WorldWideScience

Sample records for temperature nuclear

  1. Low temperature nuclear heat

    Energy Technology Data Exchange (ETDEWEB)

    Kotakorpi, J.; Tarjanne, R. (comps.)

    1977-08-01

    The meeting was concerned with the use of low grade nuclear heat for district heating, desalination, process heat, and agriculture and aquaculture. The sessions covered applications and demand, heat sources, and economics.

  2. Nuclear deformation at finite temperature.

    Science.gov (United States)

    Alhassid, Y; Gilbreth, C N; Bertsch, G F

    2014-12-31

    Deformation, a key concept in our understanding of heavy nuclei, is based on a mean-field description that breaks the rotational invariance of the nuclear many-body Hamiltonian. We present a method to analyze nuclear deformations at finite temperature in a framework that preserves rotational invariance. The auxiliary-field Monte Carlo method is used to generate a statistical ensemble and calculate the probability distribution associated with the quadrupole operator. Applying the technique to nuclei in the rare-earth region, we identify model-independent signatures of deformation and find that deformation effects persist to temperatures higher than the spherical-to-deformed shape phase-transition temperature of mean-field theory.

  3. High temperature heat exchange: nuclear process heat applications

    Energy Technology Data Exchange (ETDEWEB)

    Vrable, D.L.

    1980-09-01

    The unique element of the HTGR system is the high-temperature operation and the need for heat exchanger equipment to transfer nuclear heat from the reactor to the process application. This paper discusses the potential applications of the HTGR in both synthetic fuel production and nuclear steel making and presents the design considerations for the high-temperature heat exchanger equipment.

  4. Constant temperature description of the nuclear level densities

    Science.gov (United States)

    Horoi, Mihai; Dissanayake, Jayani

    2017-12-01

    The spin and parity dependent nuclear level densities (NLD) are calculated for medium-heavy nuclei using shell model techniques. The NLD are used to calculate cross sections and reaction rates of interest for nuclear astrophysics and nuclear energy applications. We investigate a new approach of describing the shell model NLD via a constant temperature parametrization. This approach provides new information about the effects of symmetries on the temperature of the low-lying nuclear states, and it is shown to be more versatile for applications.

  5. Nuclear Weapons Effects: Dust and Air Temperature Environment

    Science.gov (United States)

    The report presents a computer program for calculating the dust and air temperature environment resulting from nuclear weapons detonations. The...cessation of blast winds. Air temperature is treated as a dust-related phenomenon. The ground, heated by thermal radiation prior to arrival of the air

  6. HIGH TEMPERATURE, HIGH POWER HETEROGENEOUS NUCLEAR REACTOR

    Science.gov (United States)

    Hammond, R.P.; Wykoff, W.R.; Busey, H.M.

    1960-06-14

    A heterogeneous nuclear reactor is designed comprising a stationary housing and a rotatable annular core being supported for rotation about a vertical axis in the housing, the core containing a plurality of radial fuel- element supporting channels, the cylindrical empty space along the axis of the core providing a central plenum for the disposal of spent fuel elements, the core cross section outer periphery being vertically gradated in radius one end from the other to provide a coolant duct between the core and the housing, and means for inserting fresh fuel elements in the supporting channels under pressure and while the reactor is in operation.

  7. Nuclear order in silver at pico-Kelvin temperature

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

    1997-01-01

    Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 mu T. The entropy-field phase diagram was determined using the spin-dependent absorption.......Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 mu T. The entropy-field phase diagram was determined using the spin-dependent absorption....

  8. Nuclear order in silver at pico-Kelvin temperature

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

    1997-01-01

    Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 μT. The entropy-field phase diagram was determined using the spin-dependent absorption.......Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 μT. The entropy-field phase diagram was determined using the spin-dependent absorption....

  9. 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.

  10. 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.

  11. Neutron studies of nuclear magnetism at ultralow temperature

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

    1998-01-01

    Nuclear magnetic order in copper and silver has been investigated by neutron diffraction. Antiferromagnetic order is observed in these simple, diamagnetic metals at temperatures below 50 nK and 560 pK, respectively. Both crystallize in the FCC-symmetry which is fully frustrated for nearest...

  12. Surveying Temperature and Density Measurements in Nuclear Calorimetry

    Science.gov (United States)

    Raciti, G.; Bassini, R.; Begemann-Blaich, M.; Fritz, S.; Groß, C.; Immè, G.; Iori, I.; Lynen, U.; Mahi, M.; Möhlenkamp, T.; Müller, W. F. J.; Ocker, B.; Odeh, T.; Pochodzalla, J.; Riccobene, G.; Romano, F. P.; Saija, A.; Schwarz, C.; Serfling, V.; Schnittker, M.; Schüttauf, A.; Seidel, W.; Sfienti, C.; Trautmann, W.; Trzclnski, A.; Verde, G.; Xi, Hongfei; Zwieglinski, B.

    2001-11-01

    An experimental investigation on thermodynamical observables characterizing the conditions of multifragmenting systems is reported. High granularity hodoscopes allowed simultaneous measurements of isotopic and emission temperatures. HBT interferometry with light charged particles allowed radii measurements. The disagreement between the two temperature measurements could be related to the space-time evolution of the fragmentation process as confirmed by density measurements. The slope temperatures derived from the target spectator decay fragment energy spectra suggest a dependence on the Fermi motion within the initial system. The dependence of the Nuclear Caloric Curve on the mass of the systems was probed.

  13. Nuclear Quantum Vibrational Effects in Shock Hugoniot Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, N; Reed, E; Fried, L E

    2009-07-23

    We present a straightforward method for the inclusion of quantum nuclear vibrational effects in molecular dynamics calculations of shock Hugoniot temperatures. Using a Grueneisen equation of state and a quasiharmonic approximation to the vibrational energies, we derive a simple, post-processing method for calculation of the quantum corrected Hugoniot temperatures. We have used our novel technique on ab initio simulations of shock compressed water. Our results indicate significantly closer agreement with all available experimental temperature data. Our formalism and technique can be easily applied to a number of different shock compressed molecular liquids or solids.

  14. Damage tolerance of nuclear graphite at elevated temperatures

    Science.gov (United States)

    Liu, Dong; Gludovatz, Bernd; Barnard, Harold S.; Kuball, Martin; Ritchie, Robert O.

    2017-06-01

    Nuclear-grade graphite is a critically important high-temperature structural material for current and potentially next generation of fission reactors worldwide. It is imperative to understand its damage-tolerant behaviour and to discern the mechanisms of damage evolution under in-service conditions. Here we perform in situ mechanical testing with synchrotron X-ray computed micro-tomography at temperatures between ambient and 1,000 °C on a nuclear-grade Gilsocarbon graphite. We find that both the strength and fracture toughness of this graphite are improved at elevated temperature. Whereas this behaviour is consistent with observations of the closure of microcracks formed parallel to the covalent-sp2-bonded graphene layers at higher temperatures, which accommodate the more than tenfold larger thermal expansion perpendicular to these layers, we attribute the elevation in strength and toughness primarily to changes in the residual stress state at 800-1,000 °C, specifically to the reduction in significant levels of residual tensile stresses in the graphite that are `frozen-in' following processing.

  15. High-temperature glasses for nuclear waste isolation

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, L.R.; Maupin, G.D.; Oma, K.H.

    1986-03-01

    As part of the effort to discover and evaluate viable second-generation waste forms, glasses with processing temperatures higher than the 1100 to 1200/sup 0/C used for reference borosilicate glasses are being examined. This approach allows the use of previously developed technology for producing nuclear waste glasses, with a few modifications. Low alkali high alumina-boron glasses processed at 1400/sup 0/C and containing 25 wt % simulated reprocessed commercial nuclear waste have been fabricated and evaluated for chemical durability. These glasses exhibited matrix dissolution rates at 90/sup 0/C in deionized water that are at least an order of magnitude lower than current reference glass compositions over a wide range of flow conditions. 6 refs., 5 figs.

  16. High-temperature turbopump assembly for space nuclear thermal propulsion

    Science.gov (United States)

    Overholt, David M.

    1993-01-01

    The development of a practical, high-performance nuclear rocket by the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program places high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio. The operating parameters arising from these goals drive the propellant-pump design. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is effected by rapid heating of the propellant from 100 K to thousands of degrees in the particle-bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. One approach to achieve high performance is to use an uncooled carbon-carbon nozzle and duct turbine inlet. The high-temperature capability is obtained by using carbon-carbon throughout the TPA hot section. Carbon-carbon components in development include structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines plus a wide variety of other turbomachinery applications.

  17. Power cycle assessment of nuclear high temperature gas-cooled reactors

    OpenAIRE

    Herranz, L.E.; Linares, J.I.; Moratilla, B.Y.

    2009-01-01

    Power cycle assessment of nuclear high temperature gas-cooled reactors correspondance: Corresponding author. Tel.: +34 91 346 62 36; fax: +34 91 346 62 33. (Herranz, L.E.) (Herranz, L.E.) Unit of Nuclear Safety Research (CIEMAT) Avda. Complutense--> , 22 - 28040 Madrid - Spain--> - (Herranz, L.E.) Unit of Nuclear Safety Research (CIEMAT) Avda. Complutense--> , 22 - 28040 Madrid - Spain--...

  18. Containment for the low temperature district nuclear-heating reactor

    Energy Technology Data Exchange (ETDEWEB)

    He Shuyan (Institute of Nuclear Energy Technology, Tsinghua Univ., Beijing (China)); Dong Duo (Institute of Nuclear Energy Technology, Tsinghua Univ., Beijing (China))

    1993-04-01

    An integral arrangement is adopted for the Low Temperature District Nuclear-Heating Reactor. The primary heat exchangers, control rod drives and spent fuel elements are put in the reactor pressure vessel together with the reactor core. The primary coolant flows in natural circulation through the reactor core and the primary heat exchangers. The primary coolant pipes penetrating the wall of the reactor pressure vessel are all of small diameters. The reactor vessel constitutes the main part of the pressure boundary of the primary coolant. Therefore a small sized metallic containment closed to the wall of the reactor vessel can be used for the reactor. Design principles and functions of the containment are the same as for the containment of a PWR. But the adoption of a small sized containment brings about some benefits such as a short period of manufacturing, relatively low cost, and ease for sealing. A loss of primary coolant accident would not be happening during a rupture accident of the primary coolant pressure boundary inside the containment owing to its intrinsic safety. (orig.).

  19. Thermoacoustic enhancements for nuclear fuel rods and other high temperature applications

    Science.gov (United States)

    Garrett, Steven L.; Smith, James A.; Kotter, Dale K.

    2017-05-09

    A nuclear thermoacoustic device includes a housing defining an interior chamber and a portion of nuclear fuel disposed in the interior chamber. A stack is disposed in the interior chamber and has a hot end and a cold end. The stack is spaced from the portion of nuclear fuel with the hot end directed toward the portion of nuclear fuel. The stack and portion of nuclear fuel are positioned such that an acoustic standing wave is produced in the interior chamber. A frequency of the acoustic standing wave depends on a temperature in the interior chamber.

  20. High Temperature Resistance Claddings for Nuclear Thermal Rockets Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program will develop a series of nano-/micro-composite coated nuclear reactor facing components using MesoCoat's CermaCladTM process. This proposed SBIR program...

  1. The modular high-temperature gas-cooled reactor: A cost/risk competitive nuclear option

    Energy Technology Data Exchange (ETDEWEB)

    Gotschall, H.L. (Gas-Cooled Reactor Associates, San Diego, CA (United States))

    1994-01-01

    The business risks of nuclear plant ownership are identified as a constraint on the expanded use of nuclear power. Such risks stem from the exacting demands placed on owner/operator organizations of current plants to demonstrate ongoing compliance with safety regulations and the resulting high costs for operation and maintenance. This paper describes the Modular High-Temperature Gas-Cooled Reactor (MHTGR) design, competitive economics, and approach to reducing the business risks of nuclear plant ownership.

  2. Effective thermal conductivity method for predicting spent nuclear fuel cladding temperatures in a dry fill gas

    Energy Technology Data Exchange (ETDEWEB)

    Bahney, Robert

    1997-12-19

    This paper summarizes the development of a reliable methodology for the prediction of peak spent nuclear fuel cladding temperature within the waste disposal package. The effective thermal conductivity method replaces other older methodologies.

  3. Nuclear magnetic resonance force microscopy at millikelvin temperatures

    NARCIS (Netherlands)

    Haan, Arthur Mattheus Johannes den

    2016-01-01

    Nuclear magnetic resonance force microscopy (MRFM) is a technique which combines magnetic resonance imaging (MRI) with scanning probe microscopy (SPM). The final goal is to develop this technique to such a level that the atomic structure of a virus or protein can be revealed by this microscope. This

  4. Fluctuation-induced heat release from temperature-quenched nuclear spins near a quantum critical point.

    Science.gov (United States)

    Kim, Y H; Kaur, N; Atkins, B M; Dalal, N S; Takano, Y

    2009-12-11

    At a quantum critical point (QCP)--a zero-temperature singularity in which a line of continuous phase transition terminates--quantum fluctuations diverge in space and time, leading to exotic phenomena that can be observed at nonzero temperatures. Using a quantum antiferromagnet, we present calorimetric evidence that nuclear spins frozen in a high-temperature nonequilibrium state by temperature quenching are annealed by quantum fluctuations near the QCP. This phenomenon, with readily detectable heat release from the nuclear spins as they are annealed, serves as an excellent marker of a quantum critical region around the QCP and provides a probe of the dynamics of the divergent quantum fluctuations.

  5. Low temperature chemical processing of graphite-clad nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Robert A.

    2017-10-17

    A reduced-temperature method for treatment of a fuel element is described. The method includes molten salt treatment of a fuel element with a nitrate salt. The nitrate salt can oxidize the outer graphite matrix of a fuel element. The method can also include reduced temperature degradation of the carbide layer of a fuel element and low temperature solubilization of the fuel in a kernel of a fuel element.

  6. Core Physics of Pebble Bed High Temperature Nuclear Reactors

    NARCIS (Netherlands)

    Auwerda, G.J.

    2014-01-01

    To more accurately predict the temperature distribution inside the reactor core of pebble bed type high temperature reactors, in this thesis we investigated the stochastic properties of randomly stacked beds and the effects of the non-homogeneity of these beds on the neutronics and

  7. One centimeter spatial resolution temperature measurements in a nuclear reactor using Rayleigh scatter in optical fiber

    Science.gov (United States)

    Sang, A. K.; Gifford, D. K.; Dickerson, B. D.; Fielder, B. F.; Froggatt, M. E.

    2007-07-01

    We present the use of swept wavelength interferometry for distributed fiber-optic temperature measurements in a Nuclear Reactor. The sensors consisted of 2 m segments of commercially available, single mode optical fibers. The interrogation technique is based on measuring the spectral shift of the intrinsic Rayleigh backscatter signal along the optical fiber and converting the spectral shift to temperature.

  8. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification.

    Science.gov (United States)

    Dixon, Derek R; Schweiger, Michael J; Riley, Brian J; Pokorny, Richard; Hrma, Pavel

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated profile generated by a cold-cap model that has been developed to assess the rate of glass production in a melter.

  9. Wear Properties of Nuclear Graphite IG-110 at Elevated Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Dunkun; Kim, Jaehoon; Kim, Yeonwook [Chungnam National University, Daejeon (Korea, Republic of)

    2014-05-15

    The high temperature gas-cooled reactor (HTR-10) is designed to produce electricity and hydrogen. Graphite is used as reflector, support structures, and a moderator in reactor core; it has good resistance to neutron and is a suitable material at high temperatures. Friction is generated in the graphite structures for the core reflector, support structures, and moderator because of vibration from the HTR-10 fuel cycle flow. In this study, the wear characteristics of the isotropic graphite IG-110 used in HTR-10 were evaluated. The reciprocating wear test was carried out for graphite against graphite. The effects of changes in the contact load and sliding speeds at room temperature and 400℃ on the coefficient of friction and specific wear rate were evaluated. The wear behavior of graphite IG-110 was evaluated based on the wear surfaces.

  10. Electronically induced nuclear transitions - temperature dependence and Rabi oscillations

    CERN Document Server

    Niez, J J

    2002-01-01

    This paper deals with a nucleus electromagnetically coupled with the bound states of its electronic surroundings. It describes the temperature dependence of its dynamics and the onset of potential Rabi oscillations by means of a Master Equation. The latter is generalized in order to account for possible strong resonances. Throughout the paper the approximation schemes are discussed and tested. (authors)

  11. High Temperature Steam Corrosion of Cladding for Nuclear Applications: Experimental

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M; Garnier, John E; Sergey Rashkeev; Michael V. Glazoff; George W. Griffith; Shannong M. Bragg-Sitton

    2013-01-01

    Stability of cladding materials under off-normal conditions is an important issue for the safe operation of light water nuclear reactors. Metals, ceramics, and metal/ceramic composites are being investigated as substitutes for traditional zirconium-based cladding. To support down-selection of these advanced materials and designs, a test apparatus was constructed to study the onset and evolution of cladding oxidation, and deformation behavior of cladding materials, under loss-of-coolant accident scenarios. Preliminary oxidation tests were conducted in dry oxygen and in saturated steam/air environments at 1000OC. Tube samples of Zr-702, Zr-702 reinforced with 1 ply of a ß-SiC CMC overbraid, and sintered a-SiC were tested. Samples were induction heated by coupling to a molybdenum susceptor inside the tubes. The deformation behavior of He-pressurized tubes of Zr-702 and SiC CMC-reinforced Zr-702, heated to rupture, was also examined.

  12. The use of a very high temperature nuclear reactor in the manufacture of synthetic fuels

    Science.gov (United States)

    Farbman, G. H.; Brecher, L. E.

    1976-01-01

    The three parts of a program directed toward creating a cost-effective nuclear hydrogen production system are described. The discussion covers the development of a very high temperature nuclear reactor (VHTR) as a nuclear heat and power source capable of producing the high temperature needed for hydrogen production and other processes; the development of a hydrogen generation process based on water decomposition, which can utilize the outputs of the VHTR and be integrated with many different ultimate hydrogen consuming processes; and the evaluation of the process applications of the nuclear hydrogen systems to assess the merits and potential payoffs. It is shown that the use of VHTR for the manufacture of synthetic fuels appears to have a very high probability of making a positive contribution to meeting the nation's energy needs in the future.

  13. High temperature furnace for nuclear magnetic resonance experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, C.; Scheler, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Sektion Physik)

    1984-01-01

    A furnace is described for NMR experiments in the temperature range 300 to 1,100 K. It can be used both in a superconducting solenoid (Oxford Instruments, B/sub 0/ = 6.4 T, bore 52 mm) and in iron magnets with a gap d >= 48 mm. All for NMR experiments important nuclei can be measured without /sup 29/Si. The NMR probe can be used both for instationary and stationary experiments.

  14. High-temperature nuclear reactor power plant cycle for hydrogen and electricity production – numerical analysis

    Directory of Open Access Journals (Sweden)

    Dudek Michał

    2016-01-01

    Full Text Available High temperature gas-cooled nuclear reactor (called HTR or HTGR for both electricity generation and hydrogen production is analysed. The HTR reactor because of the relatively high temperature of coolant could be combined with a steam or gas turbine, as well as with the system for heat delivery for high-temperature hydrogen production. However, the current development of HTR’s allows us to consider achievable working temperature up to 750°C. Due to this fact, industrial-scale hydrogen production using copper-chlorine (Cu-Cl thermochemical cycle is considered and compared with high-temperature electrolysis. Presented calculations show and confirm the potential of HTR’s as a future solution for hydrogen production without CO2 emission. Furthermore, integration of a hightemperature nuclear reactor with a combined cycle for electricity and hydrogen production may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

  15. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    James E. O& #39; Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  16. Neutron analysis of the fuel of high temperature nuclear reactors; Analisis neutronico del combustible de reactores nucleares de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Bastida O, G. E.; Francois L, J. L., E-mail: gbo729@yahoo.com.mx [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)

    2014-10-15

    In this work a neutron analysis of the fuel of some high temperature nuclear reactors is presented, studying its main features, besides some alternatives of compound fuel by uranium and plutonium, and of coolant: sodium and helium. For this study was necessary the use of a code able to carry out a reliable calculation of the main parameters of the fuel. The use of the Monte Carlo method was convenient to simulate the neutrons transport in the reactor core, which is the base of the Serpent code, with which the calculations will be made for the analysis. (Author)

  17. Temperature effects on nuclear pseudospin symmetry in the Dirac-Hartree-Bogoliubov formalism

    Science.gov (United States)

    Lisboa, R.; Alberto, P.; Carlson, B. V.; Malheiro, M.

    2017-11-01

    We present finite-temperature Dirac-Hartree-Bogoliubov (FTDHB) calculations for the tin isotope chain to study the dependence of pseudospin on the nuclear temperature. In the FTDHB calculation, the density dependence of the self-consistent relativistic mean fields, the pairing, and the vapor phase that takes into account the unbound nucleon states are considered self-consistently. The mean-field potentials obtained in the FTDHB calculations are fit by Woods-Saxon (WS) potentials to examine how the WS parameters are related to the energy splitting of the pseudospin pairs as the temperature increases. We find that the nuclear potential surface diffuseness is the main driver for the pseudospin splittings and that it increases as the temperature grows. We conclude that pseudospin symmetry is better realized when the nuclear temperature increases. The results confirm the findings of previous works using relativistic mean field theory at T =0 , namely that the correlation between the pseudospin splitting and the parameters of the Woods-Saxon potentials implies that pseudospin symmetry is a dynamical symmetry in nuclei. We show that the dynamical nature of the pseudospin symmetry remains when the temperature is considered in a realistic calculation of the tin isotopes, such as that of the Dirac-Hartree-Bogoliubov formalism.

  18. Nuclear ordering in lithium and an upper limit on its ambient pressure superconducting transition temperature.

    Science.gov (United States)

    Juntunen, K I; Tuoriniemi, J T

    2004-10-08

    We have discovered spontaneous ordering of nuclear spins in lithium metal by NMR measurements at very low temperatures. In low magnetic fields, Blithium at normal pressure down to T(e) approximately 100 microK (B<10 nT).

  19. The Effect of Nuclear Elastic Scattering on Temperature Equilibration Rate of Ions in Fusion Plasma

    Directory of Open Access Journals (Sweden)

    M. Mahdavi

    2014-01-01

    Full Text Available A plasma with two different particle types and at different temperatures has been considered, so that each type of ion with Maxwell-Boltzmann distribution function is in temperature equilibrium with itself. Using the extracted nuclear elastic scattering differential cross-section from experimental data, solving the Boltzmann equation, and also taking into account the mobility of the background particles, temperature equilibration rate between two different ions in a fusion plasma is calculated. The results show that, at higher temperature differences, effect of nuclear elastic scattering is more important in calculating the temperature equilibration rate. The obtained expressions have general form so that they are applicable to each type of particle for background (b and each type for projectile (p. In this paper, for example, an equimolar Deuterium-Hydrogen plasma with density n=5×1025 cm−3 is chosen in which the deuteron is the background particle with temperature (also electron temperature Tb=1 keV (usual conditions for a fusion plasma at the ignition instant and the proton is the projectile with temperature Tp>Tb. These calculations, particularly, are very important for ion fast ignition in inertial confinement fusion concept.

  20. Identification of Industrial Furnace Temperature for Sintering Process in Nuclear Fuel Fabrication Using NARX Neural Networks

    Directory of Open Access Journals (Sweden)

    Dede Sutarya

    2014-01-01

    Full Text Available Nonlinear system identification is becoming an important tool which can be used to improve control performance and achieve robust fault-tolerant behavior. Among the different nonlinear identification techniques, methods based on neural network model are gradually becoming established not only in the academia, but also in industrial application. An identification scheme of nonlinear systems for sintering furnace temperature in nuclear fuel fabrication using neural network autoregressive with exogenous inputs (NNARX model investigated in this paper. The main contribution of this paper is to identify the appropriate model and structure to be applied in control temperature in the sintering process in nuclear fuel fabrication, that is, a nonlinear dynamical system. Satisfactory agreement between identified and experimental data is found with normalized sum square error 1.9e-03 for heating step and 6.3859e-08 for soaking step. That result shows the model successfully predict the evolution of the temperature in the furnace.

  1. Observation of nuclear ferromagnetic ordering in silver at negative nanokelvin temperatures

    OpenAIRE

    Hakonen, Pertti J.; Nummila, K. K.; Vuorinen, R. T.; Lounasmaa, O.V.

    1992-01-01

    The ferromagnetically ordered state in the nuclear spin system of silver has been reached at negative absolute temperatures by adiabatic nuclear demagnetization at entropies below 0.82 ln2. The ordering, caused by the antiferromagnetic Ruderman-Kittel interaction, was observed below -1.9 nK as a saturation of susceptibility close to -1 and as an increase of the NMR frequencies. Comparison with recent mean-field calculations by Viertiö and Oja suggests a domain configuration. The phase diagram...

  2. Spectral diffusion and dynamic nuclear polarization: Beyond the high temperature approximation.

    Science.gov (United States)

    Wenckebach, W Th

    2017-10-04

    Dynamic Nuclear Polarization (DNP) has proven itself most powerful for the orientation of nuclear spins in polarized targets and for hyperpolarization in magnetic resonance imaging (MRI). Unfortunately, the theoretical description of some of the processes involved in DNP invokes the high temperature approximation, in which Boltzmann factors are expanded up to first order, while the high electron and nuclear spin polarization required for many applications do not justify such an approximation. A previous article extended the description of one of the mechanisms of DNP-thermal mixing-beyond the high temperature approximation (Wenckebach, 2017). But that extension is still limited: it assumes that fast spectral diffusion creates a local equilibrium in the electron spin system. Provotorov's theory of cross-relaxation enables a consistent further extension to slower spectral diffusion, but also invokes the high temperature approximation. The present article extends the theory of cross-relaxation to low temperature and applies it to spectral diffusion in glasses doped with paramagnetic centres with anisotropic g-tensors. The formalism is used to describe DNP via the mechanism of the cross effect. In the limit of fast spectral diffusion the results converge to those obtained in Wenckebach (2017) for thermal mixing. In the limit of slow spectral diffusion a hole is burnt in the electron spin resonance (ESR) signal, just as predicted by more simple models. The theory is applied to DNP of proton and (13)C spins in samples doped with the radical TEMPO. Copyright © 2017. Published by Elsevier Inc.

  3. Temperature Profile in Fuel and Tie-Tubes for Nuclear Thermal Propulsion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vishal Patel

    2015-02-01

    A finite element method to calculate temperature profiles in heterogeneous geometries of tie-tube moderated LEU nuclear thermal propulsion systems and HEU designs with tie-tubes is developed and implemented in MATLAB. This new method is compared to previous methods to demonstrate shortcomings in those methods. Typical methods to analyze peak fuel centerline temperature in hexagonal geometries rely on spatial homogenization to derive an analytical expression. These methods are not applicable to cores with tie-tube elements because conduction to tie-tubes cannot be accurately modeled with the homogenized models. The fuel centerline temperature directly impacts safety and performance so it must be predicted carefully. The temperature profile in tie-tubes is also important when high temperatures are expected in the fuel because conduction to the tie-tubes may cause melting in tie-tubes, which may set maximum allowable performance. Estimations of maximum tie-tube temperature can be found from equivalent tube methods, however this method tends to be approximate and overly conservative. A finite element model of heat conduction on a unit cell can model spatial dependence and non-linear conductivity for fuel and tie-tube systems allowing for higher design fidelity of Nuclear Thermal Propulsion.

  4. High temperature antigen retrieval and loss of nuclear morphology: a comparison of microwave and autoclave techniques.

    Science.gov (United States)

    Hunt, N C; Attanoos, R; Jasani, B

    1996-01-01

    The use of high temperature antigen retrieval methods has been of major importance in increasing the diagnostic utility of immunocytochemistry. However, these techniques are not without their problems and in this report attention is drawn to a loss of nuclear morphological detail, including mitotic figures, following microwave antigen retrieval. This was not seen with an equivalent autoclave technique. This phenomenon was quantified using image analysis in a group of B cell lymphomas stained with the antibody L26. Loss of nuclear morphological detail may lead to difficulty in identifying cells accurately, which is important in the diagnostic setting-for example, when trying to distinguish a malignant lymphoid infiltrate within a mixed cell population. In such cases it would clearly be wise to consider the use of alternative high temperature retrieval methods and accept their slightly lower staining enhancement capability compared with the microwave technique. Images PMID:9038766

  5. Guidelines and procedures for design of Class 1 elevated temperature nuclear system components

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    This standard provides guidelines and procedures which may be used by the manufacturer in satisfying the requirements given for design of class 1 elevated temperature nuclear system components. Guidance is given regarding planning and control of design analysis. A sequence for calculations is recommended. Methods of analysis, including procedures to account for environmental effects, are given which are acceptable in principle to the owner. A format is provided for use in documentation of design analyses.

  6. Effects of nuclear radiation and elevated temperature storage on electroexplosive devices

    Science.gov (United States)

    Menichelli, V. J.

    1976-01-01

    Aerospace type electroexplosive devices (EEDs) were subjected to nuclear radiation. Components and chemicals used in the EEDs were also included. The kind of radiation and total dosage administered were those which may be experienced in a space flight of 10 years duration, based on information available at this time. After irradiation, the items were stored in elevated constant-temperature ovens to accelerate early effects of the exposure to radiation. Periodically, samples were withdrawn for visual observation and testing. Significant changes occurred which were attributed to elevated-temperature storage and not radiation.

  7. A two-axis goniometer for low-temperature nuclear magnetic resonance measurements on single crystals.

    Science.gov (United States)

    Shiroka, T; Casola, F; Mesot, J; Bachmann, W; Ott, H-R

    2012-09-01

    We report on the construction of a two-axis goniometer intended for low-temperature, single-crystal nuclear magnetic resonance (NMR) measurements. With the use of home-made and commercially available parts, our simple probe-head design achieves good sensitivity, while maintaining a high angular precision and the ability to orient samples also when cooled to liquid helium temperatures. The probe with the goniometer is adapted to be inserted into a commercial (4)He-flow cryostat, which fits into a wide-bore superconducting solenoid magnet. Selected examples of NMR measurements illustrate the operation of the device.

  8. Coplanar photonic bandgap resonators for low temperature electron and nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Sigillito, A. J.; Tyryshkin, A. M.; Lyon, S. A.

    In recent years, superconducting coplanar waveguide (CPW) resonators have become a useful tool for low temperature pulsed electron spin resonance (ESR), even at dilution refrigerator temperatures. Their small mode volumes make CPW resonators particularly well suited to measuring small numbers of spins near the resonator surface, since in this region the spin sensitivity is very high. While these resonators have proven useful for ESR at single microwave frequencies, it is difficult to also manipulate nuclear spins in electron-nuclear-double resonance (ENDOR) experiments, since manipulation of nuclear spins requires radio frequency (RF) magnetic fields. Ideally one would simply generate these fields by passing RF currents through the CPW, but because conventional CPW resonators are capacitively coupled, they will not transmit low-frequency RF currents. In this talk, we discuss the use of one dimensional photonic bandgap (PBG) resonators to overcome this challenge. PBG resonators are a promising alternative to conventional CPW resonators since they offer high quality factors at microwave frequencies, while simultaneously allowing transmission of nonresonant RF currents below the photonic bandgap. Here, we will discuss PBG resonator designs and present data showing their use for low temperature ESR of donors in 28Si. Initial ENDOR results will also be presented.

  9. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis

    Science.gov (United States)

    Adam, Zachary R.

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 105-106 years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest.

  10. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis.

    Science.gov (United States)

    Adam, Zachary R

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 10(5)-10(6) years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest.

  11. Temperature effects on the behavior of carbon 14 in nuclear graphite

    Energy Technology Data Exchange (ETDEWEB)

    Silbermann, G. [Institut de Physique Nucléaire de Lyon, CNRS/IN2P3, UMR 5822, Université Claude Bernard Lyon 1, Université de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne cedex (France); EDF/DIN/CIDEN/DIE, 154 Avenue Thiers, CS 60018, Lyon 69458 (France); Moncoffre, N., E-mail: n.moncoffre@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon, CNRS/IN2P3, UMR 5822, Université Claude Bernard Lyon 1, Université de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon, CNRS/IN2P3, UMR 5822, Université Claude Bernard Lyon 1, Université de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Commissariat à l’énergie atomique CEA/DEN, Centre de Saclay, Gif sur Yvette 91191 (France); Bérerd, N. [Institut de Physique Nucléaire de Lyon, CNRS/IN2P3, UMR 5822, Université Claude Bernard Lyon 1, Université de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Institut Universitaire de Technologie, Université Lyon 1, 94 Bd. Niels Bohr, Villeurbanne 69622 (France); Perrat-Mabilon, A. [Institut de Physique Nucléaire de Lyon, CNRS/IN2P3, UMR 5822, Université Claude Bernard Lyon 1, Université de Lyon, 4 Rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Laurent, G. [EDF/DIN/CIDEN/DIE, 154 Avenue Thiers, CS 60018, Lyon 69458 (France); and others

    2014-08-01

    The dismantling of the 1st French generation UNGG (Uranium Naturel Graphite Gas) nuclear reactors operated by the French utility, EDF (Electricité de France) will generate around 17,000 tons of irradiated graphite wastes that have to be disposed of. {sup 14}C is one of the main radioactive dose contributors over 10,000 years. For the management of this waste, it is mandatory to get an accurate estimation of {sup 14}C. The general aim of our work is therefore to simulate the behavior of {sup 14}C in nuclear graphite and to elucidate the coupled and decoupled effects of temperature, irradiation and radiolytic corrosion that mainly influence {sup 14}C behavior in graphite during reactor operation. This paper focuses on the behavior of {sup 13}C implanted into nuclear graphite and used to simulate the presence of {sup 14}C displaced from its original structural site through recoil during neutron irradiation. It aims at evaluating both the temperature and the disorder level of the implanted graphite structure effects on {sup 13}C migration using two complementary techniques, NRA and SIMS, to evaluate the {sup 13}C distribution at the millimeter and micrometer lateral scales respectively. Raman micro-spectroscopy is used to check the graphite structure evolution. The results show that {sup 13}C is not released up to 1600 °C whatever the initial structural disorder level of the implanted graphite. This might be due to the fact that {sup 13}C might be trapped into interstitial clusters. The extrapolation of our results to the behavior of {sup 14}C shows that reactor temperatures (200–500 °C) did not induce any {sup 14}C release. Moreover, as long as there is no gasification of the graphite matrix, high temperatures tend to stabilize {sup 14}C into the remaining graphite structure. This fact has to be considered in case of high temperature purification of {sup 14}C from irradiated graphite.

  12. LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

    Energy Technology Data Exchange (ETDEWEB)

    James E. O' Brien

    2010-08-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a “hydrogen economy.” The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

  13. Industrial Qualification Process for Optical Fibers Distributed Strain and Temperature Sensing in Nuclear Waste Repositories

    Directory of Open Access Journals (Sweden)

    S. Delepine-Lesoille

    2012-01-01

    Full Text Available Temperature and strain monitoring will be implemented in the envisioned French geological repository for high- and intermediate-level long-lived nuclear wastes. Raman and Brillouin scatterings in optical fibers are efficient industrial methods to provide distributed temperature and strain measurements. Gamma radiation and hydrogen release from nuclear wastes can however affect the measurements. An industrial qualification process is successfully proposed and implemented. Induced measurement uncertainties and their physical origins are quantified. The optical fiber composition influence is assessed. Based on radiation-hard fibers and carbon-primary coatings, we showed that the proposed system can provide accurate temperature and strain measurements up to 0.5 MGy and 100% hydrogen concentration in the atmosphere, over 200 m distance range. The selected system was successfully implemented in the Andra underground laboratory, in one-to-one scale mockup of future cells, into concrete liners. We demonstrated the efficiency of simultaneous Raman and Brillouin scattering measurements to provide both strain and temperature distributed measurements. We showed that 1.3 μm working wavelength is in favor of hazardous environment monitoring.

  14. The high-temperature sodium coolant technology in nuclear power installations for hydrogen power engineering

    Science.gov (United States)

    Kozlov, F. A.; Sorokin, A. P.; Alekseev, V. V.; Konovalov, M. A.

    2014-05-01

    In the case of using high-temperature sodium-cooled nuclear power installations for obtaining hydrogen and for other innovative applications (gasification and fluidization of coal, deep petroleum refining, conversion of biomass into liquid fuel, in the chemical industry, metallurgy, food industry, etc.), the sources of hydrogen that enters from the reactor plant tertiary coolant circuit into its secondary coolant circuit have intensity two or three orders of magnitude higher than that of hydrogen sources at a nuclear power plant (NPP) equipped with a BN-600 reactor. Fundamentally new process solutions are proposed for such conditions. The main prerequisite for implementing them is that the hydrogen concentration in sodium coolant is a factor of 100-1000 higher than it is in modern NPPs taken in combination with removal of hydrogen from sodium by subjecting it to vacuum through membranes made of vanadium or niobium. Numerical investigations carried out using a diffusion model showed that, by varying such parameters as fuel rod cladding material, its thickness, and time of operation in developing the fuel rods for high-temperature nuclear power installations (HT NPIs) it is possible to exclude ingress of cesium into sodium through the sealed fuel rod cladding. However, if the fuel rod cladding loses its tightness, operation of the HT NPI with cesium in the sodium will be unavoidable. Under such conditions, measures must be taken for deeply purifying sodium from cesium in order to minimize the diffusion of cesium into the structural materials.

  15. Thermodynamic instabilities of nuclear matter at finite temperature with finite range effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ventura, J.; Polls, A.; Vinas, X.; Pi, M. (Barcelona Univ. (Spain). Dept. de Estructura y Constituyentes de la Materia); Hernandez, S. (Buenos Aires Univ. (Argentina). Dept. de Fisica)

    1992-08-03

    A systematic study of the equation of state for symmetric nuclear matter is performed in the framework of a finite-temperature density dependent Hartree-Fock method using the Gogny finite-range effective interaction. Special attention is devoted to the density and temperature dependence of the single-particle spectrum, the effective mass and the momentum distributions. The liquid-gas phase transition and the spinodal lines are discussed, in connection with the breakup of heated nucleus into small clusters that takes place in medium energy heavy ion reactions. The level density parameter, which has been derived by a low temperature expansion of the internal energy, is also discussed. Comparisons with previous calculations using zero range effective interactions are also made. (orig.).

  16. Transient analysis of nuclear graphite oxidation for high temperature gas cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei, E-mail: wxu12@mails.tsinghua.edu.cn; Shi, Lei; Zheng, Yanhua

    2016-09-15

    Graphite is widely used as moderator, reflector and structural materials in the high temperature gas-cooled reactor pebble-bed modular (HTR-PM). In normal operating conditions or water/air ingress accident, the nuclear graphite in the reactor may be oxidized by air or steam. Oxidation behavior of nuclear graphite IG-110 which is used as the structural materials and reflector of HTR-PM is mainly researched in this paper. To investigate the penetration depth of oxygen in IG-110, this paper developed the one dimensional spherical oxidation model. In the oxidation model, the equations considered graphite porosity variation with the graphite weight loss. The effect of weight loss on the effective diffusion coefficient and the oxidation rate was also considered in this model. Based on this theoretical model, this paper obtained the relative concentration and local weight loss ratio profile in graphite. In addition, the local effective diffusion coefficient and oxidation rate in the graphite were also investigated.

  17. Separation Requirements for a Hydrogen Production Plant and High-Temperature Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Curtis Smith; Scott Beck; Bill Galyean

    2005-09-01

    This report provides the methods, models, and results of an evaluation for locating a hydrogen production facility near a nuclear power plant. In order to answer the risk-related questions for this combined nuclear and chemical facility, we utilized standard probabilistic safety assessment methodologies to answer three questions: what can happen, how likely is it, and what are the consequences? As part of answering these questions, we developed a model suitable to determine separation distances for hydrogen process structures and the nuclear plant structures. Our objective of the model-development and analysis is to answer key safety questions related to the placement of one or more hydrogen production plants in the vicinity of a high-temperature nuclear reactor. From a thermal-hydraulic standpoint we would like the two facilities to be quite close. However, safety and regulatory implications force the separation distance to be increased, perhaps substantially. Without answering these safety questions, the likelihood for obtaining a permit to construct and build such as facility in the U.S. would be questionable. The quantitative analysis performed for this report provides us with a scoping mechanism to determine key parameters related to the development of a nuclear-based hydrogen production facility. From our calculations, we estimate that when the separation distance is less than 100m, the core damage frequency is large enough (greater than 1E-6/yr) to become problematic in a risk-informed environment. However, a variety of design modifications, for example blast-deflection barriers, were explored to determine the impact of potential mitigating strategies. We found that these mitigating cases may significantly reduce risk and should be explored as the design for the hydrogen production facility evolves.

  18. KEY DESIGN REQUIREMENTS FOR THE HIGH TEMPERATURE GAS-COOLED REACTOR NUCLEAR HEAT SUPPLY SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    L.E. Demick

    2010-09-01

    Key requirements that affect the design of the high temperature gas-cooled reactor nuclear heat supply system (HTGR-NHSS) as the NGNP Project progresses through the design, licensing, construction and testing of the first of a kind HTGR based plant are summarized. These requirements derive from pre-conceptual design development completed to-date by HTGR Suppliers, collaboration with potential end users of the HTGR technology to identify energy needs, evaluation of integration of the HTGR technology with industrial processes and recommendations of the NGNP Project Senior Advisory Group.

  19. Lightweight Damage Tolerant, High-Temperature Radiators for Nuclear Power and Propulsion

    Science.gov (United States)

    Craven, Paul D.; SanSoucie, Michael P.

