReO 4 by acting as Pd adatom . Monte than 99% of the recovery ratio was attained for RuNo 3+ and Pd 2+ . Fundamental radio-electrochemical property of FPs/TRU in the synthetic and real dissolver solution is being investigated in the new JAERI-JNC collaboration frame. For the extended recycling of such FPs (including Cs/Sr), new precedent research programs are on-going involving universities. (author)

  17. Proceedings of the 12. International Symposium on Nuclear Physics - Heavy-Ion Collisions and Nuclear Fission - organized by the Technical University of Dresden, November 22-26, 1982 in Gaussig (GDR)

    International Nuclear Information System (INIS)

    Reif, R.; Teichert, J.

    1982-12-01

    The following problems in experimental and theoretical investigations of heavy-ion reactions and the dynamics of nuclear fission processes are discussed: (1) emission of fast light particles in heavy-ion collisions, preequilibrium effects; (2) dynamics of deep inelastic heavy-ion reactions; (3) selected topics in quasi-elastic heavy-ion collisions; and (4) collective transport theory for fission, cross sections and neutron spectra of fission. Problems of neutron induced reactions and nuclear data evaluation are also covered. (author)

  18. The limits of the nuclear chart set by fission and alpha decay

    Directory of Open Access Journals (Sweden)

    Möller Peter

    2016-01-01

    Full Text Available I will review how our picture of heavy-element nuclear structure has evolved through remarkably simple ideas and related models. It is well known that the Bethe-Weizsäcker semi-empirical mass model had an important role in unraveling radioactive decay and element transmutation in the heavy-element region in the 1930s. A remarkable aspect is that this model could immediately after the discovery of fission be generalized to explain this phenomenon through the consideration of deformation of a charged liquid drop. Bethe and Bacher already raised the possibility that shell structure (by them calculated in terms of a single-particle oscillator potential could give rise to noticeable deviations between results of the macroscopic mass model and experiment but limited data prevented firm conclusions. In the 1950s the single-particle models took a realistic form and also included deformation. The possibility of the existence of a relatively stable “island” of superheavy elements was raised already then. But it was not until the work by Strutinsky in the mid 1960s that a quantitative model for the nuclear potential-energy emerged in the form of the macroscopic-microscopic model. Although new elements have been discovered at an almost steady pace since 1940, theory indicates that we are close to the end of this era: repulsive Coulomb effects will set the limit of observable elements to near Z = 120.

  19. Nuclear fusion and fission, and related technologies department: 2007 progress report

    International Nuclear Information System (INIS)

    2007-12-01

    ENEA continues to contribute to broadening plasma physics knowledge as well as to developing the relevant technologies in the framework of the EURATOM-ENEA Association for fusion. This report describes the 2007 research activities carried out by the ENEA Fusion Research Group of the Nuclear Fusion and Fission, and Related Technologies Department (FPN). Other ENEA research groups also contributed to the activities. The following fields were addressed: magnetically confined nuclear fusion (physics and technology), superconductivity and inertial fusion. Planning of the 2007 fusion activities took into account the different scenarios determined by the new organisation of the European programme based on the start of ITER construction. The establishment of the ITER International Organisation and the European Domestic Agency (Fusion for Energy) required a new organisational scheme. This has implied not only the implementation of a more project oriented structure but also the need to launch the constitution of a consortium agreement between the Associations in order to cope with the needs for the design and construction of the components of ITER that require specific know-how, e.g., diagnostics and test blanket module

  20. Design and Test Plans for a Non-Nuclear Fission Power System Technology Demonstration Unit

    Science.gov (United States)

    Mason, Lee; Palac, Donald; Gibson, Marc; Houts, Michael; Warren, John; Werner, James; Poston, David; Qualls, Arthur Lou; Radel, Ross; Harlow, Scott

    2012-01-01

    A joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) team is developing concepts and technologies for affordable nuclear Fission Power Systems (FPSs) to support future exploration missions. A key deliverable is the Technology Demonstration Unit (TDU). The TDU will assemble the major elements of a notional FPS with a non-nuclear reactor simulator (Rx Sim) and demonstrate system-level performance in thermal vacuum. The Rx Sim includes an electrical resistance heat source and a liquid metal heat transport loop that simulates the reactor thermal interface and expected dynamic response. A power conversion unit (PCU) generates electric power utilizing the liquid metal heat source and rejects waste heat to a heat rejection system (HRS). The HRS includes a pumped water heat removal loop coupled to radiator panels suspended in the thermal-vacuum facility. The basic test plan is to subject the system to realistic operating conditions and gather data to evaluate performance sensitivity, control stability, and response characteristics. Upon completion of the testing, the technology is expected to satisfy the requirements for Technology Readiness Level 6 (System Demonstration in an Operational and Relevant Environment) based on the use of high-fidelity hardware and prototypic software tested under realistic conditions and correlated with analytical predictions.

  1. Nuclear plant aging research program

    International Nuclear Information System (INIS)

    Eissenberg, D.M.

    1987-01-01

    The U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, has established the Nuclear Plant Aging Research (NPAR) program in its Division of Engineering Technology. Principal contractors for this program include Oak Ridge National Laboratory, Brookhaven National Laboratory, Idaho National Engineering Laboratory, and Pacific Northwest Laboratory. The program goals are: to identify and characterize time-dependent degradation (aging) of nuclear plant safety-related electrical and mechanical components which could lead to loss of safety function; to identify and recommend methods for detecting and trending aging effects prior to loss of safety function so that timely maintenance can be implemented; and to recommend maintenance practices for mitigating the effects of aging. Research activities include prioritization of system and component aging in nuclear plants, characterization of aging degradation of specific components including identification of functional indicators useful for trending degradation, and testing of practical methods and devices for measuring the functional indicators. Aging assessments have been completed on electric motors, snubbers, motor-operated valves, and check valves. Testing of trending methods and devices for motor-operated valves and check valves is in progress

  2. Decree of 8 October 1969, Stb. 471, concerning the implementation of Sections 13 and 14 of the Nuclear Energy Act (Fissionable Materials and Ores (Registration))

    International Nuclear Information System (INIS)

    1969-01-01

    This Decree lays down the system for registration and notification of fissionable materials and ores in accordance with the Nuclear Energy Act. The register must list the quantities of fissionable materials and ores available in the Netherlands and their location. This procedure applies only to materials and ores subject to licensing. (NEA) [fr

  3. Passive Nuclear Plants Program (UPDATE)

    International Nuclear Information System (INIS)

    Chimeno, M. A.

    1998-01-01

    The light water passive plants program (PCNP), today Advanced Nuclear Power Plants Program (PCNA), was constituted in order to reach the goals of the Spanish Electrical Sector in the field of advanced nuclear power plants, optimize the efforts of all Spanish initiatives, and increase joint presence in international projects. The last update of this program, featured in revision 5th of the Program Report, reflects the consolidation of the Spanish sector's presence in International programs of the advanced power plants on the basis of the practically concluded American ALWR program. Since the beginning of the program , the PCNP relies on financing from the Electrical sector, Ocide, SEPI-Endesa, Westinghouse, General Electric, as well as from the industrial cooperators, Initec, UTE (Initec- Empresarios Agrupados), Ciemat, Enusa, Ensa and Tecnatom. The program is made up of the following projects, already concluded: - EPRI's Advanced Light Water Plants Certification Project - Westinghouse's AP600 Project - General Electric's SBWR Project (presently paralyzed) and ABWR project Currently, the following project are under development, at different degrees of advance: - EPP project (European Passive Plant) - EBWR project (European Advanced Boiling Water Reactor)

  4. Review of ENDF/B-VI Fission-Product Cross Sections[Evaluated Nuclear Data File

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.Q.; MacFarlane, R.E.

    2000-04-01

    In response to concerns raised in the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 93-2, the US Department of Energy (DOE) developed a comprehensive program to help assure that the DOE maintain and enhance its capability to predict the criticality of systems throughout the complex. Tasks developed to implement the response to DNFSB recommendation 93-2 included Critical Experiments, Criticality Benchmarks, Training, Analytical Methods, and Nuclear Data. The Nuclear Data Task consists of a program of differential measurements at the Oak Ridge Electron Linear Accelerator (ORELA), precise fitting of the differential data with the generalized least-squares fitting code SAMMY to represent the data with resonance parameters using the Reich-Moore formalism along with covariance (uncertainty) information, and the development of complete evaluations for selected nuclides for inclusion in the Evaluated Nuclear Data File (ENDFB).

  5. Fission energy program of the U.S. Department of Energy

    International Nuclear Information System (INIS)

    1978-06-01

    The document describes programs managed by the Program Director for Nuclear Energy, Department of Energy, and under the cognizance of the Committee on Science and Technology, United States House of Representatives. The major portion of the document is concerned with civilian nuclear power development, the policy for which has been established by the National Energy Plan of April 1977, but it also includes descriptions of the space applications and naval reactor programs

  6. Nuclear Technology Programs semiannual progress report, October 1988--March 1989

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, J.E. [ed.

    1990-12-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period October 1988--March 1989. These programs involve R&D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with examining the feasibility of substituting low-enriched for high-enriched uranium in the production of fission product {sup 99}Mo. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories. 127 refs., 76 figs., 103 tabs.

  7. Nuclear Technology Programs semiannual progress report, October 1988--March 1989

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1990-12-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period October 1988--March 1989. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with examining the feasibility of substituting low-enriched for high-enriched uranium in the production of fission product 99 Mo. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories. 127 refs., 76 figs., 103 tabs

  8. Fission product yield evaluation for the USA evaluated nuclear data files

    International Nuclear Information System (INIS)

    Rider, B.F.; England, T.R.

    1994-01-01

    An evaluated set of fission product yields for use in calculation of decay heat curves with improved accuracy has been prepared. These evaluated yields are based on all known experimental data through 1992. Unmeasured fission product yields are calculated from charge distribution, pairing effects, and isomeric state models developed at Los Alamos National Laboratory. The current evaluation has been distributed as the ENDF/B-VI fission product yield data set

  9. Studies of the nuclear inertia in fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Moeller, P.; Nix, J.R.

    1978-01-01

    On the basis of the non-self-consistent cranking model the authors study some aspects of the nuclear inertia of interest in fission and heavy-ion reactions. First, the authors consider in the adiabatic limit the inertia for a doubly closed-shell nucleus in a deformed spheroidal harmonic-oscillator single-particle potential plus a small perturbation. When expressed in terms of a coordinate that describes the deformation of the nuclear matter distribution, the inertia for small oscillations about a spherical shape is exactly equal to the incompressible, irrotational value. For large distortions it deviates from the incompressible, irrotational value by up to about +-1% away from level crossings. Second, in order to study the dependence of the inertia upon a level crossing, two levels of the above system are considered. This is done both in the adiabatic limit and for large collective velocities. At level crossings the adiabatic inertia relative to the deformation of the matter distribution diverges as 1/modΔV, where modΔV is the magnitude of the perturbation. However, for large collective velocities the contribution to the inertia from a level crossing is less than 4modΔV(d(rsub(m))/dt) 2 where d(rsub(m))/dt is the collective velocity of the matter distribution. Although the effect of large velocities on the remaining levels of the many-body system or the effect of a statistical ensemble of states has not been considered, some of the results suggest that for high excitation energies and moderately large collective velocities the nuclear inertia approaches approximately the irrotational value. (Auth.)

  10. Fission product release under severe accidental conditions: general presentation of the program and synthesis of VERCORS 1-6 results

    International Nuclear Information System (INIS)

    Ducros, G.; Malgouyres, P.P.; Kissane, M.; Boulaud, D.; Durin, M.

    2001-01-01

    The French Nuclear Protection and Safety Institute (IPSN) launched the HEVA-VERCORS program in 1983, in collaboration with Electricite de France (EDF). This program is devoted to the source term of fission products (FP) released from PWR fuel samples during a sequence representative of a severe accident. The analytical experiments are conducted in a shielded hot cell of the LAMA facility of the Grenoble center of CEA (Commissariat a l'Energie Atomique); as simplified tests addressing a limited number of phenomena, they give results complementary to those of the more global in-pile PHEBUS experiments. Six VERCORS tests have been conducted from 1989-1994 with higher fuel temperatures (up to 2600 K) compared with the earlier HEVA tests in order, in particular, to quantify better the release of lower volatile FPs. This paper gives an overview of the experimental facility, a synthesis of FP release from these tests and exhibits, as an example, some specific results of the VERCORS 6 test, performed with high burn-up fuel (60 GWd tU -1 ). The on-going VERCORS HT-RT program, designed to reach fuel liquefaction temperatures, is described before conclusions are drawn

  11. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    International Nuclear Information System (INIS)

    Palmiotti, G.

    2011-01-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 418 nuclides; (2) Covariance uncertainty data for 185 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions at higher energies for isotopes of F, Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides 235,238U and 239Pu at this point, except for delayed neutron data, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on 239Pu; and (9) A new Decay Data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide

  12. Power program and nuclear power

    International Nuclear Information System (INIS)

    Chernilin, Yu.F.

    1990-01-01

    Main points of the USSR power program and the role of nuclear power in fuel and power complex of the country are considered. Data on dynamics of economic indices of electric power generation at nuclear power plants during 1980-1988 and forecasts till 2000 are presented. It is shown that real cost of 1 kW/h of electric power is equal to 1.3-1.8 cop., and total reduced cost is equal to 1.8-2.4 cop

  13. Polarographic determination of Iodide and Iodate, in Solutions Coming from Aerosols in Fission Products Containment Studies in Nuclear Power Stations

    International Nuclear Information System (INIS)

    Sanchez, M.; Ballesteros, O.; Fernandez, M.; Clavero, M.A.; Gonzalez, A.M.

    2000-01-01

    A polarographic method is described for the iodine species determination, iodide and iodate in water solutions. the iodate can be determined by differential pulse polarography. Calibration curves and the detection and determination limits have been obtained. Iodides is oxidized to iodate with sodium hypochlorite and the excess of oxidizing agent is destroyed with sodium sulphide. The concentration of iodide is calculated as the difference between the concentration of iodate in the sample before and after the oxidation. As an application, species of iodine in samples coming from the experimental plants GIRS (Gaseous Iodine Removal by Sprays) of Nuclear Fission Department of the CIEMAT, dedicated to fission products containment studies in nuclear power station, were determined. (Author) 10 refs

  14. Systematics of Fission-Product Yields

    International Nuclear Information System (INIS)

    Wahl, A.C.

