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Sample records for alamos critical experiments

  1. Los Alamos Critical Experiments Facility

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1991-01-01

    The Critical Experiments Facility of the Los Alamos National Laboratory has been in existence for 45 years. In that period of time, thousands of measurements have been made on assemblies containing every fissionable material in various configurations that included bare metal and compounds of the nitrate, sulfate, fluoride, carbide, and oxide. Techniques developed or applied include Rossi-α, source-jerk, rod oscillator, and replacement measurements. Many of the original measurements of delay neutrons were performed at the site, and a replica of the Hiroshima weapon was operated at steady state to assist in evaluating the relative biological effectiveness (RBE) of neutrons. Solid, liquid, and gas fissioning systems were run at critical. Operation of this original critical facility has demonstrated the margin of safety that can be obtained through remote operation. Eight accidental excursions have occurred on the site, ranging from 1.5 x 10 16 to 1.2 x 10 17 fissions, with no significant exposure to personnel or damage to the facility beyond the machines themselves -- and in only one case was the machine damaged beyond further use. The present status of the facility, operating procedures, and complement of machines will be described in the context of programmatic activity. New programs will focus on training, validation of criticality alarm systems, experimental safety assessment of process applications, and dosimetry. Special emphasis will be placed on the incorporation of experience from 45 years of operation into present procedures and programs. 3 refs

  2. The Pajarito Site operating procedures for the Los Alamos Critical Experiments Facility

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1991-12-01

    Operating procedures consistent with DOE Order 5480.6, and the American National Standard Safety Guide for the Performance of Critical Experiments are defined for the Los Alamos Critical Experiments Facility (LACEF) of the Los Alamos National Laboratory. These operating procedures supersede and update those previously published in 1983 and apply to any criticality experiment performed at the facility. 11 refs

  3. Safety analysis of the Los Alamos critical experiments facility

    International Nuclear Information System (INIS)

    Paxton, H.C.

    1975-10-01

    The safety of Pajarito Site critical assembly operations depends upon protection built into the facility, upon knowledgeable personnel, and upon good practice as defined by operating procedures and experimental plans. Distance, supplemented by shielding in some cases, would protect personnel against an extreme accident generating 10 19 fissions. During the facility's 28-year history, the direct cost of criticality accidents has translated to a risk of less than $200 per year

  4. Safety analysis of the Los Alamos critical experiments facility: burst operation of Skua

    International Nuclear Information System (INIS)

    Orndoff, J.D.; Paxton, H.C.; Wimett, T.F.

    1980-12-01

    Detailed consideration of the Skua burst assembly is provided, thereby supplementing the facility Safety Analysis Report covering the operation of other critical assemblies at the Los Alamos Scientific Laboratory. As with these assemblies the small fission-product inventory, ambient pressure, and moderate temperatures in Skua are amenable to straightforward measures to ensure the protection of the public

  5. Risk management for operations of the Los Alamos critical experiments facility

    International Nuclear Information System (INIS)

    Paternoster, R.; Butterfield, K.

    1998-01-01

    The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly (SHEBA 2--Solution high-Energy Burst Assembly), two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines which may be configured with nuclear materials and assembled by remote control. SNM storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations which can include critical assembly fuel loading. The operational sequences of each mode are very nearly the same, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs

  6. Critical Infrastructure Protection- Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Bofman, Ryan K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-24

    Los Alamos National Laboratory (LANL) has been a key facet of Critical National Infrastructure since the nuclear bombing of Hiroshima exposed the nature of the Laboratory’s work in 1945. Common knowledge of the nature of sensitive information contained here presents a necessity to protect this critical infrastructure as a matter of national security. This protection occurs in multiple forms beginning with physical security, followed by cybersecurity, safeguarding of classified information, and concluded by the missions of the National Nuclear Security Administration.

  7. Los Alamos personnel and area criticality dosimeter systems

    International Nuclear Information System (INIS)

    Vasilik, D.G.; Martin, R.W.

    1981-06-01

    Fissionable materials are handled and processed at the Los Alamos National Laboratory. Although the probability of a nuclear criticality accident is very remote, it must be considered. Los Alamos maintains a broad spectrum of dose assessment capabilities. This report describes the methods employed for personnel neutron, area neutron, and photon dose evaluations with passive dosimetry systems

  8. Los Alamos personnel and area criticality dosimeter systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasilik, D.G.; Martin, R.W.

    1981-06-01

    Fissionable materials are handled and processed at the Los Alamos National Laboratory. Although the probability of a nuclear criticality accident is very remote, it must be considered. Los Alamos maintains a broad spectrum of dose assessment capabilities. This report describes the methods employed for personnel neutron, area neutron, and photon dose evaluations with passive dosimetry systems.

  9. Benchmark assemblies of the Los Alamos Critical Assemblies Facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1985-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

  10. Benchmark assemblies of the Los Alamos critical assemblies facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1985-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

  11. Benchmark assemblies of the Los Alamos critical assemblies facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1986-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described. (author)

  12. Fluctuations in three Los Alamos experiments

    International Nuclear Information System (INIS)

    Wright, B.L.

    1983-01-01

    We review results from three magnetic fusion experiments at Los Alamos: the ZT-40M, a reversed-field toroidal pinch; the CTX, a spheromak produced by a magnetized coaxial source; and the FRX-C, a field-reversed configuration generated by theta-pinch techniques. These experiments share the common feature that a major fraction of the confining magnetic field is associated with currents carried by the plasma. We emphasize here the important role that fluctuations play in the maintenance and evolution of these configurations

  13. Decommissioning the Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I)

    International Nuclear Information System (INIS)

    Harper, J.R.; Garde, R.

    1981-11-01

    The Los Alamos Molten Plutonium Reactor Experiment (LAMPRE I) was decommissioned at the Los Alamos National Laboratory, Los Alamos, New Mexico, in 1980. The LAMPRE I was a sodium-cooled reactor built to develop plutonium fuels for fast breeder applications. It was retired in the mid-1960s. This report describes the decommissioning procedures, the health physics programs, the waste management, and the costs for the operation

  14. Los Alamos critical-mass data

    International Nuclear Information System (INIS)

    Paxton, H.C.

    1975-11-01

    The original version of this report tabulates critical masses of simple systems, which have been measured through the year 1963. This revision adds data through October 1975, and modifies some of the old critical specifications that have been reevaluated. The old format and symbolism are retained to simplify reproduction

  15. The Criticality Safety Information Resource Center at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, B.D.; Meade, R.A. [Los Alamos National Lab., NM (United States); Pruvost, N.L. [Galaxy Computer Services, Inc., Santa Fe, NM (United States)

    1997-05-01

    The mission of the Criticality Safety Information Resource Center (CSIRC) at Los Alamos National Laboratory (LANL) is the preservation of primary documentation supporting criticality safety. In many cases, but not all, this primary documentation consists of experimentalists` logbooks. Experience has shown that the logbooks and other primary information are vulnerable to being discarded. Destruction of these logbooks results in a permanent loss to the criticality safety community.

  16. Experience with confirmation measurement at Los Alamos

    International Nuclear Information System (INIS)

    Marshall, R.S.; Wagner, R.P.; Hsue, F.

    1985-01-01

    Confirmation measurements are used at Los Alamos in support of incoming and outgoing shipment accountibility and for support of both at 235 U and Pu inventories. Statistical data are presented to show the consistency of measurements on items of identical composition and on items measured at two facilitis using similar instruments. A description of confirmation measurement techniques used in support of 235 U and Pu inventories and a discussion on the ability of the measurements to identify items with misstated SNM are given

  17. Experience with confirmation measurement at Los Alamos

    International Nuclear Information System (INIS)

    Marshall, R.S.; Wagner, R.P.

    1985-01-01

    Confirmation measurements are used at Los Alamos in support of incoming and outgoing shipment accountability and for support of both 235 U and Pu inventories. Statistical data are presented to show the consistency of measurements on items of identical composition and on items measured at two facilities using similar instruments. A description of confirmation measurement techniques used in support of 235 U and Pu inventories and a discussion on the ability of the measurements to identify items with misstated SNM are given

  18. The Criticality Safety Information Resource Center (CSIRC) at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, B.D.; Meade, R.A.; Pruvost, N.L.

    1999-09-20

    The Criticality Safety Information Resource Center (CSIRC) at Los Alamos National Laboratory (LANL) is a program jointly funded by the U.S. Department of Energy (DOE) and the U.S. Nuclear Regulatory Commission (NRC) in conjunction with the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 97-2. The goal of CSIRC is to preserve primary criticality safety documentation from U.S. critical experimental sites and to make this information available for the benefit of the technical community. Progress in archiving criticality safety primary documents at the LANL archives as well as efforts to make this information available to researchers are discussed. The CSIRC project has a natural linkage to the International Criticality Safety Benchmark Evaluation Project (ICSBEP). This paper raises the possibility that the CSIRC project will evolve in a fashion similar to the ICSBEP. Exploring the implications of linking the CSIRC to the international criticality safety community is the motivation for this paper.

  19. The Criticality Safety Information Resource Center (CSIRC) at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Henderson, B.D.; Meade, R.A.; Pruvost, N.L.

    1999-01-01

    The Criticality Safety Information Resource Center (CSIRC) at Los Alamos National Laboratory (LANL) is a program jointly funded by the U.S. Department of Energy (DOE) and the U.S. Nuclear Regulatory Commission (NRC) in conjunction with the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 97-2. The goal of CSIRC is to preserve primary criticality safety documentation from U.S. critical experimental sites and to make this information available for the benefit of the technical community. Progress in archiving criticality safety primary documents at the LANL archives as well as efforts to make this information available to researchers are discussed. The CSIRC project has a natural linkage to the International Criticality Safety Benchmark Evaluation Project (ICSBEP). This paper raises the possibility that the CSIRC project will evolve in a fashion similar to the ICSBEP. Exploring the implications of linking the CSIRC to the international criticality safety community is the motivation for this paper

  20. Nuclear criticality safety staff training and qualifications at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Monahan, S.P.; McLaughlin, T.P.

    1997-01-01

    Operations involving significant quantities of fissile material have been conducted at Los Alamos National Laboratory continuously since 1943. Until the advent of the Laboratory's Nuclear Criticality Safety Committee (NCSC) in 1957, line management had sole responsibility for controlling criticality risks. From 1957 until 1961, the NCSC was the Laboratory body which promulgated policy guidance as well as some technical guidance for specific operations. In 1961 the Laboratory created the position of Nuclear Criticality Safety Office (in addition to the NCSC). In 1980, Laboratory management moved the Criticality Safety Officer (and one other LACEF staff member who, by that time, was also working nearly full-time on criticality safety issues) into the Health Division office. Later that same year the Criticality Safety Group, H-6 (at that time) was created within H-Division, and staffed by these two individuals. The training and education of these individuals in the art of criticality safety was almost entirely self-regulated, depending heavily on technical interactions between each other, as well as NCSC, LACEF, operations, other facility, and broader criticality safety community personnel. Although the Los Alamos criticality safety group has grown both in size and formality of operations since 1980, the basic philosophy that a criticality specialist must be developed through mentoring and self motivation remains the same. Formally, this philosophy has been captured in an internal policy, document ''Conduct of Business in the Nuclear Criticality Safety Group.'' There are no short cuts or substitutes in the development of a criticality safety specialist. A person must have a self-motivated personality, excellent communications skills, a thorough understanding of the principals of neutron physics, a safety-conscious and helpful attitude, a good perspective of real risk, as well as a detailed understanding of process operations and credible upsets

  1. Critical mass experiment using U-235 foils and lucite plates

    International Nuclear Information System (INIS)

    Sanchez, R.; Butterfield, K.; Kimpland, R.; Jaegers, P.

    1998-01-01

    The main objective of this experiment was to show how the multiplication of the system increases as moderated material is placed between highly enriched uranium foils. In addition, this experiment served to demonstrate the hand-stacking techniques, and approach to criticality by remote operation. This experiment was designed by Tom McLaughlin in the mid seventies as part of the criticality safety course that is taught at Los Alamos Critical Experiment Facility (LACEF). The W-U-235 ratio for this experiment was 215 which is where the minimum critical mass for this configuration occurs

  2. Subpicosecond compression experiments at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Carlsten, B.E.; Russell, S.J.; Kinross-Wright, J.M. [and others

    1995-09-01

    The authors report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches at both low (0.1 nC) and high (1 nC) charges were compressed from 20 ps to less than 1 ps (FWHM). A transverse deflecting rf cavity was used to measure the bunch length at low charge; the bunch length at high charge was inferred from an induced energy spread of the beam. The longitudinal centrifugal-space charge force is calculated using a point-to-point numerical simulation and is shown not to influence the energy-spread measurement.

  3. The Los Alamos POP Project: FEL oscillator experiments in the ultraviolet and beyond

    International Nuclear Information System (INIS)

    Newnam, B.E.; Warren, R.W.; Goldstein, J.C.; Schmitt, M.J.; Bender, S.C.; Carlsten, B.E.; Feldman, D.W.; O'Shea, P.G.

    1992-01-01

    The Los Alamos POP Project will include a series of proof-of-principle FEL oscillator experiments in 1992 designed to extend FEL operation into the ultraviolet (UV) and vacuum ultraviolet (VUV). With beam energy extended to 50 MeV, enhanced beam brightness with a photoinjector, and appropriate UV and VUV resonator optics, the Los Alamos FEL oscillator should have sufficient single-pass gain (20--30%) to reach below 200 nm. The first goal will be lasing at 250 nm utilizing a permanent-magnet undulator with 5-mm period or alternatively on the third harmonic with a 1-cm period. To operate at VUV wavelengths of 200 and 150 nm (third harmonic), pulsed electromagnetic microwigglers with periods of 5.7- and 4.3 mm will be employed. 23 refs

  4. Review of the Los Alamos FRX-C experiment

    International Nuclear Information System (INIS)

    Siemon, R.E.; Armstrong, W.T.; Barnes, D.C.

    1985-01-01

    The FRX-C device is a large field-reversed theta pinch experiment, with linear dimensions twice those of its FRX-A and FRX-B predecessors. It is used to form field-reversed configurations (FRCs), which are high-beta, highly prolate compact toroids. FRX-C has demonstrated an R 2 scaling for particle confinement in FRCs, indicating particles are lost by diffusive processes. Particle losses were also observed to dominate the energy balance. FRC lifetimes exceeding 300 μs were observed when weak quadrupole fields were applied to stabilize the n = 2 rotational mode. Detailed studies of the FRC equilibrium were performed using multi-chord and holographic interferometry. Measurements of electron temperature by Thomson scattering showed a flat profile and substantial losses through the electron channel. The loss rate of the internal poloidal flux of the FRC was observed to be anomalous and to scale less strongly with temperature than predicted from classical resistivity

  5. Review of the Los Alamos FRX-C experiment

    Energy Technology Data Exchange (ETDEWEB)

    Siemon, R.E.; Armstrong, W.T.; Barnes, D.C.; Bartsch, R.R.; Chrien, R.E.; Cochrane, J.C.; Hugrass, W.; Kewish, R.W.; Klingner, P.L.; Lewis, H.R.

    1985-01-01

    The FRX-C device is a large field-reversed theta pinch experiment, with linear dimensions twice those of its FRX-A and FRX-B predecessors. It is used to form field-reversed configurations (FRCs), which are high-beta, highly prolate compact toroids. FRX-C has demonstrated an R/sup 2/ scaling for particle confinement in FRCs, indicating particles are lost by diffusive processes. Particle losses were also observed to dominate the energy balance. FRC lifetimes exceeding 300 ..mu..s were observed when weak quadrupole fields were applied to stabilize the n = 2 rotational mode. Detailed studies of the FRC equilibrium were performed using multi-chord and holographic interferometry. Measurements of electron temperature by Thomson scattering showed a flat profile and substantial losses through the electron channel. The loss rate of the internal poloidal flux of the FRC was observed to be anomalous and to scale less strongly with temperature than predicted from classical resistivity.

  6. LOS ALAMOS

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Following the historic observation of neutrinos in the mid-1950s by two Los Alamos scientists, Fred Reines and Clyde Cowan, Jr, using inverse beta decay, there has been a long and distinguished history of experimental neutrino physics at LAMPF, the Los Alamos Meson Physics Facility. LAMPF is the only meson factory to have had an experimental neutrino programme. In the late 1970s, the first LAMPF neutrino experiment used a 6-tonne water Cherenkov detector 7 metres from the beam stop. A collaboration of Yale, Los Alamos and several other institutions, this experiment searched for the forbidden decay of a muon into an electron and two neutrinos, and measured the reaction rate of a neutrino interacting with a deuteron to give two protons and an electron - the inverse of the reaction that drives the sun's primary energy source. The next LAMPF neutrino experiment, a UC Irvine/Maryland/Los Alamos collaboration, ran from 1982 through 1986 and measured the elastic scattering rate of electron neutrinos and protons, where both neutral and charged weak currents contribute. With its precision of about 15%, the experiment provided the first demonstration of (destructive) interference between the charged and neutral currents. More recent neutrino experiments at LAMPF have searched for neutrino oscillations, especially between muon- and electron-neutrinos. The newest experiment to pursue this physics (as well as oscillations in other channels) is LSND (July/ August, page 10 and cover). In addition to searching for these oscillations, LSND will measure neutrino-proton elastic scattering at low momentum transfer, providing a sensitive measure of the strange quark contribution to the proton spin. LSND began taking data in August. Los Alamos physicists have also been busy in neutrino physics experiments elsewhere. One such experiment looked at the beta decay of free molecular tritium to obtain an essentially model independent determination of the electron-neutrino mass. The

  7. Optical transition radiation measurements for the Los Alamos and Boeing Free-Electron Laser experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Feldman, R.B.; Feldman, D.W.; Apgar, S.A.; Calsten, B.E.; Fiorito, R.B.; Rule, D.W.

    1988-01-01

    Optical transition radiation (OTR) measurements of the electron-beam emittance have been performed at a location just before the wiggler in the Los Alamos Free-Electron Laser (FEL) experiment. Beam profiles and beam divergence patterns from a single macropulse were recorded simultaneously using two intensified charge-injection device (CID) television cameras and an optical beamsplitter. Both single-foil OTR and two-foil OTR interference experiments were performed. Preliminary results are compared to a reference variable quadrupole, single screen technique. New aspects of using OTR properties for pointing the e-beam on the FEL oscillator axis, as well as measuring e-beam emittance are addressed. 7 refs., 9 figs.

  8. Emittance growth caused by bends in the Los Alamos free-electron laser energy recovery experiment

    International Nuclear Information System (INIS)

    Carlsten, B.E.

    1987-01-01

    Experimentally transporting the beam from the wiggler to the decelerators in the energy recovery experiment (ERX) at the Los Alamos National Laboratory free-electron laser was more difficult than expected because of the large initial emittance in the beam. This emittance was apparently caused in an early 60 0 achromatic bend. To get this beam through subsequent bends without wall interception, the quadrupole focusing had to be changed from the design amount; as a result, the emittance grew further. This paper discusses various mechanisms for this emittance growth in the 60 0 bend, including effects caused by path changes in the bend resulting from wake-field-induced energy changes of particles in the beam and examines emittance filters, ranging from a simple aperture near a beam crossover to more complicated telescope schemes designed to regain the original emittance before the 60 0 bend

  9. First results from the Los Alamos plasma source ion implantation experiment

    International Nuclear Information System (INIS)

    Rej, D.J.; Faehl, R.J.; Gribble, R.J.; Henins, I.; Kodali, P.; Nastasi, M.; Reass, W.A.; Tesmer, J.; Walter, K.C.; Wood, B.P.; Conrad, J.R.; Horswill, N.; Shamim, M.; Sridharan, K.

    1993-01-01

    A new facility is operational at Los Alamos to examine plasma source ion implantation on a large scale. Large workpieces can be treated in a 1.5-m-diameter, 4.6-m-long plasma vacuum chamber. Primary emphasis is directed towards improving tribological properties of metal surfaces. First experiments have been performed at 40 kV with nitrogen plasmas. Both coupons and manufactured components, with surface areas up to 4 m 2 , have been processed. Composition and surface hardness of implanted materials are evaluated. Implant conformality and dose uniformity into practical geometries are estimated with multidimensional particle-in-cell computations of plasma electron and ion dynamics, and Monte Carlo simulations of ion transport in solids

  10. Electron beam diagnostic for the Los Alamos free-electron laser oscillator experiment

    International Nuclear Information System (INIS)

    Sheffield, R.L.

    1984-01-01

    An electron beam diagnostic for the Los Alamos free-electron laser (FEL) oscillator experiment has been used to measure the time dependence of the electron energy distribution in a 100-μs time interval. The electron beam consists of macropulses that have a duration of 100 μs and a repetition rate of 1 Hz. Each macropulse consists of a series of micropulses that have approx. 30 ps duration, approx. 50 A peak current, and approx. 50 ns separation. The primary purpose of the electron beam diagnostic is measurement of the time dependence of the electron energy distribution during the build-up of the photon field in the oscillator. Since the exact time of build-up depends on various rf and cavity considerations, provisions were made to allow the observation window to be varied from 10 to 100 μs and to be delayed by times up to 100 μs. 5 references, 9 figures

  11. Subharmonic buncher for the Los Alamos free-electron laser oscillator experiment

    International Nuclear Information System (INIS)

    Fraser, J.S.

    1983-01-01

    A high efficiency free-electron laser oscillator experiment is being constructed at Los Alamos National Laboratory. A buncher system has been designed to deliver 30-ps, 5-nC electron bunches to a 20-MeV standing-wave linac at the 60th subharmonic of the 1300-MHz accelerator frequency. The first 108.3-MHz buncher cavity accepts a 5-ns, 5-A peak current pulse from a triode gun. Following a 120-cm drift space, a second 108.3-MHz cavity is used, primarily to enhance the bunching of the trailing half of the bunch. A 1300-MHz cavity with 20-cm drift spaces at the each end completes the beamline components. The bunching process continues into the linac's first three accelerating cells. Two thin iron-shielded lenses and several large-diameter solenoids provide axial magnetic fields for radial focusing

  12. MCNPTM criticality primer and training experiences

    International Nuclear Information System (INIS)

    Briesmeister, J.; Forster, R.A.; Busch, R.

    1995-01-01

    With the closure of many experimental facilities, the nuclear criticality safety analyst is increasingly required to rely on computer calculations to identify safe limits for the handling and storage of fissile materials. However, the analyst may have little experience with the specific codes available at his or her facility. Usually, the codes are quite complex, black boxes capable of analyzing numerous problems with a myriad of input options. Documentation for these codes is designed to cover all the possible configurations and types of analyses but does not give much detail on any particular type of analysis. For criticality calculations, the user of a code is primarily interested in the value of the effective multiplication factor for a system (k eff ). Most codes will provide this, and truckloads of other information that may be less pertinent to criticality calculations. Based on discussions with code users in the nuclear criticality safety community, it was decided that a simple document discussing the ins and outs of criticality calculations with specific codes would be quite useful. The Transport Methods Group, XTM, at Los Alamos National Laboratory (LANL) decided to develop a primer for criticality calculations with their Monte Carlo code, MCNP. This was a joint task between LANL with a knowledge and understanding of the nuances and capabilities of MCNP and the University of New Mexico with a knowledge and understanding of nuclear criticality safety calculations and educating first time users of neutronics calculations. The initial problem was that the MCNP manual just contained too much information. Almost everything one needs to know about MCNP can be found in the manual; the problem is that there is more information than a user requires to do a simple k eff calculation. The basic concept of the primer was to distill the manual to create a document whose only focus was criticality calculations using MCNP

  13. Modeling the New UCN source at Los Alamos National Laboratory for the UCNtau Experiment

    Science.gov (United States)

    Bailey, Thomas; Young, Albert; Clayton, Steven; Makela, Mark; Saunders, Andy

    2017-09-01

    The Los Alamos Neutron Science Center uses a linear proton accelerator to make an ultracold neutron (UCN) source for use in experiments including the UCNtau and the nEDM experiments. The proton beam strikes a tungsten target, producing free neutrons through spallation. The target is embedded in beryllium and graphite moderators, coupling produced neutrons to a bucket-shaped cold moderator of polyethylene beads at 45K that surrounds a solid deuterium converter, where they are down-scattered to ultracold energies. The UCN source was upgraded over the summer of 2016 and Data taken from the 2016-2017 run cycle shows that continuous running decreases the neutron output caused by layers of deuterium frost building up on the surface of the crystal or in the low temperature part of the UCN guide, and/or other possible changes to the shape, temperature profile or energy content of the deuterium. We have simulated the source deterioration with a simple model for surface roughness and deuterium snow, to understand the expected correlations between the UCN flux and spectrum exiting from the source as snow accumulates. We plan to use the output of our simulation to compare a set of monitor detectors used to establish the output of the flux and to monitor spectral changes important for UCNtau.

  14. Evaluation of Saxton critical experiments

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Hyung Kook; Noh, Jae Man; Jung, Hyung Guk; Kim, Young Il; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    As a part of International Criticality Safety Benchmark Evaluation Project (ICSBEP), SAXTON critical experiments were reevaluated. The effects of k{sub eff} of the uncertainties in experiment parameters, fuel rod characterization, soluble boron, critical water level, core structure, {sup 241}Am and {sup 241}Pu isotope number densities, random pitch error, duplicated experiment, axial fuel position, model simplification, etc., were evaluated and added in benchmark-model k{sub eff}. In addition to detailed model, the simplified model for Saxton critical experiments was constructed by omitting the top, middle, and bottom grids and ignoring the fuel above water. 6 refs., 1 fig., 3 tabs. (Author)

  15. Environmental assessment for consolidation of certain materials and machines for nuclear criticality experiments and training

    International Nuclear Information System (INIS)

    1996-01-01

    In support of its assigned missions and because of the importance of avoiding nuclear criticality accidents, DOE has adopted a policy to reduce identifiable nuclear criticality safety risks and to protect the public, workers, government property and essential operations from the effects of a criticality accident. In support of this policy, the Los Alamos Critical Experiments Facility (LACEF) at the Los Alamos National Laboratory (LANL) Technical Area (TA) 18, provides a program of general purpose critical experiments. This program, the only remaining one of its kind in the United States, seeks to maintain a sound basis of information for criticality control in those physical situations that DOE will encounter in handling and storing fissionable material in the future, and ensuring the presence of a community of individuals competent in practicing this control

  16. History of critical experiments at Pajarito Site

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, H.C.

    1983-03-01

    This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies.

  17. History of critical experiments at Pajarito Site

    International Nuclear Information System (INIS)

    Paxton, H.C.

    1983-03-01

    This account describes critical and subcritical assemblies operated remotely at the Pajarito Canyon Site at the Los Alamos National Laboratory. Earliest assemblies, directed exclusively toward the nuclear weapons program, were for safety tests. Other weapon-related assemblies provided neutronic information to check detailed weapon calculations. Topsy, the first of these critical assemblies, was followed by Lady Godiva, Jezebel, Flattop, and ultimately Big Ten. As reactor programs came to Los Alamos, design studies and mockups were tested at Pajarito Site. For example, nearly all 16 Rover reactors intended for Nevada tests were preceded by zero-power mockups and proof tests at Pajarito Site. Expanded interest and capability led to fast-pulse assemblies, culminating in Godiva IV and Skua, and to the Kinglet and Sheba solution assemblies

  18. In-plant experience with passive-active shufflers at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Hurd, J.R.; Hsue, F.; Rinard, P.M.

    1995-09-01

    Two Canberra-built passive-active {sup 252}Cf shufflers of Los Alamos hardware and software design have been installed at Los Alamos National Laboratory, one at the Chemistry and Metallurgy Research (CMR) Facility at TA-3 and the other at the Plutonium Facility (PF-4) at TA-55. These instruments fulfill important safeguards and accountability measurement requirements for special nuclear material (SNM) in matrices too dense or otherwise not appropriate for typical gamma-ray or other neutron counting techniques. They support many programmatic requirements including measurements of transuranic (TRU) waste and inventory verification. This paper describes the instrument performance under plant conditions with various background radiations on well-characterized standards to determine long-term stability and establish a calibration. Results are also reported on verification measurements of previously unmeasured inventory items in various matrices and geometric distributions. Preliminary investigative measurements are presented on standards of mixed uranium and plutonium oxide (MOX).

  19. In-plant experience with passive-active shufflers at Los Alamos

    International Nuclear Information System (INIS)

    Hurd, J.R.; Hsue, F.; Rinard, P.M.

    1995-01-01

    Two Canberra-built passive-active 252 Cf shufflers of Los Alamos hardware and software design have been installed at Los Alamos National Laboratory, one at the Chemistry and Metallurgy Research (CMR) Facility at TA-3 and the other at the Plutonium Facility (PF-4) at TA-55. These instruments fulfill important safeguards and accountability measurement requirements for special nuclear material (SNM) in matrices too dense or otherwise not appropriate for typical gamma-ray or other neutron counting techniques. They support many programmatic requirements including measurements of transuranic (TRU) waste and inventory verification. This paper describes the instrument performance under plant conditions with various background radiations on well-characterized standards to determine long-term stability and establish a calibration. Results are also reported on verification measurements of previously unmeasured inventory items in various matrices and geometric distributions. Preliminary investigative measurements are presented on standards of mixed uranium and plutonium oxide (MOX)

  20. Review of operating experience at the Los Alamos Plutonium Electrorefining Facility, 1963-1977

    International Nuclear Information System (INIS)

    Mullins, L.J.; Morgan, A.N.

    1981-12-01

    This report reviews the operation of the Los Alamos Plutonium Electrorefining Plant at Technical Area 21 for the period 1964 through 1977. During that period, approximately 1568 kg of plutonium metal, > 99.95% pure, was produced in 653 runs from 1930 kg of metal fabrication scrap, 99% pure. General considerations of the electrorefining process and facility operation and recommendations for further improvement of the process are discussed

  1. Los Alamos nEDM Experiment and Demonstration of Ramsey's Method on Stored UCNs at the LANL UCN Source

    Science.gov (United States)

    Clayton, Steven; Chupp, Tim; Cude-Woods, Christopher; Currie, Scott; Ito, Takeyasu; Liu, Chen-Yu; Long, Joshua; MacDonald, Stephen; Makela, Mark; O'Shaughnessy, Christopher; Plaster, Brad; Ramsey, John; Saunders, Andy; LANL nEDM Collaboration

    2017-09-01

    The Los Alamos National Laboratory ultracold neutron (UCN) source was recently upgraded for a factor of 5 improvement in stored density, providing the statistical precision needed for a room temperature neutron electric dipole moment measurement with sensitivity 3 ×10-27 e . cm, a factor 10 better than the limit set by the Sussex-RAL-ILL experiment. Here, we show results of a demonstration of Ramsey's separated oscillatory fields method on stored UCNs at the LANL UCN source and in a geometry relevant for a nEDM measurement. We argue a world-leading nEDM experiment could be performed at LANL with existing technology and a short lead time, providing a physics result with sensitivity intermediate between the current limit set by Sussex-RAL-ILL, and the anticipated limit from the complex, cryogenic nEDM experiment planned for the next decade at the ORNL Spallation Neutron Source (SNS-nEDM). This work was supported by the Los Alamos LDRD Program, Project 20140015DR.

  2. Handbook of critical experiments benchmarks

    International Nuclear Information System (INIS)

    Durst, B.M.; Bierman, S.R.; Clayton, E.D.

    1978-03-01

    Data from critical experiments have been collected together for use as benchmarks in evaluating calculational techniques and nuclear data. These benchmarks have been selected from the numerous experiments performed on homogeneous plutonium systems. No attempt has been made to reproduce all of the data that exists. The primary objective in the collection of these data is to present representative experimental data defined in a concise, standardized format that can easily be translated into computer code input

  3. Shallow land burial: experience and developments at Oak Ridge and Los Alamos

    International Nuclear Information System (INIS)

    Warren, J.L.

    1979-01-01

    Since the mid-1940's, in excess of 250,000 m 3 of low- and intermediate-level radioactive solid waste, generated in operations at the Los Alamos Scientific Laboratory (LASL), has been disposed of by on-site shallow land burial and retrievable storage in dry volcanic tuff. Guidelines have been developed at LASL which regulate the construction of waste disposal facilities, burial and storage operations, disposal site maintenance and restoration, and documentation of all waste disposal activities. Monitoring programs at the past and current solid waste disposal sites have continued to show that, with the exception of low levels of tritium, no migration of contaminants away from their disposal location has been detected

  4. LOS ALAMOS: Hadron future

    International Nuclear Information System (INIS)

    Ernst, David J.

    1992-01-01

    At a Workshop on the Future of Hadron Facilities, held on 15-16 August at Los Alamos National Laboratory, several speakers pointed out that the US physics community carrying out fixed target experiments with hadron beam had not been as successful with funding as it deserved. To rectify this, they said, the community should be better organized and present a more united front

  5. Beam-dynamics design and performance of the rf deflector in the Los Alamos single-beam funnel experiment

    International Nuclear Information System (INIS)

    Guy, F.W.; Johnson, K.F.; Sander, O.R.

    1991-01-01

    Funnels in which two bunched ion beams are interlaced to form a single beam have been proposed for high-current low-emittance ion linacs. A well-designed funnel would produce a beam with twice the frequency and current and almost twice the brightness of each original beam. A single-beam funnel experiment exploring the beam- dynamics and physics issues of a discrete-element future has been completed at Los Alamos National Laboratory (LANL). The only known beam-dynamics issue of concern in a two-beam funnel not addressed was the beam-beam interaction, which is negligible. The rf deflector, in which beam merging occurs, is a key component of a discrete-element funnel. We report the beam-dynamics design procedure and experimental results for the rf deflector. 8 refs., 5 figs

  6. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory's Source Region Program

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.W.; Noel, S.D.

    1992-12-01

    The summary report by Tom Weaver gives the overall background for the series of IVE (Integrated Verification Experiment) experiments including information on the full set of measurements made. This appendix presents details of the infrasound data for the and discusses certain aspects of a few special experiments. Prior to FY90, the emphasis of the Infrasound Program was on underground nuclear test (UGT) detection and yield estimation. During this time the Infrasound Program was a separate program at Los Alamos, and it was suggested to DOE/OAC that a regional infrasound network be established around NTS. The IVE experiments took place in a time frame that allowed simultaneous testing of possible network sites and examination of propagation in different directions. Whenever possible, infrasound stations were combined with seismic stations so that a large number could be efficiently fielded. The regional infrasound network was not pursued by DOE, as world events began to change the direction of verification toward non-proliferation. Starting in FY90 the infrasound activity became part of the Source Region Program which has a goal of understanding how energy is transported from the UGT to a variety of measurement locations.

  7. Status of the free-electron laser experiment at Los Alamos

    International Nuclear Information System (INIS)

    Warren, R.W.; Brau, C.A.; Newnam, B.E.; Stein, W.E.; Winston, J.G.; Young, L.M.

    1981-01-01

    Main design parameters are presented for the accelerator, the laser, and the wiggler. Four sections are presented that discuss unusual or different features in the design, construction, alignment, and diagnostic parts of the experiment. Up-to-date performance characteristics of the components are described

  8. Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, N.G. [ed.

    1995-12-31

    There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory`s history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory`s leading epidemiologist.

  9. Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1995-01-01

    There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory's history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory's leading epidemiologist

  10. Construction of STACY (Static Experiment Critical Facility)

    International Nuclear Information System (INIS)

    Murakami, Kiyonobu; Onodera, Seiji; Hirose, Hideyuki

    1998-08-01

    Two critical assemblies, STACY (Static Experiment Critical Facility) and TRACY (Transient Experiment Critical Facility), were constructed in NUCEF (Nuclear Fuel Cycle Safety Engineering Research Facility) to promote researches on the criticality safety at a reprocessing facility. STACY aims at providing critical data of uranium nitrate solution, plutonium nitrate solution and their mixture while varying concentration of solution fuel, core tank shape and size and neutron reflecting condition. STACY achieved first criticality in February 1995, and passed the licensing inspection by STA (Science and Technology Agency of Japan) in May. After that a series of critical experiments commenced with 10 w/o enriched uranium solution. This report describes the outline of STACY at the end of FY 1996. (author)

  11. Integrated Verification Experiment data collected as part of the Los Alamos National Laboratory`s Source Region Program. Appendix B: Surface ground motion

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, T.A.; Baker, D.F.; Edwards, C.L.; Freeman, S.H.

    1993-10-01

    Surface ground motion was recorded for many of the Integrated Verification Experiments using standard 10-, 25- and 100-g accelerometers, force-balanced accelerometers and, for some events, using golf balls and 0.39-cm steel balls as surface inertial gauges (SIGs). This report contains the semi-processed acceleration, velocity, and displacement data for the accelerometers fielded and the individual observations for the SIG experiments. Most acceleration, velocity, and displacement records have had calibrations applied and have been deramped, offset corrected, and deglitched but are otherwise unfiltered or processed from their original records. Digital data for all of these records are stored at Los Alamos National Laboratory.

  12. Critical experiments at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Harms, Gary A.; Ford, John T.; Barber, Allison Delo

    2010-01-01

    Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-III is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide benchmark

  13. Critical experiments at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Harms, G.A.; Ford, J.T.; Barber, A.D.

    2011-01-01

    Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-III is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide benchmark

  14. Fast critical experiment data for space reactors

    International Nuclear Information System (INIS)

    Collins, P.J.; McFarlane, H.F.; Olsen, D.N.; Atkinson, C.A.; Ross, J.R.

    1987-01-01

    Data from a number of previous critical experiments exist that are relevant to the design concepts being considered for SP-100 and MMW space reactors. Although substantial improvements in experiment techniques have since made some of the measured quantities somewhat suspect, the basic criticality data are still useful in most cases. However, the old experiments require recalculation with modern computational methods and nuclear cross section data before they can be applied to today's designs. Recently, we have calculated about 20 fast benchmark critical experiments with the latest ENDF/B data and modern transport codes. These calculations were undertaken as a part of the planning process for a new series of benchmark experiments aimed at supporting preliminary designs of SP-100 and MMW space reactors

  15. Zeno: Critical Fluid Light Scattering Experiment

    Science.gov (United States)

    Gammon, Robert W.; Shaumeyer, J. N.; Briggs, Matthew E.; Boukari, Hacene; Gent, David A.; Wilkinson, R. Allen

    1996-01-01

    The Zeno (Critical Fluid Light Scattering) experiment is the culmination of a long history of critical fluid light scattering in liquid-vapor systems. The major limitation to making accurate measurements closer to the critical point was the density stratification which occurs in these extremely compressible fluids. Zeno was to determine the critical density fluctuation decay rates at a pair of supplementary angles in the temperature range 100 mK to 100 (mu)K from T(sub c) in a sample of xenon accurately loaded to the critical density. This paper gives some highlights from operating the instrument on two flights March, 1994 on STS-62 and February, 1996 on STS-75. More detail of the experiment Science Requirements, the personnel, apparatus, and results are displayed on the Web homepage at http://www.zeno.umd.edu.

  16. Russian nuclear criticality experiments. Status and prospects

    International Nuclear Information System (INIS)

    Gagarinski, A.Yu.

    2003-01-01

    After the nuclear criticality had been reached on a uranium-graphite assembly for the first time in the Soviet Union on December 25, 1946, by I.V. Kurchatov and his team (1), the critical conditions in a great variety of multiplying media have been realized only in the Kurchatov Institute for at least several thousand times. Even the first Russian critical experiments carried out by Igor Kurchatov confirmed the unique merits of zero-power reactors: the most practically convenient range of parameters of kinetic response for variation of critical conditions, as well as invariability, over a wide range of the most important functions of neutron flux to reactor power. Neutron physics experiments have become a necessary stage in creation and improvement of nuclear reactors. Most critical experiments were performed mainly as a necessary stage of reactor design in the 60ies and 70ies, which has been the reactor 'golden age', when most of the total of over thousand nuclear reactors of various type and destination have been created worldwide. Though the ways of conducting critical measurements were very diversified, there are two main types of experiments. The first is so-called mock-up or prototype experiments when an exact (to the extent possible) simulation of the core is constructed to minimize the error in forecasting the operating reactor characteristics. Such experiments, which often represent the quality control of the core manufacturing and adjustment of core parameters to the design requirements, were carried out in Russia on critical assemblies of several plants, in design institutions (OKBM, Nizhni Novgorod; Electrostal and others), as well as in research centers (RRC 'Kurchatov Institute', etc.). Their results, which prevail today in the criticality database, even taking into account the capabilities provided by present-day calculation codes, are not well suited for new applications. It is hard to expect that the error resulting from inevitable idealization of

  17. Underground science initiatives at Los Alamos

    International Nuclear Information System (INIS)

    Simmons, L.M. Jr.

    1985-01-01

    Recently, the Los Alamos National Laboratory has proposed two major new initiatives in underground science. Following the dissolution of the original gallium solar neutrino collaboration, Los Alamos has formed a new North American collaboration. We briefly review the rationale for solar neutrino research, outline the proposal and new Monte Carlo simulations, and describe the candidate locations for the experiment. Because there is no dedicated deep underground site in North America suitable for a wide range of experiments, Los Alamos has conducted a survey of possible sites and developed a proposal to create a new National Underground Science Facility. This paper also reviews that proposal

  18. Critical experiments facility and criticality safety programs at JAERI

    International Nuclear Information System (INIS)

    Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Miyoshi, Yoshinori; Nomura, Yasushi

    1985-10-01

    The nuclear criticality safety is becoming a key point in Japan in the safety considerations for nuclear installations outside reactors such as spent fuel reprocessing facilities, plutonium fuel fabrication facilities, large scale hot alboratories, and so on. Especially a large scale spent fuel reprocessing facility is being designed and would be constructed in near future, therefore extensive experimental studies are needed for compilation of our own technical standards and also for verification of safety in a potential criticality accident to obtain public acceptance. Japan Atomic Energy Research Institute is proceeding a construction program of a new criticality safety experimental facility where criticality data can be obtained for such solution fuels as mainly handled in a reprocessing facility and also chemical process experiments can be performed to investigate abnormal phenomena, e.g. plutonium behavior in solvent extraction process by using pulsed colums. In FY 1985 detail design of the facility will be completed and licensing review by the government would start in FY 1986. Experiments would start in FY 1990. Research subjects and main specifications of the facility are described. (author)

  19. The Los Alamos Space Science Outreach (LASSO) Program

    Science.gov (United States)

    Barker, P. L.; Skoug, R. M.; Alexander, R. J.; Thomsen, M. F.; Gary, S. P.

    2002-12-01

    The Los Alamos Space Science Outreach (LASSO) program features summer workshops in which K-14 teachers spend several weeks at LANL learning space science from Los Alamos scientists and developing methods and materials for teaching this science to their students. The program is designed to provide hands-on space science training to teachers as well as assistance in developing lesson plans for use in their classrooms. The program supports an instructional model based on education research and cognitive theory. Students and teachers engage in activities that encourage critical thinking and a constructivist approach to learning. LASSO is run through the Los Alamos Science Education Team (SET). SET personnel have many years of experience in teaching, education research, and science education programs. Their involvement ensures that the teacher workshop program is grounded in sound pedagogical methods and meets current educational standards. Lesson plans focus on current LANL satellite projects to study the solar wind and the Earth's magnetosphere. LASSO is an umbrella program for space science education activities at Los Alamos National Laboratory (LANL) that was created to enhance the science and math interests and skills of students from New Mexico and the nation. The LASSO umbrella allows maximum leveraging of EPO funding from a number of projects (and thus maximum educational benefits to both students and teachers), while providing a format for the expression of the unique science perspective of each project.

  20. Heavy water critical experiments on plutonium lattice

    International Nuclear Information System (INIS)

    Miyawaki, Yoshio; Shiba, Kiminori

    1975-06-01

    This report is the summary of physics study on plutonium lattice made in Heavy Water Critical Experiment Section of PNC. By using Deuterium Critical Assembly, physics study on plutonium lattice has been carried out since 1972. Experiments on following items were performed in a core having 22.5 cm square lattice pitch. (1) Material buckling (2) Lattice parameters (3) Local power distribution factor (4) Gross flux distribution in two region core (5) Control rod worth. Experimental results were compared with theoretical ones calculated by METHUSELAH II code. It is concluded from this study that calculation by METHUSELAH II code has acceptable accuracy in the prediction on plutonium lattice. (author)

  1. Los Alamos benchmarks: calculations based on ENDF/B-V data

    International Nuclear Information System (INIS)

    Kidman, R.B.

    1981-11-01

    The new and revised benchmark specifications for nine Los Alamos National Laboratory critical assemblies are used to compute the entire set of parameters that were measured in the experiments. A comparison between the computed and experimental values provides a measure of the adequacy of the specifications, cross sections, and physics codes used in the calculations

  2. Los Alamos National Laboratory.

    Science.gov (United States)

    Hammel, Edward F., Jr.

    1982-01-01

    Current and post World War II scientific research at the Los Alamos National Laboratory (New Mexico) is discussed. The operation of the laboratory, the Los Alamos consultant program, and continuation education, and continuing education activities at the laboratory are also discussed. (JN)

  3. A second simulated criticality accident dosimetry experiment

    CERN Document Server

    Adams, N

    1973-01-01

    This experiment was undertaken to facilitate training in criticality dose assessment by UKAEA and BNFL establishments with potential criticality hazards. Personal dosemeters, coins, samples of hair, etc. supplied by the seven participating establishments were attached to a man-phantom filled with a solution of sodium nitrate (simulating 'body-sodium'), and exposed to a burst of radiation from the AWRE pulsed reactor VIPER. The neutron and photon doses were each several hundred rads. Participants made two sets of dose assessments. The first, made solely from the evidence of their routine dosemeters the activation of body-sodium and standard monitoring data, simulated the initial dose assessment that would be made before the circumstances of a real incident were established. The second was made when the position and orientation of the phantom relative to the reactor and the shielding (20 cm of copper) between the reactor core and the phantom were disclosed. Neutron and photon dose assessments for comparison wit...

  4. UC/Los Alamos Entrepreneurial Postdoctoral Fellowship Pilot Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mariann R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clow, Shandra Deann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-06

    The UC/Los Alamos Entrepreneurial Postdoctoral Fellowship Pilot Program (Pilot) for existing postdoctoral researchers at Los Alamos National Laboratory (Los Alamos) to gain skills in entrepreneurship and commercializing technology as part of their postdoctoral experience. This program will incorporate training and mentoring during the first 6-month period, culminating in a focused 6-month Fellowship aimed at creating a new business in Northern New Mexico.

  5. High-energy density physics at Los Alamos

    International Nuclear Information System (INIS)

    Byrnes, P.; Younger, S.M.

    1993-03-01

    This brochure describes the facilities of the Above Ground Experiments II (AGEX II) and the Inertial Confinement Fusion (ICF) programs at Los Alamo. Combined, these programs represent, an unparalleled capability to address important issues in high-energy density physics that are critical to the future defense, energy, and research needs of th e United States. The mission of the AGEX II program at Los Alamos is to provide additional experimental opportunities for the nuclear weapons program. For this purpose we have assembled at Los Alamos the broadest array of high-energy density physics facilities of any laboratory in the world. Inertial confinement fusion seeks to achieve thermonuclear burn on a laboratory scale through the implosion of a small quantity of deuterium and tritium fuel to very high Pressure and temperature.The Los Alamos ICF program is focused on target physics. With the largest scientific computing center in the world, We can perform calculations of unprecedented sophistication and precision. We field experiments at facilities worldwide-including our own Trident and Mercury lasers-to confirm our understanding and to provide the necessary data base to proceed toward the historic goal of controlled fusion in the laboratory. In addition to direct programmatic high-energy density physics is a nc scientific endeavor in itself. The ultrahigh magnetic fields produced in our high explosive pulsed-power generators can be used in awide variety of solid state physics and temperature superconductor studies. The structure and dynamics of planetary atmospheres can be simulated through the compression of gas mixtures

  6. Performance of the upgraded ultracold neutron source at Los Alamos National Laboratory and its implication for a possible neutron electric dipole moment experiment

    Science.gov (United States)

    Ito, T. M.; Adamek, E. R.; Callahan, N. B.; Choi, J. H.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Ding, X.; Fellers, D. E.; Geltenbort, P.; Lamoreaux, S. K.; Liu, C.-Y.; MacDonald, S.; Makela, M.; Morris, C. L.; Pattie, R. W.; Ramsey, J. C.; Salvat, D. J.; Saunders, A.; Sharapov, E. I.; Sjue, S.; Sprow, A. P.; Tang, Z.; Weaver, H. L.; Wei, W.; Young, A. R.

    2018-01-01

    The ultracold neutron (UCN) source at Los Alamos National Laboratory (LANL), which uses solid deuterium as the UCN converter and is driven by accelerator spallation neutrons, has been successfully operated for over 10 years, providing UCN to various experiments, as the first production UCN source based on the superthermal process. It has recently undergone a major upgrade. This paper describes the design and performance of the upgraded LANL UCN source. Measurements of the cold neutron spectrum and UCN density are presented and compared to Monte Carlo predictions. The source is shown to perform as modeled. The UCN density measured at the exit of the biological shield was 184 (32 ) UCN /cm3 , a fourfold increase from the highest previously reported. The polarized UCN density stored in an external chamber was measured to be 39 (7 ) UCN /cm3 , which is sufficient to perform an experiment to search for the nonzero neutron electric dipole moment with a one-standard-deviation sensitivity of σ (dn) =3 ×10-27e cm .

  7. Completion of the first approach to critical for the seven percent critical experiment

    International Nuclear Information System (INIS)

    Barber, A. D.; Harms, G. A.

    2009-01-01

    The first approach-to-critical experiment in the Seven Percent Critical Experiment series was recently completed at Sandia. This experiment is part of the Seven Percent Critical Experiment which will provide new critical and reactor physics benchmarks for fuel enrichments greater than five weight percent. The inverse multiplication method was used to determine the state of the system during the course of the experiment. Using the inverse multiplication method, it was determined that the critical experiment went slightly supercritical with 1148 fuel elements in the fuel array. The experiment is described and the results of the experiment are presented. (authors)

  8. Fission reactor critical experiments and analysis

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Work accomplished in support of nonweapons programs by LASL Group Q-14 is described. Included are efforts in basic critical measurements, nuclear criticality safety, a plasma core critical assembly, and reactivity coefficient measurements

  9. Los Alamos science. Volume 4, No. 7

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1983-01-01

    A history of the Los Alamos National Laboratory over its 40 years is presented. The evolution of the laboratory is broken down into the Oppenheimer years, the Bradbury years, the Agnew years and the Kerr years. The weapons program is described including nuclear data, early reactors, computing and computers, plutonium, criticality, weapon design and field testing

  10. The Los Alamos primer

    CERN Document Server

    Serber, Robert

    2018-01-01

    Unabridged declassified value reproduction of The Los Alamos Primer by Robert Serber, in full color with all censor markings. This is the booklet given to new workers at Los Alamos during World War II, to catch them up on how to build a practical fission bomb. The Primer was driven by Robert Oppenheimer asking his protégé Robert Serber to summarize all knowledge and possible solutions known as of April 1943 in a series of lectures. Serber did such an excellent job that the notes from the series was turned into The Los Alamos Primer. Serber was known as an expert that bridged theory and reality, and so was also chosen to be one of the first Americans to enter Hiroshima and Nagasaki to assess the atomic damage in 1945.

