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1

Joint Actinide Shock Physics Experimental Research - JASPER  

ScienceCinema (OSTI)

Commonly known as JASPER the Joint Actinide Shock Physics Experimental Research facility is a two stage light gas gun used to study the behavior of plutonium and other materials under high pressures, temperatures, and strain rates.

None

2015-01-09T23:59:59.000Z

2

Joint Actinide Shock Physics Experimental Research - JASPER  

SciTech Connect (OSTI)

Commonly known as JASPER the Joint Actinide Shock Physics Experimental Research facility is a two stage light gas gun used to study the behavior of plutonium and other materials under high pressures, temperatures, and strain rates.

None

2014-10-31T23:59:59.000Z

3

Joint Actinide Shock Physics Experimental Research | National...  

National Nuclear Security Administration (NNSA)

the safety and security of the nation's stockpile in the absence of underground nuclear testing. For more information visit JASPER's webpage. Jasper Gun Related Topics...

4

Physics studies of higher actinide consumption in an LMR  

SciTech Connect (OSTI)

The core physics aspects of the transuranic burning potential of the Integral Fast Reactor (IFR) are assessed. The actinide behavior in fissile self-sufficient IFR closed cycles of 1200 MWt size is characterized, and the transuranic isotopics and risk potential of the working inventory are compared to those from a once-through LWR. The core neutronic performance effects of rare-earth impurities present in the recycled fuel are addressed. Fuel cycle strategies for burning transuranics from an external source are discussed, and specialized actinide burner designs are described. 4 refs., 4 figs., 3 tabs.

Hill, R.N.; Wade, D.C.; Fujita, E.K.; Khalil, H.S.

1990-01-01T23:59:59.000Z

5

E-Print Network 3.0 - actinide transmutation physics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fission Barriers and Half-Lives Summary: Acta Phys. Hung. A 251 (2006) 000-000 HEAVY ION PHYSICS On the Multiple-Humped Fission Barriers... and Half-Lives of Actinides...

6

Joint Actinide Shock Physics Experimental Research (JASPER) Facility Overview  

SciTech Connect (OSTI)

The JASPER Facility will utilize a Two-Stage Light Gas Gun to conduct equation-of-state (EOS) experiments of plutonium and other special nuclear materials. The overall facility will be discussed with emphasis on the Two-Stage Light Gas Gun characteristics and mission. The primary and secondary containment systems that were developed for this project will be presented. Primary gun diagnostics and timing will also be discussed.

C.H. Konrad; R.W. Braddy; Mark Martinez

2001-09-01T23:59:59.000Z

7

Joint Actinide Shock Physics Experimental Research (JASPER) Facility Update  

SciTech Connect (OSTI)

The JASPER Facility utilizes a Two-Stage Light Gas Gun to conduct equation-of-state(EOS) experiments on plutonium and other special nuclear materials. The overall facility will be discussed with emphasis on the Two-Stage Light Gas Gun characteristics and control interfaces and containment. The containment systems that were developed for this project will be presented.

C. H. Conrad; J. Miller; M. Cowan; M. Martinez; B. Whitcomb

2003-10-01T23:59:59.000Z

8

Joint Actinide Shock Physics Experimental Research | National Nuclear  

National Nuclear Security Administration (NNSA)

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9

Actinides-1981  

SciTech Connect (OSTI)

Abstracts of 134 papers which were presented at the Actinides-1981 conference are presented. Approximately half of these papers deal with electronic structure of the actinides. Others deal with solid state chemistry, nuclear physic, thermodynamic properties, solution chemistry, and applied chemistry.

Not Available

1981-09-01T23:59:59.000Z

10

New density functional theory approaches for enabling prediction of chemical and physical properties of plutonium and other actinides.  

SciTech Connect (OSTI)

Density Functional Theory (DFT) based Equation of State (EOS) construction is a prominent part of Sandia's capabilities to support engineering sciences. This capability is based on amending experimental data with information gained from computational investigations, in parts of the phase space where experimental data is hard, dangerous, or expensive to obtain. A prominent materials area where such computational investigations are hard to perform today because of limited accuracy is actinide and lanthanide materials. The Science of Extreme Environment Lab Directed Research and Development project described in this Report has had the aim to cure this accuracy problem. We have focused on the two major factors which would allow for accurate computational investigations of actinide and lanthanide materials: (1) The fully relativistic treatment needed for materials containing heavy atoms, and (2) the needed improved performance of DFT exchange-correlation functionals. We have implemented a fully relativistic treatment based on the Dirac Equation into the LANL code RSPt and we have shown that such a treatment is imperative when calculating properties of materials containing actinides and/or lanthanides. The present standard treatment that only includes some of the relativistic terms is not accurate enough and can even give misleading results. Compared to calculations previously considered state of the art, the Dirac treatment gives a substantial change in equilibrium volume predictions for materials with large spin-orbit coupling. For actinide and lanthanide materials, a Dirac treatment is thus a fundamental requirement in any computational investigation, including those for DFT-based EOS construction. For a full capability, a DFT functional capable of describing strongly correlated systems such as actinide materials need to be developed. Using the previously successful subsystem functional scheme developed by Mattsson et.al., we have created such a functional. In this functional the Harmonic Oscillator Gas is providing the necessary reference system for the strong correlation and localization occurring in actinides. Preliminary testing shows that the new Hao-Armiento-Mattsson (HAM) functional gives a trend towards improved results for the crystalline copper oxide test system we have chosen. This test system exhibits the same exchange-correlation physics as the actinide systems do, but without the relativistic effects, giving access to a pure testing ground for functionals. During the work important insights have been gained. An example is that currently available functionals, contrary to common belief, make large errors in so called hybridization regions where electrons from different ions interact and form new states. Together with the new understanding of functional issues, the Dirac implementation into the RSPt code will permit us to gain more fundamental understanding, both quantitatively and qualitatively, of materials of importance for Sandia and the rest of the Nuclear Weapons complex.

Mattsson, Ann Elisabet

2012-01-01T23:59:59.000Z

11

A survey of numerical methods for shock physics applications  

SciTech Connect (OSTI)

Hydrocodes or more accurately, shock physics analysis packages, have been widely used in the US Department of Energy (DOE) laboratories and elsewhere around the world for over 30 years. Initial applications included weapons effects studies where the pressure levels were high enough to disregard the material strength, hence the term hydrocode. Over the last 30 years, Sandia has worked extensively to develop and apply advanced hydrocodes to armor/anti-armor interactions, warhead design, high explosive initiation, and nuclear weapon safety issues. The needs of the DOE have changed over the last 30 years, especially over the last decade. A much stronger emphasis is currently placed on the details of material deformation and high explosive initiation phenomena. The hydrocodes of 30 years ago have now evolved into sophisticated analysis tools that can replace testing in some situations and complement it in all situations. A brief history of the development of hydrocodes in the US will be given. The author also discusses and compares the four principal methods in use today for the solution of the conservation equations of mass, momentum, and energy for shock physics applications. The techniques discussed are the Eulerian methods currently employed by the Sandia multi-dimensional shock physics analysis package known as CTH; the element based Lagrangian method currently used by codes like DYNA; the element free Lagrangian method (also known as smooth particle hydrodynamics) used by codes like the Los Alamos code SPHINX; and the Arbitrary Lagrangian Eulerian methods used by codes like the Lawrence Livermore code CALE or the Sandia code ALEGRA.

Hertel, E.S. Jr.

1997-10-01T23:59:59.000Z

12

Shock and Detonation Physics at Los Alamos National Laboratory  

SciTech Connect (OSTI)

WX-9 serves the Laboratory and the Nation by delivering quality technical results, serving customers that include the Nuclear Weapons Program (DOE/NNSA), the Department of Defense, the Department of Homeland Security and other government agencies. The scientific expertise of the group encompasses equations-of-state, shock compression science, phase transformations, detonation physics including explosives initiation, detonation propagation, and reaction rates, spectroscopic methods and velocimetry, and detonation and equation-of-state theory. We are also internationally-recognized in ultra-fast laser shock methods and associated diagnostics, and are active in the area of ultra-sensitive explosives detection. The facility capital enabling the group to fulfill its missions include a number of laser systems, both for laser-driven shocks, and spectroscopic analysis, high pressure gas-driven guns and powder guns for high velocity plate impact experiments, explosively-driven techniques, static high pressure devices including diamond anvil cells and dilatometers coupled with spectroscopic probes, and machine shops and target fabrication facilities.

Robbins, David L [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve A [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

13

PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal  

E-Print Network [OSTI]

PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal Patrick L-dynamics simulations of the single shock Hugoniot are reported for a crystalline polyethylene (PE) model. The e. INTRODUCTION The material response of polyethylene (PE) to shock and its behavior in the warm dense matter (WDM

14

X-ray Spectroscopy of O Supergiant Winds: Shock Physics, Clumping, and Mass-Loss Rates  

E-Print Network [OSTI]

X-ray Spectroscopy of O Supergiant Winds: Shock Physics, Clumping, and Mass-Loss Rates David Cohen Li (Swarthmore '16), Kelley Langhans (Swarthmore '16) #12;Talk Outline Context of O star X-ray emission: wind shocks 1. X-ray constraints on the shocked wind plasma 2. X-ray absorption as a mass

Cohen, David

15

Fundamentals of Non-relativistic Collisionless Shock Physics: III. Quasi-Perpendicular Supercritical Shocks  

E-Print Network [OSTI]

The theory and simulations of quasi-perpendicular and strictly perpendicular collisionless shocks are reviewed. The text is structured into the following sections and subsections: 1. Setting the frame, where the quasi-perpendicular shock problem is formulated, reflected particle dynamics is described in theoretical terms, foot formation and foot ion acceleration discussed, and the shock potential explained. 2. Shock structure, 3. Ion dynamics, describing its role in shock reformation and the various ion-excited instabilities. 4. Electron dynamics, describing electron instabilities in the foot; 5. The problem of stationarity, posing the theoretical reasons for shocks being non-stationary, discussing nonlinear whistler mediated variability, two-stream and modified two-stream variability, formation of ripples in two-dimensions, 6. Summary and conclusions: The possibility of shock breaking.

R. A. Treumann; C. H. Jaroschek

2008-05-14T23:59:59.000Z

16

Fundamentals of Non-relativistic Collisionless Shock Physics: IV. Quasi-Parallel Supercritical Shocks  

E-Print Network [OSTI]

1. Introduction, 2. The (quasi-parallel) foreshock; Ion foreshock, Ion foreshock boundary region; Diffuse ions;Low-frequency upstream waves; Ion beam waves; The expected wave modes; Observations; Diffuse ion waves; Electron foreshock; Electron beams; Langmuir waves; stability of the electron beam; Electron foreshock boundary waves; Nature of electron foreshock waves; Radiation; Observations; Interpretation; 3. Quasi-parallel shock reformation; Low-Mach number quasi-parallel shocks; Turbulent reformation; Observations; Simulations of quasi-parallel shock reformation; Hybrid simulations in 1D; Hybrid simulations in 2D; Full particle PIC simulations; Conclusions; 4. Hot flow anomalies; Observations; Models and simulations; Solitary shock; 5. Downstream region; 6. Summary and conclusions.

R. A. Treumann; C. H. Jaroschek

2008-05-16T23:59:59.000Z

17

E-Print Network 3.0 - actinide compounds Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

concept of valence instabilities in light actinides has been... response of ICF rare earth compounds and actinide materials. -The important aspects of physical property......

18

Actinide Chemistry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building Technologies OfficeAccountingGuideON STELLAWongActinide

19

Cavitation inception following shock wave passage Department of Applied Physics, TU Twente, Postbus 217, 7500 AE Enschede, The Netherlands  

E-Print Network [OSTI]

Cavitation inception following shock wave passage C. D. Ohl Department of Applied Physics, TU; published 5 September 2002 Cavitation bubble nucleation following the passage of an extracorporeal shock of the bubble center; however, considerable disagreement between a simple cavitation inception theory

Ohl, Claus-Dieter

20

Actinide metal processing  

DOE Patents [OSTI]

A process of converting an actinide metal such as thorium, uranium, or plnium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is provided together with a low temperature process of preparing an actinide oxide nitrate such as uranyl nitrte. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

Sauer, Nancy N. (Los Alamos, NM); Watkin, John G. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Actinide metal processing  

DOE Patents [OSTI]

A process for converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is described together with a low temperature process for preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

Sauer, N.N.; Watkin, J.G.

1992-03-24T23:59:59.000Z

22

E-Print Network 3.0 - actinides ix behavior Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Torstein - Institut for Fysik og Astronomi, Aarhus Universitet Collection: Physics ; Materials Science 5 One-electron physics of the actinides A. Toropova, C. A. Marianetti, K....

23

Actinide extraction methods  

DOE Patents [OSTI]

Methods of separating actinides from lanthanides are disclosed. A regio-specific/stereo-specific dithiophosphinic acid having organic moieties is provided in an organic solvent that is then contacted with an acidic medium containing an actinide and a lanthanide. The method can extend to separating actinides from one another. Actinides are extracted as a complex with the dithiophosphinic acid. Separation compositions include an aqueous phase, an organic phase, dithiophosphinic acid, and at least one actinide. The compositions may include additional actinides and/or lanthanides. A method of producing a dithiophosphinic acid comprising at least two organic moieties selected from aromatics and alkyls, each moiety having at least one functional group is also disclosed. A source of sulfur is reacted with a halophosphine. An ammonium salt of the dithiophosphinic acid product is precipitated out of the reaction mixture. The precipitated salt is dissolved in ether. The ether is removed to yield the dithiophosphinic acid.

Peterman, Dean R. (Idaho Falls, ID) [Idaho Falls, ID; Klaehn, John R. (Idaho Falls, ID) [Idaho Falls, ID; Harrup, Mason K. (Idaho Falls, ID) [Idaho Falls, ID; Tillotson, Richard D. (Moore, ID) [Moore, ID; Law, Jack D. (Pocatello, ID) [Pocatello, ID

2010-09-21T23:59:59.000Z

24

Research in actinide chemistry  

SciTech Connect (OSTI)

This research studies the behavior of the actinide elements in aqueous solution. The high radioactivity of the transuranium actinides limits the concentrations which can be studied and, consequently, limits the experimental techniques. However, oxidation state analogs (trivalent lanthanides, tetravalent thorium, and hexavalent uranium) do not suffer from these limitations. Behavior of actinides in the environment are a major USDOE concern, whether in connection with long-term releases from a repository, releases from stored defense wastes or accidental releases in reprocessing, etc. Principal goal of our research was expand the thermodynamic data base on complexation of actinides by natural ligands (e.g., OH[sup [minus

Choppin, G.R.

1993-01-01T23:59:59.000Z

25

Actinide recovery process  

DOE Patents [OSTI]

Process for the removal of plutonium polymer and ionic actinides from aqueous solutions by absorption onto a solid extractant loaded on a solid inert support such as polystyrenedivinylbenzene. The absorbed actinides can then be recovered by incineration, by stripping with organic solvents, or by acid digestion. Preferred solid extractants are trioctylphosphine oxide and octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide and the like.

Muscatello, Anthony C. (Arvada, CO); Navratil, James D. (Arvada, CO); Saba, Mark T. (Arvada, CO)

1987-07-28T23:59:59.000Z

26

Thermochemistry of the actinides  

SciTech Connect (OSTI)

The measurement of equilibria by Knudsen effusion techniques and the enthalpy of formation of the actinide atoms is briefly discussed. Thermochemical data on the sublimation of the actinide fluorides is used to calculate the enthalpies of formation and entropies of the gaseous species. Estimates are made for enthalpies and entropies of the tetrafluorides and trifluorides for those systems where data is not available. The pressure of important species in the tetrafluoride sublimation processes is calculated based on this thermochemical data.

Kleinschmidt, P.D.

1993-10-01T23:59:59.000Z

27

Actinide recovery process  

DOE Patents [OSTI]

Process for the removal of plutonium polymer and ionic actinides from aqueous solutions by absorption onto a solid extractant loaded on a solid inert support such as polystyrene-divinylbenzene. The absorbed actinides can then be recovered by incineration, by stripping with organic solvents, or by acid digestion. Preferred solid extractants are trioctylphosphine oxide and octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide and the like. 2 tabs.

Muscatello, A.C.; Navratil, J.D.; Saba, M.T.

1985-06-13T23:59:59.000Z

28

Mineralogy, reflectance spectra, and physical properties of the Chelyabinsk LL5 chondrite, insight into shock induced changes in asteroid regoliths  

E-Print Network [OSTI]

The mineralogy and physical properties of Chelyabinsk meteorites (fall, February 15, 2013) are presented. Three types of meteorite material are present, described as the light-colored, dark-colored, and impact-melt lithologies. All are of LL5 composition with the impact-melt lithology being close to whole-rock melt and the dark-colored lithology being shock-darkened due to partial melting of iron metal and sulfides. This enables us to study the effect of increasing shock on material with identical composition and origin. Based on the magnetic susceptibility, the Chelyabinsk meteorites are richer in metallic iron as compared to other LL chondrites. The measured bulk and grain densities and the porosity closely resemble other LL chondrites. Shock darkening does not have a significant effect on the material physical properties, but causes a decrease of reflectance and decrease in silicate absorption bands in the reflectance spectra. This is similar to the space weathering effects observed on asteroids. However, ...

Kohout, Tomas; Grokhovsky, Victor I; Yakovlev, Grigoriy A; Haloda, Jakub; Halodova, Patricie; Michallik, Radoslaw M; Penttilä, Antti; Muinonen, Karri

2014-01-01T23:59:59.000Z

29

MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

2011-08-01T23:59:59.000Z

30

Actinide halide complexes  

DOE Patents [OSTI]

A compound is described of the formula MX[sub n]L[sub m] wherein M is a metal atom selected from the group consisting of thorium, plutonium, neptunium or americium, X is a halide atom, n is an integer selected from the group of three or four, L is a coordinating ligand selected from the group consisting of aprotic Lewis bases having an oxygen-, nitrogen-, sulfur-, or phosphorus-donor, and m is an integer selected from the group of three or four for monodentate ligands or is the integer two for bidentate ligands, where the sum of n+m equals seven or eight for monodentate ligands or five or six for bidentate ligands. A compound of the formula MX[sub n] wherein M, X, and n are as previously defined, and a process of preparing such actinide metal compounds are described including admixing the actinide metal in an aprotic Lewis base as a coordinating solvent in the presence of a halogen-containing oxidant.

Avens, L.R.; Zwick, B.D.; Sattelberger, A.P.; Clark, D.L.; Watkin, J.G.

1992-11-24T23:59:59.000Z

31

Actinide halide complexes  

DOE Patents [OSTI]

A compound of the formula MX.sub.n L.sub.m wherein M is a metal atom selected from the group consisting of thorium, plutonium, neptunium or americium, X is a halide atom, n is an integer selected from the group of three or four, L is a coordinating ligand selected from the group consisting of aprotic Lewis bases having an oxygen-, nitrogen-, sulfur-, or phosphorus-donor, and m is an integer selected from the group of three or four for monodentate ligands or is the integer two for bidentate ligands, where the sum of n+m equals seven or eight for monodentate ligands or five or six for bidentate ligands, a compound of the formula MX.sub.n wherein M, X, and n are as previously defined, and a process of preparing such actinide metal compounds including admixing the actinide metal in an aprotic Lewis base as a coordinating solvent in the presence of a halogen-containing oxidant, are provided.

Avens, Larry R. (Los Alamos, NM); Zwick, Bill D. (Santa Fe, NM); Sattelberger, Alfred P. (Los Alamos, NM); Clark, David L. (Los Alamos, NM); Watkin, John G. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

32

Managing Inventories of Heavy Actinides  

SciTech Connect (OSTI)

The Department of Energy (DOE) has stored a limited inventory of heavy actinides contained in irradiated targets, some partially processed, at the Savannah River Site (SRS) and Oak Ridge National Laboratory (ORNL). The 'heavy actinides' of interest include plutonium, americium, and curium isotopes; specifically 242Pu and 244Pu, 243Am, and 244/246/248Cm. No alternate supplies of these heavy actinides and no other capabilities for producing them are currently available. Some of these heavy actinide materials are important for use as feedstock for producing heavy isotopes and elements needed for research and commercial application. The rare isotope 244Pu is valuable for research, environmental safeguards, and nuclear forensics. Because the production of these heavy actinides was made possible only by the enormous investment of time and money associated with defense production efforts, the remaining inventories of these rare nuclear materials are an important part of the legacy of the Nuclear Weapons Program. Significant unique heavy actinide inventories reside in irradiated Mark-18A and Mark-42 targets at SRS and ORNL, with no plans to separate and store the isotopes for future use. Although the costs of preserving these heavy actinide materials would be considerable, for all practical purposes they are irreplaceable. The effort required to reproduce these heavy actinides today would likely cost billions of dollars and encompass a series of irradiation and chemical separation cycles for at least 50 years; thus, reproduction is virtually impossible. DOE has a limited window of opportunity to recover and preserve these heavy actinides before they are disposed of as waste. A path forward is presented to recover and manage these irreplaceable National Asset materials for future use in research, nuclear forensics, and other potential applications.

Wham, Robert M [ORNL; Patton, Bradley D [ORNL

2011-01-01T23:59:59.000Z

33

Environmental research on actinide elements  

SciTech Connect (OSTI)

The papers synthesize the results of research sponsored by DOE's Office of Health and Environmental Research on the behavior of transuranic and actinide elements in the environment. Separate abstracts have been prepared for the 21 individual papers. (ACR)

Pinder, J.E. III; Alberts, J.J.; McLeod, K.W.; Schreckhise, R.G. (eds.)

1987-08-01T23:59:59.000Z

34

E-Print Network 3.0 - actinide nuclei indirectly Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

40 (2009) ACTA PHYSICA POLONICA B No 3 PRODUCTION OF NEW SUPERHEAVY NUCLEI IN COMPLETE FUSION... physics. The cold Pb- and Bi-based 1 and hot actinide-based 2 complete...

35

E-Print Network 3.0 - actinide nuclei induced Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

40 (2009) ACTA PHYSICA POLONICA B No 3 PRODUCTION OF NEW SUPERHEAVY NUCLEI IN COMPLETE FUSION... physics. The cold Pb- and Bi-based 1 and hot actinide-based 2 complete...

36

E-Print Network 3.0 - actinide-based complete-fusion reactions...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

fusion reactions. The yields of superheavies with Z > 118 are sensitive... physics. The cold Pb- and Bi-based 1 and hot actinide-based 2 complete fusion reactions were...

37

E-Print Network 3.0 - actinide nuclei Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

40 (2009) ACTA PHYSICA POLONICA B No 3 PRODUCTION OF NEW SUPERHEAVY NUCLEI IN COMPLETE FUSION... physics. The cold Pb- and Bi-based 1 and hot actinide-based 2 complete...

38

The development and performance of a message-passing version of the PAGOSA shock-wave physics code  

SciTech Connect (OSTI)

A message-passing version of the PAGOSA shock-wave physics code has been developed at Sandia National Laboratories for multiple-instruction, multiple-data stream (MIMD) computers. PAGOSA is an explicit, Eulerian code for modeling the three-dimensional, high-speed hydrodynamic flow of fluids and the dynamic deformation of solids under high rates of strain. It was originally developed at Los Alamos National Laboratory for the single-instruction, multiple-data (SIMD) Connection Machine parallel computers. The performance of Sandia`s message-passing version of PAGOSA has been measured on two MIMD machines, the nCUBE 2 and the Intel Paragon XP/S. No special efforts were made to optimize the code for either machine. The measured scaled speedup (computational time for a single computational node divided by the computational time per node for fixed computational load) and grind time (computational time per cell per time step) show that the MIMD PAGOSA code scales linearly with the number of computational nodes used on a variety of problems, including the simulation of shaped-charge jets perforating an oil well casing. Scaled parallel efficiencies for MIMD PAGOSA are greater than 0.70 when the available memory per node is filled (or nearly filled) on hundreds to a thousand or more computational nodes on these two machines, indicating that the code scales very well. Thus good parallel performance can be achieved for complex and realistic applications when they are first implemented on MIMD parallel computers.

Gardner, D.R.; Vaughan, C.T.

1997-10-01T23:59:59.000Z

39

33rd Actinide Separations Conference  

SciTech Connect (OSTI)

Welcome to the 33rd Actinide Separations Conference hosted this year by the Lawrence Livermore National Laboratory. This annual conference is centered on the idea of networking and communication with scientists from throughout the United States, Britain, France and Japan who have expertise in nuclear material processing. This conference forum provides an excellent opportunity for bringing together experts in the fields of chemistry, nuclear and chemical engineering, and actinide processing to present and discuss experiences, research results, testing and application of actinide separation processes. The exchange of information that will take place between you, and other subject matter experts from around the nation and across the international boundaries, is a critical tool to assist in solving both national and international problems associated with the processing of nuclear materials used for both defense and energy purposes, as well as for the safe disposition of excess nuclear material. Granlibakken is a dedicated conference facility and training campus that is set up to provide the venue that supports communication between scientists and engineers attending the 33rd Actinide Separations Conference. We believe that you will find that Granlibakken and the Lake Tahoe views provide an atmosphere that is stimulating for fruitful discussions between participants from both government and private industry. We thank the Lawrence Livermore National Laboratory and the United States Department of Energy for their support of this conference. We especially thank you, the participants and subject matter experts, for your involvement in the 33rd Actinide Separations Conference.

McDonald, L M; Wilk, P A

2009-05-04T23:59:59.000Z

40

Kinetics of actinide complexation reactions  

SciTech Connect (OSTI)

Though the literature records extensive compilations of the thermodynamics of actinide complexation reactions, the kinetics of complex formation and dissociation reactions of actinide ions in aqueous solutions have not been extensively investigated. In light of the central role played by such reactions in actinide process and environmental chemistry, this situation is somewhat surprising. The authors report herein a summary of what is known about actinide complexation kinetics. The systems include actinide ions in the four principal oxidation states (III, IV, V, and VI) and complex formation and dissociation rates with both simple and complex ligands. Most of the work reported was conducted in acidic media, but a few address reactions in neutral and alkaline solutions. Complex formation reactions tend in general to be rapid, accessible only to rapid-scan and equilibrium perturbation techniques. Complex dissociation reactions exhibit a wider range of rates and are generally more accessible using standard analytical methods. Literature results are described and correlated with the known properties of the individual ions.

Nash, K.L.; Sullivan, J.C.

1997-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

SciTech Connect: Numerical simulation of shock-heated plasma...  

Office of Scientific and Technical Information (OSTI)

Publication: United States Language: English Subject: N70100* --Physics--Controlled Thermonuclear Research-- Confinement & Heating; *HEATING-- SHOCK HEATING; *SHOCK HEATING--...

42

Actinide Lanthanide Separation Process – ALSEP  

SciTech Connect (OSTI)

Separation of the minor actinides (Am, Cm) from the lanthanides at an industrial scale remains a significant technical challenge for closing the nuclear fuel cycle. To increase the safety of used nuclear fuel (UNF) reprocessing, as well as reduce associated costs, a novel solvent extraction process has been developed. The process allows for partitioning minor actinides, lanthanides and fission products following uranium/plutonium/neptunium removal; minimizing the number of separation steps, flowsheets, chemical consumption, and waste. This new process, Actinide Lanthanide SEParation (ALSEP), uses an organic solvent consisting of a neutral diglycolamide extractant, either N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) or N,N,N',N'-tetraoctyldiglycolamide (TODGA), and an acidic extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]), dissolved in an aliphatic diluent (e.g. n-dodecane). The An/Ln co-extraction is conducted from moderate-to-strong nitric acid, while the selective stripping of the minor actinides from the lanthanides is carried out using a polyaminocarboxylic acid/citrate buffered solution at pH anywhere between 3 and 4.5. The extraction and separation of the actinides from the fission products is very effective in a wide range of HNO3 concentrations and the minimum separation factors for lanthanide/Am exceed 30 for Nd/Am, reaching > 60 for Eu/Am under some conditions. The experimental results presented here demonstrate the great potential for a combined system, consisting of a neutral extractant such as T2EHDGA or TODGA, and an acidic extractant such as HEH[EHP], for separating the minor actinides from the lanthanides.

Gelis, Artem V.; Lumetta, Gregg J.

2014-01-29T23:59:59.000Z

43

Literature review of United States utilities computer codes for calculating actinide isotope content in irradiated fuel  

SciTech Connect (OSTI)

This paper reviews the accuracy and precision of methods used by United States electric utilities to determine the actinide isotopic and element content of irradiated fuel. After an extensive literature search, three key code suites were selected for review. Two suites of computer codes, CASMO and ARMP, are used for reactor physics calculations; the ORIGEN code is used for spent fuel calculations. They are also the most widely used codes in the nuclear industry throughout the world. Although none of these codes calculate actinide isotopics as their primary variables intended for safeguards applications, accurate calculation of actinide isotopic content is necessary to fulfill their function.

Horak, W.C.; Lu, Ming-Shih

1991-12-01T23:59:59.000Z

44

Actinide Thermodynamics at Elevated Temperatures  

SciTech Connect (OSTI)

The postclosure chemical environment in the proposed Yucca Mountain repository is expected to experience elevated temperatures. Predicting migration of actinides is possible if sufficient, reliable thermodynamic data on hydrolysis and complexation are available for these temperatures. Data are scarce and scattered for 25 degrees C, and nonexistent for elevated temperatures. This collaborative project between LBNL and PNNL collects thermodynamic data at elevated temperatures on actinide complexes with inorganic ligands that may be present in Yucca Mountain. The ligands include hydroxide, fluoride, sulfate, phosphate and carbonate. Thermodynamic parameters of complexation, including stability constants, enthalpy, entropy and heat capacity of complexation, are measured with a variety of techniques including solvent extraction, potentiometry, spectrophotometry and calorimetry

Friese, Judah I.; Rao, Linfeng; Xia, Yuanxian; Bachelor, Paula P.; Tian, Guoxin

2007-11-16T23:59:59.000Z

45

X-ray Spectral Measurements of the Most Massive Stars: Stellar Wind Mass-Loss Rates and Shock Physics  

E-Print Network [OSTI]

X-ray Spectral Measurements of the Most Massive Stars: Stellar Wind Mass-Loss Rates and Shock/Themes: Significant technological advances in X-ray astronomy have driven discovery over the last few decades. New. The priorities at Swarthmore have allowed me to do careful work on the small number of X-ray spectral datasets

Cohen, David

46

Ceramic composition for immobilization of actinides  

DOE Patents [OSTI]

Disclosed is a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile.

Ebbinghaus, Bartley B. (Livermore, CA); Van Konynenburg, Richard A. (Livermore, CA); Vance, Eric R. (Kirrawee, AU); Stewart, Martin W. (Barden Ridge, AU); Jostsons, Adam (Eastwood, AU); Allender, Jeffrey S. (North Augusta, SC); Rankin, David Thomas (Aiken, SC)

2000-01-01T23:59:59.000Z

47

Analysis of large soil samples for actinides  

SciTech Connect (OSTI)

A method of analyzing relatively large soil samples for actinides by employing a separation process that includes cerium fluoride precipitation for removing the soil matrix and precipitates plutonium, americium, and curium with cerium and hydrofluoric acid followed by separating these actinides using chromatography cartridges.

Maxwell, III; Sherrod L. (Aiken, SC)

2009-03-24T23:59:59.000Z

48

PREPARATION AND SPECTROSCOPIC PROPERTIES OF THREE NEW ACTINIDE (IV) BOROHYDRIDES  

E-Print Network [OSTI]

uranium tetrakis-borohydrides were prepared by a different reaction which involves the actinide tetrafluoride

Banks, Rodney Howard

2010-01-01T23:59:59.000Z

49

Hypersonic Molecular Shocks in Star Forming Regions  

E-Print Network [OSTI]

Much emission from star forming regions is from shock-excited gas. Shocks in molecular clouds are still not fully understood, as magnetic fields, dust and chemistry all play significant roles. I review the history, physics and current work in understanding these shocks, and in their possible use as diagnostics of local conditions.

Brand, P W J L

2006-01-01T23:59:59.000Z

50

Hypersonic Molecular Shocks in Star Forming Regions  

E-Print Network [OSTI]

Much emission from star forming regions is from shock-excited gas. Shocks in molecular clouds are still not fully understood, as magnetic fields, dust and chemistry all play significant roles. I review the history, physics and current work in understanding these shocks, and in their possible use as diagnostics of local conditions.

Peter W. J. L. Brand

2006-09-08T23:59:59.000Z

51

E-Print Network 3.0 - actinides recycling studies Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

minor Actinides (predominantly... of data, the study of the possibility of transmuting heavy actinides in PWRs, the development of codes... on purely minor actinide fuel,...

52

E-Print Network 3.0 - actinide burning experiment Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

actinide burning molten salt - liquid f... for fission products and actinides in subcritical cores with different neutron spectra. This experiment... on purely minor actinide...

53

Experimental studies of actinides in molten salts  

SciTech Connect (OSTI)

This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

Reavis, J.G.

1985-06-01T23:59:59.000Z

54

Actinide removal from spent salts  

DOE Patents [OSTI]

A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

Hsu, Peter C. (Pleasanton, CA); von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

2002-01-01T23:59:59.000Z

55

BWR Assembly Optimization for Minor Actinide Recycling  

SciTech Connect (OSTI)

The Primary objective of the proposed project is to apply and extend the latest advancements in LWR fuel management optimization to the design of advanced boiling water reactor (BWR) fuel assemblies specifically for the recycling of minor actinides (MAs).

G. Ivan Maldonado; John M. Christenson; J.P. Renier; T.F. Marcille; J. Casal

2010-03-22T23:59:59.000Z

56

Actinide minimization using pressurized water reactors  

E-Print Network [OSTI]

Transuranic actinides dominate the long-term radiotoxity in spent LWR fuel. In an open fuel cycle, they impose a long-term burden on geologic repositories. Transmuting these materials in reactor systems is one way to ease ...

Visosky, Mark Michael

2006-01-01T23:59:59.000Z

57

Overview of actinide chemistry in the WIPP  

SciTech Connect (OSTI)

The year 2009 celebrates 10 years of safe operations at the Waste Isolation Pilot Plant (WIPP), the only nuclear waste repository designated to dispose defense-related transuranic (TRU) waste in the United States. Many elements contributed to the success of this one-of-the-kind facility. One of the most important of these is the chemistry of the actinides under WIPP repository conditions. A reliable understanding of the potential release of actinides from the site to the accessible environment is important to the WIPP performance assessment (PA). The environmental chemistry of the major actinides disposed at the WIPP continues to be investigated as part of the ongoing recertification efforts of the WIPP project. This presentation provides an overview of the actinide chemistry for the WIPP repository conditions. The WIPP is a salt-based repository; therefore, the inflow of brine into the repository is minimized, due to the natural tendency of excavated salt to re-seal. Reducing anoxic conditions are expected in WIPP because of microbial activity and metal corrosion processes that consume the oxygen initially present. Should brine be introduced through an intrusion scenario, these same processes will re-establish reducing conditions. In the case of an intrusion scenario involving brine, the solubilization of actinides in brine is considered as a potential source of release to the accessible environment. The following key factors establish the concentrations of dissolved actinides under subsurface conditions: (1) Redox chemistry - The solubility of reduced actinides (III and IV oxidation states) is known to be significantly lower than the oxidized forms (V and/or VI oxidation states). In this context, the reducing conditions in the WIPP and the strong coupling of the chemistry for reduced metals and microbiological processes with actinides are important. (2) Complexation - For the anoxic, reducing and mildly basic brine systems in the WIPP, the most important inorganic complexants are expected to be carbonate/bicarbonate and hydroxide. There are also organic complexants in TRU waste with the potential to strongly influence actinide solubility. (3) Intrinsic and pseudo-actinide colloid formation - Many actinide species in their expected oxidation states tend to form colloids or strongly associate with non actinide colloids present (e.g., microbial, humic and organic). In this context, the relative importance of actinides, based on the TRU waste inventory, with respect to the potential release of actinides from the WIPP, is greater for plutonium and americium, and to less extent for uranium and thorium. The most important oxidation states for WIPP-relevant conditions are III and IV. We will present an update of the literature on WIPP-specific data, and a summary of the ongoing research related to actinide chemistry in the WIPP performed by the Los Alamos National Laboratory (LANL) Actinide Chemistry and Repository Science (ACRSP) team located in Carlsbad, NM [Reed 2007, Lucchini 2007, and Reed 2006].

Borkowski, Marian [Los Alamos National Laboratory; Lucchini, Jean - Francois [Los Alamos National Laboratory; Richmann, Michael K [Los Alamos National Laboratory; Reed, Donald T [Los Alamos National Laboratory; Khaing, Hnin [Los Alamos National Laboratory; Swanson, Juliet [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

58

Advanced Aqueous Separation Systems for Actinide Partitioning  

SciTech Connect (OSTI)

One of the most challenging aspects of advanced processing of spent nuclear fuel is the need to isolate transuranium elements from fission product lanthanides. This project expanded the scope of earlier investigations of americium (Am) partitioning from the lanthanides with the synthesis of new separations materials and a centralized focus on radiochemical characterization of the separation systems that could be developed based on these new materials. The primary objective of this program was to explore alternative materials for actinide separations and to link the design of new reagents for actinide separations to characterizations based on actinide chemistry. In the predominant trivalent oxidation state, the chemistry of lanthanides overlaps substantially with that of the trivalent actinides and their mutual separation is quite challenging.

Nash, Kenneth L.; Sue Clark; G. Patrick Meier; Spiro Alexandratos; Robert Paine; Robert Hancock; Dale Ensor

2012-03-21T23:59:59.000Z

59

E-Print Network 3.0 - accretion shocks application Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

California Institute of Technology Collection: Physics 24 Shock Waves in Out ows from Young Stars Patrick Hartigan Summary: of a shock front given by Draine (1980) as an...

60

MOLECULAR SPECTROSCPY AND REACTIONS OF ACTINIDES IN THE GAS PHASE AND CRYOGENIC MATRICES  

SciTech Connect (OSTI)

In this chapter we review the spectroscopic data for actinide molecules and the reaction dynamics for atomic and molecular actinides that have been examined in the gas phase or in inert cryogenic matrices. The motivation for this type of investigation is that physical properties and reactions can be studied in the absence of external perturbations (gas phase) or under minimally perturbing conditions (cryogenic matrices). This information can be compared directly with the results from high-level theoretical models. The interplay between experiment and theory is critically important for advancing our understanding of actinide chemistry. For example, elucidation of the role of the 5f electrons in bonding and reactivity can only be achieved through the application of experimentally verified theoretical models. Theoretical calculations for the actinides are challenging due the large numbers of electrons that must be treated explicitly and the presence of strong relativistic effects. This topic has been reviewed in depth in Chapter 17 of this series. One of the goals of the experimental work described in this chapter has been to provide benchmark data that can be used to evaluate both empirical and ab initio theoretical models. While gas-phase data are the most suitable for comparison with theoretical calculations, there are technical difficulties entailed in generating workable densities of gas-phase actinide molecules that have limited the range of species that have been characterized. Many of the compounds of interest are refractory, and problems associated with the use of high temperature vapors have complicated measurements of spectra, ionization energies, and reactions. One approach that has proved to be especially valuable in overcoming this difficulty has been the use of pulsed laser ablation to generate plumes of vapor from refractory actinide-containing materials. The vapor is entrained in an inert gas, which can be used to cool the actinide species to room temperature or below. For many spectroscopic measurements, low temperatures have been achieved by co-condensing the actinide vapor in rare gas or inert molecule host matrices. Spectra recorded in matrices are usually considered to be minimally perturbed. Trapping the products from gas-phase reactions that occur when trace quantities of reactants are added to the inert host gas has resulted in the discovery of many new actinide species. Selected aspects of the matrix isolation data were discussed in chapter 17. In the present chapter we review the spectroscopic matrix data in terms of its relationship to gas-phase measurements, and update the description of the new reaction products found in matrices to reflect the developments that have occurred during the past two years. Spectra recorded in matrix environments are usually considered to be minimally perturbed, and this expectation is borne out for many closed shell actinide molecules. However, there is growing evidence that significant perturbations can occur for open shell molecules, resulting in geometric distortions and/or electronic state reordering. Studies of actinide reactions in the gas phase provide an opportunity to probe the relationship between electronic structure and reactivity. Much of this work has focused on the reactions of ionic species, as these may be selected and controlled using various forms of mass spectrometry. As an example of the type of insight derived from reaction studies, it has been established that the reaction barriers for An+ ions are determined by the promotion energies required to achieve the 5fn6d7s configuration. Gas-phase reaction studies also provide fundamental thermodynamic properties such as bond dissociation and ionization energies. In recent years, an increased number of gas-phase ion chemistry studies of bare (atomic) and ligated (molecular) actinide ions have appeared, in which relevant contributions to fundamental actinide chemistry have been made. These studies were initiated in the 1970's and carried out in an uninterrupted way over the course of the past three d

Heaven, Michael C.; Gibson, John K.; Marcalo, Joaquim

2009-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Ultratrace analysis of transuranic actinides by laser-induced fluorescence  

DOE Patents [OSTI]

Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

Miller, S.M.

1983-10-31T23:59:59.000Z

62

Rapid determination of actinides in asphalt samples  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organics present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.

Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

2014-01-12T23:59:59.000Z

63

Characterization of transuranium actinide alloy phase diagrams  

SciTech Connect (OSTI)

Alloys of Np have been studied less than those,of the neighboring elements, U and Pu; the higher actinides have received even less attention. Recent interest in {sup 237}Np, {sup 241}Am and other actinide isotopes as significant, long-lived and highly radiotoxic nuclear waste components, and particularly the roles of metallic materials new handling/separations and remediation technologies, demands that this paucity of information concerning alloy behaviors be addressed. An additional interest in these arises from the possibility of revealing fundamental properties and bonding interactions, which would further characterize the unique electronic structures (e.g., 5f electrons) of the actinide elements. The small empirical knowledge basis presently available for understanding and modeling the alloying behavior of Np is summarized here, with emphasis on our recent results for the Np-Am, Np-Zr and Np-Fe phase diag rams. In view of the limited experimental data base for neptunium and the transplutonium metals, the value of semi-empirical intermetallic bonding models for predicting actinide alloy thermodynamics is evaluated.

Gibson, J.K.; Haire, R.G.; Gensini, M.M. [Oak Ridge National Lab., TN (United States); Ogawa, T. [Japan Atomic Energy Research Inst., Tokai (Japan)

1994-05-02T23:59:59.000Z

64

Synthesis of actinide nitrides, phosphides, sulfides and oxides  

DOE Patents [OSTI]

A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g., uranium mononitride, by subliming an actinide organometallic precursor, e.g., a uranium amide precursor, in the presence of an effectgive amount of a protic Lewis base, e.g., ammonia, within a reactor at temperatures and for time sufficient to form a thin film of the actinide compound, are disclosed.

Van Der Sluys, William G. (Missoula, MT); Burns, Carol J. (Los Alamos, NM); Smith, David C. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

65

Remote shock sensing and notification system  

DOE Patents [OSTI]

A low-power shock sensing system includes at least one shock sensor physically coupled to a chemical storage tank to be monitored for impacts, and an RF transmitter which is in a low-power idle state in the absence of a triggering signal. The system includes interference circuitry including or activated by the shock sensor, wherein an output of the interface circuitry is coupled to an input of the RF transmitter. The interface circuitry triggers the RF transmitting with the triggering signal to transmit an alarm message to at least one remote location when the sensor senses a shock greater than a predetermined threshold. In one embodiment the shock sensor is a shock switch which provides an open and a closed state, the open state being a low power idle state.

Muralidharan, Govindarajan (Knoxville, TN); Britton, Charles L. (Alcoa, TN); Pearce, James (Lenoir City, TN); Jagadish, Usha (Knoxville, TN); Sikka, Vinod K. (Oak Ridge, TN)

2008-11-11T23:59:59.000Z

66

Molecular dynamics simulation and topological analysis of the network structure of actinide-bearing materials  

E-Print Network [OSTI]

Actinide waste production and storage is a complex problem, and a whole-cycle approach to actinide management is necessary to minimize the total volume of waste. In this dissertation, I examine three actinide-bearing ...

Dewan, Leslie

2013-01-01T23:59:59.000Z

67

Collisionless Weibel shocks: Full formation mechanism and timing  

SciTech Connect (OSTI)

Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.

Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Stockem, A. [GoLP/Instituto de Plasmas e Fusăo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal); Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Narayan, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, Massachusetts 02138 (United States); Silva, L. O. [GoLP/Instituto de Plasmas e Fusăo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal)

2014-07-15T23:59:59.000Z

68

SciTech Connect: Numerical studies of shock focusing in a coaxial...  