    2002-01-01

    Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z F = 90 thru 98, mass number A F = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru ∼200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from ∼ 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron (∼ fission spectrum) induced fission reactions

  15. Systematics of Fission-Product Yields

    Energy Technology Data Exchange (ETDEWEB)

    A.C. Wahl

    2002-05-01

    Empirical equations representing systematics of fission-product yields have been derived from experimental data. The systematics give some insight into nuclear-structure effects on yields, and the equations allow estimation of yields from fission of any nuclide with atomic number Z{sub F} = 90 thru 98, mass number A{sub F} = 230 thru 252, and precursor excitation energy (projectile kinetic plus binding energies) PE = 0 thru {approx}200 MeV--the ranges of these quantities for the fissioning nuclei investigated. Calculations can be made with the computer program CYFP. Estimates of uncertainties in the yield estimates are given by equations, also in CYFP, and range from {approx} 15% for the highest yield values to several orders of magnitude for very small yield values. A summation method is used to calculate weighted average parameter values for fast-neutron ({approx} fission spectrum) induced fission reactions.

  16. The U.S. program for fusion nuclear technology development

    International Nuclear Information System (INIS)

    Clarke, J.F.; Haas, G.M.

    1989-01-01

    The Fusion Nuclear Technology (FNT) research and development program in the United States is shaped by a hierarchy of documents and by the environment for nuclear energy existing in the United States. The fission nuclear industry in the United States has suffered problems with public perception of safety, waste disposal issues, and economics as influenced by safety and environmental issues. For fusion to be a viable energy alternative, it must offer significant improvements in these areas. The hierarchy of documents defining objectives, plans, and strategy of the U.S. FNT program consists of the Magnetic Fusion Program Plan (MFPP) (February 1985), the Technical Planning Activity Final Report (January 1987), the Finesse Program Report (January 1987), and the Blanket Comparison and Selection Study Final Report (September 1984). In addition, two other documents are also significant in shaping FNT policy. These are the IEA report on Material for Fusion (December 1986) and the Summary of the Report of the Senior Committee on Environmental, Safety, and Economic Aspects of Magnetic Fusion Energy (September 1987). The U.S. Magnetic Fusion Program Plan defines four key technical issues (magnetic confinement systems, properties of burning plasmas, fusion nuclear technology, and fusion materials). (orig./KP)

  17. QA programs in nuclear power plants

    International Nuclear Information System (INIS)

    Ellingson, A.C.

    1976-01-01

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

  18. Monte Carlo code Serpent calculation of the parameters of the stationary nuclear fission wave

    Directory of Open Access Journals (Sweden)

    V. M. Khotyayintsev

    2017-12-01

    Full Text Available n this work, propagation of the stationary nuclear fission wave was simulated for series of fixed power values using Monte Carlo code Serpent. The wave moved in the axial direction in 5 m long cylindrical core of fast reactor with pure 238U raw fuel. Stationary wave mode arises some period later after the wave ignition and lasts sufficiently long to determine kef with high enough accuracy. The velocity characteristic of the reactor was determined as the dependence of the wave velocity on the neutron multiplication factor. As we have recently shown within a one-group diffusion description, the velocity characteristic is two-valued due to the effect of concentration mechanisms, while thermal feedback affects it only quantitatively. The shape and parameters of the velocity characteristic critically affect feasibility of the reactor design since stationary wave solutions of the lower branch are unstable and do not correspond to any real waves in self-regulated reactor, like CANDLE. In this work calculations were performed without taking into account thermal feedback. They confirm that theoretical dependence correctly describes the shape of the velocity characteristic calculated using the results of the Serpent modeling.

  19. Management of radioactive waste from 99Mo production by nuclear fission

    International Nuclear Information System (INIS)

    Rego, Maria Eugenia de Melo

    2013-01-01

    Brazil intends to build a facility for the 99 Mo production through 235 U fission, once this radioisotope is largely used in nuclear medicine. This study aimed at estimating the physical, chemical and radiological characteristics of radioactive waste expected to be generated in that facility, and to provide theoretical subsides that can be used on the definition of a proper waste management system. Two production scenarios were established and the radioisotope inventories of the wastes were calculated by Scale®. From the chemical processing of the uranium targets the wastes were characterized on their chemical and radiological features. MicroShield® was used to determine the activity concentrations up to three months of 99 Mo production. In addition, this work presents dose rate calculation for several sizes of shielding and different amount of wastes, collected in a proper package for in-site transportation. Radionuclides responsible for higher doses were identified in order to facilitate choosing the most appropriate method for managing the wastes after their chemical separation and before their storage. These results are part of what is expected on radioactive wastes at a 99 Mo production facility and might help on the development of the waste management planning for that facility. (author)

  20. GROGi-F. Modified version of GROGi 2 nuclear evaporation computer code including fission decay channel

    International Nuclear Information System (INIS)

    Delagrange, H.

    1977-01-01

    This report is the user manual of the GR0GI-F code, modified version of the GR0GI-2 code. It calculates the cross sections for heavy ion induced fission. Fission probabilities are calculated via the Bohr-Wheeler formalism

  1. Calculation of the nuclear fission data based on the framework of the QMD + SDM

    International Nuclear Information System (INIS)

    Rong Jian; Iwamoto, O.; Fukahori, T.

    2002-01-01

    The quantum molecular dynamics (QMD), statistical decay model (SDM) and the statistical fission theory were used to analyze the mass distribution of the fission products, the prompt fission neutron spectrum (x(E)) and the prompt fission neutron multiplicities (ν-bar pf (E)) caused by the intermediate energy nucleon-induced fission. The semi-empirical formula of energy level density parameter used in the statistical process was also studied. Very few adjustable parameters were included in the present method. By some physical analysis, it can be thought that the present results are reasonable. The x(E) and ν-bar pf (E) can be obtained in the intermediate energy region by the present method

  2. Energy dissipation in the process of ternary fission in heavy nuclear reaction

    International Nuclear Information System (INIS)

    Li Xian; Wang Chengqian; Yan Shiwei

    2015-01-01

    We studied the evolution of the collective motion, interaction potential, the total kinetic and excitation energies in ternary fissions of 197 Au + 197 Au system at 15 MeV/u, and discussed energy dissipation of this reaction. Through the comparison with energy-angle correlation data in binary fissions, we preliminarily concluded that the rst fission of ternary fission was an extreme deep-inelastic process. We further analyzed the correlation of the total kinetic energy with impact parameters in both binary and ternary reactions, and found that the total energy of binary reactions systems was lost about 150 MeV more than ternary fission with small impact parameters, and with larger impact parameters the total energy of ternary reactions were lost 300 MeV more than binary reactions. (authors)

  3. Development and manufacturing of special fission chambers for in-core measurement requirements in nuclear reactors

    International Nuclear Information System (INIS)

    Geslot, B.; Berhouet, F.; Oriol, L.; Breaud, S.; Jammes, C.; Filliatre, P.; Villard, J. F.

    2009-01-01

    The Dosimetry Command control and Instrumentation Laboratory (LDCI) at CEA/Cadarache is specialized in the development, design and manufacturing of miniature fission chambers (from 8 mm down to 1.5 mm in diameter). The LDCI fission chambers workshop specificity is its capacity to manufacture and distribute special fission chambers with fissile deposits other than U 235 (typically Pu 242 , Np 237 , U 238 , Th 232 ). We are also able to define the characteristics of the detector for any in-core measurement requirements: sensor geometry, fissile deposit material and mass, filling gas composition and pressure, operating mode (pulse, current or Campbelling) with associated cable and electronics. The fission chamber design relies on numerical simulation and modeling tools developed by the LDCI. One of our present activities in fission chamber applications is to develop a fast neutron flux instrumentation using Campbelling mode dedicated to measurements in material testing reactors. (authors)

  4. Development and manufacturing of special fission chambers for in-core measurement requirements in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Geslot, B.; Berhouet, F.; Oriol, L.; Breaud, S.; Jammes, C.; Filliatre, P.; Villard, J. F. [CEA, DEN, Dosimetry Command Control and Instrumentation Laboratory, F-13109 Saint-Paul-lez-Durance (France)

    2009-07-01

    The Dosimetry Command control and Instrumentation Laboratory (LDCI) at CEA/Cadarache is specialized in the development, design and manufacturing of miniature fission chambers (from 8 mm down to 1.5 mm in diameter). The LDCI fission chambers workshop specificity is its capacity to manufacture and distribute special fission chambers with fissile deposits other than U{sup 235} (typically Pu{sup 242}, Np{sup 237}, U{sup 238}, Th{sup 232}). We are also able to define the characteristics of the detector for any in-core measurement requirements: sensor geometry, fissile deposit material and mass, filling gas composition and pressure, operating mode (pulse, current or Campbelling) with associated cable and electronics. The fission chamber design relies on numerical simulation and modeling tools developed by the LDCI. One of our present activities in fission chamber applications is to develop a fast neutron flux instrumentation using Campbelling mode dedicated to measurements in material testing reactors. (authors)

  5. EU research in 'operational safety of existing installations' under the nuclear fission programme 1998-2002

    International Nuclear Information System (INIS)

    Goethem, G. van; Zurita, A.; Manolatos, P.; Bermejo, J. Martin; Casalta, S.

    2003-01-01

    In this paper, an overview is given of the most important aspects of the research activities organised by the European Union (EU) in the area of reactor safety under the current 5th Euratom Framework Programme 1998-2002 (FP-5). This area is focussing on 'Operational Safety of Existing Installations'. The fundamental safety objective for nuclear power plants (NPPs) consists in protecting the public and the environment from the harmful effects resulting from ionising radiations. Community research with this objective is carried out through both 'indirect actions' (organised by DG Research) and 'direct actions' (carried out by DG Joint Research Centre/JRC). The mid-term achievements of this area were discussed at the symposium FISA-2001 (EC Luxembourg, 12-14 November 2001/750 pages, EUR 20281 EN, OPOCE Luxembourg 2002). This research area is actually part of the FP-5 Key Action NUCLEAR FISSION, which consists of the following four areas: reactor safety, waste management (including partitioning and transmutation), future systems (including high temperature reactors), and radiation protection. More specifically, this paper deals with the strategy, the organisation and the main achievements of the 73 multi-partner projects cosponsored by the European Union as 'indirect actions' (shared-cost and concerted actions). These projects are organised in three clusters, each devoted to one key safety issue. Each cluster is treated in a separate section of this paper, namely: (1) Plant Life Extension and Management (PLEM cluster), (2) Severe Accident Management (SAM cluster), and (3) Evolutionary Safety Concepts (EVOL cluster). The total cost of the 'indirect actions' of this Community research area is approximately Euro 82.5 million, out of which Euro 43 million is contributed by the EU budget. At FISA-2001, only the 'indirect actions' that started before 1 January 2001, were formally presented, i.e. a total of 41 projects - the 32 more recent multi-partner projects were

  6. Accidental behaviour of nuclear fuel in a warehousing site under air: investigation of the nuclear ceramic oxidation and of fission gas release

    International Nuclear Information System (INIS)

    Desgranges, L.

    2006-12-01

    After a brief presentation of the context of his works, i.e. the nuclear fuel, its behaviour in a nuclear reactor, and studies performed in high activity laboratory, the author more precisely presents its research topic: the behaviour of defective nuclear fuel in air. Then, he describes the researches performed in three main directions: firstly, the characterization and understanding of fission gas localisation (experimental localisation, understanding of the bubble forming mechanisms), secondly, the determination of mechanisms related to oxidation (atomic mechanisms related to UO 2 oxidation, oxidation of fragments of irradiated fuel, the CROCODILE installation). He finally presents his scientific project which notably deals with fission gas release (from UO 2 to U 3 O 7 , and from U 3 O 7 to U 3 O 8 ), and with further high activity laboratory experiments

  7. New nuclear build programs status and prospects

    International Nuclear Information System (INIS)

    Tankosic, D.; Sabinov, S.

    2010-01-01

    Presentation topics: Reactor technology update OECD OEMs development; Nuclear power sector development projections - global nuclear capacity projections to 2050 (NEA low , high and phase-out scenarios); new nuclear constructions Worley Parsons support to new nuclear Programs around the world; Drivers towards increased nuclear capacity - increased demand of generating capacities; climate change concerns; Security of supply; Economics; Robust to fuel price increases

  8. Fission product release from nuclear fuel II. Validation of ASTEC/ELSA on analytical and large scale experiments

    International Nuclear Information System (INIS)

    Brillant, G.; Marchetto, C.; Plumecocq, W.

    2013-01-01

    Highlights: • A wide range of experiments is presented for the ASTEC/ELSA code validation. • Analytical tests such as AECL, ORNL and VERCORS are considered. • A large-scale experiment, PHEBUS FPT1, is considered. • The good agreement with measurements shows the efficiency of the ASTEC modelling. • Improvements concern the FP release modelling from MOX and high burn-up UO 2 fuels. - Abstract: This article is the second of two articles dedicated to the mechanisms of fission product release from a degraded core. The models of fission product release from nuclear fuel in the ASTEC code have been described in detail in the first part of this work (Brillant et al., this issue). In this contribution, the validation of ELSA, the module of ASTEC that deals with fission product and structural material release from a degraded core, is presented. A large range of experimental tests, with various temperature and conditions for the fuel surrounding atmosphere (oxidising and reducing), is thus simulated with the ASTEC code. The validation database includes several analytical experiments with both bare fuel (e.g. MCE1 experiments) and cladded fuel (e.g. HCE3, VERCORS). Furthermore, the PHEBUS large-scale experiments are used for the validation of ASTEC. The rather satisfactory comparison between ELSA calculations and experimental measurements demonstrates the efficiency of the analytical models to describe fission product release in severe accident conditions

  9. Nuclear Data Activities in Support of the DOE Nuclear Criticality Safety Program

    International Nuclear Information System (INIS)

    Westfall, R.M.; McKnight, R.D.