    2015-01-01

    NASA is increasingly emphasizing exploration to bodies beyond near-Earth orbit. New propulsion systems and new spacecraft are being built for these missions. As the target bodies get further out from Earth, high energy density systems, e.g., nuclear fusion, for propulsion and power will be advantageous. The mass and size of these systems, including supporting systems such as the heat exchange system, including thermal radiators, will need to be as small as possible. Conventional heat exchange systems are a significant portion of the total thermal management mass and size. Nuclear electric propulsion (NEP) is a promising option for high-speed, in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Heat from the reactor is converted to power for use in propulsion or for system power. The heat not used in the power conversion is then radiated to space as shown in figure 1. Advanced power conversion technologies will require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow significant decreases in the total mass of the radiators and significant increases in the operating temperature of the fins. A Center-funded project at NASA Marshall Space Flight Center has shown that high thermal conductivity, woven carbon fiber fins with no matrix material, can be used to dissipate waste heat from NEP systems and because of high specific power (kW/kg), will require less mass and possibly less total area than standard metal and composite radiator fins for radiating the same amount of heat. This project uses an innovative approach to reduce the mass and size required for the thermal radiators to the point that in-space NEP and power

  20. Future needs for inelastic analysis in design of high-temperature nuclear plant components. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Corum, J.M.

    1980-01-01

    The role that inelastic analyses play in the design of high-temperature nuclear plant components is described. The design methodology, which explicitly accounts for nonlinear material deformation and time-dependent failure modes, requires a significant level of realism in the prediction of structural response. Thus, material deformation and failure modeling are, along with computational procedures, key parts of the methodology. Each of these is briefly discussed along with validation by comparisons with benchmark structural tests, and problem areas and needs are discussed for each.

  1. Mechanisms Governing the Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Vijay [Univ. of Cincinnati, OH (United States); Carroll, Laura [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sham, Sam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-06

    This research project, which includes collaborators from INL and ORNL, focuses on the study of alloy 617 and alloy 800H that are candidates for applications as intermediate heat exchangers in GEN IV nuclear reactors, with an emphasis on the effects of grain size, grain boundaries and second phases on the creep properties; the mechanisms of dislocation creep, diffusional creep and cavitation; the onset of tertiary creep; and theoretical modeling for long-term predictions of materials behavior and for high temperature alloy design.

  2. Operation and Control Simulation of a Modular High Temperature Gas Cooled Reactor Nuclear Power Plant

    Science.gov (United States)

    Li, Haipeng; Huang, Xiaojin; Zhang, Liangju

    2008-08-01

    Issues in the operation and control of the multi-modular nuclear power plant are complicated. The high temperature gas cooled reactor pebble-bed module (HTR-PM) plant with two-module will be built as a demonstration plant in China. To investigate the operation and control characteristics of the plant, a simplified dynamic model is developed and mathematically formulated based upon the fundamental conversation of mass, energy and momentum. The model is implemented in a personal computer to simulate the power increase process of the HTR-PM operation. The open loop operation with no controller is first simulated and the results show that the essential parameter steam temperature varies drastically with time, which is not allowable in the normal operation. According to the preliminary control strategy of the HTR-PM, a simple steam temperature controller is proposed. The controller is of Proportional-type with a time lag. The closed loop operation with a steam temperature controller is then implemented and the simulation results show that the steam temperature and also other parameters are all well controlled in the allowable range.

  3. Computational model for a high temperature electrolyzer coupled to a HTTR for efficient nuclear hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Daniel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy; Gamez, Abel; Brayner, Carlos, E-mail: danielgonro@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Garcia, Lazaro; Garcia, Carlos; Torre, Raciel de la, E-mail: lgarcia@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Sanchez, Danny [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)

    2015-07-01

    High temperature electrolysis process coupled to a very high temperature reactor (VHTR) is one of the most promising methods for hydrogen production using a nuclear reactor as the primary heat source. However there are not references in the scientific publications of a test facility that allow to evaluate the efficiency of the process and other physical parameters that has to be taken into consideration for its accurate application in the hydrogen economy as a massive production method. For this lack of experimental facilities, mathematical models are one of the most used tools to study this process and theirs flowsheets, in which the electrolyzer is the most important component because of its complexity and importance in the process. A computational fluid dynamic (CFD) model for the evaluation and optimization of the electrolyzer of a high temperature electrolysis hydrogen production process flowsheet was developed using ANSYS FLUENT®. Electrolyzer's operational and design parameters will be optimized in order to obtain the maximum hydrogen production and the higher efficiency in the module. This optimized model of the electrolyzer will be incorporated to a chemical process simulation (CPS) code to study the overall high temperature flowsheet coupled to a high temperature accelerator driven system (ADS) that offers advantages in the transmutation of the spent fuel. (author)

  4. Temperature monitoring using fibre optic sensors in a lead-bismuth eutectic cooled nuclear fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    De Pauw, B., E-mail: bdepauw@vub.ac.be [Vrije Universiteit Brussel (VUB), Brussels Photonics Team (B-Phot), Brussels (Belgium); Vrije Universiteit Brussel (VUB), Acoustics and Vibration Research Group (AVRG), Brussels (Belgium); Belgian Nuclear Research Centre, (SCK-CEN), Boeretang 200, Mol (Belgium); Lamberti, A.; Ertveldt, J.; Rezayat, A.; Vanlanduit, S. [Vrije Universiteit Brussel (VUB), Acoustics and Vibration Research Group (AVRG), Brussels (Belgium); Van Tichelen, K. [Belgian Nuclear Research Centre, (SCK-CEN), Boeretang 200, Mol (Belgium); Berghmans, F. [Vrije Universiteit Brussel (VUB), Brussels Photonics Team (B-Phot), Brussels (Belgium)

    2016-02-15

    Highlights: • We demonstrate the use of optical fibre sensors in lead-bismuth cooled installations. • In this first of a kind experiment, we focus on temperature measurements of fuel rods • We acquire the surface temperature with a resolution of 30 mK. • We asses the condition of the installation during different steps of the operation. - Abstract: In-core temperature measurements are crucial to assess the condition of nuclear reactor components. The sensors that measure temperature must respond adequately in order, for example, to actuate safety systems that will mitigate the consequences of an undesired temperature excursion and to prevent component failure. This issue is exacerbated in new reactor designs that use liquid metals, such as for example a molten lead-bismuth eutectic, as coolant. Unlike water cooled reactors that need to operate at high pressure to raise the boiling point of water, liquid metal cooled reactors can operate at high temperatures whilst keeping the pressure at lower levels. In this paper we demonstrate the use of optical fibre sensors to measure the temperature distribution in a lead-bismuth eutectic cooled installation and we derive functional input e.g. the temperature control system or other systems that rely on accurate temperature actuation. This first-of-a-kind experiment demonstrates the potential of optical fibre based instrumentation in these environments. We focus on measuring the surface temperature of the individual fuel rods in the fuel assembly, but the technique can also be applied to other components or sections of the installation. We show that these surface temperatures can be experimentally measured with limited intervention on the fuel pin owing to the small geometry and fundamental properties of the optical fibres. The unique properties of the fibre sensors allowed acquiring the surface temperatures with a resolution of 30 mK. With these sensors, we assess the condition of the test section containing the fuel

  5. One-thousand-fold enhancement of high field liquid nuclear magnetic resonance signals at room temperature

    Science.gov (United States)

    Liu, Guoquan; Levien, Marcel; Karschin, Niels; Parigi, Giacomo; Luchinat, Claudio; Bennati, Marina

    2017-07-01

    Nuclear magnetic resonance (NMR) is a fundamental spectroscopic technique for the study of biological systems and materials, molecular imaging and the analysis of small molecules. It detects interactions at very low energies and is thus non-invasive and applicable to a variety of targets, including animals and humans. However, one of its most severe limitations is its low sensitivity, which stems from the small interaction energies involved. Here, we report that dynamic nuclear polarization in liquid solution and at room temperature can enhance the NMR signal of 13C nuclei by up to three orders of magnitude at magnetic fields of ∼3 T. The experiment can be repeated within seconds for signal averaging, without interfering with the sample magnetic homogeneity. The method is therefore compatible with the conditions required for high-resolution NMR. Enhancement of 13C signals on various organic compounds opens up new perspectives for dynamic nuclear polarization as a general tool to increase the sensitivity of liquid NMR.

  6. High Temperature Electrolysis for Hydrogen Production from Nuclear Energy – TechnologySummary

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; C. M. Stoots; J. S. Herring; M. G. McKellar; E. A. Harvego; M. S. Sohal; K. G. Condie

    2010-02-01

    The Department of Energy, Office of Nuclear Energy, has requested that a Hydrogen Technology Down-Selection be performed to identify the hydrogen production technology that has the best potential for timely commercial demonstration and for ultimate deployment with the Next Generation Nuclear Plant (NGNP). An Independent Review Team has been assembled to execute the down-selection. This report has been prepared to provide the members of the Independent Review Team with detailed background information on the High Temperature Electrolysis (HTE) process, hardware, and state of the art. The Idaho National Laboratory has been serving as the lead lab for HTE research and development under the Nuclear Hydrogen Initiative. The INL HTE program has included small-scale experiments, detailed computational modeling, system modeling, and technology demonstration. Aspects of all of these activities are included in this report. In terms of technology demonstration, the INL successfully completed a 1000-hour test of the HTE Integrated Laboratory Scale (ILS) technology demonstration experiment during the fall of 2008. The HTE ILS achieved a hydrogen production rate in excess of 5.7 Nm3/hr, with a power consumption of 18 kW. This hydrogen production rate is far larger than has been demonstrated by any of the thermochemical or hybrid processes to date.

  7. Prediction of concrete compressive strength considering humidity and temperature in the construction of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seung Hee; Jang, Kyung Pil [Department of Civil and Environmental Engineering, Myongji University, Yongin (Korea, Republic of); Bang, Jin-Wook [Department of Civil Engineering, Chungnam National University, Daejeon (Korea, Republic of); Lee, Jang Hwa [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of); Kim, Yun Yong, E-mail: yunkim@cnu.ac.kr [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of)

    2014-08-15

    Highlights: • Compressive strength tests for three concrete mixes were performed. • The parameters of the humidity-adjusted maturity function were determined. • Strength can be predicted considering temperature and relative humidity. - Abstract: This study proposes a method for predicting compressive strength developments in the early ages of concretes used in the construction of nuclear power plants. Three representative mixes with strengths of 6000 psi (41.4 MPa), 4500 psi (31.0 MPa), and 4000 psi (27.6 MPa) were selected and tested under various curing conditions; the temperature ranged from 10 to 40 °C, and the relative humidity from 40 to 100%. In order to consider not only the effect of the temperature but also that of humidity, an existing model, i.e. the humidity-adjusted maturity function, was adopted and the parameters used in the function were determined from the test results. A series of tests were also performed in the curing condition of a variable temperature and constant humidity, and a comparison between the measured and predicted strengths were made for the verification.

  8. THR-TH: a high-temperature gas-cooled nuclear reactor core thermal hydraulics code

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.

    1984-07-01

    The ORNL version of PEBBLE, the (RZ) pebble bed thermal hydraulics code, has been extended for application to a prismatic gas cooled reactor core. The supplemental treatment is of one-dimensional coolant flow in up to a three-dimensional core description. Power density data from a neutronics and exposure calculation are used as the basic information for the thermal hydraulics calculation of heat removal. Two-dimensional neutronics results may be expanded for a three-dimensional hydraulics calculation. The geometric description for the hydraulics problem is the same as used by the neutronics code. A two-dimensional thermal cell model is used to predict temperatures in the fuel channel. The capability is available in the local BOLD VENTURE computation system for reactor core analysis with capability to account for the effect of temperature feedback by nuclear cross section correlation. Some enhancements have also been added to the original code to add pebble bed modeling flexibility and to generate useful auxiliary results. For example, an estimate is made of the distribution of fuel temperatures based on average and extreme conditions regularly calculated at a number of locations.

  9. Platinum group metal particles aggregation in nuclear glass melts under the effect of temperature

    Science.gov (United States)

    Hanotin, Caroline; Puig, Jean; Neyret, Muriel; Marchal, Philippe

    2016-08-01

    The viscosity of simulated high level radioactive waste glasses containing platinum group metal particles is studied over a wide range of shear stress, as a function of the particles content and the temperature, thanks to a stress imposed rheometer, coupled to a high-temperature furnace. The system shows a very shear thinning behavior. At high shear rate, the system behaves as a suspension of small clusters and individual particles and is entirely controlled by the viscosity of the glass matrix as classical suspensions. At low shear rate, above a certain fraction in platinum group metal particles, the apparition of macroscopic aggregates made up of chains of RuO2 particles separated by thin layers of glass matrix strongly influences the viscosity of the nuclear glass and leads, in particular, to the apparition of yield stress and thixotropic effects. The maximum size of these clusters as well as their effective volume fraction have been estimated by a balance between Van der Waals attractive forces and hydrodynamic forces due to shear flow. We showed experimentally and theoretically that this aggregation phenomenon is favored by an increase of the temperature, owing to the viscosity decrease of the glass matrix, leading to an unusual increase of the suspension viscosity.

  10. Quantum non demolition measurement of a single nuclear spin in a room temperature solid

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Phillip; Beck, Johannes; Steiner, Matthias; Rathgen, Helmut; Rempp, Florian; Zarrabi, Navid; Dolde, Florian; Jelezko, Fedor; Wrachtrup, Joerg [Universitaet Stuttgart (Germany); Hemmer, Philip [A and M University, Texas (United States)

    2010-07-01

    The measurement process and its interpretation are in the focus of quantum mechanics since its early days. Today's ability to isolate single quantum objects allows experimental demonstration of former ''gedankenexperiments'' like measurement induced quantum state collaps. Rapidly growing quantum technologies explore fundamental aspects of measurements in quantum computing, however for solid state systems such experiments require operation at very low temperatures. Here we show that projective quantum measurement can be performed on a single nuclear spin in diamond under ambient conditions. Using quantum non demolition (QND) readout we are able to detect quantum jumps and the quantum Zeno effect emphasising the addressability of fundamental questions of quantum mechanics in solids. Single shot measurements with fidelities exceeding 0.9 enable efficient state initialization, quantum error correction and entanglement pumping that is crucial for quantum information processing including measurement based schemes and distributed quantum networks.

  11. High-temperature nuclear closed Brayton cycle power conversion system for the space exploration initiative

    Energy Technology Data Exchange (ETDEWEB)

    Brandes, D.J. (Allied-Signal Aerospace Company, Garrett Fluid Systems Division, 1300 West Warner Road, Tempe, Arizona 85284-2896 (US))

    1991-01-05

    The Space Exploration Initiative (SEI) has stated goals of colonizing the moon and conducting manned exploration of the planet Mars. Unlike previous ventures into space, both manned and unmanned, large quantities of electrical power will be required to provide the energy for lunar base sustenance and for highly efficient propulsion systems for the long trip to mars and return. Further, the requirement for electrical power of several megawatts will necessitate the use of nuclear reactor driven power conversion systems. This paper discusses a particle bed reactor closed Brayton cycle space power system that uses advanced materials technology to achieve a high-temperature, low-specific-weight modular system capable of providing the requisite electrical power for both a lunar base and a Mars flight vehicle propulsion system.

  12. Comparison of The Thermal Conductivity of selected Nuclear Graphite Grades for High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Ju; Chi, Se-Hwan; Kim, Eung-Seon; Kim, Min-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    It is well known that the thermal conductivity of nuclear graphite is influenced by factors such as phonon boundary scattering processes, Umklapp processes, electron-phonon scattering etc, and a lot of studies have been performed to investigate the neutron-irradiation effects on the thermal conductivity of graphite. However, no studies have been reported yet for the overall differences in the thermal conductivity of the nuclear graphite grades for HTGR differing in coke source (petroleum, coal), forming method and particle size. In the present study, the thermal conductivities of seven candidate nuclear graphite grades for HTGR were determined and compared based on the microstructure of the grades. The thermal conductivity is an important material input data during the design, construction and operation of HTGR. The thermal conductivities of seven nuclear graphite grades for HTGR were determined by laser flash method from room temperature to 1,100 .deg. C and compared based on the microstructure of the grade. Conclusions obtained from the study are as follow. (1) The thermal conductivity of seven nuclear graphite grades appeared to be strongly influenced by the grain size at low temperature below about 500 .deg. C and by the phonon-phonon scattering at above 800 .deg. C. (2) All the grades show a decrease in TC of 55-60 % from their room temperature TCs with increasing temperature to 1,100 .deg. C.

  13. Characterizing high-temperature deformation of internally heated nuclear fuel element simulators

    Energy Technology Data Exchange (ETDEWEB)

    Belov, A.I.; Fong, R.W.L.; Leitch, B.W.; Nitheanandan, T.; Williams, A., E-mail: alexander.belov@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    The sag behaviour of a simulated nuclear fuel element during high-temperature transients has been investigated in an experiment utilizing an internal indirect heating method. The major motivation of the experiment was to improve understanding of the dominant mechanisms underlying the element thermo-mechanical response under loss-of-coolant accident conditions and to obtain accurate experimental data to support development of 3-D computational fuel element models. The experiment was conducted using an electrically heated CANDU fuel element simulator. Three consecutive thermal cycles with peak temperatures up to ≈1000 {sup o}C were applied to the element. The element sag deflections and sheath temperatures were measured. On heating up to 600 {sup o}C, only minor lateral deflections of the element were observed. Further heating to above 700 {sup o}C resulted in an element multi-rate creep and significant permanent bow. Post-test visual and X-ray examinations revealed a pronounced necking of the sheath at the pellet-to-pellet interface locations. A wall thickness reduction was detected in the necked region that is interpreted as a sheath longitudinal strain localization effect. The sheath cross-sectioning showed signs of a 'hard' pellet-cladding interaction due to the applied cycles. A 3-D model of the experiment was generated using the ANSYS finite element code. As a fully coupled thermal mechanical simulation is computationally expensive, it was deemed sufficient to use the measured sheath temperatures as a boundary condition, and thus an uncoupled mechanical simulation only was conducted. The ANSYS simulation results match the experiment sag observations well up to the point at which the fuel element started cooling down. (author)

  14. Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Science.gov (United States)

    Wen, Xingshuo

    The Very High Temperature Reactor (VHTR) is one of the leading concepts of the Generation IV nuclear reactor development, which is the core component of Next Generation Nuclear Plant (NGNP). The major challenge in the research and development of NGNP is the performance and reliability of structure materials at high temperature. Alloy 617, with an exceptional combination of high temperature strength and oxidation resistance, has been selected as a primary candidate material for structural use, particularly in Intermediate Heat Exchanger (IHX) which has an outlet temperature in the range of 850 to 950°C and an inner pressure from 5 to 20MPa. In order to qualify the material to be used at the operation condition for a designed service life of 60 years, a comprehensive scientific understanding of creep behavior at high temperature and low stress regime is necessary. In addition, the creep mechanism and the impact factors such as precipitates, grain size, and grain boundary characters need to be evaluated for the purpose of alloy design and development. In this study, thermomechanically processed specimens of alloy 617 with different grain sizes were fabricated, and creep tests with a systematic test matrix covering the temperatures of 850 to 1050°C and stress levels from 5 to 100MPa were conducted. Creep data was analyzed, and the creep curves were found to be unconventional without a well-defined steady-state creep. Very good linear relationships were determined for minimum creep rate versus stress levels with the stress exponents determined around 3-5 depending on the grain size and test condition. Activation energies were also calculated for different stress levels, and the values are close to 400kJ/mol, which is higher than that for self-diffusion in nickel. Power law dislocation climb-glide mechanism was proposed as the dominant creep mechanism in the test condition regime. Dynamic recrystallization happening at high strain range enhanced dislocation climb and

  15. Determination of the nuclear magnetic moments of 145–148Eu by low-temperature nuclear orientation

    Directory of Open Access Journals (Sweden)

    F.G. van den Berg

    1983-01-01

    Full Text Available Nuclear orientation measurements down to 2 mK have been performed on sources of 145–148Eu in SmFe2. The gamma-ray anisotropy yields the nuclear magnetic moments of the europium nuclei with A = 145, 146, 147and148 to be 1.1 ± 0.3 μN, 0.70 ± 0.07 μN, 1.0 ± 0.1 μN and 1.33 ± 0.06 μN, respectively.

  16. Coupling of high temperature nuclear reactor with chemical plant by means of steam loop with heat pump

    Directory of Open Access Journals (Sweden)

    Kopeć Mariusz

    2017-01-01

    Full Text Available High temperature nuclear reactors (HTR can be used as an excellent, emission-free source of technological heat for various industrial applications. Their outlet helium temperature (700°-900°C allows not only for heat supply to all processes below 600°C (referred to as “steam class”, but also enables development of clean nuclear-assisted hydrogen production or coal liquefaction technologies with required temperatures up to 900°C (referred to as “chemical class”. This paper presents the results of analyses done for various configurations of the steam transport loop coupled with the high-temperature heat pump designed for “chemical class” applications. The advantages and disadvantages as well as the key issues are discussed in comparison with alternative solutions, trying to answer the question whether the system with the steam loop and the hightemperature heat pump is viable and economically justified.

  17. Low-temperature dynamic nuclear polarization at 9.4 T with a 30 mW microwave source.

    Science.gov (United States)

    Thurber, Kent R; Yau, Wai-Ming; Tycko, Robert

    2010-06-01

    Dynamic nuclear polarization (DNP) can provide large signal enhancements in nuclear magnetic resonance (NMR) by transfer of polarization from electron spins to nuclear spins. We discuss several aspects of DNP experiments at 9.4 T (400 MHz resonant frequency for (1)H, 264 GHz for electron spins in organic radicals) in the 7-80K temperature range, using a 30 mW, frequency-tunable microwave source and a quasi-optical microwave bridge for polarization control and low-loss microwave transmission. In experiments on frozen glycerol/water doped with nitroxide radicals, DNP signal enhancements up to a factor of 80 are observed (relative to (1)H NMR signals with thermal equilibrium spin polarization). The largest sensitivity enhancements are observed with a new triradical dopant, DOTOPA-TEMPO. Field modulation with a 10 G root-mean-squared amplitude during DNP increases the nuclear spin polarizations by up to 135%. Dependencies of (1)H NMR signal amplitudes, nuclear spin relaxation times, and DNP build-up times on the dopant and its concentration, temperature, microwave power, and modulation frequency are reported and discussed. The benefits of low-temperature DNP can be dramatic: the (1)H spin polarization is increased approximately 1000-fold at 7 K with DNP, relative to thermal polarization at 80K. (c) 2010 Elsevier Inc. All rights reserved.

  18. Novel Methods of Tritium Sequestration: High Temperature Gettering and Separation Membrane Materials Discovery for Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Franglin [Univ. of South Carolina, Columbia, SC (United States); Sholl, David [Georgia Inst. of Technology, Atlanta, GA (United States); Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Lyer, Ratnasabapathy [Claflin Univ., Orangeburg, SC (United States); Iyer, Ratnasabapathy [Claflin Univ., Orangeburg, SC (United States); Reifsnider, Kenneth [Univ. of South Carolina, Columbia, SC (United States)

    2015-01-22

    This project is aimed at addressing critical issues related to tritium sequestration in next generation nuclear energy systems. A technical hurdle to the use of high temperature heat from the exhaust produced in the next generation nuclear processes in commercial applications such as nuclear hydrogen production is the trace level of tritium present in the exhaust gas streams. This presents a significant challenge since the removal of tritium from the high temperature gas stream must be accomplished at elevated temperatures in order to subsequently make use of this heat in downstream processing. One aspect of the current project is to extend the techniques and knowledge base for metal hydride materials being developed for the ''hydrogen economy'' based on low temperature absorption/desorption of hydrogen to develop materials with adequate thermal stability and an affinity for hydrogen at elevated temperatures. The second focus area of this project is to evaluate high temperature proton conducting materials as hydrogen isotope separation membranes. Both computational and experimental approaches will be applied to enhance the knowledge base of hydrogen interactions with metal and metal oxide materials. The common theme between both branches of research is the emphasis on both composition and microstructure influence on the performance of sequestration materials.

  19. Nuclear transfer and anisotropic motional spin phenomena: relaxation time temperature dependence studies of water adsorbed on silica gel. Part IV

    Energy Technology Data Exchange (ETDEWEB)

    Woessner, D.E.; Zimmerman, J.R.

    1962-12-15

    An experimental investigation of the temperature dependence of the nuclear magnetic resonance relaxation phenomena of water vapor adsorbed on silica gel is described. Two-component relaxation data are observed. With temperature increase, the longer T/sub 2/ value decreases while its fractional population increases. These data are shown to be consistent with nuclear transfers between two state environments possessing distinct relaxation characteristics. and a comparison with theory is made. Evidence of a change of surface characteristics is presented; for early experiments, two-component longitudinal relaxation occurs below a transition temperature; in later experiments, only one-component T/sub 1/ behavior is found. A theory for an anisotropic motional model for nuclear magnetic dipole-dipole relaxation on surfaces is presented. The motional model is random reorientation of the interproton vector about an axis normal to the surface that occurs much faster than the time dependence of the angle between the vector and this axis. The relaxation processes are thus related to multiple nuclear correlation times. Consequences of an anisotropic model agree with experimental observations. (auth)

  20. Effect of ultra high temperature ceramics as fuel cladding materials on the nuclear reactor performance by SERPENT Monte Carlo code

    Energy Technology Data Exchange (ETDEWEB)

    Korkut, Turgay; Kara, Ayhan; Korkut, Hatun [Sinop Univ. (Turkey). Dept. of Nuclear Energy Engineering

    2016-12-15

    Ultra High Temperature Ceramics (UHTCs) have low density and high melting point. So they are useful materials in the nuclear industry especially reactor core design. Three UHTCs (silicon carbide, vanadium carbide, and zirconium carbide) were evaluated as the nuclear fuel cladding materials. The SERPENT Monte Carlo code was used to model CANDU, PWR, and VVER type reactor core and to calculate burnup parameters. Some changes were observed at the same burnup and neutronic parameters (keff, neutron flux, absorption rate, and fission rate, depletion of U-238, U-238, Xe-135, Sm-149) with the use of these UHTCs. Results were compared to conventional cladding material zircalloy.

  1. Analysis of Possible Application of High-Temperature Nuclear Reactors to Contemporary Large-Output Steam Power Plants on Ships

    Directory of Open Access Journals (Sweden)

    Kowalczyk T.

    2016-04-01

    Full Text Available This paper is aimed at analysis of possible application of helium to cooling high-temperature nuclear reactor to be used for generating steam in contemporary ship steam-turbine power plants of a large output with taking into account in particular variable operational parameters. In the first part of the paper types of contemporary ship power plants are presented. Features of today applied PWR reactors and proposed HTR reactors are discussed. Next, issues of load variability of the ship nuclear power plants, features of the proposed thermal cycles and results of their thermodynamic calculations in variable operational conditions, are presented.

  2. Selected Models for Key Processes in a Nuclear Waste Repository Temperature field - Bentonite drying/resaturation

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, Johan (Chalmers Univ. of Technology, Goeteborg (Sweden))

    2007-12-15

    The bentonite, which surrounds and protects the canisters in a nuclear waste repository deep down in rock, experiences a complex, coupled heat and moisture flow process. The emitted heat from the canisters will cause an initial drying from the warmer canister side. The water in cracks and fractures in the rock will on the other hand cause successive saturation of the bentonite from the outer rock side, These processes will interact and one key question is the degree of initial drying and the time it takes to saturate the bentonite. This paper studies this problem and presents new handy tools of analysis. A compact formula for the temperature level and gradient in the bentonite is presented. The key radial moisture flow process around a canister is shown to be governed by two flow coefficient functions. These depend on water and bentonite properties in a rather complicated way, but they are determined quite handily by one of the models. The moisture flow may have a time scale of a few years, while the canister heat emission and temperature process involve a time scale of decades. Steady-state solutions are therefore of interest. One model solves the general case of coupled nonlinear differential equations for water saturation S(r) and temperature T(r) . An analysis of the equations shows that there is a direct relation between S and T, with the initial degree of saturation as a parameter. We get a set of curves that gives the (steady-state) drying for any temperature level, canister heat emission, and water saturation level. These very instructive diagrams are generated for any set of data in a few seconds. The second part of the analysis concerns the transient moisture flow process. There are two limits. In the wet-rock case, full saturation (S = 1) is maintained at the rock boundary. The moisture flux is zero at the rock boundary in the dry-rock case. The equation for the water saturation S(r,f) involves two free flow coefficient functions which are functions of S

  3. An analysis of the thermodynamic cycles with high-temperature nuclear reactor for power generation and hydrogen co-production

    Directory of Open Access Journals (Sweden)

    Dudek Michał

    2017-01-01

    Full Text Available In the present paper, numerical analysis of the thermodynamic cycle with the high-temperature nuclear gas reactor (HTGR for electricity and hydrogen production have been done. The analysed system consists of two independent loops. The first loop is for HTGR and consists of a nuclear reactor, heat exchangers, and blower. The second loop (Rankine cycle consist of up-to four steam turbines, that operate in heat recovery system. The analysis of the system shows that it is possible to achieve significantly higher efficiency than could be offered by traditional nuclear reactor technology (PWR and BWR. It is shown that the thermal efficiency about 52.5% it is possible to achieve when reactor works at standard conditions and steam is superheated up to 530oC. For the cases when the steam has supercritical conditions the value of thermal efficiency is still very high and equal about 50%.

  4. Off-design temperature effects on nuclear fuel pins for an advanced space-power-reactor concept

    Science.gov (United States)

    Bowles, K. J.

    1974-01-01

    An exploratory out-of-reactor investigation was made of the effects of short-time temperature excursions above the nominal operating temperature of 990 C on the compatibility of advanced nuclear space-power reactor fuel pin materials. This information is required for formulating a reliable reactor safety analysis and designing an emergency core cooling system. Simulated uranium mononitride (UN) fuel pins, clad with tungsten-lined T-111 (Ta-8W-2Hf) showed no compatibility problems after heating for 8 hours at 2400 C. At 2520 C and above, reactions occurred in 1 hour or less. Under these conditions free uranium formed, redistributed, and attacked the cladding.

  5. Temperature dependence of X-ray absorption and nuclear magnetic resonance spectra: probing quantum vibrations of light elements in oxides.

    Science.gov (United States)

    Nemausat, Ruidy; Gervais, Christel; Brouder, Christian; Trcera, Nicolas; Bordage, Amélie; Coelho-Diogo, Cristina; Florian, Pierre; Rakhmatullin, Aydar; Errea, Ion; Paulatto, Lorenzo; Lazzeri, Michele; Cabaret, Delphine

    2017-02-22

    A combined experimental-theoretical study on the temperature dependence of the X-ray absorption near-edge structure (XANES) and nuclear magnetic resonance (NMR) spectra of periclase (MgO), spinel (MgAl2O4), corundum (α-Al2O3), berlinite (α-AlPO4), stishovite and α-quartz (SiO2) is reported. Predictive calculations are presented when experimental data are not available. For these light-element oxides, both experimental techniques detect systematic effects related to quantum thermal vibrations which are well reproduced by density-functional theory simulations. In calculations, thermal fluctuations of the nuclei are included by considering nonequilibrium configurations according to finite-temperature quantum statistics at the quasiharmonic level. The influence of nuclear quantum fluctuations on XANES and NMR spectroscopies is particularly sensitive to the coordination number of the probed cation. Furthermore, the relative importance of nuclear dynamics and thermal expansion is quantified over a large range of temperatures.

  6. Materials for the very high temperature reactor (VHTR): a versatile nuclear power station for combined cycle electricity and heat production

    Energy Technology Data Exchange (ETDEWEB)

    Hoffelner, W

    2005-07-01

    The International Generation IV Initiative provides a research platform for the development of advanced nuclear plants which are able to produce electricity and heat in a combined cycle. Very high-temperature gas-cooled reactors are considered as near-term deployable plants meeting these requirements. They build on high-temperature gas-cooled reactors which are already in operation. The main parts of such an advanced plant are: reactor pressure vessel, core and close-to-core components, gas turbine, intermediate heat exchanger, and hydrogen production unit. The paper discusses the VHTR concept, materials, fuel and hydrogen production based on discussions on research and development projects addressed within the generation IV community. It is shown that material limitations might restrict the outlet temperature of near-term deployable VHTRs to about 950 {sup o}C. The impact of the high temperatures on fuel development is also discussed. Current status of combined cycle hydrogen production is elaborated on. (author)

  7. Damage-Tolerant, Lightweight, High-Temperature Radiator for Nuclear Powered Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced propulsion technologies such as Nuclear Electric Propulsion (NEP) have been partially limited by the mass of thermal rejection systems. NEP was proposed for...

  8. Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2017-01-01

    Full Text Available Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3-C(sp2 bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones.

  9. Effects of temperature on Rb and 129Xe spin polarization in a nuclear magnetic resonance gyroscope with low pump power

    Science.gov (United States)

    Chen, Linlin; Zhou, Binquan; Lei, Guanqun; Wu, Wenfeng; Zhai, Yueyang; Wang, Zhuo; Fang, Jiancheng

    2017-11-01

    We propose an average Rb polarization model to analyze the influence of temperature on the spin polarization of Rb and 129Xe in a Nuclear Magnetic Resonance Gyroscope (NMRG) with low pump power. This model is essentially based on summing the Rb spin polarization along the direction of the pump beam and dividing the result by the cell length. We experimentally study the spin polarization of Rb and 129Xe atoms as a function of the cell temperature at low values of the pump power. The experimental results and the values calculated with the average Rb polarization model are in good agreement for both Rb and 129Xe. The spin polarization of Rb atoms decreases with increasing cell temperature, with a decreasing trend which is rapid at temperatures below 110 °C, and slower at temperatures above 110 °C. The experimental values of the 129Xe polarization, obtained with a pump power of 1 mW, first increase to a maximum P129X e-ave = 0.66 % at 118 °C, and then decreases as the temperature increases. Increasing the power of the pump beam shifts the temperature maximum to a higher value. Our model is suitable for the analysis of Rb and 129Xe polarization at high temperature and low pump power, i.e. when the power of the pump beam is completely absorbed within a few millimeters of the front window of the cell. Therefore, the present model can provide theoretical support for the improvement of the Signal-to-Noise-Ratio (SNR) of the NMRG, and to determine its optimal working temperature.

  10. Distributed fibre optic temperature measurement system for the safety monitoring of the next generation of large nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Fernandez, Alberto; Brichard, Benoit [SCK-CEN, Belgian Nuclear Research Center (Belgium); Hartog, Arthur H.; Hughes, Paul [SENSA, a Schlumberger Company (United Kingdom)

    2006-07-01

    The use of optical fibre distributed sensors for temperature sensing is a powerful way of monitoring, quasi simultaneously, thousands of points avoiding the requirement of optimum positioning of discrete temperature sensors. Their range of applications is rapidly expanding in the industry, and nowadays this fibre optic sensing technology is mature for industrial applications such as fire detection inside buildings and tunnels, process vessel monitoring, leak detection in cryogenic storage vessels (liquid natural gas (LNG), ammonia, ethylene) or oil wells and the measurement of energy cable thermal distribution for the power supply industry. These applications rely on the well known immunity of fibre optic sensors to electromagnetic interference and the ability of fibre sensors to be operated in hazardous environments. The nuclear industry shows a growing interest for the possibilities offered for temperature sensing applications. Fibre optic sensing technology could be considered as an alternative to classical measurements techniques in a wide range of applications. The potential of distributed temperature measurements for the monitoring of large nuclear infrastructures such as reactor containment buildings, nuclear waste repositories and reactor primary circuitry have already been shown. However, a major problem in the application of optical fibres in nuclear environments is the presence of ionizing radiation fields that induce an increase of the optical fibre attenuation. This radiation-induced degradation of the measurement signal could be critical since most commercially available distributed temperature sensors derive the temperature profile from the measurement of the Raman backscattered light intensity along the fibre, using optical time domain reflectometry techniques. The Raman signal comprises two elements: the Stokes and anti-Stokes lines. The longer wavelength Stokes line is only weakly temperature sensitive but the intensity of the backscattered light

  11. Thickness dependence of Morin transition temperature in iridium-doped hematite layers studied through nuclear resonant scattering

    Science.gov (United States)

    Mibu, Ko; Mikami, Kazuaki; Tanaka, Masaaki; Masuda, Ryo; Yoda, Yoshitaka; Seto, Makoto

    2017-11-01

    The Morin transition of very thin Ir-doped α-Fe2O3 films, which is not detectable with conventional magnetization measurements, was studied by conversion electron Mössbauer spectroscopy using a 57Co source and nuclear resonant scattering using a synchrotron light source. It was found that (i) the Morin transition temperature increases as the Ir ratio increases, (ii) it decreases when the film thickness decreases, and (iii) the transition becomes irreversible when Ir ratio is small and the thickness is thin. These tendencies were found reproducible and systematic, although the mechanisms are to be clarified by further studies.

  12. Temperature dependence of cross-effect dynamic nuclear polarization in rotating solids

    DEFF Research Database (Denmark)

    Geiger, Michel-Andreas; Orwick-Rydmark, Marcella; Märker, Katharina

    2016-01-01

    Dynamic nuclear polarization exploits electron spin polarization to boost signal-to-noise in magic-angle-spinning (MAS) NMR, creating new opportunities in materials science, structural biology, and metabolomics studies. Since protein NMR spectra recorded under DNP conditions can show improved spe...... the importance of protons in a sphere of 4-6 Å around the nitroxyl group, presumably for polarization pickup from electron spins....

  13. Studies of low temperature, low flux radiation embrittlement of nuclear reactor structural materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R.; Lucas, G.E.

    1993-06-01

    There are several existing research programs which have components pertinent to the issue of low flux/low temperature embrittlement; in particular, examination of the Shippingport shield tank which has been exposed to low flux and relatively low temperature is being performed by ANL, and evaluation of low temperature embrittlement in A508 and A533B steels in support of the HTGR is currently being performed by ORNL. However, these programs are not specifically directed at the broader issue of low flux/low temperature embrittlement in a range of structural steels. Hence, the authors coordinated their effort with these programs so that their investigations were complementary to existing programs, and they focused on a set of materials which expand the data base developed in these programs. In particular, the authors have investigated embrittlement phenomena in steels that are similar to those used in support structure.

  14. Corrosion of oxide nuclear fuels in high-temperature water (LWBR Development Program

    Energy Technology Data Exchange (ETDEWEB)

    Markowitz, J M; Clayton, J C

    1970-02-01

    The corrosion behavior of a group of nuclear fuel oxides including urania, thoria, urania-zirconia, urania-calcia-zirconia, and urania-thoria has been studied in 360/sup 0/C, pH 10 flowing water, both degassed and oxygenated (5 and 100 ppM). Weight gains of the specimens, which were of plate or cylindrical pellet shape, were determined periodically during the corrosion exposures, some of which were as long as 500 days; in addition, ceramographic examinations, x-ray diffraction measurements, and chemical analyses were carried out on selected specimens. The results are summarized and discussed. (NSA 24: 25764)

  15. Evolution of the Nuclear and Magnetic Structures with Temperature in TlFe1:6Se2

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Huibo [ORNL; Chakoumakos, Bryan C [ORNL; May, Andrew F [ORNL; McGuire, Michael A [ORNL; Cantoni, Claudia [ORNL; Custelcean, Radu [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Sales, Brian C [ORNL; Pennycook, Stephen J [ORNL

    2012-01-01

    The evolution of the nuclear and magnetic structures of TlFe1:6Se2 was determined in the temperature range of 5-450K using single crystal neutron diraction. The Fe layers in these materials develop a corrugation in the magnetically ordered state. A canting away from the block checkerboard magnetic structure is observed in the narrow temperature range between approximately 100 and 150 K. In this same temperature range, an increase in the corrugation of the Fe layers is observed. At lower temperatures, the block checkerboard magnetic structure is recovered with a suppressed magnetic moment and abrupt changes in the lattice parameters. Microstructure analysis at 300K using atomic-resolution Z-contrast scanning transmission electron microscopy does not show the clear phase separation observed in alkali-metal iron selenides. These ndings highlight the dierences between the alkali-metal and thallium materials, and indicate competition between magnetic ground states and a strong coupling of magnetism to the lattice in TlFe1:6Se2.

  16. Research of the influence of intensification of heat transfer on distribution of temperature in the active core of the gas cooled nuclear reactor of the «GT-MHR» project

    Science.gov (United States)

    Kuzevanov, V. S.; Podgorny, S. K.

    2017-11-01

    The maximum wall temperature of a cooling channel of a nuclear reactor is one of the factors that affects directly of the safety and reliability of the nuclear reactor. In this paper suggested an equation, which allows calculating the maximum wall temperature of the cooling channel of the nuclear reactor with heat transfer enhancer installed, without enormous calculations.

  17. Temperature dependence of nuclear fission time in heavy-ion fusion-fission reactions

    Science.gov (United States)

    Eccles, Chris; Roy, Sanil; Gray, Thomas H.; Zaccone, Alessio

    2017-11-01

    Accounting for viscous damping within Fokker-Planck equations led to various improvements in the understanding and analysis of nuclear fission of heavy nuclei. Analytical expressions for the fission time are typically provided by Kramers' theory, which improves on the Bohr-Wheeler estimate by including the time scale related to many-particle dissipative processes along the deformation coordinate. However, Kramers' formula breaks down for sufficiently high excitation energies where Kramers' assumption of a large barrier no longer holds. Focusing on the overdamped regime for energies T >1 MeV, Kramers' theory should be replaced by a new analytical theory derived from the Ornstein-Uhlenbeck first-passage time method that is proposed here. The theory is applied to fission time data from fusion-fission experiments on 16O+208Pb→224Th . The proposed model provides an internally consistent one-parameter fitting of fission data with a constant nuclear friction as the fitting parameter, whereas Kramers' fitting requires a value of friction which falls out of the allowed range. The theory provides also an analytical formula that in future work can be easily implemented in numerical codes such as cascade or joanne4.

  18. Glass-transition temperature gradient in nanocomposites: evidence from nuclear magnetic resonance and differential scanning calorimetry.

