WorldWideScience

Sample records for heavy element nuclear

  1. Frontiers of heavy element nuclear and radiochemistry

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1999-01-01

    The production and half-lives of the heaviest chemical elements, now known through Z=112, are reviewed. Recent experimental evidence for the stabilization of heavy element isotopes due to proximity to deformed nuclear shells at Z=108 and N=162 is compared with the theoretical predictions. The possible existence of isotopes of elements 107-110 with half-lives of seconds or longer, and production reactions and experimental techniques for increasing the overall yields of such isotopes in order to study both their nuclear and chemical properties are discussed. The present status of studies of the chemical properties of Rf, Ha, and Sg is briefly summarized and prospects for extending chemical studies beyond Sg are considered. (author)

  2. Spallation RI beam facility and heavy element nuclear chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Yuichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    An outline of the spallation RI (Radioactive Ion) beam facility is presented. Neutron-rich nuclides are produced in the reaction of high intensity (10-1000 {mu}A) protons with energy of 1.5 GeV and an uranium carbide target. Produced nuclides are ionized in an isotope separator on-line (ISOL) and accelerated by the JAERI tandem and the booster linac. Current progress and a future project on the development of the RI beam facility are given. Studies of transactinide elements, including the synthesis of superheavy elements, nuclear structure far from stability, and RI-probed material science are planned with RI beams. An outlook of the transactinide nuclear chemistry studies using neutron-rich RI beams is described. (author)

  3. Nuclear physics and heavy element research at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Stoyer, M A; Ahle, L E; Becker, J A; Bernstein, L A; Bleuel, D L; Burke, J T; Dashdorj, D; Henderson, R A; Hurst, A M; Kenneally, J M; Lesher, S R; Moody, K J; Nelson, S L; Norman, E B; Pedretti, M; Scielzo, N D; Shaughnessy, D A; Sheets, S A; Stoeffl, W; Stoyer, N J; Wiedeking, M; Wilk, P A; Wu, C Y

    2009-05-11

    This paper highlights some of the current basic nuclear physics research at Lawrence Livermore National Laboratory (LLNL). The work at LLNL concentrates on investigating nuclei at the extremes. The Experimental Nuclear Physics Group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

  4. Heavy-element nucleosynthesis

    International Nuclear Information System (INIS)

    Mathews, G.J.

    1990-01-01

    New measurements and theoretical studies of nuclear properties, together with new astronomical data on the growth of heavy-element abundances during the early history of the Galaxy, now provide a clearer picture of where in nature the elements heavier than iron are produced by rapid (r-process) and show (s-process) neutron capture reactions. The nuclear data suggest that the r-process involves a high-neutron-density beta-flow equilibrium environment and that the s-process may have occurred at a temperature and neutron density consistent with a 13 C(α,n) 16 0 neutron source. The astronomical data, when compared with simple galactic chemical evolution modes, suggests that the r-process is associated with type II supernovae and that the neutron source must be manufactured by the star. Low-mass type II supernovae are proposed as the most important contributors to the r-process. A 13 C neutron source in intermediate-mass stars is proposed for the s-process. 64 refs., 7 figs

  5. Heavy element research

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Heavy element research activities in metallurgy and ceramics during 1976 at Lawrence Berkeley Laboratory are reviewed. Topics include: microstructure, properties and alloy design; ceramic alloy program; high resolution and high voltage electron microscopy; and powder metallurgy

  6. Octupole correlations in the heavy elements

    International Nuclear Information System (INIS)

    Chasman, R.R.

    1986-01-01

    The effects of octupole correlations on the nuclear structure of the heavy elements are discussed. The cluster model description of the heavy elements is analyzed. The relevance of 2 6 -pole deformation and fast El transitions to an octupole model is considered. 30 refs., 21 figs., 1 tab

  7. Validity of M-3Y force equivalent G-matrix elements for calculations of the nuclear structure in heavy mass region

    International Nuclear Information System (INIS)

    Cheng Lan; Huang Weizhi; Zhou Baosen

    1996-01-01

    Using the matrix elements of M-3Y force as the equivalent G-matrix elements, the spectra of 210 Pb, 206 Pb, 206 Hg and 210 Po are calculated in the framework of the Folded Diagram Method. The results show that such equivalent matrix elements are suitable for microscopic calculations of the nuclear structure in heavy mass region

  8. Probing for heavy element impurities in the shell of the Pacific oyster, Crassostrea gigas, with nuclear microscopy

    International Nuclear Information System (INIS)

    Markwitz, A.; Barry, B.; Gauldie, R.W.; Roberts, R.D.

    2003-01-01

    Nuclear microscopy was performed on shells of the Pacific oyster, Crassostrea gigas, to probe for heavy element impurities. For the studies 14 shells from the Auckland and the Marlborough Sounds region were chosen. In sections, the shells appear as opaque with white and grey zones, which are related to alternating layers of calcite and aragonite. Raster scans with 2.5 MeV protons over the sections (scan area 5 x 5 mm) were used in the experiment to measure trace elements in the ppm region using proton induced X-ray spectroscopy. Two dimensional maps and line scans revealed the presence of bromine in all shells investigated. Bromine was found to be related with the pattern of calcium. Hot spots of iron proved to be a common feature in the shells as well. In some shells, copper and zinc were also measured in hot spots of a few micrometers in diameter. Spatially resolved results on the micrometer level indicate the usefulness of nuclear microscopy for the detection of heavy elements in shells of the Pacific oyster

  9. CARA Project: development of the advanced ULE fuel element for heavy water nuclear power plants

    International Nuclear Information System (INIS)

    Brasnarof, Daniel O.; Marino, Armando C.; Florido, Pablo C.; Munoz, C.; Bianchi, Daniel R.; Giorgis, Miguel A.

    2006-01-01

    The CARA Project (Spanish acronym of Combustible Avanzado para Reactores Argentinos) is a national fuel element technology development, compatible with our nuclear power plants (Atucha I, Embalse and Atucha II). It takes into account the experience obtained in our nuclear organisations (CNEA-CONUAR-NASA). The goal of the CARA fuel element is the performance improvement for those reactors and the enhancing of their normal operative conditions. The CARA design allows the burnup extension by using 52 rods of the same diameter. Likewise it keeps good thermo-hydraulic behaviour. The fuel bundle can be directly used in nuclear power plants with horizontal channels. By using an additional system it can be installed in the PHWR with vertical channels. The expected profits, by the use of the CARA in our reactors, broadly guaranty the recovery of the fund for its development, due to a reduction of the NPP fuels and back end cost. We estimate a reduction in the generation cost between 20 or 25 % in relation to the present one if we use 0.85 or 0.90% SEU (Slightly Enriched Uranium). The use of the CARA fuel in our reactors will also reduce the amount of spent fuel to be treated. The shortening could be between 17 to 27 % in Atucha I in relation to the present ULE (0.85%), between 38 to 46% for Embalse, and 45 to 53% for Atucha II. The mechanical behaviour and hydraulic compatibility have been verified. Several CARA prototypes were fabricated with a new design of the end plate and with new processes for the welding for the rods. We present in this paper the current status of the CARA fuel element development. (author) [es

  10. Nuclear physics and heavy element research at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Stoyer, Mark A; Ahle, L E; Becker, J A; Bernshein, L A; Bleuel, D L; Burke, J T; Dashdorj, D; Henderson, R A; Hurst, A M; Kenneally, Jacqueline M; Lesher, S R; Moody, K J; Nelson, S L; Norman, E B; Pedretti, M; Scielzo, N D; Shaughnessy, D A; Sheets, S A; Stoeffl, W; Stoyer, N J [Lawrence Livermore National Laboratory, University of California, Livermore (United States)

    2009-12-31

    This paper highlights some of the current basic nuclear physics research at Lawrence Livermore National Laboratory (LLNL). The work at LLNL concentrates on investigating nuclei at the extremes. The Experimental Nuclear Physics Group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

  11. Recent research on the heavy transuranium elements

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1988-09-01

    This review is devoted to recent research (performed in the 1980s) on the heavy members of the group, defined as the transcurium elements (with a few references to related work on lighter elements). It covers the discovery of the three heaviest elements, the discovery of new isotopes, investigation of interesting decay properties of some previously known isotopes, investigations of some heavy ion reaction mechanisms in this region, and recent investigations of nuclear and chemical properties. It is not exhaustive in its coverage, is necessarily succinct, and inevitably places emphasis on those aspects with which the author is most familiar. 92 refs., 3 figs

  12. Nuclear chemistry of transactinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Yuichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    The current status on the nuclear chemistry studies of transactinide elements is reviewed. The production of transactinides in heavy ion reactions is briefly discussed, and nuclear properties on the stability of transactinides are presented. Chemical properties of the trans-actinide elements 104, 105 and 106, and a typical experimental technique used to study these properties on an atom-at-a-time base are introduced. (author)

  13. Heavy-element research

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The status is reported of studies on the solid-state chemistry of the actinides and lanthanides, spectroscopy of actinide compounds, and dynamic chemical description of actinide elements in solution. Phase studies were done on Rb 2 UO 4 , K 2 UO 4 , Li 2 UO 4 , and Es 2 U 2 O 7 . The lithium neptunate (VI) system was investigated and the existence of Li 2 NpO 4 was established. In oxidation-reduction studies it was shown that Am(III) can be electrolytically oxidized to Am(IV) in strong H 3 PO 4 , but Cf(III) and Pr(III) do not oxidize. The low-temperature absorption spectrum of thin films of NpBr 3 was investigated. (U.S.)

  14. Determination of trace elements and heavy metals in agricultural products cultivated at the Rimac river valley in Lima city using nuclear and related analytical techniques

    OpenAIRE

    Bedregal, Patricia; Torres, Blanca; Olivera, Paula; Mendoza, Pablo; Ubillús, Marco; Creed-Kanashiro, H.; Penny, M.; Junco, J.; Ganoza, L.

    2004-01-01

    There are strong indications that the Rimac river valley is being contaminated with heavy metals and an excess of trace elements that come from some industrial and mining activities developed along the Rimac river valley. The agricultural products cultivated there in could be suffering the same effect. Nuclear and related analytical techniques will play an important role in the study of pollution by providing information concerning the degree of contamination in some agricultural products cul...

  15. Automated rapid chemistry in heavy element research

    International Nuclear Information System (INIS)

    Schaedel, M.

    1994-01-01

    With the increasingly short half-lives of the heavy element isotopes in the transition region from the heaviest actinides to the transactinide elements the demand for automated rapid chemistry techniques is also increasing. Separation times of significantly less than one minute, high chemical yields, high repetition rates, and an adequate detection system are prerequisites for many successful experiments in this field. The development of techniques for separations in the gas phase and in the aqueous phase for applications of chemical or nuclear studies of the heaviest elements are briefly outlined. Typical examples of results obtained with automated techniques are presented for studies up to element 105, especially those obtained with the Automated Rapid Chemistry Apparatus, ARCA. The prospects to investigate the properties of even heavier elements with chemical techniques are discussed

  16. Nuclear fuel element

    International Nuclear Information System (INIS)

    Mogard, J.H.

    1977-01-01

    A nuclear fuel element is disclosed for use in power producing nuclear reactors, comprising a plurality of axially aligned ceramic cylindrical fuel bodies of the sintered type, and a cladding tube of metal or metal alloys, wherein said cladding tube on its cylindrical inner surface is provided with a plurality of slightly protruding spacing elements distributed over said inner surface

  17. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1981-01-01

    An array of rods comprising zirconium alloy sheathed nuclear fuel pellets assembled to form a fuel element for a pressurised water reactor is claimed. The helium gas pressure within each rod differs substantially from that of its closest neighbours

  18. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1984-01-01

    The fuel elements for a pressurised water reactor comprise arrays of rods of zirconium alloy sheathed nuclear fuel pellets. The helium gas pressure within each rod differs substantially from that of its closest neighbours

  19. Nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding, and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

  20. Nuclear fuel element

    International Nuclear Information System (INIS)

    Thompson, J.R.; Rowland, T.C.

    1976-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting, fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

  1. Nuclear fuel element

    International Nuclear Information System (INIS)

    Penrose, R.T.; Thompson, J.R.

    1976-01-01

    A method of protecting the cladding of a nuclear fuel element from internal attack and a nuclear fuel element for use in the core of a nuclear reactor are disclosed. The nuclear fuel element has disposed therein an additive of a barium-containing material and the barium-containing material collects reactive gases through chemical reaction or adsorption at temperatures ranging from room temperature up to fuel element plenum temperatures. The additive is located in the plenum of the fuel element and preferably in the form of particles in a hollow container having a multiplicity of gas permeable openings in one portion of the container with the openings being of a size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles. The additive is comprised of elemental barium or a barium alloy containing one or more metals in addition to barium such as aluminum, zirconium, nickel, titanium and combinations thereof. 6 claims, 3 drawing figures

  2. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Ainsworth, K.F.

    1979-01-01

    A nuclear fuel element is described having a cluster of nuclear fuel pins supported in parallel, spaced apart relationship by transverse cellular braces within coaxial, inner and outer sleeves, the inner sleeve being in at least two separate axial lengths, each of the transverse braces having a peripheral portion which is clamped peripherally between the ends of the axial lengths of the inner sleeve. (author)

  3. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    Klepfer, H.H.

    1974-01-01

    A nuclear fuel element is described which comprises: 1) an elongated clad container, 2) a layer of high lubricity material being disposed in and adjacent to the clad container, 3) a low neutron capture cross section metal liner being disposed in the clad container and adjacent to the layer, 4) a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, 5) an enclosure integrally secured and sealed at each end of the container, and a nuclear fuel material retaining means positioned in the cavity. (author)

  4. Nuclear fuel element

    International Nuclear Information System (INIS)

    Grossman, L.N.; Levin, H.A.

    1975-01-01

    A nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smallr than the size of the particles. The container is preferably held in the spring in the plenum of the fuel element. (E.C.B.)

  5. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Nakai, Keiichi

    1983-01-01

    Purpose: To decrease the tensile stresses resulted in a fuel can as well as prevent decladding of fuel pellets into the bore holes by decreasing the inner pressure within the nuclear fuel element. Constitution: A fuel can is filled with hollow fuel pellets, inserted with a spring for retaining the hollow fuel pellets with an appropriate force and, thereafter, closely sealed at the both ends with end plugs. A cylindrical body is disposed into the bore holes of the hollow fuel pellets. Since initial sealing gases and/or gaseous nuclear fission products can thus be excluded from the bore holes where the temperature is at the highest level, the inner pressure of the nuclear fuel element can be reduced to decrease the tensile strength resulted to the fuel can. Furthermore, decladding of fuel pellets into the bore holes can be prevented. (Moriyama, K.)

  6. Frontiers of heavy-ion physics and superheavy elements

    International Nuclear Information System (INIS)

    Muenzenberg, Gottfried

    2002-01-01

    This contribution will focus on three topics of GSI nuclear structure research: super heavy elements, direct mass measurements in the storage ring, and the measurement of spallation cross section in reversed kinematics. The GSI project for an extended synchrotron facility will be outlined. (author)

  7. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Butterfield, C.E.; Waite, E.

    1982-01-01

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  8. Vented nuclear fuel element

    International Nuclear Information System (INIS)

    Oguma, M.; Hirose, Y.

    1976-01-01

    A description is given of a vented nuclear fuel element having a plenum for accumulation of fission product gases and plug means for delaying the release of the fission product gases from the plenum, the plug means comprising a first porous body wettable with a liquid metal and a second porous body non-wettable with the liquid metal, the first porous body being impregnated with the liquid metal and in contact with the liquid metal

  9. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has a metal liner disposed between the cladding and the nuclear fuel material and a high lubricity material in the form of a coating disposed between the liner and the cladding. The liner preferably has a thickness greater than the longest fission product recoil distance and is composed of a low neutron capture cross-section material. The liner is preferably composed of zirconium, an alloy of zirconium, niobium or an alloy of niobium. The liner serves as a preferential reaction site for volatile impurities and fission products and protects the cladding from contact and reaction with such impurities and fission products. The high lubricity material acts as an interface between the liner and the cladding and reduces localized stresses on the cladding due to fuel expansion and cracking of the fuel

  10. Nuclear fuel element

    International Nuclear Information System (INIS)

    Hirayama, Satoshi; Kawada, Toshiyuki; Matsuzaki, Masayoshi.

    1980-01-01

    Purpose: To provide a fuel element for reducing the mechanical interactions between a fuel-cladding tube and the fuel element and for alleviating the limits of the operating conditions of a reactor. Constitution: A fuel element having mainly uranium dioxide consists of a cylindrical outer pellet and cylindrical inner pellet inserted into the outer pellet. The outer pellet contains two or more additives selected from aluminium oxide, beryllium oxide, magnesium oxide, silicon oxide, sodium oxide, phosphorus oxide, calcium oxide and iron oxide, and the inner pellet contains nuclear fuel substance solely or one additive selected from calcium oxide, silicon oxide, aluminium oxide, magnesium oxide, zirconium oxide and iron oxide. The outer pellet of the fuel thus constituted is reduced in mechanical strength and also in the mechanical interactions with the cladding tube, and the plastic fluidity of the entire pellet is prevented by the inner pellet increased in the mechanical strength. (Kamimura, M.)

  11. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1980-01-01

    The invention is of a nuclear fuel element which comprises a central core of a body of nuclear fuel material selected from the group consisting of compounds of uranium, plutonium, thorium and mixtures thereof, and an elongated composite cladding container comprising a zirconium alloy tube containing constituents other than zirconium in an amount greater than about 5000 parts per million by weight and an undeformed metal barrier of moderate purity zirconium bonded to the inside surface of the alloy tube. The container encloses the core so as to leave a gap between the container and the core during use in a nuclear reactor. The metal barrier is of moderate purity zirconium with an impurity level on a weight basis of at least 1000ppm and less than 5000ppm. Impurity levels of specific elements are given. Variations of the invention are also specified. The composite cladding reduces chemical interaction, minimizes localized stress and strain corrosion and reduces the likelihood of a splitting failure in the zirconium alloy tube. Other benefits are claimed. (U.K.)

  12. Nuclear fuel element

    International Nuclear Information System (INIS)

    Hirama, H.

    1978-01-01

    A nuclear fuel element comprises an elongated tube having upper and lower end plugs fixed to both ends thereof and nuclear fuel pellets contained within the tube. The fuel pellets are held against the lower end plug by a spring which is supported by a setting structure. The setting structure is maintained at a proper position at the middle of the tube by a wedge effect caused by spring force exerted by the spring against a set of balls coacting with a tapered member of the setting structure thereby wedging the balls against the inner wall of the tube, and the setting structure is moved free by pushing with a push bar against the spring force so as to release the wedge effect

  13. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Kawada, Toshiyuki; Hirayama, Satoshi; Yoneya, Katsutoshi.

    1980-01-01

    Purpose: To enable load-depending operation as well as moderation for the restriction of operation conditions in the present nuclear reactors, by specifying the essential ingredients and the total weight of the additives to UO 2 fuel substances. Constitution: Two or more additives selected from Al 2 O 3 , B 2 O, CaO, MgO, SiO 2 , Na 2 O and P 2 O 5 are added by the total weight of 2 - 5% to fuel substances consisting of UO 2 or a mixture of UO 2 and PuO 2 . When the mixture is sintered, the strength of the fuel elements is decreased and the fuel-cladding interactions due to the difference in the heat expansion coefficients between the ceramic fuel elements and the metal claddings are decreased to a substantially harmless degree. (Horiuchi, T.)

  14. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E. D.

    1984-01-01

    An array of rods is assembled to form a fuel element for a pressurized water reactor, the rods comprising zirconium alloy sheathed nuclear fuel pellets and containing helium. The helium gas pressure is selected for each rod so that it differs substantially from the helium gas pressure in its closest neighbors. In a preferred arrangement the rods are arranged in a square lattice and the helium gas pressure alternates between a relatively high value and a relatively low value so that each rod has as its closest neighbors up to four rods containing helium gas at the other pressure value

  15. Nuclear reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, E. D.

    1984-10-16

    An array of rods is assembled to form a fuel element for a pressurized water reactor, the rods comprising zirconium alloy sheathed nuclear fuel pellets and containing helium. The helium gas pressure is selected for each rod so that it differs substantially from the helium gas pressure in its closest neighbors. In a preferred arrangement the rods are arranged in a square lattice and the helium gas pressure alternates between a relatively high value and a relatively low value so that each rod has as its closest neighbors up to four rods containing helium gas at the other pressure value.

  16. Nuclear fuel element

    International Nuclear Information System (INIS)

    Iwano, Yoshihiko.

    1993-01-01

    Microfine cracks having a depth of less than 10% of a pipe thickness are disposed radially from a central axis each at an interval of less than 100 micron over the entire inner circumferential surface of a zirconium alloy fuel cladding tube. For manufacturing such a nuclear fuel element, the inside of the cladding tube is at first filled with an electrolyte solution of potassium chloride. Then, electrolysis is conducted using the cladding tube as an anode and the electrolyte solution as a cathode, and the inner surface of the cladding tube with a zirconium dioxide layer having a predetermined thickness. Subsequently, the cladding tube is laid on a smooth steel plate and lightly compressed by other smooth steel plate to form microfine cracks in the zirconium dioxide layer on the inner surface of the cladding tube. Such a compressing operation is continuously applied to the cladding tube while rotating the cladding tube. This can inhibit progress of cracks on the inner surface of the cladding tube, thereby enabling to prevent failure of the cladding tube even if a pellet/cladding tube mechanical interaction is applied. Accordingly, reliability of the nuclear fuel elements is improved. (I.N.)

  17. Nuclear fuel element

    International Nuclear Information System (INIS)

    Armijo, J.S.

    1977-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed which has a composite cladding having a substrate, a metal barrier metallurgically bonded to the inside surface of the substrate and an inner layer metallurgically bonded to the inside surface of the metal barrier. In this composite cladding, the inner layer and the metal barrier shield the substrate from any impurities or fission products from the nuclear fuel material held within the composite cladding. The metal barrier forms about 1 to about 4 percent of the thickness of the cladding and is comprised of a metal selected from the group consisting of niobium, aluminum, copper, nickel, stainless steel, and iron. The inner layer and then the metal barrier serve as reaction sites for volatile impurities and fission products and protect the substrate from contact and reaction with such impurities and fission products. The substrate and the inner layer of the composite cladding are selected from conventional cladding materials and preferably are a zirconium alloy. Also in a preferred embodiment the substrate and the inner layer are comprised of the same material, preferably a zirconium alloy. 19 claims, 2 figures

  18. Photodisintegration of the heavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, R W; Collie, C H

    1950-08-01

    The photothresholds for the emission of neutrons by the following elements have been determined; the threshold in MeV is given in the brackets following the symbol: Pt(6.1 +- 0.1), Au(8.1 +- 0.1), Hg(6.6 +- 0.2), Tl(7.3 +- 0.25), Pb(6.9 +- 0.1), Bi(7.2 +- 0.1), Th(6.9 +- 0.15), U(5.8 +- 0.15). The neutrons were detected by the Szilard-Chalmers method of chemical concentration and the ..gamma.. rays were obtained from a small betatron. Rough values of the total cross sections can be estimated from the results.

  19. Lattice results for heavy light matrix elements

    International Nuclear Information System (INIS)

    Soni, A.

    1994-09-01

    Lattice results for heavy light matrix elements are reviewed and some of their implications are very briefly discussed. Despite the fact that in most cases the lattice results for weak matrix elements at the moment have only a modest accuracy of about 20--30% they already have important phenomenological repercussions; e.g. for V td /V ts , x s /x d and B → K*γ

  20. Heavy metals and related trace elements

    International Nuclear Information System (INIS)

    Leland, H.V.; Luoma, S.N.; Wilkes, D.J.

    1977-01-01

    A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow trout

  1. Nuclear research with heavy ions

    International Nuclear Information System (INIS)

    Kaplan, M.

    1991-08-01

    This report discusses the following topics: Asymmetric fission of 149 Tb* from the finite-range, rotating-liquid-drop model: mean total kinetic energies for binary fragmentation; charged-particle evaporation from hot composite nuclei: evidence over a broad Z range for distortions from cold nuclear profiles; the role of reversed kinematics and double kinematic solutions in nuclear reactions studies; production of intermediate-mass-fragments in the reaction 98 Mo + 51 V at an excitation energy E* = 224-MeV; emission of light charged particles in the reaction 344-MeV 28 Si + 121 Sb; continued developments of the statistical evaporation code LILITA N90; and planning for heavy-ion-collision studies at very high energies: the STAR collaboration at RHIC

  2. Nuclear reaction analysis (NRA) for trace element detection

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Noll, K. [Bern Univ. (Switzerland)

    1997-09-01

    Ion beam induced nuclear reactions can be used to analyse trace element concentrations in materials. The method is especially suited for the detection of light contaminants in heavy matrices. (author) 3 figs., 2 refs.

  3. Nuclear reactor fuel element splitter

    International Nuclear Information System (INIS)

    Yeo, D.

    1976-01-01

    A method and apparatus are disclosed for removing nuclear fuel from a clad fuel element. The fuel element is power driven past laser beams which simultaneously cut the cladding lengthwise into at least two longitudinal pieces. The axially cut lengths of cladding are then separated, causing the nuclear fuel contained therein to drop into a receptacle for later disposition. The cut lengths of cladding comprise nuclear waste which is disposed of in a suitable manner. 6 claims, 10 drawing figures

  4. Nuclear physics with heavy ions. 1

    International Nuclear Information System (INIS)

    Reif, R.; Schmidt, R.

    1981-01-01

    Some results obtained in nuclear physics with heavy ions in the energy range up to 10 MeV/nucleon are summarized. A short review of the tendencies in the development of heavy ion accelerators is followed by a classification of the mechanisms observed in heavy ion interactions. The characteristics of the various types of reactions are presented. Applications of heavy ion beams in other branches of sciences are discussed. (author)

  5. Nuclear fuel element

    International Nuclear Information System (INIS)

    Yamamoto, Seigoro.

    1994-01-01

    Ultrafine particles of a thermal neutron absorber showing ultraplasticity is dispersed in oxide ceramic fuels by more than 1% to 10% or lower. The ultrafine particles of the thermal neutron absorber showing ultrafine plasticity is selected from any one of ZrGd, HfEu, HfY, HfGd, ZrEu, and ZrY. The thermal neutron absorber is converted into ultrafine particles and solid-solubilized in a nuclear fuel pellet, so that the dispersion thereof into nuclear fuels is made uniform and an absorbing performance of the thermal neutrons is also made uniform. Moreover, the characteristics thereof, for example, physical properties such as expansion coefficient and thermal conductivity of the nuclear fuels are also improved. The neutron absorber, such as ZrGd or the like, can provide plasticity of nuclear fuels, if it is mixed into the nuclear fuels for showing the plasticity. The nuclear fuel pellets are deformed like an hour glass as burning, but, since the end portion thereof is deformed plastically within a range of a repulsive force of the cladding tube, there is no worry of damaging a portion of the cladding tube. (N.H.)

  6. Heavy water moderated tubular type nuclear reactor

    International Nuclear Information System (INIS)

    Oohashi, Masahisa.

    1986-01-01

    Purpose: To enable to effectively change the volume of heavy water per unit fuel lattice in heavy water moderated pressure tube type nuclear reactors. Constitution: In a nuclear reactor in which fuels are charged within pressure tubes and coolants are caused to flow between the pressure tubes and the fuels, heavy water tubes for recycling heavy water are disposed to a gas region formed to the outside of the pressure tubes. Then, the pressure tube diameter at the central portion of the reactor core is made smaller than that at the periphery of the reactor core. Further, injection means for gas such as helium is disposed to the upper portion for each of the heavy water tubes so that the level of the heavy water can easily be adjusted by the control for the gas pressure. Furthermore, heavy water reflection tubes are disposed around the reactor core. In this constitution, since the pitch for the pressure tubes can be increased, the construction and the maintenance for the nuclear reactor can be facilitated. Also, since the liquid surface of the heavy water in the heavy water tubes can be varied, nuclear properties is improved and the conversion ratio is improved. (Ikeda, J.)

  7. On the production of heavy elements by cold fusion

    International Nuclear Information System (INIS)

    Armbruster, P.

    1985-01-01

    After a short historical introduction (Section 1), this article presents new insights into the mechanism limiting the fusion of heavy nuclides (Section 2). Fusion is finally limited by the increasing Coulomb forces in the formation process of a compound system, as well as in its deexcitation. Moreover, nuclear structure effects in all stages of evaporation residue (EVR) formation are shown to be of importance. The wide field of fusion reaction studies and possible experimental techniques is projected onto the task of element synthesis, and only those aspects that are of relevance here are covered. The better understanding of EVR formation (Section 2) and the new experimental techniques (Section 3) that enabled the production of elements 107-109 (Section 4) are also discussed. In Section 5 ground-state properties and the nuclear structure of the heaviest isotopes, together with their production cross sections, are discussed. Finally, an outlook on how eventually to go beyond Z = 109 is given

  8. Heavy element affinities in Apollo 17 samples

    International Nuclear Information System (INIS)

    Allen, R.O. Jr.; Jovanovic, S.; Reed, G.W. Jr.

    1975-01-01

    204 Pb, Bi, Tl and Zn in samples from Apollo 17 exhibit relationships not found in samples from other sites. 204 Pb, Tl and Zn in residues remaining after dilute acid leaching are correlated with one another. Orange soil 74220, which is enriched in 204 Pb, Tl and Zn, is included in these relationships. In addition the submicron metallic phase generally associated with agglutinate formation is correlated with all three of these elements; this relationship has already been reported for 204 Pb in other samples. Thus, orange soil and agglutinates appear to be involved in concentrating heavy volatile metals. A process other than mixing is required to account for this. As a consequence of the isolation of the landing site by the surrounding massifs, local supply and recycling of volatile trace elements in soils may account for some of the interelement relations. (Auth.)

  9. Nuclear fuel element

    International Nuclear Information System (INIS)

    Knowles, A.N.

    1979-01-01

    A nuclear fuel-containing body for a high temperature gas cooled nuclear reactor is described which comprises a flat plate in which the nuclear fuel is contained as a dispersion of fission product-retaining coated fuel particles in a flat sheet of graphitic or carbonaceous matrix material. The flat sheet is clad with a relatively thin layer of unfuelled graphite bonded to the sheet by being formed initially from a number of separate preformed graphitic artefacts and then platen-pressed on to the exterior surfaces of the flat sheet, both the matrix material and the artefacts being in a green state, to enclose the sheet. A number of such flat plates are supported edge-on to the coolant flow in the bore of a tube made of neutron moderating material. Where a number of tiers of plates are superimposed on one another, the abutting edges are chamfered to reduce vibration. (author)

  10. The radioactivity of spirulina and its heavy elements

    International Nuclear Information System (INIS)

    Fantariandraintsoa, A.A.

    2014-01-01

    Spirulina is one of the three classes of algae that have the ability to accumulate contaminants from the environment in which they live. The main aim of this work is to study the radioactive contamination of Spirulina using gamma spectrometry and to determine its content of heavy elements using the technique of X-ray fluorescence analysis. Use of detector and Gamma Vision software, in the laboratory of nuclear analysis of the I nstitut National des Sciences et Techniques Nucleaires -Madagascar (INSTN-Madagascar), allowed us to find some amount of radioactive elements such as potassium, lead, thallium and bismuth. The elements found in the laboratory of X-ray fluorescence analysis, of the same institute, using the conventional method along with the XRF AXIL software are calcium, iron, magnesium, bromine, rubidium and strontium as well as heavy elements zinc and copper. Spirulina is rich in potassium, its activity is 98±56 Bq.Kg -1 and the average concentration of the radioactive element is 16.2 g.Kg -1 . Analysis results leads us to say that it is best to consume spirulina from well secured against pollution (greenhouse) culture and we can say that we need to improve crops in natural environments. [fr

  11. Elements of nuclear safety

    CERN Document Server

    Libmann, Jacques

    1996-01-01

    This basically educational book is intended for all involved in nuclear facility safety. It dissects the principles and experiences conducive to the adoption of attitudes compliant with what is now known as "safety culture". This book is accessible to a wide range of readers.

  12. Quasifission in heavy and superheavy element formation reactions

    International Nuclear Information System (INIS)

    Hinde, D.J.; Dasgupta, M.; Jeung, D.Y.; Mohanto, G.; Prasad, E.; Simenel, C.; Walshe, J.; Wahkle, A.; Williams, E.; Carter, I.P.; Cook, K.J.; Kalkal, Sunil; Rafferty, D.C.; Rietz, R. du; Simpson, E.C.; David, H.M.; Düllmann, Ch.E.; Khuyagbaatar, J.

    2016-01-01

    Superheavy elements are created in the laboratory by the fusion of two heavy nuclei. The large Coulomb repulsion that makes superheavy elements decay also makes the fusion process that forms them very unlikely. Instead, after sticking together for a short time, the two nuclei usually come apart, in a process called quasifission. Mass-angle distributions give the most direct information on the characteristics and time scales of quasifission. A systematic study of carefully chosen mass-angle distributions has provided information on the global trends of quasifission. Large deviations from these systematics reveal the major role played by the nuclear structure of the two colliding nuclei in determining the reaction outcome, and thus implicitly in hindering or favouring superheavy element production.

  13. Nuclear fuel element

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, J S; Coffing, L F

    1979-04-05

    The fuel element with circular cross-section for BWR and PWR consists of a core surrounded by a compound jacket container where there is a gap between the core and jacket during operation in the reactor. The core consists of U, Pu, Th compounds and mixtures of these. The compound jacket consists of zircaloy 2 or 4. In order to for example prevent the corrosion of the compound jacket, its inner surface has a metal barrier with smaller neutron absorbers than the jacket material in the form of a zirconium sponge. The zirconium of this metal barrier has impurities of various elements in the order of magnitude of 1000 to 5000 ppm. The oxygen content is in the range of 200 to 1200 ppm and the thickness of the metal barrier is 1-30% of the thickness of the jacket.

  14. Nuclear reactor fuel element

    International Nuclear Information System (INIS)

    D'Eye, R.W.M.; Shennan, J.V.; Ford, L.H.

    1977-01-01

    Fuel element with particles from ceramic fissionable material (e.g. uranium carbide), each one being coated with pyrolitically deposited carbon and all of them being connected at their points of contact by means of an individual crossbar. The crossbar consists of silicon carbide produced by reaction of silicon metal powder with the carbon under the influence of heat. Previously the silicon metal powder together with the particles was kneaded in a solvent and a binder (e.g. epoxy resin in methyl ethyl ketone plus setting agent) to from a pulp. The reaction temperature lies at 1750 0 C. The reaction itself may take place in a nitrogen atmosphere. There will be produced a fuel element with a high overall thermal conductivity. (DG) [de

  15. Heavy element abundances of Nova Cygni 1975

    International Nuclear Information System (INIS)

    Ferland, G.J.; Shields, G.A.

    1978-01-01

    McDonald observations of the nebular phase of the outburst of Nova Cygni 1975 are analyzed to measure the abundances of several heavy elements. A new analytical procedure is used to derive the electron density and temperature from the emission line intensities of [O III], [Ne III], and He I observed between days 40 and 120. These physical conditions are used to derive the abundances. We find that Fe has approximately a solar abundance, whereas C, N, O, and Ne are enhanced by factors approx.20 to 100. The enhanced abundance of neon was theoretically unexpected.The derived physical conditions and line intensities are compared with predictions of an equilibrium photoionization model. The model successfully predicts the intensities of He I, [O III], and [Ne III]; but it underestimates the strength of [Ne V] and [Fe VII], which may originate in a mechanically heated ''subcoronal'' line region

  16. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Obara, Hiroshi.

    1981-01-01

    Purpose: To suppress iodine release thereby prevent stress corrosion cracks in fuel cans by dispersing ferrous oxide at the outer periphery of sintered uranium dioxide pellets filled and sealed within zirconium alloy fuel cans of fuel elements. Constitution: Sintered uranium dioxide pellets to be filled and sealed within a zirconium alloy fuel can are prepared either by mixing ferric oxide powder in uranium dioxide powder, sintering and then reducing at low temperature or by mixing iron powder in uranium dioxide powder, sintering and then oxidizing at low temperature. In this way, ferrous oxide is dispersed on the outer periphery of the sintered uranium dioxide pellets to convert corrosive fission products iodine into iron iodide, whereby the iodine release is suppressed and the stress corrosion cracks can be prevented in the fuel can. (Moriyama, K.)

  17. Rack for nuclear fuel elements

    International Nuclear Information System (INIS)

    Rubinstein, H.J.; Gordon, C.B.; Robison, A.; Clark, P.M.

    1977-01-01

    Disclosed is a rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed spent fuel elements. Each fuel element is supported at the lower end thereof by a respective support that rests on the floor of the spent fuel pool for a nuclear power plant. An open rack frame is employed as an upright support for the enclosures containing the spent fuel elements. Legs at the lower corners of the frame rest on the floor of the pool to support the frame. In one exemplary embodiment, the support for the fuel element is in the form of a base on which a fuel element rests and the base is supported by legs. In another exemplary embodiment, each fuel element is supported on the pool floor by a self-adjusting support in the form of a base on which a fuel element rests and the base rests on a ball or swivel joint for self-alignment. The lower four corners of the frame are supported by legs adjustable in height for leveling the frame. Each adjustable frame leg is in the form of a base resting on the pool floor and the base supports a threaded post. The threaded post adjustably engages a threaded column on which rests the lower end of the frame. 16 claims, 14 figures

  18. Directions for nuclear research in the transplutonium elements

    International Nuclear Information System (INIS)

    Wilhelmy, J.B.; Chasman, R.R.; Friedman, A.M.; Ahmad, I.

    1983-01-01

    The study of the heavy nuclides has played a vital role in our understanding of the alpha decay process, nuclear fission, nuclear binding energies and the limits of nuclear stability. This study has led to the understanding of novel shape degrees of freedom, such as the very large quadrupole deformations associated with the fission isomer process, and the very recently discovered octupole deformation. The existence of these unique phenomena in the heavy element region is not accidental. Fission isomerism is due to the delicate balance between nuclear forces holding the nucleus together and Coulomb forces causing nuclear fission. Octupole deformation arises from the increasing strength of matrix elements with increasing oscillator shell. Both illustrate the unique features of the heavy element region. Fission studies have given us information about large collective aspects in nuclei and the importance that nuclear structural effects can play in altering these macro properties. A new class of atomic studies has become possible with the availability of heavy elements. With these isotopes, we are now able to produce electric fields of such magnitude that it becomes possible to spontaneously create positron-electron pairs in the vacuum. We have organized this presentation into three major sections: nuclear structure, fission studies and atomic studies of supercritical systems. In each we will try to emphasize the new directions which can benefit from the continued availability of isotopes supplied by the Trans-plutonium Production Program. 117 references

  19. Nuclear fuels and development of nuclear fuel elements

    International Nuclear Information System (INIS)

    Sundaram, C.V.; Mannan, S.L.

    1989-01-01

    Safe, reliable and economic operation of nuclear fission reactors, the source of nuclear power at present, requires judicious choice, careful preparation and specialised fabrication procedures for fuels and fuel element structural materials. These aspects of nuclear fuels (uranium, plutonium and their oxides and carbides), fuel element technology and structural materials (aluminium, zircaloy, stainless steel etc.) are discussed with particular reference to research and power reactors in India, e.g. the DHRUVA research reactor at BARC, Trombay, the pressurised heavy water reactors (PHWR) at Rajasthan and Kalpakkam, and the Fast Breeder Test Reactor (FBTR) at Kalpakkam. Other reactors like the gas-cooled reactors operating in UK are also mentioned. Because of the limited uranium resources, India has opted for a three-stage nuclear power programme aimed at the ultimate utilization of her abundant thorium resources. The first phase consists of natural uranium dioxide-fuelled, heavy water-moderated and cooled PHWR. The second phase was initiated with the attainment of criticality in the FBTR at Kalpakkam. Fast Breeder Reactors (FBR) utilize the plutonium and uranium by-products of phase 1. Moreover, FBR can convert thorium into fissile 233 U. They produce more fuel than is consumed - hence, the name breeders. The fuel parameters of some of the operating or proposed fast reactors in the world are compared. FBTR is unique in the choice of mixed carbides of plutonium and uranium as fuel. Factors affecting the fuel element performance and life in various reactors e.g. hydriding of zircaloys, fuel pellet-cladding interaction etc. in PHWR and void swelling; irradiation creep and helium embrittlement of fuel element structural materials in FBR are discussed along with measures to overcome some of these problems. (author). 15 refs., 9 tabs., 23 figs

  20. Heavy quark energy loss in nuclear medium

    International Nuclear Information System (INIS)

    Zhang, Benr-Wei; Wang, Enke; Wang, Xin-Nian

    2003-01-01

    Multiple scattering, modified fragmentation functions and radiative energy loss of a heavy quark propagating in a nuclear medium are investigated in perturbative QCD. Because of the quark mass dependence of the gluon formation time, the medium size dependence of heavy quark energy loss is found to change from a linear to a quadratic form when the initial energy and momentum scale are increased relative to the quark mass. The radiative energy loss is also significantly suppressed relative to a light quark due to the suppression of collinear gluon emission by a heavy quark

  1. Nuclear physics with polarized heavy ions

    International Nuclear Information System (INIS)

    Fick, D.; Grawert, G.; Turkiewicz, I.M.

    1992-01-01

    Polarized heavy ion beams ( 6 Li, 7 Li, 23 Na) have been in use as tools for the investigation of nuclear scattering and nuclear reactions for almost two decades. This review attempts to survey the research activities in this field with reference to nuclear structure, nuclear dynamics and reaction mechanisms. Besides reviewing the results from full quantum mechanical coupled channels analyses of data, special attention is paid to handwaving arguments and semiclassical pictures as a complementary way of obtaining a better understanding of the relevant physics. (orig.)

  2. Nuclear fuel element end fitting

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    A typical embodiment of the invention has an array of sockets that are welded to the intersections of the plates that form the upper and lower end fittings of a nuclear reactor fuel element. The sockets, which are generally cylindrical in shape, are oriented in directions that enable the longitudinal axes of the sockets to align with the longitudinal axes of the fuel rods that are received in the respective sockets. Detents impressed in the surfaces of the sockets engage mating grooves that are formed in the ends of the fuel rods to provide for the structural integrity of the fuel element

  3. Superheavy Element Synthesis and Nuclear Structure

    International Nuclear Information System (INIS)

    Ackermann, D.

    2009-01-01

    The search for the next closed proton and neutron shells beyond 2 08P b has yielded a number of exciting results in terms of the synthesis of new elements [1,2,3]. The superheavy elements (SHE), however, are a nuclear structure phenomenon. They owe their existence to the quantum mechanical origin of shell correction energies without which they would not be bound. In recent years the development of efficient experimental set-ups including separators and advanced particle and photon detection arrangements allowed for more and more detailed nuclear structure studies for nuclei at and beyond Z=100. A review of those recent achievements is given in ref. [4]. Among the most interesting features is the observation of K-isomeric states. Experimentally about 14 cases have been identified in the region of Z>96 as shown in Fig. 1. K-isomers or indications of their existence have been found for almost all even-Z elements in the region Z=100 to 110. We could recently establish and/or confirm such states in the even-even isotopes 2 52,254N o [5]. The heaviest nucleus where such a state was found is 2 70D s with Z=110 as we reported in 2001 [6]. Those nuclear structure studies lay out the grounds for a detailed understanding of these heavy and high-Z nuclear systems, and contribute at the same time valuable information to preparation of strategies to successfully continue the hunt for the localisation of the next spherical proton and neutron shells after 2 08P b. The recent activities for both SHE synthesis and nuclear structure investigations at GSI will be reported.(author)

  4. Integral nuclear fuel element assembly

    International Nuclear Information System (INIS)

    Schluderberg, D. C.

    1985-01-01

    An integral nuclear fuel element assembly utilizes longitudinally finned fuel pins. The continuous or interrupted fins of the fuel pins are brazed to fins of juxtaposed fuel pins or directly to the juxtaposed fuel pins or both. The integrally brazed fuel assembly is designed to satisfy the thermal and hydraulic requirements of a fuel assembly lattice having moderator to fuel atom ratios required to achieve high conversion and breeding ratios

  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. Production of heavy nuclides in nuclear devices

    Energy Technology Data Exchange (ETDEWEB)

    Eccles, Samuel F [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    Since the last Plowshare Symposium in 1964 a number of experiments have been carried out to study the production of heavy nuclei by rapid multiple neutron capture in specially designed nuclear devices. These experiments listed below were conducted underground at the Nevada Test Site and data were obtained radiochemically after sample recovery by drillback. The main characteristics of these experiments are 1) higher neutron fluxes than in the early events, 2) a variety of targets, including 238-U, 242-Pu, 237-Np, 243-Am, 232-Th, 3) the occurrence of an interesting 'reversal of the odd-even effect' in the mass yield curves, and 4) the absence of nuclei in the debris with (Z,A) greater than (100,257). Analysis of data from these experiments have led to capture cross sections for neutron-rich uranium isotopes (out to 249-U), and capture-to-fission ratios for the odd-A neutron-rich plutonium isotopes (out to 253-Pu). General studies of the fission process in neutron-rich nuclei have also been undertaken using the data from these experiments. The large amounts of 250Cm and 257Fm made in the recent Hutch experiment ({approx}1 x 10{sup 20} and {approx}5 x 10{sup 17} atoms, respectively) make it scientifically exciting, and economically feasible, to mine and recover enough material to produce laboratory targets of these isotopes. These targets would be used in investigations of yet-undiscovered, short-lived isotopes of Fm, Md, and No, as well as the possible production of new isotopes of element 104 and even element 105. (author)

  7. Production of heavy nuclides in nuclear devices

    International Nuclear Information System (INIS)

    Eccles, Samuel F.

    1970-01-01

    Since the last Plowshare Symposium in 1964 a number of experiments have been carried out to study the production of heavy nuclei by rapid multiple neutron capture in specially designed nuclear devices. These experiments listed below were conducted underground at the Nevada Test Site and data were obtained radiochemically after sample recovery by drillback. The main characteristics of these experiments are 1) higher neutron fluxes than in the early events, 2) a variety of targets, including 238-U, 242-Pu, 237-Np, 243-Am, 232-Th, 3) the occurrence of an interesting 'reversal of the odd-even effect' in the mass yield curves, and 4) the absence of nuclei in the debris with (Z,A) greater than (100,257). Analysis of data from these experiments have led to capture cross sections for neutron-rich uranium isotopes (out to 249-U), and capture-to-fission ratios for the odd-A neutron-rich plutonium isotopes (out to 253-Pu). General studies of the fission process in neutron-rich nuclei have also been undertaken using the data from these experiments. The large amounts of 250Cm and 257Fm made in the recent Hutch experiment (∼1 x 10 20 and ∼5 x 10 17 atoms, respectively) make it scientifically exciting, and economically feasible, to mine and recover enough material to produce laboratory targets of these isotopes. These targets would be used in investigations of yet-undiscovered, short-lived isotopes of Fm, Md, and No, as well as the possible production of new isotopes of element 104 and even element 105. (author)

  8. Research in heavy-ion nuclear physics

    International Nuclear Information System (INIS)

    Sanders, S.J.; Prosser, F.W.

    1992-01-01

    This report discusses the following topics: Fusion-fission in light nuclear systems; High-resolution Q-value measurement for the 24 Mg+ 24 Mg reaction; Heavy-ion reactions and limits to fusion; and Hybrid MWPC-Bragg curve detector development

  9. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  10. Getter for nuclear fuel elements

    International Nuclear Information System (INIS)

    Ross, W.T.; Williamson, H.E.

    1976-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has disposed therein an improved getter capable of gettering reactive gases including a source of hydrogen. The getter comprises a composite with a substrate having thereon a coating capable of gettering reactive gases. The substrate has a greater coefficient of thermal expansion than does the coating, and over a period of time at reactor operating temperatures any protective film on the coating is fractured at various places and fresh portions of the coating are exposed to getter reactive gases. With further passage of time at reactor operating temperatures a fracture of the protective film on the coating will grow into a crack in the coating exposing further portions of the coating capable of gettering reactive gases. 13 claims, 5 drawing figures

  11. Getter for nuclear fuel elements

    International Nuclear Information System (INIS)

    Ross, W.T.; Williamson, H.E.

    1976-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has disposed therein an improved getter capable of gettering reactive gases including a source of hydrogen. The getter comprises a composite with a substrate having thereon a coating capable of gettering reactive gases. The substrate has a greater coefficient of thermal expansion than does the coating, and over a period of time at reactor operating temperatures any protective film on the coating is fractured at various places and fresh portions of the coating are exposed to getter reactive gases. With further passage of time at reactor operating temperatures a fracture of the protective film on the coating will grow into a crack in the coating exposing further portions of the coating capable of gettering reactive gases

  12. Nuclear reactor fuel element assemblies

    International Nuclear Information System (INIS)

    Raven, L.F.

    1975-01-01

    A spacer grid for a nuclear fuel element comprises a plurality of cojointed cylindrical ferrules adapted to receive a nuclear fuel pin. Each ferrule has a pair of circumferentially spaced rigid stop members extending inside the ferrule and a spring locating member attached to the ferrule and also extending from the ferrule wall inwardly thereof at such a circumferential spacing relative to the rigid stop members that the line of action of the spring locating member passes in opposition to and between the rigid stop members which lie in the same diametric plane. At least some of the cylindrical ferrules have one rim shaped to promote turbulence in fluid flowing through the grid. (Official Gazette)

  13. Nuclear research with heavy ions

    International Nuclear Information System (INIS)

    Kaplan, M.

    1992-08-01

    This report discusses the following topics; studies of light-charged-particle emission from fission and er reactions in the system 344-MeV 28 Si+ 121 Sb → 149 Tb; the role of reversed kinematics and double kinematic solutions in nuclear reactions studies; improvements in interactive data analysis and graphical representations; studies of the reaction 856-MeV 98 Mo + 51 V→ 149 Tb(E*=224-MeV): emission of intermediate-mass fragments; particle-particle correlations in compound nucleus reactions: preliminary consideration of lifetime estimates from small angle data; light particle emission studies using a new scintillator array; statistical evaporation calculations: developments with the computer codes LILITA-N90 and CASCADE; star collaboration studies: simulations for the conceptual design of the STAR detector system at RHIC; asymmetric fission of 149Tb* from the finite-range, rotating-liquid-drop model: mean total kinetic energies for binary fragmentation; and charged-particle evaporation from hot composite nuclei: evidence over a broad z range for distortions from cold nuclear profiles

  14. Fuel element for nuclear reactors

    International Nuclear Information System (INIS)

    Cadwell, D.J.

    1982-01-01

    The invention concerns a fuel element for nuclear reactors with fuel rods and control rod guide tubes, where the control rod guide tubes are provided with flat projections projecting inwards, in the form of local deformations of the guide tube wall, in order to reduce the radial play between the control rod concerned and the guide tube, and to improve control rod movement. This should ensure that wear on the guide tubes is largely prevented which would be caused by lateral vibration of the control rods in the guide tubes, induced by the flow of coolant. (orig.) [de

  15. Actinide targets for the synthesis of super-heavy elements

    International Nuclear Information System (INIS)

    Roberto, J.B.; Alexander, C.W.; Boll, R.A.; Burns, J.D.; Ezold, J.G.; Felker, L.K.; Hogle, S.L.; Rykaczewski, K.P.