    2005-01-01

    The DOE Nuclear Criticality Safety Program (NCSP) provides the technical infrastructure maintenance for those technologies applied in the evaluation and performance of safe fissionable-material operations in the DOE complex. These technologies include an Analytical Methods element for neutron transport as well as the development of sensitivity/uncertainty methods, the performance of Critical Experiments, evaluation and qualification of experiments as Benchmarks, and a comprehensive Nuclear Data program coordinated by the NCSP Nuclear Data Advisory Group (NDAG).The NDAG gathers and evaluates differential and integral nuclear data, identifies deficiencies, and recommends priorities on meeting DOE criticality safety needs to the NCSP Criticality Safety Support Group (CSSG). Then the NDAG identifies the required resources and unique capabilities for meeting these needs, not only for performing measurements but also for data evaluation with nuclear model codes as well as for data processing for criticality safety applications. The NDAG coordinates effort with the leadership of the National Nuclear Data Center, the Cross Section Evaluation Working Group (CSEWG), and the Working Party on International Evaluation Cooperation (WPEC) of the OECD/NEA Nuclear Science Committee. The overall objective is to expedite the issuance of new data and methods to the DOE criticality safety user. This paper describes these activities in detail, with examples based upon special studies being performed in support of criticality safety for a variety of DOE operations

  10. Interim report on research between Oak Ridge National Laboratory and Japan Nuclear Cycle Development Institute on neutron-capture cross sections by long-lived fission product nuclides

    International Nuclear Information System (INIS)

    Furutaka, Kazuyoshi; Nakamura, Shoji; Harada, Hideo

    2004-03-01

    Neutron capture cross sections of long-lived fission products (LLFP) are important quantities as fundamental data for the study of nuclear transmutation of radioactive wastes. Previously obtained thermal-neutron capture gamma-ray data were analyzed to deduce the partial neutron-capture cross sections of LLFPs including 99 Tc, 93 Zr, and 107 Pd for thermal neutrons. By comparing the decay gamma-ray data and prompt gamma-ray data for 99 Tc, the relation between the neutron-capture cross section deduced by the two different methods was studied. For the isotopes 93 Zr and 107 Pd, thermal neutron-capture gamma-ray production cross sections were deduced for the first time. The level schemes of 99 Tc, 93 Zr, and 107 Pd have also been constructed form the analyzed data and compared with previously reported levels. This work has been done under the cooperative program 'Neutron Capture Cross Sections of Long-Lived Fission products (LLFPs)' by Japan Nuclear Cycle Development Institute (JNC) and Oak Ridge National Laboratory (ORNL). (author)

  11. Investigations of the natural fission reactor program. Progress report, October 1977--September 1978

    International Nuclear Information System (INIS)

    Cowan, G.A.; Norris, A.E.

    1978-10-01

    The U.S. study of the Oklo natural reactor began in 1973 with the principal objectives of understanding the processes that produced the reactor and that led to the retention of many of its products. Major facets of the program have been the chemical separation and mass spectrometric analysis of the reactor components and products, the petrological and mineralogical examination of samples taken from the reactor zones, and an interdisciplinary modeling of possible processes consistent with reactor physics, geophysics, and geochemistry. Most of the past work has been on samples taken within the reactor zones. Presently, these studies give greater emphasis to the measurement of mobile products in additional suites of samples collected peripherally and ''downstream'' from the reactor zones. This report summarizes the current status of research and the views of U.S. investigators, with particular reference to the extensive work of the French scientists, concerning the main features of the Oklo natural fission reactor. Also mentioned briefly is the U.S. search for natural fission reactors at other locations

  12. Feynman variance for neutrons emitted from photo-fission initiated fission chains - a systematic simulation for selected speacal nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Soltz, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Danagoulian, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheets, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Korbly, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hartouni, E. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-05-22

    Theoretical calculations indicate that the value of the Feynman variance, Y2F for the emitted distribution of neutrons from ssionable exhibits a strong monotonic de- pendence on a the multiplication, M, of a quantity of special nuclear material. In 2012 we performed a series of measurements at the Passport Inc. facility using a 9- MeV bremsstrahlung CW beam of photons incident on small quantities of uranium with liquid scintillator detectors. For the set of objects studies we observed deviations in the expected monotonic dependence, and these deviations were later con rmed by MCNP simulations. In this report, we modify the theory to account for the contri- bution from the initial photo- ssion and benchmark the new theory with a series of MCNP simulations on DU, LEU, and HEU objects spanning a wide range of masses and multiplication values.

  13. Radioactive Emissions from Fission-Based Medical Isotope Production and Their Effect on Global Nuclear Explosion Detection

    International Nuclear Information System (INIS)

    Bowyer, T.; Saey, P.

    2015-01-01

    The use of medical isotopes, such as Tc-99m, is widespread with over 30 million procedures being performed every year, but the fission-based production of isotopes used for medical procedures causes emissions into the environment. This paper will show that gaseous radioactive isotopes of xenon, such as Xe-133, are released in high quantities, because they have a high fission cross section and they are difficult to scrub from the processes used to produce the medical isotopes due to their largely unreactive nature. Unfortunately, the reasons that large amounts of radioactive xenon isotopes are emitted from isotope production are the same as those that make these isotopes the most useful isotopes for the detection of underground nuclear explosions. Relatively recently, the nuclear explosion monitoring community has established a provisional monitoring network for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) that includes radioactive xenon monitoring as a major component. This community has discovered that emissions from medical isotope production present a more serious problem to nuclear explosion monitoring than thought when the network was first conceived. To address the growing problem, a group of scientists in both the monitoring and the isotope production communities have come together to attempt to find scientific and pragmatic ways to address the emissions problems, recognizing that medical isotope production should not be adversely affected, while monitoring for nuclear explosions should remain effective as isotope production grows, changes, and spreads globally. (author)

  14. Characterization of the fusion-fission process in light nuclear systems

    International Nuclear Information System (INIS)

    Anjos, R.M. dos.

    1992-01-01

    Fusion cross sections measurements of highly damped processes and elastic scattering were performed for the 16, 17, 18 O + 10, 11 B and 19 F + 9 Be, in the incident energy interval 22 ≤ E LAB ≤ 64 MeV. Evidences are presented that highly damped binary processes observed in these systems are originated from a fusion-fission process rather than a dinuclear ''orbiting'' mechanism. The relative importance of the fusion-fission process in these very light systems is demonstrated both by the experimental results, which indicate a statistically balanced compound nucleus fission process occurrence, and theoretical calculations. (L.C.J.A.)

  15. Nuclear program of South Korea

    International Nuclear Information System (INIS)

    Brown, D.S.; James, K.R.

    1993-01-01

    Slightly larger than Portugal, South Korea comprises the lower half on the Korean Peninsula, covering approximately 38 thousand square miles. the Republic of Korea (South Korea) was established in 1948, and until 1962 the country grew slowly. However, through a series of five-year economic plans initiated by South Korean President Park Ching Hee, South Korea has since created an export-oriented economy, which now plays a major role in regional as well as global trade. South Korea has been forced to constantly upgrade its power generation structure in order to sustain the explosive growth it has experienced. Nuclear power has been a major player in this expansion and is expected to play an ever-increasing role. The country presently operates nine nuclear reactors with a total net generating capacity of 7,266 MWe. By the year 2006, the nuclear program is scheduled to grow to 27 reactors, with a net generating capacity exceeding 23 thousand MWe. Once this goal is reached, nuclear-generated power would account for more than 40 percent of the country's total installed electrical capacity

  16. Study of the prompt gamma ray signal from fissions in special nuclear materials induced using an associated particle neutron generator

    International Nuclear Information System (INIS)

    Koltick, D. S.; Kane, S. Z.

    2009-01-01

    More than 42 million cargo containers entered the United States in 2005. To search for a few kilograms of special nuclear material (SNM) within this vast stream of cargo, an inspection system based on neutron-induced fission followed by the coincident detection of multiple prompt fission gamma rays is investigated using MCNP-Polimi code. The system utilizes two deuterium-tritium (DT) associated particle neutron generators, each capable of 10 9 neutrons/s at 14.1 MeV, with sub-nanosecond timing resolution ZnO:Ga alpha detectors internal to the generator. Because prompt fission signals are approximately 100 times stronger than the delayed signals, the neutron flux is greatly reduced compared to 10 11-12 neutrons/s required for systems based on delayed signals such as the 'nuclear car wash' [4]. In addition the system utilizes 30 cm deep liquid krypton (LKr) noble gas detectors having 94% detection efficiency for 1 MeV gamma rays, high solid angle coverage (∼ 50% of the total solid angle), and sub-nanosecond timing resolution (∼ 600 ps). An algorithm for distinguishing U-235 from U-238 is presented. (authors)

  17. Fission neutron multiplicity calculations

    International Nuclear Information System (INIS)

    Maerten, H.; Ruben, A.; Seeliger, D.

    1991-01-01

    A model for calculating neutron multiplicities in nuclear fission is presented. It is based on the solution of the energy partition problem as function of mass asymmetry within a phenomenological approach including temperature-dependent microscopic energies. Nuclear structure effects on fragment de-excitation, which influence neutron multiplicities, are discussed. Temperature effects on microscopic energy play an important role in induced fission reactions. Calculated results are presented for various fission reactions induced by neutrons. Data cover the incident energy range 0-20 MeV, i.e. multiple chance fission is considered. (author). 28 refs, 13 figs

  18. A separate effect study of the influence of metallic fission products on CsI radioactive release from nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Di Lemma, F.G., E-mail: fidelma.dilemma@gmail.com [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Department of Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, 2629 JB (Netherlands); Colle, J.Y., E-mail: jean-yves.colle@ec.europa.eu [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Beneš, O. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Konings, R.J.M. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Department of Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, 2629 JB (Netherlands)

    2015-10-15

    The chemistry of cesium and iodine is of main importance to quantify the radioactive release in case of a nuclear reactor accident, or sabotage involving irradiated nuclear materials. We studied the interaction of CsI with different metallic fission products such as Mo and Ru. These elements can be released from nuclear fuel when exposed to oxidising conditions, as in the case of contact of overheated nuclear fuel with air (e.g. in a spent fuel cask sabotage, uncovering of a spent fuel pond, or air ingress accidents). Experiments were performed by vaporizing mixtures of the compounds in air, and analysing the produced aerosols in view of a possible gas–gas and gas–aerosol reactions between the compounds. These results were compared with the gaseous species predicted by thermochemical equilibrium calculations and experimental equilibrium vaporization tests using Knudsen Effusion Mass Spectrometry.

  19. Study of nuclear photoexcitation mechanisms in the Δ region (3,3) through the fission

    International Nuclear Information System (INIS)

    Arruda Neto, J.D.T.

    1986-01-01

    Experimental results and conclusions obtained for the Bi sup(209) electro and photofission in an energy range between the fission barrier (∼ Mev) and the neighbourhood of the delta peak are presented. (E.G.)

  20. Innovative High Temperature Heat Pipes for Spacecraft Nuclear Fission Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Glenn is examining small fission reactors for future space transportation and surface power applications. The reactors would have an 8 to 15 year design life...

  1. Conceptual design of a fusion-fission hybrid reactor for transmutation of high level nuclear waste

    International Nuclear Information System (INIS)

    Qiu, L.J.; Wu, Y.C.; Yang, Y.W.; Wu, Y.; Luan, G.S.; Xu, Q.; Guo, Z.J.; Xiao, B.J.

    1994-01-01

    To assess the feasibility of the transmutation of long-lived radioactive waste using fusion-fission hybrid reactors, we are studying all the possible types of blanket, including a comparison of the thermal and fast neutron spectrum blankets. Conceptual designs of a small tokamak hybrid blanket with small inventory of actinides and fission products are presented. The small inventory of wastes makes the system safer. The small hybrid reactor system based on a fusion core with experimental parameters to be realized in the near future can effectively transmute actinides and fission products at a neutron wall loading of 1MWm -2 . An innovative energy system is also presented, including a fusion driver, fuel breeder, high level waste transmuter, fission reactor and so on. An optimal combination of all types of reactor is proposed in the system. ((orig.))

  2. Fission yields data generation and benchmarks of decay heat estimation of a nuclear fuel

    Science.gov (United States)

    Gil, Choong-Sup; Kim, Do Heon; Yoo, Jae Kwon; Lee, Jounghwa

    2017-09-01

    Fission yields data with the ENDF-6 format of 235U, 239Pu, and several actinides dependent on incident neutron energies have been generated using the GEF code. In addition, fission yields data libraries of ORIGEN-S, -ARP modules in the SCALE code, have been generated with the new data. The decay heats by ORIGEN-S using the new fission yields data have been calculated and compared with the measured data for validation in this study. The fission yields data ORIGEN-S libraries based on ENDF/B-VII.1, JEFF-3.1.1, and JENDL/FPY-2011 have also been generated, and decay heats were calculated using the ORIGEN-S libraries for analyses and comparisons.

  3. Storage and Containment of Nuclear Targets for Pulsed Fission-Fusion Testing

    Data.gov (United States)

    National Aeronautics and Space Administration — The combined fission-fusion fuel target is the heart of an engine concept that can open the solar system to fast and efficient human exploration. This is a unique...

  4. Controlled isotropic fission fragment sources on the base of nuclear-physical facilities

    International Nuclear Information System (INIS)

    Sevast'yanov, V.D.; Maslov, G.N.

    1995-01-01

    Isotropic fission fragment sources (IFFS) are developed on the base of a neutron generator and pulse fast reactor. IFFS permit to calibrate fission fragment detectors. The IFFS consist of radiators with 235 U. The radiators are placed in a thermal neutron field of the neutron generator or in the reactor core center. The fragment activity is controlled by indications of an α-particle counter or by indications of a monitor of energy release in the core. 14 refs.; 1 fig.; 1 tab

  5. The CCONE Code System and its Application to Nuclear Data Evaluation for Fission and Other Reactions

    Science.gov (United States)

    Iwamoto, O.; Iwamoto, N.; Kunieda, S.; Minato, F.; Shibata, K.

    2016-01-01

    A computer code system, CCONE, was developed for nuclear data evaluation within the JENDL project. The CCONE code system integrates various nuclear reaction models needed to describe nucleon, light charged nuclei up to alpha-particle and photon induced reactions. The code is written in the C++ programming language using an object-oriented technology. At first, it was applied to neutron-induced reaction data on actinides, which were compiled into JENDL Actinide File 2008 and JENDL-4.0. It has been extensively used in various nuclear data evaluations for both actinide and non-actinide nuclei. The CCONE code has been upgraded to nuclear data evaluation at higher incident energies for neutron-, proton-, and photon-induced reactions. It was also used for estimating β-delayed neutron emission. This paper describes the CCONE code system indicating the concept and design of coding and inputs. Details of the formulation for modelings of the direct, pre-equilibrium and compound reactions are presented. Applications to the nuclear data evaluations such as neutron-induced reactions on actinides and medium-heavy nuclei, high-energy nucleon-induced reactions, photonuclear reaction and β-delayed neutron emission are mentioned.