Office of Scientific and Technical Information (OSTI)

Publication: United States Language: English Subject: N70300* --Physics--Controlled Thermonuclear Research-- Kinetics (General); *SHOCK WAVES-- FOCUSING; COMPRESSIBLE FLOW;...

69

SciTech Connect: Numerical solution of shock tube divertor and...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Publication: United States Language: English Subject: N70300* --Physics--Controlled Thermonuclear Research-- Kinetics (General); *DIVERTORS-- MATHEMATICAL MODELS; *SHOCK TUBES--...

70

Actinide and lanthanide separation process (ALSEP)  

DOE Patents [OSTI]

The process of the invention is the separation of minor actinides from lanthanides in a fluid mixture comprising, fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water by addition of an organic chelating aid to the fluid; extracting the fluid with a solvent comprising a first extractant, a second extractant and an organic diluent to form an organic extractant stream and an aqueous raffinate. Scrubbing the organic stream with a dicarboxylic acid and a chelating agent to form a scrubber discharge. The scrubber discharge is stripped with a simple buffering agent and a second chelating agent in the pH range of 2.5 to 6.1 to produce actinide and lanthanide streams and spent organic diluents. The first extractant is selected from bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA).

Guelis, Artem V.

2013-01-15T23:59:59.000Z

71

E-Print Network 3.0 - actinide partitioning studies Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

MA : Minor Actinide LLFP : Long... of data, the study of the possibility of transmuting heavy actinides in PWRs, the development of codes... and transmutation were divided in...

72

E-Print Network 3.0 - actinide separations final Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

us to explore alternatives to some... , of minor actinides, i.e. neptunium, americium and curium. If stored in geological depositories, plutonium... actinides than uranium fuels,...

73

E-Print Network 3.0 - actinides conditioning synthese Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AND CONCEPT EVOLUTIONS Summary: , of minor actinides, i.e. neptunium, americium and curium. If stored in geological depositories, plutonium... actinides than uranium fuels,...

74

E-Print Network 3.0 - actinide ma recycling Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by a chemical process. These plants can however not separate neptunium, americium and curium (minor actinides... to developing a process for separation of the minor actinides...

75

E-Print Network 3.0 - actinide target preparation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for such materials... ' actinides, to distinguish them from the larger quantities of uranium and plutonium also present in the fuel... to extract and recycle all actinides in...

76

E-Print Network 3.0 - actinide halide complexes Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

It has been observed that complexes of lanthanide, actinide, and transition metal activate... that these actinide alkyl complexes undergo interesting C-H and C-N bond...

77

E-Print Network 3.0 - actinide complexation kinetics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

It has been observed that complexes of lanthanide, actinide, and transition metal activate... that these actinide alkyl complexes undergo interesting C-H and C-N bond...

78

POTENTIAL BENCHMARKS FOR ACTINIDE PRODUCTION IN HANFORD REACTORS  

SciTech Connect (OSTI)

A significant experimental program was conducted in the early Hanford reactors to understand the reactor production of actinides. These experiments were conducted with sufficient rigor, in some cases, to provide useful information that can be utilized today in development of benchmark experiments that may be used for the validation of present computer codes for the production of these actinides in low enriched uranium fuel.

PUIGH RJ; TOFFER H

2011-10-19T23:59:59.000Z

79

Process for making a ceramic composition for immobilization of actinides  

DOE Patents [OSTI]

Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

Ebbinghaus, Bartley B. (Livermore, CA); Van Konynenburg, Richard A. (Livermore, CA); Vance, Eric R. (Kirrawee, AU); Stewart, Martin W. (Barden Ridge, AU); Walls, Philip A. (Cronulla, AU); Brummond, William Allen (Livermore, CA); Armantrout, Guy A. (Livermore, CA); Herman, Connie Cicero (Pleasanton, CA); Hobson, Beverly F. (Livermore, CA); Herman, David Thomas (Pleasanton, CA); Curtis, Paul G. (Tracy, CA); Farmer, Joseph (Tracy, CA)

2001-01-01T23:59:59.000Z

80

Improved method for extracting lanthanides and actinides from acid solutions  

DOE Patents [OSTI]

A process for the recovery of actinide and lanthanide values from aqueous acidic solutions uses a new series of neutral bi-functional extractants, the alkyl(phenyl)-N,N-dialkylcarbamoylmethylphosphine oxides. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high-level nuclear reprocessing waste solutions.

Horwitz, E.P.; Kalina, D.G.; Kaplan, L.; Mason, G.W.

1983-07-26T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

E-Print Network 3.0 - actinide iii cations Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Actinide(III) 2.26x10-7 log f(CO2) -5.50 Actinide(IV) 5.66x10... Actinide(III) case: Americium in WIPP Brine 12;Figure 2 Actinide(V) case: Neptunium in WIPP Brine 12... November...

82

Cosmological shock waves  

E-Print Network [OSTI]

Large-scale structure formation, accretion and merging processes, AGN activity produce cosmological gas shocks. The shocks convert a fraction of the energy of gravitationally accelerated flows to internal energy of the gas. Being the main gas-heating agent, cosmological shocks could amplify magnetic fields and accelerate energetic particles via the multi-fluid plasma relaxation processes. We first discuss the basic properties of standard single-fluid shocks. Cosmological plasma shocks are expected to be collisionless. We then review the plasma processes responsible for the microscopic structure of collisionless shocks. A tiny fraction of the particles crossing the shock is injected into the non-thermal energetic component that could get a substantial part of the ram pressure power dissipated at the shock. The energetic particles penetrate deep into the shock upstream producing an extended shock precursor. Scaling relations for postshock ion temperature and entropy as functions of shock velocity in strong collisionless multi-fluid shocks are discussed. We show that the multi-fluid nature of collisionless shocks results in excessive gas compression, energetic particle acceleration, precursor gas heating, magnetic field amplification and non-thermal emission. Multi-fluid shocks provide a reduced gas entropy production and could also modify the observable thermodynamic scaling relations for clusters of galaxies.

A. M. Bykov; K. Dolag; F. Durret

2008-01-07T23:59:59.000Z

83

The attenuation of strong shock waves  

E-Print Network [OSTI]

THE ATTENUATION OF STRONG SHOCK WAVES A Thesis By Ronald Crecelius Kirkpatrick Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 1963 Major Subject: Physics. THE ATTENUATION OF STRONG SHOCK WAVES A Thesis By Ronald Crecelius Kirkpatrick Approved as to style and content by: (Chairman of Committee (He of Departme ) May 1963 TABLE OF CONTENTS INT R ODU C TI ON ~Pe e...

Kirkpatrick, Ronald Crecelius

1963-01-01T23:59:59.000Z

84

Separating the Minor Actinides Through Advances in Selective Coordination Chemistry  

SciTech Connect (OSTI)

This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.

Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Carter, Jennifer C.

2012-08-22T23:59:59.000Z

85

Process to remove actinides from soil using magnetic separation  

DOE Patents [OSTI]

A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

Avens, Larry R. (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Stewart, Walter F. (Las Cruces, NM); Tolt, Thomas L. (Los Alamos, NM); Worl, Laura A. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

86

The Heliospheric Termination Shock  

E-Print Network [OSTI]

The heliospheric Termination Shock is the largest (by dimension) shock in the heliosphere. It is believed that it is also the strongest shock and is responsible for the generation of the Anomalous Cosmic Ray component in the heliosphere. This chapter review the gross properties and observations of the Termination Shock. It is structured as follows: 1. The heliosphere, providing the heliospheric stage for Termination Shock formation, 2. The argument for a heliospheric Termination Shock, 3. The global heliospheric system, 4. Termination Shock properties, 5. Observations: the Voyager passages, radio observations, plasma waves and electron beams, traces of plasma and magnetic field, energetic particles, galactic cosmic rays, Termination Shock particles, the anomalous cosmic ray component, 6. Conclusions.

R. A. Treumann; C. H. Jaroschek

2008-07-25T23:59:59.000Z

87

Separations and Actinide Science -- 2005 Roadmap  

SciTech Connect (OSTI)

The Separations and Actinide Science Roadmap presents a vision to establish a separations and actinide science research (SASR) base composed of people, facilities, and collaborations and provides new and innovative nuclear fuel cycle solutions to nuclear technology issues that preclude nuclear proliferation. This enabling science base will play a key role in ensuring that Idaho National Laboratory (INL) achieves its long-term vision of revitalizing nuclear energy by providing needed technologies to ensure our nation's energy sustainability and security. To that end, this roadmap suggests a 10-year journey to build a strong SASR technical capability with a clear mission to support nuclear technology development. If nuclear technology is to be used to satisfy the expected growth in U.S. electrical energy demand, the once-through fuel cycle currently in use should be reconsidered. Although the once-through fuel cycle is cost-effective and uranium is inexpensive, a once-through fuel cycle requires long-term disposal to protect the environment and public from long-lived radioactive species. The lack of a current disposal option (i.e., a licensed repository) has resulted in accumulation of more than 50,000 metric tons of spent nuclear fuel. The process required to transition the current once-through fuel cycle to full-recycle will require considerable time and significant technical advancement. INL's extensive expertise in aqueous separations will be used to develop advanced separations processes. Computational chemistry will be expanded to support development of future processing options. In the intermediate stage of this transition, reprocessing options will be deployed, waste forms with higher loading densities and greater stability will be developed, and transmutation of long-lived fission products will be explored. SASR will support these activities using its actinide science and aqueous separations expertise. In the final stage, full recycle will be enabled by advanced reactors and reprocessing methods based on pyrochemical methods and by using different fuel cycles that do not readily produce plutonium. SASR will facilitate the deployment of advanced pyrochemical separation technology and support development of reprocessing of thorium-based reactor fuels.

Not Available

2005-09-01T23:59:59.000Z

88

Biomass shock pretreatment  

SciTech Connect (OSTI)

Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

2014-07-01T23:59:59.000Z

89

Minor actinide waste disposal in deep geological boreholes  

E-Print Network [OSTI]

The purpose of this investigation was to evaluate a waste canister design suitable for the disposal of vitrified minor actinide waste in deep geological boreholes using conventional oil/gas/geothermal drilling technology. ...

Sizer, Calvin Gregory

2006-01-01T23:59:59.000Z

90

30th Actinide Separations Conference, PNNL-SA-50126  

SciTech Connect (OSTI)

Program booklet for the 30th Actinide Separations Conference. Contains agenda and abstracts for 27 poster and 38 oral presentations to be made during the 3-day meeting, May 23-25, 2006.

Delegard, Calvin H.

2006-05-25T23:59:59.000Z

91

actinide consumption nuclear: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in this work, fission cross-sections on 233U, the main fissile isotope of the ThU fuel cycle, and on the minor actinides 241Am, 243Am and 245Cm have been analyzed. Data on...

92

Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS  

SciTech Connect (OSTI)

Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS have been conducted. In this work, fission cross section resulted from MCNP6 prediction will be compared with result from TALYS calculation. MCNP6 with its event generator CEM03.03 and LAQGSM03.03 have been validated and verified for several intermediate and heavy nuclides fission reaction data and also has a good agreement with experimental data for fission reaction that induced by photons, pions, and nucleons at energy from several ten of MeV to about 1 TeV. The calculation that induced within TALYS will be focused mainly to several hundred MeV for actinide and sub-actinide nuclides and will be compared with MCNP6 code and several experimental data from other evaluator.

Perkasa, Y. S. [Department of Physics, Sunan Gunung Djati State Islamic University Bandung, Jl. A.H Nasution No. 105 Cibiru, Bandung (Indonesia); Waris, A., E-mail: awaris@fi.itb.ac.id; Kurniadi, R., E-mail: awaris@fi.itb.ac.id; Su'ud, Z., E-mail: awaris@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung 40132 (Indonesia)

2014-09-30T23:59:59.000Z

93

Kinematics of ICMEs/shocks: blast wave reconstruction using type II emissions  

E-Print Network [OSTI]

We present a physical methodology to reconstruct the trajectory of interplanetary shocks using type II radio emission data. This technique calculates the shock trajectory assuming that the disturbance propagates as a blast wave in the interplanetary medium. We applied this Blast Wave Reconstruction (BWR) technique to analyze eight fast Earth-directed ICMEs/shocks associated with type II emissions. The technique deduces a shock trajectory that reproduces the type II frequency drifts, and calculates shock onset speed, shock transit time and shock speed at 1~AU. There were good agreements comparing the BWR results with the type II spectra, with data from coronagraph images, {\\it in situ} measurements, and interplanetary scintillation (IPS) observations. Perturbations on the type II data affect the accuracy of the BWR technique. This methodology could be applied to track interplanetary shocks causing TII emissions in real-time, to predict the shock arrival time and shock speed at 1~AU.

Corona-Romero, P; Aguilar-Rodriguez, E; de-la-Luz, V; Mejia-Ambriz, J C

2015-01-01T23:59:59.000Z

94

Shock response of dry sand.  

SciTech Connect (OSTI)

The dynamic compaction of sand was investigated experimentally and computationally to stresses of 1.8 GPa. Experiments have been performed in the powder's partial compaction regime at impact velocities of approximately 0.25, 0.5, and 0.75 km/s. The experiments utilized multiple velocity interferometry probes on the rear surface of a stepped target for an accurate measurement of shock velocity, and an impedance matching technique was used to deduce the shock Hugoniot state. Wave profiles were further examined for estimates of reshock states. Experimental results were used to fit parameters to the P-Lambda model for porous materials. For simple 1-D simulations, the P-Lambda model seems to capture some of the physics behind the compaction process very well, typically predicting the Hugoniot state to within 3%.

Reinhart, William Dodd; Thornhill, Tom Finley, III (,; ); Chhabildas, Lalit C.. (..); Vogler, Tracy John; Brown, Justin L.

2007-08-01T23:59:59.000Z

95

E-Print Network 3.0 - actinide standard ii-iii Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of a-U (*) Summary: and costly. Thus, while we were able to study the light and heavy actinide metals 1 in their cubic (high... applied to the study of some actinide...

96

E-Print Network 3.0 - actinide compound ufe Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

49, dkcembre 1988 Summary: and actinide Laves phases. In comparison with RFE2 (R Rare earth) Laves phase compounds CeFe2 exhibits... M2 (Ac actinides) 5demon- strates that...

97

E-Print Network 3.0 - actinide system inconsistencies Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of actinide metals Summary: heats of actinide metals M. J. Mortimer Chemistry Division, AERE Harwell, Didcot, Oxon, OX11 ORA, G... 'volution de ces grandeurs ainsi que celle de...

98

E-Print Network 3.0 - actinides exposure review Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of actinide metals Summary: heats of actinide metals M. J. Mortimer Chemistry Division, AERE Harwell, Didcot, Oxon, OX11 ORA, G... 'volution de ces grandeurs ainsi que celle de...

99

E-Print Network 3.0 - actinide alloys Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of actinide metals Summary: heats of actinide metals M. J. Mortimer Chemistry Division, AERE Harwell, Didcot, Oxon, OX11 ORA, G... 'volution de ces grandeurs ainsi que celle de...

100

E-Print Network 3.0 - actinide chemistry Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Powered by Explorit Topic List Advanced Search Sample search results for: actinide chemistry Page: << < 1 2 3 4 5 > >> 1 www.emsl.pnl.gov ACTINIDE CHEMISTRY MEETS COMPUTATION...

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

E-Print Network 3.0 - actinide complexes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(04-400) Summary: of the electronic properties and reactions of actinide and transition metal complexes. Hay, who is a Laboratory... as a leader in actinide chemistry, Burns was...

102

E-Print Network 3.0 - actinide decay series Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

page C2-841 Summary: in the actinide series whereas the acti 1 es up to Pu metal are transition metal likeq" : The f states in Am... aux actinides metalliques et aux oxydes sont...

103

E-Print Network 3.0 - actinide complexing agent Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(04-400) Summary: of the electronic properties and reactions of actinide and transition metal complexes. Hay, who is a Laboratory... as a leader in actinide chemistry, Burns was...

104

Simulations of Turbulent Flows with Strong Shocks and Density Variations  

SciTech Connect (OSTI)

In this report, we present the research efforts made by our group at UCLA in the SciDAC project ���¢��������Simulations of turbulent flows with strong shocks and density variations���¢�������. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

Zhong, Xiaolin

2012-12-13T23:59:59.000Z

105

ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION  

SciTech Connect (OSTI)

Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

Martino, C.; Herman, D.; Pike, J.; Peters, T.

2014-06-05T23:59:59.000Z

106

PROTON ACCELERATION AT OBLIQUE SHOCKS  

SciTech Connect (OSTI)

Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

Galinsky, V. L.; Shevchenko, V. I., E-mail: vit@ucsd.edu [ECE Department, UC San Diego, MC 407, La Jolla, CA 92093-0407 (United States)

2011-06-20T23:59:59.000Z

107

E-Print Network 3.0 - accretion shock instability Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of California at Santa Barbara Collection: Physics 31 Shock Waves in Out ows from Young Stars Patrick Hartigan Summary: numerical codes, and learn what kinds of instabilities...

108

Actinide (III) solubility in WIPP Brine: data summary and recommendations  

SciTech Connect (OSTI)

The solubility of actinides in the +3 oxidation state is an important input into the Waste Isolation Pilot Plant (WIPP) performance assessment (PA) models that calculate potential actinide release from the WIPP repository. In this context, the solubility of neodymium(III) was determined as a function of pH, carbonate concentration, and WIPP brine composition. Additionally, we conducted a literature review on the solubility of +3 actinides under WIPP-related conditions. Neodymium(III) was used as a redox-invariant analog for the +3 oxidation state of americium and plutonium, which is the oxidation state that accounts for over 90% of the potential release from the WIPP through the dissolved brine release (DBR) mechanism, based on current WIPP performance assessment assumptions. These solubility data extend past studies to brine compositions that are more WIPP-relevant and cover a broader range of experimental conditions than past studies.

Borkowski, Marian; Lucchini, Jean-Francois; Richmann, Michael K.; Reed, Donald T.

2009-09-01T23:59:59.000Z

109

Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics Physics Print Because

110

Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A'Hearn, Michael F. - Department of Astronomy, University of Maryland at College Park Aalberts, Daniel P. - Department...

111

Method for recovery of actinides from actinide-bearing scrap and waste nuclear material using O/sub 2/F/sub 2/  

DOE Patents [OSTI]

Method for recovery of actinides from nuclear waste material containing sintered and other oxides thereof and from scrap materials containing the metal actinides using O/sub 2/F/sub 2/ to generate the hexafluorides of the actinides present therein. The fluorinating agent, O/sub 2/F/sub 2/, has been observed to perform the above-described tasks at sufficiently low temperatures that there is virtually no damage to the containment vessels. Moreover, the resulting actinide hexafluorides are not detroyed by high temperature reactions with the walls of the reaction vessel. Dioxygen difluoride is readily prepared, stored and transferred to the place of reaction.

Asprey, L.B.; Eller, P.G.

1984-09-12T23:59:59.000Z

112

RAPID SEPARATION OF ACTINIDES AND RADIOSTRONTIUM IN VEGETATION SAMPLES  

SciTech Connect (OSTI)

A new rapid method for the determination of actinides and radiostrontium in vegetation samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations or for routine analysis. The actinides in vegetation method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a streamlined column separation process with stacked TEVA, TRU and DGA Resin cartridges. Lanthanum was separated rapidly and effectively from Am and Cm on DGA Resin. Alpha emitters are prepared using rare earth microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. The actinide and {sup 90}Sr in vegetation sample analysis can be performed in less than 8 h with excellent quality for emergency samples. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory actinide particles or vegetation residue after furnace heating is effectively digested.

Maxwell, S.

2010-06-01T23:59:59.000Z

113

actinide materials annual: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

actinide materials annual First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Molecular dynamics simulation...

114

Delayed neutron measurements from fast fission of actinide waste isotopes  

E-Print Network [OSTI]

, was suggested which would yield a superior fit to the measured data. A series of measurements were performed to test the hypothesis suggested by this alternate group structure. Using a set of highly purified actinide samples (provided by Oak Ridge National...

Charlton, William S.

2012-06-07T23:59:59.000Z

115

actinides loading optimization: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

actinides loading optimization First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Building load control...

116

Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory and Modeling Los AlamosAerosol.Physics

117

Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter |Photoinduced2Zoe Martin'sPhysics Print

118

Shock compression of low-density foams  

SciTech Connect (OSTI)

Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.

Holmes, N.C.

1993-07-01T23:59:59.000Z

119

Cluster at the Bow Shock: Status and Outlook M. Scholer1, M. F. Thomsen2, D. Burgess3, S. D. Bale4,  

E-Print Network [OSTI]

of the thermal plasma accelerated to high energies? The Earth's bow shock is a collisionless shock whereChapter 7 Cluster at the Bow Shock: Status and Outlook M. Scholer1, M. F. Thomsen2, D. Burgess3, S. It turned out that physical pro- cesses at the bow shock occur on all spatial scales, from the electron

California at Berkeley, University of

120

Shock Tube Design  

E-Print Network [OSTI]

Shock accelerated flows exhibit some of the most violent and complex mechanisms in nature by which two separate fluids can be mixed. The Richtmyer-Meshkov instability (RMI) is generated when a perturbed interface between two fluids is impulsively...

Koppenberger, Peter K.

2010-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Shock Chlorination of Wells  

E-Print Network [OSTI]

Shock chlorination is a method of disinfecting a water well. This publication gives complete instructions for chlorinating with bleach or with dry chlorine. It is also available in Spanish as publication L-5441S...

McFarland, Mark L.; Dozier, Monty

2003-06-11T23:59:59.000Z

122

Independent Activity Report, Nevada National Security Site -...  

Broader source: Energy.gov (indexed) [DOE]

- July 2011 July 2011 NNSS Operational Readiness Review of the Joint Actinide Shock Physics Experimental Research Facility HIAR-NNSS-2011-07-28 This Independent Activity...

123

Magnetohydrodynamic Shocks in Non-Equatorial Plasma Flows around a Black Hole  

E-Print Network [OSTI]

We study magnetohydrodynamic (MHD) standing shocks in inflowing plasmas in a black hole magnetosphere. Fast and intermediate shock formation is explored in Schwarzschild and Kerr geometry to illustrate general relativistic effects. We find that non-equatorial standing MHD shocks are physically possible, creating a very hot plasma region close to the event horizon. Shocked downstream plasmas can be heated or magnetized depending on the values of various magnetic field-aligned parameters. Then we may expect high-energy thermal/nonthermal emissions from the shocked region. We present the properties of non-equatorial MHD shocks and discuss the shocked plasma region in the black hole magnetosphere. We also investigate the effects of the poloidal magnetic field and the black hole spin on the properties of shocks, and show that both effects can modify the distribution of the shock front and shock strength. We find for strong MHD shock formation that fast rotating magnetic fields are necessary. The physics of non-equatorial MHD shocks in the black hole magnetosphere could be very important when we are to construct the central engine model of various astrophysical phenomena.

Keigo Fukumura; Masaaki Takahashi; Sachiko Tsuruta

2006-11-08T23:59:59.000Z

124

Shock recovery experiments: An assessment  

SciTech Connect (OSTI)

Systematic shock recovery experiments, in which microstructural and mechanical property effects are characterized quantitatively, constitute an important means of increasing our understanding of shock processes. Through studies of the effects of variations in metallurgical and shock loading parameters on structure/property relationships, the micromechanisms of shock deformation, and how they differ from conventional strain rate processes, are beginning to emerge. This paper will highlight the state-of-the-art in shock recovery of metallic and ceramic materials. Techniques will be described which are utilized to ''soft'' recover shock-loaded metallic samples possessing low residual strain; crucial to accurate ''post-mortem'' metallurgical investigations of the influence of shock loading on material behavior. Illustrations of the influence of shock assembly design on the structure/property relationships in shock-recovered copper samples including such issues as residual strain and contact stresses, and their consequences are discussed. Shock recovery techniques used on brittle materials will be reviewed and discussed in light of recent experimental results. Finally, shock recovery structure/property results and VISAR data on the /alpha/--/omega/ shock-induced phase transition in titanium will be used to illustrate the beneficial link between shock recovery and ''real-time'' shock data. 26 refs., 3 figs.

Gray, G.T. III

1989-01-01T23:59:59.000Z

125

Shock compression profiles in ceramics  

SciTech Connect (OSTI)

An investigation of the shock compression properties of high-strength ceramics has been performed using controlled planar impact techniques. In a typical experimental configuration, a ceramic target disc is held stationary, and it is struck by plates of either a similar ceramic or by plates of a well-characterized metal. All tests were performed using either a single-stage propellant gun or a two-stage light-gas gun. Particle velocity histories were measured with laser velocity interferometry (VISAR) at the interface between the back of the target ceramic and a calibrated VISAR window material. Peak impact stresses achieved in these experiments range from about 3 to 70 GPa. Ceramics tested under shock impact loading include: Al{sub 2}O{sub 3}, AlN, B{sub 4}C, SiC, Si{sub 3}N{sub 4}, TiB{sub 2}, WC and ZrO{sub 2}. This report compiles the VISAR wave profiles and experimental impact parameters within a database-useful for response model development, computational model validation studies, and independent assessment of the physics of dynamic deformation on high-strength, brittle solids.

Grady, D.E.; Moody, R.L.

1996-03-01T23:59:59.000Z

126

NONTHERMAL RADIATION FROM COSMIC-RAY MODIFIED SHOCKS  

SciTech Connect (OSTI)

We calculate nonthermal radiation from cosmic-ray (CR) protons and electrons accelerated at CR modified plane and spherical shocks, using time-dependent, diffusive shock acceleration (DSA) simulations that include radiative losses of CR electrons. Strong non-relativistic shocks with physical parameters relevant for young supernova remnants (SNRs) are considered in both the plane-parallel and spherically symmetric geometries, and compared at times when their dynamical and CR properties are concordant. A thermal leakage injection model and a Bohm-like diffusion coefficient are adopted. After DSA energy gains balance radiative losses, the electron spectrum at the plane shock approaches a time-asymptotic spectrum with a super-exponential cutoff above the equilibrium momentum. The postshock electron spectrum cuts off at a progressively lower momentum downstream from the shock due to the energy losses. That results in the steepening of the volume integrated electron energy spectrum by one power of the particle energy. These features evolve toward lower energies in the spherical, SNR shocks. In a CR modified shock, pion decay gamma-ray emission reveals distinct signatures of nonlinear DSA due to the concave proton momentum spectrum. Although the electron momentum spectrum has a much weaker concavity, the synchrotron spectral slope at the shock may flatten by about 0.1-0.3 between radio and X-ray bands. The slope of the volume integrated emission spectrum behaves nonlinearly around the break frequency.

Kang, Hyesung [Department of Earth Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Edmon, Paul P. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Jones, T. W., E-mail: kang@uju.es.pusan.ac.kr, E-mail: pedmon@physics.umanitoba.ca, E-mail: twj@msi.umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

2012-02-01T23:59:59.000Z

127

Development of a remote bushing for actinide vitrification  

SciTech Connect (OSTI)

The Savannah River Site (SRS) and the Savannah River Technology Center (SRTC) are combining their existing experience in handling highly radioactive, special nuclear materials with commercial glass fiberization technology in order to assemble a small vitrification system for radioactive actinide solutions. The vitrification system or {open_quotes}brushing{close_quotes}, is fabricated from platinum-rhodium alloy and is based on early marble remelt fiberization technology. Advantages of this unique system include its relatively small size, reliable operation, geometrical safety (nuclear criticality), and high temperature capability. The bushing design should be capable of vitrifying a number of the actinide nuclear materials, including solutions of americium/curium, neptunium, and possibly plutonium. State of the art, mathematical and oil model studies are being combined with basic engineering evaluations to verify and improve the thermal and mechanical design concepts.

Schumacher, R.F.; Ramsey, W.G.; Johnson, F.M. [and others

1996-12-31T23:59:59.000Z

128

Complexation of lanthanides and actinides by acetohydroxamic acid  

SciTech Connect (OSTI)

Acetohydroxamic acid (AHA) has been proposed as a suitable reagent for the complexant-based, as opposed to reductive, stripping of plutonium and neptunium ions from the tributylphosphate solvent phase in advanced PUREX or UREX processes designed for future nuclear-fuel reprocessing. Stripping is achieved by the formation of strong hydrophilic complexes with the tetravalent actinides in nitric acid solutions. To underpin such applications, knowledge of the complexation constants of AHA with all relevant actinide (5f) and lanthanide (4f) ions is therefore important. This paper reports the determination of stability constants of AHA with the heavier lanthanide ions (Dy-Yb) and also U(IV) and Th(IV) ions. Comparisons with our previously published AHA stability-constant data for 4f and 5f ions are made. (authors)

Taylor, R.J. [British Technology Centre, Nexia Solutions, Sellafield, Seascale, CA20 1PG (United Kingdom); Sinkov, S.I. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Choppin, G.R. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL (United States)

2008-07-01T23:59:59.000Z

129

Minor Actinides Transmutation Scenario Studies in PWR with Innovative Fuels  

SciTech Connect (OSTI)

With the innovative fuels (CORAIL, APA, MIX, MOX-UE) in current PWRs, it is theoretically possible to obtain different plutonium and minor actinides transmutation scenarios, in homogeneous mode, with a significant reduction of the waste radio-toxicity inventory and of the thermal output of the high level waste. Regarding each minor actinide element transmutation in PWRs, conclusions are : neptunium : a solution exists but the gain on the waste radio-toxicity inventory is not significant, americium : a solution exists but it is necessary to transmute americium with curium to obtain a significant gain, curium: Cm244 has a large impact on radiation and residual power in the fuel cycle; a solution remains to be found, maybe separating it and keeping it in interim storage for decay into Pu240 able to be transmuted in reactor.

Grouiller, J. P.; Boucher, L.; Golfier, H.; Dolci, F.; Vasile, A.; Youinou, G.

2003-02-26T23:59:59.000Z

130

Interaction of turbulent plasma flow with a hypersonic shock wave  

SciTech Connect (OSTI)

A transient increase is observed in both the spectral energy decay rate and the degree of chaotic complexity at the interface of a shock wave and a turbulent ionized gas. Even though the gas is apparently brought to rest by the shock wave, no evidence is found either of prompt relaminarization or of any systematic influence of end-wall material thermal conductivities on the turbulence parameters. {copyright} {ital 1997 American Institute of Physics.}

Belay, K.; Valentine, J.M.; Williams, R.L.; Johnson, J.A. III [CeNNAs, Florida AM University, Tallahassee, Florida (United States)] [CeNNAs, Florida AM University, Tallahassee, Florida (United States)

1997-02-01T23:59:59.000Z

131

Comparative Study of f-Element Electronic Structure across a Series of Multimetallic Actinide, Lanthanide-Actinide and Lanthanum-Actinide Complexes Possessing Redox-Active Bridging Ligands  

SciTech Connect (OSTI)

A comparative examination of the electronic interactions across a series of trimetallic actinide and mixed lanthanide-actinide and lanthanum-actinide complexes is presented. Using reduced, radical terpyridyl ligands as conduits in a bridging framework to promote intramolecular metal-metal communication, studies containing structural, electrochemical, and X-ray absorption spectroscopy are presented for (C{sub 5}Me{sub 5}){sub 2}An[-N=C(Bn)(tpy-M{l_brace}C{sub 5}Me4R{r_brace}{sub 2})]{sub 2} (where An = Th{sup IV}, U{sup IV}; Bn = CH{sub 2}C{sub 6}H{sub 5}; M = La{sup III}, Sm{sup III}, Yb{sup III}, U{sup III}; R = H, Me, Et) to reveal effects dependent on the identities of the metal ions and R-groups. The electrochemical results show differences in redox energetics at the peripheral 'M' site between complexes and significant wave splitting of the metal- and ligand-based processes indicating substantial electronic interactions between multiple redox sites across the actinide-containing bridge. Most striking is the appearance of strong electronic coupling for the trimetallic Yb{sup III}-U{sup IV}-Yb{sup III}, Sm{sup III}-U{sup IV}-Sm{sup III}, and La{sup III}-U{sup IV}-La{sup III} complexes, [8]{sup -}, [9b]{sup -} and [10b]{sup -}, respectively, whose calculated comproportionation constant K{sub c} is slightly larger than that reported for the benchmark Creutz-Taube ion. X-ray absorption studies for monometallic metallocene complexes of U{sup III}, U{sup IV}, and U{sup V} reveal small but detectable energy differences in the 'white-line' feature of the uranium L{sub III}-edges consistent with these variations in nominal oxidation state. The sum of this data provides evidence of 5f/6d-orbital participation in bonding and electronic delocalization in these multimetallic f-element complexes. An improved, high-yielding synthesis of 4{prime}-cyano-2,2{prime}:6{prime},2{double_prime}-terpyridine is also reported.

Schelter, Eric J.; Wu, Ruilian; Veauthier, Jacqueline M.; Bauer, Eric D.; Booth, Corwin H.; Thomson, Robert K.; Graves, Christopher R.; John, Kevin D.; Scott, Brian L.; Thompson, Joe D.; Morris, David E.; Kiplinger, Jaqueline L.

2010-02-24T23:59:59.000Z

132

ACTINIDE-SPECIFIC SEQUESTERING AGENTS AND DECONTAMINATION APPLICATIONS  

SciTech Connect (OSTI)

We have briefly reviewed the biological hazards associated with the actinide elements. The most abundant transuranium element produced by both industrial nuclear power plants and nuclear weapons programs is plutonium. It is also potentially the most toxic - particularly due to its long-term hazard as a carcinogen if it is introduced into the body. This toxicity is due in large part to the chemical and biochemical similarities of Pu(IV) and Fe(III). Thus in mammals plutonium is transported and stored by the transport and storage systems for iron. This results in the concentration and long-term retention of an alpha-emitting radionuclide ({sup 239}Pu) at sites such as the bone marrow where cell division occurs at a high rate. The earliest attempts at removal of actinide contamination by chelation therapy were essentially heuristic in that sequestering agents known to be effective at binding other elements were tried with plutonium. The research described here is intended to be a rational approach that begins with the observation that since Fe(III) and Pu(IV) are so similar, and since microbes produce agents called siderophores that are extremely effective and selective sequestering agents for Fe(III), the construction of similar chelating agents for the actinides should be possible using the same chelating groups found in the siderophores. The incorporation of four such groups (primarily catechol and hydroxamic acid) results in multidentate chelating agents that can completely encapsulate the central actinide(IV) ion and achieve the eight-coordinate environment most favored by such ions. The continuing development and improvement of such sequestering agents has produced compounds which remove significant amounts of plutonium deposited in bone and which remove a greater fraction of the total body burden than any other chelation therapy developed to date.

Smith, William L.; Raymond, Kenneth N.

1980-07-01T23:59:59.000Z

133

Determination of actinides in urine and fecal samples  

DOE Patents [OSTI]

A method of determining the radioactivity of specific actinides that are carried in urine or fecal sample material is disclosed. The samples are ashed in a muffle furnace, dissolved in an acid, and then treated in a series of steps of reduction, oxidation, dissolution, and precipitation, including a unique step of passing a solution through a chloride form anion exchange resin for separation of uranium and plutonium from americium.

McKibbin, Terry T. (Larimer County, CO)

1993-01-01T23:59:59.000Z

134

Determination of actinides in urine and fecal samples  

DOE Patents [OSTI]

A method of determining the radioactivity of specific actinides that are carried in urine or fecal sample material is disclosed. The samples are ashed in a muffle furnace, dissolved in an acid, and then treated in a series of steps of reduction, oxidation, dissolution, and precipitation, including a unique step of passing a solution through a chloride form anion exchange resin for separation of uranium and plutonium from americium.

McKibbin, T.T.

1993-03-02T23:59:59.000Z

135

Chemical and Ceramic Methods Toward Safe Storage of Actinides  

SciTech Connect (OSTI)

A very import, extremely-long-term, use for monazite as a radwaste encapsulant has been proposed. THe use of ceramic La-monazite for sequestering actinides (isolating them from the environment), especially plutonium and some other radioactive elements )e.g., fission-product rare earths), had been especially championed by Lynn Boatner of ORNL. Monazite may be used alone or, copying its compatibility with many other minerals in nature, may be used in diverse composite combinations.

P.E.D. Morgan; R.M. Housley; J.B. Davis; M.L. DeHaan

2005-08-19T23:59:59.000Z

136

Method for the concentration and separation of actinides from biological and environmental samples  

DOE Patents [OSTI]

A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting. 3 figs.

Horwitz, E.P.; Dietz, M.L.

1989-05-30T23:59:59.000Z

137

Shock destruction armor system  

DOE Patents [OSTI]

A shock destruction armor system is constructed and arranged to destroy the force of impact of a projectile by shock hydrodynamics. The armor system is designed to comprise a plurality of superimposed armor plates each preferably having a thickness less than five times the projectile's diameter and are preferably separated one-from-another by a distance at least equal to one-half of the projectile's diameter. The armor plates are effective to hydrodynamically and sequentially destroy the projectile. The armor system is particularly adapted for use on various military vehicles, such as tanks, aircraft and ships.

Froeschner, Kenneth E. (Livermore, CA)

1993-01-01T23:59:59.000Z

138

A literature review of actinide-carbonate mineral interactions  

SciTech Connect (OSTI)

Chemical retardation of actinides in groundwater systems is a potentially important mechanism for assessing the performance of the Waste Isolation Pilot Plant (WIPP), a facility intended to demonstrate safe disposal of transuranic waste. Rigorous estimation of chemical retardation during transport through the Culebra Dolomite, a water-bearing unit overlying the WIPP, requires a mechanistic understanding of chemical reactions between dissolved elements and mineral surfaces. This report represents a first step toward this goal by examining the literature for pertinent experimental studies of actinide-carbonate interactions. A summary of existing models is given, along with the types of experiments on which these models are based. Articles pertaining to research into actinide interactions with carbonate minerals are summarized. Select articles involving trace element-carbonate mineral interactions are also reviewed and may serve as templates for future research. A bibliography of related articles is included. Americium(III), and its nonradioactive analog neodymium(III), partition strongly from aqueous solutions into carbonate minerals. Recent thermodynamic, kinetic, and surface studies show that Nd is preferentially removed from solution, forming a Nd-Ca carbonate solid solution. Neptunium(V) is rapidly removed from solution by carbonates. Plutonium incorporation into carbonates is complicated by multiple oxidation states. Little research has been done on the radium(H) and thorium(IV) carbonate systems. Removal of uranyl ion from solution by calcite is limited to monolayer surface coverage.

Stout, D.L. [Missouri Univ., Columbia, MO (United States). Dept. of Geological Sciences; Carroll, S.A. [Lawrence Livermore National Lab., CA (United States)

1993-10-01T23:59:59.000Z

139

RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY SOIL SAMPLES  

SciTech Connect (OSTI)

A new rapid method for the determination of actinides in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for samples up to 2 grams in emergency response situations. The actinides in soil method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride soil matrix removal step, and a streamlined column separation process with stacked TEVA, TRU and DGA Resin cartridges. Lanthanum was separated rapidly and effectively from Am and Cm on DGA Resin. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha sources are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency soil samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinides in soil results were reported within 4-5 hours with excellent quality.

Maxwell, S.; Culligan, B.; Noyes, G.

2009-11-09T23:59:59.000Z

140

RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY AIR FILTER SAMPLES  

SciTech Connect (OSTI)

A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.

Maxwell, S.; Noyes, G.; Culligan, B.

2010-02-03T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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141

Supercritical Fluid Extraction and Separation of Uranium from Other Actinides  

SciTech Connect (OSTI)

This paper investigates the feasibility of separating uranium from other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of an extraction and counter current stripping technique, which would be a more efficient and environmentally benign technology for used nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U(VI), Np(VI), Pu(IV), and Am(III)) were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, the separation of uranium from plutonium in sc-CO2 modified with TBP was successful at nitric acid concentrations of less than 3 M in the presence of acetohydroxamic acid or oxalic acid, and the separation of uranium from neptunium was successful at nitric acid concentrations of less than 1 M in the presence of acetohydroxamic acid, oxalic acid, or sodium nitrite.

Donna L. Quach; Bruce J. Mincher; Chien M. Wai

2014-06-01T23:59:59.000Z

142

The EBR-II X501 Minor Actinide Burning Experiment  

SciTech Connect (OSTI)

The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MA’s. Of primary interest are the affect of the MA’s on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior. This paper provides a summary of the X501 fabrication, characterization, irradiation, and post irradiation examination.

M. K. Meyer; S. L. Hayes; W. J. Carmack; H. Tsai

2009-07-01T23:59:59.000Z

143

The EBR-II X501 Minor Actinide Burning Experiment  

SciTech Connect (OSTI)

The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MA’s. Of primary interest are the affect of the MA’s on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior.

Jon Carmack; S. L. Hayes; M. K. Meyer; H. Tsai

2008-06-01T23:59:59.000Z

144

E-Print Network 3.0 - actinide recovery process Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

report, April 2006 The report can... is a trivalent actinide and a chemical analog to curium, and it has many chemical similarities to trivalent... complexes stay in solution....

145

E-Print Network 3.0 - actinides storage host Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of the most developed of the immobilisation technologies... - emitting radionuclides of heavy metals (actinides, Raand Po). The specific activity of the ash ... Source:...

146

E-Print Network 3.0 - actinides including cm Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: of waste actinides. Such damage can be studied by many techniques, including heavy-ionfast neutron... were presented and proposed, including; Fundamental studies...

147

E-Print Network 3.0 - advanced actinide fuels Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Breeder Summary: energy moderation, actinide solubility, and initial fuel inventory. For heavy nuclei (HN) proportions... the fuel refabrication problem in the presence of...

148

E-Print Network 3.0 - actinide decay heat Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

then on, it is the actinides... --specifically, isotopes of plutonium, americium, and curium--that will contribute most to radioactive ... Source: Massachusetts Institute of...

149

E-Print Network 3.0 - actinide separations conference Sample...  

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region 1, 2. 2. Separation in-29;ight and the parent21;daughter method for heavy... . Mnzenberg et al., Proc. Actinides-1981 Conference, Paci28;c Grove, Cali-...

150

E-Print Network 3.0 - actinides review hyperfine Sample Search...  

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Commission of the European Communities, Joint Research Centre, European... bande et la nature des liaisons chimiques sont tudies, pour les mtaux et composs d'actinides, ...

151

E-Print Network 3.0 - actinide separations thermodynamic Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of SARS (severe acute respiratory syndrome) Summary: of the actinide elements such as uranium and plutonium is central to predicting nuclear weapons performance......

152

E-Print Network 3.0 - actinides phosphinic resins Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Databases and Resources 11 Development of an Automatic Method for Americium and Plutonium Separation and Summary: tetravalent and hexavalent actinides present in the real sample,...

153

E-Print Network 3.0 - actinide region progress Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Databases and Resources 71 The materials test station: A fast-spectrum irradiation facility Eric J. Pitcher Summary: with significant inclusion of plutonium and minor actinides....

154

E-Print Network 3.0 - actinide intermetallic laves-phase Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

. - Essentially atomic electron-polaron mechanism reducing the magnetic moments of rare-earth and actinide... elements in intermetallic compounds is proposed. This mechanism is...

155

Crystal Chemistry of Early Actinides (Thorium, Uranium, and Neptunium) and Uranium Mesoporous Materials.  

E-Print Network [OSTI]

??Despite their considerable global importance, the structural chemistry of actinides remains understudied. Thorium and uranium fuel cycles are used in commercial nuclear reactors in India… (more)

Sigmon, Ginger E.

2010-01-01T23:59:59.000Z

156

MOLECULAR SPECTROSCPY AND REACTIONS OF ACTINIDES IN THE GAS PHASE AND CRYOGENIC MATRICES  

E-Print Network [OSTI]

importance in the chemistry of uranium, and these species5f orbitals in the chemistry of uranium complexes. Using CHchemistry studies involving the actinides dealt with volatile uranium

Heaven, Michael C.

2011-01-01T23:59:59.000Z

157

E-Print Network 3.0 - actinides bilan des Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(March 1977) p. 43. 8... heats of actinide metals M. J. Mortimer Chemistry Division, AERE ... Source: Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 73...

158

EA-1404: Actinide Chemistry and Repository Science Laboratory, Carlsbad, New Mexico  

Broader source: Energy.gov [DOE]

This EA evaluates the environmental impacts for the proposal to construct and operate an Actinide Chemistry and Repository Science Laboratory to support chemical research activities related to the...

159

E-Print Network 3.0 - actinide partitioning part Sample Search...  

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lowest f... . 2. -Variation of the atomic volume along the actinide, lanthanide and transition metal series Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

160

E-Print Network 3.0 - actinide bearing nitride Sample Search...  