  11. Operating manual for the critical experiments facility

    International Nuclear Information System (INIS)

    1986-01-01

    The operation of the Critical Experiments Facility (CEF) requires careful attention to procedures in order that all safety precautions are observed. Since an accident could release large amounts of radioactivity, careful operation and strict enforcement of procedures are necessary. To provide for safe operation, detailed procedures have been written for all phases of the operation of this facility. The CEF operating procedures are not to be construed to constitute a part ofthe Technical Specifications. In the event of any discrepancy between the information given herein and the Technical Specifications, limits set forth in the Technical Specifications apply. All normal and most emergency operation conditions are covered by procedures presented in this manual. These procedures are designed to be followed by the operating personnel. Strict adherence to these procedures is expected for the following reasons. (1) To provide a standard, safe method of performing all operations, the procedures were written by reactor engineers experienced in supervising the operation of reactors and were reviewed by an organization with over 30 years of reactor operating experience. (2) To have an up-to-date description of operating techniques available at all times for reference and review, it is necessary that the procedures be written

  12. Notes on Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-05

    In 1954 an unknown author drafted a report, reprinted below, describing the Laboratory and the community as they existed in late 1953. This report, perhaps intended to be crafted into a public relations document, is valuable because it gives us an autobiographical look at Los Alamos during the first half of the 1950s. It has been edited to enhance readability.

  13. Early history of NMR at Los Alamos

    International Nuclear Information System (INIS)

    Jackson, J.A.

    1985-11-01

    Nuclear magnetic resonance (NMR) spectroscopy has developed into an important research tool in chemistry. More recently, NMR imaging and in vivo spectroscopy promise to produce a revolution in medicine and biochemistry. Early experiments at Los Alamos led to DOE programs involving stable isotopes of importance to biology and to medicine. These events are briefly recounted. 2 refs

  14. Validation of Cross Sections with Criticality Experiment and Reaction Rates: the Neptunium Case

    CERN Document Server

    Leong, L S; Audouin, L; Berthier, B; Le Naour, C; Stéphan, C; Paradela, C; Tarrío, D; Duran, I

    2014-01-01

    The Np-237 neutron-induced fission cross section has been recently measured in a large energy range (from eV to GeV) at the n\\_TOF facility at CERN. When compared to previous measurements the n\\_TOF fission cross section appears to be higher by 5-7\\% beyond the fission threshold. To check the relevance of the n\\_TOF data, we considered a criticality experiment performed at Los Alamos with a 6 kg sphere of Np-237, surrounded by uranium highly enriched in U-235 so as to approach criticality with fast neutrons. The multiplication factor k(eff) of the calculation is in better agreement with the experiment when we replace the ENDF/B-VII. 0 evaluation of the Np-237 fission cross section by the n\\_TOF data. We also explored the hypothesis of deficiencies of the inelastic cross section in U-235 which has been invoked by some authors to explain the deviation of 750 pcm. The large modification needed to reduce the deviation seems to be incompatible with existing inelastic cross section measurements. Also we show that t...

  15. Los Alamos Programming Models

    Energy Technology Data Exchange (ETDEWEB)

    Bergen, Benjamin Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-07

    This is the PDF of a powerpoint presentation from a teleconference on Los Alamos programming models. It starts by listing their assumptions for the programming models and then details a hierarchical programming model at the System Level and Node Level. Then it details how to map this to their internal nomenclature. Finally, a list is given of what they are currently doing in this regard.

  16. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  17. A journey from nuclear criticality methods to high energy density radflow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-30

    Los Alamos National Laboratory is a nuclear weapons laboratory supporting our nation's defense. In support of this mission is a high energy-density physics program in which we design and execute experiments to study radiationhydrodynamics phenomena and improve the predictive capability of our largescale multi-physics software codes on our big-iron computers. The Radflow project’s main experimental effort now is to understand why we haven't been able to predict opacities on Sandia National Laboratory's Z-machine. We are modeling an increasing fraction of the Z-machine's dynamic hohlraum to find multi-physics explanations for the experimental results. Further, we are building an entirely different opacity platform on Lawrence Livermore National Laboratory's National Ignition Facility (NIF), which is set to get results early 2017. Will the results match our predictions, match the Z-machine, or give us something entirely different? The new platform brings new challenges such as designing hohlraums and spectrometers. The speaker will recount his history, starting with one-dimensional Monte Carlo nuclear criticality methods in graduate school, radiative transfer methods research and software development for his first 16 years at LANL, and, now, radflow technology and experiments. Who knew that the real world was more than just radiation transport? Experiments aren't easy, but they sure are fun.

  18. A journey from nuclear criticality methods to high energy density radflow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-08

    Los Alamos National Laboratory is a nuclear weapons laboratory supporting our nation's defense. In support of this mission is a high energy-density physics program in which we design and execute experiments to study radiationhydrodynamics phenomena and improve the predictive capability of our largescale multi-physics software codes on our big-iron computers. The Radflow project’s main experimental effort now is to understand why we haven't been able to predict opacities on Sandia National Laboratory's Z-machine. We are modeling an increasing fraction of the Z-machine's dynamic hohlraum to find multi-physics explanations for the experimental results. Further, we are building an entirely different opacity platform on Lawrence Livermore National Laboratory's National Ignition Facility (NIF), which is set to get results early 2017. Will the results match our predictions, match the Z-machine, or give us something entirely different? The new platform brings new challenges such as designing hohlraums and spectrometers. The speaker will recount his history, starting with one-dimensional Monte Carlo nuclear criticality methods in graduate school, radiative transfer methods research and software development for his first 16 years at LANL, and, now, radflow technology and experiments. Who knew that the real world was more than just radiation transport? Experiments aren't easy and they are as saturated with politics as a presidential election, but they sure are fun.

  19. Exponential and Critical Experiments. Vol. III. Proceedings of the Symposium on Exponential and Critical Experiments

    International Nuclear Information System (INIS)

    1964-01-01

    In September 1963 the International Atomic Energy Agency organized the Symposium on Exponential and Critical Experiments in Amsterdam, Netherlands, at the invitation of the Government of the Netherlands. The Symposium enabled scientists from Member States to discuss the results of such experiments which provide the physics data necessary for the design of power reactors. Great advances made in recent years in this field have provided scientists with highly sophisticated and reliable experimental and theoretical methods. This trend is reflected in the presentation, at the Symposium, of many new experimental techniques resulting in more detailed and accurate information and a reduction of costs. Both the number of experimental parameters and their range of variation have been extended, and a closer degree of simulation of the actual power reactor has been achieved, for example, by means of high temperature critical assemblies. Basic types of lattices have continued to be the objective of many investigations, and extensive theoretical analyses have been carried out to provide a more thorough understanding of the neutron physics involved. Twenty nine countries and 3 international organizations were represented by 198 participants. Seventy one papers were presented. These numbers alone show the wide interest which the topic commands in the field of reactor design. We hope that this publication, which includes the papers presented at the Symposium and a record of the discussions, will prove useful as a work of reference to scientists working in this field

  20. The impact and applicability of critical experiment evaluations

    International Nuclear Information System (INIS)

    Brewer, R.

    1997-01-01

    This paper very briefly describes a project to evaluate previously performed critical experiments. The evaluation is intended for use by criticality safety engineers to verify calculations, and may also be used to identify data which need further investigation. The evaluation process is briefly outlined; the accepted benchmark critical experiments will be used as a standard for verification and validation. The end result of the project will be a comprehensive reference document

  1. Construction of new critical experiment facilities in JAERI

    International Nuclear Information System (INIS)

    Takeshita, Isao; Itahashi, Takayuki; Ogawa, Kazuhiko; Tonoike, Kotaro; Matsumura, Tatsuro; Miyoshi, Yoshinori; Nakajima, Ken; Izawa, Naoki

    1995-01-01

    Japan Atomic Energy Research Institute (JAERI) has promoted the experiment research program on criticality safety since early in 1980s and two types of new critical facilities, Static Experiment Critical Facility (STACY) and Transient Experiment Critical Facility (TRACY) were completed on 1994 in Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF) of JAERI Tokai Research Establishment. STACY was designed so as to obtain critical mass data of low enriched uranium and plutonium solution which is extensively handled in LWR fuel reprocessing plant. TRACY is the critical facility where critical accident phenomenon is demonstrated with low enriched uranium nitrate solution. For criticality safety experiments with both facilities, the Fuel Treatment System is attached to them, where composition and concentration of uranium and plutonium nitrate solutions are widely varied so as to obtain experiments data covering fuel solution conditions in reprocessing plant. Design performances of both critical facilities were confirmed through mock-up tests of important components and cold function tests. Hot function test has started since January of 1995 and some of the results on STACY are to be reported. (author)

  2. Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Dogliani, Harold O [Los Alamos National Laboratory

    2011-01-19

    The purpose of the briefing is to describe general laboratory technical capabilities to be used for various groups such as military cadets or university faculty/students and post docs to recruit into a variety of Los Alamos programs. Discussed are: (1) development and application of high leverage science to enable effeictive, predictable and reliability outcomes; (2) deter, detect, characterize, reverse and prevent the proliferation of weapons of mass destruction and their use by adversaries and terrorists; (3) modeling and simulation to define complex processes, predict outcomes, and develop effective prevention, response, and remediation strategies; (4) energetic materials and hydrodynamic testing to develop materials for precise delivery of focused energy; (5) materials cience focused on fundamental understanding of materials behaviors, their quantum-molecular properties, and their dynamic responses, and (6) bio-science to rapidly detect and characterize pathogens, to develop vaccines and prophylactic remedies, and to develop attribution forensics.

  3. Keeping the Momentum and Nuclear Forensics at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Steiner, Robert Ernest; Dion, Heather M.; Dry, Donald E.; Kinman, William Scott; LaMont, Stephen Philip; Podlesak, David; Tandon, Lav

    2016-01-01

    LANL has 70 years of experience in nuclear forensics and supports the community through a wide variety of efforts and leveraged capabilities: Expanding the understanding of nuclear forensics, providing training on nuclear forensics methods, and developing bilateral relationships to expand our understanding of nuclear forensic science. LANL remains highly supportive of several key organizations tasked with carrying forth the Nuclear Security Summit messages: IAEA, GICNT, and INTERPOL. Analytical chemistry measurements on plutonium and uranium matrices are critical to numerous programs including safeguards accountancy verification measurements. Los Alamos National Laboratory operates capable actinide analytical chemistry and material science laboratories suitable for nuclear material and environmental forensic characterization. Los Alamos National Laboratory uses numerous means to validate and independently verify that measurement data quality objectives are met. Numerous LANL nuclear facilities support the nuclear material handling, preparation, and analysis capabilities necessary to evaluate samples containing nearly any mass of an actinide (attogram to kilogram levels).

  4. Keeping the Momentum and Nuclear Forensics at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Robert Ernest [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dion, Heather M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dry, Donald E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kinman, William Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); LaMont, Stephen Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Podlesak, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-22

    LANL has 70 years of experience in nuclear forensics and supports the community through a wide variety of efforts and leveraged capabilities: Expanding the understanding of nuclear forensics, providing training on nuclear forensics methods, and developing bilateral relationships to expand our understanding of nuclear forensic science. LANL remains highly supportive of several key organizations tasked with carrying forth the Nuclear Security Summit messages: IAEA, GICNT, and INTERPOL. Analytical chemistry measurements on plutonium and uranium matrices are critical to numerous programs including safeguards accountancy verification measurements. Los Alamos National Laboratory operates capable actinide analytical chemistry and material science laboratories suitable for nuclear material and environmental forensic characterization. Los Alamos National Laboratory uses numerous means to validate and independently verify that measurement data quality objectives are met. Numerous LANL nuclear facilities support the nuclear material handling, preparation, and analysis capabilities necessary to evaluate samples containing nearly any mass of an actinide (attogram to kilogram levels).

  5. Experiments on criticality carried out from 1975 till 1980

    International Nuclear Information System (INIS)

    Heinicke, W.; Tischer, A.; Weber, W.J.

    1981-11-01

    The report on hand includes the experiments on criticality published from 1975 till 1980. About 90 experiments with the most important related data are listed. They are capable of being called up, with the data base system KRITEXP, by 14 different descriptors or printed in any arrangement or order. This is the basis for a global or purposeful verification of the calculating method for criticality safety. The proof of reliability of the calculations for the criticality analysis are immediately relevant for the licencing procedure under atomic law for all plants of the nuclear fuel cycle where nuclear fuels are handled. Since no criticality experiments are being carried out in the Federal Republic of Germany, the data collection on hand will help to fill this gap with regard to the assessment of experiments carried out in other countries. (orig.) [de

  6. Critical Thinking in Students' Service-Learning Experiences.

    Science.gov (United States)

    Sedlak, Carol A.; Doheny, Margaret O.; Anaya, Ella; Panthofer, Nancy

    2003-01-01

    Sought to describe the growth of 94 nursing students' critical thinking through service-learning experiences. Results revealed two major themes: development of both professional and community perspectives. (EV)

  7. Deconstructing Global Markets through Critical Performative Experiences in Puerto Rico

    Science.gov (United States)

    Medina, Carmen Liliana; Weltsek, Gustave J.

    2013-01-01

    Critical Performative Pedagogies, the idea that "The nature of drama as a once removed creative experience turns non-critical implicit classroom identity formation into explicit identity performance as it asks participants to actively reflect upon how identity is created and engaged within fictional social interactions." (Weltsek and…

  8. Attachment Theory in Supervision: A Critical Incident Experience

    Science.gov (United States)

    Pistole, M. Carole; Fitch, Jenelle C.

    2008-01-01

    Critical incident experiences are a powerful source of counselor development (T. M. Skovholt & P. R. McCarthy, 1988a, 1988b) and are relevant to attachment issues. An attachment theory perspective of supervision is presented and applied to a critical incident case scenario. By focusing on the behavioral systems (i.e., attachment, caregiving, and…

  9. The National Criticality Experiments Research Center at the Device Assembly Facility, Nevada National Security Site: Status and Capabilities, Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    S. Bragg-Sitton; J. Bess; J. Werner

    2011-09-01

    The National Criticality Experiments Research Center (NCERC) was officially opened on August 29, 2011. Located within the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS), the NCERC has become a consolidation facility within the United States for critical configuration testing, particularly those involving highly enriched uranium (HEU). The DAF is a Department of Energy (DOE) owned facility that is operated by the National Nuclear Security Agency/Nevada Site Office (NNSA/NSO). User laboratories include the Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL). Personnel bring their home lab qualifications and procedures with them to the DAF, such that non-site specific training need not be repeated to conduct work at DAF. The NNSS Management and Operating contractor is National Security Technologies, LLC (NSTec) and the NNSS Safeguards and Security contractor is Wackenhut Services. The complete report provides an overview and status of the available laboratories and test bays at NCERC, available test materials and test support configurations, and test requirements and limitations for performing sub-critical and critical tests. The current summary provides a brief summary of the facility status and the method by which experiments may be introduced to NCERC.

  10. The National Criticality Experiments Research Center at the Device Assembly Facility, Nevada National Security Site: Status and Capabilities, Summary Report

    International Nuclear Information System (INIS)

    Bragg-Sitton, S.; Bess, J.; Werner, J.

    2011-01-01

    The National Criticality Experiments Research Center (NCERC) was officially opened on August 29, 2011. Located within the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS), the NCERC has become a consolidation facility within the United States for critical configuration testing, particularly those involving highly enriched uranium (HEU). The DAF is a Department of Energy (DOE) owned facility that is operated by the National Nuclear Security Agency/Nevada Site Office (NNSA/NSO). User laboratories include the Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL). Personnel bring their home lab qualifications and procedures with them to the DAF, such that non-site specific training need not be repeated to conduct work at DAF. The NNSS Management and Operating contractor is National Security Technologies, LLC (NSTec) and the NNSS Safeguards and Security contractor is Wackenhut Services. The complete report provides an overview and status of the available laboratories and test bays at NCERC, available test materials and test support configurations, and test requirements and limitations for performing sub-critical and critical tests. The current summary provides a brief summary of the facility status and the method by which experiments may be introduced to NCERC.

  11. Los Alamos Climatology 2016 Update

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-10

    The Los Alamos National Laboratory (LANL or the Laboratory) operates a meteorology monitoring network to support LANL emergency response, engineering designs, environmental compliance, environmental assessments, safety evaluations, weather forecasting, environmental monitoring, research programs, and environmental restoration. Weather data has been collected in Los Alamos since 1910. Bowen (1990) provided climate statistics (temperature and precipitation) for the 1961– 1990 averaging period, and included other analyses (e.g., wind and relative humidity) based on the available station locations and time periods. This report provides an update to the 1990 publication Los Alamos Climatology (Bowen 1990).

  12. Critical experiments on low enriched uranyl nitrate solution with STACY

    International Nuclear Information System (INIS)

    Miyoshi, Yoshinori

    1996-01-01

    As the STACY started steady operations, systematic criticality data on low enriched uranyl nitrate solution system could be accumulated. Main experimental parameters for the cylindrical tank of 60 cm in diameter were uranium concentration and the reflector condition. Basic data on a simple geometry will be helpful for the validation of the standard criticality safety codes, and for evaluating the safety margin included in the criticality designs. Experiments on the reactivity effects of structural materials such as borated concrete and polyethylene are on schedule next year as the second series of experiments using 10 wt% enriched uranyl solution. Furthermore, neutron interacting experiments with two slab tanks will be performed to investigate the fundamental properties of neutron interaction effects between core tanks. These data will be useful for making more reasonable calculation models and for evaluating the safety margin in the criticality designs for the multiple unit system. (J.P.N.)

  13. Review of studies on criticality safety evaluation and criticality experiment methods

    International Nuclear Information System (INIS)

    Naito, Yoshitaka; Yamamoto, Toshihiro; Misawa, Tsuyoshi; Yamane, Yuichi

    2013-01-01

    Since the early 1960s, many studies on criticality safety evaluation have been conducted in Japan. Computer code systems were developed initially by employing finite difference methods, and more recently by using Monte Carlo methods. Criticality experiments have also been carried out in many laboratories in Japan as well as overseas. By effectively using these study results, the Japanese Criticality Safety Handbook was published in 1988, almost the intermediate point of the last 50 years. An increased interest has been shown in criticality safety studies, and a Working Party on Nuclear Criticality Safety (WPNCS) was set up by the Nuclear Science Committee of Organisation Economic Co-operation and Development in 1997. WPNCS has several task forces in charge of each of the International Criticality Safety Benchmark Evaluation Program (ICSBEP), Subcritical Measurement, Experimental Needs, Burn-up Credit Studies and Minimum Critical Values. Criticality safety studies in Japan have been carried out in cooperation with WPNCS. This paper describes criticality safety study activities in Japan along with the contents of the Japanese Criticality Safety Handbook and the tasks of WPNCS. (author)

  14. Proceedings of the Nuclear Criticality Technology and Safety Project Workshop

    International Nuclear Information System (INIS)

    Sanchez, R.G.

    1994-01-01

    This report is the proceedings of the annual Nuclear Criticality Technology and Safety Project (NCTSP) Workshop held in Monterey, California, on April 16--28, 1993. The NCTSP was sponsored by the Department of Energy and organized by the Los Alamos Critical Experiments Facility. The report is divided into six sections reflecting the sessions outlined on the workshop agenda

  15. Proceedings of the Nuclear Criticality Technology and Safety Project Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.G. [comp.

    1994-01-01

    This report is the proceedings of the annual Nuclear Criticality Technology and Safety Project (NCTSP) Workshop held in Monterey, California, on April 16--28, 1993. The NCTSP was sponsored by the Department of Energy and organized by the Los Alamos Critical Experiments Facility. The report is divided into six sections reflecting the sessions outlined on the workshop agenda.

  16. Los Alamos Neutron Science Center

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-08

    For more than 30 years the Los Alamos Neutron Science Center (LANSCE) has provided the scientific underpinnings in nuclear physics and material science needed to ensure the safety and surety of the nuclear stockpile into the future. In addition to national security research, the LANSCE User Facility has a vibrant research program in fundamental science, providing the scientific community with intense sources of neutrons and protons to perform experiments supporting civilian research and the production of medical and research isotopes. Five major experimental facilities operate simultaneously. These facilities contribute to the stockpile stewardship program, produce radionuclides for medical testing, and provide a venue for industrial users to irradiate and test electronics. In addition, they perform fundamental research in nuclear physics, nuclear astrophysics, materials science, and many other areas. The LANSCE User Program plays a key role in training the next generation of top scientists and in attracting the best graduate students, postdoctoral researchers, and early-career scientists. The U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) —the principal sponsor of LANSCE—works with the Office of Science and the Office of Nuclear Energy, which have synergistic long-term needs for the linear accelerator and the neutron science that is the heart of LANSCE.

  17. Nuclear criticality safety: 2-day training course

    International Nuclear Information System (INIS)

    Schlesser, J.A.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course

  18. Nuclear criticality safety: 2-day training course

    Energy Technology Data Exchange (ETDEWEB)

    Schlesser, J.A. [ed.] [comp.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course.

  19. Jezebel: Reconstructing a Critical Experiment from 60 Years Ago

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-15

    The Jezebel experiment of 1954-1955 was a very small, nearly-spherical, nearly-bare (unreflected), nearly-homogeneous assembly of plutonium alloyed with gallium. This experiment was used to determine the critical mass of spherical, bare, homogeneous Pu-alloy. In 1956, the critical mass of Pu-alloy was determined to be 16.45 ± 0.05 kg. The experiment was reevaluated in 1969 using logbooks from the 1950s and updated nuclear cross sections. The critical mass of Pu-alloy was determined to be 16.57 ± 0.10 kg. In 2013, the 239Pu Jezebel experiment was again reevaluated, this time using detailed geometry and materials models and modern nuclear cross sections in high-fidelity Monte Carlo neutron transport calculations. Documentation from the 1950s was often inconsistent or missing altogether, and assumptions had to be made. The critical mass of Pu-alloy was determined to be 16.624 ± 0.075 kg. Historic documents were subsequently found that validated some of the 2013 assumptions and invalidated others. In 2016, the newly found information was used to once again reevaluate the 239Pu Jezebel experiment. The critical mass of Pu-alloy was determined to be 16.624 ± 0.065 kg. This talk will discuss each of these evaluations, focusing on the calculation of the uncertainty as well as the critical mass. We call attention to the ambiguity, consternation, despair, and euphoria involved in reconstructing the historic Jezebel experiment. This talk is quite accessible for undergraduate students as well as non-majors.

  20. Validation of KENO V.a: Comparison with critical experiments

    International Nuclear Information System (INIS)

    Jordan, W.C.; Landers, N.F.; Petrie, L.M.

    1986-12-01

    Section 1 of this report documents the validation of KENO V.a against 258 critical experiments. Experiments considered were primarily high or low enriched uranium systems. The results indicate that the KENO V.a Monte Carlo Criticality Program accurately calculates a broad range of critical experiments. A substantial number of the calculations showed a positive or negative bias in excess of 1 1/2% in k-effective (k/sub eff/). Classes of criticals which show a bias include 3% enriched green blocks, highly enriched uranyl fluoride slab arrays, and highly enriched uranyl nitrate arrays. If these biases are properly taken into account, the KENO V.a code can be used with confidence for the design and criticality safety analysis of uranium-containing systems. Sections 2 of this report documents the results of investigation into the cause of the bias observed in Sect. 1. The results of this study indicate that the bias seen in Sect. 1 is caused by code bias, cross-section bias, reporting bias, and modeling bias. There is evidence that many of the experiments used in this validation and in previous validations are not adequately documented. The uncertainty in the experimental parameters overshadows bias caused by the code and cross sections and prohibits code validation to better than about 1% in k/sub eff/. 48 refs., 19 figs., 19 tabs

  1. Forecast of criticality experiments and experimental programs needed to support nuclear operations in the United States of America: 1994-1999

    International Nuclear Information System (INIS)

    Rutherford, D.

    1995-01-01

    This Forecast is generated by the Chair of the Experiment Needs Identification Workgroup (ENIWG), with input from Department of Energy and the nuclear community. One of the current concerns addressed by ENIWG was the Defense Nuclear Facilities Safety Board's Recommendation 93-2. This Recommendation delineated the need for a critical experimental capability, which includes (1) a program of general-purpose experiments, (2) improving the information base, and (3) ongoing departmental programs. The nuclear community also recognizes the importance of criticality theory, which, as a stepping stone to computational analysis and safety code development, needs to be benchmarked against well-characterized critical experiments. A summary projection of the Department's needs with respect to criticality information includes (1) hands-on training, (2) criticality and nuclear data, (3) detector systems, (4) uranium- and plutonium-based reactors, and (5) accident analysis. The Workgroup has evaluated, prioritized, and categorized each proposed experiment and program. Transportation/Applications is a new category intended to cover the areas of storage, training, emergency response, and standards. This category has the highest number of priority-1 experiments (nine). Facilities capable of performing experiments include the Los Alamos Critical Experiment Facility (LACEF) along with Area V at Sandia National Laboratory. The LACEF continues to house the most significant collection of critical assemblies in the Western Hemisphere. The staff of this facility and Area V are trained and certified, and documentation is current. ENIWG will continue to work with the nuclear community to identify and prioritize experiments because there is an overwhelming need for critical experiments to be performed for basic research and code validation

  2. Forecast of criticality experiments and experimental programs needed to support nuclear operations in the United States of America: 1994--1999

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, D.

    1994-03-01

    This Forecast is generated by the Chair of the Experiment Needs Identification Workgroup (ENIWG), with input from Department of Energy and the nuclear community. One of the current concerns addressed by ENIWG was the Defense Nuclear Facilities Safety Board`s Recommendation 93-2. This Recommendation delineated the need for a critical experimental capability, which includes (1) a program of general-purpose experiments, (2) improving the information base, and (3) ongoing departmental programs. The nuclear community also recognizes the importance of criticality theory, which, as a stepping stone to computational analysis and safety code development, needs to be benchmarked against well-characterized critical experiments. A summary project of the Department`s needs with respect to criticality information includes (1) hands-on training, (2) criticality and nuclear data, (3) detector systems, (4) uranium- and plutonium-based reactors, and (5) accident analysis. The Workgroup has evaluated, prioritized, and categorized each proposed experiment and program. Transportation/Applications is a new category intended to cover the areas of storage, training, emergency response, and standards. This category has the highest number of priority-1 experiments (nine). Facilities capable of performing experiments include the Los Alamos Critical Experiment Facility (LACEF) along with Area V at Sandia National Laboratory. The LACEF continues to house the most significant collection of critical assemblies in the Western Hemisphere. The staff of this facility and Area V are trained and certified, and documentation is current. ENIWG will continue to work with the nuclear community to identify and prioritize experiments because there is an overwhelming need for critical experiments to be performed for basic research and code validation.

  3. The nuclear criticality information system's project to archive unpublished critical experiment data

    International Nuclear Information System (INIS)

    Koponen, B.L.; Doherty, A.L.; Clayton, E.D.

    1991-01-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. The closure of facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to ensure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to ensure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology. (Author)

  4. Critical and sub-critical experiments on U-BeO lattices

    International Nuclear Information System (INIS)

    Benoist, P.; Gourdon, Ch.; Martelly, J.; Sagot, M.; Wanner, G.

    1958-01-01

    Sub-critical experiments have allowed us to measure the material buckling of uranium natural oxide of beryllium lattices with a grid of 15 cm, and made up of uranium bars measuring 2.60 - 2.92 - 3.56 and 4.40 cm of diameter. A critical experiment has then been conducted with hollow 1.35 per cent enriched uranium bars. A study of U-BeO 18.03 cm grid lattices is at present being conducted. (author) [fr

  5. Criticality experiments of the years 1981 and 1982

    International Nuclear Information System (INIS)

    Heinicke, W.; Tischer, A.

    1983-01-01

    This report presents a collection of published criticality experiments made in 1981 and 1982 and thus continues the collection of experimental data of this type commenced with the GRS report A-644 of November 1981, which covers criticality experiments of the years 1975 to 1980. The report gives the main data of about 30 publications which, just a those cited in the GRS report, can be retrieved from the improved KRITEXP data base using 14 index terms, and printed out at random sequence. The collection of experimental data is of particular value with regard to the licensing of all installations forming part of the nuclear fuel cycle, which is subject to the atomic energy law and requires the verification of computed criticality analyses by experimental data. (orig.) [de

  6. Technical specifications for the Pajarito Site Critical Experiments Facility

    International Nuclear Information System (INIS)

    Malenfant, R.E.; Paxton, H.C.

    1980-12-01

    This document is to satisfy the requirement for technical specifications spelled out in DOE Manual Chapter 0540, Safety of DOE-Owned Reactors. Technical specifications are defined in Sec. 0540-048, and the requirement for them appears in Sec. 0540-015. The following technical specifications update the document, Technical Specifications for the Pajarito Site Critical Experiments Facility

  7. Critical Reflections: Interpretation and Analysis of Japanese Women's Settlement Experiences

    Science.gov (United States)

    Takeda, Atsushi

    2012-01-01

    In this paper, I discuss how I came to call into question the way in which I interpreted interview data in my dissertation, which investigated the migration and settlement experience of Japanese women who are married to Australian men and reside in Australia. Through critical reflections, I realized the way in which the positionality of…

  8. Nuclear criticality safety: 2-day training course

    International Nuclear Information System (INIS)

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) have participated in conducting two critical experiments

  9. Educational reactor-physics experiments with the critical assemble TCA

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsui, Hiroaki; Okubo, Masaaki; Igashira, Masayuki [Tokyo Inst. of Tech. (Japan); Horiki, Oichiro; Suzaki, Takenori

    1997-10-01

    The Tank-Type Critical Assembly (TCA) of Japan Atomic Energy Research Institute is research equipment for light water reactor physics. In the present report, the lectures given to the graduate students of Tokyo Institute of Technology who participated in the educational experiment course held on 26-30 August at TCA are rearranged to provide useful information for those who will implement educational basic experiments with TCA in the future. This report describes the principles, procedures, and data analyses for (1) Critical approach and Exponential experiment, (2) Measurement of neutron flux distribution, (3) Measurement of power distribution, (4) Measurement of fuel rod worth distribution, and (5) Measurement of safety plate worth by the rod drop method. (author)

  10. The Los Alamos foil implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Parker, J.; Bartsch, R.; Benage, J.; Bowers, R.; Cochrane, J.; Forman, P.; Goforth, J.; Greene, A.; Kruse, H.

    1993-01-01

    The goal of the Los Alamos foil implosion project is to produce an intense (>100 TW), multi-megajoule, laboratory soft x-ray source for material studies and fusion experiments. The concept involves the implosion of annular, current-carrying, cylindrical metallic plasmas via their self-magnetic forces. The project features inductive storage systems using both capacitor banks and high explosive-driven flux compression generators as prime energy sources. Fast opening switches are employed to shorten the electrical pulses. The program will be described and activities to date will be summarized

  11. Los Alamos, Hiroshima, Nagasaki - a personal recollection

    International Nuclear Information System (INIS)

    Morrison, P.

    1995-01-01

    The author, a physicist participating in the Manhattan Project, recalls his experiences and work in the laboratories at the time which marked the onset of the nuclear era, the construction of the first uranium and plutonium bombs in Los Alamos, and the hidious effects shown to the world by the nuclear bombing of Japan. His thoughts and memories presented 50 years after the nuclear destruction of Hiroshima and Nagasaki, and now that the Cold War has ended, call for a global ban of nuclear weapons. (orig.) [de

  12. Sensitivity analysis of critical experiments with evaluated nuclear data libraries

    International Nuclear Information System (INIS)

    Fujiwara, D.; Kosaka, S.

    2008-01-01

    Criticality benchmark testing was performed with evaluated nuclear data libraries for thermal, low-enriched uranium fuel rod applications. C/E values for k eff were calculated with the continuous-energy Monte Carlo code MVP2 and its libraries generated from Endf/B-VI.8, Endf/B-VII.0, JENDL-3.3 and JEFF-3.1. Subsequently, the observed k eff discrepancies between libraries were decomposed to specify the source of difference in the nuclear data libraries using sensitivity analysis technique. The obtained sensitivity profiles are also utilized to estimate the adequacy of cold critical experiments to the boiling water reactor under hot operating condition. (authors)

  13. Experience with performance based training of nuclear criticality safety engineers

    International Nuclear Information System (INIS)

    Taylor, R.G.

    1993-01-01

    Historically, new entrants to the practice of nuclear criticality safety have learned their job primarily by on-the-job training (OJT) often by association with an experienced nuclear criticality safety engineer who probably also learned their job by OJT. Typically, the new entrant learned what he/she needed to know to solve a particular problem and accumulated experience as more problems were solved. It is likely that more formalism will be required in the future. Current US Department of Energy requirements for those positions which have to demonstrate qualification indicate that it should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis i's incompletely developed in some areas. Details of this analysis are provided in this report

  14. RFQ development at Los Alamos

    International Nuclear Information System (INIS)

    Wangler, T.P.; Crandall, K.R.; Stokes, R.H.

    1982-01-01

    The basic principles of the radio-frequency quadrupole (RFQ) linac are reviewed and a summary of past and present Los Alamos work is presented. Some beam-dynamics effects, important for RFQ design, are discussed. A design example is shown for xenon and a brief discussion of low-frequency RFQ structures is given

  15. Parametric analyses of planned flowing uranium hexafluoride critical experiments

    Science.gov (United States)

    Rodgers, R. J.; Latham, T. S.

    1976-01-01

    Analytical investigations were conducted to determine preliminary design and operating characteristics of flowing uranium hexafluoride (UF6) gaseous nuclear reactor experiments in which a hybrid core configuration comprised of UF6 gas and a region of solid fuel will be employed. The investigations are part of a planned program to perform a series of experiments of increasing performance, culminating in an approximately 5 MW fissioning uranium plasma experiment. A preliminary design is described for an argon buffer gas confined, UF6 flow loop system for future use in flowing critical experiments. Initial calculations to estimate the operating characteristics of the gaseous fissioning UF6 in a confined flow test at a pressure of 4 atm, indicate temperature increases of approximately 100 and 1000 K in the UF6 may be obtained for total test power levels of 100 kW and 1 MW for test times of 320 and 32 sec, respectively.

  16. Los Alamos National Laboratory Weapons Neutron Research Facility

    International Nuclear Information System (INIS)

    Woods, R.

    1981-01-01

    The Weapons Neutron Research (WNR) spallation neutron source utilizes 800-MeV protons from the Los Alamos Meson Physics linac. The proton beam transport system, the target systems, and the data acquisition and control system are described. Operating experience, present status, and planned improvements are discussed

  17. Working with Fermi at Chicago and Los Alamos

    Science.gov (United States)

    Garwin, Richard L.

    2010-02-01

    I discuss my experience with Enrico Fermi as student and fellow faculty member at Chicago and with him as consultants to the Los Alamos Scientific Laboratory in 1950-1952. The talk shares observations about this great physicist and exemplary human being. )

  18. History of remote handling at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Wilson, M.T.; Wood, W.T.; Barnes, J.W.

    1979-01-01

    The handling of high levels of radioactive materials began at Los Alamos in 1944 with the receipt of 140 Ba sources that were milked to extract the 140 La daughter for use as a tracer in hydrodynamical experiments. Remote-handling techniques and facilities have been used to support research programs in reactor development and radiochemistry, and in support of an accelerator

  19. Reflector-moderated critical assemblies

    International Nuclear Information System (INIS)

    Paxton, H.C.; Jarvis, G.A.; Byers, C.C.

    1975-07-01

    Experiments with reflector-moderated critical assemblies were part of the Rover Program at the Los Alamos Scientific Laboratory (LASL). These assemblies were characterized by thick D 2 O or beryllium reflectors surrounding large cavities that contained highly enriched uranium at low average densities. Because interest in this type of system has been revived by LASL Plasma Cavity Assembly studies, more detailed descriptions of the early assemblies than had been available in the unclassified literature are provided. (U.S.)

  20. Four critical facilities: their capabilities and programs

    International Nuclear Information System (INIS)

    Whitesides, G.E.

    1980-01-01

    Information is presented on the critical experiments facilities at Babcock and Wilcox, Lynchburg, Virginia; at Battelle Pacific Northwest Laboratory in Hanford, Washington; at Rockwell-International in Rocky Flats, Colorado; and at Los Alamos Scientific Laboratory in New Mexico. It is noted that the critical mass facilities which still exist in this country represent a bare minimum for maintaining a measurement program sufficient for meeting data requirements

  1. A critical experiment at HFR of 19 March 2008

    International Nuclear Information System (INIS)

    Campioni, G.; Calzavara, Y.; Mollier, M.; Atkins, D.; Veler, R.; Sebie, P.; Ferrandiz, L.; Micoud, E.; Deyres, J.-C.; Chirol, P.; Puygrenier, C.; Carriere, S.; Allemmoz, S.; Samuel, M.; Meynent, P.-Y.; Laurent, C.; Mannino, E.; Bonnet, G.; Rey, J.-P.; Barbe, C.

    2009-01-01

    In this paper, we present the critical experiment performed in March 2008 in the high-flux reactor (HFR) to reproduce physical conditions similar to the core light water introduction accident. We present the HFR, the context of the study and two Monte Carlo models: TRIPOLI4 - JEFF3.1 and MCNP - ENDF/BVII. All comparisons between calculations and experimental results show, within both models, that the safety rods efficiencies, in AIC alloy, are always underestimated in normal as well as in accidental configuration of the reactor.

  2. Fast Reactor Spent Fuel Processing: Experience and Criticality Safety

    International Nuclear Information System (INIS)

    Chad Pope

    2007-01-01

    This paper discusses operational and criticality safety experience associated with the Idaho National Laboratory Fuel Conditioning Facility which uses a pyrometallurgical process to treat spent fast reactor metallic fuel. The process is conducted in an inert atmosphere hot cell. The process starts with chopping metallic fuel elements into a basket. The basket is lowered into molten salt (LiCl-KCl) along with a steel mandrel. Active metal fission products, transuranic metals and sodium metal in the spent fuel undergo chemical oxidation and form chlorides. Voltage is applied between the basket, which serves as an anode, and the mandrel, which serves as a cathode, causing metallic uranium in the spent fuel to undergo electro-chemical oxidation thereby forming uranium chloride. Simultaneously at the cathode, uranium chloride undergoes electro-chemical reduction and deposits uranium metal onto the mandrel. The uranium metal and accompanying entrained salt are placed in a distillation furnace where the uranium melts forming an ingot and the entrained salt boils and subsequently condenses in a separate crucible. The uranium ingots are placed in long term storage. During the ten year operating history, over one hundred criticality safety evaluations were prepared. All criticality safety related limits and controls for the entire process are contained in a single document which required over thirty revisions to accommodate the process changes. Operational implementation of the limits and controls includes use of a near real-time computerized tracking system. The tracking system uses an Oracle database coupled with numerous software applications. The computerized tracking system includes direct fuel handler interaction with every movement of material. Improvements to this system during the ten year history include introduction of web based operator interaction, tracking of moderator materials and the development of a plethora database queries to assist in day to day

  3. Critical experiments on enriched uranium graphite moderated cores

    International Nuclear Information System (INIS)

    Kaneko, Yoshihiko; Akino, Fujiyoshi; Kitadate, Kenji; Kurokawa, Ryosuke

    1978-07-01

    A variety of 20 % enriched uranium loaded and graphite-moderated cores consisting of the different lattice cells in a wide range of the carbon to uranium atomic ratio have been built at Semi-Homogeneous Critical Experimental Assembly (SHE) to perform the critical experiments systematically. In the present report, the experimental results for homogeneously or heterogeneously fuel loaded cores and for simulation core of the experimental reactor for a multi-purpose high temperature reactor are filed so as to be utilized for evaluating the accuracy of core design calculation for the experimental reactor. The filed experimental data are composed of critical masses of uranium, kinetic parameters, reactivity worths of the experimental control rods and power distributions in the cores with those rods. Theoretical analyses are made for the experimental data by adopting a simple ''homogenized cylindrical core model'' using the nuclear data of ENDF/B-III, which treats the neutron behaviour after smearing the lattice cell structure. It is made clear from a comparison between the measurement and the calculation that the group constants and fundamental methods of calculations, based on this theoretical model, are valid for the homogeneously fuel loaded cores, but not for both of the heterogeneously fuel loaded cores and the core for simulation of the experimental reactor. Then, it is pointed out that consideration to semi-homogeneous property of the lattice cells for reactor neutrons is essential for high temperature graphite-moderated reactors using dispersion fuel elements of graphite and uranium. (author)

  4. Electron-beam diagnostics development for the Los Alamos FEL facility

    International Nuclear Information System (INIS)

    Wilke, M.D.; O'Shea, P.G.; Pitcher, E.J.; Feldman, R.B.; Lumpkin, A.H.

    1992-01-01

    We describe some electron-beam diagnostics and results from the Los Alamos APLE Prototype Experiment (APEX) linac. The diagnostics include complementary nonintercepting and intercepting techniques with time integrated and time resolved capabilities

  5. Experiments on critical heat flux for CAREM reactor

    International Nuclear Information System (INIS)

    Mazufri, C.M.

    2000-01-01

    The prediction of critical heat flux (CHF) in rod bundles of light water reactors is basically performed with the aid of empirical correlations derived from experimental data. Many CHF correlations have been proposed and are widely used in the analysis of the thermal margin during normal operation, transient, and accident conditions. Correlations found in the open literature are not sufficiently verified for the thermal-hydraulic conditions that appear in the CAREM core under normal operation: high pressure, low flow, and low qualities. To compensate this deficiency, an experimental investigation on CHF in such thermal-hydraulic conditions is being carried out. The experiments have been performed in the Institute of Physics and Power Engineering of Russian Federation. A short description of facilities, details of the experimental program and some trends in the preliminary results obtained are presented in this work. (author)

  6. Experiments on Critical Heat Flux for CAREM -25 Reactor

    International Nuclear Information System (INIS)

    Mazufri, C.M

    2000-01-01

    The prediction of critical heat flux (CHF) in rod bundles of light water reactors is basically performed with the aid of empirical correlations derived from experimental data.Many CHF correlations have been proposed and are widely used in the analysis of the thermal margin during normal operation, transient, and accident conditions.Correlations found in the open literature are not sufficiently verified for the thermal hydraulic conditions that appear in the CAREM core under normal operation: high pressure, low flow, and low qualities.To compensate this deficiency, an experimental investigation on CHF in such thermal-hydraulic conditions was carried out.The experiments have been performed in the Institute of Physics and Power Engineering of Russian Federation.A short description of facilities, details of the experimental program and some preliminary results obtained are presented in this work

  7. Criticality experiments to provide benchmark data on neutron flux traps

    International Nuclear Information System (INIS)

    Bierman, S.R.

    1988-06-01

    The experimental measurements covered by this report were designed to provide benchmark type data on water moderated LWR type fuel arrays containing neutron flux traps. The experiments were performed at the US Department of Energy Hanford Critical Mass Laboratory, operated by Pacific Northwest Laboratory. The experimental assemblies consisted of 2 /times/ 2 arrays of 4.31 wt % 235 U enriched UO 2 fuel rods, uniformly arranged in water on a 1.891 cm square center-to-center spacing. Neutron flux traps were created between the fuel units using metal plates containing varying amounts of boron. Measurements were made to determine the effect that boron loading and distance between the fuel and flux trap had on the amount of fuel required for criticality. Also, measurements were made, using the pulse neutron source technique, to determine the effect of boron loading on the effective neutron multiplications constant. On two assemblies, reaction rate measurements were made using solid state track recorders to determine absolute fission rates in 235 U and 238 U. 14 refs., 12 figs., 7 tabs

  8. Critical experiments on STACY homogeneous core containing 10% enriched uranyl nitrate solution

    International Nuclear Information System (INIS)

    Miyoshi, Yoshinori; Yamamoto, Toshihiro; Tonoike, Kotaro; Yamane, Yuichi; Watanabe, Shouichi

    2003-01-01

    In order to investigate criticality properties of low enriched uranyl nitrate solution treated in the reprocessing facility for LWR fuel cycle, systematic and high precision critical experiments have been performed at the Static Experiment Critical Facility, STACY since 1995. Criticality benchmark data on 10% enriched uranyl nitrate solution for single core and multiple core systems have been accumulated using cylindrical and slab type core tanks. This paper overviews mains data and related criticality calculation results using standard criticality safety calculation code system. (author)

  9. Los Alamos - A Short History

    Energy Technology Data Exchange (ETDEWEB)

    Meade, Roger A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-12

    At 5:45 am on the morning of July 16, 1945, the world’s first atomic bomb exploded over a remote section of the southern New Mexican desert known as the Jornada del Muerto, the Journey of Death. Three weeks later, the atomic bombs known as Little Boy and Fat Man brought World War II to an end. Working literally around the clock, these first atomic bombs were designed and built in just thirty months by scientists working at a secret scientific laboratory in the mountains of New Mexico known by its codename, Project Y, better known to the world as Los Alamos.

  10. Los Alamos racquetball contamination incident

    International Nuclear Information System (INIS)

    McAtee, J.L.; Stafford, R.G.; Dowdy, E.J.; Prestwood, R.J.

    1985-01-01

    Several employees of the Los Alamos Plutonium Facility were found to have low levels of radioactivity on their hands and clothing when they arrived for work one morning. The initial concern was that the stringent contamination or material controls at the facility had failed, and that one or more of the employees had either accidentally or intentionally removed plutonium from the Laboratory premises. Fortunately, however, an investigation revealed that the source of the radioactivity was radon daughters electrostatically collected upon the surface of the racquetball and transferred by physical contact to the employees during an early morning racquetball game. This paper describes the events leading to the discovery of this phenomenon. 1 figure

  11. Experiences of Vulnerable Residential Customer Subpopulations with Critical Peak Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spurlock, C. Anna [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Todd, Annika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jin, Ling [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-04-13

    DOE decided to co-fund ten utilities to undertake eleven experimentally-designed Consumer Behavior Studies (CBS) that proposed to examine a wide range of the topics of interest to the electric utility industry. Each chosen utility was to design, implement and evaluate their own study in order to address questions of interest both to itself and to its applicable regulatory authority, whose approval was generally necessary for the study to proceed. The DOE Office of Energy Delivery and Electricity Reliability (OE), however, did set guidelines, both in the FOA and subsequently during the contracting period, for what would constitute an acceptable study under the Grant. To assist in ensuring these guidelines were adhered to, OE requested that LBNL act as project manager for these Consumer Behavior Studies to achieve consistency of experimental design and adherence to data collection and reporting protocols across the ten utilities. As part of its role, LBNL formed technical advisory groups (TAG) to separately assist each of the utilities by providing technical assistance in all aspects of the design, implementation and evaluation of their studies. LBNL was also given a unique opportunity to perform a comprehensive, cross-study analysis that uses the customer-level interval meter and demographic data made available by these utilities due to SGIG-imposed reporting requirements, in order to analyze critical policy issues associated with AMI-enabled rates and control/information technology. LBNL will publish the results of these analyses in a series of research reports, of which this is one, that attempt to address critical policy issues relating to a variety of topics including customer acceptance, retention and load response to time-based rates and various forms of enabling control and information technologies. This report extends the existing empirical literature on the experiences of low-income customers exposed to critical peak pricing, and provides the first glimpses

  12. ARCHITECTURAL CRITICISM IN PRACTICE: FROM AFFECTIVE TO EFFECTIVE EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Aaron T. Davis

    2012-07-01

    Full Text Available “Although many artists and architects privilege phenomenological experience, they often offer the near-reverse: ‘experience’ handed back to us as ‘atmosphere’ or ‘affect’ - that is as environments that confuse the actual with the virtual, or feelings that  are hardly our own yet interpolate us nonetheless. In the guise of our activation, some work even tends to subdue us, for the more it opts for special effects, the less it engages us as active viewers.“ (Foster, 2011 The article that follows chronicles the evolution of the respective sub-fields of endeavor from the unique perspectives of the authors and their cumulative involvements and experiences. Its main purpose is to  begin to bridge the gap between the affective and  effective goals of architectural criticism (Attoe, 1989. In other words, the attempt will be made to connect  the perceived vs. measured quality of the designed and built environment, including visual-aesthetic quality. The result is an entirely new form of criticism that is instructive as both a tool to professionals and an explication of the built environment to the layperson beyond aesthetic platitudes. Because of its cumulative nature, the2-part literature review is not intended to be exhaustive since that can be gleaned from a sample of authoritative publications on the evolution of: 1. Architectural Criticism: On Architecture: Collected Reflections on a Century of Change by Huxtable (Walker, 2010, Why Architecture Matters by Goldberger (Yale University Press, 2003, and After the End of Art: Contemporary Art and the Pale of History by Danto (Princeton University Press, 1997; 2. Post-Occupancy Evaluation/Building Performance Evaluation: Enhancing Building Performance by Mallory-Hill, Preiser and Watson (Wiley, 2012; Learning From Our Buildings: A State-ofthe-Practice Summary of Post-Occupancy Evaluation by Federal Facilities Council (National Academy Press, 2001; and, Building Evaluation Techniques by

  13. Experiment to investigate anti ν/sub μ/ → anti ν/sub e/ oscillations at Los Alamos Meson Physics Facility

    International Nuclear Information System (INIS)

    Kruse, H.W.; Toevs, J.W.