    2015-01-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of "4"8Ca beams on actinide targets. These target materials, including "2"4"2Pu, "2"4"4Pu, "2"4"3Am, "2"4"5Cm, "2"4"8Cm, "2"4"9Cf, and "2"4"9Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including "2"4"9Bk, "2"5"1Cf, and "2"5"4Es are described.

  16. Element Distribution and Multiplicity of Heavy Fragments

    CERN Multimedia

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  17. Nuclear fuel elements design, fabrication and performance

    CERN Document Server

    Frost, Brian R T

    1982-01-01

    Nuclear Fuel Elements: Design, Fabrication and Performance is concerned with the design, fabrication, and performance of nuclear fuel elements, with emphasis on fast reactor fuel elements. Topics range from fuel types and the irradiation behavior of fuels to cladding and duct materials, fuel element design and modeling, fuel element performance testing and qualification, and the performance of water reactor fuels. Fast reactor fuel elements, research and test reactor fuel elements, and unconventional fuel elements are also covered. This volume consists of 12 chapters and begins with an overvie

  18. Revamped half-lives of super heavy elements (SHE) in trans-actinide region

    International Nuclear Information System (INIS)

    Carmel Vigila Bai, G.M.; Umai Parvathiy, J.

    2015-01-01

    Analyzation of alpha decay properties and identification of Island of Stability has illuminated the theories of nuclear physics. This fundamental scientific research is the current ongoing work in the field of super heavy elements. In order to study the decay properties of super heavy elements a realistic model called as Cubic plus Yukawa plus Exponential (CYE) model is used here. This model uses a cubic potential in the pre-scission region connected by Coulomb plus Yukawa plus Exponential potential in the post scission region

  19. Nuclear fuel element and container

    International Nuclear Information System (INIS)

    Grubb, W.T.; King, L.H.

    1981-01-01

    The invention is based on the discovery that a substantial reduction in metal embrittlement or stress corrosion cracking from fuel pellet-cladding interaction can be achieved by the use of a copper layer or liner in proximity to the nuclear fuel, and an intermediate zirconium oxide barrier layer between the copper layer and the zirconium cladding substrate. The intermediate zirconia layer is a good copper diffusion barrier; also, if the zirconium cladding surface is modified prior to oxidation, copper can be deposited by electroless plating. A nuclear fuel element is described which comprises a central core of fuel material and an elongated container using the system outlined above. The method for making the container is again described. It comprises roughening or etching the surface of the zirconium or zirconium alloy container, oxidizing the resulting container, activating the oxidized surface to allow for the metallic coating of such surfaces by electroless deposition and further coating the activated-oxidized surface of the zirconium or zirconium alloy container with copper, iron or nickel or an alloy thereof. (U.K.)

  20. Apparatus for locating defective nuclear fuel elements

    International Nuclear Information System (INIS)

    Lawrie, W.E.

    1979-01-01

    An ultrasonic search unit for locating defective fuel elements within a fuel assembly used in a water cooled nuclear reactor is presented. The unit is capable of freely traversing the restricted spaces between the fuel elements

  1. Nuclear fuel element leak detection system

    International Nuclear Information System (INIS)

    John, C.D. Jr.

    1978-01-01

    Disclosed is a leak detection system integral with a wall of a building used to fabricate nuclear fuel elements for detecting radiation leakage from the nuclear fuel elements as the fuel elements exit the building. The leak detecting system comprises a shielded compartment constructed to withstand environmental hazards extending into a similarly constructed building and having sealed doors on both ends along with leak detecting apparatus connected to the compartment. The leak detecting system provides a system for removing a nuclear fuel element from its fabrication building while testing for radiation leaks in the fuel element

  2. Physical particularities of nuclear reactors using heavy moderators of neutrons

    International Nuclear Information System (INIS)

    Kulikov, G. G.; Shmelev, A. N.

    2016-01-01

    In nuclear reactors, thermal neutron spectra are formed using moderators with small atomic weights. For fast reactors, inserting such moderators in the core may create problems since they efficiently decelerate the neutrons. In order to form an intermediate neutron spectrum, it is preferable to employ neutron moderators with sufficiently large atomic weights, using "2"3"3U as a fissile nuclide and "2"3"2Th and "2"3"1Pa as fertile ones. The aim of the work is to investigate the properties of heavy neutron moderators and to assess their advantages. The analysis employs the JENDL-4.0 nuclear data library and the SCALE program package for simulating the variation of fuel composition caused by irradiation in the reactor. The following main results are obtained. By using heavy moderators with small neutron moderation steps, one is able to (1) increase the rate of resonance capture, so that the amount of fertile material in the fuel may be reduced while maintaining the breeding factor of the core; (2) use the vacant space for improving the fuel-element properties by adding inert, strong, and thermally conductive materials and by implementing dispersive fuel elements in which the fissile material is self-replenished and neutron multiplication remains stable during the process of fuel burnup; and (3) employ mixtures of different fertile materials with resonance capture cross sections in order to increase the resonance-lattice density and the probability of resonance neutron capture leading to formation of fissile material. The general conclusion is that, by forming an intermediate neutron spectrum with heavy neutron moderators, one can use the fuel more efficiently and improve nuclear safety.

  3. Physical particularities of nuclear reactors using heavy moderators of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kulikov, G. G., E-mail: ggkulikov@mephi.ru; Shmelev, A. N. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    In nuclear reactors, thermal neutron spectra are formed using moderators with small atomic weights. For fast reactors, inserting such moderators in the core may create problems since they efficiently decelerate the neutrons. In order to form an intermediate neutron spectrum, it is preferable to employ neutron moderators with sufficiently large atomic weights, using {sup 233}U as a fissile nuclide and {sup 232}Th and {sup 231}Pa as fertile ones. The aim of the work is to investigate the properties of heavy neutron moderators and to assess their advantages. The analysis employs the JENDL-4.0 nuclear data library and the SCALE program package for simulating the variation of fuel composition caused by irradiation in the reactor. The following main results are obtained. By using heavy moderators with small neutron moderation steps, one is able to (1) increase the rate of resonance capture, so that the amount of fertile material in the fuel may be reduced while maintaining the breeding factor of the core; (2) use the vacant space for improving the fuel-element properties by adding inert, strong, and thermally conductive materials and by implementing dispersive fuel elements in which the fissile material is self-replenished and neutron multiplication remains stable during the process of fuel burnup; and (3) employ mixtures of different fertile materials with resonance capture cross sections in order to increase the resonance-lattice density and the probability of resonance neutron capture leading to formation of fissile material. The general conclusion is that, by forming an intermediate neutron spectrum with heavy neutron moderators, one can use the fuel more efficiently and improve nuclear safety.

  4. Some new approaches to the synthesis of heavy and superheavy elements

    International Nuclear Information System (INIS)

    Flerov, G.N.

    1980-01-01

    The results of work on the synthesis of heavy and superheavy elements are considered. It is shown that the new regularity of the systematics of spontaneous-fission half-lives, established for heavy nuclei at Dubna, has made it possible to extend the region of the nuclei being synthesized. In particular, it becomes possible to produce relatively long-lived heavy isotopes of Z>=107. The results of experiments to study the emission of energetic α-particles in the collision of heavy nuclei are presented. It is noted that such reactions can be used to produce atomic nuclei with low excitation energy and large angular momentum. The possible use of similar reactions in the synthesis of heavy and superheavy elements is discussed. In case the existence of a naturally occurring superheavy element has been established, a possibility will arise to synthesize in nuclear reactions a number of isotopes belonging to the island of stability, and to investigate their properties. The present state of work on the search for superheavy elements in nature is briefly described

  5. THE PROPERTIES OF HEAVY ELEMENTS IN GIANT PLANET ENVELOPES

    Energy Technology Data Exchange (ETDEWEB)

    Soubiran, François; Militzer, Burkhard [Department of Earth and Planetary Science, University of California, Berkeley, CA 94720 (United States)

    2016-09-20

    The core-accretion model for giant planet formation suggests a two-layer picture for the initial structure of Jovian planets, with heavy elements in a dense core and a thick H–He envelope. Late planetesimal accretion and core erosion could potentially enrich the H–He envelope in heavy elements, which is supported by the threefold solar metallicity that was measured in Jupiter’s atmosphere by the Galileo entry probe. In order to reproduce the observed gravitational moments of Jupiter and Saturn, models for their interiors include heavy elements, Z , in various proportions. However, their effect on the equation of state of the hydrogen–helium mixtures has not been investigated beyond the ideal mixing approximation. In this article, we report results from ab initio simulations of fully interacting H–He– Z mixtures in order to characterize their equation of state and to analyze possible consequences for the interior structure and evolution of giant planets. Considering C, N, O, Si, Fe, MgO, and SiO{sub 2}, we show that the behavior of heavy elements in H–He mixtures may still be represented by an ideal mixture if the effective volumes and internal energies are chosen appropriately. In the case of oxygen, we also compute the effect on the entropy. We find the resulting changes in the temperature–pressure profile to be small. A homogeneous distribution of 2% oxygen by mass changes the temperature in Jupiter’s interior by only 80 K.

  6. Frontiers of heavy-ion physics and superheavy elements

    International Nuclear Information System (INIS)

    Muenzenberg, G.

    2003-01-01

    This contribution will focus on three topics of GSI nuclear structure research: superheavy elements, direct mass measurements in the storage ring, and studies of fission in reversed kinematics. The GSI project for a new synchrotron facility will be outlined

  7. High-energy elastic recoil detection heavy ions for light element analysis

    International Nuclear Information System (INIS)

    Goppelt-Langer, P.; Yamamoto, S.; Takeshita, H.; Aoki, Y.; Naramoto, H.

    1994-01-01

    The detection of light and medium heavy elements in not homogeneous solids is a severe problem in ion beam analysis. Heavy elements can be detected by the well established Rutherford backscattering technique (RBS). In a homogeneous host material most impurities can be easily analyzed by secondary ion mass spectroscopy (SIMS). Some isotopes ( 3 He, 6 Li, 10 B) can be measured by nuclear reaction analysis (NRA) using thermal neutrons inducing (n, p) or (n, α) reactions. Others can be detected by energetic ion beams by nuclear reactions (e.g. 15 N( 1 H, αγ) 12 C for analysis of hydrogen). A high content of H, D or T can be also determined by elastic recoil detection using an energetic He beam. The latter technique has been developed to a universal method for detection of light and heavy elements in any target, using a high energetic heavy ion beam and a detector system, which is able to identify the recoils and delivers energy and position of the particles. (author)

  8. Nuclear molecular structure in heavy mass systems

    International Nuclear Information System (INIS)

    Arctaedius, T.; Bargholtz, C.

    1989-04-01

    A study is made of nuclear molecular configurations involving one heavy mass partner. The stability of these configurations to mass flow and to fission is investigated as well as their population in fusion reactions. It is concluded that shell effects in combination with the effects of angular momentum may be important in stabilizing certain configurations. A possible relation of these configurations to the so called superdeformed states is pointed out. The spectrum of rotational and vibrational trasitions within molecular configurations is investigated. For sufficiently mass-asymmetric systems the engergies of vibrational transitions are comparable to the neutron separation energy. Gamma radiation from such transitions may then be observable above the background of statistical transitions. The gamma spectrum and the directional distribution of the radioation following fusion reactions with 12 C and 16 O are calculated. (authors)

  9. Heavy gauge plates for nuclear application

    International Nuclear Information System (INIS)

    Cheviet, A.; Roux, J.-H.

    1977-01-01

    The production of energy from nuclear sources leads to the building of very large vessels working under pressure at elevated temperatures, requiring very thick steel plate (from 50 mm to 300 mm). The plates necessary for the production of these vessels have to be as large as possible in order to reduce the length of welds on the vessels. Those two requirements lead to the manufacture of heavy products from 10 to 80 tons unit weight. These products are special, because their fabrication requires very big facilities and also extremely high quality of the steel. The main points are: high cleanliness; properties as homogeneous as possible. The tests carried out on industrially produced plates (especially on a plate of 200 mm thick show the level of quality that can be reached [fr

  10. Nuclear structure and heavy-ion fusion

    International Nuclear Information System (INIS)

    Stokstad, R.G.

    1980-10-01

    A series of lectures is presented on experimental studies of heavy-ion fusion reactions with emphasis on the role of nuclear structure in the fusion mechanism. The experiments considered are of three types: the fusion of lighter heavy ions at subcoulomb energies is studied with in-beam γ-ray techniques; the subbarrier fusion of 16 O and 40 Ar with the isotopes of samarium is detected out of beam by x-radiation from delayed activity; and measurements at very high energies, again for the lighter ions, employ direct particle identification of evaporation residues. The experimental data are compared with predictions based on the fusion of two spheres with the only degree of freedom being the separation of the centers, and which interact via potentials that vary smoothly with changes in the mass and charge of the projectile and target. The data exhibit with the isotopes of samarium, a portion of these deviations can be understood in terms of the changing deformation of the target nucleus, but an additional degree of freedom such as neck formation appears necessary. The results on 10 B + 16 O and 12 C + 14 N → 26 Al at high bombarding energies indicate a maximum limiting angular momentum characteristic of the compound nucleus. At lower energies the nuclear structure of the colliding ion seems to affect strongly the cross section for fusion. Measurements made at subbarrier energies for a variety of projectile-target combinations in the 1p and 2s - 1d shell also indicate that the valence nucleons can affect the energy dependence for fusion. About half the systems studied so far have structureless excitation functions which follow a standard prediction. The other half exhibit large variations from this prediction. The possible importance of neutron transfer is discussed. The two-center shell model appears as a promising approach for gaining a qualitative understanding of these phenomena. 95 references, 52 figures, 1 table

  11. Monitoring arrangement for vented nuclear fuel elements

    International Nuclear Information System (INIS)

    Campana, R.J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180 0 rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements

  12. Basic elements of nuclear geophysics

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.; Pereira, E.B.

    1984-01-01

    Nuclear Geophysics applies the nuclear radiation detection methodology to the geosciences, specially to study the dynamical processes of the lithosphere, the hydrosphere and the atmosphere as well as some aspects of planetology and astrophysics. Here the main methods are described: alpha-ray and gamma-ray spectrometry, the interaction of alpha and gamma radiation with matter and the detectors used (grid chambers, surface barrier silicon detector for alpha radiation; and sodium iodide thallium activated phosphors, hyperpure and lithium drifted germanium semiconductor detectors for gamma radiation). The principal applications of Nuclear Geophysics are given as examples to ilustrate the use of the methods described. (AUthor) [pt

  13. Nuclear reactor fuel element assemblies

    International Nuclear Information System (INIS)

    Krawiec, D.M.; Bevilacqua, F.

    1974-01-01

    The fuel elements of each fuel element group are separated from each other by means of a multitude of thin, intersecting plates in the from of grid strips. Flow deflectors near the surface of the fuel elements are used in order to make the coolant flow more turbulent. They are designed as vanes and arranged at a distance on the grid strips. Each deflector vane has two arms stretching in opposite directions, each one into a neighbouring channel. In outward direction, the deflector vanes are converging. The strips with the vanes can be put on the supporting grid of the fuel elements. The vane structure can be reinforced by providing distortions in the strip material near the vanes. (DG) [de

  14. Nuclear fuel elements and assemblies

    International Nuclear Information System (INIS)

    Saito, Shozo; Maki, Hideo.

    1982-01-01

    Purpose: To facilitate the attainment of the uranium enrichment or gadolinia enrichment of a pellet filled in a fuel element. Constitution: The axial length of a pellet filled in a fuel element is set to predetermined sizes according to the uranium enrichment factor, gadolinia enrichment or their combination. Thus, the uranium enrichment factor or gadolinia enrichment can be identified by attaining the axial length of the pellet by using such a pellt. (Kamimura, M.)

  15. Placental transfer of the actinides and related heavy elements

    International Nuclear Information System (INIS)

    Sikov, M.R.

    1987-01-01

    This manuscript presents a selective review of the literature dealing with prenatal exposure of experimental animals and humans to actinides and related heavy elements, and uses this information to consider comparative aspects of placental transfer and fetoplacental distribution. General patterns have been derived from typical quantitative values, and used to compare similarities and dissimilarities, and to examine factors responsible for observed differences. 37 refs.; 1 figure; 2 tabs

  16. Nucleosynthesis of heavy elements by the photonuclear reaction

    International Nuclear Information System (INIS)

    Hayakawa, Takehito

    2002-01-01

    Nucleosynthesis of heavy elements is important for understanding of the site mechanism in the stellar and cosmochronology. The nuclei heavier than iron have been synthesized mainly by the s-process and the β-decay after the r-process. The light isotope p-nuclei produced by the photonuclear reaction in Type II supernovae explosions. In order to understand the role of each process, the ratios of the processes are calculated. I propose the experimental plan using the photon sources. (author)

  17. Coefficients of viscosity for heavy impurity element in tokamak

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharif, R N; Bekhit, A M [Plasma Physics dept., NRC, Atomic energy Authority, Cairo, (Egypt)

    1997-12-31

    The transport of heavy impurity element in to tokamak was studied theoretically. The viscosity coefficients of chromium impurities has been calculated in 13 and 21 moment approximation, in the limit of strong fields where is the gyrofrequency of species it was found that the off diagonal coefficient approximately tends to zero. This means that the friction force in the off-diagonal direction is very small, for the perpendicular viscosity coefficient the two approximation coincide to each other. 3 figs.

  18. Non destructive SXRF analysis of heavy elements in lichens

    International Nuclear Information System (INIS)

    Ramos, M.T.; Figueiredo, M.O.; Pereira da Silva, T.; Basto, M.J.; Chevallier, P.

    2000-01-01

    Various species incrusting granitic and calcareous rocks were collected at different places covering a large span of atmospheric conditions. They were chemically studied by synchrotron- induced X-ray fluorescence (SXRF), a nondestructive technique of outmost importance in the field, allowing for a future use of the same lichen fragments in further tests. This study proved that lichens - at least the saxicolous species - concentrate heavy elements recognized as strong pollutants, like lead and bromine, irrespective the environmental availability of these elements, either in the atmosphere or in the rock substrate, partially frustrating the use of saxicolous lichens as pollution monitors. (author)

  19. AMS advances in the geosciences and heavy-element analysis

    International Nuclear Information System (INIS)

    Rucklidge, J.C.; Wilson, G.C.; Kilius, L.R.

    1990-01-01

    Until recently small accelerators, such as the 2 MV Tandetron, have been used only for the lighter elements such as 10 Be, 14 C and 26 Al, while the heavier isotopes such as 36 Cl, 41 Ca and 129 I have been perceived to need the higher energies only available on large machines. We describe the use of a Tandetron for measurement of 129 I/ 127 I at natural levels, and the in situ assay of some heavy elements of interest in economic geology at detection levels superior to those of more widely used techniques. A few recently described novel applications of AMS are also given. (orig.)

  20. System for assembling nuclear fuel elements

    International Nuclear Information System (INIS)

    1980-01-01

    An automatic system is described for assembling nuclear fuel elements, in particular those employing mixed oxide fuels. The system includes a sealing mechanism which allows movement during the assembling of the fuel element along the assembly stations without excessive release of contaminants. (U.K.)

  1. MODERATOR ELEMENTS FOR UNIFORM POWER NUCLEAR REACTOR

    Science.gov (United States)

    Balent, R.

    1963-03-12

    This patent describes a method of obtaining a flatter flux and more uniform power generation across the core of a nuclear reactor. The method comprises using moderator elements having differing moderating strength. The elements have an increasing amount of the better moderating material as a function of radial and/or axial distance from the reactor core center. (AEC)

  2. On elastic structural elements for nuclear reactors

    International Nuclear Information System (INIS)

    Povolo, F.

    1978-03-01

    The in-pile stress-relaxation behaviour of materials usually employed for the elastic structural elements, in nuclear reactors, is critically reviewed and the results are compared with those obtained in commercial zirconium alloys irradiated under similar conditions. Finally, it is shown that, under certain conditions, some zirconium alloys may be used as an alternative material for these structural elements. (orig.) [de

  3. Nuclear responses in INTOR plasma stabilization elements

    International Nuclear Information System (INIS)

    Gohar, Y.; Gilligan, J.; Jung, J.; Mattas, R.F.; Miley, G.H.; Wiffen, F.W.; Yang, S.

    1985-01-01

    Nuclear responses in the plasma stabilization elements were studied in a parametric fashion as a part of the transient electromagnetics critical issue C of ETR/INTOR activity. The main responses are neutron fluence and radiation dose in the insulator material, induced resistivity and atomic displacement in the conductor material, nuclear heating and life analysis for the elements. Copper and aluminum conductors with either MgAl 2 O 4 or MgO insulating material were investigated. Radiation damage and life analysis for these elements were also discussed

  4. FOIL ELEMENT FOR NUCLEAR REACTOR

    Science.gov (United States)

    Noland, R.A.; Walker, D.E.; Spinrad, B.I.

    1963-07-16

    A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

  5. Interactions of relativistic heavy ions in thick heavy element targets and some unresolved problems

    International Nuclear Information System (INIS)

    Brandt, R.; Ditlov, V.A.; Pozharova, E.A.; Smirnitskij, V.A.

    2005-01-01

    Interactions of relativistic heavy ions with total energies above 30 GeV in thick Cu and Pb targets (≥2 cm) have been studied with various techniques. Radiochemical irradiation experiments using thick Cu targets, both in a compact form or as diluted '2π-Cu targets' have been carried out with several relativistic heavy ions, such as 44 GeV 12 C (JINR, Dubna) and 72 GeV 40 Ar (LBL, Berkeley, USA). Neutron measuring experiments using thick targets irradiated with various relativistic heavy ions up to 44 GeV 12 C have been performed at JINR. In addition, the number of 'black prongs' in nuclear interactions (due to protons with energies less than 30 MeV and emitted from the target-like interaction partner at rest) produced with 72 GeV 22 Ne ions in nuclear emulsion plates has been measured in the first nuclear interaction of the primary 22 Ne ion and in the following second nuclear interaction of the secondary heavy (Z>1) ion. Some essential results have been obtained. 1) Spallation products produced by relativistic secondary fragments in interactions ([44 GeV 12 C or 72 GeV 40 Ar]+Cu) within thick copper yield less products close to the target and much more products far away from the target as compared to primary beam interactions. This applies also to secondary particles emitted into large angles (Θ>10deg). 2) The neutron production of 44 GeV 12 C within thick Cu and Pb targets is beyond the estimated yield as based on experiments with 12 GeV 12 C. These rather independent experimental results cannot be understood with well-accepted nuclear reaction models. They appear to present unresolved problems

  6. New approach to description of fusion-fission dynamics in super-heavy element formation

    International Nuclear Information System (INIS)

    Zagrebaev, V.I.

    2002-01-01

    A new mechanism of the fusion-fission process for a heavy nuclear system is proposed, which takes place in the (A 1 , A 2 ) space, where A 1 and A 2 are two nuclei, surrounded by a certain number of shared nucleons ΔA. The nuclei A 1 and A 2 gradually lose (or acquire) their individualities with increasing (or decreasing) a number of collectivized nucleons ΔA. The driving potential in the (A 1 , A 2 ) space is derived, which allows the calculation of both the probability of the compound nucleus formation and the mass distribution of fission and quasi-fission fragments in heavy ion fusion reactions. The cross sections of super-heavy element formation in the 'hot' and 'cold' fusion reactions have been calculated up to Z CN =118. (author)

  7. Inserts for nuclear fuel elements

    International Nuclear Information System (INIS)

    Cragg, P.J.

    1982-01-01

    An insert for a nuclear fuel pin which comprises a strip. The strip carries notches, which enable a coding arrangement to be carried on the strip. The notches may be of differing sizes and the coding on the strip includes identification and identification checking data. Each notch on the strip may give rise to a signal pulse which is counted by a detector to avoid errors. (author)

  8. Transuranic elements and nuclear wastes

    International Nuclear Information System (INIS)

    Bowen, V.T.

    1974-01-01

    The contamination of oceans and marine life by transuranic elements (elements of atomic number greater than 92) is the main concern of this paper. Wastes of three different types, low-level, intermediate-level, and high-level, are considered. Fallout of Pu and other transuranics is discussed as it affects marine biogeochemistry and geochemistry. Different paths of absorption or uptake under various conditions of release are pointed out in some detail. The transfer of radioactivity to mammals from marine sources is considered in some detail. Waste disposal practices at Windscale are reviewed. It is concluded that the problems associated with transuranic wastes in oceans and marine life are very complex. Monitoring of waste release and uptake is concluded to not be enough. Each situation of release of transuranics to the environment should be treated as an experiment and milked for all the information that it can reveal. The tremendous expenditure of money and manpower necessary for such an undertaking is stressed

  9. Grids for nuclear fuel elements

    International Nuclear Information System (INIS)

    Nicholson, G.

    1980-01-01

    This invention relates to grids for nuclear fuel assemblies with the object of providing an improved grid, tending to have greater strength and tending to offer better location of the fuel pins. It comprises sets of generally parallel strips arranged to intersect to define a structure of cellular form, at least some of the intersections including a strip which is keyed to another strip at more than one point. One type of strip may be dimpled along its length and another type of strip may have slots for keying with the dimples. (Auth.)

  10. Workshop of Advanced Science Research Center, JAERI. Nuclear physics and nuclear chemistry of superheavy elements

    International Nuclear Information System (INIS)

    Nishio, Katsuhisa; Nishinaka, Ichiro; Ikezoe, Hiroshi; Nagame, Yuichiro

    2004-03-01

    A liquid drop model predicts that the fission barrier of a nucleus whose atomic number (Z) is larger than 106 disappears, so that such heavier nuclei as Z > 106 cannot exist. The shell effect, however, drastically changes structure of the fission barrier and stabilizes nucleus against fission, predicting the presence of super heavy element (SHE, Z=114-126) with measurable half-life. In the SHE region, a wave function of outermost electron of an atom, which controls chemical properties of an elements, is disturbed or changed by relativistic effects compared to the one from the non-relativistic model. This suggests that the SHEs have different chemical properties from those of lighter elements belonging to the same family. The chemistry of SHEs requires event by event analysis to reveal their chemical properties, thus is called 'atom-at-a-time chemistry'. Japan Atomic Energy Research Institute (JAERI) has been investigating fusion mechanism between heavy nuclei to find out favorable reactions to produce SHE by using JAERI-tandem and booster accelerator. In the JAERI-tandem facility, isotopes of Rf and Db are produced by using actinide targets such as 248 Cm in order to investigate their chemical properties. The present workshop was held in Advanced Science Research Center of JAERI at February 27-28 (2003) in order to discuss current status and future plans for the heavy element research. The workshop also included topics of the radioactive nuclear beam project forwarded by the JAERI-KEK cooperation and the nuclear transmutation facility of J-PARC. Also included is the nuclear fission process as a decay characteristic of heavy elements. There were sixty participants in the workshop including graduate and undergraduate eleven students. We had guests from Germany and Hungary. Through the workshop, we had a common knowledge that researches on SHE in Japan should fill an important role in the world. (author)

  11. 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

  12. Damper mechanism for nuclear reactor control elements

    International Nuclear Information System (INIS)

    Taft, W.E.

    1976-01-01

    A damper mechanism which provides a nuclear reactor control element decelerating function at the end of the scram stroke is described. The total damping function is produced by the combination of two assemblies, which operate in sequence. First, a tapered dashram assembly decelerates the control element to a lower velocity, after which a spring hydraulic damper assembly takes over to complete the final damping. 3 claims, 2 figures

  13. Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Kai [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe-University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Dai, Wei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Xu, Nu [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Zhuang, Pengfei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China)

    2016-12-15

    The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

  14. Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

    International Nuclear Information System (INIS)

    Zhou, Kai; Dai, Wei; Xu, Nu; Zhuang, Pengfei

    2016-01-01

    The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

  15. Nuclear synergism of the light elements

    International Nuclear Information System (INIS)

    Harms, A.A.

    1983-05-01

    Some basic issues concerning accelerator initiated and fusion sustained nuclear energy systems are examined. For this purpose we identify selected nuclear fusion reactions characterized by a variable ion-to-neutron content and explore their intrinsic couplings and regenerative features. These are then related to particular systems concepts which emphasize fusion physics and accelerator technology. It is concluded that several light-element reaction systems possess appealing and interesting properties and can further be associated with selected advanced nuclear technologies. Their eventual implementation as nuclear energy systems requires further research in fusion physics, accelerator technology and mathematical physics. Because of the substantial potential benefits of such nuclear energy systems, it is concluded that research in this area should be pursued with much vigour. (orig.)

  16. The Origin and Distribution of Heavy Elements in HCG 62

    Science.gov (United States)

    Vrtilek, Jan; Lavoie, Anthony R. (Technical Monitor)

    2000-01-01

    We present recent data on the compact group HCG 62 taken with AXAF CCD Imaging Spectrometer-S (ACIS-S) on Chandra. The sparseness of groups and their relatively simple dynamical history allow the properties of the Intergalatic Medium (IGM) to be more directly related to galaxy evolution than may be possible in clusters, and their lower gas temperatures produce strong lines from a broader range of elements than is the case in hotter clusters. This observation exploits the high X-ray brightness of HCG 62 to determine accurately the abundances of heavy elements as a function of position in the group, to test whether abundance variations are associated with individual galaxies, and to trace the origin of the enrichment.

  17. Shock buffer for nuclear control element assembly

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1977-01-01

    A shock buffer for a control element assembly in a nuclear reactor is described, comprising a piston and a cylinder. The piston is affixed to and extends upward from the control rod guide structure; the cylinder is supported by the upper portion of the control element assembly and is vertically oriented with open end downward for receiving the piston. Coolant liquid normally has free access to the cylinder. The piston displaces liquid from the cylinder when inserted, thereby decelerating the control element assembly near its lower extent of travel. (LL)

  18. Proceedings of the workshop on the nuclear sciences of the heaviest elements

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Yuichiro; Haba, Hiromitsu; Ikezoe, Hiroshi [eds.

    2000-03-01

    The workshop on the nuclear sciences of the heaviest elements took place on July 21-22, 1999 at the Japan Atomic Energy Research Institute (JAERI), Tokai. Approximately 40 scientists and 15 graduate students participated in the workshop which was organized by the Advanced Science Research Center, JAERI. The successful syntheses of three new super-heavy elements in 1999, Z=114 at the Joint Institute for Nuclear Research in Dubna, Russia, and Z=118 (with Z=116 following from {alpha}-decay of Z=118) at the Lawrence Berkeley National Laboratory (LBNL) in USA, are tremendous progress in the field of the heavy element research. The 1st International Conference on the Chemistry and Physics of the Transactinide Elements (TAN99) was held in Germany from September 26 to 30, 1999 to discuss in a larger context all scientific aspects of the heaviest elements. Thus, it was timely to hold the present domestic workshop to summarize what has been done in recent years, to see what has come true, and to discuss the perspectives in the near feature. The subjects in the workshop were classified into; (1) synthesis of heavy elements, (2) decay properties of heavy nuclei, (3) chemistry of the heaviest elements, and (4) future plans of the heavy element research in Japan. This volume contains the papers presented in the workshop. The 14 papers are indexed individually. (J.P.N.)

  19. Reaction mechanisms for the synthesis of the heaviest elements from heavy ion reactions

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1988-10-01

    This review paper concerns fusion reactions with light heavy-ions, cold fusion, transfer reactions using light heavy-ions or heavy ions. In two appendices, methods for the separation and detection of nuclides in the domain of heaviest elements are described and a comment on the discovery of the element 104 is given. 51 figs., 10 tabs., 335 refs

  20. Charged particle induced delayed X-rays (DEX) for the analysis of intermediate and heavy elements

    Science.gov (United States)

    Pillay, A. E.; Erasmus, C. S.; Andeweg, A. H.; Sellschop, J. P. F.; Annegarn, H. J.; Dunn, J.

    1988-12-01

    The emission of K X-rays from proton-rich and metastable radionuclides, following proton activation of the stable isotopes of the elements of interest, has not been widely used as a means of analysis. The thrust of this paper proposes a nuclear technique using delayed X-rays for the analysis of low concentrations of intermediate and heavy elements. The method is similar to the delayed gamma-ray technique. Proton bombardment induces mainly (p, n) reactions whereas the delayed X-rays originate largely from e --capture and isomeric transition. Samples of rare earth and platinum group elements (PGE), in the form of compacted powders, were irradiated with an 11 MeV proton beam and delayed X-rays detected with a 100 mm 2 Ge detector. Single element spectra for a range of rare earths and PGEs are presented. Analytical conditions are demonstrated for Pd in the range 0.1-5%. Spectra from actual geological samples of a PGE ore, preconcentrated by fire-assay, and monazite are presented. All six platinum group elements are visible and interference-free in a single spectrum, a marked advance on other nuclear techniques for these elements, including PIXE and neutron activation analysis (NAA).

  1. Valuation of Embalse Nuclear Power Plant and of heavy water

    International Nuclear Information System (INIS)

    Martin, D.E.

    2008-01-01

    The author describes the Nuclear Power Plant characteristics, the building work, the heavy water valuation criteria and the reasons why he considers that any capital good can be valuated by means of cash-flow. The value of replacement of Embalse Nuclear Power Plant is of U$S 1.593.538.000 (authors) [es

  2. Embalse nuclear power plant and heavy water valuation

    International Nuclear Information System (INIS)

    Martin, Daniel E.

    2008-01-01

    The author describes the nuclear power plant characteristics, the building work, the heavy water valuation criteria and the reasons why he considers that any capital good can be valued by the cash-flow method. The Embalse nuclear power plant replacement value is of U$S 1.593.538.000. (author) [es

  3. Fundamental aspects of nuclear reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Olander, D.R.

    1976-01-01

    The book presented is designed to function both as a text for first-year graduate courses in nuclear materials and as a reference for workers involved in the materials design and performance aspects of nuclear power plants. The contents are arranged under the following chapter headings: statistical thermodynamics, thermal properties of solids, crystal structures, cohesive energy of solids, chemical equilibrium, point defects in solids, diffusion in solids, dislocations and grain boundaries, equation of state of UO/sub 2/, fuel element thermal performance, fuel chemistry, behavior of solid fission products in oxide fuel elements, swelling due to fission gases, pore migration and fuel restructuring kinetics, fission gas release, mechanical properties of UO/sub 2/, radiation damage, radiation effects in metals, interaction of sodium and stainless steel, modeling of the structural behavior of fuel elements and assemblies. (DG)

  4. Fundamental aspects of nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Olander, D.R.

    1976-01-01

    The book presented is designed to function both as a text for first-year graduate courses in nuclear materials and as a reference for workers involved in the materials design and performance aspects of nuclear power plants. The contents are arranged under the following chapter headings: statistical thermodynamics, thermal properties of solids, crystal structures, cohesive energy of solids, chemical equilibrium, point defects in solids, diffusion in solids, dislocations and grain boundaries, equation of state of UO 2 , fuel element thermal performance, fuel chemistry, behavior of solid fission products in oxide fuel elements, swelling due to fission gases, pore migration and fuel restructuring kinetics, fission gas release, mechanical properties of UO 2 , radiation damage, radiation effects in metals, interaction of sodium and stainless steel, modeling of the structural behavior of fuel elements and assemblies

  5. Heavy flavor production in nuclear collisions

    CERN Document Server

    Armesto-Pérez, Nestor; Capella, A; Pajares, C; Salgado, C A

    2001-01-01

    Heavy flavor production off nuclei is studied in the small x/sub F/ region of the produced heavy system. Corrections to the usually employed perturbative QCD factorization formula are considered in the framework of the Glauber-Gribov model. Transition from low to high energies is taken into account by using finite energy cutting rules. The low energy limit of the obtained results coincides with the probabilistic formula usually employed for quarkonium absorption. At finite energies both rescattering of the heavy flavor and corrections to nucleon parton densities inside nuclei appear, the latter also affecting lepton pair production. It turns out that at asymptotic energies both open heavy flavor and quarkonium are equally absorbed. The numerical differences between the results obtained with the probabilistic formula and the exact one are <20% up to LHC energies, and ~1/2% at SPS energies. (18 refs).

  6. Theory of nuclear excitation by electron capture for heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gagyi-Palffy, A.

    2006-07-01

    The resonant process of nuclear excitation by electron capture (NEEC) in collisions involving highly-charged ions has been investigated theoretically. NEEC is a rare recombination process in which a free electron is captured into a bound shell of an ion with the simultaneous excitation of the nucleus. Total cross sections for NEEC followed by the radiative decay of the excited nucleus are presented for various collision systems. The possibility to observe the NEEC in scattering experiments with trapped or stored ions was discussed focusing on the cases with the largest calculated resonance strength. As the photons emitted in different channels of the electron recombination process are indistinguishable in the total cross section, the interference between NEEC followed by the radiative decay of the nucleus and radiative recombination was investigated. The angular distribution of the emitted photons in the recombination process provides means to discern the two processes. Angular differential cross sections for the emitted photons in the case of E2 nuclear transitions were presented for several heavy elements. (orig.)

  7. Quantum mechanical theory of positron production in heavy ion collisions with nuclear contact

    International Nuclear Information System (INIS)

    Heinz, U.

    1986-01-01

    The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ ≥ 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T ≥ 10 -19 sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation function for the positron peak. 25 refs., 7 figs

  8. Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

    International Nuclear Information System (INIS)

    Emrich, William J. Jr.

    2008-01-01

    To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts

  9. Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

    Science.gov (United States)

    Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

    2013-10-01

    The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

  10. Single cell elemental analysis using nuclear microscopy

    International Nuclear Information System (INIS)

    Ren, M.Q.; Thong, P.S.P.; Kara, U.; Watt, F.

    1999-01-01

    The use of Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM) to provide quantitative elemental analysis of single cells is an area which has high potential, particularly when the trace elements such as Ca, Fe, Zn and Cu can be monitored. We describe the methodology of sample preparation for two cell types, the procedures of cell imaging using STIM, and the quantitative elemental analysis of single cells using RBS and PIXE. Recent work on single cells at the Nuclear Microscopy Research Centre,National University of Singapore has centred around two research areas: (a) Apoptosis (programmed cell death), which has been recently implicated in a wide range of pathological conditions such as cancer, Parkinson's disease etc, and (b) Malaria (infection of red blood cells by the malaria parasite). Firstly we present results on the elemental analysis of human Chang liver cells (ATTCC CCL 13) where vanadium ions were used to trigger apoptosis, and demonstrate that nuclear microscopy has the capability of monitoring vanadium loading within individual cells. Secondly we present the results of elemental changes taking place in individual mouse red blood cells which have been infected with the malaria parasite and treated with the anti-malaria drug Qinghaosu (QHS)

  11. Estimation of atomic masses of heavy and superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Masahiro [Ministry of Education, Science and Culture, Tokyo (Japan)

    1997-07-01

    To estimate unknown atomic masses of heavy and superheavy elements, three kinds of formula: FRDM (finite range droplet model by Moeller et al.), TUYY (an empirical formula by Tachibana et al.) and our KUTY are explained. KUTY estimates the crude shell energies of spherical nucleus from sum of single-particle energies. Then, the refined shell energies in due consideration of paring and deformation are obtained by mixing with the functions of the crude shell energies. Experimental values of U and Fm isotopes were compared with estimation mass of KUTY and FRDM. In the field with experimental values of U isotopes, the value of KUTY and FRDM separated the same difference from the experimental value. The behavior of KUTY and FRDM for Fm isotopes were same as that of U, but ETFSI deviated a little from the experimental values. (S.Y.)

  12. Fuel element for a nuclear reactor

    International Nuclear Information System (INIS)

    Linning, D.L.

    1977-01-01

    An improvement of the fuel element for a fast nuclear reactor described in patent 15 89 010 is proposed which should avoid possible damage due to swelling of the fuel. While the fuel element according to patent 15 89 010 is made in the form of a tube, here a further metal jacket is inserted in the centre of the fuel rod and the intermediate layer (ceramic uranium compound) is provided on both sides, so that the nuclear fuel is situated in the centre of the annular construction. Ceramic uranium or plutonium compounds (preferably carbide) form the fuel zone in the form of circular pellets, which are surrounded by annular gaps, so that gaseous fission products can escape. (UWI) [de

  13. 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

  14. 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.

  15. Heavy element stable isotope ratios. Analytical approaches and applications

    International Nuclear Information System (INIS)

    Tanimizu, Masaharu; Sohrin, Yoshiki; Hirata, Takafumi

    2013-01-01

    Continuous developments in inorganic mass spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of inorganic mass spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies.

  16. Probing the nuclear symmetry energy with heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    De Filippo E.

    2015-01-01

    Full Text Available Heavy ion collisions (HIC have been widely used to extract the parametrization of symmetry energy term of nuclear equation of state as a function of barionic density. HIC in fact are a unique tool in terrestrial laboratories to explore the symmetry energy around the saturation density (ρ0 = 0.16fm−3 from sub-saturation densities (Fermi energies towards compressed nuclear matter (ρ > 2 − 3ρ0 that can be reached at relativistic energies, as a function of different conditions of temperature, mass asymmetry and isospin. One of the main study at present is to reach a coherent description of EOS of asymmetric nuclear matter from heavy ion collisions of stable and exotic nuclei, nuclear structure studies and astrophysical observations. In this work an overview of the current status of the research is shortly reviewed together with new perspectives aimed to reduce the present experimental and theoretical uncertainties.

  17. Method for inspecting nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    A technique for disassembling a nuclear reactor fuel element without destroying the individual fuel pins and other structural components from which the element is assembled is described. A traveling bridge and trolley span a water-filled spent fuel storage pool and support a strongback. The strongback is under water and provides a working surface on which the spent fuel element is placed for inspection and for the manipulation that is associated with disassembly and assembly. To remove, in a non-destructive manner, the grids that hold the fuel pins in the proper relative positions within the element, bars are inserted through apertures in the grids with the aid of special tools. These bars are rotated to flex the adjacent grid walls and, in this way relax the physical engagement between protruding portions of the grid walls and the associated fuel pins. With the grid structure so flexed to relax the physical grip on the individual fuel pins, these pins can be withdrawn for inspection or replacement as necessary without imposing a need to destroy fuel element components

  18. Development of heavy load carrying vehicle for nuclear power station

    International Nuclear Information System (INIS)

    Terabayashi, Yasuharu; Oono, Hiroo; Aizu, Takao; Kawaguchi, Kaname; Yamanaka, Masayuki; Hirobe, Tamio; Inagaki, Yoshiaki.

    1985-01-01

    In nuclear power stations, in order to carry out sound and stable operation, the routine inspection and regular inspection of machinery and equipment are performed, therefore, the transportation of heavy things is frequently carried out. Especially, the transportation of heavy things over the steps of passages and stairs requires much labor. Therefore, Chubu Electric Power Co., Inc. and Chubu Plant Service Co., Ltd. carried out the research on the development of a vehicle for transporting heavy components of nuclear power plants. In this research, it was aimed at developing a vehicle which can carry heavy components and get over a step, climb and descend stairs, and run through a narrow passage having many curves as well as running on flat ground. For this purpose, the actual state of the transportation of heavy things was investigated during the regular inspection of a nuclear power station, and on the basis of this results, a prototype vehicle was made and tested. Thereafter, a transporting vehicle of actual scale was made and tested. The investigation of actual state and the examination of the fundamental concept, the design, trial manufacture and verifying test are reported. (Kako, I.)

  19. Applications of a global nuclear-structure model to studies of the heaviest elements

    International Nuclear Information System (INIS)

    Moeller, P.; Nix, J.R.

    1993-01-01

    We present some new results on heavy-element nuclear-structure properties calculated on the basis of the finite-range droplet model and folded-Yukawa single-particle potential. Specifically, we discuss calculations of nuclear ground-state masses and microscopic corrections, α-decay properties, β-decay properties, fission potential-energy surfaces, and spontaneous-fission half-lives. These results, obtained in a global nuclear-structure approach, are particularly reliable for describing the stability properties of the heaviest elements

  20. Evaluation of electon and nuclear bremsstrahlung in heavy ion collisions

    International Nuclear Information System (INIS)

    Gippner, P.

    1975-01-01

    The detection of quasimolecular X-ray continua provides the possibility of investigating the electron shells of quasimolecules transiently formed during adiabatic heavy ion-atomic collision. The contribution of the electron and nuclear bremsstrahlung to quasimolecular X-ray continua observed in bombarding various targets with 65 and 96 MeV Nb ions were estimated

  1. Dynamics of light, intermediate, heavy and superheavy nuclear ...

    Indian Academy of Sciences (India)

    2014-05-01

    May 1, 2014 ... Various features related to the dynamics of competing decay modes of nuclear systems are explored by addressing the experimental data of a number of reactions in light, intermediate, heavy and superheavy mass regions. The DCM, being a non-statistical description for the decay of a com- pound nucleus ...

  2. Nuclear fuel element nut retainer cup

    International Nuclear Information System (INIS)

    Walton, L.A.

    1977-01-01

    A typical embodiment has an end fitting for a nuclear reactor fuel element that is joined to the control rod guide tubes by means of a nut plate assembly. The nut plate assembly has an array of nuts, each engaging the respective threaded end of the control rod guide tubes. The nuts, moreover, are retained on the plate during handling and before fuel element assembly by means of hollow cylindrical locking cups that are brazed to the plate and loosely circumscribe the individual enclosed nuts. After the nuts are threaded onto the respective guide tube ends, the locking cups are partially deformed to prevent one or more of the nuts from working loose during reactor operation. The locking cups also prevent loose or broken end fitting parts from becoming entrained in the reactor coolant

  3. Superheavy Element Synthesis And Nuclear Structure

    International Nuclear Information System (INIS)

    Ackermann, D.; Block, M.; Burkhard, H.-G.; Heinz, S.; Hessberger, F. P.; Khuyagbaatar, J.; Kojouharov, I.; Mann, R.; Maurer, J.; Antalic, S.; Saro, S.; Venhart, M.; Hofmann, S.; Leino, M.; Uusitalo, J.; Nishio, K.; Popeko, A. G.; Yeremin, A. V.

    2009-01-01

    After the successful progress in experiments to synthesize superheavy elements (SHE) throughout the last decades, advanced nuclear structure studies in that region have become feasible in recent years thanks to improved accelerator, separation and detection technology. The means are evaporation residue(ER)-α-α and ER-α-γ coincidence techniques complemented by conversion electron (CE) studies, applied after a separator. Recent examples of interesting physics to be discovered in this region of the chart of nuclides are the studies of K-isomers observed in 252,254 No and in 270 Ds.

  4. Review of even element super-heavy nuclei and search for element 120

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Goethe-Universitaet Frankfurt, Institut fuer Physik, Frankfurt (Germany); Heinz, S.; Mann, R.; Maurer, J.; Barth, W.; Burkhard, H.G.; Dahl, L.; Kindler, B.; Kojouharov, I.; Lang, R.; Lommel, B.; Runke, J.; Scheidenberger, C.; Schoett, H.J.; Tinschert, K. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Muenzenberg, G. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Manipal University, Manipal Centre for Natural Sciences, Manipal, Karnataka (India); Antalic, S.; Saro, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Eberhardt, K.; Thoerle-Pospiech, P.; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz (Germany); Grzywacz, R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States); Hamilton, J.H. [Vanderbuilt University, Department of Physics and Astronomy, Nashville, TN (United States); Henderson, R.A.; Kenneally, J.M.; Moody, K.J.; Shaughnessy, D.A.; Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Miernik, K. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Warsaw, Warsaw (Poland); Miller, D. [University of Tennessee, Knoxville, TN (United States); Morita, K. [RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama (Japan); Nishio, K. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan); Popeko, A.G.; Yeremin, A.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Roberto, J.B.; Rykaczewski, K.P. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Uusitalo, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland)

    2016-06-15

    The reaction {sup 54}Cr + {sup 248}Cm was investigated at the velocity filter SHIP at GSI, Darmstadt, with the intention to study production and decay properties of isotopes of element 120. Three correlated signals were measured, which occurred within a period of 279ms. The heights of the signals correspond with the expectations for a decay sequence starting with an isotope of element 120. However, a complete decay chain cannot be established, since a signal from the implantation of the evaporation residue cannot be identified unambiguously. Measured properties of the event chain are discussed in detail. The result is compared with theoretical predictions. Previously measured decay properties of even element super-heavy nuclei were compiled in order to find arguments for an assignment from the systematics of experimental data. In the course of this review, a few tentatively assigned data could be corrected. New interpretations are given for results which could not be assigned definitely in previous studies. The discussion revealed that the cross-section for production of element 120 could be high enough so that a successful experiment seems possible with presently available techniques. However, a continuation of the experiment at SHIP for a necessary confirmation of the results obtained in a relatively short irradiation of five weeks is not possible at GSI presently. Therefore, we decided to publish the results of the measurement and of the review as they exist now. In the summary and outlook section we also present concepts for the continuation of research in the field of super-heavy nuclei. (orig.)

  5. On the domestically-made heavy forging for reactor pressure vessels of PWR nuclear power plant

    International Nuclear Information System (INIS)

    Pan Xiren; Zhang Chen.

    1988-01-01

    The present situation of the foreign heavy forgings for nuclear reactor pressure vessels and the heavy forgings condition which is used for the Qinshan 300MWe nuclear power plant are described. Some opinions of domestic products is proposed

  6. Elemental characterization of PM1 in a heavy traffic region

    Science.gov (United States)

    Ambade, Balram

    Eight hours samples of airborne aerosols PM1 were collected during summer (August-September) and winter (October-November) form one year 2010- 2011 in a intense traffic area of Rajnandgaon city, India. Inductively coupled plasma mass spectroscopy was employed to measure heavy metals (Hg, Cd, Ni, Pb, As). Water-soluble ions (Na+, NH4 +, K+, Ca2+, Cl-, NO3 -, and SO42-) and carbonaceous mass (elemental and organic carbon) were detected using ion chromatograph and CHN analyzer, respectively. The results indicate that the composition of PM10 on intense traffic area is highly affected by automobile emissions. Based on the chemical information, positive matrix factorization (PMF) was used to identify PM sources. A total of five source types were identified, including soil dust, vehicle emissions, sea salt, industrial emissions and secondary aerosols, and their contributions were estimated using PMF. The crustal enrichment factors (EF) were calculated using Al as a reference for the trace metal species to identify the sources

  7. Exploration of (super-)heavy elements using the Skyrme-Hartree-Fock model

    International Nuclear Information System (INIS)

    Erler, Jochen

    2011-01-01

    Motivated by the steadily increasing number of known nuclei and nuclear properties, theories of nuclear structure are presently a field of intense research. This work concentrates on the self-consistent description of nuclei in terms of the Skyrme-Hartree-Fock (SHF) approach. The extrapolation of nuclear shell structure to the region of super-heavy elements (SHE) using the SHF model, the dependence on different parameterization and the influence of collective correlation will be studied. The general scope of this work are large scale calculation for a global survey of properties of SHE like binding energies, separation energies and decay characteristics and lifetimes. These calculations were done in a collaboration with the theory group of the GSI in Darmstadt and have the aim to develop a database of lifetimes and reaction rates for α, β-decay and spontaneous fission in a very wide range with proton numbers 86 ≤ Z ≤ 120 and neutron numbers up to N ∼ 260 relevant for the astrophysical r-process. The results of this study for example predictions of a possible islands of very stable nuclei and information of favored decay mode for each nuclei are also applicable in the recent experimental synthesis of exotic SHE. For these calculation a framework to calculate β-decay half-lives within the SHF model has been developed and the existing axial SHF code has been extended to compute β-transition matrix elements and so to provide an estimation of half-lives. (orig.)

