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Sample records for minor actinides disposition

  1. PF-4 actinide disposition strategy

    SciTech Connect

    Margevicius, Robert W

    2010-05-28

    The dwindling amount of Security Category I processing and storage space across the DOE Complex has driven the need for more effective storage of nuclear materials at LANL's Plutonium Facility's (PF-4's) vault. An effort was begun in 2009 to create a strategy, a roadmap, to identify all accountable nuclear material and determine their disposition paths, the PF-4 Actinide Disposition Strategy (PADS). Approximately seventy bins of nuclear materials with similar characteristics - in terms of isotope, chemical form, impurities, disposition location, etc. - were established in a database. The ultimate disposition paths include the material to remain at LANL, disposition to other DOE sites, and disposition to waste. If all the actions described in the document were taken, over half of the containers currently in the PF-4 vault would been eliminated. The actual amount of projected vault space will depend on budget and competing mission requirements, however, clearly a significant portion of the current LANL inventory can be either dispositioned or consolidated.

  2. Separation of Minor Actinides from Lanthanides by Dithiophosphinic Acid Extractants

    SciTech Connect

    D. R. Peterman; M. R. Greenhalgh; R. D. Tillotson; J. R. Klaehn; M. K. Harrup; T. A. Luther; J. D. Law; L. M. Daniels

    2008-09-01

    The selective extraction of the minor actinides (Am(III) and Cm(III)) from the lanthanides is an important part of advanced reprocessing of spent nuclear fuel. This separation would allow the Am/Cm to be fabricated into targets and recycled to a reactor and the lanthanides to be dispositioned. This separation is difficult to accomplish due to the similarities in the chemical properties of the trivalent actinides and lanthanides. Research efforts at the Idaho National Laboratory have identified an innovative synthetic pathway yielding new regiospecific dithiophosphinic acid (DPAH) extractants. The synthesis provides DPAH derivatives that can address the issues concerning minor actinide separation and extractant stability. For this work, two new symmetric DPAH extractants have been prepared. The use of these extractants for the separation of minor actinides from lanthanides will be discussed.

  3. Minor Actinides Recycling in PWRs

    SciTech Connect

    Delpech, M.; Golfier, H.; Vasile, A.; Varaine, F.; Boucher, L.; Greneche, D.

    2006-07-01

    Recycling of minor actinides in current and near future PWR is considered as one of the options of the general waste management strategy. This paper presents the analysis of this option both from the core physics and fuel cycle point of view. A first indicator of the efficiency of different neutron spectra for transmutation purposes is the capture to fission cross sections ratio which is less favourable by a factor between 5 to 10 in PWRs compared to fast reactors. Another indicator presented is the production of high ranking isotopes like Curium, Berkelium or Californium in the thermal or epithermal spectrum conditions of PWR cores by successive neutron captures. The impact of the accumulation of this elements on the fabrication process of such PWR fuels strongly penalizes this option. The main constraint on minor actinides loadings in PWR (or fast reactors) fuels are related to their direct impact (or the impact of their transmutation products) on the reactivity coefficients, the reactivity control means and the core kinetics parameters. The main fuel cycle physical parameters like the neutron source, the alpha decay power, the gamma and neutrons dose rate and the criticality aspects are also affected. Recent neutronic calculations based on a reference core of the Evolutionary Pressurized Reactor (EPR), indicates typical maximum values of 1 % loadings. Different fuel design options for minor actinides transmutation purposes in PWRs are presented: UOX and MOX, homogeneous and heterogeneous assemblies. In this later case, Americium loading is concentrated in specific pins of a standard UOX assembly. Recycling of Neptunium in UOX and MOX fuels was also studied to improve the proliferation resistance of the fuel. The impact on the core physics and penalties on Uranium enrichment were underlined in this case. (authors)

  4. BWR Assembly Optimization for Minor Actinide Recycling

    SciTech Connect

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

    2010-03-22

    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).

  5. Disposition of actinides released from high-level waste glass

    SciTech Connect

    Ebert, W.L.; Bates, J.K.; Buck, E.C.; Gong, M.; Wolf, S.F.

    1994-05-01

    A series of static leach tests was conducted using glasses developed for vitrifying tank wastes at the Savannah River Site to monitor the disposition of actinide elements upon corrosion of the glasses. In these tests, glasses produced from SRL 131 and SRL 202 frits were corroded at 90{degrees}C in a tuff groundwater. Tests were conducted using crushed glass at different glass surface area-to-solution volume (S/V) ratios to assess the effect of the S/V on the solution chemistry, the corrosion of the glass, and the disposition of actinide elements. Observations regarding the effects of the S/V on the solution chemistry and the corrosion of the glass matrix have been reported previously. This paper highlights the solution analyses performed to assess how the S/V used in a static leach test affects the disposition of actinide elements between fractions that are suspended or dissolved in the solution, and retained by the altered glass or other materials.

  6. Detailed calculations of minor actinide transmutation in a fast reactor

    SciTech Connect

    Takeda, Toshikazu

    2015-12-31

    The transmutation of minor actinides in a fast reactor is investigated by a new method to investigate the transmutation behavior of individual minor actinides. It is found that Np-237 and Am-241 mainly contributes to the transmutation rate though the transmutation behaviors are very different.