    Science.gov (United States)

    Papon, Aurélie; Montes, Hélène; Hanafi, Mohamed; Lequeux, François; Guy, Laurent; Saalwächter, Kay

    2012-02-10

    The slowing-down of the dynamics of a polymer chain near a surface has been observed for many years now. Here we show that the behavior of model nanocomposites can be quantitatively described with a gradient of glass-transition temperature. We describe with a single parameter-the range of this gradient-the temperature and solvent effect on the spin relaxation dynamics. Moreover, this parameter allows a quantitative description of the nanocomposite calorimetric response from the one of the bulk polymer.

  19. Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; El-Dasher, B; de Caro, M S; Ferreira, J

    2008-11-25

    Corrosion of ferritic steels in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such a beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li{sub 2}BeF{sub 4}) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. This paper also reports electrochemical impedance spectroscopy of steels at their corrosion potentials in high-temperature molten salt environments, with the complex impedance spectra interpreted in terms of the interfacial charge transfer resistance and capacitance, as well as the electrolyte conductivity. Such in situ measurement techniques provide valuable insight into the degradation of materials under realistic conditions.

  20. Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source

    Energy Technology Data Exchange (ETDEWEB)

    Konarek, E.; Coulas, B.; Sarvinis, J. [Hatch Ltd., Mississauga, Ontario (Canada)

    2016-06-15

    This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. The . cycles considered will either utilize Gasification processes, or carbon capture as a source of feed material. In addition the cycles will be coupled to a small modular Nuclear Reactor (SMR) as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities. The technical advantages as well as the economic case are discussed for each of the cycles presented. (author)

  1. Low-temperature lithium diffusion in simulated high-level boroaluminosilicate nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Neeway, James J.; Kerisit, Sebastien N.; Gin, Stephane; Wang, Zhaoying; Zhu, Zihua; Ryan, Joseph V.

    2014-12-01

    Ion exchange is recognized as an integral, if underrepresented, mechanism influencing glass corrosion. However, due to the formation of various alteration layers in the presence of water, it is difficult to conclusively deconvolute the mechanisms of ion exchange from other processes occurring simultaneously during corrosion. In this work, an operationally inert non-aqueous solution was used as an alkali source material to isolate ion exchange and study the solid-state diffusion of lithium. Specifically, the experiments involved contacting glass coupons relevant to the immobilization of high-level nuclear waste, SON68 and CJ-6, which contained Li in natural isotope abundance, with a non-aqueous solution of 6LiCl dissolved in dimethyl sulfoxide at 90 °C for various time periods. The depth profiles of major elements in the glass coupons were measured using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Lithium interdiffusion coefficients, DLi, were then calculated based on the measured depth profiles. The results indicate that the penetration of 6Li is rapid in both glasses with the simplified CJ-6 glass (D6Li ≈ 4.0-8.0 × 10-21 m2/s) exhibiting faster exchange than the more complex SON68 glass (DLi ≈ 2.0-4.0 × 10-21 m2/s). Additionally, sodium ions present in the glass were observed to participate in ion exchange reactions; however, different diffusion coefficients were necessary to fit the diffusion profiles of the two alkali ions. Implications of the diffusion coefficients obtained in the absence of alteration layers to the long-term performance of nuclear waste glasses in a geological repository system are also discussed.

  2. Critical Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel Based on Diffusion Controlled Cavity Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, T.A.; Rosen, R.S.; Kassner, M.E.

    1999-12-01

    Interim dry storage of spent nuclear fuel (SNF) rods is of critical concern because a shortage of existing SNF wet storage capacity combined with delays in the availability of a permanent disposal repository has led to an increasing number of SNF rods being placed into interim dry storage. Safe interim dry storage must be maintained for a minimum of twenty years according to the Standard Review Plan for Dry Cask Storage Systems [1] and the Code of Federal Regulations, 10 CFR Part 72 [2]. Interim dry storage licensees must meet certain safety conditions when storing SNF rods to ensure that there is a ''very low probability (e.g. 0.5%) of cladding breach during long-term storage'' [1]. Commercial SNF typically consists of uranium oxide pellets surrounded by a thin cladding. The cladding is usually an {alpha}-zirconium based alloy know as ''Zircaloy''. In dry storage, the SNF rods are confined in one of several types of cask systems approved by the Nuclear Regulatory Commission (NRC). ''The cask system must be designed to prevent degradation of fuel cladding that results in a type of cladding breach, such as axial-splits or ductile fracture, where irradiated UO{sub 2} particles may be released. In addition, the fuel cladding should not degrade to the point where more than one percent of the fuel rods suffer pinhole or hairline crack type failure under normal storage conditions [1].'' The NRC has approved two models [3,4] for use by proposed dry storage licensees to determine the maximum initial temperature limit for nuclear fuel rods in dry storage that supposedly meet the above criteria and yield consistent temperature limits. Though these two models are based on the same fundamental failure theory, different assumptions have been made including the choice of values for material constants in the failure equation. This report will examine and compare the similarities and inconsistencies of these two models

  3. Survival of bacteria in nuclear waste buffer materials. The influence of nutrients, temperature and water activity

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, K.; Motamedi, M. [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology; Karnland, O. [Clay Technology AB, Lund (Sweden)

    1995-12-01

    The concept of deep geological disposal of spent fuel is common to many national nuclear waste programs. Long-lived radioactive waste will be encapsulated in canisters made of corrosion resistant materials e.g. copper and buried several hundred meters below ground in a geological formation. Different types of compacted bentonite clay, or mixtures with sand, will be placed as a buffer around the waste canisters. A major concern for the performance of the canisters is that sulphate-reducing bacteria (SRB) may be present in the clay and induce corrosion by production of hydrogen sulphide. This report presents data on viable counts of SRB in the bedrock of Aespoe hard rock laboratory. A theoretical background on the concept water activity is given, together with basic information about SRB. Some results on microbial populations from a full scale buffer test in Canada is presented. These results suggested water activity to be a strong limiting factor for survival of bacteria in compacted bentonite. As a consequence, experiments were set up to investigate the effect from water activity on survival of SRB in bentonite. Here we show that survival of SRB in bentonite depends on the availability of water and that compacting a high quality bentonite to a density of 2.0 g/cm{sup 3}, corresponding to a water activity (a{sub w}) of 0.96, prevented SRB from surviving in the clay. 24 refs.

  4. Response Analysis on Electrical Pulses under Severe Nuclear Accident Temperature Conditions Using an Abnormal Signal Simulation Analysis Module

    Directory of Open Access Journals (Sweden)

    Kil-Mo Koo

    2012-01-01

    Full Text Available Unlike design basis accidents, some inherent uncertainties of the reliability of instrumentations are expected while subjected to harsh environments (e.g., high temperature and pressure, high humidity, and high radioactivity occurring in severe nuclear accident conditions. Even under such conditions, an electrical signal should be within its expected range so that some mitigating actions can be taken based on the signal in the control room. For example, an industrial process control standard requires that the normal signal level for pressure, flow, and resistance temperature detector sensors be in the range of 4~20 mA for most instruments. Whereas, in the case that an abnormal signal is expected from an instrument, such a signal should be refined through a signal validation process so that the refined signal could be available in the control room. For some abnormal signals expected under severe accident conditions, to date, diagnostics and response analysis have been evaluated with an equivalent circuit model of real instruments, which is regarded as the best method. The main objective of this paper is to introduce a program designed to implement a diagnostic and response analysis for equivalent circuit modeling. The program links signal analysis tool code to abnormal signal simulation engine code not only as a one body order system, but also as a part of functions of a PC-based ASSA (abnormal signal simulation analysis module developed to obtain a varying range of the R-C circuit elements in high temperature conditions. As a result, a special function for abnormal pulse signal patterns can be obtained through the program, which in turn makes it possible to analyze the abnormal output pulse signals through a response characteristic of a 4~20 mA circuit model and a range of the elements changing with temperature under an accident condition.

  5. Studies of low temperature, low flux radiation embrittlement of nuclear reactor structural materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R.; Lucas, G.E.

    1998-09-02

    A large matrix of simple alloys and complex commercial type steels was irradiated over a range of fluxes at 60 C up to a fast fluence of about 3 {times} 10{sup 22} n/m{sup 2}. Combined with data in the literature, these results show a negligible effect of flux on irradiation hardening in the range of 2 {times} 10{sup 13} to 5 {times} 10{sup 18} n/m{sup 2}-s. This observation lends indirect support to the proposal that the accelerated embrittlement in the High Flux Isotope Reactor surveillance steels was due to an anomalously high level of damage from gamma rays. A weak dependence of hardening on a number of elements, including copper, nickel, phosphorus, molybdenum and manganese, can be described by a simple empirical chemistry factor. Particular combinations of elements resulted in hardening differences of up to about 60% in the complex commercial type steels and up to about 100% in simple model alloys. Direct effects of microstructure appear to be minimal. Hardening varies with the square root of fluence above a threshold around 4 {times} 10{sup 20} n/m{sup 2}. The results suggest that low temperature hardening is dominated by local intracascade processes leading to the formation of small defect-solute clusters/complexes. The observed hardening corresponds to nominal maximum end-of-life transition temperature shifts in support structure steels of about 120 C.

  6. Elevated-Temperature Ferritic and Martensitic Steels and Their Application to Future Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, RL

    2005-01-31

    In the 1970s, high-chromium (9-12% Cr) ferritic/martensitic steels became candidates for elevated-temperature applications in the core of fast reactors. Steels developed for conventional power plants, such as Sandvik HT9, a nominally Fe-12Cr-1Mo-0.5W-0.5Ni-0.25V-0.2C steel (composition in wt %), were considered in the United States, Europe, and Japan. Now, a new generation of fission reactors is in the planning stage, and ferritic, bainitic, and martensitic steels are again candidates for in-core and out-of-core applications. Since the 1970s, advances have been made in developing steels with 2-12% Cr for conventional power plants that are significant improvements over steels originally considered. This paper will review the development of the new steels to illustrate the advantages they offer for the new reactor concepts. Elevated-temperature mechanical properties will be emphasized. Effects of alloying additions on long-time thermal exposure with and without stress (creep) will be examined. Information on neutron radiation effects will be discussed as it applies to ferritic and martensitic steels.

  7. Fibre optic extensometer for high radiation and high temperature nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Cheymol, G. [CEA, French Nuclear Energy Commission, Nuclear Energy Div. DEN, 91191 Gif/Yvette Cedex (France); Villard, J. F. [CEA, Nuclear Energy Div. DEN, Reactors Studies Dept., Cadarache, 13108 St Paul Lez Durance (France); Gusarov, A.; Brichard, B. [SCK.CEN, ANS/ARI, Boeretang 200, 2400 Mol (Belgium)

    2011-07-01

    In the framework of the Joint Instrumentation Laboratory (LCI), gathering resources from SCK-CEN (Belgium) and CEA (France), we are developing an optical sensor in order to accurately measure radiation-induced elongation of material placed in the core of a Material Testing Reactor (MTR). This extensometer displays common advantages of Fibre Optic (FO) sensors: high resolution, easy remote sensing and multiplexing, and also compact size which is of particular interest for in pile experiments with little room available. In addition, light weight reduces gamma heating hence limiting the thermal effect. In accordance with the specifications, the sensor has preferably two fixing points defining a gauge length of 10 to 15 mm (as a minimum). The diameter is less than 2 mm. Intense gamma and neutron irradiation as well as high temperatures are the most difficult environment conditions to withstand. Reactor radiation produces huge losses in common optical fibre. The losses can be limited by selecting the fibres (mainly with high purity silica core), the wavelength range (800-1200 nm), and a measurement based on interferometry (largely insensitive to losses in the fibre thanks to the wavelength encoding of the useful signal). Heavy neutron - mainly - and gamma flux such as in MTR, also produce compaction of silica, resulting in a significant drift and preventing the use of commercial FO sensors in such environment. Knowing this issue we revised the basic scheme of Extrinsic Fabry Perot Interferometer (EFPI) in order to limit the effects of compaction. A first sensor prototype fixed on a stainless steel support was tested in the Smirnof test facility in the BR2 MTR in Mol (Belgium). The support was subject to a constant mechanical and thermal stress, and his dimensions were not supposed to vary. This test showed a very low drift of the revisited EPFI design under high irradiation field in comparison with a commercial EFPI. This result has to be confirmed with second

  8. Fabrication of cermet bearings for the control system of a high temperature lithium cooled nuclear reactor

    Science.gov (United States)

    Yacobucci, H. G.; Heestand, R. L.; Kizer, D. E.

    1973-01-01

    The techniques used to fabricate cermet bearings for the fueled control drums of a liquid metal cooled reference-design reactor concept are presented. The bearings were designed for operation in lithium for as long as 5 years at temperatures to 1205 C. Two sets of bearings were fabricated from a hafnium carbide - 8-wt. % molybdenum - 2-wt. % niobium carbide cermet, and two sets were fabricated from a hafnium nitride - 10-wt. % tungsten cermet. Procedures were developed for synthesizing the material in high purity inert-atmosphere glove boxes to minimize oxygen content in order to enhance corrosion resistance. Techniques were developed for pressing cylindrical billets to conserve materials and to reduce machining requirements. Finishing was accomplished by a combination of diamond grinding, electrodischarge machining, and diamond lapping. Samples were characterized in respect to composition, impurity level, lattice parameter, microstructure and density.

  9. ODS-materials for high temperature applications in advanced nuclear systems

    Directory of Open Access Journals (Sweden)

    C.C. Eiselt

    2016-12-01

    Full Text Available A ferritic ODS-alloy (Fe-14Cr-1W-0.25Ti has been manufactured by application of the powder metallurgical production route involving at first mechanical alloying of ∼10kg pre-alloyed steel powder together with an Y2O3 addition for 12h in a high energy industrial ball mill under hydrogen atmosphere at the company ZOZ GmbH. As a next step, one part of the alloyed powder was hot extruded into rods while another portion was hot isostatically pressed into plates. Both materials were then heat treated. A characterization program on these ODS-alloy production forms included microstructural and mechanical investigations: SANS and TEM assume the existence of Y2Ti2O7 nano clusters and show a bimodal distribution of ODS-particle sizes in both ODS variants. EBSD maps showed a strong 〈110〉 texture corresponding to the α fiber for the hot extruded ODS and a slight 〈001〉 texture for the hipped ODS material. Fracture toughness tests in different specimen orientations (extruded ODS with mini 0.2T C(T specimens together with Charpy impact tests revealed anisotropic mechanical properties: Promising (fracture toughness levels were obtained in the specimen orientation perpendicular to the extrusion direction, while the toughness levels remained low in extrusion direction and generally for the hipped ODS material at all test temperatures. The fracture toughness tests were performed according to ASTM E 1921 and 1820 standards.

  10. THATCH: A computer code for modelling thermal networks of high- temperature gas-cooled nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kroeger, P.G.; Kennett, R.J.; Colman, J.; Ginsberg, T. (Brookhaven National Lab., Upton, NY (United States))

    1991-10-01

    This report documents the THATCH code, which can be used to model general thermal and flow networks of solids and coolant channels in two-dimensional r-z geometries. The main application of THATCH is to model reactor thermo-hydraulic transients in High-Temperature Gas-Cooled Reactors (HTGRs). The available modules simulate pressurized or depressurized core heatup transients, heat transfer to general exterior sinks or to specific passive Reactor Cavity Cooling Systems, which can be air or water-cooled. Graphite oxidation during air or water ingress can be modelled, including the effects of added combustion products to the gas flow and the additional chemical energy release. A point kinetics model is available for analyzing reactivity excursions; for instance due to water ingress, and also for hypothetical no-scram scenarios. For most HTGR transients, which generally range over hours, a user-selected nodalization of the core in r-z geometry is used. However, a separate model of heat transfer in the symmetry element of each fuel element is also available for very rapid transients. This model can be applied coupled to the traditional coarser r-z nodalization. This report described the mathematical models used in the code and the method of solution. It describes the code and its various sub-elements. Details of the input data and file usage, with file formats, is given for the code, as well as for several preprocessing and postprocessing options. The THATCH model of the currently applicable 350 MW{sub th} reactor is described. Input data for four sample cases are given with output available in fiche form. Installation requirements and code limitations, as well as the most common error indications are listed. 31 refs., 23 figs., 32 tabs.

  11. J-resistance curves for Inconel 690 and Incoloy 800 nuclear steam generators tubes at room temperature and at 300 °C

    Science.gov (United States)

    Bergant, Marcos A.; Yawny, Alejandro A.; Perez Ipiña, Juan E.

    2017-04-01

    The structural integrity of steam generator tubes is a relevant issue concerning nuclear plant safety. In the present work, J-resistance curves of Inconel 690 and Incoloy 800 nuclear steam generator tubes with circumferential and longitudinal through wall cracks were obtained at room temperature and 300 °C using recently developed non-standard specimens' geometries. It was found that Incoloy 800 tubes exhibited higher J-resistance curves than Inconel 690 for both crack orientations. For both materials, circumferential cracks resulted into higher fracture resistance than longitudinal cracks, indicating a certain degree of texture anisotropy introduced by the tube fabrication process. From a practical point of view, temperature effects have found to be negligible in all cases. The results obtained in the present work provide a general framework for further application to structural integrity assessments of cracked tubes in a variety of nuclear steam generator designs.

  12. Development of the process of energy transfer from a nuclear Power Plant to an intermediate temperature electrolyse; Desarrollo del proceso de transferencia de energia desde una central nuclear a un electrolizador de temperatura intermedia

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Cervantes, A.; Cuadrado Garcia, P.; Soraino Garcia, J.

    2013-07-01

    Fifty million tons of hydrogen are consumed annually in the world in various industrial processes. Among them, the ammonia production, oil refining and the production of methanol. One of the methods to produce it is the electrolysis of water, oxygen and hydrogen. This process needs electricity and steam which a central nuclear It can be your source; Hence the importance of developing the transfer process energy between the two. The objective of the study is to characterize the process of thermal energy transfer from a nuclear power plant to an electrolyzer of intermediate temperature (ITSE) already defined. The study is limited to the intermediate engineering process, from the central to the cell.

  13. Role of temperature in the radiation stability of yttria stabilized zirconia under swift heavy ion irradiation: A study from the perspective of nuclear reactor applications

    Science.gov (United States)

    Kalita, Parswajit; Ghosh, Santanu; Sattonnay, Gaël; Singh, Udai B.; Grover, Vinita; Shukla, Rakesh; Amirthapandian, S.; Meena, Ramcharan; Tyagi, A. K.; Avasthi, Devesh K.

    2017-07-01

    The search for materials that can withstand the harsh radiation environments of the nuclear industry has become an urgent challenge in the face of ever-increasing demands for nuclear energy. To this end, polycrystalline yttria stabilized zirconia (YSZ) pellets were irradiated with 80 MeV Ag6+ ions to investigate their radiation tolerance against fission fragments. To better simulate a nuclear reactor environment, the irradiations were carried out at the typical nuclear reactor temperature (850 °C). For comparison, irradiations were also performed at room temperature. Grazing incidence X-ray diffraction and Raman spectroscopy measurements reveal degradation in crystallinity for the room temperature irradiated samples. No bulk structural amorphization was however observed, whereas defect clusters were formed as indicated by transmission electron microscopy and supported by thermal spike simulation results. A significant reduction of the irradiation induced defects/damage, i.e., improvement in the radiation tolerance, was seen under irradiation at 850 °C. This is attributed to the fact that the rapid thermal quenching of the localized hot molten zones (arising from spike in the lattice temperature upon irradiation) is confined to 850 °C (i.e., attributed to the resistance inflicted on the rapid thermal quenching of the localized hot molten zones by the high temperature of the environment) thereby resulting in the reduction of the defects/damage produced. Our results present strong evidence for the applicability of YSZ as an inert matrix fuel in nuclear reactors, where competitive effects of radiation damage and dynamic thermal healing mechanisms may lead to a strong reduction in the damage production and thus sustain its physical integrity.

  14. High Temperature Nanocomposites For Nuclear Thermal Propulsion and In-Space Fabrication by Hyperbaric Pressure Laser Chemical Vapor Deposition

    Science.gov (United States)

    Maxwell, J. L.; Webb, N. D.; Espinoza, M.; Cook, S.; Houts, M.; Kim, T.

    Nuclear Thermal Propulsion (NTP) is an indispensable technology for the manned exploration of the solar system. By using Hyperbaric Pressure Laser Chemical Vapor Deposition (HP-LCVD), the authors propose to design and build a promising next-generation fuel element composed of uranium carbide UC embedded in a latticed matrix of highly refractory Ta4HfC5 for an NTP rocket capable of sustaining temperatures up to 4000 K, enabling an Isp of up to 1250 s. Furthermore, HP-LCVD technology can also be harnessed to enable 3D rapid prototyping of a variety of materials including metals, ceramics and composites, opening up the possibility of in-space fabrication of components, replacement parts, difficult-to-launch solar sails and panels and a variety of other space structures. Additionally, rapid prototyping with HP-LCVD makes a feasible "live off the land" strategy of interplanetary and interstellar exploration ­ the precursors commonly used in the technology are found, often in abundance, on other solar system bodies either as readily harvestable gas (e.g. methane) or as a raw material that could be converted into a suitable precursor (e.g. iron oxide into ferrocene on Mars).

  15. Design and energy analysis of a electrolytic hydrogen production process by means of a high temperature nuclear reactor; Diseno y analisis energetico de un proceso de produccion de hidrogeno electrolitico por medio de un reactor nuclear de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J.; Morales S, J. B. [UNAM, DEPFI Campus Morelos, Jiutepec, Morelos (Mexico)]. e-mail: julfi_jg@yahoo.com.mx

    2008-07-01

    In this work an energy analysis to a process of production of hydrogen by means of electrolysis of high temperature is realized. This electrolysis type, unlike conventional electrolysis allows us to reach efficiencies of up to 60% because when increasing the temperature of the water, providing to its thermal energy, diminishes the demand of electrical energy required to separate the molecule of the water. Nevertheless, to obtain these efficiencies it is needed to have superheated aqueous vapor to but of 850 centigrade degrees, temperatures that can be reached about high temperature reactor; HTGR. In the present work it is mentioned to introduction way the importance of the hydrogen like energy vector and the advantages of obtaining it by means of nuclear energy. The electrolysis process of high temperature is described and a design is realized of this from its coupling to a nuclear power plant PBMR. The technological advances on which it counts the PBMR; efficiencies of 48% for optimized plants, their modular design and the thermodynamic cycle recuperative Brayton where upon operate; make the short term ideal candidate for the production of hydrogen. The thermodynamic analysis of optimized plant PBMR appears in another work, here the results of the balance of mass and energy involved in the process appear of hydrogen generation and the complete analysis of this. The result is a complete model of generation of hydrogen by electrolysis of high temperature coupled to an optimized plant PBMR that will be implemented for its dynamic simulation later. (Author)

  16. Evaluation of two processes of hydrogen production starting from energy generated by high temperature nuclear reactors; Evaluacion de dos procesos de produccion de hidrogeno a partir de energia generada por reactores nucleares de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J., E-mail: jvalle@upmh.edu.mx [Universidad Politecnica Metropolitana de Hidalgo, Boulevard Acceso a Tolcayuca 1009, Ex-Hacienda San Javier, 43860 Tolcayuca, Hidalgo (Mexico)

    2013-10-15

    In this work an evaluation to two processes of hydrogen production using energy generated starting from high temperature nuclear reactors (HTGR's) was realized. The evaluated processes are the electrolysis of high temperature and the thermo-chemistry cycle Iodine-Sulfur. The electrolysis of high temperature, contrary to the conventional electrolysis, allows reaching efficiencies of up to 60% because when increasing the temperature of the water, giving thermal energy, diminishes the electric power demand required to separate the molecule of the water. However, to obtain these efficiencies is necessary to have water vapor overheated to more than 850 grades C, temperatures that can be reached by the HTGR. On the other hand the thermo-chemistry cycle Iodine-Sulfur, developed by General Atomics in the 1970 decade, requires two thermal levels basically, the great of them to 850 grades C for decomposition of H{sub 2}SO{sub 4} and another minor to 360 grades C approximately for decomposition of H I, a high temperature nuclear reactor can give the thermal energy required for the process whose products would be only hydrogen and oxygen. In this work these two processes are described, complete models are developed and analyzed thermodynamically that allow to couple each hydrogen generation process to a reactor HTGR that will be implemented later on for their dynamic simulation. The obtained results are presented in form of comparative data table of each process, and with them the obtained net efficiencies. (author)

  17. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach Nuclear Power Plant, Units 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Laudenbach, D.H.

    1979-03-01

    The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach nuclear power plant, Units 1 and 2. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory.

  18. Thermodynamic study of residual heat from a high temperature nuclear reactor to analyze its viability in cogeneration processes; Estudio termodinamico del calor residual de un reactor nuclear de alta temperatura para analizar su viabilidad en procesos de cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Santillan R, A.; Valle H, J.; Escalante, J. A., E-mail: santillanaura@gmail.com [Universidad Politecnica Metropolitana de Hidalgo, Boulevard acceso a Tolcayuca 1009, Ex-Hacienda San Javier, 43860 Tolcayuca, Hidalgo (Mexico)

    2015-09-15

    In this paper the thermodynamic study of a nuclear power plant of high temperature at gas turbine (GTHTR300) is presented for estimating the exploitable waste heat in a process of desalination of seawater. One of the most studied and viable sustainable energy for the production of electricity, without the emission of greenhouse gases, is the nuclear energy. The fourth generation nuclear power plants have greater advantages than those currently installed plants; these advantages have to do with security, increased efficiencies and feasibility to be coupled to electrical cogeneration processes. In this paper the thermodynamic study of a nuclear power plant type GTHTR300 is realized, which is selected by greater efficiencies and have optimal conditions for use in electrical cogeneration processes due to high operating temperatures, which are between 700 and 950 degrees Celsius. The aim of the study is to determine the heat losses and the work done at each stage of the system, determining where they are the greatest losses and analyzing in that processes can be taken advantage. Based on the study was appointed that most of the energy losses are in form of heat in the coolers and usually this is emitted into the atmosphere without being used. From the results a process of desalination of seawater as electrical cogeneration process is proposed. This paper contains a brief description of the operation of the nuclear power plant, focusing on operation conditions and thermodynamic characteristics for the implementation of electrical cogeneration process, a thermodynamic analysis based on mass and energy balance was developed. The results allow quantifying the losses of thermal energy and determining the optimal section for coupling of the reactor with the desalination process, seeking to have a great overall efficiency. (Author)

  19. Proposal of new 235U nuclear data to improve keff biases on 235U enrichment and temperature for low enriched uranium fueled lattices moderated by light water

    OpenAIRE

    Wu, H; 奥村 啓介; 柴田 恵一

    2005-01-01

    The under prediction of keff depending on 235U enrichment in low enriched uranium fueled systems was studied in this report. Benchmark testing was carried out with several evaluated nuclear data files, including the new uranium evaluations from preliminary ENDF/B-VII and CENDL-3.1. Another problem reviewed here was keff underestimation vs. temperature increase, which was observed in the slightly enriched system with recent JENDL and ENDF/B uranium evaluations. Through the substitute analysis ...

  20. Bridging the Gap in the Chemical Thermodynamic Database for Nuclear Waste Repository: Studies of the Effect of Temperature on Actinide Complexation

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Linfeng; Tian, Guoxin; Xia, Yuanxian; Friese, Judah I.; Zanonato, PierLuigi; Di Bernardo, Plinio

    2009-12-21

    Recent results of thermodynamic studies on the complexation of actinides (UO{sub 2}{sup 2+}, NpO{sub 2}{sup +} and Pu{sup 4+}) with F{sup -}, SO{sub 4}{sup 2-} and H{sub 2}PO{sub 4}{sup -}/HPO{sub 4}{sup 2-} at elevated temperatures are reviewed. The data indicate that, for all systems except the 1:1 complexation of Np(V) with HPO{sub 4}{sup 2-}, the complexation of actinides is enhanced by the increase in temperature. The enhancement is primarily due to the increase in the entropy term (T{Delta}S) that exceeds the increase in the enthalpy ({Delta}H) as the temperature is increased. These data bridge the gaps in the chemical thermodynamic database for nuclear waste repository where the temperature could remain significantly higher than 25 C for a long time after the closure of the repository.

  1. Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Phillpot, Simon; Tulenko, James

    2011-09-08

    The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

  2. Numerical simulation of temperature and thermal stress for nuclear piping by using computational fluid dynamics analysis and Green’s function

    Energy Technology Data Exchange (ETDEWEB)

    Boo, Myung-Hwan [Korea Hydro and Nuclear Power Company, Daejeon (Korea, Republic of); Oh, Chang-Kyun; Kim, Hyun-Su [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of); Choi, Choeng-Ryul [ELSOLTEC, Inc., Yongin (Korea, Republic of)

    2017-05-15

    Owing to the fact that thermal fatigue is a well-known damage mechanism in nuclear power plants, accurate stress and fatigue evaluation are highly important. Operating experience shows that the design condition is conservative compared to the actual one. Therefore, various fatigue monitoring methods have been extensively utilized to consider the actual operating data. However, defining the local temperature in the piping is difficult because temperature-measuring instruments are limited. The purpose of this paper is to define accurate local temperature in the piping and evaluate thermal stress using Green’s function (GF) by performing a series of computational fluid dynamics analyses considering the complex fluid conditions. Also, the thermal stress is determined by adopting GF and comparing it with that of the design condition. The fluid dynamics analysis result indicates that the fluid temperature slowly varies compared to the designed one even when the flow rate changes abruptly. In addition, the resulting thermal stress can significantly decrease when reflecting the actual temperature.

  3. Temperature dependence of friction from pre- and post-scission neutron emission 24.75.+i; 25.70.Jj; Fission dynamics; Nuclear friction; Neutron multiplicities

    CERN Document Server

    Rudolf, G

    2001-01-01

    The magnitude of nuclear friction has been investigated in recent years by measuring pre- and post-scission neutron multiplicities. These data have been analysed mostly in the frame of the statistical model by introducing ad-hoc delays to go from equilibrium to saddle and then to scission. We present here a more simple approach based on remaining excitation energies at saddle. This leads to analytical formulae which reproduce almost all the published data. The temperature at which one observes transition from pre-scission to post-scission emission is the only parameter in the calculation. Its values show no significant variation with the total mass nor with bombarding energy, supporting the concept of temperature dependent friction. The mean value averaged over all published data is 1.11+-0.05 MeV.

  4. A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature

    Science.gov (United States)

    Zhao, J. Y.; Bi, W.; Sinogeikin, S.; Hu, M. Y.; Alp, E. E.; Wang, X. C.; Jin, C. Q.; Lin, J. F.

    2017-12-01

    A new miniature panoramic diamond anvil cell (mini-pDAC) as well as a unique gas membrane-driven mechanism is developed and implemented to measure electronic, magnetic, vibrational, and thermodynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the synchrotron Mössbauer spectroscopy (SMS) simultaneously at high pressure (over Mbar) and low temperature (T Advanced Photon Source, for NRIXS and SMS studies. The same instrument can easily be used for other X-ray techniques, such as X-ray radial diffraction, X-ray Raman scattering, X-ray emission spectroscopy, and X-ray inelastic scattering under high pressure and low temperature. In this paper, technical details of the mini-pDAC, membrane engaging mechanism, and the cryostat system are described, and some experimental results are discussed.

  5. Ionization measurement at very low temperature for nuclear and electron recoils discrimination by ionization-heat simultaneous measurement for dark matter research

    CERN Document Server

    Navick, X F; Tourbot, R

    2000-01-01

    To achieve a high level of discrimination between nuclear recoils and electron recoils for dark matter research, we realized and studied ionization-heat detectors working at very low temperature (10-20 mK). To understand the mechanisms underlying the ionization measurement at this temperature range, we made systematic studies of detectors performances (time stability, energy resolution, etc.) in X- and gamma-rays detection for Ge and Si detectors. Results are presented and discussed. We found that the time stability is governed by the progressive space charge build-up due to impurities ionization by far-infrared radiation. Moreover if the energy resolution of HPGe-pin detectors is limited by the noise, it appears to be intrinsically limited by carrier trapping on neutral impurities in Si detectors.

  6. Lowering storage temperature during ovary transport is beneficial to the developmental competence of bovine oocytes used for somatic cell nuclear transfer.

    Science.gov (United States)

    Wang, Y S; Zhao, X; Su, J M; An, Z X; Xiong, X R; Wang, L J; Liu, J; Quan, F S; Hua, S; Zhang, Y

    2011-03-01

    The objective of this study was to determine the effect of storage temperature during ovary transport on the developmental competence of bovine oocytes for use in somatic cell nuclear transfer (SCNT). Ovaries obtained from a slaughterhouse were stored in physiological saline for 3-4h at one of the three temperatures: 15 °C, 25 °C, or 35 °C. The developmental competence of oocytes used for SCNT was ascertained by cleavage and blastocyst formation rate, total cell number, apoptosis index, and the relative abundance of Bax and Hsp70.1 in day 7 blastocysts. Ovaries stored at 35 °C for 3-4h reduced the recovery rate of grade I and II oocytes compared with those stored at 25 °C or 15 °C (45.1±0.7% vs. 76.7±1.2% or 74.8±2.0%, Pstorage temperature of 15 °C for a 3-4h period had a significant beneficial effect on the quality and developmental competence of oocytes used for SCNT due to the alleviation of stresses on the oocytes compared with those subjected to storage temperatures of 25 °C or 35 °C. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. High Temperature Humidity Sensor for Detection of Leak Through Slits and Cracks in Pressurized Nuclear Power Reactor Pipes

    Directory of Open Access Journals (Sweden)

    Debdulal Saha

    2007-03-01

    Full Text Available The leak before break (LBB concept is well known to nuclear power reactor. The problem is common to water power reactor. This is based on the premise that a detectable leak will develop before catastrophic break occurs. The main purpose of the present study is to develop tape cast MgCr2O4+35mole% TiO2 and gel cast g-Al2O3 humidity sensor for use in LBB applications at 3000C. The material capacitance varies with transient injection of water vapour adsorption. In actual plant, the sensors are placed on a steam pipe surrounded by heat insulation. The pipe unites the nuclear reactor and power generator. The analysis of humidity distribution in the annulus is calculated assuring leak rate 0.1gpm in a 30 m long tube. In this paper, analysis is done on the basis of the two types of sensor using AC frequency. Performance characteristics are observed for the LLB application.

  8. Development of a nuclear magnetic resonance system for in situ analysis of hydrogen storage materials under high pressures and temperatures.

    Science.gov (United States)

    Hashimoto, S; Noda, Y; Maekawa, H; Takamura, H; Fujito, T; Moriya, J; Ikeda, T

    2010-10-01

    A NMR system for in situ analysis of hydrogen storage materials under high pressure and temperature conditions was developed. The system consists of a gas pressure and flow rate controlling unit, a temperature controller, a high temperature NMR probe tunable for both (1)H and other nuclei, and a sample tube holder. Sample temperature can be controlled up to 623 K by heated N(2) gas flow. Sample tube atmosphere can be substituted by either H(2) or Ar and can be pressurized up to 1 MPa under constant flow rate up to 100 ml/min. During the NMR measurement, the pressure can be adjusted easily by just handle a back pressure valve. On the blank NMR measurement, (1)H background noise was confirmed to be very low. (1)H and (11)B NMR spectrum of LiBH(4) were successfully observed at high temperature for the demonstration of the system. The intensity of the (1)H NMR spectra of H(2) gas was also confirmed to be proportional to the applied pressure.

  9. Method and apparatus for studying high-temperature properties of conductive materials in the interests of nuclear power engineering

    Energy Technology Data Exchange (ETDEWEB)

    Savvatimskiy, A. I., E-mail: savva@iht.mpei.ac.ru; Onufriev, S. V. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-12-15

    Physical processes during a rapid (microsecond) heating of metals, carbon, and their compounds by a single pulse of electric current are discussed. Effects arising in such short-term heating near the melting point are noted: the electron emission and heat capacity anomalies and the possible occurrence of Frenkel pair (interstitial atom and vacancy). The problem of measuring the temperature using optical methods under pulse heating is considered, including the use of a specimen in the form of a blackbody model. The melting temperature of carbon (4800–4900 K) is measured at increased pulse pressure. The results of studying the properties of metals (by example of zirconium and hafnium) and of zirconium carbide at high temperatures are discussed. The schematics of the pulse setups and the instrumentation, as well as specimens for a pulse experiment, are presented.

  10. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    Science.gov (United States)

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  11. Glass transition-related changes in molecular mobility below glass transition temperature of freeze-dried formulations, as measured by dielectric spectroscopy and solid state nuclear magnetic resonance.

    Science.gov (United States)

    Yoshioka, Sumie; Aso, Yukio

    2005-02-01

    The purpose of this study was to explore why changes in the molecular mobility associated with glass transition, the timescale of which is on the order of 100 s, can be detected by measuring the nuclear magnetic resonance relaxation times that reflect molecular motions on the order of 10 kHz and 1 MHz. The molecular motions in freeze-dried dextran 40k, dextran 1k, isomaltotriose (IMT), and alpha-glucose comprising a common unit but with different glass transition temperatures, were investigated by dielectric spectroscopy (DES) in the frequency range of 0.01 Hz to 100 kHz and in the temperature range of -20 degrees to 200 degrees C, in order to compare with the molecular motions reflected in nuclear magnetic resonance relaxation times. The alpha-relaxation process for freeze-dried alpha-glucose was visualized by DES, whereas those for freeze-dried dextran 40k, dextran 1k, and IMT were too slow to be visualized by DES. The latter freeze-dried cakes exhibited quasi-dc polarization because of proton-hopping-like motion rather than alpha-relaxation process. The correlation time (tau(c)) for the backbone carbon of dextran 40k and IMT, calculated from the measured value of spin-lattice relaxation time in the rotating frame, was found to be close to the relaxation time of proton-hopping-like motion determined by DES (tau(DES)) at temperatures around glass transition temperature. The timescales of molecular motions reflected in the tau(c) and tau(DES) were significantly smaller than that of motions leading to molecular rearrangement (molecular rearrangement motions), which correspond to alpha-relaxation. However, the shapes of temperature dependence for the tau(c) and tau(DES) were similar to that of the calorimetrically determined relaxation time of molecular rearrangement motions. Results suggest that the molecular motions reflected in the tau(c) and tau(DES) are linked to molecular rearrangement motions, such that enhancement of molecular rearrangement motions enhances

  12. NUCLEAR REACTOR

    Science.gov (United States)

    Grebe, J.J.

    1959-07-14

    High temperature reactors which are uniquely adapted to serve as the heat source for nuclear pcwered rockets are described. The reactor is comprised essentially of an outer tubular heat resistant casing which provides the main coolant passageway to and away from the reactor core within the casing and in which the working fluid is preferably hydrogen or helium gas which is permitted to vaporize from a liquid storage tank. The reactor core has a generally spherical shape formed entirely of an active material comprised of fissile material and a moderator material which serves as a diluent. The active material is fabricated as a gas permeable porous material and is interlaced in a random manner with very small inter-connecting bores or capillary tubes through which the coolant gas may flow. The entire reactor is divided into successive sections along the direction of the temperature gradient or coolant flow, each section utilizing materials of construction which are most advantageous from a nuclear standpoint and which at the same time can withstand the operating temperature of that particular zone. This design results in a nuclear reactor characterized simultaneously by a minimum critiral size and mass and by the ability to heat a working fluid to an extremely high temperature.

  13. The problems of using a high-temperature sodium coolant in nuclear power plants for the production of hydrogen and other innovative applications

    Science.gov (United States)

    Sorokin, A. P.; Alexeev, V. V.; Kuzina, Ju. A.; Konovalov, M. A.

    2017-11-01

    The intensity of the hydrogen sources arriving from the third contour of installation in second in comparison with the hydrogen sources on NPP BN-600 increases by two – three order at using of high-temperature nuclear power plants with the sodium coolant (HT-NPP) for drawing of hydrogen and other innovative applications (gasification and a liquefaction of coal, profound oil refining, transformation of biomass to liquid fuel, in the chemical industry, metallurgy, the food-processing industry etc.). For these conditions basic new technological solutions are offered. The main condition of their implementation is raise of hydrogen concentration in the sodium coolant on two – three order in comparison with the modern NPP, in a combination to hydrogen removal from sodium and its pumping out through membranes from vanadium or niobium. The researches with use diffusive model have shown possibility to expel a casium inflow in sodium through a leakproof shell of fuel rods if vary such parameters as a material of fuel rods shell, its thickness and maintenance time at design of fuel rods for high-temperature NPP. However maintenance of high-temperature NPP in the presence of casium in sodium is inevitable at loss of leakproof of a fuel rods shell. In these conditions for minimisation of casium diffusion in structural materials it is necessary to provide deep clearing of sodium from cesium.

  14. High temperature fast reactor for hydrogen production in Brazil; Reator nuclear rapido de altissima temperatura para producao de hidrogenio no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados]. E-mail: jamil@ieav.cta.br

    2008-07-01

    The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, {approx} 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

  15. High-temperature nuclear magnetic resonance study of phase transition kinetics in LiNaSO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Shakhovoy, R. A., E-mail: roman.shakhovoy@cnrs-orleans.fr, E-mail: r.a.shakhovoy@gmail.com; Sarou-Kanian, V.; Rakhmatullin, A.; Véron, E.; Bessada, C. [CNRS, CEMHTI UPR 3079, Univ. Orléans, F-45071 Orléans (France)

    2015-12-28

    A new high-temperature NMR technique for measurements of the phase transition kinetics in solids has been developed. The technique allows measuring the time evolution of the volume of the appearing phase at controlled cooling rates. Developed method was applied to study the phase transition kinetics in the superionic conductor LiNaSO{sub 4}. It was revealed that the phase transition in LiNaSO{sub 4} is governed by the diffusion-controlled growth of nuclei (“germs”). An effect of the crystallite rearrangement in the LiNaSO{sub 4} powder after cooling through the phase transition was also revealed. This effect was studied by means of high-temperature XRD and NMR.