  6. The CCONE Code System and its Application to Nuclear Data Evaluation for Fission and Other Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, O., E-mail: iwamoto.osamu@jaea.go.jp; Iwamoto, N.; Kunieda, S.; Minato, F.; Shibata, K.

    2016-01-15

    A computer code system, CCONE, was developed for nuclear data evaluation within the JENDL project. The CCONE code system integrates various nuclear reaction models needed to describe nucleon, light charged nuclei up to alpha-particle and photon induced reactions. The code is written in the C++ programming language using an object-oriented technology. At first, it was applied to neutron-induced reaction data on actinides, which were compiled into JENDL Actinide File 2008 and JENDL-4.0. It has been extensively used in various nuclear data evaluations for both actinide and non-actinide nuclei. The CCONE code has been upgraded to nuclear data evaluation at higher incident energies for neutron-, proton-, and photon-induced reactions. It was also used for estimating β-delayed neutron emission. This paper describes the CCONE code system indicating the concept and design of coding and inputs. Details of the formulation for modelings of the direct, pre-equilibrium and compound reactions are presented. Applications to the nuclear data evaluations such as neutron-induced reactions on actinides and medium-heavy nuclei, high-energy nucleon-induced reactions, photonuclear reaction and β-delayed neutron emission are mentioned.

  7. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B.; Herman, M.; Author(s): Chadwick,M.B.; Herman,M.; Oblozinsky,P.; Dunn,M.E.; Danon,Y.; Kahler,A.C.; Smith,D.L.; Pritychenko,B.; Arbanas,G.; Arcilla,R.; Brewer,R.; Brown,D.A.; Capote,R.; Carlson,A.D.; Cho,Y.S.; Derrien,H.; Guber,K.; Hale,G.M.; Hoblit,S.; Holloway,S.: Johnson,T.D.; Kawano,T.; Kiedrowski,B.C.; Kim,H.; Kunieda,S.; Larson,N.M.; Leal,L.; Lestone,J.P.; Little,R.C.; McCutchan,E.A.; MacFarlane,R.E.; MacInnes,M.; Mattoon,C.M.; McKnight,R.D.; Mughabghab,S.F.; Nobre,G.P.A.; Palmiotti,G.; Palumbo,A.; Pigni,M.T.; Pronyaev,V.G.; Sayer,R.O.; Sonzogni,A.A.; Summers,N.C.; Talou,P.; Thompson,I.J.; Trkov,A.; Vogt,R.L.; van der Marck,S.C.; Wallner,A.; White,M.C.; Wiarda,D.; Young,P.G.

    2011-12-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He, Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl, K, Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides {sup 235,238}U and {sup 239}Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es, Fm, and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on {sup 239}Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0

  8. Fission products in National Atmospheric Deposition Program—Wet deposition samples prior to and following the Fukushima Dai-Ichi Nuclear Power Plant incident, March 8?April 5, 2011

    Science.gov (United States)

    Wetherbee, Gregory A.; Debey, Timothy M.; Nilles, Mark A.; Lehmann, Christopher M.B.; Gay, David A.

    2012-01-01

    Radioactive isotopes I-131, Cs-134, or Cs-137, products of uranium fission, were measured at approximately 20 percent of 167 sampled National Atmospheric Deposition Program monitoring sites in North America (primarily in the contiguous United States and Alaska) after the Fukushima Dai-Ichi Nuclear Power Plant incident on March 12, 2011. Samples from the National Atmospheric Deposition Program were analyzed for the period of March 8-April 5, 2011. Calculated 1- or 2-week radionuclide deposition fluxes at 35 sites from Alaska to Vermont ranged from 0.47 to 5,100 Becquerels per square meter during the sampling period of March 15-April 5, 2011. No fission-product isotopes were measured in National Atmospheric Deposition Program samples obtained during March 8-15, 2011, prior to the arrival of contaminated air in North America.

  9. TRAFIC, a computer program for calculating the release of metallic fission products from an HTGR core

    International Nuclear Information System (INIS)

    Smith, P.D.

    1978-02-01

    A special purpose computer program, TRAFIC, is presented for calculating the release of metallic fission products from an HTGR core. The program is based upon Fick's law of diffusion for radioactive species. One-dimensional transient diffusion calculations are performed for the coated fuel particles and for the structural graphite web. A quasi steady-state calculation is performed for the fuel rod matrix material. The model accounts for nonlinear adsorption behavior in the fuel rod gap and on the coolant hole boundary. The TRAFIC program is designed to operate in a core survey mode; that is, it performs many repetitive calculations for a large number of spatial locations in the core. This is necessary in order to obtain an accurate volume integrated release. For this reason the program has been designed with calculational efficiency as one of its main objectives. A highly efficient numerical method is used in the solution. The method makes use of the Duhamel superposition principle to eliminate interior spatial solutions from consideration. Linear response functions relating the concentrations and mass fluxes on the boundaries of a homogeneous region are derived. Multiple regions are numerically coupled through interface conditions. Algebraic elimination is used to reduce the equations as far as possible. The problem reduces to two nonlinear equations in two unknowns, which are solved using a Newton Raphson technique

  10. Fission products and nuclear fuel behaviour under severe accident conditions part 3: Speciation of fission products in the VERDON-1 sample

    Science.gov (United States)

    Le Gall, C.; Geiger, E.; Gallais-During, A.; Pontillon, Y.; Lamontagne, J.; Hanus, E.; Ducros, G.

    2017-11-01

    Qualitative and quantitative analyses on the VERDON-1 sample made it possible to obtain valuable information on fission product behaviour in the fuel during the test. A promising methodology based on the quantitative results of post-test characterisations has been implemented to assess the release fraction of non γ-emitter fission products. The order of magnitude of the estimated release fractions for each fission product was consistent with their class of volatility.

  11. Nuclear Engineering Academic Programs Survey, 2004

    International Nuclear Information System (INIS)

    Oak Ridge Institute for Science and Education

    2005-01-01

    This annual report details the number of nuclear engineering bachelor's, master's, and doctoral degrees awarded at a sampling of academic programs from 1998-2004. It also looks at nuclear engineering degrees by curriculum and the number of students enrolled in nuclear engineering degree programs at 31 U.S. universities in 2004

  12. Fission gas release from ThO2 and ThO2--UO2 fuels (LWBR development program)

    International Nuclear Information System (INIS)

    Goldberg, I.; Spahr, G.L.; White, L.S.; Waldman, L.A.; Giovengo, J.F.; Pfennigwerth, P.L.; Sherman, J.

    1978-08-01

    Fission gas release data are presented from 51 fuel rods irradiated as part of the LWBR irradiations test program. The fuel rods were Zircaloy-4 clad and contained ThO 2 or ThO 2 -UO 2 fuel pellets, with UO 2 compositions ranging from 2.0 to 24.7 weight percent and fuel densities ranging from 77.8 to 98.7 percent of theoretical. Rod diameters ranged from 0.25 to 0.71 inches and fuel active lengths ranged from 3 to 84 inches. Peak linear power outputs ranged from 2 to 22 kw/ft for peak fuel burnups up to 56,000 MWD/MTM. Measured fission gas release was quite low, ranging from 0.1 to 5.2 percent. Fission gas release was higher at higher temperature and burnup and was lower at higher initial fuel density. No sensitivity to UO 2 composition was evidenced

  13. Nuclear Technology Programs semiannual progress report, October 1987--March 1988

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1990-08-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period October 1987--March 1988. Work in applied physical chemistry included investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with examining the feasibility of substituting low-enriched for high-enriched uranium in the production of fission product 99 Mo. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories

  14. Primary system fission product release and transport: A state-of-the-art report to the committee on the safety of nuclear installations

    International Nuclear Information System (INIS)

    Wright, A.L.

    1994-06-01

    This report presents a summary of the status of research activities associated with fission product behavior (release and transport) under severe accident conditions within the primary systems of water-moderated and water-cooled nuclear reactors. For each of the areas of fission product release and fission product transport, the report summarizes relevant information on important phenomena, major experiments performed, relevant computer models and codes, comparisons of computer code calculations with experimental results, and general conclusions on the overall state of the art. Finally, the report provides an assessment of the overall importance and knowledge of primary system release and transport phenomena and presents major conclusions on the state of the art

  15. Primary system fission product release and transport. A state-of-the-art report to the committee on the safety of nuclear installations

    International Nuclear Information System (INIS)

    Wright, A.L.

    1994-06-01

    This report presents a summary of the status of research activities associated with fission product behavior (release and transport) under severe accident conditions within the primary systems of water-moderated and water-cooled nuclear reactors. For each of the areas of fission product release and fission product transport, the report summarizes relevant information on important phenomena, major experiments performed, relevant computer models and codes, comparisons of computer code calculations with experimental results, and general conclusions on the overall state of the art. Finally, the report provides an assessment of the overall importance and knowledge of primary system release and transport phenomena and presents major conclusions on the state of the art

  16. Primary system fission product release and transport: A state-of-the-art report to the committee on the safety of nuclear installations

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A.L. [Oak Ridge National Lab., TN (United States)

    1994-06-01

    This report presents a summary of the status of research activities associated with fission product behavior (release and transport) under severe accident conditions within the primary systems of water-moderated and water-cooled nuclear reactors. For each of the areas of fission product release and fission product transport, the report summarizes relevant information on important phenomena, major experiments performed, relevant computer models and codes, comparisons of computer code calculations with experimental results, and general conclusions on the overall state of the art. Finally, the report provides an assessment of the overall importance and knowledge of primary system release and transport phenomena and presents major conclusions on the state of the art.

  17. Proceedings of the Second Fusion-Fission Energy Systems Review Meeting

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-11-02

    The agenda of the meeting was developed to address, in turn, the following major areas: specific problem areas in nuclear energy systems for application of fusion-fission concepts; current and proposed fusion-fission programs in response to the identified problem areas; target costs and projected benefits associated with fusion-fission energy systems; and technical problems associated with the development of fusion-fission concepts. The greatest emphasis was placed on the characteristics of and problems, associated with fuel producing fusion-fission hybrid reactors.

  18. Transient core characteristics of small molten salt reactor coupling problem between heat transfer/flow and nuclear fission reaction

    International Nuclear Information System (INIS)

    Yamamoto, Takahisa; Mitachi, Koshi

    2004-01-01

    This paper performed the transient core analysis of a small Molten Salt Reactor (MSR). The emphasis is that the numerical model employed in this paper takes into account the interaction among fuel salt flow, nuclear reaction and heat transfer. The model consists of two group diffusion equations for fast and thermal neutron fluexs, balance equations for six-group delayed neutron precursors and energy conservation equations for fuel salt and graphite moderator. The results of transient analysis are that (1) fission reaction (heat generation) rate significantly increases soon after step reactivity insertion, e.g., the peak of fission reaction rate achieves about 2.7 times larger than the rated power 350 MW when the reactivity of 0.15% Δk/k 0 is inserted to the rated state, and (2) the self-control performance of the small MSR effectively works under the step reactivity insertion of 0.56% Δk/k 0 , putting the fission reaction rate back on the rated state. (author)

  19. Measuring fission lifetimes with the crystal-blocking technique in mono-crystal, access to nuclear dissipation

    International Nuclear Information System (INIS)

    Basnary, St.

    2002-10-01

    Energy dissipation in nuclear matter may play an important role in the determination of the way through which heavy nuclei des-excite: fission or particle evaporation. An important dissipation should imply longer interval of time during which the nucleus is deformed. In that way the measurement of fission lifetimes may shed light on energy dissipation, but these measurements are very delicate to perform. Most available data on deformation times come from indirect measurements combined with the use of more or less valid models. The crystal-blocking lifetime technique in mono-crystals allows the direct measurement of long fission lifetimes. This technique has been applied to different nuclei situated in the proximity of lead. We have obtained relatively high values: τ > 3.10 -19 s for both lead and uranium which implies a strong dissipation of energy. The computation of dissipation coefficients has led to the following values: β ≅ 2.10 21 /s for lead and β ≥ 6.10 21 /s for uranium (E * > 120 MeV). These results show that dissipation effects have to be taken into account in the determination of the deexcitation way. (A.C.)

  20. Status of Iran's nuclear program and negotiations

    International Nuclear Information System (INIS)

    Albright, David

    2014-01-01

    Iran's nuclear program poses immense challenges to international security. Its gas centrifuge program has grown dramatically in the last several years, bringing Iran close to a point where it could produce highly enriched uranium in secret or declared gas centrifuge plants before its breakout would be discovered and stopped. To reduce the risk posed by Iran's nuclear program, the P5+1 have negotiated with Iran short term limits on the most dangerous aspects of its nuclear programs and is negotiating long-term arrangements that can provide assurance that Iran will not build nuclear weapons. These long-term arrangements need to include a far more limited and transparent Iranian nuclear program. In advance of arriving at a long-term arrangement, the IAEA will need to resolve its concerns about the alleged past and possibly on-going military dimensions of Iran's nuclear program

  1. Elements of a nuclear criticality safety program

    International Nuclear Information System (INIS)

    Hopper, C.M.

    1995-01-01

    Nuclear criticality safety programs throughout the United States are quite successful, as compared with other safety disciplines, at protecting life and property, especially when regarded as a developing safety function with no historical perspective for the cause and effect of process nuclear criticality accidents before 1943. The programs evolved through self-imposed and regulatory-imposed incentives. They are the products of conscientious individuals, supportive corporations, obliged regulators, and intervenors (political, public, and private). The maturing of nuclear criticality safety programs throughout the United States has been spasmodic, with stability provided by the volunteer standards efforts within the American Nuclear Society. This presentation provides the status, relative to current needs, for nuclear criticality safety program elements that address organization of and assignments for nuclear criticality safety program responsibilities; personnel qualifications; and analytical capabilities for the technical definition of critical, subcritical, safety and operating limits, and program quality assurance

  2. Fission product nuclear data obtained by use of an on-line mass spectrometer

    International Nuclear Information System (INIS)

    Reeder, P.L.; Wright, J.F.; Anderl, R.A.