  7. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    SciTech Connect

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

    2012-08-22

    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.

  8. Role of Minor Actinides for Long-Life Reactor Cores

    SciTech Connect

    Saito, M.; Artisyuk, V.; Shmelev, A.; Nikitin, K.; Peryoga, Y

    2002-07-01

    The paper addresses the study on advanced fuel cycles for LWR oriented to high burnup values that exceed 100 GWd/tHM, thus giving the chance to establish the long-life reactor cores without fuel reloading on site. The key element of this approach is a broad involvement of Minor Actinides whose admixture to 20% enriched uranium fuel provides safe release of initial reactivity excess and improved proliferation resistance properties. (authors)

  9. The EBR-II X501 Minor Actinide Burning Experiment

    SciTech Connect

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

    2008-06-01

    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.

  10. Utilization of Minor Actinides (Np, Am, Cm) in Nuclear Power Reactor

    NASA Astrophysics Data System (ADS)

    Gerasimov, A.; Bergelson, B.; Tikhomirov, G.

    2014-06-01

    Calculation research of the utilization process of minor actinides (transmutation with use of power released) is performed for specialized power reactor of the VVER type operating on the level of electric power of 1000 MW. Five subsequent cycles are considered for the reactor with fuel elements containing minor actinides along with enriched uranium. It was shown that one specialized reactor for the one cycle (900 days) can utilize minor actinides from several VVER-1000 reactors without any technological and structural modifications. Power released because of minor actinide fission is about 4% with respect to the total power

  11. A Heterogeneous Sodium Fast Reactor Designed to Transmute Minor Actinide Actinide Waste Isotopes into Plutonium Fuel

    SciTech Connect

    Samuel E. Bays

    2011-02-01

    An axial heterogeneous sodium fast reactor design is developed for converting minor actinide waste isotopes into plutonium fuel. The reactor design incorporates zirconium hydride moderating rods in an axial blanket above the active core. The blanket design traps the active core’s axial leakage for the purpose of transmuting Am-241 into Pu-238. This Pu-238 is then co-recycled with the spent driver fuel to make new driver fuel. Because Pu-238 is significantly more fissile than Am-241 in a fast neutron spectrum, the fissile worth of the initial minor actinide material is upgraded by its preconditioning via transmutation in the axial targets. Because, the Am-241 neutron capture worth is significantly stronger in a moderated epithermal spectrum than the fast spectrum, the axial targets serve as a neutron trap which recovers the axial leakage lost by the active core. The sodium fast reactor proposed by this work is designed as an overall transuranic burner. Therefore, a low transuranic conversion ratio is achieved by a degree of core flattening which increases axial leakage. Unlike a traditional “pancake” design, neutron leakage is recovered by the axial target/blanket system. This heterogeneous core design is constrained to have sodium void and Doppler reactivity worth similar to that of an equivalent homogeneous design. Because minor actinides are irradiated only once in the axial target region; elemental partitioning is not required. This fact enables the use of metal targets with electrochemical reprocessing. Therefore, the irradiation environment of both drivers and targets was constrained to ensure applicability of the established experience database for metal alloy sodium fast reactor fuels.

  12. Fuel Sustainability And Actinide Production Of Doping Minor Actinide In Water-Cooled Thorium Reactor

    NASA Astrophysics Data System (ADS)

    Permana, Sidik

    2017-07-01

    Fuel sustainability of nuclear energy is coming from an optimum fuel utilization of the reactor and fuel breeding program. Fuel cycle option becomes more important for fuel cycle utilization as well as fuel sustainability capability of the reactor. One of the important issues for recycle fuel option is nuclear proliferation resistance issue due to production plutonium. To reduce the proliferation resistance level, some barriers were used such as matrial barrier of nuclear fuel based on isotopic composition of even mass number of plutonium isotope. Analysis on nuclear fuel sustainability and actinide production composition based on water-cooled thorium reactor system has been done and all actinide composition are recycled into the reactor as a basic fuel cycle scheme. Some important parameters are evaluated such as doping composition of minor actinide (MA) and volume ratio of moderator to fuel (MFR). Some feasible parameters of breeding gains have been obtained by additional MA doping and some less moderation to fuel ratios (MFR). The system shows that plutonium and MA are obtained low compositions and it obtains some higher productions of even mass plutonium, which is mainly Pu-238 composition, as a control material to protect plutonium to be used as explosive devices.

  13. Plutonium and minor actinides utilization in Thorium molten salt reactor

    SciTech Connect

    Waris, Abdul; Aji, Indarta K.; Novitrian,; Kurniadi, Rizal; Su'ud, Zaki

    2012-06-06

    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.

  14. Dynamics of Critical Dedicated Cores for Minor Actinide Transmutation

    SciTech Connect

    Massara, S.; Tommasi, J.; Vanier, M.; Koeberl, O.