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> >> 41 Electronic structure and pairwise interactions in substoichiometric transition metal carbides and nitrides Summary: ) of transition metals, rare earths and actinides in...

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

E-Print Network 3.0 - actinide transmutation reactor Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

All these names are used... . The idea of combining powerful accelerators - with a subcritical reactor for transmutation purposes... homogeneous fuel Actinides MgO Tc Fast...

162

E-Print Network 3.0 - actinide burner core Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the fuel... of minor actinides whose management would be problematic. Scenario with Light Water Reactors and Fast... and difficult process. Indeed, a 1 GWe reactor, whether it is...

163

E-Print Network 3.0 - actinide based fuel Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

MA represents minor actinides such as Np, Am, and Cm. Fuel... of the performance on the subcritical level. Numerical experiments are carried out on a ... Source: Royal Institute...

164

E-Print Network 3.0 - actinide measurement quality Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4 LA-UR 09-03222 LOS ALAMOS NATIONAL LABORATORY Summary: assurance QAPD Quality Assurance Program Document SNL Sandia National Laboratories SOTERM Actinide Source... on the...

165

STEREO interplanetary shocks and foreshocks  

SciTech Connect (OSTI)

We use STEREO data to study shocks driven by stream interactions and the waves associated with them. During the years of the extended solar minimum 2007-2010, stream interaction shocks have Mach numbers between 1.1-3.8 and {theta}{sub Bn}{approx}20-86 Degree-Sign . We find a variety of waves, including whistlers and low frequency fluctuations. Upstream whistler waves may be generated at the shock and upstream ultra low frequency (ULF) waves can be driven locally by ion instabilities. The downstream wave spectra can be formed by both, locally generated perturbations, and shock transmitted waves. We find that many quasiperpendicular shocks can be accompanied by ULF wave and ion foreshocks, which is in contrast to Earth's bow shock. Fluctuations downstream of quasi-parallel shocks tend to have larger amplitudes than waves downstream of quasi-perpendicular shocks. Proton foreshocks of shocks driven by stream interactions have extensions dr {<=}0.05 AU. This is smaller than foreshock extensions for ICME driven shocks. The difference in foreshock extensions is related to the fact that ICME driven shocks are formed closer to the Sun and therefore begin to accelerate particles very early in their existence, while stream interaction shocks form at {approx}1 AU and have been producing suprathermal particles for a shorter time.

Blanco-Cano, X. [Instituto de Geofisica, UNAM, CU, Coyoacan 04510 DF (Mexico); Kajdic, P. [IRAP-University of Toulouse, CNRS, Toulouse (France); Aguilar-Rodriguez, E. [Instituto de Geofisica, UNAM, Morelia (Mexico); Russell, C. T. [ESS and IGPP, University of California, Los Angeles, 603 Charles Young Drive, Los Angeles, CA 90095 (United States); Jian, L. K. [NASA Goddard Space Flight Center, Greenbelt, MD and University of Maryland, College Park, MD (United States); Luhmann, J. G. [SSL, University of California Berkeley (United States)

2013-06-13T23:59:59.000Z

166

Computational investigation of structured shocks  

E-Print Network [OSTI]

. Grujicic, W.C. Bell and B. Pandurangan Department of Mechanical Engineering, Clemson University, Clemson, Composite materials, Wave propagation, Mechanical shock, Metal matrix composites, Structured shocks, Dynamic Detonation Explosives Shallow-Buried in Soil" Contract Number W911NF-06-2-0042. Structured shocks in MMCs 469

Grujicic, Mica

167

Advanced Extraction Methods for Actinide/Lanthanide Separations  

SciTech Connect (OSTI)

The separation of An(III) ions from chemically similar Ln(III) ions is perhaps one of the most difficult problems encountered during the processing of nuclear waste. In the 3+ oxidation states, the metal ions have an identical charge and roughly the same ionic radius. They differ strictly in the relative energies of their f- and d-orbitals, and to separate these metal ions, ligands will need to be developed that take advantage of this small but important distinction. The extraction of uranium and plutonium from nitric acid solution can be performed quantitatively by the extraction with the TBP (tributyl phosphate). Commercially, this process has found wide use in the PUREX (plutonium uranium extraction) reprocessing method. The TRUEX (transuranium extraction) process is further used to coextract the trivalent lanthanides and actinides ions from HLLW generated during PUREX extraction. This method uses CMPO [(N, N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide] intermixed with TBP as a synergistic agent. However, the final separation of trivalent actinides from trivalent lanthanides still remains a challenging task. In TRUEX nitric acid solution, the Am(III) ion is coordinated by three CMPO molecules and three nitrate anions. Taking inspiration from this data and previous work with calix[4]arene systems, researchers on this project have developed a C3-symmetric tris-CMPO ligand system using a triphenoxymethane platform as a base. The triphenoxymethane ligand systems have many advantages for the preparation of complex ligand systems. The compounds are very easy to prepare. The steric and solubility properties can be tuned through an extreme range by the inclusion of different alkoxy and alkyl groups such as methyoxy, ethoxy, t-butoxy, methyl, octyl, t-pentyl, or even t-pentyl at the ortho- and para-positions of the aryl rings. The triphenoxymethane ligand system shows promise as an improved extractant for both tetravalent and trivalent actinide recoveries form high level liquid wastes and a general actinide clean-up procedure. The selectivity of the standard extractant for tetravalent actinides, (N,N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide (CMPO), was markedly improved by the attachment of three CMPO-like functions onto a triphenoxymethane platform, and a ligand that is both highly selective and effective for An(IV) ions was isolated. A 10 fold excess of ligand will remove virtually all of the 4+ actinides from the acidic layer without extracting appreciable quantities of An(III) and Ln(III) unlike simple CMPO ligands. Inspired by the success of the DIAMEX industrial process for extractions, three new tripodal chelates bearing three diglycolamide and thiodiglycolamide units precisely arranged on a triphenoxymethane platform have been synthesized for an highly efficient extraction of trivalent f-element cations from nitric acid media. A single equivalent of ligand will remove 80% of the Ln(III) ion from the acidic layer since the ligand is perfectly suited to accommodate the tricapped trigonal prismatic geometry preferred by the metal center. The ligand is perhaps the most efficient binder available for the heavier lanthanides and due to this unique attribute, the extraction event can be easily followed by 1H NMR spectroscopy confirming the formation of a TPP complex. The most lipophilic di-n-butyl tris-diglycolamide was found to be a significantly weaker extractant in comparison to the di-isopropyl analogs. The tris-thiodiglycolamide derivative proved to be an ineffective chelate for f-elements and demonstrated the importance of the etheric oxygens in the metal binding. The results presented herein clearly demonstrate a cooperative action of these three ligating groups within a single molecule, confirmed by composition and structure of the extracted complexes, and since actinides prefer to have high coordination numbers, the ligands should be particularly adept at binding with three arms. The use of such an extractant permits the extraction of metal ions form highly acidic environment through the ability

Scott, M.J.

2005-12-01T23:59:59.000Z

168

Note LPSC 07-37 The TMSR as Actinide Burner and Thorium Breeder  

E-Print Network [OSTI]

Note LPSC 07-37 The TMSR as Actinide Burner and Thorium Breeder E. Merle-Lucotte, D. Heuer, C. Le actinides. Studies [1] have thus been done on the Molten Salt Breeder Reactor (MSBR) [2] of Oak-Ridge to re fluoride salt LiF- ThF4 with 28%- mole 232 Th. This reflector, corresponding to a fertile blanket

Paris-Sud XI, Université de

169

Shock compression and expansion in central collisions  

SciTech Connect (OSTI)

Physics of central symmetric reactions of heavy nuclei, in the beam energy range from few tens of MeV to a couple of GeV per nucleon, is discussed. Within transport simulations, it is shown that shock fronts perpendicular to the beam axis form in the head-on reactions. The fronts propagate into projectile and target and they separate hot compressed matter from normal matter. With an increase of the impact parameter, the angle of inclination of fronts relative to the beam axis decreases, and in-between the fronts a weak tangential discontinuity develops. Hot matter exposed to the vacuum in directions perpendicular to the shock motion (and parallel to fronts), starts to expand sideways, early within reactions. Expansion in the direction of shock motion follows, after the shocks traverse nuclei, but due to the delay does not acquire same strength. Expansion affects angular distributions and mean-energy components, and further shapes of spectra and mean energies of different particles emitted into any one direction, and also particle yields. Both the anisotropy in the expansion and a collective motion associated with the weak discontinuity, affect the magnitude of sideward flow within reaction plane. Differences in mean particle energy components in and out of the reaction plane in semicentral collisions, depend sensitively on the relative magnitude of shock speed in normal matter and speed of sound in hot matter. The missing energy, considered in the past in association with low measured pion-multiplicity in central reactions, may be identified with the energy of collective expansion.

Danielewicz, P. [Univ. of Washington, Seattle, WA (United States). Institute for Nuclear Theory]|[Michigan State Univ., East Lansing, MI (United States)

1995-01-01T23:59:59.000Z

170

MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS  

SciTech Connect (OSTI)

This project seeks to determine if (1) inorganic-based ion exchange materials or (2) electrochemical methods in ionic liquids can be exploited to provide effective Am and Cm separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of inorganic-based ion-exchange materials for actinide and lanthanide ions. Furthermore, we seek to determine whether ionic liquids can serve as the electrolyte that would enable formation of higher oxidation states of Am and other actinides. Experiments indicated that pH, presence of complexants and Am oxidation state exhibit significant influence on the uptake of actinides and lanthanides by layered sodium titanate and hybrid zirconium and tin phosphonate ion exchangers. The affinity of the ion exchangers increased with increasing pH. Greater selectivity among Ln(III) ions with sodium titanate materials occurs at a pH close to the isoelectric potential of the ion exchanger. The addition of DTPA decreased uptake of Am and Ln, whereas the addition of TPEN generally increases uptake of Am and Ln ions by sodium titanate. Testing confirmed two different methods for producing Am(IV) by oxidation of Am(III) in ionic liquids (ILs). Experimental results suggest that the unique coordination environment of ionic liquids inhibits the direct electrochemical oxidation of Am(III). The non-coordinating environment increases the oxidation potential to a higher value, while making it difficult to remove the inner coordination of water. Both confirmed cases of Am(IV) were from the in-situ formation of strong chemical oxidizers.

Hobbs, D.; Visser, A.; Bridges, N.

2011-09-20T23:59:59.000Z

171

Final Report on Actinide Glass Scintillators for Fast Neutron Detection  

SciTech Connect (OSTI)

This is the final report of an experimental investigation of actinide glass scintillators for fast-neutron detection. It covers work performed during FY2012. This supplements a previous report, PNNL-20854 “Initial Characterization of Thorium-loaded Glasses for Fast Neutron Detection” (October 2011). The work in FY2012 was done with funding remaining from FY2011. As noted in PNNL-20854, the glasses tested prior to July 2011 were erroneously identified as scintillators. The decision was then made to start from “scratch” with a literature survey and some test melts with a non-radioactive glass composition that could later be fabricated with select actinides, most likely thorium. The normal stand-in for thorium in radioactive waste glasses is cerium in the same oxidation state. Since cerium in the 3+ state is used as the light emitter in many scintillating glasses, the next most common substitute was used: hafnium. Three hafnium glasses were melted. Two melts were colored amber and a third was clear. It barely scintillated when exposed to alpha particles. The uses and applications for a scintillating fast neutron detector are important enough that the search for such a material should not be totally abandoned. This current effort focused on actinides that have very high neutron capture energy releases but low neutron capture cross sections. This results in very long counting times and poor signal to noise when working with sealed sources. These materials are best for high flux applications and access to neutron generators or reactors would enable better test scenarios. The total energy of the neutron capture reaction is not the only factor to focus on in isotope selection. Many neutron capture reactions result in energetic gamma rays that require large volumes or high densities to detect. If the scintillator is to separate neutrons from gamma rays, the capture reactions should produce heavy particles and few gamma rays. This would improve the detection of a signal for fast neutron capture.

Bliss, Mary; Stave, Jean A.

2012-10-01T23:59:59.000Z

172

AGN Heating through Cavities and Shocks  

E-Print Network [OSTI]

Three comments are made on AGN heating of cooling flows. A simple physical argument is used to show that the enthalpy of a buoyant radio lobe is converted to heat in its wake. Thus, a significant part of ``cavity'' enthalpy is likely to end up as heat. Second, the properties of the repeated weak shocks in M87 are used to argue that they can plausibly prevent gas close to the AGN from cooling. As the most significant heating mechanism at work closest to the AGN, shock heating probably plays a critical role in the feedback mechanism. Third, results are presented from a survey of AGN heating rates in nearby giant elliptical galaxies. With inactive systems included, the overall AGN heating rate is reasonably well matched to the total cooling rate for the sample. Thus, intermittent AGN outbursts are energetically capable of preventing the hot atmospheres of these galaxies from cooling and forming stars.

P. E. J. Nulsen; C. Jones; W. R. Forman; L. P. David; B. R. McNamara; D. A. Rafferty; L. Birzan; M. W. Wise

2006-11-04T23:59:59.000Z

173

On particle acceleration around shocks. I  

E-Print Network [OSTI]

We derive a relativistically covariant (although not manifestly so) equation for the distribution function of particles accelerated at shocks, which applies also to extremely relativistic shocks, and arbitrarily anisotropic particle distributions. The theory is formulated for arbitrary pitch angle scattering, and reduces to the well--known case for small angle scatterings via a Fokker--Planck approximation. The boundary conditions for the problem are completely reformulated introducing a physically motivated Green's function; the new formulation allows derivation of the particle spectrum both close and far away from the injection energy in an exact way, while it can be shown to reduce to a power--law at large particle energies. The particle spectral index is also recovered in a novel way. Contact is made with the Newtonian treatment.

Mario Vietri

2003-03-28T23:59:59.000Z

174

Electrical shock accident investigation  

SciTech Connect (OSTI)

This report documents results of the accident investigation of an electrical shock received by two subcontractor employees on May 13, 1994, at the Pinellas Plant. The direct cause of the electrical shock was worker contact with a cut ``hot`` wire and a grounded panelboard (PPA) enclosure. Workers presumed that all wires in the enclosure were dead at the time of the accident and did not perform thorough Lockout/Tagout (LO/TO). Three contributing causes were identified. First, lack of guidance in the drawing for the modification performed in 1987 allowed the PPA panel to be used as a junction box. The second contributing cause is that Environmental, Safety and Health (ES&H) procedures do not address multiple electrical sources in an enclosure. Finally, the workers did not consider the possibility of multiple electrical sources. The root cause of the electrical shock was the inadequacy of administrative controls, including construction requirement and LO/TO requirements, and subcontractor awareness regarding multiple electrical sources. Recommendations to prevent further reoccurrence of this type of accident include revision of ES&H Standard 2.00, Electrical Safety Program Manual, to document requirements for multiple electrical sources in a single enclosure to specify a thorough visual inspection as part of the voltage check process. In addition, the formality of LO/TO awareness training for subcontractor electricians should be increased.

Not Available

1994-09-30T23:59:59.000Z

175

Assessment of high-resolution methods for numerical simulations of compressible turbulence with shock waves  

SciTech Connect (OSTI)

Flows in which shock waves and turbulence are present and interact dynamically occur in a wide range of applications, including inertial confinement fusion, supernovae explosion, and scramjet propulsion. Accurate simulations of such problems are challenging because of the contradictory requirements of numerical methods used to simulate turbulence, which must minimize any numerical dissipation that would otherwise overwhelm the small scales, and shock-capturing schemes, which introduce numerical dissipation to stabilize the solution. The objective of the present work is to evaluate the performance of several numerical methods capable of simultaneously handling turbulence and shock waves. A comprehensive range of high-resolution methods (WENO, hybrid WENO/central difference, artificial diffusivity, adaptive characteristic-based filter, and shock fitting) and suite of test cases (Taylor-Green vortex, Shu-Osher problem, shock-vorticity/entropy wave interaction, Noh problem, compressible isotropic turbulence) relevant to problems with shocks and turbulence are considered. The results indicate that the WENO methods provide sharp shock profiles, but overwhelm the physical dissipation. The hybrid method is minimally dissipative and leads to sharp shocks and well-resolved broadband turbulence, but relies on an appropriate shock sensor. Artificial diffusivity methods in which the artificial bulk viscosity is based on the magnitude of the strain-rate tensor resolve vortical structures well but damp dilatational modes in compressible turbulence; dilatation-based artificial bulk viscosity methods significantly improve this behavior. For well-defined shocks, the shock fitting approach yields good results.

Johnsen, Eric [Center for Turbulence Research, Stanford University, Stanford, CA 94305 (United States)], E-mail: johnsen@stanford.edu; Larsson, Johan [Center for Turbulence Research, Stanford University, Stanford, CA 94305 (United States)], E-mail: jola@stanford.edu; Bhagatwala, Ankit V. [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305 (United States); Cabot, William H. [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Moin, Parviz [Center for Turbulence Research, Stanford University, Stanford, CA 94305 (United States); Olson, Britton J. [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305 (United States); Rawat, Pradeep S. [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095 (United States); Shankar, Santhosh K. [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305 (United States); Sjoegreen, Bjoern [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Yee, H.C. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Zhong Xiaolin [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095 (United States); Lele, Sanjiva K. [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305 (United States)

2010-02-20T23:59:59.000Z

176

Plutonium and minor actinides utilization in Thorium molten salt reactor  

SciTech Connect (OSTI)

FUJI-12 reactor is one of MSR systems that proposed by Japan. The original FUJI-12 design considers Th/{sup 233}U or Th/Pu as main fuel. In accordance with the currently suggestion to stay away from the separation of Pu and minor actinides (MA), in this study we evaluated the utilization of Pu and MA in FUJI-12. The reactor grade Pu was employed in the present study as a small effort of supporting THORIMS-NES scenario. The result shows that the reactor can achieve its criticality with the Pu and MA composition in the fuel of 5.96% or more.

Waris, Abdul; Aji, Indarta K.; Novitrian,; Kurniadi, Rizal; Su'ud, Zaki [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung 40132 (Indonesia)

2012-06-06T23:59:59.000Z

177

Actinide Neutron-Induced Fission Cross Section Measurements At LANSCE  

SciTech Connect (OSTI)

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub thermal energies up to 200 MeV. Parallel-plate ionization chambers are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with existing evaluations and previous data.

Tovesson, F.; Laptev, A. B. [Los Alamos National Laboratory, Los Alamos NM 87545 (United States); Hill, T. S. [Idaho National Laboratory, Idaho Falls ID 83415 (United States)

2011-06-01T23:59:59.000Z

178

UCN Actinides | Ultracold Neutrons at Los Alamos National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The U.S.1,summer gasoline priceActinides

179

Effects of adaptation to shock on shock-elicited aggression  

E-Print Network [OSTI]

EFFECTS OF ADAPTATION TO SHOCK ON SHOCK-ELICITED AGGRESSION A THESIS THONAS ANDREW BUCHANAN Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1971... Major Subject: Psychology 0 R 0 R EFFECTS OF ADAPTATION TO SHOCK ON SHOCK-ELICITED AGGRESSION fbi a z H o 0 g CC W z C 5 a N A Thesis by THO. 'LAS ANDREN BUCHANAN Approved as to style and content by: airman oz Comm ~ t ) ( Hea f D...

Buchanan, Thomas Andrew

1971-01-01T23:59:59.000Z

180

LASER-INDUCED SHOCK WAVES IN CONDENSED MATTER: SOME TECHNIQUES AND APPLICATIONS  

E-Print Network [OSTI]

LASER-INDUCED SHOCK WAVES IN CONDENSED MATTER: SOME TECHNIQUES AND APPLICATIONS S. N. LUOa,Ă? , D. C, NV 89154, USA; c GPS Division, California Institute of Technology, Pasadena, CA 91125, USA Laser pressure physics. We briefly review some techniques in laser-induced shock waves, including direct laser

Asimow, Paul D.

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181

Shock Acceleration of the Energetic Particle Background in the Solar Wind David T. Sodaitis  

E-Print Network [OSTI]

Shock Acceleration of the Energetic Particle Background in the Solar Wind David T. Sodaitis Physics Department, University of New Hampshire Durham, New Hampshire, USA sodaitis@cisunix.unh.edu ABSTRACT Lee with solar energetic particle (SEP) events (Desai et al. 2003) have shown that shock acceleration may act

182

Grain Destruction in Interstellar Shocks  

E-Print Network [OSTI]

Interstellar shock waves can erode and destroy grains present in the shocked gas, primarily as the result of sputtering and grain-grain collisions. Uncertainties in current estimates of sputtering yields are reviewed. Results are presented for the simple case of sputtering of fast grains being stopped in cold gas. An upper limit is derived for sputtering of refractory grains in C-type MHD shocks: shock speeds $v_s \\gtrsim 50 \\kms$ are required for return of more than 30\\% of the silicate to the gas phase. Sputtering can also be important for removing molecular ice mantles from grains in two-fluid MHD shock waves in molecular gas. Recent estimates of refractory grain lifetimes against destruction in shock waves are summarized, and the implications of these short lifetimes are discussed.

B. T. Draine

1995-08-16T23:59:59.000Z

183

Actinide production from xenon bombardments of curium-248  

SciTech Connect (OSTI)

Production cross sections for many actinide nuclides formed in the reaction of /sup 129/Xe and /sup 132/Xe with /sup 248/Cm at bombarding energies slightly above the coulomb barrier were determined using radiochemical techniques to isolate these products. These results are compared with cross sections from a /sup 136/Xe + /sup 248/Cm reaction at a similar energy. When compared to the reaction with /sup 136/Xe, the maxima in the production cross section distributions from the more neutron deficient projectiles are shifted to smaller mass numbers, and the total cross section increases for the production of elements with atomic numbers greater than that of the target, and decreases for lighter elements. These results can be explained by use of a potential energy surface (PES) which illustrates the effect of the available energy on the transfer of nucleons and describes the evolution of the di-nuclear complex, an essential feature of deep-inelastic reactions (DIR), during the interaction. The other principal reaction mechanism is the quasi-elastic transfer (QE). Analysis of data from a similar set of reactions, /sup 129/Xe, /sup 132/Xe, and /sup 136/Xe with /sup 197/Au, aids in explaining the features of the Xe + Cm product distributions, which are additionally affected by the depletion of actinide product yields due to deexcitation by fission. The PES is shown to be a useful tool to predict the general features of product distributions from heavy ion reactions.

Welch, R.B.

1985-01-01T23:59:59.000Z

184

Raman spectroscopy of shocked water  

SciTech Connect (OSTI)

Raman scattering has been used extensively to study the vibrational and rotational properties of molecules under a variety of conditions. Here, interest is in the behavior of water molecules shocked to high pressures and temperatures. Behind the shock front the water molecules undergo changes in bonding and the molecules may become ionized. Raman spectroscopy can be used to determine the molecular species behind the shock front. In addition, changes in Raman spectra can yield information regarding inter- and intramolecular potentials and the temperature behind the shock front.

Holmes, N.C.; Mitchell, A.C.; Nellis, W.J.; Graham, W.B.; Walrafen, G.E.

1983-07-01T23:59:59.000Z

185

The Dirac equation in electronic structure calculations: Accurate evaluation of DFT predictions for actinides  

SciTech Connect (OSTI)

Brooks, Johansson, and Skriver, using the LMTO-ASA method and considerable insight, were able to explain many of the ground state properties of the actinides. In the many years since this work was done, electronic structure calculations of increasing sophistication have been applied to actinide elements and compounds, attempting to quantify the applicability of DFT to actinides and actinide compounds and to try to incorporate other methodologies (i.e. DMFT) into DFT calculations. Through these calculations, the limits of both available density functionals and ad hoc methodologies are starting to become clear. However, it has also become clear that approximations used to incorporate relativity are not adequate to provide rigorous tests of the underlying equations of DFT, not to mention ad hoc additions. In this talk, we describe the result of full-potential LMTO calculations for the elemental actinides, comparing results obtained with a full Dirac basis with those obtained from scalar-relativistic bases, with and without variational spin-orbit. This comparison shows that the scalar relativistic treatment of actinides does not have sufficient accuracy to provide a rigorous test of theory and that variational spin-orbit introduces uncontrolled errors in the results of electronic structure calculations on actinide elements.

Wills, John M [Los Alamos National Laboratory; Mattsson, Ann E [Sandia National Laboratories

2012-06-06T23:59:59.000Z

186

Conjugates of Actinide Chelator-Magnetic Nanoparticles for Used Fuel Separation Technology  

SciTech Connect (OSTI)

The actinide separation method using magnetic nanoparticles (MNPs) functionalized with actinide specific chelators utilizes the separation capability of ligand and the ease of magnetic separation. This separation method eliminated the need of large quantity organic solutions used in the liquid-liquid extraction process. The MNPs could also be recycled for repeated separation, thus this separation method greatly reduces the generation of secondary waste compared to traditional liquid extraction technology. The high diffusivity of MNPs and the large surface area also facilitate high efficiency of actinide sorption by the ligands. This method could help in solving the nuclear waste remediation problem.

You Qiang; Andrzej Paszczynski; Linfeng Rao

2011-10-30T23:59:59.000Z

187

Integral Validation of Minor Actinide Nuclear Data by using Samples Irradiated at Dounreay Prototype Fast Reactor  

SciTech Connect (OSTI)

The reliability of nuclear data for minor actinides was evaluated by using the results of the post-irradiation experiment for actinide samples irradiated at the Dounreay Prototype Fast Reactor. The burnup calculations with JENDL-3.3, ENDF/B-VI.8, and JEFF-3.0 were performed. From the comparison between the experimental data and the calculational results, in general, the reliability of nuclear data for the minor actinides are at an adequate level for the conceptual design study of transmutation systems. It is, however, found that improvement of the accuracy is necessary for some nuclides, such as 238Pu, 242Pu, and 241Am.

Tsujimoto, Kazufumi; Oigawa, Hiroyuki; Shinohara, Nobuo [Japan Atomic Energy Research Institute, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan)

2005-05-24T23:59:59.000Z

188

Supplemental Online Materials Shock and Post-Shock Temperatures in an Ice-Quartz Mixture: Implications for Melting During  

E-Print Network [OSTI]

Alamos National Laboratory, Physics Division, Los Alamos, New Mexico, USA The supplemental material the emissivity and area fraction of H2O 8. Text S1 derives the one-dimensional radiation absorption analysis used for their different thermal transport properties. Initial conditions were 22.7 GPa and the shock temperature

Stewart, Sarah T.

189

Delayed Neutron and Delayed Photon Characteristics from Photofission of Actinides  

SciTech Connect (OSTI)

Delayed neutron (DN) and delayed photon (DP) emissions from photofission reactions play an important role for applications involving nuclear material detection and characterization. To provide new, accurate, basic nuclear data for evaluations and data libraries, an experimental programme of DN and DP measurements has been undertaken for actinides with bremsstrahlung endpoint energy in the giant resonance region ({approx}15 MeV). In this paper, the experimental setup and the data analysis method will be described. Experimental results for DN and DP characteristics will be presented for {sup 232}Th, {sup 235,238}U, {sup 237}Np, and {sup 239}Pu. Finally, an example of an application to study the contents of nuclear waste packages will be briefly discussed.

Dore, D.; Berthoumieux, E.; Leprince, A.; Ridikas, D. [DSM/IRFUS/PhN, CEA/Saclay, Gif-sur-Yvette, F-91191 (France); Ledoux, X. [CEA/DAM/DIF, Arpajon, F-91297 (France); Agelou, M.; Carrel, F.; Gmar, M. [CEA, LIST, Gif-sur-Yvette, F-91191 (France)

2011-12-13T23:59:59.000Z

190

Flammability Analysis For Actinide Oxides Packaged In 9975 Shipping Containers  

SciTech Connect (OSTI)

Packaging options are evaluated for compliance with safety requirements for shipment of mixed actinide oxides packaged in a 9975 Primary Containment Vessel (PCV). Radiolytic gas generation rates, PCV internal gas pressures, and shipping windows (times to reach unacceptable gas compositions or pressures after closure of the PCV) are calculated for shipment of a 9975 PCV containing a plastic bottle filled with plutonium and uranium oxides with a selected isotopic composition. G-values for radiolytic hydrogen generation from adsorbed moisture are estimated from the results of gas generation tests for plutonium oxide and uranium oxide doped with curium-244. The radiolytic generation of hydrogen from the plastic bottle is calculated using a geometric model for alpha particle deposition in the bottle wall. The temperature of the PCV during shipment is estimated from the results of finite element heat transfer analyses.

Laurinat, James E.; Askew, Neal M.; Hensel, Steve J.

2013-03-21T23:59:59.000Z

191

E-Print Network 3.0 - actinide elements volume Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

no 5-6, Tome 33, Mai-Juin 1972,page C3-57 RELATIVISTIC ELECTRONIC BAND STRUCTURE OF THE HEAVY METALS Summary: and properties of the actinide elements before discussing the band...

192

E-Print Network 3.0 - actinides np pu Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NpTe, PuTe. Actinides compounds with the ThCr2Si2 type structure Since the discovery of heavy... . - The magneticand electricaltransport propertiesof the U, Np and Pu...

193

E-Print Network 3.0 - actinides fuel research Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: in safety, proliferation resistance, and can be designed to breed fuel or burn heavy actinides. One... . The number of fuel pins in a fuel assembly of a PWR core is...

194

E-Print Network 3.0 - application aux actinides Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

au Journal de Physique 111, Vol. 1,dCcembre 1991 Summary: and actinides : application to curium. Radiochim. Acta. 5253, part 1, 119 (1991). 12;... . MAUCHlEN CEADCCDPESPEA...

195

E-Print Network 3.0 - actinide burning fuel Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: in safety, proliferation resistance, and can be designed to breed fuel or burn heavy actinides. One... . The number of fuel pins in a fuel assembly of a PWR core is...

196

Configuration adjustment potential of the Very High Temperature Reactor prismatic cores with advanced actinide fuels  

E-Print Network [OSTI]

Minor actinides represent the long-term radiotoxicity of nuclear wastes. As one of their potential incineration options, partitioning and transmutation in fission reactors are seriously considered worldwide. If implemented, these technologies could...

Ames, David E, II

2006-10-30T23:59:59.000Z

197

E-Print Network 3.0 - actinide waste forms Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

.-F. Lucchini, M.K. Richmann, and D.T. Reed. 2008. "Actinide (III) Solubility in WIPP Brine: Data Summary... ) but carbonate phases can be formed at the higher fugacities...

198

Optimization of actinide transmutation in innovative lead-cooled fast reactors  

E-Print Network [OSTI]

The thesis investigates the potential of fertile free fast lead-cooled modular reactors as efficient incinerators of plutonium and minor actinides (MAs) for application to dedicated fuel cycles for transmutation. A methodology ...

Romano, Antonino, 1972-

2003-01-01T23:59:59.000Z

199

E-Print Network 3.0 - actinides separation chemistry Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

separation chemistry Search Powered by Explorit Topic List Advanced Search Sample search results for: actinides separation chemistry Page: << < 1 2 3 4 5 > >> 1 www.emsl.pnl.gov...

200

E-Print Network 3.0 - actinides solution chemistry Sample Search...  

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solution chemistry Search Powered by Explorit Topic List Advanced Search Sample search results for: actinides solution chemistry Page: << < 1 2 3 4 5 > >> 1 www.emsl.pnl.gov...

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

E-Print Network 3.0 - actinide metal compounds Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

effects in the X-ray photoemission spectra of the actinides Summary: in 3d transition metal compounds and ns (n 4 , 5) levels in rare earth systems, it is clear that ME......

202

E-Print Network 3.0 - actinide elements progress Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

DE PHYSIQUE Colloque C4, supplment au n 4, Tome 40, avril 1979, page C4-207 Alkali metal actinide complex halides: thermochemical and structural Summary: Elements and...

203

Actinide-lanthanide separation with solvents on the base of amides of heterocyclic diacids  

SciTech Connect (OSTI)

The separation of actinides from lanthanides with a particular emphasis on Am(III) from Eu(III) with amides of heterocyclic dicarboxylic diacids was reviewed. It was shown that the di-amides of the 2,2'-dipyridyl-6,6'-dicarboxylic acid are the most promising ligands for the simultaneous selective recovery of actinides from HLLW (high level radioactive liquid waste) within the GANEX concept. (author)

Babain, V.A.; Alyapyshev, M.Y.; Tkachenko, L.I. [Khlopin Radium Institute, 28, 2ndMurinski pr., St-Petersburg, Russia 19402 (Russian Federation)

2013-07-01T23:59:59.000Z

204

Extraction of trivalent lanthanides and actinides by ``CMPO-like`` calixarenes  

SciTech Connect (OSTI)

Extractive properties of calix[4]arenes bearing carbamoylmethylphosphine oxide moieties on their upper rim toward trivalent lanthanide and actinide cations were investigated. The study revealed that these molecules selectively extract light lanthanides and actinides from heavy lanthanides. All parameters present in the extraction system were varied to determine the origin of the selectivity. It was found that this selectivity requires a calix[4]arene platform and acetamidophosphine oxide groups containing phenyl substituents on the four phosphorus atoms.

Delmau, L.H.; Simon, N. [CEA Cadarache, St. Paul lez Durance (France)] [CEA Cadarache, St. Paul lez Durance (France); Schwing-Weill, M.J. [ECPM, Strasbourg (France)] [and others] [ECPM, Strasbourg (France); and others

1999-04-01T23:59:59.000Z

205

CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES  

SciTech Connect (OSTI)

In this project, both the fundamental chemistry of actinides in alkaline solutions (relevant to those present in Hanford-style waste storage tanks), and their dissolution from sludge simulants (and interactions with supernatants) have been investigated under representative sludge leaching procedures. The leaching protocols were designed to go beyond conventional alkaline sludge leaching limits, including the application of acidic leachants, oxidants and complexing agents. The simulant leaching studies confirm in most cases the basic premise that actinides will remain in the sludge during leaching with 2-3 M NaOH caustic leach solutions. However, they also confirm significant chances for increased mobility of actinides under oxidative leaching conditions. Thermodynamic data generated improves the general level of experiemental information available to predict actinide speciation in leach solutions. Additional information indicates that improved Al removal can be achieved with even dilute acid leaching and that acidic Al(NO3)3 solutions can be decontaminated of co-mobilized actinides using conventional separations methods. Both complexing agents and acidic leaching solutions have significant potential to improve the effectiveness of conventional alkaline leaching protocols. The prime objective of this program was to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop.

Nash, Kenneth L.

2008-11-20T23:59:59.000Z

206

Shock temperature measurements in ammonia  

SciTech Connect (OSTI)

Our first shock temperature measurements on a cryogenic target are reported for NH/sub 3/. A new fast optical pyrometer and a cryogenic specimen holder for liquid NH/sub 3/ were developed to measure shock temperatures of 4400 and 3600 K at pressures of 61 and 48 GPa. These conditions correspond to those in the ice layers in Uranus and Neptune. The shock temperature data are in reasonable agreement with an equation of state based on an intermolecular potential derived from NH/sub 3/ Hugoniot data.

Radousky, H.B.; Mitchell, A.C.; Nellis, W.J.; Ross, M.

1985-07-01T23:59:59.000Z

207

Agonist-Activated Glucocorticoid Receptor Inhibits Binding of Heat Shock Factor 1 to the Heat Shock  

E-Print Network [OSTI]

Agonist-Activated Glucocorticoid Receptor Inhibits Binding of Heat Shock Factor 1 to the Heat Shock- cocorticoid receptor (GR) signaling in stressed cells will cause inhibition of the heat shock re- sponse as mediated by heat shock transcription factor 1 (HSF1). In that work, a full-length human heat shock protein

Abraham, Nader G.

208

Shock compression of precompressed deuterium  

SciTech Connect (OSTI)

Here we report quasi-isentropic dynamic compression and thermodynamic characterization of solid, precompressed deuterium over an ultrafast time scale (< 100 ps) and a microscopic length scale (< 1 {micro}m). We further report a fast transition in shock wave compressed solid deuterium that is consistent with the ramp to shock transition, with a time scale of less than 10 ps. These results suggest that high-density dynamic compression of hydrogen may be possible on microscopic length scales.

Armstrong, M R; Crowhurst, J C; Zaug, J M; Bastea, S; Goncharov, A F; Militzer, B

2011-07-31T23:59:59.000Z

209

Method for fluorination of actinide fluorides and oxyfluorides using O/sub 2/F/sub 2/  

DOE Patents [OSTI]

The present invention relates generally to methods of fluorination and more particularly to the use of O/sub 2/F/sub 2/ for the preparation of actinide hexafluorides, and for the extraction of deposited actinides and fluorides and oxyfluorides thereof from reaction vessels. The experiments set forth hereinabove demonstrate that the room temperature or below use of O/sub 2/F/sub 2/ will be highly beneficial for the preparation of pure actinide hexafluorides from their respective tetrafluorides without traces of HF being present as occurs using other fluorinating agents: and decontamination of equipment previously exposed to actinides: e.g., walls, feed lines, etc.

Eller, P.G.; Malm, J.G.; Penneman, R.A.

1984-08-01T23:59:59.000Z

210

Proliferation Resistance Evaluation of ACR-1000 Fuel with Minor Actinides  

SciTech Connect (OSTI)

The Global Nuclear Energy Partnership (GNEP) program is to significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs can play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In this work, an Advanced CANDU Reactor (ACR) fuel unit lattice cell model with 43 UO2 fuel rods will be used to investigate the effectiveness of a Minor Actinide Reduction Approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance. The main MARA objective is to increase the 238Pu / Pu isotope ratio by using the transuranic nuclides (237Np and 241Am) in the high burnup fuel and thereby increase the proliferation resistance even for a very low fuel burnup. As a result, MARA is a very effective approach to enhance the proliferation resistance for the on power refueling ACR system nuclear fuel. The MA transmutation characteristics at different MA loadings were compared and their impact on neutronics criticality assessed. The concept of MARA, significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy reconnaissance

Gray S. Chang

2008-09-01T23:59:59.000Z

211

Minor actinide transmutation in thorium and uranium matrices in heavy water moderated reactors  

SciTech Connect (OSTI)

The irradiation of Th{sup 232} breeds fewer of the problematic minor actinides (Np, Am, Cm) than the irradiation of U{sup 238}. This characteristic makes thorium an attractive potential matrix for the transmutation of these minor actinides, as these species can be transmuted without the creation of new actinides as is the case with a uranium fuel matrix. Minor actinides are the main contributors to long term decay heat and radiotoxicity of spent fuel, so reducing their concentration can greatly increase the capacity of a long term deep geological repository. Mixing minor actinides with thorium, three times more common in the Earth's crust than natural uranium, has the additional advantage of improving the sustainability of the fuel cycle. In this work, lattice cell calculations have been performed to determine the results of transmuting minor actinides from light water reactor spent fuel in a thorium matrix. 15-year-cooled group-extracted transuranic elements (Np, Pu, Am, Cm) from light water reactor (LWR) spent fuel were used as the fissile component in a thorium-based fuel in a heavy water moderated reactor (HWR). The minor actinide (MA) transmutation rates, spent fuel activity, decay heat and radiotoxicity, are compared with those obtained when the MA were mixed instead with natural uranium and taken to the same burnup. Each bundle contained a central pin containing a burnable neutron absorber whose initial concentration was adjusted to have the same reactivity response (in units of the delayed neutron fraction ?) for coolant voiding as standard NU fuel. (authors)

Bhatti, Zaki; Hyland, B.; Edwards, G.W.R. [Atomic Energy of Canada Limited, Chalk River Laboratories, 1 Plant Road, Chalk River, Ontario, K0J 1J0 (Canada)

2013-07-01T23:59:59.000Z

212

Actinide production in /sup 136/Xe bombardments of /sup 249/Cf  

SciTech Connect (OSTI)

The production cross sections for the actinide products from /sup 136/Xe bombardments of /sup 249/Cf at energies 1.02, 1.09, and 1.16 times the Coulomb barrier were determined. Fractions of the individual actinide elements were chemically separated from recoil catcher foils. The production cross sections of the actinide products were determined by measuring the radiations emitted from the nuclides within the chemical fractions. The chemical separation techniques used in this work are described in detail, and a description of the data analysis procedure is included. The actinide production cross section distributions from these /sup 136/Xe + /sup 249/Cf bombardments are compared with the production cross section distributions from other heavy ion bombardments of actinide targets, with emphasis on the comparison with the /sup 136/Xe + /sup 248/Cm reaction. A technique for modeling the final actinide cross section distributions has been developed and is presented. In this model, the initial (before deexcitation) cross section distribution with respect to the separation energy of a dinuclear complex and with respect to the Z of the target-like fragment is given by an empirical procedure. It is then assumed that the N/Z equilibration in the dinuclear complex occurs by the transfer of neutrons between the two participants in the dinuclear complex. The neutrons and the excitation energy are statistically distributed between the two fragments using a simple Fermi gas level density formalism. The resulting target-like fragment initial cross section distribution with respect to Z, N, and excitation energy is then allowed to deexcite by emission of neutrons in competition with fission. The result is a final cross section distribution with respect to Z and N for the actinide products. 68 refs., 33 figs., 6 tabs.

Gregorich, K.E.

1985-08-01T23:59:59.000Z

213

Numerical solution of shock and ramp compression for general material properties  

SciTech Connect (OSTI)

A general formulation was developed to represent material models for applications in dynamic loading. Numerical methods were devised to calculate response to shock and ramp compression, and ramp decompression, generalizing previous solutions for scalar equations of state. The numerical methods were found to be flexible and robust, and matched analytic results to a high accuracy. The basic ramp and shock solution methods were coupled to solve for composite deformation paths, such as shock-induced impacts, and shock interactions with a planar interface between different materials. These calculations capture much of the physics of typical material dynamics experiments, without requiring spatially-resolving simulations. Example calculations were made of loading histories in metals, illustrating the effects of plastic work on the temperatures induced in quasi-isentropic and shock-release experiments, and the effect of a phase transition.

Swift, D C

2009-01-28T23:59:59.000Z

214

THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS  

SciTech Connect (OSTI)

The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically grounded inputs for models of non-thermal emission from a variety of astrophysical sources, with particular relevance to GRB afterglows.

Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)

2013-07-01T23:59:59.000Z

215

Status of development of actinide blanket processing flowsheets for accelerator transmutation of nuclear waste  

SciTech Connect (OSTI)

An accelerator-driven subcritical nuclear system is briefly described that transmutes actinides and selected long-lived fission products. An application of this accelerator transmutation of nuclear waste (ATW) concept to spent fuel from a commercial nuclear power plant is presented as an example. The emphasis here is on a possible aqueous processing flowsheet to separate the actinides and selected long-lived fission products from the remaining fission products within the transmutation system. In the proposed system the actinides circulate through the thermal neutron flux as a slurry of oxide particles in heavy water in two loops with different average residence times: one loop for neptunium and plutonium and one for americium and curium. Material from the Np/Pu loop is processed with a short cooling time (5-10 days) because of the need to keep the total actinide inventory, low for this particular ATW application. The high radiation and thermal load from the irradiated material places severe constraints on the separation processes that can be used. The oxide particles are dissolved in nitric acid and a quarternary, ammonium anion exchanger is used to extract neptunium, plutonium, technetium, and palladium. After further cooling (about 90 days), the Am, Cm and higher actinides are extracted using a TALSPEAK-type process. The proposed operations were chosen because they have been successfully tested for processing high-level radioactive fuels or wastes in gram to kilogram quantities.

Dewey, H.J.; Jarvinen, G.D.; Marsh, S.F.; Schroeder, N.C.; Smith, B.F.; Villarreal, R.; Walker, R.B.; Yarbro, S.L.; Yates, M.A.

1993-09-01T23:59:59.000Z

216

Technical requirements for the actinide source-term waste test program  

SciTech Connect (OSTI)

This document defines the technical requirements for a test program designed to measure time-dependent concentrations of actinide elements from contact-handled transuranic (CH TRU) waste immersed in brines similar to those found in the underground workings of the Waste Isolation Pilot Plant (WIPP). This test program wig determine the influences of TRU waste constituents on the concentrations of dissolved and suspended actinides relevant to the performance of the WIPP. These influences (which include pH, Eh, complexing agents, sorbent phases, and colloidal particles) can affect solubilities and colloidal mobilization of actinides. The test concept involves fully inundating several TRU waste types with simulated WIPP brines in sealed containers and monitoring the concentrations of actinide species in the leachate as a function of time. The results from this program will be used to test numeric models of actinide concentrations derived from laboratory studies. The model is required for WIPP performance assessment with respect to the Environmental Protection Agency`s 40 CFR Part 191B.

Phillips, M.L.F.; Molecke, M.A.