    1981-01-01

    An experiment, being planned at LAMPF, aims to investigate a possible neutrino oscillation channel, anti ν/sub μ/ → anti ν/sub e/. If anti ν/sub μ/, produced in the LAMPF beam stop, oscillate to anti ν/sub e/, then interactions anti ν/sub e/ + p → e + + n, may be detected. A large volume liquid scintillator (4470 liter) emplaced at 33 m from the beam stop, detects e + and n, after moderation in the hydrogenous liquid and capture in Gd, loaded into the scintillator. Our anticipated signal rate is currently estimated at 1.67 (sigma m 2 ) 2 /day assuming full amplitude oscillation. The corresponding counting rate, assuming all anti ν/sub μ/ have oscillated to anti ν/sub e/ at the detector is 1.5/day. Cosmic rates are estimated at 0.033/day. Correlated backgrounds from the beam stop are calculated to be small in comparison to cosmic events, except for reactions of ν/sub e/ in Pb. These reactions may be reduced with an Fe shield within the detector. With the above rate, a limit on the sensitivity of our experiment for the value of sigma m 2 is estimated at 0.12 eV 2 with 70 days of counting. Detector features, estimated background rates, and sensitivity values are discussed

  14. Occurrences at Los Alamos National Laboratory: What can they tell us?

    Energy Technology Data Exchange (ETDEWEB)

    Richard A. Reichelt; A. Jeffery Eichorst; Marc E. Clay; Rita J. Henins; Judith D. DeHaven; Richard J. Brake

    2000-03-01

    The authors analyzed the evolution of institutional and facility response to groups of abnormal incidents at Los Alamos National Laboratory (LANL). The analysis is divided into three stages: (1) the LANL response to severe accidents from 1994 to 1996, (2) the LANL response to facility-specific clusters of low-consequence incidents from 1997 to 1999, and (3) the ongoing development of and response to a Laboratory-wide trending and analysis program. The first stage is characterized by five severe accidents at LANL--a shooting fatality, a forklift accident, two electrical shock incidents, and an explosion in a nuclear facility. Each accident caused LANL and the Department of Energy (DOE) to launch in-depth investigations. A recurrent theme of the investigations was the failure of LANL and DOE to identify and act on precursor or low-consequence events that preceded the severe accidents. The second stage is characterized by LANL response to precursor or low-consequence incidents over a two-year period. In this stage, the Chemistry and Metallurgy Research Facility, the Los Alamos Critical Experiments Facility, and the Los Alamos Neutron Science Center responded to an increase in low-consequence events by standing down their facilities. During the restart process, each facility collectively analyzed the low-consequence events and developed systemic corrective actions. The third stage is characterized by the development of a Laboratory-wide trending and analysis program, which involves proactive division-level analysis of incidents and development of systemic actions. The authors conclude that, while the stages show an encouraging evolution, the facility standdowns and restarts are overly costly and that the institutional trending and analysis program is underutilized. The authors therefore recommend the implementation of an institutional, mentored program of trending and analysis that identifies clusters of related low-consequence events, analyzes those events, and

  15. After the Resistance: The Alamo Today

    Centers for Disease Control (CDC) Podcasts

    2014-09-23

    Byron Breedlove reads his essay After the Resistance: The Alamo Today about the Alamo and emerging disease resistance.  Created: 9/23/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/20/2014.

  16. Analysis results from the Los Alamos 2D/3D program

    International Nuclear Information System (INIS)

    Boyack, B.E.; Cappiello, M.W.; Stumpf, H.; Shire, P.; Gilbert, J.; Hedstrom, J.

    1986-01-01

    Los Alamos National Laboratory is a participant in the 2D/3D program. Activities conducted at Los Alamos National Laboratory in support of 2D/3D program goals include analysis support of facility design, construction, and operation; provision of boundary and initial conditions for test facility operations based on analysis of pressurized water reactors; performance of pretest and posttest predictions and analyses; and use of experimental results to validate and assess the single- and multidimensional nonequilibrium features in the Transient Reactor Analysis Code (TRAC). During Fiscal Year 1986, Los Alamos conducted analytical assessment activities using data from the Cylindrical Core Test Facility and the Slab Core Test Facility. Los Alamos also continued to provide support analysis for the planning of Upper Plenum Test Facility experiments. Finally, Los Alamos either completed or is currently working on three areas of TRAC modeling improvement. In this paper, Los Alamos activities during Fiscal Year 1986 are summarized; several significant accomplishments are described in more detail to illustrate the work activities at Los Alamos

  17. Enabling software defined networking experiments in networked critical infrastructures

    Directory of Open Access Journals (Sweden)

    Béla Genge

    2014-05-01

    Full Text Available Nowadays, the fact that Networked Critical Infrastructures (NCI, e.g., power plants, water plants, oil and gas distribution infrastructures, and electricity grids, are targeted by significant cyber threats is well known. Nevertheless, recent research has shown that specific characteristics of NCI can be exploited in the enabling of more efficient mitigation techniques, while novel techniques from the field of IP networks can bring significant advantages. In this paper we explore the interconnection of NCI communication infrastructures with Software Defined Networking (SDN-enabled network topologies. SDN provides the means to create virtual networking services and to implement global networking decisions. It relies on OpenFlow to enable communication with remote devices and has been recently categorized as the “Next Big Technology”, which will revolutionize the way decisions are implemented in switches and routers. Therefore, the paper documents the first steps towards enabling an SDN-NCI and presents the impact of a Denial of Service experiment over traffic resulting from an XBee sensor network which is routed across an emulated SDN network.

  18. Recent developments in the Los Alamos radiation transport code system

    International Nuclear Information System (INIS)

    Forster, R.A.; Parsons, K.

    1997-01-01

    A brief progress report on updates to the Los Alamos Radiation Transport Code System (LARTCS) for solving criticality and fixed-source problems is provided. LARTCS integrates the Diffusion Accelerated Neutral Transport (DANT) discrete ordinates codes with the Monte Carlo N-Particle (MCNP) code. The LARCTS code is being developed with a graphical user interface for problem setup and analysis. Progress in the DANT system for criticality applications include a two-dimensional module which can be linked to a mesh-generation code and a faster iteration scheme. Updates to MCNP Version 4A allow statistical checks of calculated Monte Carlo results

  19. Proton Radiography at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-28

    The proton radiography (pRad) facility at Los Alamos National Lab uses high energy protons to acquire multiple frame flash radiographic sequences at megahertz speeds: that is, it can make movies of the inside of explosions as they happen. The facility is primarily used to study the damage to and failure of metals subjected to the shock forces of high explosives as well as to study the detonation of the explosives themselves. Applications include improving our understanding of the underlying physical processes that drive the performance of the nuclear weapons in the United States stockpile and developing novel armor technologies in collaboration with the Army Research Lab. The principle and techniques of pRad will be described, and examples of some recent results will be shown.

  20. Environmental surveillance at Los Alamos

    International Nuclear Information System (INIS)

    1979-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos Scientific Laboratory (LASL) in 1978. Routine monitoring for radiation and radioactive or chemical substances is conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of the data for 1978 on penetrating radiation, chemical and radiochemical quality of ambient air, surface and groundwater, municipal water supply, soils and sediments, food, and airborne and liquid effluents are included. Comparisons with appropriate standards and regulations or with background levels from natural or other non-LASL sources provide a basis for concluding that environmental effects attributable to LASL operations are minor and cannot be considered likely to result in any hazard to the population of the area. Results of several special studies provide documentation of some unique environmental conditions in the LASL environs

  1. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-01-01

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants

  2. Critical Pedagogy: EFL Teachers' Views, Experience and Academic Degrees

    Science.gov (United States)

    Mahmoodarabi, Mahsa; Khodabakhsh, Mohammad Reza

    2015-01-01

    Although critical pedagogy has brought about positive changes in the field of education by shifting from traditional pedagogy to emancipatory pedagogy, not much attention has been paid to the factors affecting teachers' beliefs of critical pedagogy and only few studies have been conducted to design reliable and valid instruments to study EFL…

  3. Experience with performance based training of nuclear criticality safety engineers

    International Nuclear Information System (INIS)

    Taylor, R.G.

    1993-01-01

    For non-reactor nuclear facilities, the U.S. Department of Energy (DOE) does not require that nuclear criticality safety engineers demonstrate qualification for their job. It is likely, however, that more formalism will be required in the future. Current DOE requirements for those positions which do have to demonstrate qualification indicate that qualification should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis is incompletely developed in some areas

  4. Analysis on the 237Np sphere surrounded by 235U shells experiment

    International Nuclear Information System (INIS)

    Loaiza, David; Sanchez, Rene

    2003-01-01

    The Neptunium sphere reflected by highly enriched uranium hemi-shells experiment was performed using the Planet universal critical assembly at the Los Alamos Critical Experiment Facility (LACEF) at Los Alamos National Laboratory. The experiment consisted of surrounding a Np sphere by matching pairs of highly enriched uranium hemisphere shells. This experiment was performed in an effort to decrease the uncertainty in the critical mass of 237 Np for criticality safety and nonproliferation issues. The initial configuration went critical on September of 2002. The final experimental configuration consisted of a 6.07 kg Np sphere and 62.555 kg of HEU separated by a 0.3175-cm aluminum spacer. The critical configuration had an experimental k eff of 1.003. The uncertainties affecting the experiment were divided into three categories: mass measurements, geometry and material composition. The sensitivity analysis on this experiment yielded an uncertainty in the measured k eff of ±0.0044. (author)

  5. Publications of Los Alamos research 1988

    International Nuclear Information System (INIS)

    Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A.

    1989-12-01

    This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index

  6. Technical Considerations for Alamo Lake Operation

    National Research Council Canada - National Science Library

    Kirby, Ken

    1998-01-01

    .... The analyses specifically addresses three questions of interest to the District: (1) can Alamo Lake be operated to protect against bald eagle nest inundation and if so, what are the downstream impacts; (2...

  7. Publications of Los Alamos research 1988

    Energy Technology Data Exchange (ETDEWEB)

    Varjabedian, K.; Dussart, S.A.; McClary, W.J.; Rich, J.A. (comps.)

    1989-12-01

    This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.

  8. Monte Carlo code development in Los Alamos

    International Nuclear Information System (INIS)

    Carter, L.L.; Cashwell, E.D.; Everett, C.J.; Forest, C.A.; Schrandt, R.G.; Taylor, W.M.; Thompson, W.L.; Turner, G.D.

    1974-01-01

    The present status of Monte Carlo code development at Los Alamos Scientific Laboratory is discussed. A brief summary is given of several of the most important neutron, photon, and electron transport codes. 17 references. (U.S.)

  9. Environmental surveillance at Los Alamos during 1994

    International Nuclear Information System (INIS)

    1996-07-01

    This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance

  10. Environmental surveillance at Los Alamos during 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance.

  11. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, N.G. [ed.

    1997-12-31

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  12. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1997-01-01

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos

  13. Materials accounting at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Erkkila, B.H.; Roberts, N.J.

    1989-01-01

    This presentation gives an overview of the accounting system used at the Los Alamos National Laboratory by the Los Alamos Nuclear Material Accounting and Safeguards System (MASS). This system processes accounting data in real time for bulk materials, discrete items, and materials undergoing dynamic processing. The following topics are covered in this chapter: definitions; nuclear material storage; nuclear material storage; computer system; measurement control program; inventory differences; and current programs and future plans

  14. ICF research at Los Alamos

    International Nuclear Information System (INIS)

    Goldstone, P.D.; Ackerhalt, J.R.; Blair, L.S.

    1987-01-01

    It is apparent that short wavelength lasers (<500 nm) provide efficient coupling of laser energy into ICF target compression. KrF lasers (248 nm) operate at near-optimum wavelength and provide other potential benefits to ICF target coupling (e.g., bandwidth) and applications (high wallplug efficiency and relatively low cost). However, no driver technology has yet been shown to meet all of the requirements for a high-gain ICF capability at a currently acceptable cost, and there are still significant uncertainties in the driver-target coupling and capsule hydrodynamics that must be addressed. The Los Alamos research program is designed to assess the potential of KrF lasers for ICF and to determine the feasibility of achieving high gain in the laboratory with a KrF laser driver. Major efforts in KrF laser development and technology, target fabrication and materials development, and laser-matter interaction and hydrodynamics research are discussed. 27 refs., 10 figs

  15. Feasibility of performing criticality experiments with spent LWR fuel

    International Nuclear Information System (INIS)

    Bierman, S.R.

    1989-01-01

    Considering fuel operating histories, i.e., burnup, in criticality analyses and control involves two distinctly different issues. One of these issues is concerned with the design and fabrication of fuel shipping and storage systems. The other issue is concerned with the verification of actual operating practices in the field. Both design and verification activities would benefit from physical measurement data as opposed to relying on administrative controls and calculations; however, it is the authors intention to address only the feasibility of obtaining experimental spent fuel criticality data in support of the design effort. The author discusses the background, obstacles, feasibility conclusions reached when applying burnup concepts to spent fuels

  16. Tiger Team Assessment of the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-01

    The purpose of the safety and health assessment was to determine the effectiveness of representative safety and health programs at the Los Alamos National Laboratory (LANL). Within the safety and health programs at LANL, performance was assessed in the following technical areas: Organization and Administration, Quality Verification, Operations, Maintenance, Training and Certification, Auxiliary Systems, Emergency Preparedness, Technical Support, Packaging and Transportation, Nuclear Criticality Safety, Security/Safety Interface, Experimental Activities, Site/Facility Safety Review, Radiological Protection, Personnel Protection, Worker Safety and Health (OSHA) Compliance, Fire Protection, Aviation Safety, Explosives Safety, Natural Phenomena, and Medical Services.

  17. Tiger Team Assessment of the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    1991-11-01

    The purpose of the safety and health assessment was to determine the effectiveness of representative safety and health programs at the Los Alamos National Laboratory (LANL). Within the safety and health programs at LANL, performance was assessed in the following technical areas: Organization and Administration, Quality Verification, Operations, Maintenance, Training and Certification, Auxiliary Systems, Emergency Preparedness, Technical Support, Packaging and Transportation, Nuclear Criticality Safety, Security/Safety Interface, Experimental Activities, Site/Facility Safety Review, Radiological Protection, Personnel Protection, Worker Safety and Health (OSHA) Compliance, Fire Protection, Aviation Safety, Explosives Safety, Natural Phenomena, and Medical Services

  18. Utilization of the BARC critical facility for ADS related experiments

    Indian Academy of Sciences (India)

    The fast assembly is chosen as the Mark II mixed carbide fuel of the FBTR at IGCAR, Kalpakkam. This combination is enclosed in a cadmium shell to prevent the thermal flux from entering the fast core region. This cadmium shell is surrounded by critical facility reference core with heavy water. This complete configuration is ...

  19. Critical and Creative Thinking Nexus: Learning Experiences of Doctoral Students

    Science.gov (United States)

    Brodin, Eva M.

    2016-01-01

    Critical and creative thinking constitute important learning outcomes at doctoral level across the world. While the literature on doctoral education illuminates this matter through the lens of experienced senior researchers, the doctoral students' own perspective is missing. Based upon interviews with 14 doctoral students from four disciplines at…

  20. Effects of Diversity Experiences on Critical Thinking Skills: Who Benefits?

    Science.gov (United States)

    Loes, Chad; Pascarella, Ernest; Umbach, Paul

    2012-01-01

    This study analyzed data from the Wabash National Study of Liberal Arts Education to estimate the unique effects of exposure to classroom diversity and involvement in interactional diversity on growth in critical thinking skills during the first year of college. Net of important confounding influences, neither classroom nor interactional diversity…

  1. Beam funneling studies at Los Alamos

    International Nuclear Information System (INIS)

    Stovall, J.E.; Guy, F.W.; Stokes, R.H.; Wangler, T.P.

    1989-01-01

    Funneling two ion beams by interlacing their bunches can reduce the cost and complexity of systems producing intense beams. Applications of funneling could include accelerators for heavy-ion inertial fusion, electronuclear breeding and fusion materials irradiation. Funneling in an RFQ-like structure is an elegant solution at low energy where electric fields are needed to provide strong focusing. Discrete-element funnels, with separate focusing elements, bending magnets, rebunchers and rf deflectors, are more flexible. At sufficiently high energies magnetic-quadrupole lenses can provide strong focusing in a discrete-element funnel. Such a funnel has been designed as a preliminary example of a second funnel in the HIBALL-II accelerator system. In a simulation, two Bi 1+ (mass = 209 amu) beams at 0.5 MeV/A, 20 MHz and 40 mA, separated by 55 cm and angled at ±6 0 were combined into a single 80 mA beam at 40 MHz. Emittance growth was calculated, by a modified version of the PIC (particle-in-cell) code PARMILA, to be about 1%. Funnel design experience at Los Alamos has evolved rules of thumb that reduce emittance growth. Some of these are to maintain focusing periodicity and strength in both transverse and longitudinal directions; use strong focusing so that the bunch will be small; minimize angles of bend and rf deflection; adjust longitudinal focusing to produce a short bunch at the rf deflector; and design rf deflectors for a uniform electrical field. (orig.)

  2. ACCELERATION OF LOS ALAMOS NATIONAL LABORATORY TRANSURANIC WASTE DISPOSITION

    International Nuclear Information System (INIS)

    O'Leary, Gerald A.

    2007-01-01

    Energy Los Alamos Site Office, Carlsbad Field Office and the Department of Energy Headquaeters. Rather than simply processing containers as retrieved, the plan places priority on efficient curie disposition, a direct correlation to reducing risk. Key elements of the approch include balancing inventory and operational risks, tailoring methods to meet requirements, optimizing existing facilities, equipment and staff, and incorporating best practices from other Department of Energy sites. With sufficient funding this will enable LANL to ship the above-ground high activity contact-handled transuranic waste offsite by the end of Fiscal Year (FY) 2007 and to disposition the remaining above- and below-ground contact-handled and remote-handled transuranic waste inventory by December 2010. Nearly 70% of the contact-handled transuranic waste containers, including the high activity waste, require processing and repackaging before characterization and certification for shipment to the Waste Isolation Pilot Plant. LANL is employing a balanced risk approach that accomplishes significant long-term risk reduction by accepting short-term increased facility operations risk under well-developed and justified interim controls. Reviews of facility conditions and additional analyses show that the Waste Characterization, Reduction and Repackaging Facility and the Radioassay and Nondestructive Testing Facility are the most appropriate facilities to safetly remediate, repackage, and ship lower activity and the remaining high activity drums. Updated safety documentation supporting limited Hazard Category 2 operations in these facilities has been developed. Once approved, limited-term operations to process the high activity drums can begin in early 2007, building upon the experience base established performing Hazard Category 3 operations processing lower activity waste in these facilities. LANL is also implementing a series of actions to improve and sustain operations for processing contact

  3. Using Critical Care Simulations to Prepare Nursing Students for Capstone Clinical Experiences.

    Science.gov (United States)

    Smallheer, Benjamin; Hunt, Jennifer; Smith, Judson

    The purpose of this innovative learning strategy was to decrease students' fear and anxiety within the critical care environment before the initiation of a critical care capstone clinical experience by enhancing their familiarity of the critical care environment through deliberate practice and experiential learning. This will in turn increase student knowledge and competence in the critical care setting.Critical care units are often used during a capstone clinical experience to enhance critical thinking and clinical reasoning. Student preparation for these rotations, however, is varied and often inadequate. The resulting fear and anxiety impair learning and also contribute to an unsafe environment for this at-risk population.Before the capstone experience, students participated in 3 simulation experiences, each addressing a core concept of critical care nursing. Faculty engaged students during the simulations, while modeling the confidence and critical thinking of a critical care nurse.After both the critical care simulation and the capstone rotation, students stated that the simulation allowed them the time in a safe environment to critically think through the steps to care for critical patients before the capstone rotation. The experience provided them with increased confidence necessary to discharge the responsibilities of a critical care nurse-attention to critical thinking and reasoning.Mindfully constructed simulations with clear objectives help to inoculate the student against fears associated with high-risk patients. This decrease in fear and anxiety before a hands-on clinical experience may improve patient safety. More confident students are also better able to engage in both experiential and deliberate learning, resulting in a more enhanced and meaningful clinical experience.

  4. Progress in inertial fusion research at Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Perkins, R.B.

    1981-01-01

    The Los Alamos Scientific Laboratory Inertial Confinement Fusion Program is reviewed. Experiments using the Helios CO 2 laser system delivering up to 6kJ on target are described. Because breakeven energy estimates for laser drivers of 1 μm and above have risen and there is a need for CO 2 experiments in the tens-of-kJ regime as soon as practical, a first phase of Antares construction is now directed toward completion of two of the six original modules in 1983. These modules are designed to deliver 40kJ of CO 2 laser light on target. (author)

  5. Experiments for IFR fuel criticality in ZPPR-21

    International Nuclear Information System (INIS)

    Olsen, D.N.; Collins, P.J.; Carpenter, S.G.

    1991-01-01

    A series of benchmark measurements was made in ZPPR-21 to validate criticality calculations for fuel processing operations for Argonne's Integral Fast Reactor program. Six different mixtures of Pu/U/Zr fuel with a graphite reflector were built and criticality was determined by period measurements. The assemblies were isolated from room return neutrons by a lithium hydride shield. Analysis was done using a fully-detailed model with the VIM Monte Carlo code and ENDF/B-V.2 data. Sensitivity analysis was used to validate the measurements against other benchmark data. A simple RZ model was defined and used with the KENO code. Corrections to the RZ model were provided by the VIM calculations with low statistical uncertainty. (Author)

  6. Experiments for IFR fuel criticality in ZPPR-21

    International Nuclear Information System (INIS)

    Olsen, D.N.; Collins, P.J.; Carpenter, S.G.

    1991-01-01

    A series of benchmark measurements was made in ZPPR-21 to validate criticality calculations for fuel operations in Argonne's Integral Fast Reactor. Six different mixtures of Pu/U/Zr fuel with a graphite reflector were built and criticality was determined by period measurements. The assemblies were isolated from room return problems by a lithium hydride shield. Analysis was done using a fully-detailed model with the VIM Monte Carlo code and ENDF/B-V.2 data. Sensitivity analysis was used to validate the measurements against other benchmark data. A simple RZ model was defined the used with the KENO code. Corrections to the RZ model were provided by the VIM calculations with low statistical uncertainty. 7 refs., 5 figs., 5 tabs

  7. Utilization of the BARC critical facility for ADS related experiments

    Indian Academy of Sciences (India)

    . It has been proposed to utilize the CF for ADSS experiments also, with some appropriate neutron source at the center. Recently BARC has proposed a one way coupled core configuration for ADSS application. This coupled core consists.

  8. Nuclear criticality research at the University of New Mexico

    International Nuclear Information System (INIS)

    Busch, R.D.

    1997-01-01

    Two projects at the University of New Mexico are briefly described. The university's Chemical and Nuclear Engineering Department has completed the final draft of a primer for MCNP4A, which it plans to publish soon. The primer was written to help an analyst who has little experience with the MCNP code to perform criticality safety analyses. In addition, the department has carried out a series of approach-to-critical experiments on the SHEBA-II, a UO 2 F 2 solution critical assembly at Los Alamos National Laboratory. The results obtained differed slightly from what was predicted by the TWODANT code

  9. Publications of Los Alamos Research, 1983

    International Nuclear Information System (INIS)

    Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L.

    1984-10-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

  10. Publications of Los Alamos research 1980

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, C.A.; Willis, J.K. (comps.)

    1981-09-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1980. Papers published in 1980 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted-even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was pubished more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-laboratory reports, journal articles, books, chapters of books, conference papers published either separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  11. Status of Monte Carlo at Los Alamos

    International Nuclear Information System (INIS)

    Thompson, W.L.; Cashwell, E.D.

    1980-01-01

    At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time

  12. Publications of Los Alamos Research, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Rodriguez, L.L. (comps.)

    1984-10-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1983. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers publishd in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  13. Publications of Los Alamos Research 1982

    International Nuclear Information System (INIS)

    McClary, W.J.; Rodriguez, L.L.; Sheridan, C.J.

    1983-10-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1982. Papers published in 1982 are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassfiication of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

  14. Environmental surveillance at Los Alamos during 1976

    Energy Technology Data Exchange (ETDEWEB)

    1977-04-01

    This report documents the environmental monitoring program at the Los Alamos Scientific Laboratory (LASL) in 1976. Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized.

  15. Environmental surveillance at Los Alamos during 1975

    Energy Technology Data Exchange (ETDEWEB)

    Apt, K.E.; Lee, V.J. (comps.)

    1976-04-01

    This report documents the CY 1975 environmental monitoring program of the Los Alamos Scientific Laboratory (LASL). Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized.

  16. Environmental surveillance at Los Alamos during 1975

    International Nuclear Information System (INIS)

    Apt, K.E.; Lee, V.J.

    1976-04-01

    This report documents the CY 1975 environmental monitoring program of the Los Alamos Scientific Laboratory (LASL). Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized

  17. Environmental surveillance at Los Alamos during 1976

    International Nuclear Information System (INIS)

    1977-04-01

    This report documents the environmental monitoring program at the Los Alamos Scientific Laboratory (LASL) in 1976. Data are presented for concentrations of radioactivity measured in air, ground and surface waters, sediments, soils, and foodstuffs, and are compared with relevant U.S. Energy Research and Development Administration guides and/or data from other reporting periods. Levels of external penetrating radiation measured in the LASL environs are given. The average whole-body radiation dose to residents of Los Alamos County resulting from LASL operations is calculated. Chemical qualities of surface and ground waters in the LASL environs have been determined and compared to applicable standards. Results of related environmental studies are summarized

  18. Status of the WNR/PSR at Los Alamos

    International Nuclear Information System (INIS)

    Silver, R.N.

    1982-01-01

    A proton storage ring is presently under construction at Los Alamos for initial operation in 1985 to provide the world's highest peak neutron flux for neutron scattering experiments. The operational WNR pulsed neutron source is in use for TOF instrument development and condensed matter research. Experimental results have been obtained in incoherent inelastic scattering, liquids and powder diffraction, single crystal diffraction and eV spectroscopy using nuclear resonances. Technical problems being addressed include chopper phasing, scintillator detector development, shielding and collimation. A crystal analyzer spectrometer in the constant Q configuration is being assembled. The long range plan for the WNR/PSR facility is described

  19. Laser protective eyewear program at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Winburn, D.C.

    1980-01-01

    The proliferation of lasers at Los Alamos focused considerable attention on providing adequate eye protection for experimenters involved in the use of a wide variety of nonionizing radiation. Experiments with fast-pulsed lasers (Nd:YAG, HF, and CO 2 ) were performed to gain biological threshold data on ocular damage. In parallel, eye protection devices were evaluated, which resulted in the development of lightweight, comfortable spectacles of colored glass filters that can be ground to prescription specifications. Goggle styles are employed in specific applications

  20. Midface rejuvenation: a critical evaluation of a 7-year experience.

    Science.gov (United States)

    Pascali, Michele; Botti, Chiara; Cervelli, Valerio; Botti, Giovanni

    2015-05-01

    Although "traditional" face-lifting techniques can achieve excellent improvement along the jawline and neck, they often have little impact on the midface area. Thus, many different types of procedures have been developed to provide rejuvenation in this region, usually contemplating various dissection planes, incisions, and suspension vectors. A 7-year observational study of 350 patients undergoing midface lift was analyzed. The authors suspended the midface flap, anchoring to the deep temporal aponeurosis with a suspender-like suture (superolateral vector), or directly to the lower orbital rim with a belt-like suture (superomedial vector). Subjective and objective methods were used to evaluate the results. The subjective methods included a questionnaire completed by the patients. The objective method involved the evaluation of preoperative and postoperative photographs by a three-member jury instructed to compare the "critical" anatomical areas of the midface region: malar eminence, nasojugal groove, nasolabial fold, and jowls in the lower portion of the cheeks. The average follow-up period was 24 months. High satisfaction was noticeable from the perceptions of both the jury and the patients. Objective evaluation evidenced that midface lift with temporal anchoring was more efficient for the treatment of malar eminence, whereas midface lift with transosseous periorbital anchoring was more efficient for the treatment of nasojugal groove. The most satisfying aspect of the adopted techniques is a dramatic facial rejuvenation and preservation of the patient's original youthful identity. Furthermore, choosing the most suitable technique respects the patient's needs and enables correction of the specific defects. Therapeutic, IV.

  1. SANDIA pulsed reactor facility seven percent critical experiment (7uPCX)

    International Nuclear Information System (INIS)

    Barber, A.; Harms, G.

    2011-01-01

    The Seven Percent Critical Experiment (7uPCX) is a reactor physics and critical benchmark experiment designed to provide data for the validation of the reactor physics codes used to design commercial reactor fuel elements. The first operation of the experiment occurred on May 11, 2009. Since then, more than 50 different fuel element configurations have been addressed in the experiment. The 7uPCX is seven weight percent enriched, UO2 fueled, square lattice, water moderated experiment. The pitches of the two grid plate sets fabricated for the experiments were chosen to bracket the fuel-to-water ratios in the current US fleet of commercial light water reactors. The first set of experiments was with the tighter pitch core with water holes dispersed in the array. An inverse-multiplication approach to critical was implemented. The approach started with cores that had calculated multiplication factors of 0.9 and 0.95. From these two points the next critical loading was predicated and half of fuel increment between the current core size and the predicted critical size was loaded. This process was continued through an inverse multiplication of zero and on to configurations that were supercritical. In the second experiment, fuel rods were inserted into the water holes in the first configuration to offer a solid (no water holes) core design. In this and the first experiments, startup source was located in the center of the core configuration in a water hole. The third set of experiments relocated the source outside of the perimeter of the core and filled the central location with a fuel rod. Further experiments in the series addressed the reactivity worth of water holes as a function of position in the array. The initial set of experiments for the tight fuel rod pitch is complete. The next step in the experiment program is to exchange the assembly grid plates for those with the looser fuel rod pitch. When that is done, the same set of experiments will be performed as for the

  2. Beam funneling studies at Los Alamos

    International Nuclear Information System (INIS)

    Stovall, J.E.; Guy, F.W.; Stokes, R.H.; Wangler, T.P.

    1988-01-01

    Funneling two ion beams by interlacing their bunches can reduce the cost and complexity of systems producing intense beams. Applications of funneling could include accelerators for heavy ion inertial fusion, electronuclear breeding, and fusion materials irradiation. Funneling in an RFQ-like structure is an elegant solution at low energy where electric fields are needed to provide strong focusing. Discrete-element funnels, with separate focusing elements, bending magnets, rebunchers and if deflectors, are more flexible. At sufficiently high energies, magnetic-quadrupole lenses can provide strong focusing in a discrete-element funnel. Such a funnel has been designed as a preliminary example of a second funnel in the HIBALL-II accelerator system. In a simulation, two Bi +1 (mass = 209 amu) beams at 0.5 MeV/A, 20 MHz, 40-mA, separated by 55 cm and angled at +-6/degree/ were combined into a single 80-mA beam at 40 MHz. Emittance growth was calculated, by a modified version of the PIC (particle-in-cell) code PARMILA, to be about 1%. Funnel design experience at Los Alamos has evolved rules-of-thumb that reduce emittance growth. Some of these are to maintain focusing periodicity and strength in both transverse and longitudinal directions; use strong focusing so that the bunch will be small; minimize angles of bend and rf deflection; adjust longitudinal focusing to produce a short bunch at the rf deflector; and design rf deflectors for a uniform electrical field. 4 refs., 3 figs., 2 tabs

  3. Recent UCN source developments at Los Alamos

    International Nuclear Information System (INIS)

    Seestrom, S.J.; Anaya, J.M.; Bowles, T.J.

    1998-01-01

    The most intense sources of ultra cold neutrons (UCN) have bee built at reactors where the high average thermal neutron flux can overcome the low UCN production rate to achieve usable densities of UCN. At spallation neutron sources the average flux available is much lower than at a reactor, though the peak flux can be comparable or higher. The authors have built a UCN source that attempts to take advantage of the high peak flux available at the short pulse spallation neutron source at the Los Alamos Neutron Science Center (LANSCE) to generate a useful number of UCN. In the source UCN are produced by Doppler-shifted Bragg scattering of neutrons to convert 400-m/s neutrons down into the UCN regime. This source was initially tested in 1996 and various improvements were made based on the results of the 1996 running. These improvements were implemented and tested in 1997. In sections 2 and 3 they discuss the improvements that have been made and the resulting source performance. Recently an even more interesting concept was put forward by Serebrov et al. This involves combining a solid Deuterium UCN source, previously studied by Serebrov et al., with a pulsed spallation source to achieve world record UCN densities. They have initiated a program of calculations and measurements aimed at verifying the solid Deuterium UCN source concept. The approach has been to develop an analytical capability, combine with Monte Carlo calculations of neutron production, and perform benchmark experiments to verify the validity of the calculations. Based on the calculations and measurements they plan to test a modified version of the Serebrov UCN factory. They estimate that they could produce over 1,000 UCN/cc in a 15 liter volume, using 1 microamp of 800 MeV protons for two seconds every 500 seconds. They will discuss the result UCN production measurements in section 4

  4. Student research in criticality safety at the University of Arizona

    International Nuclear Information System (INIS)

    Hetrick, D.L.

    1997-01-01

    A very brief progress report on four University of Arizona student projects is given. Improvements were made in simulations of power pulses in aqueous solutions, including the TWODANT model. TWODANT calculations were performed to investigate the effect of assembly shape on the expansion coefficient of reactivity for solutions. Preliminary calculations were made of critical heights for the Los Alamos SHEBA assembly. Calculations to support French experiments to measure temperature coefficients of dilute plutonium solutions confirmed feasibility

  5. Publications of Los Alamos research, 1985

    International Nuclear Information System (INIS)

    Sheridan, C.J.; McClary, W.J.; Rich, J.A.; Dussart, S.A.

    1986-11-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1985, including laboratory reports, papers released as non-laboratory reports, journal articles, books, conference papers, papers published in congrssional hearings, theses, and US patents

  6. Los Alamos waste drum shufflers users manual

    Energy Technology Data Exchange (ETDEWEB)

    Rinard, P.M.; Adams, E.L.; Painter, J.

    1993-08-24

    This user manual describes the Los Alamos waste drum shufflers. The primary purpose of the instruments is to assay the mass of {sup 235}U (or other fissile materials) in drums of assorted waste. It can perform passive assays for isotopes that spontaneously emit neutrons or active assays using the shuffler technique as described on this manual.

  7. Proceedings of the Los Alamos neutrino workshop

    International Nuclear Information System (INIS)

    Boehm, F.; Stephenson, G.J. Jr.

    1982-08-01

    A workshop on neutrino physics was held at Los Alamos from June 8 to 12, 1981. The material presented has been provided in part by the organizers, in part by the chairmen of the working sessions. Closing date for contributions was October 1981

  8. Los Alamos waste drum shufflers users manual

    International Nuclear Information System (INIS)

    Rinard, P.M.; Adams, E.L.; Painter, J.

    1993-01-01

    This user manual describes the Los Alamos waste drum shufflers. The primary purpose of the instruments is to assay the mass of 235 U (or other fissile materials) in drums of assorted waste. It can perform passive assays for isotopes that spontaneously emit neutrons or active assays using the shuffler technique as described on this manual

  9. A Sailor in the Los Alamos Navy

    Energy Technology Data Exchange (ETDEWEB)

    Judd, D. L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States

    2016-12-20

    As part of the War Department’s Manhattan Engineer District (MED), Los Alamos was an Army installation during World War II, complete with a base commander and a brace of MPs. But it was a unique Army installation, having more civilian then military personnel. Even more unique was the work performed by the civilian population, work that required highly educated scientists and engineers. As the breadth, scope, and complexity of the Laboratory’s work increased, more and more technically educated and trained personnel were needed. But, the manpower needs of the nation’s war economy had created a shortage of such people. To meet its manpower needs, the MED scoured the ranks of the Army for anyone who had technical training and reassigned these men to its laboratories, including Los Alamos, as part of its Special Engineer Detachment (SED). Among the SEDs assigned to Los Alamos was Val Fitch, who was awarded the Nobel Prize in Physics in 1980. Another was Al Van Vessem, who helped stack the TNT for the 100 ton test, bolted together the Trinity device, and rode shotgun with the bomb has it was driven from Los Alamos to ground zero.

  10. Proceedings of the Los Alamos neutrino workshop

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, F.; Stephenson, G.J. Jr. (comps.)

    1982-08-01

    A workshop on neutrino physics was held at Los Alamos from June 8 to 12, 1981. The material presented has been provided in part by the organizers, in part by the chairmen of the working sessions. Closing date for contributions was October 1981.

  11. Induction inserts at the Los Alamos PSR

    International Nuclear Information System (INIS)

    King-Yuen Ng

    2002-01-01

    Ferrite-loaded induction tuners installed in the Los Alamos Proton Storage Ring have been successful in compensating space-charge effects. However, the resistive part of the ferrite introduces unacceptable microwave instability and severe bunch lengthening. An effective cure was found by heating the ferrite cores up to ∼ 130 C. An understanding of the instability and cure is presented

  12. Alecto - results obtained with homogeneous critical experiments on plutonium 239, uranium 235 and uranium 233

    International Nuclear Information System (INIS)

    Bruna, J.G.; Brunet, J.P.; Caizegues, R.; Clouet d'Orval, Ch.; Kremser, J.; Tellier, H.; Verriere, Ph.

    1965-01-01

    In this report are given the results of the homogeneous critical experiments ALECTO, made on plutonium 239, uranium 235 and uranium 233. After a brief description of the equipment, the critical masses for cylinders of diameters varying from 25 to 42 cm, are given and compared with other values (foreign results, criticality guide). With respect to the specific conditions of neutron reflection in the ALECTO experiments the minimal values of critical masses are: Pu239 M c = 910 ± 10 g, U235 M c = 1180 ± 12 g and U233 M c = 960 ± 10 g. Experiments relating to cross sections and constants to be used on these materials are presented. Lastly, kinetic experiments allow to compare pulsed neutron methods to fluctuation methods [fr

  13. Analysis of Fresh Fuel Critical Experiments Appropriate for Burnup Credit Validation

    International Nuclear Information System (INIS)

    DeHart, M.D.

    1995-01-01

    The ANS/ANS-8.1 standard requires that calculational methods used in determining criticality safety limits for applications outside reactors be validated by comparison with appropriate critical experiments. This report provides a detailed description of 34 fresh fuel critical experiments and their analyses using the SCALE-4.2 code system and the 27-group ENDF/B-IV cross-section library. The 34 critical experiments were selected based on geometry, material, and neutron interaction characteristics that are applicable to a transportation cask loaded with pressurized-water-reactor spent fuel. These 34 experiments are a representative subset of a much larger data base of low-enriched uranium and mixed-oxide critical experiments. A statistical approach is described and used to obtain an estimate of the bias and uncertainty in the calculational methods and to predict a confidence limit for a calculated neutron multiplication factor. The SCALE-4.2 results for a superset of approximately 100 criticals are included in uncertainty analyses, but descriptions of the individual criticals are not included

  14. Los Alamos contribution to target diagnostics on the National Ignition Facility

    International Nuclear Information System (INIS)

    Mack, J.M.; Baker, D.A.; Caldwell, S.E.

    1994-01-01

    The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ''phase I diagnostics.'' Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given

  15. Los Alamos contribution to target diagnostics on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mack, J.M.; Baker, D.A.; Caldwell, S.E. [and others

    1994-07-01

    The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ``phase I diagnostics.`` Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given.

  16. RCRA facility investigation for the townsite of Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dorries, A.M.; Conrad, R.C.; Nonno, L.M.

    1992-01-01

    During World War II, Los Alamos, New Mexico was established as an ideal location for the secrecy and safety needed for the research and development required to design a nuclear fission bomb. Experiments carried out in the 1940s generated both radioactive and hazardous waste constituents on what is presently part of the Los Alamos townsite. Under the RCRA permit issued to Los alamos national Laboratory in 1990, the Laboratory is scheduled for investigation of its solid waste management units (SWMUs). The existing information on levels of radioactivity on the townsite is principally data from soil samples taken during the last site decontamination in 1976, little information on the presence of hazardous constituents exists today. This paper addresses pathway analysis and a preliminary risk assessment for current residents of the Los Alamos townsite. The estimated dose levels, in mrem per year, show that the previously decontaminated SWMU areas on the Los Alamos townsite will not contribute a radiation dose of any concern to the current residents.

  17. RCRA facility investigation for the townsite of Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dorries, A.M.; Conrad, R.C.; Nonno, L.M.

    1992-02-01

    During World War II, Los Alamos, New Mexico was established as an ideal location for the secrecy and safety needed for the research and development required to design a nuclear fission bomb. Experiments carried out in the 1940s generated both radioactive and hazardous waste constituents on what is presently part of the Los Alamos townsite. Under the RCRA permit issued to Los alamos national Laboratory in 1990, the Laboratory is scheduled for investigation of its solid waste management units (SWMUs). The existing information on levels of radioactivity on the townsite is principally data from soil samples taken during the last site decontamination in 1976, little information on the presence of hazardous constituents exists today. This paper addresses pathway analysis and a preliminary risk assessment for current residents of the Los Alamos townsite. The estimated dose levels, in mrem per year, show that the previously decontaminated SWMU areas on the Los Alamos townsite will not contribute a radiation dose of any concern to the current residents.

  18. Sensitivity analysis of critical experiment with direct perturbation compared to TSUNAMI-3D sensitivity analysis

    International Nuclear Information System (INIS)

    Barber, A. D.; Busch, R.

    2009-01-01

    The goal of this work is to obtain sensitivities from direct uncertainty analysis calculation and correlate those calculated values with the sensitivities produced from TSUNAMI-3D (Tools for Sensitivity and Uncertainty Analysis Methodology Implementation in Three Dimensions). A full sensitivity analysis is performed on a critical experiment to determine the overall uncertainty of the experiment. Small perturbation calculations are performed for all known uncertainties to obtain the total uncertainty of the experiment. The results from a critical experiment are only known as well as the geometric and material properties. The goal of this relationship is to simplify the uncertainty quantification process in assessing a critical experiment, while still considering all of the important parameters. (authors)

  19. Los Alamos Controlled Air Incinerator for radioactive waste. Volume II. Engineering design reference manual

    International Nuclear Information System (INIS)

    Koenig, R.A.; Draper, W.E.; Newmyer, J.M.; Warner, C.L.

    1982-10-01

    This two-volume report is a detailed design and operating documentation of the Los Alamos National Laboratory Controlled Air Incinerator (CAI) and is an aid to technology transfer to other Department of Energy contractor sites and the commercial sector. Volume I describes the CAI process, equipment, and performance, and it recommends modifications based on Los Alamos experience. It provides the necessary information for conceptual design and feasibility studies. Volume II provides descriptive engineering information such as drawings, specifications, calculations, and costs. It aids duplication of the process at other facilities

  20. Los Alamos Controlled Air Incinerator for radioactive waste. Volume I. Rationale, process, equipment, performance, and recommendations

    International Nuclear Information System (INIS)

    Neuls, A.S.; Draper, W.E.; Koenig, R.A.; Newmyer, J.M.; Warner, C.L.

    1982-08-01

    This two-volume report is a detailed design and operating documentation of the Los Alamos National Laboratory Controlled Air Incinerator (CAI) and is an aid to technology transfer to other Department of Energy contractor sites and the commercial sector. Volume I describes the CAI process, equipment, and performance, and it recommends modifications based on Los Alamos experience. It provides the necessary information for conceptual design and feasibility studies. Volume II provides descriptive engineering information such as drawing, specifications, calculations, and costs. It aids duplication of the process at other facilities

  1. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    International Nuclear Information System (INIS)

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies

  2. Analysis and evaluation of critical experiments for validation of neutron transport calculations

    International Nuclear Information System (INIS)

    Bazzana, S.; Blaumann, H; Marquez Damian, J.I

    2009-01-01

    The calculation schemes, computational codes and nuclear data used in neutronic design require validation to obtain reliable results. In the nuclear criticality safety field this reliability also translates into a higher level of safety in procedures involving fissile material. The International Criticality Safety Benchmark Evaluation Project is an OECD/NEA activity led by the United States, in which participants from over 20 countries evaluate and publish criticality safety benchmarks. The product of this project is a set of benchmark experiment evaluations that are published annually in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. With the recent participation of Argentina, this information is now available for use by the neutron calculation and criticality safety groups in Argentina. This work presents the methodology used for the evaluation of experimental data, some results obtained by the application of these methods, and some examples of the data available in the Handbook. [es

  3. Tritium operating safety seminar, Los Alamos, New Mexico, July 30, 1975

    International Nuclear Information System (INIS)

    1976-03-01

    A seminar for the exchange of information on tritium operating and safety problems was held at the Los Alamos Scientific Laboratory. The topics discussed are: (1) material use (tubing, lubricants, valves, seals, etc.); (2) hardware selection (valves, fittings, pumps, etc.); (3) biological effects; (4) high pressure; (5) operating procedures (high pressure tritium experiment at LLL); (6) incidents; and (7) emergency planning

  4. Benchmark Evaluation of the Medium-Power Reactor Experiment Program Critical Configurations

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall; John D. Bess

    2013-02-01

    A series of small, compact critical assembly (SCCA) experiments were performed in 1962-1965 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for the Medium-Power Reactor Experiment (MPRE) program. The MPRE was a stainless-steel clad, highly enriched uranium (HEU)-O2 fuelled, BeO reflected reactor design to provide electrical power to space vehicles. Cooling and heat transfer were to be achieved by boiling potassium in the reactor core and passing vapor directly through a turbine. Graphite- and beryllium-reflected assemblies were constructed at ORCEF to verify the critical mass, power distribution, and other reactor physics measurements needed to validate reactor calculations and reactor physics methods. The experimental series was broken into three parts, with the third portion of the experiments representing the beryllium-reflected measurements. The latter experiments are of interest for validating current reactor design efforts for a fission surface power reactor. The entire series has been evaluated as acceptable benchmark experiments and submitted for publication in the International Handbook of Evaluated Criticality Safety Benchmark Experiments and in the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  5. Proceedings of the workshop on integral experiment covariance data for critical safety validation

    Energy Technology Data Exchange (ETDEWEB)

    Stuke, Maik (ed.)

    2016-04-15

    For some time, attempts to quantify the statistical dependencies of critical experiments and to account for them properly in validation procedures were discussed in the literature by various groups. Besides the development of suitable methods especially the quality and modeling issues of the freely available experimental data are in the focus of current discussions, carried out for example in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECD-NEA Nuclear Science Committee. The same committee compiles and publishes also the freely available experimental data in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Most of these experiments were performed as series and might share parts of experimental setups leading to correlated results. The quality of the determination of these correlations and the underlying covariance data depend strongly on the quality of the documentation of experiments.

  6. Proceedings of the workshop on integral experiment covariance data for critical safety validation

    International Nuclear Information System (INIS)

    Stuke, Maik

    2016-04-01

    For some time, attempts to quantify the statistical dependencies of critical experiments and to account for them properly in validation procedures were discussed in the literature by various groups. Besides the development of suitable methods especially the quality and modeling issues of the freely available experimental data are in the focus of current discussions, carried out for example in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECD-NEA Nuclear Science Committee. The same committee compiles and publishes also the freely available experimental data in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Most of these experiments were performed as series and might share parts of experimental setups leading to correlated results. The quality of the determination of these correlations and the underlying covariance data depend strongly on the quality of the documentation of experiments.

  7. Smart instrumentation development at Los Alamos

    International Nuclear Information System (INIS)

    Erkkila, B.

    1984-01-01

    For several years Los Alamos has incorporated microprocessors into instruments to expand the capability of portable survey type equipment. Beginning with portable pulse height analyzers, the developments have expanded to small dedicated instruments which handle the measurement and interpretation of various radiation fields. So far, instruments to measure gamma rays, neutrons, and beta particles have been produced. The computer capability built into these instruments provides significant computational power into the instruments. Capability unheard of a few years ago in small portable instruments is routine today. Large computer-based laboratory measurement systems which required much space and electrical power can now be incorporated in a portable hand-held instrument. The microprocessor developments at Los Alamos are now restricted to radiation monitoring equipment but can be expanded to chemical and biological applications as well. Applications for radiation monitoring equipment and others are discussed

  8. System requirements for the Los Alamos foil-implosion project

    International Nuclear Information System (INIS)

    Brownell, J.; Bowers, R.; Greene, A.; Lindemuth, I.; Nickel, G.; Oliphant, T.; Weiss, D.

    1983-01-01

    The goal of the Los Alamos imploding foil project is the development of an intense source of soft x rays and hot plasma produced from the thermalization of 1 to 10 MJ of plasma kinetic energy. The source will be used for material studies and fusion experiments. Specifically, thin, current-carrying cylindrical metallic plasmas are imploded via their self-magnetic forces. Features of this project are the use of high-explosive-driven flux-compression generators as the prime power source to achieve very high energies and fast opening switches to shorten the electrical pulses. To reach a load kinetic energy of 10 MJ, it is expected that the foil-plasma must carry about 50 MA of current and must implode in less than 1/2 μsec. This imposes the requirements that switch opening times must be less than 1/2 μsec and the transmission line must withstand voltages of about 1 MV. The system being pursued at Los Alamos is described, and model calculations are presented

  9. Seismic vulnerability study Los Alamos Meson Physics Facility (LAMPF)

    International Nuclear Information System (INIS)

    Salmon, M.; Goen, L.K.

    1995-01-01

    The Los Alamos Meson Physics Facility (LAMPF), located at TA-53 of Los Alamos National Laboratory (LANL), features an 800 MeV proton accelerator used for nuclear physics and materials science research. As part of the implementation of DOE Order 5480.25 and in preparation for DOE Order 5480.28, a seismic vulnerability study of the structures, systems, and components (SSCs) supporting the beam line from the accelerator building through to the ends of die various beam stops at LAMPF has been performed. The study was accomplished using the SQUG GIP methodology to assess the capability of the various SSCs to resist an evaluation basis earthquake. The evaluation basis earthquake was selected from site specific seismic hazard studies. The goals for the study were as follows: (1) identify SSCs which are vulnerable to seismic loads; and (2) ensure that those SSCs screened during die evaluation met the performance goals required for DOE Order 5480.28. The first goal was obtained by applying the SQUG GIP methodology to those SSCS represented in the experience data base. For those SSCs not represented in the data base, information was gathered and a significant amount of engineering judgment applied to determine whether to screen the SSC or to classify it as an outlier. To assure the performance goals required by DOE Order 5480.28 are met, modifications to the SQUG GIP methodology proposed by Salmon and Kennedy were used. The results of this study ire presented in this paper

  10. Amphibians and Reptiles of Los Alamos County

    Energy Technology Data Exchange (ETDEWEB)

    Teralene S. Foxx; Timothy K. Haarmann; David C. Keller

    1999-10-01

    Recent studies have shown that amphibians and reptiles are good indicators of environmental health. They live in terrestrial and aquatic environments and are often the first animals to be affected by environmental change. This publication provides baseline information about amphibians and reptiles that are present on the Pajarito Plateau. Ten years of data collection and observations by researchers at Los Alamos National Laboratory, the University of New Mexico, the New Mexico Department of Game and Fish, and hobbyists are represented.

  11. Los Alamos National Laboratory Facility Review

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Ronald Owen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-05

    This series of slides depicts the Los Alamos Neutron Science Center (LANSCE). The Center's 800-MeV linac produces H+ and H- beams as well as beams of moderated (cold to 1 MeV) and unmoderated (0.1 to 600 MeV) neutrons. Experimental facilities and their capabilities and characteristics are outlined. Among these are LENZ, SPIDER, and DANCE.

  12. Los Alamos transuranic waste size reduction facility

    International Nuclear Information System (INIS)

    Briesmeister, A.; Harper, J.; Reich, B.; Warren, J.L.