    2005-02-15

    Fast spectrum minor actinide (MA) burner designs, with high minor actinide loads and consumptions, have been assessed. As reactivity and kinetic coefficients are poor in such cores (low delayed neutron fraction and Doppler feedback, high coolant void coefficient), special attention has been paid to their dynamic behavior during transient conditions. A dynamics code, MAT4 DYN, has been expressly developed to study loss-of-flow, reactivity insertion, and loss-of-coolant accidents. It takes into account two fuel geometries (cylindrical and spherical) and two thermal-hydraulics models for the coolant (incompressible for liquid metals and compressible for helium).Three nitride-fuel configurations are analyzed according to their coolant: sodium and lead (both with pin fuel) and helium (with particle fuel). Dynamics calculations show that if the fuel nature is appropriately chosen, with sufficient margins during transients, then this can counterbalance the poor reactivity coefficients for liquid-metal-cooled cores, thus proving the interest of this kind of concept. On the other hand, the gas-cooled core dynamics is very badly affected by the high value of the helium void coefficient in a hard spectrum, this effect being amplified by the very low thermal inertia of the fuel particles. Hence, concepts other than a particle-bed fuel should be investigated for a helium-cooled fast-spectrum MA burner.

  15. The EBR-II X501 Minor Actinide Burning Experiment

    SciTech Connect

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

    2008-01-01

    The X501 experiment was conducted in EBR II as part of the 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 MA bearing fuel irradiation tests conducted worldwide, and knowledge can be gained by understanding the changes in fuel behavior due to addition of MAs. Of primary interest are the effect of the MAs 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 report provides a summary of the X501 fabrication, characterization, irradiation, and post irradiation examination.

  16. Processing and Disposition of Special Actinide Target Materials - 13138

    SciTech Connect

    Robinson, Sharon M.; Patton, Brad D.; Allender, Jeffrey S.

    2013-07-01

    The Department of Energy (DOE) manages an inventory of materials that contains a range of long-lived radioactive isotopes that were produced from the 1960's through the 1980's by irradiating targets in high-flux reactors at the Savannah River Site (SRS) to produce special heavy isotopes for DOE programmatic use, scientific research, and industrial and medical applications. Among the products were californium-252, heavy curium (including Cm-246 through Cm-248), and plutonium-242 and -244. Many of the isotopes are still in demand today, and they can be recovered from the remaining targets previously irradiated at SRS or produced from the recovered isotopes. Should the existing target materials be discarded, the plutonium (Pu) and curium (Cm) isotopes cannot be replaced readily with existing production sources. Some of these targets are stored at SRS, while other target material is stored at Oak Ridge National Laboratory (ORNL) at several stages of processing. The materials cannot be stored in their present form indefinitely. Their long-term management involves processing items for beneficial use and/or for disposition, using storage and process facilities at SRS and ORNL. Evaluations are under way for disposition options for these materials, and demonstrations of improved flow sheets to process the materials are being conducted at ORNL and the Savannah River National Laboratory (SRNL). The disposition options and a management evaluation process have been developed. Processing demonstrations and evaluations for these unique materials are under way. (authors)

  17. Casting of metallic fuel containing minor actinide additions

    NASA Astrophysics Data System (ADS)

    Trybus, C. L.; Sanecki, J. E.; Henslee, S. P.

    1993-09-01

    Metallic U-20%Pu-10%Zr (by weight) nuclear fuel was injection cast with the addition of two minor actinides, 2.1% Am and 1.3% Np. Three full length fuel slugs (4.3 mm × 340 mm) were successfully cast incorporating both Np and Am. No unusual macrosegregation of the major constituents was observed. About 60% of the initial Am and 100% of the Np charge was present in the as-cast fuel. Am loss was attributed to volatile contaminants in the feed stock and evaporation at the casting temperature (1465°C). Microstructural and microchemical characterization of the as-cast fuel along with bulk chemical analyses are reported.

  18. ENHANCING ADVANCED CANDU PROLIFERATION RESISTANCE FUEL WITH MINOR ACTINIDES

    SciTech Connect

    Gray S. Chang

    2010-05-01

    The advanced nuclear system will significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. 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.

  19. Enhancing BWR proliferation resistance fuel with minor actinides

    NASA Astrophysics Data System (ADS)

    Chang, Gray S.

    2009-03-01

    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 light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu 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, 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. 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 UO 2 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/cm 3) to the top (0.35 g/cm 3) 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. 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

  20. Enhancing BWR Proliferation Resistance Fuel with Minor Actinides

    SciTech Connect

    Gray S. Chang

    2009-03-01

    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 light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu 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, 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. 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. 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

  1. Enhancing VVER Annular Proliferation Resistance Fuel with Minor Actinides

    SciTech Connect

    G. S. Chang

    2007-06-01

    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. The merits of nuclear energy are the high-density energy, and 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 LWR 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 the 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, (b) use of transuranic nuclides (237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope 238Pu /Pu ratio. For future advanced nuclear systems, the minor actinides 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. In this paper, a typical pressurized water reactor (PWR) VVER-1000 annular 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. We concluded that the concept of MARA, involves the use of transuranic nuclides (237Np and/or 241Am), can not only drastically

  2. Proliferation Resistance Evaluation of ACR-1000 Fuel with Minor Actinides

    SciTech Connect

    Gray S. Chang

    2008-09-01

    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

  3. Enhancing BWR Proliferation Resistance Fuel with Minor Actinides

    SciTech Connect

    Gray S. Chang

    2008-07-01

    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

  4. Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR

    SciTech Connect

    G. S. Chang; Hongbin Zhang

    2009-09-01

    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.