  8. Exploration of (super-)heavy elements using the Skyrme-Hartree-Fock model

    Energy Technology Data Exchange (ETDEWEB)

    Erler, Jochen

    2011-01-31

    Motivated by the steadily increasing number of known nuclei and nuclear properties, theories of nuclear structure are presently a field of intense research. This work concentrates on the self-consistent description of nuclei in terms of the Skyrme-Hartree-Fock (SHF) approach. The extrapolation of nuclear shell structure to the region of super-heavy elements (SHE) using the SHF model, the dependence on different parameterization and the influence of collective correlation will be studied. The general scope of this work are large scale calculation for a global survey of properties of SHE like binding energies, separation energies and decay characteristics and lifetimes. These calculations were done in a collaboration with the theory group of the GSI in Darmstadt and have the aim to develop a database of lifetimes and reaction rates for {alpha}, {beta}-decay and spontaneous fission in a very wide range with proton numbers 86 {<=} Z {<=} 120 and neutron numbers up to N {approx} 260 relevant for the astrophysical r-process. The results of this study for example predictions of a possible islands of very stable nuclei and information of favored decay mode for each nuclei are also applicable in the recent experimental synthesis of exotic SHE. For these calculation a framework to calculate {beta}-decay half-lives within the SHF model has been developed and the existing axial SHF code has been extended to compute {beta}-transition matrix elements and so to provide an estimation of half-lives. (orig.)

  9. Theory of nuclear excitation by electron capture for heavy ions

    International Nuclear Information System (INIS)

    Palffy, Adriana; Scheid, Werner; Harman, Zoltan

    2006-01-01

    We investigate the resonant process of nuclear excitation by electron capture (NEEC), in which a continuum electron is captured into a bound state of an ion with the simultaneous excitation of the nucleus. In order to derive the cross section a Feshbach projection operator formalism is introduced. Nuclear states and transitions are described by a nuclear collective model and making use of experimental data. Transition rates and total cross sections for NEEC followed by the radiative decay of the excited nucleus are calculated for various heavy-ion collision systems

  10. Correlation of Heavy Element in Sea Water and Sediment Samples from Peninsula of Muria

    International Nuclear Information System (INIS)

    Rosidi; Sukirno

    2007-01-01

    The analysis of heavy metals in marine environmental samples peninsula of Muria in the year 2004 has been carried out by using neutron activation analysis (NAA) method. The objective of this analysis is to know the distribution of heavy metals in the sea water and sediment, which accommodate the recent environmental data in supporting the license of site for the nuclear power plants (NPP). The result of the analysis show that there were only 5 observed elements found in sea water and sediment were Cd, Co, Cr, Sb and Sc. All of heavy metals from sea water (0.002 mg/l) are obviously lower than the threshold value established by environmental minister Act; Kep LH No 51/2004. From the observed data to use software of SPSS version 10, application of the Pearson correlation (r) shows that between Co with Sc was indicator show a highly positive significant correlation (r=0.928), between Cr with Sc was sufficiently positive high (r=0.756), between Cr with Cd was precisely (r=0.611) while Co with Sb shows the significantly low (r=0.429). (author)

  11. Method of manufacturing nuclear fuel elements

    International Nuclear Information System (INIS)

    Ishida, Masao; Oguma, Masaomi.

    1980-01-01

    Purpose: To effectively prevent the bending of nuclear fuel elements in the reactor by grinding the end faces of pellets due to their mutual sliding. Method: In the manufacturing process of nuclear fuel elements, a plurality of pellets whose sides have been polished are fed one by one by way of a feeding mechanism through the central aperture in an electric motor into movable arms and retained horizontally with the central axis by being held on the side. Then, the pellet held by one of the arms is urged to another pellet held by the other of the arms by way of a pressing mechanism and the mating end faces of both of the pellets are polished by mutual sliding. Thereafter, the grinding dusts resulted are eliminated by drawing pressurized air and then the pellets are enforced into a cladding tube. Thus, the pellets are charged into the cladding tube with both polished end faces being contacted to each other, whereby the axial force is uniformly transmitted within the end faces to prevent the bending of the cladding tube. (Kawakami, Y.)

  12. Nuclear transfer in peripheral heavy ion reactions

    International Nuclear Information System (INIS)

    Werner, K.

    1984-01-01

    The aim of the whole thesis is to understand the experimental results of N. Frascaria et al. (1980), namely structures in the cross section as function of the excitation energy for the reaction 40 Ca + 40 Ca at 400 MeV incident energy. We present therefore in chapter 1 a simple model of two identical potentials with only two energy levels. On the base of statistically independent T-L excitations and by fitting a two parameters to the experiments it succeeds to reproduce sufficiently the experimental results. The next step is a microscopical treatment of these parameters for the understanding and the foundation of the fitted values. For this we develop in chapter 2 a theory of collective variables in the framework of TDHF which allows to perform in chapter 3 in a very transparent way microscopical calculations and especially to understand the transfer behaviour in peripheral heavy ion reactions. This transfer behaviour will also be the key for the understanding of the experimental structures. (orig.) [de

  13. 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

  14. Fuel element concept for long life high power nuclear reactors

    Science.gov (United States)

    Mcdonald, G. E.; Rom, F. E.

    1969-01-01

    Nuclear reactor fuel elements have burnups that are an order of magnitude higher than can currently be achieved by conventional design practice. Elements have greater time integrated power producing capacity per unit volume. Element design concept capitalizes on known design principles and observed behavior of nuclear fuel.

  15. Study of the behaviour of some heavy elements in solvents containing hydrogen fluoride

    International Nuclear Information System (INIS)

    Tarnero, M.

    1967-01-01

    The anhydrous liquid mixtures: dinitrogen tetroxide-hydrogen fluoride and antimony pentafluoride-hydrogen fluoride were studied as solvents for heavy elements interesting nuclear energy: uranium, thorium, zirconium and for some of their compounds. For N 2 O 4 -HF mixtures, electric conductivity measurements and liquid phase infrared spectra were also obtained. Uranium and zirconium tetrafluoride are much more soluble in N 2 O 4 -HF mixtures than in pure hydrogen fluoride. Uranium dissolved in these mixtures is pentavalent. In SbF 5 -HF mixtures, uranium dissolves with hydrogen evolution and becomes trivalent. The solid compound resulting from the dissolution is a fluoro-antimonate: U(SbF 6 ) 3 . (author) [fr

  16. K-edge x-ray fluorescence analysis for actinide and heavy elements solution concentration measurements

    International Nuclear Information System (INIS)

    Camp, D.C.

    1984-07-01

    Advantages of using Co-57 as an exciter for K XRFA include: a compact design that requires no x-ray tubes; the exciter-detector assembly locates remote from support electronics; on-line, at-line, or off-line configurations for monitor/measurements; systems that can be run by semi-skilled technicians, once programmed; and operated via remote terminals with results sent to control rooms; heavy element concentrations that are measurable thru industrial pipes; independent of minor changes in solution matrix or source half life with concentration results reported in near-real-time; a dynamic range of measurable concentrations that is greater than 10 4 ; measurement times that are reasonable even at 1 gram/liter; and for nuclear safeguards, it provides the <0.5% accuracy required by DOE for the accountability of U, Pu, or both, once the system is calibrated

  17. The fabrication of nuclear fuel elements in Mexico

    International Nuclear Information System (INIS)

    Guerrero Morillo, H.L.

    1977-01-01

    The situation of the nucleoelectrical generation in Mexico by 1976 is described: two nuclear reactors under construction but no defined program on the type and start-up dates for the next power plants. However the existence of a general plan on nuclear power plants is mentioned, which, according to the last estimates reaches to 10,000 MW installed by 1990. The national intension, definitely expressed in the Law, is to supply domestic nuclear fuel to the power reactors operating in the country, starting with the first reload for the two BWR's at the first national station in Laguna Verde, which will be required at the end of 1981 and of 1982, respectively. Before such circumstances and the relatively short amounts of fuel elements that should be produced for those two unique reactors, Mexico already has to adopt a strategy to follow in respect to fuel elements fabrication. The two main options are analyzed: 1. To delay the local fabrication until a National Nuclear Program may be defined, meanwhile purchasing abroad the necessary reloads and initial cores; and 2. To start as soon as possible the local fuel elements fabrication in order to supply fuel for the first reload of the first unit of Laguna Verde, confronting the economical risks of such posture with the advantages of an immediate action. Both options are analyzed in detail comparing them specially under the economic point of view, standing out immediately the big effect of some factors which are economically imponderable, as experience and independance that would be gained with the second option. Emphasis is made on the advantages and risks of any case. According to the first option and once a National Program is defined, the work would be heavy but of simple strategy. On the contrary, the second option requires the adoption of a more complicated strategy, as either the project of the factory as its initial operation should be made under transient conditions, in view of the expected future expansion still

  18. [Research in heavy ion nuclear reactions

    International Nuclear Information System (INIS)

    Howell, E.H.; Liu, X.T.; Petitt, G.A.; Zhang, Z.

    1994-01-01

    The authors have been involved in several projects during the present contract period. These include participation in the RD93 test run performed last summer at the Alternating Gradient Synchrotron (AGS) at Brookhaven, analysis of the data from this run, Monte Carlo simulations using the GEANT code of the performance of the calorimeter/absorber used in RD45, and simulations of the performance of the muon detector system for the PHENIX detector at RHIC using the PISA code. They have been preparing for tests to be performed this summer at the AGS of a prototype muon identifier using limited streamer tube detectors of the type selected for use in the muon arm of the PHENIX detector at RHIC. They have begun work on Monte Carlo simulations of particle detection in the presence of intense background events for the E864 experiment which is approved for running at the AGS. Finally, the authors have completed their work on leakage from the absorber/calorimeter and have submitted a paper to Nuclear Instruments and Methods

  19. Nuclear reactor core and fuel element therefor

    International Nuclear Information System (INIS)

    Fortescue, P.

    1986-01-01

    This patent describes a nuclear reactor core. This core consists of vertical columns of disengageable fuel elements stacked one atop another. These columns are arranged in side-by-side relationship to form a substantially continuous horizontal array. Each of the fuel elements include a block of refractory material having relatively good thermal conductivity and neutron moderating characteristics. The block has a pair of parallel flat top and bottom end faces and sides which are substantially prependicular to the end faces. The sides of each block is aligned vertically within a vertical column, with the sides of vertically adjacent blocks. Each of the blocks contains fuel chambers, including outer rows containing only fuel chambers along the sides of the block have nuclear fuel material disposed in them. The blocks also contain vertical coolant holes which are located inside the fuel chambers in the outer rows and the fuel chambers which are not located in the outer rows with the fuel chambers and which extend axially completely through from end face to end face and form continuous vertical intracolumn coolant passageways in the reactor core. The blocks have vertical grooves extending along the sides of the blocks form interblock channels which align in groups to form continuous vertical intercolumn coolant passsageways in the reactor core. The blocks are in the form of a regular hexagonal prism with each side of the block having vertical gooves defining one half of one of the coolant interblock channels, six corner edges on the blocks have vertical groves defining one-third of an interblock channel, the vertical sides of the blocks defining planar vertical surfaces

  20. Glenn T. Seaborg and heavy ion nuclear science

    International Nuclear Information System (INIS)

    Loveland, W.

    1992-04-01

    Radiochemistry has played a limited but important role in the study of nucleus-nucleus collisions. Many of the important radiochemical studies have taken place in Seaborg's laboratory or in the laboratories of others who have spent time in Berkeley working with Glenn T. Seaborg. I will discuss studies of low energy deep inelastic reactions with special emphasis on charge equilibration, studies of the properties of heavy residues in intermediate energy nuclear collisions and studies of target fragmentation in relativistic and ultrarelativistic reactions. The emphasis will be on the unique information afforded by radiochemistry and the physical insight derived from radiochemical studies. Future roles of radiochemistry in heavy ion nuclear science also will be discussed

  1. The Zintl Chemistry of the Heavy Tetrel Elements

    Energy Technology Data Exchange (ETDEWEB)

    Klem, Michael Thomas [Iowa State Univ., Ames, IA (United States)

    2002-12-31

    Exploration of the alkali metal/alkaline-earth metal/heavy tetrel (Sn or Pb) systems has revealed a vast array of new chemistry and novel structure types. The structures and properties of these new materials have been studied in an attempt to understand the chemistry of these and other related systems. The first phase reported is Rb4Pb9 (K4Pb9 type). The compound contains two different types of Pb94- deltahedra, a monocapped square pyramid and a distorted tricapped trigonal prism. Both cluster geometries correspond to a nido assignment even though the tricapped trigonal prism is not the classic Wade's rules nido deltahedron expected for a monocapped square antiprism. Also, a series of compounds that contain square pyramidal Tt5 polyanions of tin and lead has been obtained in alkaline-earth or rare-earth metal-tetrel systems by direct fusion of the elements to yield Sr3Sn5, Ba3Pb5, and La3Sn5. These phases contain square pyramidal clusters of the tetrel elements that are weakly interlinked into chains via two types of longer intercluster interactions that are mediated by bridging cations and substantially influenced by cation size and the free electron count. Attempts at incorporating another main-group element to form heteroatomic clusters were also successful. In the case of A5InPb8 (A = K, Rb), the compounds contain clusters composed of two Pb4 tetrahedra that are interbridged by a lone μ6-In atom. The InPb8 units are weakly interlinked into sheets in the ab plane by long intercluster Pb-Pb interactions. Using As led to the formation of the compound K5As3Pb3 which is made up of As3Pb35- crown clusters that can be likened to a 6-atom hypho-cluster based on the tricapped trigonal parent as the closo

  2. Signatures of Heavy Element Production in Neutron Star Mergers

    Science.gov (United States)

    Barnes, Jennifer

    2018-06-01

    Compact object mergers involving at least one neutron star have long been theorized to be sites of astrophysical nucleosynthesis via rapid neutron capture (the r-process). The observation in light and gravitational waves of the first neutron star merger (GW1701817) this past summer provided a stunning confirmation of this theory. Electromagnetic emission powered by the radioactive decay of freshly synthesized nuclei from mergers encodes information about the composition burned by the r-process, including whether a particular merger event synthesized the heaviest nuclei along the r-process path, or froze out at lower mass number. However, efforts to model the emission in detail must still contend with many uncertainties. For instance, the uncertain nuclear masses far from the valley of stability influence the final composition burned by the r-process, as will weak interactions operating in the merger’s immediate aftermath. This in turn can affect the color electromagnetic emission. Understanding the details of these transients’ spectra will also require a detailed accounting the electronic transitions of r-process elements and ions, in order to identify the strong transitions that underlie spectral formation. This talk will provide an overview of our current understanding of radioactive transients from mergers, with an emphasis on the role of experiment in providing critical inputs for models and reducing uncertainty.

  3. Heavy Metallic Element Distribution in Cisadane River Estuary's Water and Sediment

    OpenAIRE

    M. Taufik Kaisupy; Abdul Rozak; Endang Rochyatun

    2006-01-01

    Observation of heavy metallic elements in Cisadane River Estuary has been done in July and November 2005. The results show that heavy metallic elements content in seawater is lower and still below the treshold value stated by government for fisheries. There was an indication of heavy metallic elements on sediment. Distribution of Pb on July and of Cu on November 2005 were found higher near the coast and decrease towards the sea, and commonly were found in front of estuary such as Cisadane, Mu...

  4. EDRXF measurements of heavy elements in soil samples from some potentially polluted sites in zambia

    International Nuclear Information System (INIS)

    Hayumbu, P.; Phiri, L.K.; Mambo, A.; Sokotela, S.B.

    2001-01-01

    A survey of heavy element levels in top soils collected around four industrial plants and along four highway stretches demonstrated that there was significant pollution only around an abandoned Pb/Zn mine. Sample collection in a rectangular grid encompassing each source sought to depict the spatial extent of pollution. Ascertaining levels of heavy elements in potentially polluted soils in urban areas of Zambia and along major highways was deemed desirable because it is common practice to grow maize and vegetables in lots adjacent to accessible industrial sites and highways. Pb is a heavy element of interest for all sampled sites whose distribution at the abandoned mine ranged from 13 to 2028 ppm

  5. Nuclear structure studies towards superheavy elements and perspectives with AGATA

    International Nuclear Information System (INIS)

    Korichi, A.

    2005-01-01

    A variety of theoretical approaches have been used to calculate the shell closure of spherical Super Heavy Elements (SHE) but the predictions of the location of the 'island of stability' vary from Z=114 to 120 and 126, with neutron numbers around N=172 or N=184 depending on the model employed. A deformed minimum around Z=108 and N=162 is predicted and an increase of the half-life of Hassium (Z=108) is experimentally observed when approaching the neutron number N=162. Super heavy nuclei are produced with very low cross-section (a few picobarns) and this makes their spectroscopic study impossible with today's beam intensities and detectors. However, important information can be obtained from the structure of mid-shell deformed nuclei (Z∼104) where selected single particle orbitals, which lie close to the spherical shell gap in SHE, are close to the Fermi level. The information will come from decay and in-beam spectroscopy. A promising area of progress, using the state-of-the art instruments, is represented by the observation of rotational gamma-ray transitions in No and Fm isotopes showing the deformed character of these nuclei. One of the objectives and focus of the nuclear structure community is related to the investigation of Single particle excitations beyond the N=152 neutron gap and collective properties of heavier systems towards Z∼104. The IN2P3-JINR collaboration has launched a project of electron and gamma-ray spectroscopy studies of heavy nuclei at the FLNR. This project benefits from the radioactive actinide targets uniquely available at Dubna and from the very intense stable beams provided by the U400 cyclotron. This offers a unique opportunity for the study of nuclei above Z=100 along an isotopic chain approaching N=162. In this contribution, the emphasis will be on the GABRIELA project and its issues. I will finally point out the perspectives with the new generation of gamma detectors such as AGATA

  6. Heavy-Quark Effective Theory and Weak Matrix Elements

    CERN Document Server

    Neubert, Matthias

    1999-01-01

    Recent developments in the theory of weak decays of heavy flavours are reviewed. Applications to exclusive semileptonic B decays, the semileptonic branching ratio and charm counting, beauty lifetimes, and hadronic B decays are discussed.

  7. Nuclear analytical methods for platinum group elements

    International Nuclear Information System (INIS)

    2005-04-01

    Platinum group elements (PGE) are of special interest for analytical research due to their economic importance like chemical peculiarities as catalysts, medical applications as anticancer drugs, and possible environmental detrimental impact as exhaust from automobile catalyzers. Natural levels of PGE are so low in concentration that most of the current analytical techniques approach their limit of detection capacity. In addition, Ru, Rh, Pd, Re, Os, Ir, and Pt analyses still constitute a challenge in accuracy and precision of quantification in natural matrices. Nuclear analytical techniques, such as neutron activation analysis, X ray fluorescence, or proton-induced X ray emission (PIXE), which are generally considered as reference methods for many analytical problems, are useful as well. However, due to methodological restrictions, they can, in most cases, only be applied after pre-concentration and under special irradiation conditions. This report was prepared following a coordinated research project and a consultants meeting addressing the subject from different viewpoints. The experts involved suggested to discuss the issue according to the (1) application, hence, the concentration levels encountered, and (2) method applied for analysis. Each of the different fields of application needs special consideration for sample preparation, PGE pre-concentration, and determination. Additionally, each analytical method requires special attention regarding the sensitivity and sample type. Quality assurance/quality control aspects are considered towards the end of the report. It is intended to provide the reader of this publication with state-of-the-art information on the various aspects of PGE analysis and to advise which technique might be most suitable for a particular analytical problem related to platinum group elements. In particular, many case studies described in detail from the authors' laboratory experience might help to decide which way to go. As in many cases

  8. Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

    Science.gov (United States)

    Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

    2011-12-01

    Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

  9. Synthesis of superheavy elements and application of nuclear physics methods in related fields

    International Nuclear Information System (INIS)

    Flerov, G.

    1985-01-01

    Heavy ion accelerators are used not only for the synthesis of new elements but also for the production of nuclear filters from polymers. The principle is described of the manufacture of such filters, and their chemical processing. By changes in irradiation conditions and in conditions of chemical leaching, nuclear filters may be obtained of various density, shape and size of pores and with a different angular distribution of tracks in the polymer material. The most frequently used polymer is polyethylene terephthalate film. The uses are described of nuclear filters, such as water treatment in the production of semiconductor instruments, in cryogenic instruments, in the purification concentration and sterilization filtration of viruses and vaccines, etc. Other uses of heavy ion beams are suggested, such as the method of nuclear tracks, the manufacture of membranes with a single opening, the manufacture of laser diaphragms, lithography, etc. (E.S.)

  10. Targeting heavy rare earth elements in carbonatite complexes

    Science.gov (United States)

    Broom-Fendley, S.; Wall, F.; Gunn, A. G.; Dowman, E.

    2012-04-01

    The world's main sources of the rare earth elements (REE) are concentrated in carbonatite complexes. These have the advantages of high grade and tonnage, combined with low thorium contents, yet they are generally enriched in light rare earths (LREE). The heavy rare earths (HREE, which include Eu-Lu and Y) are more highly sought after because of their role in new and green technologies. HREE are predominantly extracted from ion-adsorption clays in China. These are small, low grade deposits, which are often illegally mined by artisans. Increased government control, environmental legislation and local demand for REE in China have led to high prices and global concerns about the security of supply of the HREE. Alternative sources of the HREE are poorly documented. We present a review of such targets, including: (1) 'abnormal' carbonatites; (2) areas around LREE-rich complexes such as breccia, fenite and latter stage veins; and (3) weathered carbonatites. At Lofdal, Namibia, carbonatite dykes contain xenotime-(Y) together with LREE minerals. The original chemistry of the carbonatite magma, coupled with late-stage magma and fluid evolution, seem to be controlling factors [1, 2]. The Khibina carbonatite, Kola Peninsula, Russia, is an example of where early LREE carbonatites become increasing HREE-enriched as magmas evolve to carbo-hydrothermal fluids [3]. Around carbonatite complexes in Malawi HREE enrichment can be found in breccia and in fenite. Breccia around Songwe shows areas with high Y/La ratios within the matrix caused by narrow zones of xenotime enrichment. Fenite around Kangankunde and Chilwa Island has higher HREE:LREE ratios than the carbonatite [4]. At weathered complexes, such as at Mount Weld in Western Australia, changes in both HREE concentration and LREE:HREE ratios are observed. In currently unworked sections of the deposit, the HREE mineral churchite (YPO4.H2O) has formed concentrations due to groundwater flow [5]. These areas of enrichment are

  11. Separation process of heavy rare earth elements from xenotime ore

    International Nuclear Information System (INIS)

    Sri Sukmajaya; Tri Handini; Wahyu Rachmi Pusparini; Dwi Biyantoro

    2016-01-01

    Separation process of heavy rare earth elements from xenotime ore had been done. A 100 mesh of xenotime ore was upgrade using water, sodium silicate and oleic acid in pH 9. Mixed of slurry by air blown in room temperature along 30 minutes. The middle of slurry xenotime was be separated, then dried and so added soda caustic, potassium carbonate and ammonium dihydrogen phosphate. The mix was be homogenized then leached in furnace to 700°C temperature along 4 hours. The frits of leaching product would be leached using 1200 mL volume of water that made oxidation by HCl onto pH 4 by agitated heated in 70°C temperature. The mix was filtered, then solid settled was be dried and then to processed again in water HCl acidified leaching alike before until pH 4 with minimized HCl added least 2 mL. The solid settled filled into 1000 mL of beker glass, added HCl viscous in 300 mL volume, hydrogen peroxide and BaCl_2/Na_2SO_4/Na_2S then heated to 100°C temperature. Let in room temperature then was filtrated. The solid settled as ThSO_4/ThS, RaSO_4/RaS. The filtrate to be settled using 15g (NH_4)_2CO_3 in 100 mL volume of water while mixed until the solution reached pH 2. The solid settled was be dried, then into the filtrate added 10 mL volume of formic acid. The solid settled of filtration was be dried. The solution of filtrate to be settled using (NH_4)_2CO_3 until pH 4. The solid settled was be filtered and dried. The filtrate was be settled using oxalic acid. The analysis of standard of oxide rare earth had been done using XRF Am"2"4"1 source. Result of these process got 100 mesh xenotime upgrade those leached in 700°C along 4 hours used (NH_4)H_2PO_4 so HRE total lifted up from 4.31 to 8.16%. Resulted of HRE oxide yield was 17.76% in pH 2. HRE oxide yield in pH 4 was 38.45%, and HRE oxide yield was 6.38% as oxalic compound, so the total HRE oxide yield was 62.59%. (author)

  12. Relativistic heavy-atom effects on heavy-atom nuclear shieldings

    Science.gov (United States)

    Lantto, Perttu; Romero, Rodolfo H.; Gómez, Sergio S.; Aucar, Gustavo A.; Vaara, Juha

    2006-11-01

    The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X2+, X4+, XH2, and XH3- (X =Si-Pb) as well as X3+, XH3, and XF3 (X =P-Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH3-, XH3, and XF3, and is equally large in XH2 as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of ˜1500ppm between BiH3 and BiF3. The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom, with values diminishing with the principal

  13. Neutrinoless ββ decay mediated by the exchange of light and heavy neutrinos: the role of nuclear structure correlations

    Science.gov (United States)

    Menéndez, J.

    2018-01-01

    Neutrinoless β β decay nuclear matrix elements calculated with the shell model and energy-density functional theory typically disagree by more than a factor of two in the standard scenario of light-neutrino exchange. In contrast, for a decay mediated by sterile heavy neutrinos the deviations are reduced to about 50%, an uncertainty similar to the one due to short-range effects. We compare matrix elements in the light- and heavy-neutrino-exchange channels, exploring the radial, momentum transfer and angular momentum-parity matrix element distributions, and considering transitions that involve correlated and uncorrelated nuclear states. We argue that the shorter-range heavy-neutrino exchange is less sensitive to collective nuclear correlations, and that discrepancies in matrix elements are mostly due to the treatment of long-range correlations in many-body calculations. Our analysis supports previous studies suggesting that isoscalar pairing correlations, which affect mostly the longer-range part of the neutrinoless β β decay operator, are partially responsible for the differences between nuclear matrix elements in the standard light-neutrino-exchange mechanism.

  14. MEGHNAD – A multi element detector array for heavy ion collision ...

    Indian Academy of Sciences (India)

    When heavy ion beam available from such machines fall on a target and undergo collision, very rich and often pristine fields of research open up. In order to carry on such activities, we have taken up a project to build a multi element gamma, heavy ion and neutron array of detectors (MEGHNAD) to detect and study the ...

  15. Heavy Metallic Element Distribution in Cisadane River Estuary's Water and Sediment

    Directory of Open Access Journals (Sweden)

    M. Taufik Kaisupy

    2006-04-01

    Full Text Available Observation of heavy metallic elements in Cisadane River Estuary has been done in July and November 2005. The results show that heavy metallic elements content in seawater is lower and still below the treshold value stated by government for fisheries. There was an indication of heavy metallic elements on sediment. Distribution of Pb on July and of Cu on November 2005 were found higher near the coast and decrease towards the sea, and commonly were found in front of estuary such as Cisadane, Muara Saban and Tanjung Pasir. High Pb and Zn distributions on November 2005 were found only in front of Cisadane estuary. Cd distribution of Cisadane estuary was constant at all station but did not show any correlation with the distance of station and estuary. The Cd content on July and November 2005 is lower than 0,001 ppm. Generally, heavy metallic elements content have a uniform distribution at all stations inspite of its distance to estuary.

  16. Nuclear Fragmentation in Clinical Heavy Ion Beams, Should We Worry?

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Toftegaard, Jakob

    2012-01-01

    Particle therapy with fast ions is increasingly applied as a treatment option for localized inoperable tumour sites. One of the reasons for the increased complications of understanding heavy ion dosimetry and radiobiology stems from the mixed particle spectrum which occurs due to nuclear fragment......Particle therapy with fast ions is increasingly applied as a treatment option for localized inoperable tumour sites. One of the reasons for the increased complications of understanding heavy ion dosimetry and radiobiology stems from the mixed particle spectrum which occurs due to nuclear....... The concept of relative biological effectiveness (RBE) translates the physical dose to a biological effective dose which is iso-effective to photon radiation. Radiobiological models based on amorphous track structure such as the Local Effect Model, but also microdosimetry based models both rely on a full...... the sensitivity on the three fields mentioned above, including: turning off nuclear fragmentation entirely, changing all ineleastic cross sections +/- 20%, changing key parameters in the Fermi-Breakup (FB) model. Results show nuclear effects have their largest impact on the dose distribution. Stopping power...

  17. Heavy water radiolysis and chemistry control of the Fugen Nuclear Power Station

    International Nuclear Information System (INIS)

    Ibuki, Y.; Kitabata, T.; Kato, T.

    1989-01-01

    A computer analysis for heavy water radiolysis clarified the mechanism of the heavy water radiolysis rate change with impurities in the heavy water and cover gas, helium. The mechanism is supported by over ten years' operational data of the heavy water radiolysis in the Fugen nuclear power station. (author)

  18. HEAVY-ELEMENT ENRICHMENT OF A JUPITER-MASS PROTOPLANET AS A FUNCTION OF ORBITAL LOCATION

    International Nuclear Information System (INIS)

    Helled, R.; Schubert, G.

    2009-01-01

    One possible mechanism for giant planet formation is disk instability in which the planet is formed as a result of gravitational instability in the protoplanetary disk surrounding the young star. The final composition and core mass of the planet will depend on the planet's mass, environment, and the planetesimal accretion efficiency. We calculate heavy-element enrichment in a Jupiter-mass protoplanet formed by disk instability at various radial distances from the star, considering different disk masses and surface density distributions. Although the available mass for accretion increases with radial distance (a) for disk solid surface density (σ) functions σ = σ 0 a -α with α 5 years of planetary evolution, when the planet is extended and before gap opening and type II migration take place. The accreted mass is calculated for disk masses of 0.01, 0.05, and 0.1 M sun with α = 1/2, 1, and 3/2. We show that a Jupiter-mass protoplanet can accrete 1-110 M + of heavy elements, depending on the disk properties. Due to the limitation on the accretion timescale, our results provide lower bounds on heavy-element enrichment. Our results can explain the large variation in heavy-element enrichment found in extrasolar giant planets. Since higher disk surface density is found to lead to larger heavy-element enrichment, our model results are consistent with the correlation between heavy-element enrichment and stellar metallicity. Our calculations also suggest that Jupiter could have formed at a larger radial distance than its current location while still accreting the mass of heavy elements predicted by interior models. We conclude that in the disk instability model the final composition of a giant planet is strongly determined by its formation environment. The heavy-element abundance of a giant planet does not discriminate between its origin by either disk instability or core accretion.

  19. The importance of heavy water in nuclear technology

    International Nuclear Information System (INIS)

    Gharib, A.G.

    2004-01-01

    Due to similarities of chemical and almost physical properties in H 2 O and D 2 O but differences in nuclear and particle peculiarities provide valuable application for D 2 O. To sustain a controlled chain reaction, the energy of neutrons produced by fission must be reduced through collisions with other nuclei, a process called moderation. A good moderator has a mass close to that of the neutron to maximize energy loss per collision and a very small neutron capture cross section to minimize unwanted nuclear reactions. Deuterium is far the best moderator, more than 80 times better than hydrogen and 30 times better than 12 C ir 18 O. Heavy water is almost as good as deuterium and has the distinct advantage of being a nonflammable liquid. Heavy water is also an excellent neutron reflector, and thus decreases the number of neutrons that escape the reactor core without participating in fission reactions. For this reason a feasibility study and subsequently a technical survey was carried out on engineering of a pilot scale plant. As the result of this studies, the know-how of heavy water production on basis of selected method including dual temperature isotopic exchange and distillation techniques developed. Subsequently the primary and almost detail engineering documents prepared on best knowledge of our own engineers without external contribution

  20. Fuel element clusters for nuclear reactors

    International Nuclear Information System (INIS)

    Anthony, A.J.; Hutchinson, J.J.

    1975-01-01

    In the fuel element assembly for nuclear reactors the influence of temperature cycles upon the stability of the joints between the individual components, especially between the control rod guide tubes and the connecting rods and end plates, respectively, is reduced. For this purpose, the connection is designed as a bolted connection connecting, on the one hand, the guide tubes and guide bolts and, on the other hand, these two components and the end plates. Moreover, the materials of the guide tubes, bolts and end plates are selected so that their respective thermal expansion coefficients differ. The material which can be used for the end plates and the guide bolts is stainless steel and stainless steel plus inconel (nickel-chrome-iron alloy), respectively; for the guide tubes it is a zirconium alloy (zircaloy). In addition to some technical designs of the bolted connections the materials and lengths of the components are selected in such a way that the expansion path of the components held by a bolted connection is equal to that of the stressing part. (DG/RF) [de

  1. 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

  2. Nuclear fuel element recovery using PEDSCO RMI Unit

    International Nuclear Information System (INIS)

    Martin, D.G.; Pedersen, B.V.

    1984-01-01

    In September 1982, a PEDSCO Remote Mobile Investigation Unit was used to recover damaged irradiated fuel elements from a fueling machine and trolley deck at Bruce Nuclear Generating Station 'A'. This Canadian-made remote controlled vehicle was originally designed for explosive ordinance disposal by law enforcement agencies. This paper describes its adaptation to nuclear service and its first mission, within a nuclear facility

  3. Medical applications of nuclear physics and heavy-ion beams

    International Nuclear Information System (INIS)

    Alonso, Jose R.

    2000-01-01

    Isotopes and accelerators, hallmarks of nuclear physics, are finding increasingly sophisticated and effective applications in the medical field. Diagnostic and therapeutic uses of radioisotopes are now a $10B/yr business worldwide, with over 10 million procedures and patient studies performed every year. This paper will discuss the use of isotopes for these applications. In addition, beams of protons and heavy ions are being more and more widely used clinically for treatment of malignancies. To be discussed here as well will be the rationale and techniques associated with charged-particle therapy, and the progress in implementation and optimization of these technologies for clinical use

  4. 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

  5. Nuclear data evaluation for medium and heavy nuclei

    International Nuclear Information System (INIS)

    Mizumoto, Motoharu

    1988-01-01

    Present status of nuclear data evaluation works for medium and heavy nuclei is described in this paper. These data are being prepared for JENDL-3 (Japanese Evaluated Nuclear Data Library-Version 3). At present, about a half of the data files, which are expected to be stored in the final library, has been brought into a temporary library called JENDL-3T. The remaining works and additional revisions are still needed to be made in order to finalize the data library as JENDL-3. Special emphases have been put on the high energy neutron data for which the previous JENDL-2 had some inadequacies, and gamma-ray production cross sections have been newly evaluated. Systematic and consistent evaluations have been intended for the new evaluations. (author)

  6. LIBS detection of heavy metal elements in liquid solutions by using wood pellet as sample matrix

    International Nuclear Information System (INIS)

    Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong

    2013-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid sample. A new approach was presented to improve the detection limit and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions, respectively. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to obtained LOD of 0.07 ppm for Cr element in solutions. (author)

  7. LIBS Detection of Heavy Metal Elements in Liquid Solutions by Using Wood Pellet as Sample Matrix

    International Nuclear Information System (INIS)

    Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid samples. A new approach was presented to lower the limit of detection (LOD) and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to the obtained LOD of 0.07 ppm for Cr element in solutions

  8. Chemical and nuclear properties of lawrencium (element 103) and hahnium (element 105)

    International Nuclear Information System (INIS)

    Henderson, R.A.

    1990-01-01

    The chemical and nuclear properties of Lr and Ha have been studied, using 3-minute 260 Lr and 35-second 262 Ha. The crystal ionic radius of Lr 3+ was determined by comparing its elution position from a cation-exchange resin column with those of lanthanide elements having known ionic radii. Comparisons are made to the ionic radii of the heavy actinides, Am 3+ through Es 3+ , obtained by x-ray diffraction methods, and to Md 3+ and Fm 3+ which were determined in the same manner as Lr 3+ . The hydration enthalpy of -3622 kJ/mol was calculated from the crystal ionic radius using an empirical form of the Born equation. Comparisons to the spacings between the ionic radii of the heaviest members of the lanthanide series show that the 2Z spacing between Lr 3+ and Md 3+ is anomalously small, as the ionic radius of Lr 3+ of 0.0886 nm is significantly smaller than had been expected. The chemical properties of Ha were determined relative to the lighter homologs in group 5, Nb and Ta. Group 4 and group 5 tracer activities, as well as Ha, were absorbed onto glass surfaces as a first step toward the determination of the chemical properties of Ha. Ha was found to adsorb on surfaces, a chemical property unique to the group 5 elements, and as such demonstrates that Ha has the chemical properties of a group 5 element. A solvent extraction procedure was adapted for use as a micro-scale chemical procedure to examine whether or not Ha displays eka-Ta-like chemical under conditions where Ta will be extracted into the organic phase and Nb will not. Under the conditions of this experiment Ha did not extract, and does not show eka-Ta-like chemical properties

  9. A study of pollution extent in some drinking water resources by heavy elements in Hadramout governorate

    International Nuclear Information System (INIS)

    Barheyan, Saad Awadh

    2001-01-01

    The paper is considered as a preliminary study of pollution extent in some drinking water resources in Hadramout governorate by heavy elements which differ in their toxicity. The elements subjected to study are Cd, Pb, Fe, Cr, Mn, Zn, Co and Cu. Atomic absorption spectrometric method of analysis (AAS) is used for the determination of heavy elements concentrations. The elemental analysis of drinking water samples shows that the concentration of the above-mentioned elements in drinking water resources, lies in the permissible limit given by the WHO. Similarity of elements content is observed in Thela and Fuwah waters, bu the case is different for Ghail Bawzeer and Asshihir waters due to their different lithospheric structures. Drinking water used by the civilians is not subjected to physical, biological or chemical treatment which may lead to total or partial removal of heavy elements and other rejected impurities. Drinking water running in distribution nets is a hard water and has a weak base (Ph which explains the reason why heavy elements are absorbed and precipitated inside drinking water pipes before they reach consumers. This type of hard water causes accumulation of salt precipitates inside the water pipes which results in many economic and health disturbances to consumers. The slight increase of Cr, Mn, and Co concentration in drinking water flowing in the pipes may be due to the effect of some anions such as nitrates which form soluble compounds with the elements contained in the chemical composition of the drinking water pipes. This paper is a strong indicator for determination of heavy elements concentrations in different drinking water resources in Hadramout govemorate. Such approach seeks a further comprehensive work with special focus on the study of lithospheric structure of the feeding water regions of Hadramout aquifers. (author)

  10. Application of insoluble tannin to recovery of uranium, TRU and heavy metals elements form radioactive liquid waste

    International Nuclear Information System (INIS)

    Hamaguchi, Kazuhiko; Shirato, Wataru; Nakamura, Yasuo; Matsumura, Tatsuro; Takeshita, Kenji; Nakano, Yoshio

    1999-01-01

    Mitsubishi Nuclear Fuel Co., Ltd. (MNF) has developed a new adsorbent, TANNIX (tread mark), for the recovery of uranium, TRU and heavy metal elements in the liquid waste, in which TANNIX derived from a natural tannin polymer. TANNIX has same advantages that handling is easier than that of standard IX-resin, and that the volume of secondary waste is reduced by burning the used TANNIX. We have replaced its radioactive liquid waste treatment system from the conventional co-precipitation process to adsorption process by using TANNIX. TANNIX was founded to be more effective for the recovery of Pu, TRU, and hexavalent chromium Cr-(VI) as well as Uranium. (author)

  11. Heavy particle decay studies using different versions of nuclear potentials

    Science.gov (United States)

    Santhosh, K. P.; Sukumaran, Indu

    2017-10-01

    The heavy particle decay from 212-240Pa , 219-245Np , 228-246Pu , 230-249Am , and 232-252Cm leading to doubly magic 208Pb and its neighboring nuclei have been studied using fourteen versions of nuclear potentials. The study has shown that the barrier penetrability as well as the decay half-lives are found to vary with the nuclear potential used. The investigated decay events of the emission of the clusters 22Ne , 24Ne , 26Mg , 28Mg , 32Si and 33Si are not experimentally detected yet but may be detectable in the future. As most of the half-lives predicted are found to lie within the experimental upper limit, T 1/2 parents with varying slopes and intercepts. Also, it is to be noted that the linearity of the GN plots is unaltered using different nuclear potentials. The universal curve studied ( log10 T 1/2 vs. -ln P for various clusters emitted from various parents shows a linear behavior with the same slope and intercept irrespective of the nuclear potential used.

  12. Heavy elements abundances in metal-poor stars

    International Nuclear Information System (INIS)

    Magain, P.; Jehin, E.; Neuforge, C.; Noels, A.

    1998-01-01

    A sample of 21 metal-poor stars have been analysed on the basis of high resolution and high signal-to-noise spectra. Correlations between relative abundances of 16 elements have been studied, with a special emphasis on the neutron-capture ones. This analysis reveals the existence of two sub-populations of field halo stars, namely Pop IIa and Pop IIb. They differ by the behaviour of the s-process elements versus the α and r-process elements. We suggest a scenario of formation of these stars, which closely relates the field halo stars to the evolution of globular clusters. The two sub-populations would have evaporated the clusters during two different stages of their chemical evolution

  13. X-ray spectroscopy of highly ionized heavy ions as an advanced research for controlled nuclear fusion power

    International Nuclear Information System (INIS)

    Zschornack, G.; Musiol, G.

    1988-01-01

    Diagnostics and modelling of nuclear fusion plasmas require a detailed knowledge of atomic and molecular data for highly ionized heavy ions. Experimental verification of atomic data is made on the basis of IAEA recommendations using the method of high-resolution wavelength-dispersive X-ray spectroscopy in order to obtain contributions extensioning the available atomic data lists. Basic facilities for producing highly charged heavy ions are the electron-ion rings of the heavy ion collective accelerator and the electron beam ion source KRYON-2 at the Joint Institute for Nuclear Research at Dubna. For high-resolution X-ray spectroscopy with these sources a computer-aided crystal diffraction spectrometer has been developed the precision of which is achieved by using advanced principles of measurement and control. Relativistic atomic structure calculations have been carried out for a great number of elements and configurations to obtain data in ionization regions heavily accessible to the experiment. (author)

  14. Heavy flavor operator matrix elements at O({alpha}{sub s}{sup 3})

    Energy Technology Data Exchange (ETDEWEB)

    Bierenbaum, Isabella; Buemlein, Johannes; Klein, Sebastian

    2008-12-15

    The heavy quark effects in deep.inelastic scattering in the asymptotic regime Q{sup 2}>>m{sup 2} can be described by heavy flavor operator matrix elements. Complete analytic expressions for these objects are currently known to NLO. We present first results for fixed moments at NNLO. This involves a recalculation of fixed moments of the corresponding NNLO anomalous dimensions, which we thereby confirm. (orig.)

  15. Recent developments in the synthesis of super heavy elements

    International Nuclear Information System (INIS)

    Ackermann, D.

    2001-01-01

    Throughout the passed two decades isotopes of the elements with atomic numbers 107-112 have been synthesized and unambiguously identified at the velocity filter SHIP at GSI. In a recent experiment at SHIP the results for element 112 have been confirmed and a third decay chain of the isotope 277 112 has been observed. Cold fusion reactions using Pb- and Bi- targets and evaporation residue(ER)-α-α correlations together with an efficient separation and detection system are the major ingredients for the success of these experiments. The sensitivity limit of the set-up at GSI has reached the 1pb level. For a systematic investigation in this region of the chart of nuclei and to synthesize heavier nuclei this limit has to be pushed to even lower values. An extensive development program is pursued at SHIP in order to reach at least an order of magnitude lower cross sections. Systematic investigations, the construction of decay chain networks and mass measurements are some of the possible approaches to study the decay chains attributed to isotopes of the elements 114, 116 and 118 at Dubna and Berkeley, which are, in contrast to those observed at GSI, not connected to decays of known isotopes. For the Berkeley results, in particular, several trials of confirmation have been undertaken at various laboratories including GSI

  16. Nuclear structure notes on element 115 decay chains

    International Nuclear Information System (INIS)

    Rudolph, D.; Sarmiento, L. G.; Forsberg, U.

    2015-01-01

    Hitherto collected data on more than hundred α-decay chains stemming from element 115 are combined to probe some aspects of the underlying nuclear structure of the heaviest atomic nuclei yet created in the laboratory

  17. Nuclear structure notes on element 115 decay chains

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, D., E-mail: Dirk.Rudolph@nuclear.lu.se; Sarmiento, L. G.; Forsberg, U. [Department of Physics, Lund University, 22100 Lund (Sweden)

    2015-10-15

    Hitherto collected data on more than hundred α-decay chains stemming from element 115 are combined to probe some aspects of the underlying nuclear structure of the heaviest atomic nuclei yet created in the laboratory.

  18. Nuclear research with heavy ions. Annual progress report, January 1, 1981-December 31, 1981

    International Nuclear Information System (INIS)

    Kaplan, M.

    1981-11-01

    The experimental research program is primarily concerned with the nuclear reactions induced by collisions between heavy-ion projectiles and complex target nuclei, the dynamics and thermodynamics associated with such collisions, and the relationships of the observables to the equilibrium and non-equilibrium properties of nuclear matter. As a sensitive probe of the nuclear interactions, detailed measurements of light-charged-particle emission were performed using counter telescopes for atomic number and mass number identification. Preliminary results from a new experiment on direct and evaporation-like emission of 4 He from reactions of 340-MeV 40 Ar with 238 U are reported. Using a large two-dimensional position-sensitive avalanche detector, and measuring three-fold coincidence events between two fission fragments and an emitted 4 He particle, we were able to distinguish emission processes in fusion-like fission from those associated with inelastic reactions. Analysis of the data shows isotropic and strongly forward-peaked 4 He components for both fusion and sequential fission, and kinematic evidence indicates substantial evaporation-like emission from the composite system rather than from fission fragments. The effects of light element impurities on charged particle spectra from heavy ion collisions are discussed, and a technique for directly evaluating the impurity contribution is briefly described

  19. CORONAL SOURCES, ELEMENTAL FRACTIONATION, AND RELEASE MECHANISMS OF HEAVY ION DROPOUTS IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Weberg, Micah J. [PhD Candidate in Space Science, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2134A Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Lepri, Susan T. [Associate Professor, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2429 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Zurbuchen, Thomas H., E-mail: mjweberg@umich.edu, E-mail: slepri@umich.edu, E-mail: thomasz@umich.edu [Professor, Space Science and Aerospace Engineering, Associate Dean for Entrepreneurship Senior Counselor of Entrepreneurship Education, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2431 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States)

    2015-03-10

    The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) 'where are the source loops located in the large-scale corona?'; (2) 'how does the interplay between coronal processes influence the end elemental abundances?'; and (3) 'what are the most probable release mechanisms'? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space.

  20. CORONAL SOURCES, ELEMENTAL FRACTIONATION, AND RELEASE MECHANISMS OF HEAVY ION DROPOUTS IN THE SOLAR WIND

    International Nuclear Information System (INIS)

    Weberg, Micah J.; Lepri, Susan T.; Zurbuchen, Thomas H.

    2015-01-01

    The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) 'where are the source loops located in the large-scale corona?'; (2) 'how does the interplay between coronal processes influence the end elemental abundances?'; and (3) 'what are the most probable release mechanisms'? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space

  1. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Upgrade Activities

    Science.gov (United States)

    Emrich, William J. Jr.; Moran, Robert P.; Pearson, J. Boise

    2012-01-01

    To support the on-going nuclear thermal propulsion effort, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The facility to perform this testing is referred to as the Nuclear Thermal Rocket Element Environment Simulator (NTREES). This device can simulate the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner so as to accurately reproduce the temperatures and heat fluxes which would normally occur as a result of nuclear fission and would be exposed to flowing hydrogen. Initial testing of a somewhat prototypical fuel element has been successfully performed in NTREES and the facility has now been shutdown to allow for an extensive reconfiguration of the facility which will result in a significant upgrade in its capabilities

  2. What can we learn from the fission time of the super-heavy elements?

    OpenAIRE

    Boilley, D.; Marchix, A.; Wilgenbus, D.; Lallouet, Y.; Gimbert, F.; Abe, Y.

    2007-01-01

    International audience; Recent experiments performed at GANIL with a crystal blocking technique have shown direct evidences of long fission times in the Super-Heavy Elements (SHE) region. Aimed to localize the SHE island of stability, can these experiments give access to the fission barrier and then to the shell-correction energy? In this paper, we calculate the fission time of heavy elements by using a new code, KEWPIE2, devoted to the study of the SHE.We also investigate the effect of poten...

  3. Status on the heavy elements research using the DV-DFS method

    International Nuclear Information System (INIS)

    Hirata, Masaru; Bastug, T.; Sekine, Rika; Onoe, Jun; Nakamatsu, Hirohide; Mukoyama, Takeshi

    1999-03-01

    In this review report, we describe recent progress on the heavy elements research using the discrete-variational Dirac-Fock-Slater (DV-DFS) method which is being improved by Kyoto University, Shizuoka University, RIKEN and JAERI. The DV-DFS is a versatile method for interpreting spectroscopic data and predicting chemical bonding of polyatomic systems including heavy elements. This review is based on the lectures given in 74th spring meeting of chemical Society of Japan (March, 1998) and also at the workshop on the XAFS-relativistic electronic structure calculation for the actinides research which was held at Tokai Research Establishment of JAERI (November, 1998). (author)

  4. Measurements of Plutonium isotopes and the search for super-heavy elements via AMS

    International Nuclear Information System (INIS)

    Wallner, A.; Steier, P.; Golser, R.; Knie, K.; Kutschera, W.; Priller, A.; Hrnecek, E.; Jakopic, R.; Korschinek, G.

    2006-01-01

    Full text: Accelerator Mass Spectrometry (AMS) - being independent on the half-life of a radionuclide - provides a technique to determine isotope ratios with the highest sensitivity and allows the measurement of radionuclides over a wide dynamic range of concentration levels. A combination of AMS, Alpha Spectrometry and Liquid Scintillation Counting was used for the determination of the complete information on isotope ratios of Plutonium isotopes in different environmental reference samples (e.g. from the atolls of Mururoa and Fangataufa) and samples contaminated from nuclear reprocessing. Results for the isotopic ratios of the samples will be shown and the capabilities and detection limits achievable for determination of Pu will be discussed. The long-lived 244 Pu (t 1/2 = 80 Ma) and 247 Cm (t 1/2 = 15.6 Ma) have a very interesting application in astrophysics by detecting possible supernova-produced 244 Pu and 247 Cm in terrestrial archives. The expected extremely small concentrations of 244 Pu makes AMS the favorite method. The actual search for such long-lived extraterrestrial radionuclides and possible implications will be presented. The same method has also been explored for a pinprick-search of long-lived super-heavy elements in the mass region above Z=100. (author)

  5. Alpha decay properties of heavy and superheavy elements

    International Nuclear Information System (INIS)

    Vigila Bai, G.M. Carmel; Umai Parvathiy, J.