  16. Development and Experimental Benchmark of Simulations to Predict Used Nuclear Fuel Cladding Temperatures during Drying and Transfer Operations

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, Miles [Univ. of Nevada, Reno, NV (United States)

    2017-03-31

    Radial hydride formation in high-burnup used fuel cladding has the potential to radically reduce its ductility and suitability for long-term storage and eventual transport. To avoid this formation, the maximum post-reactor temperature must remain sufficiently low to limit the cladding hoop stress, and so that hydrogen from the existing circumferential hydrides will not dissolve and become available to re-precipitate into radial hydrides under the slow cooling conditions during drying, transfer and early dry-cask storage. The objective of this research is to develop and experimentallybenchmark computational fluid dynamics simulations of heat transfer in post-pool-storage drying operations, when high-burnup fuel cladding is likely to experience its highest temperature. These benchmarked tools can play a key role in evaluating dry cask storage systems for extended storage of high-burnup fuels and post-storage transportation, including fuel retrievability. The benchmarked tools will be used to aid the design of efficient drying processes, as well as estimate variations of surface temperatures as a means of inferring helium integrity inside the canister or cask. This work will be conducted effectively because the principal investigator has experience developing these types of simulations, and has constructed a test facility that can be used to benchmark them.

  17. Modeling and Simulation of the Sulfur-Iodine Process Coupled to a Very High-Temperature Gas-Cooled Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Youngjoon; Lee, Taehoon; Lee, Kiyoung; Kim, Minhwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Hydrogen produced from water using nuclear energy will avoid both the use of fossil fuel and CO{sub 2} emission presumed to be the dominant reason for global warming. A thermo-chemical sulfur-iodine (SI) process coupled to a Very High Temperature Gas-Cooled Reactor(VHTR) is one of the most prospective hydrogen production methods that split water using nuclear energy because the SI process is suitable for large-scale hydrogen production without CO{sub 2} emission. The dynamic simulation code to evaluate the start-up behavior of the chemical reactors placed on the secondary helium loop of the SI process has been developed and partially verified using the steady state values obtained from the Aspen Plus{sup TM} Code simulation. As the start-up dynamic simulation results of the SI process coupled to the IHX, which is one of components in the VHTR system, it is expected that the integrated secondary helium loop of the SI process can be successfully and safely approach the steady state condition.

  18. Comparison of applicability of current transition temperature shift models to SA533B-1 reactor pressure vessel steel of Korean nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ji Hyun; Lee, Bong Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-08-15

    The precise prediction of radiation embrittlement of aged reactor pressure vessels (RPVs) is a prerequisite for the long-term operation of nuclear power plants beyond their original design life. The expiration of the operation licenses for Korean reactors the RPVs of which are made from SA533B-1 plates and welds is imminent. Korean regulatory rules have adopted the US Nuclear Regulatory Commission's transition temperature shift (TTS) models to the prediction of the embrittlement of Korean reactor pressure vessels. The applicability of the TTS model to predict the embrittlement of Korean RPVs made of SA533B-1 plates and welds was investigated in this study. It was concluded that the TTS model of 10 CFR 50.61a matched the trends of the radiation embrittlement in the SA533B-1 plates and welds better than did that of Regulatory Guide (RG) 1.99 Rev. 2. This is attributed to the fact that the prediction performance of 10 CFR 50.61a was enhanced by considering the difference in radiation embrittlement sensitivity among the different types of RPV materials.

  19. Structural characterization of porous solids by simultaneously monitoring the low-temperature phase equilibria and diffusion of intrapore fluids using nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashova, Daria; Dvoyashkin, Muslim; Valiullin, Rustem, E-mail: valiullin@uni-leipzig.de [Institute of Experimental Physics I, University of Leipzig, Leipzig (Germany)

    2011-01-15

    Nuclear magnetic resonance (NMR) provides a variety of tools for the structural characterization of porous solids. In this paper, we discuss a relatively novel approach called NMR cryodiffusometry, which is based on a simultaneous assessment of both the phase state of intraporous liquids at low temperatures, using NMR cryoporometry, and their transport properties, using NMR diffusometry. Choosing two model porous materials with ordered and disordered pore structures as the host systems, we discuss the methodological and fundamental aspects of the method. Thus, with the use of an intentionally micro-structured mesoporous silicon, we demonstrate how its structural features give rise to specific patterns in the effective molecular diffusivities measured upon progressive melting of a frozen liquid in the mesopores. We then present the results of a detailed study of the transport properties of the same liquid during both melting and freezing processes in Vycor porous glass, a material with a random pore structure.

  20. The preliminary design of bearings for the control system of a high-temperature lithium-cooled nuclear reactor

    Science.gov (United States)

    Yacobucci, H. G.; Waldron, W. D.; Walowit, J. A.

    1973-01-01

    The design of bearings for the control system of a fast reactor concept is presented. The bearings are required to operate at temperatures up to 2200 F in one of two fluids, lithium or argon. Basic bearing types are the same regardless of the fluid. Crowned cylindrical journals were selected for radially loaded bearings and modified spherical bearings were selected for bearings under combined thrust and radial loads. Graphite and aluminum oxide are the materials selected for the argon atmosphere bearings while cermet compositions (carbides or nitrides bonded with refractory metals) were selected for the lithium lubricated bearings. Mounting of components is by shrink fit or by axial clamping utilizing differential thermal expansion.

  1. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J. K. R.; Alderman, O. L. G. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Tamalonis, A.; Sendelbach, S. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Benmore, C. J. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hebden, A.; Williamson, M. A. [Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2016-07-15

    An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.

  2. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials.

    Science.gov (United States)

    Weber, J K R; Tamalonis, A; Benmore, C J; Alderman, O L G; Sendelbach, S; Hebden, A; Williamson, M A

    2016-07-01

    An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.

  3. Nuclear Medicine

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  4. PIE of nuclear grade SiC/SiC flexural coupons irradiated to 10 dpa at LWR temperature

    Energy Technology Data Exchange (ETDEWEB)

    Koyanagi, Takaaki [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    Silicon carbide fiber-reinforced SiC matrix (SiC/SiC) composites are being actively investigated for accident-tolerant core structures of light water reactors (LWRs). Owing to the limited number of irradiation studies previously conducted at LWR-coolant temperature, this study examined SiC/SiC composites following neutron irradiation at 230–340°C to 2.0 and 11.8 dpa in the High Flux Isotope Reactor. The investigated materials are chemical vapor infiltrated (CVI) SiC/SiC composites with three different reinforcement fibers. The fiber materials were monolayer pyrolytic carbon (PyC)-coated Hi-NicalonTM Type-S (HNS), TyrannoTM SA3 (SA3), and SCS-UltraTM (SCS) SiC fibers. The irradiation resistance of these composites was investigated based on flexural behavior, dynamic Young’s modulus, swelling, and microstructures. There was no notable mechanical properties degradation of the irradiated HNS and SA3 SiC/SiC composites except for reduction of the Young’s moduli by up to 18%. The microstructural stability of these composites supported the absence of degradation. In addition, no progressive swelling from 2.0 to 11.8 dpa was confirmed for these composites. On the other hand, the SCS composite showed significant mechanical degradation associated with cracking within the fiber. This study determined that SiC/SiC composites with HNS or SA3 SiC/SiC fibers, a PyC interphase, and a CVI SiC matrix retain their properties beyond the lifetime dose for LWR fuel cladding at the relevant temperature.

  5. Exploring nuclear magnetic resonance at the highest pressure. Closing the pseudogap under pressure in a high temperature superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Meissner, Thomas

    2013-05-13

    In the present work, a novel probe design for high pressure NMR experiments in gem anvil cells (GAC) was used which places a small microcoil inside the high pressure volume as the detection coil. Based on tests carried out at ambient pressure and high pressure of 42 kbar it is demonstrated that this approach is indeed feasible and results in an increase of sensitivity by two orders of magnitude compared to previous GAC-NMR designs. The design was then successfully employed in the investigation of the electronic properties of metallic aluminum and the high temperature superconductor YBa{sub 2}Cu{sub 4}O{sub 8} at pressures of up to 101 kbar. Because of its improved sensitivity and the potential to achieve even higher pressures, the microcoil GAC-NMR setup should prove useful in the investigation of materials under high pressure conditions in the future. In the case of metallic aluminum, the effect of pressure on the electronic density of states at the Fermi level was probed via the Knight-shift K and the spin-lattice relaxation time T{sub 1} at room temperature up to a pressure of 101 kbar, extending the pressure range of previous NMR measurements by a factor of 14 [72]. Most notably, a decrease of K(p) by 11% is detected in the investigated pressure range that is inconsistent with a free electron behavior of the density of states. Numerical band structure calculations that are in excellent agreement with the experimental data suggest that the observed changes of K and T{sub 1} are due to a kink in the electronic states at a Lifshitz-transition at about 75 kbar which has not been observed previously. A further decrease of K by a factor of 2 is predicted to occur in the pressure range up to 300 kbar. In addition, an increase of the NMR linewidths of the metallic aluminum signal was observed above about 42 kbar that is inconsistent with a pure dipolar linewidth. Based on an analysis of the field dependence of this effect it was ascribed to a small additional

  6. Procedure of calculation of the spatial distribution of temperatures and heat fluxes in the steam generator of a nuclear power installation with an RBEC fast-neutron reactor

    Science.gov (United States)

    Frolov, A. A.; Sedov, A. A.

    2016-08-01

    A method for combined 3D/1D-modeling of thermohydraulics of a once-through steam generator (SG) based on the joint analysis of three-dimensional thermo- and hydrodynamics of a single-phase heating coolant in the intertube space and one-dimensional thermohydraulics of steam-generating channels (tubes) with the use of well-known friction and heat-transfer correlations under various boiling conditions is discussed. This method allows one to determine the spatial distribution of temperatures and heat fluxes of heat-exchange surfaces of SGs with a single-phase heating coolant in the intertube space and with steam generation within tubes. The method was applied in the analytical investigation of typical operation of a once-through SG of a nuclear power installation with an RBEC fast-neutron heavy-metal reactor that is being designed by Kurchatov Institute in collaboration with OKB GIDROPRESS and Leipunsky Institute of Physics and Power Engineering. Flow pattern and temperature fields were obtained for the heavy-metal heating coolant in the intertube space. Nonuniformities of heating of the steam-water coolant in different heat-exchange tubes and nonuniformities in the distribution of heat fluxes at SG heat-exchange surfaces were revealed.

  7. A high-throughput investigation of Fe-Cr-Al as a novel high-temperature coating for nuclear cladding materials.

    Science.gov (United States)

    Bunn, Jonathan Kenneth; Fang, Randy L; Albing, Mark R; Mehta, Apurva; Kramer, Matthew J; Besser, Matthew F; Hattrick-Simpers, Jason R

    2015-07-10

    High-temperature alloy coatings that can resist oxidation are urgently needed as nuclear cladding materials to mitigate the danger of hydrogen explosions during meltdown. Here we apply a combination of computationally guided materials synthesis, high-throughput structural characterization and data analysis tools to investigate the feasibility of coatings from the Fe–Cr–Al alloy system. Composition-spread samples were synthesized to cover the region of the phase diagram previous bulk studies have identified as forming protective oxides. The metallurgical and oxide phase evolution were studied via in situ synchrotron glancing incidence x-ray diffraction at temperatures up to 690 K. A composition region with an Al concentration greater than 3.08 at%, and between 20.0 at% and 32.9 at% Cr showed the least overall oxide growth. Subsequently, a series of samples were deposited on stubs and their oxidation behavior at 1373 K was observed. The continued presence of a passivating oxide was confirmed in this region over a period of 6 h.

  8. Adaptation of a High Frequency Ultrasonic Transducer to the Measurement of Water Temperature in a Nuclear Reactor

    Science.gov (United States)

    Zaz, G.; Calzavara, Y.; Le Clézio, E.; Despaux, G.

    Most high flux reactors possess for research purposes fuel elements composed of plates. Their relative distance is a crucial parameter, particularly concerning the irradiation history. For the High Flux Reactor (RHF) of the Institute Laue-Langevin (ILL), the measurement of this distance with a microscopic resolution becomes extremely challenging. To address this issue, a specific ultrasonic transducer, presented in a first paper, has been designed and manufactured to be inserted into the 1.8 mm width channel existing between curved fuel plates. It was set on a blade yielding a total device thickness of 1 mm. To achieve the expected resolution, the system is excited with frequencies up to 70 MHz and integrated into a set of high frequency acquisition instruments. Thanks to a specific signal processing, this device allows the distance measurement through the evaluation of the ultrasonic wave time of fight. One of the crucial points is then the evaluation of the local water temperature inside the water channel. To obtain a precise estimation of this parameter, the ultrasonic sensor is used as a thermometer thanks to the analysis of the spectral components of the acoustic signal propagating inside the sensor multilayered structure. The feasibility of distance measurement was proved during the December 2013 experiment in the RHF fuel element of the ILL. Some of the results will be presented as well as some experimental constraints identified to improve the accuracy of the measurement in future works.

  9. Updating of ASME Nuclear Code Case N-201 to Accommodate the Needs of Metallic Core Support Structures for High Temperature Gas Cooled Reactors Currently in Development

    Energy Technology Data Exchange (ETDEWEB)

    Mit Basol; John F. Kielb; John F. MuHooly; Kobus Smit

    2007-05-02

    On September 29, 2005, ASME Standards Technology, LLC (ASME ST-LLC) executed a multi-year, cooperative agreement with the United States DOE for the Generation IV Reactor Materials project. The project's objective is to update and expand appropriate materials, construction, and design codes for application in future Generation IV nuclear reactor systems that operate at elevated temperatures. Task 4 was embarked upon in recognition of the large quantity of ongoing reactor designs utilizing high temperature technology. Since Code Case N-201 had not seen a significant revision (except for a minor revision in September, 2006 to change the SA-336 forging reference for 304SS and 316SS to SA-965 in Tables 1.2(a) and 1.2(b), and some minor editorial changes) since December 1994, identifying recommended updates to support the current high temperature Core Support Structure (CSS) designs and potential new designs was important. As anticipated, the Task 4 effort identified a number of Code Case N-201 issues. Items requiring further consideration range from addressing apparent inconsistencies in definitions and certain material properties between CC-N-201 and Subsection NH, to inclusion of additional materials to provide the designer more flexibility of design. Task 4 developed a design parameter survey that requested input from the CSS designers of ongoing high temperature gas cooled reactor metallic core support designs. The responses to the survey provided Task 4 valuable input to identify the design operating parameters and future needs of the CSS designers. Types of materials, metal temperature, time of exposure, design pressure, design life, and fluence levels were included in the Task 4 survey responses. The results of the survey are included in this report. This research proves that additional work must be done to update Code Case N-201. Task 4 activities provide the framework for the Code Case N-201 update and future work to provide input on materials. Candidate

  10. Effect of heat curing methods on the temperature history and strength development of slab concrete for nuclear power plant structures in cold climates

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gun Cheol [Korea Conformity Laboratories, Seoul (Korea, Republic of); Han, Min Cheol [Cheong-ju University, Cheong Ju (Korea, Republic of); Baek, Dae Hyun; Koh, Kyung Taek [Korea Institute of Construction Technology, Goyang (Korea, Republic of)

    2012-06-15

    The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to -10 degrees Celsius. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of 1200, 600, 200 mm and a design strength of 27 MPa were fabricated and cured at -10 degrees Celsius for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below 0 degrees Celsius within 40 h after exposure to -10 degrees Celsius, and then, the temperature dropped to -10 degrees Celsius and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around 5 degrees Celsius for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around 10 degrees Celsius for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after

  11. Quantum nuclear pasta and nuclear symmetry energy

    Science.gov (United States)

    Fattoyev, F. J.; Horowitz, C. J.; Schuetrumpf, B.

    2017-05-01

    Complex and exotic nuclear geometries, collectively referred to as "nuclear pasta," are expected to appear naturally in dense nuclear matter found in the crusts of neutron stars and supernovae environments. The pasta geometries depend on the average baryon density, proton fraction, and temperature and are critically important in the determination of many transport properties of matter in supernovae and the crusts of neutron stars. Using a set of self-consistent microscopic nuclear energy density functionals, we present the first results of large scale quantum simulations of pasta phases at baryon densities 0.03 ≤ρ ≤0.10 fm-3 , proton fractions 0.05 ≤Yp≤0.40 , and zero temperature. The full quantum simulations, in particular, allow us to thoroughly investigate the role and impact of the nuclear symmetry energy on pasta configurations. We use the Sky3D code that solves the Skyrme Hartree-Fock equations on a three-dimensional Cartesian grid. For the nuclear interaction we use the state-of-the-art UNEDF1 parametrization, which was introduced to study largely deformed nuclei, hence is suitable for studies of the nuclear pasta. Density dependence of the nuclear symmetry energy is simulated by tuning two purely isovector observables that are insensitive to the current available experimental data. We find that a minimum total number of nucleons A =2000 is necessary to prevent the results from containing spurious shell effects and to minimize finite size effects. We find that a variety of nuclear pasta geometries are present in the neutron star crust, and the result strongly depends on the nuclear symmetry energy. The impact of the nuclear symmetry energy is less pronounced as the proton fractions increase. Quantum nuclear pasta calculations at T =0 MeV are shown to get easily trapped in metastable states, and possible remedies to avoid metastable solutions are discussed.

  12. Hydride reorientation and its impact on ambient temperature mechanical properties of high burn-up irradiated and unirradiated recrystallized Zircaloy-2 nuclear fuel cladding with an inner liner

    Science.gov (United States)

    Auzoux, Q.; Bouffioux, P.; Machiels, A.; Yagnik, S.; Bourdiliau, B.; Mallet, C.; Mozzani, N.; Colas, K.

    2017-10-01

    Precipitation of radial hydrides in zirconium-based alloy cladding concomitant with the cooling of spent nuclear fuel during dry storage can potentially compromise cladding integrity during its subsequent handling and transportation. This paper investigates hydride reorientation and its impact on ductility in unirradiated and irradiated recrystallized Zircaloy-2 cladding with an inner liner (cladding for boiling water reactors) subjected to hydride reorientation treatments. Cooling from 400 °C, hydride reorientation occurs in recrystallized Zircaloy-2 with liner at a lower effective stress in irradiated samples (below 40 MPa) than in unirradiated specimens (between 40 and 80 MPa). Despite significant hydride reorientation, unirradiated recrystallized Zircaloy-2 with liner cladding containing ∼200 wppm hydrogen shows a high diametral strain at fracture (>15%) during burst tests at ambient temperature. This ductile behavior is due to (1) the lower yield stress of the recrystallized cladding materials in comparison to hydride fracture strength (corrected by the compression stress arising from the precipitation) and (2) the hydride or hydrogen-depleted zone as a result of segregation of hydrogen into the liner layer. In irradiated Zircaloy-2 with liner cladding containing ∼340 wppm hydrogen, the conservation of some ductility during ring tensile tests at ambient temperature after reorientation treatment at 400 °C with cooling rates of ∼60 °C/h is also attributed to the existence of a hydride-depleted zone. Treatments at lower cooling rates (∼6 °C/h and 0.6 °C/h) promote greater levels of hydrogen segregation into the liner and allow for increased irradiation defect annealing, both of which result in a significant increase in ductility. Based on this investigation, given the very low cooling rates typical of dry storage systems, it can be concluded that the thermal transients associated with dry storage should not degrade, and more likely should actually

  13. Nuclear "waffles"

    Science.gov (United States)

    Schneider, A. S.; Berry, D. K.; Briggs, C. M.; Caplan, M. E.; Horowitz, C. J.

    2014-11-01

    Background: The dense neutron-rich matter found in supernovae and inside neutron stars is expected to form complex nonuniform phases, often referred to as nuclear pasta. The pasta shapes depend on density, temperature and proton fraction and determine many transport properties in supernovae and neutron star crusts. Purpose: To characterize the topology and compute two observables, the radial distribution function (RDF) g (r ) and the structure factor S (q ) , for systems with proton fractions Yp=0.10 ,0.20 ,0.30 , and 0.40 at about one-third of nuclear saturation density, n =0.050 fm-3 , and temperatures near k T =1 MeV . Methods: We use two recently developed hybrid CPU/GPU codes to perform large scale molecular dynamics (MD) simulations with 51 200 and 409 600 nucleons. From the output of the MD simulations we obtain the two desired observables. Results: We compute and discuss the differences in topology and observables for each simulation. We observe that the two lowest proton fraction systems simulated, Yp=0.10 and 0.20 , equilibrate quickly and form liquidlike structures. Meanwhile, the two higher proton fraction systems, Yp=0.30 and 0.40 , take a longer time to equilibrate and organize themselves in solidlike periodic structures. Furthermore, the Yp=0.40 system is made up of slabs, lasagna phase, interconnected by defects while the Yp=0.30 systems consist of a stack of perforated plates, the nuclear waffle phase. Conclusions: The periodic configurations observed in our MD simulations for proton fractions Yp≥0.30 have important consequences for the structure factors S (q ) of protons and neutrons, which relate to many transport properties of supernovae and neutron star crust. A detailed study of the waffle phase and how its structure depends on temperature, size of the simulation, and the screening length showed that finite-size effects appear to be under control and, also, that the plates in the waffle phase merge at temperatures slightly above 1.0 MeV and

  14. Chiral thermodynamics of nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Fiorilla, Salvatore

    2012-10-23

    The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.

  15. Transactions of the fifth symposium on space nuclear power systems

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1988-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these paper include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  16. Transactions of the fourth symposium on space nuclear power systems

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1987-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these papers include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, refractory alloys and high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  17. Nuclear physics today

    CERN Document Server

    Galès, Sydney

    1999-01-01

    This brief review explores the future perspectives of nuclear physics at the dawn of the next millennium, a century after the great discoveries of H. Becquerel, Marie and Pierre Curie. Nuclear physics plays an important role in the understanding of the formation of matter in the universe. Today, fundamental research is moving towards new frontiers. Challenging physics issues like the quest for the quark-gluon plasma, the structure and the dynamics of hadrons, the properties of nuclei under extreme conditions of spin, mass, temperature and/or far off stability are the main research avenues for the future. The methods and the tools developed both experimentally and theoretically to probe and understand the nucleus at the microscopic level have a broad spectrum of applications both in other fields of sciences and in our society. Specific examples related to nuclear medicine and nuclear energy will illustrate the possible impact of the applications of Nuclear Physics to our everyday life.

  18. Nuclear expansion with excitation

    Energy Technology Data Exchange (ETDEWEB)

    De, J.N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Samaddar, S.K. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Vinas, X. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Centelles, M. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)]. E-mail: mario@ecm.ub.es

    2006-07-06

    The expansion of an isolated hot spherical nucleus with excitation energy and its caloric curve are studied in a thermodynamic model with the SkM{sup *} force as the nuclear effective two-body interaction. The calted results are shown to compare well with the recent experimental data from energetic nuclear collisions. The fluctuations in temperature and density are also studied. They are seen to build up very rapidly beyond an excitation energy of {approx}9 MeV/u. Volume-conserving quadrupole deformation in addition to expansion indicates, however, nuclear disassembly above an excitation energy of {approx}4 MeV/u.

  19. A new Brute force low-temperature nuclear orientation set-up to search for physics beyond the standard electroweak model

    Czech Academy of Sciences Publication Activity Database

    Kraev, I.; Beck, M.; Coeck, S.; Delaure, B.; Golovko, VV.; Kozlov, VY; Lindroth, A.; Phalet, T.; Severijns, N.; Versyck, S.; Zákoucký, Dalibor

    2005-01-01

    Roč. 555, 1/2 (2005), s. 420-425 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10480505 Keywords : weak interakcion * beta decay * tensor currents Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.224, year: 2005

  20. Nuclear order in copper

    DEFF Research Database (Denmark)

    Annila, A.J.; Clausen, K.N.; Lindgård, P-A.

    1990-01-01

    A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show the prese......A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show...

  1. Nuclear order in copper

    DEFF Research Database (Denmark)

    Annila, A.J.; Clausen, K.N.; Lindgård, P.-A.

    1990-01-01

    The new antiferromagnetic reflection (02/32/3) has been found by neutron diffraction experiments at nanokelvin temperatures in the nuclear spin system of a 65CU single crystal. The corresponding three-sublattice structure has not been observed previously in any fcc antiferromagnet.......The new antiferromagnetic reflection (02/32/3) has been found by neutron diffraction experiments at nanokelvin temperatures in the nuclear spin system of a 65CU single crystal. The corresponding three-sublattice structure has not been observed previously in any fcc antiferromagnet....

  2. Nuclear Chemistry.

    Science.gov (United States)

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  3. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  4. Nuclear weapons, nuclear effects, nuclear war

    Energy Technology Data Exchange (ETDEWEB)

    Bing, G.F.

    1991-08-20

    This paper provides a brief and mostly non-technical description of the militarily important features of nuclear weapons, of the physical phenomena associated with individual explosions, and of the expected or possible results of the use of many weapons in a nuclear war. Most emphasis is on the effects of so-called ``strategic exchanges.``

  5. JPRS Report, Nuclear Developments

    National Research Council Canada - National Science Library

    1989-01-01

    Partial Contents: Nuclear Weapons, Nuclear Development, Nuclear Power Plant, Uranium, Missiles, Space Firm Protested, Satellite, Rocket Launching, Nuclear Submarine, Environmental, Radioactivity, Nuclear Plant...

  6. Solid-State Nuclear Power

    Science.gov (United States)

    George, Jeffrey A.

    2012-01-01

    A strategy for "Solid-State" Nuclear Power is proposed to guide development of technologies and systems into the second 50 years of nuclear spaceflight. The strategy emphasizes a simple and highly integrated system architecture with few moving parts or fluid loops; the leverage of modern advances in materials, manufacturing, semiconductors, microelectromechanical and nanotechnology devices; and the targeted advancement of high temperature nuclear fuels, materials and static power conversion to enable high performance from simple system topologies.

  7. Nuclear spectroscopy

    CERN Document Server

    Ajzenberg-Selove, Fay

    1960-01-01

    Nuclear Spectroscopy, Part B focuses on the ways in which experimental data may be analyzed to furnish information about nuclear parameters and nuclear models in terms of which the data are interpreted.This book discusses the elastic and inelastic potential scattering amplitudes, role of beta decay in nuclear physics, and general selection rules for electromagnetic transitions. The nuclear shell model, fundamental coupling procedure, vibrational spectra, and empirical determination of the complex potential are also covered. This publication is suitable for graduate students preparing for exper

  8. Nuclear networking.

    Science.gov (United States)

    Xie, Wei; Burke, Brian

    2017-07-04

    Nuclear lamins are intermediate filament proteins that represent important structural components of metazoan nuclear envelopes (NEs). By combining proteomics and superresolution microscopy, we recently reported that both A- and B-type nuclear lamins form spatially distinct filament networks at the nuclear periphery of mouse fibroblasts. In particular, A-type lamins exhibit differential association with nuclear pore complexes (NPCs). Our studies reveal that the nuclear lamina network in mammalian somatic cells is less ordered and more complex than that of amphibian oocytes, the only other system in which the lamina has been visualized at high resolution. In addition, the NPC component Tpr likely links NPCs to the A-type lamin network, an association that appears to be regulated by C-terminal modification of various A-type lamin isoforms. Many questions remain, however, concerning the structure and assembly of lamin filaments, as well as with their mode of association with other nuclear components such as peripheral chromatin.

  9. The energy release and temperature field in the ultracold neutron source of the WWR-M reactor at the Petersburg Nuclear Physics Institute

    Energy Technology Data Exchange (ETDEWEB)

    Serebrov, A. P., E-mail: serebrov@pnpi.spb.ru; Kislitsin, B. V.; Onegin, M. S.; Lyamkin, V. A.; Prudnikov, D. V.; Ilatovskiy, V. A.; Orlov, S. P.; Kirsanov, G. A.; Fomin, A. K.; Filchenkova, D. V. [National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)

    2016-12-15

    Results of calculations of energy releases and temperature fields in the ultracold neutron source under design at the WWR-M reactor are presented. It is shown that, with the reactor power of 18 MW, the power of energy release in the 40-L volume of the source with superfluid helium will amount to 28.5 W, while 356 W will be released in a liquid-deuterium premoderator. The lead shield between the reactor core and the source reduces the radiative heat release by an order of magnitude. A thermal power of 22 kW is released in it, which is removed by passage of water. The distribution of temperatures in all components of the vacuum structure is presented, and the temperature does not exceed 100°C at full reactor power. The calculations performed make it possible to go to design of the source.

  10. Experimental study of high-temperature properties of zirconium carbide as a protective material for nuclear power and aerospace technologies (from 2000 to 5000 K)

    Science.gov (United States)

    Savvatimskiy, A. I.; Onufriev, S. V.; Muboyadzhyan, S. A.; Seredkin, N. N.

    2017-11-01

    The temperature dependences of the thermal and electro physical properties of the zirconium carbide ZrC + C and ZrCa0.95 were studied in the temperature range 2000-5000 K. The Zr+C specimens were in the form of thin layers sputtered on quarts substrate and ZrC0.95 specimens were in the form of plates cut off from the sintered block. The properties are measured: temperature and heat of fusion, enthalpy, specific heat and resistivity, referred to the initial dimensions. A steep increase in the specific heat of these substances before melting and a sharp decrease after melting were observed at a heating rate of ∼ 108 K/s, which is possibly due to the formation of Frenkel pair defects in the specimens.

  11. Post-growth annealing of Bridgman-grown CdZnTe and CdMnTe crystals for room-temperature nuclear radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Egarievwe, Stephen U. [Nuclear Engineering and Radiological Science Center, Alabama A& M University, Normal 35762 (United States); Nonproliferation & National Security Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Yang, Ge [Nonproliferation & National Security Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Egarievwe, Alexander A.; Okwechime, Ifechukwude O.; Gray, Justin; Hales, Zaveon M. [Nuclear Engineering and Radiological Science Center, Alabama A& M University, Normal 35762 (United States); Hossain, Anwar; Camarda, Giuseppe S.; Bolotnikov, Aleksey E.; James, Ralph B. [Nonproliferation & National Security Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-06-01

    Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that limit their performances as X-ray- and gamma-ray-detectors. We present here the results of post-growth thermal annealing aimed at reducing and eliminating Te inclusions in them. In a 2D analysis, we observed that the sizes of the Te inclusions declined to 92% during a 60-h annealing of CZT at 510 °C under Cd vapor. Further, tellurium inclusions were eliminated completely in CMT samples annealed at 570 °C in Cd vapor for 26 h, whilst their electrical resistivity fell by an order of 10{sup 2}. During the temperature-gradient annealing of CMT at 730 °C and an 18 °C/cm temperature gradient for 18 h in a vacuum of 10{sup −5} mbar, we observed the diffusion of Te from the sample, so causing a reduction in size of the Te inclusions. For CZT samples annealed at 700 °C in a 10 °C/cm temperature gradient, we observed the migration of Te inclusions from a low-temperature region to a high one at 0.022 μm/s. During the temperature-gradient annealing of CZT in a vacuum of 10{sup −5} mbar at 570 °C and 30 °C/cm for 18 h, some Te inclusions moved toward the high-temperature side of the wafer, while other inclusions of the same size, i.e., 10 µm in diameter, remained in the same position. These results show that the migration, diffusion, and reaction of Te with Cd in the matrix of CZT- and CMT-wafers are complex phenomena that depend on the conditions in local regions, such as composition and structure, as well as on the annealing conditions.

  12. Application of techniques of dynamic reliability to the assessment of safety a high-temperature Nuclear reactor; Aplicacion de Tecnicas de Fiabilidad Dinamica a la Evaluacion de Seguridad de un Reactor Nuclear de Alta Temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Flores, A.; Gallego Diaz, E.

    2011-07-01

    The main objective of this work is to describe the application of the methodology of integrated analysis of safety to safety assessment of High Temperature Engineering Test Reactor (HTTR), as a demonstration of its ability to be applied to technologies other than light-water reactors, which was initially conceived. The practical application of the method in the case of the HTTR has required the development of a basic model of the HTTR, called DD-HTTR5+, that it allows to represent in a way joint dynamics of the plant and its characteristics of reliability, as well as existing interactions.

  13. Nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F

    2009-07-01

    nature of spent nuclear fuel, Anticipated evolution of fuel in dry storage, Anticipated evolution of fuel in deep geological disposal); Boiling-water reactor fuel (Similarities, and differences with PWR fuel, Axial and radial zoning, Rod and channel box sizes, Poisoning and reactivity control, Cladding specific characteristics, Trends in fuel evolution); 3 - Liquid-metal-cooled fast reactor fuel: Fast-neutron irradiation damage in structural materials (Fast-neutron-induced damage in metals, What materials should be used?); Fuels and targets for fast-reactor transmutation (Fast reactors: reactors affording the ability to carry out effective actinide transmutation, Recycling: homogeneous, or heterogeneous?); 4 - gas-cooled reactor fuel: Particle fuel (From the initial concept to the advanced TRISO particle concept, Kernel fabrication processes, Particle coating by chemical vapor deposition, Fuel element fabrication: particle compaction, Characterization of fuel particles, and elements, From HTR fuel to VHTR and GFR fuels: the GAIA facility at CEA/Cadarache); Irradiation behavior of particle fuels (Particle fuel: a variety of failure modes for a high-strength object, The amoeba effect, Fission product behavior, and diffusion in particle fuels); Mechanical modeling of particle fuel; Very-high-temperature reactor (VHTR) fuel; Gas-cooled fast reactor (GFR) fuel (The specifications for GFR fuel, GFR fissile material, First containment baffler materials, GFR fuel element concepts); 5 - Research reactor fuels (A considerable feedback from experience, Conversion of French reactors to low-enriched ({<=}20% U-235)U{sub 3}Si{sub 2} fuel, Conversion of all reactors: R and D requirements for high-performance reactors, An 'advanced' research reactor fuel: UMo, The startup fuel for the Jules Horowitz Reactor (JHR) will still be U{sub 3}Si{sub 2}-Al; 6 - An instrument for future fuel research: the Jules Horowitz Reactor (JHR): Fuel irradiation experiments in JHR, JHR: a flexible

  14. Nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, W.C.

    1992-01-01

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  15. Nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, W.C.

    1992-12-31

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  16. Nuclear quantum effects on the structure and the dynamics of [H{sub 2}O]{sub 8} at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Videla, Pablo E. [Departamento de Química Inorgánica Analítica y Química-Física e INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428 Buenos Aires (Argentina); Rossky, Peter J. [Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712-0165 (United States); Laria, D., E-mail: dhlaria@cnea.gov.ar [Departamento de Química Inorgánica Analítica y Química-Física e INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428 Buenos Aires (Argentina); Departamento de Física de la Materia Condensada, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429 Buenos Aires (Argentina)

    2013-11-07

    We use ring-polymer-molecular-dynamics (RPMD) techniques and the semi-empirical q-TIP4P/F water model to investigate the relationship between hydrogen bond connectivity and the characteristics of nuclear position fluctuations, including explicit incorporation of quantum effects, for the energetically low lying isomers of the prototype cluster [H{sub 2}O]{sub 8} at T = 50 K and at 150 K. Our results reveal that tunneling and zero-point energy effects lead to sensible increments in the magnitudes of the fluctuations of intra and intermolecular distances. The degree of proton spatial delocalization is found to map logically with the hydrogen-bond connectivity pattern of the cluster. Dangling hydrogen bonds exhibit the largest extent of spatial delocalization and participate in shorter intramolecular O-H bonds. Combined effects from quantum and polarization fluctuations on the resulting individual dipole moments are also examined. From the dynamical side, we analyze the characteristics of the infrared absorption spectrum. The incorporation of nuclear quantum fluctuations promotes red shifts and sensible broadening relative to the classical profile, bringing the simulation results in much more satisfactory agreement with direct experimental information in the mid and high frequency range of the stretching band. While RPMD predictions overestimate the peak position of the low frequency shoulder, the overall agreement with that reported using an accurate, parameterized, many-body potential is reasonable, and far superior to that one obtains by implementing a partially adiabatic centroid molecular dynamics approach. Quantum effects on the collective dynamics, as reported by instantaneous normal modes, are also discussed.

  17. Nuclear Safety

    Energy Technology Data Exchange (ETDEWEB)

    Silver, E G [ed.

    1989-01-01

    This document is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated.

  18. Nuclear Energy's Renaissance

    Science.gov (United States)

    Kadak, Andrew C.

    2006-10-01

    Nuclear energy is about to enter its renaissance. After almost 30 years of new plant construction dormancy, utilities are seriously preparing for ordering new plants in the next two years. This resurgence in interest is based on improved plant performance, new Nuclear Regulatory Commission licensing processes, significant incentives introduced by Congress in the Energy Policy Act of 2005 to encourage new orders, and new technologies that are competitive, simpler to operate and safer. These new evolutionary light water reactors will pave the way to more advanced high temperature gas reactors such as the pebble bed or prismatic reactors that will provide improved efficiency and safety leading to more process heat applications in oil extraction or hydrogen production. The Next Generation Nuclear Plant (NGNP) also authorized by the Energy Policy act will provide the fundamental technical basis for the future of these technologies. Progress continues on the Yucca Mountain nuclear waste disposal site enabling this expansion. When coupled with the long term strategy of waste minimization through reprocessing and actinide destruction as proposed in the Global Nuclear Energy Partnership, the future of nuclear energy as part of this nation's energy mix appears to be assured.

  19. The effects of host age, host nuclear background and temperature on phenotypic effects of the virulent Wolbachia strain popcorn in Drosophila melanogaster.

    OpenAIRE

    Reynolds, K. Tracy; Thomson, Linda J; Ary A Hoffmann

    2003-01-01

    Because of their obligate endosymbiotic nature, Wolbachia strains by necessity are defined by their phenotypic effects upon their host. Nevertheless, studies on the influence of host background and environmental conditions upon the manifestation of Wolbachia effects are relatively uncommon. Here we examine the behavior of the overreplicating Wolbachia strain popcorn in four different Drosophila melanogaster backgrounds at two temperatures. Unlike other strains of Wolbachia in Drosophila, popc...

  20. Next Generation Nuclear Plant Project Technology Development Roadmaps: The Technical Path Forward for 750–800°C Reactor Outlet Temperature

    Energy Technology Data Exchange (ETDEWEB)

    John Collins

    2009-08-01

    This document presents the NGNP Critical PASSCs and defines their technical maturation path through Technology Development Roadmaps (TDRMs) and their associated Technology Readiness Levels (TRLs). As the critical PASSCs advance through increasing levels of technical maturity, project risk is reduced and the likelihood of within-budget and on-schedule completion is enhanced. The current supplier-generated TRLs and TDRMs for a 750–800°C reactor outlet temperature (ROT) specific to each supplier are collected in Appendix A.

  1. The effects of host age, host nuclear background and temperature on phenotypic effects of the virulent Wolbachia strain popcorn in Drosophila melanogaster.

    Science.gov (United States)

    Reynolds, K Tracy; Thomson, Linda J; Hoffmann, Ary A

    2003-07-01

    Because of their obligate endosymbiotic nature, Wolbachia strains by necessity are defined by their phenotypic effects upon their host. Nevertheless, studies on the influence of host background and environmental conditions upon the manifestation of Wolbachia effects are relatively uncommon. Here we examine the behavior of the overreplicating Wolbachia strain popcorn in four different Drosophila melanogaster backgrounds at two temperatures. Unlike other strains of Wolbachia in Drosophila, popcorn has a major fitness impact upon its hosts. The rapid proliferation of popcorn causes cells to rupture, resulting in the premature death of adult hosts. Apart from this effect, we found that popcorn delayed development time, and host background influenced both this trait and the rate of mortality associated with infection. Temperature influenced the impact of popcorn upon host mortality, with no reduction in life span occurring in flies reared at 19 degrees. No effect upon fecundity was found. Contrary to earlier reports, popcorn induced high levels of incompatibility when young males were used in tests, and CI levels declined rapidly with male age. The population dynamics of popcorn-type infections will therefore depend on environmental temperature, host background, and the age structure of the population.

  2. Nuclear Astrophysics

    Science.gov (United States)

    Drago, Alessandro

    2005-04-01

    The activity of the Italian nuclear physicists community in the field of Nuclear Astrophysics is reported. The researches here described have been performed within the project "Fisica teorica del nucleo e dei sistemi a multi corpi", supported by the Ministero dell'Istruzione, dell'Università e della Ricerca.

  3. Nuclear Astrophysics

    CERN Document Server

    Langanke, K

    1999-01-01

    The manuscript reviews progress achieved in recent years in various aspects of nuclear astrophysics, including stellar nucleosynthesis, nuclear aspects of supernova collapse and explosion, neutrino-induced reactions and their possible role in the supernova mechanism and nucleosynthesis, explosive hydrogen burning in binary systems, and finally the observation of gamma-rays from supernova remnants.

  4. Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning 13C and 29Si NMR Enhanced by Dynamic Nuclear Polarization

    Energy Technology Data Exchange (ETDEWEB)

    Lafon, Olivier [Universite de Lille Nord de France; Thankamony, Aany S. Lilly [Universite de Lille Nord de France; Kokayashi, Takeshi [Ames Laboratory; Carnevale, Diego [Ecole Polytechnique Federale de Lausanne; Vitzthum, Veronika [Ecole Polytechnique Federale de Lausanne; Slowing, Igor I. [Ames Laboratory; Kandel, Kapil [Ames Laboratory; Vezin, Herve [Universite de Lille Nord de France; Amoureux, Jean-Paul [Universite de Lille Nord de France; Bodenhausen, Geoffrey [Ecole Polytechnique Federale de Lausanne; Pruski, Marek [Ames Laboratory

    2012-12-21

    We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of 13C and 29Si nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surrounding frozen disordered water. The approach is demonstrated using mesoporous silica nanoparticles (MSN), functionalized with 3-(N-phenylureido)propyl (PUP) groups, filled with the surfactant cetyltrimethylammonium bromide (CTAB). The DNP-enhanced proton magnetization is transported into the mesopores via 1H–1H spin diffusion and transferred to rare spins by cross-polarization, yielding signal enhancements εon/off of around 8. When the CTAB molecules are extracted, so that the radicals can enter the mesopores, the enhancements increase to εon/off ≈ 30 for both nuclei. A quantitative analysis of the signal enhancements in MSN with and without surfactant is based on a one-dimensional proton spin diffusion model. The effect of solvent deuteration is also investigated.