    1982-01-01

    To facilitate disposal of transuranic (TRU) waste, Los Alamos National Laboratory designed and constructed the Size Reduction Facility (SRF) during the period 1977 to 1981. This report summarizes the engineering development, installation, and early test operations of the SRF. The facility incorporates a large stainless steel enclosure fitted with remote handling and cutting equipment to obtain an estimated 4:1 volume reduction of gloveboxes and other bulky metallic wastes

  13. The Los Alamos accelerator code group

    International Nuclear Information System (INIS)

    Krawczyk, F.L.; Billen, J.H.; Ryne, R.D.; Takeda, Harunori; Young, L.M.

    1995-01-01

    The Los Alamos Accelerator Code Group (LAACG) is a national resource for members of the accelerator community who use and/or develop software for the design and analysis of particle accelerators, beam transport systems, light sources, storage rings, and components of these systems. Below the authors describe the LAACG's activities in high performance computing, maintenance and enhancement of POISSON/SUPERFISH and related codes and the dissemination of information on the INTERNET

  14. The Los Alamos accelerator code group

    Energy Technology Data Exchange (ETDEWEB)

    Krawczyk, F.L.; Billen, J.H.; Ryne, R.D.; Takeda, Harunori; Young, L.M.

    1995-05-01

    The Los Alamos Accelerator Code Group (LAACG) is a national resource for members of the accelerator community who use and/or develop software for the design and analysis of particle accelerators, beam transport systems, light sources, storage rings, and components of these systems. Below the authors describe the LAACG`s activities in high performance computing, maintenance and enhancement of POISSON/SUPERFISH and related codes and the dissemination of information on the INTERNET.

  15. Los Alamos transuranic waste size reduction facility

    International Nuclear Information System (INIS)

    Briesmeister, A.; Harper, J.; Reich, B.; Warren, J.L.

    1982-01-01

    A transuranic (TRU) Waste Size Reduction Facility (SRF) was designed and constructed at the Los Alamos National Laboratory during the period of 1977 to 1981. This paper summarizes the engineering development, installation, and early test operations of the SRF. The facility incorporates a large stainless steel enclosure fitted with remote handling and cutting equipment to obtain an estimated 4:1 volume reduction of gloveboxes and other bulky metallic wastes

  16. Scheduling at the Los Alamos Neutron Science Center (LANSCE)

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1999-01-01

    The centerpieces of the Los Alamos Neutron Science Center (LANSCE) are a half-mile long 800-MeV proton linear accelerator and proton storage ring. The accelerator, storage ring, and target stations provide the protons and spallation neutrons that are used in the numerous basic research and applications experimental programs supported by the US Department of Energy. Experimental users, facility maintenance personnel, and operations personnel must work together to achieve the most program benefit within defined budget and resource constraints. In order to satisfy the experimental users programs, operations must provide reliable and high quality beam delivery. Effective and efficient scheduling is a critical component to achieve this goal. This paper will detail how operations scheduling is presently executed at the LANSCE accelerator facility

  17. Scheduling at the Los Alamos Neutron Science Center (LANSCE)

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, F.R.

    1999-02-01

    The centerpieces of the Los Alamos Neutron Science Center (LANSCE) are a half-mile long 800-MeV proton linear accelerator and proton storage ring. The accelerator, storage ring, and target stations provide the protons and spallation neutrons that are used in the numerous basic research and applications experimental programs supported by the US Department of Energy. Experimental users, facility maintenance personnel, and operations personnel must work together to achieve the most program benefit within defined budget and resource constraints. In order to satisfy the experimental users programs, operations must provide reliable and high quality beam delivery. Effective and efficient scheduling is a critical component to achieve this goal. This paper will detail how operations scheduling is presently executed at the LANSCE accelerator facility.

  18. Hydrologic transport of depleted uranium associated with open air dynamic range testing at Los Alamos National Laboratory, New Mexico, and Eglin Air Force Base, Florida

    International Nuclear Information System (INIS)

    Becker, N.M.; Vanta, E.B.

    1995-01-01

    Hydrologic investigations on depleted uranium fate and transport associated with dynamic testing activities were instituted in the 1980's at Los Alamos National Laboratory and Eglin Air Force Base. At Los Alamos, extensive field watershed investigations of soil, sediment, and especially runoff water were conducted. Eglin conducted field investigations and runoff studies similar to those at Los Alamos at former and active test ranges. Laboratory experiments complemented the field investigations at both installations. Mass balance calculations were performed to quantify the mass of expended uranium which had transported away from firing sites. At Los Alamos, it is estimated that more than 90 percent of the uranium still remains in close proximity to firing sites, which has been corroborated by independent calculations. At Eglin, we estimate that 90 to 95 percent of the uranium remains at test ranges. These data demonstrate that uranium moves slowly via surface water, in both semi-arid (Los Alamos) and humid (Eglin) environments

  19. Hydrologic transport of depleted uranium associated with open air dynamic range testing at Los Alamos National Laboratory, New Mexico, and Eglin Air Force Base, Florida

    Energy Technology Data Exchange (ETDEWEB)

    Becker, N.M. [Los Alamos National Lab., NM (United States); Vanta, E.B. [Wright Laboratory Armament Directorate, Eglin Air Force Base, FL (United States)

    1995-05-01

    Hydrologic investigations on depleted uranium fate and transport associated with dynamic testing activities were instituted in the 1980`s at Los Alamos National Laboratory and Eglin Air Force Base. At Los Alamos, extensive field watershed investigations of soil, sediment, and especially runoff water were conducted. Eglin conducted field investigations and runoff studies similar to those at Los Alamos at former and active test ranges. Laboratory experiments complemented the field investigations at both installations. Mass balance calculations were performed to quantify the mass of expended uranium which had transported away from firing sites. At Los Alamos, it is estimated that more than 90 percent of the uranium still remains in close proximity to firing sites, which has been corroborated by independent calculations. At Eglin, we estimate that 90 to 95 percent of the uranium remains at test ranges. These data demonstrate that uranium moves slowly via surface water, in both semi-arid (Los Alamos) and humid (Eglin) environments.

  20. An Anesthetist’s Experience and the Incidence of Critical Cases in Ambulatory Surgery

    Directory of Open Access Journals (Sweden)

    R. V. Bolshedvorov

    2009-01-01

    Full Text Available Objective: to evaluate the impact of experience on the quality of anesthesia in ambulatory surgery. Materials and methods. The authors undertook a study of the role of experience and specialization on the occurrence of complications in ambulatory anesthesia care. By using the internal audit and calculating the frequency of critical cases, they examined the results of the work of two groups of anesthetists: 1 medical beginners after 2-year adjunct practice and 2 one-day hospital specialists having an at least 7-year practice length. Results. In the beginner group, the number of critical cases per operation was twice higher than that in the experienced specialists. The paper shows the detrimental pattern of the residual principle in selecting anesthetists for work at a one-day hospital and provides evidence that specialization is required in the area under discussion. Key words: ambulatory anesthesiology, role of an anesthetist’s experience, critical cases.

  1. Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills

    Science.gov (United States)

    Simon, Nicole A.

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.

  2. Experiments on spherical critical assemblies possessing a large central cavity in the core

    International Nuclear Information System (INIS)

    Kuvshinov, Mikhail I.; Bogdanov, Vladimir N.; Vorontsov, Sergei V.

    2003-01-01

    There are presented the results of benchmark experiments on spherical critical assemblies where the core of metal 235 U (90%) and 235 U (36%) has a large (up to ∼250 mm) central air cavity. In the majority of experiments this cavity is filled with spherical inserts: of fluoride mixtures [(NaF + ZrF 4 + 235 U) and (NaF + ZrF 4 )] vanadium and nickel. There are measured critical parameters, energy spectra of neutrons in the center of assemblies, reactivity disturbance by inserts, constants of prompt neutrons density fall. (author)

  3. Los Alamos National Security, LLC Request for Information from industrial entities that desire to commercialize Laboratory-developed Extremely Low Resource Optical Identifier (ELROI) tech

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, Michael Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-10

    Los Alamos National Security, LLC (LANS) is the manager and operator of the Los Alamos National Laboratory for the U.S. Department of Energy National Nuclear Security Administration under contract DE-AC52-06NA25396. LANS is a mission-centric Federally Funded Research and Development Center focused on solving the most critical national security challenges through science and engineering for both government and private customers.

  4. An investigation of emotion experiences at work : a critical incident technique approach / Natalie Booth

    OpenAIRE

    Booth, Natalie

    2013-01-01

    Orientation: Emotions at work have been considered as an important facet of employees’ work life. However, research regarding the investigation of the emotion experiences at work per se has been lacking. Research Purpose: The general objective of this study is to critically investigate what emotion events are experienced and how these events are appraised for them to result in specific emotions. Motivation for the study: Currently a lack of research regarding emotion experiences as a pr...

  5. Conceptual design of a digital control system for nuclear criticality experiments

    International Nuclear Information System (INIS)

    Rojas, S.P.

    1994-04-01

    Nuclear criticality is a concern in many areas of nuclear engineering including waste management, nuclear weapons testing and design, basic nuclear research, and nuclear reactor design and analysis. As in many areas of science and engineering, experimental work conducted in this field has provided a wealth of data and insight essential to the formulation of theory and the advancement in knowledge of fissioning systems. In light of the many diverse applications of nuclear criticality, there is a continuing interest to learn and understand more about the fundamental physical processes through continued experimentation. This thesis addresses the problem of setting up and programming a microprocessor-based digital control system (PLC) for a proposed critical experiment using, among other devices, a stepper motor, a joystick control mechanism, and switches. This experiment represents a revised configuration to test cylindrical nuclear waste packages. A Monte Carlo numerical study for the proposed critical assembly has been performed in order to illustrate how results from numerical calculations are used in the process of assembling the control system and to corroborate previous experimental data. In summary, a control system utilizing some common devices necessary to perform a critical experiment (stepper motor, push-buttons, etc.) has been assembled. Control components were sized using the results of a probabilistic computer code (MCNP). Finally, a program was written that illustrates the coupling between the hardware and the devices being controlled in the new test fixture

  6. Being family: the family experience when an adult member is hospitalized with a critical illness.

    Science.gov (United States)

    Eggenberger, Sandra K; Nelms, Tommie P

    2007-09-01

    The purpose of this qualitative study was to understand and interpret the 'family experience' with an adult member hospitalized with a critical illness. Nursing practice in critical care settings has traditionally focused on individual patient needs with only tangential recognition of family needs. Investigation to describe the family experience to illuminate family nursing practice has been lacking. The majority of studies thus far related to critical illness and family are quantitative and reveal constraints to family care and problematic nurse-family interactions. The logical next step is a new kind of family research to enhance nursing of the family as a whole. Family systems theory and existential phenomenology provided the frameworks guiding the study. Semi-structured 'family as a group' interviews were performed with 11 families. Data were analysed using Van Manen's hermeneutic method. Rigor was addressed with trustworthiness criteria. The family experience was analysed within Van Manen's framework of lived space, lived relation, lived body and lived time. A constitutive pattern of being family was revealed. Being family bonds families and makes them exceedingly strong during the critical illness experience. Being a family unit is what gives most families the ability to endure the emotional upheaval and suffering that come with the critical illness experience. Nurses have profound power to help families bear this experience. Family caring is enhanced with the presence of nurses who recognize the importance of 'Being Family' for the family, acknowledge the significance of the nurse-family relationship and act on a commitment to be with and for the family.

  7. GROWTH OF THE INTERNATIONAL CRITICALITY SAFETY AND REACTOR PHYSICS EXPERIMENT EVALUATION PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    J. Blair Briggs; John D. Bess; Jim Gulliford

    2011-09-01

    Since the International Conference on Nuclear Criticality Safety (ICNC) 2007, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) have continued to expand their efforts and broaden their scope. Eighteen countries participated on the ICSBEP in 2007. Now, there are 20, with recent contributions from Sweden and Argentina. The IRPhEP has also expanded from eight contributing countries in 2007 to 16 in 2011. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments1' have increased from 442 evaluations (38000 pages), containing benchmark specifications for 3955 critical or subcritical configurations to 516 evaluations (nearly 55000 pages), containing benchmark specifications for 4405 critical or subcritical configurations in the 2010 Edition of the ICSBEP Handbook. The contents of the Handbook have also increased from 21 to 24 criticality-alarm-placement/shielding configurations with multiple dose points for each, and from 20 to 200 configurations categorized as fundamental physics measurements relevant to criticality safety applications. Approximately 25 new evaluations and 150 additional configurations are expected to be added to the 2011 edition of the Handbook. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Reactor Physics Benchmark Experiments2' have increased from 16 different experimental series that were performed at 12 different reactor facilities to 53 experimental series that were performed at 30 different reactor facilities in the 2011 edition of the Handbook. Considerable effort has also been made to improve the functionality of the searchable database, DICE (Database for the International Criticality Benchmark Evaluation Project) and verify the accuracy of the data contained therein. DICE will be discussed in separate papers at ICNC 2011. The status of the

  8. Mock-up critical experiments for prototype fast breeder reactor 'Monju'

    International Nuclear Information System (INIS)

    Zukeran, Atsushi; Inoue, Teruji; Suzuki, Takeo; Kawashima, Kanau

    1976-01-01

    The mock-up criticality experiments for Monju are roughly divided into the full mock-up test using the ZEBRA of Winfrith Institute, UK AEA, and the partial mock-up experiment with FCA of JAERI. The former test has been carried out over 18 months from September 1971 as the Japan-UK cooperative research project MOZART. With the FCA, the experiment complementing the MOZART has been carried out, focusing on the nuclear characteristics of Monju which can be simulated with a relatively small core, and the experiment on highly enriched control rods and shielding is being continued now with the FCA 7 core. The experimental data of the MOZART and the ZPPR series in USA were exchanged at the international symposium in Tokyo, thus the prediction and the accuracy evaluation of the nuclear characteristics of Monju became possible, and the highly reliable core design was able to be accomplished. The simulated criticality experiment is necessary for directly grasping the reliability of calculated values in comparison with the experimental values, and also for the experimental prediction of the nuclear characteristics. The outline and the analysis of the simulated criticality experiment such as reactivity factor, control rod value, reaction rate distribution and sodium void reactivity are described, and the reflection of the results to the design of the core of Monju is explained. (Kako, I.)

  9. Progress of criticality experiments and nuclear design studies on Erbia-bearing super high burnup fuel

    International Nuclear Information System (INIS)

    Yamasaki, Masatoshi; Kuroishi, Takeshi; Takeda, Toshikazu; Yamamoto, Akio; Unesaki, Hironobu; Sano, Tadafumi; Mori, Masaaki

    2009-01-01

    To cope with the '5wt% enrichment barrier', the development project on Erbia bearing super high-burnup fuel with high uranium enrichment, such as critical experiments with fully Erbia loaded core in KUCA, criticality safety analyses against simple shapes, physicochemical properties measurement and so on, is under going. Following the three experiments of fully-Er-loaded core, the result of the fourth core of higher content of Erbia is presented. As a second topic, fuel design using isotopically modified Erbia, such as a) Er-166 removed from Erbium content, b) Only Er-167 used, is shown. In use of isotopically modified Erbia, the ECOS diagram, which shows minimum Erbia contents that should be mixed into above 5wt% enriched fuel, so that the criticality safety will be equivalent to that with the conventional below 5wt% enriched fuel, should be modified in order to correspond to various Erbia isotope vectors. (author)

  10. Nuclear criticality safety experiments, calculations, and analyses: 1958 to 1982. Volume 1. Lookup tables

    International Nuclear Information System (INIS)

    Koponen, B.L.; Hampel, V.E.

    1982-01-01

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains - in chronological order - the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41

  11. How Do Virtual World Experiences Bring about Learning? A Critical Review of Theories

    Science.gov (United States)

    Loke, Swee-Kin

    2015-01-01

    While students do learn real-world knowledge and skills in virtual worlds, educators have yet to adequately theorise how students' virtual world experiences bring about this learning. This paper critically reviewed theories currently used to underpin empirical work in virtual worlds for education. In particular, it evaluated how applicable these…

  12. Calculational assessment of critical experiments with mixed oxide fuel pin arrays moderated by organic solution

    International Nuclear Information System (INIS)

    Smolen, G.R.

    1987-01-01

    Critical experiments have been conducted with organic-moderated mixed oxide (MOX) fuel pin assemblies at the Pacific Northwest Laboratory (PNL) Critical Mass Laboratory (CML). These experiments are part of a joint exchange program between the United States Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan in the area of criticality data development. The purpose of these experiments is to benchmark computer codes and cross-section libraries and to assess the reactivity difference between systems moderated by water and those moderated by an organic solution. Past studies have indicated that some organic mixtures may be better moderators than water. This topic is of particular importance to the criticality safety of fuel processing plants where fissile material is dissolved in organic solutions during the solvent extraction process. In the past, it has been assumed that the codes and libraries benchmarked with water-moderated experiments were adequate when performing design and licensing studies of organic-moderated systems. Calculations presented in this paper indicated that the SCALE code system and the 27-energy-group cross-section accurately compute k-effectives for organic moderated MOX fuel-pin assemblies. Furthermore, the reactivity of an organic solution with a 32-vol-% TBP/68-vol-% NPH mixture in a heterogeneous configuration is the same, for practical purposes, as water. 5 refs

  13. Interrogating Students' Perceptions of Their Online Learning Experiences with Brookfield's Critical Incident Questionnaire

    Science.gov (United States)

    Phelan, Liam

    2012-01-01

    This article discusses whether the very act of accessing online students' experiences of teaching may itself foster students' sense of belonging to a learning community. The article reports and reflects on the application of Brookfield's critical incident questionnaire (CIQ) in postgraduate courses delivered online in 2008-2010 through the…

  14. Modeling of critical experiments employing Raschig rings in uranyl nitrate solution

    International Nuclear Information System (INIS)

    Tanner, J.E.

    1989-01-01

    Four critical experiments employing borated glass rings in concentrated uranyl nitrate solution yielded k eff higher by 0. 04 when modeled with a flux-weighted, homogenized cross section set than when modeled with discrete rings. k eff varied by 0.014 for a 10% boron uncertainty and by up to 0.04 for a 10% packing fraction uncertainty

  15. The Experience of Critical Self-Reflection by Life Coaches: A Phenomenological Study

    Science.gov (United States)

    Shaw, Deanna Lynn

    2012-01-01

    The purpose of this study was to describe the experience of critical self-reflection by life coaches. Life coaching is expanding within many disciplines including education, health care, business, social work, and wellness. Life coaching involves a coach working with an individual or groups aimed at effecting change for professional and personal…

  16. The Brazilian Experience with Agroecological Extension: A Critical Analysis of Reform in a Pluralistic Extension System

    Science.gov (United States)

    Diesel, Vivien; Miná Dias, Marcelo

    2016-01-01

    Purpose: To analyze the Brazilian experience in designing and implementing a recent extension policy reform based on agroecology, and reflect on its wider theoretical implications for extension reform literature. Design/methodology/approach: Using a critical public analysis we characterize the evolution of Brazilian federal extension policy…

  17. The Impact of Simulation-Based Learning Experience on Critical Thinking Acquisition

    Science.gov (United States)

    Rome, Candice

    2012-01-01

    The purpose of this comparative experimental project was to compare the impact of simulation-based learning experiences to traditional clinical rotations on critical thinking acquisition of associate nursing students within a maternal-child course. Innovative pedagogies have been integrated in nursing programs to augment inadequate clinical…

  18. Critical Race Theory, Disability Microaggressions and Latina/o Student Experiences in Special Education

    Science.gov (United States)

    Dávila, Brianne

    2015-01-01

    This research draws upon critical race theory (CRT) to explore the experiences of Latina/o students in special education. It seeks to extend the theoretical construct of racial microaggressions and illustrate the additional layer of disability as I present data that are particular to the context of special education and the assigned label of…

  19. A Critical Reflection on a Suggested Return to Aesthetic Experience in Socialist China

    Science.gov (United States)

    Man, Eva Kit Wah

    2001-01-01

    It is said that aestheticians today, including art critics and philosophers, are yearning for some kind of salvation for contemporary art. This salvation would come in the form of a return to aesthetic experience that would act as a foundation enabling resistance to pure discursive reflection and intertextuality. These debates concerning…

  20. Overview of Experiments for Physics of Fast Reactors from the International Handbooks of Evaluated Criticality Safety Benchmark Experiments and Evaluated Reactor Physics Benchmark Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bess, J. D.; Briggs, J. B.; Gulliford, J.; Ivanova, T.; Rozhikhin, E. V.; Semenov, M. Yu.; Tsibulya, A. M.; Koscheev, V. N.

    2017-07-01

    Overview of Experiments to Study the Physics of Fast Reactors Represented in the International Directories of Critical and Reactor Experiments John D. Bess Idaho National Laboratory Jim Gulliford, Tatiana Ivanova Nuclear Energy Agency of the Organisation for Economic Cooperation and Development E.V.Rozhikhin, M.Yu.Sem?nov, A.M.Tsibulya Institute of Physics and Power Engineering The study the physics of fast reactors traditionally used the experiments presented in the manual labor of the Working Group on Evaluation of sections CSEWG (ENDF-202) issued by the Brookhaven National Laboratory in 1974. This handbook presents simplified homogeneous model experiments with relevant experimental data, as amended. The Nuclear Energy Agency of the Organization for Economic Cooperation and Development coordinates the activities of two international projects on the collection, evaluation and documentation of experimental data - the International Project on the assessment of critical experiments (1994) and the International Project on the assessment of reactor experiments (since 2005). The result of the activities of these projects are replenished every year, an international directory of critical (ICSBEP Handbook) and reactor (IRPhEP Handbook) experiments. The handbooks present detailed models of experiments with minimal amendments. Such models are of particular interest in terms of the settlements modern programs. The directories contain a large number of experiments which are suitable for the study of physics of fast reactors. Many of these experiments were performed at specialized critical stands, such as BFS (Russia), ZPR and ZPPR (USA), the ZEBRA (UK) and the experimental reactor JOYO (Japan), FFTF (USA). Other experiments, such as compact metal assembly, is also of interest in terms of the physics of fast reactors, they have been carried out on the universal critical stands in Russian institutes (VNIITF and VNIIEF) and the US (LANL, LLNL, and others.). Also worth mentioning

  1. Modeling of FREYA fast critical experiments with the Serpent Monte Carlo code

    International Nuclear Information System (INIS)

    Fridman, E.; Kochetkov, A.; Krása, A.

    2017-01-01

    Highlights: • FREYA – the EURATOM project executed to support fast lead-based reactor systems. • Critical experiments in the VENUS-F facility during the FREYA project. • Characterization of the critical VENUS-F cores with Serpent. • Comparison of the numerical Serpent results to the experimental data. - Abstract: The FP7 EURATOM project FREYA has been executed between 2011 and 2016 with the aim of supporting the design of fast lead-cooled reactor systems such as MYRRHA and ALFRED. During the project, a number of critical experiments were conducted in the VENUS-F facility located at SCK·CEN, Mol, Belgium. The Monte Carlo code Serpent was one of the codes applied for the characterization of the critical VENUS-F cores. Four critical configurations were modeled with Serpent, namely the reference critical core, the clean MYRRHA mock-up, the full MYRRHA mock-up, and the critical core with the ALFRED island. This paper briefly presents the VENUS-F facility, provides a detailed description of the aforementioned critical VENUS-F cores, and compares the numerical results calculated by Serpent to the available experimental data. The compared parameters include keff, point kinetics parameters, fission rate ratios of important actinides to that of U235 (spectral indices), axial and radial distribution of fission rates, and lead void reactivity effect. The reported results show generally good agreement between the calculated and experimental values. Nevertheless, the paper also reveals some noteworthy issues requiring further attention. This includes the systematic overprediction of reactivity and systematic underestimation of the U238 to U235 fission rate ratio.

  2. Study of polyelectrolytes for Los Alamos National Laboratory. Final report

    International Nuclear Information System (INIS)

    Labonne, N.

    1994-11-01

    To assess the safety of a potential radioactive waste repository, analysis of the fluid solution containing low levels of activity need to be performed. In some cases, the radioactivity would be so weak (3--30 pCi/L) that the solution must be concentrated for measurement. For this purpose, Los Alamos National Laboratory scientists are synthesizing some water soluble polyelectrolytes, which, because they are strong complexing agents for inorganic cations, can concentrate the radioelements in solution. To assist in characterization of these polyelectrolytes, the author has performed experiments to determine physico-chemical constants, such as pKa values and stability constants. The complexation constants between both polyelectrolytes and europium were determined by two methods: solvent extraction and ion exchange. Results are presented

  3. Recent results from the Los Alamos CTX spheromak

    International Nuclear Information System (INIS)

    Barnes, C.W.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; Knox, S.O.; Linford, R.K.; Platts, D.A.; Sherwood, A.R.

    1982-01-01

    Continued discharge cleaning, improved vacuum practices, and optimized plasma formation operation have resulted in the Los Alamos CTX spheromak experiment achieving 1 millisecond plasma lifetimes with average temperatures of 20 to 40 eV. Impurity radiation power loss has been reduced significantly and the plasma behavior appears to be dominated by pressure-driven instabilities causing increased particle loss. The major advance in operation has been the use of a constant, uniform background of 5 to 20 mTorr of H 2 filling the vacuum tank, flux conserver, and plasma source. This fill operation directly reduces the impurities generated in the plasma source, allows operation of the source at parameters resulting in fewer impurities, and provides a neutral source to maintain the density for long lifetimes. In this paper we present data on the improved operation of CTX, and present evidence for its β-limited operation

  4. Lasing attempts with a microwiggler on the Los Alamos FEL

    International Nuclear Information System (INIS)

    Warren, R.W.; O'Shea, P.G.; Bender, S.C.; Carlsten, B.E.; Early, J.W.; Feldman, D.W.; Fortgang, C.M.; Goldstein, J.C.; Schmitt, M.J.; Stein, W.E.; Wilke, M.D.; Zaugg, T.J.; Newnam, B.E.; Sheffield, R.L.

    1992-01-01

    The APEX FEL normally lases near a wavelength of 3μm using a permanent magnet wiggler with a 2.7-cm period and a linear accelerator of 40-MeV energy. Los Alamos National Laboratory is conducting a series of experiments with the goal of lasing at significantly shorter wavelengths with the same accelerator and the same kind of near-concentric resonator, but using a novel pulsed microwiggler of 0.5-cm period capable of generating a peak field of several tesla. We plan to lase on a fundamental wavelength of ∼0.8 μm and on the third harmonic at 0.25 μm

  5. Decommissioning the UHTREX Reactor Facility at Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Salazar, M.; Elder, J.

    1992-08-01

    The Ultra-High Temperature Reactor Experiment (UHTREX) facility was constructed in the late 1960s to advance high-temperature and gas-cooled reactor technology. The 3-MW reactor was graphite moderated and helium cooled and used 93% enriched uranium as its fuel. The reactor was run for approximately one year and was shut down in February 1970. The decommissioning of the facility involved removing the reactor and its associated components. This document details planning for the decommissioning operations which included characterizing the facility, estimating the costs of decommissioning, preparing environmental documentation, establishing a system to track costs and work progress, and preplanning to correct health and safety concerns in the facility. Work to decommission the facility began in 1988 and was completed in September 1990 at a cost of $2.9 million. The facility was released to Department of Energy for other uses in its Los Alamos program

  6. SNM holdup assessment of Los Alamos exhaust ducts

    International Nuclear Information System (INIS)

    Marshall, R.S.

    1994-02-01

    Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of 235 U in a duct servicing a shut-down uranium-machining facility to 39 g of 239 Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of 235 U in a duct servicing analytical laboratories to 1 g of 235 U and 1 g of 239 Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern

  7. LAMPF II workshop, Los Alamos National Laboratory, Los Alamos, New Mexico, February 1-4, 1982

    International Nuclear Information System (INIS)

    Thiessen, H.A.

    1982-01-01

    This report contains the proceedings of the first LAMPF II Workshop held at Los Alamos February 1 to 4, 1982. Included are the talks that were available in written form. The conclusion of the participants was that there are many exciting areas of physics that will be addressed by such a machine

  8. Biological assessment for the effluent reduction program, Los Alamos National Laboratory, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.P.

    1996-08-01

    This report describes the biological assessment for the effluent recution program proposed to occur within the boundaries of Los Alamos National Laboratory. Potential effects on wetland plants and on threatened and endangered species are discussed, along with a detailed description of the individual outfalls resulting from the effluent reduction program.

  9. The experience of critically ill children: A phenomenological study of discomfort and comfort.

    Science.gov (United States)

    Carnevale, Franco A; Gaudreault, Josée

    2013-01-01

    Emerging evidence indicates that critically ill children are particularly at risk for incurring significant psychological harm. Little is known about these children's actual experiences. The aim of the study was to examine children's experience of critical illness. The research question was: What are a critically ill child's sources of discomfort and comfort? Interpretive phenomenology was selected as the study's method. Children's accounts were examined to identify what they considered meaningful, in terms of their experienced discomfort and comfort. Data sources included formal and informal interviews with child-participants, drawings provided by some participants, and field-notes documenting observed non-verbal data. Twelve children were enrolled in the study, ranging from 3 to 17years of age; including four girls and eight boys. Although all participants were able to discuss the discomfort and comfort they experienced, they reported difficulties in remembering part or most of their experience. Some participants characterized their Pediatric Intensive Care Unit stay quite favourably or as "not that bad", while some described their experience unfavourably. Diverse types of discomforts were reported, including fears and worries, hurt and pain, invasive interventions, missing significant people, noise, food or eating problems, boredom, physical symptoms, as well as four additional discomforts reported by individual participants. Several sources of comfort were described, including parents, visitors and friends, hospital staff (principally nurses), stuffed animal/favourite blanket, entertainment and play, food, selected medical interventions, thinking of going home, being able to walk or run, sleep, waking up, gifts, along with two other comforts reported by individual participants. Embodiment and a tension between aloneness and being with were identified as the principal phenomena underlying these children's experiences. The findings complement existing knowledge

  10. Materials accounting at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Roberts, N.J.; Erkkila, B.H.; Kelso, H.F.

    1985-01-01

    The materials accounting system at Los Alamos has evolved from an ''80-column'' card system to a very sophisticated near-real-time computerized nuclear material accountability and safeguards system (MASS). The present hardware was designed and acquired in the late 70's and is scheduled for a major upgrade in Fiscal Year 1986. The history of the system from 1950 through the DYMAC of the late 70's up to the present will be discussed. The philosophy of the system along with the details of the system will be covered. This system has addressed the integrated problems of management, control, and accounting of nuclear material successfully

  11. Environmental Programs at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Patricia [Los Alamos National Laboratory

    2012-07-11

    Summary of this project is: (1) Teamwork, partnering to meet goals - (a) Building on cleanup successes, (b) Solving legacy waste problems, (c) Protecting the area's environment; (2) Strong performance over the past three years - (a) Credibility from four successful Recovery Act Projects, (b) Met all Consent Order milestones, (c) Successful ramp-up of TRU program; (3) Partnership between the National Nuclear Security Administration's Los Alamos Site Office, DOE Carlsbad Field Office, New Mexico Environment Department, and contractor staff enables unprecedented cleanup progress; (4) Continued focus on protecting water resources; and (5) All consent order commitments delivered on time or ahead of schedule.

  12. Optics code development at Los Alamos

    International Nuclear Information System (INIS)

    Mottershead, C.T.; Lysenko, W.P.

    1988-01-01

    This paper is an overview of part of the beam optics code development effort in the Accelerator Technology Division at Los Alamos National Laboratory. The aim of this effort is to improve our capability to design advanced beam optics systems. The work reported is being carried out by a collaboration of permanent staff members, visiting consultants, and student research assistants. The main components of the effort are: building a new framework of common supporting utilities and software tools to facilitate further development; research and development on basic computational techniques in classical mechanics and electrodynamics; and evaluation and comparison of existing beam optics codes, and support for their continuing development. 17 refs

  13. Commercialization of Los Alamos National Laboratory technologies via small businesses. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brice, R.; Cartron, D.; Rhyne, T.; Schulze, M.; Welty, L.

    1997-06-01

    Over the past decade, numerous companies have been formed to commercialize research results from leading U.S. academic and research institutions. Emerging small businesses in areas such as Silicon Valley, Boston`s Route 128 corridor, and North Carolina`s Research Triangle have been especially effective in moving promising technologies from the laboratory bench to the commercial marketplace--creating new jobs and economic expansion in the process. Unfortunately, many of the U.S. national laboratories have not been major participants in this technology/commercialization activity, a result of a wide variety of factors which, until recently, acted against successful commercialization. This {open_quotes}commercialization gap{close_quotes} exists partly due to a lack, within Los Alamos in particular and the DOE in general, of in-depth expertise and experience in such business areas as new business development, securities regulation, market research and the determination of commercial potential, the identification of entrepreneurial management, marketing and distribution, and venture capital sources. The immediate consequence of these factors is the disappointingly small number of start-up companies based on technologies from Los Alamos National Laboratory that have been attempted, the modest financial return Los Alamos has received from these start-ups, and the lack of significant national recognition that Los Alamos has received for creating and commercializing these technologies.

  14. The Experience of African Students Studying Nursing in the United States in Relation to Their Use of Critical Thinking

    Science.gov (United States)

    Tyson, Donald Lee

    2012-01-01

    This qualitative study explores the critical thinking experiences of African nursing students enrolled in several universities in the U.S. Using a semi-structured interview approach, twelve African students discussed their experiences using and learning a western critical thinking approach, as well as described their educational experiences in…

  15. Nuclear criticality experiments from 1943 to 1978: an annotated bibliography. Volume 1. Main listing

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, B.L.; Wilcox, T.P.; Hampel, V.E.

    1979-04-24

    The bibliography contains 1067 citations from the literature of critical and near-critical nuclear experiments. It provides an up-to-date index to reports containing useful data for many types of criticality studies. Most of the reports can provide specifications for relatively simple critical configurations necessary for validating nuclear constants and calculational techniques. The reports of more than 1143 experimentors at 38 international facilities since 1943 are cross-referenced. The collection contains the prototypes of many different designs of nuclear reactors and studies performed to insure the safe use of fissile materials in chemical processing plants, storage facilities, and transportation containers. The bibliography has three volumes. Volume 1 contains the main listing of citations with abstracts. Volume 2 is a set of indexes organized by report number, publication date, experimental facility, and author name. Volume 3 provides a subject index, concorded on the significant keyphrases derived from titles, and an index of keyterms derived from titles, and an index of keyterms extracted from titles and abstracts. The bibliography was printed by computer as a selection from a computerized system at Lawrence Livermore Laboratory contaning information and data on criticality experiments.

  16. DOE Los Alamos National Laboratory – PV Feasibility Assessment, 2015 Update, NREL Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Witt, Monica Rene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-06

    This report summarizes solar and wind potential for Los Alamos National Laboratory (LANL). This report is part of the “Los Alamos National Laboratory and Los Alamos County Renewable Generation” study.

  17. Planning the Unplanned Experiment: Assessing the Efficacy of Standards for Safety Critical Software

    Science.gov (United States)

    Graydon, Patrick J.; Holloway, C. Michael

    2015-01-01

    We need well-founded means of determining whether software is t for use in safety-critical applications. While software in industries such as aviation has an excellent safety record, the fact that software aws have contributed to deaths illustrates the need for justi ably high con dence in software. It is often argued that software is t for safety-critical use because it conforms to a standard for software in safety-critical systems. But little is known about whether such standards `work.' Reliance upon a standard without knowing whether it works is an experiment; without collecting data to assess the standard, this experiment is unplanned. This paper reports on a workshop intended to explore how standards could practicably be assessed. Planning the Unplanned Experiment: Assessing the Ecacy of Standards for Safety Critical Software (AESSCS) was held on 13 May 2014 in conjunction with the European Dependable Computing Conference (EDCC). We summarize and elaborate on the workshop's discussion of the topic, including both the presented positions and the dialogue that ensued.

  18. Calculation of critical experiment parameters for the High Flux Isotope Reactor

    International Nuclear Information System (INIS)

    Primm, R.T. III.

    1991-01-01

    Six critical experiments were performed shortly before the initial ascension to power of the High Flux Isotope Reactor (HFIR). Critical configurations were determined at various control rod positions by varying the soluble boron content in the light water coolant. Calculated k-effective was 2% high at beginning-of-life (BOL) typical conditions, but was 1.0 at end-of-life (EOL) typical conditions. Axially averaged power distributions for a given radial location were frequently within experimental error. At specific r,z locations with the core, the calculated power densities were significantly different from the experimentally derived values. A reassessment of the foil activation data seems desirable

  19. MCNP benchmark analyses of critical experiments for the Space Nuclear Thermal Propulsion program

    Science.gov (United States)

    Selcow, Elizabeth C.; Cerbone, Ralph J.; Ludewig, Hans; Mughabghab, Said F.; Schmidt, Eldon; Todosow, Michael; Parma, Edward J.; Ball, Russell M.; Hoovler, Gary S.

    1993-01-01

    Benchmark analyses have been performed of Particle Bed Reactor (PBR) critical experiments (CX) using the MCNP radiation transport code. The experiments have been conducted at the Sandia National Laboratory reactor facility in support of the Space Nuclear Thermal Propulsion (SNTP) program. The test reactor is a nineteen element water moderated and reflected thermal system. A series of integral experiments have been carried out to test the capabilities of the radiation transport codes to predict the performance of PBR systems. MCNP was selected as the preferred radiation analysis tool for the benchmark experiments. Comparison between experimental and calculational results indicate close agreement. This paper describes the analyses of benchmark experiments designed to quantify the accuracy of the MCNP radiation transport code for predicting the performance characteristics of PBR reactors.

  20. MCNP benchmark analyses of critical experiments for the Space Nuclear Thermal Propulsion program

    International Nuclear Information System (INIS)

    Selcow, E.C.; Cerbone, R.J.; Ludewig, H.; Mughabghab, S.F.; Schmidt, E.; Todosow, M.; Parma, E.J.; Ball, R.M.; Hoovler, G.S.

    1993-01-01

    Benchmark analyses have been performed of Particle Bed Reactor (PBR) critical experiments (CX) using the MCNP radiation transport code. The experiments have been conducted at the Sandia National Laboratory reactor facility in support of the Space Nuclear Thermal Propulsion (SNTP) program. The test reactor is a nineteen element water moderated and reflected thermal system. A series of integral experiments have been carried out to test the capabilities of the radiation transport codes to predict the performance of PBR systems. MCNP was selected as the preferred radiation analysis tool for the benchmark experiments. Comparison between experimental and calculational results indicate close agreement. This paper describes the analyses of benchmark experiments designed to quantify the accuracy of the MCNP radiation transport code for predicting the performance characteristics of PBR reactors

  1. CICE, The Los Alamos Sea Ice Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-05-12

    The Los Alamos sea ice model (CICE) is the result of an effort to develop a computationally efficient sea ice component for a fully coupled atmosphere–land–ocean–ice global climate model. It was originally designed to be compatible with the Parallel Ocean Program (POP), an ocean circulation model developed at Los Alamos National Laboratory for use on massively parallel computers. CICE has several interacting components: a vertical thermodynamic model that computes local growth rates of snow and ice due to vertical conductive, radiative and turbulent fluxes, along with snowfall; an elastic-viscous-plastic model of ice dynamics, which predicts the velocity field of the ice pack based on a model of the material strength of the ice; an incremental remapping transport model that describes horizontal advection of the areal concentration, ice and snow volume and other state variables; and a ridging parameterization that transfers ice among thickness categories based on energetic balances and rates of strain. It also includes a biogeochemical model that describes evolution of the ice ecosystem. The CICE sea ice model is used for climate research as one component of complex global earth system models that include atmosphere, land, ocean and biogeochemistry components. It is also used for operational sea ice forecasting in the polar regions and in numerical weather prediction models.

  2. Los Alamos Waste Management Cost Estimation Model

    International Nuclear Information System (INIS)

    Matysiak, L.M.; Burns, M.L.

    1994-03-01

    This final report completes the Los Alamos Waste Management Cost Estimation Project, and includes the documentation of the waste management processes at Los Alamos National Laboratory (LANL) for hazardous, mixed, low-level radioactive solid and transuranic waste, development of the cost estimation model and a user reference manual. The ultimate goal of this effort was to develop an estimate of the life cycle costs for the aforementioned waste types. The Cost Estimation Model is a tool that can be used to calculate the costs of waste management at LANL for the aforementioned waste types, under several different scenarios. Each waste category at LANL is managed in a separate fashion, according to Department of Energy requirements and state and federal regulations. The cost of the waste management process for each waste category has not previously been well documented. In particular, the costs associated with the handling, treatment and storage of the waste have not been well understood. It is anticipated that greater knowledge of these costs will encourage waste generators at the Laboratory to apply waste minimization techniques to current operations. Expected benefits of waste minimization are a reduction in waste volume, decrease in liability and lower waste management costs

  3. Critical experiment on natural uranium assembly in Kinki University Reactor UTR-KINKI, 1

    International Nuclear Information System (INIS)

    Ito, Tetsuo; Miki, Ryota; Tsuchihashi, Keiichiro; Kobayashi, Keiji; Ishihara, Shinji; Hayashi, Masatoshi; Shiroya, Seiji; Kanda, Keiji.

    1986-01-01

    Integral critical experiments on natural uranium assemblies (3 x 3 elements) which are set up in the central region of the enlarged central vertical stringer, 16.4 x 16.4 x 122 cm, located at the center of internal graphite refrector between two fuel tanks of Kinki University Research Reactor, UTR-KINKI, has been performed as a complement to the experiment in Kyoto University Critical Assembly, KUCA, to check and evaluate calculation methods of critical experiment and analysis on thorium assembly in UTR-KINKI. Enlarged natural uranium assemblies are composed of square natural uranium metal plates and square graphite plates. The experiments include the followings: (1) Measurement of reactivity of various enlarged natural uranium assemblies (2) Measurement of relative neutron flux distribution (Au foil reaction rate distribution) in various enlarged natural uranium assemblies. Experimental results on reactivity effect of natural uranium and thorium assemblies show different tendency, but the neutron flux distribution in various natural uranium and thorium assemblies have similar pattern. (author)

  4. A Critical Study of C.F.Davis's Views on Revelatory Religious Experiences

    Directory of Open Access Journals (Sweden)

    Ali Shirvani

    2010-12-01

    Full Text Available Revelatory experiences which are regarded as a major type of religious experiences comprise what their subjects may call sudden convictions, inspiration, revelation, enlightenment, the mystical vision and flashes of insight. In Davis's point of view, these experiences have distinctive features: (i They are usually sudden and of short duration (ii the alleged new knowledge seems to the subject to have been acquired not through reasoning or sense perception (iii the alleged new knowledge usually seems to the subject to have been ' poured into ' or ' showered upon ' him her by an external agency (iv the revelations carry with them utter convicition (v the gained insights are often claimed to be impossible to put into words.  This paper is to present how Davis describes religious experiences of this category from a Christian philosophical approach to religion. It also studies her point of views from a critical Islamic mystical vision. Through this critical and comparative study, it would be revealed that what Davis claimed to be known as revelatory religious experiences has close relationship with what is called "Kashfe Ma'lanavi" (spiritual intuition in Islamic mysticism. These are examined closely in Muslims' mystical sources. Distinction between Prophet's revelation and other instances of revelatory religious experiences and exploring their main differences were of close attention for Muslim mystics (Orafa.

  5. Critical heat-flux experiments under low-flow conditions in a vertical annulus

    International Nuclear Information System (INIS)

    Mishima, K.; Ishii, M.

    1982-03-01

    An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF

  6. Critical experiments on minimal-content gadolinia for above-5wt% enrichment fuels in Toshiba NCA

    International Nuclear Information System (INIS)

    Kikuchi, Tsukasa; Watanabe, Shouichi; Yoshioka, Kenichi; Mitsuhashi, Ishi; Kumanomido, Hironori; Sugahara, Satoshi; Hiraiwa, Kouji

    2009-01-01

    A concept of 'minimal-content gadolinia' with a content of less than several hundred ppm mixed in the 'above-5wt% enrichment UO 2 fuel' for super high burnup is proposed for ensuring the criticality safety in the UO 2 fuel fabrication facility for light water reactors (LWRs) without increase in investment cost. Required gadolinia contents calculated were from 53 to 305 ppm for enrichments of UO 2 powders for boiling water reactor (BWR) fuel from 6 to 10 wt%. It is expected that the minimal-content gadolinia yields an acceptable reactivity suppression at the beginning of operating cycle and no reactivity penalty at the end of operating cycle due to no residual gadolinium. A series of critical experiments were carried out in the Toshiba Nuclear Critical Assembly (NCA). Reactivity effects of the gadolinia were measured to clarify the nuclear characteristics, and the measured values and the calculated values agreed within 5%. (author)

  7. Evaluation of the French Haut Taux de Combustion (HTC) Critical Experiment Data

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Hollenbach, Karla Riggle [ORNL; Fox, Patricia B [ORNL

    2008-09-01

    In the 1980s, a series of critical experiments referred to as the Haut Taux de Combustion (HTC) experiments was conducted by the Institut de Radioprotection et de Surete Nucleaire (IRSN) at the experimental criticality facility in Valduc, France. The plutonium-to- uranium ratio and the isotopic compositions of both the uranium and plutonium used in the simulated fuel rods were designed to be similar to what would be found in a typical pressurized-water reactor fuel assembly that initially had an enrichment of 4.5 wt% {sup 235}U and was burned to 37,500 MWd/MTU. The fuel material also includes {sup 241}Am, which is present due to the decay of {sup 241}Pu. The HTC experiments include configurations designed to simulate fuel handling activities, pool storage, and transport in casks constructed of thick lead or steel. Rights of use for the HTC experiment data were purchased under an agreement that limits release of the information. Consequently, a detailed and complete description of the experiments is not presented in this report. This report discusses evaluation of the four HTC data reports, modeling of the experiments, sensitivity and uncertainty analysis, and upper subcritical limit (USL) calculation. The report also presents some conclusions and recommendations concerning use of the HTC experiment data for burnup credit applications. The similarity of the HTC experiments with PWR spent nuclear fuel has been quantified using sensitivity/uncertainty analysis, confirming that the HTC experiments are significantly more applicable to the validation of burnup credit calculations than other available mixed-oxide (MOX) experiments. The HTC experiments were designed and executed with a high level of rigor, resulting in experimental uncertainties that are lower than many of the earlier MOX experiments. The HTC data reports, together with information provided in this report, provide sufficient data to allow for either detailed or simplified computational models to be

  8. The challenges of caring in a technological environment: critical care nurses' experiences.

    Science.gov (United States)

    McGrath, Mary

    2008-04-01

    This paper presents and discusses the findings from a phenomenological study which illuminated the lived experiences of experienced critical care nurses caring within a technological environment. While nursing practice is interwoven with technology, much of the literature in this area is speculative. Moreover, there is a debate as to whether and how 'high tech' and 'high touch' are reconcilable; this orientation is referred to as the optimism vs. pessimism debate. On a personal level, the motivation for this study came from the author's 13 years' experience in the critical care area. Following ethical approval, 10 experienced nurses from two cardiothoracic critical care units in Ireland participated in the study. A Heideggerian phenomenological methodology was used. Data collection consisted of unstructured interviews. A method of data analysis described by Walters was used. The findings provide research-based evidence to illuminate further the optimistic/pessimistic debate on technology in nursing. While the study demonstrates that the debate is far from resolved, it reveals a new finding: life-saving technology that supports the lives of critically ill patients can bring experienced nurses very close to their patients/families. The three main themes that emerged: 'alien environment', 'pulling together' and 'sharing the journey' were linked by a common thread of caring. Experienced critical care nurses are able to transcend the obtrusive nature of technology to deliver expert caring to their patients. However, the journey to proficiency in technology is very demanding and novice nurses have difficulty in caring with technology. Relevance to clinical practice. It is recommended that more emphasis be placed on supporting, assisting and educating inexperienced nurses in the critical care area and that the use of technology in nursing be given serious consideration.

  9. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    International Nuclear Information System (INIS)

    Rothe, R.E.

    1996-01-01

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution's concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the 'Poisoned Tube Tank' because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service

  10. Criticality experiments with low enriched UO2 fuel rods in water containing dissolved gadolinium

    International Nuclear Information System (INIS)

    Bierman, S.R.; Murphy, E.S.; Clayton, E.D.; Keay, R.T.

    1984-02-01

    The results obtained in a criticality experiments program performed for British Nuclear Fuels, Ltd. (BNFL) under contract with the United States Department of Energy (USDOE) are presented in this report along with a complete description of the experiments. The experiments involved low enriched UO 2 and PuO 2 -UO 2 fuel rods in water containing dissolved gadolinium, and are in direct support of BNFL plans to use soluble compounds of the neutron poison gadolinium as a primary criticality safeguard in the reprocessing of low enriched nuclear fuels. The experiments were designed primarily to provide data for validating a calculation method being developed for BNFL design and safety assessments, and to obtain data for the use of gadolinium as a neutron poison in nuclear chemical plant operations - particularly fuel dissolution. The experiments program covers a wide range of neutron moderation (near optimum to very under-moderated) and a wide range of gadolinium concentration (zero to about 2.5 g Gd/l). The measurements provide critical and subcritical k/sub eff/ data (1 greater than or equal to k/sub eff/ greater than or equal to 0.87) on fuel-water assemblies of UO 2 rods at two enrichments (2.35 wt % and 4.31 wt % 235 U) and on mixed fuel-water assemblies of UO 2 and PuO 2 -UO 2 rods containing 4.31 wt % 235 U and 2 wt % PuO 2 in natural UO 2 respectively. Critical size of the lattices was determined with water containing no gadolinium and with water containing dissolved gadolinium nitrate. Pulsed neutron source measurements were performed to determine subcritical k/sub eff/ values as additional amounts of gadolinium were successively dissolved in the water of each critical assembly. Fission rate measurements in 235 U using solid state track recorders were made in each of the three unpoisoned critical assemblies, and in the near-optimum moderated and the close-packed poisoned assemblies of this fuel

  11. Knowledge, Skills and Experience Managing Tracheostomy Emergencies: A Survey of Critical Care Medicine trainees

    LENUS (Irish Health Repository)

    Nizam, AA

    2016-10-01

    Since the development of percutaneous tracheostomy, the number of tracheostomy patients on hospital wards has increased. Problems associated with adequate tracheostomy care on the wards are well documented, particularly the management of tracheostomy-related emergencies. A survey was conducted among non-consultant hospital doctors (NCHDs) starting their Critical Care Medicine training rotation in a university affiliated teaching hospital to determine their basic knowledge and skills in dealing with tracheostomy emergencies. Trainees who had received specific tracheostomy training or who had previous experience of dealing with tracheostomy emergencies were more confident in dealing with such emergencies compared to trainees without such training or experience. Only a minority of trainees were aware of local hospital guidelines regarding tracheostomy care. Our results highlight the importance of increased awareness of tracheostomy emergencies and the importance of specific training for Anaesthesia and Critical Care Medicine trainees.