    1975-01-01

    A Spectrometer for On-Line Analysis of Radionuclides (SOLAR) has been installed at a 1 MW TRIGA reactor at Washington State University. Fission product ions from a combination target/ion source located within the thermal column are brought out to a 60 0 magnetic sector mass spectrometer. Surface ionization provides copious beams of Rb + and Cs + ions and less intense beams of Br - and I - ions with negligible contamination by other elements. About 40 fission product nuclides can thus be chemically and physically separated in times of less than 1 second. Past results on independent and cumulative fission yields along with measurements of half-lives of some very neutron-rich nuclides are presented. Current work on delayed-neutron emission probabilities and energy spectra of delayed neutrons from individual nuclides is described. (7 tables, 2 figures) (U.S.)

  3. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M. B. [Los Alamos National Laboratory (LANL); Herman, Micheal W [Brookhaven National Laboratory (BNL); Oblozinsky, Pavel [Brookhaven National Laboratory (BNL); Dunn, Michael E [ORNL; Danon, Y. [Rensselaer Polytechnic Institute (RPI); Kahler, A. [Los Alamos National Laboratory (LANL); Smith, Donald L. [Argonne National Laboratory (ANL); Pritychenko, B [Brookhaven National Laboratory (BNL); Arbanas, Goran [ORNL; Arcilla, r [Brookhaven National Laboratory (BNL); Brewer, R [Los Alamos National Laboratory (LANL); Brown, D A [Brookhaven National Laboratory (BNL); Capote, R. [International Atomic Energy Agency (IAEA); Carlson, A. D. [National Institute of Standards and Technology (NIST); Cho, Y S [Korea Atomic Energy Research Institute; Derrien, Herve [ORNL; Guber, Klaus H [ORNL; Hale, G. M. [Los Alamos National Laboratory (LANL); Hoblit, S [Brookhaven National Laboratory (BNL); Holloway, Shannon T. [Los Alamos National Laboratory (LANL); Johnson, T D [Brookhaven National Laboratory (BNL); Kawano, T. [Los Alamos National Laboratory (LANL); Kiedrowski, B C [Los Alamos National Laboratory (LANL); Kim, H [Korea Atomic Energy Research Institute; Kunieda, S [Los Alamos National Laboratory (LANL); Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Lestone, J P [Los Alamos National Laboratory (LANL); Little, R C [Los Alamos National Laboratory (LANL); Mccutchan, E A [Brookhaven National Laboratory (BNL); Macfarlane, R E [Los Alamos National Laboratory (LANL); MacInnes, M [Los Alamos National Laboratory (LANL); Matton, C M [Lawrence Livermore National Laboratory (LLNL); Mcknight, R D [Argonne National Laboratory (ANL); Mughabghab, S F [Brookhaven National Laboratory (BNL); Nobre, G P [Brookhaven National Laboratory (BNL); Palmiotti, G [Idaho National Laboratory (INL); Palumbo, A [Brookhaven National Laboratory (BNL); Pigni, Marco T [ORNL; Pronyaev, V. G. [Institute of Physics and Power Engineering (IPPE), Obninsk, Russia; Sayer, Royce O [ORNL; Sonzogni, A A [Brookhaven National Laboratory (BNL); Summers, N C [Lawrence Livermore National Laboratory (LLNL); Talou, P [Los Alamos National Laboratory (LANL); Thompson, I J [Lawrence Livermore National Laboratory (LLNL); Trkov, A. [Jozef Stefan Institute, Slovenia; Vogt, R L [Lawrence Livermore National Laboratory (LLNL); Van der Marck, S S [Nucl Res & Consultancy Grp, Petten, Netherlands; Wallner, A [University of Vienna, Austria; White, M C [Los Alamos National Laboratory (LANL); Wiarda, Dorothea [ORNL; Young, P C [Los Alamos National Laboratory (LANL)

    2011-01-01

    The ENDF/B-VII.1 library is our latest recommended evaluated nuclear data file for use in nuclear science and technology applications, and incorporates advances made in the five years since the release of ENDF/B-VII.0. These advances focus on neutron cross sections, covariances, fission product yields and decay data, and represent work by the US Cross Section Evaluation Working Group (CSEWG) in nuclear data evaluation that utilizes developments in nuclear theory, modeling, simulation, and experiment. The principal advances in the new library are: (1) An increase in the breadth of neutron reaction cross section coverage, extending from 393 nuclides to 423 nuclides; (2) Covariance uncertainty data for 190 of the most important nuclides, as documented in companion papers in this edition; (3) R-matrix analyses of neutron reactions on light nuclei, including isotopes of He; Li, and Be; (4) Resonance parameter analyses at lower energies and statistical high energy reactions for isotopes of Cl; K; Ti, V, Mn, Cr, Ni, Zr and W; (5) Modifications to thermal neutron reactions on fission products (isotopes of Mo, Tc, Rh, Ag, Cs, Nd, Sm, Eu) and neutron absorber materials (Cd, Gd); (6) Improved minor actinide evaluations for isotopes of U, Np, Pu, and Am (we are not making changes to the major actinides (235,238)U and (239)Pu at this point, except for delayed neutron data and covariances, and instead we intend to update them after a further period of research in experiment and theory), and our adoption of JENDL-4.0 evaluations for isotopes of Cm, Bk, Cf, Es; Fm; and some other minor actinides; (7) Fission energy release evaluations; (8) Fission product yield advances for fission-spectrum neutrons and 14 MeV neutrons incident on (239)Pu; and (9) A new decay data sublibrary. Integral validation testing of the ENDF/B-VII.1 library is provided for a variety of quantities: For nuclear criticality, the VII.1 library maintains the generally-good performance seen for VII.0 for a wide

  4. Inventories of radioactive fission products in the core of thermal nuclear reactor

    International Nuclear Information System (INIS)

    Marinkovic, N.

    1977-01-01

    As a part of the analysis concerning radiological consequences of a major LWR accident, inventories of the most significant radioactive nuclides and stable fission gases in the core of a PWR type reactor have been calculated. Calculations were performed by the DELFIN code using nuclide data and neutron flux data earlier obtained by the METHUSELAH code. Comparison with simplified calculation method show that it is quite rough for certain nuclides but the accuracy may be sufficient for safety analysis purposes recalling the inaccuracies in the later parts of fission product transport process (author)

  5. Advanced nuclear fuel production by using fission-fusion hybrid reactor

    International Nuclear Information System (INIS)

    Al-Kusayer, T.A.; Sahin, S.; Abdulraoof, M.

    1993-01-01

    Efforts are made at the College of Engineering, King Saud University, Riyadh to lay out the main structure of a prototype experimental fusion and fusion-fission (hybrid) reactor blanket in cylindrical geometry. The geometry is consistent with most of the current fusion and hybrid reactor design concepts in respect of the neutronic considerations. Characteristics of the fusion chamber, fusion neutrons and the blanket are provided. The studies have further shown that 1 GWe fission-fusion reactor can produce up to 957 kg/year which is enough to fuel five light water reactors of comparable power. Fuel production can be increased further. 29 refs

  6. High-safety and economical small molten-salt fission power stations and their developmental program

    International Nuclear Information System (INIS)

    Furukawa, K.; Mitachi, K.; Minami, K.; Kato, Y.

    1988-01-01

    The nuclear energy industry is not settled yet as one of the sound economical industries. Its establishment should obviously depend on the solution of the following problems: ''natural'' safety (depending on inherent natures), nuclear proliferation resistance - nearly non-production and effective incineration of Pu, Am and Om, universal resource, flexible power-size and excellent economy - wide applicability including Developing Countries. Therefore, some essentially new principles have to introduce in the nuclear energy system design. These are thorium utilization, fluid-fuel concepts, especially molten-fluoride technology, and separation of fissile-breeding and power-generation. This philosophy is named Thorium Molten-Salt Nuclear Energy Synergetics [THOMSNES]. Its practical development program is presented

  7. Relativistic Coulomb Fission

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Nuclear fission reactions induced by the electromagnetic field of relativistic nuclei are studied for energies relevant to present and future relativistic heavy ion accelerators. Cross sections are calculated for U-238 and Pu-239 fission induced by C-12, Si-28, Au-197, and U-238 projectiles. It is found that some of the cross sections can exceed 10 b.

  8. Overview of the DOE nuclear data program

    International Nuclear Information System (INIS)

    Whetstone, S.L.

    1991-01-01

    Numerous researchers receive support from the US Department of Energy's (DOE's) nuclear data program; others work closely with it, attending coordination meetings and contributing to data activities. Since fiscal year (FY) 1988, the nuclear data program has been included in the budget of the Division of Nuclear Physics in the DOE's Office of High Energy and Nuclear Physics. The budget for nuclear data consists of two budget categories: nuclear data compilation and evaluation and nuclear data measurements, both of which are contained within the low-energy nuclear physics program. The program has become essentially the sole supporter of the National Nuclear Data Center at Brookhaven National Laboratory. The Center coordinates the production of the ENSDF data base and Nuclear Data Sheets as well as, through the Cross Section Evaluation Working Group (CSEWG138), the production of the ENDF. Two rather large accelerator facilities, completely supported by the program, the Oak Ridge Electron Linear Accelerator and the fast neutron generator at Argonne National Laboratory, form the core of the nuclear data measurement activity together with measurement programs at Los Alamos National Laboratory's LAMPF/WNR facility, and at accelerator laboratories at Ohio University, Duke University, the University of Lowell, the University of Michigan, and the Colorado School of Mines. Some history is discussed and future modernizing plans are identified

  9. Underground Nuclear Testing Program, Nevada Test Site

    International Nuclear Information System (INIS)

    1975-09-01

    The Energy Research and Development Administration (ERDA) continues to conduct an underground nuclear testing program which includes tests for nuclear weapons development and other tests for development of nuclear explosives and methods for their application for peaceful uses. ERDA also continues to provide nuclear explosive and test site support for nuclear effects tests sponsored by the Department of Defense. This Supplement extends the Environmental Statement (WASH-1526) to cover all underground nuclear tests and preparations for tests of one megaton (1 MT) or less at the Nevada Test Site (NTS) during Fiscal Year 1976. The test activities covered include numerous continuing programs, both nuclear and non-nuclear, which can best be conducted in a remote area. However, if nuclear excavation tests or tests of yields above 1 MT or tests away from NTS should be planned, these will be covered by separate environmental statements

  10. Choice of initial conditions in dynamical calculations of distributions of nuclear fission fragments

    International Nuclear Information System (INIS)

    Kosenko, G.I.

    1993-01-01

    The distribution function in the coordinates and momenta for a fissioning system traversing a barrier is determined in terms of Langevin fluctuation-dissipation dynamics. It is shown that this distribution is best described by the Kramers distribution. The equilibrium distribution can be used as the initial condition, provided that the system is in the overdamping regime. 28 refs., 5 figs., 3 tabs

  11. Dual-fission chamber and neutron beam characterization for fission product yield measurements using monoenergetic neutrons

    Science.gov (United States)

    Bhatia, C.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rundberg, R. S.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2014-09-01

    A program has been initiated to measure the energy dependence of selected high-yield fission products used in the analysis of nuclear test data. We present out initial work of neutron activation using a dual-fission chamber with quasi-monoenergetic neutrons and gamma-counting method. Quasi-monoenergetic neutrons of energies from 0.5 to 15 MeV using the TUNL 10 MV FM tandem to provide high-precision and self-consistent measurements of fission product yields (FPY). The final FPY results will be coupled with theoretical analysis to provide a more fundamental understanding of the fission process. To accomplish this goal, we have developed and tested a set of dual-fission ionization chambers to provide an accurate determination of the number of fissions occurring in a thick target located in the middle plane of the chamber assembly. Details of the fission chamber and its performance are presented along with neutron beam production and characterization. Also presented are studies on the background issues associated with room-return and off-energy neutron production. We show that the off-energy neutron contribution can be significant, but correctable, while room-return neutron background levels contribute less than <1% to the fission signal.

  12. Dynamical effects and time scale in fission processes in nuclear collisions in the fermi energy range

    International Nuclear Information System (INIS)

    Colin, J.; Bocage, F.; Louvel, M.; Bellaize, N.; Bougault, R.; Brou, R.; Cussol, D.; Durand, D.; Genouin-Duhamel, E.; Lecolley, J.F.; Le Neindre, N.; Lopez, O.; Nguyen, A.D.; Peter, J.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Brun, C. le; Genoux-Lubain, A.

    1999-01-01

    Recent experimental results concerning heavy systems (Pb+Au, Pb+Ag, Pb+Al, Gd+U, Gd+C, Ta+Au, U+U, U+C, Xe+Sn... o btained at Ganil by the Indra and Nautilus collaborations will be presented. A study of reaction mechanisms has shown the dominant binary and highly dissipative character of the process. The two heavy and excited fragments produced after the first stage of the interaction can experience various decay modes: evaporation, fission, multifragmentation. However, deviations from this simple picture have been found by analysing angular and velocity distributions of light charge particles, IMF's (Intermediate Mass Fragment) and fragments. Indeed, there is an amount of matter in excess emitted in-between the two primary sources suggesting either the existence of a mid-rapidity source similar to the one observed in the relativistic regime (participants) or a strong deformation induced by the dynamics of the collision (neck instability). This last scenario is explored by analysing in details the angular distributions of the fission fragments. More precisely, authors observed two components: The first one is isotropic and consistent with the predictions of a statistical model, the second is aligned along the velocity direction of the fissioning nuclei and has to be compared with the predictions of dynamical calculations. In this talk, authors present the probability associated to each component as a function of the system size, the charge asymmetry of the fission fragments, the incident energy and the impact parameter. From the statistical component authors extract the temperature, the charge and the angular momentum of the fissioning nuclei. From the second component authors propose a scenario to explain such process and authors discuss the physical parameters which can be extracted

  13. Dynamical effects and time scale in fission processes in nuclear collisions in the Fermi energy range

    International Nuclear Information System (INIS)

    Colin, J.; Bocage, F.; Louvel, M.