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

    SciTech Connect

    Bhatti, Zaki; Hyland, B.; Edwards, G.W.R.

    2013-07-01

    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 β) for coolant voiding as standard NU fuel. (authors)

  6. Partitioning of minor actinides from PUREX raffinate by the TODGA process

    SciTech Connect

    Magnusson, D.; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano Purroy, D.; Modolo, G.; Sorel, C.

    2007-07-01

    A genuine High Active Raffinate (HAR) was produced from small scale PUREX reprocessing of a UO{sub 2} spent fuel solution as feed for a subsequent TODGA/TBP process. In this process, efficient recovery of the trivalent Minor Actinides (MA) actinides could be demonstrated using a hot cell set-up of 32 centrifugal contactor stages. The feed decontamination factors obtained for Am and Cm were in the range of 4 x 10{sup 4} which corresponds to a recovery of more than 99.99 % in the product fraction. Trivalent lanthanides and Y were co-extracted, otherwise only a small part of the Ru ended up in the product. The collected actinide/lanthanide fraction can be used as feed for a SANEX (separation actinides from lanthanides) with some modification of the acidity depending on the extracting molecule. (authors)

  7. Plutonium and minor actinide utilisation in a pebble-bed high temperature reactor

    SciTech Connect

    Petrov, B. Y.; Kuijper, J. C.; Oppe, J.; De Haas, J. B. M.

    2012-07-01

    This paper contains results of the analysis of the pebble-bed high temperature gas-cooled PUMA reactor loaded with plutonium and minor actinide (Pu/MA) fuel. Starting from knowledge and experience gained in the Euratom FP5 projects HTR-N and HTR-N1, this study aims at demonstrating the potential of high temperature reactors to utilize or transmute Pu/MA fuel. The work has been performed within the Euratom FP6 project PUMA. A number of different fuel types and fuel configurations have been analyzed and compared with respect to incineration performance and safety-related reactor parameters. The results show the excellent plutonium and minor actinide burning capabilities of the high temperature reactor. The largest degree of incineration is attained in the case of an HTR fuelled by pure plutonium fuel as it remains critical at very deep burnup of the discharged pebbles. Addition of minor actinides to the fuel leads to decrease of the achievable discharge burnup and therefore smaller fraction of actinides incinerated during reactor operation. The inert-matrix fuel design improves the transmutation performance of the reactor, while the 'wallpaper' fuel does not have advantage over the standard fuel design in this respect. After 100 years of decay following the fuel discharge, the total amount of actinides remains almost unchanged for all of the fuel types considered. Among the plutonium isotopes, only the amount of Pu-241 is reduced significantly due to its relatively short half-life. (authors)

  8. Electro-deposition behavior of minor actinides with liquid cadmium cathodes

    NASA Astrophysics Data System (ADS)

    Kofuji, H.; Fukushima, M.; Kitawaki, S.; Myochin, M.; Kormilitsyn, M. V.; Terai, T.

    2010-03-01

    Transuranic elements have been simultaneously electro-deposited on a liquid cadmium cathode and decontaminated from fission products dissolved in molten 3LiCl-2KCl in the electrorefining of a pyrochemical reprocessing. Some lab-scale electrolysis experiments were carried out using uranium, plutonium and minor actinide elements in order to evaluate the performance of liquid cadmium cathodes. The results of several experiment confirmed that neptunium, americium and curium could be recovered together with Pu by the liquid cadmium cathodes through electrolysis operation. The separation factors of minor actinide vs. Pu were estimated to be about 0.5 to 2.5 and those of rare earth element vs. total actinides 18 to 32.

  9. MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS

    SciTech Connect

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

    2011-09-20

    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.

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

    SciTech Connect

    Bouineau, V.; Lainet, M.; Chauvin, N.; Pelletier, M.

    2013-07-01

    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)

  11. Research and development for accuracy improvement of neutron nuclear data on minor actinides

    NASA Astrophysics Data System (ADS)

    Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki; Katabuchi, Tatsuya; Sano, Tadafumi; Shibahara, Yuji; Takahashi, Yoshiyuki; Takamiya, Koichi; Pyeon, Cheol Ho; Fukutani, Satoshi; Fujii, Tosiyuki; Hori, Jun-ichi; Yashima, Hiroshi

    2017-09-01

    To improve accuracy of neutron nuclear data on minor actinides, a Japanese nuclear data project entitled "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been implemented. Several independent measurement techniques were developed for improving measurement precision at J-PARC/MLF/ANNRI and KURRI/LINAC facilities. Effectiveness of combining the independent techniques has been demonstrated for identifying bias effects and improving accuracy, especially in characterization of samples used for nuclear data measurements. Capture cross sections and/or total cross sections have been measured for Am-241, Am-243, Np-237, Tc-99, Gd-155, and Gd-157. Systematic nuclear data evaluation has also been performed by taking into account the identified bias effect. Highlights of the AIMAC project are outlined.