  12. Applicable regulations and development of surveillance experiments of criticality approach in the TRIGA III Mark reactor

    International Nuclear Information System (INIS)

    Gonzalez M, J.L.; Aguilar H, F.; Rivero G, T.; Sainz M, E.

    2000-01-01

    In the procedure elaborated to repair the vessel of TRIGA III Mark reactor is required to move toward two tanks of temporal storage the fuel elements which are in operation and the spent fuel elements which are in decay inside the reactor pool. The National Commission of Nuclear Safety and Safeguards (CNSNS) has requested as protection measure that it is carried out a surveillance of the criticality approach of the temporal storages. This work determines the main regulation aspects that entails an experiment of criticality approach, moreover, informing about the results obtained in the developing of this experiments. The regulation aspects are not exclusives for this work in the TRIGA Mark III reactor but they also apply toward any assembling of fissile material. (Author)

  13. Critical experiments analyses by using 70 energy group library based on ENDF/B-VI

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Yoshihisa; Matsumoto, Hideki [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Nuclear Energy Systems Engineering Center; Huria, H.C.; Ouisloumen, M.

    1998-03-01

    The newly developed 70-group library has been validated by comparing kinf from a continuous energy Monte-Carlo code MCNP and two dimensional spectrum calculation code PHOENIX-CP. The code employs Discrete Angular Flux Method based on Collision Probability. The library has been also validated against a large number of critical experiments and numerical benchmarks for assemblies with MOX and Gd fuels. (author)

  14. A double concern: Grandmothers' experiences when a small grandchild is critically ill

    DEFF Research Database (Denmark)

    Hall, Elisabeth

    2004-01-01

    Grandmothers play an active part in family health and illness, but so far they are peripheral in both nursing and nursing research. This article addresses grandmothers' lived experiences when a small grandchild is critically ill. A convenience sample of 7 grandmothers was interviewed once....... With the use of the methodology of Van Manen, (1990), the essence of the phenomenon was found to be a "double concern," a worry and loving care that encompassed both parents and grandchildren. Although the findings have limitations, they constitute a systematic and thematic description of Danish grandmothers......' experiences and therefore add to a family-oriented body of knowledge in pediatric nursing....

  15. Critical experiments on interaction systems using STACY and their analytical evaluation

    International Nuclear Information System (INIS)

    Tonoike, Kotaro; Yamamoto, Toshihiro; Miyoshi, Yoshinori

    2005-01-01

    A series of experiments with neutron interactive cores that consisted of two slab tanks was conducted to measure the neutronic characteristics of the multiple-unit system. The measured characteristics are useful to discuss the issues of criticality safety design such as the modeling scheme of multiple-unit systems, the accuracy of computation methods of the weekly-coupled system, and so far. In this presentation, conditions of the series of experiments will be outlined. Their analytical evaluation for the validation of computational methods will be also discussed. (author)

  16. Experience-Dependent Equilibration of AMPAR-Mediated Synaptic Transmission during the Critical Period

    Directory of Open Access Journals (Sweden)

    Kyung-Seok Han

    2017-01-01

    Full Text Available Experience-dependent synapse refinement is essential for functional optimization of neural circuits. However, how sensory experience sculpts excitatory synaptic transmission is poorly understood. Here, we show that despite substantial remodeling of synaptic connectivity, AMPAR-mediated synaptic transmission remains at equilibrium during the critical period in the mouse primary visual cortex. The maintenance of this equilibrium requires neurogranin (Ng, a postsynaptic calmodulin-binding protein important for synaptic plasticity. With normal visual experience, loss of Ng decreased AMPAR-positive synapse numbers, prevented AMPAR-silent synapse maturation, and increased spine elimination. Importantly, visual deprivation halted synapse loss caused by loss of Ng, revealing that Ng coordinates experience-dependent AMPAR-silent synapse conversion to AMPAR-active synapses and synapse elimination. Loss of Ng also led to sensitized long-term synaptic depression (LTD and impaired visually guided behavior. Our synaptic interrogation reveals that experience-dependent coordination of AMPAR-silent synapse conversion and synapse elimination hinges upon Ng-dependent mechanisms for constructive synaptic refinement during the critical period.

  17. Nuclear knowledge management experience of the International Criticality Safety Benchmark Evaluation Project

    International Nuclear Information System (INIS)

    Briggs, J.B.; Nouri, A.; Dean, V.A.F.

    2004-01-01

    The International Criticality Safety Benchmark Evaluation Project (ICSBEP) was initiated in 1992 by the United States Department of Energy. The ICSBEP became an official activity of the Organization for Economic Cooperation and Development (OECD) -- Nuclear Energy Agency (NEA) in 1995. Representatives from the United States, United Kingdom, France, Japan, the Russian Federation, Hungary, Republic of Korea, Slovenia, Serbia and Montenegro (formerly Yugoslavia), Kazakhstan, Spain, Israel, Brazil, Poland, and the Czech Republic are now participating. South Africa, India, China, and Germany are considering participation. The purpose of the ICSBEP is to identify, evaluate, verify, and formally document a comprehensive and internationally peer-reviewed set of criticality safety benchmark data. The work of the ICSBEP is published as an OECD handbook entitled 'International Handbook of Evaluated Criticality Safety Benchmark Experiments'. The 2004 Edition of the Handbook contains benchmark specifications for 3331 critical or subcritical configurations that are intended for use in validation efforts and for testing basic nuclear data. The Handbook is being used extensively for validation of criticality safety methodologies and nuclear data testing and is expected to be a valuable resource for code and data validation and improvement efforts for decades to come. (author)

  18. Benchmark criticality experiments for fast fission configuration with high enriched nuclear fuel

    International Nuclear Information System (INIS)

    Sikorin, S.N.; Mandzik, S.G.; Polazau, S.A.; Hryharovich, T.K.; Damarad, Y.V.; Palahina, Y.A.

    2014-01-01

    Benchmark criticality experiments of fast heterogeneous configuration with high enriched uranium (HEU) nuclear fuel were performed using the 'Giacint' critical assembly of the Joint Institute for Power and Nuclear Research - Sosny (JIPNR-Sosny) of the National Academy of Sciences of Belarus. The critical assembly core comprised fuel assemblies without a casing for the 34.8 mm wrench. Fuel assemblies contain 19 fuel rods of two types. The first type is metal uranium fuel rods with 90% enrichment by U-235; the second one is dioxide uranium fuel rods with 36% enrichment by U-235. The total fuel rods length is 620 mm, and the active fuel length is 500 mm. The outer fuel rods diameter is 7 mm, the wall is 0.2 mm thick, and the fuel material diameter is 6.4 mm. The clad material is stainless steel. The side radial reflector: the inner layer of beryllium, and the outer layer of stainless steel. The top and bottom axial reflectors are of stainless steel. The analysis of the experimental results obtained from these benchmark experiments by developing detailed calculation models and performing simulations for the different experiments is presented. The sensitivity of the obtained results for the material specifications and the modeling details were examined. The analyses used the MCNP and MCU computer programs. This paper presents the experimental and analytical results. (authors)

  19. Radionuclide concentrations in pinto beans, sweet corn, and zucchini squash grown in Los Alamos Canyon at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, P.R.; Mullen, M.A.; Naranjo, L. Jr.; Armstrong, D.R.

    1997-05-01

    Pinto beans, sweet corn, and zucchini squash (Cucurbita pepo var. black beauty) were grown in a randomized complete-block field/pot experiment at a site that contained the highest observed levels of surface gross gamma radioactivity within Los Alamos Canyon (LAC) at Los Alamos National Laboratory. Soils as well as washed edible and nonedible crop tissues were analyzed for various radionuclides and heavy metals . Most radionuclides, with the exception of {sup 3}H and {sup tot}U, in soil from LAC were detected in significantly higher concentrations (p <0.01) than in soil collected from regional background (RBG) locations. Similarly, most radionuclides in edible crop portions of beans, squash, and corn were detected in significantly higher (p <0.01 and 0.05) concentrations than RBG. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues from LAC were within the default values given by the Nuclear Regulatory Commission and Environmental Protection Agency. All heavy metals in soils, as well as edible and nonedible crop tissues grown in soils from LAC, were within RBG concentrations. Overall, the total maximum net positive committed effective dose equivalent (CEDE)--the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed--to a hypothetical 50-year resident that ingested 160 kg of beans, corn, and squash in equal proportions, was 74 mrem y{sup -1}. This dose was below the International Commission on Radiological Protection permissible dose limit (PDL) of 100 mrem y{sup -1} from all pathways; however, the addition of other internal and external exposure route factors may increase the overall dose over the PDL. Also, the risk of an excess cancer fatality, based on 74 mrem y{sup -1}, was 3.7 x 10{sup -5} (37 in a million), which is above the Environmental Protection Agency`s (acceptable) guideline of one in a million. 31 refs., 15 tabs.

  20. Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

    International Nuclear Information System (INIS)

    Oothoudt, M.; Pillai, C.; Zumbro, M.

    1997-01-01

    Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances

  1. Los Alamos Transuranic Waste Size Reduction Facility

    International Nuclear Information System (INIS)

    Harper, J.; Warren, J.

    1987-06-01

    The Los Alamos Transuranic (TRU) Waste Size Reduction Facility (SRF) is a production oriented prototype. The facility is operated to remotely cut and repackage TRU contaminated metallic wastes (e.g., glove boxes, ducting and pipes) for eventual disposal at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. The resulting flat sections are packaged into a tested Department of Transportation Type 7A metal container. To date, the facility has successfully processed stainless steel glove boxes (with and without lead shielding construction) and retention tanks. We have found that used glove boxes generate more cutting fumes than do unused glove boxes or metal plates - possibly due to deeply embedded chemical residues from years of service. Water used as a secondary fluid with the plasma arc cutting system significantly reduces visible fume generation during the cutting of used glove boxes and lead-lined glove boxes. 2 figs., 1 tab

  2. Los Alamos Transuranic Waste Size Reduction Facility

    International Nuclear Information System (INIS)

    Harper, J.; Warren, J.

    1987-01-01

    The Los Alamos Transuranic (TRU) Waste Size Reduction Facility (SRF) is a production oriented prototype completed in 1981 and later modified during 1986 to enhance production. The facility is operated to remotely cut (with a plasma arc torch) and repackage TRU contaminated metallic wastes (e.g., glove boxes, ducting and pipes) for eventual disposal at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. The resulting flat sections are packaged into a tested Department of Transportation Type 7A metal container. To date, the facility has successfully processed stainless steel glove boxes (with and without lead shielding construction) and retention tanks. It was found that used glove boxes generate more cutting fumes than do unused glove boxes or metal plates - possibly due to deeply embedded chemical residues from years of service. Water used as a secondary fluid with the plasma arc cutting system significantly reduces visible fume generation during the cutting of used glove boxes and lead-lined glove boxes

  3. Environmental surveillance at Los Alamos during 1992

    International Nuclear Information System (INIS)

    Kohen, K.; Stoker, A.; Stone, G.

    1994-07-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory during 1992. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring results to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1992 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, laboratory employees, or the environment

  4. Los Alamos controlled-air incineration studies

    International Nuclear Information System (INIS)

    Koenig, R.A.; Warner, C.L.

    1983-01-01

    Current regulations of the Environmental Protection Agency (EPA) require that PCBs in concentrations greater than 500 ppM be disposed of in EPA-permitted incinerators. Four commercial incineration systems in the United States have EPA operating permits for receiving and disposing of concentrated PCBs, but none can accept PCBs contaminated with nuclear materials. The first section of this report presents an overview of an EPA-sponsored program for studying PCB destruction in the large-scale Los Alamos controlled-air incinerator. A second major FY 1983 program, sponsored by the Naval Weapons Support Center, Crane, Indiana, is designed to determine operating conditions that will destroy marker smoke compounds without also forming polycyclic aromatic hydrocarbons (PAHs), some of which are known or suspected to be carcinogenic. We discuss the results of preliminary trial burns in which various equipment and feed formulations were tested. We present qualitative analyses for PAHs in the incinerator offgas as a result of these tests

  5. Environmental surveillance at Los Alamos during 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos Scientific Laboratory (LASL) in 1979. Routine monitoring for radiation and radioactive or chemical substances was conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of the data for 1979 on penetrating radiation, chemical and radiochemical quality of ambient air, surface and ground water, municipal water supply, soils and sediments, food, and airborne and liquid effluents are included. Comparisons with appropriate standards and regulations or with background levels from natural or other non-LASL sources provide a basis for concluding that environmental effects attributable to LASL operations are minor and cannot be considered likely to result in any hazard to the population of the area. Results of several special studies provide documentation of some unique environmental conditions in the LASL environs.

  6. Environmental surveillance at Los Alamos during 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory (LANL or the Laboratory) during 1995. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring result to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1995 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, Laboratory employees, or the environment.

  7. Environmental surveillance at Los Alamos during 1990

    International Nuclear Information System (INIS)

    1992-03-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1990. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1990 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment

  8. Environmental surveillance at Los Alamos during 1979

    International Nuclear Information System (INIS)

    1980-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos Scientific Laboratory (LASL) in 1979. Routine monitoring for radiation and radioactive or chemical substances was conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of the data for 1979 on penetrating radiation, chemical and radiochemical quality of ambient air, surface and ground water, municipal water supply, soils and sediments, food, and airborne and liquid effluents are included. Comparisons with appropriate standards and regulations or with background levels from natural or other non-LASL sources provide a basis for concluding that environmental effects attributable to LASL operations are minor and cannot be considered likely to result in any hazard to the population of the area. Results of several special studies provide documentation of some unique environmental conditions in the LASL environs

  9. Environmental surveillance at Los Alamos during 1992

    Energy Technology Data Exchange (ETDEWEB)

    Kohen, K.; Stoker, A.; Stone, G. [and others

    1994-07-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory during 1992. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring results to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1992 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, laboratory employees, or the environment.

  10. Optical engineering at Los Alamos: a history

    International Nuclear Information System (INIS)

    Brixner, B.

    1983-01-01

    Optical engineering at Los Alamos, which began in 1943, has continued because scientific researchers usually want more resolving power than commercially available optical instruments provide. In addition, in-house engineering is often advantageous - when the technology for designing and making improved instrumentation is available locally - because of our remote location and the frequent need for accurate data. As a consequence, a number of improved research cameras and lens systems have been developed locally - especially for explosion and implosion photography, but even for oscilloscope photography. The development of high-speed cameras led to the ultimate in practical high-speed rotating mirrors and to the invention of a rapid, precise, and effective lens design procedure that has produced more than a hundred lens system that gives improved imaging in special conditions of use. Representative examples of this work are described

  11. Los Alamos advanced free-electron laser

    Science.gov (United States)

    Chan, K. C. D.; Kraus, R. H.; Ledford, J.; Meier, K. L.; Meyer, R. E.; Nguyen, D.; Sheffield, R. L.; Sigler, F. L.; Young, L. M.; Wang, T. S.; Wilson, W. L.; Wood, R. L.

    1992-07-01

    Los Alamos researchers are building a free-electron laser (FEL) for industrial, medical, and research applications. This FEL, which will incorporate many of the new technologies developed over the last decade, will be compact, robust, and user-friendly. Electrons produced by a photocathode will be accelerated to 20 MeV by a high-brightness accelerator and transported by permanent-magnet quadrupoles and dipoles. The resulting electron beam will have an excellent instantaneous beam quality of 10πmm mrad in transverse emittance and 0.3% in energy spread at a peak current up to 300 A. Including operation at higher harmonics, the laser wavelength extends from 3.7 μm to 0.4 μm.

  12. Environmental surveillance at Los Alamos during 1984

    International Nuclear Information System (INIS)

    1985-04-01

    This report describes the environmental surveillance program conducted by the Los Alamos National Laboratory during 1984. Routine monitoring for radiation and radioactive or chemical substances is conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of data for 1984 are included on external penetrating radiation; on the chemical and radiochemical quality of ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and on the quantities of airborne emissions and liquid effluents. Comparisons with appropriate standards, regulations, and background levels from natural or other non-Laboratory sources provide a basis for concluding that environmental effects attributable to Laboratory operations are insignificant and are not considered hazardous to the population of the area or Laboratory employees. 8 refs., 38 figs., 57 tabs

  13. Environmental surveillance at Los Alamos during 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-05-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1987. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1987 cover: external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are insignificant and do not pose a threat to the public, Laboratory employees, or the environment. 113 refs., 33 figs., 120 tabs.

  14. Environmental surveillance at Los Alamos during 1985

    International Nuclear Information System (INIS)

    1986-04-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1985. Routine monitoring for radiation and radioactive or chemical substances is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of possible undesirable trends. Results and interpretation of data for 1985 cover: external penetrating radiation; chemical and radiochemical quality of ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; quantities of airborne emissions and liquid effluents; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels from natural or other non-Laboratory sources provide the basis for concluding that environmental effects attributable to Laboratory operations are insignificant and are not considered hazardous to the population of the area or Laboratory employees

  15. Environmental surveillance at Los Alamos during 1986

    International Nuclear Information System (INIS)

    1987-04-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1986. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit eartly identification of potentially undesirable trends. Results and interpertation of data for 1986 cover: external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparison with appropriate standards, regulations, and backgound levels provide the basis for concluding that environmental effects from Laboratory operations are insignificant and do not impact the public, Laboratory employees, or the environment. 52 refs., 32 figs., 117 tabs

  16. Environmental surveillance at Los Alamos during 1989

    International Nuclear Information System (INIS)

    1990-12-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1989. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1989 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment. 58 refs., 31 figs., 39 tabs

  17. Environmental surveillance at Los Alamos during 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1989. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1989 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment. 58 refs., 31 figs., 39 tabs.

  18. Environmental surveillance at Los Alamos during 1995

    International Nuclear Information System (INIS)

    1996-10-01

    This report describes the environmental surveillance program at Los Alamos National Laboratory (LANL or the Laboratory) during 1995. The Laboratory routinely monitors for radiation and for radioactive and nonradioactive materials at (or on) Laboratory sites as well as in the surrounding region. LANL uses the monitoring result to determine compliance with appropriate standards and to identify potentially undesirable trends. Data were collected in 1995 to assess external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Using comparisons with standards, regulations, and background levels, this report concludes that environmental effects from Laboratory operations are small and do not pose a demonstrable threat to the public, Laboratory employees, or the environment

  19. Los Alamos Plutonium Facility Waste Management System

    International Nuclear Information System (INIS)

    Smith, K.; Montoya, A.; Wieneke, R.; Wulff, D.; Smith, C.; Gruetzmacher, K.

    1997-01-01

    This paper describes the new computer-based transuranic (TRU) Waste Management System (WMS) being implemented at the Plutonium Facility at Los Alamos National Laboratory (LANL). The Waste Management System is a distributed computer processing system stored in a Sybase database and accessed by a graphical user interface (GUI) written in Omnis7. It resides on the local area network at the Plutonium Facility and is accessible by authorized TRU waste originators, count room personnel, radiation protection technicians (RPTs), quality assurance personnel, and waste management personnel for data input and verification. Future goals include bringing outside groups like the LANL Waste Management Facility on-line to participate in this streamlined system. The WMS is changing the TRU paper trail into a computer trail, saving time and eliminating errors and inconsistencies in the process

  20. Environmental surveillance at Los Alamos during 1983

    International Nuclear Information System (INIS)

    1984-04-01

    This report documents the environmental surveillance program conducted by the Los Alamos National Laboratory during 1983. Routine monitoring for radiation and radioactive or chemical substances is conducted on the Laboratory site and in the surrounding region to determine compliance with appropriate standards and permit early identification of possible undesirable trends. Results and interpretation of data for 1983 are included on external penetrating radiation; on the chemical and radiochemical quality of ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and on the quantities of airborne emissions and liquid effluents. Comparisons with appropriate standards, regulations, and background levels from natural or other non-Laboratory sources provide a basis for concluding that environmental effects attributable to Laboratory operations are insignificant and are not considered hazardous to the population of the area of Laboratory employees. 61 references, 34 figures, 22 tables

  1. Environmental surveillance at Los Alamos during 1987

    International Nuclear Information System (INIS)

    1988-05-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1987. Routine monitoring for radiation and radioactive or chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1987 cover: external penetrating radiation; quantities of airborne emissions and liquid effluents; concentrations of chemicals and radionuclides in ambient air, surface and ground waters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are insignificant and do not pose a threat to the public, Laboratory employees, or the environment. 113 refs., 33 figs., 120 tabs

  2. Environmental surveillance at Los Alamos during 1991

    International Nuclear Information System (INIS)

    Dewart, J.; Kohen, K.L.

    1993-08-01

    This report describes the environmental surveillance program conducted by Los Alamos National Laboratory during 1991. Routine monitoring for radiation and for radioactive and chemical materials is conducted on the Laboratory site as well as in the surrounding region. Monitoring results are used to determine compliance with appropriate standards and to permit early identification of potentially undesirable trends. Results and interpretation of data for 1991 cover external penetrating radiation; quantities of airborne emissions and effluents; concentrations of chemicals and radionuclides in ambient air, surface waters and groundwaters, municipal water supply, soils and sediments, and foodstuffs; and environmental compliance. Comparisons with appropriate standards, regulations, and background levels provide the basis for concluding that environmental effects from Laboratory operations are small and do not pose a threat to the public, Laboratory employees, or the environment

  3. Critical Experiments With Aqueous Solutions of {sup 233}UO{sub 2}(NO{sub ;3}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J T

    2001-05-17

    This report provides the critical experimenter's interpretations and descriptions of informal critical experiment logbook notes and associated information (e.g., experimental equipment designs/sketches, chemical and isotopic analyses, etc.) for the purpose of formally documenting the results of critical experiments performed in the late 1960s at the Oak Ridge Critical Experiments Facility. The experiments were conducted with aqueous solutions of 97.6 wt % {sup 233}U uranyl nitrate having uranium densities varying between about 346 g U/l and 45 g U/l. Criticality was achieved with single simple units (e.g., cylinders and spheres) and with spaced subcritical simple cylindrical units arranged in unreflected, water-reflected, and polyethylene reflected critical arrays.

  4. Critical Experiments With Aqueous Solutions of {sup 233}UO{sub 2}(NO{sub 3}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.T.

    2001-05-17

    This report provides the critical experimenter's interpretations and descriptions of informal critical experiment logbook notes and associated information (e.g., experimental equipment designs/sketches, chemical and isotopic analyses, etc.) for the purpose of formally documenting the results of critical experiments performed in the late 1960s at the Oak Ridge Critical Experiments Facility. The experiments were conducted with aqueous solutions of 97.6 wt % {sup 233}U uranyl nitrate having uranium densities varying between about 346 g U/l and 45 g U/l. Criticality was achieved with single simple units (e.g., cylinders and spheres) and with spaced subcritical simple cylindrical units arranged in unreflected, water-reflected, and polyethylene reflected critical arrays.

  5. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative

  6. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

  7. Environmental surveillance at Los Alamos during 2005

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (LANL or the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.IA, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory's efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory's major environmental programs. Chapter 2 reports the Laboratory's compliance status for 2005. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, Air; Chapters 5 and 6, Water and Sediments; Chapter 7, Soils; and Chapter 8, Foodstuffs and Biota) in a format to meet the needs of a general and scientific audience. Chapter 9, new for this year, provides a summary of the status of environmental restoration work around LANL. A glossary and a list ofacronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory's technical areas and their associated programs, and Appendix D provides web links to more information.

  8. Environmental surveillance at Los Alamos during 2008

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gallagher, Pat [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hjeresen, Denny [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Isaacson, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johson, Scot [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morgan, Terry [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Paulson, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rogers, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2009-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Programs Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information.

  9. Environmental surveillance at Los Alamos during 2009

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poff, Ben [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hjeresen, Denny [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Isaacson, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johnson, Scot [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morgan, Terry [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Paulson, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Salzman, Sonja [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rogers, David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2010-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) environmental organization, as required by US Department of Energy Order 5400.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2009. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (air in Chapter 4; water and sediments in Chapters 5 and 6; soils in Chapter 7; and foodstuffs and biota in Chapter 8) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. The new Chapter 10 describes the Laboratory’s environmental stewardship efforts and provides an overview of the health of the Rio Grande. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the Laboratory’s technical

  10. Nurturing a lexical legacy: reading experience is critical for the development of word reading skill

    Science.gov (United States)

    Nation, Kate

    2017-12-01

    The scientific study of reading has taught us much about the beginnings of reading in childhood, with clear evidence that the gateway to reading opens when children are able to decode, or `sound out' written words. Similarly, there is a large evidence base charting the cognitive processes that characterise skilled word recognition in adults. Less understood is how children develop word reading expertise. Once basic reading skills are in place, what factors are critical for children to move from novice to expert? This paper outlines the role of reading experience in this transition. Encountering individual words in text provides opportunities for children to refine their knowledge about how spelling represents spoken language. Alongside this, however, reading experience provides much more than repeated exposure to individual words in isolation. According to the lexical legacy perspective, outlined in this paper, experiencing words in diverse and meaningful language environments is critical for the development of word reading skill. At its heart is the idea that reading provides exposure to words in many different contexts, episodes and experiences which, over time, sum to a rich and nuanced database about their lexical history within an individual's experience. These rich and diverse encounters bring about local variation at the word level: a lexical legacy that is measurable during word reading behaviour, even in skilled adults.

  11. Arid-site SLB technology development at the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    DePoorter, G.L.

    1981-01-01

    The program goal for shallow land burial (SLB) Technology Development at the Los Alamos National Laboratory is to field test new disposal concepts and strategies for all aspects of arid SLB on an accelerated basis and on a reasonable scale. The major accomplishments during FY-1981 were the development of the Los Alamos Experimental Engineered Test Facility, the emplacement of the biointrusion barrier testing experiments, the design and emplacement of the moisture cycling experiments, the design and construction of the experiment clusters, and the planning for the experiments to be emplaced in these units. This paper will describe the site development work, the design and construction of the experiment clusters, and the experiments planned for these units. The experimental Engineered Test Facility was brought from idea to reality and two experiments were emplaced (biointrusion barrier and moisture cycling). The experiment clusters were designed and constructed, and are now available for experimentation. These units are reusable. After an experiment is complete it can be removed and another experiment put in its place. Several of the experiments were planned and designed while some of the other experiments are still in the planning stage. Based on the work done in FY-1981, significant progress toward Milestones, C, D, and E should be made in FY-1982

  12. Los Alamos High-Brightness Accelerator FEL (HIBAF) facility

    Energy Technology Data Exchange (ETDEWEB)

    Cornelius, W.D.; Bender, S.; Meier, K.; Thode, L.E.; Watson, J.M.

    1989-01-01

    The 10-/mu/m Los Alamos free-electron laser (FEL) facility is being upgraded. The conventional electron gun and bunchers have been replaced with a much more compact 6-MeV photoinjector accelerator. By adding existing parts from previous experiments, the primary beam energy will be doubled to 40 MeV. With the existing 1-m wiggler (/lambda//sub w/ = 2.7 cm) and resonator, the facility can produce photons with wavelengths from 3 to 100 /mu/m when lasing on the fundamental mode and produce photons in the visible spectrum with short-period wigglers or harmonic operation. After installation of a 150/degree/ bend, a second wiggler will be added as an amplifier. The installation of laser transport tubes between the accelerator vault and an upstairs laboratory will provide experimenters with a radiation-free environment for experiments. Although the initial experimental program of the upgraded facility will be to test the single accelerator-master oscillator/power amplifier configuration, some portion of the operational time of the facility can be dedicated to user experiments. 13 refs., 5 figs., 6 tabs.

  13. Survey of Canadian critical care nurses' experiences of conflict in intensive care units.

    Science.gov (United States)

    Edwards, Marie; Throndson, Karen; Girardin, Julie

    2012-01-01

    The purpose of this study was to enhance our understanding of Canadian critical care nurses' experiences of and responses to situations of conflict in the ICU. Through a 35-item web-based survey, members of the Canadian Association of Critical Care Nurses were asked questions regarding the types, causes and frequency of conflict experienced, the nursing interventions found most helpful in situations of conflict, and the resources found most helpful in responding to situations of conflict. A total of 241 nurses responded to the survey. The mean age of the nurses was 43 years, and the majority were female (89.2%), direct care providers (66.4%), with greater than 11 years of experience in critical care (58.3%), and working in medical/surgical ICUs (66.4%) in tertiary care hospitals (67.2%). Approximately 51% of the nurses reported being involved in at least one situation of conflict related to the management of a patient in the last week worked. The most common types of conflict encountered were disagreements between the team and family (46.5%) or within the team (35.3%). The nurses acknowledged the importance of clear, consistent and honest communication with patients and families when conflict arises and rank-ordered the resources found most helpful to patients, families, and nurses in conflict situations. Implications for practice and education are discussed and recommendations for future research are outlined.

  14. Lessons learned from applying VIM to fast reactor critical experiments, summary

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, R.W.; McKnight, R.D.; Collins, P.J.

    1995-05-17

    VIM is a continuous energy Monte Carlo code first developed around 1970 for the analysis of plate-type, fast-neutron, zero-power critical assemblies. In most respects, VIM is functionally equivalent to the MCNP code but it has two features that make uniquely suited to the analysis of fast reactor critical experiments: (1) the place lattice geometry option, which allows efficient description of and neutron tracking in the assembly geometry, and (2) a statistical treatment of neutron cross section data in the unresolved resonance range. Since its inception, VIM`s capabilities have expanded to include numerous features, such as thermal neutron cross sections, photon cross sections, and combinatorial and other geometry options, that have allowed its use in a wide range of neutral-particle transport problems. The earliest validation work at Argonne National Laboratory (ANL) focused on the validation of VIM itself. This work showed that, in order for VIM to be a ``rigomus`` tool, extreme detail in the pointwise Monte Carlo libraries was needed, and the required detail was added. The emphasis soon shifted to validating models, methods, data and codes against VIM. Most of this work was done in the context of analyzing critical experiments in zero power reactor (ZPR) assemblies. The purpose of this paper is to present some of the lessons learned from using VIM in ZPR analysis work.

  15. Critical power experiment with a tight-lattice 37-rod bundle

    International Nuclear Information System (INIS)

    Kureta, Masatoshi; Tamai, Hidesada; Ohnuki, Akira; Sato, Takashi; Liu, Wei; Akimoto, Hajime

    2006-01-01

    Since most of critical power or CHF data have been collected in tube, annulus, or BWR geometries under BWR flow conditions, critical power data for highly tight and triangular lattice bundles under low mass velocity are indispensable for thermal-hydraulic design of Reduced-Moderation Water Reactor. Large-scale thermal-hydraulic experiments which use a basic 37-rod bundle test section (rod diameter: 13.0 mm, gap width between rods: 1.3 mm) were therefore carried out in this study within range of 2-9 MPa in pressure and 150-1,000 kg/(m 2 ·s) in mass velocity. Fundamental characteristics of boiling transition were investigated through effects of flow parameter on critical power and those of rod number. It was confirmed that the fundamental characteristics in 37-rod bundle are similar to those in 7-rod bundle and in case of the BWR geometry. The results of the transverse non-uniform power distribution test and subchannel analysis suggest that the critical power becomes higher when the transverse local quality distribution closes to uniform. (author)

  16. From idealistic helper to enterprising learner: critical reflections on personal development through experiences from Afghanistan.

    Science.gov (United States)

    Wickford, Jenny; Rosberg, Susanne

    2012-05-01

    There is little written about the cultural, social, and ethical challenges encountered by physiotherapists engaging in development work. This article takes a critical perspective on what it means to engage in development work as an expatriate physiotherapist, through a self-critical reflection on experiences from Afghanistan. The field notes from an ethnographic study of a development project conducted in Afghanistan were analysed to explore the transformative process of personal and professional development of the development worker. The critical reflective process entailed a change in meaning perspective, described as a shift from the position of an Idealistic Helper to an Enterprising Learner. Of importance in this process were "disorienting dilemmas" that challenged personal perceptions. Critical reflection over such dilemmas led to deeper understanding facilitating the process of change. The essential lesson learned is that the baseline for understanding others is an understanding of one's own meaning perspectives and manner of participation in relation to others and their context. The insights gained have implications for physiotherapists working in development contexts, for other development workers, and for physiotherapists working with patients in clinical practice in a nondevelopment context. Exploring how to collaborate in development contexts could be done using reflective groups with expatriate and local physiotherapists and/or patients. This could lead to greater understanding of oneself, each other, and the local context.

  17. Evaluation of undergraduate clinical learning experiences in the subject of pediatric dentistry using critical incident technique

    Directory of Open Access Journals (Sweden)

    S Vyawahare

    2013-01-01

    Full Text Available Introduction: In pediatric dentistry, the experiences of dental students may help dental educators better prepare graduates to treat the children. Research suggests that student′s perceptions should be considered in any discussion of their education, but there has been no systematic examination of India′s undergraduate dental students learning experiences. Aim: This qualitative investigation aimed to gather and analyze information about experiences in pediatric dentistry from the students′ viewpoint using critical incident technique (CIT. Study Design: The sample group for this investigation came from all 240 3 rd and 4 th year dental students from all the four dental colleges in Indore. Using CIT, participants were asked to describe at least one positive and one negative experience in detail. Results: They described 308 positive and 359 negative experiences related to the pediatric dentistry clinic. Analysis of the data resulted in the identification of four key factors related to their experiences: 1 The instructor; 2 the patient; 3 the learning process; and 4 the learning environment. Conclusion: The CIT is a useful data collection and analysis technique that provides rich, useful data and has many potential uses in dental education.

  18. Evaluation of undergraduate clinical learning experiences in the subject of pediatric dentistry using critical incident technique.

    Science.gov (United States)

    Vyawahare, S; Banda, N R; Choubey, S; Parvekar, P; Barodiya, A; Dutta, S

    2013-01-01

    In pediatric dentistry, the experiences of dental students may help dental educators better prepare graduates to treat the children. Research suggests that student's perceptions should be considered in any discussion of their education, but there has been no systematic examination of India's undergraduate dental students learning experiences. This qualitative investigation aimed to gather and analyze information about experiences in pediatric dentistry from the students' viewpoint using critical incident technique (CIT). The sample group for this investigation came from all 240 3rd and 4th year dental students from all the four dental colleges in Indore. Using CIT, participants were asked to describe at least one positive and one negative experience in detail. They described 308 positive and 359 negative experiences related to the pediatric dentistry clinic. Analysis of the data resulted in the identification of four key factors related to their experiences: 1) The instructor; 2) the patient; 3) the learning process; and 4) the learning environment. The CIT is a useful data collection and analysis technique that provides rich, useful data and has many potential uses in dental education.

  19. Resilience in Survivors of Critical Illness in the Context of the Survivors' Experience and Recovery.

    Science.gov (United States)

    Maley, Jason H; Brewster, Isabel; Mayoral, Iris; Siruckova, Renata; Adams, Sarah; McGraw, Kelley A; Piech, Angela A; Detsky, Michael; Mikkelsen, Mark E

    2016-08-01

    Post-intensive care syndrome (PICS), defined as new or worsening impairment in cognition, mental health, or physical function after critical illness, is an important development in survivors. Although studies to date have focused on the frequency of these impairments, fundamental questions remain unanswered regarding the survivor experience and the impact of the critical illness event on survivor resilience and recovery. To examine the association between resilience and neuropsychological and physical function and to contextualize these findings within the survivors' recovery experience. We conducted a mixed-methods pilot investigation of resilience among 43 survivors from two medical intensive care units (ICUs) within an academic health-care system. We interviewed survivors to identify barriers to and facilitators of recovery in the ICU, on the medical ward, and at home, using qualitative methods. We used a telephone battery of standardized tests to examine resilience, neuropsychological and physical function, and quality of life. We examined PICS in two ways. First, we identified how frequently survivors were impaired in one or more domains 6-12 months postdischarge. Second, we identified how frequently survivors reported that neuropsychological or physical function was worse. Resilience was low in 28% of survivors, normal in 63% of survivors, and high in 9% of survivors. Resilience was inversely correlated with self-reported executive dysfunction, symptoms of anxiety, depression, and post-traumatic stress disorder, difficulty with self-care, and pain (P critical illness. We identified challenges along the recovery path of ICU survivors, finding that physical limitations and functional dependence were the most frequent challenges experienced in the ICU, medical ward, and on return to home. Spiritual and family support facilitated recovery. Resilience was inversely correlated with neuropsychological impairment, pain, and difficulty with self-care. PICS was

  20. NARCISS critical stand experiments for studying the nuclear safety in accident water immersion of highly enriched uranium dioxide fuel elements

    International Nuclear Information System (INIS)

    Ponomarev-Stepnoj, N.N.; Glushkov, E.S.; Bubelev, V.G.

    2005-01-01

    A brief description of the Topaz-2 SNPS designed under scientific supervision of RRC KI in Russia, and of the NARCISS critical facility, is given. At the NARCISS critical facility, neutronic peculiarities and nuclear safety issues of the Topaz-2 system reactor were studied experimentally. This work is devoted to a detailed description of experiments on investigation of criticality safety in accident water immersion og highly enriched uranium dioxide fuel elements, performed at the NARCISS facility. The experiments were carried out at water-moderated critical assemblies with varying height, number, and spacing of fuel elements. The results obtained in the critical experiments, computational models of the investigated critical configurations, and comparison of the computational and experimental results are given [ru

  1. Critical experiments on single-unit spherical plutonium geometries reflected and moderated by oil

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, R.E.

    1997-05-01

    Experimental critical configurations are reported for several dozen spherical and hemispherical single-unit assemblies of plutonium metal. Most were solid but many were hollow-centered, thick, shell-like geometries. All were constructed of nested plutonium (mostly {sup 2139}Pu) metal hemispherical shells. Three kinds of critical configurations are reported. Two required interpolation and/or extrapolation of data to obtain the critical mass because reflector conditions were essentially infinite. The first finds the plutonium essentially fully reflected by a hydrogen-rich oil; the second is essentially unreflected. The third kind reports the critical oil reflector height above a large plutonium metal assembly of accurately known mass (no interpolation required) when that mass was too great to permit full oil reflection. Some configurations had thicknesses of mild steel just outside the plutonium metal, separating it from the oil. These experiments were performed at the Rocky Flats Critical Mass Laboratory in the late 1960s. They have not been published in a form suitable for benchmark-quality comparisons against state-of-the-art computational techniques until this paper. The age of the data and other factors lead to some difficulty in reconstructing aspects of the program and may, in turn, decrease confidence in certain details. Whenever this is true, the point is acknowledged. The plutonium metal was alpha-phase {sup 239}Pu containing 5.9 wt-% {sup 240}Pu. All assemblies were formed by nesting 1.667-mm-thick (nominal) bare plutonium metal hemispherical shells, also called hemishells, until the desired configuration was achieved. Very small tolerance gaps machined into radial dimensions reduced the effective density a small amount in all cases. Steel components were also nested hemispherical shells; but these were nominally 3.333-mm thick. Oil was used as the reflector because of its chemical compatibility with plutonium metal.

  2. Critical experiments on single-unit spherical plutonium geometries reflected and moderated by oil

    International Nuclear Information System (INIS)

    Rothe, R.E.

    1997-05-01

    Experimental critical configurations are reported for several dozen spherical and hemispherical single-unit assemblies of plutonium metal. Most were solid but many were hollow-centered, thick, shell-like geometries. All were constructed of nested plutonium (mostly 2139 Pu) metal hemispherical shells. Three kinds of critical configurations are reported. Two required interpolation and/or extrapolation of data to obtain the critical mass because reflector conditions were essentially infinite. The first finds the plutonium essentially fully reflected by a hydrogen-rich oil; the second is essentially unreflected. The third kind reports the critical oil reflector height above a large plutonium metal assembly of accurately known mass (no interpolation required) when that mass was too great to permit full oil reflection. Some configurations had thicknesses of mild steel just outside the plutonium metal, separating it from the oil. These experiments were performed at the Rocky Flats Critical Mass Laboratory in the late 1960s. They have not been published in a form suitable for benchmark-quality comparisons against state-of-the-art computational techniques until this paper. The age of the data and other factors lead to some difficulty in reconstructing aspects of the program and may, in turn, decrease confidence in certain details. Whenever this is true, the point is acknowledged. The plutonium metal was alpha-phase 239 Pu containing 5.9 wt-% 240 Pu. All assemblies were formed by nesting 1.667-mm-thick (nominal) bare plutonium metal hemispherical shells, also called hemishells, until the desired configuration was achieved. Very small tolerance gaps machined into radial dimensions reduced the effective density a small amount in all cases. Steel components were also nested hemispherical shells; but these were nominally 3.333-mm thick. Oil was used as the reflector because of its chemical compatibility with plutonium metal

  3. Integrating Safety with Science,Technology and Innovation at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rich, Bethany M [Los Alamos National Laboratory

    2012-04-02

    The mission of Los Alamos National Laboratory (LANL) is to develop and apply science, technology and engineering solutions to ensure the safety, security, and reliability of the U.S. nuclear deterrent; reduce global threats; and solve emerging national security challenges. The most important responsibility is to direct and conduct efforts to meet the mission with an emphasis on safety, security, and quality. In this article, LANL Environmental, Safety, and Health (ESH) trainers discuss how their application and use of a kinetic learning module (learn by doing) with a unique fall arrest system is helping to address one the most common industrial safety challenges: slips and falls. A unique integration of Human Performance Improvement (HPI), Behavior Based Safety (BBS) and elements of the Voluntary Protection Program (VPP) combined with an interactive simulator experience is being used to address slip and fall events at Los Alamos.

  4. Generation of integral experiment covariance data and their impact on criticality safety validation

    Energy Technology Data Exchange (ETDEWEB)

    Stuke, Maik; Peters, Elisabeth; Sommer, Fabian

    2016-11-15

    The quantification of statistical dependencies in data of critical experiments and how to account for them properly in validation procedures has been discussed in the literature by various groups. However, these subjects are still an active topic in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECDNEA Nuclear Science Committee. The latter compiles and publishes the freely available experimental data collection, the International Handbook of Evaluated Criticality Safety Benchmark Experiments, ICSBEP. Most of the experiments were performed as series and share parts of experimental setups, consequently leading to correlation effects in the results. The correct consideration of correlated data seems to be inevitable if the experimental data in a validation procedure is limited or one cannot rely on a sufficient number of uncorrelated data sets, e.g. from different laboratories using different setups. The general determination of correlations and the underlying covariance data as well as the consideration of them in a validation procedure is the focus of the following work. We discuss and demonstrate possible effects on calculated k{sub eff}'s, their uncertainties, and the corresponding covariance matrices due to interpretation of evaluated experimental data and its translation into calculation models. The work shows effects of various modeling approaches, varying distribution functions of parameters and compares and discusses results from the applied Monte-Carlo sampling method with available data on correlations. Our findings indicate that for the reliable determination of integral experimental covariance matrices or the correlation coefficients a detailed study of the underlying experimental data, the modeling approach and assumptions made, and the resulting sensitivity analysis seems to be inevitable. Further, a Bayesian method is discussed to include integral experimental covariance data when estimating an

  5. Generation of integral experiment covariance data and their impact on criticality safety validation

    International Nuclear Information System (INIS)

    Stuke, Maik; Peters, Elisabeth; Sommer, Fabian

    2016-11-01

    The quantification of statistical dependencies in data of critical experiments and how to account for them properly in validation procedures has been discussed in the literature by various groups. However, these subjects are still an active topic in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECDNEA Nuclear Science Committee. The latter compiles and publishes the freely available experimental data collection, the International Handbook of Evaluated Criticality Safety Benchmark Experiments, ICSBEP. Most of the experiments were performed as series and share parts of experimental setups, consequently leading to correlation effects in the results. The correct consideration of correlated data seems to be inevitable if the experimental data in a validation procedure is limited or one cannot rely on a sufficient number of uncorrelated data sets, e.g. from different laboratories using different setups. The general determination of correlations and the underlying covariance data as well as the consideration of them in a validation procedure is the focus of the following work. We discuss and demonstrate possible effects on calculated k eff 's, their uncertainties, and the corresponding covariance matrices due to interpretation of evaluated experimental data and its translation into calculation models. The work shows effects of various modeling approaches, varying distribution functions of parameters and compares and discusses results from the applied Monte-Carlo sampling method with available data on correlations. Our findings indicate that for the reliable determination of integral experimental covariance matrices or the correlation coefficients a detailed study of the underlying experimental data, the modeling approach and assumptions made, and the resulting sensitivity analysis seems to be inevitable. Further, a Bayesian method is discussed to include integral experimental covariance data when estimating an application

  6. Critical fields and growth rates of the Tayler instability as probed by a columnar gallium experiment

    OpenAIRE

    Ruediger, Guenther; Gellert, Marcus; Schultz, Manfred; Strassmeier, Klaus G.; Stefani, Frank; Gundrum, Thomas; Seilmayer, Martin; Gerbeth, Gunter

    2012-01-01

    Many astrophysical phenomena (such as the slow rotation of neutron stars or the rigid rotation of the solar core) can be explained by the action of the Tayler instability of toroidal magnetic fields in the radiative zones of stars. In order to place the theory of this instability on a safe fundament it has been realized in a laboratory experiment measuring the critical field strength, the growth rates as well as the shape of the supercritical modes. A strong electrical current flows through a...

  7. Verification of calculational methods for light water high converter reactors by critical experiments

    International Nuclear Information System (INIS)

    Berger, H.D.

    1988-01-01

    Calculational results relevant to the physics characteristics of PuO 2 /UO 2 -fueled light water high converter reactors (LWHCR) are discussed in the context of three particular codes and their associated data libraries, viz. WIMS/D, KARBUS (GRUCAH) and SPEKTRA. Analysis of various critical experiments - from the PROTEUS-LWHCR Phase I and Phase II programmes in particular - has demonstrated the importance of having a representative and comprehensive integral data base for identifying specific shortcomings in the calculational tools employed. (orig./DG)

  8. Critical experiments supporting underwater storage of tightly packed configurations of spent fuel rods

    International Nuclear Information System (INIS)

    Hoovler, G.S.; Baldwin, M.N.

    1981-04-01

    Criticla arrays of 2.5%-enriched UO 2 fuel rods that simulate underwater rod storage of spent power reactor fuel are being constructed. Rod storage is a term used to describe a spent fuel storage concept in which the fuel bundles are disassembled and the rods are packed into specially designed cannisters. Rod storage would substantially increase the amount of fuel that could be stored in available space. These experiments are providing criticality data against which to benchmark nuclear codes used to design tightly packed rod storage racks

  9. Acoustic Experiment to Measure the Bulk Viscosity of Near-Critical Xenon in Microgravity

    Science.gov (United States)

    Gillis, K. A.; Shinder, I.; Moldover, M. R.; Zimmerli, G. A.

    2002-01-01

    We plan a rigorous test of the theory of dynamic scaling by accurately measuring the bulk viscosity of xenon in microgravity 50 times closer to the critical temperature T(sub c) than previous experiments. The bulk viscosity zeta (or "second viscosity" or "dilational viscosity") will be determined by measuring the attenuation length of sound alpha lambda and also measuring the frequency-dependence of the speed of sound. For these measurements, we developed a unique Helmholtz resonator and specialized electro-acoustic transducers. We describe the resonator, the transducers, their performance on Earth, and their expected performance in microgravity.

  10. The Qualification Experiences for Safety-critical Software of POSAFE-Q

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Yeol; Son, Kwang Seop; Cheon, Se Woo; Lee, Jang Soo; Kwon, Kee Choon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    Programmable Logic Controllers (PLC) have been applied to the Reactor Protection System (RPS) and the Engineered Safety Feature (ESF)-Component Control System (CCS) as the major safety system components of nuclear power plants. This paper describes experiences on the qualification of the safety-critical software including the pCOS kernel and system tasks related to a safety-grade PLC, i.e. the works done for the Software Verification and Validation, Software Safety Analysis, Software Quality Assurance, and Software Configuration Management etc.

  11. Analysis of a boron-carbide-drum-controlled critical reactor experiment

    Science.gov (United States)

    Mayo, W. T.

    1972-01-01

    In order to validate methods and cross sections used in the neutronic design of compact fast-spectrum reactors for generating electric power in space, an analysis of a boron-carbide-drum-controlled critical reactor was made. For this reactor the transport analysis gave generally satisfactory results. The calculated multiplication factor for the most detailed calculation was only 0.7-percent Delta k too high. Calculated reactivity worth of the control drums was $11.61 compared to measurements of $11.58 by the inverse kinetics methods and $11.98 by the inverse counting method. Calculated radial and axial power distributions were in good agreement with experiment.

  12. Space, the final frontier: A critical review of recent experiments performed in microgravity.

    Science.gov (United States)

    Vandenbrink, Joshua P; Kiss, John Z

    2016-02-01

    Space biology provides an opportunity to study plant physiology and development in a unique microgravity environment. Recent space studies with plants have provided interesting insights into plant biology, including discovering that plants can grow seed-to-seed in microgravity, as well as identifying novel responses to light. However, spaceflight experiments are not without their challenges, including limited space, limited access, and stressors such as lack of convection and cosmic radiation. Therefore, it is important to design experiments in a way to maximize the scientific return from research conducted on orbiting platforms such as the International Space Station. Here, we provide a critical review of recent spaceflight experiments and suggest ways in which future experiments can be designed to improve the value and applicability of the results generated. These potential improvements include: utilizing in-flight controls to delineate microgravity versus other spaceflight effects, increasing scientific return via next-generation sequencing technologies, and utilizing multiple genotypes to ensure results are not unique to one genetic background. Space experiments have given us new insights into plant biology. However, to move forward, special care should be given to maximize science return in understanding both microgravity itself as well as the combinatorial effects of living in space. Copyright © 2015. Published by Elsevier Ireland Ltd.

  13. Sandbox rheometry: Co-evolution of stress and strain in Riedel- and Critical Wedge-experiments

    Science.gov (United States)

    Ritter, Malte C.; Santimano, Tasca; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2018-01-01

    Analogue sandbox experiments have been used for a long time to understand tectonic processes, because they facilitate detailed measurements of deformation at a spatio-temporal resolution unachievable from natural data. Despite this long history, force measurements to further characterise the mechanical evolution in analogue sandbox experiments have only emerged recently. Combined continuous measurements of forces and deformation in such experiments, an approach here referred to as "sandbox rheometry", are a new tool that may help to better understand work budgets and force balances for tectonic systems and to derive constitutive laws for regional scale deformation. In this article we present an experimental device that facilitates precise measurements of boundary forces and surface deformation at high temporal and spatial resolution. We demonstrate its capabilities in two classical experiments: one of strike-slip deformation (the Riedel set-up) and one of compressional accretionary deformation (the Critical Wedge set-up). In these we are able to directly observe a correlation between strain weakening and strain localisation that had previously only been inferred, namely the coincidence of the maximum localisation rate with the onset of weakening. Additionally, we observe in the compressional experiment a hysteresis of localisation with respect to the mechanical evolution that reflects the internal structural complexity of an accretionary wedge.