1993-10-01T23:59:59.000Z

217

Thermally unstable complexants: Stability of lanthanide/actinide complexes, thermal instability of the ligands, and applications in actinide separations  

SciTech Connect (OSTI)

Water soluble complexing agents are commonly used in separations to enhance the selectivity of both ion exchange and solvent extraction processes. Applications of this type in the treatment of nuclear wastes using conventional complexing agents have found mixed success due to the nature of the complexants. In addition, the residual solutions containing these species have led to potentially serious complications in waste storage. To overcome some of the limitations of carboxylic acid and aminopolycarboxylate ligands, we have initiated a program to investigate the complexing ability, thermal/oxidative instability, and separation potential of a group of water soluble organophosphorus compounds which we call Thermally Unstable Complexants, or simply TUCS. Complexants of this type appear to be superior to conventional analogues in a number of respects. In this report, we will summarize our research to date on the actinide/lanthanide complexes with a series of substituted methanediphosphonic acids, the kinetics of their oxidative decomposition, and a few applications which have been developed for their use. 17 refs., 5 figs., 3 tab.

Nash, K.L.; Rickert, P.G.

1991-01-01T23:59:59.000Z

218

Maximum Fuel Utilization in Advanced Fast Reactors without Actinides Separation  

E-Print Network [OSTI]

Physics Optimization of Breed and Burn Fast Reactor Systems.reactors: Fabrication and properties and their optimization.

Heidet, Florent

2010-01-01T23:59:59.000Z

219

Particle seeding flow system for horizontal shock tube  

SciTech Connect (OSTI)

The Extreme Fluids Team in P-23, Physics Division, studies fluid dynamics at high speeds using high resolution diagnostics. The unsteady forces on a particle driven by a shock wave are not well understood, and they are difficult to model. A horizontal shock tube (HST) is being modified to collect data about the behavior of particles accelerated by shocks. The HST has been used previously for studies of Richtmyer-Meshkov instability using Planar Laser-Induced Fluorescence (PLIF) as well as Particle Image Velocimetry (PIV), diagnostics that measure density and velocity. The purpose of our project is to design a flow system that will introduce particles into the HST. The requirements for this particle flow system (PFS) are that it be non-intrusive, be able to introduce either solid or liquid particles, have an exhaust capability, not interfere with existing diagnostics, and couple with the existing HST components. In addition, the particles must flow through the tube in a uniform way. We met these design criteria by first drawing the existing shock tube and diagnostics and doing an initial design of the ducts for the PFS. We then estimated the losses through the particle flow system from friction and researched possible fans that could be used to drive the particles. Finally, the most challenging component of the design was the coupling to the HST. If we used large inlets, the shock would lose strength as it passed by the inlet, so we designed a novel coupling inlet and outlet that minimize the losses to the shock wave. Our design was reviewed by the Extreme Fluids Team, and it is now being manufactured and built based upon our technical drawings.

Johnston, Stephen [Los Alamos National Laboratory; Garcia, Nicolas J. [Los Alamos National Laboratory; Martinez, Adam A. [Los Alamos National Laboratory; Orlicz, Gregory C. [Los Alamos National Laboratory; Prestridge, Katherine P. [Los Alamos National Laboratory

2012-08-01T23:59:59.000Z

220

Enhancing BWR Proliferation Resistance Fuel with Minor Actinides  

SciTech Connect (OSTI)

Key aspects of the Global Nuclear Energy Partnership (GNEP) are to significantly advance the science and technology of nuclear energy systems and the Advanced Fuel Cycle (AFC) program. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. To accomplish these goals, international cooperation is very important and public acceptance is crucial. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. The challenges are solving the energy needs of the world, protection against nuclear proliferation, the problem of nuclear waste, and the global environmental problem. To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu and 240Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides (237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu /Pu. For future advanced nuclear systems, the minor actinides (MA) are viewed more as a resource to be recycled, or transmuted to less hazardous and possibly more useful forms, rather than simply as a waste stream to be disposed of in expensive repository facilities. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm3) to the top (0.35 g/cm3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. We concluded that the concept of MARA, which involves the use of transuranic nuclides (237Np and/or 241Am), significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy rennaissance.

Gray S. Chang

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Experimental level-structure determination in odd-odd actinide nuclei  

SciTech Connect (OSTI)

The status of experimental determination of level structure in odd-odd actinide nuclei is reviewed. A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei is applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation are derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings are used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Applications of this modeling technique are discussed.

Hoff, R.W.

1985-04-04T23:59:59.000Z

222

Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR  

SciTech Connect (OSTI)

One approach to address the United States Nuclear Power (NP) 2010 program for the advanced light water reactor (LWR) (Gen-III+) intermediate-term spent fuel disposal need is to reduce spent fuel storage volume while enhancing proliferation resistance. One proposed solution includes increasing burnup of the discharged spent fuel and mixing minor actinide (MA) transuranic nuclides (237Np and 241Am) in the high burnup fuel. Thus, we can reduce the spent fuel volume while increasing the proliferation resistance by increasing the isotopic ratio of 238Pu/Pu. For future advanced nuclear systems, MAs are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. A typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of adding MAs (237Np and/or 241Am) to enhance proliferation resistance and improve fuel cycle performance for the intermediate-term goal of future nuclear energy systems. However, adding MAs will increase plutonium production in the discharged spent fuel. In this work, the Monte-Carlo coupling with ORIGEN-2.2 (MCWO) method was used to optimize the MA loading in the UO2 fuel such that the discharged spent fuel demonstrates enhanced proliferation resistance, while minimizing plutonium production. The axial averaged MA transmutation characteristics at different burnup were compared and their impact on neutronics criticality and the ratio of 238Pu/Pu discussed.

G. S. Chang; Hongbin Zhang

2009-09-01T23:59:59.000Z

223

[working paper] Regional Economic Capacity, Economic Shocks,  

E-Print Network [OSTI]

1 [working paper] Regional Economic Capacity, Economic Shocks, and Economic that makes them more likely to resist economic shocks or to recover quickly from of resilience capacity developed by Foster (2012) is related to economic resilience

Sekhon, Jasjeet S.

224

Separation and analysis of actinides by extraction chromatography coupled with alpha-particle liquid scintillation spectrometry  

SciTech Connect (OSTI)

This work describes the development and testing of a new method for the separation and analysis of most actinides of interest in environmental samples. It combines simplified extraction chromatography using highly selective absorption resins (EiChrom columns) to partition the individual actinides with the measurement of their alpha-particle activities by liquid scintillation spectrometry using the Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{sup TM}) system. Water and soil samples along with environment quality-assurance standards are routinely processed by this method with an accuracy of {+-}5 to 20% at activity levels of 0.01 to 0.1 Bq.

Cadieux, J.R. Jr.; Reboul, S.H. [Westinghouse Savannah River Co., Aiken, SC (United States)

1996-11-01T23:59:59.000Z

225

Reliable estimation of shock position in shock-capturing compressible hydrodynamics codes  

SciTech Connect (OSTI)

The displacement method for estimating shock position in a shock-capturing compressible hydrodynamics code is introduced. Common estimates use simulation data within the captured shock, but the displacement method uses data behind the shock, making the estimate consistent with and as reliable as estimates of material parameters obtained from averages or fits behind the shock. The displacement method is described in the context of a steady shock in a one-dimensional lagrangian hydrodynamics code, and demonstrated on a piston problem and a spherical blast wave.The displacement method's estimates of shock position are much better than common estimates in such applications.

Nelson, Eric M [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

226

Stability of shocks relating to the shock ignition inertial fusion energy scheme  

SciTech Connect (OSTI)

Motivated by the shock ignition approach to improve the performance of inertial fusion targets, we make a series of studies of the stability of shock waves in planar and converging geometries. We examine stability of shocks moving through distorted material and driving shocks with non-uniform pressure profiles. We then apply a fully 3D perturbation, following this spherically converging shock through collapse to a distorted plane, bounce and reflection into an outgoing perturbed, broadly spherical shock wave. We find broad shock stability even under quite extreme perturbation.

Davie, C. J., E-mail: c.davie10@imperial.ac.uk; Bush, I. A.; Evans, R. G. [Imperial College London, London SW7 2AZ (United Kingdom)

2014-08-15T23:59:59.000Z

227

SCATTERING BEHAVIOR OF TRANSITIONAL SHOCK WAVES  

E-Print Network [OSTI]

SCATTERING BEHAVIOR OF TRANSITIONAL SHOCK WAVES Kevin R. Zumbrun Bradley J. Plohr Dan Marchesin September, 1991 Abstract. We study the stability and asymptotic behavior of transitional shock waves as solutions of a parabolic system of conservation laws. In contrast to classical shock waves, transitional

New York at Stoney Brook, State University of

228

Heliospheric shocks and sheaths John D. Richardson  

E-Print Network [OSTI]

into the thermal ions but instead heated these pickup ions. ICME-driven shocks are studied and compared to planetary bow shocks and the TS to see if pickup ions affect the heating at these shocks. The percentage in planetary magnetosheaths at the same distance. However, outside 35 AU, no reflected thermal ions

Richardson, John

229

Shock waves in strongly coupled plasmas  

SciTech Connect (OSTI)

Shock waves are supersonic disturbances propagating in a fluid and giving rise to dissipation and drag. Weak shocks, i.e., those of small amplitude, can be well described within the hydrodynamic approximation. On the other hand, strong shocks are discontinuous within hydrodynamics and therefore probe the microscopics of the theory. In this paper, we consider the case of the strongly coupled N=4 plasma whose microscopic description, applicable for scales smaller than the inverse temperature, is given in terms of gravity in an asymptotically AdS{sub 5} space. In the gravity approximation, weak and strong shocks should be described by smooth metrics with no discontinuities. For weak shocks, we find the dual metric in a derivative expansion, and for strong shocks we use linearized gravity to find the exponential tail that determines the width of the shock. In particular, we find that, when the velocity of the fluid relative to the shock approaches the speed of light v{yields}1 the penetration depth l scales as l{approx}(1-v{sup 2}){sup 1/4}. We compare the results with second-order hydrodynamics and the Israel-Stewart approximation. Although they all agree in the hydrodynamic regime of weak shocks, we show that there is not even qualitative agreement for strong shocks. For the gravity side, the existence of shock waves implies that there are disturbances of constant shape propagating on the horizon of the dual black holes.

Khlebnikov, Sergei; Kruczenski, Martin; Michalogiorgakis, Georgios [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907 (United States)

2010-12-15T23:59:59.000Z

230

Hydraulic/Shock-Jumps in Protoplanetary Disks  

E-Print Network [OSTI]

In this paper, we describe the nonlinear outcome of spiral shocks in protoplanetary disks. Spiral shocks, for most protoplanetary disk conditions, create a loss of vertical force balance in the post-shock region and result in rapid expansion of the gas perpendicular to the disk midplane. This expansion has characteristics similar to hydraulic jumps, which occur in incompressible fluids. We present a theory to describe the behavior of these hybrids between shocks and hydraulic jumps (shock bores) and then compare the theory to three-dimensional hydrodynamics simulations. We discuss the fully three-dimensional shock structures that shock bores produce and discuss possible consequences for disk mixing, turbulence, and evolution of solids.

A. C. Boley; R. H. Durisen

2006-03-10T23:59:59.000Z

231

Shock-induced chemistry in organic materials  

SciTech Connect (OSTI)

The combined 'extreme' environments of high pressure, temperature, and strain rates, encountered under shock loading, offer enormous potential for the discovery of new paradigms in chemical reactivity not possible under more benign conditions. All organic materials are expected to react under these conditions, yet we currently understand very little about the first bond-breaking steps behind the shock front, such as in the shock initiation of explosives, or shock-induced reactivity of other relevant materials. Here, I will present recent experimental results of shock-induced chemistry in a variety of organic materials under sustained shock conditions. A comparison between the reactivity of different structures is given, and a perspective on the kinetics of reaction completion under shock drives.

Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve [Los Alamos National Laboratory; Engelke, Ray [Los Alamos National Laboratory; Manner, Virginia [Los Alamos National Laboratory; Chellappa, Raja [Los Alamos National Laboratory; Yoo, Choong - Shik [WASHINGTON STATE UNIV

2011-01-20T23:59:59.000Z

232

ELECTRONIC STRUCTURE IN METALS AND ALLOYS. ELECTRONIC STRUCTURE OF THE LIGHT ACTINIDES  

E-Print Network [OSTI]

ELECTRONIC STRUCTURE IN METALS AND ALLOYS. ELECTRONIC STRUCTURE OF THE LIGHT ACTINIDES B. D. DUNLAP electrons. A review is given of some areas of current interest, especially where hyperfine techniques have the 60 keV y-ray of 237Np[l]. At that time, our understanding of the electronic properties

Boyer, Edmond

233

Assessment of SFR fuel pin performance codes under advanced fuel for minor actinide transmutation  

SciTech Connect (OSTI)

Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. In the SUPERFACT Experiment four different oxide fuels containing high and low concentrations of {sup 237}Np and {sup 241}Am, representing the homogeneous and heterogeneous in-pile recycling concepts, were irradiated in the PHENIX reactor. The behavior of advanced fuel materials with minor actinide needs to be fully characterized, understood and modeled in order to optimize the design of this kind of fuel elements and to evaluate its performances. This paper assesses the current predictability of fuel performance codes TRANSURANUS and GERMINAL V2 on the basis of post irradiation examinations of the SUPERFACT experiment for pins with low minor actinide content. Their predictions have been compared to measured data in terms of geometrical changes of fuel and cladding, fission gases behavior and actinide and fission product distributions. The results are in good agreement with the experimental results, although improvements are also pointed out for further studies, especially if larger content of minor actinide will be taken into account in the codes. (authors)

Bouineau, V.; Lainet, M.; Chauvin, N.; Pelletier, M. [French Alternative Energies and Atomic Energy Commission - CEA, CEA Cadarache, DEN/DEC/SESC, 13108 Saint Paul lez Durance (France); Di Marcello, V.; Van Uffelen, P.; Walker, C. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Hermann-von-Helmholtz-Platz 1, D- 76344 Eggenstein-Leopoldshafen (Germany)

2013-07-01T23:59:59.000Z

234

EXPERIENCE SUMMARY Development of the TALSqueak (Trivalent Actinide Lanthanide Separation using QUicker Extractants and  

E-Print Network [OSTI]

trivalent actinides Development of Warm Water Oxidation chemistry for remediation of Hanford's K Basin Development of the LimeAid Process to compliment the efforts of Hanford's Waste Treatment Plant Investigation sludge remediation of the Hanford Site Determination of thermodynamic parameters for biphasic systems

235

Head-on collision of dust-acoustic shock waves in strongly coupled dusty plasmas  

SciTech Connect (OSTI)

A theoretical investigation is carried out to study the propagation and the head-on collision of dust-acoustic (DA) shock waves in a strongly coupled dusty plasma consisting of negative dust fluid, Maxwellian distributed electrons and ions. Applying the extended Poincaré–Lighthill–Kuo method, a couple of Korteweg–deVries–Burgers equations for describing DA shock waves are derived. This study is a first attempt to deduce the analytical phase shifts of DA shock waves after collision. The impacts of physical parameters such as the kinematic viscosity, the unperturbed electron-to-dust density ratio, parameter determining the effect of polarization force, the ion-to-electron temperature ratio, and the effective dust temperature-to-ion temperature ratio on the structure and the collision of DA shock waves are examined. In addition, the results reveal the increase of the strength and the steepness of DA shock waves as the above mentioned parameters increase, which in turn leads to the increase of the phase shifts of DA shock waves after collision. The present model may be useful to describe the structure and the collision of DA shock waves in space and laboratory dusty plasmas.

EL-Shamy, E. F., E-mail: emadel-shamy@hotmail.com [Department of physics, Faculty of Science, Damietta University, New Damietta 34517 (Egypt); Department of Physics, College of Science, King Khalid University, P.O. 9004, Abha (Saudi Arabia); Al-Asbali, A. M., E-mail: aliaa-ma@hotmail.com [Department of Physics, College of Science for Girls in Abha, King Khalid University, Abha, P.O. 960 (Saudi Arabia)

2014-09-15T23:59:59.000Z

236

Shock Properties of Fansteel85  

SciTech Connect (OSTI)

The shock response of Fansteel85 was investigated in the pressure range 10-90 GPa. The linear U{sub s}-U{sub p} coefficients were found to be C = 4.160 {+-} .015 km/s and S = 1.195 {+-} .015. Ultrasound measurements yielded C{sub L} = 4.827 and C{sub T} = 2.101, implying a bulk sound speed C{sub B} = 4.173, which is in excellent agreement with the measured value for C. The Hugoniot elastic limit was determined to be 3.11 {+-} .05 GPa at U{sub p} = .0595 {+-} .001 km/s and U{sub s} = 4.886 {+-} .01 km/s. The speed of sound in the material behind the shock front was determined to be 5.10 {+-} .06 km/s at 10.2 GPa and 5.25 {+-} .06 km/s at 20.6 GPa.

Erskine, D J; Nellis, W J

2008-08-22T23:59:59.000Z

237

THREE-DIMENSIONAL MODELING OF RELATIVISTIC COLLISIONLESS ION-ELECTRON SHOCKS  

SciTech Connect (OSTI)

Two-dimensional (2D) modeling of collisionless shocks has been of tremendous importance in understanding the physics of nonlinear evolution, momentum transfer, and particle acceleration, but current computer capacities have now reached a point where three-dimensional (3D) modeling is becoming feasible. We present the first 3D model of a fully developed and relaxed relativistic ion-electron shock, and analyze and compare it to similar 2D models. Quantitative and qualitative differences are found with respect to the 2D models. The shock jump conditions are naturally different, because of the extra degree of freedom, but in addition it is found that strong parallel electric fields develop at the shock interface, the level of magnetic field energy is lower, and the non-thermal particle distribution is shallower with a power-law index of {approx}2.2.

Haugboelle, Troels, E-mail: haugboel@nbi.dk [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Oester Voldgade 5-7, DK-1350 Copenhagen (Denmark)

2011-10-01T23:59:59.000Z

238

actinide multi recycling: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Robert B. 38 DOI: 10.1002adem.201400414 Self-Assembled Recyclable Hierarchical Bucky Aerogels** Physics Websites Summary: DOI: 10.1002adem.201400414 Self-Assembled Recyclable...

239

A numerical scheme for ionizing shock waves  

SciTech Connect (OSTI)

A two-dimensional (2D) visual computer code to solve the steady state (SS) or transient shock problems including partially ionizing plasma is presented. Since the flows considered are hypersonic and the resulting temperatures are high, the plasma is partially ionized. Hence the plasma constituents are electrons, ions and neutral atoms. It is assumed that all the above species are in thermal equilibrium, namely, that they all have the same temperature. The ionization degree is calculated from Saha equation as a function of electron density and pressure by means of a nonlinear Newton type root finding algorithms. The code utilizes a wave model and numerical fluctuation distribution (FD) scheme that runs on structured or unstructured triangular meshes. This scheme is based on evaluating the mesh averaged fluctuations arising from a number of waves and distributing them to the nodes of these meshes in an upwind manner. The physical properties (directions, strengths, etc.) of these wave patterns are obtained by a new wave model: ION-A developed from the eigen-system of the flux Jacobian matrices. Since the equation of state (EOS) which is used to close up the conservation laws includes electronic effects, it is a nonlinear function and it must be inverted by iterations to determine the ionization degree as a function of density and temperature. For the time advancement, the scheme utilizes a multi-stage Runge-Kutta (RK) algorithm with time steps carefully evaluated from the maximum possible propagation speed in the solution domain. The code runs interactively with the user and allows to create different meshes to use different initial and boundary conditions and to see changes of desired physical quantities in the form of color and vector graphics. The details of the visual properties of the code has been published before (see [N. Aslan, A visual fluctuation splitting scheme for magneto-hydrodynamics with a new sonic fix and Euler limit, J. Comput. Phys. 197 (2004) 1-27]). The two-dimensional nature of ION-A was presented by a planar shock wave propagating over a circular obstacle. It was demonstrated that including the effects of ionization in calculating complex flows is important, even when they appear initially negligible. This code can be used to accurately simulate the nonlinear time dependent evolution of neutral or ionized plasma flows from supersonic to hypersonic regimes.

Aslan, Necdet [Yeditepe University, Physics Department, Kayisda g-circumflex i, 34755 Istanbul (Turkey)]. E-mail: naslan@yeditepe.edu.tr; Mond, Michael [Ben Gurion University, Mechanical Engineering Department, Beer Sheva (Israel)

2005-12-10T23:59:59.000Z

240

Normal shock solutions to the viscous shock layer equations including thermal, chemical, thermodynamic, and radiative nonequilibrium  

E-Print Network [OSTI]

An existing axisymmetric body viscous shock layer code including chemical, thermal, and thermodynamic nonequilibrium and nonequilibrium radiative gasdynamic coupling is adapted to simulate the one-dimensional flow within a shock tube. A suitable...

Mott, David Ray

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Shock-activated electrochemical power supplies  

DOE Patents [OSTI]

A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolyte rendering the electrolyte electrochemically active. 2 figs.

Benedick, W.B.; Graham, R.A.; Morosin, B.

1987-04-20T23:59:59.000Z

242

Shock-activated electrochemical power supplies  

DOE Patents [OSTI]

A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolytes rendering the electrolyte electrochemically active. 2 figs.

Benedick, W.B.; Graham, R.A.; Morosin, B.

1988-11-08T23:59:59.000Z

243

Shocks and sheaths in the heliosphere John D. Richardson  

E-Print Network [OSTI]

: Heliosphere Shocks Sheaths a b s t r a c t This paper compares three kinds of shocks and sheaths; the bow compares shocks and sheaths which form in the solar wind due to interactions with planets (bow shocks of the termination shock but the average increases by a factor of 2, and the temperature of the thermal protons

Richardson, John

244

Potentiometric Sensor for Real-Time Remote Surveillance of Actinides in Molten Salts  

SciTech Connect (OSTI)

A potentiometric sensor is being developed at the Idaho National Laboratory for real-time remote surveillance of actinides during electrorefining of spent nuclear fuel. During electrorefining, fuel in metallic form is oxidized at the anode while refined uranium metal is reduced at the cathode in a high temperature electrochemical cell containing LiCl-KCl-UCl3 electrolyte. Actinides present in the fuel chemically react with UCl3 and form stable metal chlorides that accumulate in the electrolyte. This sensor will be used for process control and safeguarding of activities in the electrorefiner by monitoring the concentrations of actinides in the electrolyte. The work presented focuses on developing a solid-state cation conducting ceramic sensor for detecting varying concentrations of trivalent actinide metal cations in eutectic LiCl-KCl molten salt. To understand the basic mechanisms for actinide sensor applications in molten salts, gadolinium was used as a surrogate for actinides. The ß?-Al2O3 was selected as the solid-state electrolyte for sensor fabrication based on cationic conductivity and other factors. In the present work Gd3+-ß?-Al2O3 was prepared by ion exchange reactions between trivalent Gd3+ from GdCl3 and K+-, Na+-, and Sr2+-ß?-Al2O3 precursors. Scanning electron microscopy (SEM) was used for characterization of Gd3+-ß?-Al2O3 samples. Microfocus X-ray Diffraction (µ-XRD) was used in conjunction with SEM energy dispersive X-ray spectroscopy (EDS) to identify phase content and elemental composition. The Gd3+-ß?-Al2O3 materials were tested for mechanical and chemical stability by exposing them to molten LiCl-KCl based salts. The effect of annealing on the exchanged material was studied to determine improvements in material integrity post ion exchange. The stability of the ß?-Al2O3 phase after annealing was verified by µ-XRD. Preliminary sensor tests with different assembly designs will also be presented.

Natalie J. Gese; Jan-Fong Jue; Brenda E. Serrano; Guy L. Fredrickson

2012-07-01T23:59:59.000Z

245

SC Brochure_Final_10dec12.indd  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

performance. Joint Actinide Shock Physics Experimental Research (JASPER) https:www2.nstec.comPagesDESS.aspx JASPER is a two-stage light-gas gun used to study the behavior of...

246

Time reversal duality of magnetohydrodynamic shocks  

SciTech Connect (OSTI)

The shock conditions in magnetohydrodynamics (MHD) are reduced to their most concise, three-parameter, distilled form by consistent use of the scale independence of the MHD equations and of the de Hoffmann-Teller transformation. They then exhibit a distinct time reversal duality between entropy-allowed shocks and entropy-forbidden jumps. This yields a new classification of MHD shocks by means of the monotonicity properties with respect to upstream and downstream Alfven Mach numbers, it exhibits the central role of intermediate discontinuities, and permits straightforward construction of all relevant dimensionless quantities of the shocks. An exhaustive overview is presented of solutions in the different parameter regimes.

Goedbloed, J. P. [FOM-Institute for Plasma Physics 'Rijnhuizen', Nieuwegein and Astronomical Institute, Utrecht University, Utrecht 3439 MN (Netherlands)

2008-06-15T23:59:59.000Z

247

Acceleration time scale at ultrarelativistic shock waves  

E-Print Network [OSTI]

The first-order cosmic ray acceleration at ultrarelativistic shocks is investigated using the Monte Carlo method. We apply a method of discrete particle momentum scattering as a model of particle pitch angle diffusion to reproduce highly anisotropic conditions at the shock wave. Shocks with Lorentz factors $\\gamma$ up to 320 and varying magnetic field inclinations $\\psi$ are considered. Values of diffusion coefficients upstream in the point where energy spectral indices stabilize to the limit 2.2 were calculated. The obtained acceleration time does not depend on shock conditions.

J. Bednarz

1998-08-26T23:59:59.000Z

248

Transient absorption spectroscopy of laser shocked explosives  

SciTech Connect (OSTI)

Transient absorption spectra from 390-890 nm of laser shocked RDX, PETN, sapphire, and polyvinylnitrate (PVN) at sub-nanosecond time scales are reported. RDX shows a nearly linear increase in absorption with time after shock at {approx}23 GPa. PETN is similar, but with smaller total absorption. A broad visible absorption in sapphire begins nearly immediately upon shock loading but does not build over time. PVN exhibits thin film interference in the absorption spectra along with increased absorption with time. The absorptions in RDX and PETN are suggested to originate in chemical reactions happening on picosecond time scales at these shock stresses, although further diagnostics are required to prove this interpretation.

Mcgrane, Shawn D [Los Alamos National Laboratory; Dang, Nhan C [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Bolome, Cindy A [Los Alamos National Laboratory; Moore, D S [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

249

APPLIED PHYSICS APPLIED PHYSICS  

E-Print Network [OSTI]

MSc APPLIED PHYSICS #12;MSc APPLIED PHYSICS This taught Masters course is based on the strong research in Applied Physics in the University's Department of Physics. The department has an impressive photonics and quantum optics, Physics and the Life Sciences, and solid state physics. The knowledge gained

Mottram, Nigel

250

Thermal Shock-resistant Cement  

SciTech Connect (OSTI)

We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved cement, causing its volume to expand.

Sugama T.; Pyatina, T.; Gill, S.

2012-02-01T23:59:59.000Z

251

Test of Actinide-Lanthanide Separation in an Aluminum-Based Pyrochemical System  

SciTech Connect (OSTI)

The investigation of the actinide and lanthanide distribution between a liquid metal and a molten fluoride salt shows a significant increase of the separation coefficient by using an aluminum-based pyrochemical system instead of a zinc-based system. The obtained values partly depend on the LiF/AlF{sub 3} ratio and can reach more than 30 000 when AlF{sub 3} is in excess with regard to the formation of the cryolite (Li{sub 3} AlF{sub 6}). Furthermore, in the metal phase, the aluminum interacts with the lanthanides to a lesser extent than in other usual metallic solvents. This opens a new way to explore the feasibility of the separation of actinides and lanthanides in the field of nuclear fuel reprocessing.

Rault, Laurence [Institut National Polytechnique de Grenoble (France); Heusch, Murielle [Institut National Polytechnique de Grenoble (France); Allibert, Michel [Institut National Polytechnique de Grenoble (France); Lemort, Florent [Commissariat a l'Energie Atomique (CEA) (France); Deschane, Xavier [Commissariat a l'Energie Atomique (CEA) (France); Boen, Roger [Commissariat a l'Energie Atomique (CEA) (France)

2002-08-15T23:59:59.000Z

252

Evaluation of Fluid Conduction and Mixing within a Subassembly of the Actinide Burner Test Reactor  

SciTech Connect (OSTI)

The RELAP5-3D code is being considered as a thermal-hydraulic system code to support the development of the sodium-cooled Actinide Burner Test Reactor as part of the Global Nuclear Energy Partnership. An evaluation was performed to determine whether the control system could be used to simulate the effects of non-convective mechanisms of heat transport in the fluid, including axial and radial heat conduction and subchannel mixing, that are not currently represented with internal code models. The evaluation also determined the relative importance of axial and radial heat conduction and fluid mixing on peak cladding temperature for a wide range of steady conditions and during a representative loss-of-flow transient. The evaluation was performed using a RELAP5-3D model of a subassembly in the Experimental Breeder Reactor-II, which was used as a surrogate for the Actinide Burner Test Reactor.

Cliff B. Davis

2007-09-01T23:59:59.000Z

253

Final Technical Progress Report Long term risk from actinides in the environment: Modes of mobility  

SciTech Connect (OSTI)

The key source of uncertainty in assessing actinide mobility is the relative importance of transport by: (1) wind erosion, (2) water erosion, and (3) vertical migration. Each of these three processes depends on several environmental factors and they compete with one another. A scientific assessment of the long-term risks associated with actinides in surface soils depends on better quantifying each of these three modes of mobility. The objective from our EMSP study was to quantify the mobility of soil actinides by wind erosion, water erosion, and vertical migration at three semiarid sites where actinide mobility is a key technical, social and legal issue. This EMSP project was the first to evaluate all three factors at a site. The approach has been to investigate both short- and long-term issues based on field and lab studies and model comparisons. Our results demonstrate the importance of incorporating threshold responses into a modeling framework that accounts for environmental factors and natural disturbances that trigger large changes in actinide mobility. The study measured erosional losses of sediment and fallout cesium (an actinide analogue) from field plots located near WIPP in 1998. The results highlight the large effect of burning as a disturbance on contaminant transport and mobility via runoff and erosion. The results show that runoff, erosion, and actinide transport are (1) strongly site specific-differences in radionuclide transport between WIPP and Rocky Flats differed by a factor of twelve because of soil and vegetation differences, and (2) are strongly impacted by disturbances such as fire, which can increase runoff, erosion, and actinide transport by more than an order of magnitude. In addition, a laboratory experiment using soil columns was conducted to investigate the vertical transport of contaminants in sandy soils. Nine columns of soil collected from the vicinity of the WIPP site were prepared. The column consisted of a piece of PVC pipe 20 cm in diameter and approximately 22 cm long. A thin ''marker layer'' of white soil was added to the top of each column followed by a thin layer of soil that had been spiked with 137Cs, cerium and lanthanum was applied to the surface. Approximately 900 cm of water (the equivalent of about 30 years of rainfall) was then applied at a rate of 3.2 L d-1. All of the activity contained in the soil core appeared to be in the top few mm of soil, i.e. there was virtually no movement of the 134Cs labeled particles. Finally, a library of object-oriented model components was created using Visual Basic to support the construction of contaminant transport models. These components greatly simplify the task of building 1- to 3- dimensional simulation models for risk assessment. The model components created under this funding were subsequently applied to help answer questions regarding risks from irrigation associated with potential releases from the Yucca Mountain waste repository.

Thomas B. Kirchner

2002-03-22T23:59:59.000Z

254

Relativistic Jets Shine through Shocks or Magnetic Reconnection?  

E-Print Network [OSTI]

Observations of gamma-ray-bursts and jets from active galactic nuclei reveal that the jet flow is characterized by a high radiative efficiency and that the dissipative mechanism must be a powerful accelerator of non-thermal particles. Shocks and magnetic reconnection have long been considered as possible candidates for powering the jet emission. Recent progress via fully-kinetic particle-in-cell simulations allows us to revisit this issue on firm physical grounds. We show that shock models are unlikely to account for the jet emission. In fact, when shocks are efficient at dissipating energy, they typically do not accelerate particles far beyond the thermal energy, and vice versa. In contrast, we show that magnetic reconnection can deposit more than 50% of the dissipated energy into non-thermal leptons as long as the energy density of the magnetic field in the bulk flow is larger than the rest mass energy density. The emitting region, i.e., the reconnection downstream, is characterized by a rough energy equipa...

Sironi, Lorenzo; Giannios, Dimitrios

2015-01-01T23:59:59.000Z

255

Strategic Design and Optimization of Inorganic Sorbents for Cesium, Strontium and Actinides  

SciTech Connect (OSTI)

The basic science goal in this project is to identify structure/affinity relationships for selected radionuclides and existing sorbents. The research will then apply this knowledge to the design and synthesis of sorbents that will exhibit increased cesium, strontium and actinide removal. The target problem focuses on the treatment of high-level nuclear wastes. The general approach can likewise be applied to non-radioactive separations.

Maginn, Edward J.

2005-07-01T23:59:59.000Z

256

Strategic Design and Optimization of Inorganic Sorbents For Cesium, Strontium and Actinides  

SciTech Connect (OSTI)

The basic science goal in this project identifies structure/affinity relationships for selected radionuclides and existing sorbents. The task will apply this knowledge to the design and synthesis of new sorbents that will exhibit increased affinity for cesium, strontium and actinide separations. The target problem focuses on the treatment of high-level nuclear wastes. The general approach can likewise be applied to nonradioactive separations.

Hobbs, D.; Nyman, M.; Clearfield, A.; Maginn, E.

2006-06-01T23:59:59.000Z

257

Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions  

SciTech Connect (OSTI)

The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.

Reed, Donald Timothy [Los Alamos National Laboratory; Borkowski, Marian [Los Alamos National Laboratory; Lucchini, Jean - Francois [Los Alamos National Laboratory; Ams, David [Los Alamos National Laboratory; Richmann, M. K. [Los Alamos National Laboratory; Khaing, H. [Los Alamos National Laboratory; Swanson, J. S. [Los Alamos National Laboratory

2010-12-10T23:59:59.000Z

258

Dynamic tests for actinide/lanthanide separation by CMPO solvent in fluorinated diluents  

SciTech Connect (OSTI)

Actinide and lanthanide extraction by new solvent: 0.2 M phenyl-octyl-N,N-diiso-butylcarbamoyl-phosphine oxide (CMPO) + 30% TBP + formal of octafluoro-pentanol was studied. A dynamic test with this solvent was performed. It was shown that americium and lanthanides are effectively extracted from PUREX process raffinate. The separation of americium from light lanthanides was confirmed in the modified SETFICS flowsheet with this new solvent. (authors)

Tkachenko, L.; Babain, V.; Alyapyshev, M.; Vizniy, A.; Il'in, A. [V. G. Khlopin Radium Institute, 2nd Murinskiy Ave 28., St. Petersburg 194021 (Russian Federation); Shadrin, A. [A.A. Bochvar High-technology Research Institute of Inorganic Materials, 5-a, Rogova str., Moscow 123098 (Russian Federation)

2013-07-01T23:59:59.000Z

259

Electronic Structure of Transition Metal Clusters and Actinide Complexes and Their Reactivity  

SciTech Connect (OSTI)

Our research in this area since October 2007 has resulted in seven completed publications and more papers of the completed work are in progress. Our work during this period principally focused on actinide complexes with secondary emphasis on spectroscopic properties and electronic structure of metal complexes. As the publications are available online with all of the details of the results, tables and figures, we are providing here only a brief summary of major highlights, in each of the categories.

Balasubramanian, K

2008-10-06T23:59:59.000Z

260

Shear shocks in fragile networks  

E-Print Network [OSTI]

A minimal model for studying the mechanical properties of amorphous solids is a disordered network of point masses connected by unbreakable springs. At a critical value of its mean connectivity, such a network becomes fragile: it undergoes a rigidity transition signaled by a vanishing shear modulus and transverse sound speed. We investigate analytically and numerically the linear and non-linear visco-elastic response of these fragile solids by probing how shear fronts propagate through them. Our approach, that we tentatively label shear front rheology, provides an alternative route to standard oscillatory rheology. In the linear regime, we observe at late times a diffusive broadening of the fronts controlled by an effective shear viscosity that diverges at the critical point. No matter how small the microscopic coefficient of dissipation, strongly disordered networks behave as if they were over-damped because energy is irreversibly leaked into diverging non-affine fluctuations. Close to the transition, the regime of linear response becomes vanishingly small: the tiniest shear strains generate strongly non-linear shear shock waves qualitatively different from their compressional counterparts in granular media. The inherent non-linearities trigger an energy cascade from low to high frequency components that keep the network away from attaining the quasi-static limit. This mechanism, reminiscent of acoustic turbulence, causes a super-diffusive broadening of the shock width.

Stephan Ulrich; Nitin Upadhyaya; Bas van Opheusden; Vincenzo Vitelli

2013-07-29T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Acceleration of Energetic Particles Through Self-Generated Waves in a Decelerating Coronal Shock  

E-Print Network [OSTI]

, Finland Department of Physics, University of Helsinki, Finland Abstract. We have developed a simulation- ered the primary source of large solar energetic parti- cle (SEP) intensities. Injected particles repeatedly cross the shock front, scattering from the plasma waves, and gain energy on each crossing

Sanahuja, Blai

262

Forecast of the arrival of interplanetary shocks by measuring cosmic ray fluctuations in the interplanetary  

E-Print Network [OSTI]

interplanetary shocks, for which a large flux of low-energy particles (10 keV - 10 MeV) of solar. of Physics, University of Oulu, Finland E-mail: ilya.usoskin@oulu.fi Abstract. Here we present a method cosmic ray fluctuations and solar wind parameters measured onboard the ACE spacecraft. The method

Usoskin, Ilya G.

263

URTeC 1620617 Thermal Shock in Reservoir Rock Enhances the Hydraulic  

E-Print Network [OSTI]

URTeC 1620617 Thermal Shock in Reservoir Rock Enhances the Hydraulic Fracturing of Gas Shales Saeid through strain and stress. As the temperature diffuses from hydraulic fracture into reservoir the rock matrix beyond hydraulic fracturing stimulation by cooling down the rock. The physics

Patzek, Tadeusz W.

264

Heating of Heavy Ions by Interplanetary Coronal Mass Ejection (ICME) Driven Collisionless Shocks  

E-Print Network [OSTI]

Shock heating and particle acceleration processes are some of the most fundamental physical phenomena of plasma physics with countless applications in laboratory physics, space physics, and astrophysics. This study is motivated by previous observations of non-thermal heating of heavy ions in astrophysical shocks (Korreck et al. 2004). Here, we focus on shocks driven by Interplanetary Coronal Mass Ejections (ICMEs) which heat the solar wind and accelerate particles. This study focuses specifically on the heating of heavy ions caused by these shocks. Previous studies have focused only on the two dynamically dominant species, H+ and He2+ . This study utilizes thermal properties measured by the Solar Wind Ion Composition Spectrometer (SWICS) aboard the Advanced Composition Explorer (ACE) spacecraft to examine heavy ion heating. This instrument provides data for many heavy ions not previously available for detailed study, such as Oxygen (O6+, O7+), Carbon (C5+, C6+), and Iron (Fe10+). The ion heating is found to depend critically on the upstream plasma

K. E. Korreck; T. H. Zurbuchen; S. T. Lepri; J. M . Raines

2006-12-28T23:59:59.000Z

265

Nanoscale Strainability of Graphene by Laser Shock-Induced Three-Dimensional Shaping  

E-Print Network [OSTI]

Nanoscale Strainability of Graphene by Laser Shock-Induced Three- Dimensional Shaping Ji Li,, Ting, West Lafayette, Indiana 47907, United States ABSTRACT: Graphene has many promising physical properties. It has been discovered that local strain in a graphene sheet can alter its conducting properties

Chen, Yong P.

266

Larmor radius size density holes discovered in the solar wind upstream of Earth's bow shock  

E-Print Network [OSTI]

Larmor radius size density holes discovered in the solar wind upstream of Earth's bow shock G. K. Cao Key Laboratory for Space Weather, CSSAR, CAS, Beijing, China K. Meziane Physics Department that are five or more times the solar wind density. Particle distributions show the steepened edge can behave

California at Berkeley, University of

267

Bulk nanocomposite magnets produced by dynamic shock compaction K. H. Chen and Z. Q. Jin  

E-Print Network [OSTI]

single-phaselike behavior, indicating effective exchange coupling between hard and soft magnetic phases. © 2004 American Institute of Physics. DOI: 10.1063/1.1760834 The figure of merit for a permanent magnet of bulk exchange-coupled nanocomposite magnets still remains a great challenge. Shock compaction employs

Wang, Zhong L.

268

QUANTIFICATION OF ACTINIDE ALPHA-RADIATION DAMAGE IN MINERALS AND CERAMICS  

SciTech Connect (OSTI)

There are large amounts of heavy alpha-emitters in nuclear waste and nuclear materials inventories stored in various sites around the world. These include plutonium and minor actinides such as americium and curium. In preparation for geological disposal there is a consensus that actinides that have been separated from spent nuclear fuel should be immobilised within mineral-based ceramics rather than glass. Over the long-term, the alpha-decay taking place in these ceramics will severely disrupt their crystalline structure and reduce their durability. A fundamental property in predicting cumulative radiation damage is the number of atoms permanently displaced per alpha–decay. Currently, this number is estimated as 1000-2000 atoms/alpha decay event. Here, we report nuclear magnetic resonance, spin-counting experiments that measure close to 5000 atoms/alpha decay event in radiation damaged natural zircons. New radiological NMR measurements on highly radioactive, 239Pu zircon show damage similar to that created by 238U and 232Th in mineral zircons at the same dose, indicating no significant effect of dose rate. Based on these measurements, the initially crystalline structure of a 10 wt% 239Pu zircon would be amorphous after only 1400 years in a geological repository. These measurements establish a basis for assessing the long-term structural durability of actinide-containing ceramics based on an atomistic understanding of the fundamental damage event.

Farnan, Ian E.; Cho, Herman M.; Weber, William J.

2007-01-11T23:59:59.000Z

269

Dissolution of metal oxides and separation of uranium from lanthanides and actinides in supercritical carbon dioxide  

SciTech Connect (OSTI)

This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO{sub 2}) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO{sub 2} modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO{sub 2} modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO{sub 2} and counter current stripping columns is presented. (authors)

Quach, D.L.; Wai, C.M. [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 (United States); Mincher, B.J. [Idaho National Lab, Idaho Falls, Idaho (United States)

2013-07-01T23:59:59.000Z

270

Actinide chemistry research supporting the Waste Isolation Pilot Plant (WIPP): FY94 results  

SciTech Connect (OSTI)

This document contains six reports on actinide chemistry research supporting the Waste Isolation Pilot Plant (WIPP). These reports, completed in FY94, are relevant to the estimation of the potential dissolved actinide concentrations in WIPP brines under repository breach scenarios. Estimates of potential dissolved actinide concentrations are necessary for WIPP performance assessment calculations. The specific topics covered within this document are: the complexation of oxalate with Th(IV) and U(VI); the stability of Pu(VI) in one WIPP-specific brine environment both with and without carbonate present; the solubility of Nd(III) in a WIPP Salado brine surrogate as a function of hydrogen ion concentration; the steady-state dissolved plutonium concentrations in a synthetic WIPP Culebra brine surrogate; the development of a model for Nd(III) solubility and speciation in dilute to concentrated sodium carbonate and sodium bicarbonate solutions; and the development of a model for Np(V) solubility and speciation in dilute to concentrated sodium Perchlorate, sodium carbonate, and sodium chloride media.

Novak, C.F. [ed.

1995-08-01T23:59:59.000Z

271

JOWOG 22/2 - Actinide Chemical Technology (July 9-13, 2012)  

SciTech Connect (OSTI)

The Plutonium Science and Manufacturing Directorate provides world-class, safe, secure, and reliable special nuclear material research, process development, technology demonstration, and manufacturing capabilities that support the nation's defense, energy, and environmental needs. We safely and efficiently process plutonium, uranium, and other actinide materials to meet national program requirements, while expanding the scientific and engineering basis of nuclear weapons-based manufacturing, and while producing the next generation of nuclear engineers and scientists. Actinide Process Chemistry (NCO-2) safely and efficiently processes plutonium and other actinide compounds to meet the nation's nuclear defense program needs. All of our processing activities are done in a world class and highly regulated nuclear facility. NCO-2's plutonium processing activities consist of direct oxide reduction, metal chlorination, americium extraction, and electrorefining. In addition, NCO-2 uses hydrochloric and nitric acid dissolutions for both plutonium processing and reduction of hazardous components in the waste streams. Finally, NCO-2 is a key team member in the processing of plutonium oxide from disassembled pits and the subsequent stabilization of plutonium oxide for safe and stable long-term storage.