  5. Study of the influence of temperature and time on the electroplating nickel layer in Inconel 718 strips used in spacer grid of Pressurized Water Cooled nuclear reactors (PWR)

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Renato; Abati, Amanda; Verne, Júlio; Panossian, Zehbour, E-mail: amanda.abati@marinha.mil.br, E-mail: jvernegropp@gmail.com, E-mail: renato.rezende@marinha.mil.br, E-mail: zep@ipt.br [Centro Tecnológico da Marinha em São Paulo (CTMSP), São Paulo, SP (Brazil). Laboratório de Desenvolvimento e Instrumentação de Combustível Nuclear; Instituto de Pesquisas Tecnológicas (IPT), São Paulo, SP (Brazil)

    2017-07-01

    The Inconel 718 (UNS N07718: Ni-{sup 19}Cr-{sup 18}Fe-{sup 5}Nb-3 Mo) is a precipitation hardenable nickel alloy that has good corrosion resistance and high mechanical strength. These strips are used for assembling the spacer grid of fuel element of pressurized water cooled nuclear reactors (PWR). The spacer grid is a structural component of fundamental importance in fuel elements of PWR reactors, maintaining the position and necessary spacing of the fuel rods within the arrangement of the fuel element. The spacer grid is formed by joining the points of intersection of the strips, by a joint process called brazing. For this process, these strips are stamped and plated with a thin layer of nickel by means of electroplating in order to protect against oxidation and allow a better flowability and wettability of the addition metal in the strips during brazing. Oxidation at the surface of the base material harms wettability and inhibits spreading of the liquid addition metal on the substrate surface during the brazing process. The use of coatings such as nickel plating is used to ensure such conditions. The results showed that there is a process of diffusion de some chemical elements such as chromium, iron, titanium and aluminum from the substrate to the nickel layer and nickel from the layer to the substrate. These chemical elements are responsible for the oxidation at the surface of the strip. (author)

  6. A Comparative Study for Modeling Displacement Instabilities due to TGO Formation in TBCs of High-Temperature Components in Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xia Huang

    2016-01-01

    Full Text Available This paper reports two numerical simulation methods for modeling displacement instabilities around a surface groove in a metal substrate used in nuclear power plant. The amplitude change in the groove, the downward displacement at the base node, and the groove displacement at the periphery were simulated using ABAQUS to compare the results from two methods, as well as the tangential stress in the elements at the groove base and periphery. The comparison showed that for the tangential stress two methods were in close agreement for all thermal cycles. For the amplitude change, the downward displacement, the groove displacement, and the stress distribution, the two methods were in close agreement for the first 3 to 6 thermal cycles. After that, inconsistency increased with the number of thermal cycles. It is interesting that the thermal cycle at which the discrepancy between the two methods began to occur corresponded to a thermally grown oxide (TGO thickness of 1 μm, which showed the accuracy of the present work over the classic method. It is concluded that the present work’s numerical simulation scheme worked better with a thinner TGO layer than the classic method and could overcome the limitation of TGO thickness by simulating any thickness.

  7. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  8. Temperature-tuned Maxwell-Boltzmann neutron spectra for kT ranging from 30 up to 50 keV for nuclear astrophysics studies.

    Science.gov (United States)

    Martín-Hernández, G; Mastinu, P F; Praena, J; Dzysiuk, N; Capote Noy, R; Pignatari, M

    2012-08-01

    The need of neutron capture cross section measurements for astrophysics motivates present work, where calculations to generate stellar neutron spectra at different temperatures are performed. The accelerator-based (7)Li(p,n)(7)Be reaction is used. Shaping the proton beam energy and the sample covering a specific solid angle, neutron activation for measuring stellar-averaged capture cross section can be done. High-quality Maxwell-Boltzmann neutron spectra are predicted. Assuming a general behavior of the neutron capture cross section a weighted fit of the spectrum to Maxwell-Boltzmann distributions is successfully introduced. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Nuclear questions

    Energy Technology Data Exchange (ETDEWEB)

    Durrani, M. [Physics World (United Kingdom)

    2006-01-01

    The future of nuclear power has returned to centre stage. Freezing weather on both sides of the Atlantic and last month's climate-change talks in Montreal have helped to put energy and the future of nuclear power right back on the political agenda. The issue is particularly pressing for those countries where existing nuclear stations are reaching the end of their lives. In the UK, prime minister Tony Blair has commissioned a review of energy, with a view to deciding later this year whether to build new nuclear power plants. The review comes just four years after the Labour government published a White Paper on energy that said the country should keep the nuclear option open but did not follow this up with any concrete action. In Germany, new chancellor and former physicist Angela Merkel is a fan of nuclear energy and had said she would extend the lifetime of its nuclear plants beyond 2020, when they are due to close. However, that commitment has had to be abandoned, at least for the time being, following negotiations with her left-wing coalition partners. The arguments in favour of nuclear power will be familiar to all physicists - it emits almost no carbon dioxide and can play a vital role in maintaining a diverse energy supply. To over-rely on imported supplies of oil and gas can leave a nation hostage to fortune. The arguments against are equally easy to list - the public is scared of nuclear power, it generates dangerous waste with potentially huge clean-up costs, and it is not necessarily cheap. Nuclear plants could also be a target for terrorist attacks. Given political will, many of these problems can be resolved, or at least tackled. China certainly sees the benefits of nuclear power, as does Finland, which is building a new 1600 MW station - the world's most powerful - that is set to open in 2009. Physicists, of course, are essential to such developments. They play a vital role in ensuring the safety of such plants and developing new types of

  10. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  11. Nuclear war and nuclear peace

    Energy Technology Data Exchange (ETDEWEB)

    Segal, G.; Moreton, E.; Freedman, L.; Baylis, J.

    1983-01-01

    This book is an in-depth examination of East-West tactical and strategic nuclear weapons policy. The contributors explore such issues as the history and implications of tactical weapons in Europe, the general conflicts that have characterized US and Soviet interaction, the development of British nuclear weapons policy, and arms control including SALT I and II and the START talks.

  12. TINTE. Nuclear calculation theory description report

    Energy Technology Data Exchange (ETDEWEB)

    Gerwin, H.; Scherer, W.; Lauer, A. [Forschungszentrum Juelich GmbH (DE). Institut fuer Energieforschung (IEF), Sicherheitsforschung und Reaktortechnik (IEF-6); Clifford, I. [Pebble Bed Modular Reactor (Pty) Ltd. (South Africa)

    2010-01-15

    The Time Dependent Neutronics and Temperatures (TINTE) code system deals with the nuclear and the thermal transient behaviour of the primary circuit of the High-temperature Gas-cooled Reactor (HTGR), taking into consideration the mutual feedback effects in twodimensional axisymmetric geometry. This document contains a complete description of the theoretical basis of the TINTE nuclear calculation, including the equations solved, solution methods and the nuclear data used in the solution. (orig.)

  13. Evaluation of the security of a hydrogen producing plant by means of the S I cycle coupled to a nuclear reactor of high temperature; Evaluacion de la seguridad de una planta productora de hidrogeno mediante el ciclo SI acoplada a un reactor nuclear de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz S, T.; Francois, J. L.; Nelson, P. F. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac No. 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico); Cruz G, M. J., E-mail: truizsmx@yahoo.com.mx [UNAM, Facultad de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (MX)

    2011-11-15

    At the present one of the processes that demonstrates, theoretically, to be one of the most efficient for the hydrogen production is the thermal-chemistry cycle Sulfur-Iodine. One way of obtaining the temperature ranges required by the process is through the helium coming from a very high temperature reactor. The coupling of the chemical plant with the nuclear plant presents aspects of security that should be analyzed; among them the analysis of the danger of the process materials is, with the purpose of implementing security measures to protect the facilities and equipment s, the environment and the population. These measures can be: emergency answer plans of the stations, definition of the minimum distance required among facilities, determination of the exclusion area, etc. In this study simulations were made with the computer code Phast in order to knowing the possible affectation areas due to the liberation of a great quantity of energy due to a helium leak to very high temperature, of toxic materials or by a possible hydrogen combustion. The results for the liberations of sulfuric acid, hydrogen, iodine, helium and sulfur dioxide are shown, specially. The operation conditions were taken of a combination of the preliminary design proposed by General Atomics and the optimized conditions by the Korea Advanced Institute of Science and Technology, considering a production of 1 kg-mol/s of hydrogen. The iodine was the material that presented a major affectation area. (Author)

  14. Nuclear Physics

    CERN Document Server

    Savage, Martin J

    2016-01-01

    Lattice QCD is making good progress toward calculating the structure and properties of light nuclei and the forces between nucleons. These calculations will ultimately refine the nuclear forces, particularly in the three- and four-nucleon sector and the short-distance interactions of nucleons with electroweak currents, and allow for a reduction of uncertainties in nuclear many-body calculations of nuclei and their reactions. After highlighting their importance, particularly to the Nuclear Physics and High-Energy Physics experimental programs, I discuss the progress that has been made toward achieving these goals and the challenges that remain.

  15. Preliminary risk analysis of an Hydrogen production plant using the reformed process of methane with vapor coupled to a high temperature nuclear reactor; Analisis preliminar de riesgo de una planta de produccion de hidrogeno utilizando el proceso de reformado de metano con vapor acoplada a un reactor nuclear de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Flores y Flores, A. [Facultad de Ingenieria, UNAM, 04510 Mexico D.F. (Mexico)]. E-mail: alain_fyf@yahoo.com; Nelson E, P.F.; Francois L, J.L. [Facultad de Ingenieria, Laboratorio de Analisis en Ingenieria de Reactores Nucleares, UNAM, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)

    2004-07-01

    It is necessary to identify the different types of dangers, as well as their causes, probabilities and consequences of the same ones, inside plants, industries and any process to classify the risks. This work is focused in particular to a study using the technical HAZOP (Hazard and Operability) for a plant of reformed of methane with vapor coupled to a nuclear reactor of the type HTTR (High Temperature Test Reactor), which is designed to be built in Japan. In particular in this study the interaction is analyzed between the nuclear reactor and the plant of reformed of methane with vapor. After knowing the possible causes of risk one it is built chart of results of HAZOP to have a better vision of the consequences of this faults toward the buildings and constructions, to people and the influence of the fault on each plant; for what there are proposed solutions to mitigate these consequences or to avoid them. The work is divided in three sections: a brief introduction about the technique of HAZOP; some important aspects of the plant of reformed of methane with vapor; and the construction of the chart of results of HAZOP. (Author)

  16. (Nuclear theory). [Research in nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion. (LSP)

  17. Nuclear rocket engine reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lanin, Anatoly

    2013-07-01

    Covers a new technology of nuclear reactors and the related materials aspects. Integrates physics, materials science and engineering Serves as a basic book for nuclear engineers and nuclear physicists. The development of a nuclear rocket engine reactor (NRER) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  18. Temperature-Sensitive Mutants in the Influenza A Virus RNA Polymerase: Alterations in the PA Linker Reduce Nuclear Targeting of the PB1-PA Dimer and Result in Viral Attenuation.

    Science.gov (United States)

    Da Costa, Bruno; Sausset, Alix; Munier, Sandie; Ghounaris, Alexandre; Naffakh, Nadia; Le Goffic, Ronan; Delmas, Bernard

    2015-06-01

    The influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. The ts phenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed that ts and lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of the Gaussia princeps luciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Two ts mutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a "hot spot" to engineer ts mutants that could be used to design novel attenuated vaccines. By targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number of ts mutations were

  19. Nuclear reaction

    CERN Multimedia

    Penwarden, C

    2001-01-01

    At the European Research Organization for Nuclear Research, Nobel laureates delve into the mysteries of particle physics. But when they invited artists from across the continent to visit their site in Geneva, they wanted a new kind of experiment.

  20. Nuclear Fusion

    National Research Council Canada - National Science Library

    Ghoranneviss, Mahmood; Parashar, S. K. S; Aslan, Necdet; Aslaninejad, Morteza; Salar Elahi, A

    2014-01-01

    ... in both inertial and magnetic confinement fusion, with attendees from major fusion energy research centers worldwide. It is one of the most important issues in this field. Nuclear fusion continues t...

  1. Nuclear Structure

    Science.gov (United States)

    Gargano, Angela

    2003-04-01

    An account of recent studies in the field of theoretical nuclear structure is reported. These studies concern essentially research activities performed under the Italian project "Fisica Teorica del Nucleo e dei Sistemi a Molti Corpi". Special attention is addressed to results obtained during the last two years as regards the development of new many-body techniques as well as the interpretation of new experimental aspects of nuclear structure.

  2. Nuclear Data

    Energy Technology Data Exchange (ETDEWEB)

    White, Morgan C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-23

    PowerPoint presentation targeted for educational use. Nuclear data comes from a variety of sources and in many flavors. Understanding where the data you use comes from and what flavor it is can be essential to understand and interpret your results. This talk will discuss the nuclear data pipeline with particular emphasis on providing links to additional resources that can be used to explore the issues you will encounter.

  3. Nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Program on Nuclear Safety comprehends Radioprotection, Radioactive Waste Management and Nuclear Material Control. These activities are developed at the Nuclear Safety Directory. The Radioactive Waste Management Department (GRR) was formally created in 1983, to promote research and development, teaching and service activities in the field of radioactive waste. Its mission is to develop and employ technologies to manage safely the radioactive wastes generated at IPEN and at its customer’s facilities all over the country, in order to protect the health and the environment of today's and future generations. The Radioprotection Service (GRP) aims primarily to establish requirements for the protection of people, as workers, contractors, students, members of the general public and the environment from harmful effects of ionizing radiation. Furthermore, it also aims to establish the primary criteria for the safety of radiation sources at IPEN and planning and preparing for response to nuclear and radiological emergencies. The procedures about the management and the control of exposures to ionizing radiation are in compliance with national standards and international recommendations. Research related to the main activities is also performed. The Nuclear Material Control has been performed by the Safeguard Service team, which manages the accountability and the control of nuclear material at IPEN facilities and provides information related to these activities to ABACC and IAEA. (author)

  4. Using Secondary Nuclear Reaction Products to Infer the Fuel Areal Density, Convergence, and Electron Temperatures of Imploding D2 and D3 He Filled Capsules on the NIF

    Science.gov (United States)

    Lahmann, B.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Hartouni, E. P.; Yeamans, C. B.; Rinderknecht, H. G.; Sayre, D. B.; Grim, G.; Baker, K.; Casey, D. T.; Dewald, E.; Goyon, C.; Jarrott, L. C.; Khan, S.; Lepape, S.; Ma, T.; Pickworth, L.; Shah, R.; Kline, J. L.; Perry, T.; Zylstra, A.; Yi, S. A.

    2017-10-01

    In deuterium-filled inertial confinement fusion implosions, 0.82 MeV 3He and 1.01 MeV T (generated by the primary DD reaction branches) can undergo fusion reactions with the thermal deuterium plasma to create secondary D3He protons and DT neutrons, respectively. In regimes of moderate fuel areal density (ρR 5 - 100 mg/cm2) the ratio of both of these secondary yields to the primary yield can be used to infer the fuel ρR, convergence ratio (CR), and an electron temperature (Te) . This technique has been used on a myriad of deuterium filled capsule implosion experiments on the NIF using the neutron time of flight (nTOF) diagnostics to measure the yield of secondary DT neutrons and CR-39 based wedge range filters (WRFs) to measure the yield of secondary D3He protons. This work is supported in part by the U.S. DoE and LLNL.

  5. Correlation of radioactive waste treatment costs and the environmental impact of waste effluents in the nuclear fuel cycle: reprocessing of high-temperature gas-cooled reactor fuel containing U-233 and thorium

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W. Jr.; Blanco, R.E.; Finney, B.C.; Hill, G.S.; Moore, R.E.; Witherspoon, J.P.

    1976-05-01

    A cost/benefit study was made to determine the cost and effectiveness of various radioactive waste (radwaste) treatment systems for decreasing the release of radioactive materials from a model high-temperature gas-cooled reactor (HTGR) fuel reprocessing plant and to determine the radiological impact (dose commitment) of the released materials on the environment. The study is designed to assist the U. S. Nuclear Regulatory Commission in defining the term as low as reasonably achievable as it applies to this nuclear facility. The base case is representative of conceptual, developing technology of head-end graphite-burning operations and of extensions of solvent-extraction technology of current designs for light-water-reactor (LWR) fuel reprocessing plants. The model plant has an annual capacity of 450 metric tons of heavy metal (MTHM, where heavy metal is uranium plus thorium), as charged to about fifty 1000-MW(e) HTGRs. Additional radwaste treatment systems are added to the base-case plant in a series of case studies to decrease the amounts of radioactive materials released and to reduce the radiological dose commitment to the population in the surrounding area. The capital and annual costs for the added waste treatment operations and the corresponding reductions in dose commitments are calculated for each case. In the final analysis, the cost/benefit of each case, calculated as additional cost of radwaste system divided by the reduction in dose commitment, is tabulated or the dose commitment is plotted with cost as the variable. The status of each of the radwaste treatment methods used in the case studies is discussed.

  6. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging ... the limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch ...

  7. Children's (Pediatric) Nuclear Medicine

    Science.gov (United States)

    ... Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small amounts ... Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  8. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small amounts ... Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  9. General Nuclear Medicine

    Science.gov (United States)

    ... Resources Professions Site Index A-Z General Nuclear Medicine Nuclear medicine imaging uses small amounts of radioactive ... of General Nuclear Medicine? What is General Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  10. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses ... limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of ...

  11. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small ... of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical ...

  12. World nuclear performance report 2017

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Jonathan [World Nuclear Association, London (United Kingdom)

    2017-08-15

    World Nuclear Association recently published the 2017 edition of the World Nuclear Performance Report. The report presents key metrics that illustrate current performance, both of reactors currently operating and those under construction. The article highlights some of the most important findings of the report. The pace of new build will need to accelerate if nuclear energy is going to make a growing contribution to the global electricity generation mix, a requirement of many projections of future scenarios that aim to meet the objective of limiting the rise average temperatures to below two degrees Celsius, while at the same time meeting the growing worldwide demand for electricity.

  13. Accident tolerant composite nuclear fuels

    Directory of Open Access Journals (Sweden)

    Szpunar Barbara

    2017-01-01

    Full Text Available Investigated accident tolerant nuclear fuels are fuels with enhanced thermal conductivity, which can withstand the loss of coolant for a longer time by allowing faster dissipation of heat, thus lowering the centerline temperature and preventing the melting of the fuel. Traditional nuclear fuels have a very low thermal conductivity and can be significantly enhanced if transformed into a composite with a very high thermal conductivity components. In this study, we analyze the thermal properties of various composites of mixed oxides and thoria fuels to improve thermal conductivity for the next generation safer nuclear reactors.

  14. Nuclear scales

    Energy Technology Data Exchange (ETDEWEB)

    Friar, J.L.

    1998-12-01

    Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

  15. Nuclear astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2010-08-01

    The International Year of Astronomy 2009 (IYA2009) was declared by the 62nd General Assembly of the United Nations and was also endorsed by UNESCO. Investigations in the realms of particle and nuclear physicsmake a large contribution in the development of our ideas of the properties of the Universe. The present article discusses some problems of the evolution of the Universe, nucleosyntheses, and cosmochronology from the point of view of nuclear and particle physics. Processes occurring in the Universe are compared with the mechanisms of the production and decay of nuclei, as well as with the mechanisms of their interaction at high energies. Examples that demonstrate the potential of nuclearphysics methods for studying cosmic objects and the properties of the Universe are given. The results that come from investigations into nuclear reactions induced by beams of radioactive nuclei and which make it possible to take a fresh look at the nucleosynthesis scenario in the range at light nuclei are presented.

  16. Nuclear enthalpies

    Directory of Open Access Journals (Sweden)

    Rozynek Jacek

    2015-01-01

    Full Text Available Even small departures from a nuclear equilibrium density with constant nucleon masses require an increase of a nucleon enthalpy. This process can be described as volume corrections to a nucleon rest energy, which are proportional to pressure and absent in a standard Relativistic Mean Field (RMF with point-like nucleons. Bag model and RMF calculations show the modifications of nucleon mass, nucleon radius and a Parton Distribution Function (PDF of Nuclear Matter (NM above the saturation point originated from the pressure correction.

  17. Nuclear spectroscopy

    CERN Document Server

    Ajzenberg-Selove, Fay

    1960-01-01

    Nuclear Spectroscopy, Part A deals with the experimental and theoretical techniques involved in nuclear spectroscopy.This book discusses the interactions of charged particles with matter, gaseous ionization detectors, and particular mass attenuation coefficients. The magnetic gamma-ray spectrometers for photo or internal-conversion electrons, general characteristics of cross-section variation with energy, and measurement of fast neutron spectra are also elaborated. This text likewise covers the elastic scattering of photons by nuclei and measurement of widths of gamma-radiating levels.This pub

  18. Nuclear energy.

    Science.gov (United States)

    Wilson, Peter D

    2010-01-01

    The technical principles and practices of the civil nuclear industry are described with particular reference to fission and its products, natural and artificial radioactivity elements principally concerned and their relationships, main types of reactor, safety issues, the fuel cycle, waste management, issues related to weapon proliferation, environmental considerations and possible future developments.

  19. Concavity for nuclear bindings

    CERN Document Server

    Barrett, B R; Jennings, B K; Toberg, N P

    2010-01-01

    Sequences of experimental ground-state energies for both odd and even A are mapped onto concave patterns cured from convexities due to pairing. These patterns yield improved estimates by interpolation or extrapolation (as appropriate) of ground-state energies for nuclei, which have not yet been measured. An example of this procedure, using the tin isotopes is given. The same patterns, completed by a list of excitation energies, give numerical estimates of thermodynamical functions, which lead to the average nucleon number hAi(β, μ) becoming a continuous variable at low to moderate temperatures, allowing extrapolations towards nuclear masses closer to drip lines. Estimates of the free energy and the average energy, as functions of hAi, provide upper and lower bounds, respectively, to ground-state energy. Finally, we discuss extensions to a two-dimensional analysis and how concavity and universality are related to the theory of the nuclear density functional.

  20. Semiconductors for room temperature nuclear detector applications

    CERN Document Server

    James, Ralph B

    1995-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The""Willardson and Beer""Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series.

  1. Nuclear politics

    Science.gov (United States)

    Ranson, John

    2009-04-01

    The sentiments expressed by Sidney Drell in his forum article "The nuclear threat: a new start" (February pp16-17) are laudable, but it was disappointing to find this almost entirely political story in isolation. The article, which outlined the prospects for reducing weapons stockpiles under the new US administration, would have been more pertinent as an introduction to a series describing the technology used in detecting nuclear-testing activity. It would have been interesting to discuss the specific equipment and methods used, together with the analysis and correlation techniques - along with an indication of how sensitive and reliable they are (if the information is not classified). It is far easier to detect an explosive event than it is to detect and quantify weapons stores, which is a key factor for any negotiated solution. Apart from deductions based on actual inspection and satellite surveillance, are there other techniques that can be applied to this issue?

  2. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... are the limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a ... top of page What are some common uses of the procedure? Children's (pediatric) nuclear medicine imaging is ...

  3. Nuclear photonics

    Science.gov (United States)

    Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

    2012-07-01

    With the planned new γ-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 γ/s and a band width of ΔEγ/Eγ≈10-3, a new era of γ beams with energies up to 20MeV comes into operation, compared to the present world-leading HIγS facility at Duke University (USA) with 108 γ/s and ΔEγ/Eγ≈3ṡ10-2. In the long run even a seeded quantum FEL for γ beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused γ beams. Here we describe a new experiment at the γ beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for γ beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for γ beams are being developed. Thus, we have to optimize the total system: the γ-beam facility, the γ-beam optics and γ detectors. We can trade γ intensity for band width, going down to ΔEγ/Eγ≈10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with γ-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, γ beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to μm resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

  4. Nuclear symmetry energy: An experimental overview

    Indian Academy of Sciences (India)

    Abstract. The nuclear symmetry energy is a fundamental quantity important for study- ing the structure of systems as diverse as the atomic nucleus and the neutron star. Con- siderable efforts are being made to experimentally extract the symmetry energy and its dependence on nuclear density and temperature. In this article ...

  5. Nuclear symmetry energy: An experimental overview

    Indian Academy of Sciences (India)

    The nuclear symmetry energy is a fundamental quantity important for studying the structure of systems as diverse as the atomic nucleus and the neutron star. Considerable efforts are being made to experimentally extract the symmetry energy and its dependence on nuclear density and temperature. In this article, the ...

  6. HOMOGENEOUS NUCLEAR POWER REACTOR

    Science.gov (United States)

    King, L.D.P.

    1959-09-01

    A homogeneous nuclear power reactor utilizing forced circulation of the liquid fuel is described. The reactor does not require fuel handling outside of the reactor vessel during any normal operation including complete shutdown to room temperature, the reactor being selfregulating under extreme operating conditions and controlled by the thermal expansion of the liquid fuel. The liquid fuel utilized is a uranium, phosphoric acid, and water solution which requires no gus exhaust system or independent gas recombining system, thereby eliminating the handling of radioiytic gas.

  7. Fission hindrance and nuclear viscosity

    Indian Academy of Sciences (India)

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

  8. Correlation of radioactive waste treatment costs and the environmental impact of waste effluents in the nuclear fuel cycle: fabrication of high-temperature gas-cooled reactor fuel containing uranium-233 and thorium

    Energy Technology Data Exchange (ETDEWEB)

    Roddy, J.W.; Blanco, R.E.; Hill, G.S.; Moore, R.E.; Seagren, R.D.; Witherspoon, J.P.

    1976-06-01

    A cost/benefit study was made to determine the cost and effectiveness of various radioactive waste (radwaste) treatment systems for decreasing the release of radioactive materials from model High-Temperature Gas-Cooled (HTGR) fuel fabrication plants and to determine the radiological impact (dose commitment) of the released materials on the environment. The study is designed to assist in defining the term ''as low as reasonably achievable'' as it applies to these nuclear facilities. The base cases of the two model plants, a fresh fuel fabrication plant and a refabrication plant, are representative of current proposed commercial designs or are based on technology that is being developed to fabricate uranium, thorium, and graphite into fuel elements. The annual capacities of the fresh fuel plant and the refabrication plant are 450 and 245 metric tons of heavy metal (where heavy metal is uranium plus thorium), as charged to about fifty 1000-MW(e) HTGRs. Additional radwaste treatment systems are added to the base case plants in a series of case studies to decrease the amounts of radioactive materials released and to reduce the radiological dose commitment to the population in the surrounding area. The capital and annual costs for the added waste treatment operations and the corresponding reductions in dose commitments are calculated for each case. In the final analysis, the cost/benefit of each case, calculated as additional cost of radwaste system divided by the reduction in dose commitment, is tabulated or the dose commitment is plotted with cost as the variable. The status of each of the radwaste treatment methods is discussed. 48 figures, 74 tables.

  9. Condensed Matter Nuclear Science

    Science.gov (United States)

    Biberian, Jean-Paul

    2006-02-01

    1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

  10. Experimental study of the temperature distribution in the TRIGA IPR-R1 Brazilian research reactor; Investigacao experimental da distribuicao de temperaturas no reator nuclear de pesquisa TRIGA IPR-R1

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Amir Zacarias

    2005-07-01

    The TRIGA-IPR-R1 Research Nuclear Reactor has completed 44 years in operation in November 2004. Its initial nominal thermal power was 30 kW. In 1979 its power was increased to 100 kW by adding new fuel elements to the reactor. Recently some more fuel elements were added to the core increasing the power to 250 kW. The TRIGA-IPR-R1 is a pool type reactor with a natural circulation core cooling system. Although the large number of experiments had been carried out with this reactor, mainly on neutron activation analysis, there is not many data on its thermal-hydraulics processes, whether experimental or theoretical. So a number of experiments were carried out with the measurement of the temperature inside the fuel element, in the reactor core and along the reactor pool. During these experiments the reactor was set in many different power levels. These experiments are part of the CDTN/CNEN research program, and have the main objective of commissioning the TRIGA-IPR-R1 reactor for routine operation at 250 kW. This work presents the experimental and theoretical analyses to determine the temperature distribution in the reactor. A methodology for the calibration and monitoring the reactor thermal power was also developed. This methodology allowed adding others power measuring channels to the reactor by using thermal processes. The fuel thermal conductivity and the heat transfer coefficient from the cladding to the coolant were also experimentally valued. lt was also presented a correlation for the gap conductance between the fuel and the cladding. The experimental results were compared with theoretical calculations and with data obtained from technical literature. A data acquisition and processing system and a software were developed to help the investigation. This system allows on line monitoring and registration of the main reactor operational parameters. The experiments have given better comprehension of the reactor thermal-fluid dynamics and helped to develop numerical

  11. Nuclear tele medicine; Telemedicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, L.; Hernandez, F.; Fernandez, R. [Departamento de Medicina Nuclear, Imagenologia Diagnostica, Xalapa, Veracruz (Mexico)

    2005-07-01

    The great majority of the digital images of nuclear medicine are susceptible of being sent through internet. This has allowed that the work in diagnosis cabinets by image it can benefit of this modern technology. We have presented in previous congresses works related with tele medicine, however, due to the speed in the evolution of the computer programs and the internet, becomes necessary to make a current position in this modality of work. (Author)

  12. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  13. Applications of nuclear physics

    Science.gov (United States)

    Hayes, A. C.

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  14. Applications of nuclear physics.

    Science.gov (United States)

    Hayes, A C

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  15. Physisorbed Water on Silica at Mars Temperatures

    Science.gov (United States)

    Sutter, B.; Sriwatanapongse, W.; Quinn, R.; Klug, C.; Zent, A.

    2002-01-01

    The usefulness of nuclear magnetic resonance spectroscopy in probing water interactions on silica at Mars temperatures is discussed. Results indicate that two types of water occur with silica at Mars temperatures. Additional information is contained in the original extended abstract.

  16. Dictionary of nuclear engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sube, R.

    1985-01-01

    Ralf Sube, an experienced compiler of three wellknown four-language reference works has now prepared this glossary of nuclear engineering terms in English, German, French and Russian. Based on the proven lexicography of the Technik-Worterbuch series, it comprises about 30,000 terms in each language covering the following: Nuclear and Atomic Physics; Nuclear Radiation and Isotopes; Nuclear Materials; Nuclear Facilties; Nuclear Power Industry; Nuclear Weapons.

  17. Applications of Nuclear Physics

    OpenAIRE

    Hayes, Anna C.

    2017-01-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that und...

  18. NASA program planning on nuclear electric propulsion

    Science.gov (United States)

    Bennett, Gary L.; Miller, Thomas J.

    1992-01-01

    As part of the focused technology planning for future NASA space science and exploration missions, NASA has initiated a focused technology program to develop the technologies for nuclear electric propulsion and nuclear thermal propulsion. Beginning in 1990, NASA began a series of interagency planning workshops and meetings to identify key technologies and program priorities for nuclear propulsion. The high-priority, near-term technologies that must be developed to make NEP operational for space exploration include scaling thrusters to higher power, developing high-temperature power processing units, and developing high power, low-mass, long-lived nuclear reactors.

  19. Nuclear spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  20. Development of nanosensors in nuclear technology

    Science.gov (United States)

    Hassan, Thamir A. A.

    2017-01-01

    Selectivity, sensitivity, and stability (three S parameters) are developed as a new range of sensor this provided instruments for harsh, radioactive waste polluted environment monitoring. Isotope effect is very effective for nuclear radiation sensors preparation.in this presentation are reviewed of the development of Nanosensors in nuclear technology, such as high temperature boron and its compounds with suitable physical and chemical features as sensitive element for temperature and nuclear sensor, Boron isotopes based semiconductor nanosensors and studies of the mechanism of the removal uranium from radioactive wastewater with graphene oxide (GO).

  1. Application of a room temperature ionic liquid for nuclear spent fuel reprocessing: speciation of trivalent europium and solvatation effects; Application d'un liquide ionique basse temperature pour les procedes de separation: speciation de l'europium trivalent et effets solvatation

    Energy Technology Data Exchange (ETDEWEB)

    Moutiers, G.; Mekki, S. [CEA Saclay, Dept. de Physico-Chimie, Service de Chimie Physique, 91 - Gif sur Yvette (France); Billard, I. [IN2P3/CNRS, 69 - Villeurbanne (France)

    2007-07-01

    One of the solutions proposed for the optimization of the long term storage and conditioning of spent nuclear fuel is to separate actinide and lanthanide both from each other and from other less radioactive metallic species. The industrial proposed processes, based on liquid liquid extraction steps, involve solvents with non negligible vapour pressure and may generate contaminated liquid wastes that will have to be reprocessed. During the last decade, some room-temperature ionic liquids have been studied and integrated into industrial processes. The interest on this class of solvent came out from their 'green' properties (non volatile, non flammable, recyclable, etc...), but also from the variability of their physico-chemical properties (stability, hydrophobicity, viscosity) as a function of the RTIL chemical composition. Indeed, it has been shown that classical chemical industrial processes could be transferred into those media, even more improved, while a certain number of difficulties arising from using traditional solvent can be avoided. In this respect, it could be promising to investigate the ability to use room temperature ionic liquid into the spent nuclear fuel reprocessing field. The aim of this this study is to test the ability of the specific ionic liquid bumimTf{sub 2}N to allow trivalent europium extraction. The choice of this metal is based on the chemical analogy with trivalent minor actinides Curium and Americium which are contributing the greatest part of the long-lived high level radioactive wastes. Handling these elements needs to be very cautious for the safety and radioprotection aspect. Moreover, europium is a very sensitive luminescent probe to its environment even at the microscopic scale. The report is structured with four parts. In a first chapter, we present the main physico-chemical properties of an imidazolium-based ionic liquid family, and then we choose the ionic liquid bumimTf{sub 2}N for the whole thesis and start with

  2. Nuclear eclectic power.

    Science.gov (United States)

    Rose, D J

    1974-04-19

    The uranium and thorium resources, the technology, and the social impacts all seem to presage an even sharper increase in nuclear power for electric generation than had hitherto been predicted. There are more future consequences. The "hydrogen economy." Nuclear power plants operate best at constant power and full load. Thus, a largely nuclear electric economy has the problem of utilizing substantial off-peak capacity; the additional energy generation can typically be half the normal daily demand. Thus, the option of generating hydrogen as a nonpolluting fuel receives two boosts: excess nuclear capacity to produce it, plus much higher future costs for oil and natural gas. However, the so-called "hydrogen economy" must await the excess capacity, which will not occur until the end of the century. Nonelectric uses. By analyses similar to those performed here, raw nuclear heat can be shown to be cheaper than heat from many other fuel sources, especially nonpolluting ones. This will be particularly true as domestic natural gas supplies become more scarce. Nuclear heat becomes attractive for industrial purposes, and even for urban district heating, provided (i) the temperature is high enough (this is no problem for district heating, but could be for industry; the HTGR's and breeders, with 600 degrees C or more available, have the advantage); (ii) there is a market for large quantities (a heat rate of 3800 Mw thermal, the reactor size permitted today, will heat Boston, with some to spare); and (iii) the social costs become more definitely resolved in favor of nuclear power. Capital requirements. Nuclear-electric installations are very capital-intensive. One trillion dollars for the plants, backup industry, and so forth is only 2 percent of the total gross national product (GNP) between 1974 and 2000, at a growth rate of 4 percent per year. But capital accumulation tends to run at about 10 percent of the GNP, so the nuclear requirements make a sizable perturbation. Also

  3. NUCLEAR REACTOR

    Science.gov (United States)

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

    1958-01-21

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

  4. On China's Nuclear Doctrine

    Directory of Open Access Journals (Sweden)

    Xia Liping

    2015-12-01

    Full Text Available Nuclear weapons have played an important role in China's national strategy. China’s nuclear doctrine has a very strong continuity. Nevertheless, China has made readjustments in its nuclear doctrine according to the changes of its internal and external situation and its general strategic threat perception. China’s nuclear doctrine has experienced a process of evolution from anti-nuclear blackmail to minimum deterrence. There are five major parts in China's nuclear doctrine: policy of declaration, nuclear development, nuclear deployment, nuclear employment, and nuclear disarmament. Because China is faced with a different situation from other nuclear powers and has its own strategic culture, China has a nuclear doctrine with its own characteristics. China’s nuclear doctrine has been affiliated with and has served the national development strategy, national security strategy, national defense policy and military strategy of China.

  5. Reconversion of nuclear weapons

    CERN Document Server

    Kapitza, Sergei P

    1992-01-01

    The nuclear predicament or nuclear option. Synopsis of three lectures : 1- The physical basis of nuclear technology. Physics of fission. Chain reaction in reactors and weapons. Fission fragments. Separration of isotopes. Radiochemistry.2- Nuclear reactors with slow and fast neutrons. Power, size, fuel and waste. Plutonium production. Dose rate, shielding and health hazard. The lessons of Chernobyl3- Nuclear weapons. Types, energy, blast and fallout. Fusion and hydrogen bombs. What to do with nuclear weapons when you cannot use them? Testing. Nonmilittary use. Can we get rid of the nuclear weapon? Nuclear proliferation. Is there a nuclear future?

  6. LASL nuclear rocket propulsion program

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, R.E.

    1956-04-01

    The immediate objective of the LASL nuclear propulsion (Rover) program is the development of a heat exchanger reactor system utilizing uranium-graphite fuel elements and ammonia propellant. This program is regarded as the first step in the development of nuclear propulsion systems for missiles. The major tasks of the program include the investigation of materials at high temperatures, development of fuel elements, investigation of basic reactor characteristics, investigation of engine control problems, detailed engine design and ground testing. The organization and scheduling of the initial development program have been worked out in some detail. Only rather general ideas exist concerning the projection of this work beyond 1958.

  7. Pions in the nuclear medium

    Energy Technology Data Exchange (ETDEWEB)

    Chanfray, G.

    1996-07-01

    We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then address the question of p-wave pion-nucleus interaction and collective pionic modes in nuclei and draw the consequences for in medium {pi}{pi} correlations especially in the scalar-isoscalar channel. We finally discuss the modification of the rho meson mass spectrum at finite density and/or temperature in connection with relativistic heavy ion collisions. 37 refs.

  8. Trends in Nuclear Astrophysics

    OpenAIRE

    Schatz, Hendrik

    2016-01-01

    Nuclear Astrophysics is a vibrant field at the intersection of nuclear physics and astrophysics that encompasses research in nuclear physics, astrophysics, astronomy, and computational science. This paper is not a review. It is intended to provide an incomplete personal perspective on current trends in nuclear astrophysics and the specific role of nuclear physics in this field.

  9. Studying Nuclear Astrophysics at NIF

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, R; Bernstein, L; Brune, C

    2009-07-01

    The National Ignition Facility's primary goal is to generate fusion energy. But the starlike conditions that it creates will also enable NIF scientists to study astrophysically important nuclear reactions. When scientists at the stadium-sized National Ignition Facility attempt to initiate fusion next year, 192 powerful lasers will direct 1.2 MJ of light energy toward a two-mm-diameter pellet of deuterium ({sup 2}H, or D) and tritium ({sup 3}H, or T). Some of that material will be gaseous, but most will be in a frozen shell. The idea is to initiate 'inertial confinement fusion', in which the two hydrogen isotopes fuse to produce helium-4, a neutron, and 17.6 MeV of energy. The light energy will be delivered to the inside walls of a hohlraum, a heavy-metal, centimeter-sized cylinder that houses the pellet. The container's heated walls will produce x rays that impinge on the pellet and ablate its outer surface. The exiting particles push inward on the pellet and compresses the DT fuel. Ultimately a hot spot develops at the pellet's center, where fusion produces {sup 4}He nuclei that have sufficient energy to propagate outward, trigger successive reactions, and finally react the frozen shell. Ignition should last several tens of picoseconds and generate more than 10 MJ of energy and roughly 10{sup 19} neutrons. The temperature will exceed 10{sup 8} K and fuel will be compressed to a density of several hundred g/cm{sup 3}, both considerably greater than at the center of the Sun. The figure shows a cutaway view of NIF. The extreme conditions that will be produced there simulate those in nuclear weapons and inside stars. For that reason, the facility is an important part of the US stockpile stewardship program, designed to assess the nation's aging nuclear stockpile without doing nuclear tests. In this Quick Study we consider a third application of NIF - using the extraordinary conditions it will produce to perform experiments in basic

  10. Production of Synthetic Nuclear Melt Glass.

    Science.gov (United States)

    Molgaard, Joshua J; Auxier, John D; Giminaro, Andrew V; Oldham, Colton J; Gill, Jonathan; Hall, Howard L

    2016-01-04

    Realistic surrogate nuclear debris is needed within the nuclear forensics community to test and validate post-detonation analysis techniques. Here we outline a novel process for producing bulk surface debris using a high temperature furnace. The material developed in this study is physically and chemically similar to trinitite (the melt glass produced by the first nuclear test). This synthetic nuclear melt glass is assumed to be similar to the vitrified material produced near the epicenter (ground zero) of any surface nuclear detonation in a desert environment. The process outlined here can be applied to produce other types of nuclear melt glass including that likely to be formed in an urban environment. This can be accomplished by simply modifying the precursor matrix to which this production process is applied. The melt glass produced in this study has been analyzed and compared to trinitite, revealing a comparable crystalline morphology, physical structure, void fraction, and chemical composition.