    2015-01-01

    Analysing accurately the lifetimes of α-decay chains is an important tool to detect and study the properties of superheavy nuclei. 48 Ca is used in the synthesis of superheavy nuclei Z = 106-118 at Dubna. The experimental work of 48 Ca projectiles at Dubna has given an opportunity to study the superheavy element (SHE). Here, the α-decay properties for Z = 106-118 are evaluated using our CYE model and are compared with the available experimental and theoretical values. (author)

  6. Theory of nuclear heavy-ion direct transfer reactions

    International Nuclear Information System (INIS)

    Crowley, B.J.B.

    1979-01-01

    We review the distorted-wave approach to direct transfer reactions and draw attention to some of the shortcomings of current theories. We show that a reformulated form of the distorted-wave Born approximation (DWBA) for transfer can lead to important simplifications of the theory, which are valid for nuclear heavy-ion induced reactions at energies > or approx. =MeV/nucleon. In particular, in the semiclassical limit, it leads to a new and simple formula for the transfer t-matrix which includes all the essential physics while offering several important advantages over standard ''full-recoil finite-range'' DWBA. One such advantage is that the new formula is more transparent in that it is amendable to interpretation and analytical manipulation. At high-energy it is shown to reduce to one earlier deduced using eikonal-DWBA. The conditions for the validity of the new theory are discussed in detail. They are shown to be generally well satisfied for small-mass transfer between heavy-ions at energies at or above those particularly favour transfer (> or approx. =10 MeV/nucleon for transfer of valence nucleons). The restriction to small mass is not due to any recoil approximation; in fact, it is only a necessary restriction at certain energies. The theory treats recoil exactly. Consideration of the optimum dynamical conditions for transfer leads to a set of matching conditions. The presence of hitherto neglected absorption, arising from dynamical effects of poor matching, it suggested and qualitatively discussed. Condition under which such absorption may be neglected are derived. Results of numerical calculations are presented showing that the theory is capable of good agreement with standard full-recoil finite-range DWBA, and that it is capable of giving at least as good an account of experimental data for nucleon-transfer between heavy-ions at energies approx.10 MeV/nucleon

  7. Human factor as nuclear safety element

    International Nuclear Information System (INIS)

    Valeca, S.C.; Preda, M.; Valeca, M.; Ana, E. M.; Popescu, D.

    2008-01-01

    National nuclear power system is based on western technology, it covers almost 20% from national need and could be briefly described by: - Safety and economic performances of Cernavoda NPP Unit 1; - Reduced influence on environment, population and workers; - Excellent ranking (place 4) among CANDU units from all over the world. Also, the national nuclear power system plays a major role in Romanian power policy accomplishment: - Energy safety and independence assurance; - Decrease of production of greenhouse effect gases; - Preserve the stability and adequacy of energy cost. 'Nuclear Safety' concept covers all the activities resulting from nuclear fuel cycle. By taking into account the international experience, the related activities are estimated to last around 70 years in Romania: - 10 years for site description and selection, design, manufacturing and commissioning activities; - 40 years for Nuclear Power Plant operation, maintenance and modernization activities; - 20 years for preservation and decommissioning activities. The above mentioned activities requires human resources, qualified and specialized in the following areas: - research and development; - equipment design, manufacturing and operation; - components construction and assembly, operation and maintenance. (authors)

  8. Double β-decay nuclear matrix elements and lepton conservation

    International Nuclear Information System (INIS)

    Vergados, J.D.

    1976-01-01

    The nuclear matrix elements involved in the double β-decay of 48 Ca, 130 Te, and 128 Te were calculated using realistic nuclear interactions and shell model nuclear wave functions. The double doorway state is not appreciably mixed in the ground state of the final nuclei. So the ground state transitions contain a small fraction of the sum rule. A lepton nonconservation parameter eta -4 was deduced

  9. Handling system for nuclear reactor fuel and reflector elements

    International Nuclear Information System (INIS)

    Hawke, B.C.; Goldman, L.A.

    1980-01-01

    A system for canning, inspecting and transferring to a storage area fuel and reflector elements from a nuclear reactor is described. The canning mechanism operates in a sealed gaseous environment and visual and mechanical inspection of the elements is possible by an operator from a remote shielded area. (UK)

  10. Assembly for transport and storage of radioactive nuclear fuel elements

    International Nuclear Information System (INIS)

    Myers, G.

    1978-01-01

    The invention concerns the self-control of coolant deficiencies on the transport of spent fuel elements from nuclear reactors. It guarantees that drying out of the fuel elements is prevented in case of a change of volume of the fluid contained in storage tanks and accumulators and serving as coolant and shielding medium. (TK) [de

  11. Contribution of Heavy Water Board in nuclear fuel cycle technologies. Contributed Paper IT-03

    International Nuclear Information System (INIS)

    Mohanty, P.R.

    2014-01-01

    The three stage Indian nuclear power programme envisages use of closed nuclear fuel cycle and thorium utilization as its mainstay for long term energy security on sustainable basis. India is committed to realize this objective through the development and deployment of frontier technologies pertaining to all aspects of a closed nuclear fuel cycle. Comprehensive indigenous capabilities have been developed in all aspects of nuclear power and associated fuel cycles. Heavy Water Board (HWB), with its abiding objective of fulfilling demand of heavy water for India's flourishing nuclear power program, is one of the frontrunner in Nuclear Fuel Cycle Technology. HWB is now engaged in wide spectrum of activities in various facets of fuel cycle covering all the three stages of Indian Nuclear Power Programme. HWB is contributing to Nuclear Fuel Cycle through large scale production and sustained supply of key input materials including heavy water, solvents for nuclear hydrometallurgy, 10 B enriched boron etc

  12. Process to separate transuranic elements from nuclear waste

    International Nuclear Information System (INIS)

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1989-01-01

    A process is described for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs

  13. Process to separate transuranic elements from nuclear waste

    Science.gov (United States)

    Johnson, T.R.; Ackerman, J.P.; Tomczuk, Z.; Fischer, D.F.

    1989-03-21

    A process is described for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste may be disposed of more easily and the valuable transuranic elements may be recovered for reuse. The salt is contacted with a cadmium-uranium alloy which selectively extracts the transuranic elements from the salt. The waste salt is generated during the reprocessing of nuclear fuel associated with the Integral Fast Reactor (IFR). 2 figs.

  14. Present status of research activities conducted by research group for heavy elements microbiology in JAERI

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko; Ozaki, Takuo; Yoshida, Takahiro

    2004-01-01

    It has been recognized that microbial transformations of radionuclides and toxic metals could be significant in the environment, but there is a paucity of information on the mechanisms of biotransformation of radionuclides by the microorganisms. An understanding at the fundamental level the mechanisms of mobilization, immobilization and bioavailability of radioactive elements in particular the actinides is important from the standpoint of mobility of actinides in the environment, disposal of radioactive wastes in deep geological formation, remediation of contaminated soils and materials, and development of strategies for the long-term stewardship of the contaminated sites. The microbiology research group in Japan Atomic Energy Research Institute (JAERI) is conducting basic scientific research on microbial interactions with actinides. Fundamental research on microbial transformations of actinides include elucidation of the mechanisms of dissolution and precipitation of various chemical forms such as ionic, oxides, organic and inorganic complexes of actinides by aerobic or anaerobic microorganisms under relevant microbial process conditions. State-of-the-art analytical techniques are used to determine the interaction of actinides with microorganisms at the molecular level to understand the structure function relationship. These techniques include time-resolved laser fluorescence spectroscopy (TRLFS) to determine the coordination number, oxidation states and the nearest neighbor by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) at the Synchrotron Light Source, identification of functional groups by nuclear magnetic resonance (NMR), determination of chemical forms by transmission electron microscopy (TEM), and genomic (DNA) manipulation by molecular techniques. We here report the present status of our research activities on accumulation of lanthanides(III) by microorganisms, application of micro-particle induced X

  15. Spacer device for nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Anthony, A.J.; Gaines, A.L.; Krawiec, D.M.

    1974-01-01

    The grid-type spacer device consists of two rows of main spacers arranged parallel to each other with some space in between, the first row extending perpendicular to the second row. Parallel to the respective rows of main spacers there are rows of secondary spacers interlocked with the main spacers. The individual spacers are welded together at their points of intersection. A large number of spring cages are installed within the spacer device to hold in place the main spacers which are oriented at right angles relative to each other. In addition, the spring cages serve for supporting the fuel elements. The spacers are made of zirconium which does not greatly influence the neutron capture cross section of the reactor. The material of the spring cages with the spring elements is a nickel alloy. It has the necessary stress relaxation properties to be able to force the fuel elements against the spacers under the action of the spring. (DG) [de

  16. Nuclear power: Health implications of transuranium elements

    International Nuclear Information System (INIS)

    1982-01-01

    This report provides general guidelines for national public health and environmental authorities. It does not provide detailed technical data, but instead broadly surveys the whole field, indicating the present position as assessed by members of the Working Group. The Working Group considered three major facets: physiological, toxicological and dosimetric aspects of the transuranium elements; the application of occupational health control, including health physics; and environmental behaviour together with public health implications associated with the transuranium elements. The intention was to cover all aspects relevant to health, with respect both to those who are occupationally engaged in work with such elements and to the general public who might be affected as the result of such operations. Consideration was also given to routine and emergency situations

  17. Recent Investigations of Heavy Elements (37≤Z≤92)

    International Nuclear Information System (INIS)

    Biemont, E.

    2011-01-01

    The present paper is an update and extension of previous compilations [1, 2] and it describes recent progress regarding the investigation of the radiative properties of the elements and ions (first three ionization stages) of the fifth and sixth rows of the periodic table and of the rare earths (mostly the lanthanides). From a combination of experimental radiative lifetimes obtained with laser spectroscopy and of theoretical branching fractions calculated with a quasirelativistic Hartree-Fock approach taking configuration interaction and core-polarization effects into account, transition probabilities have been deduced for a large number of transitions of astrophysical interest. Some new results are briefly described here. The numerical values are stored in the databases DESIRE and DREAM, which are developped and progressively updated on a web site of Mons University in Belgium.

  18. Determining fissile content of nuclear fuel elements

    International Nuclear Information System (INIS)

    Arya, S.P.; Grossman, L.N.; Schoenig, F.C.

    1980-01-01

    This invention relates to the determination of the fissile fuel content of fuel for nuclear reactors. A nondestructive method is described for determining rapidly, accurately and simultaneously the fissile content, enrichment and location of fuel material which may also contain amounts of burnable poison, by detecting the γ-rays emitted from the fuel material due to natural radioactive decay. (U.K.)

  19. Method of dismantling nuclear fuel elements

    International Nuclear Information System (INIS)

    Adams, G.J.

    1983-01-01

    Nuclear fuel assemblies of the kind comprising fuel pins in dimpled cellular grids are freed from the grids to aid dismantling of the assemblies by causing a rotary sleeve to pass concentrically over the pins to remove the dimples in the grids and thereby increase the freedom of the pins in the cells of the grids. (author)

  20. Fuel element cluster for nuclear reactors

    International Nuclear Information System (INIS)

    Anthony, A.J.; Hutchinson, J.J.

    1976-01-01

    The claim refers to the constructional design of a fuel element cluster the elements of which are held by upper and lower end plates connected to each other in upright position, the bearing being formed by a screw connection between at least one guide tube for control rods and the two end plates. The claims are directed, especially, to the connection of the parts as well as to the materials selection which are determined to a high degree by the thermal expansion coefficients. (UA) [de

  1. Survival and compound nucleus probability of super heavy element Z = 117

    Energy Technology Data Exchange (ETDEWEB)

    Manjunatha, H.C. [Government College for Women, Department of Physics, Kolar, Karnataka (India); Sridhar, K.N. [Government First grade College, Department of Physics, Kolar, Karnataka (India)

    2017-05-15

    As a part of a systematic study for predicting the most suitable projectile-target combinations for heavy-ion fusion experiments in the synthesis of {sup 289-297}Ts, we have calculated the transmission probability (T{sub l}), compound nucleus formation probabilities (P{sub CN}) and survival probability (P{sub sur}) of possible projectile-target combinations. We have also studied the fusion cross section, survival cross section and fission cross sections for different projectile-target combination of {sup 289-297}Ts. These theoretical parameters are required before the synthesis of the super heavy element. The calculated probabilities and cross sections show that the production of isotopes of the super heavy element with Z = 117 is strongly dependent on the reaction systems. The most probable reactions to synthetize the super heavy nuclei {sup 289-297}Ts are worked out and listed explicitly. We have also studied the variation of P{sub CN} and P{sub sur} with the mass number of projectile and target nuclei. This work is useful in the synthesis of the super heavy element Z = 117. (orig.)

  2. Survival and compound nucleus probability of super heavy element Z = 117

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Sridhar, K.N.

    2017-01-01

    As a part of a systematic study for predicting the most suitable projectile-target combinations for heavy-ion fusion experiments in the synthesis of "2"8"9"-"2"9"7Ts, we have calculated the transmission probability (T_l), compound nucleus formation probabilities (P_C_N) and survival probability (P_s_u_r) of possible projectile-target combinations. We have also studied the fusion cross section, survival cross section and fission cross sections for different projectile-target combination of "2"8"9"-"2"9"7Ts. These theoretical parameters are required before the synthesis of the super heavy element. The calculated probabilities and cross sections show that the production of isotopes of the super heavy element with Z = 117 is strongly dependent on the reaction systems. The most probable reactions to synthetize the super heavy nuclei "2"8"9"-"2"9"7Ts are worked out and listed explicitly. We have also studied the variation of P_C_N and P_s_u_r with the mass number of projectile and target nuclei. This work is useful in the synthesis of the super heavy element Z = 117. (orig.)

  3. Ageing evaluation model of nuclear reactors structural elements

    International Nuclear Information System (INIS)

    Ziliukas, A.; Jutas, A.; Leisis, V.

    2002-01-01

    In this article the estimation of non-failure probability by random faults on the structural elements of nuclear reactors is presented. Ageing is certainly a significant factor in determining the limits of nuclear plant lifetime or life extensions. Usually the non failure probability rates failure intensity, which is characteristic for structural elements ageing in nuclear reactors. In practice the reliability is increased incorrectly because not all failures are fixed and cumulated. Therefore, the methodology with using the fine parameter of the failures flow is described. The comparison of non failure probability and failures flow is carried out. The calculation of these parameters in the practical example is shown too. (author)

  4. Fuel element for a nuclear reactor

    International Nuclear Information System (INIS)

    Tanihiro, Yasunori; Sumita, Isao.

    1970-01-01

    An improved fuel element of the heat pipe type is disclosed in which the fuel element itself is given a heat pipe structure and filled with a coated particle fuel at the section thereof having a capillary tube construction, whereby the particular advantages of heat pipes and coated fuels are combined and utilized to enhance thermal control and reactor efficiency. In an embodiment, the fuel element of the present invention is filled at its lower capillary tube section with coated fuel and at its upper section with a granurated neutron absorber. Both sections are partitioned from the central shaft by a cylindrically shaped wire mesh defining a channel through which the working liquid is vaporized from below and condensed by the coolant external to the fuel element. If the wire mesh is chosen to have a melting point lower than that of the fuel but higher than that of the operating temperature of the heat pipe, the mesh will melt and release the neutron absorbing particles should hot spots develop, thus terminating fission. (Owens, K. J.)

  5. Exploration of new biological specific function by heavy elements stimulus

    International Nuclear Information System (INIS)

    Macaskie, Lynne; Renshaw, Joanna; Ohnuki, Toshihiko; Nishiguchi, Norihiko; Utsunomiya, Satoshi; Suzuki, Yoshinori; Shirai, Osamu

    2014-01-01

    We have carried out experiments to investigate bio-mineralization of rare earth elements (REE) on the cell surface of yeast Saccharomyces cerevisiae, and the bacteria Bacillus subtilis, Pseudomonas fluorescens and Serratia sp. The continuous removal of 1 mM La (100%) Nd (100%) and Eu (>80%) was observed using a continuous flow through immobilized Serratia sp cell columns. Chemical and physical characterization of bio-mineralized La and Eu was done by XRD at Birmingham and showed the formation of phosphate minerals. Additional cell column work using S. cerevisiae, B. subtilis, or P. fluorescens, showed that these bacteria are capable of bio-mineralizing Ce(III) and Sm(III). Chemical and physical characterizations of bio-transformed Ce and Sm were analyzed by JAEA, Kyushu U., Tokyo U. Tech. and Kyoto U. using XAFS, SEM and TEM. Results showed that Ce and Sm nanoparticles were formed. The high radiostability of the metal accumulating enzyme of Serratia sp. (which promotes metal phosphate deposition) was shown in whole cells, whereas pure enzyme lost its activity quickly under irradiation. Additional work on radionuclide (Cm) incorporation into Serratia sp calcium phosphate minerals (analogue for human bones) using EXAFS and Time Resolved Laser Fluorescence Spectroscopy (in collaboration with Karlsruhe Institute of Technology) showed that this actinide binds at the grain boundaries between crystallites, which has health implications for human exposure. (author)

  6. Exploration of new biological specific function by heavy elements stimulus

    International Nuclear Information System (INIS)

    Macaskie, Lynne; Renshaw, Joanna; Ohnuki, Toshihiko; Nishiguchi, Norihiko; Utsunomiya, Satoshi; Suzuki, Yoshinori; Shirai, Osamu

    2012-01-01

    We have carried out experiments to investigate bio-mineralization of rare earth elements (REE) on the cell surface of yeast Saccharomyces cerevisiae, and the bacteria Bacillus subtilis, Pseudomonas fluorescens and Serratia sp. The continuous removal of 1 mM La (100%) Nd (100%) and Eu(>80%) was observed using a continuous flow through immobilized Serratia sp cell columns. Chemical and physical characterization of bio-mineralized La and Eu was done by XRD at Birmingham and showed the formation of phosphate minerals. Additional cell column work using S. cerevisiae, B. subtilis, or P. fluorescens, showed that these bacteria are capable of bio-mineralizing Ce(III) and Sm(III). Chemical and physical characterizations of bio-transformed Ce and Sm were analyzed by JAEA, Kyushu U., Tokyo U. Tech. and Kyoto U. using XAFS, SEM and TEM. Results showed that Ce and Sm nanoparticles were formed. The high radiostability of the metal accumulating enzyme of Serratia sp. (which promotes metal phosphate deposition) was shown in whole cells, whereas pure enzyme lost its activity quickly under irradiation. Additional work on radionuclide (Cm) incorporation into Serratia sp calcium phosphate minerals (analogue for human bones) using EXAFS and Time Resolved Laser Fluorescence Spectroscopy (in collaboration with Karlsruhe Institute of Technology) showed that this actinide binds at the grain boundaries between crystallites, which has health implications for human exposure. (author)

  7. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1993-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the course of this reporting period, the PI returned to Kent from a 15-month leave at Lawrence Berkeley Lab, which had been devoted 100% to work on this research project. The EOS Time Projection Chamber at LBL's Bevalac accelerator has continued to be the major focus of research for all of the supported personnel; about a year ago, this detector successfully took data in production mode for the first time, and accumulated in excess of 1000 hours of beam time before the termination of the Bevalac in February 1993. Reduction and analysis of these data is currently our first priority. Effort has also been devoted to the STAR detector at the Relativistic Heavy Ion Collider, in the form of contributions to the Conceptual Design Report, work on HV control hardware and software for use with the STAR Time Projection Chamber, and tracking software development

  8. X-ray Ionization of Heavy Elements Applied to Protoplanetary Disks

    NARCIS (Netherlands)

    Ádámkovics, Máté; Glassgold, Alfred E.; Meijerink, Rowin

    The consequences of the Auger effect on the population of heavy-element ions are analyzed for the case of relatively cool gas irradiated by keV X-rays with intended applications to the accretion disks of young stellar objects. Highly charged ions are rapidly reduced to the doubly charged state in

  9. Key elements of a sustainable nuclear business case

    Energy Technology Data Exchange (ETDEWEB)

    Naidoo, D [Nuclear Consultants International - South Africa and AMEC Nuclear - United Kingdom, 20-35th Avenue, Umhlatuzana, Chatsworth, Durban (South Africa)

    2008-07-01

    The argument for nuclear power generation grows stronger internationally. Its increasing acceptance is attributable to scarcity of fossil fuel resources and environmental concerns. However, the potential implementation of nuclear power plants to solve our energy need has become an economic issue. The relatively high capital costs, the need to internalise all waste disposal and decommissioning costs are perceived barriers to the expansion of the nuclear industry. South Africa has embarked on an ambitious plan to provide 20 GW of electricity through the use of nuclear power by 2025. The success of the governments drive to stabilise electricity supply shall depend on the socio-economic conditions prevalent in the country over the stipulated period, but more specifically on the execution of a sustainable nuclear business model beyond the initial nuclear plant construction phases. This paper shall examine briefly, the key elements of a nuclear business case within the South African context. (authors)

  10. Key elements of a sustainable nuclear business case

    International Nuclear Information System (INIS)

    Naidoo, D

    2008-01-01

    The argument for nuclear power generation grows stronger internationally. Its increasing acceptance is attributable to scarcity of fossil fuel resources and environmental concerns. However, the potential implementation of nuclear power plants to solve our energy need has become an economic issue. The relatively high capital costs, the need to internalise all waste disposal and decommissioning costs are perceived barriers to the expansion of the nuclear industry. South Africa has embarked on an ambitious plan to provide 20 GW of electricity through the use of nuclear power by 2025. The success of the governments drive to stabilise electricity supply shall depend on the socio-economic conditions prevalent in the country over the stipulated period, but more specifically on the execution of a sustainable nuclear business model beyond the initial nuclear plant construction phases. This paper shall examine briefly, the key elements of a nuclear business case within the South African context. (authors)

  11. Fuel element shipping shim for nuclear reactor

    International Nuclear Information System (INIS)

    Gehri, A.

    1975-01-01

    A shim is described for use in the transportation of nuclear reactor fuel assemblies. It comprises a member preferably made of low density polyethylene designed to have three-point contact with the fuel rods of a fuel assembly and being of sufficient flexibility to effectively function as a shock absorber. The shim is designed to self-lock in place when associated with the fuel rods. (Official Gazette)

  12. Heavy-Ion Fusion Mechanism and Predictions of Super-Heavy Elements Production

    International Nuclear Information System (INIS)

    Abe, Yasuhisa; Shen Caiwan; Boilley, David; Giraud, Bertrand G.; Kosenko, Grigory

    2009-01-01

    Fusion process is shown to firstly form largely deformed mono-nucleus and then to undergo diffusion in two-dimensions with the radial and mass-asymmetry degrees of freedom. Examples of prediction of residue cross sections are given for the elements with Z = 117 and 118.

  13. Temperature measuring element in nuclear reactors

    International Nuclear Information System (INIS)

    Wada, Takashi.

    1987-01-01

    Purpose: To easily measure the partial maximum temperature at a portion within the nuclear reactor where the connection with the external portion is difficult. Constitution: Sodium, potassium or the alloy thereof with high heat expansion coefficient is packed into an elastic vessel having elastic walls contained in a capsule. A piercing member formed into an acute triangle is attached to one end in the direction of expansion and contraction of the elastic container. The two sides of the triangle form an acute knife edge. A diaphragm is disposed within a capsule at a position opposed to the sharpened direction of the piercing member. Such a capsule is placed in a predetermined position of the nuclear reactor. The elastic vessel causes thermal expansion displacement depending on the temperature at a certain position, by which the top end of the pierce member penetrates through the diaphragm. A pierced scar of a penetration length depending on the temperature is resulted to the diaphragm. The length of the piercing damage is electroscopically observed and compared with the calibration curve to recognize the maximum temperature in the predetermined portion of the nuclear reactor. (Kamimura, M.)

  14. Reliability analysis of dispersion nuclear fuel elements

    Science.gov (United States)

    Ding, Shurong; Jiang, Xin; Huo, Yongzhong; Li, Lin an

    2008-03-01

    Taking a dispersion fuel element as a special particle composite, the representative volume element is chosen to act as the research object. The fuel swelling is simulated through temperature increase. The large strain elastoplastic analysis is carried out for the mechanical behaviors using FEM. The results indicate that the fission swelling is simulated successfully; the thickness increments grow linearly with burnup; with increasing of burnup: (1) the first principal stresses at fuel particles change from tensile ones to compression ones, (2) the maximum Mises stresses at the particles transfer from the centers of fuel particles to the location close to the interfaces between the matrix and the particles, their values increase with burnup; the maximum Mises stresses at the matrix exist in the middle location between the two particles near the mid-plane along the length (or width) direction, and the maximum plastic strains are also at the above region.

  15. Reliability analysis of dispersion nuclear fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Ding Shurong [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China)], E-mail: dsr1971@163.com; Jiang Xin [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China); Huo Yongzhong [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China)], E-mail: yzhuo@fudan.edu.cn; Li Linan [Department of Mechanics, Tianjin University, Tianjin 300072 (China)

    2008-03-15

    Taking a dispersion fuel element as a special particle composite, the representative volume element is chosen to act as the research object. The fuel swelling is simulated through temperature increase. The large strain elastoplastic analysis is carried out for the mechanical behaviors using FEM. The results indicate that the fission swelling is simulated successfully; the thickness increments grow linearly with burnup; with increasing of burnup: (1) the first principal stresses at fuel particles change from tensile ones to compression ones, (2) the maximum Mises stresses at the particles transfer from the centers of fuel particles to the location close to the interfaces between the matrix and the particles, their values increase with burnup; the maximum Mises stresses at the matrix exist in the middle location between the two particles near the mid-plane along the length (or width) direction, and the maximum plastic strains are also at the above region.

  16. Laser assisted decontamination of nuclear fuel elements

    International Nuclear Information System (INIS)

    Padma Nilaya, J.; Biswas, Dhruba J.; Kumar, Aniruddha

    2010-04-01

    Laser assisted removal of loosely bound fuel particulates from the clad surface following the process of pellet loading has decided advantages over conventional methods. It is a dry and noncontact process that generates very little secondary waste and can occur inside a glove box without any manual interference minimizing the possibility of exposure to personnel. The rapid rise of the substrate/ particulate temperature owing to the absorption of energy from the incident laser pulse results in a variety of processes that may lead to the expulsion of the particulates. As a precursor to the cleaning of the fuel elements, initial experiments were carried out on contamination simulated on commonly used clad surfaces to gain a first hand experience on the various laser parameters for which as efficient cleaning can be obtained without altering the properties of the clad surface. The cleaning of a dummy fuel element was subsequently achieved in the laboratory by integrating the laser with a work station that imparted simultaneous rotational and linear motion to the fuel element. (author)

  17. Nuclear X-ray emission after fusion of heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Christian; Muecher, Dennis; Gernhaeuser, Roman; Faestermann, Thomas [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Henning, Walter [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Argonne National Laboratory (United States); Morita, Kosuke; Morimoto, Kouji; Kaji, Daija [RIKEN, Research Group for Superheavy Elements (Japan)

    2015-07-01

    The goal is to establish in-beam K-X-ray spectroscopy as a sensitive tool to identify super heavy elements (SHEs) produced in fusion reactions via their proton number. SHEs, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. In case of hot fusion, the daughter nuclei quickly undergo spontaneous fission, so that the identification of the produced SHEs is difficult. Using the hot fusion approach in our first test experiments, the resultant products will be analysed by the gas-filled GARIS separator at the RILAC facility at RIKEN. As the X-ray detector is required to have superior energy and timing resolution to best identify the rare events at highest masses and to supress random coincidences as sufficient as possible, we chose a thin and planar geometry, which also reduces the damage caused by fast neutrons. We show first measurements using the MINIBALL Ge array at Munich. Additionally we report on our feasibility studies and on first tests using the new detector at high count rates together with a powerful DAQ system and transistor reset preamplifiers.

  18. Development of nuclear standard filter elements for PWR plant

    International Nuclear Information System (INIS)

    Weng Minghui; Wu Jidong; Gu Xiuzhang; Zhang Jinghua

    1988-11-01

    Model FRX-5 and FRX-10 nuclear standard filter elements are used for the fluid clarification of the chemical and volume control system (CVCS), boron recycle system (BRS), spent fuel pit cooling system (SFPCS) and steam generator blowdown system (SGBS) in Qinshan Nuclear Power Plant. The radioactive contaminant, fragment of resin and impurity are collected by these filter elements, The core of filter elements consists of polypropylene frames and paper filter medium bonded by resin. A variety of filter papers are tested for optimization. The flow rate and comprehensive performance have been measured in the simulation condition. The results showed that the performance and lifetime have met the designing requirements. The advantages of the filter elements are simple in manufacturing, less expense and facilities for waste-disposal. At present, some of filter elements have been produced and put in operation

  19. Production of pellets for nuclear fuel elements

    International Nuclear Information System (INIS)

    Butler, G.G.

    1982-01-01

    A method for producing nuclear fuel pellets each made up of a central portion and an outer annular portion surrounding the central portion, the two portions differing in composition. Such pellets are termed annular-layered pellets. The method comprises the steps of pressing powdered refractory material which has been granulated to form separately a central portion and an outer annular portion, assembling the portions together, compacting the assembly and sintering the compact. The portions are bonded together during sintering. The difference in composition may include a difference in density or isotopic enrichment as well as a chemical difference. (author)

  20. Elements of nuclear reactor fueling theory

    International Nuclear Information System (INIS)

    Egan, M.R.

    1984-01-01

    Starting with a review of the simple batch size effect, a more general theory of nuclear fueling is derived to describe the behavior and physical requirements of operating cycle sequences and fueling strategies having practical use in the management of nuclear fuel. The generalized theory, based on linear reactivity modeling, is analytical and represents the effects of multiple-stream, multiple-depletion-batch fueling configurations in systems employing arbitrary, non-integer batch size strategies, and containing fuel with variable energy generation rates. Reactor operating cycles and cycle sequences are represented with realistic structure that includes the effects of variable cycle energy production, cycle lengths, end-of-cycle operating extensions and maneuvering allowances. Results of the analytical theory are first applied to the special case of degenerate equilibrium cycle sequences, yielding several fundamental principles related to the selection of refueling strategy, and which govern fueling decisions normally made by the fuel manager. It is also demonstrated in this application that the simple batch size effect is not valid for non-integer fueling strategies, even in the simplest sequence configurations, and that it systematically underestimates the fueling requirements of degenerate sequences in general

  1. Matrix elements of Δ B =0 operators in heavy hadron chiral perturbation theory

    Science.gov (United States)

    Lee, Jong-Wan

    2015-05-01

    We study the light-quark mass and spatial volume dependence of the matrix elements of Δ B =0 four-quark operators relevant for the determination of Vu b and the lifetime ratios of single-b hadrons. To this end, one-loop diagrams are computed in the framework of heavy hadron chiral perturbation theory with partially quenched formalism for three light-quark flavors in the isospin limit; flavor-connected and -disconnected diagrams are carefully analyzed. These calculations include the leading light-quark flavor and heavy-quark spin symmetry breaking effects in the heavy hadron spectrum. Our results can be used in the chiral extrapolation of lattice calculations of the matrix elements to the physical light-quark masses and to infinite volume. To provide insight on such chiral extrapolation, we evaluate the one-loop contributions to the matrix elements containing external Bd, Bs mesons and Λb baryon in the QCD limit, where sea and valence quark masses become equal. In particular, we find that the matrix elements of the λ3 flavor-octet operators with an external Bd meson receive the contributions solely from connected diagrams in which current lattice techniques are capable of precise determination of the matrix elements. Finite volume effects are at most a few percent for typical lattice sizes and pion masses.

  2. Fuel element for a nuclear reactor

    International Nuclear Information System (INIS)

    Rau, P.

    1981-01-01

    Fuel elements which consist of parallel longitudinal fuel rods of circular crossection, can be provided with spiral distance pieces, by which the fuel rods support one another, if they are collected together by an outer enclosure. According to the invention, the enclosure includes several strips extending over a small fraction of the rod length, which are connected together by a skeleton rod instead of a fuel rod. The strips can be composed of flat parts which are connected together by the skeleton rod acting as a hinge. The invention is particularly suitable for breeder or converter reactors. (orig.) [de

  3. Investigation of Nuclear Fragmentation in Relativistic Heavy Ion Collisions Using Plastic - Nuclear - Track Detectors

    CERN Multimedia

    2002-01-01

    In this experiment CR39 plastic nuclear track detectors will be used which are sensitive to detect relativistic nuclear fragments with charges Z@$>$5. They will be analyzed using an automatic track measuring system which was developed at the University of Siegen.\\\\ \\\\ This allows to measure large quantities of tracks in these passive detectors and to perform high statistics experiments. We intend to measure cross sections for the production of nuclear fragments from heavy ion beams at the SPS. \\\\ \\\\ The energy independence of the cross sections predicted by the idea of limiting fragmentation will be tested at high energies. In exposures with different targets we plan to analyze the factorization of the fragmentation cross sections into a target depending factor and a factor depending on the beam particle and the fragment. The cross sections for one proton remov Coulomb dissociation. \\\\ \\\\ We plan to investigate Coulomb dissociation for different targets and different energies. Fragment and projectile charges ...

  4. Nuclear reactor fuel element sub-assemblies

    International Nuclear Information System (INIS)

    Hill, G.D.; Trevalion, P.A.

    1977-01-01

    A fuel element sub-assembly for a liquid metal cooled fast reactor is described. It comprises a bundle of fuel pins enclosed by a tubular wrapper having a lower end journal for plugging into an upper aperture in a core supporting structure and a spike bar with an articulated bush for engaging a lower aperture in the core supporting structure. The articulated bush is retained on a spherical end portion of the spike bar by a pair of parallel retaining pins arranged transversely and disposed one each side of the spike bar. The pins are tubular and collapsible at a predetermined loading to enable the spherical end portion to pass between them. The articulated bush has an internal groove for engagement by a lifting grab, this groove being formed in a bore for receiving the spherical end portion of the spike bar. The construction lessens liability to rattling of the fuel element sub-assemblies and aids removal for replacement. (U.K.)

  5. The quality control for biological-shield heavy concrete construction of nuclear power project

    International Nuclear Information System (INIS)

    Sun Hongjun; Ma Xinchao

    2012-01-01

    The paper introduces the function and characteristics of biological protective heavy-concrete, and its main application scope and role in Fangjiashan nuclear power project. From the aspects of raw material selection, mixing ratio test, heavy concrete production, the paper discusses the main control points of heavy concrete construction process, points out the basic characteristics of heavy concrete construction, and put forward measures to prevent density non-uniformity during heavy concrete construction and to control slump during transportation. Results prove that reasonable construction process control can assure the engineering quality. (authors)

  6. Influence of the nuclear autocorrelation function on the positron production in heavy-ion collisions

    International Nuclear Information System (INIS)

    Tomoda, T.; Weidenmueller, H.A.

    1983-01-01

    The influence of a nuclear reaction on atomic positron production in heavy-ion collisions is investigated. Using statistical concepts, we describe the nuclear S matrix for a heavy-ion induced reaction as a statistically fluctuating function of energy. The positron production rate is then dependent on the autocorrelation function of this S matrix, and on the ratio of the ''direct'' versus the ''fluctuating'' part of the nuclear cross section. Numerical calculations show that in this way, current experimental results on positron production in heavy-ion collisions can be reproduced in a semiquantitative fashion

  7. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1992-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the past year, the PI has been on leave at Lawrence Berkeley Lab and has worked on this research project full-time. A large fraction of the effort of the PI and graduate students has gone into preparing for experiments using the Time Projection Chamber at LBL's Bevalac accelerator; in March 1992, this device successfully took data in production mode for the first time, and the first physics analysis is now under way. The PI has carried out simulations that help to define the physics performance and engineering specifications of the recently-approved STAR detector for the Relativistic Heavy Ion Collider, and has identified a new capability of this device with the potential for being an important quark-gluon plasma signature. A Postdoctoral Fellow, jointly supported by this grant and Kent State University, has been recruited to augment these efforts. Since May 1991, 11 journal papers have been published or submitted for publication; 2 conference proceedings and 9 reports or abstracts have also been published during the past year. One paper in Phys. Rev. Left., one in Phys. Rev. C, and one conference proceedings are based on the thesis project of one of the PI's Ph.D. students who is expected to graduate later this year. Partly in response to the impending closure of the Bevalac, the PI's group has recently joined the NA49 experiment at CERN

  8. Nonlinear finite element analysis of nuclear reinforced prestressed concrete containments up to ultimate load capacity

    International Nuclear Information System (INIS)

    Gupta, A.; Singh, R.K.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.

    1996-01-01

    For safety evaluation of nuclear structures a finite element code ULCA (Ultimate Load Capacity Assessment) has been developed. Eight/nine noded isoparametric quadrilateral plate/shell element with reinforcement as a through thickness discrete but integral smeared layer of the element is presented to analyze reinforced and prestressed concrete structures. Various constitutive models such as crushing, cracking in tension, tension stiffening and rebar yielding are studied and effect of these parameters on the reserve strength of structures is brought out through a number of benchmark tests. A global model is used to analyze the prestressed concrete containment wall of a typical 220 MWe Pressurized Heavy Water Reactor (PHWR) up to its ultimate capacity. This demonstrates the adequacy of Indian PHWR containment design to withstand severe accident loads

  9. Plant Design Nuclear Fuel Element Production Capacity Optimization to Support Nuclear Power Plant in Indonesia

    International Nuclear Information System (INIS)

    Bambang Galung Susanto

    2007-01-01

    The optimization production capacity for designing nuclear fuel element fabrication plant in Indonesia to support the nuclear power plant has been done. From calculation and by assuming that nuclear power plant to be built in Indonesia as much as 12 NPP and having capacity each 1000 MW, the optimum capacity for nuclear fuel element fabrication plant is 710 ton UO 2 /year. The optimum capacity production selected, has considered some aspects such as fraction batch (cycle, n = 3), length of cycle (18 months), discharge burn-up value (Bd) 35,000 up 50,000 MWD/ton U, enriched uranium to be used in the NPP (3.22 % to 4.51 %), future market development for fuel element, and the trend of capacity production selected by advances country to built nuclear fuel element fabrication plant type of PWR. (author)

  10. Quality assurance in nuclear fuel element component supply

    International Nuclear Information System (INIS)

    Jenkins, B.P.

    1987-01-01

    The paper describes the application of Quality Assurance to nuclear fuel element component supply. The Quality Assurance programme includes integrated procurement, purchasing, surveillance and receipt inspection functions. Purchasing policy is based on a consistent preference for competitive tendering. Multiple sourcing is used to encourage competitive pricing and increase security of supply. A receipt inspection facility is maintained to ensure the high product quality levels demanded by the nuclear industry. (U.K.)

  11. Application of finite element numerical technique to nuclear reactor geometries

    Energy Technology Data Exchange (ETDEWEB)

    Rouai, N M [Nuclear engineering department faculty of engineering Al-fateh universty, Tripoli (Libyan Arab Jamahiriya)

    1995-10-01

    Determination of the temperature distribution in nuclear elements is of utmost importance to ensure that the temperature stays within safe limits during reactor operation. This paper discusses the use of Finite element numerical technique (FE) for the solution of the two dimensional heat conduction equation in geometries related to nuclear reactor cores. The FE solution stats with variational calculus which considers transforming the heat conduction equation into an integral equation I(O) and seeks a function that minimizes this integral and hence gives the solution to the heat conduction equation. In this paper FE theory as applied to heat conduction is briefly outlined and a 2-D program is used to apply the theory to simple shapes and to two gas cooled reactor fuel elements. Good results are obtained for both cases with reasonable number of elements. 7 figs.

  12. Application of finite element numerical technique to nuclear reactor geometries

    International Nuclear Information System (INIS)

    Rouai, N. M.

    1995-01-01

    Determination of the temperature distribution in nuclear elements is of utmost importance to ensure that the temperature stays within safe limits during reactor operation. This paper discusses the use of Finite element numerical technique (FE) for the solution of the two dimensional heat conduction equation in geometries related to nuclear reactor cores. The FE solution stats with variational calculus which considers transforming the heat conduction equation into an integral equation I(O) and seeks a function that minimizes this integral and hence gives the solution to the heat conduction equation. In this paper FE theory as applied to heat conduction is briefly outlined and a 2-D program is used to apply the theory to simple shapes and to two gas cooled reactor fuel elements. Good results are obtained for both cases with reasonable number of elements. 7 figs

  13. The Distribution of Heavy Element From Fish, Algae, Water and Sea Sediment In Lemahabang Muria Peninsula

    International Nuclear Information System (INIS)

    Sukirno; J-Djati-Pramana; Sumining

    2005-01-01

    The analysis of heavy elements from fish, algae, water and sea sediments in Muria peninsula Jepara has been carried out using neutron activation analysis (NAA) method. Irradiation of sample was carried out for twelve hours with using Lazy Susan facility with neutron flux of 0.585x10 11 n.cm -2 .S -1 . Comparative mode of measurement was used for avoiding the effects of neutron flux parameters on the results. The result on analysis using gamma spectrometry with a Ge(Li) detector showed that there were 6 elements which observed. Those elements contained in algae, fish, water and sea sediment were Co, Sb, Sc, Fe, Cr and Cd. The highest element concentration found in sediment was Fe of 65.625 ± 3.12 % and the lowest was Co of 0.00256 ± 0.00045 μg/g for sea water. This method give precision and relative accuracy of < 10 % for all elements. (author)

  14. Application of alpha spectrometry to the discovery of new elements by heavy-ion-beam bombardment

    International Nuclear Information System (INIS)

    Nitschke, J.M.

    1983-05-01

    Starting with polonium in 1898, α-spectrometry has played a decisive role in the discovery of new, heavy elements. For even-even nuclei, α-spectra have proved simple to interpret and exhibit systematic trends that allow extrapolation to unknown isotopes. The early discovery of the natural α-decay series led to the very powerful method of genetically linking the decay of new elements to the well-established α-emission of daughter and granddaughter nuclei. This technique has been used for all recent discoveries of new elements including Z = 109. Up to mendelevium (Z = 101), thin samples suitable for α-spectrometry were prepared by chemical methods. With the advent of heavy-ion accelerators new sample preparation methods emerged. These were based on the large momentum transfer associated with heavy-ion reactions, which produced energetic target recoils that, when ejected from the target, could be thermalized in He gas. Subsequent electrical deposition or a He-jet technique yielded samples that were not only thin enough for α-spectroscopy, but also for α- and #betta#-recoil experiments. Many variations of these methods have been developed and are discussed. For the synthesis of element 106 an aerosol-based recoil transport technique was devised. In the most recent experiments, α-spectrometry has been coupled with the magnetic analysis of the recoils. The time from production to analysis of an isotope has thereby been reduced to 10 - 6 s; while it was 10 - 1 to 10 0 s for He-jets and 10 1 to 10 3 s for rapid chemical separations. Experiments are now in progress to synthesize super heavy elements (SHE) and to analyze them with these latest techniques. Again, α-spectrometry will play a major role since the expected signature for the decay of a SHE is a sequence of α-decays followed by spontaneous fission

  15. The permission of transport of irradiated nuclear fuel elements

    International Nuclear Information System (INIS)

    Klomberg, T.J.M.

    2000-01-01

    In July and October 2000 the Dutch government granted permits for the transportation of irradiated nuclear fuel elements. The environmental organization Greenpeace objected against the permit, but that was rejected by the Dutch Council of State. A brief overview is given of the judgements and the state-of-the-art with respect to the transportation of the elements from Dutch reactors and storage facilities in Petten, Dodewaard and Borssele to Cogema in La Hague, France and BNFL in Sellafield, England

  16. Elements of nuclear reactor fueling theory

    International Nuclear Information System (INIS)

    Egan, M.R.

    1984-01-01

    Starting with a review of the simple batch size effect, a more general theory of nuclear fueling is derived to describe the behaviour and physical requirements of operating cycle sequences and fueling strategies having practical use in fuel management. The generalized theory, based on linear reactivity modeling, is analytical and represents the effects of multiple-stream, multiple-depletion-batch fueling configurations in systems employing arbitrary, non-integer batch size strategies, and containing fuel with variable energy generation rates. Reactor operating cycles and cycle sequences are represented with realistic structure that includes the effects of variable cycle energy production, cycle lengths, end-of-cycle operating extensions and manoeuvering allowances. Results of the analytical theory are first applied to the special case of degenerate equilibrium cycle sequences, yielding several fundamental principles related to the selection of refueling strategy. Numerical evaluations of degenerate equilibrium cycle sequences are then performed for a typical PWR core, and accompanying fuel cycle costs are calculated. The impact of design and operational limits as constraints on the performance mappings for this reactor are also studied with respect to achieving improved cost performance from the once-through fuel cycle. The dynamics of transition cycle sequences are then examined using the generalized theory. Proof of the existence of non-degenerate equilibrium cycle sequences is presented when the mechanics of the fixed reload batch size strategy are developed analytically for transition sequences. Finally, an analysis of the fixed reload enrichment strategy demonstrates the potential for convergence of the transition sequence to a fully degenerate equilibrium sequence. (author)

  17. Effect of γ-ray emission on transuranium element production cross sections in heavy ion reactions

    International Nuclear Information System (INIS)

    Il'inov, A.S.; Oganesyan, Yu.Ts.; Cherepanov, E.A.

    1980-01-01

    The effect of competition of the γ ray emission with neutron evaporation and of compound nuclei fission induced by heavy ion reactions on the production cross sections for transuranium elements is considered. It is shown that taking account of γ ray emission leads to the broadening of the excitation functions of the (HI, xny) reactions such as 18 O+ 238 U, 40 Ar+ 206 Pb, 40 Ar+ 207 Pb and 40 Ar+ 208 Pb reactions and to the displacement of their maximum toward the higher energies as well as to an increase of the absolute cross sections which is especially strong close to the fusion barrier. Cross sections for the radiative capture of heavy ions by a heavy target nucleus in 40 Ar+ 206 Pb, 40 Ar+ 208 Pb, 48 Ca+ 204 Pb and 48 Ca+ 208 Pb reactions are estimated

  18. A novel approach to the island of stability of super-heavy elements search

    Directory of Open Access Journals (Sweden)

    Wieloch A.

    2016-01-01

    Full Text Available It is expected that the cross section for super-heavy nuclei production of Z > 118 is dropping into the region of tens of femto barns. This creates a serious limitation for the complete fusion technique that is used so far. Moreover, the available combinations of the neutron to proton ratio of stable projectiles and targets are quite limited and it can be difficult to reach the island of stability of super heavy elements using complete fusion reactions with stable projectiles. In this context, a new experimental investigation of mechanisms other than complete fusion of heavy nuclei and a novel experimental technique are invented for our search of super- and hyper-nuclei. This contribution is focused on that technique.

  19. Review of fuel element development for nuclear rocket engines

    International Nuclear Information System (INIS)

    Taub, J.M.

    1975-06-01

    The Los Alamos Scientific Laboratory (LASL) entered the nuclear propulsion field in 1955 and began work on all aspects of a nuclear propulsion program involving uranium-loaded graphite fuels, hydrogen propellant, and a target exhaust temperature of approximately 2500 0 C. A very extensive uranium-loaded graphite fuel element technology evolved from the program. Selection and composition of raw materials for the extrusion mix had to be coupled with heat treatment studies to give optimum element properties. The highly enriched uranium in the element was incorporated as UO 2 , pyrocarbon-coated UC 2 , or solid solution UC . ZrC particles. An extensive development program resulted in successful NbC or ZrC coatings on elements to withstand hydrogen corrosion at elevated temperatures. Hot gas, thermal shock, thermal stress, and NDT evaluation procedures were developed to monitor progress in preparation of elements with optimum properties. Final evaluation was made in reactor tests at NRDS. Aerojet-General, Westinghouse Astronuclear Laboratory, and the Oak Ridge Y-12 Plant of Union Carbide Nuclear Company entered the program in the early 1960's, and their activities paralleled those of LASL in fuel element development. (U.S.)

  20. Multidimensional elemental analysis with the Sandia nuclear microprobe

    International Nuclear Information System (INIS)

    Doyle, B.L.

    1988-01-01

    It is well known that many of the ion beam analysis techniques such as Rutherford backscattering spectrometry, elastic recoil detection, resonant and nonresonant nuclear reaction analysis can be used to nondestructively obtain concentration depth profiles of elements in solids. When these techniques are combined with the small beam spot capabilities of a scanned nuclear microprobe, sample composition can be determined in up to three dimensions. This paper will review the various procedures used to collect and analyze multidimensional data using the Sandia nuclear microprobe. In addition, examples of how these data are being used in the study of materials will be shown. (author)

  1. Nuclear structure effects in quasifission – understanding the formation of the heaviest elements

    Directory of Open Access Journals (Sweden)

    Hinde D. J.

    2016-01-01

    Full Text Available Quasifission is an important process suppressing the fusion of two heavy nuclei in reactions used to create superheavy elements. Quasifission results in rapid separation of the dinuclear system initially formed at contact. Achieving reliable a priori prediction of quasifission probabilities is a very diffcult problem. Through measurements with projectiles from C to Ni, the Australian National University’s Heavy Ion Accelerator Facility and CUBE spectrometer have been used to map out mass-angle distributions (MAD - the fission mass-ratio as a function of centre-of-mass angle. These provide information on quasifission dynamics in the least modeldependent way. Average quasifission time-scales have been extracted, and compared with TDHF calculations of the collisions, with good agreement being found. With the baseline information from the survey of experimental MAD, strong influences of the nuclear structure of the projectile and target nuclei can be clearly determined.

  2. PROBABILISTIC FINITE ELEMENT ANALYSIS OF A HEAVY DUTY RADIATOR UNDER INTERNAL PRESSURE LOADING

    Directory of Open Access Journals (Sweden)

    ROBIN ROY P.

    2017-09-01

    Full Text Available Engine cooling is vital in keeping the engine at most efficient temperature for the different vehicle speed and operating road conditions. Radiator is one of the key components in the heavy duty engine cooling system. Heavy duty radiator is subjected to various kinds of loading such as pressure, thermal, vibration, internal erosion, external corrosion, creep. Pressure cycle durability is one of the most important characteristic in the design of heavy duty radiator. Current design methodologies involve design of heavy duty radiator using the nominal finite element approach which does not take into account of the variations occurring in the geometry, material and boundary condition, leading to over conservative and uneconomical designs of radiator system. A new approach is presented in the paper to integrate traditional linear finite element method and probabilistic approach to design a heavy duty radiator by including the uncertainty in the computational model. As a first step, nominal run is performed with input design variables and desired responses are extracted. A probabilistic finite elementanalysis is performed to identify the robust designs and validated for reliability. Probabilistic finite element includes the uncertainty of the material thickness, dimensional and geometrical variation. Gaussian distribution is employed to define the random variation and uncertainty. Monte Carlo method is used to generate the random design points.Output response distributions of the random design points are post-processed using different statistical and probability technique to find the robust design. The above approach of systematic virtual modelling and analysis of the data helps to find efficient and reliable robust design.