Jackson, Jay M. [Los Alamos National Laboratory; Lopez, Jacquelyn C. [Los Alamos National Laboratory; Wayne, David M. [Los Alamos National Laboratory; Schulte, Louis D. [Los Alamos National Laboratory; Finstad, Casey C. [Los Alamos National Laboratory; Stroud, Mary Ann [Los Alamos National Laboratory; Mulford, Roberta Nancy [Los Alamos National Laboratory; MacDonald, John M. [Los Alamos National Laboratory; Turner, Cameron J. [Los Alamos National Laboratory; Lee, Sonya M. [Los Alamos National Laboratory

2012-07-05T23:59:59.000Z

272

DISSOLUTION OF METAL OXIDES AND SEPARATION OF URANIUM FROM LANTHANIDES AND ACTINIDES IN SUPERCRITICAL CARBON DIOXIDE  

SciTech Connect (OSTI)

This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO2 modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO2 and counter current stripping columns is presented.

Donna L. Quach; Bruce J. Mincher; Chien M. Wai

2013-10-01T23:59:59.000Z

273

Fundamental Thermodynamics of Actinide-Bearing Mineral Waste Forms - Final Report  

SciTech Connect (OSTI)

The end of the Cold War raised the need for the technical community to be concerned with the disposition of excess nuclear weapon material. The plutonium will either be converted into mixed-oxide fuel for use in nuclear reactors or immobilized in glass or ceramic waste forms and placed in a repository. The stability and behavior of plutonium in the ceramic materials as well as the phase behavior and stability of the ceramic material in the environment is not well established. In order to provide technically sound solutions to these issues, thermodynamic data are essential in developing an understanding of the chemistry and phase equilibria of the actinide-bearing mineral waste form materials proposed as immobilization matrices. Mineral materials of interest include zircon, zirconolite, and pyrochlore. High temperature solution calorimetry is one of the most powerful techniques, sometimes the only technique, for providing the fundamental thermodynamic data needed to establish optimum material fabrication parameters, and more importantly understand and predict the behavior of the mineral materials in the environment. The purpose of this project is to experimentally determine the enthalpy of formation of actinide orthosilicates, the enthalpies of formation of actinide substituted zirconolite and pyrochlore, and develop an understanding of the bonding characteristics and stabilities of these materials.

Williamson, Mark A.; Ebbinghaus, Bartley B.; Navrotsky, Alexandra

2001-03-01T23:59:59.000Z

274

Heat Shock Response Modulators as Therapeutic  

E-Print Network [OSTI]

Heat Shock Response Modulators as Therapeutic Tools for Diseases of Protein Conformation* Published. This review addresses the regulation of molecular chaperones and components of protein homeostasis by heat understanding of pharmacologically active small molecule regu- lators of the heat shock response

Morimoto, Richard

275

Quasi-perpendicular Shock Structure and Processes  

E-Print Network [OSTI]

and Thermalization 5.2.1 Bow shock orientation and global structure Knowledge of the basic parameters of a shock responsible for the overall thermalization of the principle plasma populations as well as the acceleration of an energetic non-thermal com- ponent. Despite the considerable effort, key questions remained unanswered or re

California at Berkeley, University of

276

Ion acceleration processes at reforming collisionless shocks  

E-Print Network [OSTI]

The identification of pre-acceleration mechanisms for cosmic ray ions in supernova remnant shocks is an important problem in astrophysics. Recent particle-in-cell (PIC) shock simulations have shown that inclusion of the full electron kinetics yields non-time-stationary solutions, in contrast to previous hybrid (kinetic ions, fluid electrons) simulations. Here, by running a PIC code at high phase space resolution, ion acceleration mechanisms associated with the time dependence of a supercritical collisionless perpendicular shock are examined. In particular the components of $\\int \\mathbf{F} \\cdot \\mathbf{v} dt$ are analysed along trajectories for ions that reach both high and low energies. Selection mechanisms for the ions that reach high energies are also examined. In contrast to quasi-stationary shock solutions, the suprathermal protons are selected from the background population on the basis of the time at which they arrive at the shock, and thus are generated in bursts.

R. E. Lee; S. C. Chapman; R. O. Dendy

2004-10-25T23:59:59.000Z

277

Oil Price Shocks: Causes and Consequences  

E-Print Network [OSTI]

Research on oil markets conducted during the last decade has challenged long-held beliefs about the causes and consequences of oil price shocks. As the empirical and theoretical models used by economists have evolved, so has our understanding of the determinants of oil price shocks and of the interaction between oil markets and the global economy. Some of the key insights are that the real price of oil is endogenous with respect to economic fundamentals, and that oil price shocks do not occur ceteris paribus. This makes it necessary to explicitly account for the demand and supply shocks underlying oil price shocks when studying their transmission to the domestic economy. Disentangling cause and effect in the relationship between oil prices and the economy requires structural models of the global economy including oil and other commodity markets.

Lutz Kilian; Key Words

278

Molecular shock response of explosives: electronic absorption spectroscopy  

SciTech Connect (OSTI)

Electronic absorption spectroscopy in the range 400-800 nm was coupled to ultrafast laser generated shocks to begin addressing the question of the extent to which electronic excitations are involved in shock induced reactions. Data are presented on shocked polymethylmethacrylate (PMMA) thin films and single crystal pentaerythritol tetranitrate (PETN). Shocked PMMA exhibited thin film interference effects from the shock front. Shocked PETN exhibited interference from the shock front as well as broadband increased absorption. Relation to shock initiation hypotheses and the need for time dependent absorption data (future experiments) is briefly discussed.

Mcgrne, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory; Eakins, Daniel E [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

279

An Assessment of Spent Fuel Reprocessing for Actinide Destruction and Resource Sustainability.  

SciTech Connect (OSTI)

The reprocessing and recycling of spent nuclear fuel can benefit the nuclear fuel cycle by destroying actinides or extending fissionable resources if uranium supplies become limited. The purpose of this study was to assess reprocessing and recycling in both fast and thermal reactors to determine the effectiveness for actinide destruction and resource utilization. Fast reactor recycling will reduce both the mass and heat load of actinides by a factor of 2, but only after 3 recycles and many decades. Thermal reactor recycling is similarly effective for reducing actinide mass, but the heat load will increase by a factor of 2. Economically recoverable reserves of uranium are estimated to sustain the current global fleet for the next 100 years, and undiscovered reserves and lower quality ores are estimated to contain twice the amount of economically recoverable reserves--which delays the concern of resource utilization for many decades. Economic analysis reveals that reprocessed plutonium will become competitive only when uranium prices rise to about %24360 per kg. Alternative uranium sources are estimated to be competitive well below that price. Decisions regarding the development of a near term commercial-scale reprocessing fuel cycle must partially take into account the effectiveness of reactors for actnides destruction and the time scale for when uranium supplies may become limited. Long-term research and development is recommended in order to make more dramatic improvements in actinide destruction and cost reductions for advanced fuel cycle technologies.The original scope of this work was to optimize an advanced fuel cycle using a tool that couples a reprocessing plant simulation model with a depletion analysis code. Due to funding and time constraints of the late start LDRD process and a lack of support for follow-on work, the project focused instead on a comparison of different reprocessing and recycling options. This optimization study led to new insight into the fuel cycle. AcknowledgementThe authors would like to acknowledge the support of Laboratory Directed Research and Development Project 125862 for funding this research.

Cipiti, Benjamin B.; Smith, James D.

2008-09-01T23:59:59.000Z

280

The technical and economic impact of minor actinide transmutation in a sodium fast reactor  

SciTech Connect (OSTI)

Within the frame work of the French National Act of June 28, 2006 pertaining to the management of high activity, long-lived radioactive waste, one of the proposed processes consists in transmuting the Minor Actinides (MA) in the radial blankets of a Sodium Fast Reactor (SFR). With this option, we may assess the additional cost of the reactor by comparing two SFR designs, one with no Minor Actinides, and the other involving their transmutation. To perform this exercise, we define a reference design called SFRref, of 1500 MWe that is considered to be representative of the Reactor System. The SFRref mainly features a pool architecture with three pumps, six loops with one steam generator per loop. The reference core is the V2B core that was defined by the CEA a few years ago for the Reactor System. This architecture is designed to meet current safety requirements. In the case of transmutation, for this exercise we consider that the fertile blanket is replaced by two rows of assemblies having either 20% of Minor Actinides or 20% of Americium. The assessment work is performed in two phases. - The first consists in identifying and quantifying the technical differences between the two designs: the reference design without Minor Actinides and the design with Minor Actinides. The main differences are located in the reactor vessel, in the fuel handling system and in the intermediate storage area for spent fuel. An assessment of the availability is also performed so that the impact of the transmutation can be known. - The second consists in making an economic appraisal of the two designs. This work is performed using the CEA's SEMER code. The economic results are shown in relative values. For a transmutation of 20% of MA in the assemblies (S/As) and a hypothesis of 4 kW allowable for the washing device, there is a large external storage demanding a very long cooling time of the S/As. In this case, the economic impact may reach 5% on the capital part of the Levelized Unit Electricity Cost (LUEC). A diminished concentration at 10% of MA, reduces the size of the external storage and the cooling time of the assemblies becomes compatible with the management of the irradiated fuel. Even with a low allowable power for the washing device, the economic impact on the capital cost is less than 2.5%. (authors)

Gautier, G. M.; Morin, F. [Alternative Energy and Atomic Energy Commission, CEA, DEN, F - 13108 St Paul lez Durance (France); Dechelette, F.; Sanseigne, E. [Alternative Energy and Atomic Energy Commission, CEA, DEN DTN, F - 13108 St Paul lez Durance (France); Chabert, C. [Alternative Energy and Atomic Energy Commission, CEA, DEN, F - 13108 St Paul lez Durance (France)

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Utilization of Minor Actinides as a Fuel Component for Ultra-Long Life Bhr Configurations: Designs, Advantages and Limitations  

SciTech Connect (OSTI)

This project assessed the advantages and limitations of using minor actinides as a fuel component to achieve ultra-long life Very High Temperature Reactor (VHTR) configurations. Researchers considered and compared the capabilities of pebble-bed and prismatic core designs with advanced actinide fuels to achieve ultra-long operation without refueling. Since both core designs permit flexibility in component configuration, fuel utilization, and fuel management, it is possible to improve fissile properties of minor actinides by neutron spectrum shifting through configuration adjustments. The project studied advanced actinide fuels, which could reduce the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository and enable recovery of the energy contained in spent fuel. The ultra-long core life autonomous approach may reduce the technical need for additional repositories and is capable to improve marketability of the Generation IV VHTR by allowing worldwide deployment, including remote regions and regions with limited industrial resources. Utilization of minor actinides in nuclear reactors facilitates developments of new fuel cycles towards sustainable nuclear energy scenarios.

Dr. Pavel V. Tsvetkov

2009-05-20T23:59:59.000Z

282

Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols  

SciTech Connect (OSTI)

In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one–dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 10{sup 6} simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

Bragard, Jean, E-mail: jbragard@unav.es; Simic, Ana; Elorza, Jorge [Department of Physics and Applied Math., University of Navarra, Pamplona (Spain)] [Department of Physics and Applied Math., University of Navarra, Pamplona (Spain); Grigoriev, Roman O.; Fenton, Flavio H. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)] [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Cherry, Elizabeth M. [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States)] [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States); Gilmour, Robert F. [University of Prince Edward Island, Charlottetown C1A 4P3 (Canada)] [University of Prince Edward Island, Charlottetown C1A 4P3 (Canada); Otani, Niels F. [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States) [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 (United States)

2013-12-15T23:59:59.000Z

283

Full particle simulation of a perpendicular collisionless shock: A shock-rest-frame model  

E-Print Network [OSTI]

The full kinetic dynamics of a perpendicular collisionless shock is studied by means of a one-dimensional electromagnetic full particle simulation. The present simulation domain is taken in the shock rest frame in contrast to the previous full particle simulations of shocks. Preliminary results show that the downstream state falls into a unique cyclic reformation state for a given set of upstream parameters through the self-consistent kinetic processes.

Takayuki Umeda; Ryo Yamazaki

2006-10-30T23:59:59.000Z

284

Carrier field shock formation of long wavelength femtosecond pulses in dispersive media  

E-Print Network [OSTI]

We numerically demonstrate the formation of carrier field shocks in various dispersive media for a wide variety of input conditions using two different electric field propagation models. In addition, an investigation of the impact of numerous physical effects on carrier wave shock is performed. It is shown that in many cases a field shock is essentially unavoidable and therefore extremely important in the propagation of intense long wavelength pulses in weakly dispersive nonlinear media such as noble gases, air, and single-crystal diamond. The results presented here are expected to have a significant impact in the field of ultrashort nonlinear optics, attosecond pulse generation, and wavepacket synthesis where the use of mid-IR wavelengths is becoming increasingly more important.

Panagiotopoulos, Paris; Kolesik, Miroslav; Moloney, Jerome V

2015-01-01T23:59:59.000Z

285

Long-term risk from actinides in the environment: Modes of mobility. 1998 annual progress report  

SciTech Connect (OSTI)

'The mobility of actinides in surface soils is a key issue of concern at several DOE facilities in arid and semiarid environments, including Rocky Flats, Hanford, Nevada Test Site, Idaho National Engineering Laboratory, and Los Alamos National Laboratory and the Waste Isolation Pilot Plant (WIPP). Key sources of uncertainty in assessing Pu mobility are the magnitudes of mobility resulting from three modes of transport: (1) wind erosion, (2) water erosion, and (3) vertical migration. Each of these three processes depend on numerous environmental factors and they compete with one another, particularly for actinides in very shallow soils ({approximately} 1 \\265m). The overall goal of the study is to quantify the mobility of soil actinides from all three modes. The authors study is using field measurements, laboratory experiments, and ecological modeling to address these three processes at three DOE facilities where actinide kinetics are of concern: WIPP, Rocky Flats, and Hanford. Wind erosion is being measured with suite of monitoring equipment, water erosion is being studied with rainfall simulation experiments, vertical migration is being studied in controlled laboratory experiments, and the three processes are being integrated using ecological modeling. Estimates for clean up of soil actinides for the extensive tracts of DOE land range to hundreds of billion $ in the US Without studies of these processes, unnecessary clean-up of these areas may waste billions of dollars and cause irreparable ecological damage through the soil removal. Further, the outcomes of litigation against DOE are dependent on quantifying the mobility of actinides in surface soils. This report provides a summary of work for the first year of a 3-year project; subcontracts to collaborating institutions (Colorado State University and New Mexico State University) were not in place until late December 1997, and hence this report focuses on the results of the 5 months from January through May 1998. The major result to date is a review of literature on the potential for using soil concentrations of {sup 137}Cs and {sup 241}Am as tracers for plutonium in soil. Measurements of {sup 239}Pu contamination in the environment are expensive and time consuming, requiring radiochemical analysis and alpha spectroscopy. They evaluated the literature for measurements of {sup 137}Cs and {sup 241}Am, both of which are more cost-effectively measured by gamma spectrometry, as tracers for Pu in soil. Their results indicate that: significant positive correlation exists between Pu, Cs, and Am in soils and sediments at several locations including Rocky Flats, Los Alamos, and Hanford; atmospheric transport of Pu and Cs from worldwide fallout is essentially the same; the attachment of Pu and Cs to soil particles of various size is very similar; both Pu and Cs movement in the environment correlate well with soil and sediment particle movements; a significant correlation between Pu, Cs, and Am was found in soil as a function of depth, indicating similar vertical migration behavior (most of the activity of these radionuclides is confined to the top 10--20 cm of soil at virtually all locations); most Pu and Cs are strongly absorbed onto clay and organic matter in soils and there is essentially very little leaching of Pu, Am and Cs through soil columns. Based on the above information, they believe that {sup 137}Cs and {sup 241}Am are excellent tracers for both {sup 239}Pu and soil particle transport processes in clay, mineral bearing and/or organic soils. Therefore, Cs and Am would be good tracers for the proposed water erosion and vertical migration work, at least for both Rocky Flats and Hanford. The correlation between Pu and Cs may not be as strong in sandy soil (e.g. WIPP site), however, examination of more data is needed.'

Breshears, D.D.; Whicker, J.J. [Los Alamos National Lab., NM (US); Ibrahim, S.A.; Whicker, F.W.; Hakonson, T.E. [Colorado State Univ., Fort Collins, CO (US); Kirchner, T. [New Mexico State Univ., Las Cruces, NM (US)

1998-06-01T23:59:59.000Z

286

Condensed matter at high shock pressures  

SciTech Connect (OSTI)

Experimental techniques are described for shock waves in liquids: Hugoniot equation-of-state, shock temperature and emission spectroscopy, electrical conductivity, and Raman spectroscopy. Experimental data are reviewed and presented in terms of phenomena that occur at high densities and temperatures in shocked He, Ar, N/sub 2/, CO, SiO/sub 2/-aerogel, H/sub 2/O, and C/sub 6/H/sub 6/. The superconducting properties of Nb metal shocked to 100 GPa (1 Mbar) and recovered intact are discussed in terms of prospects for synthesizing novel, metastable materials. Ultrahigh pressure data for Cu is reviewed in the range 0.3 to 6TPa (3 to 60 Mbar). 56 refs., 9 figs., 1 tab.

Nellis, W.J.; Holmes, N.C.; Mitchell, A.C.; Radousky, H.B.; Hamilton, D.

1985-07-12T23:59:59.000Z

287

Particle acceleration in relativistic subluminal shock environments  

E-Print Network [OSTI]

The understanding of the particle spectra resulting from acceleration in relativistic shocks as they occur in extragalactic sources, is essential for the interpretation of the cosmic ray spectrum above the ankle ($E_p>3\\cdot 10^{18}$ eV). It is believed that extragalactic sources like Active Galactic Nuclei and Gamma Ray Bursts can produce particle spectra up to $E_p\\sim 10^{21}$ eV. In this contribution, subluminal shocks are investigated with respect to different shock boost factors $\\Gamma$ and the inclination angle between the shock normal and the magnetic field $\\psi$. A correlation between the boost factor and the spectral behavior of the emitted particles is found. The results are compared to Active Galactic Nuclei and Gamma Ray Burst diffuse cosmic ray contribution and the observed cosmic ray spectrum at the highest energies.

A. Meli; J. Becker; J. J. Quenby; J. Luenemann

2007-08-10T23:59:59.000Z

288

Efficiency limits of diffusive shock acceleration  

E-Print Network [OSTI]

It is well accepted today that diffusive acceleration in shocks results to the cosmic ray spectrum formation. This is in principle true for non-relativistic shocks, since there is a detailed theory covering a large range of their properties and the resulting power-law spectrum, which is nevertheless not as efficient to reach the very high energies observed in the cosmic ray spectrum. On the other hand, the cosmic ray maximum energy and the resulting spectra from relativistic shocks, are still under investigation and debate concerning their contribution to the features of the cosmic ray spectrum and the measured, or implied, cosmic ray radiation from candidate astrophysical sources. Here, we discuss the efficiency of the first order Fermi (diffusive) acceleration mechanism up to relativistic shock speeds, presenting Monte Carlo simulations.

A. Meli; A. Mastichiadis

2007-08-10T23:59:59.000Z

289

Critical point anomalies include expansion shock waves  

SciTech Connect (OSTI)

From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium. In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.

Nannan, N. R., E-mail: ryan.nannan@uvs.edu [Mechanical Engineering Discipline, Anton de Kom University of Suriname, Leysweg 86, PO Box 9212, Paramaribo, Suriname and Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands); Guardone, A., E-mail: alberto.guardone@polimi.it [Department of Aerospace Science and Technology, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Colonna, P., E-mail: p.colonna@tudelft.nl [Propulsion and Power, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)

2014-02-15T23:59:59.000Z

290

Disinfecting Water Wells by Shock Chlorination  

E-Print Network [OSTI]

If your well has been flooded, it must be shock chlorinated before it can be used as a source of drinking water. This publication explains how to disinfect a well using either dry chlorine or liquid household bleach....

Dozier, Monty; McFarland, Mark L.

2005-09-30T23:59:59.000Z

291

Electron Heating in Quasi-Perpendicular Shocks  

E-Print Network [OSTI]

Seventy crossings of the Earths bow shock by the THEMIS satellites have been used to study thermal electron heating in collisionless, quasi-perpendicular shocks. It was found that the temperature increase of thermal electrons differed from the magnetic field increase by factors as great as three, that the parallel electron temperature increase was not produced by parallel electric fields, and that the parallel and perpendicular electron temperature increases were the same on the average. It was also found that the perpendicular and parallel electron heating occurred simultaneously so that the isotropization time is the same as the heating time. These results cannot be explained by energy transfer from waves to electrons or by the motion of magnetized electrons through the shock. Electric field fluctuations on the scale of the electron gyro-diameter were found to be of finite amplitude in the shock ramp, which requires that the electron trajectories be more random and chaotic than orderly and adiabatic. The da...

Mozer, F S

2013-01-01T23:59:59.000Z

292

Fluid description of shock phenomena in  

E-Print Network [OSTI]

an overview of the results on MHD bow shock ows which are presented throughout this dissertation. We. 2.1 represents the contribution from irreversible dissipative processes like viscosity and thermal

De Sterck, Hans

293

Actinide Production in the Reaction of Heavy Ions withCurium-248  

SciTech Connect (OSTI)

Chemical experiments were performed to examine the usefulness of heavy ion transfer reactions in producing new, neutron-rich actinide nuclides. A general quasi-elastic to deep-inelastic mechanism is proposed, and the utility of this method as opposed to other methods (e.g. complete fusion) is discussed. The relative merits of various techniques of actinide target synthesis are discussed. A description is given of a target system designed to remove the large amounts of heat generated by the passage of a heavy ion beam through matter, thereby maximizing the beam intensity which can be safely used in an experiment. Also described is a general separation scheme for the actinide elements from protactinium (Z = 91) to mendelevium (Z = 101), and fast specific procedures for plutonium, americium and berkelium. The cross sections for the production of several nuclides from the bombardment of {sup 248}Cm with {sup 18}O, {sup 86}Kr and {sup 136}Xe projectiles at several energies near and below the Coulomb barrier were determined. The results are compared with yields from {sup 48}Ca and {sup 238}U bombardments of {sup 248}Cm. Simple extrapolation of the product yields into unknown regions of charge and mass indicates that the use of heavy ion transfer reactions to produce new, neutron-rich above-target species is limited. The substantial production of neutron-rich below-target species, however, indicates that with very heavy ions like {sup 136}Xe and {sup 238}U the new species {sup 248}Am, {sup 249}Am and {sup 247}Pu should be produced with large cross sections from a {sup 248}Cm target. A preliminary, unsuccessful attempt to isolate {sup 247}Pu is outlined. The failure is probably due to the half life of the decay, which is calculated to be less than 3 minutes. The absolute gamma ray intensities from {sup 251}Bk decay, necessary for calculating the {sup 251}Bk cross section, are also determined.

Moody, K.J.

1983-07-01T23:59:59.000Z

294

Shock-induced enhancement of learning  

E-Print Network [OSTI]

Subject: Psychology SHOCK INDUCFD ENHANCEMENT OF LEARNING A Thesis by ADAM RICHARD FERGUSON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved... as to style and content by: I ames Grau ( air of Committee) Mary Meagher (Member) Ra ond Battalio (Member) u3 Paul Wellman (Head of Department) December 2000 Major Subject: Psychology ABSTRACT Shock-Induced Enhancement of Learning. (December...

Ferguson, Adam Richard

2000-01-01T23:59:59.000Z

295

Shock wave propagation in vibrofluidized granular materials  

E-Print Network [OSTI]

Shock wave formation and propagation in two-dimensional granular materials under vertical vibration are studied by digital high speed photography. The steepen density and temperature wave fronts form near the plate as granular layer collides with vibrating plate and propagate upward through the layer. The temperature front is always in the transition region between the upward and downward granular flows. The effects of driving parameters and particle number on the shock are also explored.

Kai Huang; Guoqing Miao; Peng Zhang; Yi Yun; Rongjue Wei

2005-11-29T23:59:59.000Z

296

Shock Chlorination of Stored Water Supplies  

E-Print Network [OSTI]

of their well water. While these procedures effectively may san- itize water wells and distribution systems, addition- al steps may be necessary to shock- chlorinate water stored in tanks. Storage Tanks In several regions of Texas, such as the Texas Hill... Country and the Central Texas Blacklands, water is pumped from wells into large storage tanks. Pipes from such tanks then deliver water to houses for domestic use. However, shock-chlorinating a water well alone may not provide enough chlorinated water...

Dozier, Monty; McFarland, Mark L.

2005-05-25T23:59:59.000Z

297

POST-SHOCK-REVIVAL EVOLUTION IN THE NEUTRINO-HEATING MECHANISM OF CORE-COLLAPSE SUPERNOVAE  

SciTech Connect (OSTI)

We perform experimental simulations with spherical symmetry and axisymmetry to understand the post-shock-revival evolution of core-collapse supernovae. Assuming that the stalled shock wave is relaunched by neutrino heating and employing the so-called light bulb approximation, we induce shock revival by raising the neutrino luminosity up to the critical value, which is determined by dynamical simulations. A 15 M{sub Sun} progenitor model is employed. We incorporate nuclear network calculations with a consistent equation of state in the simulations to account for the energy release by nuclear reactions and their feedback to hydrodynamics. Varying the shock-relaunch time rather arbitrarily, we investigate the ensuing long-term evolutions systematically, paying particular attention to the explosion energy and nucleosynthetic yields as a function of relaunch time, or equivalently, the accretion rate at shock revival. We study in detail how the diagnostic explosion energy approaches the asymptotic value and which physical processes contribute in what proportions to the explosion energy. Furthermore, we study the dependence of physical processes on the relaunch time and the dimension of dynamics. We find that the contribution of nuclear reactions to the explosion energy is comparable to or greater than that of neutrino heating. In particular, recombinations are dominant over burnings in the contributions of nuclear reactions. Interestingly, one-dimensional (1D) models studied in this paper cannot produce the appropriate explosion energy and nickel mass simultaneously; nickels are overproduced. This problem is resolved in 2D models if the shock is relaunched at 300-400 ms after the bounce.

Yamamoto, Yu; Yamada, Shoichi [Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Fujimoto, Shin-ichiro [Kumamoto National College of Technology, 2659-2 Suya, Goshi, Kumamoto 861-1102 (Japan); Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

2013-07-01T23:59:59.000Z

298

Sigma Team for Minor Actinide Separation: PNNL FY 2011 Status Report  

SciTech Connect (OSTI)

This report summarizes work conducted in FY 2011 at PNNL to investigate new methods of separating the minor actinide elements (Am and Cm) from the trivalent lanthanide elements, and separation of Am from Cm. For the former, work focused on a solvent extraction system combining an acidic extractant (HDEHP) with a neutral extractant (CMPO) to form a hybrid solvent extraction system referred to as TRUSPEAK (combining the TRUEX and TALSPEAK processes). For the latter, ligands that strongly bing uranyl ion were investigated for stabilizing corresponding americyl ion.

Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Levitskaia, Tatiana G.; Carter, Jennifer C.; Warner, Marvin G.; Pittman, Jonathan W.

2011-08-13T23:59:59.000Z

299

Micro-Analysis of Actinide Minerals for Nuclear Forensics and Treaty Verification  

SciTech Connect (OSTI)

Micro-Raman spectroscopy has been demonstrated to be a viable tool for nondestructive determination of the crystal phase of relevant minerals. Collecting spectra on particles down to 5 microns in size was completed. Some minerals studied were weak scatterers and were better studied with the other techniques. A decent graphical software package should easily be able to compare collected spectra to a spectral library as well as subtract out matrix vibration peaks. Due to the success and unequivocal determination of the most common mineral false positive (zircon), it is clear that Raman has a future for complementary, rapid determination of unknown particulate samples containing actinides.

M. Morey, M. Manard, R. Russo, G. Havrilla

2012-03-22T23:59:59.000Z

300

Actinide extraction from simulated and irradiated spent nuclear fuel using TBP solutions in HFC-134a  

SciTech Connect (OSTI)

It was demonstrated that solutions of TBP-nitric acid adduct in liquid Freon HFC-134a (1.2 MPa, 25 deg. C) allowed for recovery of uranium with nearly the same effectiveness as supercritical CO{sub 2} at 30 MPa. At nearly quantitative recovery of U and Pu, a DF of ca. 10 can be attained on dissolution and extraction of simulated SNF samples. The possibility of recovery of actinides contained in cakes produced by oxide conversion of simulated and irradiated SNF with solutions of TBP and DBE in Freon HFC-134a was shown. (authors)

Shadrin, A.; Babain, V.; Kamachev, V.; Murzin, A.; Shafikov, D.; Dormidonova, A. [Khlopin Radium Institute, RPA, 28, 2-nd Murinskii ay., St-Petersburg (Russian Federation)

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Low-Temperature Synthesis of Actinide Tetraborides by Solid-State Metathesis Reactions  

SciTech Connect (OSTI)

The synthesis of actinide tetraborides including uranium tetraboride (UB,), plutonium tetraboride (PUB,) and thorium tetraboride (ThB{sub 4}) by a solid-state metathesis reaction are demonstrated. The present method significantly lowers the temperature required to {approx_equal}850 C. As an example, when UCl{sub 4}, is reacted with an excess of MgB{sub 2}, at 850 C, crystalline UB, is formed. Powder X-ray diffraction and ICP-AES data support the reduction of UCl{sub 3}, as the initial step in the reaction. The UB, product is purified by washing water and drying.

Lupinetti, Anthony J.; Garcia, Eduardo; Abney, Kent D.

2004-12-14T23:59:59.000Z

302

Conceptual configurations of an accelerator-driven subcritical system utilizing minor actinides  

SciTech Connect (OSTI)

This paper purposes an Accelerator-Driven Subcritical (ADS) system which utilizes the Minor Actinides (MAs) from the US spent nuclear fuel inventory. A mobile fuel concept with micro-particles suspended in the liquid metal is adopted in the purposed system to avoid difficulties of developing and testing new MAs solid fuel forms. Three ADS configurations were developed and analyzed using the Monte Carlo fuel burnup methodology. The analyses demonstrated the capabilities of the proposed system to utilize the MAs and to dispose of the US spent nuclear fuels. (authors)

Cao, Y.; Gohar, Y. [Nuclear Engineering Div., Argonne National Laboratory, 9700 South Cass Ave., IL 60439 (United States)

2012-07-01T23:59:59.000Z

303

Design of an Actinide-Burning, Lead or Lead-Bismuth Cooled Reactor that Produces Low-Cost Electricity  

SciTech Connect (OSTI)

The purpose of this Idaho National Engineering and Environmental Laboratory (INEEL) and Massachusetts Institute of Technology (MIT) University Research Consortium (URC) project is to investigate the suitability of lead or lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The goal is to identify and analyze the key technical issues in core neutronics, materials, thermal-hydraulics, fuels, and economics associated with the development of this reactor concept. Work has been accomplished in four major areas of research: core neutronic design, material compatibility, plant engineering, and coolant activation. In the area of core neutronic design, the reactivity vs. burnup and discharge isotopics of both non-fertile and fertile fuels were evaluated. An innovative core for pure actinide burning that uses streaming, fertile-free fuel assemblies was studied in depth. This particular core exhibits excellent reactivity performance upon coolant voiding, even for voids that occur in the core center, and has a transuranic (TRU) destruction rate that is comparable to the proposed accelerator transmutation of waste (ATW) facility. These studies suggest that a core can be designed to achieve a long life while maintaining safety and minimizing waste. In the area of material compatibility studies, an experimental apparatus for the investigation of the flow-assisted dissolution and precipitation (corrosion) of potential fuel cladding and structural materials has been designed and built at the INEEL. The INEEL forced-convection corrosion cell consists of a small heated vessel with a shroud and gas flow system. The corrosion cell is being used to test steel that is commercially available in the United States to temperatures above 650°C. Progress in plant engineering was made for two reactor concepts, one utilizing an indirect cycle with heat exchangers and the other utilizing a direct-contact steam cycle. The evaluation of the indirect cycle designs has investigated the effects of various parameters to increase electric production at full power. For the direct-contact reactor, major issues related to the direct-contact heat transfer rate and entrainment and carryover of liquid lead-bismuth to the turbine have been identified and analyzed. An economic analysis approach was also developed to determine the cost of electricity production in the lead-bismuth reactor. The approach will be formulated into a model and applied to develop scientific cost estimates for the different reactor designs and thus aid in the selection of the most economic option. In the area of lead-bismuth coolant activation, the radiological hazard was evaluated with particular emphasis on the direct-contact reactor. In this system, the lack of a physical barrier between the primary and secondary coolant favors the release of the alpha-emitter Po?210 and its transport throughout the plant. Modeling undertaken on the basis of the scarce information available in the literature confirmed the importance of this issue, as well as the need for experimental work to reduce the uncertainties on the basic characteristics of volatile polonium chemical forms.

Mac Donald, Philip Elsworth; Weaver, Kevan Dean; Davis, Cliff Bybee; MIT folks

2000-07-01T23:59:59.000Z

304

Investigation of the unsteady Edney type IV and VII shock-shock interaction  

E-Print Network [OSTI]

adaptation, thermochemical nonequilibrium. 1. Introduction The proper prediction of thermal and structural loads is crucial for the design of future space transportation systems. Especially the thermal of an incident shock wave which impinges on the bow shock in front of a blunt body. A supersonic jet forms

305

Ab Initio Enhanced calphad Modeling of Actinide-Rich Nuclear Fuels  

SciTech Connect (OSTI)

The process of fuel recycling is central to the Advanced Fuel Cycle Initiative (AFCI), where plutonium and the minor actinides (MA) Am, Np, and Cm are extracted from spent fuel and fabricated into new fuel for a fast reactor. Metallic alloys of U-Pu-Zr-MA are leading candidates for fast reactor fuels and are the current basis for fast spectrum metal fuels in a fully recycled closed fuel cycle. Safe and optimal use of these fuels will require knowledge of their multicomponent phase stability and thermodynamics (Gibbs free energies). In additional to their use as nuclear fuels, U-Pu-Zr-MA contain elements and alloy phases that pose fundamental questions about electronic structure and energetics at the forefront of modern many-body electron theory. This project will validate state-of-the-art electronic structure approaches for these alloys and use the resulting energetics to model U-Pu-Zr-MA phase stability. In order to keep the work scope practical, researchers will focus on only U-Pu-Zr-{Np,Am}, leaving Cm for later study. The overall objectives of this project are to: Provide a thermodynamic model for U-Pu-Zr-MA for improving and controlling reactor fuels; and, Develop and validate an ab initio approach for predicting actinide alloy energetics for thermodynamic modeling.

Morgan, Dane [Univ. of Wisconsin, Madison, WI (United States); Yang, Yong Austin [Univ. of Wisconsin, Madison, WI (United States)

2013-10-28T23:59:59.000Z

306

Beta-delayed fission and neutron emission calculations for the actinide cosmochronometers  

SciTech Connect (OSTI)

The Gamow-Teller beta-strength distributions for 19 neutron-rich nuclei, including ten of interest for the production of the actinide cosmochronometers, are computed microscopically with a code that treats nuclear deformation explicitly. The strength distributions are then used to calculate the beta-delayed fission, neutron emission, and gamma deexcitation probabilities for these nuclei. Fission is treated both in the complete damping and WKB approximations for penetrabilities through the nuclear potential-energy surface. The resulting fission probabilities differ by factors of 2 to 3 or more from the results of previous calculations using microscopically computed beta-strength distributions around the region of greatest interest for production of the cosmochronometers. The indications are that a consistent treatment of nuclear deformation, fission barriers, and beta-strength functions is important in the calculation of delayed fission probabilities and the production of the actinide cosmochronometers. Since we show that the results are very sensitive to relatively small changes in model assumptions, large chronometric ages for the Galaxy based upon high beta-delayed fission probabilities derived from an inconsistent set of nuclear data calculations must be considered quite uncertain.

Meyer, B.S.; Howard, W.M.; Mathews, G.J.; Takahashi, K.; Moeller, P.; Leander, G.A.

1989-05-01T23:59:59.000Z

307

Separation and Analysis of Actinides by Extraction Chromotography Coupled with Alpha Liquid Scintillation Spectrometry  

SciTech Connect (OSTI)

This work describes the development and testing of a new method for the separation and analysis of most actinides of interest in environmental samples. It combines simplified extraction chromatography using highly selective absorption resins to partition the individual actinides with the measurement of their alpha activities by liquid scintillation spectrometry. The liquid scintillation counting technique pioneered by McDowell proved useful in determination of alpha emitting radionuclide in a wide variety of matrices. Alpha emitters are chemically extracted into an organic phase which also contains the scintillation cocktail. Oxygen is purged from the solution to improve the energy resolution of the measurement and the counting sample is sealed in a small glass tube for assay. The Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{trademark}) Spectrometer provides high counting efficiency, low background, pulse shape discrimination for photon/electron/{beta} particle rejection and moderate energy resolution in a compact package. Chemical extraction/liquid scintillation counting significantly reduces the extensive chemical purification and electroplating required for conventional alpha spectrometry with semiconductor detectors. PERALS{trademark} analyses have been used routinely for quickly surveying suspect samples and determining the source of unknown alpha activities.

Cadieux, J.R.; Reboul, S.H.

1995-09-21T23:59:59.000Z

308

Selective partitioning of mercury from co-extracted actinides in a simulated acidic ICPP waste stream  

SciTech Connect (OSTI)

The TRUEX process is being evaluated at the Idaho Chemical Processing Plant (ICPP) as a means to partition the actinides from acidic sodium-bearing waste (SBW). The mercury content of this waste averages 1 g/l. Because the chemistry of mercury has not been extensively evaluated in the TRUEX process, mercury was singled out as an element of interest. Radioactive mercury, {sup 203}Hg, was spiked into a simulated solution of SBW containing 1 g/l mercury. Successive extraction batch contacts with the mercury spiked waste simulant and successive scrubbing and stripping batch contacts of the mercury loaded TRUEX solvent (0.2 M CMPO-1.4 M TBP in dodecane) show that mercury will extract into and strip from the solvent. The extraction distribution coefficient for mercury, as HgCl{sub 2} from SBW having a nitric acid concentration of 1.4 M and a chloride concentration of 0.035 M was found to be 3. The stripping distribution coefficient was found to be 0.5 with 5 M HNO{sub 3} and 0.077 with 0.25 M Na{sub 2}CO{sub 3}. An experimental flowsheet was designed from the batch contact tests and tested counter-currently using 5.5 cm centrifugal contactors. Results from the counter-current test show that mercury can be removed from the acidic mixed SBW simulant and recovered separately from the actinides.

Brewer, K.N.; Herbst, R.S.; Tranter, T.J. [and others

1995-12-01T23:59:59.000Z

309

Technical and economic assessment of different options for minor actinide transmutation: the French case  

SciTech Connect (OSTI)

Studies have been performed to assess the industrial perspectives of partitioning and transmutation of long-lived elements. These studies were carried out in tight connection with GEN-IV systems development. The results include the technical and economic evaluation of fuel cycle scenarios along with different options for optimizing the processes between the minor actinide transmutation in fast neutron reactors, their interim storage and geological disposal of ultimate waste. The results are analysed through several criteria (impacts on waste, on waste repository, on fuel cycle plants, on radiological exposure of workers, on costs and on industrial risks). These scenario evaluations take place in the French context which considers the deployment of the first Sodium-cooled Fast Reactor (SFR) in 2040. 3 management options of minor actinides have been studied: no transmutation, transmutation in SFR and transmutation in an accelerator-driven system (ADS). Concerning economics the study shows that the cost overrun related to the transmutation process could vary between 5 to 9% in SFR and 26 % in the case of ADS.

Chabert, C.; Coquelet-Pascal, C. [CEA-Cadarache, DEN, Saint-Paul-lez-Durance (France); Saturnin, A. [CEA, DEN, Marcoule (France); Mathonniere, G.; Boullis, B.; Warin, D. [CEA-Saclay, DEN, Gif-sur-Yvette (France); Van Den Durpel, L. [AREVA-NC, Paris-la-Defense (France); Caron-Charles, M. [AREVA-NP, Paris-la-Defense (France); Garzenne, C. [EDF, Paris (France)

2013-07-01T23:59:59.000Z

310

Determining the dissolution rates of actinide glasses: A time and temperature Product Consistency Test study  

SciTech Connect (OSTI)

Vitrification has been identified as one potential option for the e materials such as Americium (Am), Curium (Cm), Neptunium (Np), and Plutonium (Pu). A process is being developed at the Savannah River Site to safely vitrify all of the highly radioactive Am/Cm material and a portion of the fissile (Pu) actinide materials stored on site. Vitrification of the Am/Cm will allow the material to be transported and easily stored at the Oak Ridge National Laboratory. The Am/Cm glass has been specifically designed to be (1) highly durable in aqueous environments and (2) selectively attacked by nitric acid to allow recovery of the valuable Am and Cm isotopes. A similar glass composition will allow for safe storage of surplus plutonium. This paper will address the composition, relative durability, and dissolution rate characteristics of the actinide glass, Loeffler Target, that will be used in the Americium/Curium Vitrification Project at Westinghouse Savannah River Company near Aiken, South Carolina. The first part discusses the tests performed on the Loeffler Target Glass concerning instantaneous dissolution rates. The second part presents information concerning pseudo-activation energy for the one week glass dissolution process.

Daniel, W.E.; Best, D.R.

1995-12-01T23:59:59.000Z

311

Conceptual design of minor actinides burner with an accelerator-driven subcritical system.  

SciTech Connect (OSTI)

In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS systems consume about 1.2 tons of actinides per year and produce 3 GW thermal power, with a proton beam power of 25 MW. Total MA fuel that would be consumed in the first 10 years of operation is 9.85, 11.80, or 12.68 tons, respectively, for the systems with 5, 7, or 10% actinide fuel particles loaded in the LBE. The corresponding annual MA fuel transmutation rate after reaching equilibrium at 10 years of operation is 0.83, 0.94, or 1.02 tons/year, respectively. Assuming that the ADS systems can be operated for 35 full-power years, the total MAs consumed in the three ADS systems are 30.6, 35.3, and 37.2 tons, respectively. For the three configurations, it is estimated that 3.8, 3.3, or 3.1 ADS system units are required to utilize the entire 115 tons of MA fuel in the SNF inventory, respectively.

Cao, Y.; Gohar, Y. (Nuclear Engineering Division)

2011-11-04T23:59:59.000Z

312

Binary Pulsar Shock Emissions as Galactic Gamma-Ray Sources  

E-Print Network [OSTI]

We address several issues regarding the interpretation of galactic \\ggg-ray sources. We consider powerful pulsars in binaries producing X-ray and gamma-ray {\\it unpulsed} emission from the shock interaction of relativistic pulsar winds with circumbinary material. Nebular mass outflows from companion stars of binary pulsars can provide the right {\\it calorimeters} to transform a fraction of the electromagnetic and kinetic energy of pulsar winds into high energy radiation. We discuss the physics of interaction of relativistic pulsar winds with gaseous material and show that the conditions in pulsar binary systems might be ideal to constrain shock acceleration mechanisms and pulsar wind composition and structure. We briefly discuss the example of the 47~ms pulsar PSR~1259-63 orbiting around a massive Be~star companion and monitored by X-ray and gamma-ray instruments during its recent periastron passage. In addition to young pulsars in massive binaries, also a class of recycled millisecond pulsars in low-mass binaries can be interesting high energy emitters.

M. Tavani

1995-02-13T23:59:59.000Z

313

A REVERSE SHOCK IN GRB 130427A  

SciTech Connect (OSTI)

We present extensive radio and millimeter observations of the unusually bright GRB 130427A at z = 0.340, spanning 0.67-12 days after the burst. We combine these data with detailed multi-band UV, optical, NIR, and Swift X-ray observations and find that the broadband afterglow emission is composed of distinct reverse shock and forward shock contributions. The reverse shock emission dominates in the radio/millimeter and at ?< 0.1 days in the UV/optical/NIR, while the forward shock emission dominates in the X-rays and at ?> 0.1 days in the UV/optical/NIR. We further find that the optical and X-ray data require a wind circumburst environment, pointing to a massive star progenitor. Using the combined forward and reverse shock emission, we find that the parameters of the burst include an isotropic kinetic energy of E{sub K,{sub iso}} ? 2 × 10{sup 53} erg, a mass loss rate of M-dot ?3×10{sup -8} M{sub ?} yr{sup –1} (for a wind velocity of 1000 km s{sup –1}), and a Lorentz factor at the deceleration time of ?(200 s) ? 130. Due to the low density and large isotropic energy, the absence of a jet break to ?15 days places only a weak constraint on the opening angle, ?{sub j} ?> 2.°5, and therefore a total energy of E{sub ?} + E{sub K} ?> 1.2 × 10{sup 51} erg, similar to other gamma-ray bursts (GRBs). The reverse shock emission is detectable in this burst due to the low circumburst density, which leads to a slow cooling shock. We speculate that this property is required for the detectability of reverse shocks in radio and millimeter bands. Following on GRB 130427A as a benchmark event, observations of future GRBs with the exquisite sensitivity of the Very Large Array and ALMA, coupled with detailed modeling of the reverse and forward shock contributions, will test this hypothesis.