  11. Physics through the 1990s: Nuclear physics

    Science.gov (United States)

    1986-01-01

    The volume begins with a non-mathematical introduction to nuclear physics. A description of the major advances in the field follows, with chapters on nuclear structure and dynamics, fundamental forces in the nucleus, and nuclei under extreme conditions of temperature, density, and spin. Impacts of nuclear physics on astrophysics and the scientific and societal benefits of nuclear physics are then discussed. Another section deals with scientific frontiers, describing research into the realm of the quark-gluon plasma; the changing description of nuclear matter, specifically the use of the quark model; and the implications of the standard model and grand unified theories of elementary-particle physics; and finishes with recommendations and priorities for nuclear physics research facilities, instrumentation, accelerators, theory, education, and data bases. Appended are a list of national accelerator facilities, a list of reviewers, a bibliography, and a glossary.

  12. High temperature materials; Materiaux a hautes temperatures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... What are the limitations of Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is ... this time is PET/MRI. top of page What are some common uses of the procedure? Children's ( ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... previous nuclear medicine exam. top of page What are the limitations of Children's (Pediatric) Nuclear Medicine? Nuclear medicine procedures can be time consuming. It can take several hours to days ...

  15. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

  16. Nuclear Quadrupole Moments and Nuclear Shell Structure

    Science.gov (United States)

    Townes, C. H.; Foley, H. M.; Low, W.

    1950-06-23

    Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

  17. Communicating Certainty About Nuclear Winter

    Science.gov (United States)

    Robock, A.

    2013-12-01

    I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment

  18. Nuclear energy data 2010

    CERN Document Server

    2010-01-01

    This 2010 edition of Nuclear Energy Data , the OECD Nuclear Energy Agency's annual compilation of official statistics and country reports on nuclear energy, provides key information on plans for new nuclear plant construction, nuclear fuel cycle developments as well as current and projected nuclear generating capacity to 2035 in OECD member countries. This comprehensive overview provides authoritative information for policy makers, experts and other interested stakeholders.

  19. Nuclear Fuel Cycle & Vulnerabilities

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian D. [Los Alamos National Laboratory

    2012-06-18

    The objective of safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. The safeguards system should be designed to provide credible assurances that there has been no diversion of declared nuclear material and no undeclared nuclear material and activities.

  20. Nuclear weapons modernizations

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, Hans M. [Federation of American Scientists, Washington, DC (United States)

    2014-05-09

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludes that new limits on nuclear modernizations are needed.

  1. Nuclear energy data 2011

    CERN Document Server

    2011-01-01

     . Nuclear Energy Data, the OECD Nuclear Energy Agency's annual compilation of statistics and country reports on nuclear energy, contains official information provided by OECD member country governments on plans for new nuclear plant construction, nuclear fuel cycle developments as well as current and projected nuclear generating capacity to 2035. For the first time, it includes data for Chile, Estonia, Israel and Slovenia, which recently became OECD members. Key elements of this edition show a 2% increase in nuclear and total electricity production and a 0.5% increase in nuclear generating ca

  2. Nuclear magnetic ordering in silver

    Energy Technology Data Exchange (ETDEWEB)

    Lefmann, K.

    1995-12-01

    Nuclear antiferromagnetic ordering has been observed by neutron diffraction in a single crystal of {sup 109}Ag. The critical temperature is found to 700 pK, and the critical field is 100 {mu}T. From the paramagnetic phase a second order phase transition leads into a type-I 1-k structure with long range order. The experiments have taken place at the Hahn-Meitner Institut in Berlin in collaboration with the low Temperature Laboratory in Helsinki, the Niels Bohr Institute in Copenhagen, and Risoe National Laboratory, Roskilde. The present report is a Ph.D. thesis which has been successfully defended at the Niels Bohr Institute. Besides the results of the nuclear ordering experiments the thesis contains a description of the theoretical background for nuclear magnetism and a review of earlier nuclear ordering experiments as well as theoretical work. The principles for studying polarized nuclei with use of polarized and unpolarized neutrons are presented, as well as the results of such experiments. (au) 11 tabs., 59 ills., 143 refs.

  3. Heating device for nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shiratori, Yoshitake; Ijima, Takashi; Katano, Yoshiaki; Saito, Masaki

    1996-05-31

    The present invention provides a control system of a heating device which elevates the temperature of a reactor from a normal temperature to an operation temperature by using a nuclear heating. Namely, the device of the present invention comprises (1) means for detecting reactor temperature, (2) means for detecting reactor power, (3) means for memorizing the corresponding relation of each value of the means (1) and means (2) as standard data when temperature is elevated at a predetermined temperature elevation rate, (4) means for calculating the power corresponding to the current temperature based on the standard data upon elevation of the reactor temperature, and (5) means for controlling the progress or retraction of the power control material of the reactor core based on the power calculated by the means (4). With such a constitution, since the current reactor power elevation rate corresponding to the coolants is controlled based on the standard data upon actual start-up of the reactor, the control for the temperature of coolants can be facilitated. (I.S.)

  4. Gaseous fuel nuclear reactor research

    Science.gov (United States)

    Schwenk, F. C.; Thom, K.

    1975-01-01

    Gaseous-fuel nuclear reactors are described; their distinguishing feature is the use of fissile fuels in a gaseous or plasma state, thereby breaking the barrier of temperature imposed by solid-fuel elements. This property creates a reactor heat source that may be able to heat the propellant of a rocket engine to 10,000 or 20,000 K. At this temperature level, gas-core reactors would provide the breakthrough in propulsion needed to open the entire solar system to manned and unmanned spacecraft. The possibility of fuel recycling makes possible efficiencies of up to 65% and nuclear safety at reduced cost, as well as high-thrust propulsion capabilities with specific impulse up to 5000 sec.

  5. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  6. Nuclear fuel element

    Science.gov (United States)

    Zocher, Roy W.

    1991-01-01

    A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

  7. Uranium immobilization and nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, C.J.; Ogard, A.E.

    1982-02-01

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species.

  8. Energy from nuclear fission(*

    Directory of Open Access Journals (Sweden)

    Ripani M.

    2015-01-01

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

  9. [Chilean nuclear policy].

    Science.gov (United States)

    Bobadilla, E

    1996-06-01

    This official document is statement of the President of the Chilean Nuclear Energy Commission, Dr. Eduardo Bobadilla, about the nuclear policy of the Chilean State, Thanks to the international policy adopted by presidents Aylwin (1990-1994) and his successor Frei Ruiz Tagle (1994-), a nuclear development plan, protected by the Chilean entrance to the nuclear weapons non proliferation treaty and Tlatelolco Denuclearization treaty, has started. Chile will be able to develop without interference, an autonomous nuclear electrical system and other pacific uses of nuclear energy. Chile also supports a new international treaty to ban nuclear weapon tests.

  10. IAEA nuclear security program

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  11. Hot magnetized nuclear matter: Thermodynamic and saturation properties

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, Z. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Bordbar, G.H. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM)-Maragha, Maragha (Iran, Islamic Republic of)

    2017-03-15

    We have used a realistic nuclear potential, AV{sub 18}, and a many-body technique, the lowest-order constraint variational (LOCV) approach, to calculate the properties of hot magnetized nuclear matter. By investigating the free energy, spin polarization parameter, and symmetry energy, we have studied the temperature and magnetic field dependence of the saturation properties of magnetized nuclear matter. In addition, we have calculated the equation of state of magnetized nuclear matter at different temperatures and magnetic fields. It was found that the flashing temperature of nuclear matter decreases by increasing the magnetic field. In addition, we have studied the effect of the magnetic field on liquid gas phase transition of nuclear matter. The liquid gas coexistence curves, the order parameter of the liquid gas phase transition, and the properties of critical point at different magnetic fields have been calculated. (orig.)

  12. Nuclear energy data 2005

    CERN Document Server

    Publishing, OECD

    2005-01-01

    This 2005 edition of Nuclear Energy Data, the OECD Nuclear Energy Agency's annual compilation of essential statistics on nuclear energy in OECD countries, offers a projection horizon lengthened to 2025 for the first time.  It presents the reader with a comprehensive overview on the status and trends in nuclear electricity generation in OECD countries and in the various sectors of the nuclear fuel cycle.

  13. The environmental effects of nuclear war

    Energy Technology Data Exchange (ETDEWEB)

    MacCracken, M.C.

    1988-09-01

    Substantial environmental disruption will significantly add to the disastrous consequences caused by the direct thermal, blast, and radiological effects brought on by a major nuclear war. Local fallout could cover several percent of the Northern Hemisphere with potentially lethal doses. Smoke from post-nuclear fires could darken the skies and induce temperature decreases of tens of degrees in continental interiors. Stratospheric ozone could be significantly reduced due to nitric oxide injections and smoke-induced circulation changes. The environmental effects spread the consequences of a nuclear war to the world population, adding to the potentially large disruptive effects a further reason to avoid such a catastrophe. 27 refs., 4 figs.

  14. Space nuclear power system studies in France

    Science.gov (United States)

    Carre, F.; Delaplace, J.; Proust, E.; Tilliette, Z.

    A program is described to investigate the feasibility, development, cost, and lead time of 20-200-kWe space nuclear power system adapted to powering different space missions as space-based radar for earth observation, LEO-GEO orbit-transfer vehicle and space transportation systems using electrical propulsion (200-400 kWe). Several concepts of nuclear power systems are studied including: a 200 kWe power system operating at very high temperatures and needing a long development program; and a 20 kWe power system using available technologies developed for terrestrial nuclear reactors achievable in 10-12 years.

  15. Non-equilibrium radiation nuclear reactor

    Science.gov (United States)

    Thom, K.; Schneider, R. T. (Inventor)

    1978-01-01

    An externally moderated thermal nuclear reactor is disclosed which is designed to provide output power in the form of electromagnetic radiation. The reactor is a gaseous fueled nuclear cavity reactor device which can operate over wide ranges of temperature and pressure, and which includes the capability of processing and recycling waste products such as long-lived transuranium actinides. The primary output of the device may be in the form of coherent radiation, so that the reactor may be utilized as a self-critical nuclear pumped laser.

  16. Advances in nuclear science and technology

    CERN Document Server

    Henley, Ernest J

    1970-01-01

    Advances in Nuclear Science and Technology, Volume 5 presents the underlying principles and theory, as well as the practical applications of the advances in the nuclear field. This book reviews the specialized applications to such fields as space propulsion.Organized into six chapters, this volume begins with an overview of the design and objective of the Fast Flux Test Facility to provide fast flux irradiation testing facilities. This text then examines the problem in the design of nuclear reactors, which is the analysis of the spatial and temporal behavior of the neutron and temperature dist

  17. Symmetry energy of warm nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, B.K.; De, J.N.; Samaddar, S.K. [Saha Institute of Nuclear Physics, Kolkata (India); Centelles, M.; Vinas, X. [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, and Institut de Ciencies del Cosmos, Barcelona (Spain)

    2014-02-15

    The temperature dependence of the symmetry energy and symmetry free energy coefficients of infinite nuclear matter and of finite nuclei is investigated. For infinite matter, both these coefficients are found to have a weaker dependence on temperature at densities close to saturation; at low but homogeneous densities, the temperature dependence becomes stronger. For finite systems, different definitions of symmetry energy coefficients are encountered in the literature yielding different values. A resolution to this problem is suggested from a global liquid-drop-inspired fit of the energies and free energies of a host of nuclei covering the entire periodic table. The hot nucleus is modeled in a subtracted finite-temperature Thomas-Fermi framework, with dynamical surface phonon coupling to nucleonic motion plugged in. Contrary to infinite nuclear matter, a substantial change in the symmetry energy coefficients is observed for finite nuclei with temperature. (orig.)

  18. Temperature variation on the Mediterranean Sea by the exploitation of the Vandellos II Nuclear Power Plant; Variacion de temperatura en el mar mediterraneo por la explotacion de la C.N. de Vandellos II

    Energy Technology Data Exchange (ETDEWEB)

    Villarreal Romero, M.; Ribes Hernandez, G.; Esparza Martin, J. L.

    2010-07-01

    The aim of this study is to verify the compliance with the Resolution of 7th February MAH/285/2007 Departament de Medi Ambient I Habitatge de la Generalitat de Catalunya establishing discharges limits to the Mediterranean Sea and, in particular, the section that references the thermal rise. The study area include about 1.5 km coastline, which is located in the vicinity of the Vandellos II Nuclear Power Plant.

  19. Technology Roadmaps: Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This nuclear energy roadmap has been prepared jointly by the IEA and the OECD Nuclear Energy Agency (NEA). Unlike most other low-carbon energy sources, nuclear energy is a mature technology that has been in use for more than 50 years. The latest designs for nuclear power plants build on this experience to offer enhanced safety and performance, and are ready for wider deployment over the next few years. Several countries are reactivating dormant nuclear programmes, while others are considering nuclear for the first time. China in particular is already embarking on a rapid nuclear expansion. In the longer term, there is great potential for new developments in nuclear energy technology to enhance nuclear's role in a sustainable energy future.

  20. Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters

    Energy Technology Data Exchange (ETDEWEB)

    Robert J. Goldston

    2010-03-03

    Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ~30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64oC long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.

  1. Nuclear Winter: Global Consequences of Multiple Nuclear Explosions

    Science.gov (United States)

    Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, Carl

    1983-12-01

    The potential global atmospheric and climatic consequences of nuclear war are investigated using models previously developed to study the effects of volcanic eruptions. Although the results are necessarily imprecise, due to a wide range of possible scenarios and uncertainty in physical parameters, the most probable first-order effects are serious. Significant hemispherical attenuation of the solar radiation flux and subfreezing land temperatures may be caused by fine dust raised in high-yield nuclear surface bursts and by smoke from city and forest fires ignited by airbursts of all yields. For many simulated exchanges of several thousand megatons, in which dust and smoke are generated and encircle the earth within 1 to 2 weeks, average light levels can be reduced to a few percent of ambient and land temperatures can reach -15 degrees to -25 degrees C. The yield threshold for major optical and climatic consequences may be very low: only about 100 megatons detonated over major urban centers can create average hemispheric smoke optical depths greater than 2 for weeks and, even in summer, subfreezing land temperatures for months. In a 5000-megaton war, at northern mid-latitude sites remote from targets, radioactive fallout on time scales of days to weeks can lead to chronic mean doses of up to 50 rads from external whole-body gamma-ray exposure, with a likely equal or greater internal dose from biologically active radionuclides. Large horizontal and vertical temperature gradients caused by absorption of sunlight in smoke and dust clouds may greatly accelerate transport of particles and radioactivity from the Northern Hemisphere to the Southern Hemisphere. When combined with the prompt destruction from nuclear blast, fires, and fallout and the later enhancement of solar ultraviolet radiation due to ozone depletion, long-term exposure to cold, dark, and radioactivity could pose a serious threat to human survivors and to other species.

  2. Nuclear and radiochemistry

    CERN Document Server

    Konya, Jozsef

    2012-01-01

    The field of nuclear and radiochemistry is wide-reaching, with results having functions and use across a variety of disciplines. Drawing on 40 years of experience in teaching and research, this concise book explains the basic principles and applications of the primary areas of nuclear and radiochemistry. Separate chapters cover each main area of recent radiochemistry. This includes nuclear medicine and chemical aspects of nuclear power plants, namely the problems of nuclear wastes and nuclear analysis (both bulk and surface analysis), with the analytical methods based on the interactions of

  3. Nuclear Science References Database

    Science.gov (United States)

    Pritychenko, B.; Běták, E.; Singh, B.; Totans, J.

    2014-06-01

    The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center http://www.nndc.bnl.gov/nsr.

  4. Once more about cold nuclear fusion

    Science.gov (United States)

    Brudanin, V. B.; Bystritsky, V. M.; Egorov, V. G.; Shamsutdinov, S. G.; Shyshkin, A. L.; Stolupin, V. A.; Yutlandov, I. A.

    1990-06-01

    Results of the experiments on the search for cold nuclear d-d fusion in chemically pure titanium are given both for electrolysis of heavy water D 2O and for titanium saturation with deuterium gas. The saturation took place at a temperature of 77 K and pressures of 50 and 150 atm. A series of experiments with temperature varying from 1 to 600 atm was carried out. The limiting values of the partial rate of the nuclear reaction of d-d fusion with neutron production were obtained per deuteron pair (at 95% confidence level): λf⩽8×10 -27s-1 (experiment with deuterium gas).

  5. Nuclear Security for Floating Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Skiba, James M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scherer, Carolynn P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-13

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  6. Multimegawatt nuclear power systems for nuclear electric propulsion

    Science.gov (United States)

    George, Jeffrey A.

    1991-01-01

    Results from systems analysis studies of multimegawatt nuclear power systems are presented for application to nuclear electric propulsion. Specific mass estimates are presented for nearer term SP-100 reactor-based potassium Rankine and Brayton power systems for piloted and cargo missions. Growth SP-100/Rankine systems were found to range from roughly 7 to 10 kg/kWe specific mass depending on full power life requirements. The SP-100/Rankine systems were also found to result in a 4-kg/kWe savings in specific mass over SP-100/Brayton systems. The potential of advanced, higher temperature reactor and power conversion technologies for achieving reduced mass Rankine and Brayton systems was also investigated. A target goal of 5 kg/kWe specific mass was deemed reasonable given either 1400 K potassium Rankine with 1500 K lithium-cooled reactors or 2000 K gas cooled reactors with Brayton conversion.

  7. Nuclear energy and process heating

    Energy Technology Data Exchange (ETDEWEB)

    Kozier, K.S

    1999-10-01

    Nuclear energy generated in fission reactors is a versatile commodity that can, in principle, satisfy any and all of mankind's energy needs through direct or indirect means. In addition to its dominant current use for electricity generation and, to a lesser degree, marine propulsion, nuclear energy can and has been used for process heat applications, such as space heating, industrial process heating and seawater desalination. Moreover, a wide variety of reactor designs has been employed to this end in a range of countries. From this spectrum of experience, two design approaches emerge for nuclear process heating (NPH): extracting a portion of the thermal energy from a nuclear power plant (NPP) (i.e., creating a combined heat and power, or CHP, plant) and transporting it to the user, or deploying dedicated nuclear heating plants (NHPs) in generally closer proximity to the thermal load. While the former approach is the basis for much of the current NPH experience, considerable recent interest exists for the latter, typically involving small, innovative reactor plants with enhanced and passive safety features. The high emphasis on inherent nuclear safety characteristics in these reactor designs reflects the need to avoid any requirement for evacuation of the public in the event of an accident, and the desire for sustained operation and investment protection at minimum cost. Since roughly 67% of mankind's primary energy usage is not in the form of electricity, a vast potential market for NPH systems exists, particularly at the low-to-moderate end-use temperatures required for residential space heating and several industrial applications. Although only About 0.5% of global nuclear energy production is presently used for NPH applications, an expanded role in the 21st century seems inevitable, in part, as a measure to reduce greenhouse gas emissions and improve air quality. While the technical aspects of many NPH applications are considered to be well proven, a

  8. Exotic States of Nuclear Matter

    Science.gov (United States)

    Lombardo, Umberto; Baldo, Marcello; Burgio, Fiorella; Schulze, Hans-Josef

    2008-02-01

    ência et al. Quartetting in nuclear matter and [symbol] particle condensation in nuclear systems / G. Röpke & P. Schuck et al. -- pt. C. Neutron star structure and dynamics. Shear viscosity of neutron matter from realistic nuclear interactions / O. Benhar & M. Valli. Protoneutron star dynamo: theory and observations / A. Bonanno & V. Urpin. Magnetic field dissipation in neutron stars: from magnetars to isolated neutron stars / J. A. Pons. Gravitational radiation and equations of state in super-dense cores of core-collapse supernovae / K. Kotake. Joule heating in the cooling of magnetized neutron stars / D. N. Aguilera, J. A. Pons & J. A. Miralles. Exotic fermi surface of dense neutron matter / M. V. Zverev, V. A. Khodel & J. W. Clark. Coupling of nuclear and electron modes in relativistic stellar matter / A. M. S. Santos et al. Neutron stars in the relativistic Hartree-Fock theory and hadron-quark phase transition / B. Y. Sun ... [et al.] -- pt. D. Prospects of present and future observations. Measurements of neutron star masses / D. G. Yakovlev. Dense nuclear matter: constraints from neutron stars / J. M. Lattimer. Neutron star versus heavy-ion data: is the nuclear equation of state hard or soft? / J. Schaffner-Bielich ... [et al.]. Surface emission from x-ray dim isolated neutron stars / R. Turolla. High energy neutrino astronomy / E. Migneco. What gravitational waves say about the inner structure of neutron stars / V. Ferrari. Reconciling 2 M[symbol] pulsars and SN1987A: two branches of neutron stars / P. Haensel, M. Bejger & J. L. Zdunik. EOS of dense matter and fast rotation of neutron stars / J. L. Zdunik ... [et al.] -- pt. E. Quark and strange matter in neutron stars. Bulk viscosity of color-superconducting quark matter / M. Alford. Chiral symmetry restoration and quark deconfinement at large densities and temperature / A. Drago, L. Bonanno & A. Lavagno. Color superconducting quark matter in compact stars / D. B. Blaschke, T. Klähn & F. Sandin. Thermal

  9. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... child is taking as well as vitamins and herbal supplements and if he or she has any ... What are the limitations of Children's (Pediatric) Nuclear Medicine? Nuclear medicine procedures can be time consuming. It ...

  10. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... MRI. top of page What are some common uses of the procedure? Children's (pediatric) nuclear medicine imaging ... at birth) or that develop during childhood. Physicians use nuclear medicine imaging to evaluate organ systems, including ...

  11. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential to ... otherwise, your child may resume his/her normal activities after the nuclear medicine scan. If the child ...

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page How does the nuclear medicine procedure work? With ordinary x-ray examinations, an image is ... until the nuclear physician checks the images in case additional images are needed. top of page What ...

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... bones. liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. Nuclear medicine scans are typically used to ... A radiologist or other physician who has specialized training in nuclear medicine will interpret the images and ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. Nuclear medicine scans are typically used to help ... children. epilepsy . location, anatomy and function of the thyroid gland. top of page How does the nuclear ...

  15. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... function of the thyroid gland. top of page How does the nuclear medicine procedure work? With ordinary ... area of your child's body. top of page How is the procedure performed? Nuclear medicine imaging is ...

  16. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... usually mild. Nevertheless, you should inform the nuclear medicine personnel of any allergies your child may have or other problems that may have occurred during a previous nuclear ...

  17. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential ... or imaging device that produces pictures and provides molecular information. In many centers, nuclear medicine images can ...

  18. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page How does the nuclear medicine procedure work? With ordinary x-ray examinations, an image is ... with other imaging techniques, such as CT or MRI. However, nuclear medicine scans are more sensitive than ...

  19. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Tell your doctor about your child’s recent illnesses, medical conditions, medications and allergies. Depending on the type ... Nuclear Medicine? Nuclear medicine is a branch of medical imaging that uses small amounts of radioactive material ...

  20. Triangle Universities Nuclear Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This report contains brief papers that discusses the following topics: Fundamental Symmetries in the Nucleus; Internucleon Interactions; Dynamics of Very Light Nuclei; Facets of the Nuclear Many-Body Problem; and Nuclear Instruments and Methods.

  1. Nuclear disarmament verification

    Energy Technology Data Exchange (ETDEWEB)

    DeVolpi, A.

    1993-12-31

    Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification.

  2. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? Children's (pediatric) nuclear medicine imaging is performed ... the thyroid gland. top of page How does the nuclear medicine procedure work? With ordinary x-ray ...

  3. RBC nuclear scan

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  4. Nuclear fear revisited

    Science.gov (United States)

    Crease, Robert P.

    2010-10-01

    In 1988 the science historian Spencer Weart published a groundbreaking book called Nuclear Fear: A History of Images, which examined visions of radiation damage and nuclear disaster in newspapers, television, film, literature, advertisements and popular culture.

  5. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... body. jaundice in newborns and older children. epilepsy . location, anatomy and function of the thyroid gland. top ... Epilepsy Images related to Children's (Pediatric) Nuclear Medicine Videos related to Children's (Pediatric) Nuclear Medicine Sponsored by ...

  6. Guidebook to nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Nero, A.V. Jr.

    1976-05-01

    A general introduction to reactor physics and theory is followed by descriptions of commercial nuclear reactor types. Future directions for nuclear power are also discussed. The technical level of the material is suitable for laymen.

  7. JPRS Report, Nuclear Developments

    Science.gov (United States)

    1988-06-03

    Nuclear Power Station Projected for Jorf Lasfar [Casablanca LA VIE ECONOMIQUE , 18 Mar 88] 26 WEST EUROPE IRELAND Energy Minister Fights UK...factors mili- tate against further expansion. MOROCCO Nuclear Power Station Projected for Jorf Lasfar 51004603 Casablanca LA VIE ECONOMIQUE in...body to oversee nuclear activities at the national level and to hire and train personnel in nuclear sciences and techniques. A bill relating to the

  8. NUCLEAR REACTOR CONTROL SYSTEM

    Science.gov (United States)

    Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

    1959-11-01

    A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

  9. Effects of Nuclear Weapons.

    Science.gov (United States)

    Sartori, Leo

    1983-01-01

    Fundamental principles governing nuclear explosions and their effects are discussed, including three components of a nuclear explosion (thermal radiation, shock wave, nuclear radiation). Describes how effects of these components depend on the weapon's yield, its height of burst, and distance of detonation point. Includes effects of three…

  10. Workflow in nuclear medicine.

    Science.gov (United States)

    Laet, G D; Naudts, J; Vandevivere, J

    2001-01-01

    This paper discusses a workflow management system for nuclear medicine. It augments the more conventional PACS with automatic transfer of studies along the chain of activities making up an examination in nuclear medicine. A prototype system has been designed, built, and installed in a department of nuclear medicine, active in a network of hospitals.

  11. Nuclear energy technology

    Science.gov (United States)

    Buden, David

    1992-01-01

    An overview of space nuclear energy technologies is presented. The development and characteristics of radioisotope thermoelectric generators (RTG's) and space nuclear power reactors are discussed. In addition, the policy and issues related to public safety and the use of nuclear power sources in space are addressed.

  12. Nuclear fact book

    Energy Technology Data Exchange (ETDEWEB)

    Hill, O. F.; Platt, A. M.; Robinson, J. V. [comps

    1983-05-01

    This reference provides significant highlights and summary facts in the following areas: general energy; nuclear energy; nuclear fuel cycle; uranium supply and enrichment; nuclear reactors; spent fuel and advanced repacking concepts; reprocessing; high-level waste; gaseous waste; transuranic waste; low-level waste; remedial action; transportation; disposal; radiation information; environment; legislation; socio-political aspects; conversion factors; and a glossary. (GHT)

  13. Basic Nuclear Physics.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    Basic concepts of nuclear structures, radiation, nuclear reactions, and health physics are presented in this text, prepared for naval officers. Applications to the area of nuclear power are described in connection with pressurized water reactors, experimental boiling water reactors, homogeneous reactor experiments, and experimental breeder…

  14. Nuclear Binding Near a Quantum Phase Transition.

    Science.gov (United States)

    Elhatisari, Serdar; Li, Ning; Rokash, Alexander; Alarcón, Jose Manuel; Du, Dechuan; Klein, Nico; Lu, Bing-Nan; Meißner, Ulf-G; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Lee, Dean; Rupak, Gautam

    2016-09-23

    How do protons and neutrons bind to form nuclei? This is the central question of ab initio nuclear structure theory. While the answer may seem as simple as the fact that nuclear forces are attractive, the full story is more complex and interesting. In this work we present numerical evidence from ab initio lattice simulations showing that nature is near a quantum phase transition, a zero-temperature transition driven by quantum fluctuations. Using lattice effective field theory, we perform Monte Carlo simulations for systems with up to twenty nucleons. For even and equal numbers of protons and neutrons, we discover a first-order transition at zero temperature from a Bose-condensed gas of alpha particles (^{4}He nuclei) to a nuclear liquid. Whether one has an alpha-particle gas or nuclear liquid is determined by the strength of the alpha-alpha interactions, and we show that the alpha-alpha interactions depend on the strength and locality of the nucleon-nucleon interactions. This insight should be useful in improving calculations of nuclear structure and important astrophysical reactions involving alpha capture on nuclei. Our findings also provide a tool to probe the structure of alpha cluster states such as the Hoyle state responsible for the production of carbon in red giant stars and point to a connection between nuclear states and the universal physics of bosons at large scattering length.

  15. Lightweight, High-Temperature Radiator Panels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high-temperature radiators are needed for future, high-efficiency power conversion systems for Nuclear Electric Propulsion (NEP). Creare has developed...

  16. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  17. Nuclear energy; Le nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This digest document was written by members of the union of associations of ex-members and retired people of the Areva group (UARGA). It gives a comprehensive overview of the nuclear industry world, starting from radioactivity and its applications, and going on with the fuel cycle (front-end, back-end, fuel reprocessing, transports), the nuclear reactors (PWR, BWR, Candu, HTR, generation 4 systems), the effluents from nuclear facilities, the nuclear wastes (processing, disposal), and the management and safety of nuclear activities. (J.S.)

  18. Nuclear parton distributions

    Directory of Open Access Journals (Sweden)

    Kulagin S. A.

    2017-01-01

    Full Text Available We review a microscopic model of the nuclear parton distribution functions, which accounts for a number of nuclear effects including Fermi motion and nuclear binding, nuclear meson-exchange currents, off-shell corrections to bound nucleon distributions and nuclear shadowing. We also discuss applications of this model to a number of processes including lepton-nucleus deep inelastic scattering, proton-nucleus Drell-Yan lepton pair production at Fermilab, as well as W± and Z0 boson production in proton-lead collisions at the LHC.

  19. History of Nuclear India

    Science.gov (United States)

    Chaturvedi, Ram

    2000-04-01

    India emerged as a free and democratic country in 1947, and entered into the nuclear age in 1948 by establishing the Atomic Energy Commission (AEC), with Homi Bhabha as the chairman. Later on the Department of Atomic Energy (DAE) was created under the Office of the Prime Minister Jawahar Lal Nehru. Initially the AEC and DAE received international cooperation, and by 1963 India had two research reactors and four nuclear power reactors. In spite of the humiliating defeat in the border war by China in 1962 and China's nuclear testing in 1964, India continued to adhere to the peaceful uses of nuclear energy. On May 18, 1974 India performed a 15 kt Peaceful Nuclear Explosion (PNE). The western powers considered it nuclear weapons proliferation and cut off all financial and technical help, even for the production of nuclear power. However, India used existing infrastructure to build nuclear power reactors and exploded both fission and fusion devices on May 11 and 13, 1998. The international community viewed the later activity as a serious road block for the Non-Proliferation Treaty and the Comprehensive Test Ban Treaty; both deemed essential to stop the spread of nuclear weapons. India considers these treaties favoring nuclear states and is prepared to sign if genuine nuclear disarmament is included as an integral part of these treaties.

  20. Sustainable nuclear energy dilemma

    Directory of Open Access Journals (Sweden)

    Afgan Naim H.

    2013-01-01

    Full Text Available Sustainable energy development implies the need for the emerging potential energy sources which are not producing adverse effect to the environment. In this respect nuclear energy has gained the complimentary favor to be considered as the potential energy source without degradation of the environment. The sustainability evaluation of the nuclear energy systems has required the special attention to the criteria for the assessment of nuclear energy system before we can make firm justification of the sustainability of nuclear energy systems. In order to demonstrate the sustainability assessment of nuclear energy system this exercise has been devoted to the potential options of nuclear energy development, namely: short term option, medium term option, long term option and classical thermal system option. Criteria with following indicators are introduced in this analysis: nuclear indicator, economic indicator, environment indicator, social indicator... The Sustainability Index is used as the merit for the priority assessment among options under consideration.

  1. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H.B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  2. Advanced nuclear precleaner

    Energy Technology Data Exchange (ETDEWEB)

    Wright, S.R. [InnovaTech, Inc., Durham, NC (United States)

    1997-10-01

    This Phase II Small Business Innovation Research (SBIR) program`s goal is to develop a dynamic, self-cleaning air precleaner for high-efficiency particulate air (HEPA) filtration systems that would extend significantly the life of HEPA filter banks by reducing the particulate matter that causes filter fouling and increased pack pressure. HEPA filters are widely used in DOE, Department of Defense, and a variety of commercial facilities. InnovaTech, Inc. (Formerly Micro Composite materials Corporation) has developed a proprietary dynamic separation device using a concept called Boundary Layer Momentum Transfer (BLMT) to extract particulate matter from fluid process streams. When used as a prefilter in the HVAC systems or downstream of waste vitrifiers in nuclear power plants, fuel processing facilities, and weapons decommissioning factories, the BLMT filter will dramatically extend the service life and increase the operation efficiency of existing HEPA filtration systems. The BLMT filter is self cleaning, so there will be no degraded flow or increased pressure drop. Because the BLMT filtration process is independent of temperature, it can be designed to work in ambient, medium, or high-temperature applications. During Phase II, the authors are continuing development of the computerized flow simulation model to include turbulence and incorporate expansion into a three-dimensional model that includes airflow behavior inside the filter housing before entering the active BLMT device. A full-scale (1000 ACFM) prototype filter is being designed to meet existing HEPA filter standards and will be fabricated for subsequent testing. Extensive in-house testing will be performed to determine a full range of performance characteristics. Final testing and evaluation of the prototype filter will be conducted at a DOE Quality Assurance Filter Test Station.

  3. Nuclear physics from strong coupling QCD

    CERN Document Server

    Fromm, Michael

    2009-01-01

    The strong coupling limit (beta_gauge = 0) of QCD offers a number of remarkable research possibilities, of course at the price of large lattice artifacts. Here, we determine the complete phase diagram as a function of temperature T and baryon chemical potential mu_B, for one flavor of staggered fermions in the chiral limit, with emphasis on the determination of a tricritical point and on the T ~ 0 transition to nuclear matter. The latter is known to happen for mu_B substantially below the baryon mass, indicating strong nuclear interactions in QCD at infinite gauge coupling. This leads us to studying the properties of nuclear matter from first principles. We determine the nucleon-nucleon potential in the strong coupling limit, as well as masses m_A of nuclei as a function of their atomic number A. Finally, we clarify the origin of nuclear interactions at strong coupling, which turns out to be a steric effect.

  4. Underground nuclear astrophysics: why and how

    CERN Document Server

    Best, A; Fülöp, Zs; Gyürky, Gy; Laubenstein, M; Napolitani, E; Rigato, V; Roca, V; Szücs, T

    2016-01-01

    The goal of nuclear astrophysics is to measure cross sections of nuclear physics reactions of interest in astrophysics. At stars temperatures, these cross sections are very low due to the suppression of the Coulomb barrier. Cosmic ray induced background can seriously limit the determination of reaction cross sections at energies relevant to astrophysical processes and experimental setups should be arranged in order to improve the signal-to-noise ratio. Placing experiments in underground sites, however, reduces this background opening the way towards ultra low cross section determination. LUNA (Laboratory for Underground Nuclear Astrophysics) was pioneer in this sense. Two accelerators were mounted at the INFN National Laboratories of Gran Sasso (LNGS) allowing to study nuclear reactions close to stellar energies. A summary of the relevant technology used, including accelerators, target production and characterisation, and background treatment is given.

  5. Modelling property changes in graphite irradiated at changing irradiation temperature

    CSIR Research Space (South Africa)

    Kok, S

    2011-01-01

    Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

  6. Concept of an Accelerator-Driven Advanced Nuclear Energy System

    Directory of Open Access Journals (Sweden)

    Xuesong Yan

    2017-07-01

    Full Text Available The utilization of clean energy is a matter of primary importance for sustainable development as well as a vital approach for solving worldwide energy-related issues. If the low utilization rate of nuclear fuel, nuclear proliferation, and insufficient nuclear safety can be solved, nuclear fission energy could be used as a sustainable and low-carbon clean energy form for thousands of years, providing steady and base-load electrical resources. To address these challenges, we propose an accelerator-driven advanced nuclear energy system (ADANES, consisting of a burner system and a fuel recycle system. In ADANES, the ideal utilization rate of nuclear fuel will be >95%, and the final disposal of nuclear waste will be minimized. The design of a high-temperature ceramic reactor makes the burner system safer. Part of fission products (FPs are removed during the simple reprocessing in the fuel recycle system, significantly reducing the risks of nuclear proliferation of nuclear technology and materials. The ADANES concept integrates nuclear waste transmutation, nuclear fuel breeding, and safety power production, with an ideal closed loop operation of nuclear fission energy, constituting a major innovation of great potential interest for future energy applications.

  7. The prospective environmental impacts of Iran nuclear energy expansion

    Energy Technology Data Exchange (ETDEWEB)

    Beheshti, Hamed, E-mail: Beheshti@zedat.fu-berlin.de [Renewable Energy Policy Planning, Freie Universitaet Berlin BC CARE, Berlin Center for Caspian Region Energy and Environment Studies, Ihnestrasse 22, 14195 Berlin (Germany)

    2011-10-15

    Nuclear energy has direct impacts on the environment. Uranium mining, milling, and enrichment affect the livelihoods around and stress on the water resources. In addition, nuclear power plants consume huge amount of water and elevate the water temperature of the ambient water resources. The Iranian nuclear program has pledged for 20,000 MW of nuclear energy by 2025. The fulfillment of such ambitious target stresses the environment and increases the environmental degradation cost of the country. Iran central semi-arid area and the Persian Gulf are the major regions with high risk of impacts from the current nuclear program. - Highlights: > Fragile ecosystem of the Persian Gulf would not tolerate the ambitious nuclear programs of its coastal countries. > Water resources in Iran inland area are depleting fast due to the unsustainable development on the past. > Iranian nuclear program is going to put an additional serious stress on the water resources of the country.

  8. Global warming and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Wood, L., LLNL

    1998-07-10

    Nuclear fission power reactors represent a potential solution to many aspects of global change possibly induced by inputting of either particulate or carbon or sulfur oxides into the Earth`s atmosphere. Of proven technological feasibility, they presently produce high-grade heat for large-scale electricity generation, space heating and industrial process-energizing around the world, without emitting greenhouse gases or atmospheric particulates; importantly, electricity production costs from the best nuclear plants presently are closely comparable with those of the best fossil-fired plants. However, a substantial number of issues currently stand between nuclear power and widespread substitution for large stationary fossil fuel-fired systems. These include perceptual ones regarding both long-term and acute operational safety, plant decommissioning, fuel reprocessing, radwaste disposal, fissile materials diversion to military purposes and - perhaps most seriously- readily quantifiable concerns regarding long-term fuel supply and total unit electrical energy cost. We sketch a road-map for proceeding from the present situation toward a nuclear power-intensive world, addressing along the way each of the concerns which presently impede widespread nuclear substitution for fossil fuels, particularly for coal in the most populous and rapidly developing portions of the world, e.g., China and India. This `design to societal specifications` approach to large-scale nuclear fission power systems may lead to energy sources meeting essentially all stationary demands for high-temperature heat. Such advanced options offer a human population of ten billion the electricity supply levels currently enjoyed by Americans for 10,000 years. Nuclear power systems tailored to local needs-and-interests and having a common advanced technology base could reduce present-day world-wide C0{sub 2} emissions by two-fold, if universally employed. By application to small mobile demands, a second two

  9. Quantum fluctuation effects on nuclear fragment and atomic cluster formation

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Akira [Hokkaido Univ., Sapporo (Japan). Dept. of Physics; Randrup, J.

    1997-05-01

    We investigate the nuclear fragmentation and atomic cluster formation by means of the recently proposed quantal Langevin treatment. It is shown that the effect of the quantal fluctuation is in the opposite direction in nuclear fragment and atomic cluster size distribution. This tendency is understood through the effective classical temperature for the observables. (author)

  10. From chemical mapping to pressure temperature deformation micro-cartography: mineralogical evolution and mass transport in thermo-mechanic disequilibrium systems: application to meta-pelites and confinement nuclear waste materials; De l'imagerie chimique a la micro-cartographie Pression-Temperature-Deformation: evolution mineralogique et transport de matiere dans des systemes en desequilibre thermomecanique. Applications aux metapelites et aux materiaux de stockage de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, V. de

    2006-03-15

    The mineralogical composition of metamorphic rocks or industrial materials evolves when they are submitted to thermomechanical disequilibria, i.e. a spatial or temporal pressure and temperature evolution, or chemical disequilibria as variations in redox conditions, pH... For example, during low temperature metamorphic processes, rocks re-equilibrate only partially, and thus record locally thermodynamic equilibria increasing so the spatial chemical heterogeneities. Understanding the P-T evolution of such systems and deciphering modalities of their mineralogical transformation imply to recognize and characterize the size of these local 'paleo-equilibria', and so to have a spatial chemical information at least in 2 dimensions. In order to get this information, microprobe X-ray fluorescence maps have been used. Computer codes have been developed with Matlab to quantify these maps in view of thermo-barometric estimations. In this way, P-T maps of mineral crystallisation were produced using the multi-equilibria thermodynamic technique. Applications on two meta-pelites from the Sambagawa blue-schist belt (Japan) and from the Caledonian eclogitic zone in Spitsbergen, show that quantitative chemical maps are a powerful tool to retrieve the metamorphic history of rocks. From these chemical maps have been derived maps of P-T-time-redox-deformation that allow to characterize P-T conditions of minerals formation, and so, the P-T path of the sample, the oxidation state of iron in the chlorite phase. As a result, we underline the relation between deformation and crystallisation, and propose a relative chronology of minerals crystallisation and deformations. The Fe{sup 3+} content map in chlorite calculated by thermodynamic has also been validated by a {mu}-XANES mapping at the iron K-edge measured at the ESRF (ID24) using an innovative method. Another application relates to an experimental study of clay materials, main components of an analogical model of a nuclear

  11. Studies of Fourteen Nuclear-Powered Airplanes

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, J. N.; McCulloch, J. C.; Schmill, W. C.; Ward, W. H.

    1952-09-01

    A representative series of aircraft which could be powered by a relatively low-temperature liquid-coolant-cycle nuclear power plant are described. Present aircraft such as the B-36, B-52, and B-47 bombers as well as new designs were investigated. Design and performance characteristics of all the aircraft are presented.