  14. Handling of time-critical Conditions Data in the CMS experiment - Experience of the first year of data taking

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Data management for a wide category of non-event data plays a critical role in the operation of the CMS experiment. The processing chain (data taking-reconstruction-analysis) relies in the prompt availability of specific, time dependent data describing the state of the various detectors and their calibration parameters, which are treated separately from event data. The Condition Database system is the infrastructure established to handle these data and to make sure that they are available to both offline and online workflows. The Condition Data layout is designed such that the payload data (the Condition) is associated to an Interval Of Validity (IOV). The IOV allows accessing selectively the sets corresponding to specific intervals of time, run number or luminosity section. Both payloads and IOVs are stored in a cluster of relational database servers (Oracle) using an object-relational access approach. The strict requirements of security and isolation of the CMS online systems are imposing a redundant archit...

  15. 2015 Los Alamos Space Weather Summer School Research Reports

    International Nuclear Information System (INIS)

    Cowee, Misa; Chen, Yuxi; Desai, Ravindra; Hassan, Ehab; Kalmoni, Nadine; Lin, Dong; Depascuale, Sebastian; Hughes, Randall Scott; Zhou, Hong

    2015-01-01

    The fifth Los Alamos Space Weather Summer School was held June 1st - July 24th, 2015, at Los Alamos National Laboratory (LANL). With renewed support from the Institute of Geophysics, Planetary Physics, and Signatures (IGPPS) and additional support from the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) Office of Science, we hosted a new class of five students from various U.S. and foreign research institutions. The summer school curriculum includes a series of structured lectures as well as mentored research and practicum opportunities. Lecture topics including general and specialized topics in the field of space weather were given by a number of researchers affiliated with LANL. Students were given the opportunity to engage in research projects through a mentored practicum experience. Each student works with one or more LANL-affiliated mentors to execute a collaborative research project, typically linked with a larger ongoing research effort at LANL and/or the student's PhD thesis research. This model provides a valuable learning experience for the student while developing the opportunity for future collaboration. This report includes a summary of the research efforts fostered and facilitated by the Space Weather Summer School. These reports should be viewed as work-in-progress as the short session typically only offers sufficient time for preliminary results. At the close of the summer school session, students present a summary of their research efforts. Titles of the papers included in this report are as follows: Full particle-in-cell (PIC) simulation of whistler wave generation, Hybrid simulations of the right-hand ion cyclotron anisotropy instability in a sub-Alfv@@nic plasma flow, A statistical ensemble for solar wind measurements, Observations and models of substorm injection dispersion patterns, Heavy ion effects on Kelvin-Helmholtz instability: hybrid study, Simulating plasmaspheric electron densities with a

  16. 2015 Los Alamos Space Weather Summer School Research Reports

    Energy Technology Data Exchange (ETDEWEB)

    Cowee, Misa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Yuxi [Univ. of Michigan, Ann Arbor, MI (United States); Desai, Ravindra [Univ. College London, Bloomsbury (United Kingdom); Hassan, Ehab [Univ. of Texas, Austin, TX (United States); Kalmoni, Nadine [Univ. College London, Bloomsbury (United Kingdom); Lin, Dong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Depascuale, Sebastian [Univ. of Iowa, Iowa City, IA (United States); Hughes, Randall Scott [Univ. of Southern California, Los Angeles, CA (United States); Zhou, Hong [Univ. of Colorado, Boulder, CO (United States)

    2015-11-24

    The fifth Los Alamos Space Weather Summer School was held June 1st - July 24th, 2015, at Los Alamos National Laboratory (LANL). With renewed support from the Institute of Geophysics, Planetary Physics, and Signatures (IGPPS) and additional support from the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) Office of Science, we hosted a new class of five students from various U.S. and foreign research institutions. The summer school curriculum includes a series of structured lectures as well as mentored research and practicum opportunities. Lecture topics including general and specialized topics in the field of space weather were given by a number of researchers affiliated with LANL. Students were given the opportunity to engage in research projects through a mentored practicum experience. Each student works with one or more LANL-affiliated mentors to execute a collaborative research project, typically linked with a larger ongoing research effort at LANL and/or the student’s PhD thesis research. This model provides a valuable learning experience for the student while developing the opportunity for future collaboration. This report includes a summary of the research efforts fostered and facilitated by the Space Weather Summer School. These reports should be viewed as work-in-progress as the short session typically only offers sufficient time for preliminary results. At the close of the summer school session, students present a summary of their research efforts. Titles of the papers included in this report are as follows: Full particle-in-cell (PIC) simulation of whistler wave generation, Hybrid simulations of the right-hand ion cyclotron anisotropy instability in a sub-Alfvénic plasma flow, A statistical ensemble for solar wind measurements, Observations and models of substorm injection dispersion patterns, Heavy ion effects on Kelvin-Helmholtz instability: hybrid study, Simulating plasmaspheric electron densities with a two

  17. The Los Alamos Neutron Science Center Spallation Neutron Sources

    Science.gov (United States)

    Nowicki, Suzanne F.; Wender, Stephen A.; Mocko, Michael

    The Los Alamos Neutron Science Center (LANSCE) provides the scientific community with intense sources of neutrons, which can be used to perform experiments supporting civilian and national security research. These measurements include nuclear physics experiments for the defense program, basic science, and the radiation effect programs. This paper focuses on the radiation effects program, which involves mostly accelerated testing of semiconductor parts. When cosmic rays strike the earth's atmosphere, they cause nuclear reactions with elements in the air and produce a wide range of energetic particles. Because neutrons are uncharged, they can reach aircraft altitudes and sea level. These neutrons are thought to be the most important threat to semiconductor devices and integrated circuits. The best way to determine the failure rate due to these neutrons is to measure the failure rate in a neutron source that has the same spectrum as those produced by cosmic rays. Los Alamos has a high-energy and a low-energy neutron source for semiconductor testing. Both are driven by the 800-MeV proton beam from the LANSCE accelerator. The high-energy neutron source at the Weapons Neutron Research (WNR) facility uses a bare target that is designed to produce fast neutrons with energies from 100 keV to almost 800 MeV. The measured neutron energy distribution from WNR is very similar to that of the cosmic-ray-induced neutrons in the atmosphere. However, the flux provided at the WNR facility is typically 5×107 times more intense than the flux of the cosmic-ray-induced neutrons. This intense neutron flux allows testing at greatly accelerated rates. An irradiation test of less than an hour is equivalent to many years of neutron exposure due to cosmic-ray neutrons. The low-energy neutron source is located at the Lujan Neutron Scattering Center. It is based on a moderated source that provides useful neutrons from subthermal energies to ∼100 keV. The characteristics of these sources, and

  18. Los Alamos loses physics archive as preprint pioneer heads east

    CERN Multimedia

    Butler, D

    2001-01-01

    The Los Alamos preprint server is to move to Cornell University. Paul Ginsparg who created the server cites a lack of enthusiasm among senior staff at LANL as a major reason for his departure (1/2 page).

  19. Lujan at Los Alamos Neutron Science Center (LANSCE)

    Data.gov (United States)

    Federal Laboratory Consortium — The Lujan Neutron Scattering Center (Lujan Center) at Los Alamos National Laboratory is an intense pulsed neutrons source operating at a power level of 80 -100 kW....

  20. Review of liquid metal heat pipe work at Los Alamos

    International Nuclear Information System (INIS)

    Reid, R.S.; Merrigan, M.A.; Sena, J.T.

    1990-01-01

    A survey of space-power related liquid metal heat pipe work at Los Alamos National Laboratory is presented. Heat pipe development at Los Alamos has been on-going since 1963. Heat pipes were initially developed for thermionic nuclear-electrical power production in space. Since then Los Alamos has developed liquid metal heat pipes for numerous applications related to high temperature systems in both the space and terrestrial environments. Some of these applications include thermionic electrical generators, thermoelectric energy conversion (both in-core and direct radiation), thermal energy storage, hypersonic vehicle leading edge cooling, and heat pipe vapor laser cells. Some of the work performed at Los Alamos has been documented in internal reports that are often little-known. A representative description and summary of progress in space-related liquid metal heat pipe technology is provided followed by a reference section citing sources where these works may be found. 53 refs

  1. Environmental Surveillance at Los Alamos during 2007

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-09-30

    Environmental Surveillance at Los Alamos reports are prepared annually by the Los Alamos National Laboratory (the Laboratory) Environmental Directorate, as required by US Department of Energy Order 450.1, General Environmental Protection Program, and US Department of Energy Order 231.1A, Environment, Safety, and Health Reporting. These annual reports summarize environmental data that are used to determine compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and departmental policies. Additional data, beyond the minimum required, are also gathered and reported as part of the Laboratory’s efforts to ensure public safety and to monitor environmental quality at and near the Laboratory. Chapter 1 provides an overview of the Laboratory’s major environmental programs and explains the risks and the actions taken to reduce risks at the Laboratory from environmental legacies and waste management operations. Chapter 2 reports the Laboratory’s compliance status for 2007. Chapter 3 provides a summary of the maximum radiological dose the public and biota populations could have potentially received from Laboratory operations and discusses chemical exposures. The environmental surveillance and monitoring data are organized by environmental media (Chapter 4, air; Chapters 5 and 6, water and sediments; Chapter 7, soils; and Chapter 8, foodstuffs and biota) in a format to meet the needs of a general and scientific audience. Chapter 9 provides a summary of the status of environmental restoration work around LANL. A glossary and a list of acronyms and abbreviations are in the back of the report. Appendix A explains the standards for environmental contaminants, Appendix B explains the units of measurements used in this report, Appendix C describes the laboratory’s technical areas and their associated programs, and Appendix D provides web links to more information. In printed copies of this report or Executive Summary, we have

  2. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    International Nuclear Information System (INIS)

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations

  3. Mothers and Fathers Experience Stress of Congenital Heart Disease Differently: Recommendations for Pediatric Critical Care.

    Science.gov (United States)

    Sood, Erica; Karpyn, Allison; Demianczyk, Abigail C; Ryan, Jennie; Delaplane, Emily A; Neely, Trent; Frazier, Aisha H; Kazak, Anne E

    2018-03-10

    To inform pediatric critical care practice by examining how mothers and fathers experience the stress of caring for a young child with congenital heart disease and use hospital and community supports. Qualitative study of mothers and fathers of young children with congenital heart disease. Tertiary care pediatric hospital in the Mid-Atlantic region of the United States. Thirty-four parents (20 mothers, 14 fathers) from diverse backgrounds whose child previously underwent cardiac surgery during infancy. Subjects participated in semi-structured, individual interviews about their experiences and psychosocial needs at the time of congenital heart disease diagnosis, surgical admission, and discharge to home after surgery. Qualitative interview data were coded, and consistent themes related to emotional states, stressors, and supports were identified. Fathers experience and respond to the stressors and demands of congenital heart disease in unique ways. Fathers often described stress from not being able to protect their child from congenital heart disease and the associated surgeries/pain and from difficulties balancing employment with support for their partner and care of their congenital heart disease child in the hospital. Fathers were more likely than mothers to discuss support from the work environment (coworkers/managers, flexible scheduling, helpful distraction) and were less likely to describe the use of hospital-based resources or congenital heart disease peer-to-peer supports. This study highlights the importance of understanding the paternal experience and tailoring interventions to the unique needs of both mothers and fathers. Opportunities for critical care practice change to promote the mental health of mothers and fathers following a diagnosis of congenital heart disease are discussed.

  4. Integrating Critical Pedagogy theory and practice: classroom experiences in Argentinean EFL teacher education

    Directory of Open Access Journals (Sweden)

    Zelmira Álvarez

    2012-10-01

    Full Text Available Argentinean ESL teacher education presupposes an understanding of the past and present world role of English. Thus, the curriculum of the ESL Teacher Education Program at Universidad Nacional de Mar del Plata includes subjects dealing with historical, cultural, and social questions concerning English-cultures worldwide. This paper explains how some of these issues are addressed in activities carried out in the sophomore course Overall Communication. They involve critical and postcolonial analysis of the film Slumdog millionaire (2008 and the story “The free radio” (Rushdie, 1994. Activities aim at making student-teachers aware of their need to critically address concepts related to race, ethnicity, class, religion, education, and language to unveil the political, economic, and social issues underlying the teaching and learning of English. The choice of materials and authors also aims at listening to English-speaking voices other than those stemming from (former imperial centers. Activities involve research and discussions of problematics such as oppression, exclusion, and illiteracy. This paper will analyze sample written productions by students working collaboratively among themselves and cooperatively with their teachers. In short, this is an experience that strives at showing how Critical Pedagogy can become a site for raising questions concerning power and EFL teaching and learning.

  5. The effect of leadership behaviours on followers’ experiences and expectations in a safety-critical industry

    Directory of Open Access Journals (Sweden)

    Christiaan G. Joubert

    2017-04-01

    Full Text Available Background: Motivation for this study was found in concern expressed by civil aviation organisations that specialists in the air navigation services provider sector require appropriate and beneficial organisational leadership to encourage, enable and manage transformation within this highly structured setting. Also, academic research puts emphasis on a need for investigations of the roles, expectations and requirements of followers in the leadership–followership relationship. Followers’ experiences and expectations of leadership behaviours in an air navigation service provider (ANSP organisation were investigated and served as orientation and setting applicable to this study. Aim: The aim of the research was to identify and understand how follower experiences and expectations of leadership behaviours in a safety-critical commercial environment can affect leadership training and growth. The above-mentioned motivated this investigation of leadership traits and behaviours within an explicit context and from a follower’s viewpoint. Setting: The setting for the study was twenty two Air Traffic and Navigation Services Company sites where followers’ experiences and expectations of leadership behaviours in an air navigation service provider (ANSP organisation were investigated and served as orientation and setting applicable to this study. Methods: An ethnographic case study research style was adopted and followed because it allowed for an all-inclusive, holistic narrative report and interpretation. The samples for the quantitative and qualitative components of this study were parallel and methods employed addressed different aspects of the phenomenon, which allowed for a mixed methods research design. A one-way causality in the research design was observed because traits of followers that might influence leaders’ behaviours were excluded. Data were collected by means of a Leader Trait and Behaviour Questionnaire completed by participants

  6. Critical and Exponential Experiments on 19-Rod Clusters (R3 Fuel) in Heavy Water

    Energy Technology Data Exchange (ETDEWEB)

    Persson, R.; Wikdahl, C.E.; Zadworski, Z.

    1962-03-15

    Buckling measurements on clusters of 19 UO{sub 2} rods in heavy water have been performed in an exponential assembly and by means of substitution measurements in a critical facility. The material buckling was determined as a function of lattice pitch (range of V{sub mod} /V{sub fuel}: 7-22), internal spacing, void, and temperature (20 < T < 90 deg C). The change of diffusion coefficients (about 6-8 per cent) caused by voids was studied with single test fuel assemblies. The progressive substitution measurements have been analysed by means of a modified one-group perturbation theory in combination with an unconventional cell definition. The buckling differences between test and reference lattices are of the order of -1.0 to -3.5/m{sup 2}, The results of the exponential and the critical experiments are compared with similar measurements on the same kind of fuel at the Savannah River Laboratory. This comparison shows that the results of the various experiments agree quite well, whereas theoretical predictions fail in the extreme ranges.

  7. Experience using individually supplied heater rods in critical power testing of advanced BWR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Majed, M.; Morback, G.; Wiman, P. [ABB Atom AB, Vasteras (Sweden)] [and others

    1995-09-01

    The ABB Atom FRIGG loop located in Vasteras Sweden has during the last six years given a large experience of critical power measurements for BWR fuel designs using indirectly heated rods with individual power supply. The loop was built in the sixties and designed for maximum 100 bar pressure. Testing up to the mid eighties was performed with directly heated rods using a 9 MW, 80 kA power supply. Providing test data to develop critical power correlations for BWR fuel assemblies requires testing with many radial power distributions over the full range of hydraulic conditions. Indirectly heated rods give large advantages for the testing procedure, particularly convenient for variation of individual rod power. A test method being used at Stern Laboratories (formerly Westinghouse Canada) since the early sixties, allows one fuel assembly to simulate all required radial power distributions. This technique requires reliable indirectly heated rods with independently controlled power supplies and uses insulated electric fuel rod simulators with built-in instrumentation. The FRIGG loop was adapted to this system in 1987. A 4MW power supply with 10 individual units was then installed, and has since been used for testing 24 and 25 rod bundles simulating one subbundle of SVEA-96/100 type fuel assemblies. The experience with the system is very good, as being presented, and it is selected also for a planned upgrading of the facility to 15 MW.

  8. Nursing care in a high-technological environment: Experiences of critical care nurses.

    Science.gov (United States)

    Tunlind, Adam; Granström, John; Engström, Åsa

    2015-04-01

    Management of technical equipment, such as ventilators, infusion pumps, monitors and dialysis, makes health care in an intensive care setting more complex. Technology can be defined as items, machinery and equipment that are connected to knowledge and management to maximise efficiency. Technology is not only the equipment itself, but also the knowledge of how to use it and the ability to convert it into nursing care. The aim of this study is to describe critical care nurses' experience of performing nursing care in a high technology healthcare environment. Qualitative, personal interviews were conducted during 2012 with eight critical care nurses in the northern part of Sweden. Interview transcripts were analysed using qualitative content analysis. Three themes with six categories emerged. The technology was described as a security that could facilitate nursing care, but also one that could sometimes present obstacles. The importance of using the clinical gaze was highlighted. Nursing care in a high technological environment must be seen as multi-faceted when it comes to how it affects CCNs' experience. The advanced care conducted in an ICU could not function without high-tech equipment, nor could care operate without skilled interpersonal interaction and maintenance of basal nursing. That technology is seen as a major tool and simultaneously as a barrier to patient-centred care. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Clinical accompaniment: the critical care nursing students’ experiences in a private hospital

    Directory of Open Access Journals (Sweden)

    N. Tsele

    2000-09-01

    Full Text Available The quality of clinical accompaniment of the student enrolled for the post-basic diploma in Medical and Surgical Nursing Science: Critical Care Nursing (General is an important dimension of the educational/learning programme. The clinical accompanist/mentor is responsible for ensuring the student’s compliance with the clinical outcomes of the programme in accordance with the requirements laid down by the Nursing Education Institution and the South African Nursing Council. The purpose of this study was to explore and describe the experiences of the students enrolled for a post-basic diploma in Medical and Surgical Nursing Science: Critical Care Nursing (General, in relation to the clinical accompaniment in a private hospital in Gauteng. An exploratory, descriptive and phenomenological research design was utilised and individual interviews were conducted with the ten students in the research hospital. A content analysis was conducted and the results revealed both positive and negative experiences by the students in the internal and external worlds. The recommendations include the formulation of standards for clinical accompaniment of students. the evaluation of the quality of clinical accompaniment of students and empowerment of the organisation, clinical accompanists/mentors and clinicians.

  10. Los Alamos low-level waste performance assessment status

    International Nuclear Information System (INIS)

    Wenzel, W.J.; Purtymun, W.D.; Dewart, J.M.; Rodgers, J.E.

    1986-06-01

    This report reviews the documented Los Alamos studies done to assess the containment of buried hazardous wastes. Five sections logically present the environmental studies, operational source terms, transport pathways, environmental dosimetry, and computer model development and use. This review gives a general picture of the Los Alamos solid waste disposal and liquid effluent sites and is intended for technical readers with waste management and environmental science backgrounds but without a detailed familiarization with Los Alamos. The review begins with a wide perspective on environmental studies at Los Alamos. Hydrology, geology, and meteorology are described for the site and region. The ongoing Laboratory-wide environmental surveillance and waste management environmental studies are presented. The next section describes the waste disposal sites and summarizes the current source terms for these sites. Hazardous chemical wastes and liquid effluents are also addressed by describing the sites and canyons that are impacted. The review then focuses on the transport pathways addressed mainly in reports by Healy and Formerly Utilized Sites Remedial Action Program. Once the source terms and potential transport pathways are described, the dose assessment methods are addressed. Three major studies, the waste alternatives, Hansen and Rogers, and the Pantex Environmental Impact Statement, contributed to the current Los Alamos dose assessment methodology. Finally, the current Los Alamos groundwater, surface water, and environmental assessment models for these mesa top and canyon sites are described

  11. Critical Periods after Stroke Study: Translating animal stroke recovery experiments into a clinical trial

    Directory of Open Access Journals (Sweden)

    Alexander W Dromerick

    2015-04-01

    Full Text Available Introduction: 795,000 Americans will have a stroke this year, and half will have a chronic hemiparesis. Substantial animal literature suggests that the mammalian brain has much potential to recover from acute injury using mechanisms of neuroplasticity, and that these mechanisms can be accessed using training paradigms and neurotransmitter manipulation. However, most of these findings have not been tested or confirmed in the rehabilitation setting, in large part because of the challenges in translating a conceptually straightforward laboratory experiment into a meaningful and rigorous clinical trial in humans. Through presentation of methods for a Phase II trial, we discuss these issues and describe our approach. Methods: In rodents there is compelling evidence for timing effects in rehabilitation; motor training delivered at certain times after stroke may be more effective than the same training delivered earlier or later, suggesting that there is a critical or sensitive period for strongest rehabilitation training effects. If analogous critical/sensitive periods can be identified after human stroke, then existing clinical resources can be better utilized to promote recovery. The Critical Periods after Stroke Study (CPASS is a phase II randomized, controlled trial designed to explore whether such a sensitive period exists. We will randomize 64 persons to receive an additional 20 hours of upper extremity therapy either immediately upon rehab admission, 2-3 months after stroke onset, 6 months after onset, or to an observation-only control group. The primary outcome measure will be the Action Research Arm Test at one year. Blood will be drawn at up to 3 time points for later biomarker studies. Conclusion: CPASS is an example of the translation of rodent motor recovery experiments into the clinical setting; data obtained from this single site randomized controlled trial will be used to finalize the design of a Phase III trial.

  12. Critical periods after stroke study: translating animal stroke recovery experiments into a clinical trial

    Science.gov (United States)

    Dromerick, Alexander W.; Edwardson, Matthew A.; Edwards, Dorothy F.; Giannetti, Margot L.; Barth, Jessica; Brady, Kathaleen P.; Chan, Evan; Tan, Ming T.; Tamboli, Irfan; Chia, Ruth; Orquiza, Michael; Padilla, Robert M.; Cheema, Amrita K.; Mapstone, Mark E.; Fiandaca, Massimo S.; Federoff, Howard J.; Newport, Elissa L.

    2015-01-01

    Introduction: Seven hundred ninety-five thousand Americans will have a stroke this year, and half will have a chronic hemiparesis. Substantial animal literature suggests that the mammalian brain has much potential to recover from acute injury using mechanisms of neuroplasticity, and that these mechanisms can be accessed using training paradigms and neurotransmitter manipulation. However, most of these findings have not been tested or confirmed in the rehabilitation setting, in large part because of the challenges in translating a conceptually straightforward laboratory experiment into a meaningful and rigorous clinical trial in humans. Through presentation of methods for a Phase II trial, we discuss these issues and describe our approach. Methods: In rodents there is compelling evidence for timing effects in rehabilitation; motor training delivered at certain times after stroke may be more effective than the same training delivered earlier or later, suggesting that there is a critical or sensitive period for strongest rehabilitation training effects. If analogous critical/sensitive periods can be identified after human stroke, then existing clinical resources can be better utilized to promote recovery. The Critical Periods after Stroke Study (CPASS) is a phase II randomized, controlled trial designed to explore whether such a sensitive period exists. We will randomize 64 persons to receive an additional 20 h of upper extremity therapy either immediately upon rehab admission, 2–3 months after stroke onset, 6 months after onset, or to an observation-only control group. The primary outcome measure will be the Action Research Arm Test (ARAT) at 1 year. Blood will be drawn at up to 3 time points for later biomarker studies. Conclusion: CPASS is an example of the translation of rodent motor recovery experiments into the clinical setting; data obtained from this single site randomized controlled trial will be used to finalize the design of a Phase III trial. PMID

  13. The Los Alamos high-brightness photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, P.G.

    1991-01-01

    For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven photocathode is placed directly in a high-gradient RF accelerating cavity. A photocathode allows unsurpassed control over the current, and the spatial and temporal profile of the beam. In addition the electrodeless emission'' avoids many of the difficulties associated with multi-electrode guns, i.e. the electrons are accelerated very rapidly to relativistic energies, and there are no electrodes to distort the accelerating fields. For the past two years we have been integrating a photocathode into our existing FEL facility by replacing our thermionic gun and subharmonic bunchers with a high-gradient 1.3 GHz photoinjector. The photoinjector, which is approximately 0.6 m in length, produces 6 MeV, 300 A, 15 ps linac, and accelerated to a final energy of 40 MeV. We have recently begun lasing at wavelengths near 3 {mu}m. 16 refs., 2 figs., 5 tabs.

  14. Expanded recycling at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Betschart, J.F.; Malinauskas, L.; Burns, M.

    1996-01-01

    The Pollution Prevention Program Office has increased recycling activities, reuse, and options to reduce the solid waste streams through streamlining efforts that applied best management practices. The program has prioritized efforts based on volume and economic considerations and has greatly increased Los Alamos National Laboratory's (LANL's) recycle volumes. The Pollution Prevention Program established and chairs a Solid Waste Management Solutions Group to specifically address and solve problems in nonradioactive, Resource Conservation and Recovery Act (RCRA), state-regulated, and sanitary and industrial waste streams (henceforth referred to as sanitary waste in this paper). By identifying materials with recycling potential, identifying best management practices and pathways to return materials for reuse, and introducing the concept and practice of open-quotes asset management,open-quotes the Group will divert much of the current waste stream from disposal. This Group is developing procedures, agreements, and contracts to stage, collect, sort, segregate, transport and process materials, and is also garnering support for the program through the involvement of upper management, facility managers, and generators

  15. Los Alamos KrF laser program

    International Nuclear Information System (INIS)

    Jensen, R.J.; Cartwright, D.C.

    1985-01-01

    Los Alamos is currently developing the krypton fluoride (KrF) laser - a highly efficient laser able to emit very intense bursts of short-wavelength photons - as a research tool for the general study of high-density matter, as well as for use in laser fusion. The KrF laser operates at 1/4 μm, close to the short-wavelength limit for conventional optical material, but still in the region where standard optical techniques can be used. The excited-state lifetime of the KrF lasing medium is short - as a result of both spontaneous emission and deactivation from collisions - making it impossible to store energy within the lasing medium for times significant to electrical pumping. However, an optical multiplexing scheme is being developed that will generate short, intense pulses of 1/4-μm light by overcoming the short storage time of the laser and taking advantage of the high gain of the KrF medium

  16. Los Alamos Scientific Laboratory building cost index

    International Nuclear Information System (INIS)

    Lemon, G.D.; Morris, D.W.; McConnell, P.H.

    1977-11-01

    The Controller's budget request for FY-1979 established guidance for escalation rates at 6 to 8 percent for construction projects beyond FY-1976. The Los Alamos Scientific Laboratory (LASL) has chosen to use an annual construction escalation rate of 10 percent. Results of this study should contribute toward the establishment of realistic construction cost estimate totals and estimates of annual construction funding requirements. Many methods were used to arrive at the LASL escalation rate recommendation. First, a computer program was developed which greatly expanded the number of materials previously analyzed. The program calculated the 1970 to 76 weighted averages for labor, materials, and equipment for the base line project. It also plotted graphs for each category and composite indexes for labor and material/equipment. Second, estimated increases for 1977 were obtained from several sources. The Zia Company provided labor cost estimates. Projected increases for material and equipment were obtained through conversations with vendors and analysis of trade publications. Third, economic forecast reports and the Wall Street Journal were used for source material, narrative, and forecast support. Finally, we compared LASL Building Cost Index with the effects of escalation associated with three recently developed projects at LASL

  17. The Los Alamos Neutron Science Center

    International Nuclear Information System (INIS)

    Lisowski, Paul W.; Schoenberg, Kurt F.

    2006-01-01

    The Los Alamos Neutron Science Center, or LANSCE, uses the first truly high-current medium-energy proton linear accelerator, which operated originally at a beam power of 1 MW for medium-energy nuclear physics. Today LANSCE continues operation as one of the most versatile accelerator-based user facilities in the world. During eight months of annual operation, scientists from around the world work at LANSCE to execute an extraordinarily broad program of defense and civilian research. Several areas operate simultaneously. The Lujan Neutron Scattering Center (Lujan Center) is a moderated spallation source (meV to keV), the Weapons Neutron Research Facility (WNR) is a bare spallation neutron source (keV to 800 MeV), and a new ultra-cold neutron source will be operational in 2005. These sources give LANSCE the ability to produce and use neutrons with energies that range over 14 orders of magnitude. LANSCE also supplies beam to WNR and two other areas for applications requiring protons. In a proton radiography (pRad) area, a sequence of narrow proton pulses is transmitted through shocked materials and imaged to study dynamic properties. In 2005, LANSCE began operating a facility that uses 100-MeV protons to produce medical radioisotopes. To sustain a vigorous program beyond this decade, LANSCE has embarked on a project to refurbish key elements of the facility and to plan capabilities beyond those that presently exist

  18. The Los Alamos Neutron Science Center

    Science.gov (United States)

    Lisowski, Paul W.; Schoenberg, Kurt F.

    2006-06-01

    The Los Alamos Neutron Science Center, or LANSCE, uses the first truly high-current medium-energy proton linear accelerator, which operated originally at a beam power of 1 MW for medium-energy nuclear physics. Today LANSCE continues operation as one of the most versatile accelerator-based user facilities in the world. During eight months of annual operation, scientists from around the world work at LANSCE to execute an extraordinarily broad program of defense and civilian research. Several areas operate simultaneously. The Lujan Neutron Scattering Center (Lujan Center) is a moderated spallation source (meV to keV), the Weapons Neutron Research Facility (WNR) is a bare spallation neutron source (keV to 800 MeV), and a new ultra-cold neutron source will be operational in 2005. These sources give LANSCE the ability to produce and use neutrons with energies that range over 14 orders of magnitude. LANSCE also supplies beam to WNR and two other areas for applications requiring protons. In a proton radiography (pRad) area, a sequence of narrow proton pulses is transmitted through shocked materials and imaged to study dynamic properties. In 2005, LANSCE began operating a facility that uses 100-MeV protons to produce medical radioisotopes. To sustain a vigorous program beyond this decade, LANSCE has embarked on a project to refurbish key elements of the facility and to plan capabilities beyond those that presently exist.

  19. Cancer patients' experiences of nurses' behaviour and health promotion activities: a critical incident analysis.

    Science.gov (United States)

    Björklund, M; Fridlund, B

    1999-12-01

    Patients with head and neck cancer report several disease- and health-related problems before, during and a long time after completed treatment. Nurses have an important role in educating/supporting these patients about/through the disease and treatment so that they can attain well-being. This study describes the cancer patients' experiences of nurses' behaviour in terms of critical incidents after nurses had given them care to promote health. The study had a qualitative, descriptive design and the method used was the critical incident technique. Twenty-one informants from the Nordic countries diagnosed with head and neck cancer were strategically selected. It was explained to the informants what a critical incident implies before the interviews took place; this was defined as a major event of great importance, an incident, which the informants still remember, due to its great importance for the outcome of their health and well-being. The nurses' behaviour was examined, and critical incidents were involved in 208 cases-150 positive and 58 negative ones-the number of incidents varying between three and 20 per informant. The nurses' health promotion activities or lack of such activities based on the patients' disease, treatment and symptoms, consisted of informing and instructing the patients as well as enabling their participation. Personal consideration and the nurses' cognisance, knowledge, competence, solicitude, demeanour and statements of understanding were found to be important. Continuous health promotion nursing interventions were of considerable value for the majority of this group of cancer patients. Oncology nurses could reconfirm and update the care of head and neck cancer patients by including health promotion activities in individual care plans. By more frequent use of health promotion models, such as the empowerment model, the nurses could identify and focus on those individuals who needed to alter their life-style as well as tailor their approach

  20. On the Evaluation of Pebble Bead Reactor Critical Experiments Using the Pebbed Code

    International Nuclear Information System (INIS)

    Gougar, Hans D.; Sen, R. Sonat

    2014-01-01

    Critical experiments pose a particular but necessary challenge to validating pebble bed reactor design codes. Fuel and core heterogeneities, impurities in graphite, variable packing of pebbles, and moderately strong neutronic coupling are among the factors that inject uncertainty into the results obtained with lower fidelity core physics models. Some of these are addressed in this study. The PEBBED pebble bed reactor fuel management code under development at the Idaho National Laboratory is designed for rapid design and analysis of pebble bed high temperature reactors (PBRs). Embedded within the code are the THERMIX-KONVEK thermal fluid solver and the COMBINE-7 spectrum generation code for inline cross section homogenization. Because 1D symmetry can be found at each stage of core heterogeneity; spherical at TRISO and pebble levels, and cylindrical at the control rod and core levels, the 1-D transport capability of ANISN is assumed to be sufficient in most cases for generating flux solutions for cross section homogenization. Furthermore, it is fast enough to be executed during the analysis or the equilibrium core. Multi-group diffusion-based design codes such as PEBBED and VSOP are not expected to yield the accuracy and resolution of continuous energy Monte Carlo codes for evaluation of critical experiments. Nonetheless, if the preparation of multigroup cross sections can adequately capture the physics of the mixing of PBR fuel elements and leakage from the core, reasonable results may be obtained. In this paper, results of the application of PEBBED to two critical experiments (HTR Proteus and HTR-10) and associated computational models are presented. The embedded 1-D transport solver is shown to capture the double heterogeneity of the pebble fuel in unit cell calculations. Eigenvalue calculations of a whole core are more challenging, particularly if the boron concentration is uncertain. The sensitivity of major safety parameters to variations in modeling

  1. The Relationship between College Experience at a Historically Black College and Students' Critical Thinking Skills

    Science.gov (United States)

    Little, Irene Pruitt

    2017-01-01

    The purpose of this quantitative correlational study was to examine the relationship between college experience at a HBCU and students' critical thinking skills. The theoretical framework included Astin's theory of involvement and Facione's taxonomy of critical thinking. The research site was a private four-year HBCU in the state of Alabama. The…

  2. Critical experiment program of heterogeneous core composed for LWR fuel rods and low enriched uranyl nitrate solution

    International Nuclear Information System (INIS)

    Miyoshi, Yoshinori; Yamamoto, Toshihiro; Watanabe, Shouichi; Nakamura, Takemi

    2003-01-01

    In order to stimulate the criticality characteristics of a dissolver in a reprocessing plant, a critical experiment program of heterogeneous cores is under going at a Static Critical Experimental Facility, STACY in Japan Atomic Energy Research Institute, JAERI. The experimental system is composed of 5w/o enriched PWR-type fuel rod array immersed in 6w/o enriched uranyl nitrate solution. First series of experiments are basic benchmark experiments on fundamental critical data in order to validate criticality calculation codes for 'general-form system' classified in the Japanese Criticality Safety Handbook, JCSHB. Second series of experiments are concerning the neutron absorber effects of fission products related to the burn-up credit Level-2. For demonstrating the reactivity effects of fission products, reactivity effects of natural elements such as Sm, Nd, Eu and 103 Rh, 133 Cs, solved in the nitrate solution are to be measured. The objective of third series of experiments is to validate the effect of gadolinium as a soluble neutron poison. Properties of temperature coefficients and kinetic parameters are also studied, since these parameters are important to evaluate the transient behavior of the criticality accident. (author)

  3. Facility model for the Los Alamos Plutonium Facility

    International Nuclear Information System (INIS)

    Coulter, C.A.; Thomas, K.E.; Sohn, C.L.; Yarbro, T.F.; Hench, K.W.

    1986-01-01

    The Los Alamos Plutonium Facility contains more than sixty unit processes and handles a large variety of nuclear materials, including many forms of plutonium-bearing scrap. The management of the Plutonium Facility is supporting the development of a computer model of the facility as a means of effectively integrating the large amount of information required for material control, process planning, and facility development. The model is designed to provide a flexible, easily maintainable facility description that allows the faciltiy to be represented at any desired level of detail within a single modeling framework, and to do this using a model program and data files that can be read and understood by a technically qualified person without modeling experience. These characteristics were achieved by structuring the model so that all facility data is contained in data files, formulating the model in a simulation language that provides a flexible set of data structures and permits a near-English-language syntax, and using a description for unit processes that can represent either a true unit process or a major subsection of the facility. Use of the model is illustrated by applying it to two configurations of a fictitious nuclear material processing line

  4. Pre-X Experimental Re-Entry Lifting Body: Design of Flight Test Experiments for Critical Aerothermal Phenomena

    Science.gov (United States)

    2007-06-01

    PRE-X EXPERIMENTAL RE-ENTRY LIFTING BODY: DESIGN OF FLIGHT TEST EXPERIMENTS FOR CRITICAL AEROTHERMAL PHENOMENA Paolo Baiocco * * CNES...ACRONYMS ACS Attitude Control System AEDB Aero Dynamic Data Base AoA Angle of Attack ARD Atmospheric Re-entry Demonstrator ATD Aero Termo ...1 Baiocco, P. (2007) Pre-X Experimental Re-entry Lifting Body: Design of Flight Test Experiments for Critical Aerothermal Phenomena. In Flight

  5. Critical plane analysis of multiaxial fatigue experiments leading to White Etching Crack formation

    Science.gov (United States)

    Averbeck, S.; Kerscher, E.

    2017-05-01

    Various researchers have shown that rolling contact fatigue can be reproduced with cyclic compression-torsion experiments, with the load components either in-phase or out of phase. As reported previously, the authors used such experiments to reproduce the rolling contact fatigue phenomenon “White Etching Cracks” which can cause premature failures of rolling element bearings. It is characterized by subsurface crack initiation and propagation coupled with microstructural changes alongside the crack flanks. Surprisingly, only in-phase load superposition caused these microstructural changes to occur. This suggests that White Etching Crack formation is somehow linked to the multiaxial stress state in the specimens, as this was the only variable that changed between in-phase and out-of-phase testing. In this study, the multiaxial stress state in the two experiments is analysed and compared using different critical plane criteria. In contrast to common ways of characterizing the stress state, e.g. equivalent stress approaches, this class of criteria is explicitly designed for multiaxial stress states. Special attention is given to the Dang Van criterion, which has been used in a number of rolling contact fatigue studies.

  6. The undergraduate premedical experience in the United States: a critical review.

    Science.gov (United States)

    Lin, Katherine Y; Parnami, Sonali; Fuhrel-Forbis, Andrea; Anspach, Renee R; Crawford, Brett; De Vries, Raymond G

    2013-01-01

    To better understand the consequences of the premedical years for the character of (future) physicians by critically reviewing the empirical research done on the undergraduate premedical experience in the United States. We searched ERIC, JSTOR, PubMed, Scopus, ISI Web of Science, and PsycINFO from the earliest available date for empirical, peer-reviewed studies of premedical students in the United States. We then used qualitative methods to uncover overall themes present in this literature. The initial literature search identified 1,168 articles, 19 of which were included for review. Reviewed articles were published between 1976 and 2010 with the majority published prior to 1990. Articles covered two broad topics: explaining attrition from the premedical track, and investigating the personality traits and stereotypes of premedical students. Self-selection bias and high attrition rates were among the limitations of the reviewed articles. There is very little current research on the premedical experience. Given the importance of the premedical years on the process of becoming a medical professional, it is imperative that we do more and better research on how the premedical experience shapes future physicians.

  7. Capabilities of the Los Alamos National Laboratory in nuclear target technology

    International Nuclear Information System (INIS)

    Gursky, J.C.

    1984-01-01

    Targets are made at Los Alamos for experiments at the Ion Beam Facility (Van de Graaff), the Medium Energy Physics Facility (LAMPF), and for experiments conducted at many other accelerators in the US and Europe. Thin, isotopic targets are made by sputtering and evaporation. Versatile, large-scale facilities exist for ceramics and plastics fabrication, electroplating, powder metallurgy, fabrication by pressing, casting and rolling, chemical and physical vapor deposition and sputtering. Special developments include ultra-precision machining, cryogenic targets and shaped-foil targets. 20 references

  8. Micafungin Plasma Levels Are Not Affected by Continuous Renal Replacement Therapy: Experience in Critically Ill Patients

    Science.gov (United States)

    Haidinger, M.; Lemmerer, R.; Unger, M.; Pferschy, S.; Lamm, W.; Maier-Salamon, A.; Jäger, W.; Thalhammer, F.

    2017-01-01

    ABSTRACT Critically ill patients often experience acute kidney injury and the need for renal replacement therapy in the course of their treatment in an intensive care unit (ICU). These patients are at an increased risk for candidiasis. Although there have been several reports of micafungin disposition during renal replacement therapy, to this date there are no data describing the elimination of micafungin during high-dose continuous venovenous hemodiafiltration with modified AN69 membranes. The aim of this prospective open-label pharmacokinetic study was to assess whether micafungin plasma levels are affected by continuous hemodiafiltration in critical ill patients using the commonly employed AN69 membrane. A total of 10 critically ill patients with micafungin treatment due to suspected or proven candidemia were included in this trial. Prefilter/postfilter micafungin clearance was measured to be 46.0 ml/min (±21.7 ml/min; n = 75 individual time points), while hemofilter clearance calculated by the sieving coefficient was 0.0038 ml/min (±0.002 ml/min; n = 75 individual time points). Total body clearance was measured to be 14.0 ml/min (±7.0 ml/min; n = 12). The population area under the curve from 0 to 24 h (AUC0–24) was calculated as 158.5 mg · h/liter (±79.5 mg · h/liter; n = 13). In spite of high protein binding, no dose modification is necessary in patients receiving continuous venovenous hemodiafiltration with AN69 membranes. A dose elevation may, however, be justified in certain cases. (This study has been registered at ClinicalTrials.gov under identifier NCT02651038.) PMID:28584142

  9. Preparation of a criticality benchmark based on experiments performed at the RA-6 reactor

    International Nuclear Information System (INIS)

    Bazzana, S.; Blaumann, H; Marquez Damian, J.I

    2009-01-01

    The operation and fuel management of a reactor uses neutronic modeling to predict its behavior in operational and accidental conditions. This modeling uses computational tools and nuclear data that must be contrasted against benchmark experiments to ensure its accuracy. These benchmarks have to be simple enough to be possible to model with the desired computer code and have quantified and bound uncertainties. The start-up of the RA-6 reactor, final stage of the conversion and renewal project, allowed us to obtain experimental results with fresh fuel. In this condition the material composition of the fuel elements is precisely known, which contributes to a more precise modeling of the critical condition. These experimental results are useful to evaluate the precision of the models used to design the core, based on U 3 Si 2 and cadmium wires as burnable poisons, for which no data was previously available. The analysis of this information can be used to validate models for the analysis of similar configurations, which is necessary to follow the operational history of the reactor and perform fuel management. The analysis of the results and the generation of the model were done following the methodology established by International Criticality Safety Benchmark Evaluation Project, which gathers and analyzes experimental data for critical systems. The results were very satisfactory resulting on a value for the multiplication factor of the model of 1.0000 ± 0.0044, and a calculated value of 0.9980 ± 0.0001 using MCNP 5 and ENDF/B-VI. The utilization of as-built dimensions and compositions, and the sensitivity analysis allowed us to review the design calculations and analyze their precision, accuracy and error compensation. [es

  10. Alize 3 - first critical experiment for the franco-german high flux reactor - calculations

    International Nuclear Information System (INIS)

    Scharmer, K.

    1969-01-01

    The results of experiments in the light water cooled D 2 O reflected critical assembly ALIZE III have been compared to calculations. A diffusion model was used with 3 fast and epithermal groups and two overlapping thermal groups, which leads to good agreement of calculated and measured power maps, even in the case of strong variations of the neutron spectrum in the core. The difference of calculated and measured k eff was smaller than 0.5 per cent δk/k. Calculations of void and structure material coefficients of the reactivity of 'black' rods in the reflector, of spectrum variations (Cd-ratio, Pu-U-ratio) and to the delayed photoneutron fraction in the D 2 O reflector were made. Measurements of the influence of beam tubes on reactivity and flux distribution in the reflector were interpreted with regard to an optimum beam tube arrangement for the Franco- German High Flux Reactor. (author) [fr

  11. Impediments to User Gains: Experiences from a Critical Participatory Design Project

    DEFF Research Database (Denmark)

    Bossen, Claus; Dindler, Christian; Iversen, Ole Sejer

    2012-01-01

    Actual studies of user gains from involvement in design processes are few, although a concern for users’ gains is a core characteristic of participatory design (PD). We explore the question of user gains through a retrospective evaluation of a critical PD project. We conducted ten qualitative...... interviews with participants in a project aimed at developing technology that fosters engaging museum experiences, and rethinking cultural heritage communication. Despite the use of established PD techniques by experienced PD practitioners, a significant number of frustrations relating to the PD process were...... prominent in the research study. Based on these findings, we provide an analysis of impediments for users gains in PD projects: Differences between aims were unresolved, absence of a shared set-up for collaboration and different conceptions of technology....

  12. New directions for critical internet health studies: representing cancer experience on the web.

    Science.gov (United States)

    Seale, Clive

    2005-05-01

    Studies of health representations on the internet have been preoccupied with the assessment of their (medically-defined) accuracy and quality. This contrasts with studies of health representations in 'old' media, where critical sociological analyses are common. Medical sociologists have been concerned to establish the potential of web information in transforming professional-client relations. A case study of breast and prostate cancer web sites provides evidence of the increasing convergence of the 'new' medium of the internet and old media such as newspapers and television. Large institutions are now consolidating their presence on the web so that users experience increasingly similar messages across media platforms. Search engines and links to the web from old media sources direct people to heavily resourced, mainstream health sites where, in the case of cancer, representations of gender are strikingly similar to those found in studies of old media sources. The media convergence thesis contrasts with earlier celebrations of the internet as a new medium that would promote a diversity of perspectives on health. Using existing methods for analysing media texts and developing new methods where appropriate, sociologists and media analysts interested in health need to develop more critical perspectives on this important new medium.

  13. Catalog and history of the experiments of criticality Saclay (1958-1964) Valduc / Building 10 (1964-2003)

    International Nuclear Information System (INIS)

    Poullot, G.; Dumont, V.; Anno, J.; Cousinou, P.; Grivot, P.; Girault, E.; Fouillaud, P.; Barbry, F.

    2003-01-01

    The group ' International Criticality Safety Evaluation Benchmark evaluation project ' (I.C.S.B.E.P.) has for aim to supply to the international community experiments of benchmarks criticality, of certified quality, used to guarantee the qualification of criticality calculation codes. Have been defined: a structure of experiments classification, a format of standard presentation, a structure of work with evaluation, internal and external checks, presentation in plenary session. After favourable opinion of the work group, the synthesis document called evaluation is integrated to the general report I.C.S.B.E.P. (N.C.)

  14. Summary of ORSphere Critical and Reactor Physics Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Margaret A.; Bess, John D.

    2016-09-01

    In the early 1970s Dr. John T. Mihalczo (team leader), J. J. Lynn, and J. R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s. The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. This critical configuration has been evaluated. Preliminary results were presented at ND2013. Since then, the evaluation was finalized and judged to be an acceptable benchmark experiment for the International Criticality Safety Benchmark Experiment Project (ICSBEP). Additionally, reactor physics measurements were performed to determine surface button worths, central void worth, delayed neutron fraction, prompt neutron decay constant, fission density and neutron importance. These measurements have been evaluated and found to be acceptable experiments and are discussed in full detail in the International Handbook of Evaluated Reactor Physics Benchmark Experiments. The purpose of this paper is summary summarize all the critical and reactor physics measurements evaluations and, when possible, to compare them to GODIVA experiment results.

  15. Validation of VHTRC calculation benchmark of critical experiment using the MCB code

    Directory of Open Access Journals (Sweden)

    Stanisz Przemysław

    2016-01-01

    Full Text Available The calculation benchmark problem Very High Temperature Reactor Critical (VHTR a pin-in-block type core critical assembly has been investigated with the Monte Carlo Burnup (MCB code in order to validate the latest version of Nuclear Data Library based on ENDF format. Executed benchmark has been made on the basis of VHTR benchmark available from the International Handbook of Evaluated Reactor Physics Benchmark Experiments. This benchmark is useful for verifying the discrepancies in keff values between various libraries and experimental values. This allows to improve accuracy of the neutron transport calculations that may help in designing the high performance commercial VHTRs. Almost all safety parameters depend on the accuracy of neutron transport calculation results that, in turn depend on the accuracy of nuclear data libraries. Thus, evaluation of the libraries applicability to VHTR modelling is one of the important subjects. We compared the numerical experiment results with experimental measurements using two versions of available nuclear data (ENDF-B-VII.1 and JEFF-3.2 prepared for required temperatures. Calculations have been performed with the MCB code which allows to obtain very precise representation of complex VHTR geometry, including the double heterogeneity of a fuel element. In this paper, together with impact of nuclear data, we discuss also the impact of different lattice modelling inside the fuel pins. The discrepancies of keff have been successfully observed and show good agreement with each other and with the experimental data within the 1 σ range of the experimental uncertainty. Because some propagated discrepancies observed, we proposed appropriate corrections in experimental constants which can improve the reactivity coefficient dependency. Obtained results confirm the accuracy of the new Nuclear Data Libraries.

  16. Critical Race Media Projects: Counterstories and Praxis (Re)Claim Chicana/o Experiences

    Science.gov (United States)

    Alemán, Sonya M.; Alemán, Enrique, Jr.

    2016-01-01

    This article maps out two critical race media projects -- a documentary and a Chicana/o-centric student newspaper--developed by Chicana/o scholars seeking to fulfilll the promise of praxis hailed by critical race theorists. Fortified and guided by the quintessential tenets of critical race theory and Latino critical race theory, these critical…

  17. Creating an Alternate Reality: Critical, Creative, and Empathic Thinking Generated in the "Global Village Playground" Capstone Experience

    Science.gov (United States)

    Dondlinger, Mary Jo; Wilson, Douglas A.