  12. Minor Actinides, Major Challenges, the Needs for and Benefits of International Collaboration

    NASA Astrophysics Data System (ADS)

    Plompen, A. J. M.

    2014-04-01

    The role of experiments for the determination of minor actinide nuclear data is presented as essential to meet the tight uncertainties requirements derived by sensitivity analyses for innovative systems designed to significantly reduce the amount of high level nuclear waste. Recent, ongoing and planned experiments are highlighted emphasizing international collaboration and the European context. Specifically, the role of the MANREAD CRP, the European projects ANDES, ERINDA and EURFRAT, and the NEA databank and WPEC subgroups will be addressed. For 241Am capture and 240Pu fission are used to illustrate the generic situation with minor actinide experimental data and the discrepancy between achieved and target uncertainties. The importance of new high quality experiments, high quality reporting, diversity, new techniques, methods and facilities is stressed.

  13. Detailed studies of Minor Actinide transmutation-incineration in high-intensity neutron fluxes

    SciTech Connect

    Bringer, O.; Blandin, C.; Oriol, L.

    2006-07-01

    The Mini-INCA project is dedicated to the measurement of incineration-transmutation chains and potentials of minor actinides in high-intensity thermal neutron fluxes. In this context, new types of detectors and methods of analysis have been developed. The {sup 241}Am and {sup 232}Th transmutation-incineration chains have been studied and several capture and fission cross sections measured very precisely, showing some discrepancies with existing data or evaluated data. An impact study was made on different based-like GEN-IV reactors. It underlines the necessity to proceed to precise measurements for a large number of minor-actinides that contribute to these future incineration scenarios. (authors)

  14. French R and D program for minor actinide bearing fuel developments

    SciTech Connect

    Warin, Dominique; Brossard, Philippe; Nabot, Jean-Philippe

    2007-07-01

    One of the main objectives of future Generation IV fast neutron systems is the minimization of waste which will necessitate the recycling of the trans-uranium elements. In order to fulfill this objective, R and D work has to cope with the development of Minor Actinide bearing fuels and, in this context, this paper presents an overview of the results already obtained and the research program to be carried out in the future about fabrication and irradiation behavior at significant scale of such fuels. In France, the results have been obtained, for a large part, thanks to an important experimental irradiation programme using the Phenix fast reactor and the European HFR in Petten. Flux conditions of Phenix are well suited to allow the studies of irradiation damages of fuels and targets for transmutation under representative conditions of fast or partly moderated neutron flux, which are considered to be the most efficient for transmutation of MA. The fuels are now developed for sodium (more mature) and gas (alternative track) fast reactor with in both cases Minor Actinide recycling as a progressive approach in the future nuclear cycles of these reactors. This strategy is based upon the two possible recycling modes: - the homogeneous (using the so called 'GANEX' grouped Transuranics recovery treatment of the irradiated fuel) recycling of Minor Actinides, at low concentration in the standard U-Pu fuel of fast GEN IV systems, - the heterogeneous (using a partitioning process such as the French 'DIAMEX-SANEX') recycling with specific Minor Actinide bearing target in fast critical GEN IV reactors or fuel in sub critical system. (authors)

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

    SciTech Connect

    Gautier, G. M.; Morin, F.; Dechelette, F.; Sanseigne, E.; Chabert, C.

    2012-07-01

    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

  16. The Minor Actinide Transmutation-Incineration Potential Studies in High Intensity Neutron Fluxes

    SciTech Connect

    Letourneau, A.; Chabod, S.; Foucher, Y.; Marie, F.; Ridikas, D.; Veyssiere, Ch.; Blandin, Ch.

    2005-05-24

    In the framework of nuclear waste transmutation studies, the Mini-INCA project has been initiated at CEA/DSM with objectives to determine optimal conditions for transmutation and incineration of Minor Actinides (MA) in high intensity neutron fluxes. Our experimental tools based on alpha- and gamma-spectroscopy of irradiated samples and the development of fission micro-chambers could gather both microscopic information on nuclear reactions (total and partial cross sections for neutron capture and/or fission reactions) and macroscopic information on transmutation and incineration potentials. Cross sections of selected actinides (241Am, 242Am, 242Pu, 237Np, 238Np) have already been measured at ILL, showing some discrepancies when compared to evaluated data libraries but in overall good agreement with recent experimental data.

  17. Benchmark Evaluation of Dounreay Prototype Fast Reactor Minor Actinide Depletion Measurements

    SciTech Connect

    Hess, J. D.; Gauld, I. C.; Gulliford, J.; Hill, I.; Okajima, S.

    2017-01-01

    Historic measurements of actinide samples in the Dounreay Prototype Fast Reactor (PFR) are of interest for modern nuclear data and simulation validation. Samples of various higher-actinide isotopes were irradiated for 492 effective full-power days and radiochemically assayed at Oak Ridge National Laboratory (ORNL) and Japan Atomic Energy Research Institute (JAERI). Limited data were available regarding the PFR irradiation; a six-group neutron spectra was available with some power history data to support a burnup depletion analysis validation study. Under the guidance of the Organisation for Economic Co-Operation and Development Nuclear Energy Agency (OECD NEA), the International Reactor Physics Experiment Evaluation Project (IRPhEP) and Spent Fuel Isotopic Composition (SFCOMPO) Project are collaborating to recover all measurement data pertaining to these measurements, including collaboration with the United Kingdom to obtain pertinent reactor physics design and operational history data. These activities will produce internationally peer-reviewed benchmark data to support validation of minor actinide cross section data and modern neutronic simulation of fast reactors with accompanying fuel cycle activities such as transportation, recycling, storage, and criticality safety.