  3. Nuclear microprobe study of heavy metal uptake and transport in aquatic plant species

    International Nuclear Information System (INIS)

    Kertesz, Zs.; Kocsar, I.; Szikszai, Z.; Lakatos, Gy.

    2005-01-01

    Complete text of publication follows. In aquatic ecosystems water contamination by trace metals is one of the main types of pollution that may stress the biotic community. Although some metals are needed as micronutrients for autotrophic organisms, they can have toxic effects at higher concentration. Aquatic plants can take up large quantities of nutrients and metals from the environment, they can live under extreme environmental conditions therefore they are being increasingly used in remediation processes to reduce contamination. Besides the usually applied bulk analytical techniques quantitative micro-PIXE investigation of the macro, micro and trace element distribution within the root can lead to a better understanding of the heavy metal up-take, transport and detoxification mechanisms of the plants and thus helps to select the proper species for the remedial activity, or possibly to increase the efficiency of the remediation. In this work we determined the elemental distributions in root cross sections and along the roots of reed (Phragmaties australis), bulrush (Typha angustifolia) and sea club-rush (Bolboschoemus maritimus) using the Debrecen nuclear microprobe. The plants originate from the dried units of the wastewater sedimentation pond system of the tannery of Kunszentmarton. 1500 m 3 waste water containing lime, sodium-salts, ammonium-salts, chromium-salts, sodium, chlorine and magnesium ions, sulphur and organic material was released to the pond system every day till 1988. The chosen species are the dominant species of the area, composing 85-90% of the green plant covering. This heavily contaminated area has been regularly monitored by the colleagues of the Dept. of Applied Ecology of the Univ. of Debrecen since 1998. They focused their work the potentially toxic heavy metal chromium. In order to conserve the samples in the living state, the roots were frozen in liquid nitrogen. 16-20 μm thick cross sections were made with cryo-microtome, and all the

  4. Simulation studies of acceleration of heavy ions and their elemental compositions

    International Nuclear Information System (INIS)

    Toida, Mieko; Ohsawa, Yukiharu

    1996-07-01

    By using a one-dimensional, electromagnetic particle simulation code with full ion and electron dynamics, we have studied the acceleration of heavy ions by a nonlinear magnetosonic wave in a multi-ion-species plasma. First, we describe the mechanism of heavy ion acceleration by magnetosonic waves. We then investigate this by particle simulations. The simulation plasma contains four ion species: H, He, O, and Fe. The number density of He is taken to be 10% of that of H, and those of O and Fe are much lower. Simulations confirm that, as in a single-ion-species plasma, some of the hydrogens can be accelerated by the longitudinal electric field formed in the wave. Furthermore, they show that magnetosonic waves can accelerate all the particles of all the heavy species (He, O, and Fe) by a different mechanism, i.e., by the transverse electric field. The maximum speeds of the heavy species are about the same, of the order of the wave propagation speed. These are in good agreement with theoretical prediction. These results indicate that, if high-energy ions are produced in the solar corona through these mechanisms, the elemental compositions of these heavy ions can be similar to that of the background plasma, i.e., the corona

  5. Relative radiative decay rates of vacancies in L-subshells of heavy elements

    International Nuclear Information System (INIS)

    Barros Leite, C.V. de; Pinho, A.G. de; Castro Faria, N.V. de.

    1977-01-01

    Relative radiative decay of vacancies in L-subshells were measured for a large number of heavy elements with a Si(Li) detection system. A graphical method was employed to analyze the x-ray spectra so obtained. Systematic results are presented together with other already published results obtained in our laboratories in recent years. This covers the interval 74<=Z<=93. Results are compared with theoretical predictions and experimental data from other authors and some general features are noted

  6. Long-lived heavy mass elements half-lives (A > 125)

    International Nuclear Information System (INIS)

    Holden, N.E.

    1985-01-01

    Reported values of half-lives of intermediate mass and heavy elements are evaluated. The evaluation analysis estimates the systematic error the resulting standard deviation. Recommended values are then presented for 128 Te, 130 Te, 129 I, 138 La, 144 Nd, 145 Nd, /sup 146,147,148/Sm, 152 Gd, 154 Dy, 176 Lu, 174 Hf, 180 Ta, 187 Re, 186 Os, 190 Pt, /sup 204,205/Pb, and /sup 230,232/Th. 103 refs., 21 tabs

  7. Experimental study of water flow in nuclear fuel elements

    International Nuclear Information System (INIS)

    Rodrigues, Lorena Escriche; Rezende, Hugo Cesar; Mattos, Joao Roberto Loureiro de; Barros Filho, Jose Afonso; Santos, Andre Augusto Campagnole dos

    2013-01-01

    This work aims to develop an experimental methodology for investigating the water flow through rod bundles after spacer grids of nuclear fuel elements of PWR type reactors. Speed profiles, with the device LDV (Laser Doppler Velocimetry), and the pressure drop between two sockets located before and after the spacer grid, using pressure transducers were measured

  8. Structure of nuclear transition matrix elements for neutrinoless ...

    Indian Academy of Sciences (India)

    Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

  9. Structure of nuclear transition matrix elements for neutrinoless ...

    Indian Academy of Sciences (India)

    Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double-β decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

  10. The fabrication of nuclear fuel elements in Mexico

    International Nuclear Information System (INIS)

    Guerrero Morillo, H.L.

    1977-01-01

    The situation of nuclear electricity generation in Mexico in 1976 is described: two nuclear reactors were under construction but no definite programme on the type and start-up dates for the next power plants existed. However, the existence of a general plan on nuclear power plants is mentioned, which, according to the latest estimates, will provide 10,000MW installed by 1990. The national intention, as laid down in an appropriate Law, is to supply domestic nuclear fuel to the power reactors operating in the country, starting with the first reloading of the two BWRs at the first national station in Laguna Verde, required at the end of 1981 and 1982, respectively. Before this can be achieved and to provide the relatively small amounts of fuel elements for the two reactors, Mexico must adopt a strategy of fuel elements fabrication. The two main options are analysed: (1) to delay local fabrication until a national nuclear programme has been defined, meanwhile purchasing abroad the necessary initial cores and refuelling; (2) to start local fabrication of fuel elements as soon as possible in order to provide the first refuelling of the first unit of Laguna Verde, confronting the economic risks of such a decision with the advantages of immediate action. Both options are analysed in detail, comparing them especially from the economic point of view. Current information from potential licensors for design and manufacture are used in the analysis. (author)

  11. 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

  12. Study of the Matrix Effect on the Plasma Characterization of Heavy Elements in Soil Sediments

    Directory of Open Access Journals (Sweden)

    Tawfik W.

    2007-01-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to perform a study of the matrix effect on the plasma characterization of soil sediment targets. The plasma is generated by focusing a pulsed Nd: YAG laser on the target in air at atmospheric pressure. The plasma emission spectrum was detected using a portable Echelle spectrometer (Mechelle 7500 — Multichannel Instruments, Stockholm, Sweden with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, and electron temperature. Four heavy elements V, Pb, Mn and Co were determined in the obtained spectra. The LTE and optically thin plasma conditions were verified for the produced plasma. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of the spectral lines of the heavy elements in the soil sediments. The electron temperature does not change with concentration. For environmental applications, the obtained results showed the capability of the proposed LIBS setup with the portable Mechelle 7500 spectrometer to be applied in-situ for real-time measurements of the variation of the matrix elemental composition of soil sediments by following up only a single element as a marker for the composition of the soil sediment without need of analysis of the other elements.

  13. Studies in High Energy Heavy Ion Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Gerald W. [Univ. of Texas, Austin, TX (United States); Markert, Christina [Univ. of Texas, Austin, TX (United States)

    2016-09-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or "decay" into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  14. Studies in High Energy Heavy Ion Nuclear Physics

    International Nuclear Information System (INIS)

    Hoffmann, Gerald W.; Markert, Christina

    2016-01-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or 'decay' into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  15. Initial Operation of the Nuclear Thermal Rocket Element Environmental Simulator

    Science.gov (United States)

    Emrich, William J., Jr.; Pearson, J. Boise; Schoenfeld, Michael P.

    2015-01-01

    The Nuclear Thermal Rocket Element Environmental Simulator (NTREES) facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The NTREES facility has recently been upgraded such that the power capabilities of the facility have been increased significantly. At its present 1.2 MW power level, more prototypical fuel element temperatures nay now be reached. The new 1.2 MW induction heater consists of three physical units consisting of a transformer, rectifier, and inverter. This multiunit arrangement facilitated increasing the flexibility of the induction heater by more easily allowing variable frequency operation. Frequency ranges between 20 and 60 kHz can accommodated in the new induction heater allowing more representative power distributions to be generated within the test elements. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during testing In this new higher power configuration, NTREES will be capable of testing fuel elements and fuel materials at near-prototypic power densities. As checkout testing progressed and as higher power levels were achieved, several design deficiencies were discovered and fixed. Most of these design deficiencies were related to stray RF energy causing various components to encounter unexpected heating. Copper shielding around these components largely eliminated these problems. Other problems encountered involved unexpected movement in the coil due to electromagnetic forces and electrical arcing between the coil and a dummy test article. The coil movement and arcing which were encountered during the checkout testing effectively destroyed the induction coil in use at

  16. Anatomy of double beta decay nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr, E-mail: pxv@caltech.ed [Kellogg Radiation Laboratory 106-38 Caltech. Pasadena, CA 91125 (United States)

    2009-06-01

    The necessary ingredients for a realistic evaluation of the 0vbetabeta nuclear matrix elements are reviewed. It is argued that the short range nucleon correlations, nucleon finite size, and higher order nuclear currents need to be included in the calculation, even though a consensus on the best way to treat all of these effects has not been reached. Another positive development is the realization that the two alternative and complementary methods, the Quasiparticle Random Phase Approximation and the Nuclear Shell Model, agree on many aspects of the calculation, in particular on the competition, or cancelation, between the contribution of nuclear pairing on one hand, and the other pieces of interaction that result in admixtures of broken pairs or higher seniority states on the other hand. The relatively short range (r <= 2-3 fm) of the effective 0vbetabeta operator found in both methods is a consequence of that competition.

  17. HAIR HEAVY METAL AND ESSENTIAL TRACE ELEMENT CONCENTRATION IN CHILDREN WITH AUTISM SPECTRUM DISORDER.

    Science.gov (United States)

    Tabatadze, T; Zhorzholiani, L; Kherkheulidze, M; Kandelaki, E; Ivanashvili, T

    2015-11-01

    Our study aims evaluation of level of essential trace elements and heavy metals in the hair samples of children with autistic spectrum disorder (ASD) and identification of changes that are associated with autistic spectrum disorders. Case-control study was conducted at Child Development Center of Iashvili Children's Central Hospital (LD).We studied 60 children aged from 4 to 5 years old. The concentrations of 28 elements among (Ca,Zn, K, Fe, Cu, Se, Mn, Cr, S, Br, Cl, Co, Ag, V, Ni, Rb, Mo, Sr, Ti, Ba, Pb, As, Hg, Cd, Sb, Zr, Sn, Bi) them trace elements and toxic metals) were determined in scalp hair samples of children (n=30) with autistic spectrum disorder (ASD) and from control group of healthy children (n=30) with matched sex and age. Micro-elemental status was detected in the hair, with roentgen-fluorescence spectrometer method (Method MBИ 081/12-4502-000, Apparatus ALVAX- CIP, USA - UKRAIN) .To achieve the similarity of study and control groups, pre and postnatal as well as family and social history were assessed and similar groups were selected. Children with genetic problems, malnourished children, children from families with social problems were excluded from the study. The diagnosis of ASD were performed by pediatrician and psychologist (using M-CHAT and ADOS) according to DSM IV (Diagnostic and Statistical Manual of Mental Disorders from the American Psychiatric association) criteria. The study was statistically analyzed using computer program SPSS 19. Deficiencies of essential trace microelements revealed in both group, but there was significant difference between control and studied groups. The most deficient element was zinc (92% in target and 20% in control), then - manganese (55% and 8%) and selenium (38% and 4%). In case of cooper study revealed excess concentration of this element only in target group in 50% of cases. The contaminations to heavy metals were detected in case of lead (78% and 16), mercury (43% and 10%) and cadmium (38% and 8%). The

  18. Objective and Essential Elements of a State's Nuclear Security Regime. Nuclear Security Fundamentals (Chinese Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    The possibility that nuclear material or other radioactive material could be used for criminal purposes or intentionally used in an unauthorized manner cannot be ruled out in the current global situation. States have responded to this risk by engaging in a collective commitment to strengthen the protection and control of such material and to respond effectively to nuclear security events. States have agreed to strengthen existing instruments and have established new international legal instruments to enhance nuclear security worldwide. Nuclear security is fundamental in the management of nuclear technologies and in applications where nuclear material or other radioactive material is used or transported. Through its nuclear security programme, the IAEA supports States to establish, maintain and sustain an effective nuclear security regime. The IAEA has adopted a comprehensive approach to nuclear security. This recognizes that an effective national nuclear security regime builds on: the implementation of relevant international legal instruments; information protection; physical protection; material accounting and control; detection of and response to trafficking in such material; national response plans; and contingency measures. With its Nuclear Security Series, the IAEA aims to assist States in implementing and sustaining such a regime in a coherent and integrated manner. The IAEA Nuclear Security Series comprises: Nuclear Security Fundamentals, which include the objective and essential elements of a State's nuclear security regime; Recommendations; Implementing Guides; and Technical Guidance. Each State carries the full responsibility for nuclear security. Specifically, each State has the responsibility to provide for the security of nuclear material and other radioactive material and their associated facilities and activities; to ensure the security of such material in use, storage, or in transport; to combat illicit trafficking and the inadvertent movement of

  19. Objective and Essential Elements of a State's Nuclear Security Regime. Nuclear Security Fundamentals (Arabic Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    The possibility that nuclear material or other radioactive material could be used for criminal purposes or intentionally used in an unauthorized manner cannot be ruled out in the current global situation. States have responded to this risk by engaging in a collective commitment to strengthen the protection and control of such material and to respond effectively to nuclear security events. States have agreed to strengthen existing instruments and have established new international legal instruments to enhance nuclear security worldwide. Nuclear security is fundamental in the management of nuclear technologies and in applications where nuclear material or other radioactive material is used or transported. Through its nuclear security programme, the IAEA supports States to establish, maintain and sustain an effective nuclear security regime. The IAEA has adopted a comprehensive approach to nuclear security. This recognizes that an effective national nuclear security regime builds on: the implementation of relevant international legal instruments; information protection; physical protection; material accounting and control; detection of and response to trafficking in such material; national response plans; and contingency measures. With its Nuclear Security Series, the IAEA aims to assist States in implementing and sustaining such a regime in a coherent and integrated manner. The IAEA Nuclear Security Series comprises: Nuclear Security Fundamentals, which include the objective and essential elements of a State's nuclear security regime; Recommendations; Implementing Guides; and Technical Guidance. Each State carries the full responsibility for nuclear security. Specifically, each State has the responsibility to provide for the security of nuclear material and other radioactive material and their associated facilities and activities; to ensure the security of such material in use, storage, or in transport; to combat illicit trafficking and the inadvertent movement of

  20. Objective and Essential Elements of a State's Nuclear Security Regime. Nuclear Security Fundamentals

    International Nuclear Information System (INIS)

    2013-01-01

    The possibility that nuclear material or other radioactive material could be used for criminal purposes or intentionally used in an unauthorized manner cannot be ruled out in the current global situation. States have responded to this risk by engaging in a collective commitment to strengthen the protection and control of such material and to respond effectively to nuclear security events. States have agreed to strengthen existing instruments and have established new international legal instruments to enhance nuclear security worldwide. Nuclear security is fundamental in the management of nuclear technologies and in applications where nuclear material or other radioactive material is used or transported. Through its nuclear security programme, the IAEA supports States to establish, maintain and sustain an effective nuclear security regime. The IAEA has adopted a comprehensive approach to nuclear security. This recognizes that an effective national nuclear security regime builds on: the implementation of relevant international legal instruments; information protection; physical protection; material accounting and control; detection of and response to trafficking in such material; national response plans; and contingency measures. With its Nuclear Security Series, the IAEA aims to assist States in implementing and sustaining such a regime in a coherent and integrated manner. The IAEA Nuclear Security Series comprises: Nuclear Security Fundamentals, which include the objective and essential elements of a State's nuclear security regime; Recommendations; Implementing Guides; and Technical Guidance. Each State carries the full responsibility for nuclear security. Specifically, each State has the responsibility to provide for the security of nuclear material and other radioactive material and their associated facilities and activities; to ensure the security of such material in use, storage, or in transport; to combat illicit trafficking and the inadvertent movement of

  1. Objective and Essential Elements of a State's Nuclear Security Regime. Nuclear Security Fundamentals (Spanish Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    The possibility that nuclear material or other radioactive material could be used for criminal purposes or intentionally used in an unauthorized manner cannot be ruled out in the current global situation. States have responded to this risk by engaging in a collective commitment to strengthen the protection and control of such material and to respond effectively to nuclear security events. States have agreed to strengthen existing instruments and have established new international legal instruments to enhance nuclear security worldwide. Nuclear security is fundamental in the management of nuclear technologies and in applications where nuclear material or other radioactive material is used or transported. Through its nuclear security programme, the IAEA supports States to establish, maintain and sustain an effective nuclear security regime. The IAEA has adopted a comprehensive approach to nuclear security. This recognizes that an effective national nuclear security regime builds on: the implementation of relevant international legal instruments; information protection; physical protection; material accounting and control; detection of and response to trafficking in such material; national response plans; and contingency measures. With its Nuclear Security Series, the IAEA aims to assist States in implementing and sustaining such a regime in a coherent and integrated manner. The IAEA Nuclear Security Series comprises: Nuclear Security Fundamentals, which include the objeurity Fundamentals, which include the objective and essential elements of a State's nuclear security regime; Recommendations; Implementing Guides; and Technical Guidance. Each State carries the full responsibility for nuclear security. Specifically, each State has the responsibility to provide for the security of nuclear material and other radioactive material and their associated facilities and activities; to ensure the security of such material in use, storage, or in transport; to combat illicit

  2. Objective and Essential Elements of a State's Nuclear Security Regime. Nuclear Security Fundamentals (French Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    The possibility that nuclear material or other radioactive material could be used for criminal purposes or intentionally used in an unauthorized manner cannot be ruled out in the current global situation. States have responded to this risk by engaging in a collective commitment to strengthen the protection and control of such material and to respond effectively to nuclear security events. States have agreed to strengthen existing instruments and have established new international legal instruments to enhance nuclear security worldwide. Nuclear security is fundamental in the management of nuclear technologies and in applications where nuclear material or other radioactive material is used or transported. Through its nuclear security programme, the IAEA supports States to establish, maintain and sustain an effective nuclear security regime. The IAEA has adopted a comprehensive approach to nuclear security. This recognizes that an effective national nuclear security regime builds on: the implementation of relevant international legal instruments; information protection; physical protection; material accounting and control; detection of and response to trafficking in such material; national response plans; and contingency measures. With its Nuclear Security Series, the IAEA aims to assist States in implementing and sustaining such a regime in a coherent and integrated manner. The IAEA Nuclear Security Series comprises: Nuclear Security Fundamentals, which include the objective and essential elements of a State's nuclear security regime; Recommendations; Implementing Guides; and Technical Guidance. Each State carries the full responsibility for nuclear security. Specifically, each State has the responsibility to provide for the security of nuclear material and other radioactive material and their associated facilities and activities; to ensure the security of such material in use, storage, or in transport; to combat illicit trafficking and the inadvertent movement of

  3. Empirical description of the element production cross sections in dissipative heavy-ion collisions

    International Nuclear Information System (INIS)

    Wollersheim, H.J.

    1984-06-01

    Correlations between experimental observables yield analytical expressions for the energy dsigma/dE and element distributions dsigma/dZ, d 2 sigma/dZdE in dissipative collisions. These empirical formulas are applied to twelve heavy ion systems at bombarding energies well above the Coulomb barrier. The element production can be calculated for all kinetic energies of the reaction fragments from the quasi-elastic region down to a minimum total kinetic energy Vsub(c)sup(def) which is the result of the Coulomb repulsion of two deformed nuclei prior to scission. In cases where the dissipative collisions are the dominant part of the reaction process, the deformed Coulomb energy can also be deduced from the total reaction cross section. For these heavy ion systems the empirical formulas depend only on quantities of the ingoing channels. Especially, the normalization of the Gaussian shaped element distributions indicates that the reminiscence on the entrance channel is not completely lost in dissipative collisions. For the 209 Bi + 136 Xe reaction at a laboratory bombarding energy of 1130 MeV the energy and element distributions are calculated which show an excellent agreement with the experimental data. (orig.)

  4. Trace elements and heavy metals in hair of stage III breast cancer patients.

    Science.gov (United States)

    Benderli Cihan, Yasemin; Sözen, Selim; Oztürk Yıldırım, Sema

    2011-12-01

    This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p heavy metals and trace elements in the hair of breast cancer patients in comparison to healthy controls. These results could be of significance in the diagnosis of breast cancer.

  5. Nuclear analytical methods for trace element studies in calcified tissues

    International Nuclear Information System (INIS)

    Chaudhry, M.A.; Chaudhry, M.N.

    2001-01-01

    Full text: Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19 F(p,ag) 16 O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues, enamel, dentine, cement, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction

  6. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  7. Public information - the crucial element in nuclear power acceptance

    International Nuclear Information System (INIS)

    Hayes, R.; Middlemiss, N.

    1996-01-01

    The British nuclear industry approach to the public information is described as the crucial element in nuclear power acceptance. The industry need to be a reliable, trustworthy source of information. There is evidence that when issues are examined in court or in quasi-judicial contexts, the public gains a better appreciation of the issues. The media report both sides of debate more evenly. Therefore the best way to deal with the most hostile opposition may be to take into a legal framework, rather than engage in hand-to-hand battle

  8. Public information - the crucial element in nuclear power acceptance

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, R; Middlemiss, N [British Nuclear Industry Forum, London (United Kingdom)

    1996-07-01

    The British nuclear industry approach to the public information is described as the crucial element in nuclear power acceptance. The industry need to be a reliable, trustworthy source of information. There is evidence that when issues are examined in court or in quasi-judicial contexts, the public gains a better appreciation of the issues. The media report both sides of debate more evenly. Therefore the best way to deal with the most hostile opposition may be to take into a legal framework, rather than engage in hand-to-hand battle.

  9. Exploring Ultra-Heavy Cosmic Rays with the Trans-Iron Galactic Element Recorder (TIGER)

    Science.gov (United States)

    Link, Jason; Supertiger Collaboration

    2017-01-01

    Elements heavier than iron are primarily synthesized by neutron capture. These elements can be accelerated as cosmic-rays and measuring their abundances at Earth can yield information about galactic cosmic-rays' sources, the acceleration processes and the composition of the universe beyond the boundaries of our solar system. The Trans-Iron Galactic Element Recorder (TIGER) and its larger successor SuperTIGER was designed to measure the abundance of these ultra-heavy cosmic rays between Z=10 and Z=60. These detectors utilize scintillators with a wavelength shifter bar and PMT readout system as well as aerogel and acrylic Cherenkov detectors to identify the charge and energy of a particle and utilize a scintillating fiber hodoscope to provide trajectory information. In this talk I will review the results from this highly successful program, give the status for the next SuperTIGER flight planned for a December 2017 launch from Antarctica, and discuss the future direction of the program.

  10. Estimation of Heavy Elements Pollution in Sea Plants (Algae) by Using Neutron Activation Analysis

    International Nuclear Information System (INIS)

    El-Ghondi, A. A.; El-Mismary, Y. A.; Etwir, R. H.; Machiouf, M. A.; Ben Shaban, Y.; Abia, R.

    2007-01-01

    The total content of trace elements were determined in 50 samples of sea plants (macro algae) collected from Tripoli coast area (Tajura, El schab, Dat Elemad ) in Libya. The samples were investigated as an indication of heavy elements pollution. In this paper, the total amounts of Zn, Sc, Fe, Co, Cr, Ba, Cs, Sb, Rb, and Hf concentration were determined by using Neutron Activation Analysis in Tajura research center. High levels of Zn and Cr and slightly increasing in amount of Co and Fe are considered as normal values comparing with polluted area particularly with Fe and Co in investigated samples. Statistical calculation of the results have shown a positive relationship between the contents of Ba, Sc, Hf, Cr and Fe-Sb but no relation with Zn and other investigated trace elements contents. Further investigation should be carried out to confirm these findings and correlate them to source attribution.

  11. In vivo detection of the toxic heavy elements, lead and cadmium

    International Nuclear Information System (INIS)

    Thomas, B.J.; Thomas, B.W.; Davey, J.F.; Baddeley, H.; Summers, V.; Craswell, P.

    1986-01-01

    Portable systems for the in vivo measurement of the toxic heavy elements, cadmium and lead are described. The cadmium concentration in either the liver or left kidney is determined using a technique of thermal neutron capture gamma-ray analysis. X-ray fluorescence analysis is used to measure lead within the bone of the second phalanx of the index finger. Each of the measurements is used as an index of long term exposure to the element and applied to screening of exposed industrial workers. The results of these industrial health applications are presented. Clinical application of the measurements to the study of the involvement of these elements in renal disease is described in brief. (author)

  12. Accelerator mass spectrometry of heavy elements: /sup 36/Cl to /sup 205/Pb

    Energy Technology Data Exchange (ETDEWEB)

    Henning, W

    1987-08-25

    Measurements are discussed in which the technique of accelerator mass spectrometry was applied to problems involving heavy radioisotopes. These measurements, which depend on the ion energies that can be reached with the new heavy-ion accelerator facilities, were performed at the Argonne tandem linac accelerator system (ATLAS) and at the UNILAC accelerator at GSI. The topics include a discussion of measurements of long nuclear lifetimes, of radioisotope detection of interest to solar neutrino experiments, and of a determination of the /sup 41/Ca concentration in natural samples of terrestrial origin by making use of isotopic pre-enrichment in an isotope separator. A long-known method of isobar separation, employing a gas-filled magnetic field region, has been revived for some of these measurements and its characteristics and advantages are briefly reviewed.

  13. End plug welding of nuclear fuel elements-AFFF experience

    International Nuclear Information System (INIS)

    Bhatt, R.B.; Singh, S.; Aniruddha Kumar; Amit; Arun Kumar; Panakkal, J.P.; Kamath, H.S.

    2004-01-01

    Advanced Fuel Fabrication Facility is engaged in the fabrication of mixed oxide (U,Pu)O 2 fuel elements of various types of nuclear reactors. Fabrication of fuel elements involves pellet fabrication, stack making, stack loading and end plug welding. The requirement of helium bonding gas inside the fuel elements necessitates the top end plug welding to be carried out with helium as the shielding gas. The severity of the service conditions inside a nuclear reactor imposes strict quality control criteria, which demands for almost defect free welds. The top end plug welding being the last process step in fuel element fabrication, any rejection at this stage would lead to loss of effort prior to this step. Moreover, the job becomes all the more difficult with mixed oxide (MOX) as the entire fabrication work has to be carried out in glove box trains. In the case of weld rejection, accepted pellets are salvaged by cutting the clad tube. This is a difficult task and recovery of pellets is low (requiring scrap recovery operation) and also leads to active metallic waste generation. This paper discusses the experience gained at AFFF, in the past 12 years in the area of end plug welding for different types of MOX fuel elements

  14. Contamination and Health Risks from Heavy Metals (Cd and Pb and Trace Elements (Cu and Zn in Dairy Products

    Directory of Open Access Journals (Sweden)

    Hamid Reza Ghafari

    2017-08-01

    Conclusion: Considering the serious contamination of some brands of butter and cheese by Cu and Pb, a control of heavy metals and trace elements levels during the whole production processing of dairy products must be applied.

  15. Nuclear fuel element, and method of producing same

    International Nuclear Information System (INIS)

    Armijo, J.S.; Esch, E.L.

    1986-01-01

    This invention relates to an improvement in nuclear fuel elements having a composite container comprising a cladding sheath provided with a protective barrier of zirconium metal covering the inner surface of the sheath, rendering such fuel elements more resistant to hydrogen accumulation in service. The invention specifically comprises removing substantially all zirconium metal of the barrier layer from the part of the sheath surrounding and defining the plenum region. Thus the protective barrier of zirconium metal covers only the inner surface of the fuel container in the area immediately embracing the fissionable fuel material

  16. Store for burnt-up fuel elements of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1981-01-01

    Burnt-up fuel elements of nuclear reactors have to be cooled during storage. For this reason the boxes which surround the fuel elements can have cooling air flowing round them in natural flow. This air is taken through the walls of a storage building through zones of parallel pipes, whose diameter and spacing are in the ratio of 1 : 0.5 to 1 : 2. The pipes have dust filters. Prefilters with fan drive are situated in parallel with the inlet pipe zones. (orig.) [de

  17. FABRICATION OF TUBE TYPE FUEL ELEMENT FOR NUCLEAR REACTORS

    Science.gov (United States)

    Loeb, E.; Nicklas, J.H.

    1959-02-01

    A method of fabricating a nuclear reactor fuel element is given. It consists essentially of fixing two tubes in concentric relationship with respect to one another to provide an annulus therebetween, filling the annulus with a fissionablematerial-containing powder, compacting the powder material within the annulus and closing the ends thereof. The powder material is further compacted by swaging the inner surface of the inner tube to increase its diameter while maintaining the original size of the outer tube. This process results in reduced fabrication costs of powdered fissionable material type fuel elements and a substantial reduction in the peak core temperatures while materially enhancing the heat removal characteristics.

  18. The heavy-ion total reaction cross-section and nuclear transparancy

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-10-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparancy is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determing σ sub(R) at lower energies. (Author) [pt

  19. The heavy-ion total reaction cross-section and nuclear transparency

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-01-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparency is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determining σ(sub R) at lower energies. (Author) [pt

  20. Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions

    OpenAIRE

    Nefiodov, A. V.; Plunien, G.; Soff, G.

    2002-01-01

    The influence of nuclear polarization on the bound-electron $g$ factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron $g$ factor in highly charged ions.

  1. Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions.

    Science.gov (United States)

    Nefiodov, A V; Plunien, G; Soff, G

    2002-08-19

    The influence of nuclear polarization on the bound-electron g factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron g factor in highly charged ions.

  2. Study of Particle Production and Nuclear Fragmentation in Relativistic Heavy-Ion Collisions in Nuclear Emulsions

    CERN Multimedia

    2002-01-01

    % EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...

  3. Two-loop massive operator matrix elements for unpolarized heavy flavor production to O({epsilon})

    Energy Technology Data Exchange (ETDEWEB)

    Bierenbaum, I.; Bluemlein, J.; Klein, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

    2008-02-15

    We calculate the O({alpha}{sup 2}{sub s}) massive operator matrix elements for the twist-2 operators, which contribute to the heavy flavor Wilson coefficients in unpolarized deeply inelastic scattering in the region Q{sup 2}>>m{sup 2}, up to the O({epsilon}) contributions. These terms contribute through the renormalization of the O({alpha}{sup 3}{sub s}) heavy flavor Wilson coefficients of the structure function F{sub 2}(x,Q{sup 2}). The calculation has been performed using light-cone expansion techniques without using the integration-by-parts method. We represent the individual Feynman diagrams by generalized hypergeometric structures, the {epsilon}-expansion of which leads to infinite sums depending on the Mellin variable N. These sums are finally expressed in terms of nested harmonic sums using the general summation techniques implemented in the Sigma package. (orig.)

  4. The influence of nuclear structure on the Lamb shift in hydrogenlike heavy atoms

    International Nuclear Information System (INIS)

    Beier, T.; Plunien, G.; Soff, G.

    1997-01-01

    We evaluate and list the various contributions to the Lamb shift in hydrogenlike heavy atoms which arise from parameters describing shape, size and structure of the nucleus. We compare these contributions with those obtained from quantum electrodynamics. It is found that in heavy nuclei, nuclear contributions depending on experimental parameters and nuclear models are of the same size as QED contributions of order a 2 . Therefore, in these systems the theoretical predictions for binding energies are limited by the exact knowledge of the nuclear parameters. In addition, we tabulate all corrections contributing to the 1s 1/2 Lamb shift in hydrogenlike Pb and U. (orig.)

  5. Modeling and Simulation of a Nuclear Fuel Element Test Section

    Science.gov (United States)

    Moran, Robert P.; Emrich, William

    2011-01-01

    "The Nuclear Thermal Rocket Element Environmental Simulator" test section closely simulates the internal operating conditions of a thermal nuclear rocket. The purpose of testing is to determine the ideal fuel rod characteristics for optimum thermal heat transfer to their hydrogen cooling/working fluid while still maintaining fuel rod structural integrity. Working fluid exhaust temperatures of up to 5,000 degrees Fahrenheit can be encountered. The exhaust gas is rendered inert and massively reduced in temperature for analysis using a combination of water cooling channels and cool N2 gas injectors in the H2-N2 mixer portion of the test section. An extensive thermal fluid analysis was performed in support of the engineering design of the H2-N2 mixer in order to determine the maximum "mass flow rate"-"operating temperature" curve of the fuel elements hydrogen exhaust gas based on the test facilities available cooling N2 mass flow rate as the limiting factor.

  6. Fluorine: A key enabling element in the nuclear fuel cycle

    OpenAIRE

    Crouse, P.L.

    2015-01-01

    Fluorine - in the form of hydrofluoric acid, anhydrous hydrogen fluoride, elemental gaseous fluorine, fluoropolymers, volatile inorganic fluorides, and more - has played, and still plays, a major role in the nuclear industry. In order to enrich uranium, the metal has to be in the gaseous state. While more exotic methods are known, the standard and most cost-competitive way of achieving this is by means of uranium hexafluoride (UF6). This compound sublimates at low temperatures, and the vapour...

  7. Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy)

    International Nuclear Information System (INIS)

    Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

    2014-01-01

    Highlights: • Heavy element concentrations in sediments of a transitional system were studied. • Element contamination in the recent years has generally declined. • Mercury and cadmium contamination still remain above the limits in hot spots. • The role of sediment resuspension due to anthropogenic activity is discussed. • A basic knowledge to assess the impact of the MOSE construction is provided. - Abstract: The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered

  8. Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

    Science.gov (United States)

    Bradley, David E.; Mireles, Omar R.; Hickman, Robert R.

    2011-01-01

    Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

  9. Incorporation of transuranic elements in titanate nuclear waste ceramics

    International Nuclear Information System (INIS)

    Matzke, H.J.; Ray, I.L.F.; Theile, H.; Trisoglio, C.; Walker, C.T.; White, T.J.

    1990-01-01

    The incorporation of actinide elements and their rare-earth element analogues in titanate nuclear waste forms in reviewed. New partitioning data are presented for three waste forms containing Purex waste simulant in combination with either NpO 2 , PuO 2 , or Am 2 O 3 . The greater proportion of transuranics partition between perovskite and zirconolite, while some americium may enter loveringite. Autoradiography revealed clusters of plutonium atoms which have been interpreted as unreacted dioxide or sesquioxide. It is concluded that the solid-state behavior of transuranic elements in titanate waste forms is poorly understood, certainly not well enough to tailor a ceramic for the incorporation of waste from reprocessing of fast breeder reactor fuel in which transuranic species are more abundant than in Purex waste

  10. Status of the low-energy super-heavy element facility at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Schury, P., E-mail: schury@riken.jp [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Wada, M.; Ito, Y. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Arai, F. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Institute of Physics, University of Tsukuba, Tsukuba City, Ibaraki (Japan); Kaji, D. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Kimura, S. [Institute of Physics, University of Tsukuba, Tsukuba City, Ibaraki (Japan); Morimoto, K.; Haba, H. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Jeong, S. [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Koura, H. [Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Miyatake, H. [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Morita, K.; Reponen, M. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Ozawa, A. [Institute of Physics, University of Tsukuba, Tsukuba City, Ibaraki (Japan); Sonoda, T.; Takamine, A. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Wollnik, H. [Dept. Chemistry and BioChemistry, New Mexico State University, Las Cruces, NM (United States)

    2016-06-01

    In order to investigate nuclei produced via fusion–evaporation reactions, especially super-heavy elements (SHE), we have begun construction of a facility for conversion of fusion–evaporation residues (EVR) to low-energy beams. At the base of this facility is a small cryogenic gas cell utilizing a traveling wave RF-carpet, located directly following the gas-filled recoil ion separator GARIS-II, which will thermalize EVRs to convert them into ion beams amenable to ion trapping. We present here the results of initial studies of this small gas cell.

  11. Evolution of heavy-element abundances in the galactic halo and disk

    International Nuclear Information System (INIS)

    Mathews, G.J.; Cowan, J.J.; Schramm, D.N.

    1988-05-01

    The constraints on the universal energy density and cosmological constant from cosmochronological ages and the Hubble age are reviewed. Observational evidence for the galactic chemical evolution of the heavy-element chronometers is described in the context of numerical models. The viability of the recently discovered Th/Nd stellar chronometer is discussed, along with the suggestion that high r-process abundances in metal-poor stars may have resulted from a primordial r-process, as may be required by some inhomogeneous cosmologies

  12. FONLL calculations for heavy quark production in nuclear collisions

    CERN Document Server

    Niel, Elisabeth Maria

    2017-01-01

    The ALICE detector at the LHC has been designed to study the collisions of heavy nuclei at energies much higher then the previous dedicated experiments at the Relativistic Heavy-Ion Collider (RHIC) of the Brookhaven National Laboratory. Colliding heavy nuclei allows to reproduce the hot and dense plasma of quarks and gluons (QGP) existing right after the Big Bang and hence study the very first instants of universe’s existence. In heavy ions collisions, heavy flavours, such as beauty and charm quark, are fundamental probes for the quark gluon plasma properties. That is because they experience the entire evolution of the system since they are produced at the very beginning. They are indeed a very powerful tool to test field theories such as Quantum Chromodynamics (QCD). Theoretical models predict that a fast parton(quark or gluon) looses energy while traversing a medium composed of colour charges. This phenomenon is called "jet quenching", it can be used to describe the QGP. It was first observed at RHIC by m...

  13. Nuclear-physical methods of investigation of an element composition in samples of soils and plants

    International Nuclear Information System (INIS)

    Hushmurodov, Sh.; Botaev, N.

    2002-01-01

    Soil (ground) and vegetative covers of the Earth are one of the most responsive and specific parts of the biosphere with respect to pollution. A proper control after them is of fundamental importance in creating and protecting optical surrounding. Analysis of soils and plants is a necessary and important stage in the process of investigation of microelements' migration in biogeochemical cycles. For this purpose we studied some reserved terrains of Uzbekistan to reveal a level of their contamination by heavy metals, as well as to find out typical and territorial singularities in accumulation of a number of elements by soils and plants. In order to decrease an influence of systematic errors, and to obtain more precise and reliable data, we carried out the element analysis of the samples by different methods, such as gamma-activation analysis, neutron-activation analysis, X-ray spectral analysis, and X-ray fluorescent analysis. As a result of our investigations we have obtained rather great information, which can be used in future to estimate the conditions of the surrounding nature. The investigations allowed us to determine the content of about 40 elements, as well as to show that the data, obtained by different nuclear-physical methods, are in rather good agreement. A reproducibility of the results of the methods, determined in control measurements, depends on the concentration of the analyzed elements, and is equal to 10-35 %. A comparison of the obtained data allowed us to reveal some singularities in element composition of the investigated samples depending on their type and territorial factor. It has been revealed that the data, obtained by different methods, are in rather good agreement. Our investigations allowed us to find out a series of regularities and singularities in accumulation of elements in plants, as well as to show the possibility of using nuclear-physical methods in such investigations

  14. Finite element modeling of AP1000 nuclear island

    International Nuclear Information System (INIS)

    Tinic, S.; Orr, R.

    2003-01-01

    The AP1000 is a standard design developed by Westinghouse and its partners for an advanced nuclear power plant utilizing passive safety features. It is based on the certified design of the AP600 and has been uprated to 1000 MWe. The plant has five principal building structures; the nuclear island, the turbine building; the annex building; the diesel generator building and the radwaste building. The nuclear island consists of the containment building (the steel containment vessel and the containment internal structures), the shield building, and the auxiliary building. These structures are founded on a common basemat and are collectively known as the nuclear island. This paper describes use of the general purpose finite element program ANSYS [2] in structural analyses and qualification of the AP1000 nuclear island buildings. It describes the modeling of the shield building and the auxiliary building and the series of analyses and the flow of information from the global analyses to the detailed analyses and building qualification. (author)

  15. The human elements in phenomena giving rise to nuclear accidents

    International Nuclear Information System (INIS)

    Carnino, A.; Raggenbass, A.

    1977-01-01

    In its search for a high degree of safety, the nuclear industry should take into account the human parameters, which play an important role. This role is reflected in the individual records kept on incidents and analysis of these records, as has been carried out in conventional industry, represents a first attempt to allow for this factor. The first inquiries covering the background of incidents led to a series of studies and action in respect of individual staff members: on the part of operators, education of personnel in relation to their duties (for example, simulation of reactor control) and attempts to find objective selection criteria for certain specific posts; on the part of those responsible for safety, ergonomic studies and studies on human reliability. For effective prevention of accidents it is necessary to move backwards along the causality chains and therefore to study a nuclear facility as a man-machine system in order to discover the greatest number of potential accident factors. The nuclear facility is introduced into an environment which imposes its rules, constraints and checks and a full study of the human element in safety implies that they should be taken into account. The programme of the Nuclear Safety Department of the Institute of Protection and Nuclear Safety includes not only systematic updating of incident records but also special ergonomic studies (maintenance in a radioactive environment), studies of human reliability and overall studies known as safety management studies. (author)

  16. Nuclear physics research requirements for electron and heavy ion machines

    International Nuclear Information System (INIS)

    Vogt, E.

    1983-03-01

    There has been a great deal of interest in a variety of new machines intended to probe atomic nuclei for hadronic and quark aspects which lie beyond the familiar shell model view of nuclei. This paper gives the physics perspective within which the proposals for such machines have arisen and discusses the two classes of tools - high energy cw electron machines and relativistic heavy ion machines - which lie at opposite ends of the arsenal being gathered for the pursuit of QCD in nuclei. The electron machines present a reasoned analytic approach to the simplest systems and the heavy ion machines a major thrust for starting new physics in the quark-gluon sea

  17. A Taxonomy for Heavy-Duty Telemanipulation Tasks Using Elemental Actions

    Directory of Open Access Journals (Sweden)

    Alexander Owen-Hill

    2013-10-01

    Full Text Available In the maintenance of large scientific facilities, telemanipulation procedures can involve various subprocedures which in turn are made up of a sequence of subtasks. This work presents a taxonomy which describes a set of elemental actions for heavy-duty telemanipulation, along with an example of these actions in a standard maintenance subprocedure. As maintenance tasks are often very different at high-level, this generalized way of deconstructing tasks allows a highly adaptable approach to describe the sequence of any procedure, which can then be used for such applications as task monitoring, automation or detection of incomplete tasks. We describe in detail the properties of each elemental action and apply the taxonomy to an example subprocedure to show how the process can be generalizable. An automatic state-machine creation stage is shown, which would be used at the task scheduling stage to simplify calculations carried out during the moment-by-moment execution of the task.

  18. The determination of sulfur and some heavy elements in the coke

    International Nuclear Information System (INIS)

    Ma'rouf, M.

    2003-01-01

    The content of free sulfur and some heavy elements in the coke resulting from the residua of oil industry was determined bu using various technical analytical methods. The flame technique of atomic absorption FAAS was used to identify lead, copper, zinc, chromium, VGA-AAS and determine arsenic and selenium, CV-AAS to the determination of mercury. As for sulfur, it was determined by using the total oxidation method at high temperatures (1100 C 0 ). The IR indicator was used for further determination. The relative standard deviation in the determination of sulfur did not exceed the limits of 0.01 and 0.02, compared to the determination of other elements by using the atomic absorption method. (Author)

  19. Nuclear structure of light Ca and heavy Cr isotopes

    International Nuclear Information System (INIS)

    Buerger, A.

    2007-01-01

    In the present thesis, the shell structure in exotic nuclei has been investigated. The focus of the work was on finding new experimental data in neutron-rich Cr and proton-rich Ca isotopes. The investigation of light Ca isotopes concentrated on the nucleus 36 Ca which was produced in a knockout reaction from a radioactive 37 Ca beam. For 36 Ca, the excitation energy of the first 2 + state has been measured for the first time. Furthermore, momentum distributions were analyzed using a Monte-Carlo simulation of the knockout reaction. This analysis yielded the contributions of neutrons from individual orbitals to the total knockout cross section. In principle, these may be used to calculate spectroscopic factors, but such a calculation is hampered by difficulties of present knockout-reaction models in predicting precise single-particle cross sections. The measured branching ratio to the ground and excited states, on the other hand, is close to the predicted value. A remaining difference might be due to emission of protons which cannot be detected with the present experimental setup. Both the branching ratio and the large excitation energy are compatible with a large N=16 gap in 36 Ca that leads to relatively pure configurations both in the ground state and the excited 2 + state. As a by-product of the experiment, two excitation energies in the T=2 nuclei 32 Ar and 28 S have been confirmed, and two γ-ray transitions have been observed for the first time in 37 Ca. While the mirror energy differences in the T=2 pairs 36 Ca- 36 S, 32 Ar- 32 Si, and 28 S- 28 Mg can be reproduced in shell model calculations using a modified USD interaction, these modifications are not sufficient to explain the mirror energy differences for the pair 37 Ca- 37 Cl. In the heavy Cr isotopes, new experimental evidence for a sub-shell closure at N=32 was found in a measurement of B(E2) values using high-energy Coulomb excitation of radioactive beams. Prior to this experiment, the assumption of a

  20. Nuclear structure of light Ca and heavy Cr isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, A.

    2007-07-01

    In the present thesis, the shell structure in exotic nuclei has been investigated. The focus of the work was on finding new experimental data in neutron-rich Cr and proton-rich Ca isotopes. The investigation of light Ca isotopes concentrated on the nucleus {sup 36}Ca which was produced in a knockout reaction from a radioactive {sup 37}Ca beam. For {sup 36}Ca, the excitation energy of the first 2{sup +} state has been measured for the first time. Furthermore, momentum distributions were analyzed using a Monte-Carlo simulation of the knockout reaction. This analysis yielded the contributions of neutrons from individual orbitals to the total knockout cross section. In principle, these may be used to calculate spectroscopic factors, but such a calculation is hampered by difficulties of present knockout-reaction models in predicting precise single-particle cross sections. The measured branching ratio to the ground and excited states, on the other hand, is close to the predicted value. A remaining difference might be due to emission of protons which cannot be detected with the present experimental setup. Both the branching ratio and the large excitation energy are compatible with a large N=16 gap in {sup 36}Ca that leads to relatively pure configurations both in the ground state and the excited 2{sup +} state. As a by-product of the experiment, two excitation energies in the T=2 nuclei {sup 32}Ar and {sup 28}S have been confirmed, and two {gamma}-ray transitions have been observed for the first time in {sup 37}Ca. While the mirror energy differences in the T=2 pairs {sup 36}Ca-{sup 36}S, {sup 32}Ar-{sup 32}Si, and {sup 28}S-{sup 28}Mg can be reproduced in shell model calculations using a modified USD interaction, these modifications are not sufficient to explain the mirror energy differences for the pair {sup 37}Ca-{sup 37}Cl. In the heavy Cr isotopes, new experimental evidence for a sub-shell closure at N=32 was found in a measurement of B(E2) values using high

  1. Heavy metals and trace elements in atmospheric fall-out: Their relationship with topsoil and wheat element composition

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, Gonzalo M.A., E-mail: gbermudez@com.uncor.edu [Instituto Multidisciplinario de Biologia Vegetal (IMBIV), CONICET (Argentina); Catedra de Quimica General, FCEFyN, Universidad Nacional de Cordoba, Avda. Velez Sarsfield 1611, Ciudad Universitaria (X5016 GCA), Cordoba (Argentina); Jasan, Raquel; Pla, Rita [Tecnicas Analiticas Nucleares, Comision Nacional de Energia Atomica (CAE), Presbitero Gonzalez y Aragon N Degree-Sign 15 (B1802AYA), Ezeiza (Argentina); Pignata, Maria L. [Instituto Multidisciplinario de Biologia Vegetal (IMBIV), CONICET (Argentina); Catedra de Quimica General, FCEFyN, Universidad Nacional de Cordoba, Avda. Velez Sarsfield 1611, Ciudad Universitaria (X5016 GCA), Cordoba (Argentina)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Metal and trace element deposition rates and concentrations in bulk samples. Black-Right-Pointing-Pointer Anthropogenic vs. natural sources were identified using enrichment factors and PCA. Black-Right-Pointing-Pointer Anthropogenic sources for Ca, Cd, Cu, Fe, Mn, Ni, Pb, Sb, U, Zn and lanthanides. Black-Right-Pointing-Pointer Main sources were a cement plant, chemical-mechanical industries, cities and mining. Black-Right-Pointing-Pointer Metals in wheat grain were predicted by soil and bulk deposition composition. - Abstract: The objectives of this study were to determine the average concentrations and deposition rates of 28 elements in atmospheric bulk deposition and to elucidate associations among topsoil, bulk deposition and wheat element composition. The fluxes of arsenic (As), copper (Cu), lead (Pb) and zinc (Zn) deposition in Cordoba were higher than in other agro-ecosystems, which reflects both natural (geochemistry and topsoil removal) and anthropogenic sources. High lanthanide, uranium (U) and thorium (Th) concentrations revealed the impact of an open cast uranium mine. The highest enrichment factors (EF) were those of Cu, Pb, Zn and nickel (Ni), with calcium (Ca) being the most prominent in the surroundings of a cement plant. Industries and the transport of airborne urban pollutants were the main anthropogenic sources for Ca, Cu, Ni, Pb, Zn, cadmium (Cd), iron (Fe), manganese (Mn) and antimony (Sb). The concentrations of metals in wheat grain were predicted using the topsoil and atmospheric fall-out composition with R{sup 2} = 0.90, with the latter being the best explanatory variable. The present study highlights the potential health hazards of wheat consumption (Environmental Protection Agency) by the assessment of heavy metals in bulk atmospheric deposition.

  2. Probing the nuclear structure with heavy-ion reactions

    International Nuclear Information System (INIS)

    Broglia, R.A.

    1982-01-01

    Nuclei display distortions in both ordinary space and in gauge space. It is suggested that it is possible to learn about the spatial distribution of the Nilsson orbitals and about the change of the pairing gap with the rotational frequency through the analysis of one- and two-nucleon transfer reactions induced in heavy-ion collisions

  3. Performance of Canadian commercial nuclear units and heavy water plants

    International Nuclear Information System (INIS)

    Woodhead, L.W.; Ingolfsrud, L.J.