    2012-01-01

    The "Global Village Playground" ("GVP") was a capstone learning experience designed to address institutional assessment needs while providing an integrated and authentic learning experience for students aimed at fostering critical and creative thinking. In the "GVP", students work on simulated and real-world problems as a design team tasked with…

  18. Critical Ethnographic Analysis of "Doing Good" on Short-Term International Immersion Experiences.

    Science.gov (United States)

    Elliot, Michelle L

    2015-09-01

    Reciprocal partnerships are growing alongside the rise of international learning and "doing" experiences for students and clinicians. This paper questions how global citizenship, the acquisition of awareness and skills to sensitively navigate through a rapidly globalized social world, is cultivated amidst international partnerships focused on short-term immersion opportunities. Using an ethnographic methodology to examine the experiences of occupational therapy students abroad, this paper addresses the potential for competing agendas when the motivation to participate within these partnerships is driven in part by a desire to "do good." The empirical lens was directed towards the students' verbal, written and enacted narratives rather than the sociocultural realm of the sending institution, the host organization or the occupational realities of the local communities, therefore is limited in discursive scope. Nevertheless, the need is great for further critical appraisal of objectives and expectations by all parties to foster a partnership culture of reciprocity and equality and to diminish the neocolonial legacy of Western expertise dissemination. By examining how the stated and implied desire to do good exists alongside the risk to do harm to individuals and international networks, the conclusions can be extended locally to highlight the challenges to "partnering up" between clinicians and patients. © 2015 John Wiley & Sons, Ltd.

  19. Comparison of self-assessed competence and experience among critical care nurses.

    Science.gov (United States)

    O'Leary, Jerry

    2012-07-01

    To determine the level of self-assessed nursing competence and the relationship to age and experience in nursing. Nursing competence is a concern for all health-care stakeholders. Methods to measure competence have been evaluated worldwide. There is little agreement about the development or reliable measure of competence. Exploring these relationships can identify strategies for education, retention, professional growth and potentially affect patient outcome measures. The Nurse Competence Scale (NCS) was completed by 101 critical care nurses. Statistical methods were used to analyse the data. The nurses self-assessed level of competence ranged from good to excellent along with an increased frequency of using competencies. Statistically significant relationships were found among the variables. Measurable, significant relationships exist among the variables. The NCS proved to be a valid and reliable instrument to measure competence. Objective and reliable assessment of nursing competence is an important measure for leadership and education. Further studies to identify other factors affecting the nurses' experience and the effect on competence will help to develop and promote supportive strategies. © 2012 Blackwell Publishing Ltd.

  20. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    Energy Technology Data Exchange (ETDEWEB)

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations.

  1. Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

    International Nuclear Information System (INIS)

    1985-11-01

    The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of this research was also established. This volume contains the first two of the five technical sessions. The first one being the BCX overview, the second on the BCX candidate materials. The remaining three sessions in volume two are on the plasma materials interaction issues, research facilities and small working group meeting on graphite, beryllium, advanced materials and future collaborations

  2. Summary of ORSphere critical and reactor physics measurements

    Directory of Open Access Journals (Sweden)

    Marshall Margaret A.

    2017-01-01

    Full Text Available In the early 1970s Dr. John T. Mihalczo (team leader, J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF with highly enriched uranium (HEU metal (called Oak Ridge Alloy or ORALLOY to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s. The purpose of the Oak Ridge ORALLOY Sphere (ORSphere experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. This critical configuration has been evaluated. Preliminary results were presented at ND2013. Since then, the evaluation was finalized and judged to be an acceptable benchmark experiment for the International Criticality Safety Benchmark Experiment Project (ICSBEP. Additionally, reactor physics measurements were performed to determine surface button worths, central void worth, delayed neutron fraction, prompt neutron decay constant, fission density and neutron importance. These measurements have been evaluated and found to be acceptable experiments and are discussed in full detail in the International Handbook of Evaluated Reactor Physics Benchmark Experiments. The purpose of this paper is to summarize all the evaluated critical and reactor physics measurements evaluations.

  3. Summary of ORSphere critical and reactor physics measurements

    Science.gov (United States)

    Marshall, Margaret A.; Bess, John D.

    2017-09-01

    In the early 1970s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950s. The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. This critical configuration has been evaluated. Preliminary results were presented at ND2013. Since then, the evaluation was finalized and judged to be an acceptable benchmark experiment for the International Criticality Safety Benchmark Experiment Project (ICSBEP). Additionally, reactor physics measurements were performed to determine surface button worths, central void worth, delayed neutron fraction, prompt neutron decay constant, fission density and neutron importance. These measurements have been evaluated and found to be acceptable experiments and are discussed in full detail in the International Handbook of Evaluated Reactor Physics Benchmark Experiments. The purpose of this paper is to summarize all the evaluated critical and reactor physics measurements evaluations.

  4. Clinical Experiences and Mediational Activities in Urban Teacher Preparation: Learning and Critical Consciousness

    Directory of Open Access Journals (Sweden)

    Craig Willey

    2016-11-01

    Full Text Available In a longitudinal design experiment conducted within an urban teacher preparation program, we employed ethnographic and auto-ethnographic methods to investigate the following questions: 1 In what ways do clinical experiences (CEs support prospective teachers’ (PTs development of knowledge, skills, and dispositions necessary for urban teaching? 2 How is it determined that adjustments need to be made to the design and facilitation of CEs, and what did these adjustments yield in terms of student learning outcomes? The program centers and leverages CEs in order for PTs to connect theory and practice, particularly an awareness of, and skills associated with, equitable teaching practices. In our two-year field-based program, CEs included community explorations, one-on-one and small group work with children, two student teaching practicums, and various school-community events. We describe the process undertaken to maximize the benefits yielded from CEs. After working with three cohorts of PTs for their entire professional training, we found that: 1 focusing attention on the intentional design and assessment of the mediational activities coupled with CEs leads to more nuanced understandings and enactments of culturally relevant teaching among PTs; and 2 CEs afford PTs abundant opportunities to shape complex identities as urban teachers. Specifically, we found that clinical experiences and corresponding mediational activities support PTs’ understanding of families of color, allow them to recognize and address problematic schooling practices, and strengthen PTs’ otherwise fragile critical consciousness. We conclude that strategic interventions can provide clarity for PTs around what has been learned, and what is left to be developed

  5. 1993 Northern goshawk inventory on portions of Los Alamos National Laboratory, Los Alamos, NM. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, D.T.; Kennedy, P.L. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Fishery and Wildlife Biology

    1994-06-01

    Northern goshawks (Accipiter gentilis) (hereafter referred to as goshawk) is a large forest dwelling hawk. Goshawks may be declining in population and reproduction in the southwestern United States. Reasons for the possible decline in goshawk populations include timber harvesting resulting in the loss of nesting habitat, toxic chemicals, and the effects of drought, fire, and disease. Thus, there is a need to determine their population status and assess impacts of management activities in potential goshawk habitat. Inventory for the goshawk was conducted on 2,254 ha of Los Alamos National Laboratory (LANL) to determine the presence of nesting goshawks on LANL lands. This information can be incorporated into LANL`s environmental management program. The inventory was conducted by Colorado State University personnel from May 12 to July 30, 1993. This report summarizes the results of this inventory.

  6. Progress report on the Los Alamos tritium beta decay experiment

    International Nuclear Information System (INIS)

    Wilkerson, J.F.; Bowles, T.J.; Knapp, D.A.; Robertson, R.G.H.; Wark, D.L.

    1988-01-01

    Measurements near the endpoint of the tritium beta-decay spectrum using a gaseous molecular tritium source yield an essentially model-independent upper limit of 27 eV on the /ovr ν//sub e/ mass at the 95% confidence level. Since demonstrating from this initial measurement the successful operation of a gaseous source based system, most of our effort has been concentrated towards the upgrade and optimization of the experimental apparatus. The emphasis of this work has been to eliminate or further reduce effects that generate systematic errors. Based on realistic projections from our initial measurement, an ultimate sensitivity to neutrino mass of 10 eV is expected. 12 refs., 1 fig

  7. Publications of Los Alamos research, 1977-1981

    International Nuclear Information System (INIS)

    Sheridan, C.J.; Garcia, C.A.

    1983-03-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them

  8. Publications of Los Alamos research, 1977-1981

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, C.J.; Garcia, C.A. (comps.)

    1983-03-01

    This bibliography is a compilation of unclassified publications of work done at the Los Alamos National Laboratory for 1977-1981. Papers published in those years are included regardless of when they were actually written. Publications received too late for inclusion in earlier compilations have also been listed. Declassification of previously classified reports is considered to constitute publication. All classified issuances are omitted - even those papers, themselves unclassified, which were published only as part of a classified document. If a paper was published more than once, all places of publication are included. The bibliography includes Los Alamos National Laboratory reports, papers released as non-Laboratory reports, journal articles, books, chapters of books, conference papers either published separately or as part of conference proceedings issued as books or reports, papers published in congressional hearings, theses, and US patents. Publications by Los Alamos authors that are not records of Laboratory-sponsored work are included when the Library becomes aware of them.

  9. Sedation in palliative care – a critical analysis of 7 years experience

    Directory of Open Access Journals (Sweden)

    Andres Inge

    2003-05-01

    Full Text Available Abstract Background The administration of sedatives in terminally ill patients becomes an increasingly feasible medical option in end-of-life care. However, sedation for intractable distress has raised considerable medical and ethical concerns. In our study we provide a critical analysis of seven years experience with the application of sedation in the final phase of life in our palliative care unit. Methods Medical records of 548 patients, who died in the Palliative Care Unit of GK Havelhoehe between 1995–2002, were retrospectively analysed with regard to sedation in the last 48 hrs of life. The parameters of investigation included indication, choice and kind of sedation, prevalence of intolerable symptoms, patients' requests for sedation, state of consciousness and communication abilities during sedation. Critical evaluation included a comparison of the period between 1995–1999 and 2000–2002. Results 14.6% (n = 80 of the patients in palliative care had sedation given by the intravenous route in the last 48 hrs of their life according to internal guidelines. The annual frequency to apply sedation increased continuously from 7% in 1995 to 19% in 2002. Main indications shifted from refractory control of physical symptoms (dyspnoea, gastrointestinal, pain, bleeding and agitated delirium to more psychological distress (panic-stricken fear, severe depression, refractory insomnia and other forms of affective decompensation. Patients' and relatives' requests for sedation in the final phase were significantly more frequent during the period 2000–2002. Conclusion Sedation in the terminal or final phase of life plays an increasing role in the management of intractable physical and psychological distress. Ethical concerns are raised by patients' requests and needs on the one hand, and the physicians' self-understanding on the other hand. Hence, ethically acceptable criteria and guidelines for the decision making are needed with special regard to

  10. Analysis of MOZART critical experiment using the IRPhEP handbook data

    International Nuclear Information System (INIS)

    Chiba, Go

    2010-12-01

    Using the experimental data described in the IRPhEP handbook, an experimental analysis of the MOZART experiment is carried out with the nuclear data JENDL-4.0, and the reactor physics codes SLAROM-UF and CBG. The following results are obtained: -The C/E values for criticality are 0.9981 for the small-sized core MZA and 1.0006 for the middle-sized core MZB. Good agreement between calculation and experimental values has been observed similarly in the analyses for criticality of other MOX-fueled fast reactors. Hence, consistency between the present analysis and the others is confirmed. -In reaction rate ratios at the core center, calculation values agree with experimental values within 1.0% for F25/F49 and C28/F49, and within 4.0% for F28/F25, F40/F49 and F41/F49. -In sodium void reactivity worths, calculation values are about 10% larger than experimental values for the non-leakage-dominated data. For the data to which the leakage component largely contributes, absolute differences normalized by the leakage component are less than 10%. -In material worths, calculation values are about 5% larger than experimental values for plutonium. Calculation values agree with experimental values within 10% differences for uranium and SS. -In control rod worths, calculation values are 2% to 5% larger than experimental values. -In reaction rate distributions, calculation values agree well with experimental values in core regions. On the other hand, underestimation is observed systematically in calculation values of threshold reactions in blanket regions. For the reactivity characteristic, overestimation is systematically observed in calculations. While the reason has not yet been investigated, the result suggests underestimation of β eff . (author)

  11. Status and future program of reactor physics experiments in JAERI Critical facilities, FCA and TCA

    International Nuclear Information System (INIS)

    Okajima, Shigeaki; Osugi, Toshitaka; Nakajima, Ken; Suzaki, Takenori; Miyoshi, Yoshinori

    1999-01-01

    The critical facilities in JAERI, FCA (Fast Critical Assembly) and TCA (Tank-type Critical Assembly), have been used to provide integral data for evaluation of nuclear data as well as for development of various types of reactor since they went critical in 1960's. In this paper a review is presented on the experimental programs in both facilities. And the experimental programs in next 5 years are also shown. (author)

  12. The development of the atomic bomb, Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, R.W.

    1993-11-01

    The historical presentation begins with details of the selection of Los Alamos as the site of the Army installation. Wartime efforts of the Army Corps of Engineers, and scientists to include the leader of Los Alamos, Robert Oppenheimer are presented. The layout and construction of the facilities are discussed. The monumental design requirements of the bombs are discussed, including but not limited to the utilization of the second choice implosion method of detonation, and the production of bomb-grade nuclear explosives. The paper ends with a philosophical discussion on the use of nuclear weapons.

  13. A physicists guide to The Los Alamos Primer

    International Nuclear Information System (INIS)

    Reed, B Cameron

    2016-01-01

    In April 1943, a group of scientists at the newly established Los Alamos Laboratory were given a series of lectures by Robert Serber on what was then known of the physics and engineering issues involved in developing fission bombs. Serber’s lectures were recorded in a 24 page report titled The Los Alamos Primer , which was subsequently declassified and published in book form. This paper describes the background to the Primer and analyzes the physics contained in its 22 sections. The motivation for this paper is to provide a firm foundation of the background and contents of the Primer for physicists interested in the Manhattan Project and nuclear weapons. (invited comment)

  14. Fifty-one years of Los Alamos Spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-04

    From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

  15. Los Alamos DP West Plutonium Facility decontamination project

    International Nuclear Information System (INIS)

    Garde, R.; Cox, E.J.; Valentine, A.M.

    1982-01-01

    The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico, was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation

  16. The LANSCE (Los Alamos Neutron Scattering Center) target data collection system

    International Nuclear Information System (INIS)

    Kernodle, A.K.

    1989-01-01

    The Los Alamos Neutron Scattering Center (LANSCE) Target Data Collection System is the result of an effort to provide a base of information from which to draw conclusions on the performance and operational condition of the overall LANSCE target system. During the conceptualization of the system, several goals were defined. A survey was made of both custom-made and off-the-shelf hardware and software that were capable of meeting these goals. The first stage of the system was successfully implemented for the LANSCE run cycle 52. From the operational experience gained thus far, it appears that the LANSCE Target Data Collection System will meet all of the previously defined requirements

  17. Los Alamos National Laboratory case studies on decommissioning of research reactors and a small nuclear facility

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.D.

    1998-12-01

    Approximately 200 contaminated surplus structures require decommissioning at Los Alamos National Laboratory. During the last 10 years, 50 of these structures have undergone decommissioning. These facilities vary from experimental research reactors to process/research facilities contaminated with plutonium-enriched uranium, tritium, and high explosives. Three case studies are presented: (1) a filter building contaminated with transuranic radionuclides; (2) a historical water boiler that operated with a uranyl-nitrate solution; and (3) the ultra-high-temperature reactor experiment, which used enriched uranium as fuel.

  18. Magnetic field-aligned plasma expansion in critical ionization velocity space experiments

    International Nuclear Information System (INIS)

    Singh, N.

    1989-01-01

    Motivated by the recent Critical Ionization Velocity (CIV) experiments in space, the temporal evolution of a plasma cloud released in an ambient plasma is studied. Time-dependent Vlasov equations for both electrons and ions, along with the Poisson equation for the self-consistent electric field parallel to the ambient magnetic field, are solved. The initial cloud is assumed to consist of cold, warm, and hot electrons with temperatures T/sub c/ ≅ 0.2 eV, T/sub w/ ≅ 2 eV, and T/sub h/ ≅ 10 eV, respectively. It is found that the minor hot electrons escape the cloud, and their velocity distribution function shows the typical time-of-flight dispersion feature - that is, the larger the distance from the cloud, the larger is the average drift velocity of the escaping electrons. The major warm electrons expand along the magnetic field line with the corresponding ion-acoustic speed. The combined effect of the escaping hot electrons and the expanding warm ones sets up an electric potential structure which accelerates the ambient electrons into the cloud. Thus, the energy loss due to the electron escape is partly replenished. The electric field distribution in the potential structure depends on the stage of the evolution; before the rarefaction waves propagating from the edges of the cloud reach its center, the electric fields point into the cloud. After this stage the cloud divides into two subclouds, with each having their own bipolar electric fields. Effects of collisions on the evolution of plasma clouds are also discussed. The relevance of the results seen from the calculations are discussed in the context of recent space experiments on CIV

  19. Critical heat flux experiments for high conversion light water reactor, (3)

    International Nuclear Information System (INIS)

    Iwamura, Takamichi; Okubo, Tsutomu; Suemura, Takayuki; Hiraga, Fujio; Murao, Yoshio

    1990-03-01

    As a part of the thermal-hydraulic feasibility study of a high conversion light water reactor (HCLWR), critical heat flux (CHF) experiments were performed using triangular array rod bundles under steady-state and flow reduction transient conditions. The geometries of test sections were: rod outer diameter 9.5 mm, number of rods 4∼7, heated length 0.5∼1.0 m, and pitch to diameter ratio (P/D) 1.126∼1.2. The simulated fuel rod was a stainless steel tube and uniformly heated electrically with direct current. In the steady-state tests, pressures ranged: 1.0∼3.9 Mpa, mass velocities: 460∼4270 kg/s·m 2 , and exit qualities: 0.02∼0.35. In the transient tests, the times to CHF detection ranged from 0.5 to 25.4 s. The steady-state CHF's for the 4-rod test sections were higher than those for the 7-rod test sections with respect to the bundle averaged flow conditions. The measured CHF's increased with decreasing the heated length and decreased with decreasing the P/D. Based on the local flow conditions obtained with the subchannel analysis code COBRA-IV-I, KfK correlation agreed with the CHF data within 20 %, while WSC-2, EPRI-B and W, EPRI-Columbia and Kattor correlations failed to give satisfactory agreements. Under flow reduction rates less than 6 %/s, no significant difference in the onset conditions of DNB (departure from nucleate boiling) was recognized between the steady-state and transient conditions. At flow reduction rates higher than 6 %/s, on the other hand, the DNB occurred earlier than the DNB time predicted with the steady-state experiments. (author)

  20. Needs assessment for fire department services and resources for the Los Alamos National Laboratory, Los Alamos, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-15

    This report has been developed in response to a request from the Los Alamos National Laboratory (LANL) to evaluate the need for fire department services so as to enable the Laboratory to plan effective fire protection and thereby: meet LANL`s regulatory and contractual obligations; interface with the Department of Energy (DOE) and other agencies on matters relating to fire and emergency services; and ensure appropriate protection of the community and environment. This study is an outgrowth of the 1993 Fire Department Needs Assessment (prepared for DOE) but is developed from the LANL perspective. Input has been received from cognizant and responsible representatives at LANL, DOE, Los Alamos County (LAC) and the Los Alamos Fire Department (LAFD).

  1. Critical Heat Flux Experiments on the Reactor Vessel Wall Using 2-D Slice Test Section

    International Nuclear Information System (INIS)

    Jeong, Yong Hoon; Chang, Soon Heung; Baek, Won-Pil

    2005-01-01

    The critical heat flux (CHF) on the reactor vessel outer wall was measured using the two-dimensional slice test section. The radius and the channel area of the test section were 2.5 m and 10 cm x 15 cm, respectively. The flow channel area and the heater width were smaller than those of the ULPU experiments, but the radius was greater than that of the ULPU. The CHF data under the inlet subcooling of 2 to 25 deg. C and the mass flux 0 to 300 kg/m 2 .s had been acquired. The measured CHF value was generally slightly lower than that of the ULPU. The difference possibly comes from the difference of the test section material and the thickness. However, the general trend of CHF according to the mass flux was similar with that of the ULPU. The experimental CHF data were compared with the predicted values by SULTAN correlation. The SULTAN correlation predicted well this study's data only for the mass flux higher than 200 kg/m 2 .s, and for the exit quality lower than 0.05. The local condition-based correlation was developed, and it showed good prediction capability for broad quality (-0.01 to 0.5) and mass flux ( 2 .s) conditions with a root-mean-square error of 2.4%. There were increases in the CHF with trisodium phosphate-added water

  2. BWR core simulator using three-dimensional direct response matrix and analysis of cold critical experiments

    International Nuclear Information System (INIS)

    Hino, Tetsushi; Ishii, Kazuya; Mitsuyasu, Takeshi; Aoyama, Motoo

    2010-01-01

    A new core analysis method has been developed in which neutronic calculations using a three-dimensional direct response matrix (3D-DRM) method are coupled with thermal-hydraulic calculations. As it requires neither a diffusion approximation nor a homogenization process of lattice constants, a precise representation of the neutronic heterogeneity effect in an advanced core design is possible. Moreover, the pin-by-pin power distribution can be directly evaluated, which enables precise evaluations of core thermal margins. Verification of the neutronic calculation using the 3D-DRM method was examined by analyses of cold criticality experiments of commercial power plants. The standard deviations and maximum differences in predicted neutron multiplication factors were 0.07% Δk and 0.19% Δk for a BWR5 plant, and 0.11% Δk and 0.25% Δk for an ABWR plant, respectively. A coupled analysis of the 3D-DRM method and thermal-hydraulic calculations for a quarter ABWR core was done, and it was found that the thermal power and coolant-flow distributions were smoothly converged. (author)

  3. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) and The International Reactor Reactor Physics Experiment Evaluation Project (IRPhEP)

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J.B.; Bess, J. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Gulliford, J. [Organization for Economic Cooperation and Development (OECD),Nuclear Energy Agency, Paris, (France)

    2011-07-01

    The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) are sources of evaluated integral benchmark data that may be used for validation of reactor physics / nuclear criticality safety analytical methods and data, nuclear data testing, and safety analysis licensing activities. The IRPhEP is patterned after its predecessor, the ICSBEP, but focuses on other integral measurements such as buckling, spectral characteristics, reactivity effects, reactivity coefficients, kinetics measurements, reaction-rate and power distributions, nuclide compositions and other miscellaneous types of measurements in addition to the critical configuration. Both projects will be discussed.

  4. A survey of macromycete diversity at Los Alamos National Laboratory, Bandelier National Monument, and Los Alamos County; A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Jarmie, N.; Rogers, F.J. [Mycology Associates, Los Alamos, NM (United States)

    1997-11-01

    The authors have completed a 5-year survey (1991--1995) of macromycetes found in Los Alamos County, Los Alamos National Laboratory, and Bandelier National Monument. The authors have compiled a database of 1,048 collections, their characteristics, and identifications. The database represents 123 (98%) genera and 175 (73%) species reliably identified. Issues of habitat loss, species extinction, and ecological relationships are addressed, and comparisons with other surveys are made. With this baseline information and modeling of this baseline data, one can begin to understand more about the fungal flora of the area.

  5. Critical Components of a Successful Undergraduate Research Experience in the Geosciences for Minority Students

    Science.gov (United States)

    Liou-Mark, J.; Blake, R.; Chukuigwe, C.

    2013-12-01

    For the past five years, the New York City College of Technology has administered a successful National Science Foundation (NSF) Research Experience for Undergraduates (REU) program. The program provides rich, substantive, academic and life-transformative STEM educational experiences for students who would otherwise not pursue STEM education altogether or would not pursue STEM education through to the graduate school level. The REU Scholars are provided with an opportunity to conduct intensive satellite and ground-based remote sensing research at the National Oceanic and Atmospheric Administration Cooperative Remote Sensing Science and Technology Center (NOAA-CREST). Candidates for the program are recruited from the City University of New York's twenty-three separate campuses. These students engage in a research experience that spans the summer and the fall and spring semesters. Eighty-four percent (84%) of the program participants are underrepresented minorities in STEM, and they are involved in a plethora of undergraduate research best practice activities that include: training courses in MATLAB programming, Geographic Information Systems, and Remote Sensing; workshops in Research Ethics, Scientific Writing, and Oral and Poster Research Presentations; national, regional, and local conference presentations; graduate school support; and geoscience exposure events at national laboratories, agencies, and research facilities. To enhance their success in the program, the REU Scholars are also provided with a comprehensive series of safety nets that include a multi-tiered mentoring design specifically to address critical issues faced by this diverse population. Since the inception of the REU program in 2008, a total of 61 undergraduate students have finished or are continuing with their research or are pursuing their STEM endeavors. All the REU Scholars conducted individual satellite and ground-based remote sensing research projects that ranged from the study of

  6. Trauma-exposed firefighters: relationships among posttraumatic growth, posttraumatic stress, resource availability, coping and critical incident stress debriefing experience.

    Science.gov (United States)

    Sattler, David N; Boyd, Bill; Kirsch, Julie

    2014-12-01

    This project examines protective factors associated with resilience/posttraumatic growth and risk factors associated with posttraumatic stress among firefighters exposed to critical incidents. The participants were 286 (257 men and 29 women) volunteer and paid firefighters in Whatcom County, Washington. Participants completed an anonymous survey asking about demographics, critical incident exposure, posttraumatic stress symptoms, posttraumatic growth, resource availability, coping, occupational stress and critical incident stress debriefing experience. Most participants had significant critical incident exposure, and about half had attended critical incident stress debriefing sessions. Posttraumatic growth was associated with being female, critical incident exposure, critical incident stress debriefing attendance, posttraumatic stress symptoms (negative association), occupational support, occupation satisfaction, occupational effort, problem-focused coping, emotion-focused coping and personal characteristic resources. Posttraumatic stress symptoms were positively associated with years of firefighting, burnout, occupational effort and disengagement coping and negatively associated with critical incident stress debriefing attendance, posttraumatic growth, social support, internal locus of control, personal characteristic resources, energy resources and condition resources. The findings support conservation of resources stress theory and show that the maintenance and acquisition of resources can offset losses and facilitate resilience/posttraumatic growth. Implications of the findings for enhancing firefighter resources, facilitating resilience and minimizing occupational stressors are discussed. © 2014 John Wiley & Sons, Ltd.

  7. Direct-current proton-beam measurements at Los Alamos

    International Nuclear Information System (INIS)

    Sherman, J.; Stevens, R.R.; Schneider, J.D.; Zaugg, T.

    1994-01-01

    Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H 2 gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos is given

  8. Aqueous Nitrate Recovery Line at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Finstad, Casey Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-15

    This powerpoint is part of the ADPSM Plutonium Engineering Lecture Series, which is an opportunity for new hires at LANL to get an overview of work done at TA55. It goes into detail about the aqueous nitrate recovery line at Los Alamos National Laboratory.

  9. Mercury: The Los Alamos ICF KrF laser system

    International Nuclear Information System (INIS)

    Czuchlewski, S.J.; York, G.W.; Bigio, I.J.; Brucker, J.; Hanson, D.; Honig, E.M.; Kurnit, N.; Leland, W.; McCown, A.W.; McLeod, J.; Rose, E.; Thomas, S.; Thompson, D.

    1993-01-01

    The Mercury KrF laser facility at Los Alamos is being built with the benefit of lessons learned from the Aurora system. An increased understanding of KrF laser engineering, and the designed implementation of system flexibility, will permit Mercury to serve as a tested for a variety of advanced KrF technology concepts

  10. Waste management at Los Alamos: Protecting our environment

    International Nuclear Information System (INIS)

    1993-01-01

    This report consists of a broad overview of activities at Los Alamos National Laboratory (LANL). The following topics are discussed: The growth of the waste management group; what we do today; the mission of the waste management group; the liquid waste treatment section; the radioactive liquid waste project office; the chemical waste section; the radioactive waste section; and the technical support section

  11. Brief history of the Los Alamos laser programs

    International Nuclear Information System (INIS)

    Boyer, K.

    1983-01-01

    The laser programs at Los Alamos began in 1969 to investigate the feasibility of laser-induced fusion. However, within a year they had been expanded to include a number of other applications including laser isotope separation. These programs now compose a substantial part of the Laboratory's research programs

  12. Summary of environmental surveillance at Los Alamos during 1995

    International Nuclear Information System (INIS)

    1996-10-01

    Linking the Rio Grande Valley and the Jemez Mountains, New Mexico's Pajarito Plateau is home to a world-class scientific institution. Los Alamos National Laboratory (or the Laboratory), managed by the Regents of the University of California, is a government-owned, Department of Energy-supervised complex investigating all areas of modern science for the purposes of national defense, health, conservation, and ecology. The Laboratory was founded in 1943 as part of the Manhattan Project, whose members assembled to create the first nuclear weapon. Occupying the campus of the Los Alamos Ranch School, American and British scientists gathered on the isolated mesa tops to harness recently discovered nuclear power with the hope of ending World War II. In July 1945, the initial objective of the Laboratory, a nuclear device, was achieved in Los Alamos and tested in White Sands, New Mexico. Today the Laboratory continues its role in defense, particularly in nuclear weapons, including developing methods for safely handling weapons and managing waste. For the past twenty years, the Laboratory has published an annual environmental report. This pamphlet offers a synopsis that briefly explains important concepts, such as radiation and provides a summary of the monitoring results and regulatory compliance status that are explained at length in the document entitled Environmental Surveillance at Los Alamos during 1995

  13. Inertial confinement fusion at the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Lindman, E.; Baker, D.; Barnes, C.; Bauer, B.; Beck, J.B.

    1997-01-01

    The Los Alamos National Laboratory is contributing to the resolution of key issues in the US Inertial-Confinement-Fusion Program and plans to play a strong role in the experimental program at the National Ignition Facility when it is completed

  14. Some history of liquid scintillator development at Los Alamos

    International Nuclear Information System (INIS)

    Ott, D.G.

    1979-01-01

    The early developments in liquid scintillation counting made at Los Alamos Scientific Laboratory are reviewed. Most of the work was under the direction of F.N. Hayes and included counter development and applications as well as synthesis and chemistry of liquid scintillators

  15. Inertial confinement fusion at the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lindman, E.; Baker, D.; Barnes, C.; Bauer, B.; Beck, J.B. [and others

    1997-11-01

    The Los Alamos National Laboratory is contributing to the resolution of key issues in the US Inertial-Confinement-Fusion Program and plans to play a strong role in the experimental program at the National Ignition Facility when it is completed.

  16. Equilibrium and stability of the Los Alamos spheromak

    International Nuclear Information System (INIS)

    Marklin, G.

    1984-01-01

    The open mesh flux conserver (MFC) on the Los Alamos spheromak (CTX) has been equipped with a large number of Rogowski loops measuring the current in the individual segments of the MFC, providing a complete picture of the surface current pattern induced by the equilibrium and oscillations of the confined plasma. An analysis was made of the data from these Rogowski loops

  17. Los Alamos high-power proton linac designs

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.P. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    Medium-energy high-power proton linear accelerators have been studied at Los Alamos as drivers for spallation neutron applications requiring large amounts of beam power. Reference designs for such accelerators are discussed, important design factors are reviewed, and issues and concern specific to this unprecedented power regime are discussed.

  18. Sports Management for Sports Massification Planned and Executed by Social Organizations. Critics to Models, Experiences and Proposal Methodological Accompaniment

    OpenAIRE

    Lorenza Antonia Reyes de Duran

    2016-01-01

    The proposal analysis, interpretation, disassembly, self-criticism and guidance is born and comes from work experience planned mass sports and social organizations opposed-not in the conventional sense comparative-private business models and sport, state and management. The contribution made by the sports management experience from positions of power, either state or business are undeniable and its impact is difficult to express in numbers for its humanistic value, which is incalculable. Howe...

  19. Campus Climate and the Underrepresented Minority Engineering Student Experience: A Critical Race Study

    Science.gov (United States)

    Mayes, Terrance

    In the current technological era, the number of minorities in science, technology, engineering, and mathematics (STEM) is a crucial factor in predetermining the economic growth of the United States. Since the minority population is growing at much faster rates than the non-minority population, the lack of proportionate production of minority engineers poses a threat to the United States' ability to remain a global competitor in technological innovation. Sixty-three per cent (63%) of undergraduate students who enter engineering majors continue on to graduate in that major. The graduation rate, however, for African-American, Hispanic, and Native-American students in engineering is significantly lower at 39%. As this group represents only a small fraction of the annual student enrollment, engineering programs are graduating these minority groups at rates that are greatly disproportionate to United States demographics. Therefore, researchers are thoroughly investigating certain initiatives that promote academic success among underrepresented minority students in engineering. Colleges and universities have attempted to address the growing achievement gap between underrepresented minority and non-minority engineering students, predominately through various deficit-based interventions, focusing on the student's flaws and problems. As the pipeline for minorities in engineering continues to narrow, it begs the question of whether institutions are focusing on the right solutions to the problem. Critical Race Theory scholars argue that colleges and universities must address institutional climate issues around students, such as racism, microaggressions, and marginalization, before members of oppressed groups can truly succeed. This dissertation explored the unique experiences of underrepresented minority engineering students in a predominately White and Asian campus.

  20. Promotion of critical thinking in e-learning: a qualitative study on the experiences of instructors and students

    Science.gov (United States)

    Gharib, Mitra; Zolfaghari, Mitra; Mojtahedzadeh, Rita; Mohammadi, Aeen; Gharib, Atoosa

    2016-01-01

    Background With the increasing popularity of e-learning programs, educational stakeholders are attempting to promote critical thinking in the virtual education system. This study aimed to explore the experiences of both the instructors and the students about critical thinking promotion within the virtual education system. Methods This qualitative study recruited the instructors and students from four academic disciplines provided by the Virtual School of Tehran University of Medical Sciences (Tehran, Iran). All programs were master’s degree programs and utilized a blended (combination of e-learning and face to face) training. Semistructured interviews with the participants were used to collect data. Results The participants had a variety of experiences about how to promote critical thinking. These experiences were conceptualized in four main themes, namely, instructional design, educational leadership and management, local evidence, and belief systems. Conclusion The present study clarified the factors affecting critical thinking promotion in e-learning. Not only the instructors but also the educational designers and leaders can benefit from our findings to improve the quality of virtual education programs and promote critical thinking. PMID:27217807

  1. Promotion of critical thinking in e-learning: a qualitative study on the experiences of instructors and students.

    Science.gov (United States)

    Gharib, Mitra; Zolfaghari, Mitra; Mojtahedzadeh, Rita; Mohammadi, Aeen; Gharib, Atoosa

    2016-01-01

    With the increasing popularity of e-learning programs, educational stakeholders are attempting to promote critical thinking in the virtual education system. This study aimed to explore the experiences of both the instructors and the students about critical thinking promotion within the virtual education system. This qualitative study recruited the instructors and students from four academic disciplines provided by the Virtual School of Tehran University of Medical Sciences (Tehran, Iran). All programs were master's degree programs and utilized a blended (combination of e-learning and face to face) training. Semistructured interviews with the participants were used to collect data. The participants had a variety of experiences about how to promote critical thinking. These experiences were conceptualized in four main themes, namely, instructional design, educational leadership and management, local evidence, and belief systems. The present study clarified the factors affecting critical thinking promotion in e-learning. Not only the instructors but also the educational designers and leaders can benefit from our findings to improve the quality of virtual education programs and promote critical thinking.

  2. Environmental Survey preliminary report, Los Alamos National Laboratory, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    1988-01-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy's (DOE) Los Alamos National Laboratory (LANL), conducted March 29, 1987 through April 17, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are outside experts being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the LANL. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at the LANL, and interviews with site personnel. The Survey team developed Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by the Idaho National Engineering Laboratory. When completed, the results will be incorporated into the LANL Environmental Survey Interim Report. The Interim Report will reflect the final determinations of the Survey for the LANL. 65 refs., 68 figs., 73 tabs

  3. Environmental assessment for effluent reduction, Los Alamos National Laboratory, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-11

    The Department of Energy (DOE) proposes to eliminate industrial effluent from 27 outfalls at Los Alamos National Laboratory (LANL). The Proposed Action includes both simple and extensive plumbing modifications, which would result in the elimination of industrial effluent being released to the environment through 27 outfalls. The industrial effluent currently going to about half of the 27 outfalls under consideration would be rerouted to LANL`s sanitary sewer system. Industrial effluent from other outfalls would be eliminated by replacing once-through cooling water systems with recirculation systems, or, in a few instances, operational changes would result in no generation of industrial effluent. After the industrial effluents have been discontinued, the affected outfalls would be removed from the NPDES Permit. The pipes from the source building or structure to the discharge point for the outfalls may be plugged, or excavated and removed. Other outfalls would remain intact and would continue to discharge stormwater. The No Action alternative, which would maintain the status quo for LANL`s outfalls, was also analyzed. An alternative in which industrial effluent would be treated at the source facilities was considered but dismissed from further analysis because it would not reasonably meet the DOE`s purpose for action, and its potential environmental effects were bounded by the analysis of the Proposed Action and the No Action alternatives.

  4. Environmental assessment for effluent reduction, Los Alamos National Laboratory, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    1996-01-01

    The Department of Energy (DOE) proposes to eliminate industrial effluent from 27 outfalls at Los Alamos National Laboratory (LANL). The Proposed Action includes both simple and extensive plumbing modifications, which would result in the elimination of industrial effluent being released to the environment through 27 outfalls. The industrial effluent currently going to about half of the 27 outfalls under consideration would be rerouted to LANL's sanitary sewer system. Industrial effluent from other outfalls would be eliminated by replacing once-through cooling water systems with recirculation systems, or, in a few instances, operational changes would result in no generation of industrial effluent. After the industrial effluents have been discontinued, the affected outfalls would be removed from the NPDES Permit. The pipes from the source building or structure to the discharge point for the outfalls may be plugged, or excavated and removed. Other outfalls would remain intact and would continue to discharge stormwater. The No Action alternative, which would maintain the status quo for LANL's outfalls, was also analyzed. An alternative in which industrial effluent would be treated at the source facilities was considered but dismissed from further analysis because it would not reasonably meet the DOE's purpose for action, and its potential environmental effects were bounded by the analysis of the Proposed Action and the No Action alternatives

  5. Environmental Survey preliminary report, Los Alamos National Laboratory, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy's (DOE) Los Alamos National Laboratory (LANL), conducted March 29, 1987 through April 17, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are outside experts being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the LANL. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at the LANL, and interviews with site personnel. The Survey team developed Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by the Idaho National Engineering Laboratory. When completed, the results will be incorporated into the LANL Environmental Survey Interim Report. The Interim Report will reflect the final determinations of the Survey for the LANL. 65 refs., 68 figs., 73 tabs.

  6. Racial Inequality in Critical Thinking Skills: The Role of Academic and Diversity Experiences

    Science.gov (United States)

    Roksa, Josipa; Trolian, Teniell L.; Pascarella, Ernest T.; Kilgo, Cindy A.; Blaich, Charles; Wise, Kathleen S.

    2017-01-01

    While racial inequalities in college entry and completion are well documented, much less is known about racial disparities in the development of general collegiate skills, such as critical thinking. Using data from the Wabash National Study of Liberal Arts Education, we find substantial inequality in the development of critical thinking skills…

  7. KEOPS and other VENUS experiments dedicated to the criticality safety of a MOX fuel fabrication facility

    International Nuclear Information System (INIS)

    Lance, Benoit; Van Den Hende, Paul; Marloye, Daniel; Basselier, Jacques; Libon, Henri; De Vleeschhauwer, Marc; Moerenhout, Jeremie; Baeten, Peter

    2005-01-01

    The qualification scheme of criticality computer codes for Pu bearing powders lies upon databases which suffer from a lack of recent experimental results. As a MOX manufacture, BELGONUCLEAIRE is especially concerned by criticality safety and would like to address such an issue by launching with SCK-CEN an International Programme called KEOPS. (author)

  8. Analysis of driver critical reason and years of driving experience in large truck crashes, analysis brief.

    Science.gov (United States)

    2017-01-01

    The 2005 Large Truck Crash Causation Study (LTCCS)i was the first-ever national study to attempt to determine the critical reasons and associated factors that contribute to serious large truck crashes. The LTCCS defines critical reason as the r...

  9. Validation of the ABBN/CONSYST constants system. Part 2: Validation through the critical experiments on cores with uranium solutions

    International Nuclear Information System (INIS)

    Ivanova, T.T.; Manturov, G.N.; Nikolaev, M.N.; Rozhikhin, E.V.; Semenov, M.Yu.; Tsiboulia, A.M.

    1999-01-01

    Results of calculations of critical assemblies with the cores of uranium solutions for the considered series of the experiments are presented in this paper. The conclusions about acceptability of the ABBN-93.1 cross sections for the calculations of such systems are made. (author)

  10. A Course in Critical Thinking for PhD Students in Biomolecular Sciences and Biotechnology: Classical Experiments in Biochemistry

    Science.gov (United States)

    Hirschberg, Carlos B.

    2016-01-01

    This essay presents and discusses an eight-session seminar course designed to develop critical thinking skills in doctoral biochemistry students by exposing them to classical experiments in biochemistry. During each 2.5 session, different key topics of the discovery and development of biochemical concepts are discussed. Before each session,…

  11. Diversity and Collegiate Experiences Affecting Self-Perceived Gains in Critical Thinking: Which Works, and Who Benefits?

    Science.gov (United States)

    Cole, Darnell; Zhou, Ji

    2014-01-01

    This study is grounded in the theoretical and conceptual frameworks that postulate diversity and collegiate experiences as triggers for the cognitive disequilibrium that fosters critical thinking (CT). With the assumption that CT is both a general and a discipline-specific facility, this longitudinal, single-institution study of 447 students…

  12. Commercialization of Los Alamos National Laboratory technologies via small businesses. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brice, R.; Carton, D.; Rhyne, T. [and others

    1997-06-01

    Appendices are presented from a study performed on a concept model system for the commercialization of Los Alamos National Laboratory technologies via small businesses. Topics include a summary of information from the joint MCC/Los Alamos technology conference; a comparison of New Mexico infrastructure to other areas; a typical licensing agreement; technology screening guides; summaries of specific DOE/UC/Los Alamos documents; a bibliography; the Oak Ridge National Laboratory TCRD; The Ames Center for Advanced Technology Development; Los Alamos licensing procedures; presentation of slides from monthly MCC/Los Alamos review meetings; generalized entrepreneurship model; and a discussion on receiving equity for technology.

  13. Monitoring Sensitive Bat Species at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberg, Kari M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-15

    Bats play a critical role in ecosystems and are vulnerable to disturbance and disruption by human activities. In recent decades, bat populations in the United States and elsewhere have decreased tremendously. There are 47 different species of bat in the United States and 28 of these occur in New Mexico with 15 different species documented at the Los Alamos National Laboratory (LANL) and surrounding areas. Euderma maculatum(the spotted bat) is listed as “threatened” by the state of New Mexico and is known to occur at LANL. Four other species of bats are listed as “sensitive” and also occur here. In 1995, a four year study was initiated at LANL to assess the status of bat species of concern, elucidate distribution and relative abundance, and obtain information on roosting sites. There have been no definitive studies since then. Biologists in the Environmental Protection Division at LANL initiated a multi-year monitoring program for bats in May 2013 to implement the Biological Resources Management Plan. The objective of this ongoing study is to monitor bat species diversity and seasonal activity over time at LANL. Bat species diversity and seasonal activity were measured using an acoustic bat detector, the Pettersson D500X. This ultrasound recording unit is intended for long-term, unattended recording of bat and other high frequency animal calls. During 2013, the detector was deployed at two locations around LANL. Study sites were selected based on proximity to water where bats may be foraging. Recorded bat calls were analyzed using Sonobat, software that can help determine specific species of bat through their calls. A list of bat species at the two sites was developed and compared to lists from previous studies. Species diversity and seasonal activity, measured as the number of call sequences recorded each month, were compared between sites and among months. A total of 17,923 bat calls were recorded representing 15 species. Results indicate that there is a

  14. Contributions to the qualification of the ''CRISTAL'' criticality calculi scheme: interpretation of critical experiments. Elaboration of a characterization system of neutronic configurations

    International Nuclear Information System (INIS)

    Gagnier, E.

    1999-06-01

    This thesis work is about the validation of the new criticality-safety package CRISTAL and contributes to the modernization and the improvement of the computational tools. The first part presents neutronic elements, the objectives of safety criticality studies and the package CRISTAL. Then, the validation work concerned two series of experiments involving uranyl solutions (UO 2 F 2 ) and UO 2 powders. For these experiments, the differences between the computation results and the experimental results were analysed. It was highlighted interesting physical phenomena such of the compensations of errors between the approximate representation by the 99 energy group structure on the first resonance of oxygen and the anisotropy of the diffusion simulation as well as the influence of uranium 234 in high enriched solutions in uranium 235. Once the work of the experimental qualification carried out, raises the question of the use the base of qualification and the ''calculation-experiment'' variations which are referred to it. It is often difficult to establish the link between the ''studied configuration'' and the experiments of the base of qualification. The presented characterisation system proposes to answer in a way automatic and quantified this difficulty: - in bringing an answer on the package qualification for the studied configuration, - in giving an estimate of the package bias. To answer these points, it was defined a set of 35 characteristic neutronic parameters representing the behaviour of the medium. To process the information brought by these parameters and to use it to answer the objectives of the system, we called upon statistical methods (Principal Components Analysis and Sliced Inverse Regression). The results obtained in the feasibility studies showed the relevance of these methods for the considered objectives. (author)

  15. LANSCE: Los Alamos Neutron Science Center

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-02

    The principle goals of this project is to increase flux and improve resolution for neutron energies above 1 keV for nuclear physics experiments; and preserve current strong performance at thermal energies for material science.

  16. Transactions of the criticality alarm systems workshop

    International Nuclear Information System (INIS)

    1988-01-01

    The first Criticality Alarm workshop was held by the US Department of Energy Albuquerque Operations Office in 1985. This second workshop is the first held on an international level. There were 98 persons in attendance. They represented the Department of Energy (DOE) field offices, DOE contractors, the Nuclear Regulatory Commission (NRC), NRC licensees, and agencies in the United Kingdom, France, West Germany, and Japan. Topics were on practices experience, and development. A key value of the workshop was the sharing of critical alarm system experiences, problems, and advances in the state of the art. In addition, several Criticality Alarm Systems (CAS) equipment systems were exhibited. Papers were presented on: nature of criticality accidents; lessons learned from past accidents; application of ANS 8.3 standard; gamma and neutron detection systems; research and development in progress; testing at Oak Ridge and Los Alamos; methods used to place detectors; centralized readout feature; false alarms; trip-point settings; and testing and maintenance. The individual papers have been cataloged separately

  17. A CRITICISM OF MONETARISM : WITH SOME POINTS FROM THE JAPANESE EXPERIENCE

    OpenAIRE

    BRAGUINSKY, Serguey

    1988-01-01

    The paper attempts at unifying the criticism of "classical dichotomy" made by J. A. Schumpeter and J. M. Keynes. Though Schumpeter's vision was that of the developing economy, with money being an important source of that development, while Keynes dealt primarily with an economy in a state of depression, Keynes's criticism is conjectured to presuppose the existence of the Schumpeterian world in the background, because only in this case can money play an active role by linking the past, present...

  18. Critical heat flux experiments in a circular tube with heavy water and light water. (AWBA Development Program)

    International Nuclear Information System (INIS)

    Williams, C.L.; Beus, S.G.

    1980-05-01

    Experiments were performed to establish the critical heat flux (CHF) characteristics of heavy water and light water. Testing was performed with the up-flow of heavy and of light water within a 0.3744 inch inside diameter circular tube with 72.3 inches of heated length. Comparisons were made between heavy water and light water critical heat flux levels for the same local equilibrium quality at CHF, operating pressure, and nominal mass velocity. Results showed that heavy water CHF values were, on the average, 8 percent below the light water CHF values

  19. Recent developments in the Los Alamos National Laboratory Plutonium Facility Waste Tracking System-automated data collection pilot project

    International Nuclear Information System (INIS)

    Martinez, B.; Montoya, A.; Klein, W.

    1999-01-01

    The waste management and environmental compliance group (NMT-7) at the Los Alamos National Laboratory has initiated a pilot project for demonstrating the feasibility and utility of automated data collection as a solution for tracking waste containers at the Los Alamos National Laboratory Plutonium Facility. This project, the Los Alamos Waste Tracking System (LAWTS), tracks waste containers during their lifecycle at the facility. LAWTS is a two-tiered system consisting of a server/workstation database and reporting engine and a hand-held data terminal-based client program for collecting data directly from tracked containers. New containers may be added to the system from either the client unit or from the server database. Once containers are in the system, they can be tracked through one of three primary transactions: Move, Inventory, and Shipment. Because LAWTS is a pilot project, it also serves as a learning experience for all parties involved. This paper will discuss many of the lessons learned in implementing a data collection system in the restricted environment. Specifically, the authors will discuss issues related to working with the PPT 4640 terminal system as the data collection unit. They will discuss problems with form factor (size, usability, etc.) as well as technical problems with wireless radio frequency functions. They will also discuss complications that arose from outdoor use of the terminal (barcode scanning failures, screen readability problems). The paper will conclude with a series of recommendations for proceeding with LAWTS based on experience to date

  20. An Overview of the Los Alamos Inertial Confinement Fusion and High-Energy-Density Physics Research Programs

    Energy Technology Data Exchange (ETDEWEB)

    Batha, Steven H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Physics Division

    2016-07-15

    The Los Alamos Inertial Confinement Fusion and Science Programs engage in a vigorous array of experiments, theory, and modeling. We use the three major High Energy Density facilities, NIF, Omega, and Z to perform experiments. These include opacity, radiation transport, hydrodynamics, ignition science, and burn experiments to aid the ICF and Science campaigns in reaching their stewardship goals. The ICF program operates two nuclear diagnostics at NIF, the neutron imaging system and the gamma reaction history instruments. Both systems are being expanded with significant capability enhancements.

  1. Tiger Team Assessment of the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    1991-11-01

    This report documents the Tiger Team Assessment of the Los Alamos National Laboratory (LANL) located in Los Alamos, New Mexico. LANL is operated for the US Department of Energy (DOE) by the University of California. The Tiger Team Assessment was conducted from September 23 to November 8, 1991, under the auspices of the DOE Office of Special Projects, Office of Assistant Secretary for Environment, Safety and Health. The assessment was comprehensive, encompassing environmental, safety, and health (ES ampersand H) disciplines; management; and contractor and DOE self-assessments. Compliance with applicable Federal, state, and local regulations; applicable DOE Orders; best management practices; and internal LANL site requirements was assessed. In addition, an evaluation of the adequacy and effectiveness of the DOE and the site contractors' management of ES ampersand H/quality assurance programs was conducted. This volume discusses findings concerning the environmental assessment

  2. Tiger Team Assessment of the Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-01

    This report documents the Tiger Team Assessment of the Los Alamos National Laboratory (LANL) located in Los Alamos, New Mexico. LANL is operated for the US Department of Energy (DOE) by the University of California. The Tiger Team Assessment was conducted from September 23 to November 8, 1991, under the auspices of the DOE Office of Special Projects, Office of Assistant Secretary for Environment, Safety and Health. The assessment was comprehensive, encompassing environmental, safety, and health (ES H) disciplines; management; and contractor and DOE self-assessments. Compliance with applicable Federal, state, and local regulations; applicable DOE Orders; best management practices; and internal LANL site requirements was assessed. In addition, an evaluation of the adequacy and effectiveness of the DOE and the site contractors' management of ES H/quality assurance programs was conducted. This volume discusses findings concerning the environmental assessment.