    1999-10-01

    Recent experimental results concerning heavy systems (Pb+Au, Pb+Ag, Pb+Al, Gd+U, Gd+C, Ta+Au, U+U, U+C, Xe+Sn...) obtained at Ganil by the Indra and Nautilus collaborations will be presented. A study of reaction mechanisms has shown the dominant binary and highly dissipative character of the process. The two heavy and excited fragments produced after the first stage of the interaction can experience various decay modes: evaporation, fission, multifragmentation. However, deviations from this simple picture have been found by analysing angular and velocity distribution of light charge particles, IMF's (Intermediate Mass Fragment) and fragments. Indeed, there is an amount of matter in excess emitted in-between the two primary sources suggesting either the existence of a mi-rapidity source similar to the one observed in the relativistic regime (participants) or a strong deformation induced by the dynamics of the collision (neck instability). This last scenario is explored by analysing in details the angular distributions of the fission fragments. More precisely, we observed two components: the first one is isotropic and consistent with the predictions of a statistical model, the second is aligned along the velocity direction of the fissioning nuclei and has to be compared with the predictions of dynamical calculations. In this talk, we present the probability associated to each component as a function of the system size, the charge asymmetry of the fission fragments, the incident energy and the impact parameter. From the statistical component we extract the temperature, the charge and the angular momentum of the fissioning nuclei. From the second component we propose a scenario to explain such process and we discuss the physical parameters which can be extracted. (authors)

  14. Status of fission power

    International Nuclear Information System (INIS)

    Levenson, M.

    1977-01-01

    Fission energy is reviewed from the viewpoints of technology, economics, politics, manufacturers, consumers, and foreign countries. Technically, the reactor program is operating and the light water reactor industry shows signs of maturing, although recent business has been disappointing. Marketing of gas-cooled reactors depends, not on technical, but economic and political issues. Liquid metal fast breeder reactors have been demonstrated worldwide, while the gas-cooled fast breeder remains an undemonstrated option. Nuclear plants, currently costing the same as coal plants with scrubbers, are the cheapest option for utilities because most of the cost is imbedded. The defeat of nuclear initiatives in seven states indicates that public feeling is not as anti-nuclear as opponents to nuclear power claim. The harshness of last winter demonstrated the advantages of a power source that is not so sensitive to the weather for reliable operation and transport, as well as low cost energy. Other nations are proceeding to build a nuclear capability, which the U.S. may jeopardize because of concerns about the fuel cycle, nuclear waste disposal, uranium reserves, and nuclear proliferation

  15. Nuclear safeguards research and development. Program status report, October 1980-January 1981

    International Nuclear Information System (INIS)

    Henry, C.N.

    1981-11-01

    This report presents the status of the Nuclear Safeguards Research and Development Program pursued by the Energy, Chemistry-Materials Science, and Operational Security/Safeguards Divisions of the Los Alamos National Laboratory. Topics include nondestructive assay technology development and applications, international safeguards systems. Also discussed are training courses, technology transfer, analytical chemistry methods for fissionable materials safeguards, the Department of Energy Computer Security Technical Center, and operational security

  16. Nuclear safeguards research and development. Program status report, October 1980-January 1981

    Energy Technology Data Exchange (ETDEWEB)

    Henry, C.N. (comp.)

    1981-11-01

    This report presents the status of the Nuclear Safeguards Research and Development Program pursued by the Energy, Chemistry-Materials Science, and Operational Security/Safeguards Divisions of the Los Alamos National Laboratory. Topics include nondestructive assay technology development and applications, international safeguards systems. Also discussed are training courses, technology transfer, analytical chemistry methods for fissionable materials safeguards, the Department of Energy Computer Security Technical Center, and operational security.

  17. Monthly highlights for Office of Nuclear Regulatory Research Programs at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Fee, G.G.

    1976-08-01

    Brief highlights are presented for the following programs: heavy section steel technology, fission product beta and gamma energy release, LOCA release from LWR fuel, multirod burst tests, Nuclear Safety Information Center, PWR blowdown heat transfer-separate effects, zircaloy fuel cladding collapse studies, zirconium metal-water oxidation kinetics, aerosol release and transport from LMFBR fuel, HTGR safety analysis, design criteria for piping and nozzles, and dose conversion factors for inhalation of radionuclides

  18. Monthly highlights for Office of Nuclear Regulatory research programs at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Fee, G.G.

    1975-04-01

    Summaries are given of the following programs: heavy section steel technology, fission product beta and gamma energy release, LOCA release from LWR fuel, multirod burst tests, Nuclear Safety Information Center, PWR blowdown heat transfer--separate effects, Zircaloy fuel cladding collapse studies, Zr metal--water oxidation kinetics, transient vaporization of LMFBR fuel, and HTGR safety analysis and research. Technical highlights and cost/budget reports are included. (U.S.)

  19. Monthly highlights for Office of Nuclear Regulatory Research Programs at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Fee, G.G.

    1976-02-01

    Brief highlights are presented for the following activities: heavy section steel technology program, fission product β and γ energy release, LOCA release from LWR fuel, multirod burst tests, Nuclear Safety Information Center, PWR blowdown heat transfer-separate effects, zircaloy fuel cladding collapse studies, zirconium metal-water oxidation kinetics, aerosol release and transport from LMFBR fuel, HTGR safety analysis and research, and design criteria for piping and nozzles

  20. Cement As a Waste Form for Nuclear Fission Products: The Case of (90)Sr and Its Daughters.

    Science.gov (United States)

    Dezerald, Lucile; Kohanoff, Jorge J; Correa, Alfredo A; Caro, Alfredo; Pellenq, Roland J-M; Ulm, Franz J; Saúl, Andrés

    2015-11-17

    One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of (90)Sr insertion and decay in C-S-H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold this radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that (90)Sr is stable when it substitutes the Ca(2+) ions in C-S-H, and so is its daughter nucleus (90)Y after β-decay. Interestingly, (90)Zr, daughter of (90)Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Therefore, cement appears as a suitable waste form for (90)Sr storage.

  1. Nuclear data needs of Indian nuclear program

    International Nuclear Information System (INIS)

    Fernando, M.P.S.

    2015-01-01

    Currently 17 Pressurised Heavy water Reactors (PHWRs), 2 Boiling water reactors (BWRs) and 1 Pressurised water reactor (PWR) are being operated for power production by Nuclear Power Corporation India Limited (NPCIL). For PHWRs, different types of fuel bundles are simulated by the integral transport theory code, CLUB using a combination of collision probability method and interface current technique and employing IAEA supplied 69 /172 group WIMS cross section library based on ENDF-BVI, BVII. Ring power factors are calculated at different burnups and are used to estimate linear heat rating. The two group neutron cross sections of different type of lattices at different core irradiations are also generated by lattice code CLUB. Wherever reactivity devices are present, supercell approach is adopted and the suitable incremental absorption cross sections are obtained using BOXER which is based on 3-D integral transport theory considering two neutron energy groups. Using the appropriate properties for normal lattices and ones affected by reactivity devices, fuel management and core follow up studies are carried out using 3-D diffusion theory based TRIVENI code. The KAPS-1 power rise transient on March 10, 2004 brought to focus the importance of accurate nuclear data for reactor physics estimation in Indian PHWRs. With IAEA supplied libraries in WIMS format we could satisfactorily resolve the rate of power increase. Stability analysis and sensitivity analysis was carried out for different incore burnup situations resulting from peak flux operation. The quantification of output uncertainties is necessary to adequately establish safety margins of nuclear facilities. The uncertainties in the integral parameters such as reactivity worth and coefficients due to cross section can be assessed using cross section covariance data produced directly from the uncertainties of measurements. Covariance data processing codes and sensitivity analysis tools have to be developed. The part

  2. Assessment of the situation of centres of competence in the fields of nuclear fission and radiation protection. Final report

    CERN Document Server

    Wolfert, K; Glaeser, H; Klener, V; Métivier, H; Richard, P; Riebold, W L; Vasa, I; Zimmermann, M

    2003-01-01

    An assessment of the present situation concerning centres of competence in the fields of Nuclear Fission and Radiation Protection has been carried out with the intention to draw strategic conclusions as regards further needs in these fields, based on the actual situation and perceived future developments. This study was initiated by the programme committee for the Euratom research and training programme in the field of Nuclear Energy (1998 - 2002). To carry out this exercise, a Panel of four independent experts had been set up. The Panel had prepared a questionnaire comprising a comprehensive set of questions aiming at the acquisition of the information needed to carry out the assessment exercise. The questionnaire consisted in ten different form sheets and had been put on the Internet in order to ease the access and offer a comfortable way of filling in the form sheets. Out of 420 organisations invited to participate in the exercise, 293 organisations from EU member states, Central and Eastern European Acces...

  3. Future developments of power supply from nuclear fission and fusion until the middle of the 21st century

    International Nuclear Information System (INIS)

    1987-03-01

    The purpose of this study made by General Technology Systems (Netherlands) is to provide information about nuclear fission and fusion as methods for power generation, with which, in the framework of a study into the possibilities of durable energy sources, choices may be made from the various possibilities for future energy supply. The physical processes upon which the power generation relies are treated briefly. The technologies employed are discussed together with their changes and improvements, now and in the future, and the economic factors by which they are accompanied. How much of this energy will be used in the Netherlands, is discussed. In order to know the opinion of others about these subjects the dealers of the current nuclear power stations were asked to give their opinions which are collected in a supplement. 166 refs.; 18 figs.; 19 tabs

  4. Influence of differences in the proton and neutron distributions on nuclear fusion and fission; Infuence de la difference entre les distributions de protons et de neutrons dans le noyau sur les processus de fusion et de fission

    Energy Technology Data Exchange (ETDEWEB)

    Dobrowolski, A

    2006-04-15

    This thesis work is centred on some essential ingredients of a theoretical description of the reaction dynamics of the nuclear fusion and fission process, such as the interaction potential between projectile and target nuclei for fusion and the deformation energy landscape in a multidimensional space for the fission process. We have in particular evaluated the importance of the difference between the neutron and proton density distributions on these 2 processes. The fusion potential between the two interacting nuclei is obtained through the nucleon densities, determined in a self-consistent way through semiclassical density variational calculations for a given effective nucleon-nucleon effective interaction of the Skyrme type. These fusion barriers can then be used in a Langevin formalism to evaluation fusion cross sections. For the fission process it turns out to be essential to allow for the large variety of shapes which appear between the nuclear ground state and the the scission configuration. We show that a shape parametrisation taking into account elongation, as well as possible neck formation, left-right asymmetry and non-axiality allows a precise description of this phenomena in the framework of the macroscopic-microscopic approach. We are thus able to enrich the expression of the liquid-drop type energy through a term which describes the variation of the nuclear energy due to a deformation difference between the proton and neutron distribution. The resulting reduction of the fission barriers is only of the order of one MeV but this can easily cause a change in the fission cross-section by an order of magnitude and thus plays a capital role for the stability of super-heavy of exotic nuclei. (author)

  5. Management plan for the Nuclear Standards Program

    International Nuclear Information System (INIS)

    1979-11-01

    This Management Plan was prepared to describe the manner in which Oak Ridge National Laboratory will provide technical management of the Nuclear Standards Program. The organizational structure that has been established within ORNL for this function is the Nuclear Standards Management Center, which includes the Nuclear Standards Office (NSO) already in existence at ORNL. This plan is intended to support the policies and practices for the development and application of technical standards in ETN projects, programs, and technology developments as set forth in a standards policy memorandum from the DOE Program Director for Nuclear Energy

  6. Multi-channel probes to understand fission dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mosby, Shea Morgan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-15

    Explaining the origin of the elements is a major outstanding question in nuclear astrophysics. Observed elemental abundance distribution shows strong nuclear physics effects. In conclusion, neutron-induced reactions are important for nuclear astrophysics and applied fields in nuclear energy and security. LANSCE has a program to address many of these questions directly with neutron beams on (near-)stable nuclei. Increasing demand for correlated data to test details of fission models poses additional challenges. Possibilities exist to extend existing experimental efforts to radioactive beam facilities. Kinematic focusing from using inverse kinematics has potential to circumvent some challenges associated with measuring correlations between fission output channels.

  7. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    Science.gov (United States)

    Siegel, Edward

    2011-10-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility /factor-ization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 × 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 × 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 × 4 = 2 × 2 × 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 × 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16,... Could inter-digit Feshbach-resonances exist??? Applications to: quantum-information/computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory ``short-cut'' method: Rayleigh(1870)-Polya(1922)-``Anderson'' (1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics;... abound!!!

  8. Transmutations of nuclear waste. Progress report RAS programme 1995: Recycling and transmutation of actinides and fission products

    International Nuclear Information System (INIS)

    Gruppelaar, H.; Cordfunke, E.H.P.; Konings, R.J.M.; Bultman, J.H.; Dodd, D.H.; Franken, W.M.P.; Kloosterman, J.L.; Koning, A.J.; Wichers, V.A.

    1996-04-01

    This report describes the progress of the Dutch RAS programme on 'Recycling and Transmutation of Actinides and Fission Products' over the year 1995, which is the second year of the 4-year programme 1994-1997. An extensive listing of reports and publications from 1991 to 1995 is given. Highlights in 1995 were: -The completion of the European Strategy Study on Nuclear Waste Transmutation as a result of which the understanding of transmutation of plutonium, minor actinides and long-lived fission products in thermal and fast reactors has been increased significantly. Important ECN contributions were given on Am, 99 Tc and 129 I transmutation options. Follow-up contracts have been obtained for the study of 100% MOX cores and accelerator-based transmutation. - Important progress in the evaluation of CANDU reactors for burning very large amounts of transuranium mixtures in inert matrices. - The first RAS irradiation experiment in the HFR, in which the transmutation of technetium and iodine was examined, has been completed and post-irradiation examination has been started. - A joint proposal of the EFTTRA cooperation for the 4 th Framework Programme of the EU, to demonstrate the feasibility of the transmutation of americium in an inert matrix by an irradiation in the HFR, has been granted. - A bilateral contract with CEA has been signed to participate in the CAPRA programme, and the work in this field has been started. - The thesis work on Actinide Transmutation in Nuclear Reactor Systems was succesfully defended. New PhD studies on Pu burning in HTGR, on nuclear data for accelerator-based systems, and on the SLM-technique for separation of actinides were started. - A review study of the use of the thorium cycle as a means for nuclear waste reduction, has been completed. A follow-up of this work is embedded in an international project for the 4th Framework Programme of the EU. (orig./DG)

  9. ORNL Nuclear Safety Research and Development Program Bimonthly Report for July-August 1968

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, W.B.