    The operating history of Canadian commercial CANDU type reactors, i.e. Pickering generating station-A, is described. Capacity factors and unit energy costs are analyzed in detail. Equipment performance highlights are given. The performance of the two Canadian heavy water plants is described and five more are under construction or planned. (E.C.B.)

  4. [Determination of Heavy Metal Elements in Diatomite Filter Aid by Inductively Coupled Plasma Mass Spectrometry].

    Science.gov (United States)

    Nie, Xi-du; Fu, Liang

    2015-11-01

    This study established a method for determining Be, Cr, Ni, As, Cd, Sb, Sn, Tl, Hg and Pb, total 10 heavy metals in diatomite filter aid. The diatomite filter aid was digested by using the mixture acid of HNO₃ + HF+ H₃PO₄ in microwave system, 10 heavy metals elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The interferences of mass spectrometry caused by the high silicon substrate were optimized, first the equipment parameters and isotopes of test metals were selected to eliminate these interferences, the methane was selected as reactant gas, and the mass spectral interferences were eliminated by dynamic reaction cell (DRC). Li, Sc, Y, In and Bi were selected as the internal standard elements to correct the interferences caused by matrix and the drift of sensitivity. The results show that the detection limits for analyte is in the range of 3.29-15.68 ng · L⁻¹, relative standard deviations (RSD) is less than 4.62%, and the recovery is in the range of 90.71%-107.22%. The current method has some advantages such as, high sensitivity, accurate, and precision, which can be used in diatomite filter aid quality control and safety estimations.

  5. AMS of heavy elements with an ECR ion source and the ATLAS linear accelerator

    CERN Document Server

    Paul, M; Ahmad, I; Borasi, F; Caggiano, J; Davids, C N; Greene, J P; Harss, B; Heinz, A; Henderson, D J; Henning, W F; Jiang, C L; Pardo, R C; Rehm, K E; Rejoub, R; Seweryniak, D; Sonzogni, A; Uusitalo, J; Vondrasek, R C

    2000-01-01

    Detection of heavy elements by accelerator mass spectrometry with the electron cyclotron resonance ion source, Argonne linear accelerator and fragment mass analyzer (ECRIS-ATLAS-FMA) system has been developed. The use of the ECR-ATLAS system for AMS of heavy elements has two interesting features: (i) the efficient production of high-charge state ions in the ECR source ensures the elimination of molecular ions at the source stage, a highly attractive feature for any mass-spectrometric use not exploited so far; (ii) the linear acceleration based on velocity matching and the beam transport system act as a powerful mass filter for background suppression. We have shown that our system reaches an abundance sensitivity of 1x10 sup - sup 1 sup 4 for Pb isotopes. The sup 2 sup 3 sup 6 U detection sensitivity is sup 2 sup 3 sup 6 U/U > or approx. 1x10 sup - sup 1 sup 2 , limited mainly by the ion source output.

  6. PWR heavy equipments manufacture for nuclear power plants

    International Nuclear Information System (INIS)

    Boury, C.; Terrien, J.F.

    1983-10-01

    The manufacture of boilers has been imported by the French nuclear program to the societe FRAMATOME. FRAMATOME, because of the size of this market, has constructed two special plants for manufacturing of nuclear components (vapor generators, reactor tanks, pressurizers); these two high technical facilities are presented: production, staff training, technical overseas assistance, and technical and economical repercussions on the industrial vicinity [fr

  7. Determination of trace elements and heavy metals in sediment using x-ray fluorescence

    International Nuclear Information System (INIS)

    Sidahmed, Muataz Ahmed Ibrahem

    2014-01-01

    In this study, 30 sediment samples were taken randomly from the area of Suba south of Khartoum state. Trace elements and heavy metal were determined in sediments samples using x-ray fluoresce spectroscopy (X RF). K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were determined by X RF. Standard Reference Material (SRM) from international Atomic Energy Agency (IAEA-Soil-7) has been used to achieve accuracy of X RF method. Measured values were found in agreements with certified values. The average elemental concentrations of K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were 5882.7, 20703.3, 6264.3, 460.97, 26713.3, 7.7, 43.4, 18.6, 28.6, 144.8, and 173.06, respectively. Correlation between elements was performed also cluster analysis was used to check the similarly between the samples result. The result of study were compared with previous studies and the concentrations of some elements found to be similar.(Author)

  8. Experimental investigation in separating the heavy metal elements of refuse incineration fly ashes by using molten iron

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J. [Chongqing Univ., Chongqing (China)]|[CPI-Yuanda Environmental-protection Engineering Co. Ltd., Chongqing (China); Liu, Q.; Dong, L. [Chongqing Univ., Chongqing (China); Du, Y. [CPI-Yuanda Environmental-protection Engineering Co. Ltd., Chongqing (China)

    2008-07-01

    One of the main waste treatment methods in the world for municipal solid waste (MSW) is incineration. It is effective in toxic substance destruction, waste volume reduction, and energy recovery. Some chemical substances are accumulated during incineration, most notably lead, zinc, chromium and cadmium, as well as other heavy metals. Untreated fly ash disposed in landfills can pollute the soil, surface water and groundwater because of the high levels of hazardous heavy metals and high salt concentration that can be leached out. This paper presented an experiment that melt-separated the heavy metal elements from fly ash generated during refuse incineration. Molted iron, was used as resolvent to dissolve the heavy metal elements in it. The paper described the materials and methods as well as the results of the study. It was concluded that using molted iron to separate the heavy metal elements from MSW incineration fly ash was feasible. The removal ratio of the main heavy metal elements was above 80 per cent, and some of it was above 99 per cent. 5 refs., 7 tabs., 1 fig.

  9. Nuclear fuel element and a method of manufacture thereof

    International Nuclear Information System (INIS)

    Wood, J.C.

    1975-01-01

    A nuclear fuel element having a sheath of zirconium or a zirconium alloy and a cross-linked siloxane lacquer coating on the inner surface of the sheath and separating the nuclear fuel material from the sheath is described. The siloxane lacquer coating retards cracking of the sheath by iodine vapor emitted by the fuel during burn-up, and acts as a lubricant for the fuel to prevent rupture of the sheath by thermal ratchetting of the fuel against the sheath and caused by differential thermal expansion between the fuel and the sheath. A silicone grease is applied as a thin layer in the sheath and then baked so that oxidative cleavage of the side chains of the grease occurs to form a cross-linked siloxane lacquer coating bonded to the sheath

  10. Surface coating Zr or Zr alloy nuclear fuel elements

    International Nuclear Information System (INIS)

    Donaghy, R.E.; Sherman, A.H.

    1980-01-01

    A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer. (author)

  11. Relative measurement of heavy elements in the bile gallbladder and gallstone

    International Nuclear Information System (INIS)

    Moosavi, K.; Vatankhah, S.; Salimi, J.

    2006-01-01

    Particle Induced X-Ray Emission is a suitable method for the analysis of biological samples in which heavy trace elements are contained in light matrix elements. It is very important to know which factors or probably elements act as initial seed and lead to growing the sands. The goal of this study was to compare the relative values of Fe/K, Cu/K and Zn/K for gallstones, gallbladder, and bile of a specific patient for studying the origination of forming the gallstones. Materials and Methods Human gallbladder, bile, and gallstone samples were obtained by surgical operation from 15 patients and are bombarded by 2.0 MeV energy proton beams produced by van de Graaff accelerator in vacuum. All .. the gallstones were chosen of pigment type of stones and, all the patients were adults. In contrast with conventional methods, the shell and center of the sands has been analyzed separately. The PIXE spectrum analysis was performed using the nonlinear least square fitting code AXIL and GUPIX. Results: The results of detected minor and trace elements shows that the precipitation of calcium salt in the bile lead to reduction of crystals' formation. Elemental comparison of pigment type of gallstone and bile shows that the concentration of calcium in the shell of the stones is four times more than that in the bile. Conclusion: Precipitation of the calcium from the saturated bile on the cholesterols as a seed of gallstones led to reduced sands formation. Analysis of the gallbladder of the same patients revealed no relation between elemental concentrations of bile and gallstones

  12. Nuclear-bound quarkonia and heavy-flavor hadrons

    Science.gov (United States)

    Krein, G.; Thomas, A. W.; Tsushima, K.

    2018-05-01

    In our quest to win a deeper understanding of how QCD actually works, the study of the binding of heavy quarkonia and heavy-flavor hadrons to atomic nuclei offers enormous promise. Modern experimental facilities such as FAIR, Jefferson Lab at 12 GeV and J-PARC offer exciting new experimental opportunities to study such systems. These experimental advances are complemented by new theoretical approaches and predictions, which will both guide these experimental efforts and be informed and improved by them. This review will outline the main theoretical approaches, beginning with QCD itself, summarize recent theoretical predictions and relate them both to past experiments and those from which we may expect results in the near future.

  13. Nuclear polarization study: new frontiers for tests of QED in heavy highly charged ions.

    Science.gov (United States)

    Volotka, Andrey V; Plunien, Günter

    2014-07-11

    A systematic investigation of the nuclear polarization effects in one- and few-electron heavy ions is presented. The nuclear polarization corrections in the zeroth and first orders in 1/Z are evaluated to the binding energies, the hyperfine splitting, and the bound-electron g factor. It is shown that the nuclear polarization contributions can be substantially canceled simultaneously with the rigid nuclear corrections. This allows for new prospects for probing the QED effects in a strong electromagnetic field and the determination of fundamental constants.

  14. Compactable control element assembly for a nuclear reactor

    International Nuclear Information System (INIS)

    Dupen, C.F.G.

    1976-01-01

    A description is given of a compactable control element assembly for a nuclear reactor in which the absorber pins of the assembly are compacted during downward movement of the pin and are returned to their uncompacted state when downward movement is stopped. The control element assembly comprises a support member longitudinally movable within a control assembly duct and a plurality of absorber pins supported laterally outward of the support member and within the duct by pairs of support arms. The absorber pins are pivotably mounted to the support arms and the support arms in turn are supported from the support member for upward pivotable movement in a longitudinal plane. As the support member is moved downward, the support arms pivot upwardly and the absorber pins move upwardly and inwardly towards the support member. When the support member is stopped the absorber pins return to their uncompacted position

  15. Storage ponds for fuel elements of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1981-01-01

    Heat exchangers are inserted in storage ponds for fuel elements of nuclear reactors, so that the heat to be removed is given up to an external coolant, without any radio-activity being emitted. The heat exchanger is a hollow body, which is connected to an air cooler, which works with a cooling circuit with natural circulation. A cooling pipe is enclosed in the hollow body, which forms a cooling circuit with forced flow with an open pond. One therefore obtains two successive separating walls for the external coolant. (orig.) [de

  16. Nuclear Effects on Heavy Boson Production at RHIC and LHC

    CERN Document Server

    Zhang, X; Zhang, Xiaofei; Fai, George

    2002-01-01

    We predict W and Z transverse momentum distributions from proton-proton and nuclear collisions at RHIC and LHC. A resummation formalism with power corrections to the renormalization group equations is used. The dependence of the resummed QCD results on the non-perturbative input is very weak for the systems considered. Shadowing effects are discussed and found to be unimportant at RHIC, but important for LHC. We study the enhancement of power corrections due to multiple scattering in nuclear collisions and numerically illustrate the weak effects of the dependence on the nuclear mass.

  17. The development of reactor vessel internal heavy forging for 1000 MW pressurized-water reactor nuclear power plant

    International Nuclear Information System (INIS)

    Zhang Zhifeng; Chen Yongbo; Ding Xiuping; Zhang Lingfang

    2012-01-01

    This Paper introduced the development of Reactor Vessel Internal (RVI) heavy forgings for 1000 MW Pressurized Water Reactor (PWR) nuclear power plant, analyzed the manufacture difficulties and technical countermeasures. The testing result of the product indicated that the performance of RVI heavy forgings manufactured by Shanghai Heavy Machinery Plant Ld. (SHMP) is outstanding and entirely satisfy the technical requirements for RVI product. (authors)

  18. Heavy element accumulation in Evernia prunastri lichen transplants around a municipal solid waste landfill in central Italy.

    Science.gov (United States)

    Nannoni, Francesco; Santolini, Riccardo; Protano, Giuseppe

    2015-09-01

    This paper presents the results of a biomonitoring study to evaluate the environmental impact of airborne emissions from a municipal solid waste landfill in central Italy. Concentrations of 11 heavy elements, as well as photosynthetic efficiency and cell membrane integrity were measured in Evernia prunastri lichens transplanted for 4months in 17 monitoring sites around the waste landfill. Heavy element contents were also determined in surface soils. Analytical data indicated that emissions from the landfill affected Cd, Co, Cr, Cu, Ni, Pb, Sb and Zn concentrations in lichens transplanted within the landfill and along the fallout direction. In these sites moderate to severe accumulation of these heavy elements in lichens was coupled with an increase in cell membrane damage and decrease in photosynthetic efficiency. Nevertheless, results indicated that landfill emissions had no relevant impact on lichens, as heavy element accumulation and weak stress symptoms were detected only in lichen transplants from sites close to solid waste. The appropriate management of this landfill poses a low risk of environmental contamination by heavy elements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Calculation of nuclear parameters for some heavy isotopes

    International Nuclear Information System (INIS)

    Corcuera, R.P.; Pinheiro, A.M.B.S.

    1981-01-01

    Some integrals are calculated using different weighting functions, the basic data come from two different nuclear data libraries, ENDF/B IV and ENDL/78. Significant discrepancies are found when are or the other lirary are used. (author) [pt

  20. Trace elements in land plants: concentration ranges and accumulators of rare earths, Ba, Ra, Mn, Fe, Co and heavy halogens

    International Nuclear Information System (INIS)

    Koyama, M.; Shirakawa, M.; Takada, J.; Katayama, Y.; Matsubara, T.

    1987-01-01

    More than 2000 samples of land plant leaves, mostly of tree, were analyzed by neutron activation analysis in order to find out macroscopic relations between distributions of chemical elements in plants and soil characteristics. The distributions of the elements in plants were also examined from the view point of botanical taxonomy or phylogeny. New species which accumulate Co, rare earths, Ba, Ra, heavy halogens and some other elements were found. Capability or potentiality for accumulating elements could be related to higher ranks of taxonomy, that is, genus or family. The nature of soil is also found to have profound effects on the extent of accumulation of elements in plants. (author)

  1. Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

    International Nuclear Information System (INIS)

    Faessler, Amand

    2005-01-01

    The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

  2. Effects of elemental sulphur on heavy metal uptake by plants growing on municipal sewage sludge.

    Science.gov (United States)

    Dede, Gulgun; Ozdemir, Saim

    2016-01-15

    In this study experiment was carried out to determine the phytoextraction potential of six plant species (Conium maculatum, Brassica oleraceae var. oleraceae, Brassica juncea, Datura stramonium, Pelargonium hortorum and Conyza canadensis) grown in a sewage sludge medium amended with metal uptake promoters. The solubility of Cu, Cd and Pb was significantly increased with the application of elemental S due to decrease of pH. Faecal coliform number was markedly decreased by addition of elemental sulphur. The extraction of Cu, Cr and Pb from sewage sludge by using B. juncea plant was observed as 65%, 65% and 54% respectively that is statistically similar to EDTA as sulphur. The bioaccumulation factors were found higher (>1) in the plants tested for Cu and Pb like B. juncea. Translocation index (TI) calculated values for Cd and Pb were greater than one (>1) in both C. maculatum and B. oleraceae var. oleraceae. The results cleared that the amendment of sludge with elemental sulphur showed potential to solubilize heavy metals in phytoremediation as much as EDTA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Heavy metals and other elements in serum of cattle from organic and conventional farms.

    Science.gov (United States)

    Tomza-Marciniak, Agnieszka; Pilarczyk, Bogumiła; Bąkowska, Małgorzata; Pilarczyk, Renata; Wójcik, Jerzy

    2011-11-01

    Concentrations of cadmium, lead, iron, zinc, copper, chromium, nickel, aluminium and arsenium were analysed in blood serum of cattle from organic (n=20) and conventional (n=21) farms. The elements were determined by inductively coupled plasma atomic emission spectrometry using an Optima 2000 DV instrument (Perkin Elmer Inc.). Animals from the organic farm were characterised by significantly lower (Panimals from the conventional farm. The concentration of Cd was similar in animals from both organic and conventional farms. The concentration of toxic elements in cattle from organic and conventional farms studied was very low. The trace essential elements were generally within the adequate ranges except Zn and Cu, which were deficient. In organically reared animals, also serum Fe content was below the critical level for diagnosing iron deficiency. Pb was significantly correlated with Cd, Zn, Fe, Cu and Ni. A significant positive correlation between the concentration of Cd and Zn, Cu and Ni concentrations was only observed in cows from the organic farm. The present results suggest that organically raised animals are less exposed to harmful environmental influences such as the environmental pollution with heavy metals. On the other hand, these animals are at a greater risk of mineral deficiency compared to animals kept on conventional farms.

  4. Mapping of transuranic elements in soil by nuclear track methodology

    International Nuclear Information System (INIS)

    Espinosa, G.

    2001-01-01

    An alternative method is presented to map the distribution of transuranic elements, which is characterized by its simplicity in both implementation and instrumentation. The method is based on the interaction of alpha particles in polymeric materials and the formation of tracks, which become visible after chemical etching. Nuclear track detectors are placed on the soil in order to evaluate the distribution of the radioactive material and its relative intensity for transuranic contaminants. CR-39 polycarbonate was used as a nuclear track detector in this study. Chemical etching was done with a 6.25M KOH solution in a closed system for 16 hours. The readings were performed in an automatic system using digital image analysis. The results show the distribution of the contaminants and their location, identifying the zones with large intensities. This method is attractive for use in areas contaminated with alpha particles, and specially transuranic elements, because it involves in situ measurements, generates very low amounts of radioactive waste, and the detectors are easily handled. (author)

  5. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Upgrade Activities

    Science.gov (United States)

    Emrich, William J., Jr.

    2014-01-01

    Over the past year the Nuclear Thermal Rocket Element Environmental Simulator (NTREES) has been undergoing a significant upgrade beyond its initial configuration. The NTREES facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The first phase of the upgrade activities which was completed in 2012 in part consisted of an extensive modification to the hydrogen system to permit computer controlled operations outside the building through the use of pneumatically operated variable position valves. This setup also allows the hydrogen flow rate to be increased to over 200 g/sec and reduced the operation complexity of the system. The second stage of modifications to NTREES which has just been completed expands the capabilities of the facility significantly. In particular, the previous 50 kW induction power supply has been replaced with a 1.2 MW unit which should allow more prototypical fuel element temperatures to be reached. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during. This new setup required that the NTREES vessel be raised onto a platform along with most of its associated gas and vent lines. In this arrangement, the induction heater and water systems are now located underneath the platform. In this new configuration, the 1.2 MW NTREES induction heater will be capable of testing fuel elements and fuel materials in flowing hydrogen at pressures up to 1000 psi at temperatures up to and beyond 3000 K and at near-prototypic reactor channel power densities. NTREES is also capable of testing potential fuel elements with a variety of propellants, including hydrogen with additives to inhibit

  6. Heavy residue properties in intermediate energy nuclear collisions with gold

    International Nuclear Information System (INIS)

    Aleklett, K.; Sihver, L.; Liljenzin, J.O.; Seaborg, G.T.

    1990-10-01

    We have measured the target fragment production cross sections and angular distributions for the interaction of 32, 44 and 93 MeV/nucleon argon, 35 and 43 MeV/nucleon krypton with gold. The fragment isobaric yield distributions, moving frame angular distributions and velocities have been deduced from these data. This fission cross section decreases with increasing projectile energy and the heavy residue cross section increases. The ratio v parallel /v cn increases approximately linearly with mass removed from the target. 21 refs., 8 figs

  7. Study of nuclear reactions involving heavy nuclei and intermediate- and high-energy protons and an application in nuclear reactor physics (ADS)

    International Nuclear Information System (INIS)

    Matuoka, Paula Fernanda Toledo

    2016-01-01

    In the present work, intermediate- and high-energy nuclear reactions involving heavy nuclei and protons were studied with the Monte Carlo CRISP (Rio - Ilheus - Sao Paulo Collaboration) model. The most relevant nuclear processes studied were intranuclear cascade and fission-evaporation competition. Preliminary studies showed fair agreement between CRISP model calculation and experimental data of multiplicity of evaporated neutrons (E 20 MeV) were emitted mostly in the intranuclear cascade stage, while evaporation presented larger neutron multiplicity. Fission cross section of 209 mb and spallation cross section of 1788 mb were calculated { both in agreement with experimental data. The fission process resulted in a symmetric mass distribution. Another Monte Carlo code, MCNP, was used for radiation transport in order to understand the role of a spallation neutron source in a ADS (Accelerator Driven System) nuclear reactor. Initially, a PWR reactor was simulated to study the isotopic compositions in spent nuclear fuel. As a rst attempt, a spallation neutron source was adapted to an industrial size nuclear reactor. The results showed no evidence of incineration of transuranic elements and modifications were suggested. (author)

  8. Convective parameters in fuel elements for research nuclear reactors

    International Nuclear Information System (INIS)

    Lopez Martinez, C.D.

    1992-01-01

    The study of a prototype for the simulation of fuel elements for research nuclear reactors by natural convection in water is presented in this paper. This project is carry out in the thermofluids laboratory of National Institute of Nuclear Research. The fuel prototype has already been test for natural convection in air, and the first results in water are presented in this work. In chapter I, a general description of Triga Mark III is made, paying special atention to fuel-moderator components. In chapter II and III an approach to convection subject in its global aspects is made, since the intention is to give a general idea of the events occuring around fuel elements in a nuclear reactor. In chapter II, where an emphasis on forced convection is made, some basic concepts for forced convection as well as for natural convection are included. The subject of flow through cylinders is annotated only as a comparative reference with natural convection in vertical cylinders, noting the difference between used correlations and the involved variables. In chapter III a compilation of correlation found in the bibliography about natural convection in vertical cylinders is presented, since its geometry is the more suitable in the analysis of a fuel rod. Finally, in chapter IV performed experiments in the test bench are detailed, and the results are presented in form of tables and graphs, showing the used equations for the calculations and the restrictions used in each case. For the analysis of the prototypes used in the test bench, a constant and uniform flow of heat in the whole length of the fuel rod is considered. At the end of this chapter, the work conclusions and a brief explanation of the results are presented (Author)

  9. After the activation of heavy elements in the course of experiments: intermediate storage and disposal

    International Nuclear Information System (INIS)

    Ehrlicher, U.; Beer, H.F.

    2005-01-01

    When materials are foreseen to be activated in the course of experiments, radiation protection must also be considered from the aspect of waste disposal. Materials containing heavy elements still can bear some TBq of activity 10 years after irradiation with neutrons or heavy particles in an accelerator. The potential danger has to be assessed for each storage position in behalf of planning protective measures. For the longest period, however, the material will rest in an interim storage like the BZL in Wuerenlingen, Switzerland, waiting for its final disposal. PSI calculates the maximum personal dose for accidents (plane crash followed by a fire hazard) to assess the potential risk around the BZL. The following speech will deal with items like: personal dose for the inhabitants of communities in the vicinity of the BZL after a possible accident before and after the storage of the activated materials, adherence to the aims of protection (personal dose of less than 100 mSv), possible measures to minimize the potential danger, (orig.)

  10. Heavy particle scattering by atomic and nuclear systems

    International Nuclear Information System (INIS)

    Lazauskas, R.

    2003-10-01

    In this thesis quantum mechanical non-relativistic few-body problem is discussed. Basing on fundamentals ideas from Faddeev and Yakubovski three and four body equations are formulated and solved for fermionic atomic and nuclear systems. Former equations are modified to include long range interactions. Original results for nuclear and molecular physics were obtained: -) positively charged particle scattering on hydrogen atoms was considered; predictions for π + → H, μ + → H and p + → H scattering lengths were given. Existence of an unknown, very weakly bound H + 2 bound state was predicted. -) Motivated by the possible observation of bound four neutron structure at GANIL we have studied compatibility of such an existence within the current nuclear interaction models. -) 4 nucleon scattering at low energies was investigated. Results for n → 3 H, p → 3 H and p → 3 He systems were compared with the experimental data. Validity of realistic nucleon-nucleon interaction models is questioned. (author)

  11. A method for the quantitative analysis of heavy elements by X-ray fluorescence

    International Nuclear Information System (INIS)

    Souza Caillaux, Z. de

    1981-01-01

    A study of quantitative analysis methodology by X-ray fluorescence analysis is presented. With no damage to precision it makes possible an analysis of heavy elements in samples with the form and texture as they present themselves. Some binary alloys were examined such as: FeCo; CuNi; CuZn; AgCd; AgPd; AuPt e PtIr. The possibility of application of this method is based on the compromise solutIon of wave lengths and the intensity of the homologous emission and absorption edges of constituents with the quantic efficiency of the detector, the dispersion and the wave lenght resolution of crystal analyser, and the uniformity of the excitation intensity. (Author) [pt

  12. Study of particulates and heavy elements in air of some Syrian cities

    International Nuclear Information System (INIS)

    Othman, I.; Al-Oudat, M.; Al-Rayes, A. H.; Al- Kharfan, K.

    1999-11-01

    A study of air pollution in different sites of five Syrian cities (Damascus, Aleppo, Tartous, Homs, and Sweda) was carried out. The concentration of total suspended particulate (TSP), particulate less than 10 microns (PM 10) and less than 3 microns (PM 3) were measured using high volume air sampler (HVAS). Heavy element concentration, Pb, Cd, Zn, and Cu were also determined using anodic stripping voltametry. The result showed that TSP, PM 10 and PM 3 were higher than WHO standards in several times. Mean lead concentrations ranged between 0.58 and 2.96 μg/m 3 and 0.56 and 1.53 μg/m 3 in Damascus and Aleppo respectively, while in the other cities these concentrations were less than WHO standards (0.5 - 1 μg/m 3 ). (author)

  13. Recovery of the heavy elements by NaY AND NaZSM-5 sorbant materials

    International Nuclear Information System (INIS)

    Nibou, D.; Lebail, S.

    1997-04-01

    Porous sorbants as zeolites have a several applications in differents fiels: industrial gas purification, catalysis, transformation hydrocarbures prosesses and exchange ions. The hiogh capacity to exchange their cations with those of aqueous solutions was known (1). Since the accession of synthetic zeolites, these silicates have invaded the market and the firstindustrial applications were in exchange field. Studies at Battelle Northwest in Rchland, Washington have shown that zeolites may be used in treatment of radioactive wastes (2). The used method for storing the isotopes is based on selective removal by ion exchange. Clinoptilolite, zeolite (modernite), NaA, and AW-500 have been used. In this context, the present work deals with the recovery of heavy metals like lead and uranium using some microporous materials. The obtained results show that NaY faujasite and NaZSM-5 of the FAU- and MFI-type structure respectively are very effective in removing these elements from waste water

  14. Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy).

    Science.gov (United States)

    Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

    2014-12-15

    The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. HELAC-Onia: an automatic matrix element generator for heavy quarkonium physics

    CERN Document Server

    Shao, Hua-Sheng

    2013-01-01

    By the virtues of the Dyson-Schwinger equations, we upgrade the published code \\mtt{HELAC} to be capable to calculate the heavy quarkonium helicity amplitudes in the framework of NRQCD factorization, which we dub \\mtt{HELAC-Onia}. We rewrote the original \\mtt{HELAC} to make the new program be able to calculate helicity amplitudes of multi P-wave quarkonium states production at hadron colliders and electron-positron colliders by including new P-wave off-shell currents. Therefore, besides the high efficiencies in computation of multi-leg processes within the Standard Model, \\mtt{HELAC-Onia} is also sufficiently numerical stable in dealing with P-wave quarkonia (e.g. $h_{c,b},\\chi_{c,b}$) and P-wave color-octet intermediate states. To the best of our knowledge, it is a first general-purpose automatic quarkonium matrix elements generator based on recursion relations on the market.

  16. Heavy flavours production in quark-gluon plasma formed in high energy nuclear reactions

    Science.gov (United States)

    Kloskinski, J.

    1985-01-01

    Results on compression and temperatures of nuclear fireballs and on relative yield of strange and charmed hadrons are given . The results show that temperatures above 300 MeV and large compressions are unlikely achieved in average heavy ion collision. In consequence, thermal production of charm is low. Strange particle production is, however, substantial and indicates clear temperature - threshold behavior.

  17. Nuclear interaction contribution to SEUs in heavy ion energy deposition in the ESA monitor

    CERN Document Server

    Bahamonde, Cristina

    2013-01-01

    The effects of nuclear interactions inducing Single Event Upsets in ESA SEU monitor are explored for heavy ion beams of different energies. The experimental and simulated results are compared, the possible causes of disagreement are suggested as well as the future steps to take.

  18. The separation of heavy ion tracks in nuclear emulsions by means of the pulsed electric field

    International Nuclear Information System (INIS)

    Akopova, A.B.; Magradze, N.V.; Melkumyan, L.V.; Prokhorenko, Y.P.

    1976-01-01

    The pulsed electric field (PEF) technique is developed for the separation of heavy ion tracks from the intense background caused by high energy electrons, protons and γ-radiation. The tracks of Ne, Cr, Ar-ions accelerated at the Dubna Nuclear Reactions Laboratory have been separated from the background, the voltage of the applied PEF being 10 5 V/cm. (orig.) [de

  19. Heavy-flavor production and medium properties in high-energy nuclear collisions --What next?

    NARCIS (Netherlands)

    Aarts, G.; Aichelin, J.; Allton, C.; Arnaldi, R.; Bass, S. A.; Bedda, C.; Brambilla, N.; Bratkovskaya, E.; Braun-Munzinger, P.; Bruno, G. E.; Dahms, T.; Das, S. K.; Dembinski, H.; Djordjevic, M.; Ferreiro, E. G.; Frawley, A.; Gossiaux, P. B.; Granier de Cassagnac, R.; Grelli, A.; He, Ming; Horowitz, W. A.; Innocenti, G. M.; Jo, M.; Kaczmarek, O.; Kuijer, P; Laine, M.; Lombardo, M. P.; Mischke, A.; Munhoz, M. G.; Nahrgang, M.; Nguyen, Mai; Oliveira da Silva, A. C.; Petreczky, P.; Rothkopf, A.; Schmelling, M.; Scomparin, E.; Song, Ting; Stachel, J.; Suaide, A. A P; Tolos, L.; Trzeciak, B.; Uras, A.; van Doremalen, L.; Vermunt, L.; Vigolo, S.; Xu, N.; Ye, Z.; Zanoli, H.J.C.; Zhuang, P.

    2017-01-01

    Open and hidden heavy-flavor physics in high-energy nuclear collisions are entering a new and exciting stage towards reaching a clearer understanding of the new experimental results with the possibility to link them directly to the advancement in lattice Quantum Chromo-Dynamics (QCD). Recent results

  20. Porous nuclear fuel element with internal skeleton for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L.; Williams, Brian E.; Benander, Robert E.

    2013-09-03

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  1. Porous nuclear fuel element for high-temperature gas-cooled nuclear reactors

    Science.gov (United States)

    Youchison, Dennis L [Albuquerque, NM; Williams, Brian E [Pacoima, CA; Benander, Robert E [Pacoima, CA

    2011-03-01

    Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

  2. Sub-barrier quasifission in heavy element formation reactions with deformed actinide target nuclei

    Science.gov (United States)

    Hinde, D. J.; Jeung, D. Y.; Prasad, E.; Wakhle, A.; Dasgupta, M.; Evers, M.; Luong, D. H.; du Rietz, R.; Simenel, C.; Simpson, E. C.; Williams, E.

    2018-02-01

    Background: The formation of superheavy elements (SHEs) by fusion of two massive nuclei is severely inhibited by the competing quasifission process. Low excitation energies favor SHE survival against fusion-fission competition. In "cold" fusion with spherical target nuclei near 208Pb, SHE yields are largest at beam energies significantly below the average capture barrier. In "hot" fusion with statically deformed actinide nuclei, this is not the case. Here the elongated deformation-aligned configurations in sub-barrier capture reactions inhibits fusion (formation of a compact compound nucleus), instead favoring rapid reseparation through quasifission. Purpose: To determine the probabilities of fast and slow quasifission in reactions with prolate statically deformed actinide nuclei, through measurement and quantitative analysis of the dependence of quasifission characteristics at beam energies spanning the average capture barrier energy. Methods: The Australian National University Heavy Ion Accelerator Facility and CUBE fission spectrometer have been used to measure fission and quasifission mass and angle distributions for reactions with projectiles from C to S, bombarding Th and U target nuclei. Results: Mass-asymmetric quasifission occurring on a fast time scale, associated with collisions with the tips of the prolate actinide nuclei, shows a rapid increase in probability with increasing projectile charge, the transition being centered around projectile atomic number ZP=14 . For mass-symmetric fission events, deviations of angular anisotropies from expectations for fusion fission, indicating a component of slower quasifission, suggest a similar transition, but centered around ZP˜8 . Conclusions: Collisions with the tips of statically deformed prolate actinide nuclei show evidence for two distinct quasifission processes of different time scales. Their probabilities both increase rapidly with the projectile charge. The probability of fusion can be severely

  3. Elements of a national emergency response system for nuclear accidents

    International Nuclear Information System (INIS)

    Dickerson, M.H.

    1987-01-01

    The purpose of this paper is to suggest elements for a general emergency response system, employed at a national level, to detect, evaluate and assess the consequences of a radiological atmospheric release occurring within or outside of national boundaries. These elements are focused on the total aspect of emergency response ranging from providing an initial alarm to a total assessment of the environmental and health effects. Elements of the emergency response system are described in such a way that existing resources can be directly applied if appropriate; if not, newly developed or an expansion of existing resources can be employed. The major thrust of this paper is toward a philosophical discussion and general description of resources that would be required to implementation. If the major features of this proposal system are judged desirable for implementation, then the next level of detail can be added. The philosophy underlying this paper is preparedness - preparedness through planning, awareness and the application of technology. More specifically, it is establishment of reasonable guidelines including the definition of reference and protective action levels for public exposure to accidents involving nuclear material; education of the public, government officials and the news media; and the application of models and measurements coupled to computer systems to address a series of questions related to emergency planning, response and assessment. It is the role of a proven national emergency response system to provide reliable, quality-controlled information to decision makers for the management of environmental crises

  4. Nuclear

    International Nuclear Information System (INIS)

    2014-01-01

    This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

  5. Nuclear momentum distribution and relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    In terms of a direct fragmentation process and a hard-scattering process, the proton-inclusive data for the reaction α + 12 C → p + X have been successfully analyzed. The extracted semiempirical momentum distribution indicates possible evidence of nuclear correlations and final-state interactions. 4 figures

  6. Atomic data for heavy element impurities in fusion reactors. Summary report of the final research coordination meeting

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2009-04-01

    Eleven experts on the properties of heavy elements of relevance to fusion energy research attended the final Research Coordination Meeting (RCM) on Data for Heavy Element Impurities in Fusion Reactors, held at IAEA Headquarters on 4-6 March 2009. Participants summarized their accomplishments with respect to the revised work plan formulated at the second RCM. The overall work plan for the CRP was assessed and reviewed in detail, and achievements were noted. Discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

  7. Atomic data for heavy element impurities in fusion reactors. Summary report of first IAEA research co-ordination meeting

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2006-01-01

    Twelve international experts discussed in detail the properties of heavy elements relevant to fusion energy research participated at the first Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Atomic data for heavy element impurities in fusion reactors' at IAEA Headquarters on 14-15 November 2005. The participants summarized all recent relevant developments in their research efforts. Detailed discussions took place to formulate specific objectives for the CRP. From a list of data needs and a review of current research capabilities, a detailed work plan was formulated for the first phase of the CRP. The discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

  8. Improved moulding material for addition to nuclear fuel particles to produce nuclear fuel elements

    International Nuclear Information System (INIS)

    Miertschin, G.N.; Leary, D.F.

    1976-01-01

    A suggestion is made to improve the moulding materials used to produce carbon-contained nuclear fuel particles by a coke-reducing added substance. The nuclear fuel particles are meant for the formation of fuel elements for gas-cooled high-temperature nuclear reactors. The moulding materials are above all for the formation of coated particles which are burnt in situ in nuclear fuel element chambers out of 'green' nuclear fuel bodies. The added substance improves the shape stability of the particles forming and prevents a stiding or bridge formation between the particles or with the surrounding walls. The following are named as added substances: 1) Polystyrene and styrene-butadiene-Co polymers (mol. wt. between 5oo and 1,000,000), 2) aromatic compounds (mol. wt. 75 to 300), 3) saturated hydrocarbon polymers (mol. wt. 5,000 to 1,000,000). Additional release agents further improve the properties in the same direction (e.g. alcohols, fatty acids, amines). (orig.) [de

  9. Study on the prediction of soil heavy metal elements content based on visible near-infrared spectroscopy

    Science.gov (United States)

    Liu, Jinbao; Zhang, Yang; Wang, Huanyuan; Du, Yichun

    2018-06-01

    The estimation of soils heavy metal content can reflect the impending surroundings of surface, which lays theoretical foundation for using covered vegetation to monitor environment and investigate resource. In this study, the contents of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD FieldSpec HR (350-2500 nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal spectroscopy estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb was established by regression method. Comparing the diffuse reflectance characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results of chemical analysis show that there was a serious Hg pollution in the study area, and the Cd content was close to the critical value. The results show that: (1) NOR, MSC and SNV were adopted for the acquisition of visible near-infrared. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy Significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb by PLSR method were 0.70, 0.79, 0.69, 0.81, 0.86, 0.58, 0.55, 0.99, 0.62. (3) The optimal estimation model of different elements using different treatment methods has better stability and higher precision, and can realize the rapid prediction of nine kinds of heavy metal elements in this region.

  10. Study on the prediction of soil heavy metal elements content based on visible near-infrared spectroscopy.

    Science.gov (United States)

    Liu, Jinbao; Zhang, Yang; Wang, Huanyuan; Du, Yichun

    2018-06-15

    The estimation of soils heavy metal content can reflect the impending surroundings of surface, which lays theoretical foundation for using covered vegetation to monitor environment and investigate resource. In this study, the contents of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD FieldSpec HR (350-2500nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal spectroscopy estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb was established by regression method. Comparing the diffuse reflectance characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results of chemical analysis show that there was a serious Hg pollution in the study area, and the Cd content was close to the critical value. The results show that: (1) NOR, MSC and SNV were adopted for the acquisition of visible near-infrared. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy Significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, Zn, As, Cd, Hg and Pb by PLSR method were 0.70, 0.79, 0.69, 0.81, 0.86, 0.58, 0.55, 0.99, 0.62. (3) The optimal estimation model of different elements using different treatment methods has better stability and higher precision, and can realize the rapid prediction of nine kinds of heavy metal elements in this region. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Ground test facilities for evaluating nuclear thermal propulsion engines and fuel elements

    International Nuclear Information System (INIS)

    Allen, G.C.; Beck, D.F.; Harmon, C.D.; Shipers, L.R.

    1992-01-01

    Interagency panels evaluating nuclear thermal propulsion development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and design issues of a proposed ground test complex for evaluating nuclear thermal propulsion engines and fuel elements being developed for the Space Nuclear Thermal Propulsion (SNTP) program. 2 refs

  12. The origin of nuclear spin and its effect durning intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Zhang Guoqiang; Cao Xiguang; Fu Yao; Ma Yugang; Cai Xiangzhou; Wang Hongwei; Fang Deqing; Tian Wendong; Chen Jingen; Guo Wei; Liu Guihua

    2010-01-01

    We use the heavy-ion phase-space exploration (HIPSE) model to discuss the origin of the nuclear spin and its effect in Intermediate energy nuclear reaction. It is found that the spin of projectile depends on the impact parameter of the reaction system heavily, while on the violence lightly by contrast. Some interesting multifragmentation phenomena related to the spin are shown, especially those of phase transition. At the same time, the role of excited energy for multifragmentation is also invested. We find the later plays a more robust role durning the nuclear disintegration. (authors)

  13. b-jet tagged nuclear modification factors in heavy ion collisions with CMS

    CERN Document Server

    Jung, Kurt

    2014-01-01

    The energy loss of jets in heavy-ion collisions is expected to depend on the flavor of the fragmenting parton. Thus, measurements of jet quenching as a function of flavor place powerful constraints on the thermodynamical and transport properties of the hot and dense medium. Measurements of the nuclear modification factors of the heavy-flavor-tagged jets in both PbPb and pPb collisions can quantify such energy loss effects. Specifically, pPb measurements provide crucial insights into the behavior of the cold nuclear matter effect, which is required to fully understand the hot and dense medium effects on jets in PbPb collisions. In this talk, we present the b-jet spectra and the first measurement of the nuclear modification factors as a function of transverse momentum and pseudorapidity, using the high statistics pp, pPb and PbPb data taken in 2011 and 2013.

  14. Indian nuclear power programme with pressurised heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-09-01

    This compilation is a part of ongoing efforts by Nuclear Power Corporation (NPC) to enable persons: to visit the plants under construction and operation to see for themselves adoption of new and advanced techniques; to have contact with the realities of NPC`s facilities; to familiarize themselves with the regulatory aspects on radiological and environmental protection; and assess for themselves the extent of thrust and importance given to overall safety. figs., tabs.

  15. Determination of Heavy Metals and Radioactive Elements in Alluvial Soil using Atomic Absorption and Gamma Spectroscopy

    International Nuclear Information System (INIS)

    Hamed, S.S.; Walley EI Dine, N.; Soliman, S.I.; Moussa, W.M.

    2008-01-01

    The paper describes some methods dealing with measurements of some heavy and radioactive elements (U, Th and K) in Egyptian cultivated soil samples. Samples were collected from Toshka area. Also, soil and plant samples were collected from Kalube and EI - Gabal EI - Asfar to compare the obtained results from both region. Flame atomic absorption spectrometry (FAAS),Neutron activation analysis (INAA) and Natural radioactivity techniques were followed. FAAS and INAA techniques agreed fairly well for the compared elements Co,Zn and Fe which determined by the two techniques. Also for K which was determined by FAAS and natural radioactivity. It was found that the concentration range in soil samples for Co, Fe, K and Zn lies between 4.18 and 29.2 μg/g, 3.0 and 3.8 mg/g, 3.49 and 13.28 mg/g and 120 and 663 μg/g respectively while in plant samples the concentration of Co was from 3.02 to 4.02 μg/g, Fe from 1.18 to 1.35 mg/g and Zn from 29.63 to 73.02 μg/g

  16. TFIIIC bound DNA elements in nuclear organization and insulation.

    Science.gov (United States)

    Kirkland, Jacob G; Raab, Jesse R; Kamakaka, Rohinton T

    2013-01-01

    tRNA genes (tDNAs) have been known to have barrier insulator function in budding yeast, Saccharomyces cerevisiae, for over a decade. tDNAs also play a role in genome organization by clustering at sites in the nucleus and both of these functions are dependent on the transcription factor TFIIIC. More recently TFIIIC bound sites devoid of pol III, termed Extra-TFIIIC sites (ETC) have been identified in budding yeast and these sites also function as insulators and affect genome organization. Subsequent studies in Schizosaccharomyces pombe showed that TFIIIC bound sites were insulators and also functioned as Chromosome Organization Clamps (COC); tethering the sites to the nuclear periphery. Very recently studies have moved to mammalian systems where pol III genes and their associated factors have been investigated in both mouse and human cells. Short interspersed nuclear elements (SINEs) that bind TFIIIC, function as insulator elements and tDNAs can also function as both enhancer - blocking and barrier insulators in these organisms. It was also recently shown that tDNAs cluster with other tDNAs and with ETCs but not with pol II transcribed genes. Intriguingly, TFIIIC is often found near pol II transcription start sites and it remains unclear what the consequences of TFIIIC based genomic organization are and what influence pol III factors have on pol II transcribed genes and vice versa. In this review we provide a comprehensive overview of the known data on pol III factors in insulation and genome organization and identify the many open questions that require further investigation. This article is part of a Special Issue entitled: Transcription by Odd Pols. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Heavy ion collisions with A = 1057: Aspects of nuclear stability and the nuclear equation of state in coalescing neutron-star binary systems

    International Nuclear Information System (INIS)

    Mathews, G.J.; Wilson, J.R.; Evans, C.R.; Detweiler, S.L.

    1987-12-01

    The dynamics of the final stages of the coalescence of two neturon stars (such as the binary pulsar PSR 1913+16) is an unsolved problem in astrophysics. Such systems are probably efficient generators of gravitational radiation, and may be significant contributors to heavy-element nucleosynthesis. The input physics for the study of such systems is similar to that required for the strudy of heavy-ion collision hydrodynamics; e.g., a finite temperature nuclear equation of state, properties of nuclei away from stability, etc. We discuss the development of a relativistic hydrodynamics code in three spatial dimensions for the purpose of studying such neutron-star systems. The properties of the mass-radius relation (determined by the nuclear equation of state) may lead to a proposed mechanism by which hot, highly neutronized matter is ejected from the coalescing stars. This material is photodisintegrated into a free (mostly) neutron gas which may subsequently experience rapid-neutron capture (r-process) nucleosynthesis. 15 refs., 4 figs

  18. Control of information as an element of nuclear safeguards

    International Nuclear Information System (INIS)

    Green, J.N.

    1982-03-01

    Control of information as an element of physical protection has a long history in the field of national security. The nuclear industry is familiar with the constraints on proprietary information; and, with an effective date of October 1, 1980 for Parts 25 and 95 in Title 10 of the code of Federal Regulations, certain activities had to cope with rules for safeguarding of classified information. In applying the rules it is important to understand the differences between national security information and restricted data, and how guidance is promulgated both by the Nuclear Regulatory Commission (NRC) and by the Department of Energy. More recently, with a fully effective date of January 20, 1982, the NRC published rules for the protection of unclassified safeguards information. The scope is much broader than for the classified information. For example, the rules are applicable to power reactors. In this paper the directives which provide the details for compliance with all these rules are identified, and their application is discussed. NRC inspectors will be checking for compliance with the rules. Once problems of compliance are resolved, the more difficult question of evaluating the impact of information control procedures on the effectiveness of a physical protection system can be addressed

  19. Origin of the finite nuclear spin and its effect in intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Zhang Guoqiang; Cao Xiguang; Fu Yao

    2012-01-01

    The heavy-ion phase-space exploration (HIPSE) model is used to discuss the origin of the nuclear spin in intermediate energy heavy-ion collision (HIC). The spin of maximal projectile-like fragment is found to depend strongly on impact parameter of a reaction system,while it relates weakly to the collision violence. Some interesting multi-fragmentation phenomena related to the spin are shown. We also found that the excitation energy in the de-excitation stage plays a robust role at the de-excitation stage in HIC. (authors)

  20. {gamma}-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Korotkikh, V.L.; Chikin, K.A. [Scobeltsyn Institute of Nuclear Physics, Moscow State University (Russian Federation)

    2002-06-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant {gamma}-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  1. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Science.gov (United States)

    Korotkikh, V. L.; Chikin, K. A.

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions.

  2. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    International Nuclear Information System (INIS)

    Korotkikh, V.L.; Chikin, K.A.

    2002-01-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  3. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil

    International Nuclear Information System (INIS)

    Grytsyuk, N.; Arapis, G.; Perepelyatnikova, L.; Ivanova, T.; Vynograds'ka, V.

    2006-01-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time

  4. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil.

    Science.gov (United States)

    Grytsyuk, N; Arapis, G; Perepelyatnikova, L; Ivanova, T; Vynograds'ka, V

    2006-02-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

  5. Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

    Science.gov (United States)

    Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

    2016-09-01

    Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

  6. Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

    Science.gov (United States)

    The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

  7. Radionuclides and heavy elements containing in the soil and vegetation in the area of Didmay tailing pit

    International Nuclear Information System (INIS)

    Razikov, Z.A.; Yunusov, M.M.

    1997-01-01

    In this article on the base of carried out investigations authors made conclusion on effectiveness of obtaining of geo botanical methods of territory investigation adjoining to the tailing pits. With the purpose of decreasing of radionuclides and heavy metals concentration in the soil it was determined for this spot the plant-indicators and association which can accumulate radioactive and attendant them chemical elements

  8. 3D finite element analysis of a nuclear fuel rod with gap elements between the pellet and the cladding

    International Nuclear Information System (INIS)

    Kang, Chang-Hak; Lee, Sung-Uk; Yang, Dong-Yol; Kim, Hyo-Chan; Yang, Yong-Sik

    2016-01-01

    Nuclear fuel rods which comprises an important component of a nuclear power plant are composed of nuclear fuel and cladding. Simulating the nuclear fuel rod using a computer program is the universal method to verify its safety. The computer program used for this is called the fuel performance code. The main objective of this study is to simulate the nuclear fuel rod behavior considering the gap conductance using three-dimensional gap elements. Gap elements are used because, unlike other methods, this approach does not require special methods or other variables such as the Lagrange multiplier. In this work, a nuclear fuel rod has been simulated and the results are compared with the experimental results. (author)

  9. Effect of heavy atoms on photochemically induced dynamic nuclear polarization in liquids

    Science.gov (United States)

    Okuno, Yusuke; Cavagnero, Silvia

    2018-01-01

    Given its short hyperpolarization time (∼10-6 s) and mostly non-perturbative nature, photo-chemically induced dynamic nuclear polarization (photo-CIDNP) is a powerful tool for sensitivity enhancement in nuclear magnetic resonance. In this study, we explore the extent of 1H-detected 13C nuclear hyperpolarization that can be gained via photo-CIDNP in the presence of small-molecule additives containing a heavy atom. The underlying rationale for this methodology is the well-known external-heavy-atom (EHA) effect, which leads to significant enhancements in the intersystem-crossing rate of selected photosensitizer dyes from photoexcited singlet to triplet. We exploited the EHA effect upon addition of moderate amounts of halogen-atom-containing cosolutes. The resulting increase in the transient triplet-state population of the photo-CIDNP sensitizer fluorescein resulted in a significant increase in the nuclear hyperpolarization achievable via photo-CIDNP in liquids. We also explored the internal-heavy-atom (IHA) effect, which is mediated by halogen atoms covalently incorporated into the photosensitizer dye. Widely different outcomes were achieved in the case of EHA and IHA, with EHA being largely preferable in terms of net hyperpolarization.

  10. Perspectives for nuclear structure research at GSI: from halo nuclei to superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Muenzenberg, G.

    1997-11-01

    After a brief overview on recent advances in the investigation of nuclei at the driplines and the upper end of the nuclear table key issues of nuclear structure research as adressed by new theoretical developments will be discussed in context with new developments in heavy-ion accelerators and experimental techniques. (orig.)

  11. Perspectives for nuclear structure research at GSI--from halo nuclei to superheavy elements

    International Nuclear Information System (INIS)

    Munzenberg, G.

    1997-01-01

    After a brief overview on recent advances in the investigation of nuclei at the drip lines and the upper end of the nuclear table key issues of nuclear structure research as addressed by new theoretical developments will be discussed in context with new developments in heavy-ion accelerators and experimental techniques

  12. Investigation on laser welding characteristics for appendage of bearing pads of nuclear fuel element

    International Nuclear Information System (INIS)

    Kim, S. S.; Kim, W. K.; Park, C. H.; Ko, J. H.; Lee, J. W.; Yang, M. S.