  3. Hazardous waste systems analysis at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Urioste, J.

    1997-01-01

    Los Alamos National Laboratory produces routine and non-routine hazardous waste as a by-product of mission operations. Hazardous waste commonly generated at the Laboratory includes many types of laboratory research chemicals, solvents, acids, bases, carcinogens, compressed gases, metals, and other solid waste contaminated with hazardous waste. The Los Alamos National Laboratory Environmental Stewardship Office has established a Hazardous Waste Minimization Coordinator to specifically focus on routine and non-routine RCRA, TSCA, and other administratively controlled wastes. In this process, the Waste Minimization Coordinator has developed and implemented a systems approach to define waste streams, estimate waste management costs and develop plans to implement avoidance practices, and develop projects to reduce or eliminate the waste streams at the Laboratory. The paper describes this systems approach

  4. A proposal for a Los Alamos international facility for transmutations (LIFT)

    International Nuclear Information System (INIS)

    Venneri, F.; Williamson, M.A.; Li, Ning; Doolen, G.

    1996-01-01

    The major groups engaged in transmutation research are converging towards a common objective and similar technology. It is now possible to envision an international program of research aimed at the destruction of reactor-generated (and other) nuclear waste using a series of multipurpose experimental facilities in the near future. Los Alamos National Laboratory, as the home of the highest power LINAC and a very active transmutation technology project, is the ideal host for the first of such facilities. The next step in the international program (a facility 10 times more powerful, for engineering-scale demonstrations) could be built in Europe, where there is substantial interest in the construction of such a device in the framework of international cooperation. A series of experiments at Las Alamos could explore the key transmutation technologies. Liquid lead loops, a liquid lead spallation target, and a large size liquid lead facility with provision for irradiation, cooling and diagnostics of several types of 'transmutation assemblies', where different transmutation concepts will be tested in different media and environments, from transmutation of fission products to destruction by fission of higher actinides, to other waste management applications. The engineering-scale facility, which will follow the initial testing phase, will extend the best concepts to full scale implementation

  5. The Los Alamos Laser Acceleration of Particles Workshop and beginning of the advanced accelerator concepts field

    Science.gov (United States)

    Joshi, C.

    2012-12-01

    The first Advanced Acceleration of Particles-AAC-Workshop (actually named Laser Acceleration of Particles Workshop) was held at Los Alamos in January 1982. The workshop lasted a week and divided all the acceleration techniques into four categories: near field, far field, media, and vacuum. Basic theorems of particle acceleration were postulated (later proven) and specific experiments based on the four categories were formulated. This landmark workshop led to the formation of the advanced accelerator R&D program in the HEP office of the DOE that supports advanced accelerator research to this day. Two major new user facilities at Argonne and Brookhaven and several more directed experimental efforts were built to explore the advanced particle acceleration schemes. It is not an exaggeration to say that the intellectual breadth and excitement provided by the many groups who entered this new field provided the needed vitality to then recently formed APS Division of Beams and the new online journal Physical Review Special Topics-Accelerators and Beams. On this 30th anniversary of the AAC Workshops, it is worthwhile to look back at the legacy of the first Workshop at Los Alamos and the fine groundwork it laid for the field of advanced accelerator concepts that continues to flourish to this day.

  6. Los Alamos National Laboratory Science Education Programs. Progress report, October 1, 1994--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Gill, D.H.

    1995-02-01

    During the 1994 summer institute NTEP teachers worked in coordination with LANL and the Los Alamos Middle School and Mountain Elementary School to gain experience in communicating on-line, to gain further information from the Internet and in using electronic Bulletin Board Systems (BBSs) to exchange ideas with other teachers. To build on their telecommunications skills, NTEP teachers participated in the International Telecommunications In Education Conference (Tel*ED `94) at the Albuquerque Convention Center on November 11 & 12, 1994. They attended the multimedia keynote address, various workshops highlighting many aspects of educational telecommunications skills, and the Telecomm Rodeo sponsored by Los Alamos National Laboratory. The Rodeo featured many presentations by Laboratory personnel and educational institutions on ways in which telecommunications technologies can be use din the classroom. Many were of the `hands-on` type, so that teachers were able to try out methods and equipment and evaluate their usefulness in their own schools and classrooms. Some of the presentations featured were the Geonet educational BBS system, the Supercomputing Challenge, and the Sunrise Project, all sponsored by LANL; the `CU-seeMe` live video software, various simulation software packages, networking help, and many other interesting and useful exhibits.

  7. Summary of environmental surveillance at Los Alamos during 1994

    International Nuclear Information System (INIS)

    1996-03-01

    Linking the Rio Grande Valley and the Jemez Mountains, New Mexico's Pajarito Plateau is home to a world-class scientific institution. Los Alamos National Laboratory (or the Laboratory), managed by the Regents of the University of California, is a government-owned, Department of Energy-supervised complex investigating all areas of modern science for the purposes of national defense, health, conservation, and ecology. This report briefly describes the environmental monitoring program for the Laboratory

  8. HTGR safety research at the Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Stroh, K.R.; Anderson, C.A.; Kirk, W.L.

    1982-01-01

    This paper summarizes activities undertaken at the Los Alamos National Laboratory as part of the High-Temperature Gas-Cooled Reactor (HTGR) Safety Research Program sponsored by the US Nuclear Regulatory Commission. Technical accomplishments and analysis capabilities in six broad-based task areas are described. These tasks are: fission-product technology, primary-coolant impurities, structural investigations, safety instrumentation and control systems, accident delineation, and phenomena modeling and systems analysis

  9. Decommissioning three nuclear reactors at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Montoya, G.M.; Salazar, M.

    1992-01-01

    Three nuclear reactors, including the historic water boiler reactor, were decommissioned at Los Alamos National Laboratory (LANL). The decommissioning of the facilities involved removing the reactors and their associated components. Planning for the decommissioning operation included characterizing the facilities, estimating the costs of decommissioning operations, preparing environmental documentation, establishing systems to track costs and work progress, and preplanning to correct health and safety concerns in each facility

  10. Medical record automation at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Hogle, G.O.; Grier, R.S.

    1979-01-01

    With the increase in population at the Los Alamos Scientific Laboratory and the growing concern over employee health, especially concerning the effects of the work environment, the Occupational Medicine Group decided to automate its medical record keeping system to meet these growing demands. With this computer system came not only the ability for long-term study of the work environment verses employee health, but other benefits such as more comprehensive records, increased legibility, reduced physician time, and better records management

  11. Evolution of the Field of Statistics at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Picard, Richard Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-24

    Through years of technological improvements, cultural change, advances in statistical theory, revisions of federal government structure and policies, Laboratory re-organizations, offce re-locations, and so on, the practice of statistics at Los Alamos has evolved from its origins in the early 1950s, with a handful of statisticians working in LASL group T-1, to present-day group CCS-6. This report chronicles that history.

  12. Coretran/Vipre assembly critical power assessment against Nupec BWR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Aounallah, Y. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    2001-07-01

    This study has been performed, in the framework of the STARS project, to assess CORETRAN-01/VIPRE-02 code capability to predict critical heat flux conditions for BWR fuel assemblies. The assessment is based on comparisons of the code results with the NUPEC steady-state critical power measurements on full-scale assemblies tested under a range of flow conditions. Two assembly types were considered, the standard BWR 8 x 8 and the so-called ''high-burnup'' assembly, similar to GE-10. Code modelling options that have a significant impact on the results have been identified, along with code limitations. (author)

  13. Tests of HAMMER (original) and HAMMER-TECHNION systems with critical experiments

    International Nuclear Information System (INIS)

    Santos, A. dos

    1986-01-01

    Performances of the reactor cell codes HAMMER (original) and HAMMER-TECHNION were tested against experimental results of critical benchmarks. The option made was the utilization of consistent methodologies so that only the NIT (Nordheim Integral Technique) was utilized in the HAMMER-TECHNION. All differences encountered in the analysis made with these systems can be attributed to their basic nuclear data library. Five critical benchmarks was utilized on this study. Surprisingly, the performance of the original HAMMER system was betterthan that of the HAMMER-TECHNION. (Author) [pt

  14. The experience of communication difficulties in critically ill patients in and beyond intensive care: Findings from a larger phenomenological study.

    Science.gov (United States)

    Tembo, Agness C; Higgins, Isabel; Parker, Vicki

    2015-06-01

    Communication difficulties in intensive care units (ICU) with critically ill patients have been well documented for more than three decades. However, there is only a paucity of literature that has explored communication difficulties beyond the ICU environment. This paper discusses the experience of communication difficulties in critically ill patients in ICU and beyond as part of findings from a larger study that explored the lived experiences of critically ill patients in ICU in the context of daily sedation interruption (DSI). The aim of the study was to describe the lived experience of people who experienced critical illness in ICU using a hermeneutic phenomenological approach in the DSI context. Twelve participants aged between 20 and 76 years with an ICU stay ranging from 3 to 36 days were recruited from a 16 bed ICU in a large regional referral hospital in New South Wales (NSW), Australia. Participants were intubated, mechanically ventilated and subjected to (DSI) during their critical illness in ICU. In-depth face to face interviews with participants were conducted at two weeks after discharge from ICU and at six to eleven months later. Interviews were audio taped and transcribed. Thematic analysis using van Manen's (1990) method was completed. The overarching theme; 'Being in limbo' and subthemes 'Being disrupted'; 'Being imprisoned' and 'Being trapped' depict the main elements of the experience. This paper discusses communication difficulties in critically ill patients as one of the main findings relating to the theme 'Being trapped'. Participants' reports of communication difficulties in ICU are similar to those reported by patients in other studies where DSI was not used. However, not many studies have reported ongoing communication difficulties after ICU hospitalisation. Recommendations are made for new models of care and support to mitigate critically ill patients' communication concerns in ICU and for further research into the causes and treatment to

  15. Radioisotope research and development at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Peterson, E.J.

    1993-01-01

    Throughout its fifty year history, Los Alamos National Laboratory has conducted research and development in the production, isolation, purification, and application of radioactive isotopes. Initially this work supported the weapons development mission of the Laboratory. Over the years the work has evolved to support basic and applied research in many diverse fields, including nuclear medicine, biomedical studies, materials science, environmental research and the physical sciences. In the early 1970s people in the Medical Radioisotope Research Program began irradiating targets at the Los Alamos Meson Physics Facility (LAMPF) to investigate the production and recovery of medically important radioisotopes. Since then spallation production using the high intensity beam at LAMPF has become a significant source of many important radioisotopes. Los Alamos posesses other facilities with isotope production capabilities. Examples are the Omega West Reactor (OWR) and the Van de Graaf Ion Beam Facility (IBF). Historically these facilities have had limited availability for radioisotope production, but recent developments portend a significant radioisotope production mission in the future

  16. James L. Tuck Los Alamos ball lightning pioneer

    Energy Technology Data Exchange (ETDEWEB)

    Baker, D.A.

    1999-07-01

    James Tuck was well known for starting the Project Sherwood group at Los Alamos Scientific Laboratory in 1952. This group was formed to study and develop concepts for controlled fusion energy. In his later years after retiring from Controlled Fusion Division, he continued research at Los Alamos on the topic of ball lightning. He traveled widely giving lectures on both observations of others and his own experimental efforts. He collected anecdotal observations obtained from those in his lecture audiences during his travels and from responses from newspaper articles where he asked for specific information from ball lightning observers. He finally cut off this collection of data when the number of responses became overwhelming. The author's primary publication on ball lightning was a short laboratory report. He planned on publishing a book on the subject but this was never completed before his death. Tuck focused his experimental effort on attempting to duplicate the production of plasma balls claimed to be observed in US Navy submarines when a switch was opened under overload conditions with battery power. During lunch breaks he made use of a Los Alamos N-division battery bank facility to mock up a submarine power pack and switch gear. This non-funded effort was abruptly terminated when an explosion occurred in the facility. An overview of Tuck's research and views will be given. The flavor Jim's personality as well as a ball produced with his experimental apparatus will be shown using video chips.

  17. Los Alamos Science: The Human Genome Project. Number 20, 1992

    Science.gov (United States)

    Cooper, N. G.; Shea, N. eds.

    1992-01-01

    This document provides a broad overview of the Human Genome Project, with particular emphasis on work being done at Los Alamos. It tries to emphasize the scientific aspects of the project, compared to the more speculative information presented in the popular press. There is a brief introduction to modern genetics, including a review of classic work. There is a broad overview of the Genome Project, describing what the project is, what are some of its major five-year goals, what are major technological challenges ahead of the project, and what can the field of biology, as well as society expect to see as benefits from this project. Specific results on the efforts directed at mapping chromosomes 16 and 5 are discussed. A brief introduction to DNA libraries is presented, bearing in mind that Los Alamos has housed such libraries for many years prior to the Genome Project. Information on efforts to do applied computational work related to the project are discussed, as well as experimental efforts to do rapid DNA sequencing by means of single-molecule detection using applied spectroscopic methods. The article introduces the Los Alamos staff which are working on the Genome Project, and concludes with brief discussions on ethical, legal, and social implications of this work; a brief glimpse of genetics as it may be practiced in the next century; and a glossary of relevant terms.

  18. Water supply at Los Alamos during 1996. Progress report

    International Nuclear Information System (INIS)

    McLin, S.G.; Purtymun, W.D.; Maes, M.N.; Longmire, P.A.

    1997-12-01

    Production of potable municipal water supplies during 1996 totaled about 1,368.1 million gallons from wells in the Guaje, Pajarito, and Otowi well fields. There was no water used from either the spring gallery in Water Canyon or from Guaje Reservoir during 1996. About 2.6 million gallons of water from Los Alamos Reservoir was used for lawn irrigation. The total water usage in 1996 was about 1,370.7 million gallons, or about 131 gallons per day per person living in Los Alamos County. Groundwater pumpage was up about 12.0 million gallons in 1996 compared with the pumpage in 1995. This report fulfills requirements specified in US Department of Energy (DOE) Order 5400.1 (Groundwater Protection Management Program), which requires the Los Alamos National Laboratory (LANL) to monitor and document groundwater conditions below Pajarito Plateau and to protect the regional aquifer from contamination associated with Laboratory operations. Furthermore, this report also fulfills special conditions by providing information on hydrologic characteristics of the regional aquifer, including operating conditions of the municipal water supply system

  19. Los Alamos Science: The Human Genome Project. Number 20, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, N G; Shea, N [eds.

    1992-01-01

    This article provides a broad overview of the Human Genome Project, with particular emphasis on work being done at Los Alamos. It tries to emphasize the scientific aspects of the project, compared to the more speculative information presented in the popular press. There is a brief introduction to modern genetics, including a review of classic work. There is a broad overview of the Genome Project, describing what the project is, what are some of its major five-year goals, what are major technological challenges ahead of the project, and what can the field of biology, as well as society expect to see as benefits from this project. Specific results on the efforts directed at mapping chromosomes 16 and 5 are discussed. A brief introduction to DNA libraries is presented, bearing in mind that Los Alamos has housed such libraries for many years prior to the Genome Project. Information on efforts to do applied computational work related to the project are discussed, as well as experimental efforts to do rapid DNA sequencing by means of single-molecule detection using applied spectroscopic methods. The article introduces the Los Alamos staff which are working on the Genome Project, and concludes with brief discussions on ethical, legal, and social implications of this work; a brief glimpse of genetics as it may be practiced in the next century; and a glossary of relevant terms.

  20. Challenging "Size Matters" Messages: An Exploration of the Experiences of Critical Obesity Scholars in Higher Education

    Science.gov (United States)

    Cameron, Erin

    2016-01-01

    Given that postsecondary institutions are increasingly seen as sites to promote health, critical scholars are calling attention to how the contemporary Western weight-centred health paradigm reinforces a "size matters" message that is fueling harmful attitudes towards and judgments of bodies. As such, research that highlights strategies…

  1. New Graduate Nurses' Perceived Definition of Critical Thinking during Their First Nursing Experience

    Science.gov (United States)

    Kaddoura, Mahmoud

    2013-01-01

    Critical thinking (CT) is a flourishing concept that has been developing throughout the fields of both nursing education and practice. In fact, every person thinks in his or her own way that is varied among individuals; it is the nature of human mankind to do so. Nevertheless, much of our thinking might be subjective, indefinite, limited,…

  2. Intertextualizing Interactive Texts for Critical Thinking: A South Korean EFL Experience

    Science.gov (United States)

    Chandrasoma, Ranamukalage; Ananda, Lalith

    2017-01-01

    In the past three decades or so, the conceptual rigour of intertextuality has exercised enormous influence on pedagogical practices. In this context, intertextuality can also be used as a means of harnessing students' critical stances that are crucial for teaching language skills. Based on eight qualitative student interviews at a university in…

  3. Los Alamos Science, Number 13, Spring 1986

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1986-01-01

    A review of the advances that have been made in the field of x-ray astrophysics is presented. A discussion of the information which can be gleaned from the spectra is also presented. The internal dynamics of neutron stars is discussed. Models of neutron star structure are discussed. A cooperative experiment which measured the spectra of Cygnus X-3 (10 9 to 10 18 hertz) is discussed. The role of angular momentum in the cosmology of the universe is discussed. 33 refs., 40 figs

  4. Measuring the coefficient of restitution and more: a simple experiment to promote students’ critical thinking and autonomous work

    Science.gov (United States)

    González, Manuel Á.; González, Miguel Á.; Vegas, Jesús; Llamas, César

    2017-09-01

    A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to think of physics as a whole subject instead of a set of, more or less, isolated parts. The experiment can be done either in teaching laboratories or as an autonomous work by students at home. Students’ smartphones and cheap balls of different materials are the only experimental materials required to do the experiment. The proposed work also permits the students to analyse the limitations of a physical model used in the experiment by analysing the approximations considered in it, and then enhancing their critical thinking.

  5. Comparative study on neutron data in integral experiments of MYRRHA mockup critical cores in the VENUS-F reactor

    Directory of Open Access Journals (Sweden)

    Krása Antonín

    2017-01-01

    Full Text Available VENUS-F is a fast, zero-power reactor with 30% wt. metallic uranium fuel and solid lead as coolant simulator. It serves as a mockup of the MYRRHA reactor core. This paper describes integral experiments performed in two critical VENUS-F core configurations (with and without graphite reflector. Discrepancies between experiments and Monte Carlo calculations (MCNP5 of keff, fission rate spatial distribution and reactivity effects (lead void and fuel Doppler depending on a nuclear data library used (JENDL-4.0, ENDF-B-VII.1, JEFF-3.1.2, 3.2, 3.3T2 are presented.

  6. Comparative study on neutron data in integral experiments of MYRRHA mockup critical cores in the VENUS-F reactor

    Science.gov (United States)

    Krása, Antonín; Kochetkov, Anatoly; Baeten, Peter; Vittiglio, Guido; Wagemans, Jan; Bécares, Vicente

    2017-09-01

    VENUS-F is a fast, zero-power reactor with 30% wt. metallic uranium fuel and solid lead as coolant simulator. It serves as a mockup of the MYRRHA reactor core. This paper describes integral experiments performed in two critical VENUS-F core configurations (with and without graphite reflector). Discrepancies between experiments and Monte Carlo calculations (MCNP5) of keff, fission rate spatial distribution and reactivity effects (lead void and fuel Doppler) depending on a nuclear data library used (JENDL-4.0, ENDF-B-VII.1, JEFF-3.1.2, 3.2, 3.3T2) are presented.

  7. Los Alamos Science, Number 19, 1990

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1990-01-01

    This article explores the physics of various neutron-scattering processes, introduces the experimental techniques and instruments that make neutron scattering so versatile, and discusses the single equation that unifies the interpretation of neutron scattering data. The history of the field, its successes around the world, its present problems in the United States, and the plans for opening it to a wide spectrum of users from academia and industry. This articles traces neutrons from their ''birth'' in the spallation target through beam-tailoring devices and scattering samples to their ''death'' in neutron detectors. Samll-angle neutron-scattering experiments provide evidence that calmodulin, a protein that mediates calcium regulation of biological processes, is flexible in solution. Neutron scattering can detect subtle structures beneath the disorder that give advanced materials their extraordinary combinations of strength, elasticity, and low density. Recent neutron-scattering experiments on model systems are revealing how metal atoms loosen the bonds of hydrogen molecules, and essential first step in hydrogenation reactions. Combining data from neutron and x-ray diffraction is the only way to resolve ambiguities in the crystal structure of various materials, including high-temperature superconductors. Although the Bose condensate cannot be observed directly, an interpretation of neutron-scattering data according to a new first-principles theory of final-state effects has at last confirmed its existence in superfluid helium. The maximum entropy method has been applied successfully to neutron-scattering data and could even influence the design of neutron-scattering instruments

  8. HBCUs as Critical Context for Identity Work: Reflections, Experiences, and Lessons Learned

    Science.gov (United States)

    Greenfield, Derek F.; Innouvong, Tony; Aglugub, Richard Jay; Yusuf, Ismail A.

    2015-01-01

    Using narratives from a diverse group of students and staff in terms of race and religion, this chapter gives voice to these individuals' experiences with issues of diversity and inclusion at an HBCU. This chapter also discusses how these experiences helped to facilitate the authors' racial and cultural identity development.

  9. Effects of Diversity Experiences on Critical Thinking Skills over 4 Years of College

    Science.gov (United States)

    Pascarella, Ernest T.; Martin, Georgianna L.; Hanson, Jana M.; Trolian, Teniell L.; Gillig, Benjamin; Blaich, Charles

    2014-01-01

    The benefits of student engagement in diversity experiences on a range of college outcomes have been well documented. However, the potential influence of involvement in diversity experiences during college on the cognitive and intellectual outcomes of post-secondary education is only beginning to be understood. Gurin et al. (2002) made a…

  10. Factors affecting experiences of intensive care patients in Turkey: patient outcomes in critical care setting.

    Science.gov (United States)

    Demir, Yurdanur; Korhan, Esra Akin; Eser, Ismet; Khorshid, Leyla

    2013-07-01

    To determine the factors affecting a patient's intensive care experience. The descriptive study was conducted at an intensive care unit in the Aegean Region of Turkey, and comprised 158 patients who spent at least 48 hours at the unit between June and November 2009. A questionnaire form and the Intensive Care Experience Scale were used as data collection tools. SPSS 11.5 was used for statistical analysis of the data. Of the total, 86 (54.4%) patients related to the surgical unit, while 72 (45.5%) spent time at the intensive care unit. Most of the subjects (n=113; 71.5%) reported that they constantly experienced pain during hospitalisation. Patients receiving mechanical ventilation support and patients reporting no pain had significantly higher scores on the intensive care experience scale. Patients who reported pain remembered their experiences less than those having no pain. Interventions are needed to make the experiences of patients in intensive care more positive.

  11. Growth promotion and colonization of switchgrass (Panicum virgatum cv. Alamo by bacterial endophyte Burkholderia phytofirmans strain PsJN

    Directory of Open Access Journals (Sweden)

    Kim Seonhwa

    2012-05-01

    Full Text Available Abstract Background Switchgrass is one of the most promising bioenergy crop candidates for the US. It gives relatively high biomass yield and can grow on marginal lands. However, its yields vary from year to year and from location to location. Thus it is imperative to develop a low input and sustainable switchgrass feedstock production system. One of the most feasible ways to increase biomass yields is to harness benefits of microbial endophytes. Results We demonstrate that one of the most studied plant growth promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, and greenhouse conditions. In several in vitro experiments, the average fresh weight of PsJN-inoculated plants was approximately 50% higher than non-inoculated plants. When one-month-old seedlings were grown in a growth chamber for 30 days, the PsJN-inoculated Alamo plants had significantly higher shoot and root biomass compared to controls. Biomass yield (dry weight averaged from five experiments was 54.1% higher in the inoculated treatment compared to non-inoculated control. Similar results were obtained in greenhouse experiments with transplants grown in 4-gallon pots for two months. The inoculated plants exhibited more early tillers and persistent growth vigor with 48.6% higher biomass than controls. We also found that PsJN could significantly promote growth of switchgrass cv. Alamo under sub-optimal conditions. However, PsJN-mediated growth promotion in switchgrass is genotype specific. Conclusions Our results show B. phytofirmans strain PsJN significantly promotes growth of switchgrass cv. Alamo under different conditions, especially in the early growth stages leading to enhanced production of tillers. This phenomenon may benefit switchgrass establishment in the first year. Moreover, PsJN significantly stimulated growth of switchgrass cv. Alamo under sub

  12. Experiences and needs of parents of critically injured children during the acute hospital phase: A qualitative investigation.

    Science.gov (United States)

    Foster, Kim; Young, Alexandra; Mitchell, Rebecca; Van, Connie; Curtis, Kate

    2017-01-01

    Physical injury is a leading cause of death and disability among children worldwide and the largest cause of paediatric hospital admission. Parents of critically injured children are at increased risk of developing mental and emotional distress in the aftermath of child injury. In the Australian context, there is limited evidence on parent experiences of child injury and hospitalisation, and minimal understanding of their support needs. The aim of this investigation was to explore parents' experiences of having a critically injured child during the acute hospitalisation phase of injury, and to determine their support needs during this time. This multi-centre study forms part of a larger longitudinal mixed methods study investigating the experiences, unmet needs and well-being of parents of critically injured children over the two-year period following injury. This paper describes parents' experiences of having a child 0-13 years hospitalised with critical injury in one of four Australian paediatric hospitals. Semi-structured interviews were conducted with forty parents and transcribed verbatim. The data were managed using NVIVO 10 software and thematically analysed. Forty parents (26 mothers and 14 fathers) of 30 children (14 girls and 16 boys aged 1-13 years) from three Australian States participated. The majority of children were Australian born. Three main themes with sub-themes were identified: navigating the crisis of child injury; coming to terms with the complexity of child injury; and finding ways to meet the family's needs. There is a need for targeted psychological care provision for parents of critically injured children in the acute hospital phase, including psychological first aid and addressing parental blame attribution. Parents and children would benefit from the implementation of anticipatory guidance frameworks informed by a family-centred social ecological approach to prepare them for the trauma journey and for discharge. This approach could

  13. Analysis of Np-237 ENDF for the theortical interpretation of critical assembly experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Mihaila, B. (Bogdan); Chadwick, M. B. (Mark B.); MacFarlane, R. E. (Robert E.); Kawano, T. (Toshihiko)

    2004-01-01

    We report on the present status of our effort toward an improved Np-237 evaluated nuclear data file (ENDF). The aim here is to bridge the gap between calculated and observed k-eff values, as measured at the Np-U critical assembly at LANL, TA-18. As such, we perform a critical analysis of the existing body of experimental data and recommended evaluations. We are targeting in principal the fission nu-bar and cross section in Np-237, as well as the inelastic scattering which is particularly important since Np-237 is a threshold fissioner. This analysis will be employed in a future sensitivity study of the calculated k-eff with respect to variations of the afore mentioned nuclear data.

  14. Modelling critical Casimir force induced self-assembly experiments on patchy colloidal dumbbells.

    Science.gov (United States)

    Newton, Arthur C; Nguyen, T Anh; Veen, Sandra J; Kraft, Daniela J; Schall, Peter; Bolhuis, Peter G

    2017-07-19

    Colloidal particles suspended in a binary liquid mixture can interact via solvent mediated interactions, known as critical Casimir forces. For anisotropic colloids this interaction becomes directional, which leads to rich phase behavior. While experimental imaging and particle tracking techniques allow determination of isotropic effective potentials via Boltzmann inversion, the modeling of effective interaction in anisotropic systems is non-trivial precisely because of this directionality. Here we extract effective interaction potentials for non-spherical dumbbell particles from observed radial and angular distributions, by employing reference interaction site model (RISM) theory and direct Monte Carlo simulations. For colloidal dumbbell particles dispersed in a binary liquid mixture and interacting via induced critical Casimir forces, we determine the effective site-site potentials for a range of experimental temperatures. Using these potentials to simulate the system for strong Casimir forces, we reproduce the experimentally observed collapse, and provide a qualitative explanation for this behavior.

  15. Professorial Views of the Use of Diversity Experiences to Develop Students' Critical Thinking Skills in the Pakistani College Context

    Science.gov (United States)

    Tahir, Khazima

    2017-01-01

    This study explored the interplay of diversity experiences and critical thinking of Pakistani college students and determined how the classroom experience supported and exposed students to diversity and critical thinking. The researcher conducted teachers' interviews to gather data in a college in Pakistan. Teachers were asked to respond to a…

  16. Analysis results from the Los Alamos 2D/3D program

    International Nuclear Information System (INIS)

    Boyack, B.E.; Cappiello, M.W.; Harmony, S.C.; Shire, P.R.; Siebe, D.A.

    1987-01-01

    Los Alamos National Laboratory is a participant in the 2D/3D program. Activities conducted at Los Alamos National Laboratory in support of 2D/3D program goals include analysis support of facility design, construction, and operation; provision of boundary and initial conditions for test-facility operations based on analysis of pressurized water reactors; performance of pretest and posttest predictions and analyses; and use of experimental results to validate and assess the single- and multi-dimensional, nonequilibrium features in the Transient Reactor Analysis Code (TRAC). During fiscal year 1987, Los Alamos conducted analytical assessment activities using data from the Slab Core Test Facility, The Cylindrical Core Test Facility, and the Upper Plenum Test Facility. Finally, Los Alamos continued work to provide TRAC improvements. In this paper, Los Alamos activities during fiscal year 1987 will be summarized; several significant accomplishments will be described in more detail to illustrate the work activities at Los Alamos

  17. Progress in inertial fusion research at the Los Alamos Scientific Laboratory. Paper No. IAEA-CN-38/B-2

    International Nuclear Information System (INIS)

    Perkins, R.B.

    1980-01-01

    The Los Alamos Scientific Laboratory Inertial Confinement Fusion Program is reviewed. Experiments using the Helios CO 2 laser system delivering up to 6 kJ on target are described. Because breakeven energy estimates for laser drivers of 1 μm and above have risen and there is a need for CO 2 experiments in the tens-of-kilojoule regime as soon as practical, a first phase of Antares construction is now directed toward completion of two of the six original modules in 1983. These modules are designed to deliver 40 kJ of CO 2 laser light on target

  18. Gender and the experience of moral distress in critical care nurses.

    Science.gov (United States)

    O'Connell, Christopher B

    2015-02-01

    Nursing practice is complex, as nurses are challenged by increasingly intricate moral and ethical judgments. Inadequately studied in underrepresented groups in nursing, moral distress is a serious problem internationally for healthcare professionals with deleterious effects to patients, nurses, and organizations. Moral distress among nurses has been shown to contribute to decreased job satisfaction and increased turnover, withdrawal from patients, physical and psychological symptoms, and intent to leave current position or to leave the profession altogether. Do significant gender differences exist in the moral distress scores of critical care nurses? This study utilized a quantitative, descriptive methodology to explore moral distress levels in a sample of critical care nurses to determine whether gender differences exist in their mean moral distress scores. Participants (n = 31) were critical care nurses from an American Internet nursing community who completed the Moral Distress Scale-Revised online over a 5-day period in July 2013. Institutional review board review approved the study, and accessing and completing the survey implied informed consent. The results revealed a statistically significant gender difference in the mean moral distress scores of participants. Females reported statistically significantly higher moral distress scores than did males. Overall, the moral distress scores for both groups were relatively low. The findings of a gender difference have not previously been reported in the literature. However, other findings are consistent with previous studies on moral distress. Although the results of this study are not generalizable, they do suggest the need for continuing research on moral distress in underrepresented groups in nursing, including cultural and ethnic groups. © The Author(s) 2014.

  19. Benchmark calculations of the solution-fuel criticality experiments by SRAC code system

    International Nuclear Information System (INIS)

    Senuma, Ichiro; Miyoshi, Yoshinori; Suzaki, Takenori; Kobayashi, Iwao

    1984-06-01

    Benchmark calculations were performed by using newly developed SRAC (Standard Reactor Analysis Code) system and nuclear data library based upon JENDL-2. The 34 benchmarks include variety of composition, concentration and configuration of Pu homogeneous and U/Pu homogeneous systems (nitrate, mainly), also include UO 2 /PuO 2 rods in fissile solution: a simplified model of the dissolver process of the fuel reprocessing plant. Calculation results shows good agreement with Monte Carlo method. This code-evaluation work has been done for the the part of the Detailed Design of CSEF (Critical Satety Experimental Facility), which is now in Progress. (author)

  20. Dissolved Pesticides in the Alamo River and the Salton Sea, California, 1996-1997

    National Research Council Canada - National Science Library

    Crepeau, Kathryn L; Kuivila, Kathryn M; Bergamaschi, Brian

    2002-01-01

    .... Generally, the highest concentrations were measured in the Alamo River. The concentrations of carbaryl, chlorpyrifos, cycloate, dacthal, diazinon, and eptam were highest in samples collected in autumn 1996...

  1. Animal and non-animal experiments in nanotechnology - the results of a critical literature survey.

    Science.gov (United States)

    Sauer, Ursula G

    2009-01-01

    A literature survey funded by the Foundation Animalfree Research was performed to obtain an overview on animal experiments in nanotechnology. Scientific articles from Germany, France, the United Kingdom, Italy, the Netherlands and Switzerland published between 2004 and 2007 were collected. A total of 164 articles was retrieved covering in vivo nanotechnological research. The majority of animal experiments were conducted in "nanomedicine", i.e. nanotechnology in the health care area, to study targeted drug, vaccine or gene delivery. Further areas of research relate to nanotechnology-based imaging technologies, the toxicity of nanomaterials, tissue engineering for regenerative treatments, and magnetic tumour thermotherapy. Many experiments were classified as moderately and even severely distressful to the animals. Due to the significance of the scientific topics pursued, the possible scientific benefit of the research depicted in the articles is also assigned to be moderate to high. Nevertheless, it has to be asked whether such animal experiments are truly the only means to answer the scientific questions addressed in nanotechnology. An overview on non-animal test methods used in nanotechnological research revealed a broad spectrum of methodologies applied in a broad spectrum of scientific areas, including those for which animal experiments are being performed. Explicit incentives to avoid animal experiments in nanotechnology currently can only be found in the area of nanotoxicology, but not in the area of nanomedicine. From the point of view of animal welfare, not least because of the new technologies that arise due to nanotechnology, it is time for a paradigm change both in fundamental and applied biomedical research to found research strategies on non-animal test methods.

  2. Accelerators for critical experiments involving single-particle upset in solid-state microcircuits

    Science.gov (United States)

    Zoutendyk, J. A.

    1985-01-01

    Charged-particle interactions in microelectronic circuit chips (integrated circuits) present a particularly insidious problem for solid-state electronic systems due to the generation of soft errors or single-particle event upset (SEU) by either cosmic rays or other radiation sources. Particle accelerators are used to provide both light and heavy ions in order to assess the propensity of integrated circuit chips for SEU. Critical aspects of this assessment involve the ability to analytically model SEU for the prediction of error rates in known radiation environments. In order to accurately model SEU, the measurement and prediction of energy deposition in the form of an electron-hole plasma generated along an ion track is of paramount importance. This requires the use of accelerators which allow for ease in both energy control (change of energy) and change of ion species. This and other aspects of ion-beam control and diagnostics (e.g., uniformity and flux) are of critical concern for the experimental verification of theoretical SEU models.

  3. Below the knee PTA in critical limb ischemia results after 12 months: Single center experience

    Energy Technology Data Exchange (ETDEWEB)

    Balzer, Joern O., E-mail: balzerjo@t-online.d [Dept. for Radiology and Nuclear medicine, Catholic Clinic Mainz, An der Goldgrube 11, Mainz 55131 (Germany); Khan, Verena [Dept. of Diagnostic and Interventional Radiology, Clinic Nurnberg North (Germany); Thalhammer, Axel; Vogl, Thomas J.; Lehnert, Thomas [Dept. of Diagnostic and Interventional Radiology, Univ. Clinic, Johann Wolfgang Goethe-University Frankfurt/Main (Germany)

    2010-07-15

    Purpose: Evaluation of angioplasty with bare metal stents in infrapopliteal occlusions or severe stenoses in patients with critical limb ischemia. Material and methods: Percutaneous stent angioplasty was performed in 58 limbs in 47 patients with critical limb ischemia (CLI) in Rutherford stage 4-6. Lesions with up to 5 cm in length with at least one patent vessel below the obstruction were treated. 121 bare metal stents (diameter of 2.5-4 mm; length of 18-38 mm) were implanted. Follow-up examinations were performed up to 12 months postinterventionally using clinical examination, ABI calculation, and color-coded duplex sonography. Patency rates were calculated on the basis of the Kaplan-Meier analysis. Results: Technical success was achieved in 100%. Minor complications (hematoma, distal emboli, vessel dissection) were documented in 5.17% (n = 3) limbs, respectively. The 3-month, 6-month, and 1-year primary patency rate was 93.0%, 78.9% and 66.7%, respectively. 86.9% of the lesions healed postinterventionally. The cumulative limb salvage rate was 96.6%. Conclusion: Stent angioplasty in infrapopliteal arteries is a safe and effective technique for the treatment of patients with CLI. By consequent clinical monitoring high secondary patency rates can be achieved. The use of a bare metal stent seems to result in high limb salvage, primary and secondary patency rates in the mid-term follow-up.

  4. Addressing concerns related to geologic hazards at the site of the proposed Transuranic Waste Facility , TA-63, Los Alamos National Laboratory: focus on the current Los Alamos Seismic Network earthquake catalog, proximity of identified seismic events to the proposed facility , and evaluation of prev

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Peter M. [Los Alamos National Laboratory; Schultz-Fellenz, Emily S. [Los Alamos National Laboratory; Kelley, Richard E. [Los Alamos National Laboratory

    2012-04-02

    . Understanding the subtle differences between Tshirege Member cooling units and the nature of the contacts between cooling units is critical to identifying the presence or absence of faults associated with the Pajarito fault system on the Pajarito Plateau. The Los Alamos Seismic Network (LASN) continuously monitors local earthquake activity in the Los Alamos area in support of LANL's Seismic Hazards program. Seismic monitoring of LANL facilities is a requirement of DOE Order 420.1B (Facility Safety). LASN currently consists of nine permanent seismic instrument field stations that telemeter real-time sensitive ground motion data to a central recording facility. Four of these stations are located on LANL property, with three of those within 2.5 miles of TA-63. The other five stations are in remote locations in the Jemez Mountains, Valles Caldera, St Peters Dome, and the Caja del Rio plateau across the Rio Grande from the Los Alamos area. Local earthquakes are defined as those with locations within roughly 100 miles of Los Alamos. Plate 1 shows the current LASN station locations and all local earthquakes recorded from 1973 through 2011. During this time period, LASN has detected and recorded over 850 local earthquakes in north-central New Mexico. Over 650 of these were located within about 50 miles of Los Alamos, and roughly 60 were within 10 miles. The apparent higher density of earthquakes close to Los Alamos, relative to the rest of north-central New Mexico, is due largely to the fact that LASN is a sensitive local seismic network, recording many very small nearby events (magnitude less than 1.0) that are undetectable at greater distances.

  5. ORSPHERE: CRITICAL, BARE, HEU(93.2)-METAL SPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall

    2013-09-01

    In the early 1970’s Dr. John T. Mihalczo (team leader), J.J. Lynn, and J.R. Taylor performed experiments at the Oak Ridge Critical Experiments Facility (ORCEF) with highly enriched uranium (HEU) metal (called Oak Ridge Alloy or ORALLOY) in an attempt to recreate GODIVA I results with greater accuracy than those performed at Los Alamos National Laboratory in the 1950’s (HEU-MET-FAST-001). The purpose of the Oak Ridge ORALLOY Sphere (ORSphere) experiments was to estimate the unreflected and unmoderated critical mass of an idealized sphere of uranium metal corrected to a density, purity, and enrichment such that it could be compared with the GODIVA I experiments. “The very accurate description of this sphere, as assembled, establishes it as an ideal benchmark for calculational methods and cross-section data files.” (Reference 1) While performing the ORSphere experiments care was taken to accurately document component dimensions (±0. 0001 in. for non-spherical parts), masses (±0.01 g), and material data The experiment was also set up to minimize the amount of structural material in the sphere proximity. A three part sphere was initially assembled with an average radius of 3.4665 in. and was then machined down to an average radius of 3.4420 in. (3.4425 in. nominal). These two spherical configurations were evaluated and judged to be acceptable benchmark experiments; however, the two experiments are highly correlated.

  6. Temperature dependence of the critical current of the superconducting microladder in zero magnetic field: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fink, H.J. (Department of Electrical Engineering and Computer Science, University of California, Davis, Davis, California 95616 (USA)); Buisson, O.; Pannetier, B. (Centre de Recherches sur les Tres Basses Temperature, Centre National de la Recherche Scientifique, Boite Postale 166X, 38042 Grenoble CEDEX, France (FR))

    1991-05-01

    The largest supercurrent which can be injected into a superconducting microladder was calculated as a function of nodal spacing {ital scrL} and temperature for zero magnetic flux using (i) exact solutions of the Ginzburg-Landau equation in terms of Jacobian elliptic functions and (ii) approximate solutions in terms of hyperbolic functions. The agreement is good for {ital scrL}/{xi}({ital T}){lt}3, where {xi}({ital T}) is the temperature-dependent coherence length. Since solution (ii) is much simpler than solution (i), it is of considerable value when calculating critical currents of micronets with nodal spacings comparable to {xi}({ital T}). We find that the temperature-dependent critical current deviates significantly from the classical 3/2 power law of the Ginzburg-Landau theory. Preliminary experiments on a submicrometer ladder confirm such deviations.

  7. Is This a Meaningful Learning Experience? Interactive Critical Self-Inquiry as Investigation

    Science.gov (United States)

    Allard, Andrea C.; Gallant, Andrea

    2012-01-01

    What conditions enable educators to engage in meaningful learning experiences with peers and beginning practitioners? This article documents a self-study on our actions-in-practice in a peer mentoring project. The investigation involved an iterative process to improve our knowledge as teacher educators, reflective practitioners, and researchers.…

  8. A Critical Reflection: Foster Care Youth Experiences at a Four Year Postsecondary Institution

    Science.gov (United States)

    Greer, Renada D.

    2016-01-01

    Foster care youth face significant challenges to postsecondary educational success, especially while enrolled at four-year institutions. Foster care youth are absent of family support that their non-foster peers receive throughout the college experience. Without family support, foster care youth encounter greater challenges to persevere through…

  9. Ameloblastoma of the jaws: a critical reappraisal based on a 40-years single institution experience

    NARCIS (Netherlands)

    Hertog, D.; van der Waal, I.

    2010-01-01

    The 40-years of experience in a single institution with the treatment of previously untreated ameloblastoma have been reported, followed by a management protocol. Retrospectively, 25 consecutive patients treated between 1969 and 2009 have been analyzed. In 11 patients, a preoperative diagnosis of

  10. Enhancing Critical Consciousness through a Cross-Cultural Immersion Experience in South Africa

    Science.gov (United States)

    Choi, Kyoung Mi; VanVoorhis, Richard W.; Ellenwood, Audrey E.

    2015-01-01

    Using phenomenological approaches, the author explored the meanings and essences of a cross-cultural immersion experience in South Africa among counseling master's-level students. Five core themes--the meaning of being American, sociopolitical awareness, engagement with South Africans and their communities, appreciation of life, and commitment to…

  11. Critical and Subcritical 0-Power Experiment at Rensselaer (CaSPER)

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Jennifer Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-09

    This report discusses the 0-power experiment at Rensselaer Polytechnic Institute (CaSPER). Keff simulation results, list-mode multiplication results, and related work are included. The aim of the work is subcritical measurements for code and nuclear data validation.

  12. Are Sojourners Natural Comparativists? Critical Perspectives on the Learning Experiences of International Students

    Science.gov (United States)

    Schweisfurth, Michele

    2012-01-01

    Students who spend a period of time studying outside of their own national systems have a number of advantages in terms of developing a comparative perspective on education. The experience of living and studying abroad provides them with the opportunity to act as participant observers of at least two different systems, and the natural…

  13. Near-critical density filling of the SF6 fluid cell for the ALI-R-DECLIC experiment in weightlessness

    Science.gov (United States)

    Lecoutre, C.; Marre, S.; Garrabos, Y.; Beysens, D.; Hahn, I.

    2018-05-01

    Analyses of ground-based experiments on near-critical fluids to precisely determine their density can be hampered by several effects, especially the density stratification of the sample, the liquid wetting behavior at the cell walls, and a possible singular curvature of the "rectilinear" diameter of the density coexisting curve. For the latter effect, theoretical efforts have been made to understand the amplitude and shape of the critical hook of the density diameter, which depart from predictions from the so-called ideal lattice-gas model of the uniaxial 3D-Ising universality class. In order to optimize the observation of these subtle effects on the position and shape of the liquid-vapor meniscus in the particular case of SF6, we have designed and filled a cell that is highly symmetrized with respect to any median plane of the total fluid volume. In such a viewed quasi-perfect symmetrical fluid volume, the precise detection of the meniscus position and shape for different orientations of the cell with respect to the Earth's gravity acceleration field becomes a sensitive probe to estimate the cell mean density filling and to test the singular diameter effects. After integration of this cell in the ALI-R insert, we take benefit of the high optical and thermal performances of the DECLIC Engineering Model. Here we present the sensitive imaging method providing the precise ground-based SF6 benchmark data. From these data analysis it is found that the temperature dependence of the meniscus position does not reflect the expected critical hook in the rectilinear density diameter. Therefore the off-density criticality of the cell is accurately estimated, before near future experiments using the same ALI-R insert in the DECLIC facility already on-board the International Space Station.

  14. The trajectory of experience of critical care nurses in providing end-of-life care: A qualitative descriptive study.

    Science.gov (United States)

    Ong, Keh Kiong; Ting, Kit Cheng; Chow, Yeow Leng

    2018-01-01

    To understand the perceptions of critical care nurses towards providing end-of-life care. There has been an increasing interest in end-of-life care in the critical care setting. In Singapore, approximately half of deaths in the hospital occur during critical care. While nurses are well positioned to provide end-of-life care to patients and their family members, they faced barriers to providing end-of-life care. Also, providing end-of-life care has profound positive and negative psychological effects on nurses, with the latter being more prominent. Qualitative descriptive design. Data collection was performed in a medical intensive care unit of a public tertiary hospital in Singapore. Ten registered nurses were purposively sampled and interviewed individually using a semi-structured interview guide. A codebook was developed to guide coding, and data were thematically analysed. Rigour was maintained. Nurses went through a trajectory of experience. They experienced the culture of care and developed dissatisfaction with it. The tension shaped their perception and meaning of life and death, and they developed mechanisms to reach resolution. This study provides insight on nurses' perception as a trajectory of experience and raised several implications on clinical practice, policy and research. There is a need to alleviate the tension nurses face and to facilitate coming to terms with the tension by improving the culture of care and supporting nurses. Nurses could be involved more in decision-making and empowered to start end-of-life care conversations within the team and with family members. Communication with family members and between nurses and doctors could be improved. Support for nurses providing end-of-life care could be enhanced through promoting social networks, education and bereavement support. Further research is needed to explore ways to support and empower nurses to provide end-of-life care in critical care. © 2017 John Wiley & Sons Ltd.

  15. Studying the old masters of nursing: A critical student experience for developing nursing identity.

    Science.gov (United States)

    Kelly, Jacinta; Watson, Roger; Watson, James; Needham, Malachi; Driscoll, Laura O

    2017-09-01

    In the past professional identity in nursing was inculcated in students alongside institutional pride. A strong sense of professional identity is key to staff retention and recruitment and key to the delivery of quality nursing care. With the wholesale transfer of pre-registration nursing education to the third level sector, however, the reality is that students now divide their affiliations between university and healthcare institutions and professional identity development may be stymied. For this reason, there is need to explore alternative means of developing professional identity. Exposure to nursing history may counteract this tendency. Based on adult nursing students' reflections of a visit to the Florence Nightingale Museum, we discuss the potential of this activity in aiding development of critical professional identity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Critical evaluation of the anastomoses in large bowel surgery: experience gained in 533 cases.

    Science.gov (United States)

    Montesani, C; De Milito, R; Chiappalone, S; Narilli, P; D'Amato, A; Ribotta, G

    1992-08-01

    We critically examined the morbidity and mortality of manual and stapled colorectal anastomosis in a retrospective study of 533 patients who underwent colorectal resection for neoplastic and non-neoplastic disease. The clinically detected anastomotic dehiscence rate was 4.5%, and the mortality rate 1.8%. The extraperitoneal site of the anastomosis after rectal anterior resection with stapled anastomosis and surgery for cancer showed a statistically significant predisposition to anastomotic dehiscence. Age, emergency surgical intervention, curative versus palliative resection, the location of the anastomosed intestinal segments, type of anastomosis and presence of a protective colostomy did not appear to be statistically significant factors for anastomotic dehiscence. While the stapler may offer an advantage in the individual case, the low incidence of morbidity and mortality for manual anastomosis in this study reaffirms the soundness and importance of the manual colorectal anastomosis in the surgeon's technical armamentarium.

  17. The Los Alamos 600 MJ, 1500 MW inertial energy storage and pulsed power unit

    International Nuclear Information System (INIS)

    Boenig, H.J.

    1991-01-01

    A 1430 MVA synchronous generator from a cancelled nuclear power plant has been installed and commissioned at Los Alamos National Laboratory (LANL) to be used as the pulsed power generator for physics experiments. The generator is mounted on a spring foundation to prevent dynamic forces from being transmitted to the substructure and into the ground. A 6 MW load-commutated inverter drive accelerates the machine from standstill to the maximum operating speed of 1800 rpm and from 1260 rpm to 1800 rpm between load pulses. The generator cooling method has been changed from hydrogen to air cooling to facilitate operation. A current limiting fuse, with a fuse clearing current of 90 kA, will protect the generator output against short circuit currents. An overview of the installation is presented. The paper also addresses the overload capability of the generator for pulsed loads. 7 figs., 1 tab

  18. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-04-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory.

  19. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    International Nuclear Information System (INIS)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-01-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory

  20. Groundwater level status report for 2010, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Richard J.; Schmeer, Sarah

    2011-03-01

    The status of groundwater level monitoring at Los Alamos National Laboratory in 2010 is provided in this report. This report summarizes groundwater level data for 194 monitoring wells, including 63 regional aquifer wells (including 10 regional/intermediate wells), 34 intermediate wells, 97 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 162 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells and seasonal responses to snowmelt runoff observed in intermediate wells.