Laskar, T.; Berger, E.; Zauderer, B. A.; Margutti, R.; Soderberg, A. M.; Chakraborti, S.; Lunnan, R.; Chornock, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chandra, P. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Ganeshkhind, Pune 411 007 (India); Ray, A. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India)

2013-10-20T23:59:59.000Z

314

Analytical model for fast-shock ignition  

SciTech Connect (OSTI)

A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ?4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ?0.3??micron and the shock ignitor energy weight factor about 0.25.

Ghasemi, S. A., E-mail: abo.ghasemi@yahoo.com; Farahbod, A. H. [Plasma Physics Research School, NSTRI, North Kargar Avenue, Tehran (Iran, Islamic Republic of); Sobhanian, S. [Department of Physics, Tabriz University, Tabriz (Iran, Islamic Republic of)

2014-07-15T23:59:59.000Z

315

Actinide Corroles: Synthesis and Characterization of Thorium(IV) and Uranium(IV) bis(-chloride) Dimers  

SciTech Connect (OSTI)

The first synthesis and structural characterization of actinide corroles is presented. Thorium(IV) and uranium(IV) macrocycles of Mes2(p-OMePh)corrole were synthesised and characterized by single-crystal X-ray diffraction, UV-Visible spectroscopy, variable-temperature 1H NMR, ESI mass spectrometry and cyclic voltammetry.

Ward, Ashleigh L.; Buckley, Heather L.; Gryko, Daniel T.; Lukens, Wayne W.; Arnold, John

2013-12-01T23:59:59.000Z

316

RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH  

SciTech Connect (OSTI)

A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead. Multiple vacuum box locations may be set-up to supply several ICP-MS units with purified sample fractions such that a high sample throughput may be achieved, while still allowing for rapid measurement of short-lived actinides by alpha spectrometry.

Maxwell, S.; Jones, V.

2009-05-27T23:59:59.000Z

317

On the simulation of shock-driven material mixing in high-Re flows (u)  

SciTech Connect (OSTI)

Implicit large eddy simulation proposes to effectively rely on the use of subgrid modeling and filtering provided implicitly by physics capturing numerics. Extensive work has demonstrated that predictive simulations of turbulent velocity fields are possible using a class of high resolution, non-oscillatory finite-volume (NFV) numerical algorithms. Truncation terms associated with NFV methods implicitly provide subgrid models capable of emulating the physical dynamics of the unresolved turbulent velocity fluctuations by themselves. The extension of the approach to the substantially more difficult problem of under-resolved material mixing by an under-resolved velocity field has not yet been investigated numerically, nor are there any theories as to when the methodology may be expected to be successful. Progress in addressing these issues in studies of shock-driven scalar mixing driven by Ritchmyer-Meshkov instabilities will be reported in the context of ongoing simulations of shock-tube laboratory experiments.

Grinstein, Fernando F [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

318

A lecture on detonation-shock dynamics  

SciTech Connect (OSTI)

We summarize recent investigations into the theory of multi-dimensional, time-dependent detonation. These advances have led to the development of a theory for describing the propagation of high-order detonation in condensed-phase explosives. The central approximation in the theory is that the detonation shock is weakly curved. Specifically, we assume that the radius of curvature of the detonation shock is large compared to a relevant reaction-zone thickness. Our main findings are: (1) the flow is quasi-steady and nearly one dimensional along the normal to the detonation shock; and (2) the small deviation of the normal detonation velocity from the Chapman-Jouguet (CJ) value is generally a function of curvature. The exact functional form of the correction depends on the equation of state (EOS) and the form of the energy-release law. 8 refs.

Stewart, D.S.; Bdzil, J.B.

1987-01-01T23:59:59.000Z

319

Nonlinear dust acoustic waves and shocks  

SciTech Connect (OSTI)

We describe experiments on (1) nonlinear dust acoustic waves and (2) dust acoustic shocks performed in a direct current (DC) glow discharge dusty plasma. First, we describe experiments showing nonlinear dust acoustic waves characterized by waveforms of the dust density that are typically sharper in the wave crests and flatter in the wave troughs (compared to sinusoidal waves), indicating the development of wave harmonics. We discuss this behavior in terms of a second-order fluid theory for dust acoustic waves. Second, experimental observations of the propagation and steepening of large-amplitude dust acoustic waves into dust acoustic shock waves are presented. The observed shock wave evolution is compared with numerical calculations based on the Riemann solution of the fully nonlinear fluid equations for dust acoustic waves.

Merlino, R. L.; Heinrich, J. R.; Hyun, S.-H.; Meyer, J. K. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

2012-05-15T23:59:59.000Z

320

LIBS Spectral Data for a Mixed Actinide Fuel Pellet Containing Uranium, Plutonium, Neptunium and Americium  

SciTech Connect (OSTI)

Laser-induced breakdown spectroscopy (LIBS) was used to analyze a mixed actinide fuel pellet containing 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2}. The preliminary data shown here is the first report of LIBS analysis of a mixed actinide fuel pellet, to the authors knowledge. The LIBS spectral data was acquired in a plutonium facility at Los Alamos National Laboratory where the sample was contained within a glove box. The initial installation of the glove box was not intended for complete ultraviolet (UV), visible (VIS) and near infrared (NIR) transmission, therefore the LIBS spectrum is truncated in the UV and NIR regions due to the optical transmission of the window port and filters that were installed. The optical collection of the emission from the LIBS plasma will be optimized in the future. However, the preliminary LIBS data acquired is worth reporting due to the uniqueness of the sample and spectral data. The analysis of several actinides in the presence of each other is an important feature of this analysis since traditional methods must chemically separate uranium, plutonium, neptunium, and americium prior to analysis. Due to the historic nature of the sample fuel pellet analyzed, the provided sample composition of 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2} cannot be confirm without further analytical processing. Uranium, plutonium, and americium emission lines were abundant and easily assigned while neptunium was more difficult to identify. There may be several reasons for this observation, other than knowing the exact sample composition of the fuel pellet. First, the atomic emission wavelength resources for neptunium are limited and such techniques as hollow cathode discharge lamp have different dynamics than the plasma used in LIBS which results in different emission spectra. Secondly, due to the complex sample of four actinide elements, which all have very dense electronic energy levels, there may be reactions and interactions occurring within the plasma, such as collisional energy transfer, that might be a factor in the reduction in neptunium emission lines. Neptunium has to be analyzed alone using LIBS to further understand the dynamics that may be occurring in the plasma of the mixed actinide fuel pellet sample. The LIBS data suggests that the emission spectrum for the mixed actinide fuel pellet is not simply the sum of the emission spectra of the pure samples but is dependent on the species present in the plasma and the interactions and reactions that occur within the plasma. Finally, many of the neptunium lines are in the near infrared region which is drastically reduced in intensity by the current optical setup and possibly the sensitivity of the emission detector in the spectral region. Once the optics are replaced and the optical collection system is modified and optimized, the probability of observing emission lines for neptunium might be increased significantly. The mixed actinide fuel pellet was analyzed under the experimental conditions listed in Table 1. The LIBS spectra of the fuel pellet are shown in Figures 1-49. The spectra are labeled with the observed wavelength and atomic species (both neutral (I) and ionic (II)). Table 2 is a complete list of the observed and literature based emission wavelengths. The literature wavelengths have references including NIST Atomic Spectra Database (NIST), B.A. Palmer et al. 'An Atlas of Uranium Emission Intensities in a Hollow Cathode Discharge' taken at the Kitt Peak National Observatory (KPNO), R.L. Kurucz 1995 Atomic Line Data from the Smithsonian Astrophysical Observatory (SAO), J. Blaise et al. 'The Atomic Spectrum of Plutonium' from Argonne National Laboratory (BFG), and M. Fred and F.S. Tomkins, 'Preliminary Term Analysis of Am I and Am II Spectra' (FT). The dash (-) shown under Ionic State indicates that the ionic state of the transition was not available. In the spectra, the dash (-) is replaced with a question mark (?). Peaks that are not assigned are most likely real features and not noise but cannot be confidently assi

Judge, Elizabeth J. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Le, Loan A. [Los Alamos National Laboratory; Lopez, Leon N. [Los Alamos National Laboratory; Barefield, James E. [Los Alamos National Laboratory

2012-06-18T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Infrared Images of Shock-Heated Tin  

SciTech Connect (OSTI)

High-resolution, gated infrared images were taken of tin samples shock heated to just below the 505 K melting point. Sample surfaces were either polished or diamond-turned, with grain sizes ranging from about 0.05 to 10 mm. A high explosive in contact with a 2-mm-thick tin sample induced a peak sample stress of 18 GPa. Interferometer data from similarly-driven tin shots indicate that immediately after shock breakout the samples spall near the free (imaged) surface with a scab thickness of about 0.1 mm.

Craig W. McCluskey; Mark D. Wilke; William D. Turley; Gerald D. Stevens; Lynn R. Veeser; Michael Grover

2004-09-01T23:59:59.000Z

322

Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms  

SciTech Connect (OSTI)

Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am and Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their academic experience. New information has been developed to qualify the extraction potential of a class of pyridine-functionalized tetraaza complexants indicating potential single contact Am-Nd separation factors of about 40. The methodology developed for characterization will find further application in our continuing efforts to synthesize and characterize new reagents for this separation. Significant new insights into the performance envelope and supporting information on the TALSPEAK process has also been developed.

Kenneth L. Nash

2009-09-22T23:59:59.000Z

323

DEPARTMENT OF PHYSICS Physics 32100  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 32100 Modern Physics for Engineers Designation to one- electron atoms, atomic shell structure and periodic table; nuclear physics, relativity. Prerequisites: Prereq.: Physics 20800 or equivalent, Math 20300 or 20900 (elective for Engineering students

Lombardi, John R.

324

DEPARTMENT OF PHYSICS Physics 21900  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 21900 Physics for Architecture Students Designation suggested material: Giancoli, Physics, Principles with Applications (6th ed.) (required), Prentice Hall Giancoli, Physics, Principles with Applications, Student Guide (6th ed.) (optional), Prentice Hall Course

Lombardi, John R.

325

DEPARTMENT OF PHYSICS Physics 20300  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 20300 General Physics Designation: Required Undergraduate Catalog description: For majors in the life sciences (biology, medicine, dentistry, psychology, physical therapy) and for liberal arts students. Fundamental ideas and laws of physics from mechanics to modern

Lombardi, John R.

326

Dynamic Response Of Complex Materials Under Shock Loading  

E-Print Network [OSTI]

resin and its carbon-nanotube (CNT) composites to shock wave compression. For phenolic resin, our simulations yielded shock states in agreement with experiments on similar polymers, except the "phase change" observed in experiments, indicating...

Arman, Bedri

2012-10-19T23:59:59.000Z

327

Prediction of Septic Shock in Patients with Hematologic Malignancies  

E-Print Network [OSTI]

65 and SMRT-CO in the prediction of early transfers to theThiel, S.W. , et al. , Early prediction of septic shock inCALIFORNIA   Los  Angeles   Prediction of Septic Shock in

Hu, Scott Bin-Ti

2013-01-01T23:59:59.000Z

328

acoustic shock waves: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

shock waves. We address the method in detail and present results of the modeling of the propagation of shock-associated extreme-ultraviolet (EUV) waves as well as Moreton waves...

329

Localized enhancements of energetic particles at oblique collisionless shocks  

E-Print Network [OSTI]

We investigate the spatial distribution of charged particles accelerated by non-relativistic oblique fast collisionless shocks using three-dimensional test-particle simulations. We find that the density of low-energy particles exhibit a localised enhancement at the shock, resembling the "spike" measured at interplanetary shocks. In contrast to previous results based on numerical solutions to the focused transport equation, we find a shock spike for any magnetic obliquity, from quasi-perpendicular to parallel. We compare the pitch-angle distribution with respect to the local magnetic field and the momentum distribution far downstream and very near the shock within the spike; our findings are compatible with predictions from the scatter-free shock drift acceleration (SDA) limit in these regions. The enhancement of low-energy particles measured by Voyager 1 at solar termination shock is comparable with our profiles. Our simulations allow for predictions of supra-thermal protons at interplanetary shocks within te...

Fraschetti, Federico

2015-01-01T23:59:59.000Z

330

Actinide Chemistry  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre the EffectsAcknowledgment StatementGuidance »| Y-12

331

SHOCK EMERGENCE IN SUPERNOVAE: LIMITING CASES AND ACCURATE APPROXIMATIONS  

SciTech Connect (OSTI)

We examine the dynamics of accelerating normal shocks in stratified planar atmospheres, providing accurate fitting formulae for the scaling index relating shock velocity to the initial density and for the post-shock acceleration factor as functions of the polytropic and adiabatic indices which parameterize the problem. In the limit of a uniform initial atmosphere, there are analytical formulae for these quantities. In the opposite limit of a very steep density gradient, the solutions match the outcome of shock acceleration in exponential atmospheres.

Ro, Stephen; Matzner, Christopher D. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON M5S 3H4 (Canada)

2013-08-10T23:59:59.000Z

332

Compressible Turbulence and Interactions with Shock Waves and...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in various disciplines, including supernova explosions, inertial confinement fusion, hypersonic flight and propulsion, and shock wave lithotripsy. Accomplishments: A novel...

333

Cyclic Mode of Transmutation of Minor Actinides in Heavy-Water Reactor  

SciTech Connect (OSTI)

Characteristics of process of transmutation of americium and curium from spent nuclear fuel in heavy-water reactor during first 10 lifetimes and at transition to equilibrium mode are calculated. During transmutation, dangerous nuclides, first of all, {sup 244}Cm and {sup 238}Pu are accumulated. They cause an increase of radiotoxicity. At first 10 cycles of a transmutation, the radiotoxicity is increased by 11 times in comparison with initial load of transmuted actinides. Heavy-water reactor with thermal power of 1000 MW can transmute americium and curium extracted from 7-8 VVER-1000 type reactors. It means that the required power of transmutation reactor makes about 4 % of thermal power of VVER-1000 type reactors. (authors)

Gerasimov, Aleksander S.; Kiselev, Gennady V.; Myrtsymova, Lidia A.; Zaritskaya, Tamara S. [Institute of Theoretical and Experimental Physics, SSC RF ITEP, Bolshaya Cheremushkinskaya, 25, 117218 Moscow (Russian Federation)

2002-07-01T23:59:59.000Z

334

High Pressure Phase Transformations in Heavy Rare Earth Metals and Connections to Actinide Crystal Structures  

SciTech Connect (OSTI)

High-pressure studies have been performed on heavy rare earth metals Terbium (Tb) to 155 GPa and Holmium (Ho) to 134 GPa in a diamond anvil cell at room temperature. The following crystal structure sequence was observed in both metals hcp {yields} Sm-type {yields} dhcp {yields} distorted fcc (hR-24) {yields} monoclinic (C2/m) with increasing pressure. The last transformation to a low symmetry monoclinic phase is accompanied by a volume collapse of 5 % for Tb at 51 GPa and a volume collapse of 3 % for Ho at 103 GPa. This volume collapse under high pressure is reminiscent of f-shell delocalization in light rare earth metal Cerium (Ce), Praseodymium (Pr), and heavy actinide metals Americium (Am) and Curium (Cm). The orthorhombic Pnma phase that has been reported in Am and Cm after f-shell delocalization is not observed in heavy rare earth metals under high pressures. (authors)

Vohra, Yogesh K.; Sangala, Bagvanth Reddy; Stemshorn, Andrew K. [Physics, University of Alabama at Birmingham (UAB), 310 Campbell Hall, 1300 University Boulevard, Birmingham, AL, 35294-1170 (United States); Hope, Kevin M. [Biology, Chemistry, and Mathematics, University of Montevallo, Harman Hall, Station 6480, Montevallo, AL, 35115 (United States)

2008-07-01T23:59:59.000Z

335

Pre-neutron emission mass distributions for low-energy neutron-induced actinide fission  

E-Print Network [OSTI]

According to the driving potential of a fissile system, we propose a phenomenological fission potential for a description of the pre-neutron emission mass distributions of neutron-induced actinide fission. Based on the nucleus-nucleus potential with the Skyrme energy-density functional, the driving potential of the fissile system is studied considering the deformations of nuclei. The energy dependence of the potential parameters is investigated based on the experimental data for the heights of the peak and valley of the mass distributions. The pre-neutron emission mass distributions for reactions 238U(n, f), 237Np(n, f), 235U(n, f), 232Th(n, f) and 239Pu(n, f) can be reasonably well reproduced. Some predictions for these reactions at unmeasured incident energies are also presented.

Xiaojun Sun; Chenggang Yu; Ning Wang

2012-01-15T23:59:59.000Z

336

Tunneling through equivalent multihumped fission barriers: Some implications for the actinide nuclei  

SciTech Connect (OSTI)

A comparison of the penetrabilities calculated in the Wentzel-Kramers-Brillouin approximation through equivalent multihumped fission barriers shows that the penetrability saturates to its maximum value much more slowly for a three-humped potential than that for comparable two-humped and single-humped potentials. An analysis of the slopes of the near-barrier photofission cross sections of actinides yields results that can be understood in terms of the predicted potential barrier shapes for these nuclei, and thus provides evidence in support of resolving the ''thorium anomaly'' along the lines suggested by Moeller and Nix. Our results further indicate that the uranium nuclei, and in particular /sup 236/U, may more likely exhibit three-humped potential shapes in which the apparent consequences of both the second and third minima may be observable.

Bhandari, B.S.; Al-Kharam, A.S.

1989-03-01T23:59:59.000Z

337

Method for digesting spent ion exchange resins and recovering actinides therefrom using microwave radiation  

DOE Patents [OSTI]

The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.

Maxwell, III, Sherrod L. (Aiken, SC); Nichols, Sheldon T. (Augusta, GA)

1999-01-01T23:59:59.000Z

338

Low-temperature synthesis of actinide tetraborides by solid-state metathesis reactions  

DOE Patents [OSTI]

The synthesis of actinide tetraborides including uranium tetraboride (UB.sub.4), plutonium tetraboride (PuB.sub.4) and thorium tetraboride (ThB.sub.4) by a solid-state metathesis reaction are demonstrated. The present method significantly lowers the temperature required to .ltoreq.850.degree. C. As an example, when UCl.sub.4 is reacted with an excess of MgB.sub.2, at 850.degree. C., crystalline UB.sub.4 is formed. Powder X-ray diffraction and ICP-AES data support the reduction of UCl.sub.3 as the initial step in the reaction. The UB.sub.4 product is purified by washing water and drying.

Lupinetti, Anthony J. (Los Alamos, NM); Garcia, Eduardo (Los Alamos, NM); Abney, Kent D. (Los Alamos, NM)

2004-12-14T23:59:59.000Z

339

Sub-barrier capture with quantum diffusion approach: actinide-based reactions  

E-Print Network [OSTI]

With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed nuclei at subbarrier energies. The calculated results are in a good agreement with existing experimental data. With decreasing bombarding energy under the barrier the external turning point of the nucleusnucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is expected at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum of captured system on the bombarding energy. From the comparison of calculated and experimental capture cross sections, the importance of quasifission near the entrance channel is shown for the actinide-based reactions leading to superheavy nuclei.

V. V. Sargsyan; G. G. Adamian; N. V. Antonenko; W. Scheid; H. Q. Zhang

2011-06-14T23:59:59.000Z

340

Yields of neutron-rich nuclei by actinide photofission in giant dipole resonance region  

E-Print Network [OSTI]

Photofission of actinides is studied in the region of nuclear excitation energies that covers the entire giant dipole resonance (GDR) region. A comparative analysis of the behavior of the symmetric and asymmetric modes of photon induced fission as a function of the average excitation energy of the fissioning nucleus is performed. The mass distributions of $^{238}$U photofission fragments are obtained at the endpoint bremsstrahlung energy of 29.1 MeV which corresponds to mean photon energy of 13.7$\\pm$0.3 MeV that coincides with GDR peak for $^{238}$U photofission. The integrated yield of $^{238}$U photofission as well as charge distribution of photofission products are calculated and its role in the production of neutron-rich nuclei and their exoticity is explored.

Debasis Bhowmick; Debasis Atta; D. N. Basu; Alok Chakrabarti

2015-01-19T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

FEASIBILITY OF RECYCLING PLUTONIUM AND MINOR ACTINIDES IN LIGHT WATER REACTORS USING HYDRIDE FUEL  

SciTech Connect (OSTI)

The objective of this DOE NERI program sponsored project was to assess the feasibility of improving the plutonium (Pu) and minor actinide (MA) recycling capabilities of pressurized water reactors (PWRs) by using hydride instead of oxide fuels. There are four general parts to this assessment: 1) Identifying promising hydride fuel assembly designs for recycling Pu and MAs in PWRs 2) Performing a comprehensive systems analysis that compares the fuel cycle characteristics of Pu and MA recycling in PWRs using the promising hydride fuel assembly designs identified in Part 1 versus using oxide fuel assembly designs 3) Conducting a safety analysis to assess the likelihood of licensing hydride fuel assembly designs 4) Assessing the compatibility of hydride fuel with cladding materials and water under typical PWR operating conditions Hydride fuel was found to offer promising transmutation characteristics and is recommended for further examination as a possible preferred option for recycling plutonium in PWRs.

Greenspan, Ehud; Todreas, Neil; Taiwo, Temitope

2009-03-10T23:59:59.000Z

342

Study on Equilibrium Characteristics of Thorium-Plutonium-Minor Actinides Mixed Oxides Fuel in PWR  

SciTech Connect (OSTI)

A study on characteristics of thorium-plutonium-minor actinides utilization in the pressurized water reactor (PWR) with the equilibrium burnup model has been conducted. For a comprehensive evaluation, several fuel cycles scenario have been included in the present study with the variation of moderator-to-fuel volume ratio (MFR) of PWR core design. The results obviously exhibit that the neutron spectra grow to be harder with decreasing of the MFR. Moreover, the neutron spectra also turn into harder with the rising number of confined heavy nuclides. The required {sup 233}U concentration for criticality of reactor augments with the increasing of MFR for all heavy nuclides confinement and thorium and uranium confinement in PWR.

Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z. [Bosscha Laboratory, Department of Physics, Nuclear Physics and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia); Sekimoto, H. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology (Japan)

2010-06-22T23:59:59.000Z

343

Dynamical approach to heavy-ion induced fusion using actinide target  

SciTech Connect (OSTI)

To treat heavy-ion reactions using actinide target nucleus, we propose a model which takes into account the coupling to the collective states of interacting nuclei in the penetration of the Coulomb barrier and the dynamical evolution of nuclear shape from the contact configuration. A fluctuation-dissipation model (Langevin equation) was applied in the dynamical calculation, where effect of nuclear orientation at the initial impact on the prolately deformed target nucleus was considered. Using this model, we analyzed the experimental data for the mass distribution of fission fragments (MDFF) in the reaction of {sup 36}S+{sup 238}U at several incident energies. Fusion-fission, quasifission and deep-quasi-fission are separated as different trajectories on the potential energy surface. We estimated the fusion cross section of the reaction.

Aritomo, Y.; Hagino, K.; Chiba, S.; Nishio, K. [Flerov Laboratory of Nuclear Reactions, JINR, Dubna, 141980 (Russian Federation); Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195 (Japan)

2012-10-20T23:59:59.000Z

344

Yields of neutron-rich nuclei by actinide photofission in giant dipole resonance region  

E-Print Network [OSTI]

Photofission of actinides is studied in the region of nuclear excitation energies that covers the entire giant dipole resonance (GDR) region. A comparative analysis of the behavior of the symmetric and asymmetric modes of photon induced fission as a function of the average excitation energy of the fissioning nucleus is performed. The mass distributions of $^{238}$U photofission fragments are obtained at the endpoint bremsstrahlung energy of 29.1 MeV which corresponds to mean photon energy of 13.7$\\pm$0.3 MeV that coincides with GDR peak for $^{238}$U photofission. The integrated yield of $^{238}$U photofission as well as charge distribution of photofission products are calculated and its role in the production of neutron-rich nuclei and their exoticity is explored.

Bhowmick, Debasis; Basu, D N; Chakrabarti, Alok

2015-01-01T23:59:59.000Z

345

Fabrication of advanced oxide fuels containing minor actinide for use in fast reactors  

SciTech Connect (OSTI)

R and D of advanced fuel containing minor actinide for use in fast reactors is described related to the composite fuel with MgO matrix. Fabrication tests of MgO composite fuels containing Am were done by a practical process that could be adapted to the presently used commercial manufacturing technology. Am-containing MgO composite fuels having good characteristics, i.e., having no defects, a high density, a homogeneous dispersion of host phase, were obtained. As related technology, burn-up characteristics of a fast reactor core loaded with the present MgO composite fuel were also analyzed, mainly in terms of core criticality. Furthermore, phase relations of MA oxide which was assumed to be contained in MgO matrix fuel were experimentally investigated. (authors)

Miwa, Shuhei; Osaka, Masahiko; Tanaka, Kosuke; Ishi, Yohei; Yoshimochi, Hiroshi; Tanaka, Kenya [Oarai Research and Development Center, Japan Atomic Energy Agency, 4002 Oarai-machi, Higashi-ibaraki-gun, Ibaraki, 311-1393 (Japan)

2007-07-01T23:59:59.000Z

346

TAILORING INORGANIC SORBENTS FOR SRS STRONTIUM AND ACTINIDE SEPARATIONS: OPTIMIZED MONOSODIUM TITANATE PHASE II FINAL REPORT  

SciTech Connect (OSTI)

This document provides a final report of Phase II testing activities for the development of a modified monosodium titanate (MST) that exhibits improved strontium and actinide removal characteristics compared to the baseline MST material. The activities included determining the key synthesis conditions for preparation of the modified MST, preparation of the modified MST at a larger scale by a commercial vendor, demonstration of the strontium and actinide removal characteristics with actual tank waste supernate and measurement of filtration characteristics. Key findings and conclusions include the following. Testing evaluated three synthetic methods and eleven process parameters for the optimum synthesis conditions for the preparation on an improved form of MST. We selected the post synthesis method (Method 3) for continued development based on overall sorbate removal performance. We successfully prepared three batches of the modified MST using Method 3 procedure at a 25-gram scale. The laboratory prepared modified MST exhibited increased sorption kinetics with simulated and actual waste solutions and similar filtration characteristics to the baseline MST. Characterization of the modified MST indicated that the post synthesis treatment did not significantly alter the particle size distribution, but did significantly increase the surface area and porosity compared to the original MST. Testing indicated that the modified MST exhibits reduced affinity for uranium compared to the baseline MST, reducing risk of fissile loading. Shelf-life testing indicated no change in strontium and actinide performance removal after storing the modified MST for 12-months at ambient laboratory temperature. The material releases oxygen during the synthesis and continues to offgas after the synthesis at a rapidly diminishing rate until below a measurable rate after 4 months. Optima Chemical Group LLC prepared a 15-kilogram batch of the modified MST using the post synthesis procedure (Method 3). Performance testing with simulated and actual waste solutions indicated that the material performs as well as or better than batches of modified MST prepared at the laboratory-scale. Particle size data of the vendor-prepared modified MST indicates a broader distribution centered at a larger particle size and microscopy shows more irregular particle morphology compared to the baseline MST and laboratory prepared modified MST. Stirred-cell (i.e., dead-end) filter testing revealed similar filtration rates relative to the baseline MST for both the laboratory and vendor-prepared modified MST materials. Crossflow filtration testing indicated that with MST-only slurries, the baseline MST produced between 30-100% higher flux than the vendor-prepared modified MST at lower solids loadings and comparable flux at higher solids loadings. With sludge-MST slurries, the modified MST produced 1.5-2.2 times higher flux than the baseline MST at all solids loadings. Based on these findings we conclude that the modified MST represents a much improved sorbent for the separation of strontium and actinides from alkaline waste solutions and recommend continued development of the material as a replacement for the baseline MST for waste treatment facilities at the Savannah River Site.

Hobbs, D; Thomas Peters, T; Michael Poirier, M; Mark Barnes, M; Major Thompson, M; Samuel Fink, S

2007-06-29T23:59:59.000Z

347

Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report  

SciTech Connect (OSTI)

The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNS databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is outlined as follows. Section 2 shows an assessment of numerical algorithms that are best suited for the numerical simulation of compressible flows involving turbulence and shock phenomena. Sections 3 and 4 deal with the canonical shock-turbulence interaction problem, from the DNS and LES perspectives, respectively. Section 5 considers the shock-turbulence inter-action in spherical geometry, in particular, the interaction of a converging shock with isotropic turbulence as well as the problem of the blast wave. Section 6 describes the study of shock-accelerated mixing through planar and spherical Richtmyer-Meshkov mixing as well as the shock-curtain interaction problem In section 7 we acknowledge the different interactions between Stanford and other institutions participating in this SciDAC project, as well as several external collaborations made possible through it. Section 8 presents a list of publications and presentations that have been generated during the course of this SciDAC project. Finally, section 9 concludes this report with the list of personnel at Stanford University funded by this SciDAC project.

Sanjiva Lele

2012-10-01T23:59:59.000Z

348

A FRONT TRACKING METHOD FOR TRANSITIONAL SHOCK WAVES  

E-Print Network [OSTI]

A FRONT TRACKING METHOD FOR TRANSITIONAL SHOCK WAVES HYUN­CHEOL HWANG Abstract. Non of transitional shock waves, which are dependent on the parabolic regularization of the conservation laws transitional shock waves correctly. The algorithm includes the computation of saddle­to­saddle connec­ tions

New York at Stoney Brook, State University of

349

Responses of African economies to the international economic shocks: an  

E-Print Network [OSTI]

rate shocks and five to World price of oil shocks. Furthermore, we investigate the viability of the African economies after an international income, monetary or price shocks tend to be in general more economies (Madeley, 2003). Contrary to the assumption of decoupling for the economic cycles, these countries

Paris-Sud XI, Université de

350

Introduction Organisms exhibit a heat shock response in which  

E-Print Network [OSTI]

Introduction Organisms exhibit a heat shock response in which increased expression of stress proteins (or heat shock proteins, HSPs) is coincident with the induction of thermotolerance (the ability tissue because heat shock (HS) can protect neurons against ischaemic damage1 and this protection may

Robertson, Meldrum

351

Shock wave propagation in composites and active Vinamra Agrawal  

E-Print Network [OSTI]

Shock wave propagation in composites and active Vinamra Agrawal California Institute of Technology travel through a material. These waves are characterized as a discontinuity propagating through shock waves propagate in heterogeneous materials. Shock waves are also being used to o pulsed currents

Shyamasundar, R.K.

352

Injection and acceleration of H at Earth's bow shock  

E-Print Network [OSTI]

Injection and acceleration of H and He2 at Earth's bow shock M. Scholer1 , H. Kucharek1 , K the injection and subsequent acceleration of part of the solar wind ions at the Earth's bow shock. The shocks particles does not contribute to ion injection. Acceleration models that permit thermal particles to scatter

Paris-Sud XI, Université de

353

Comparison of actinide production in traveling wave and pressurized water reactors  

SciTech Connect (OSTI)

The geopolitical problems associated with civilian nuclear energy production arise in part from the accumulation of transuranics in spent nuclear fuel. A traveling wave reactor is a type of breed-burn reactor that could, if feasible, reduce the overall production of transuranics. In one possible configuration, a cylinder of natural or depleted uranium would be subjected to a fast neutron flux at one end. The neutrons would transmute the uranium, producing plutonium and higher actinides. Under the right conditions, the reactor could become critical, at which point a self-stabilizing fission wave would form and propagate down the length of the reactor cylinder. The neutrons from the fission wave would burn the fissile nuclides and transmute uranium ahead of the wave to produce additional fuel. Fission waves in uranium are driven largely by the production and fission of {sup 239}Pu. Simulations have shown that the fuel burnup can reach values greater than 400 MWd/kgIHM, before fission products poison the reaction. In this work we compare the production of plutonium and minor actinides produced in a fission wave to that of a UOX fueled light water reactor, both on an energy normalized basis. The nuclide concentrations in the spent traveling wave reactor fuel are computed using a one-group diffusion model and are verified using Monte Carlo simulations. In the case of the pressurized water reactor, a multi-group collision probability model is used to generate the nuclide quantities. We find that the traveling wave reactor produces about 0.187 g/MWd/kgIHM of transuranics compared to 0.413 g/MWd/kgIHM for a pressurized water reactor running fuel enriched to 4.95 % and burned to 50 MWd/kgIHM. (authors)

Osborne, A.G.; Smith, T.A.; Deinert, M.R. [Department of Mechanical Engineering, University of Texas at Austin, Austin, TX (United States)

2013-07-01T23:59:59.000Z

354

Hardening Neutron Spectrum for Advanced Actinides Transmutation Experiments in the ATR  

SciTech Connect (OSTI)

The most effective method for transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products is in a fast neutron spectrum reactor. In the absence of a fast rest reactor in the United States, initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. Such a test facility, with a spectrum similar but somewhat softer than that of the liquid-metal fast breeder reactor (LMFBR), has been constructed in the INEEL's Advanced Test Reactor (ATR). The radial fission power distribution of the actinide fuel pin, which is an important parameter in fission gas released modelling, needs to be accurately predicted and the hardened neturon spectrum in the ATR and the LMFBR fast neutron spectrum is compared. The comparison analyses in this study are peformed using MCWO, a well-developed tool that couples the Monte Carlo transport code MCNP with the isotope depletion and build-up code ORIGEN-2. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations and detailed radial fission power profile calculations for a typical fast reactor (LMFBR) neutron spectrum and the hardened neturon spectrum test region in the ATR. The MCWO-calculated results indicate that the cadmium basket used in the advanced fuel test assembly in the ATR can effectively depress the linear heat generation rate in the experimental fuels and harden the neutron spectrum in the test region.

G. S. Chang; R. G. Ambrosek

2004-05-01T23:59:59.000Z

355

Plant Mounds as Concentration and Stabilization Agents for Actinide Soil Contaminants in Nevada  

SciTech Connect (OSTI)

Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around the base of shrubs and are common features in deserts in the southwestern United States. An important factor in their formation is that shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, 241Am, and U in plant mounds at safety experiment and storage-transportation test sites of nuclear devices. Although aerial concentrations of these contaminants were highest in the intershrub or desert pavement areas, the concentration in mounds were higher than in equal volumes of intershrub or desert pavement soil. The NAEG studies found the ratio of contaminant concentration of actinides in soil to be greater (1.6 to 2.0) in shrub mounds than in the surrounding areas of desert pavement. At Project 57 on the NTTR, 17 percent of the area was covered in mounds while at Clean Slate III on the TTR, 32 percent of the area was covered in mounds. If equivalent volumes of contaminated soil were compared between mounds and desert pavement areas at these sites, then the former might contain as much as 34 and 62 percent of the contaminant inventory, respectively. Not accounting for radionuclides associated with shrub mounds would cause the inventory of contaminants and potential exposure to be underestimated. In addition, preservation of shrub mounds could be important part of long-term stewardship if these sites are closed by fencing and posting with administrative controls.

D.S. Shafer; J. Gommes

2009-02-03T23:59:59.000Z

356

Three-dimensional shock-shock interactions on the scramjet inlet  

SciTech Connect (OSTI)

The effects of shock impingement on the inlet of a scramjet engine are investigated numerically. The impinging shock is caused by the vehicle forebody. The interaction of this forebody shock with the inlet leading edge shock results in a very complex fully three-dimensional flowfield containing local regions of high pressure and intense heating. In the present investigation, this complex flowfield is calculated by solving the thin-layer Navier-Stokes equations using a finite-volume flux splitting technique due to van Leer. For zero or small sweep angles a Type IV interaction occurs while for moderate sweep of about 25 deg, a Type V interaction occurs. Both Type IV and Type V interactions are investigated. 25 refs.

Singh, D.J.; Tiwari, S.N.; Kumar, A.

1990-01-01T23:59:59.000Z

357

Shock wave absorber having a deformable liner  

DOE Patents [OSTI]

This invention discloses a shock wave absorber for a piping system carrying liquid. The absorber has a plastically deformable liner defining the normal flow boundary for an axial segment of the piping system, and a nondeformable housing is spaced outwardly from the liner so as to define a gas-tight space therebetween. The flow capacity of the liner generally corresponds to the flow capacity of the piping system line, but the liner has a noncircular cross section and extends axially of the piping system line a distance between one and twenty times the diameter thereof. Gas pressurizes the gas-tight space equal to the normal liquid pressure in the piping system. The liner has sufficient structural capacity to withstand between one and one-half and two times this normal liquid pressures; but at greater pressures it begins to plastically deform initially with respect to shape to a more circular cross section, and then with respect to material extension by circumferentially stretching the wall of the liner. A high energy shock wave passing through the liner thus plastically deforms the liner radially into the gas space and progressively also as needed in the axial direction of the shock wave to minimize transmission of the shock wave beyond the absorber.

Youngdahl, C.K.; Wiedermann, A.H.; Shin, Y.W.; Kot, C.A.; Ockert, C.E.

1983-08-26T23:59:59.000Z

358

Gravimagnetic shock waves in the anisotropic plasma  

E-Print Network [OSTI]

The relativistic magnetohydrodynamic equations for the anisotropic magnetoactive plasma are obtained and accurately integrated in the plane gravitational wave metrics. The dependence of the induction mechanism of the gravimagnetic shock waves on the degree of the magnetoactive plasma anisotropy is analyzed.

Yu. G. Ignatyev; D. N. Gorokhov

2011-01-01T23:59:59.000Z

359

Interaction of an oblique shock wave with a pair of parallel vortices: Shock dynamics and mechanism of sound generation  

E-Print Network [OSTI]

and the mechanism of sound generation in the interaction between an oblique shock wave and a pair of vortices. We is related to the interaction of the reflected shock waves and sound waves. The first mechanism is dominating affected by the interaction of the reflected shock waves and sound waves. © 2006 American Institute

Zhang, Yong-Tao

360

Strong shock generation by fast electron energy deposition  

SciTech Connect (OSTI)

It has been suggested that fast electrons may play a beneficial role in the formation of the ignitor shock in shock ignition owing to the high areal density of the fuel at the time of the ignitor pulse. In this paper, we extend previous studies which have focused on monoenergetic electron sources to populations with extended energy distributions. In good agreement with analytic scalings, we show that strong shocks can be produced with peak pressures of a few hundred Mbar to over 1 Gbar using fast electron intensities of 1–10 PW/cm{sup 2} in a uniform deuterium-tritium plasma at 10 g/cm{sup 3}. However, the length required for shock formation increases with fast electron temperature. As this shock formation distance becomes comparable to the target size, the shock is not able to fully develop, and this implies a limit on the ability of fast electrons to aid shock formation.

Fox, T. E.; Pasley, J. [York Plasma Institute, University of York, York YO10 5DD (United Kingdom) [York Plasma Institute, University of York, York YO10 5DD (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Robinson, A. P. L. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)] [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)

2013-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Demonstration of a TODGA/TBP process for recovery of trivalent actinides and lanthanides from a PUREX raffinate  

SciTech Connect (OSTI)

The efficiency of the partitioning of trivalent actinides from a PUREX raffinate has been demonstrated with a TODGA + TBP extractant mixture dissolved in an industrial aliphatic solvent TPH. Based on the results coming from cold and hot batch extraction studies and with the aid of computer code calculations a continuous counter current process have been developed and two flowsheets were tested using miniature centrifugal contactors. The feed solutions was a synthetic PUREX raffinate, spiked with {sup 241}Am, {sup 244}Cm, {sup 252}Cf, {sup 152}Eu and {sup 134}Cs. More than 99.9 % of the trivalent actinides and lanthanides were extracted and back-extracted and very high decontamination factors to most fission products were obtained. Co-extraction of zirconium, molybdenum and palladium was prevented using oxalic acid and HEDTA. However 10% of ruthenium was extracted and only 3 % could be back extracted using diluted nitric acid. (authors)

Modolo, G.; Asp, H.; Vijgen, H. [Forschungszentrum Juelich GmbH, Institut fuer Energieforschung, 52425 Juelich (Germany); Malmbeck, R.; Magnusson, D. [European Commission, JRC, Institute for Transuranium Elements - ITU, 76125 Karlsruhe (Germany); Sorel, C. [Commissariat a l'Energie Atomique Valrho - CEA, DRCP/SCPS, BP17171, 30207 Bagnols-sur-Ceze (France)

2007-07-01T23:59:59.000Z

362

Extraction processes and solvents for recovery of cesium, strontium, rare earth elements, technetium and actinides from liquid radioactive waste  

DOE Patents [OSTI]

Cesium and strontium are extracted from aqueous acidic radioactive waste containing rare earth elements, technetium and actinides, by contacting the waste with a composition of a complex organoboron compound and polyethylene glycol in an organofluorine diluent mixture. In a preferred embodiment the complex organoboron compound is chlorinated cobalt dicarbollide, the polyethylene glycol has the formula RC.sub.6 H.sub.4 (OCH.sub.2 CH.sub.2).sub.n OH, and the organofluorine diluent is a mixture of bis-tetrafluoropropyl ether of diethylene glycol with at least one of bis-tetrafluoropropyl ether of ethylene glycol and bis-tetrafluoropropyl formal. The rare earths, technetium and the actinides (especially uranium, plutonium and americium), are extracted from the aqueous phase using a phosphine oxide in a hydrocarbon diluent, and reextracted from the resulting organic phase into an aqueous phase by using a suitable strip reagent.

Zaitsev, Boris N. (St. Petersburg, RU); Esimantovskiy, Vyacheslav M. (St. Petersburg, RU); Lazarev, Leonard N. (St. Petersburg, RU); Dzekun, Evgeniy G. (Ozersk, RU); Romanovskiy, Valeriy N. (St. Petersburg, RU); Todd, Terry A. (Aberdeen, ID); Brewer, Ken N. (Arco, ID); Herbst, Ronald S. (Idaho Falls, ID); Law, Jack D. (Pocatello, ID)

2001-01-01T23:59:59.000Z

363

Speciation and structural characterization of plutonium and actinide-organic complexes in surface and groundwaters. 1998 annual progress report  

SciTech Connect (OSTI)

'The authors proposed research is designed to study the association of actinides with dissolved organic complexes in subsurface waters. This study expands considerably on prior work due to the combination of Pu oxidation studies (for Pu speciation/chemical reactivity information), Pu isotope ratio work (for Pu source function information), and the detailed characterization of organic matter in size-fractionated groundwater samples. They have postulated that actinide associations with organic matter may be enhanced due to colloidal biopolymers. This report summarizes work completed after less than 2 years of a 3-year project. Activities thus far have included: (1) the development of sampling techniques to minimize contamination and artifact formation, (2) the separation of Pu isotopes by oxidation state in groundwater, (3) the development of techniques for the separation and identification of organic constituents from natural waters, (4) a study of background Pu and organic carbon concentrations at the proposed study sites, and (5) field work at the Savannah River site (SRS).'

Buesseler, K.O.; Repeta, D.J. [Woods Hole Oceanographic Inst., MA (US); Kelley, J.M. [Pacific Northwest National Lab., Richland, WA (US)

1998-06-01T23:59:59.000Z

364

@Why Physics Comprehensive Physics Major.  