    2001-01-01

    In CANDU nuclear fuel manufacturing the brazing technology has been adopted conventionally to attach the bearing pads of nuclear fuel elements. However, in order to meet good performance of nuclear fuel and improved working efficiency, we started developing the laser welding technology for attachments of the bearing pads. Since the YAG laser can be suitable for small parts and transmit the beam through the optical fiber, the process is corresponding to mass-production with working shops. Making the most of this feature, we have developed the laser welding for appendage of the bearing pads of nuclear fuel elements, and has studied on the laser welding characterisitcs of appendages for nuclear fuel element

  13. Heavy-flavor production and medium properties in high-energy nuclear collisions. What next?

    Energy Technology Data Exchange (ETDEWEB)

    Aarts, G.; Allton, C. [Swansea University, Swansea (United Kingdom); Aichelin, J.; Gossiaux, P.B.; Nahrgang, M. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, Nantes (France); Arnaldi, R.; Scomparin, E. [INFN, Sezione di Torino, Torino (Italy); Bass, S.A. [Duke University, Durham, NC (United States); Bedda, C.; Grelli, A.; Trzeciak, B.; Doremalen, L. van; Vermunt, L.; Vigolo, S. [Utrecht University, Institute for Subatomic Physics, Utrecht (Netherlands); Brambilla, N. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Technische Universitaet Muenchen, Institute for Advanced Study, Munich (Germany); Bratkovskaya, E. [GSI Helmholtzzentrum fuer Schwerionenforschung, Research Division and ExtreMe Matter Institute EMMI, Darmstadt (Germany); Frankfurt University, Institute for Theoretical Physics, Frankfurt am Main (Germany); Braun-Munzinger, P. [GSI Helmholtzzentrum fuer Schwerionenforschung, Research Division and ExtreMe Matter Institute EMMI, Darmstadt (Germany); Ruprecht-Karls-Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Bruno, G.E. [Dipartimento di Fisica and INFN, Bari (Italy); European Organization for Nuclear Research, Geneva (Switzerland); Dahms, T. [Technische Universitaet Muenchen, Physik-Department and Excellence Cluster Universe, Garching (Germany); Das, S.K. [University of Catania, Catania (Italy); Dembinski, H.; Schmelling, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Djordjevic, M. [University of Belgrade, Institute of Physics, Belgrade (Serbia); Ferreiro, E. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain); Frawley, A. [Florida State University, Tallahassee, FL (United States); Granier de Cassagnac, R.; Jo, M.; Nguyen, M. [Ecole Polytechnique, Laboratoire Leprince-Ringuet, Palaiseau (France); He, M. [Nanjing University of Science and Technology, Department of Applied Physics, Nanjing (China); Horowitz, W.A. [University of Cape Town, Department of Physics, Rondebosch (South Africa); Innocenti, G.M. [Massachusetts Institute of Technology, Cambridge, MA (United States); Kaczmarek, O. [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan (China); University of Bielefeld, Bielefeld (Germany); Kuijer, P.G. [National Institute for Subatomic Physics, Amsterdam (Netherlands); Laine, M. [University of Bern, AEC, Institute for Theoretical Physics, Bern (Switzerland); Lombardo, M.P. [INFN - Laboratori Nazionali di Frascati, Frascati (Italy); Mischke, A. [Utrecht University, Institute for Subatomic Physics, Utrecht (Netherlands); National Institute for Subatomic Physics, Amsterdam (Netherlands); Munhoz, M.G.; Suaide, A.A.P. [Universidade de Sao Paulo (USP), Sao Paulo (Brazil); Oliveira da Silva, A.C.; Zanoli, H.J.C. [Utrecht University, Institute for Subatomic Physics, Utrecht (Netherlands); Universidade de Sao Paulo (USP), Sao Paulo (Brazil); Petreczky, P. [Brookhaven National Laboratory, Upton, NY (United States); Rothkopf, A. [Ruprecht-Karls-Universitaet Heidelberg, Institute for Theoretical Physics, Heidelberg (Germany); Song, T. [Frankfurt University, Institute for Theoretical Physics, Frankfurt am Main (Germany); Stachel, J. [Ruprecht-Karls-Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Tolos, L. [Frankfurt Institute for Advanced Studies (FIAS), Frankfurt (Germany); Institut de Ciencies de l' Espai (IEEC-CSIC), Bellaterra (Spain); Uras, A. [Domaine Scientifique de la Doua, Institute of Nuclear Physics, Villeurbanne Cedex (France); Xu, N. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Ye, Z. [University of Illinois, Chicago, IL (United States); Zhuang, P. [Tsinghua University, Beijng Shi (China)

    2017-05-15

    Open and hidden heavy-flavor physics in high-energy nuclear collisions are entering a new and exciting stage towards reaching a clearer understanding of the new experimental results with the possibility to link them directly to the advancement in lattice Quantum Chromo-Dynamics (QCD). Recent results from experiments and theoretical developments regarding open and hidden heavy-flavor dynamics have been debated at the Lorentz Workshop Tomography of the Quark-Gluon Plasma with Heavy Quarks, which was held in October 2016 in Leiden, The Netherlands. In this contribution, we summarize identified common understandings and developed strategies for the upcoming five years, which aim at achieving a profound knowledge of the dynamical properties of the quark-gluon plasma. (orig.)

  14. Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event.

    Science.gov (United States)

    Kasen, Daniel; Metzger, Brian; Barnes, Jennifer; Quataert, Eliot; Ramirez-Ruiz, Enrico

    2017-11-02

    The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted to power a distinctive thermal glow (a 'kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements. Here we report models that predict the electromagnetic emission of kilonovae in detail and enable the mass, velocity and composition of ejecta to be derived from observations. We compare the models to the optical and infrared radiation associated with the GW170817 event to argue that the observed source is a kilonova. We infer the presence of two distinct components of ejecta, one composed primarily of light (atomic mass number less than 140) and one of heavy (atomic mass number greater than 140) r-process elements. The ejected mass and a merger rate inferred from GW170817 imply that such mergers are a dominant mode of r-process production in the Universe.

  15. In vivo XRF measurements of heavy elements: Summary of a workshop

    International Nuclear Information System (INIS)

    Wielopolski, L.; Ryon, R.W.

    1995-01-01

    This is a brief summary of the first workshop of open-quotes In Vivo XRF Measurements of Heavy Elements,close quotes at the Denver Conference on Applications of X-Ray Analysis. In vivo x-ray fluorescence has been applied to medical applications since the 1960's, with much of the pioneering work being done in Sweden (1). First measurements were of iodine in the thyroid. Elements from iron ID uranium have now been measured, at natural and elevated levels. Elevated levels occur either unintentionally through occupational or environmental exposure, or intentionally through medical administration. Examples of measurements are cadmium in kidney and liver, platinum in kidneys and tumors, mercury in the wrists and skulls of dentists, lead in various near-surface bones, copper in the eye and iron in skin. Nearly all measurements make use of either silicon or germanium detectors; radioisotopes and less frequently x-ray tubes are used for excitation. One question that those who work in an analytical chemistry laboratory often ask concerns radiation doses. Concern for x-ray safety ordinarily precludes putting living subjects into the x-ray beam. It turns out that radiation exposure due to in vivo x-ray fluorescence is quite low. The effective dose values for measurement of tibia lead concentration using a 109 Cd source (30 minute exposure) ranges from 0.036 uSv for adults to 1.1 uSv for infants (less than one tenth of a single dental x-ray) (2). Lower effective doses were reported when an x-ray machine was Used to measure L x-rays (3). These values are far below proposed limits of negligibility (10 USv) and average annual U.S. natural background radiation (3000 uSv). 17 refs

  16. The WWER fuel element safety research under the design and heavy accident imitation on the 'PARAMETR' stand

    International Nuclear Information System (INIS)

    Deniskin, V.P.; Nalivaev, V.I.; Parshin, N. Ya.; Fedik, I.I.

    2000-01-01

    Analysis of fuel element behavior in the course of the design and heavy accidents is the component of reactor facility safety prevention. Many tasks of fuel element behavior research may be solved with the help of thermophysical stands. One of such stands implemented in 1991 was thermophysical stand 'PARAMETER'.Several experiments on model assemblies chiefly imitating both heavy accident and design basic accident have already been conducted in 'PARAMETER' stand. There were obtained data about fuel claddings seal failure and deformation condition. In particular it was defined that seal failure of all fuel claddings occurs on stage of fuel element warming, in temperature range (770-900) degree celsius and almost does not depend on inner pressure level

  17. 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

  18. Heavy density concrete for nuclear radiation shielding and power stations: [Part]2

    International Nuclear Information System (INIS)

    Singha Roy, P.K.

    1987-01-01

    This article is the second part of the paper entitled 'Heavy density concrete for nuclear radiation shielding and power stations'. In this part, some of the important properties of heavy density concrete are discussed. They include density, water retentivity, air content, permeability with special reference to concrete mixes used in India's nuclear power reactors. All these properties are affected to various extents by heating. Indian shield concrete is rarely subjected to temperatures above 60degC during its life, because of thermal shield protection. During placement, the maximum anticipated rise in temperature due to heat of hydration is restricted to around 45degC by chilling, if necessary to reduce shrinkage stresses and cracks. (M.G.B.)

  19. Nuclear research with heavy ions. Annual progress report. January 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, M.

    1980-10-01

    The program of research is oriented towards experimental studies of the interactions between heavy ions and complex nuclei. These interactions are probed by detailed measurements of light-charged-particle emission using counter telescopes for atomic number and mass number identification. Singles measurements of the charged-particle energy spectra and angular distributions, together with coincidence correlations with heavy nuclear-reaction fragments, provide insight into the contributing reaction mechanisms. The application of the statistical model to the appropriate experimental data allows the determination of parameters necessary to calibrate the theory, and gives indications of dynamical control vs. equilibrium in the several degrees of freedom associated with the nuclear collisions. A large body of data are presented and discussed for /sup 40/Ar reactions with /sup 116/Sn, /sup 154/Sm, /sup 164/Dy, and /sup 197/Au targets. Complete results are also given for twelve reactions which produce /sup 194/Hg compound nuclei at several excitation energies.

  20. Generic safety issues for nuclear power plants with pressurized heavy water reactors and measures for their resolution

    International Nuclear Information System (INIS)

    2007-06-01

    be used in reassessing the safety of individual operating plants. In 1998, the IAEA completed IAEA-TECDOC-1044 entitled Generic Safety Issues for Nuclear Power Plants with Light Water Reactors and Measures Taken for their Resolution and established the associated LWRGSIDB database (Computer Manual Series No. 13). The present compilation, which is based on broad international experience, is an extension of this work to cover pressurized heavy water reactors (PHWRs). As in the case of LWRs, it is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. It addresses generic safety issues identified in nuclear power plants using PHWRs. In most cases, the measures taken or planned to resolve these issues are also identified. The work on this report was initiated by the Senior Regulators of Countries Operating CANDU-Type Nuclear Power Plants at one of their annual meetings. It was carried out within the framework of the IAEA's programme on National Regulatory Infrastructure for Nuclear Installation Safety and serves to enhance regulatory effectiveness through the exchange of safety related information

  1. 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)

  2. Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

    Directory of Open Access Journals (Sweden)

    James R. Hein

    2016-08-01

    Full Text Available Marine phosphorites are known to concentrate rare earth elements and yttrium (REY during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm and high heavy REY (HREY complements (mean 49%, while seamount phosphorites have 4–6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm, and very high HREY complements (mean 60%. The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.

  3. Uranium fluoride and metallic uranium as target materials for heavy-element experiments at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Kindler, Birgit [Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-64291 Darmstadt (Germany)], E-mail: b.kindler@gsi.de; Ackermann, Dieter; Hartmann, Willi; Hessberger, Fritz Peter; Hofmann, Sigurd; Huebner, Annett; Lommel, Bettina; Mann, Rido; Steiner, Jutta [Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-64291 Darmstadt (Germany)

    2008-06-01

    In this contribution we describe the production and application of uranium targets for synthesis of heavy elements. The targets are prepared from uranium fluoride (UF{sub 4}) and from metallic uranium with thin carbon foils as backing. Targets of UF{sub 4} were produced by thermal evaporation in a similar way as the frequently applied targets out of Bi, Bi{sub 2}O{sub 3}, Pb, PbS, SmF{sub 3}, and NdF{sub 3,} prepared mostly from isotopically enriched material [Birgit Kindler, et al., Nucl. Instr. and Meth. A 561 (2006) 107; Bettina Lommel, et al., Nucl. Instr. and Meth. A 561 (2006) 100]. In order to use more intensive beams and to avoid scattering of the reaction products in the target, metallic uranium is favorable. However, evaporation of metallic uranium is not feasible at a sustainable yield. Therefore, we established magnetron sputtering of metallic uranium. We describe production and properties of these targets. First irradiation tests show promising results.

  4. Heavy metal elements in toiletries analyzed by INAA, ICP-MS and SEM-EDX

    International Nuclear Information System (INIS)

    Furuta, E.; Tagami, K.; Okada, Y.; Nakahara, H.

    2011-01-01

    Recently, many toiletries claiming inclusion of platinum (Pt), silver (Ag) and gold (Au) as additives are sold in ordinary cosmetics shops. However, their concentrations are not clearly indicated. In the present work, these toiletries were analyzed for heavy metal elements by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS), and the particle sizes were observed by scanning electron microscope (SEM) and the constitutions of the small particles were analyzed by energy dispersive X-ray spectroscopy (EDX). The concentrations of Pt in the toiletries observed were from 1 to 80 ppm. The lower detection limit of Pt by INAA was about 1 ppm because of the presence of sodium in high concentrations for those samples. Consequently, some toiletries which should have had Pt according to the manufactures were found not to contain Pt probably because it was less than the detection limit. On the other hand, there were a few toiletries that were found to contain Ag although the addition of Ag was not mentioned by the manufactures. It is considered that these non-indicated Ag were included as impurities of the added Au. The concentrations of the non-indicated Ag were even higher than those of the indicated Ag. A very small amount of Sr, which was nominated in the negative list of Japan, was also detected in 2 out of 5 kinds of toiletries analyzed by ICP-MS. (orig.)

  5. Nuclear generating station and heavy water plant cost estimates for strategy studies

    International Nuclear Information System (INIS)

    Archinoff, G.H.

    1979-07-01

    Nuclear generating station capital, operating and maintenance costs are basic input data for strategy analyses of alternate nuclear fuel cycles. This report presents estimates of these costs for natural uranium CANDU stations, CANDU stations operating on advanced fuel cycles, and liquid metal fast breeder reactors. Cost estimates for heavy water plants are also presented. The results show that station capital costs for advanced fuel cycles are not expected to be significantly greater than those for natural uranium stations. LMFBR capital costs are expected to be 25-30 percent greater than for CANDU's. (auth)

  6. Heavy density concrete for nuclear radiation shielding and power stations: [Part]3

    International Nuclear Information System (INIS)

    Singha Roy, P.K.

    1987-01-01

    This article is the third part of the paper entitled 'Heavy density concrete for nuclear radiation shielding and power stations'. Specific considerations relevant to natural but manufactured heavy aggregates like haematite used in India are briefly discussed. They include water-cement ratio, strength versus water-cement ratio, mix design strength and aggregate grading. Some typical mix proportions in haematite concretes used in India are given. Equipment for heavy density concrete is mentioned. Quality control methods and tests for heavy density concrete are described under the heading: type and chemical composition of the rock, specific gravity and surface absorption of the aggregates, grading of aggregates, cement, batching, mixing, compressive strength, and density. Construction aspects such as form work, placement, vibration, finishing, and temperature control are discussed. Finally it is pointed out that for optimising the design and economy of heavy density concrete, it is necessary to carry out country-wide survey of suitable materials, to study their properties, suitability and effectiveness in shielding radiation. (M.G.B.)

  7. The relevance of rare earth elements to nuclear medicine

    International Nuclear Information System (INIS)

    Cox, P.H.

    1998-01-01

    Full text: The lanthanides are an interesting series of metallic elements which have almost identical chemical characteristics and which offer a variety of radioisotopes with differing energy spectra suitable for open source therapy. Their inorganic salts tend to form chemically and biological stable colloids which have proved to be useful for intercavity therapies, in particular for synovectomy. Yttrium-90 silicate is a standard product for large joints with a thick synovium whilst for smaller joints Erbium-169, with its shorter tissue penetration, is more widely used for smaller joints to reduce the risk of radiation induced bone necrosis. Recently the development of an inert biodegradable colloid, chitosan, labelled with Holmium 166. for intercavity therapy of cystic brain tumours has been reported. Yttrium-90 has been chelated to peptide and antibody fragments for tumour targeting as a potentially more effective radionuclide than Iodine-131. The search for alternatives to Strontium-89 for the palliative treatment of pain arising from bone metastases has led to the introduction of diphosphonate complexes of Samarium-153, Lutetium-177 and Holmium-166. These complexes are of special interest because the radionuclides can be produced economically in developing countries. Terbium-149, an alpha emitter, has been mentioned as a possible therapeutic radionuclide. Yttrium-90 and Holmium-166 can an both be made available as generator products which is an added potential advantage for developing nuclear medical applications

  8. Trace elements in land plants: concentration ranges and accumulators of rare earths, Ba, Ra, Mn, Fe, Co, and heavy halogens

    International Nuclear Information System (INIS)

    Koyama, Mutsuo; Shirakawa, Masahiro; Takada, Jitsuya; Katayama, Yukio; Matsubara, Takashi

    1986-01-01

    More than 2000 samples of land plant leaves, mostly of tree, have been analysed by neutron activation analysis in order to find out macroscopic relations between distributions of chemical elements in plants and soil characteristics. The distributions of the elements in plants were also examined from the view point of botanical taxonomy or phylogeny. New species which accumulate Co, rare earths, Ba, Ra, heavy halogens and other elements have been found. Capability or potentiality for accumulating elements could be related to primarily to species. In several cases, however, it is related to higher ranks of taxonomy, that is, genus or family. The nature of soil is also found to have profound effects on the extent of accumulation of elements in plants. (author)

  9. Considerations concerning the physics of nuclear matter under extreme conditions and an accelerator for relativistic heavy ions

    International Nuclear Information System (INIS)

    Blasche, K.; Bock, R.; Franzke, B.; Greiner, W.; Gutbrod, H.H.; Povh, B.; Schmelzer, C.; Stock, R.

    1977-01-01

    The future problems of heavy-ion physics in the 10 GeV/U range are dealt with: the dynamics of relativistic nuclear collisions, phase transitions, nuclear matter, quantum electrodynamics of extremely strong fields, and astrophysical aspects. In the second part, the project of a heavy-ion accelerator in the 10 GeV/U range to be coupled to the present GSI UNILAC accelerator is discussed. (WL) [de

  10. Nuclear criticality assessment of LEU and HEU fuel element storage

    International Nuclear Information System (INIS)

    Pond, R.B.; Matos, J.E.

    1984-01-01

    Criticality aspects of storing LEU (20%) and HEU (93%) fuel elements have been evaluated as a function of 235 U loading, element geometry, and fuel type. Silicide, oxide, and aluminide fuel types have been evaluated ranging in 235 U loading from 180 to 620 g per element and from 16 to 23 plates per element. Storage geometry considerations have been evaluated for fuel element separations ranging from closely packed formations to spacings of several centimeters between elements. Data are presented in a form in which interpolations may be made to estimate the eigenvalue of any fuel element storage configuration that is within the range of the data. (author)

  11. The effects of fuel characteristics and engine operating conditions on the elemental composition of emissions from heavy duty diesel buses

    Energy Technology Data Exchange (ETDEWEB)

    M.C.H. Lim; G.A. Ayoko; L. Morawska; Z.D. Ristovski; E.R. Jayaratne [Queensland University of Technology, Brisbane, Qld. (Australia). International Laboratory for Air Quality and Health, School of Physical and Chemical Sciences

    2007-08-15

    The effects of fuel characteristics and engine operating conditions on elemental composition of emissions from twelve heavy duty diesel buses have been investigated. Two types of diesel fuels - low sulfur diesel (LSD) and ultra low sulfur diesel (ULSD) fuels with 500 ppm and 50 ppm sulfur contents respectively and 3 driving modes corresponding to 25%, 50% and 100% power were used. Elements present in the tailpipe emissions were quantified by inductively coupled plasma mass spectrometry (ICPMS) and those found in measurable quantities included Mg, Ca, Cr, Fe, Cu, Zn, Ti, Ni, Pb, Be, P, Se, Ti and Ge. Multivariate analyses using multi-criteria decision making methods (MCDM), principal component analysis (PCA) and partial least squares (PLS) facilitated the extraction of information about the structure of the data. MCDM showed that the emissions of the elements were strongly influenced by the engine driving conditions while the PCA loadings plots showed that the emission factors of the elements were correlated with those of other pollutants such as particle number, total suspended particles, CO, CO{sub 2} and NOx. Partial least square analysis revealed that the emission factors of the elements were strongly dependent on the fuel parameters such as the fuel sulfur content, fuel density, distillation point and cetane index. Strong correlations were also observed between these pollutants and the engine power or exhaust temperature. The study provides insights into the possible role of fuel sulfur content in the emission of inorganic elements from heavy duty diesel vehicles. 39 refs., 1 fig., 4 tabs.

  12. Fluid pressure method for recovering fuel pellets from nuclear fuel elements

    International Nuclear Information System (INIS)

    John, C.D. Jr.

    1979-01-01

    A method is described for removing fuel pellets from a nuclear fuel element without damaging the fuel pellets or fuel element sheath so that both may be reused. The method comprises holding the fuel element while a high pressure stream internally pressurizes the fuel element to expand the fuel element sheath away from the fuel pellets therein so that the fuel pellets may be easily removed

  13. Some internationl law elements of national nuclear regulations from the Polish point of view

    International Nuclear Information System (INIS)

    Gadkowski, T.

    1992-01-01

    The essential contents of the Polish Nuclear Act from 1986 reflects on one hand needs and possibilities of the industrial use of nuclear energy and, on the other, international obligations of Poland. Poland is a State with a limited activity regarding to industrial use of nuclear energy; the main international-law elements of national nuclear regulations can be described as follows: 1. The good-neighborliness principle concerning the siting of nuclear installations in border areas. 2. An adequate concept of nuclear damage. 3. An adequate concept of liability for nuclear damage. (orig./HSCH)

  14. Transuranium element recovering method for spent nuclear fuel

    International Nuclear Information System (INIS)

    Todokoro, Akio; Kihara, Yoshiyuki; Okada, Hisashi

    1998-01-01

    Spent fuels are dissolved in nitric acid, the obtained dissolution liquid is oxidized by electrolysis, and nitric acid of transuranium elements are precipitated together with nitric acid of uranium elements from the dissolution solution and recovered. Namely, the transuranium elements are oxidized to an atomic value level at which nitric acid can be precipitated by an oxidizing catalyst, and cooled to precipitate nitric acid of transuranium elements together with nitric acid of transuranium elements, accordingly, it is not necessary to use a solvent which has been used so far upon recovering transuranium elements. Since no solvent waste is generated, a recovery method taking the circumstance into consideration can be provided. Further, nitric acid of uranium elements and nitric acid of transuranium elements precipitated and recovered together are dissolved in nitric acid again, cooled and only uranium elements are precipitated selectively, and recovered by filtration. The amount of wastes can be reduced to thereby enabling to mitigate control for processing. (N.H.)

  15. High-entropy ejections from magnetized proto-neutron star winds: implications for heavy element nucleosynthesis

    Science.gov (United States)

    Thompson, Todd A.; ud-Doula, Asif

    2018-06-01

    Although initially thought to be promising for production of the r-process nuclei, standard models of neutrino-heated winds from proto-neutron stars (PNSs) do not reach the requisite neutron-to-seed ratio for production of the lanthanides and actinides. However, the abundance distribution created by the r-, rp-, or νp-processes in PNS winds depends sensitively on the entropy and dynamical expansion time-scale of the flow, which may be strongly affected by high magnetic fields. Here, we present results from magnetohydrodynamic simulations of non-rotating neutrino-heated PNS winds with strong dipole magnetic fields from 1014 to 1016 G, and assess their role in altering the conditions for nucleosynthesis. The strong field forms a closed zone and helmet streamer configuration at the equator, with episodic dynamical mass ejections in toroidal plasmoids. We find dramatically enhanced entropy in these regions and conditions favourable for third-peak r-process nucleosynthesis if the wind is neutron-rich. If instead the wind is proton-rich, the conditions will affect the abundances from the νp-process. We quantify the distribution of ejected matter in entropy and dynamical expansion time-scale, and the critical magnetic field strength required to affect the entropy. For B ≳1015 G, we find that ≳10-6 M⊙ and up to ˜10-5 M⊙ of high-entropy material is ejected per highly magnetized neutron star birth in the wind phase, providing a mechanism for prompt heavy element enrichment of the universe. Former binary companions identified within (magnetar-hosting) supernova remnants, the remnants themselves, and runaway stars may exhibit overabundances. We provide a comparison with a semi-analytic model of plasmoid eruption and discuss implications and extensions.

  16. HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

    Science.gov (United States)

    Wakeford, Hannah R; Sing, David K; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D; Tremblin, Pascal; Amundsen, David S; Lewis, Nikole K; Mandell, Avi M; Fortney, Jonathan J; Knutson, Heather; Benneke, Björn; Evans, Thomas M

    2017-05-12

    A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H 2 O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals. Copyright © 2017, American Association for the Advancement of Science.

  17. The NUMEN project: NUclear Matrix Elements for Neutrinoless double beta decay

    Science.gov (United States)

    Cappuzzello, F.; Agodi, C.; Cavallaro, M.; Carbone, D.; Tudisco, S.; Lo Presti, D.; Oliveira, J. R. B.; Finocchiaro, P.; Colonna, M.; Rifuggiato, D.; Calabretta, L.; Calvo, D.; Pandola, L.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Brunasso, O.; Burrello, S.; Calabrese, S.; Calanna, A.; Chávez Lomelí, E. R.; D'Agostino, G.; De Faria, P. N.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; Ferreira, J. L.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia-Tecocoatzi, H.; Greco, V.; Hacisalihoglu, A.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lay, J. A.; La Via, F.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lubian, J.; Medina, N. H.; Mendes, D. R.; Moralles, M.; Muoio, A.; Pakou, A.; Petrascu, H.; Pinna, F.; Reito, S.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Santos, R. B. B.; Sgouros, O.; da Silveira, M. A. G.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Magana Vsevolodovna, R.; Yildirim, A.; Zagatto, V. A. B.

    2018-05-01

    The article describes the main achievements of the NUMEN project together with an updated and detailed overview of the related R&D activities and theoretical developments. NUMEN proposes an innovative technique to access the nuclear matrix elements entering the expression of the lifetime of the double beta decay by cross section measurements of heavy-ion induced Double Charge Exchange (DCE) reactions. Despite the fact that the two processes, namely neutrinoless double beta decay and DCE reactions, are triggered by the weak and strong interaction respectively, important analogies are suggested. The basic point is the coincidence of the initial and final state many-body wave functions in the two types of processes and the formal similarity of the transition operators. First experimental results obtained at the INFN-LNS laboratory for the 40Ca(18O,18Ne)40Ar reaction at 270MeV give an encouraging indication on the capability of the proposed technique to access relevant quantitative information. The main experimental tools for this project are the K800 Superconducting Cyclotron and MAGNEX spectrometer. The former is used for the acceleration of the required high resolution and low emittance heavy-ion beams and the latter is the large acceptance magnetic spectrometer for the detection of the ejectiles. The use of the high-order trajectory reconstruction technique, implemented in MAGNEX, allows to reach the experimental resolution and sensitivity required for the accurate measurement of the DCE cross sections at forward angles. However, the tiny values of such cross sections and the resolution requirements demand beam intensities much larger than those manageable with the present facility. The on-going upgrade of the INFN-LNS facilities in this perspective is part of the NUMEN project and will be discussed in the article.

  18. Ultrasonic evaluation of end cap weld joints of fuel elements of pressurized heavy water reactors using signal analysis methods

    International Nuclear Information System (INIS)

    Raj, B.; Thavasimuthu, M.; Subramanian, C.V.; Kalyanasundaram, P.; Rajagopalan, C.

    1992-01-01

    This paper describes the application of ultrasonic digital signal analysis for the detection of fine defects of the order of 10% or lower of wall thickness (WT) of 370 microns in the resistance welded end cap-cladding tube joints of fuel elements used in Pressurised Heavy Water Reactors (PHWR s). The results obtained for the detection of such defects, have confirmed the sensitivity and reliability of this approach, and were further validated by destructive metallography. (author)

  19. Reactor physics measurements with 19-element ThOsub(2)-sup(235)UOsub(2) cluster fuel in heavy water moderator

    International Nuclear Information System (INIS)

    French, P.M.

    1985-02-01

    Low power lattice physics measurements have been performed with a single rod of 19-element thorium oxide fuel enriched with 1.45 wt. percent sub(235)UOsub(2) (93 percent enriched) in a simulated heavy water moderated and cooled power reactor core. The experiments were designed to provide data relevant to a power reactor irradiation and to obtain some basic information on the physics of uranium-thorium fuel material. Some theoretical flux calculations are summarized and show reasonable agreement with experiment

  20. Quark-level analogue of nuclear fusion with doubly heavy baryons.

    Science.gov (United States)

    Karliner, Marek; Rosner, Jonathan L

    2017-11-01

    The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm quarks (c) and one up quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm quarks. Here we report that this strong binding enables a quark-rearrangement, exothermic reaction in which two heavy baryons (Λ c ) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4 He n). The much larger binding energy (approximately 280 MeV) between two bottom quarks (b) causes the analogous reaction with bottom quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setups in which the highly exothermic nature of the fusion of two heavy-quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

  1. Theory of nuclear reactions, with applications to heavy ion scattering reactions

    International Nuclear Information System (INIS)

    Youssef, M.S.A.

    1981-01-01

    Nuclear science to day, has gained its stature through the pioneer work of both theorists and experimentalists within its two main divisions, Nuclear Reaction and Nuclear Structure theories. Our main interest in this theoretical work in nuclear reaction theory is focused on three topics, come under the headings of three parts which are the constituents of the present paper. Part 1 is concerned with ''Contributions to the theory of Threshold phenomena in nuclear reactions; cluster threshold states in heavy ion reactions''. Part II is devoted to ''Hermiticity of the Laplacian operator, R-matrix theories and direct interaction theory'', while part xII is ascribed to ''Heavy ion transfer reactions and scattering''. The aforementioned selected topics are the backbones of this thesis, which starts with general introduction giving a brief account about the material included in. In each part, investiqations are given in an extended manner through several chapters. Finally, the thesis is ended eith the chapter on ''General Discussions and Conclusions''. Appendices, references, and figure captions are found at the end of each part, the matter which we believe to facilitate much the reading through of the thesis. The first two parts are based (to some extent) on the same formal background (R-matrix, Kapur-Peierls-theories) and they converge to solve some physical problems originating from flux conservation laws in nuclear reactions, while the third part is indirect related to the first two; in principle it joins the other two parts under computational aspects. All of them after all, form the solidarity of the material included in the thesis. (author)

  2. Direct harvesting of Helium-3 (3He) from heavy water nuclear reactors

    International Nuclear Information System (INIS)

    Bentoumi, G.; Didsbury, R.; Jonkmans, G.; Rodrigo, L.; Sur, B.

    2013-01-01

    The thermal neutron activation of deuterium inside a heavy-water-moderated or -cooled nuclear reactor produces a build-up of tritium in the heavy water. The in situ decay of tritium can, for certain reactor types and operating conditions, produce potentially useable amounts of 3 He, which can be directly extracted via the heavy-water cover gas without first separating, collecting and storing tritium outside the reactor. It is estimated that the amount of 3 He available for recovery from the moderator cover gas of a 700 MWe class Pressurized Heavy Water Reactor (PHWR) ranges from 0.1 to 0.7 m 3 (STP) per annum, varying with the tritium activity buildup in the moderator. The harvesting of 3 He would generate approximately 12.7 m 3 (STP) of 3 He, worth more than $30M at current market rates, over a typical 25-year operating cycle of the PHWR. This paper discusses the production of 3 He in the moderator of a PHWR and its extraction from the 4 He moderator cover gas system using conventional methods. (author)

  3. Device for preventing spontaneous repositioning of a control element of a nuclear reactor

    International Nuclear Information System (INIS)

    Maslenok, B.A.; Chegaj, A.S.; Slobin, W.G.; Mednickij, W.G.; Genkin, L.I.; Petritschenko, N.F.; Mitrofanow, B.I.

    1976-01-01

    The invention concerns the control element of a nuclear reactor. The vertical connecting rod is to be prevented from spontaneous repositioning if the pressurized housing which encloses the control element becomes leaky. It is proposed to provide spheres as wedging elements locking the connecting rod, but also allowing easy loosening. (UWI) [de

  4. Distribution of Heavy Metal Elements in the Sea Water, Algae and Fish ofMuria Peninsula Area

    International Nuclear Information System (INIS)

    Djati-Pramana, J; Agus-Taftazani; Sudarmadji

    2000-01-01

    Analysis of heavy metal elements in the specimens of sea water, brownalgae and kerapu fish from two area sampling Lemah Abang and Semat beach byINAA method was done. The same of such specimens from Krakal beach was takenfor control specimen. The aim of this investigation was to obtain a part ofinput data for EMSB program. Preparation after sampling was performed asfollows. Sea water sample was concentrated using 1/5 times of the initialvolume. Algae and fish specimens were crushed using N 2 liquid, dried at thefreeze dryer than were homogenized and screened through 100 mesh. The threeof those specimens were irradiated together for 12 hours in the Lazy Susanirradiation facility of Kartini reactor. Flux neutron was 5.85 . 10 10 n/cm 2 .sec. The heavy metal elements that could be identified were Sm, Se,Cr, Zr, Fe and Co. Concentration in the specimens from Muria peninsula wasrelatively higher comparated to control specimens. This might be use to thefound of these indicators to concentrated that of heavy metals from sea wateror their environment which has a higher concentration. From t test for 95 %probability to control specimens was showed that these was a significantdifference from all the detected elements. From the obtained data there was apollution indication in the area at the period of sampling. (author)

  5. Determination of trace element and heavy metal in black tea and tea leaves using x-ray fluorescence

    International Nuclear Information System (INIS)

    Salih, Mohamed Abualgasim Abdalhakam

    2016-08-01

    The aim of this study was to provide information about the trace element and heavy metals concentrations in black tea and tea leaves. 23 different samples were collected from the Sudanese local market. The collected samples were characterized as the most common used items in Sudan. The concentration of trace and heavy elements were determined using x-ray fluorescence (X RF) technique. The standard reference materials (IAEA-V-10) and hay (powder) were used to evaluate the accuracy of the analytical result. The measured values were found in agreement with the certified values. The elements determined were K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb, and Sr. The average concentration of the elements is black tea were 2277.43, 7245.71, 1.11, 1025.29, 334.29, 6.88, 11.24, 9.47, 1.02, 7.08, 97.4 and 63.21 respectively while the average concentration of the elements in leaves tea were 2644.44, 8805.56, 1.02, 571.81, 295.44, 6.19, 10.69, 9.26, 0.91, 13.42, 63.03 and 67.14 respectively. The results showed an increase in the concentration of some elements such as calcium, chromium, manganese, iron, nickel, copper, zinc, bromine, rubidium and strontium (22500, 6.75, 48.9, 194, 4.37, 9,77, 24.9, 8.23, 7.79, 40,9) ppm respectively compared to certified values. Correlation between concentration of certain element and cluster analysis were preformed and the results compared with values of literature and the concentrations of some elements found to be similar.(Author)

  6. Chemical elimination of alumina in suspension in nuclear reactors heavy water

    International Nuclear Information System (INIS)

    Ledoux, A.

    1967-02-01

    Corrosion of aluminium in contact with moderating water in nuclear reactor leads to the formation of an alumina hydrosol which can have an adverse effect on the operation of the reactor. Several physical methods have been used in an attempt to counteract this effect. The method proposed here consists in the elimination of the aluminium by dissolution and subsequent fixation in the ionic form on mixed-bed ion-exchange resin. In order to do this, the parameters and the values of these parameters most favorable to the dissolution process have been determined. If the moderator is heavy water, the deuterated acid can be prepared by converting a solution in heavy water to a salt of the acid using a deuterated cationic resin. (author) [fr

  7. Detection of heavy-water leaks in nuclear reactors : a novel method

    International Nuclear Information System (INIS)

    Murthy, M.S.; Gor, M.K.

    2002-01-01

    Technical Physics and Prototype Engineering Division, BARC has designed, developed and produced several high sensitivity mass spectrometer helium leak detectors over a period of two decades. Sometimes back, when there was a problem of detecting heavy water leaks in situ in one of the nuclear power reactors of the Department of Atomic Energy, it was referred to this division for a technical solution. After discussing with the site engineers, the various problems involved in the on-line detection of heavy water leaks especially near the end fittings of the coolant assemblies, a novel method of leak detection was developed. Some of the salient features of the method and the results obtained in the laboratory tests are given in this paper. (author)

  8. Nuclear interactions in high energy heavy ions and applications in astrophysics

    International Nuclear Information System (INIS)

    Wefel, J.P.; Guzik, T.G.

    1993-01-01

    The overall objective is to study the mechanisms and the energy dependence of heavy ion fragmentation by studying the reactions of heavy ion projectiles (e.g. 4 He, 16 O, 20 Ne, 28 Si, 56 Fe) in a variety of targets (H, He, C, Si, Cu, Pb) and at a number of beam energies exceeding 0.1 GeV/nucleon. The results have application to questions in high-energy nuclear astrophysics. Most of the discussion is on low-energy 16 O, 28 Si data analysis. The description includes analysis procedures and techniques, detector calibrations, data selections and normalizations. Cross section results for the analysis are also presented. 83 figs., 6 tabs., 73 refs

  9. [Comparison of heavy metal elements between natural and plantation forests in a subtropical Montane forest].

    Science.gov (United States)

    Nie, Ming; Wan, Jia-Rong; Chen, Xiao-Feng; Wang, Li; Li, Bo; Chen, Jia-Kuan

    2011-11-01

    Heavy metals as one of major pollutants is harmful to the health of forest ecosystems. In the present paper, the concentrations of thirteen heavy metals (Fe, Al, Ti, Cr, Cu, Mn, V, Zn, Ni, Co, Pb, Se and Cd) were compared between natural and plantation forests in the Mt. Lushan by ICP-AES and atomic absorption spectroscopy. The results suggest that the soil of natural forest had higher concentrations of Fe, Al, Ti, Cu, Mn, V, Zn, Ni, Co, Pb, Se, and Cd than the plantation forest except for Cr. The soil of natural forest had a higher level of heavy metals than that of the plantation forest as a whole. This might be due to that the natural forest has longer age than the plantation forest, and fixed soil heavy metals take a longer period of time than the plantation forest.

  10. Elements to be considered in planning heavy ion fusion program: a summary

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.

    1978-01-01

    A summary of Battelle's Engineering Development Program Plan for inertial confinement fusion is presented. Included are development objectives, facilities to achieve these objectives, program strategies, and a discussion of heavy-ion driver development

  11. Heavy metals-bioremediation by highly radioresistant Deinococcus radiodurans biofilm prospective use in nuclear reactor decontamination

    International Nuclear Information System (INIS)

    Shukla, Sudhir K.; Subba Rao, T.

    2015-01-01

    Over the past few decades, rapid growth of chemical industries have enhanced the heavy metal contamination in water, thereby raising environmental concerns. In the nuclear power industry, decontamination procedure also generates radioactive heavy metal containing wastes. Radio-resistant Deinococcus radiodurans R1 is reported to be a potential candidate for the treatment of low active waste material. To use any bacterium for bioremediation purpose, knowledge about its biofilm production characteristics is a prerequisite. This is because biofilm-mediated bioremediation processes are more efficient as compared to processes mediated by their planktonic counterparts. However, so far there are no reports on the biofilm producing capability of D. radiodurans. We observed that tagging of D. radiodurans by a plasmid harbouring gfp and kan R conferred significant biofilm producing property to the bacterium. Chemical analysis of biofilm matrix components produced by D. radiodurans showed that the matrix consists primarily of proteins and carbohydrates with small amount of extracellular DNA (eDNA). Further, we studied the effect of Ca 2+ on D. radiodurans biofilm formation and it was observed that D. radiodurans biofilm formation was enhanced at higher concentrations of Ca 2+ . We investigated the capability of D. radiodurans biofilm to remove the heavy metals Co and Ni from synthetic waste streams. Results showed that Ca 2+ enhanced the bioremediation of both heavy metals (Co, Ni) by D. radiodurans biofilms in a highly significant manner. In the presence of 50 mM Ca 2+ 35% Co removal and 25% Ni removal was observed, when compared to biofilm grown in the absence of Ca 2+ , which showed mere 7% Co and 3% Ni removal, respectively. The results showed that the presence of Ca 2+ significantly enhanced exopolysaccharide and eDNA (both negatively charged) production in the biofilm matrix. This indicated adsorption could be the major mechanism behind enhanced biofilm mediated removal

  12. MODAL ANALYSIS OF CARRIER SYSTEM FOR HEAVY HORIZONTAL MULTIFUNCTION MACHINING CENTER BY FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2014-01-01

    Full Text Available The aim of the paper is to reveal and analyze resonance modes of a large-scale milling-drilling-boring machine. The machine has a movable column with vertical slot occupied by a symmetrical carriage with horizontal ram. Static rigidity of the machine is relatively low due to its large dimensions. So it is necessary to assess possible vibration activity. Virtual and operational trials of the machine have been carried out simultaneously. Modeling has been executed with the help of a finite element method (FEM. The FEM-model takes into account not only rigidity of machine structures but also flexibility of bearings, feed drive systems and guides. Modal FEM-analysis has revealed eight resonance modes that embrace the whole machine tool. They form a frequency interval from 12 to 75 Hz which is undesirable for machining. Three closely located resonances (31-37 Hz are considered as the most dangerous ones. They represent various combinations of three simple motions: vertical oscillations of a carriage, horizontal vibrations of a ram and column torsion. Reliability of FEM- estimations has been proved by in-situ vibration measurements.An effect for stabilization of resonance modes has been detected while making variations in design parameters of the machine tool. For example, a virtual replacement of cast iron for steel in machine structures practically does not have any effect on resonance frequencies. Rigidity increase in some parts (e.g. a ram has also a small effect on a resonance pattern. On the other hand, resonance stability makes it possible to avoid them while selecting a spindle rotation frequency.It is recommended to set double feed drives for all axes. A pair of vertical screws prevents a “pecking” resonance of the carriage at frequency of 54 Hz. It is necessary to foresee an operation of a main drive of such heavy machine tool in the above resonance interval with the spindle frequency of more than 75 Hz. For this purpose it is necessary

  13. FINITE ELEMENT ANALYSIS OF CONCRETE FILLER INFLUENCE ON DYNAMIC RIGIDITY OF HEAVY MACHINE TOOL PORTAL

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2016-01-01

    Full Text Available Virtual testing of portal machine tool has been carried out with the help of finite elements method (FEM. Static, modal and harmonic analyses have been made for a heavy planer. The paper reveals influence of concrete filler on machine tool dynamic flexibility. A peculiar feature of the simulation is concrete filling of a high-level transverse beam. Such approach oes look a typical one for machine-tool industry. Concrete has been considered as generalized material in two variants. It has been established that concrete application provides approximately 3-fold increase in machine tool rigidity per each coordinate. In this regard it is necessary to arrange closure of rigidity contour by filling all the cavities inside of the portal. Modal FEA makes it possible to determine that concrete increases comparatively weakly (1.3–1.4-fold frequencies of resonance modes. Frequency of the lowest mode rises only from 30.25 to 42.86 Hz. The following most active whole-machine eigenmodes have been revealed in the paper: “Portal pecking”, “Parallelogram” and “Traverse pecking”. In order to restrain the last mode it is necessary to carry out concrete filling of the traverse, in particular. Frequency-response characteristics and curves of dynamic rigidity for a spindle have been plotted for 0–150 Hz interval while using harmonic FEM. It has been determined that concrete increases dynamic machine tool rigidity by 2.5–3.5-fold. The effect is obtained even in the case when weakly damping concrete (2 % is used. This is due to distribution of vibrational energy flow along concrete and along cast iron as well. Thus energy density and vibration amplitudes must decrease. The paper shows acceptability for internal reinforcement of high-level machine tool parts (for example, portal traverses and fillers are applied for this purpose. Traverse weighting is compensated by additional torsional, shear and bending rigidity. The machine tool obtains the

  14. Heavy rare earth elements affect early life stages in Paracentrotus lividus and Arbacia lixula sea urchins

    International Nuclear Information System (INIS)

    Oral, Rahime; Pagano, Giovanni; Siciliano, Antonietta; Gravina, Maria; Palumbo, Anna; Castellano, Immacolata; Migliaccio, Oriana; Thomas, Philippe J.; Guida, Marco; Tommasi, Franca; Trifuoggi, Marco

    2017-01-01

    Background: Heavy rare earth elements (HREEs) have been scarcely studied for their toxicity, in spite of their applications in several technologies. Thus HREEs require timely investigations for their adverse health effects. Methods: Paracentrotus lividus and Arbacia lixula embryos and sperm were exposed to trichloride salts of five HREEs (Dy, Ho, Er, Yb and Lu) and to Ce(III) as a light REE (LREE) reference to evaluate: 1) developmental defects (% DD) in HREE-exposed larvae or in the offspring of HREE-exposed sperm; 2) mitotic anomalies; 3) fertilization success; and 4) reactive oxygen species (ROS) formation, and nitric oxide (NO) and malondialdehyde (MDA) levels. Nominal HREE concentrations were confirmed by inductively coupled plasma mass spectrometry (ICP-MS). Results: HREEs induced concentration-related DD increases in P. lividus and A. lixula larvae, ranging from no significant DD increase at 10 −7 M HREEs up to ≅100% DD at 10 −5 M HREE. Larvae exposed to 10 −5 M Ce(III) resulted in less severe DD rates compared to HREEs. Decreased mitotic activity and increased aberration rates were found in HREE-exposed P. lividus embryos. Significant increases in ROS formation and NO levels were found both in HREE-exposed and in Ce(III) embryos, whereas only Ce(III), but not HREEs resulted in significant increase in MDA levels. Sperm exposure to HREEs (10 −5 –10 −4 M) resulted in a concentration-related decrease in fertilization success along with increase in offspring damage. These effects were significantly enhanced for Dy(III), Ho(III), Er(III) and Yb(III), compared to Lu(III) and to Ce(III). Conclusion: HREE-associated toxicity affected embryogenesis, fertilization, cytogenetic and redox endpoints showing different toxicities of tested HREEs. - Highlights: • Different toxicities were exerted by five tested HREEs on sea urchin early life stages. • Sea urchin embryos and sperm were sensitive to HREE levels ranging from 1 to 100 μM, according to

  15. Heavy rare earth elements affect early life stages in Paracentrotus lividus and Arbacia lixula sea urchins

    Energy Technology Data Exchange (ETDEWEB)

    Oral, Rahime [Ege University, Faculty of Fisheries, TR-35100 Bornova, İzmir (Turkey); Pagano, Giovanni, E-mail: gbpagano@tin.it [“Federico II” University of Naples, Department of Chemical Sciences, I-80126 Naples (Italy); Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples (Italy); Siciliano, Antonietta; Gravina, Maria [“Federico II” University of Naples, Department of Biology, I-80126 Naples (Italy); Palumbo, Anna; Castellano, Immacolata; Migliaccio, Oriana [Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples (Italy); Thomas, Philippe J. [Environment and Climate Change Canada, Science & Technology Branch, National Wildlife Research Center – Carleton University, Ottawa, Ontario, Canada K1A 0H3 (Canada); Guida, Marco [“Federico II” University of Naples, Department of Biology, I-80126 Naples (Italy); Tommasi, Franca [University of Bari, Department of Biology, Bari (Italy); Trifuoggi, Marco [“Federico II” University of Naples, Department of Chemical Sciences, I-80126 Naples (Italy)

    2017-04-15

    Background: Heavy rare earth elements (HREEs) have been scarcely studied for their toxicity, in spite of their applications in several technologies. Thus HREEs require timely investigations for their adverse health effects. Methods: Paracentrotus lividus and Arbacia lixula embryos and sperm were exposed to trichloride salts of five HREEs (Dy, Ho, Er, Yb and Lu) and to Ce(III) as a light REE (LREE) reference to evaluate: 1) developmental defects (% DD) in HREE-exposed larvae or in the offspring of HREE-exposed sperm; 2) mitotic anomalies; 3) fertilization success; and 4) reactive oxygen species (ROS) formation, and nitric oxide (NO) and malondialdehyde (MDA) levels. Nominal HREE concentrations were confirmed by inductively coupled plasma mass spectrometry (ICP-MS). Results: HREEs induced concentration-related DD increases in P. lividus and A. lixula larvae, ranging from no significant DD increase at 10{sup −7} M HREEs up to ≅100% DD at 10{sup −5} M HREE. Larvae exposed to 10{sup −5} M Ce(III) resulted in less severe DD rates compared to HREEs. Decreased mitotic activity and increased aberration rates were found in HREE-exposed P. lividus embryos. Significant increases in ROS formation and NO levels were found both in HREE-exposed and in Ce(III) embryos, whereas only Ce(III), but not HREEs resulted in significant increase in MDA levels. Sperm exposure to HREEs (10{sup −5}–10{sup −4} M) resulted in a concentration-related decrease in fertilization success along with increase in offspring damage. These effects were significantly enhanced for Dy(III), Ho(III), Er(III) and Yb(III), compared to Lu(III) and to Ce(III). Conclusion: HREE-associated toxicity affected embryogenesis, fertilization, cytogenetic and redox endpoints showing different toxicities of tested HREEs. - Highlights: • Different toxicities were exerted by five tested HREEs on sea urchin early life stages. • Sea urchin embryos and sperm were sensitive to HREE levels ranging from 1 to 100

  16. Nuclear quantum many-body dynamics: from collective vibrations to heavy-ion collisions

    International Nuclear Information System (INIS)

    Simenel, Cedric

    2012-01-01

    This report gives a summary of my research on nuclear dynamics during the past ten years. The choice of this field has been motivated by the desire to understand the physics of complex systems obeying quantum mechanics. In particular, the interplay between collective motion and single-particle degrees of freedom is a source of complex and fascinating behaviours. For instance, giant resonances are characterised by a collective vibration of many nucleons, but their decay may occur by the emission of a single nucleon. Another example could be taken from the collision of nuclei where the transfer of few nucleons may have a strong impact on the formation of a compound system is non trivial. To describe these complex systems, one needs to solve the quantum many-body problem. The description of the dynamics of composite systems can be very challenging, especially when two such systems interact. An important goal of nuclear physics is to find a unified way to describe the dynamics of nuclear systems. Ultimately, the same theoretical model should be able to describe vibrations, rotations, fission, all the possible outcomes of heavy-ion collisions (elastic and inelastic scattering, particle transfer, fusion, and multifragmentation), and even the dynamics of neutron star crust. This desire for a global approach to nuclear dynamics has strongly influenced my research activities. In particular, all the numerical applications presented in this report have been obtained from few numerical codes solving equations derived from the same variational principle. Beside the quest for a unified model of nuclear dynamics, possible applications of heavy-ion collisions such as the formation of new nuclei is also a strong motivation for the experimental and theoretical studies of reaction mechanisms. This report is not a review article, but should be considered as a reading guide of the main papers my collaborators and myself have published. It also gives the opportunity to detail some

  17. Nuclear fuel element containing strips of an alloyed Zr, Ti, and Ni getter material

    International Nuclear Information System (INIS)

    Grossman, L.N.; Packard, D.R.