  18. The concept of electro-nuclear facility for useful power generation and minor actinides transmutation

    NASA Astrophysics Data System (ADS)

    Bergelson, B. R.; Balyuk, S. A.

    1995-09-01

    The possibility is shown to design in principle the double-purpose liquid fuel electro nuclear facility for useful power generation and minor actinides transmutation in U-Pu fuel cycle conditions. D2O and a melt of fluorine salts are considered as a working media for liquid fuel. Such facility replenished with depicted or natural uranium only makes it possible to generate power of 900 MW (c) for external consumers and serve 20 WWER-1000 reactors for transmutation of MA. The facility could be thought as an alternative to fast reactors since appr. 30% of the total power confined in uranium is utilized in it.

  19. The concept of electro-nuclear facility for useful power generation and minor actinides transmutation

    SciTech Connect

    Bergelson, B.R.; Balyuk, S.A.

    1995-10-01

    The possibility is shown to design in principle the double-purpose liquid fuel electro nuclear facility for useful power generation and minor actinides transmutation in U-Pu fuel cycle conditions. D{sub 2}O and a melt of fluorine salts are considered as a working media for liquid fuel. Such facility replenished with depicted or natural uranium only makes it possible to generate power of 900 MW (c) for external consumers and serve 20 WWER-1000 reactors for transmutation of MA. The facility could be thought as an alternative to fast reactors since appr. 30% of the total power confined in uranium is utilized in it.

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

    SciTech Connect

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

    2011-08-13

    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.

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

    SciTech Connect

    Chabert, C.; Coquelet-Pascal, C.; Saturnin, A.; Mathonniere, G.; Boullis, B.; Warin, D.; Van Den Durpel, L.; Caron-Charles, M.; Garzenne, C.

    2013-07-01

    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.

  2. On the use of moderating material to enhance the feedback coefficients in SFR cores with high minor actinide content

    SciTech Connect

    Merk, B.; Weiss, F. P.

    2012-07-01

    The use of fine distributed moderating material to enhance the feedback effects and to reduce the sodium void effecting sodium cooled fast reactor cores is described. The influence of the moderating material on the neutron spectrum, the power distribution, and the burnup distribution is shown. The consequences of the use of fine distributed moderating material into fuel assemblies with fuel configurations foreseen for minor actinide transmutation is analyzed and the transmutation efficiency is compared. The degradation of the feedback effects due to the insertion of minor actinides and the compensation by the use of moderating materials is discussed. (authors)

  3. Assessment of sensitivity of neutron-physical parameters of fast neutron reactor to purification of reprocessed fuel from minor actinides

    NASA Astrophysics Data System (ADS)

    Cherny, V. A.; Kochetkov, L. A.; Nevinitsa, A. I.

    2013-12-01

    The work is devoted to computational investigation of the dependence of basic physical parameters of fast neutron reactors on the degree of purification of plutonium from minor actinides obtained as a result of pyroelectrochemical reprocessing of spent nuclear fuel and used for manufacturing MOX fuel to be reloaded into the reactors mentioned. The investigations have shown that, in order to preserve such important parameters of a BN-800 type reactor as the criticality, the sodium void reactivity effect, the Doppler effect, and the efficiency of safety rods, it is possible to use the reprocessed fuel without separation of minor actinides for refueling (recharging) the core.

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

    SciTech Connect

    Dr. Pavel V. Tsvetkov

    2009-05-20

    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.

  5. 25 CFR 11.1111 - Minor-in-need-of-care dispositional hearing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Minor-in-need-of-care dispositional hearing. 11.1111 Section 11.1111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1111...

  6. Recent progress on minor-actinide-bearing oxide fuel fabrication at CEA Marcoule

    NASA Astrophysics Data System (ADS)

    Lebreton, Florent; Prieur, Damien; Horlait, Denis; Delahaye, Thibaud; Jankowiak, Aurélien; Léorier, Caroline; Jorion, Frédéric; Gavilan, Elisabeth; Desmoulière, François

    2013-07-01

    Partitioning and transmutation (P&T) of minor actinides (MA: americium, neptunium and curium) in fast neutron reactors or accelerator-driven systems is a route envisaged to reduce nuclear waste inventory. Over the years, several modes of P&T were proposed, each being based on the use of dedicated fuels such as inert-matrix fuels, MA-bearing MOX or MA-bearing blankets. In this context, progress on the manufacturing of such fuels is a key-challenge in order to render P&T viable at the industrial scale. Here, MA-bearing oxide fuel fabrication and characterization conducted in the CEA Marcoule Atalante facility is reviewed. A particular attention is also given to the research conducted on uranium-americium mixed-oxides fuels, which are now considered the reference fuels for MA transmutation in France.