E-Print Network [OSTI]

@Why Physics Comprehensive Physics Major. From the basic laws of physics to the resulting emergent behavior, physics studies what the universe is made of and how it works. As a Physics major that surrounds us, to the structure and evolution of the entire universe. We offer three degrees in Physics

Yoo, S. J. Ben

365

Actinide destruction and power peaking analysis in a 1000 MWt advanced burner reactor using moderated heterogeneous target assemblies  

SciTech Connect (OSTI)

The purpose of this research was to determine the effect of moderated heterogeneous subassemblies located in the core of a sodium-cooled fast reactor on minor actinide (MA) destruction rates over the lifecycle of the core. Additionally, particular emphasis was placed on the power peaking of the pins and the assemblies with the moderated targets as compared to standard unmoderated heterogeneous targets and a core without MA targets present. Power peaking analysis was performed on the target assemblies and on the fuel assemblies adjacent to the targets. The moderated subassemblies had a marked improvement in the overall destruction of heavy metals in the targets. The design with acceptable power peaking results had a 12.25% greater destruction of heavy metals than a similar ex-core unmoderated assembly. The increase in minor actinide destruction was most evident with americium where the moderated assemblies reduced the initial amount to less than 3% of the initial loading over a period of five years core residency. In order to take advantage of the high minor actinide destruction and minimize the power peaking effects, a hybrid scenario was devised where the targets resided ex-core in a moderated assembly for the first 506.9 effective full power days (EFPDs) and were moved to an in-core arrangement with the moderated targets removed for the remainder of the lifecycle. The hybrid model had an assembly and pin power peaking of less than 2.0 and a higher heavy metal and minor actinide destruction rate than the standard unmoderated heterogeneous targets either in-core or ex-core. The hybrid model has a 54.5% greater Am reduction over the standard ex-core model. It also had a 27.8% greater production of Cm and a 41.5% greater production of Pu than the standard ex-core model. The radiotoxicity of the targets in the hybrid design was 20% less than the discharged standard ex-core targets.

Kenneth Allen; Travis Knight; Samuel Bays

2011-05-01T23:59:59.000Z

366

Gas-phase energies of actinide oxides -- an assessment of neutral and cationic monoxides and dioxides from thorium to curium  

SciTech Connect (OSTI)

An assessment of the gas-phase energetics of neutral and singly and doubly charged cationic actinide monoxides and dioxides of thorium, protactinium, uranium, neptunium, plutonium, americium, and curium is presented. A consistent set of metal-oxygen bond dissociation enthalpies, ionization energies, and enthalpies of formation, including new or revised values, is proposed, mainly based on recent experimental data and on correlations with the electronic energetics of the atoms or cations and with condensed-phase thermochemistry.

Marcalo, Joaquim; Gibson, John K.

2009-08-10T23:59:59.000Z

367

A comparison of radioactive waste from first generation fusion reactors and fast fission reactors with actinide recycling  

SciTech Connect (OSTI)

Limitations of the fission fuel resources will presumably mandate the replacement of thermal fission reactors by fast fission reactors that operate on a self-sufficient closed fuel cycle. This replacement might take place within the next one hundred years, so the direct competitors of fusion reactors will be fission reactors of the latter rather than the former type. Also, fast fission reactors, in contrast to thermal fission reactors, have the potential for transmuting long-lived actinides into short-lived fission products. The associated reduction of the long-term activation of radioactive waste due to actinides makes the comparison of radioactive waste from fast fission reactors to that from fusion reactors more rewarding than the comparison of radioactive waste from thermal fission reactors to that from fusion reactors. Radioactive waste from an experimental and a commercial fast fission reactor and an experimental and a commercial fusion reactor has been characterized. The fast fission reactors chosen for this study were the Experimental Breeder Reactor 2 and the Integral Fast Reactor. The fusion reactors chosen for this study were the International Thermonuclear Experimental Reactor and a Reduced Activation Ferrite Helium Tokamak. The comparison of radioactive waste parameters shows that radioactive waste from the experimental fast fission reactor may be less hazardous than that from the experimental fusion reactor. Inclusion of the actinides would reverse this conclusion only in the long-term. Radioactive waste from the commercial fusion reactor may always be less hazardous than that from the commercial fast fission reactor, irrespective of the inclusion or exclusion of the actinides. The fusion waste would even be far less hazardous, if advanced structural materials, like silicon carbide or vanadium alloy, were employed.

Koch, M.; Kazimi, M.S.

1991-04-01T23:59:59.000Z

368

X-RAY EMISSION LINE PROFILES FROM WIND CLUMP BOW SHOCKS IN MASSIVE STARS  

SciTech Connect (OSTI)

The consequences of structured flows continue to be a pressing topic in relating spectral data to physical processes occurring in massive star winds. In a preceding paper, our group reported on hydrodynamic simulations of hypersonic flow past a rigid spherical clump to explore the structure of bow shocks that can form around wind clumps. Here we report on profiles of emission lines that arise from such bow shock morphologies. To compute emission line profiles, we adopt a two-component flow structure of wind and clumps using two 'beta' velocity laws. While individual bow shocks tend to generate double-horned emission line profiles, a group of bow shocks can lead to line profiles with a range of shapes with blueshifted peak emission that depends on the degree of X-ray photoabsorption by the interclump wind medium, the number of clump structures in the flow, and the radial distribution of the clumps. Using the two beta law prescription, the theoretical emission measure and temperature distribution throughout the wind can be derived. The emission measure tends to be power law, and the temperature distribution is broad in terms of wind velocity. Although restricted to the case of adiabatic cooling, our models highlight the influence of bow shock effects for hot plasma temperature and emission measure distributions in stellar winds and their impact on X-ray line profile shapes. Previous models have focused on geometrical considerations of the clumps and their distribution in the wind. Our results represent the first time that the temperature distribution of wind clump structures are explicitly and self-consistently accounted for in modeling X-ray line profile shapes for massive stars.

Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States); Waldron, W. L. [Eureka Scientific Inc., 2452 Delmer Street, Oakland, CA 94602 (United States); Cassinelli, J. P. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53711 (United States); Burke, A. E., E-mail: ignace@etsu.edu, E-mail: wwaldron@satx.rr.com, E-mail: cassinelli@astro.wisc.edu, E-mail: burke.alexander@gmail.com [990 Washington Street 317, Dedham, MA 02026 (United States)

2012-05-01T23:59:59.000Z

369

ON THE AMPLIFICATION OF MAGNETIC FIELD BY A SUPERNOVA BLAST SHOCK WAVE IN A TURBULENT MEDIUM  

SciTech Connect (OSTI)

We have performed extensive two-dimensional magnetohydrodynamic simulations to study the amplification of magnetic fields when a supernova blast wave propagates into a turbulent interstellar plasma. The blast wave is driven by injecting high pressure in the simulation domain. The interstellar magnetic field can be amplified by two different processes, occurring in different regions. One is facilitated by the fluid vorticity generated by the 'rippled' shock front interacting with the background turbulence. The resulting turbulent flow keeps amplifying the magnetic field, consistent with earlier work. The other process is facilitated by the growth of the Rayleigh-Taylor instability at the contact discontinuity between the ejecta and the shocked medium. This can efficiently amplify the magnetic field and tends to produce the highest magnetic field. We investigate the dependence of the amplification on numerical parameters such as grid-cell size and on various physical parameters. We show that the magnetic field has a characteristic radial profile such that the downstream magnetic field gets progressively stronger away from the shock. This is because the downstream magnetic field needs a finite time to reach the efficient amplification, and will get further amplified in the Rayleigh-Taylor region. In our simulation, we do not observe a systematic strong magnetic field within a small distance to the shock. This indicates that if the magnetic-field amplification in supernova remnants indeed occurs near the shock front, other processes such as three-dimensional instabilities, plasma kinetics, and/or cosmic ray effect may need to be considered to explain the strong magnetic field in supernova remnants.

Guo Fan; Li Shengtai; Li Hui; Li, David [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Giacalone, Joe; Jokipii, J. R. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States)

2012-03-10T23:59:59.000Z

370

MIX and Instability Growth from Oblique Shock  

SciTech Connect (OSTI)

We have studied the formation and evolution of shock-induced mix resulting from interface features in a divergent cylindrical geometry. In this research a cylindrical core of high-explosive was detonated to create an oblique shock wave and accelerate the interface. The interfaces studied were between the high-explosive/aluminum, aluminum/plastic, and finally plastic/air. Pre-emplaced surface features added to the aluminum were used to modify this interface. Time sequence radiographic imaging quantified the resulting instability formation from the growth phase to over 60 {micro}s post-detonation. Thus allowing the study of the onset of mix and evolution to turbulence. The plastic used here was porous polyethylene. Radiographic image data are compared with numerical simulations of the experiments.

Molitoris, J D; Batteux, J D; Garza, R G; Tringe, J W; Souers, P C; Forbes, J W

2011-07-22T23:59:59.000Z

371

Shock wave absorber having apertured plate  

DOE Patents [OSTI]

The shock or energy absorber disclosed herein utilizes an apertured plate maintained under the normal level of liquid flowing in a piping system and disposed between the normal liquid flow path and a cavity pressurized with a compressible gas. The degree of openness (or porosity) of the plate is between 0.01 and 0.60. The energy level of a shock wave travelling down the piping system thus is dissipated by some of the liquid being jetted through the apertured plate toward the cavity. The cavity is large compared to the quantity of liquid jetted through the apertured plate, so there is little change in its volume. The porosity of the apertured plate influences the percentage of energy absorbed.

Shin, Yong W. (Western Springs, IL); Wiedermann, Arne H. (Chicago Heights, IL); Ockert, Carl E. (Vienna, VA)

1985-01-01T23:59:59.000Z

372

Shock wave absorber having apertured plate  

DOE Patents [OSTI]

The shock or energy absorber disclosed herein utilizes an apertured plate maintained under the normal level of liquid flowing in a piping system and disposed between the normal liquid flow path and a cavity pressurized with a compressible gas. The degree of openness (or porosity) of the plate is between 0.01 and 0.60. The energy level of a shock wave travelling down the piping system thus is dissipated by some of the liquid being jetted through the apertured plate toward the cavity. The cavity is large compared to the quantity of liquid jetted through the apertured plate, so there is little change in its volume. The porosity of the apertured plate influences the percentage of energy absorbed.

Shin, Y.W.; Wiedermann, A.H.; Ockert, C.E.

1983-08-26T23:59:59.000Z

373

Shocks and Wind Bubbles Around Energetic Pulsars  

E-Print Network [OSTI]

The Crab Nebula demonstrates that neutron stars can interact with their environments in spectacular fashion, their relativistic winds generating nebulae observable across the electromagnetic spectrum. At many previous conferences, astronomers have discussed, debated and puzzled over the complicated structures seen in the Crab, but have been limited to treating most other pulsar wind nebulae (PWNe) as simple calorimeters for a pulsar's spin-down energy. However, with the wealth of high-quality data which have now become available, this situation has changed dramatically. I here review some of the main observational themes which have emerged from these new measurements. Highlights include the ubiquity of pulsar termination shocks, the unambiguous presence of relativistic jets in PWNe, complicated time variability seen in PWN structures, and the use of bow shocks to probe the interaction of pulsar winds with the ambient medium.

Bryan M. Gaensler

2004-05-14T23:59:59.000Z

374

Transportation Shock and Vibration Literature Review  

SciTech Connect (OSTI)

This report fulfills the M4 milestone M4FT-13OR08220112, "Report Documenting Experimental Activities." The purpose of this report is to document the results of a literature review conducted of studies related to the vibration and shock associated with the normal conditions of transport for rail shipments of used nuclear fuel from commercial light-water reactors. As discussed in Adkins (2013), the objective of this report is to determine if adequate data exist that would enable the impacts of the shock and vibration associated with the normal conditions of transport on commercial light-water reactor used nuclear fuel shipped in current generation rail transportation casks to be realistically modeled.

Maheras, Steven J.; Lahti, Erik A.; Ross, Steven B.

2013-06-06T23:59:59.000Z

375

Shock phenomena in baryonless strongly interacting matter  

SciTech Connect (OSTI)

Shock phenomena associated with the quark-to-hadron matter phase transition are studied using the concept of adiabats. To allow for an analysis of a medium with vanishing baryon density, the shock and Poisson adiabats are formulated in terms of hydrodynamic fluxes, rather than only thermodynamic variables. The bag-model equation of state is used to describe the phase transition. It is shown that deflagrations from the quark phase above the critical temperature and strong detonations from the supercooled quark phase to the superheated hadron phase are unlikely. Instead the possibility of weak condensation detonations from the supercooled quark phase to a mixed phase is indicated. Strong detonations can occur if the latent energy density of the phase transition is small compared to the energy density of the hadron gas. Simple properties of the adiabats and of the equation of state are employed to derive several analytic results.

Danielewicz, P.; Ruuskanen, P.V.

1987-01-01T23:59:59.000Z

376

Introduction to Plasma Dynamo, Reconnection and Shocks  

SciTech Connect (OSTI)

In our plasma universe, most of what we can observe is composed of ionized gas, or plasma. This plasma is a conducting fluid, which advects magnetic fields when it flows. Magnetic structure occurs from the smallest planetary to the largest cosmic scales. We introduce at a basic level some interesting features of non linear magnetohydrodynamics (MHD). For example, in our plasma universe, dynamo creates magnetic fields from gravitationally driven flow energy in an electrically conducting medium, and conversely magnetic reconnection annihilates magnetic field and accelerates particles. Shocks occur when flows move faster than the local velocity (sonic or Alfven speed) for the propagation of information. Both reconnection and shocks can accelerate particles, perhaps to gigantic energies, for example as observed with 10{sup 20} eV cosmic rays.

Intrator, Thomas P. [Los Alamos National Laboratory

2012-08-30T23:59:59.000Z

377

Test of the adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers in actinides  

SciTech Connect (OSTI)

The adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers has been tested by examining its simultaneous consistency with the three relevant fission observables, namely, the near-barrier fission cross sections, isomeric half-lives, and the ground-state spontaneous fission half-lives of a wide variety of a total of 25 actinide nuclides. The penetrabilities through such multihumped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The results of our systematic analysis of these actinide nuclides suggest that such a parametrization is quite adequate at least for the even-even nuclei, as it reproduces satisfactorily their various observed fission characteristics. Major difficulties remain, however, for the odd mass and for the doubly odd nuclei where the calculated ground-state spontaneous fission half-lives are found to be several orders of magnitude larger than those measured. Possible reasons for such discrepancies are discussed. Fission branching ratios of the decay of the shape isomers in various actinide nuclides have also been calculated and are compared with their measured values.

Bhandari, B.S. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi (Libya))

1990-10-01T23:59:59.000Z

378

Review Article: The Effects of Radiation Chemistry on Solvent Extraction 3: A Review of Actinide and Lanthanide Extraction  

SciTech Connect (OSTI)

The partitioning of the long-lived ?-emitters and the high-yield fission products from dissolved nuclear fuel is a key component of processes envisioned for the safe recycling of nuclear fuel and the disposition of high-level waste. These future processes will likely be based on aqueous solvent extraction technologies for light water reactor fuel and consist of four main components for the sequential separation of uranium, fission products, group trivalent actinides and lanthanides, and then trivalent actinides from lanthanides. Since the solvent systems will be in contact with highly radioactive solutions, they must be robust toward radiolytic degradation in an irradiated mixed organic, aqueous acidic environment. Therefore, an understanding of their radiation chemistry is important to the design of a practical system. In the first paper in this series we reviewed the radiation chemistry of irradiated aqueous nitric acid and the tributyl phosphate ligand for uranium extraction in the first step of these extractions. In the second, we reviewed the radiation chemistry of the ligands proposed for use in the extraction of cesium and strontium fission products. Here, we review the radiation chemistry of the ligands that might be used in the third step in the series of separations, for the group extraction of the lanthanides and actinides. This includes traditional organophosphorous reagents such as CMPO and HDEHP, as well as novel reagents such as the amides and diamides currently being investigated.

Bruce J. Mincher; Giuseppe Modolo; Stephen P. Mezyk

2009-12-01T23:59:59.000Z

379

Measurements of actinide-fission product yields in Caliban and Prospero metallic core reactor fission neutron fields  

SciTech Connect (OSTI)

In the 1970's and early 1980's, an experimental program was performed on the facilities of the CEA Valduc Research Center to measure several actinide-fission product yields. Experiments were, in particular, completed on the Caliban and Prospero metallic core reactors to study fission-neutron-induced reactions on {sup 233}U, {sup 235}U, and {sup 239}Pu. Thick actinide samples were irradiated and the number of nuclei of each fission product was determined by gamma spectrometry. Fission chambers were irradiated simultaneously to measure the numbers of fissions in thin deposits of the same actinides. The masses of the thick samples and the thin deposits were determined by mass spectrometry and alpha spectrometry. The results of these experiments will be fully presented in this paper for the first time. A description of the Caliban and Prospero reactors, their characteristics and performances, and explanations about the experimental approach will also be given in the article. A recent work has been completed to analyze and reinterpret these measurements and particularly to evaluate the associated uncertainties. In this context, calculations have also been carried out with the Monte Carlo transport code Tripoli-4, using the published benchmarked Caliban description and a three-dimensional model of Prospero, to determine the average neutron energy causing fission. Simulation results will be discussed in this paper. Finally, new fission yield measurements will be proposed on Caliban and Prospero reactors to strengthen the results of the first experiments. (authors)

Casoli, P.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille (France); Laurec, J.; Bauge, E.; Granier, T. [CEA, Centre DIF, 91297 Arpajon (France)

2011-07-01T23:59:59.000Z

380

Smoothed Particle Magnetohydrodynamics (some shocking results...)  

E-Print Network [OSTI]

There have been some issues in the past in attempts to simulate magnetic fields using the Smoothed Particle Hydrodynamics (SPH) method. SPH is well suited to star formation problems because of its Lagrangian nature. We present new, stable and conservative methods for magnetohydrodynamics (MHD) in SPH and present numerical tests on both waves and shocks in one dimension to show that it gives robust and accurate results.

D. J. Price; J. J. Monaghan

2003-10-06T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
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381

GRB060218: A Relativistic Supernova Shock Breakout  

E-Print Network [OSTI]

We show that the prompt and afterglow X-ray emission of GRB060218, as well as its early (tsun envelope of the star, which was heated to high temperature during shock passage. The observed X-ray afterglow and the early optical-UV emission are both consistent with those expected in this model. Detailed analysis of the early optical-UV emission may provide detailed constraints on the density distribution near the stellar surface.

E. Waxman; P. Meszaros; S. Campana

2007-02-16T23:59:59.000Z

382

Collisionless Shocks and TeV Neutrinos before Supernova Shock Breakout from an Optically Thick Wind  

E-Print Network [OSTI]

During a supernova explosion, a radiation-dominated shock (RDS) travels through its progenitor. A collisionless shock (CS) is usually assumed to replace it during shock breakout (SB). We demonstrate here that for some realistic progenitors enshrouded in optically thick winds, such as possibly SN 2008D, a CS forms deep inside the wind, soon after the RDS leaves the core, and therefore significantly before SB. The RDS does not survive the transition from the core to the thick wind when the wind close to the core is not sufficiently dense to compensate for the $r^{-2}$ dilution of photons due to shock curvature. This typically happens when the shock velocity is $\\lesssim 0.1 {\\rm c} \\, (\\frac{u_{\\rm w}}{10\\,{\\rm km/s}}) (\\frac{\\dot{M}}{5 \\cdot 10^{-4} \\, {\\rm M}_\\odot {\\rm /yr}})^{-1} (\\frac{r_\\ast}{10^{13}\\,{\\rm cm}})$, where $u_{\\rm w}$, $\\dot{M}$ and $r_\\ast$ are respectively the wind velocity, mass-loss rate and radius of the progenitor star. The radiative CS results in a hard spectrum of the photon flash at...

Giacinti, G

2015-01-01T23:59:59.000Z

383

The structure of hypersonic shock waves using Navier-Stokes equations modified to include mass diffusion  

E-Print Network [OSTI]

Howard Brenner has recently proposed modifications to the Navier-Stokes equations that relate to a diffusion of fluid volume that would be significant for flows with high density gradients. In a previous paper (Greenshields & Reese, 2007), we found these modifications gave good predictions of the viscous structure of shock waves in argon in the range Mach 1.0-12.0 (while conventional Navier-Stokes equations are known to fail above about Mach 2). However, some areas of concern with this model were a somewhat arbitrary choice of modelling coefficient, and potentially unphysical and unstable solutions. In this paper, we therefore present slightly different modifications to include molecule mass diffusion fully in the Navier-Stokes equations. These modifications are shown to be stable and produce physical solutions to the shock problem of a quality broadly similar to those from the family of extended hydrodynamic models that includes the Burnett equations. The modifications primarily add a diffusion term to t...

Greenshields, Christopher J

2007-01-01T23:59:59.000Z

384

DEVELOPMENT AND APPLICATION OF A FAST-RUNNING TOOL TO CHARACTERIZE SHOCK DAMAGE WITHIN TUNNEL STRUCTURES  

SciTech Connect (OSTI)

Successful but time-intensive use of high-fidelity computational capabilities for shock loading events and resultant effects on and within enclosed structures, e.g., tunnels, has led to an interest in developing more expedient methods of analysis. While several tools are currently available for the general study of the failure of structures under dynamic shock loads at a distance, presented are a pair of statistics- and physics-based tools that can be used to differentiate different types of damage (e.g., breach versus yield) as well as quantify the amount of damage within tunnels for loads close-in and with standoff. Use of such faster running tools allows for scoping and planning of more detailed model and test analysis and provides a way to address parametric sensitivity over a large multivariate space.

Glascoe, L; Morris, J; Glenn, L; Krnjajic, M

2009-03-31T23:59:59.000Z

385

MEASUREMENT OF THE SHOCK-HEATED MELT CURVE OF LEAD USING PYROMETRY AND REFLECTOMETRY  

SciTech Connect (OSTI)

Data on the high-pressure melting temperatures of metals is of great interest in several fields of physics including geophysics. Measuring melt curves is difficult but can be performed in static experiments (with laser-heated diamond-anvil cells for instance) or dynamically (i.e., using shock experiments). However, at the present time, both experimental and theoretical results for the melt curve of lead are at too much variance to be considered definitive. As a result, we decided to perform a series of shock experiments designed to provide a measurement of the melt curve of lead up to about 50 GPa in pressure. At the same time, we developed and fielded a new reflectivity diagnostic, using it to make measurements on tin. The results show that the melt curve of lead is somewhat higher than the one previously obtained with static compression and heating techniques.

D. Partouche-Sebban and J. L. Pelissier, Commissariat a` l'Energie Atomique,; F. G. Abeyta, Los Alamos National Laboratory; W. W. Anderson, Los Alamos National Laboratory; M. E. Byers, Los Alamos National Laboratory; D. Dennis-Koller, Los Alamos National Laboratory; J. S. Esparza, Los Alamos National Laboratory; S. D. Borror, Bechtel Nevada; C. A. Kruschwitz, Bechtel Nevada

2004-01-01T23:59:59.000Z

386

Investigation of ALEGRA shock hydrocode algorithms using an exact free surface jet flow solution.  

SciTech Connect (OSTI)

Computational testing of the arbitrary Lagrangian-Eulerian shock physics code, ALEGRA, is presented using an exact solution that is very similar to a shaped charge jet flow. The solution is a steady, isentropic, subsonic free surface flow with significant compression and release and is provided as a steady state initial condition. There should be no shocks and no entropy production throughout the problem. The purpose of this test problem is to present a detailed and challenging computation in order to provide evidence for algorithmic strengths and weaknesses in ALEGRA which should be examined further. The results of this work are intended to be used to guide future algorithmic improvements in the spirit of test-driven development processes.

Hanks, Bradley Wright.; Robinson, Allen Conrad

2014-01-01T23:59:59.000Z

387

Heating Cooling Flows with Weak Shock Waves  

E-Print Network [OSTI]

The discovery of extended, approximately spherical weak shock waves in the hot intercluster gas in Perseus and Virgo has precipitated the notion that these waves may be the primary heating process that explains why so little gas cools to low temperatures. This type of heating has received additional support from recent gasdynamical models. We show here that outward propagating, dissipating waves deposit most of their energy near the center of the cluster atmosphere. Consequently, if the gas is heated by (intermittent) weak shocks for several Gyrs, the gas within 30-50 kpc is heated to temperatures that far exceed observed values. This heating can be avoided if dissipating shocks are sufficiently infrequent or weak so as not to be the primary source of global heating. Local PV and viscous heating associated with newly formed X-ray cavities are likely to be small, which is consistent with the low gas temperatures generally observed near the centers of groups and clusters where the cavities are located.

W. G. Mathews; A. Faltenbacher; F. Brighenti

2005-11-05T23:59:59.000Z

388

Direct Simulation of Shock Layer Plasmas  

SciTech Connect (OSTI)

Approximate models of the electric field used with the DSMC method all impose quasi-neutrality everywhere in the shock layer plasma. The shortcomings of these models are examined in this study by simulating a weak shock layer plasma with a coupled DSMC-Particle-In-Cell (PIC) method. The stagnation streamline of an axisymmetric shock layer is simulated for entry velocities in air that correspond to both lunar and Mars return trajectories. The atmospheric densities, particle diameters and chemical reaction rates are varied from the actual values to make the computations tractable while retaining the mean free path of air at 85 km altitude. In contrast to DSMC flow field predictions, regions of non-neutrality are predicted by the DSMC-PIC method, and the electrons are predicted to be isothermal. Perhaps the most important result of this study is that the DSMC-PIC results at both reentry energies yield a 14% increase in heat flux to the vehicle surface relative to the DSMC results. Rather unintuitively, this is mostly due to an increase in ion flux to the surface, rather than the potential energy gained by each ion as it traverses the plasma sheath. In this study, an approximate electric field model is presented, with the goal of accounting for this heat flux augmentation without the need for a computationally expensive DSMC-PIC calculation of the entire flow-field. Convective heat flux results obtained with new electric field model are compared to results from the rigorous DSMC-PIC calculations.

Farbar, E. D.; Boyd, I. D. [Dept. of Aerospace Engineering, University of Michigan, 1320 Beal Ave., Ann Arbor MI, 48109 (United States)

2011-05-20T23:59:59.000Z

389

Reactor Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Reactor Physics Reactor and nuclear physics is a key area of research at INL. Much of the research done in reactor physics can be separated into one of three categories:...

390

GRB Phenomenology, Shock Dynamo, and the First Magnetic Fields  

E-Print Network [OSTI]

A relativistic collisionless shock propagating into an unmagnetized medium leaves behind a strong large-scale magnetic field. This seems to follow from two assumptions: (i) GRB afterglows are explained by synchrotron emission of a relativistic shock, (ii) magnetic field can't exist on microscopic scales only, it would decay by phase space mixing. Assumption (i) is generally accepted because of an apparent success of the shock synchrotron phenomenological model of GRB afterglow. Assumption (ii) is confirmed in this work by a low-dimensional numerical simulation. One may hypothesize that relativistic shock velocities are not essential for the magnetic field generation, and that all collisionless shocks propagating into an unmagnetized medium generate strong large-scale magnetic fields. If this hypothesis is true, the first cosmical magnetic fields could have been generated in shocks of the first virialized objects.

Andrei Gruzinov

2001-07-05T23:59:59.000Z

391

Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production  

SciTech Connect (OSTI)

The use of supercritical temperature and pressure light water as the coolant in a direct-cycle nuclear reactor offers potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to 46%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type recirculation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If a tight fuel rod lattice is adopted, it is possible to significantly reduce the neutron moderation and attain fast neutron energy spectrum conditions. In this project a supercritical water reactor concept with a simple, blanket-free, pancake-shaped core will be developed. This type of core can make use of either fertile or fertile-free fuel and retain the hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity.

Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

2002-01-01T23:59:59.000Z

392

REVIEW OF EXPERIMENTAL STUDIES INVESTIGATING THE RATE OF STRONTIUM AND ACTINIDE ADSORPTION BY MONOSODIUM TITANATE  

SciTech Connect (OSTI)

A number of laboratory studies have been conducted to determine the influence of mixing and mixing intensity, solution ionic strength, initial sorbate concentrations, temperature, and monosodium titanate (MST) concentration on the rates of sorbate removal by MST in high-level nuclear waste solutions. Of these parameters, initial sorbate concentrations, ionic strength, and MST concentration have the greater impact on sorbate removal rates. The lack of a significant influence of mixing and mixing intensity on sorbate removal rates indicates that bulk solution transport is not the rate controlling step in the removal of strontium and actinides over the range of conditions and laboratory-scales investigated. However, bulk solution transport may be a significant parameter upon use of MST in a 1.3 million-gallon waste tank such as that planned for the Small Column Ion Exchange (SCIX) program. Thus, Savannah River National Laboratory (SRNL) recommends completing the experiments in progress to determine if mixing intensity influences sorption rates under conditions appropriate for this program. Adsorption models have been developed from these experimental studies that allow prediction of strontium (Sr), plutonium (Pu), neptunium (Np) and uranium (U) concentrations as a function of contact time with MST. Fairly good agreement has been observed between the predicted and measured sorbate concentrations in the laboratory-scale experiments.

Hobbs, D.

2010-10-01T23:59:59.000Z

393

REVIEW OF ACTINIDE AND STRONTIUM LOADING DATA FOR MST AND MMST  

SciTech Connect (OSTI)

SRNL reviewed the relevant data from MST and mMST fissile loading studies to determine if further studies were required. With respect to MST, SRNL found that the published results adequately bound the expected conditions that Small Column Ion Exchange (SCIX) process will operate under. The lack of strontium data does not represent an issue as strontium is not relevant to criticality. There is no threat to criticality safety from the lack of strontium loading data. However, SRNL proposes a single test with MST to ensure that future SCIX operations are conservatively bounded and strontium maximum loading is understood. With respect to attempts to maximally load mMST, SRNL's knowledge on actinide and strontium loading is limited to uranium behavior. mMST has a very weak affinity for uranium, and even extended contact time at high uranium concentration shows minimal loading onto mMST. This leaves questions about the ability to load plutonium, neptunium and strontium. SRNL proposes to perform two tests with mMST to ensure that questions on plutonium, neptunium, and strontium sorption are answered, as well as ensuring that future mMST operations are conservatively bounded.

Peters, T.; Hobbs, D.; Fink, S.

2010-10-20T23:59:59.000Z

394

Approach for Validating Actinide and Fission Product Compositions for Burnup Credit Criticality Safety Analyses  

SciTech Connect (OSTI)

This paper describes a depletion code validation approach for criticality safety analysis using burnup credit for actinide and fission product nuclides in spent nuclear fuel (SNF) compositions. The technical basis for determining the uncertainties in the calculated nuclide concentrations is comparison of calculations to available measurements obtained from destructive radiochemical assay of SNF samples. Probability distributions developed for the uncertainties in the calculated nuclide concentrations were applied to the SNF compositions of a criticality safety analysis model by the use of a Monte Carlo uncertainty sampling method to determine bias and bias uncertainty in effective neutron multiplication factor. Application of the Monte Carlo uncertainty sampling approach is demonstrated for representative criticality safety analysis models of pressurized water reactor spent fuel pool storage racks and transportation packages using burnup-dependent nuclide concentrations calculated with SCALE 6.1 and the ENDF/B-VII nuclear data. The validation approach and results support a recent revision of the U.S. Nuclear Regulatory Commission Interim Staff Guidance 8.

Radulescu, Georgeta [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Wagner, John C [ORNL

2014-01-01T23:59:59.000Z

395

Strategic Design and Optimization of Inorganic Sorbents for Cesium, Strontium and Actinides  

SciTech Connect (OSTI)

It has been determined that poorly crystalline CST and SNT prepared at low temperature (100-150 C) exhibit much faster kinetics in uptake of Sr2+. In-situ X-ray studies has shown that SNT is a precursor phase to the formation of CST. It is possible to form mixtures of CST and SNT in a single reactant mix by control of temperature and time of reaction. It has been found that addition of a small amount of Cs+ to the reactant mix for the preparation of Nb-CST allows formation of the crystals in one day rather than ten days at 200 C. These discoveries suggest that a proper mix of sorbents (SNT, CST, Nb-CST) can be made easily at low cost that would remove all the HLW at the Savannah River site with a single in-tank procedure. The basic science goal in this project is to identify structure/affinity relationships for selected radionuclides and existing sorbents. The research will then apply this knowledge to the design and synthesis of sorbents that will exhibit increased cesium, strontium and actinide removal. The target problem focuses on the treatment of high-level nuclear wastes. The general approach can likewise be applied to non-radioactive separations.

Clearfield, Abraham

2005-07-01T23:59:59.000Z

396

Strategic Design and Optimization of Inorganic Sorbents for Cesium, Strontium and Actinides  

SciTech Connect (OSTI)

It has been determined that poorly crystalline CST and SNT prepared at low temperature (100-150 deg. C) exhibit much faster kinetics in uptake of Sr2+. 2. In-situ X-ray studies has shown that SNT is a precursor phase to the formation of CST. 3. It is possible to form mixtures of CST and SNT in a single reactant mix by control of temperature and time of reaction. 4. It has been found that addition of a small amount of Cs+ to the reactant mix for the preparation of Nb-CST allows formation of the crystals in one day rather than ten days at 200 deg. C. 5. These discoveries suggest that a proper mix of sorbents (SNT, CST, Nb-CST) can be made easily at low cost that would remove all the HLW at the Savannah River site with a single in-tank procedure. Research Objective The basic science goal in this project is to identify structure/affinity relationships for selected radionuclides and existing sorbents. The research will then apply this knowledge to the design and synthesis of sorbents that will exhibit increased cesium, strontium and actinide removal. The target problem focuses on the treatment of high-level nuclear wastes. The general approach can likewise be applied to non-radioactive separations.

Clearfield, Abraham

2005-07-01T23:59:59.000Z

397

Microbial Transformation of TRU and Mixed Waste: Actinide Speciation and Waste Volume  

SciTech Connect (OSTI)

In order to understand the susceptibility of transuranic and mixed waste to microbial degradation (as well as any mechanism which depends upon either complexation and/or redox of metal ions), it is essential to understand the association of metal ions with organic ligands present in mixed wastes. These ligands have been found in our previous EMSP study to limit electron transfer reactions and strongly affect transport and the eventual fate of radionuclides in the environment. As transuranic waste (and especially mixed waste) will be retained in burial sites and in legacy containment for (potentially) many years while awaiting treatment and removal (or remaining in place under stewardship agreements at government subsurface waste sites), it is also essential to understand the aging of mixed wastes and its implications for remediation and fate of radionuclides. Mixed waste containing actinides and organic materials are especially complex and require extensive study. The EMSP program described in this report is part of a joint program with the Environmental Sciences Department at Brookhaven National Laboratory. The Stony Brook University portion of this award has focused on the association of uranium (U(VI)) and transuranic analogs (Ce(III) and Eu(III)) with cellulosic materials and related compounds, with development of implications for microbial transformation of mixed wastes. The elucidation of the chemical nature of mixed waste is essential for the formulation of remediation and encapsulation technologies, for understanding the fate of contaminant exposed to the environment, and for development of meaningful models for contaminant storage and recovery.

Halada, Gary P

2008-04-10T23:59:59.000Z

398

Solubility testing of actinides on breathing-zone and area air samples  

SciTech Connect (OSTI)

A solubility testing method for several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{reg_sign}) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of U{sub 3}O{sub 8}. Profiles developed for U{sub 3}O{sub 8} samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills.

Metzger, R.L.; Jessop, B.H.; McDowell, B.L. [Radiation Safety Engineering, Inc., Chandler, AZ (United States)

1996-02-01T23:59:59.000Z

399

Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation  

SciTech Connect (OSTI)

The ingenious combination of lactate and diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention has been devoted to the understanding of the basic thermodynamic features of the complex fluids responsible for the separation. The available thermochemical information of both lactate and DTPA protonation and metal complexation reactions are representative of the behavior of these ions under idealized conditions. Our previous studies of medium effects on lactate protonation suggest that significant departures from the speciation predicted based on reported thermodynamic values should be expected in the TALSPEAK aqueous environment. Thermodynamic parameters describing the separation chemistry of this process thus require further examination at conditions significantly removed from conventional ideal systems commonly employed in fundamental solution chemistry. Such thermodynamic characterization is the key to predictive modelling of TALSPEAK. Improved understanding will, in principle, allow process technologists to more efficiently respond to off-normal conditions during large scale process operation. In this report, the results of calorimetric and potentiometric investigations of the effects of aqueous electrolytes on the thermodynamic parameters for lactate protonation and lactate complexation of americium and neodymium will be presented. Studies on the lactate protonation equilibrium will clearly illustrate distinct thermodynamic variations between strong electrolyte aqueous systems and buffered lactate environment.

Peter R Zalupski; Leigh R Martin; Ken Nash; Yoshinobu Nakamura; Masahiko Yamamoto

2009-07-01T23:59:59.000Z

400

Improving the actinides recycling in closed fuel cycles, a major step towards nuclear energy sustainability  

SciTech Connect (OSTI)

Increasing the sustainability of nuclear energy is a longstanding road that requires a stepwise approach to successively tackle the following 3 objectives. First of all, optimize the consumption of natural resource to preserve them for future generations and hence guarantee the energetic independence of the countries (no uranium ore is needed anymore). The current twice-through cycle of Pu implemented by France, UK, Japan and soon China is a first step in this direction and already allows the development and optimization of the relevant industrial processes. It also allows a major improvement regarding the conditioning of the ultimate waste in a durable and robust nuclear glass. Secondly, the recycling of americium could be an interesting option for the future with the deployment of FR fleet to save the repository resource and optimize its use by allowing a denser disposal. It would limit the burden towards the future generations and the need for additional repositories before several centuries. Thirdly, the recycling of the whole minor actinides inventory could be an interesting option for the far-future for strongly decreasing the waste long-term toxicity, down to a few centuries. It would bring the waste issue back within the human history, which should promote its acceptance by the social opinion.

Poinssot, C.; Grandjean, S.; Masson, M. [RadioChemistry and Processes Department, CEA Marcoule, 30207 Bagnols sur Ceze (France); Bouillis, B.; Warin, D. [Innovation and Industrial Support Direction, CEA Saclay, F-91191 Gif-sur-Yvette (France)

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

DEPARTMENT OF PHYSICS Physics 32300  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 32300 Quantum Mechanics for Engineers Designation: required for Physics majors in the Applied Physics Option Undergraduate Catalog description: Basic experiments, wave: Physics 20700 and 20800, Math 39100 and Math 39200 Textbook and other suggested material: Scherrer

Lombardi, John R.

402

DEPARTMENT OF PHYSICS Physics 42200  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 42200 Biophysics Designation: Undergraduate Catalog and membranes. In depth study of the physical basis of selected systems including vision, nerve transmission. Prerequisites: Prereq.: 1 yr. of Math, 1 yr. of Physics (elective for Physics Majors and Biomedical Engineering

Lombardi, John R.

403

Shock compression of liquid helium to 56 GPa (560 kbar)  

SciTech Connect (OSTI)

The first shock-compression experiments on liquid helium are reported. With a two-stage light-gas gun, liquid He at 4.3 K and 1 atm was shocked to 16 GPa and 12 000 K and double shocked to 56 GPa and 21 000 K. Liquid perturbation theory has been used to determine an effective interatomic potential from which the equation of state of He can be obtained over a wide range of densities and temperatures.

Nellis, W.J.; Holmes, N.C.; Mitchell, A.C.; Trainor, R.J.; Governo, G.K.; Ross, M.; Young, D.A.

1984-09-24T23:59:59.000Z

404

Self-similar spherical shock solution with sustained energy injection  

E-Print Network [OSTI]

We present the generalization of the Sedov-Taylor self-similar strong spherical shock solution for the case of a central energy source varying in time, $E=A t^k$, where $A$ and $k$ are constants. The known Sedov-Taylor solution corresponds to a particular adiabatic case of $k=0$ or \\emph{instant shock} with an instant energy source of the shock, $E=A$. The self-similar hydrodynamic flow in the nonadiabatic $k\

V. I. Dokuchaev

2002-09-20T23:59:59.000Z

405

Optical Response of Shocked Cerium-Doped Lutetium Oxyorthosilicate  

SciTech Connect (OSTI)

Shock experiments were performed in order to characterize the triboluminescent signature of cerium-doped lutetium oxyorthosilicate (LSO:Ce). This material shows prompt, nano-second timescale light emission when driven by explosive detonation. When properly applied to a surface, it may be used as a shock arrival sensor, and also for imaging the propagation of a shock front. Triboluminescent rise times, spectral content, and spatial resolution measurements are presented.

G. D. Stevens

2003-03-01T23:59:59.000Z

406

acute cardiogenic shock: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

they jam, these fragile and disordered solids exhibit a vanishing rigidity and sound speed, so that even tiny mechanical perturbations form supersonic shocks. Here, we perform...

407

CRUDE OIL PRICE SHOCKS AND GROSS DOMESTIC PRODUCT.  

E-Print Network [OSTI]

??This study uses ordinary least squares estimation to test multivariate models in order to find out whether or not crude oil price shocks are contractionary… (more)

Hernandez, Jordan

2012-01-01T23:59:59.000Z

408

Remarks on the formation and decay of multidimensional shock waves  

E-Print Network [OSTI]

In this paper, we present a formula describing the formation and decay of shock wave type solutions in some special cases.

V. G. Danilov

2005-12-27T23:59:59.000Z

409

Reversal of Hugoniot locus for strong shocks due to radiation  

SciTech Connect (OSTI)

Shock Hugoniot can be used to express the response of a material to shocks, and the compression ratio of the shock can be determined by the Hugoiot locus. When the shock is strong, it will become radiating, and the radiation will affect the Hugoniot. The role of radiation on the Hugoniot condition is studied in the paper. For the radiative flux-dominated shocks, the radiative flux if large enough may render the structure of the shock Hugoniot locus totally different with the case for the pure hydrodynamic shock: the two branches with one in quadrant I and the other in quadrant III are reversed into two in quadrants IV and II, respectively, correspondingly the compression ratio may be larger than the limiting value ({gamma}+1)/({gamma}-1) for ideal gases with index {gamma}. For the radiative shock in which the radiative heat wave propagates supersonically, a threshold value for the net radiative flux to the preshock is also defined which determines whether the Hugoniot locus is reversed and the compression ratio exceeds the limiting value. Numerical results also verify the reversal of the Hugoniot locus of the shocks if the net radiative flux to the preshock exceeds the threshold value.

Li Jiwei; Li Jinghong; Meng Guangwei [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

2011-04-15T23:59:59.000Z

410

Internal energy relaxation in shock wave structure  

SciTech Connect (OSTI)

The Wang Chang-Uhlenbeck (WCU) equation is numerically integrated to characterize the internal structure of Mach 3 and Mach 5 shock waves in a gas with excitation in the internal energy states for the treatment of inelastic collisions. Elastic collisions are modeled with the hard sphere collision model and the transition rates for the inelastic collisions modified appropriately using probabilities based on relative velocities of the colliding particles. The collision integral is evaluated by the conservative discrete ordinate method [F. Tcheremissine, “Solution of the Boltzmann kinetic equation for high-speed flows,” Comput. Math. Math. Phys. 46, 315–329 (2006); F. Cheremisin, “Solution of the Wang Chang-Uhlenbeck equation,” Dokl. Phys. 47, 487–490 (2002)] developed for the Boltzmann equation. For the treatment of the diatomic molecules, the internal energy modes in the Boltzmann equation are described quantum mechanically given by the WCU equation. As a first step in the treatment of the inelastic collisions by the WCU equation, a two- and three-quantum system is considered to study the effect of the varying of (1) the inelastic cross section and (2) the energy gap between the quantum energy states. An alternative method, the direct simulation Monte Carlo method, is used for the Mach 3 shock wave to ensure the consistency of implementation in the two methods and there is an excellent agreement between the two methods. The results from the WCU implementation showed consistent trends for the Mach 3 and Mach5 standing shock waves simulations. Inelastic contributions change the downstream equilibrium state and allow the flow to transition to the equilibrium state further upstream.

Josyula, Eswar, E-mail: Eswar.Josyula@us.af.mil; Suchyta, Casimir J. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)] [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Boyd, Iain D. [University of Michigan, Ann Arbor, Michigan 48109 (United States)] [University of Michigan, Ann Arbor, Michigan 48109 (United States); Vedula, Prakash [University of Oklahoma, Norman, Oklahoma 73019 (United States)] [University of Oklahoma, Norman, Oklahoma 73019 (United States)

2013-12-15T23:59:59.000Z

411

Sharp shock model for propagating detonation waves  

SciTech Connect (OSTI)

Recent analyses of the reactive Euler equations have led to an understanding of the effect of curvature on an underdriven detonation wave. This advance can be incorporated into an improved sharp shock model for propagating detonation waves in hydrodynamic calculations. We illustrate the model with two simple examples: time dependent propagation of a diverging detonation wave in 1-D, and the steady 2-D propagation of a detonation wave in a rate stick. Incorporating this model into a 2-D front tracking code is discussed. 20 refs., 3 figs.

Bukiet, B.; Menikoff, R.