    2001-08-17

    The accomplishments during the months of July and August in the research and development program under way at ORNL as part of the U.S. Atomic Energy Commission's Nuclear Safety Program are summarized, Included in this report are work on various chemical reactions, as well as the release, characterization, and transport of fission products in containment systems under various accident conditions and on problems associated with the removal of these fission products from gas streams. Although most of this work is in general support of water-cooled power reactor technology, including LOFT and CSE programs, the work reflects the current safety problems, such as measurements of the prompt fuel element failure phenomena and the efficacy of containment spray and pool-suppression systems for fission-product removal. Several projects are also conducted in support of the high-temperature gas-cooled reactor (HTGR). Other major projects include fuel-transport safety investigations, a series of discussion papers on various aspects of water-reactor technology, antiseismic design of nuclear facilities, and studies of primary piping and steel, pressure-vessel technology. Experimental work relative to pressure-vessel technology includes investigations of the attachment of nozzles to shells and the implementation of joint AEX-PVFX programs on heavy-section steel technology and nuclear piping, pumps, and valves. Several of the projects are directly related to another major undertaking; namely, the AEC's standards program, which entails development of engineering safeguards and the establishment of codes and standards for government-owned or -sponsored reactor facilities. Another task, CHORD-S, is concerned with the establishment of computer programs for the evaluation of reactor design data, The recent activities of the NSIC and the Nuclear Safety journal in behalf of the nuclear community are also discussed.

  10. Analytical methods for fissionable materials in the nuclear fuel cycle. Covering June 1974--June 1975

    International Nuclear Information System (INIS)

    Waterbury, G.R.

    1975-10-01

    Research progress is reported on method development for the dissolution of difficult-to-dissolve materials, the automated analysis of plutonium and uranium, the preparation of plutonium materials for the Safeguard Analytical Laboratory Evaluation (SALE) Program, and the analysis of HTGR fuel and SALE uranium materials. The previously developed Teflon-container, metal-shell apparatus was applied to the dissolution of various nuclear materials. Gas--solid reactions, mainly using chlorine at elevated temperatures, are promising for separating uranium from refractory compounds. An automated spectrophotometer designed for determining plutonium and uranium was tested successfully. Procedures were developed for this instrument to analyze uranium--plutonium mixtures and the effects of diverse ions upon the analysis of plutonium and uranium were further established. A versatile apparatus was assembled to develop electrotitrimetric methods that will serve as the basis for precise automated determinations of plutonium. Plutonium materials prepared for the Safeguard Analytical Laboratory Evaluation (SALE) Program were plutonium oxide, uranium--plutonium mixed oxide, and plutonium metal. Improvements were made in the methods used for determining uranium in HTGR fuel materials and SALE uranium materials. Plutonium metal samples were prepared, characterized, and distributed, and half-life measurements were in progress as part of an inter-ERDA-laboratory program to measure accurately the half-lives of long-lived plutonium isotopes

  11. Nuclear technology programs semiannual progress report, April--September 1989

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1991-08-01

    This document reports on the work done by the Nuclear Technology Program of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1989. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned with developing a process for separating the organic and inorganic constitutents of the red-water waste stream generated in production of 2,4,6-trinitrotoluene. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories. 154 refs., 154 figs., 100 tabs

  12. Nuclear Technology Programs semiannual progress report, April-- September 1990

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, J.E. (ed.)

    1992-06-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1990. These programs involve R D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories.

  13. Nuclear Technology Programs semiannual progress report, April-- September 1990

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, J.E. [ed.

    1992-06-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1990. These programs involve R&D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories.

  14. Nuclear technology programs; Semiannual progress report, October 1989--March 1990

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, J.E. [ed.

    1992-01-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period October 1989--March 1990. These programs involve R&D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions, the thermophysical properties of metal fuel and blanket materials of the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. Another effort is concerned water waste stream generated in production of 2,4,6-trinitrotoluene. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation`s high-level waste repositories.

  15. Nuclear technology programs. Semiannual progress report, April--September 1991

    International Nuclear Information System (INIS)

    1993-07-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April through September 1991. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories

  16. Nuclear Technology Programs semiannual progress report, April-- September 1990

    International Nuclear Information System (INIS)

    Harmon, J.E.

    1992-06-01

    This document reports on the work done by the Nuclear Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April--September 1990. These programs involve R ampersand D in three areas: applied physical chemistry, separation science and technology, and nuclear waste management. The work in applied physical chemistry includes investigations into the processes that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor, and the properties of selected materials in environments simulating those of fusion energy systems. In the area of separation science and technology, the bulk of the effort is concerned with developing and implementing processes for the removal and concentration of actinides from waste streams contaminated by transuranic elements. In the area of waste management, investigations are underway on the performance of materials in projected nuclear repository conditions to provide input to the licensing of the nation's high-level waste repositories

  17. The potential of fission nuclear power in resolving global climate change under the constraints of nuclear fuel resources and once-through fuel cycles

    International Nuclear Information System (INIS)

    Knapp, Vladimir; Pevec, Dubravko; Matijevic, Mario

    2010-01-01

    Nuclear fission is receiving new attention as a developed source of carbon-free energy. A much larger number of nuclear reactors would be needed for a major impact on carbon emission. The crucial question is whether it can be done without increasing the risk of nuclear proliferation. Specifically, can a larger nuclear share in world energy production, well above the present 6%, be achieved in the next few decades without adding the proliferation-sensitive technologies of reprocessing spent fuel and recycling plutonium to the problems of the unavoidable use of enrichment technology? The answer depends on the available uranium resources. We first looked for the maximum possible nuclear build-up in the 2025-2065 period under the constraints of the estimated uranium resources and the use of once-through nuclear fuel technology. Our results show that nuclear energy without reprocessing could reduce carbon emission by 39.6% of the total reduction needed to bring the WEO 2009 Reference Scenario prediction of total GHG emissions in 2065 to the level of the WEO 450 Scenario limiting global temperature increase to 2 deg. C. The less demanding strategy of the nuclear replacement of all non-CCS coal power plants retiring during the 2025-2065 period would reduce emission by 26.1%.

  18. Mirror fusion--fission hybrids

    International Nuclear Information System (INIS)

    Lee, J.D.

    1978-01-01

    The fusion-fission concept and the mirror fusion-fission hybrid program are outlined. Magnetic mirror fusion drivers and blankets for hybrid reactors are discussed. Results of system analyses are presented and a reference design is described

  19. The University of Utah Nuclear Engineering Program

    International Nuclear Information System (INIS)

    Jevremovic, T.; McDonald, L. IV; Schow, R.

    2016-01-01

    As of 2014, the University of Utah Nuclear Engineering Program (UNEP) manages and maintains over 7,000 ft 2 (~650 m 2 ) nuclear engineering facilities that includes 100 kW TRIGA Mark I and numerous laboratories such as radiochemistry, microscopy, nuclear forensics, nuclear medicine, radiation detection and instrumentation laboratories. The UNEP offers prestigious educational and training programs in the field of faculty reserach: reactor physics, reactor design and operation, advanced numerical modeling and visualizations in radiation transport, radiochemistry, nuclear forensics, radiation detection and detector designs, signal processing, nuclear medicine, nuclear space and nuclear robotic’s engineering and radiological sciences. With the state-of-the-art nuclear instrumentation and state-of-the-art numerical modeling tools, reserach reactor and modernized educational and training programs, we positioned ourselves in the last five years as the fastest growing national nuclear engineering program attracting the students from many disciplines such as but not limited to: chemical engineering, civil engineering, environmental engineering, chemistry, physics, astronomy, medical sciences, and others. From 2012, we uniquely developed and implemented the nuclear power plants’ safety culture paradigm that we use for day-to-day operation, management and maintenance of our facilities, as well as train all our students at undergraduate and graduate levels of studies. We developed also a new distance-learning approaches in sharing knowledge about experiential learning based on no-cost internet-tools combined with the use of mobile technologies. (author)

  20. The Soviet program for peaceful uses of nuclear explosions

    International Nuclear Information System (INIS)

    Nordyke, M.D.

    1996-01-01

    The concept of utilizing the weapons of war to serve the peaceful pursuits of mankind is as old as civilization itself. Perhaps the most famous reference to this basic desire is recorded in the Book of Micah where the great prophet Isiah called upon his people 'to turn your spears into pitchforks and your swords into plowshares.' As the scientists at Los Alamos worked on developing the world's first atomic bomb, thoughts of how this tremendous new source of energy could be used for peaceful purposes generally focused on using the thermal energy generated by the slow fission of uranium in a reactor, such as those being used to produce Plutonium to drive electric power stations. However, being scientists in a new, exciting field, it was impossible to avoid letting their minds wander from the task at hand to other scientific or non-military uses for the bombs themselves. During the Manhattan Project, Otto Frisch, one of the pioneers in the development of nuclear fission process in the 1930s, first suggested using an atomic explosion as a source for a large quantities of neutrons which could used in scientific experiments designed to expand their understanding of nuclear physics. After the war was over, many grandiose ideas appeared in the popular press on how this new source of energy should be to serve mankind. Not to be left out of the growing enthusiasm for peaceful uses of atomic energy, the Soviet Union added their visions to the public record. This document details the Soviet program for using nuclear explosions in peacetime pursuits

  1. The Soviet program for peaceful uses of nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Nordyke, M.D.

    1996-07-24

    The concept of utilizing the weapons of war to serve the peaceful pursuits of mankind is as old as civilization itself. Perhaps the most famous reference to this basic desire is recorded in the Book of Micah where the great prophet Isiah called upon his people `to turn your spears into pitchforks and your swords into plowshares.` As the scientists at Los Alamos worked on developing the world`s first atomic bomb, thoughts of how this tremendous new source of energy could be used for peaceful purposes generally focused on using the thermal energy generated by the slow fission of uranium in a reactor, such as those being used to produce Plutonium to drive electric power stations. However, being scientists in a new, exciting field, it was impossible to avoid letting their minds wander from the task at hand to other scientific or non-military uses for the bombs themselves. During the Manhattan Project, Otto Frisch, one of the pioneers in the development of nuclear fission process in the 1930s, first suggested using an atomic explosion as a source for a large quantities of neutrons which could used in scientific experiments designed to expand their understanding of nuclear physics. After the war was over, many grandiose ideas appeared in the popular press on how this new source of energy should be to serve mankind. Not to be left out of the growing enthusiasm for peaceful uses of atomic energy, the Soviet Union added their visions to the public record. This document details the Soviet program for using nuclear explosions in peacetime pursuits.

  2. IAEA Nuclear Security Human Resource Development Program

    International Nuclear Information System (INIS)

    Braunegger-Guelich, A.

    2009-01-01

    The IAEA is at the forefront of international efforts to strengthen the world's nuclear security framework. The current Nuclear Security Plan for 2006-2009 was approved by the IAEA Board of Governors in September 2005. This Plan has three main points of focus: needs assessment, prevention, detection and response. Its overall objective is to achieve improved worldwide security of nuclear and other radioactive material in use, storage and transport, and of their associated facilities. This will be achieved, in particular, through the provision of guidelines and recommendations, human resource development, nuclear security advisory services and assistance for the implementation of the framework in States, upon request. The presentation provides an overview of the IAEA nuclear security human resource development program that is divided into two parts: training and education. Whereas the training program focuses on filling gaps between the actual performance of personnel working in the area of nuclear security and the required competencies and skills needed to meet the international requirements and recommendations described in UN and IAEA documents relating to nuclear security, the Educational Program in Nuclear Security aims at developing nuclear security experts and specialists, at fostering a nuclear security culture and at establishing in this way sustainable knowledge in this field within a State. The presentation also elaborates on the nuclear security computer based learning component and provides insights into the use of human resource development as a tool in achieving the IAEA's long term goal of improving sustainable nuclear security in States. (author)

  3. Steady state behaviour of gaseous fission products in UO2 nuclear fuel at low temperature

    International Nuclear Information System (INIS)

    Rao, C.B.; Raj, Baldev

    1980-01-01

    Theoretical modelling studies have been performed on steady state fission gas behaviour in UO 2 fuels at temperatures in the range 1073deg K to 1473deg K. The concentrations of gas atoms in the matrix and in the bubbles are determined. Fraction of total generated gas atoms migrating to and forming bubbles at grain boundaries is calculated. Contributions of intragranular and intergranular bubbles to the swelling are also computed. The various assumptions made to simplify computer calculations and their validity are discussed at length. Effects of changes in the fission rate, the resolution parameter, bubble concentration, gas atom diffusivity and grain radius on swelling and gas release are studied. The results of this model are compared to other theoretical models and experimental results available in literature. Possibility of extending the present model to advanced carbide and nitride fuels is discussed. (auth.)

  4. Laser microsampling method for determination of retained fission gas in irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Graczyk, D.G.; Bandyopadhyay, G.; Gehl, S.M.; Hughes, J.P.; Goodspeed, H.T.

    1979-10-01

    A small ruby laser adapted to fire through a microscope is used to release fission gases from specific sites on a plane surface of an irradiated fuel specimen. Interaction of the focused laser pulse with the specimen surface results in a conical crater from which sampled material has been vaporized; the crater is surrounded by a heat-affected zone in which intergranular fracture and grain separation allow release of grain-boundary gases. Procedures for measuring the amount of krypton-85 released by laser heating and the volume of material from which the release occurred are presented. The data obtained may be used to obtain local krypton fission-gas concentrations and the intragranular/intergranular distribution

  5. The congruence energy: a contribution to nuclear masses, deformation energies and fission barriers

    International Nuclear Information System (INIS)

    Myers, W.D.; Swiatecki, W.J.

    1997-01-01

    The difference between measured binding energies and those calculated using a shell- and pairing-corrected Thomas-Fermi model can be described approximately by C(I)=-10 exp(-4.2 vertical stroke I vertical stroke) MeV, where I=(N-Z)/A. Our interpretation of this extra binding is in terms of the granularity of quantal nucleonic density distributions, which leads to a stronger interaction for a neutron and proton with congruent nodal structures of their wave functions. The predicted doubling of this congruence energy in fission is supported by an analysis of measured fission barriers and by a study of wave functions in a dividing Hill-Wheeler box potential. A semi-empirical formula for the shape-dependent congruence energy is described. (orig.)

  6. Benchmark criticality experiments for fast fission configuration with high enriched nuclear fuel

    International Nuclear Information System (INIS)

    Sikorin, S.N.; Mandzik, S.G.; Polazau, S.A.; Hryharovich, T.K.; Damarad, Y.V.; Palahina, Y.A.