  7. Minor Actinide Recycle in Sodium Cooled Fast Reactors Using Heterogeneous Targets

    SciTech Connect

    Samuel Bays; Pavel Medvedev; Michael Pope; Rodolfo Ferrer; Benoit Forget; Mehdi Asgari

    2009-04-01

    This paper investigates the plausible design of transmutation target assemblies for minor actinides (MA) in Sodium Fast Reactors (SFR). A heterogeneous recycling strategy is investigated, whereby after each reactor pass, un-burned MAs from the targets are blended with MAs produced by the driver fuel and additional MAs from Spent Nuclear Fuel (SNF). A design iteration methodology was adopted for customizing the core design, target assembly design and matrix composition design. The overall design was constrained against allowable peak or maximum in-core performances. While respecting these criteria, the overall design was adjusted to reduce the total number of assemblies fabricated per refueling cycle. It was found that an inert metal-hydride MA-Zr-Hx target matrix gave the highest transmutation efficiency, thus allowing for the least number of targets to be fabricated per reactor cycle.

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

    SciTech Connect

    Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z.; Sekimoto, H.

    2010-06-22

    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.

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

    SciTech Connect

    Greenspan, Ehud; Todreas, Neil; Taiwo, Temitope

    2009-03-10

    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.

  10. Impact of Resonance Treatment on Minor Actinide Incineration in a D-T Thorium Fusion Concept

    NASA Astrophysics Data System (ADS)

    Acır, Adem

    2009-12-01

    Resonance treatments have an essential role to reliable neutronic calculations with different neutronic parameters. In this study presents the effect of resonance treatment and various tritium breeder materials on the incineration of the nitride fuels containing minor actinide mixed thoria in the Deuterium-Tritium fusion driven hybrid reactor as time dependent. Neutron transport calculations under resonance treatment and without resonance treatment are performed by using XSDRNPM/SCALE 5 codes. The impact of resonance treatments and various tritium breeder materials on tritium breeding, energy multiplication, total fission rate (∑f), cumulative fissile fuel enrichment, fissile fuel breeding, average burn up values are comparatively investigated. It is observed that the neutronic results affect from both resonance treatment and the tritium breeder materials as time dependent.

  11. Minor Actinide Transmutation Physics for Low Conversion Ratio Sodium Fast Reactors

    SciTech Connect

    Mehdi Asgari; Samuel E. Bays; Benoit Forget; Rodolfo Ferrer

    2007-09-01

    The effects of varying the reprocessing strategy used in the closed cycle of a Sodium Fast Reactor (SNF) prototype are presented in this paper. The isotopic vector from the aqueous separation of transuranic (TRU) elements in Light Water Reactor (LWR) spent nuclear fuel (SNF) is assumed to also vary according to the reprocessing strategy of the closed fuel cycle. The decay heat, gamma energy, and neutron emission of the fuel discharge at equilibrium are found to vary depending on the separation strategy. The SFR core used in this study corresponds to a burner configuration with a conversion ratio of ~0.5 based on the Super-PRISM design. The reprocessing strategies stemming from the choice of either metal or oxide fuel for the SFR are found to have a large impact on the equilibrium discharge decay heat, gamma energy, and neutron emission. Specifically, metal fuel SFR with pyroprocessing of the discharge produces the largest amount of TRU consumption (166 kg per Effective Full Power Year or EFPY), but also the highest decay heat, gamma energy, and neutron emission. On the other hand, an oxide fuel SFR with PUREX reprocessing minimizes the decay heat and related parameters of interest to a minimum, even when compared to thermal Mixed Oxide (MOX) or Inert Matrix Fuel (IMF) on a per mass basis. On an assembly basis, however, the metal SFR discharge has a lower decay heat than an equivalent oxide SFR assembly for similar minor actinide consumptions (~160 kg/EFPY.) Another disadvantage in the oxide PUREX reprocessing scenario is that there is no consumption of americium and curium, since PUREX reprocessing separates these minor actinides (MA) and requires them to be disposed of externally.

  12. 25 CFR 11.1111 - Minor-in-need-of-care dispositional hearing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Minor-in-need-of-care dispositional hearing. 11.1111 Section 11.1111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1111 Minor-in-need-of-care...

  13. 25 CFR 11.1111 - Minor-in-need-of-care dispositional hearing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Minor-in-need-of-care dispositional hearing. 11.1111 Section 11.1111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1111 Minor-in-need-of-care...

  14. 25 CFR 11.1111 - Minor-in-need-of-care dispositional hearing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Minor-in-need-of-care dispositional hearing. 11.1111 Section 11.1111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1111 Minor-in-need-of-care...

  15. 25 CFR 11.1111 - Minor-in-need-of-care dispositional hearing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Minor-in-need-of-care dispositional hearing. 11.1111 Section 11.1111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1111 Minor-in-need-of-care...

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

    SciTech Connect

    Cao, Y.; Gohar, Y.

    2011-11-04

    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

  17. Extraction chromatographic separation of minor actinides from PUREX high-level wastes using CMPO

    SciTech Connect

    Mathur, J.N.; Murali, M.S.; Iyer, R.H.; Ramanujam, A.; Dhami, P.S.; Gopalakrishnan, V.; Rao, M.K.; Badheka, L.P.; Banerji, A.