1989-01-01T23:59:59.000Z

412

Demagnetized Electron Heating at Collisionless Shocks  

E-Print Network [OSTI]

Seventy measurements of electron heating at the Earth's quasi-perpendicular bow shock are analyzed in terms of Maxwellian-temperatures obtained from fits to the core electrons that separate thermal heating from supra-thermal acceleration. The perpendicular temperatures are both greater and lesser than expected for adiabatic compression. The average parallel and perpendicular heating is the same. These results are explained because, over the electron gyroradius, $\\delta B/B\\sim 1$ and $e\\delta \\phi/T_e\\sim 1$, so electron trajectories are more random and chaotic than adiabatic. Because density fluctuations are also large, trapping and wave growth in density holes may be important.

Sundkvist, David

2013-01-01T23:59:59.000Z

413

DIFFUSIVE ACCELERATION OF PARTICLES AT OBLIQUE, RELATIVISTIC, MAGNETOHYDRODYNAMIC SHOCKS  

SciTech Connect (OSTI)

Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma-ray bursts. These sources remain good candidate sites for the generation of ultrahigh energy cosmic rays. In this paper, key predictions of DSA at relativistic shocks that are germane to the production of relativistic electrons and ions are outlined. The technique employed to identify these characteristics is a Monte Carlo simulation of such diffusive acceleration in test-particle, relativistic, oblique, magnetohydrodynamic (MHD) shocks. Using a compact prescription for diffusion of charges in MHD turbulence, this approach generates particle angular and momentum distributions at any position upstream or downstream of the shock. Simulation output is presented for both small angle and large angle scattering scenarios, and a variety of shock obliquities including superluminal regimes when the de Hoffmann-Teller frame does not exist. The distribution function power-law indices compare favorably with results from other techniques. They are found to depend sensitively on the mean magnetic field orientation in the shock, and the nature of MHD turbulence that propagates along fields in shock environs. An interesting regime of flat-spectrum generation is addressed; we provide evidence for it being due to shock drift acceleration, a phenomenon well known in heliospheric shock studies. The impact of these theoretical results on blazar science is outlined. Specifically, Fermi Large Area Telescope gamma-ray observations of these relativistic jet sources are providing significant constraints on important environmental quantities for relativistic shocks, namely, the field obliquity, the frequency of scattering, and the level of field turbulence.

Summerlin, Errol J. [Heliospheric Physics Laboratory, Code 672, NASA's Goddard Space Flight Center, Greenbelt, MD 20770 (United States); Baring, Matthew G., E-mail: errol.summerlin@nasa.gov, E-mail: baring@rice.edu [Department of Physics and Astronomy, MS 108, Rice University, Houston, TX 77251 (United States)

2012-01-20T23:59:59.000Z

414

Time-Dependent MHD Shocks and Line Emission: The Case of the DG Tau Jet  

E-Print Network [OSTI]

The line emission from a growing number of Herbig-Haro jets can be observed and resolved at angular distances smaller than a few arcseconds from the central source. The interpretation of this emission is problematic, since the simplest model of a cooling jet cannot sustain it. It has been suggested that what one actually observes are shocked regions with a filling factor of $\\sim 1%$. In this framework, up to now, comparisons with observations have been based on stationary shock models. Here we introduce for the first time the self-consistent dynamics of such shocks and we show that considering their properties at different times, i.e. locations, we can reproduce observational data of the DG Tau microjet. In particular, we can interpret the spatial behavior of the [SII]6716/6731 and [NII]/[OI]6583/6300 line intensity ratios adopting a set of physical parameters that yield values of mass loss rates and magnetic fields consistent with previous estimates. We also obtain the values of the mean ionization fraction...

Massaglia, S; Bodo, G

2005-01-01T23:59:59.000Z

415

The formation of reverse shocks in magnetized high energy density supersonic plasma flows  

SciTech Connect (OSTI)

A new experimental platform was developed, based on the use of supersonic plasma flow from the ablation stage of an inverse wire array z-pinch, for studies of shocks in magnetized high energy density physics plasmas in a well-defined and diagnosable 1-D interaction geometry. The mechanism of flow generation ensures that the plasma flow (Re{sub M}???50, M{sub S}???5, M{sub A}???8, V{sub flow}???100?km/s) has a frozen-in magnetic field at a level sufficient to affect shocks formed by its interaction with obstacles. It is found that in addition to the expected accumulation of stagnated plasma in a thin layer at the surface of a planar obstacle, the presence of the magnetic field leads to the formation of an additional detached density jump in the upstream plasma, at a distance of ?c/?{sub pi} from the obstacle. Analysis of the data obtained with Thomson scattering, interferometry, and local magnetic probes suggests that the sub-shock develops due to the pile-up of the magnetic flux advected by the plasma flow.

Lebedev, S. V., E-mail: s.lebedev@imperial.ac.uk, E-mail: l.suttle10@imperial.ac.uk; Suttle, L.; Swadling, G. F.; Bennett, M.; Bland, S. N.; Burdiak, G. C.; Chittenden, J. P.; Grouchy, P. de; Hall, G. N.; Hare, J. D.; Kalmoni, N.; Niasse, N.; Patankar, S.; Smith, R. A.; Suzuki-Vidal, F. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)] [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Burgess, D.; Clemens, A. [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)] [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); Ciardi, A. [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France)] [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France); Sheng, L. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Yuan, J. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); and others

2014-05-15T23:59:59.000Z

416

International shock-wave database project : report of the requirements workshop.  

SciTech Connect (OSTI)

We report on the requirements workshop for a new project, the International Shock-Wave database (ISWdb), which was held October 31 - November 2, 2011, at GSI, Darmstadt, Germany. Participants considered the idea of this database, its structure, technical requirements, content, and principles of operation. This report presents the consensus conclusions from the workshop, key discussion points, and the goals and plan for near-term and intermediate-term development of the ISWdb. The main points of consensus from the workshop were: (1) This international database is of interest and of practical use for the shock-wave and high pressure physics communities; (2) Intermediate state information and off-Hugoniot information is important and should be included in ISWdb; (3) Other relevant high pressure and auxiliary data should be included to the database, in the future; (4) Information on the ISWdb needs to be communicated, broadly, to the research community; and (5) Operating structure will consist of an Advisory Board, subject-matter expert Moderators to vet submitted data, and the database Project Team. This brief report is intended to inform the shock-wave research community and interested funding agencies about the project, as its success, ultimately, depends on both of these groups finding sufficient value in the database to use it, contribute to it, and support it.

Aidun, John Bahram (Institute of Problems of chemical Physics of Russian Academy of Sciences); Lomonosov, Igor V. (Institute of Problems of chemical Physics of Russian Academy of Sciences); Levashov, Pavel R. (Joint Institute for High Temperatures of Russian Academy of Sciences)

2012-03-01T23:59:59.000Z

417

Simulations of the symbiotic recurrent nova V407 Cyg. I. Accretion and shock evolutions  

E-Print Network [OSTI]

The shock interaction and evolution of nova ejecta with a wind from a red giant star in a symbiotic binary system are investigated via three-dimensional hydrodynamics simulations. We specifically model the March 2010 outburst of the symbiotic recurrent nova V407~Cygni from the quiescent phase to its eruption phase. The circumstellar density enhancement due to wind-white dwarf interaction is studied in detail. It is found that the density-enhancement efficiency depends on the ratio of the orbital speed to the red giant wind speed. Unlike another recurrent nova, RS~Ophiuchi, we do not observe a strong disk-like density enhancement, but instead observe an aspherical density distribution with $\\sim 20\\%$ higher density in the equatorial plane than at the poles. To model the 2010 outburst, we consider several physical parameters, including the red giant mass loss rate, nova eruption energy, and ejecta mass. A detailed study of the shock interaction and evolution reveals that the interaction of shocks with the red ...

Pan, Kuo-Chuan; Taam, Ronald E

2015-01-01T23:59:59.000Z

418

APEX observations of non-stationary magneto-hydrodynamical shocks in W44  

E-Print Network [OSTI]

Supernova remnants (SNRs) are considered as being the sources of galactic cosmic rays. In order to understand the origin, acceleration, and composition of these cosmic rays, detailed knowledge of the physical conditions in the local interstellar medium is needed. The shock interaction of SNRs with molecular clouds that gives rise to strong molecular emission in the far-IR and sub-mm wavelength regimes can be used as a highly valuable tracer of these conditions. The application of MHD shock models in the interpretation of the resulting line emission can yield information on the energetic and chemical impact of supernova remnants. We have mapped two regions in the supernova remnant W44 with the APEX telescope in ${}^{12}$CO (3-2), (4-3), (6-5), (7-6) and ${}^{13}$CO (3-2). The extraction of integrated intensities on five different positions, corresponding to local maxima of CO emission, allows to compare these intensities to the outputs of a grid of models, which combine an MHD shock code with a radiative trans...

Anderl, Sibylle; Güsten, Rolf

2015-01-01T23:59:59.000Z

419

Testing hyperalgesia and hypoalgesia in human pain reactivity using shock and radiant heat  

E-Print Network [OSTI]

the elects of an unpredictable shock and the threat of an unpredictable shock on pain thresholds using a radiant heat test (putative spinal mediation). Experiment 2 examined the effects of the same unpredictable shock and its threat on pain thresholds...

Rhudy, Jamie Lynn

1998-01-01T23:59:59.000Z

420

Role of the opioid system in the behavioral deficit observed after uncontrollable shock  

E-Print Network [OSTI]

to minimize shock exposure by maintaining a hindlimb in a flexed position. Preexposure to uncontrollable shock (shock independent of leg position) disrupts this learning. Activation of opioid receptors seems to contribute to the expression of the behavioral...

Washburn, Stephanie Nicole

2006-08-16T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Characterization of an Aerosol Shock Tube Facility for Heterogeneous Combustion Studies  

E-Print Network [OSTI]

tube prior to running the experiment. An incident shock wave vaporizes the liquid fuel droplets, then the reflected shock wave initiates ignition of the mixture. This study presents the characterization of an aerosol fuel injection method to the shock...

Sandberg, Lori Marie

2013-04-05T23:59:59.000Z

422

Adaptive mesh refinement for shocks and material interfaces  

SciTech Connect (OSTI)

There are three kinds of adaptive mesh refinement (AMR) in structured meshes. Block-based AMR sometimes over refines meshes. Cell-based AMR treats cells cell by cell and thus loses the advantage of the nature of structured meshes. Patch-based AMR is intended to combine advantages of block- and cell-based AMR, i.e., the nature of structured meshes and sharp regions of refinement. But, patch-based AMR has its own difficulties. For example, patch-based AMR typically cannot preserve symmetries of physics problems. In this paper, we will present an approach for a patch-based AMR for hydrodynamics simulations. The approach consists of clustering, symmetry preserving, mesh continuity, flux correction, communications, management of patches, and load balance. The special features of this patch-based AMR include symmetry preserving, efficiency of refinement across shock fronts and material interfaces, special implementation of flux correction, and patch management in parallel computing environments. To demonstrate the capability of the AMR framework, we will show both two- and three-dimensional hydrodynamics simulations with many levels of refinement.

Dai, William Wenlong [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

423

Fabrication and Pre-irradiation Characterization of a Minor Actinide and Rare Earth Containing Fast Reactor Fuel Experiment for Irradiation in the Advanced Test Reactor  

SciTech Connect (OSTI)

The United States Department of Energy, seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter lived fission products, thereby decreasing the volume of material requiring disposal and reducing the long-term radiotoxicity and heat load of high-level waste sent to a geologic repository. This transmutation of the long lived actinides plutonium, neptunium, americium and curium can be accomplished by first separating them from spent Light Water Reactor fuel using a pyro-metalurgical process, then reprocessing them into new fuel with fresh uranium additions, and then transmuted to short lived nuclides in a liquid metal cooled fast reactor. An important component of the technology is developing actinide-bearing fuel forms containing plutonium, neptunium, americium and curium isotopes that meet the stringent requirements of reactor fuels and materials.

Timothy A. Hyde

2012-06-01T23:59:59.000Z

424

Shock fragmentation model for gravitational collapse This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network [OSTI]

¨oteborg University, Gothenburg 41296, Sweden 3 Department of Physics, Seattle University, Seattle, WA 98122, USA can be produced by gravitational collapse. Key words: gravitation -- instabilities -- shock waves by a power-law (Salpeter 1955), an observation which a fully-developed theory should explain. In this paper

Wilkinson, Michael

425

Analysis on fuel breeding capability of FBR core region based on minor actinide recycling doping  

SciTech Connect (OSTI)

Nuclear fuel breeding based on the capability of fuel conversion capability can be achieved by conversion ratio of some fertile materials into fissile materials during nuclear reaction processes such as main fissile materials of U-233, U-235, Pu-239 and Pu-241 and for fertile materials of Th-232, U-238, and Pu-240 as well as Pu-238. Minor actinide (MA) loading option which consists of neptunium, americium and curium will gives some additional contribution from converted MA into plutonium such as conversion Np-237 into Pu-238 and it's produced Pu-238 converts to Pu-239 via neutron capture. Increasing composition of Pu-238 can be used to produce fissile material of Pu-239 as additional contribution. Trans-uranium (TRU) fuel (Mixed fuel loading of MOX (U-Pu) and MA composition) and mixed oxide (MOX) fuel compositions are analyzed for comparative analysis in order to show the effect of MA to the plutonium productions in core in term of reactor criticality condition and fuel breeding capability. In the present study, neptunium (Np) nuclide is used as a representative of MAin trans-uranium (TRU) fuel composition as Np-MOX fuel type. It was loaded into the core region gives significant contribution to reduce the excess reactivity in comparing to mixed oxide (MOX) fuel and in the same time it contributes to increase nuclear fuel breeding capability of the reactor. Neptunium fuel loading scheme in FBR core region gives significant production of Pu-238 as fertile material to absorp neutrons for reducing excess reactivity and additional contribution for fuel breeding.

Permana, Sidik; Novitrian,; Waris, Abdul [Nuclear Physics and Biophysics Research Division, Physics Department, Institut Teknologi Bandung (Indonesia); Ismail [Center for Technical Assessment of Nuclear Installation and Materials, Indonesian Nuclear Energy Regulatory (Indonesia); Suzuki, Mitsutoshi [Department of Science and Technology for Nuclear Material Management (STNM), Japan Atomic Energy Agency (JAEA) (Japan); Saito, Masaki [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology (Japan)

2014-09-30T23:59:59.000Z

426

Microbially-Promoted Solubilization of Steel Corrosion Products and Fate of Associated Actinides  

SciTech Connect (OSTI)

Microorganisms have the capacity to modify iron oxides during anaerobic respiration. When the dissimilatory sulfate-reducing bacterium Desulfovibrio desulfuricans G20 respires soluble sulfate during colonization of the solid-phase iron oxide hematite, the sulfide product reacts with the iron to produce the insoluble iron sulfide, pyrrhotite. When soluble uranium is present as uranyl ion, these microorganisms reduce the U(VI) to U(IV) as insoluble uraninite on the hematite surface. There is also evidence that a stable form of U is produced under these conditions that displays an oxidation state between U(VI) and U(iv). The dissimilatory iron reducing bacterium, Shewanella oneidensis MR1 can utilize insoluble hematite as the sole electron acceptor for anaerobic respiration during growth and biofilm development on the mineral. The growth rate, maximum cell density and detachment rate for this bacterium are significantly greater on hematite than on magnetite (111) and (100). The difference could not be attributed to iron site density in the iron oxide. A gene (ferA) encoding a c-tyoe cytochrome involved in dissimulatory iron reduction in the bacterium Geobacter sulfurreducens was completed sequenced and characterized. The sequence information was used to develop an in-situ reverse transcriptase polymerase chain reaction assay that could detect expression of the gene during growth and biofilm development on ferrihydrite at the single cell and microcolony level. X-ray photoelectron spectroscopic analysis revealed that the ferrihydrite was reduced during expression of this gene. The assay was extended to detect expression of genes involved in sulfate reduction and hydrogen reduction in sulfate-reducing bacteria. This assay will be useful to assess mechanisms of biotransformation of minerals including corrosion products on buried metal containers containing radionuclide waste. In summary, the research has shown that dissimilatory sulfate and iron reducing bacteria can modify the iron oxide surfaces that they colonize and promote the reduction and precipitation of actinides such as uranium at these sites

Gill Geesey; Timothy Magnuson; Andrew Neal

2002-06-15T23:59:59.000Z

427

DEPARTMENT OF PHYSICS Physics 35400  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 35400 Electricity and Magnetism II Designation potentials and radiation, special relativity. 3 HR./WK.; 3 CR. Prerequisites: Prereq.: Physics 35300; pre- or coreq.: Math 39200 (required for Physics majors, except those in the Biomedical Option). Textbook

Lombardi, John R.

428

Oblique and conical shock similarity laws for non-equilibrium flows  

E-Print Network [OSTI]

. IV. VI. INTRODUCTION REVIEN OF PREVIOUS WORK. OBl I'VE SHOCK VIBRATIONAL SIMILITUDE CHEilllCAL iNOZ -EQUILI BRIIVl EXTENSIOiN TO CONICAL FLON. RE1IARKS AND CONCLUSIONS. REFERENCES APPENDIX Page 12 22 31 37 39 LIST OF FIGUWHS Figure... Normal Shock Vibrational Similarity Param ter Normal Shock Dissociation Similarity Parameter Page 10 Oblique Shock Vibrational Similarity Law 19 Oblique Shock Dissociation Similarity Parameter Conical Shock Dissociation Similarity Parameter...

Holster, Jesse Louis

1968-01-01T23:59:59.000Z

429

Electronic Structure of Transition Metal Clusters, Actinide Complexes and Their Reactivities  

SciTech Connect (OSTI)

This is a continuing DOE-BES funded project on transition metal and actinide containing species, aimed at the electronic structure and spectroscopy of transition metal and actinide containing species. While a long term connection of these species is to catalysis and environmental management of high-level nuclear wastes, the immediate relevance is directly to other DOE-BES funded experimental projects at DOE-National labs and universities. There are a number of ongoing gas-phase spectroscopic studies of these species at various places, and our computational work has been inspired by these experimental studies and we have also inspired other experimental and theoretical studies. Thus our studies have varied from spectroscopy of diatomic transition metal carbides to large complexes containing transition metals, and actinide complexes that are critical to the environment. In addition, we are continuing to make code enhancements and modernization of ALCHEMY II set of codes and its interface with relativistic configuration interaction (RCI). At present these codes can carry out multi-reference computations that included up to 60 million configurations and multiple states from each such CI expansion. ALCHEMY II codes have been modernized and converted to a variety of platforms such as Windows XP, and Linux. We have revamped the symbolic CI code to automate the MRSDCI technique so that the references are automatically chosen with a given cutoff from the CASSCF and thus we are doing accurate MRSDCI computations with 10,000 or larger reference space of configurations. The RCI code can also handle a large number of reference configurations, which include up to 10,000 reference configurations. Another major progress is in routinely including larger basis sets up to 5g functions in thee computations. Of course higher angular momenta functions can also be handled using Gaussian and other codes with other methods such as DFT, MP2, CCSD(T), etc. We have also calibrated our RECP methods with all-electron Douglas-Kroll relativistic methods. We have the capabilities for computing full CI extrapolations including spin-orbit effects and several one-electron properties and electron density maps including spin-orbit effects. We are continuously collaborating with several experimental groups around the country and at National Labs to carry out computational studies on the DOE-BES funded projects. The past work in the last 3 years was primarily motivated and driven by the concurrent or recent experimental studies on these systems. We were thus significantly benefited by coordinating our computational efforts with experimental studies. The interaction between theory and experiment has resulted in some unique and exciting opportunities. For example, for the very first time ever, the upper spin-orbit component of a heavy trimer such as Au{sub 3} was experimentally observed as a result of our accurate computational study on the upper electronic states of gold trimer. Likewise for the first time AuH{sub 2} could be observed and interpreted clearly due to our computed potential energy surfaces that revealed the existence of a large barrier to convert the isolated AuH{sub 2} back to Au and H{sub 2}. We have also worked on yet to be observed systems and have made predictions for future experiments. We have computed the spectroscopic and thermodynamic properties of transition metal carbides transition metal clusters and compared our electronic states to the anion photodetachment spectra of Lai Sheng Wang. Prof Mike Morse and coworkers(funded also by DOE-BES) and Prof Stimle and coworkers(also funded by DOE-BES) are working on the spectroscopic properties of transition metal carbides and nitrides. Our predictions on the excited states of transition metal clusters such as Hf{sub 3}, Nb{sub 2}{sup +} etc., have been confirmed experimentally by Prof. Lombardi and coworkers using resonance Raman spectroscopy. We have also been studying larger complexes critical to the environmental management of high-level nuclear wastes. In collaboration with experimental co

Krishnan Balasubramanian

2009-07-18T23:59:59.000Z

430

Water purification by shock electrodialysis: Deionization, filtration, separation, and disinfection  

E-Print Network [OSTI]

purification is performed primarily by reverse osmosis (RO) plants and in some cases by electrodialysis (EDWater purification by shock electrodialysis: Deionization, filtration, separation, and disinfection H L I G H T S · Experiments demonstrate the multi- functionality of shock electrodialysis. · Besides

Bazant, Martin Z.

431

Micromechanics applied to the thermal shock behavior of refractory ceramics  

E-Print Network [OSTI]

Micromechanics applied to the thermal shock behavior of refractory ceramics N. Schmitt a,*, A. Burr-phase ceramics subjected to thermal shock. A macroscopic fracture criterion is proposed that accounts for local, F-59 381 Dunkerque, France Received 3 May 2002 Abstract Oxides­carbon refractories are ceramics

432

Ion Heating in Collisionless Shocks in Supernovae and the Heliosphere  

E-Print Network [OSTI]

Collisionless shocks play a role in many astrophysical phenomena, from coronal mass ejections (CMEs) in the heliosphere to supernova remnants. Their role in heating and accelerating particles is well accepted yet the exact mechanism for ion heating is not well understood. Two systems, CMEs and supernova remnants, were examined to determine the heating of heavy ions as they pass through collisionless shocks thus providing a seed population for cosmic ray acceleration processes. Three parameters are examined, the plasma beta, the Mach number of the shock and the magnetic angle of the shock. CMEs heat heavy ions preferentially. This is in contrast to the supernova data which shows less than mass proportional heating. In addition to these studies, heating in astrophysical systems involves neutral atoms. A Monte Carlo model simulated neutral particles as they pass through the shock. Neutrals can create a precursor to the shock additionally heating the plasma. This work uses in situ data from the heliosphere to study astronomical systems because of common shock properties is a unique way to study magnetic components of shocks remotely.

K. E. Korreck

2005-06-14T23:59:59.000Z

433

Introduction to Macroeconomic Dynamics Special Issue on Oil Price Shocks  

E-Print Network [OSTI]

Introduction to Macroeconomic Dynamics Special Issue on Oil Price Shocks Apostolos Serletisy in macroeconometrics and ...nancial econometrics to investigate the e¤ects of oil price shocks and uncertainty about the price of oil on the level of economic activity. JEL classi...cation: G31, E32, C32. Keywords: Oil price

Garousi, Vahid

434

POST-SHOCK TEMPERATURE MEASUREMENTS OF ALUMINUM A. Seifter1  

E-Print Network [OSTI]

POST-SHOCK TEMPERATURE MEASUREMENTS OF ALUMINUM A. Seifter1 , S. T. Stewart2 , M. R. Furlanetto1 concurrent VISAR measurements in the same optical path, validation experiments on aluminum have been-shock temperature of 495 K ± 30 K was recorded from a polished free surface of aluminum 2024-T4 subject to a peak

Stewart, Sarah T.

435

Economic Analysis of "Steam-Shock" and "Pasteurization"  

E-Print Network [OSTI]

Economic Analysis of "Steam-Shock" and "Pasteurization" Processes for Oyster Shucking JOHN W. BROWN Introduction "Steam-shock" is an oyster shucking process that uses steam to relax the oyster's adductor muscle of the shucking process as in integral part of the operation of an existing oyster-shucking house. The term "steam

436

Thermal analysis for fuel handling system for sodium cooled reactor considering minor actinide-bearing metal fuel.  

SciTech Connect (OSTI)

The Advanced Burner Reactor (ABR) is one of the components of the Global Nuclear Energy Partnership (GNEP) used to close the fuel cycle. ABR is a sodium-cooled fast reactor that is used to consume transuranic elements resulting from the reprocessing of light water reactor spent nuclear fuel. ABR-1000 [1000 MW(thermal)] is a fast reactor concept created at Argonne National Laboratory to be used as a reference concept for various future trade-offs. ABR-1000 meets the GNEP goals although it uses what is considered base sodium fast reactor technology for its systems and components. One of the considerations of any fast reactor plant concept is the ability to perform fuel-handling operations with new and spent fast reactor fuel. The transmutation fuel proposed as the ABR fuel has a very little experience base, and thus, this paper investigates a fuel-handling concept and potential issues of handling fast reactor fuel containing minor actinides. In this study, two thermal analyses supporting a conceptual design study on the ABR-1000 fuel-handling system were carried out. One analysis investigated passive dry spent fuel storage, and the other analysis investigated a fresh fuel shipping cask. Passive dry storage can be made suitable for the ABR-1000 spent fuel storage with sodium-bonded metal fuel. The thermal analysis shows that spent fast reactor fuel with a decay heat of 2 kW or less can be stored passively in a helium atmosphere. The 2-kW value seems to be a reasonable and practical level, and a combination of reasonably-sized in-sodium storage followed by passive dry storage could be a candidate for spent fuel storage for the next-generation sodium-cooled reactor with sodium-bonded metal fuel. Requirements for the shipping casks for minor actinide-bearing fuel with a high decay heat level are also discussed in this paper. The shipping cask for fresh sodium-cooled-reactor fuel should be a dry type to reduce the reaction between residual moisture on fresh fuel and the sodium coolant. The cladding temperature requirement is maintained below the creep temperature limit to avoid any damage before core installation. The thermal analysis shows that a helium gas-filled cask can accommodate ABR-1000 fresh minor actinide-bearing fuel with 700-W decay heat. The above analysis results revealed the overall requirement for minor actinide-bearing metal fuel handling. The information is thought to be helpful in the design of the ABR-1000 and future sodium-cooled-reactor fuel-handling system.

Chikazawa, Y.; Grandy, C.; Nuclear Engineering Division

2009-03-01T23:59:59.000Z

437

Evaluation of Homogeneous Options: Effects of Minor Actinide Exclusion from Single and Double Tier Recycle in Sodium Fast Reactors  

SciTech Connect (OSTI)

The Systems Analysis Campaign under the Global Nuclear Energy Partnership (GNEP) has requested the fuel cycle analysis group at the Idaho National Laboratory (INL) to analyze and provide isotopic data for four scenarios in which different strategies for Minor Actinides (MA) management are investigated. A 1000 MWth commercial-scale Sodium Fast Reactor (SFR) design was selected as the baseline in this scenario study. Two transuranic (TRU) conversion ratios, defined as the ratio of the amount of TRU produced over the TRU destroyed in the reactor core, along with different fuel-types were investigated.

R. M. Ferrer; S. Bays; M. Pope

2008-03-01T23:59:59.000Z

438

Atomistic Calculations of the Effect of Minor Actinides on Thermodynamic and Kinetic Properties of UO{sub 2{+-}x}  

SciTech Connect (OSTI)

The team will examine how the incorporation of actinide species important for mixed oxide (MOX) and other advanced fuel designs impacts thermodynamic quantities of the host UO{sub 2} nuclear fuel and how Pu, Np, Cm and Am influence oxygen mobility. In many cases, the experimental data is either insufficient or missing. For example, in the case of pure NpO2, there is essentially no experimental data on the hyperstoichiometric form it is not even known if hyperstoichiometry NpO{sub 2{+-}x} is stable. The team will employ atomistic modeling tools to calculate these quantities

Deo, Chaitanya; Adnersson, Davis; Battaile, Corbett; uberuaga, Blas

2012-10-30T23:59:59.000Z

439

Use of Information Theory Concepts for Developing Contaminated Site Detection Method: Case for Fission Product and Actinides Accumulation Modeling  

SciTech Connect (OSTI)

Information theory concepts and their fundamental importance for environmental pollution analysis in light of experience of Chernobyl accident in Belarus are discussed. An information and dynamic models of the radionuclide composition formation in the fuel of the Nuclear Power Plant are developed. With the use of code DECA numerical calculation of actinides (58 isotopes are included) and fission products (650 isotopes are included) activities has been carried out and their dependence with the fuel burn-up of the RBMK-type reactor have been investigated. (authors)

Harbachova, N.V.; Sharavarau, H.A. [Joint Institute of Power and Nuclear Research - 'Sosny' National Academy of Sciences, 99 Academic, A.K. Krasin Str., 220109 Minsk (Belarus)

2006-07-01T23:59:59.000Z

440

Acceleration at Relativistic Shocks in Gamma-Ray Bursts  

E-Print Network [OSTI]

Most recent extragalactic models of gamma-ray bursts consider the expansion of a relativistic blast wave, emanating from a solar-mass type progenitor, into the surrounding interstellar medium as the site for their activity. The popular perception is that the optical afterglows result from the external shock interface, while the prompt transient gamma-ray signal arises from multiple shocks internal to the expansion. This paper illustrates a number of acceleration properties of relativistic and ultrarelativistic shocks that pertain to GRB models, by way of a standard Monte Carlo simulation. Computations of the spectral shape, the range of spectral indices, and the energy gain per shock crossing are presented, as functions of the shock speed and the type of particle scattering.

Baring, M G

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "actinide shock physics" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


441

Shock-ignition relevant experiments with planar targets on OMEGA  

SciTech Connect (OSTI)

We report on laser-driven, strong-shock generation and hot-electron production in planar targets in the presence of a pre-plasma at shock-ignition (SI) relevant laser and pre-plasma conditions. 2-D simulations reproduce the shock dynamics well, indicating ablator shocks of up to 75 Mbar have been generated. We observe hot-electron temperatures of ?70?keV at intensities of 1.4?×?10{sup 15}?W/cm{sup 2} with multiple overlapping beams driving the two-plasmon decay instability. When extrapolated to SI-relevant intensities of ?10{sup 16}?W/cm{sup 2}, the hot electron temperature will likely exceed 100?keV, suggesting that tightly focused beams without overlap are better suited for launching the ignitor shock.

Hohenberger, M.; Hu, S. X.; Anderson, K. S.; Boehly, T. R.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Yaakobi, B. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States) [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Casner, A. [CEA, DAM, DIF, Arpajon (France)] [CEA, DAM, DIF, Arpajon (France); Fratanduono, D. E. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Ribeyre, X.; Schurtz, G. [Centre Lasers Intenses et Applications, CELIA, Université Bordeaux 1-CEA-CNRS, Talence (France)] [Centre Lasers Intenses et Applications, CELIA, Université Bordeaux 1-CEA-CNRS, Talence (France)

2014-02-15T23:59:59.000Z

442

Species separation and kinetic effects in collisional plasma shocks  

SciTech Connect (OSTI)

The properties of collisional shock waves propagating in uniform plasmas are studied with ion-kinetic calculations, in both slab and spherical geometry and for the case of one and two ion species. Despite the presence of an electric field at the shock front—and in contrast to the case where an interface is initially present [C. Bellei et al., Phys. Plasmas 20, 044702 (2013)]—essentially no ion reflection at the shock front is observed due to collisions, with a probability of reflection ?10{sup ?4} for the cases presented. A kinetic two-ion-species spherical convergent shock is studied in detail and compared against an average-species calculation, confirming effects of species separation and differential heating of the ion species at the shock front. The effect of different ion temperatures on the DT and D{sup 3}He fusion reactivity is discussed in the fluid limit and is estimated to be moderately important.

Bellei, C., E-mail: bellei1@llnl.gov; Wilks, S. C.; Amendt, P. A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Rinderknecht, H.; Zylstra, A.; Rosenberg, M.; Sio, H.; Li, C. K.; Petrasso, R. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-05-15T23:59:59.000Z

443

E-Print Network 3.0 - adiabatic shock capturing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of shock acceleration, adiabatic and radiative losses as well as diffusive spatial transport in various... of shock and stochastic acceleration, adiabatic and radiative losses...

444

QUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON A NOVEL TEST TECHNIQUE  

E-Print Network [OSTI]

QUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON AQUANTITATIVE STUDIES OF THERMAL SHOCK IN CERAMICS BASED ON AAl 203). The thermal failure of another ceramic material (

Faber, K.T.

2013-01-01T23:59:59.000Z

445

SELF-REGULATED SHOCKS IN MASSIVE STAR BINARY SYSTEMS  

SciTech Connect (OSTI)

In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L{sub X}, remains largely unaltered, with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L{sub X}/L{sub bol}). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).

Parkin, E. R.; Sim, S. A., E-mail: parkin@mso.anu.edu.au, E-mail: s.sim@qub.ac.uk [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia)

2013-04-20T23:59:59.000Z

446

physics | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

physics physics Leads No leads are available at this time. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOxCeO2. Abstract: Pulsing 15N18O onto...

447

Electroweak Physics  

E-Print Network [OSTI]

Work on electroweak precision calculations and event generators for electroweak physics studies at current and future colliders is summarized.

W. Hollik

2005-01-26T23:59:59.000Z

448

Flash photolysis-shock tube studies  

SciTech Connect (OSTI)

Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

Michael, J.V. [Argonne National Laboratory, IL (United States)

1993-12-01T23:59:59.000Z

449

High Bandwidth Differential Amplifier for Shock Experiments  

SciTech Connect (OSTI)

We developed a high bandwidth differential amplifier for gas gun shock experiments/applications. The circuit has a bandwidth > 1 GHz, and is capable of measuring signals of ?1.5 V with a common mode rejection of 250 V. Conductivity measurements of gas gun targets are measured by flowing high currents through the targets. The voltage is measured across the target using a technique similar to a four-point probe. Because of the design of the current source and load, the target voltage is approximately 250 V relative to ground. Since the expected voltage change in the target is < 1 V, the differential amplifier must have a large common mode rejection. High pass filters suppress internal ringing of operational amplifiers. Results of bench tests are shown.

Ross, P. W., Tran, V., Chau, R.

2012-04-30T23:59:59.000Z

450

Reverse-Shock in Tycho's Supernova Remnant  

E-Print Network [OSTI]

Thermal X-ray emission from young supernova remnants (SNRs) is usually dominated by the emission lines of the supernova (SN) ejecta, which are widely believed being crossed and thus heated by the inwards propagating reverse shock (RS). Previous works using imaging X-ray data have shown that the ejecta are heated by the RS by locating the peak emission region of the most recently ionized matter, which is found well separated towards the inside from the outermost boundary. Here we report the discovery of a systematic increase of the Sulfur (S) to Silicon (Si) K$\\alpha$ line flux ratio with radius in Tycho's SNR. This allows us, for the first time, to present continuous radial profiles of the ionization age and, furthermore, the elapsed ionization time since the onset of the ionization, which tells the propagation history of the ionization front into the SNR ejecta.

Lu, F J; Zheng, S J; Zhang, S N; Long, X; Aschenbach, B

2015-01-01T23:59:59.000Z

451

E-Print Network 3.0 - actinide targets extracted Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by a chemical process. These plants can however not separate neptunium, americium and curium (minor ... Source: Uppsala Universitet, Department of Theoretical Physics...

452

E-Print Network 3.0 - actinide thermodynamic predictions Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Brine: LCO-ACP-08, ... Source: Yucca Mountain Project, US EPA Collection: Environmental Sciences and Ecology 6 PHYSICAL PROPERTIES OF METALLIC MAGNETIC COMPOUNDS : 5f-BAND...

453

E-Print Network 3.0 - actinide complexes pt Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laboratory. NMR spectra of the complexes... and physical properties of heavy transition metal, lanthanide and ... Source: Pacific Northwest National Laboratory, Data Quality...

454

SHOCK BREAKOUT FROM TYPE Ia SUPERNOVA  

SciTech Connect (OSTI)

The mode of explosive burning in Type Ia supernovae (SNe Ia) remains an outstanding problem. It is generally thought to begin as a subsonic deflagration, but this may transition into a supersonic detonation (the delayed detonation transition, DDT). We argue that this transition leads to a breakout shock, which would provide the first unambiguous evidence that DDTs occur. Its main features are a hard X-ray flash (approx20 keV) lasting approx10{sup -2} s with a total radiated energy of approx10{sup 40} erg, followed by a cooling tail. This creates a distinct feature in the visual light curve, which is separate from the nickel decay. This cooling tail has a maximum absolute visual magnitude of M{sub V} approx -9 to -10 at approx1 day, which depends most sensitively on the white dwarf radius at the time of the DDT. As the thermal diffusion wave moves in, the composition of these surface layers may be imprinted as spectral features, which would help to discern between SN Ia progenitor models. Since this feature should accompany every SNe Ia, future deep surveys (e.g., m = 24) will see it out to a distance of approx80 Mpc, giving a maximum rate of approx60 yr{sup -1}. Archival data sets can also be used to study the early rise dictated by the shock heating (at approx20 days before maximum B-band light). A similar and slightly brighter event may also accompany core bounce during the accretion-induced collapse to a neutron star, but with a lower occurrence rate.

Piro, Anthony L.; Chang, Philip; Weinberg, Nevin N., E-mail: tpiro@astro.berkeley.ed, E-mail: pchang@astro.berkeley.ed, E-mail: nweinberg@astro.berkeley.ed [Astronomy Department and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)

2010-01-01T23:59:59.000Z

455

SiC Schottky Diode Detectors for Measurement of Actinide Concentrations from Alpha Activities in Molten Salt Electrolyte  

SciTech Connect (OSTI)

In this project, we have designed a 4H-SiC Schottky diode detector device in order to monitor actinide concentrations in extreme environments, such as present in pyroprocessing of spent fuel. For the first time, we have demonstrated high temperature operation of such a device up to 500 {degrees}C, in successfully detecting alpha particles. We have used Am-241 as an alpha source for our laboratory experiments. Along with the experiments, we have developed a multi scale model to study the phenomena controlling the device behavior and to be able to predict the device performance. Our multi scale model consists of ab initio modeling to understand defect energetics and their effect on electronic structure and carrier mobility in the material. Further, we have developed the basis for a damage evolution model incorporating the outputs from ab initio model in order to predict respective defect concentrations in the device material. Finally, a fully equipped TCAD-based device model has been developed to study the phenomena controlling the device behavior. Using this model, we have proven our concept that the detector is capable of performing alpha detection in a salt bath with the mixtures of actinides present in a pyroprocessing environment.

Windl, Wolfgang; Blue, Thomas

2013-01-28T23:59:59.000Z

456

Speciation and structural characterization of plutonium and actinide-organic complexes in surface and groundwaters. 1998 annual progress report  

SciTech Connect (OSTI)

'The authors proposed research is designed to study the association of actinides with dissolved organic complexes in subsurface waters. This study expands considerably on prior work due to the combination of Pu oxidation studies (for Pu speciation/chemical reactivity information), Pu isotope ratio work (for Pu source function information), and the detailed characterization of organic matter in size-fractionated groundwater samples. The authors have postulated that actinide associations with organic matter may be enhanced due to colloidal biopolymers. This report summarizes work completed after less than 2 years of a 3-year project. Activities thus far have included: (1) the development of sampling techniques to minimize contamination and artifact formation, (2) the separation of Pu isotopes by oxidation state in groundwater, (3) the development of techniques for the separation and identification of organic constituents from natural waters, (4) a study of background Pu and organic carbon concentrations at the proposed study sites, and (5) field work at the Savannah River Site (SRS).'

Buesseler, K.O.; Repeta, D.J. [Woods Hole Oceanographic Inst., Woods Hole, MA (US); Kelley, J.M. [Pacific Northwest National Lab., Richland, WA (US)

1998-06-01T23:59:59.000Z

457

ON THE EXISTENCE OF SHOCKS IN IRRADIATED EXOPLANETARY ATMOSPHERES  

SciTech Connect (OSTI)

Supersonic flows are expected to exist in the atmospheres of irradiated exoplanets, but the question of whether shocks develop lingers. Specifically, it reduces to whether continuous flow in a closed loop may become supersonic and if some portions of the supersonic flow steepen into shocks. We first demonstrate that continuous, supersonic flow may exist in two flavors: isentropic and non-isentropic, with shocks being included in the latter class of solutions. Supersonic flow is a necessary but insufficient condition for shocks to develop. The development of a shock requires the characteristics of neighboring points in a flow to intersect. We demonstrate that the intersection of characteristics may be quantified via the knowledge of the Mach number. Finally, we examine three-dimensional simulations of hot Jovian atmospheres and demonstrate that shock formation is expected to occur mostly on the dayside hemisphere, upstream of the substellar point, because the enhanced temperatures near the substellar point provide a natural pressure barrier for the returning flow. Understanding the role of shocks in irradiated exoplanetary atmospheres is relevant to correctly modeling observables such as the peak offsets of infrared phase curves.

Heng, Kevin [Institute for Astronomy, ETH Zuerich, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland)

2012-12-10T23:59:59.000Z

458

Impacts of pure shocks in the BHR71 bipolar outflow  

E-Print Network [OSTI]

During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks is therefore essential to the study of star formation. We present comparisons of shock models with CO, H2, and SiO observations in a 'pure' shock position in the BHR71 bipolar outflow. These comparisons provide an insight into the shock and pre-shock characteristics, and allow us to understand the energetic and chemical feedback of star formation on Galactic scales. New CO (Jup = 16, 11, 7, 6, 4, 3) observations from the shocked regions with the SOFIA and APEX telescopes are presented and combined with earlier H2 and SiO data (from the Spitzer and APEX telescopes). The integrated intensities are compared to a grid of models that were obtained from a magneto-hydrodynamical shock code which calculates the dynamical and chemical structure of these regions combined with a radi...

Gusdorf, Antoine; Anderl, Sibylle; Eisloeffel, Jochen; Codella, Claudio; Gomez-Ruiz, Arturo; Graf, Urs; Kristensen, Lars; Leurini, Silvia; Parise, Berengere; Requena-Torres, Migel; Ricken, Oliver; Guesten, Rolf

2015-01-01T23:59:59.000Z

459

Destruction of Interstellar Dust in Evolving Supernova Remnant Shock Waves  

E-Print Network [OSTI]

Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al. (1996), we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities >~ 200 km/s for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are incre...

Slavin, Jonathan D; Jones, Anthony P

2015-01-01T23:59:59.000Z

460

Shock Initiation of Energetic Materials at Different Initial Temperatures  

SciTech Connect (OSTI)

Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 (92.5 % triaminotrinitrobenzene (TATB) with 7.5 % Kel-F binder) and LX-04 (85 % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15 % Viton binder) at several initial temperatures.

Urtiew, P A; Tarver, C M

2005-01-14T23:59:59.000Z

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461

Adjustable Shock Test Sled for Haversine Pulses at 250 fps  

SciTech Connect (OSTI)

New test requirements were developed by Sandia National Laboratory to simulate a regime of shock testing not previously performed at the Kansas City Plant operated by Honeywell Federal Manufacturing & Technologies. These environments were unique in that they involved amplitude of shock >1000g with relatively long pulse durations (greater 5 ms but less than 10 ms) and involved velocity changes up to 235 ft/sec. Ten months were available to develop, design, manufacture and prove-in this new capability. We designed a new shock sled to deliver this new family of shock environments in a laboratory test. The performance range of the new sled includes five specific shocks (1000 g – 8 ms, 1300 - 6 ms, 1500 g – 5.4 ms, 1950 g – 6 ms, 2250 g – 5.4 ms; all haversine shaped), and it also incorporates adjustability to accommodate new shocks within this range. These shock environments result in velocity changes ranging from 160 fps to 250 fps. The test sled accommodates test articles weighing up to 20 lbs and measuring up to 10” along any axis.

Troy Hartwig; Brent Hower; Aaron Seaholm

2008-05-05T23:59:59.000Z

462

Extended supernova shock breakout signals from inflated stellar envelopes  

E-Print Network [OSTI]

Stars close to the Eddington luminosity can have large low-density inflated envelopes. We show that the rise times of shock breakout signals from supernovae can be extended significantly if supernova progenitors have an inflated stellar envelope. If the shock breakout occurs in such inflated envelopes, the shock breakout signals diffuse in them, and their rise time can be significantly extended. Then, the rise times of the shock breakout signals are dominated by the diffusion time in the inflated envelope rather than the light-crossing time of the progenitors. We show that our inflated Wolf-Rayet star models whose radii are of the order of the solar radius can have shock breakout signals which are longer than ~100 sec. The existence of inflated envelopes in Wolf-Rayet supernova progenitors may be related to the mysterious long shock breakout signal observed in Type Ib SN 2008D. Extended shock breakout signals may provide evidence for the existence of inflated stellar envelopes and can be used to constrain the...

Moriya, Takashi J; Langer, Norbert

2015-01-01T23:59:59.000Z