    2014-01-01

    Benchmark criticality experiments of fast heterogeneous configuration with high enriched uranium (HEU) nuclear fuel were performed using the 'Giacint' critical assembly of the Joint Institute for Power and Nuclear Research - Sosny (JIPNR-Sosny) of the National Academy of Sciences of Belarus. The critical assembly core comprised fuel assemblies without a casing for the 34.8 mm wrench. Fuel assemblies contain 19 fuel rods of two types. The first type is metal uranium fuel rods with 90% enrichment by U-235; the second one is dioxide uranium fuel rods with 36% enrichment by U-235. The total fuel rods length is 620 mm, and the active fuel length is 500 mm. The outer fuel rods diameter is 7 mm, the wall is 0.2 mm thick, and the fuel material diameter is 6.4 mm. The clad material is stainless steel. The side radial reflector: the inner layer of beryllium, and the outer layer of stainless steel. The top and bottom axial reflectors are of stainless steel. The analysis of the experimental results obtained from these benchmark experiments by developing detailed calculation models and performing simulations for the different experiments is presented. The sensitivity of the obtained results for the material specifications and the modeling details were examined. The analyses used the MCNP and MCU computer programs. This paper presents the experimental and analytical results. (authors)

  7. High temperature fission chambers. Fast breeder reactor research and development program

    International Nuclear Information System (INIS)

    Berlin, C.; Perrigueur, J.C.

    1984-04-01

    Development of a high temperature fission chamber and experimentations of measuring channels (detectors and electronic devices) in similar conditions as those of power plants: development of measuring channels (impulses and current) of the Super Phenix neutronic measures auxiliary system, development of a measuring channel with impulses for the surveillance system of the clad failures, based on integrated detectors, and development of a fission chamber for experimentations in similar conditions as in Superphenix [fr

  8. Delayed neutrons as a probe of nuclear charge distribution in fission of heavy nuclei by neutrons

    CERN Document Server

    Isaev, S G; Piksaikin, V M; Roshchenko, V A

    2001-01-01

    A method of the determination of cumulative yields of delayed neutron precursors is developed. This method is based on the iterative least-square procedure applied to delayed neutron decay curves measured after irradiation of sup 2 sup 3 sup 5 U sample by thermal neutrons. Obtained cumulative yields in turns were used for deriving the values of the most probable charge in low-energy fission of the above-mentioned nucleus.

  9. A long term radiological risk model for plutonium-fueled and fission reactor space nuclear system

    International Nuclear Information System (INIS)

    Bartram, B.W.; Dougherty, D.K.

    1987-01-01

    This report describes the optimization of the RISK III mathematical model, which provides risk assessment for the use of a plutonium-fueled, fission reactor in space systems. The report discusses possible scenarios leading to radiation releases on the ground; distinctions are made for an intact reactor and a dispersed reactor. Also included are projected dose equivalents for various accident situations. 54 refs., 31 figs., 11 tabs

  10. Delayed neutrons as a probe of nuclear charge distribution in fission of heavy nuclei by neutrons

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.; Kazakov, L.E.; Roshchenko, V.A.

    2002-01-01

    A method of the determination of cumulative yields of delayed neutron precursors is developed. This method is based on the iterative least-square procedure applied to delayed neutron decay curves measured after irradiation of 235 U sample by thermal neutrons. Obtained cumulative yields in turns were used for deriving the values of the most probable charge in low-energy fission of the above-mentioned nucleus. (author)

  11. A high temperature heating device for the study of fission product release from nuclear fuel

    International Nuclear Information System (INIS)

    Svedkauskaite-Le Gore, Jolanta; Kivel, Niko; Guenther-Leopold, Ines

    2010-01-01

    At the Paul Scherrer Institute a high temperature inductive heating furnace, which can heat fuel samples up to 2300 deg. C, has been developed in order to study the release of fission products. The furnace can be directly connected to an inductively coupled plasma mass spectrometer for online monitoring of the released elements and does not require their trapping before measurement. This paper describes the design of the inductive heating furnace, discusses its operating parameters, limitations and illustrates foreseen applications. (authors)

  12. Fission-gas release in fuel performing to extended burnups in Ontario Hydro nuclear generating stations

    International Nuclear Information System (INIS)

    Floyd, M.R.; Novak, J.; Truant, P.T.

    1992-06-01

    The average discharge burnup of CANDU fuel is about 200 MWh/kgU. A significant number of 37-element bundles have achieved burnups in excess of 400 MWh/kgU. Some of these bundles have experienced failures related to their extended operation. To date, hot-cell examinations have been performed on fuel elements from nine 37-element bundles irradiated in Bruce NGS-A that have burnups in the range of 300-800 MWh/kgU. 1 Most of these have declining power histories from peak powers of up to 59 kW/m. Fission-gas releases of up to 26% have been observed and exhibit a strong dependence on fuel power. This obscures any dependence on burnup. The extent of fission-gas release at extended burnups was not predicted by low-burnup code extrapolations. This is attributed primarily to a reduction in fuel thermal conductivity which results in elevated operating temperatures. Reduced conductivity is due, at least in part, to the buildup of fission products in the fuel matrix. Some evidence of hyperstoichiometry exists, although this needs to be further investigated along with any possible relation to CANLUB graphite coating behaviour and sheath oxidation. Residual tensile sheath strains of up to 2% have been observed and can be correlated with fuel power/fission-gas release. SCC 2 -related defects have been observed in the sheath and endcaps of elements from bundles experiencing declining power histories to burnups in excess of 500 MWh/kgU. This indicates that the current recommended burnup limit of 450 MWh/kgU is justified. SCC-related defects have also been observed in ramped bundles having burnups < 450 MWh/kgU. Hence, additional guidelines are in place for power ramping extended-burnup fuel

  13. 238U and 237Np nuclear fission by 90-270 MeV electrons

    International Nuclear Information System (INIS)

    Kuznetsov, V.L.; Nedorezov, V.G.; Nikitina, N.V.; Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.; Smirnov, A.N.; Ehjsmont, V.P.

    1981-01-01

    A technique for measuring cross sections of 238 U and 237 Np nuclei fission caused by 90-270 MeV electrons is described. Measurement results are given. The results obtained are discussed on the basis of the virtual photon method. It is shown that the difference in cross sections of 238 U and 237 Np electrofission is due to the different contribution of the giant resonance [ru

  14. Nuclear Power Infrastructure Development Program: Korean Education Program

    International Nuclear Information System (INIS)

    Choi, Sung Yeol; Hwang, Il Soon; Kim, Si Hwan

    2009-01-01

    Many countries have decided nuclear power for next energy resources as one of the long-term energy supply options. IAEA projected nuclear power expansion up to 2030 reaching between 447 GWe and 691 GWe compared to 370 GWe and 2660 TWh at the end of 2006. Both low and high projection is accompanied with new nuclear power plant constructions respectively 178 and 357, about 11 units per year, and most new construction is in North America, the Far East, Eastern Europe, the Middle East, and Southeast Asia. During the last forty years, thirty three countries have established commercial nuclear power programs but only some of them have developed comprehensive and large scale peaceful nuclear power infrastructure. Although various cooperation and guidance program of nuclear power infrastructure, developing appropriate environment and infrastructure of nuclear power plant is still challenging problems for developing countries launching nuclear power program. With increasing the demand of safety and safeguard from international society, creating appropriate infrastructure becomes essential requirements in national nuclear power program. In the viewpoint of developing countries, without sufficient explanation and proper guidance, infrastructure could be seen only as another barrier in its nuclear power program. The importance of infrastructure development would be obscured by ostensible business and infrastructure program can result in increasing entering barriers to peaceful nuclear power application field without benefits to developing countries and international community. To avoid this situation by providing enough explanation and realistic case example and cooperate with the countries wanting to establish comprehensive nuclear power infrastructure in the peaceful applications, we are creating the education program of infrastructure development with basic guidelines of the IAEA infrastructure series and Korean experiences from least developed country to advanced country

  15. Contribution to the study of the fission-gas release in metallic nuclear fuels

    International Nuclear Information System (INIS)

    Kryger, B.

    1969-10-01

    In order to study the effect of an external pressure on the limitation of swelling due to fission-gas precipitation, some irradiations have been carried out at burn-ups of about 35.000 MWd/ton, and at average sample temperatures of 575 Celsius degrees, of non-alloyed uranium and uranium 8 per cent molybdenum gained in a thick stainless steel can. A cylindrical central hole allows a fuel swelling from 20 to 33 per cent according to the experiment. After irradiation, the uranium samples showed two types of can rupture: one is due to the fuel swelling, and the other, to the pressure of the fission gases, released through a network of microcracks. The cans of the uranium-molybdenum samples are all undamaged and it is shown that the gas release occurs by interconnection of the bubbles for swelling values higher than those obtained in the case of uranium. For each type of fuel, a swelling-fission gas release relationship is established. The results suggest that good performances with a metallic fuel intended for use in fast reactor conditions can be obtained. (author) [fr

  16. Neutronics issues in fusion-fission hybrid reactor design

    International Nuclear Information System (INIS)

    Liu Chengan

    1995-01-01

    The coupled neutron and γ-ray transport equations and nuclear number density equations, and its computer program systems concerned in fusion-fission hybrid reactor design are briefly described. The current status and focal point for coming work of nuclear data used in fusion reactor design are explained

  17. Radiochemistry and the Study of Fission

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-14

    These are slides from a lecture given at UC Berkeley. Radiochemistry has been used to study fission since its discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution. The following topics are covered: In the beginning: the discovery of fission; forensics using fission products: what can be learned from fission products, definitions of R-values and Q-values, fission bases, K-factors and fission chambers, limitations; the neutron energy dependence of the mass yield distribution (the two mode fission hypothesis); the influence of nuclear structure on the mass yield distribution. In summary: Radiochemistry has been used to study fission since its discovery. Radiochemical measurement of fission product yields have provided the highest precision data for developing fission models and for nuclear forensics. The two-mode fission hypothesis provides a description of the neutron energy dependence of the mass yield curve. However, data is still rather sparse and more work is needed near second and third chance fission. Radiochemical measurements have provided evidence for the importance of nuclear states in the compound nucleus in predicting the mass yield curve in the resonance region.

  18. Radiochemistry and the Study of Fission

    International Nuclear Information System (INIS)

    Rundberg, Robert S.

    2016-01-01

    These are slides from a lecture given at UC Berkeley. Radiochemistry has been used to study fission since its discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution. The following topics are covered: In the beginning: the discovery of fission; forensics using fission products: what can be learned from fission products, definitions of R-values and Q-values, fission bases, K-factors and fission chambers, limitations; the neutron energy dependence of the mass yield distribution (the two mode fission hypothesis); the influence of nuclear structure on the mass yield distribution. In summary: Radiochemistry has been used to study fission since its discovery. Radiochemical measurement of fission product yields have provided the highest precision data for developing fission models and for nuclear forensics. The two-mode fission hypothesis provides a description of the neutron energy dependence of the mass yield curve. However, data is still rather sparse and more work is needed near second and third chance fission. Radiochemical measurements have provided evidence for the importance of nuclear states in the compound nucleus in predicting the mass yield curve in the resonance region.

  19. Nuclear spectroscopy by radioactivity. Study of nuclei adjacent to the 82 neutron closed shell and application to fission

    International Nuclear Information System (INIS)

    Carraz, L.-C.

    1974-01-01

    Chemical separation techniques have been developed which make it possible to obtain a certain number of isotopes presenting anomalies in the fission efficiencies (near the magic shell N=82). A short description is given of the fission phenomenon by analysing the selection of isotopes investigated; it is shown how it was possible to explain the results by means of computers and the various chemical separations perfected are described. Thus a study was made of the 144 La direct γ spectrum. It was shown that the anomalies in the fission efficiencies of certain nuclei are apparent only. Hence, it is the presence of isomers and the distribution of the corresponding efficiency between two isomers which are the cause of the apparent weakness of the efficiency of 134 I, 136 I and 136 Cs, and of certain isotopes of Nb(Z=41). The nuclear spectrometry of nuclei of the area N=82 has made it possible to extend the existence of a metastable state to 136 Xe and 138 Ba. The value of the energies of the first 2 + , 4 + , 6 + levels and the half life duration of the 6 + metastable state are given. The discussion of the results and of the models show that the interpretation of the 0 + , 2 + , 4 + of the 82 neutron nuclei by means of a two quasi-particle (protons) model gives a fairly satisfactory description of the various experimental events: elastic scattering, gamma spectrometry and proton transfer reactions; on the other hand the interpretation of higher energy levels, requires the use of more complicated configurations [fr

  20. 75 years ago. The discovery of nuclear fission during the neutron irradiation of uranium on 17 December 1938 in Berlin

    International Nuclear Information System (INIS)

    Kuczera, Bernhard

    2013-01-01

    A ground-breaking, scientific discovery made in the Berlin experiments of the year 1938 on neutron irradiation of uranium, was that atom nuclei can be fissured and, during the fission energy, so-called nuclear energy, is released. If further U-235 atoms are in the immediate vicinity, the released neutrons can trigger a chain reaction of the nuclear fission. The story of this ground-breaking discovery that led to the worldwide civil utilisation of nuclear energy is outlined here. The discovery of neutrons and their implementation in radiation experiments occurred in the 1930s. The research work followed the model of the Stockholm citizen Niels Bohr on the configuration of an atom. In 1930, Walther Bothe reported on the occurrence of a high-energy radiation when beryllium was irradiated with alpha-particles. James Chadwick could prove experimentally in 1932 that this is a current of high-energy, electrically neutral particles. He called these particles neutrons. In Berlin, the radio-chemist Otto Hahn is the Director at the Kaiser-Wilhelm-Institute for Chemistry and head of the chemical-radioactive department. In the years 1935 to 1938, the radiation experiments of uranium with neutrons were at the centre of the research in Berlin. In October 1938, Hahn and Strassmann responded with their own experiments to the scientific challenge of Irene Curie and Paul Savitch of 3.5-hours of activity when uranium was radiated with neutrons. The decisive discovery for the neutron radiation of uranium was made by Hahn and Strassmann on 17 December 1938. From the results of different experiments, they conclude: 'Our radium isotopes have the properties of barium.' On 19 December, Hahn informs Lise Meitner and speaking on the issue of 'Where does the barium come from?' addresses a possible 'bursting' of the uranium nucleus. That is Hahn's 'Heureka.' moment: He recognises that the neutron radiation does not only effect radiochemical transformations, but can also cause the uranium