  12. Fuel Temperature Coefficient of Reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Loewe, W.E.

    2001-07-31

    A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.

  13. Nuclear energy - some aspects; Energia nuclear - alguns aspectos

    Energy Technology Data Exchange (ETDEWEB)

    Bandeira, Fausto de Paula Menezes

    2005-05-15

    This work presents a brief history of research and development concerning to nuclear technology worldwide and in Brazil, also information about radiations and radioactive elements as well; the nuclear technology applications; nuclear reactor types and functioning of thermonuclear power plants; the number of existing nuclear power plants; the nuclear hazards occurred; the national fiscalization of nuclear sector; the Brazilian legislation in effect and the propositions under proceduring at House of Representatives related to the nuclear energy.

  14. Nuclear power industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-28

    This press dossier presented in Shanghai (China) in April 1999, describes first the activities of the Framatome group in the people`s republic of China with a short presentation of the Daya Bay power plant and of the future Ling Ao project, and with a description of the technological cooperation with China in the nuclear domain (technology transfers, nuclear fuels) and in other industrial domains (mechanics, oil and gas, connectors, food and agriculture, paper industry etc..). The general activities of the Framatome group in the domain of energy (nuclear realizations in France, EPR project, export activities, nuclear services, nuclear fuels, nuclear equipments, industrial equipments) and of connectors engineering are presented in a second and third part with the 1998 performances. (J.S.)

  15. Nuclear Threats and Security

    Directory of Open Access Journals (Sweden)

    Garry Jacobs

    2012-10-01

    Full Text Available This article presents highlights and insights from the International Conference on “Nuclear Threats and Security” organized by the World Academy of Art and Science in association with the European Leadership Network and the Dag Hammarskjöld University College of International Relations and Diplomacy and sponsored by NATO at the Inter-University Centre, Dubrovnik on September 14-16, 2012. The conference examined important issues related to nuclear non-proliferation and disarmament, the legality of nuclear weapons and their use, illicit trade in nuclear materials, the dangers of nuclear terrorism, nuclear- and cyber-security. Papers and video recordings of the major presentations and session summaries can be found here.

  16. Nuclear Science References Database

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko, B., E-mail: pritychenko@bnl.gov [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Běták, E. [Institute of Physics, Slovak Academy of Sciences, 84511 Bratislava (Slovakia); Singh, B. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1 (Canada); Totans, J. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2014-06-15

    The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center (http://www.nndc.bnl.gov/nsr) and the International Atomic Energy Agency (http://www-nds.iaea.org/nsr)

  17. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  18. Financing the Nuclear Renaissance

    OpenAIRE

    NUTTALL, William J.; Taylor, S

    2008-01-01

    This paper considers the key economic risks associated with nuclear power. The authors observe that the bulk of the risks of a nuclear power station project fall during the roughly five year period of plant construction. This window of risk follows a lengthy siting process and comes before power station operations lasting up to sixty years. As a consequence of the nature of the economic risks, operational nuclear power plants are more attractive targets for initial investment than new build p...

  19. Nuclear Parity with China?

    Science.gov (United States)

    2012-01-01

    Comprehensive Nuclear-Test- Ban Treaty (CTBT) in 1996, and applied for membership in the Missile Technology Control Regime (MTCR) in 2004. Since at least the...first nuclear test ban agreements? Is the United States seeking to gain relative advantage under the guise of nuclear parity? Caroline Ziemke-Dickens...of what senior State Department officials call “doing our homework ” for future arms control negotiations, and even there is has a low standing

  20. Nuclear Fabrication Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, Stephen [EWI, Columbus, OH (United States)

    2013-04-05

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. Supporting industry in helping to create a larger qualified nuclear supplier network. Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium

  1. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  2. [On Atomic Nuclear Fusion Processes at Low-Temperatures. An Enhancement of the Probability of Transition through a Potential Barrier Due to the So-Called Barrier Anti-Zeno Effect].

    Science.gov (United States)

    Namiot, V A

    2016-01-01

    It is known that in quantum mechanics the act of observing the experiment can affect the experimental findings in some cases. In particular, it happens under the so-called Zeno effect. In this work it is shown that in contrast to the "standard" Zeno-effect where the act of observing a process reduces the probability of its reality, an inverse situation when a particle transmits through a potential barrier (a so-called barrier anti-Zeno effect) can be observed, the observation of the particle essentially increases the probability of its transmission through the barrier. The possibility of using the barrier anti-Zeno effect is discussed to explain paradoxical results of experiments on "cold nuclear fusion" observed in various systems including biological ones. (According to the observers who performed the observations, the energy generation, which could not be explained by any chemical processes, as well as the change in the isotope and even element composition of the studied object may occur in these systems.

  3. Nuclear reactor apparatus

    Science.gov (United States)

    Wade, Elman E.

    1978-01-01

    A lifting, rotating and sealing apparatus for nuclear reactors utilizing rotating plugs above the nuclear reactor core. This apparatus permits rotation of the plugs to provide under the plug refueling of a nuclear core. It also provides a means by which positive top core holddown can be utilized. Both of these operations are accomplished by means of the apparatus lifting the top core holddown structure off the nuclear core while stationary, and maintaining this structure in its elevated position during plug rotation. During both of these operations, the interface between the rotating member and its supporting member is sealingly maintained.

  4. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... variety of diseases, including many types of cancers, heart disease, gastrointestinal, endocrine, neurological disorders and other abnormalities within the body. Because nuclear medicine procedures are ...

  5. Nuclear medicine physics

    CERN Document Server

    De Lima, Joao Jose

    2011-01-01

    Edited by a renowned international expert in the field, Nuclear Medicine Physics offers an up-to-date, state-of-the-art account of the physics behind the theoretical foundation and applications of nuclear medicine. It covers important physical aspects of the methods and instruments involved in modern nuclear medicine, along with related biological topics. The book first discusses the physics of and machines for producing radioisotopes suitable for use in conventional nuclear medicine and PET. After focusing on positron physics and the applications of positrons in medicine and biology, it descr

  6. Nuclear structure theory

    CERN Document Server

    Irvine, J M

    1972-01-01

    Nuclear Structure Theory provides a guide to nuclear structure theory. The book is comprised of 23 chapters that are organized into four parts; each part covers an aspect of nuclear structure theory. In the first part, the text discusses the experimentally observed phenomena, which nuclear structure theories need to look into and detail the information that supports those theories. The second part of the book deals with the phenomenological nucleon-nucleon potentials derived from phase shift analysis of nucleon-nucleon scattering. Part III talks about the phenomenological parameters used to de

  7. Nuclear criticality safety guide

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.L.; Paxton, H.C. [eds.

    1996-09-01

    This technical reference document cites information related to nuclear criticality safety principles, experience, and practice. The document also provides general guidance for criticality safety personnel and regulators.

  8. PACS in nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Keon Wook [National Cancer Center, Koyang (Korea, Republic of)

    2000-12-01

    PACS (Picture Archiving and Communication System) is being rapidly spread and installed in many hospitals, but most of the system do not include nuclear medicine field. Although additional costs of hardware for nuclear medicine PACS is low, the complexity in developing viewing software and little market have made the nuclear medicine PACS not popular. Most PACS utilize DICOM 3.0 as standard format, but standard format in nuclear medicine has been Interfile. Interfile should be converted into DICOM format if nuclear images are to be stored and visualized in most PACS. Nowadays, many vendors supply the DICOM option in gamma camera and PET. Several hospitals in Korea have already installed nucler PACS with DICOM, but only the screen captured images are supplied. Software for visualizing pseudo-color with color lookup tables and expressing with volume view should be developed to fulfill the demand of referring physicians and nuclear medicine physicians. PACS is going to integrate not only radiologic images but also endoscopic and pathologic images. Web and PC based PACS is now a trend and is much compatible with nuclear medicine PACS. Most important barrier for nuclear medicine PACS that we encounter is not a technical problem, but indifference of investor such as administrator of hospital or PACS. Now it is time to support and invest for the development of nuclear medicine PACS.

  9. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... heart disease, gastrointestinal, endocrine, neurological disorders and other abnormalities within the body. Because nuclear medicine procedures are able to pinpoint molecular activity ...

  10. Temperature measurement

    Science.gov (United States)

    ... an oral temperature. Other factors to take into account are: In general, rectal temperatures are considered to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  11. Recent irradiation tests for future nuclear system at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Man Soon; Choo, Kee Nam; Yang, Seong Woo; Park, Sang Jun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-05-15

    The capsule at HANARO is a device that evaluates the irradiation effects of nuclear materials and fuels, which can reproduce the environment of nuclear power plants and accelerate to reach to the end of life condition. As the integrity assessment and the extension of lifetime of nuclear power plants are recently considered as important issues in Korea, the requirements for irradiation test are gradually being increased. The capacity and capability irradiation tests at HANARO are becoming important because Korea strives to develop SFR (Sodium-cooled Fast Reactor) and VHTR (Very High Temperature Reactor) among the future nuclear system and to export the research reactors and to develop the fusion reactor technology.

  12. Shear viscosity of nuclear matter

    Science.gov (United States)

    Magner, A. G.; Gorenstein, M. I.; Grygoriev, U. V.; Plujko, V. A.

    2016-11-01

    Shear viscosity η is calculated for the nuclear matter described as a system of interacting nucleons with the van der Waals (VDW) equation of state. The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of the collective overdamped motion. In the frequent-collision regime, the shear viscosity depends on the particle-number density n through the mean-field parameter a , which describes attractive forces in the VDW equation. In the temperature region T =15 -40 MeV, a ratio of the shear viscosity to the entropy density s is smaller than 1 at the nucleon number density n =(0.5 -1.5 ) n0 , where n0=0.16 fm-3 is the particle density of equilibrium nuclear matter at zero temperature. A minimum of the η /s ratio takes place somewhere in a vicinity of the critical point of the VDW system. Large values of η /s ≫1 are, however, found in both the low-density, n ≪n0 , and high-density, n >2 n0 , regions. This makes the ideal hydrodynamic approach inapplicable for these densities.

  13. Nuclear spectroscopic studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R&D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  14. Steady Nuclear Combustion in Rockets

    Science.gov (United States)

    Saenger, E.

    1957-01-01

    The astrophysical theory of stationary nuclear reactions in stars is applied to the conditions that would be met in the practical engineering cases that would differ from the former, particularly with respect to the much lower combustion pressures, dimensions of the reacting volume, and burnup times. This application yields maximum rates of hear production per unit volume of reacting gas occurring at about 10(exp 8) K in the cases of reactions between the hydrogen isotopes, but yields higher rates for heavier atoms. For the former, with chamber pressures of the order of 100 atmospheres, the energy production for nuclear combustion reaches values of about 10(exp 4) kilocalories per cubic meter per second, which approaches the magnitude for the familiar chemical fuels. The values are substantially lower for heavier atoms, and increase with the square of the combustion pressure. The half-life of the burnup in the fastest reactions may drop to values as low as those for chemical fuels so that, despite the high temperature, the radiated energy can remain smaller than the energy produced, particularly if an inefficiently radiating (i.e., easily completely ionized reacting material like hydrogen), is used. On the other hand, the fraction of completely ionized particles in the gases undergoing nuclear combustion must not exceed a certain upper limit because the densities (approximately 10(exp -10) grams per cubic centimeter)) lie in the range of high vacua and only for the previously mentioned fraction of nonionized particles can mean free paths be retained small enough so that the chamber diameters of several dozen meters will suffice. Under these conditions it appears that continuously maintained stable nuclear reactions at practical pressures and dimensions are fundamentally possible and their application can be visualized as energy sources for power plants and propulsion units.

  15. Water/rock interactions and mass transport within a thermal gradient Application to the confinement of high level nuclear waste; Interactions solide/solution et transferts de matiere dans un gradient de temperature. Application au confinement des dechets nucleaires de haute-activite

    Energy Technology Data Exchange (ETDEWEB)

    Poinssot, Ch. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Entreposage et de Stockage des Dechets]|[Ecole Normale Superieure, 92 - Fontenay-aux-Roses (France). Laboratoire de Geologie

    1998-12-31

    The initial stage of a high level nuclear waste disposal will be characterised by a large heat release within the near-field environment of the canisters. This heat flux caused by radioactive decay will lead to an increase of temperature and a subsequent thermal gradient between the `hot` canisters and the `cold`geological medium. In addition, this thermal gradient will decrease with time due to the heat decay although it could last hundred years. What will be the consequences of such a thermal field varying both on space and time for the alteration of the different constituents of the near field environment. In particular, what could be the effects on the radionuclides migration in the accidental case of an early breach of a canister during the thermal stage? This study brings significant answers to these questions in the light of a performance assessment study. This work is supported by a triple methodological approach involving experimental studies, modelling calculations and a natural analogues study. This complete work demonstrates that a thermal gradient leads to a large re-distribution of elements within the system: some elements are incorporated in the solid phases of the hot end (Si, Zr, Ca) whereas some others are in those of the cold end (Fe, Al, Zn). The confrontation of the results of very simple experiments with the results of a model built on equilibrium thermodynamics allow us to evidence the probable mechanisms causing this mass transport: out-of-equilibrium thermodiffusion processes coupled to irreversible precipitation. Moreover, the effects of the variation of temperatures with time is studied by the way of a natural system which underwent a similar temperature evolution as a disposal and which was initially rich in uranium: the Jurassic Alpine bauxites. In addition, part of the initial bauxite escaped this temperature transformations due to their incorporation in outer thrusting nappes. They are used as a reference. (author)

  16. Modeling of Flow in Nuclear Reactor Fuel Cell Outlet

    Directory of Open Access Journals (Sweden)

    František URBAN

    2010-12-01

    Full Text Available Safe and effective load of nuclear reactor fuel cells demands qualitative and quantitative analysis of relations between coolant temperature in fuel cell outlet temperature measured by thermocouple and middle temperature of coolant in thermocouple plane position. In laboratory at Insitute of thermal power engineering of the Slovak University of Technology in Bratislava was installed an experimental physical fuel cell model of VVER 440 nuclear power plant with V 213 nuclear reactors. Objective of measurements on physical model was temperature and velocity profiles analysis in the fuel cell outlet. In this paper the measured temperature and velocity profiles are compared with the results of CFD simulation of fuel cell physical model coolant flow.

  17. Agriculture Impacts of Regional Nuclear Conflict

    Science.gov (United States)

    Xia, Lili; Robock, Alan; Mills, Michael; Toon, Owen Brian

    2013-04-01

    One of the major consequences of nuclear war would be climate change due to massive smoke injection into the atmosphere. Smoke from burning cities can be lofted into the stratosphere where it will have an e-folding lifetime more than 5 years. The climate changes include significant cooling, reduction of solar radiation, and reduction of precipitation. Each of these changes can affect agricultural productivity. To investigate the response from a regional nuclear war between India and Pakistan, we used the Decision Support System for Agrotechnology Transfer agricultural simulation model. We first evaluated the model by forcing it with daily weather data and management practices in China and the USA for rice, maize, wheat, and soybeans. Then we perturbed observed weather data using monthly climate anomalies for a 10-year period due to a simulated 5 Tg soot injection that could result from a regional nuclear war between India and Pakistan, using a total of 100 15 kt atomic bombs, much less than 1% of the current global nuclear arsenal. We computed anomalies using the NASA Goddard Institute for Space Studies ModelE and NCAR's Whole Atmosphere Community Climate Model (WACCM). We perturbed each year of the observations with anomalies from each year of the 10-year nuclear war simulations. We found that different regions respond differently to a regional nuclear war; southern regions show slight increases of crop yields while in northern regions crop yields drop significantly. Sensitivity tests show that temperature changes due to nuclear war are more important than precipitation and solar radiation changes in affecting crop yields in the regions we studied. In total, crop production in China and the USA would decrease 15-50% averaged over the 10 years using both models' output. Simulations forced by ModelE output show smaller impacts than simulations forced by WACCM output at the end of the 10 year period because of the different temperature responses in the two models.

  18. Commercial nuclear power 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-28

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs.

  19. Nuclear Energy and the Environment.

    Science.gov (United States)

    International Atomic Energy Agency, Vienna (Austria).

    "Nuclear Energy and the Environment" is a pocket folder of removable leaflets concerned with two major topics: Nuclear energy and Nuclear Techniques. Under Nuclear Energy, leaflets concerning the topics of "Radiation--A Fact of Life,""The Impact of a Fact: 1963 Test Ban Treaty,""Energy Needs and Nuclear Power,""Power Reactor Safety,""Transport,"…

  20. Nuclear Power Plant Technician

    Science.gov (United States)

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  1. JPRS Report, Nuclear Developments.

    Science.gov (United States)

    1989-09-18

    105 of them new internationally) and a determination of their characteris- tics ; it includes a uniform quantum mechanical descrip- tion of the... Empresas Nucleares Brasileiras S.A. (Nuclebras) to Industrias Nucleares do Brasil S.A. (INB), and trans- ferred the shares of its capital stock

  2. Nuclear Weapons and Schools.

    Science.gov (United States)

    Howie, David I.

    1984-01-01

    The growing debate on nuclear weapons in recent years has begun to make inroads into school curricula. Elementary and secondary school teachers now face the important task of educating their students on issues relating to nuclear war without indoctrinating them to a particular point of view. (JBM)

  3. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging ...

  4. Nuclear-Powered Debate.

    Science.gov (United States)

    Arce, Gary

    1992-01-01

    Describes an exercise to develop interest and understanding about nuclear energy in which students make presentations regarding a proposal to build a hypothetical nuclear power plant. Students spend two weeks researching the topic; give testimony before a "Senate Energy Committee"; and vote on the proposal. Background information is…

  5. Exotic nuclear matter

    Directory of Open Access Journals (Sweden)

    Lenske H.

    2016-01-01

    Full Text Available Recent developments of nuclear structure theory for exotic nuclei are addressed. The inclusion of hyperons and nucleon resonances is discussed. Nuclear multipole response functions, hyperon interactions in infinite matter and in neutron stars and theoretical aspects of excitations of nucleon resonances in nuclei are discussed.

  6. Nuclear Energy Policy

    Science.gov (United States)

    2010-05-27

    Down by Lengthy Outages,” Nucleonics Week, April 1, 2010, p. 1. Totals are for gross generation, including electricity used for reactor operation. 5...would 7World Nuclear Performance in 2009 Pushed Down by Lengthy Outages,” Nucleonics Week... Nucleonics Week, April 15, 2010, p. 1. 12 ESBWR: Economic Simplified Boiling Water Reactor; APWR: Advanced Pressurized Water Reactor. Nuclear Energy

  7. Nuclear Power Plants. Revised.

    Science.gov (United States)

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  8. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... radioactive energy that is emitted from the patient's body and converts it into an image. The gamma camera itself does not emit any ... View full size with caption Related Articles and Media General Nuclear ... to Children's (Pediatric) Nuclear Medicine Videos related ...

  9. Nuclear multifragmentation: Basic concepts

    Indian Academy of Sciences (India)

    2014-05-02

    May 2, 2014 ... Abstract. We present a brief overview of nuclear multifragmentation reaction. Basic formalism of canonical thermodynamical model based on equilibrium statistical mechanics is described. This model is used to calculate basic observables of nuclear multifragmentation like mass distribution, fragment ...

  10. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... medicine refers to imaging examinations done in babies, young children and teenagers. Nuclear medicine imaging procedures are noninvasive ... exams at the same time. An emerging imaging technology, but not readily available at ... procedure? Children's (pediatric) nuclear medicine imaging is performed to help ...

  11. Themes in nuclear law; Temas de Derecho Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The nuclear law was analyzed during a workshop. The main aspects were: the law of population to access to information on nuclear energy and the relationship between the Regulator Organism and the nuclear power plants managers.

  12. Nuclear-pumped lasers

    CERN Document Server

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  13. Nuclear power economics

    Energy Technology Data Exchange (ETDEWEB)

    Emsley, Ian; Cobb, Jonathan [World Nuclear Association, London (United Kingdom)

    2017-04-15

    Many countries recognize the substantial role which nuclear power has played in providing energy security of supply, reducing import dependence and reducing greenhouse gas and polluting emissions. Nevertheless, as such considerations are far from being fully accounted for in liberalized or deregulated power markets, nuclear plants must demonstrate their viability in these markets on commercial criteria as well as their lifecycle advantages. Nuclear plants are operating more efficiently than in the past and unit operating costs are low relative to those of alternative generating technologies. The political risk facing the economic functioning of nuclear in a number of countries has increased with the imposition of nuclear-specific taxes that in some cases have deprived operators of the economic incentive to continue to operate existing plants.

  14. Latest nuclear emulsion technology

    Science.gov (United States)

    Rokujo, Hiroki; Kawahara, Hiroaki; Komatani, Ryosuke; Morishita, Misaki; Nakano, Toshiyuki; Otsuka, Naoto; Yoshimoto, Masahiro

    2017-06-01

    Nuclear emulsion is a extremely high-resolution 3D tracking detector. Since the discovery of the pion by C.F. Powell et al. in 1946, experiments with nuclear emulsions have contributed to the development of particle physics. (e.g. the OPERA collaboration reported the discovery of νμ * ντ oscillations in appearance mode in 2015) The technology of nuclear emulsion still keeps making progress. Since 2010, we have introduced a system of nuclear emulsion gel production to our laboratory in Nagoya University, and have started self-development of the new gel, instead of from the photographic film companies. Moreover, a faster automated emulsion scanning system is developed. Its scanning speed reaches 4000 cm2/h, and the load for analyzing becomes more and more lighter. In this presentation, we report the status of nuclear emulsion technologies for cosmic ray experiments.

  15. World nuclear outlook 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-29

    As part of the EIA program to provide energy information, this analysis report presents the current status and projections through 2015 of nuclear capacity, generation, and fuel cycle requirements for all countries in the world using nuclear power to generate electricity for commercial use. It also contains information and forecasts of developments in the uranium market. Long-term projections of US nuclear capacity, generation, and spent fuel discharges for two different scenarios through 2040 are developed for the Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM). In turn, the OCRWM provides partial funding for preparation of this report. The projections of uranium requirements are provided to the Organization for Economic Cooperation and Development (OECD) for preparation of the Nuclear Energy Agency/OECD report, Summary of Nuclear Power and Fuel Cycle Data in OECD Member Countries.

  16. World nuclear outlook 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    As part of the EIA program to provide energy information, this analysis report presents the current status and projections through 2010 of nuclear capacity, generation, and fuel cycle requirements for all countries in the world using nuclear power to generate electricity for commercial use. It also contains information and forecasts of developments in the uranium market. Long-term projections of US nuclear capacity, generation, and spent fuel discharges for three different scenarios through 2040 are developed for the Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM). In turn, the OCRWM provides partial funding for preparation of this report. The projections of uranium requirements are provided to the Organization for Economic Cooperation and Development (OECD) for preparation of the Nuclear Energy Agency/OECD report, Summary of Nuclear Power and Fuel Cycle Data in OECD Member Countries.

  17. Fundamentals of nuclear physics

    CERN Document Server

    Takigawa, Noboru

    2017-01-01

    This book introduces the current understanding of the fundamentals of nuclear physics by referring to key experimental data and by providing a theoretical understanding of principal nuclear properties. It primarily covers the structure of nuclei at low excitation in detail. It also examines nuclear forces and decay properties. In addition to fundamentals, the book treats several new research areas such as non-relativistic as well as relativistic Hartree–Fock calculations, the synthesis of super-heavy elements, the quantum chromodynamics phase diagram, and nucleosynthesis in stars, to convey to readers the flavor of current research frontiers in nuclear physics. The authors explain semi-classical arguments and derivation of its formulae. In these ways an intuitive understanding of complex nuclear phenomena is provided. The book is aimed at graduate school students as well as junior and senior undergraduate students and postdoctoral fellows. It is also useful for researchers to update their knowledge of diver...

  18. Comprehensive nuclear materials

    CERN Document Server

    Allen, Todd; Stoller, Roger; Yamanaka, Shinsuke

    2012-01-01

    Comprehensive Nuclear Materials encapsulates a panorama of fundamental information on the vast variety of materials employed in the broad field of nuclear technology. The work addresses, in five volumes, 3,400 pages and over 120 chapter-length articles, the full panorama of historical and contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds' leading scientists and engineers. It synthesizes the most pertinent research to support the selection, assessment, validation and engineering of materials in extreme nuclear environments. The work discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials.

  19. Nuclear war, nuclear proliferation, and their consequences

    Energy Technology Data Exchange (ETDEWEB)

    Sanruddin, A.K.

    1986-01-01

    The proceedings of a colloquium convened by the Groupe de Bellerive offers the contributions of Carl Sagan, Gabriel Garcia Marquez, Kenneth Galbraith, Pierre Trudeau, Edward Kennedy, and other eminent scientists, politicians, and strategists on the subject of the proliferation of nuclear weaponry and its potential ramifications.

  20. Nuclear Powerplant Safety: Source Terms. Nuclear Energy.

    Science.gov (United States)

    Department of Energy, Washington, DC. Nuclear Energy Office.

    There has been increased public interest in the potential effects of nuclear powerplant accidents since the Soviet reactor accident at Chernobyl. People have begun to look for more information about the amount of radioactivity that might be released into the environment as a result of such an accident. When this issue is discussed by people…

  1. The nuclear pore complex and nuclear transport.

    Science.gov (United States)

    Wente, Susan R; Rout, Michael P

    2010-10-01

    Internal membrane bound structures sequester all genetic material in eukaryotic cells. The most prominent of these structures is the nucleus, which is bounded by a double membrane termed the nuclear envelope (NE). Though this NE separates the nucleoplasm and genetic material within the nucleus from the surrounding cytoplasm, it is studded throughout with portals called nuclear pore complexes (NPCs). The NPC is a highly selective, bidirectional transporter for a tremendous range of protein and ribonucleoprotein cargoes. All the while the NPC must prevent the passage of nonspecific macromolecules, yet allow the free diffusion of water, sugars, and ions. These many types of nuclear transport are regulated at multiple stages, and the NPC carries binding sites for many of the proteins that modulate and modify the cargoes as they pass across the NE. Assembly, maintenance, and repair of the NPC must somehow occur while maintaining the integrity of the NE. Finally, the NPC appears to be an anchor for localization of many nuclear processes, including gene activation and cell cycle regulation. All these requirements demonstrate the complex design of the NPC and the integral role it plays in key cellular processes.

  2. 77 FR 76541 - Entergy Nuclear Operations, Inc.; Pilgrim Nuclear Power Station

    Science.gov (United States)

    2012-12-28

    ... Nuclear Operations, Inc.; Pilgrim Nuclear Power Station AGENCY: Nuclear Regulatory Commission. ACTION... Nuclear Operations, Inc. (the licensee), for operation of the Pilgrim Nuclear Power Station (Pilgrim... Renewal of Nuclear Plants Regarding Pilgrim Nuclear Power Station, Final Report- Appendices,'' published...

  3. US nuclear weapons policy

    Energy Technology Data Exchange (ETDEWEB)

    May, M.

    1990-12-05

    We are closing chapter one'' of the nuclear age. Whatever happens to the Soviet Union and to Europe, some of the major determinants of nuclear policy will not be what they have been for the last forty-five years. Part of the task for US nuclear weapons policy is to adapt its nuclear forces and the oganizations managing them to the present, highly uncertain, but not urgently competitive situation between the US and the Soviet Union. Containment is no longer the appropriate watchword. Stabilization in the face of uncertainty, a more complicated and politically less readily communicable goal, may come closer. A second and more difficult part of the task is to deal with what may be the greatest potential source of danger to come out of the end of the cold war: the breakup of some of the cooperative institutions that managed the nuclear threat and were created by the cold war. These cooperative institutions, principally the North Atlantic Treaty Organization (NATO), the Warsaw Pact, the US-Japan alliance, were not created specifically to manage the nuclear threat, but manage it they did. A third task for nuclear weapons policy is that of dealing with nuclear proliferation under modern conditions when the technologies needed to field effective nuclear weapons systems and their command and control apparatus are ever more widely available, and the leverage over some potential proliferators, which stemmed from superpower military support, is likely to be on the wane. This paper will make some suggestions regarding these tasks, bearing in mind that the unsettled nature of that part of the world most likely to become involved in nuclear weapons decisions today must make any suggestions tentative and the allowance for surprise more than usually important.

  4. Study of the iodine transport mechanisms in a nuclear accidental medium by high temperature mass spectrometry in the framework of the 'CHIP' (Iodine Chemistry in the reactor coolant system) program. I - Thermodynamics of CsOH vaporization; Etude des mecanismes de transport de l iode en milieu nucleaire accidentel par spectrometrie de masse haute temperature dans le cadre du programme CHIP (CHimie de l Iode dans le circuit Primaire). I - Thermodynamique de la vaporisation de CsOH

    Energy Technology Data Exchange (ETDEWEB)

    Roki, F.Z.; Ohnet, M.N.; Jacquemain, D. [IRSN, DPAM, SEREA, Laboratoire d Essais Analytiques, Centre de Cadarache, BP 3, 13115 St Paul-Lez- Durance Cedex, (France); Chatillon, C. [Laboratoire de Thermodynamique et Physico-Chimie Metallurgiques (associe au CNRS, UMR 5614), BP 75 - 38402 Saint Martin d Heres, (France)

    2006-07-01

    Iodine is one of the fission products which vaporizes in a complex chemical medium and can be transported under different gaseous forms in the PWR primary coolant system during a severe nuclear accident. The 'CHIP' analytical program has been implemented to study in a first time, the quaternary complex systems of the type Cs-I-O-H. In this system, the CsOH(l or s) vaporization is an important element. A study by high temperature mass spectrometry shows that the vapor species are the CsOH(g), its dimers Cs{sub 2}O{sub 2}H{sub 2}(g) and its trimers Cs{sub 3}O{sub 3}H{sub 3}(g). For this last specie, no thermodynamic determination has been done until today. The quantitative exploitation of the vapor pressures leads to the determination of the dimerization enthalpy reaction: (CsOH){sub 2}(g)=2 CsOH(g) {delta}H(average)(298.14 K)136.5 {+-} 3.85 kJ.mol{sup -1} (calculated with the third thermodynamic law). (O.M.)

  5. Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Weber, William J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Zhang, Yanwen [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering

    2016-09-20

    This is the final report of the NEUP project “Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms.” This project started on July 1, 2012 and was successfully completed on June 30, 2016. This report provides an overview of the main achievements, results and findings through the duration of the project. Additional details can be found in the main body of this report and in the individual Quarterly Reports and associated Deliverables of this project, which have been uploaded in PICS-NE. The objective of this research was to advance understanding and develop validated models on the effects of self-radiation from beta and alpha decay on the response of used nuclear fuel and nuclear waste forms during high-temperature interim storage and long-term permanent disposition. To achieve this objective, model used-fuel materials and model waste form materials were identified, fabricated, and studied.

  6. Core Outlet Temperature Study

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A. [Argonne National Laboratory (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Laboratory (ANL), Argonne, IL (United States); Majumdar, S. [Argonne National Laboratory (ANL), Argonne, IL (United States)

    2008-07-28

    It is a known fact that the power conversion plant efficiency increases with elevation of the heat addition temperature. The higher efficiency means better utilization of the available resources such that higher output in terms of electricity production can be achieved for the same size and power of the reactor core or, alternatively, a lower power core could be used to produce the same electrical output. Since any nuclear power plant, such as the Advanced Burner Reactor, is ultimately built to produce electricity, a higher electrical output is always desirable. However, the benefits of the higher efficiency and electricity production usually come at a price. Both the benefits and the disadvantages of higher reactor outlet temperatures are analyzed in this work.

  7. 77 FR 70847 - Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc., Indian Point Nuclear...

    Science.gov (United States)

    2012-11-27

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc., Indian Point Nuclear Generating Unit No. 2, Request for Action AGENCY: Nuclear Regulatory Commission. ACTION: Request for Action...

  8. 77 FR 8904 - Entergy Nuclear Indian Point 3, LLC.; Entergy Nuclear Operations, Inc., Indian Point Nuclear...

    Science.gov (United States)

    2012-02-15

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Indian Point 3, LLC.; Entergy Nuclear Operations, Inc., Indian Point Nuclear Generating Unit 3; Exemption 1.0 Background Entergy Nuclear Operations, Inc. (Entergy or the licensee) is the...

  9. 75 FR 39057 - Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee Nuclear...

    Science.gov (United States)

    2010-07-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee Nuclear... CFR), Section 2.206, ``Requests for Action under this Subpart,'' the U.S. Nuclear Regulatory...

  10. 76 FR 19148 - Entergy Nuclear Operations, Inc., Entergy Nuclear Vermont Yankee, LLC, Vermont Yankee Nuclear...

    Science.gov (United States)

    2011-04-06

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc., Entergy Nuclear Vermont Yankee, LLC, Vermont Yankee Nuclear... (10 CFR), Section 2.206, ``Requests for Action under this Subpart,'' the U.S. Nuclear Regulatory...

  11. Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces

    Energy Technology Data Exchange (ETDEWEB)

    Togashi, H., E-mail: hajime.togashi@riken.jp [Nishina Center for Accelerator-Based Science, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Nakazato, K. [Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Takehara, Y.; Yamamuro, S.; Suzuki, H. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan); Takano, M. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2017-05-15

    A new table of the nuclear equation of state (EOS) based on realistic nuclear potentials is constructed for core-collapse supernova numerical simulations. Adopting the EOS of uniform nuclear matter constructed by two of the present authors with the cluster variational method starting from the Argonne v18 and Urbana IX nuclear potentials, the Thomas–Fermi calculation is performed to obtain the minimized free energy of a Wigner–Seitz cell in non-uniform nuclear matter. As a preparation for the Thomas–Fermi calculation, the EOS of uniform nuclear matter is modified so as to remove the effects of deuteron cluster formation in uniform matter at low densities. Mixing of alpha particles is also taken into account following the procedure used by Shen et al. (1998, 2011). The critical densities with respect to the phase transition from non-uniform to uniform phase with the present EOS are slightly higher than those with the Shen EOS at small proton fractions. The critical temperature with respect to the liquid–gas phase transition decreases with the proton fraction in a more gradual manner than in the Shen EOS. Furthermore, the mass and proton numbers of nuclides appearing in non-uniform nuclear matter with small proton fractions are larger than those of the Shen EOS. These results are consequences of the fact that the density derivative coefficient of the symmetry energy of our EOS is smaller than that of the Shen EOS.

  12. Inhibition of Oxidation in Nuclear Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Phil Winston; James W. Sterbentz; William E. Windes

    2013-10-01

    Graphite is a fundamental material of high temperature gas cooled nuclear reactors, providing both structure and neutron moderation. Its high thermal conductivity, chemical inertness, thermal heat capacity, and high thermal structural stability under normal and off normal conditions contribute to the inherent safety of these reactor designs. One of the primary safety issues for a high temperature graphite reactor core is the possibility of rapid oxidation of the carbon structure during an off normal design basis event where an oxidizing atmosphere (air ingress) can be introduced to the hot core. Although the current Generation IV high temperature reactor designs attempt to mitigate any damage caused by a postualed air ingress event, the use of graphite components that inhibit oxidation is a logical step to increase the safety of these reactors. Recent experimental studies of graphite containing between 5.5 and 7 wt% boron carbide (B4C) indicate that oxidation is dramatically reduced even at prolonged exposures at temperatures up to 900°C. The proposed addition of B4C to graphite components in the nuclear core would necessarily be enriched in B-11 isotope in order to minimize B-10 neutron absorption and graphite swelling. The enriched boron can be added to the graphite during billet fabrication. Experimental oxidation rate results and potential applications for borated graphite in nuclear reactor components will be discussed.

  13. Radiological Effects of Nuclear War.

    Science.gov (United States)

    Shapiro, Charles S.

    1988-01-01

    Described are the global effects of nuclear war. Discussed are radiation dosages, limited nuclear attacks, strategic arms reductions, and other results reported at the workshop on nuclear war issues in Moscow in March 1988. (CW)

  14. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org Hello! ... d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify disease ...

  15. Your Radiologist Explains Nuclear Medicine

    Medline Plus

    Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org ... I’d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify ...

  16. Nuclear Magnetic Moment of 59Cu with On-line $\\beta$-NMR on Oriented Nuclei

    CERN Document Server

    Golovko, V V; Phalet, T; Severijns, N; Delauré, B J; Beck, M; Kozlov, Yu V; Lindroth, A; Versyck, S; Zákoucký, D; Vénos, D; Srnka, D; Honusek, M; Herzog, P; Tramm, C; Köster, U; Towner, I S

    2004-01-01

    The nuclear magnetic moment of the nucleus 59Cu with one proton and two neutrons outside the closed N = Z = 28 shells, was measured in an on-line experiment combining beta-NMR with low temperature nuclear orientation and with particle detectors operating at a temperature of about 10K. From the data the center frequency \

  17. Nuclear magnetic moment of $^{59}$Cu with on-line $\\beta$-NMR on oriented nuclei

    CERN Document Server

    Golovko, V V; Phalet, T; Severijns, N; Delauré, B J; Beck, M; Kozlov, V; Lindroth, A; Versyck, S; Zákoucký, D; Srnka, D; Honusek, M; Herzog, P; Köster, U; Tramm, C; Towner, I S

    2004-01-01

    The nuclear magnetic moment of the nucleus $^{59}\\!$Cu, with one proton and two neutrons outside the closed N = Z = 28 shells, was measured in an on-line experiment combining $\\beta$-NMR with low temperature nuclear orientation and with particle detectors operating at a temperature of about 10 K. From the data the center frequency $\

  18. Nuclear Material Management Abstract

    Energy Technology Data Exchange (ETDEWEB)

    Jesse C. Schreiber

    2007-07-10

    Nevada Test Site (NTS) has transitioned from its historical and critical role of weapons testing to another critical role for the nation. This new role focuses on being a integral element in solving the multiple challenges facing the National Nuclear Security Administration (NNSA) with nuclear material management. NTS is positioned to be a solution for other NNSA sites challenged with safe nuclear materials storage and disposition. NNSA, with site involvement, is currently transforming the nuclear stockpile and supporting infrastructure to meet the 2030 vision. Efforts are under way to consolidate and modernize the production complex . With respect to the nuclear material stockpile, the NNSA sites are currently reducing the complex nuclear material inventory through disposition and consolidation. This includes moving material from other sites to NTS. State of the art nuclear material management and control practices at NTS are essential for NTS to ensure that assigned activities are accomplished in a safe, secure, efficient, and environmentally responsible manner. NTS activities and challenges will be addressed.

  19. Advances in nuclear physics

    CERN Document Server

    Vogt, Erich

    1975-01-01

    Review articles on three topics of considerable current interest make up the present volume. The first, on A-hypernuclei, was solicited by the editors in order to provide nuclear physicists with a general description of the most recent developments in a field which this audience has largely neglected or, perhaps, viewed as a novelty in which a bizarre nuclear system gave some information about the lambda-nuclear intersection. That view was never valid. The very recent developments reviewed here-particularly those pertaining to hypernuclear excitations and the strangeness exchange reactions-emphasize that this field provides important information about the models and central ideas of nuclear physics. The off-shell behavior of the nucleon-nucleon interaction is a topic which was at first received with some embarrassment, abuse, and neglect, but it has recently gained proper attention in many nuclear problems. Interest was first focused on it in nuclear many-body theory, but it threatened nuclear physicists'comf...

  20. Evaluated Nuclear Data

    Energy Technology Data Exchange (ETDEWEB)

    Oblozinsky, P.; Oblozinsky,P.; Herman,M.; Mughabghab,S.F.

    2010-10-01

    This chapter describes the current status of evaluated nuclear data for nuclear technology applications. We start with evaluation procedures for neutron-induced reactions focusing on incident energies from the thermal energy up to 20 MeV, though higher energies are also mentioned. This is followed by examining the status of evaluated neutron data for actinides that play dominant role in most of the applications, followed by coolants/moderators, structural materials and fission products. We then discuss neutron covariance data that characterize uncertainties and correlations. We explain how modern nuclear evaluated data libraries are validated against an extensive set of integral benchmark experiments. Afterwards, we briefly examine other data of importance for nuclear technology, including fission yields, thermal neutron scattering and decay data. A description of three major evaluated nuclear data libraries is provided, including the latest version of the US library ENDF/B-VII.0, European JEFF-3.1 and Japanese JENDL-3.3. A brief introduction is made to current web retrieval systems that allow easy access to a vast amount of up-to-date evaluated nuclear data for nuclear technology applications.

  1. Nuclear forensics: Soil content

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, Merilyn Amy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-31

    Nuclear Forensics is a growing field that is concerned with all stages of the process of creating and detonating a nuclear weapon. The main goal is to prevent nuclear attack by locating and securing nuclear material before it can be used in an aggressive manner. This stage of the process is mostly paperwork; laws, regulations, treaties, and declarations made by individual countries or by the UN Security Council. There is some preliminary leg work done in the form of field testing detection equipment and tracking down orphan materials; however, none of these have yielded any spectacular or useful results. In the event of a nuclear attack, the first step is to analyze the post detonation debris to aid in the identification of the responsible party. This aspect of the nuclear forensics process, while reactive in nature, is more scientific. A rock sample taken from the detonation site can be dissolved into liquid form and analyzed to determine its chemical composition. The chemical analysis of spent nuclear material can provide valuable information if properly processed and analyzed. In order to accurately evaluate the results, scientists require information on the natural occurring elements in the detonation zone. From this information, scientists can determine what percentage of the element originated in the bomb itself rather than the environment. To this end, element concentrations in soils from sixty-nine different cities are given, along with activity concentrations for uranium, thorium, potassium, and radium in various building materials. These data are used in the analysis program Python.

  2. Nuclear movement in fungi.

    Science.gov (United States)

    Xiang, Xin

    2017-12-11

    Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle. Published by Elsevier Ltd.