    1975-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. The nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of strips and preferably the strips are positioned inside a helical member in the plenum. The position of the alloy strips permits gases and liquids entering the plenum to contact and react with the alloy strips. (U.S.)

  18. Canning and inspection system for nuclear reactor fuel and reflector elements

    International Nuclear Information System (INIS)

    Goldman, L.A.; Hawke, B.C.

    1980-01-01

    A system is disclosed for canning, inspecting and transferring to a storage area fuel and reflector elements from a nuclear reactor. The system includes a transfer chute, environmental chamber, conveyor and canning mechanism operative to remove and replace closures on containers into which fuel and reflector elements are inserted or from which stored elements are removed while maintaining a sealed gaseous environment and permitting visual and mechanical inspection of the elements by an operator located in a remote shielded area

  19. Nuclear rotational population patterns in heavy-ion scattering and transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, J O; Stoyer, M A [Lawrence Berkeley Lab., CA (USA); Canto, L F; Donangelo, R [Universidade Federal do Rio de Janeiro, RJ (Brazil); Ring, P [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

    1991-05-01

    A model of {sup 239}Pu with decoupled neutron is used for theoretical calculations of rotational population patterns in heavy ion inelastic scattering and one-neutron transfer reactions. The system treated in {sup 90}Zr on {sup 239}Pu at the near-barrier energy of 500 MeV and backscattering angles of 180deg and 140deg. The influence of the complex nuclear optical potential is seen to be very strong, and the Nilsson wave function of the odd neutron produces a distinctive pattern in the transfer reaction. (orig.).

  20. Study relating to the physico-chemical behaviour of heavy water in nuclear reactors

    International Nuclear Information System (INIS)

    Chenouard, J.; Dirian, G.; Roth, E.; Vignet, P.; Platzer, R.

    1959-01-01

    Chemical and isotope pollution, and radiolytic decomposition are the two most important ways in which heavy water becomes degraded in nuclear reactors. Chemical pollution has led to the creation of ion exchange purification loops specially designed for reactors: the report contains a description in detail of the application of this purification method in CEA research reactors, including the analysis required, results obtained, and their interpretation. The intelligence obtained on radiolytic decomposition with the same facilities is also discussed, as well as the recombination apparatus and control equipment utilized. Finally, investigation to date in the CEA on recombination circuits for power reactors is also discussed. (author) [fr

  1. Squids, supercurrents, and slope anomalies: Nuclear structure from heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Guidry, M.W.

    1989-01-01

    Within the past five years we have developed experimental techniques to study heavy-ion transfer reactions to high spin states in deformed nuclei. These methods have been turned into a quantitative tool to assess the influence of collective excitation on single-particle and pairing structure. I discuss some of the nuclear structure questions which are being answered in these experiments: How strong is ground state pairing? How does pairing change with angular momentum? Why is two-neutron transfer much stronger than expected at large radial separation? What is the evidence for a nuclear Josephson Effect? What is the evidence for a nuclear Berry phase effect (nuclear SQUID)? Why does one-neutron transfer populate much higher spins than would be naively expected? Conversely, why does two-neutron transfer populate much lower spins than anyone expected? The answer to each of these questions involves the influence of detailed nuclear structure on transfer reactions, and represents quantitative new information about the effect of angular momentum and excitation energy on many-body systems with a finite number of particles. 8 refs., 6 figs

  2. Knowledge management as an element in realizing nuclear technology

    International Nuclear Information System (INIS)

    Schmatjko, K.J.

    2007-01-01

    Full text: A company is not defined by its competences but it lives in realizing these competences in products. The technical knowledge within the field, i.e. here in nuclear technology, is taken as granted at a first glance. For analyzing the role of knowledge management (KM) in the application this knowledge for our products, one can follow two different dimensions, thereby elucidating the needs and development requirements for KM methods: When first considering the 'operational' dimension, one can start from the scope of the manufacturer's knowledge which covers the construction of plants, then accompanying its life cycle, and pursues the development of the technology for the future. A board spectrum of KM activities has been established yet for these different phases, comprising tools with close product orientation or KM elements applied in 'support processes'. In cases of close KM integration in the business process, diversity over the different sectors of the company has emerged: 'locally' optimized solutions are favoured due to specific requirements of the technical field, to continuity or to ease of daily application. On the other hand, 'global' KM tools are often preferred for integration in 'global' support processes (as human resource (HR) management). This can be illustrated by some examples deployed yet, and their benefit: 1. Feedback procedures for new plant projects: capturing the experience during construction (e.g. by standardised reports), thereby strengthening quality criteria for the project and integrating evaluation into the project management (PM) process of the current project; thus reducing erection time - and related capital cost - for future plants. 2. Follow up event information on nuclear plants globally: by collecting and assessing events systematically for proactive technical action and as input for quality management (QM); thus identifying market needs in advance also. 3. IT based KM tool used in nuclear maintenance service

  3. Application of the UKP-2-1 accelerator of heavy ions in the field of nuclear and radiation physics. Chapter 2

    International Nuclear Information System (INIS)

    2003-01-01

    The UKP-2-1 accelerator is intended for research works conducting in the field of solid state physics, low energy nuclear physics, nuclear microanalysis, materials modification and others. The accelerator includes two autonomous beam transporting channels jointed by one accelerating potential. One of the channel is intended for hydrogen and inert gases' ions acceleration, obtained from duoplasmatron. The second one includes the source with cesium dispersion and it is intended for heavy ions acceleration. On the base of the accelerator the set of the analytical methods such as PIXE, RBS, NRA were developed allowing to study of samples element content, distribution of elements by depth, analysis of thin films thickness. The accelerator intensively using in the filed of inertial nuclear fusion and studies on Coulomb energy losses of plasma target fast protons. The experience of the accelerator in different environmental researches is gained as well. In particular of deuterium determination in the water samples by the nuclear reaction method and study of plutonium and uranium distribution in 'hot' particles by the proton-induced X-ray method are developed. Beginning of 1999 on the accelerator a new research activity trend related with nuclear physical analysis methods adaptation on charged particles beams for study of a biological objects has been developed. At present the accelerator hardware does not concedes to hardware of the best world laboratories

  4. Investigative radiochemistry. A key element in nuclear forensics

    International Nuclear Information System (INIS)

    Mayer, K.; Wallenius, M.; Varga, Z.; Wiss, T.; Fanghaenel, T.

    2011-01-01

    Since the fall of the Iron Curtain illicit trafficking of nuclear and radioactive material has become an issue of concern both on the political and the scientific level. Seized material may be analysed in order to obtain clues on its origin and intended use and to prevent diversion of material from the same source in the future. Nuclear materials (uranium or plutonium) are of particular worry due to the nuclear proliferation risk associated with the material. Nuclear forensic investigations are aimed at the fact that nuclear material carries (inherent) information on its history, including on its origin and the processes applied for its production. Important conclusions can be drawn from decay products, activation products and fission products. Chemical impurities and the isotopic composition of certain major and minor constituents may provide additional information. Comparison of the measured results with nuclear material databases may yield evidence on the production site. The paper will describe the methodologies developed for addressing the above issues, focussing on radiochemical methods. Examples of nuclear forensic casework will illustrate the experience gathered in these areas. (orig.)

  5. Ages and Heavy Element Abundances from Very Metal-poor Stars in the Sagittarius Dwarf Galaxy

    Science.gov (United States)

    Hansen, Camilla Juul; El-Souri, Mariam; Monaco, Lorenzo; Villanova, Sandro; Bonifacio, Piercarlo; Caffau, Elisabetta; Sbordone, Luca

    2018-03-01

    Sagittarius (Sgr) is a massive disrupted dwarf spheroidal galaxy in the Milky Way halo that has undergone several stripping events. Previous chemical studies were restricted mainly to a few, metal-rich ([Fe/H] \\gtrapprox -1) stars that suggested a top-light initial mass function (IMF). Here we present the first high-resolution, very metal-poor ([Fe/H] =‑1 to ‑3) sample of 13 giant stars in the main body of Sgr. We derive abundances of 13 elements, namely C, Ca, Co, Fe, Sr, Ba, La, Ce, Nd, Eu, Dy, Pb, and Th, that challenge the interpretation based on previous studies. Our abundances from Sgr mimic those of the metal-poor halo, and our most metal-poor star ([Fe/H] ∼ -3) indicates a pure r-process pollution. Abundances of Sr, Pb, and Th are presented for the first time in Sgr, allowing for age determination using nuclear cosmochronology. We calculate ages of 9+/- 2.5 {Gyr}. Most of the sample stars have been enriched by a range of asymptotic giant branch (AGB) stars with masses between 1.3 and 5 M ⊙. Sgr J190651.47–320147.23 shows a large overabundance of Pb (2.05 dex) and a peculiar abundance pattern best fit by a 3 M ⊙ AGB star. Based on star-to-star scatter and observed abundance patterns, a mixture of low- and high-mass AGB stars and supernovae (15–25 M ⊙) is necessary to explain these patterns. The high level (0.29 ± 0.05 dex) of Ca indicates that massive supernovae must have existed and polluted the early ISM of Sgr before it lost its gas. This result is in contrast with a top-light IMF with no massive stars polluting Sgr. Based on data obtained UVES/VLT ID: 083.B-0774, 075.B-0127.

  6. Nuclear criticality assessment of Oak Ridge research fuel element storage

    International Nuclear Information System (INIS)

    Thomas, J.T.

    1978-06-01

    Spent and partially spent Oak Ridge Research Reactor (ORR) fuel elements are retained in the storage section of the ORR pool facility. Determination of a maximum expected neutron multiplication factor for the storage area is accomplished by a validated calculational method. The KENO Monte Carlo code and the Hansen-Roach 16-group neutron cross section sets were validated by calculations of critical experiments performed with early ORR fuel elements and with SPERT-D fuel elements. Calculations of various fuel element arrangements are presented which confirm the subcriticality previously inferred from critical experiments and indicate the k/sub eff/ would not exceed 0.85, were the storage area to be filled to capacity with storage racks containing elements with the fissionable material loading increased to 350 g of 235 U

  7. Study of trace elements in milk by nuclear analytical techniques

    International Nuclear Information System (INIS)

    Gharib, A.; Rahimi, H.; Pyrovan, H.; Raoffi, N.J.; Taherpoor, H.

    1985-01-01

    This work is part of project with the IAEA in a coordinated program on 'Trace Elements in Human and Bio-environmental Systems' to evaluate their nutritional requierements, interrelations and the role of trace elements in health, metabolism, etc. Cow's milk is regarded to be one of the most important and most nutritious foodstuffs of mankind. Hence, as a first step, an elemental analysis for milk was carried out: a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of the project was the assessment of various analytical techniques involved. AAS, PIXE and NAA are presented here. The latter was applied both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is, however, some justification to clarify this internal inconsistency. PIXE analysis is very fast and rather routine, but the technique for trace element analysis needs certain adaptations and improvement. (author)

  8. Formation and disintegration of high-density nuclear matter in heavy-ion collisions

    International Nuclear Information System (INIS)

    Kitazoe, Yasuhiro; Matsuoka, Kazuo; Sano, Mitsuo

    1976-01-01

    The formation of high-density nuclear matter which may be expected to be attained in high-energy heavy-ion collisions and the subsequent disintegration of dense matter are investigated by means of the hydrodynamics. Head-on collisions of identical nuclei are considered in the nonrelativistic approximation. The compressed density cannot exceed 4 times of the normal one so long as the freedom of only nucleons is considered, and can become higher than 4 times when other freedoms such as the productions of mesons and also nucleon isobars are additionally taken into account. The angular distributions for ejected particles predominate both forwards and backwards at low collision energies, corresponding to the formation of nuclear density less than 2 times of the normal density and become isotropic at the point of 2 times of the normal one. As the collision energy increases further, lateral ejection is intensified gradually. (auth.)

  9. Density slope of the nuclear symmetry energy from the neutron skin thickness of heavy nuclei

    International Nuclear Information System (INIS)

    Chen Liewen; Ko Che Ming; Xu Jun; Li Baoan

    2010-01-01

    Expressing explicitly the parameters of the standard Skyrme interaction in terms of the macroscopic properties of asymmetric nuclear matter, we show in the Skyrme-Hartree-Fock approach that unambiguous correlations exist between observables of finite nuclei and nuclear matter properties. We find that existing data on neutron skin thickness Δr np of Sn isotopes give an important constraint on the symmetry energy E sym (ρ 0 ) and its density slope L at saturation density ρ 0 . Combining these constraints with those from recent analyses of isospin diffusion and the double neutron/proton ratio in heavy-ion collisions at intermediate energies leads to a more stringent limit on L approximately independent of E sym (ρ 0 ). The implication of these new constraints on the Δr np of 208 Pb as well as the core-crust transition density and pressure in neutron stars is discussed.

  10. Analysis of the doubly heavy baryons in the nuclear matter with the QCD sum rules

    International Nuclear Information System (INIS)

    Wang, Zhi-Gang

    2012-01-01

    In this article, we study the doubly heavy baryon states Ξ cc , Ω cc , Ξ bb and Ω bb in the nuclear matter using the QCD sum rules, and derive three coupled QCD sum rules for the masses, vector self-energies and pole residues. The predictions for the mass-shifts in the nuclear matter ΔM Ξ cc =-1.11simGeV, ΔM Ω cc =-0.33∝GeV, ΔM Ξ bb =-3.37∝GeV and ΔM Ω bb =-1.05∝GeV can be confronted with experimental data in the future. (orig.)

  11. Radiation Monitoring - A Key Element in a Nuclear Power Program

    International Nuclear Information System (INIS)

    Hussein, A.S.; El-dally, T.A.

    2008-01-01

    For a nuclear power plant, radiation is especially of great concern to the public and the environment. Therefore, a radiation monitoring program is becoming a critical importance. This program covers all phases of the nuclear plant including preoperational, normal operation, accident and decommissioning. The fundamental objective of radiation monitoring program is to ensure that the health and safety of public inside and around the plant and to confirm the radiation doses are below the dose limits for workers and the public. This paper summarizes the environmental radiation monitoring program for a nuclear power plant

  12. Transplutonium elements - a literature survey

    International Nuclear Information System (INIS)

    Sivaramakrishnan, C.K.; Jadhav, A.V.

    1974-01-01

    The report surveys reported work on the discovery of transplutonium elements and their production through various methods like bombardment of heavy elements with charged ions, successive neutron captures on heavy elements in reactors and multiple neutron captures by heavy elements during nuclear explosions. Estimated yields of transplutonium elements in special targets irradiated in reactors, and also as byproducts from spent power reactor fuels are quoted. Various chemical procedures adopted for recovery of these elements from irradiated target and also from power reactor fuel reprocessing streams are described. A brief survey of shielded facilities available at various centres for transplutonium programmes is also included. Major uses of some of these heavy elements are described. (author)

  13. Some elements of thought about nuclear in France

    International Nuclear Information System (INIS)

    Soulie, Charles

    2012-01-01

    This article was a contribution of a colloquium held at the French-Japanese House in Tokyo in February 2012. The author first gives an overview of the history of the development of nuclear activities in France from the creation of the CEA just after the Second World War, and of the evolution of the French nuclear energy policy. He notices that this development and the role of nuclear energy in power generation have been at the expense of the development of renewable energies for a while. He quotes statements made by the different French presidents on the issue of nuclear energy, and on energy independence. Then, he comments how the Fukushima accident has been perceived in France

  14. Instrumental nuclear physics: elements for a proper choice

    International Nuclear Information System (INIS)

    1994-01-01

    This report consists of 11 documents about instrumental nuclear physics. It describes several detectors and data analysis techniques. Separate abstracts were prepared for all the papers in this volume. (TEC)

  15. The Role of Nuclear Physics in Understanding the Cosmos and the Origin of Elements

    International Nuclear Information System (INIS)

    Balantekin, A. B.

    2011-01-01

    This popular lecture, given in the conference celebrating contributions of Akito Arima to physics on the occasion of his 80th anniversary, outlines the role of nuclear physics in understanding the origin of elements.

  16. Nuclear techniques for toxic elements in foodstuffs. Report on an IAEA co-ordinated research programme

    International Nuclear Information System (INIS)

    1994-01-01

    The document includes 10 final reports on the IAEA Co-ordinated Research Programme on Nuclear Techniques for Toxic Elements in Foodstuffs. A separate abstract was prepared for each report. Refs, figs and tabs

  17. Nuclear techniques for toxic elements in foodstuffs. Report on an IAEA co-ordinated research programme

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The document includes 10 final reports on the IAEA Co-ordinated Research Programme on Nuclear Techniques for Toxic Elements in Foodstuffs. A separate abstract was prepared for each report. Refs, figs and tabs.

  18. Storage device for a long nuclear reactor fuel element and/or a long nuclear reactor fuel element part

    International Nuclear Information System (INIS)

    Vogt, M.; Schoenwitz, H.P.; Dassbach, W.

    1986-01-01

    The storage device can be erected in a dry storage room for new fuel elements and also in a storage pond for irradiated fuel elements. It consists of shells, which are arranged vertically and which have a lid. A suspension for the fuel element is provided on the underside of the lid, which acts as a support against squashing or bending in case of vertical forces acting (earthquake). (DG) [de

  19. Dependence of heavy metal burnup on nuclear data libraries for fast reactors

    CERN Document Server

    Ohki, S

    2003-01-01

    Japan Nuclear Cycle Development Institute (JNC) is considering the highly burnt fuel as well as the recycling of minor actinide (MA) in the development of commercialized fast reactor cycle systems. Higher accuracy in burnup calculation is going to be required for higher mass plutonium isotopes ( sup 2 sup 4 sup 0 Pu, etc.) and MA nuclides. In the framework of research and development aiming at the validation and necessary improvements of fast reactor burnup calculation, we investigated the differences among the burnup calculation results with the major nuclear data libraries: JEF-2.2, ENDF/B-VI Release 5, JENDL-3.2, and JENDL-3.3. We focused on the heavy metal nuclides such as plutonium and MA in the central core region of a conventional sodium-cooled fast reactor. For main heavy metal nuclides ( sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 8 U, sup 2 sup 3 sup 9 Pu, sup 2 sup 4 sup 0 Pu, and sup 2 sup 4 sup 1 Pu), number densities after 1-cycle burnup did not change over one or two percent. Library dependence was re...

  20. On-line mass spectometry of nuclear reactions induced by heavy ions

    International Nuclear Information System (INIS)

    Saint Simon, M. de.

    1977-01-01

    The adaptation of the on-line mass-spectrometric technique to the special conditions of heavy ion induced reactions is described. The method is very selective about A and Z, even for the very heavy reaction products in counterpart of the limitation of its applications to the alkaline elements only. This method is used in order to study the effects of angular momentum brought by the projectile in the complete fusion process and in the following neutron evaporation. The analysis of excitation functions shows that the increase in mass of the projectile has not always the effect of increasing the rotation energy of the compound nucleus. The on-line mass spectrometry has allowed to study heavy ion induced fission. Measurements of complementary isotopic distributions of fission products make it possible to explain that the total number of neutrons emitted per fission can be always deduced from the fragment excitation energy. The study of the isotope distribution variance shows that the statistical model for fission is in good agreement with experimental results after taking into account the non-fusion processes [fr

  1. Recording of heavy ion tracks in silicates. Application to the determination of the abundance of ultra-heavy elements in old solar cosmic radiation

    International Nuclear Information System (INIS)

    Duraud, J.-P.

    1978-12-01

    The aim of this thesis is to determine the abundance A(Z) and energy spectrum of the elements of atomic number Z present in cosmic radiation, by means of fossil traces recorded in moon and meteorite minerals. The difficulties due amongst other things to natural annealing are examined in detail in part one, of this paper, the outcome being a thorough study of the processes responsible for the formation, chemical attack and annealing of heavy ion tracks. Part two describes an original approach used here and consisting of a combined analysis as a function of annealing for a given track, of the microscopic structure of the latent track and its attack rate. Part three uses the new rules established beforehand to propose a new method of studying the UH ion (Z>30) to VH ion (20 [fr

  2. Levels determination of heavy elements (Fe, Cu, Zn, Pb and Hg) in sword fish caught from the bay of Ghazaouet

    International Nuclear Information System (INIS)

    Chalabi, A.; Malek, M.; Ghomari, M.; Benamar, M.A.; Tchantchane, A.; Azbouche, A.; Toumert, I.; Benouali, N.; Tobbeche, S. , Algiers; Algeria)

    1993-04-01

    The nuclear technics 'PIXE' and 'XRF', were used for heavy metals analysis (Fe, Cu, Zn, Pb, and Hg), in sword fish (xiphias Gladius) caught in Ghazaouet bay. Muscles, liver and gonads were analysed. The methods gave similar results. A bioaccumulation phenomenon was observed except for Hg. The high amount of concentrations found liver, especially in the case of confirms that liver is a storage organ. The high levels of Zn seem to be due to the industrial wastes from the electrolyte plant in the region. All values were lower than the admissible norms

  3. High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

    International Nuclear Information System (INIS)

    Zheng Yongnan; Xu Yongjun; Yuan Daqing

    2014-01-01

    Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

  4. Progress Report. Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, Department of Heavy Ion Physics. 1992-1993

    International Nuclear Information System (INIS)

    Grama, C.; Ionescu-Bujor, M.; Poenaru, D.; Pop, A.

    1994-01-01

    A brief account of the research and development activities carried out in the Department of Heavy Ion Physics, Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, Bucharest, during the period January 1992 to December 1993 is presented. The main topics concern nuclear structure models and methods, heavy-ion-induced reactions, and general properties of nuclei and nuclear energy levels. Also, works dealing with particle detection, measuring instruments and methods are reported. The report contains two sections. The first covers the research in progress in the fields of nuclear structure, nuclear reactions, atomic physics, accelerator, instrumentation, methods and computer codes. The second one, the appendix, contains the list of publications of the Department staff in journals and proceedings, books, and preprints, the conference contributions, the academic degrees awarded, the scientific exchanges, and the list of scientific personnel

  5. Mobilization of heavy metals from contaminated paddy soil by EDDS, EDTA, and elemental sulfur

    NARCIS (Netherlands)

    Wang, G.; Koopmans, G.F.; Song, J.; Temminghoff, E.J.M.; Luo, Y.; Zhao, Q.; Japenga, J.

    2007-01-01

    For enhanced phytoextraction, mobilization of heavy metals (HMs) from the soil solid phase to soil pore water is an important process. A pot incubation experiment mimicking field conditions was conducted to investigate the performance of three soil additives in mobilizing HMs from contaminated paddy

  6. The role fo the Pygmy resonance in the synthesis of heavy elements with radioactive beams

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1990-12-01

    It is suggested that the inclusion of the virtual excitation of the soft giant dipole (pygmy) resonance in the calculation of the cross-section for very neutron-rich radioactive beam-induced fusion reactions may enhance the formation probability of the heavy compound nucleus produced at low excitation energy. (author)

  7. Dynamic SPR monitoring of yeast nuclear protein binding to a cis-regulatory element

    International Nuclear Information System (INIS)

    Mao, Grace; Brody, James P.

    2007-01-01

    Gene expression is controlled by protein complexes binding to short specific sequences of DNA, called cis-regulatory elements. Expression of most eukaryotic genes is controlled by dozens of these elements. Comprehensive identification and monitoring of these elements is a major goal of genomics. In pursuit of this goal, we are developing a surface plasmon resonance (SPR) based assay to identify and monitor cis-regulatory elements. To test whether we could reliably monitor protein binding to a regulatory element, we immobilized a 16 bp region of Saccharomyces cerevisiae chromosome 5 onto a gold surface. This 16 bp region of DNA is known to bind several proteins and thought to control expression of the gene RNR1, which varies through the cell cycle. We synchronized yeast cell cultures, and then sampled these cultures at a regular interval. These samples were processed to purify nuclear lysate, which was then exposed to the sensor. We found that nuclear protein binds this particular element of DNA at a significantly higher rate (as compared to unsynchronized cells) during G1 phase. Other time points show levels of DNA-nuclear protein binding similar to the unsynchronized control. We also measured the apparent association complex of the binding to be 0.014 s -1 . We conclude that (1) SPR-based assays can monitor DNA-nuclear protein binding and that (2) for this particular cis-regulatory element, maximum DNA-nuclear protein binding occurs during G1 phase

  8. 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)

  9. Studies on Elemental Contents of Some Biological and Environmental Materials Using Nuclear And Atomic Techniques

    International Nuclear Information System (INIS)

    Abd-El Aziz, W.M.M.

    2013-01-01

    The elemental concentration values of 31 elements in the fertilizer samples, have been determined by applying a sensitive nondestructive analytical techniques such as INAA. It has also shown enough sensitivity to determine the concentrations of several trace and rare earth elements, The concentration values of elements were compared with the corresponding elements obtained by the ICP-MS and XRF techniques, for the same samples. Phosphorus fertilizers contain varying amounts of heavy metals and other rare earth elements as contaminants from either phosphate rock ores or other ingredients used in the phosphate fertilizer industry. As some heavy metals are potentially harmful to human health, attention is being given to its avenues of entry into the human food chain. Uptake of such elements by plants consumed directly or indirectly by humans is one avenue of entry, so the effects of heavy metal contaminants in phosphate fertilizers are of concern. Commercial fertilizers have been used for decades and will probably continue to be used for many decades to come. Hence, even low annual accumulations may finally build up undesired concentrations in soil, especially where fertilizers with high heavy metal or rare earth element concentrations are used.Thus, a total of three synthetic and natural eye-liner samples of known origin that are commercially available in the Egyptian market were analyzed using Energy Dispersive X-ray (EDX), Atomic Absorption Mass Spectroscopy (AA-MS) and elemental analysis using Thermal Neutron Activation Technique (TNAT) for the natural one in powder form. It was found that lead (>86%) represents the main hazardous element in the natural eye-liner from African sources. Aluminum and Antimony were also found in the later sample in considerable concentration 0.92% and 0.71% respectively. For the synthetic two samples from French and American sources, the major hazardous element found to be Carbon in high concentration 94% and 52% respectively. The

  10. Effects of heavy elements in the sludge conveyed by the 2011 tsunami on human health and the recovery of the marine ecosystem

    International Nuclear Information System (INIS)

    Sera, K.; Goto, S.; Takahashi, C.; Saitoh, Y.; Yamauchi, K.

    2014-01-01

    The 2011 tsunami not only caused significant damage, but also drew a large amount of sludge from the bottom of the sea. This may have exerted negative effects on human health. In order to evaluate changes in elemental concentrations in the body before and after the tsunami, we collected long hairs from victims of the disaster. Furthermore, sludge and plant samples were collected from three prefectures. The sludge samples on land were found to be still contaminated with heavy elements. The concentrations of heavy elements in the soils and plants gathered from the same tidelands decreased after one year. In hair analyses, no clear changes have been observed in heavy element concentrations measured before and after the tsunami. However, the concentration of some essential elements, such as Cu, Ca and Mg, showed a decreasing tendency after the tsunami

  11. Effects of heavy elements in the sludge conveyed by the 2011 tsunami on human health and the recovery of the marine ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Sera, K., E-mail: ksera@iwate-med.ac.jp [Cyclotron Research Center, Iwate Medical University, 348-58 Tomegamori, Takizawa 020-0173 (Japan); Goto, S.; Takahashi, C.; Saitoh, Y. [Takizawa Laboratory, Japan Radioisotope Association, 348-58 Tomegamori, Takizawa 020-0173 (Japan); Yamauchi, K. [Division of Pulmonary Medicine, Department of Internal Medicine, Iwate Medical University, 19-1 Uchimaru, Morioka 020-8505 (Japan)

    2014-01-01

    The 2011 tsunami not only caused significant damage, but also drew a large amount of sludge from the bottom of the sea. This may have exerted negative effects on human health. In order to evaluate changes in elemental concentrations in the body before and after the tsunami, we collected long hairs from victims of the disaster. Furthermore, sludge and plant samples were collected from three prefectures. The sludge samples on land were found to be still contaminated with heavy elements. The concentrations of heavy elements in the soils and plants gathered from the same tidelands decreased after one year. In hair analyses, no clear changes have been observed in heavy element concentrations measured before and after the tsunami. However, the concentration of some essential elements, such as Cu, Ca and Mg, showed a decreasing tendency after the tsunami.

  12. Use of M and L transitions of heavy elements for the determination of a Si(Li) detector's efficiency

    International Nuclear Information System (INIS)

    Morales, J.R.; Romo, C.; Dinator, M.I.; Llona, F.; Tabacniks, M.

    1987-01-01

    The verification of the Si(Li) cryogenic detector's efficiency may be fastly carried out using the M radiations of the heavy elements, such as Pb and Au. Thin targets have been bombarded with protons of 2.0 and 6.6 MeV, thus resulting the transitions M and L. The number of emitted photons are possible to be inferred using tabulated cross sections from different authors. The comparison with the number of photons registered allows to determine the efficiency. (S.M.) [es

  13. Study of trace elements in milk by nuclear analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

    This work is part of a project with the IAEA, in a coordinated programme on ''trace elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of trace elements in health, metabolism etc. Cow's milk is regarded as one of the most important and nutritious foodstuffs consumed by people. Hence, as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is very fast and rather routine, the technique of trace element analysis needs certain adaptations and developments.

  14. Trace elements retained in washed nuclear fuel reprocessing solvents

    International Nuclear Information System (INIS)

    Gray, L.W.; MacMurdo, K.W.

    1979-09-01

    Analysis of purified TBP extractant from solvent extraction processes at Savannah River Plant showed several stable elements and several long-lived radioisotopes. Stable elements Al, Na, Br, Ce, Hg, and Sm are found in trace quantities in the solvent. The only stable metallic element consistently found in the solvent was Al, with a concentration which varies from about 30 ppM to about 10 ppM. The halogens Br and Cl appear to be found in the solvent systems as organo halides. Radionuclides found were principally 106 Ru, 129 I, 3 H, 235 U, and 239 Pu. The 129 I concentration was about 1 ppM in the first solvent extraction cycle of each facility. In the other cycles, 129 I concentration varied from about 0.1 to 0.5 ppM. Both 129 I and 3 H appear to be in the organic solvent as a result of exchange with hydrogen

  15. The nuclear equation of state in effective relativistic field theories and pion yields in heavy-ion collisions

    International Nuclear Information System (INIS)

    Schoenhofen, M.; Cubero, M.; Gering, M.; Sambataro, M.; Feldmeier, H.; Noerenberg, W.

    1989-06-01

    Within the framework of relativistic field theory for nucleons, deltas, scalar and vector mesons, a systematic study of the nuclear equation of state and its relation to pion yields in heavy-ion collisions is presented. Not the compressibility but the effective nucleon mass at normal nuclear density turns out to be the most sensitive parameter. Effects from vaccum fluctuations are well modelled within the mean-field no-sea approximation by self-interaction terms for the scalar meson field. Incomplete thermalization in the fireball may be the reason for the low pion yields observed in heavy-ion collisions. (orig.)

  16. Constraining the EOS of Neutron-Rich Nuclear Matter and Properties of Neutron Stars with Heavy-Ion Reactions

    International Nuclear Information System (INIS)

    Li Baoan; Worley, Aaron; Chen, L.-W.; Ko, Che Ming; Krastev, Plamen G.; Wen Dehua; Xiao Zhigang; Zhang Ming; Xu Jun; Yong Gaochan

    2009-01-01

    Heavy-ion reactions especially those induced by radioactive beams provide useful information about the density dependence of the nuclear symmetry energy, thus the Equation of State of neutron-rich nuclear matter, relevant for many astrophysical studies. The latest developments in constraining the symmetry energy at both sub- and supra-saturation densities from analyses of the isopsin diffusion and the π - /π + ratio in heavy-ion collisions using the IBUU04 transport model are discussed. Astrophysical ramifications of the partially constrained symmetry energy on properties of neutron star crusts, gravitational waves emitted by deformed pulsars and the w-mode oscillations of neutron stars are presented briefly.

  17. 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)

  18. Elemental characterization of the Persian Gulf sediments near the Bushehr Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sohrabpour, M.

    2004-01-01

    Thirty-three sediment samples from four shoreline and three sea positions in a defined sampling grid around the Bushehr Nuclear Power Plant (BNPP) have been taken over six sampling periods during 1996-1997. Elemental analysis of the samples has been performed with neutron activation and concentrations of seventeen elements have been obtained. Cross-correlation analysis has been carried out and four categories of related elements have been defined. (author)

  19. Theoretical basis for a transient thermal elastic-plastic stress analysis of nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hsu, T.R.; Bertels, A.W.M.; Banerjee, S.; Harrison, W.C.

    1976-07-01

    This report presents the theoretical basis for a transient thermal elastic-plastic stress analysis of a nuclear reactor fuel element subject to severe transient thermo-mechanical loading. A finite element formulation is used for both the non-linear stress analysis and thermal analysis. These two major components are linked together to form an integrated program capable of predicting fuel element transient behaviour in two dimensions. Specific case studies are presented to illustrate capabilities of the analysis. (author)

  20. Legal Elements For Nuclear Security: Egyptian Nuclear Law As A Case Study

    International Nuclear Information System (INIS)

    Ali, A.M.

    2013-01-01

    This paper deals with the legal bases for nuclear security. First, It analysis the international legal framework for nuclear security. Second, it analysis the legal bases for the import-export control. The legal aspects related with illicit trafficking (IT) were also reviewed. Third, It deals with the Egyptian nuclear law no. 7 and its executive regulation. The Egyptian legal regime for nuclear security and the role of State System for Accounting and Control of Nuclear Materials (SSAC) in realizing the nuclear security were also discussed. The purpose of the paper is to evaluate the Egyptian legal framework for nuclear security.

  1. Exploring Elements of Fun to Motivate Heavy Drinking Youth to (retrain Cognition

    Directory of Open Access Journals (Sweden)

    Wouter Boendermaker

    2015-09-01

    Adding (social game elements can increase motivation to train, and while the mobile training did not appear to be more motivating, it also did not underperform compared to the regular training in this sample. This warrants more research into motivational elements for CBM training in younger audiences.

  2. Finite element modeling simulation-assisted design of integrated microfluidic chips for heavy metal ion stripping analysis

    International Nuclear Information System (INIS)

    Hong, Ying; Zou, Jianhua; Ge, Gang; Xiao, Wanyue; Shao, Jinjun; Dong, Xiaochen; Gao, Ling

    2017-01-01

    In this article, a transparent integrated microfluidic device composed of a 3D-printed thin-layer flow cell (3D-PTLFC) and an S-shaped screen-printed electrode (SPE) has been designed and fabricated for heavy metal ion stripping analysis. A finite element modeling (FEM) simulation is employed to optimize the shape of the electrode, the direction of the inlet pipeline, the thin-layer channel height and the sample flow rate to enhance the electron-enrichment efficiency for stripping analysis. The results demonstrate that the S-shaped SPE configuration matches the channel in 3D-PTLFC perfectly for the anodic stripping behavior of the heavy metal ions. Under optimized conditions, a wide linear range of 1–80 µ g l −1 is achieved for Pb 2+ detection with a limit of 0.3 µ g l −1 for the microfluidic device. Thus, the obtained integrated microfluidic device proves to be a promising approach for heavy metal ions stripping analysis with low cost and high performance. (paper)

  3. Physical linkage of a human immunoglobulin heavy chain variable region gene segment to diversity and joining region elements

    International Nuclear Information System (INIS)

    Schroeder, H.W. Jr.; Walter, M.A.; Hofker, M.H.; Ebens, A.; Van Dijk, K.W.; Liao, L.C.; Cox, D.W.; Milner, E.C.B.; Perlmutter, R.M.

    1988-01-01

    Antibody genes are assembled from a series of germ-line gene segments that are juxtaposed during the maturation of B lymphocytes. Although diversification of the adult antibody repertoire results in large part from the combinatorial joining of these gene segments, a restricted set of antibody heavy chain variable (V H ), diversity (D H ), and joining (J H ) region gene segments appears preferentially in the human fetal repertoire. The authors report here that one of these early-expressed V H elements (termed V H 6) is the most 3' V H gene segment, positioned 77 kilobases on the 5' side of the J H locus and immediately adjacent to a set of previously described D H sequences. In addition to providing a physical map linking human V H , D H , and J H elements, these results support the view that the programmed development of the antibody V H repertoire is determined in part by the chromosomal position of these gene segments

  4. Seismic analysis of the APR1400 nuclear reactor system using a verified beam element model

    International Nuclear Information System (INIS)

    Park, Jong-beom; Park, No-Cheol; Lee, Sang-Jeong; Park, Young-Pil; Choi, Youngin

    2017-01-01

    Highlights: • A simplified beam element model is constructed based on the real dynamic characteristics of the APR1400. • Time history analysis is performed to calculate the seismic responses of the structures. • Large deformations can be observed at the in-phase mode of reactor vessel and core support barrel. - Abstract: Structural integrity is the first priority in the design of nuclear reactor internal structures. In particular, nuclear reactor internals should be designed to endure external forces, such as those due to earthquakes. Many researchers have performed finite element analyses to meet these design requirements. Generally, a seismic analysis model should reflect the dynamic characteristics of the target system. However, seismic analysis based on the finite element method requires long computation times as well as huge storage space. In this research, a beam element model was developed and confirmed based on the real dynamic characteristics of an advanced pressurized water nuclear reactor 1400 (APR1400) system. That verification process enhances the accuracy of the finite element analysis using the beam elements, remarkably. Also, the beam element model reduces seismic analysis costs. Therefore, the beam element model was used to perform the seismic analysis. Then, the safety of the APR1400 was assessed based on a seismic analysis of the time history responses of its structures. Thus, efficient, accurate seismic analysis was demonstrated using the proposed beam element model.

  5. Seismic analysis of the APR1400 nuclear reactor system using a verified beam element model

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong-beom [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Park, No-Cheol, E-mail: pnch@yonsei.ac.kr [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Lee, Sang-Jeong; Park, Young-Pil [Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Choi, Youngin [Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon 34142 (Korea, Republic of)

    2017-03-15

    Highlights: • A simplified beam element model is constructed based on the real dynamic characteristics of the APR1400. • Time history analysis is performed to calculate the seismic responses of the structures. • Large deformations can be observed at the in-phase mode of reactor vessel and core support barrel. - Abstract: Structural integrity is the first priority in the design of nuclear reactor internal structures. In particular, nuclear reactor internals should be designed to endure external forces, such as those due to earthquakes. Many researchers have performed finite element analyses to meet these design requirements. Generally, a seismic analysis model should reflect the dynamic characteristics of the target system. However, seismic analysis based on the finite element method requires long computation times as well as huge storage space. In this research, a beam element model was developed and confirmed based on the real dynamic characteristics of an advanced pressurized water nuclear reactor 1400 (APR1400) system. That verification process enhances the accuracy of the finite element analysis using the beam elements, remarkably. Also, the beam element model reduces seismic analysis costs. Therefore, the beam element model was used to perform the seismic analysis. Then, the safety of the APR1400 was assessed based on a seismic analysis of the time history responses of its structures. Thus, efficient, accurate seismic analysis was demonstrated using the proposed beam element model.

  6. Storage frame for long fuel elements for nuclear reactors

    International Nuclear Information System (INIS)

    Ristow, U.; Krainer, F.; Heinz, G.

    1986-01-01

    Vertical shafts with a cross section suitable for the fuel element cross section and made of metal can have corrugations for spacing from one another. These corrugations are machined parallel to the wall surface of the shafts. One thus obtains great accuracy of distancing. (orig./HP) [de

  7. Model calculations of nuclear data for biologically-important elements

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Blann, M.; Reffo, G.; Young, P.G.

    1994-05-01

    We describe calculations of neutron-induced reactions on carbon and oxygen for incident energies up to 70 MeV, the relevant clinical energy in radiation neutron therapy. Our calculations using the FKK-GNASH, GNASH, and ALICE codes are compared with experimental measurements, and their usefulness for modeling reactions on biologically-important elements is assessed

  8. Positioning device for fuel rods of nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    1987-01-01

    The positioning device consists of individual containers, similar to cases, for the fuel elements. These cases are arranged vertically next to one another and are held by means of vertical support posts and horizontal arms. The openings of the cases can be individually approached by the trolleys. (DG) [de

  9. Device for manipulating a nuclear reactor fuel element in a fuel element pond containing water

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1977-01-01

    Using this device a fuel element can be manipulated inside a water filled storage pond for inspection purposes. A transport arrangement which is normally situated above such a pond is modified for this purpose. A crane bridge runs on rails on the upper edge of the pond. A type of trolley runs transversely to the direction of travel of the bridge between 2 wide flange supports forming the crane support. During movement this trolley moves a submerged combination of periscope and TV camera pendant from it at about half the pond height horizontally along the crane support. 2 vehicles move between these on 4 rollers each, on the under flanges of the crane support at spacings of about one fuel element length. A pendant arm of the same length as the periscope dips vertically into the pond from each vehicle. There is a bar of about fuel element length resting on the lower ends of both arms. The surface of a fuel element lying on this bar can be inspected through the periscope on longitudinal travel of the trolley. The bar with the fuel element can be rotated 90 0 downwards into a vertical position after removal of one or more rotating kingpins and release of a rope hanging on the end away from the kingpin. The rope is actuated by a winch on the crane support. The bar has vertical plates at both ends to hold the fuel element in its vertical position. (HP) [de

  10. Heavy metal, trace element and petroleum hydrocarbon pollution in the Arabian Gulf: Review

    OpenAIRE

    Afnan Mahmood Freije

    2015-01-01

    The Arabian Gulf environmental status was assessed based on studies conducted in Bahrain, Kuwait, Oman, Saudi Arabia, Qatar, and United Arab Emirates (UAE) during 1983–2011. This review examines all sorts of pollutions in the Arabian Gulf area over the last three decades. Approximately 50 published studies were reviewed in order to determine the pollution status in the Arabian Gulf regarding heavy metals and organic substances. Three types of environmental pollutions including marine and coas...

  11. Proposal of a system for fuel elements inspection of CDTN TRIGA nuclear reactor

    International Nuclear Information System (INIS)

    Rodrigues, Rogerio Rivail; Mesquita, Amir Zacarias

    2013-01-01

    The CDTN has in its facilities a TRIGA-type nuclear reactor. The reactor's cooling water must be treated and managed with the goal of keeping its low conductivity to minimize corrosion of the reactor components, mainly of fuel elements (FE), and reduce the level of radioactivity. The aim of this paper is to present a proposal for the development of a system for verification of some possible leaks in FE nuclear research reactors, based on the sipping test. This type of testing is a way to check for leaks of fission products from fuel element of nuclear research reactor. In the future, when the test will do, it will have a correlation between the components found in the reactor cooling water pool and integrity of nuclear fuel elements. The device development and its application will be presented here, covering results that were not previously investigated yet, giving originality to this project. (author)

  12. Report of the joint seminar on heavy-ion nuclear physics and nuclear chemistry in the energy region of tandem accelerators (II)

    International Nuclear Information System (INIS)

    1986-04-01

    A meeting of the second joint seminar on Heavy-Ion Nuclear Physics and Nuclear Chemistry in the Energy Region of Tandem Accelerators was held after an interval of two years at the Tokai Research Establishment of the JAERI, for three days from January 9 to 11, 1986. In the seminar, about 70 nuclear physicists and nuclear chemists of JAERI and other Institutes participated, and 38 papers were presented. These include general reviews and topical subjects which have been developed intensively in recent years, as well as the new results obtained by using the JAERI tandem accelerator. This report is a collection of the papers presented to the seminar. (author)

  13. Use of nuclear and nuclear-related analytical techniques in studies of trace and minor elements in air pollution

    International Nuclear Information System (INIS)

    Smodis, Borut; Stropnik, Boris

    1994-01-01

    Among nuclear and nuclear-related analytical techniques, neutron activation and X-ray fluorescence analysis are particularly useful for environmental studies owing to their non-destructive character and multi-element capability. In this work, procedures for k o -standardized instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) spectrometry for trace and minor elements in air pollution studies were investigated. The methods applied were validated by the analysis of suitable reference materials. Using INAA, 20 experimentally obtained elemental values out of 21 certified and all 29 experimentally obtained values compared with 'consensus' values (for the elements where no certified numbers are available) in two SRMs were statistically indistinguishable. Also, the contents of 28 elements in candidate NIST SRM 1573a Tomato Leaves are reported. The EDXRF results were statistically indistinguishable from certified values for eight out of nine elements in NIST SRM 3087. The detection limit for this method is around at 0.1 μg cm -2 per element, so in BCR CRM No. 128, which is intended for ambient air pollution data, only Fe and Zn out of 14 elements reported in the certificate were detected with acceptable precision (i.e., 10%) owing to the very low air particulate matter loading, lying in the region of only 250 μg cm -2 . (Author)

  14. Nuclear fuel element containing particles of an alloyed Zr, Ti, and Ni getter material

    International Nuclear Information System (INIS)

    Grossman, L.N.; Levin, H.A.

    1975-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. The nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles of alloy. The container is preferably held in the spring in the plenum of the fuel element. (Official Gazette)

  15. Heavy quarks and nuclei, or the charm & beauty of nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Kharzeev, D.

    1997-09-22

    This report contains viewgraphs on the following: why heavy quarks? Heavy quarkonium in QCD vacuum and in matter; Phenomenology of quarkonium production; Induced decay of QCD vacuum in heavy ion collisions? Implications for quarkonium production; and Outlook.

  16. Heavy Scalar, Vector, and Axial-Vector Mesons in Hot and Dense Nuclear Medium

    Directory of Open Access Journals (Sweden)

    Arvind Kumar

    2014-01-01

    Full Text Available In this work we shall investigate the mass modifications of scalar mesons (D0; B0, vector mesons (D*; B*, and axial-vector mesons (D1; B1 at finite density and temperature of the nuclear medium. The above mesons are modified in the nuclear medium through the modification of quark and gluon condensates. We will find the medium modification of quark and gluon condensates within chiral SU(3 model through the medium modification of scalar-isoscalar fields σ and ζ at finite density and temperature. These medium modified quark and gluon condensates will further be used through QCD sum rules for the evaluation of in-medium properties of the above mentioned scalar, vector, and axial vector mesons. We will also discuss the effects of density and temperature of the nuclear medium on the scattering lengths of the above scalar, vector, and axial-vector mesons. The study of the medium modifications of the above mesons may be helpful for understanding their production rates in heavy-ion collision experiments. The results of present investigations of medium modifications of scalar, vector, and axial-vector mesons at finite density and temperature can be verified in the compressed baryonic matter (CBM experiment of FAIR facility at GSI, Germany.

  17. The nuclear fuel cycle: (2) fuel element manufacture

    International Nuclear Information System (INIS)

    Doran, J.

    1976-01-01

    Large-scale production of nuclear fuel in the United Kingdom is carried out at Springfields Works of British Nuclear Fuels Ltd., a company formed from the United Kingdom Atomic Energy Authority in 1971. The paper describes in some detail the Springfields Works processes for the conversion of uranium ore concentrate to uranium tetrafluoride, then conversion of the tetrafluoride to either uranium metal for cladding in Magnox to form fuel for the British Mk I gas-cooled reactors, or to uranium hexafluoride for enrichment of the fissile 235 U isotope content at the Capenhurst Works of BNFL. Details are given of the reconversion at Springfields Works of this enriched uranium hexafluoride to uranium dioxide, which is pelleted and then clad in either stainless steel or zircaloy containers to form the fuel assemblies for the British Mk II AGR or advanced gas-cooled reactors or for the water reactor fuels. (author)

  18. Labile rhizosphere soil solution fraction for prediction of bioavailability of heavy metals and rare earth elements to plants.

    Science.gov (United States)

    Shan, Xiao-Quan; Wang, Zhongwen; Wang, Weisheng; Zhang, Shuzhen; Wen, Bei

    2003-02-01

    A labile rhizosphere soil solution fraction has been recommended to predict the bioavailability of heavy metals and rare earth elements to plants. This method used moist rhizosphere soil in combination with a mixture of 0.01 mol L(-1) of low-molecular-weight organic acids (LMWOAs) as extractant. The extracted soil solutions were fractionated into two colloidal fractions of soil solution fraction, F(lrss). For the soil solutions extracted with a mixture of LMWOAs the concentrations of heavy metals and rare earth elements in F(2) and F(3) were quite similar. However, the mean concentrations of Cr, Ni, Zn, Cu, Pb, Cd, La, Ce, Pr, and Nd in F(lrss) accounted for 79.9%, 91.3%, 90.8%, 60.1%, 77.5%, 75.3%, 81.2%, 77.2%, 80.3%, and 79.5%, respectively, of their concentrations in F(2). In contrast, there were no differences in the extractable metal concentrations between the three fractions while the first step of the method recommended by the European Community of Reference (BCR), where 0.1 mol L(-1) acetic acid was used as an extractant. The single correlation analysis was made between metal concentrations in the different fractions of soil solutions and their concentrations in wheat. If the first step of BCR method was used there was no good correlation between heavy metals in soil pools and that in wheat shoots and roots. When LMWAOs were used a good correlation was obtained between the concentrations of heavy metals in soil pools and that in wheat roots, which followed a general order of r(1 kD, LMWOAs) >r(0.2 microm, LMWOAs) approximately r(0.45 microm, LMWOAs). In the case of rare earth elements the good correlation was obtained for both the wheat roots and shoots. Generally, the correlation coefficients obtained by LMWAOs were better than that obtained by the first step of BCR method. Therefore, LMWAOs and F(lrss) were strongly recommended to predict the bioavailability of metals in soil pools to plants.

  19. Support grid for fuel elements in a nuclear reactor

    International Nuclear Information System (INIS)

    Finch, L.M.

    1977-01-01

    A support grid is provided for holding nuclear fuel rods in a rectangular array. Intersecting sheet metal strips are interconnected using opposing slots in the strips to form a rectangular cellular grid structure for engaging the sides of a multiplicity of fuel rods. Spring and dimple supports for engaging fuel and guide rods extending through each cell in the support grid are formed in the metal strips with the springs thus formed being characterized by nonlinear spring rates

  20. Development of nuclear transmutation technology for transuranic elements

    International Nuclear Information System (INIS)

    Mukaiyama, Takehiko

    1996-01-01

    Partitioning and Transmutation (P-T) of long-lived radioactive nuclides is conceived as the technology to improve the high-level radioactive waste management. This report discusses the incentives of P-T, generation of long-lived nuclides in fission reactors, nuclear transmutation technologies, R and D activities of the partitioning and transmutation technology development programs at JAERI and in the world. (author)