  3. Multiphase flow dynamics 5 nuclear thermal hydraulics

    CERN Document Server

    Kolev, Nikolay Ivanov

    2015-01-01

    This Volume 5 of the successful book package "Multiphase Flow Dynamics" is devoted to nuclear thermal hydraulics which is a substantial part of nuclear reactor safety. It provides knowledge and mathematical tools for adequate description of the process of transferring the fission heat released in materials due to nuclear reactions into its environment. It step by step introduces into the heat release inside the fuel, temperature fields in the fuels, the "simple" boiling flow in a pipe described using ideas of different complexity like equilibrium, non equilibrium, homogeneity, non homogeneity. Then the "simple" three-fluid boiling flow in a pipe is described by gradually involving the mechanisms like entrainment and deposition, dynamic fragmentation, collisions, coalescence, turbulence. All heat transfer mechanisms are introduced gradually discussing their uncertainty. Different techniques are introduced like boundary layer treatments or integral methods. Comparisons with experimental data at each step demons...

  4. Multiphase Flow Dynamics 5 Nuclear Thermal Hydraulics

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    The present Volume 5 of the successful book package "Multiphase Flow Dynamics" is devoted to nuclear thermal hydraulics which is a substantial part of nuclear reactor safety. It provides knowledge and mathematical tools for adequate description of the process of transferring the fission heat released in materials due to nuclear reactions into its environment. It step by step introduces into the heat release inside the fuel, temperature fields in the fuels, the "simple" boiling flow in a pipe described using ideas of different complexity like equilibrium, non equilibrium, homogeneity, non homogeneity. Then the "simple" three-fluid boiling flow in a pipe is described by gradually involving the mechanisms like entrainment and deposition, dynamic fragmentation, collisions, coalescence, turbulence. All heat transfer mechanisms are introduced gradually discussing their uncertainty. Different techniques are introduced like boundary layer treatments or integral methods. Comparisons with experimental data at each step...

  5. Virtual nuclear weapons

    Energy Technology Data Exchange (ETDEWEB)

    Pilat, J.F.

    1997-08-01

    The term virtual nuclear weapons proliferation and arsenals, as opposed to actual weapons and arsenals, has entered in recent years the American lexicon of nuclear strategy, arms control, and nonproliferation. While the term seems to have an intuitive appeal, largely due to its cyberspace imagery, its current use is still vague and loose. The author believes, however, that if the term is clearly delineated, it might offer a promising approach to conceptualizing certain current problems of proliferation. The first use is in a reference to an old problem that has resurfaced recently: the problem of growing availability of weapon-usable nuclear materials in civilian nuclear programs along with materials made `excess` to defense needs by current arms reduction and dismantlement. It is argued that the availability of these vast materials, either by declared nuclear-weapon states or by technologically advanced nonweapon states, makes it possible for those states to rapidly assemble and deploy nuclear weapons. The second use has quite a different set of connotations. It is derived conceptually from the imagery of computer-generated reality. In this use, one thinks of virtual proliferation and arsenals not in terms of the physical hardware required to make the bomb but rather in terms of the knowledge/experience required to design, assemble, and deploy the arsenal. Virtual weapons are a physics reality and cannot be ignored in a world where knowledge, experience, materials, and other requirements to make nuclear weapons are widespread, and where dramatic army reductions and, in some cases, disarmament are realities. These concepts are useful in defining a continuum of virtual capabilities, ranging from those at the low end that derive from general technology diffusion and the existence of nuclear energy programs to those at the high end that involve conscious decisions to develop or maintain militarily significant nuclear-weapon capabilities.

  6. Nuclear Physics Department annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    This annual report presents articles and abstracts published in foreign journals, covering the following subjects: nuclear structure, nuclear reactions, applied physics, instrumentation, nonlinear phenomena and high energy physics

  7. Thermodynamics of Rh nuclear spins calculated by exact diagonalization

    DEFF Research Database (Denmark)

    Lefmann, K.; Ipsen, J.; Rasmussen, F.B.

    2000-01-01

    We have employed the method of exact diagonalization to obtain the full-energy spectrum of a cluster of 16 Rh nuclear spins, having dipolar and RK interactions between first and second nearest neighbours only. We have used this to calculate the nuclear spin entropy, and our results at both positive...... and negative temperatures follow the second-order high-temperature series expansions for |T| > 3 nK. Our findings do not agree with the measurements of the former Rh experiment in Helsinki, where a deviation is seen at much higher temperatures....

  8. Nuclear manpower training

    Energy Technology Data Exchange (ETDEWEB)

    Suh, In Suk; Lee, H. Y.; Joe, B. J.; Lee, S. H.; Lee, E. J.; Yoo, B. H.; Seo, K. W.; Lee, W. K.; Jun, H. I.; Yang, K. N.; Kim, Y. J.; Kim, I. H.; Kim, M. Y.; Ju, Y. C.; Hyun, H. Y.; Choi, I. G.; Hong, C. S.; Won, J. Y.; Nam, J. Y.; Lee, H. J.

    1997-01-01

    This report describes the annual results of training courses. the scope and contents are as follows: 1. Regional and interregional training courses 2. Training courses assisted by foreign experts 3. Training courses for nuclear industry personnel 4. Training courses for internal staff-members 5. Training courses under the law. This Nuclear Training Center executed the open-door training courses for 2,400 engineers/scientists from the regulatory body, nuclear industries, research institutes and other related organizations by means of offering 51 training courses during the fiscal year 1996. (author). 23 refs.

  9. Nuclear Regulatory Commission issuances

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This document is the March 1996 listing of NRC issuances. Included are: (1) NRC orders granting Cleveland Electric Illuminating Company`s petition for review of the ASLB order LBP-95-17, (2) NRC orders relating to the potential disqualification of two commissioners in the matter of the decommissioning of Yankee Nuclear Power Station, (3) ASLB orders pertaining to the Oncology Services Corporation, (4) ASLB orders pertaining to the Radiation Oncology Center, (5) ASLB orders pertaining to the Yankee Nuclear Power Station, and (6) Director`s decision pertaining to the Yankee Nuclear Power Station.

  10. Practical nuclear medicine

    CERN Document Server

    Gemmell, Howard G; Sharp, Peter F

    2006-01-01

    Nuclear medicine plays a crucial role in patient care, and this book is an essential guide for all practitioners to the many techniques that inform clinical management. The first part covers the scientific basis of nuclear medicine, the rest of the book deals with clinical applications. Diagnostic imaging has an increasingly important role in patient management and, despite advances in other modalities (functional MRI and spiral CT), nuclear medicine continues to make its unique contribution by its ability to demonstrate physiological function. This book is also expanded by covering areas of d

  11. Nuclear engineering vocabulary

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, X. [FRAMATOME, Dept. Corporate R and D, 92 - Paris-La-Defence (France); Andrieux, C. [CEA Saclay, Direction des Technologies de l' Information, DTI, 91 - Gif sur Yvette (France)

    2001-07-01

    The members of the CSTNIN - the Special Commission for Nuclear Engineering Terminology and Neology - have just produced a Nuclear Engineering Vocabulary, published by SFEN. A 120-page document which, to date, includes 400 nuclear engineering terms or expressions. For each term or expression, this Glossary gives: the primary and secondary subject field in which it is applied, a possible abbreviation, its definition, a synonym if appropriate, any relevant comments, any associated word(s), the English equivalent, its status on the date of publication of the Glossary. (author)

  12. Nuclear shell theory

    CERN Document Server

    de-Shalit, Amos; Massey, H S W

    1963-01-01

    Nuclear Shell Theory is a comprehensive textbook dealing with modern methods of the nuclear shell model. This book deals with the mathematical theory of a system of Fermions in a central field. It is divided into three parts. Part I discusses the single particle shell model. The second part focuses on the tensor algebra, two-particle systems. The last part covers three or more particle systems. Chapters on wave functions in a central field, tensor fields, and the m-Scheme are also presented. Physicists, graduate students, and teachers of nuclear physics will find the book invaluable.

  13. Nuclear regulation and safety

    Energy Technology Data Exchange (ETDEWEB)

    Hendrie, J.M.

    1982-01-01

    Nuclear regulation and safety are discussed from the standpoint of a hypothetical country that is in the process of introducing a nuclear power industry and setting up a regulatory system. The national policy is assumed to be in favor of nuclear power. The regulators will have responsibility for economic, reliable electric production as well as for safety. Reactor safety is divided into three parts: shut it down, keep it covered, take out the afterheat. Emergency plans also have to be provided. Ways of keeping the core covered with water are discussed. (DLC)

  14. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...... (range 5.0-8.4 years). Cox regression analysis (automatic forward selection) showed the MNV to be the most significant prognostic parameter followed by the P-stage. Patients who had localized tumors or tumors with small nuclei had a better probability of surviving than did women with advanced tumors...

  15. New nuclear power sources

    Science.gov (United States)

    Nuclear electric-power generation sources for the future include two viable candidates as viewed now: the fast breeder and the nuclear fusion reactors. Breeder reactors, which produce more radioactive fuels than they consume, are in the realm of existing technology. They are also categorized as potentially most harmful to the environment. Nuclear fusion reactors, on the other hand, will not be available in this century, based on current levels of development. However, they will be categorized as inherently much safer and thus potentially least harmful to the environment of all fueled electric-power generators.

  16. Monitoring international nuclear activity

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B.

    2006-05-19

    The LBNL Table of Isotopes website provides primary nuclearinformation to>150,000 different users annually. We have developedthe covert technology to identify users by IP address and country todetermine the kinds of nuclear information they are retrieving. Wepropose to develop pattern recognition software to provide an earlywarning system to identify Unusual nuclear activity by country or regionSpecific nuclear/radioactive material interests We have monitored nuclearinformation for over two years and provide this information to the FBIand LLNL. Intelligence is gleaned from the website log files. Thisproposal would expand our reporting capabilities.

  17. Theoretical nuclear physics

    CERN Document Server

    Blatt, John M

    1979-01-01

    A classic work by two leading physicists and scientific educators endures as an uncommonly clear and cogent investigation and correlation of key aspects of theoretical nuclear physics. It is probably the most widely adopted book on the subject. The authors approach the subject as ""the theoretical concepts, methods, and considerations which have been devised in order to interpret the experimental material and to advance our ability to predict and control nuclear phenomena.""The present volume does not pretend to cover all aspects of theoretical nuclear physics. Its coverage is restricted to

  18. Nuclear manpower training

    Energy Technology Data Exchange (ETDEWEB)

    Suh, In Suk; Lee, H. Y.; Lee, E. J.; Yang, K. N.; Jun, H. R.; Seo, K. W.; Lee, S. H.; Kim, Y. J.; Kim, I. H.; Joe, B. J.; Koh, Y. S.; Yoo, B. H.; Kim, M. Y.; Ju, Y. C.; Hyun, H. U.; Choi, I. K.; Hong, C. S.; Won, J. Y.; Nam, J. Y.; Lee, H. J

    1997-12-01

    This report describes the annual results of training courses. The scope and contents are as follows: 1. Education program development of nuclear field 2. International training courses for foreigners 3. Training courses for industry personnel 4. Training courses for R and D staff-members 5. Training courses under the law. The nuclear training center executed 65 training courses for 2,700 engineers/ scientists from the regulatory body, nuclear industries, research institutes and other related organizations during the fiscal year 1997. (author). 18 refs., 3 tabs.

  19. Nuclear physics of stars

    CERN Document Server

    Iliadis, Christian

    2015-01-01

    Most elements are synthesized, or ""cooked"", by thermonuclear reactions in stars. The newly formed elements are released into the interstellar medium during a star's lifetime, and are subsequently incorporated into a new generation of stars, into the planets that form around the stars, and into the life forms that originate on the planets. Moreover, the energy we depend on for life originates from nuclear reactions that occur at the center of the Sun. Synthesis of the elements and nuclear energy production in stars are the topics of nuclear astrophysics, which is the subject of this book

  20. Fictions of nuclear disaster

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, D.

    1987-01-01

    This work is critical study of literary interpretations of the nuclear holocaust. The author examines more than 250 stories and novels dealing with the theme of nuclear power and its devastating potential implications. Addressing such topics as the scientist and Armageddon, the role of religion, future evolution and mutation, and the postnuclear society, the author assesses the response of Bradbury, Lessing, Malamud, Shute, Huxley, Vonnegut, Heinlein, and others to the threat of nuclear apocalypse, with in-depth analyses of Alter Miller's A canticle for Leibowitz and Russell Hoban's Riddley Walker.

  1. Nuclear Winter: Implications for civil defense

    Energy Technology Data Exchange (ETDEWEB)

    Chester, C.V.; Perry, A.M.; Hobbs, B.F.

    1988-05-01

    ''Nuclear Winter'' is the term given to the cooling hypothesized to occur in the Northern Hemisphere following a nuclear war as the result of the injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the paper was published in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. Three-dimensional global circulation models have resulted in reduced estimates of cooling---15 to 25/degree/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought is likely to be a direct threat to human survival for populations with the wherewithal to survive normal January temperatures. The principal threat from nuclear winter is to food production, and this could present problems to third parties who are without food reserves. Loss of a crop year is neither a new nor an unexpected threat from nuclear war to the United States and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the United States due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year.

  2. Nuclear reactor PBMR and cogeneration; Reactor nuclear PBMR y cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Alonso V, G., E-mail: ramon.ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    In recent years the nuclear reactor designs for the electricity generation have increased their costs, so that at the moment costs are managed of around the 5000 US D for installed kw, reason for which a big nuclear plant requires of investments of the order of billions of dollars, the designed reactors as modular of low power seek to lighten the initial investment of a big reactor dividing the power in parts and dividing in modules the components to lower the production costs, this way it can begin to build a module and finished this to build other, differing the long term investment, getting less risk therefore in the investment. On the other hand the reactors of low power can be very useful in regions where is difficult to have access to the electric net being able to take advantage of the thermal energy of the reactor to feed other processes like the water desalination or the vapor generation for the processes industry like the petrochemical, or even more the possible hydrogen production to be used as fuel. In this work the possibility to generate vapor of high quality for the petrochemical industry is described using a spheres bed reactor of high temperature. (Author)

  3. Nuclear Fuels & Materials Spotlight Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    Petti, David Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-10-01

    As the nation's nuclear energy laboratory, Idaho National Laboratory brings together talented people and specialized nuclear research capability to accomplish our mission. This edition of the Nuclear Fuels and Materials Division Spotlight provides an overview of some of our recent accomplishments in research and capability development. These accomplishments include: • Evaluation and modeling of light water reactor accident tolerant fuel concepts • Status and results of recent TRISO-coated particle fuel irradiations, post-irradiation examinations, high-temperature safety testing to demonstrate the accident performance of this fuel system, and advanced microscopy to improve the understanding of fission product transport in this fuel system. • Improvements in and applications of meso and engineering scale modeling of light water reactor fuel behavior under a range of operating conditions and postulated accidents (e.g., power ramping, loss of coolant accident, and reactivity initiated accidents) using the MARMOT and BISON codes. • Novel measurements of the properties of nuclear (actinide) materials under extreme conditions, (e.g. high pressure, low/high temperatures, high magnetic field) to improve the scientific understanding of these materials. • Modeling reactor pressure vessel behavior using the GRIZZLY code. • New methods using sound to sense temperature inside a reactor core. • Improved experimental capabilities to study the response of fusion reactor materials to a tritium plasma. Throughout Spotlight, you'll find examples of productive partnerships with academia, industry, and government agencies that deliver high-impact outcomes. The work conducted at Idaho National Laboratory helps spur innovation in nuclear energy applications that drive economic growth and energy security. We appreciate your interest in our work here at Idaho National Laboratory, and hope that you find this issue informative.

  4. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... may be placed into the bladder, which may cause temporary discomfort. It is important that your child ... images are being recorded. Though nuclear imaging itself causes no pain, children may experience some discomfort from ...

  5. Nuclear Fuel Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Michael F. Simpson; Jack D. Law

    2010-02-01

    This is an a submission for the Encyclopedia of Sustainable Technology on the subject of Reprocessing Spent Nuclear Fuel. No formal abstract was required for the article. The full article will be attached.

  6. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... as well as a patient’s immediate response to therapeutic interventions. Children's (pediatric) nuclear medicine refers to imaging ... top of page Additional Information and Resources The Alliance for Radiation Safety in Pediatric Imaging's "Image Gently" ...

  7. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... variety of diseases, including many types of cancers, heart disease, gastrointestinal, endocrine, neurological disorders and other abnormalities ... and bladder. bones. liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. Nuclear medicine scans are typically ...

  8. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... can be superimposed with computed tomography (CT) or magnetic resonance imaging (MRI) to produce special views, a ... In contrast, nuclear medicine procedures use a radioactive material, called a radiopharmaceutical or radiotracer, which is injected ...

  9. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... and still during imaging. Comfort items such as pacifiers, blankets and books are also very helpful. Often, ... illnesses or other medical conditions. Depending on the type of nuclear scan being performed, you will receive ...

  10. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... leaving the nuclear medicine facility. Through the natural process of radioactive decay, the small amount of radiotracer ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  11. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... stool. Your child should also drink plenty of water to help flush the radioactive material from his ... substantially shorten the procedure time. The resolution of structures of the body with nuclear medicine may not ...

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... molecular information. In many centers, nuclear medicine images can be superimposed with computed tomography (CT) or magnetic ... small hand-held device resembling a microphone that can detect and measure the amount of the radiotracer ...

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... including many types of cancers, heart disease, gastrointestinal, endocrine, neurological disorders and other abnormalities within the body. ... Physicians use nuclear medicine imaging to evaluate organ systems, including the: kidneys and bladder. bones. liver and ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... endocrine, neurological disorders and other abnormalities within the body. Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential to identify disease in ...

  15. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... as well as a patient’s immediate response to therapeutic interventions. Children's (pediatric) nuclear medicine refers to imaging ... be needed for the duration of the exam. Oral: for some exams, the radiotracer is taken by ...

  16. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... used. Most nuclear medicine exams will involve an injection in a vein in your child’s arm or ... are noninvasive and, with the exception of intravenous injections, are usually painless medical tests that help physicians ...

  17. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... nuclear medicine imaging uses small amounts of radioactive materials called radiotracers, a special camera and a computer ... medical imaging that uses small amounts of radioactive material to diagnose and determine the severity of or ...

  18. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... differently than when breathing room air or holding his or her breath. With some exams, a catheter ... physician tells you otherwise, your child may resume his/her normal activities after the nuclear medicine scan. ...

  19. International Nuclear Security

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, James E. [Los Alamos National Laboratory

    2012-08-14

    This presentation discusses: (1) Definitions of international nuclear security; (2) What degree of security do we have now; (3) Limitations of a nuclear security strategy focused on national lock-downs of fissile materials and weapons; (4) What do current trends say about the future; and (5) How can nuclear security be strengthened? Nuclear security can be strengthened by: (1) More accurate baseline inventories; (2) Better physical protection, control and accounting; (3) Effective personnel reliability programs; (4) Minimize weapons-usable materials and consolidate to fewer locations; (5) Consider local threat environment when siting facilities; (6) Implement pledges made in the NSS process; and (7) More robust interdiction, emergency response and special operations capabilities. International cooperation is desirable, but not always possible.

  20. Recapitalizing Nuclear Weapons

    National Research Council Canada - National Science Library

    Vaughan, Edgar M

    2007-01-01

    The US nuclear weapons stockpile is aging and undergoing an extensive and expensive life-extension program to ensure the continuing safety, security, and reliability of the legacy weapons well into the future...

  1. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... the procedure? How does the nuclear medicine procedure work? What does the equipment look like? How is the procedure performed? What will my child experience during and after the procedure? How should ...

  2. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... bladder. bones. liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. Nuclear medicine scans are typically used ... gas via a mask, such as with a lung scan. Bladder: some exams require a catheter to ...

  3. Nuclear Waste and Ethics

    Energy Technology Data Exchange (ETDEWEB)

    Damveld, Herman [Groningen (Netherlands)

    2003-10-01

    In the past years in almost all conferences on storage of nuclear waste, ethics has been considered as an important theme. But what is ethics? We will first give a sketch of this branch of philosophy. We will then give a short explanation of the three principal ethical theories. In the discussion about storage of nuclear waste, the ethical theory of utilitarianism is often implicitly invoked. In this system future generations weigh less heavily than the present generation, so that people of the future are not considered as much as those now living. We reject this form of reasoning. The discussion about nuclear waste is also sometimes pursued from ethical points of departure such as equality and justice. But many loose ends remain in these arguments, which gives rise to the question of whether the production and storage of nuclear waste is responsible.

  4. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... Because the doses of radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. Thus, the radiation risk is very low ...

  5. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... are some common uses of the procedure? Children's (pediatric) nuclear medicine imaging is performed to help diagnose childhood disorders that are congenital (present at birth) or that develop during childhood. ...

  6. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... or treat a variety of diseases, including many types of cancers, heart disease, gastrointestinal, endocrine, neurological disorders and other abnormalities within the body. Because nuclear medicine procedures are ...

  7. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... kidneys and bladder. bones. liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. Nuclear medicine scans are typically used to help diagnose and evaluate: urinary blockage in the kidney. backflow of urine from ...

  8. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page How does the nuclear medicine procedure work? With ordinary x-ray examinations, an image is ... The exception to this is if the child’s mother is pregnant. When the examination is completed, your ...

  9. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... the radiotracer will be inhaled as a gas via a mask, such as with a lung scan. ... being recorded. Though nuclear imaging itself causes no pain, children may experience some discomfort from having to ...

  10. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... the procedure? Except for intravenous injections, most nuclear medicine procedures are painless and are rarely associated with significant discomfort or side effects. If the radiotracer is given intravenously, your child ...

  11. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... medications and allergies. Depending on the type of exam, your doctor will instruct you on what your ... sedation is to be used. Most nuclear medicine exams will involve an injection in a vein in ...

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... a special camera or imaging device that produces pictures and provides molecular information. In many centers, nuclear ... and with the help of a computer, create pictures offering details on both the structure and function ...

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... or that develop during childhood. Physicians use nuclear medicine imaging to evaluate organ systems, including the: kidneys and bladder. bones. liver and gallbladder. gastrointestinal tract. heart. lungs. brain. thyroid. ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... in its earliest stages as well as a patient’s immediate response to therapeutic interventions. Children's (pediatric) nuclear medicine refers to imaging examinations done in ...

  15. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... done in babies, young children and teenagers. Nuclear medicine imaging procedures are noninvasive and, with the exception of intravenous injections, are usually painless medical tests that help physicians diagnose and evaluate medical conditions. ...

  16. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... are rarely associated with significant discomfort or side effects. If the radiotracer is given intravenously, your child ... diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. Thus, the radiation risk ...

  17. Nuclear material operations manual

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, R.P.

    1981-02-01

    This manual provides a concise and comprehensive documentation of the operating procedures currently practiced at Sandia National Laboratories with regard to the management, control, and accountability of nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion.

  18. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... stool. Your child should also drink plenty of water to help flush the radioactive material from his ... radiation risk is very low compared with the potential benefits. Nuclear medicine diagnostic procedures have been used ...

  19. Living with nuclear weapons

    Energy Technology Data Exchange (ETDEWEB)

    Carnesale, A.; Doty, P.; Hoffmann, S.; Huntington, S.P.; Nye, J.S. Jr.; Sagan, S.D.

    1983-01-01

    At Harvard President Derek Bok's request, six Harvard professors explain nuclear arms issues to help citizens understand all sides of the national security debates. The goal is to encourage public participation in policy formulation. The book emphasizes that escapism will not improve security; that idealistic plans to eliminate nuclear weapons are a form of escapism. Learning to live with nuclear weapons, they suggest, requires an understanding of the current nuclear predicament and the implications of alternative weapons and policy choices. After reviewing these matters, they emphasize that informed persons will continue to disagree, but that knowledge will improve understanding and appreciation of their differences and improve the quality of policy debates. 54 references, 5 figures, 2 tables. (DCK)

  20. Desalting and Nuclear Energy

    Science.gov (United States)

    Burwell, Calvin C.

    1971-01-01

    Future use of nuclear energy to produce electricity and desalted water is outlined. Possible desalting processes are analyzed to show economic feasibility and the place in planning in world's economic growth. (DS)

  1. Nuclear Test Limitations Issues

    National Research Council Canada - National Science Library

    Mahoney, Rob

    2000-01-01

    .... It also summarizes public views concerning test limitations and the nuclear stockpile. The second portion of the paper appraises issues that developed during consideration of the CTBT that involve 1...

  2. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits The information provided by nuclear medicine examinations ... diagnosis or to determine appropriate treatment, if any. Risks Because the doses of radiotracer administered are small, ...

  3. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page How does the nuclear medicine procedure work? With ordinary x-ray examinations, an image is ... such low-dose exposure. For more information about safety in pediatric radiology procedures, visit the Image Gently ...

  4. Modeling nuclear explosion

    Science.gov (United States)

    Redd, Jeremy; Panin, Alexander

    2012-10-01

    As a result of the Nuclear Test Ban Treaty, no nuclear explosion tests have been performed by the US since 1992. This appreciably limits valuable experimental data needed for improvement of existing weapons and development of new ones, as well as for use of nuclear devices in non-military applications (such as making underground oil reservoirs or compressed air energy storages). This in turn increases the value of numerical modeling of nuclear explosions and of their effects on the environment. We develop numerical codes simulating fission chain reactions in a supercritical U and Pu core and the dynamics of the subsequent expansion of generated hot plasma in order to better understand the impact of such explosions on their surroundings. The results of our simulations (of both above ground and underground explosions) of various energy yields are presented.

  5. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... determine appropriate treatment, if any. Risks Because the doses of radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. Thus, the radiation ...

  6. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... used in children with cancer, epilepsy and back pain. top of page What does the equipment look ... being recorded. Though nuclear imaging itself causes no pain, children may experience some discomfort from having to ...

  7. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... computer, create pictures offering details on both the structure and function of organs and tissues in your ... substantially shorten the procedure time. The resolution of structures of the body with nuclear medicine may not ...

  8. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... organs and tissues in your body. Hybrid imaging techniques (PET/CT, SPECT/CT and PET/MR) are ... equipment look like? The special camera and imaging techniques used in nuclear medicine include the gamma camera ...

  9. The Nuclear Strategy Tripod

    DEFF Research Database (Denmark)

    Nellemann, Camilla

    In March 2011, the global nuclear industry was struck by the Fukushima accident which immediately and greatly affected the global business environment for nuclear power. I analyze how the industry-leader Toshiba adapted to the changing circumstances from the perspectives of the strategy tripod...... is that the company maintains its strategy for nuclear power because the management perceives the negative consequences of 3/11 as manageable........ However, I amend the tripod-framework by defining operationalizable variables based on my literature review of nuclear research to be able to apply it in my study. At the industry level, I identify coopetitive behavior as the most important variable, while the critical resources and capabilities...

  10. 2011 Japanese Nuclear Incident

    Science.gov (United States)

    EPA’s RadNet system monitored the environmental radiation levels in the United States and parts of the Pacific following the Japanese Nuclear Incident. Learn about EPA’s response and view historical laboratory data and news releases.

  11. Nuclear data interface retrospective

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Mark G [Los Alamos National Laboratory

    2008-01-01

    The Nuclear Data Interface (NDI) code library and data formats are the standards for multigroup nuclear data at Los Alamos National Laboratory. NDI's analysis, design, implementation, testing, integration, and maintenance required a ten person-year and ongoing effort by the Nuclear Data Team. Their efforts provide a unique, contemporary experience in producing a standard component library. In reflection upon that experience at NDI's decennial, we have identified several factors critical to NDI's success: it addressed real problems with appropriate simplicity, it fully supported all users, it added extra value through the code to the raw nuclear data, and its team went the distance from analysis through maintenance. In this report we review these critical success factors and discuss their implications for future standardization projects.

  12. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... when breathing room air or holding his or her breath. With some exams, a catheter may be ... tells you otherwise, your child may resume his/her normal activities after the nuclear medicine scan. If ...

  13. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of the thyroid gland. top of page How does the nuclear medicine procedure work? With ordinary x- ... epilepsy and back pain. top of page What does the equipment look like? The special camera and ...

  14. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... the procedure. top of page Who interprets the results and how do we get them? A radiologist ... radiotracer administered are small, diagnostic nuclear medicine procedures result in low radiation exposure, acceptable for diagnostic exams. ...

  15. Western Nuclear Science Alliance

    Energy Technology Data Exchange (ETDEWEB)

    Steve Reese; George Miller; Stephen Frantz; Denis Beller; Denis Beller; Ed Morse; Melinda Krahenbuhl; Bob Flocchini; Jim Elliston

    2010-12-07

    The primary objective of the INIE program is to strengthen nuclear science and engineering programs at the member institutions and to address the long term goal of the University Reactor Infrastructure and Education Assistance Program.

  16. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... earliest stages as well as a patient’s immediate response to therapeutic interventions. Children's (pediatric) nuclear medicine refers ... Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 Radiological Society of North America, ...

  17. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... information you were looking for? Yes No Please type your comment or suggestion into the following text box: Comment: ... Images related to Children's (Pediatric) Nuclear Medicine Videos ...

  18. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... is performed to help diagnose childhood disorders that are congenital (present at birth) or that develop during childhood. Physicians use nuclear medicine imaging to evaluate organ systems, including the: kidneys and bladder. bones. liver and ...

  19. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... radiation exposure, acceptable for diagnostic exams. Thus, the radiation risk is very low compared with the potential benefits. Nuclear medicine diagnostic procedures have been used for more than ...

  20. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... of page How does the nuclear medicine procedure work? With ordinary x-ray examinations, an image is ... your child or the camera will stay in one position and your child will be asked to ...

  1. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... body. jaundice in newborns and older children. epilepsy . location, anatomy and function of the thyroid gland. top ... to be followed after leaving the nuclear medicine facility. Through the natural process of radioactive decay, the ...

  2. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... both imaging exams at the same time. An emerging imaging technology, but not readily available at this ... top of page What are the benefits vs. risks? Benefits The information provided by nuclear medicine examinations ...

  3. Nuclear Mechanics in Disease

    Science.gov (United States)

    Zwerger, Monika; Ho, Chin Yee; Lammerding, Jan

    2015-01-01

    Over the past two decades, the biomechanical properties of cells have emerged as key players in a broad range of cellular functions, including migration, proliferation, and differentiation. Although much of the attention has focused on the cytoskeletal networks and the cell’s microenvironment, relatively little is known about the contribution of the cell nucleus. Here, we present an overview of the structural elements that determine the physical properties of the nucleus and discuss how changes in the expression of nuclear components or mutations in nuclear proteins can affect not only nuclear mechanics but also modulate cytoskeletal organization and diverse cellular functions. These findings illustrate that the nucleus is tightly integrated into the surrounding cellular structure. Consequently, changes in nuclear structure and composition are highly relevant to normal development and physiology and can contribute to many human diseases, such as muscular dystrophy, dilated cardiomyopathy, (premature) aging, and cancer. PMID:21756143

  4. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... small amount of energy in the form of gamma rays. Special cameras detect this energy, and with ... imaging techniques used in nuclear medicine include the gamma camera and single-photon emission-computed tomography (SPECT). ...

  5. Children's (Pediatric) Nuclear Medicine

    Medline Plus

    Full Text Available ... until the nuclear physician checks the images in case additional images are needed. top of page What ... will lose its radioactivity over time. In many cases, the radioactivity will dissipate over the first 24 ...

  6. Nuclear reactor shutdown control rod assembly

    Science.gov (United States)

    Bilibin, Konstantin

    1988-01-01

    A temperature responsive, self-actuated nuclear reactor shutdown control rod assembly 10. The upper end 18 of a lower drive line 17 fits within the lower end of an upper drive line 12. The lower end (not shown) of the lower drive line 17 is connected to a neutron absorber. During normal temperature conditions the lower drive line 17 is supported by detent means 22,26. When an overtemperature condition occurs thermal actuation means 34 urges ring 26 upwardly sufficiently to allow balls 22 to move radially outwardly thereby allowing lower drive line 17 to move downwardly toward the core of the nuclear reactor resulting in automatic reduction of the reactor powder.

  7. Evolution of nuclear spectroscopy at Saha Institute of Nuclear Physics

    Indian Academy of Sciences (India)

    physics pp. 5–9. Evolution of nuclear spectroscopy at Saha Institute of Nuclear Physics. P MUKHERJEE. Formerly of Saha Institute of Nuclear Physics, Kolkata 700 064, India. Present Address: 85 Block A, Bangur Avenue, Kolkata 700 055, India. Abstract. Experimental studies of nuclear excitations have been an important ...

  8. Restructuring nuclear regulations.

    OpenAIRE

    Mossman, Kenneth L

    2003-01-01

    Nuclear regulations are a subset of social regulations (laws to control activities that may negatively impact the environment, health, and safety) that concern control of ionizing radiation from radiation-producing equipment and from radioactive materials. The impressive safety record among nuclear technologies is due, in no small part, to the work of radiation safety professionals and to a protection system that has kept pace with the rapid technologic advancements in electric power generati...

  9. Nuclear Plant Inspection

    Science.gov (United States)

    1983-01-01

    Engineers from the Power Authority of the State of New York use a Crack Growth Analysis Program supplied by COSMIC (Computer Software Management and Information Center) in one stage of nuclear plant inspection. Welds of the nuclear steam supply system are checked for cracks; radiographs, dye penetration and visual inspections are performed to locate cracks in the metal structure and welds. The software package includes three separate crack growth analysis models and enables necessary repairs to be planned before serious problems develop.

  10. JPRS Report, Nuclear Developments

    Science.gov (United States)

    1991-04-23

    version of anti-aircraft, shoulder -fired apparent reason being her full readiness in nuclear and missile system to be known with Pakistani designation of...its being a shoulder -fired capability like the Stinger, a credible "nuclear deterrent" to avoid the dangers of Sam-7 and RBS-20". war permanently in the...balance. A readaptation launched group of European NATO nations and made it clear that with much fanfare last year with the publication of a Europe

  11. Pakistans Nuclear Weapons

    Science.gov (United States)

    2016-02-12

    intensity conflict or proxy war in Kashmir , while effectively deterring India at the strategic level. 96 In any case, Pakistani statements suggest that the ...Furthermore, continued Indian and Pakistani nuclear weapons development could jeopardize strategic stability between the two countries. For a...context where these broader tensions and conflicts are present. 1 Pakistani efforts to improve the security of its nuclear weapons have been ongoing

  12. The climatic effects of nuclear war

    Science.gov (United States)

    Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, C.

    1984-01-01

    The effects of various US-USSR nuclear-exchange scenarios on global climate are investigated by means of computer simulations, summarizing the results of Turco et al. (1983) and follow-up studies using 3D global-circulation models. A nuclear-scenario model is used to determine the amounts of dust, smoke, radioactivity, and pyrotoxins generated by a particular type of nuclear exchange (such as a general 5,000-Mt exchange, a 1,000-Mt limited exchange, a 5,000-Mt hard-target counterforce attack, and a 100-Mt attack on cities only): a particle-microphysics model predicts the evolution of the dust and smoke particles; and a radiative-convective climate model estimates the effects of the dust and smoke clouds on the global radiation budget. The findings are presented in graphs, diagrams, and a table. Thick clouds blocking most sunlight over the Northern Hemisphere midlatitudes for weeks or months and producing ground-temperature reductions of 20-40 C, disruption of global circulation patterns, and rapid spread of clouds to the Southern Hemisphere are among the 'nuclear-winter' effects predicted for the 5,000-Mt baseline case. The catastrophic consequences for plant, animal, and human populations are considered, and the revision of superpower nuclear strategies is urged.

  13. Nuclear Fuels & Materials Spotlight Volume 4

    Energy Technology Data Exchange (ETDEWEB)

    I. J. van Rooyen,; T. M. Lillo; Y. Q. WU; P.A. Demkowicz; L. Scott; D.M. Scates; E. L. Reber; J. H. Jackson; J. A. Smith; D.L. Cottle; B.H. Rabin; M.R. Tonks; S.B. Biner; Y. Zhang; R.L. Williamson; S.R. Novascone; B.W. Spencer; J.D. Hales; D.R. Gaston; C.J. Permann; D. Anders; S.L. Hayes; P.C. Millett; D. Andersson; C. Stanek; R. Ali; S.L. Garrett; J.E. Daw; J.L. Rempe; J. Palmer; B. Tittmann; B. Reinhardt; G. Kohse; P. Ramuhali; H.T. Chien; T. Unruh; B.M. Chase; D.W. Nigg; G. Imel; J. T. Harris

    2014-04-01

    As the nation's nuclear energy laboratory, Idaho National Laboratory brings together talented people and specialized nuclear research capability to accomplish our mission. This edition of the Nuclear Fuels and Materials Division Spotlight provides an overview of some of our recent accomplishments in research and capability development. These accomplishments include: • The first identification of silver and palladium migrating through the SiC layer in TRISO fuel • A description of irradiation assisted stress corrosion testing capabilities that support commercial light water reactor life extension • Results of high-temperature safety testing on coated particle fuels irradiated in the ATR • New methods for testing the integrity of irradiated plate-type reactor fuel • Description of a 'Smart Fuel' concept that wirelessly provides real time information about changes in nuclear fuel properties and operating conditions • Development and testing of ultrasonic transducers and real-time flux sensors for use inside reactor cores, and • An example of a capsule irradiation test. Throughout Spotlight, you'll find examples of productive partnerships with academia, industry, and government agencies that deliver high-impact outcomes. The work conducted at Idaho National Laboratory helps to spur innovation in nuclear energy applications that drive economic growth and energy security. We appreciate your interest in our work here at INL, and hope that you find this issue informative.

  14. Superpower nuclear minimalism

    Energy Technology Data Exchange (ETDEWEB)

    Graben, E.K.

    1992-01-01

    During the Cold War, the United States and the Soviet Union competed in building weapons -- now it seems like America and Russia are competing to get rid of them the fastest. The lengthy process of formal arms control has been replaced by exchanges of unilateral force reductions and proposals for reciprocal reductions not necessarily codified by treaty. Should superpower nuclear strategies change along with force postures President Bush has yet to make a formal pronouncement on post-Cold War American nuclear strategy, and it is uncertain if the Soviet/Russian doctrine of reasonable sufficiency formulated in the Gorbachev era actually heralds a change in strategy. Some of the provisions in the most recent round of unilateral proposals put forth by Presidents Bush and Yeltsin in January 1992 are compatible with a change in strategy. Whether such a change has actually occurred remains to be seen. With the end of the Cold War and the breakup of the Soviet Union, the strategic environment has fundamentally changed, so it would seem logical to reexamine strategy as well. There are two main schools of nuclear strategic thought: a maximalist school, mutual assured destruction (MAD) which emphasizes counterforce superiority and nuclear war- fighting capability, and a MAD-plus school, which emphasizes survivability of an assured destruction capability along with the ability to deliver small, limited nuclear attacks in the event that conflict occurs. The MAD-plus strategy is based on an attempt to conventionalize nuclear weapons which is unrealistic.

  15. Plant nuclear photorelocation movement.

    Science.gov (United States)

    Higa, Takeshi; Suetsugu, Noriyuki; Wada, Masamitsu

    2014-06-01

    Organelle movement and positioning are essential for proper cellular function. A nucleus moves dynamically during cell division and differentiation and in response to environmental changes in animal, fungal, and plant cells. Nuclear movement is well-studied and the mechanisms have been mostly elucidated in animal and fungal cells, but not in plant cells. In prothallial cells of the fern Adiantum capillus-veneris and leaf cells of the flowering plant Arabidopsis thaliana, light induces nuclear movement and nuclei change their position according to wavelength, intensity, and direction of light. This nuclear photorelocation movement shows some common features with the photorelocation movement of chloroplasts, which is one of the best-characterized plant organelle movements. This review summarizes nuclear movement and positioning in plant cells, especially plant-specific nuclear photorelocation movement and discusses the relationship between nuclear photorelocation movement and chloroplast photorelocation movement. © The Author 2013. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. Collective dynamics in relativistic nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Niemi, Harri [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland)

    2014-11-15

    I will review the current status of describing spacetime evolution of the relativistic nuclear collisions with fluid dynamics, and of determining the transport coefficients of strongly interacting matter. The fluid dynamical models suggest that shear viscosity to entropy density ratio of the matter is small. However, there are still considerable challenges in determining the transport coefficients, and especially their temperature dependence is still poorly constrained.

  17. Nuclear reaction rates and the primordial nucleosynthesis

    OpenAIRE

    Mishra, Abhishek; Basu, D. N.

    2011-01-01

    The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a littl...

  18. Nuclear cogeneration based on HTR technology

    Energy Technology Data Exchange (ETDEWEB)

    Haverkate, B.R.W.; Van Heek, A.I.; Jehee, J.N.T

    1998-03-01

    The Dutch market for combined generation of heat and power identifies a unit size of 40 MW thermal for the conceptual design of an Inherently safe Nuclear COGENeration plant (INCOGEN). Technical, economical and licensing issues have been investigated of the INCOGEN design which comprises pebble fuel cooled by helium, and directly coupled with a helium compressor and turbine. Thermohydraulic and reactor physics analyses show favourable control characteristics during normal operation and a benign response to loss of helium coolant and loss of flow conditions. Throughout the response on these highly infrequent conditions, ample margin exists between the highest fuel temperatures and the temperature above which fuel degradation will occur. 7 refs.

  19. High Temperature Heat Exchanger Project

    Energy Technology Data Exchange (ETDEWEB)

    Anthony E. Hechanova, Ph.D.

    2008-09-30

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  20. Nuclear Propulsion for Space (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, William R; Schwenk, Francis C

    1971-01-01

    The operation of nuclear rockets and a description of the development of nuclear rockets in the U.S. is given. Early developments and Project Rover, Project Pluto, and the NERVA (Nuclear Engine for Rocket Vehicle Application) Program are detailed. The Nuclear Rocket Development Station facilities in Nevada are described. The possibilities and advantages of using nuclear rockets for missions beginning from an earth orbit and moving outward toward higher earth orbits, the moon, and the planets are discussed.