    1995-02-01

    An extraction chromatographic technique using octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) adsorbed on chromosorb-102 (CAC) has been tested as an alternative to the TRUEX solvent extraction process, where CMPO has been used as the extracting agent to recover minor actinides from high-activity waste (HAW) solutions of PUREX origin. The batchwise uptake behavior of U(VI), Pu(IV), Am(III), Eu(III), Zr(IV), Fe(III), Ru(III), and TcO{sub 4}{sup {minus}} from a nitric acid medium by CAC has been studied. The uptake of actinides and lanthanides are higher than those of other fission products and inert materials. The batchwise loading experiments in the presence of Nd(III)/U(VI) have shown that at lower concentrations of these metal ions, the uptake of Pu(IV), U(VI), and Am(III) are reasonably high. Studies on loading of Nd(III), U(VI), and Pu(IV) on a column containing 1.7 g of CAC have shown that Nd(III) (30 mg) and U(VI) (90 mg) could be loaded, while Pu(IV) ({approximately}0.6) was loaded on a small column containing 100 mg of CAC without any break-through. Further, a synthetic HAW solution as such and the actual PUREX HAW solution, after depleting the uranium content by a 30% tributyl-phosphate contact, were loaded on a CAC column. The effluents did not contain any alpha activity above the background level. The activities could subsequently be eluted with 0.0.4 M HNO{sub 3} (americium and rare earths), 0.01 M oxalic acid (plutonium), and 0.25 M Na{sub 2}CO{sub 3} [U(VI)]. The recoveries of these metal ions were found to be >99%.

  18. The optimization of an AP1000 fuel assembly for the transmutation of plutonium and minor actinides

    NASA Astrophysics Data System (ADS)

    Washington, Jeremy A.

    The average nuclear power plant produces twenty metric tons of used nuclear fuel per year, containing approximately 95 wt% uranium, 1 wt% plutonium, and 4 wt% fission products and transuranic elements. Fast reactors are a preferred option for the transmutation of plutonium and minor actinides; however, an optimistic deployment time of at least 20 years indicates a need for a near-term solution. The goal of this thesis is to examine the potential of light water reactors for plutonium and minor actinides transmutation as a near-term solution. This thesis screens the available nuclear isotope database to identify potential absorbers as coatings on a transmutation fuel in a light water reactor. A spectral shift absorber coating tunes the neutron energy spectrum experienced by the underlying target fuel. Eleven different spectral shift absorbers (B4C, CdO, Dy2O3, Er 2O3, Eu2O3, Gd2O3, HfO2, In2O3, Lu2O3, Sm2O3, and TaC) have been selected for further evaluation. A model developed using the NEWT module of SCALE 6.1 code provided performance data for the burnup of the target fuel rods. Irradiation of the target fuels occurs in a Westinghouse 17x17 XL Robust Fuel Assembly over a 1400 Effective Full Power Days (EFPD) interval. The fuels evaluated in this thesis include PuO2, Pu3Si2, PuN, MOX, PuZrH, PuZrHTh, PuZrO 2, and PuUZrH. MOX (5 wt% PuO2), Pu0.31ZrH 1.6Th1.08, and PuZrO2MgO (8 wt%) are selected for detailed analysis in a multi-pin transmutation assembly. A coupled model optimized the resulting transmutation fuel elements. The optimization considered three stages of fuel assemblies containing target fuel pins. The first stage optimized four target fuel pins adjacent to the central instrumentation channel. The second stage evaluated a variety of assemblies with multiple target fuel pins and the third stage re-optimized target fuel pins in the second-stage assembly. A PuZrO2MgO (8 wt%) target fuel with a coating of Lu 2O3 resulted in the greatest reduction in curium-244

  19. AECL/US INERI - Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Power Reactors -- Fuel Requirements and Down-Select Report

    SciTech Connect

    William Carmack; Randy D. Lee; Pavel Medvedev; Mitch Meyer; Michael Todosow; Holly B. Hamilton; Juan Nino; Simon Philpot; James Tulenko

    2005-06-01

    potential advantage for more efficient destruction of plutonium and minor actinides (MA) relative to MOX fuel. Greater efficiency in plutonium reduction results in greater flexibility in managing plutonium inventories and in developing strategies for disposition of MA, as well as a potential for fuel cycle cost savings. Because fabrication of plutonium-bearing (and MA-bearing) fuel is expensive relative to UO{sub 2} in terms of both capital and production, cost benefit can be realized through a reduction in the number of plutonium-bearing elements required for a given burn rate. In addition, the choice of matrix material may be manipulated either to facilitate fuel recycling or to make plutonium recovery extremely difficult. In addition to plutonium/actinide management, an inert matrix fuel having high thermal conductivity may have operational and safety benefits; lower fuel temperatures could be used to increase operating and safety margins, uprate reactor power, or a combination of both. The CANDU reactor offers flexibility in plutonium management and MA burning by virtue of online refueling, a simple bundle design, and good neutron economy. A full core of inert matrix fuel containing either plutonium or a plutonium-actinide mix can be utilized, with plutonium destruction efficiencies greater than 90%, and high (>60%) actinide destruction efficiencies. The Advanced CANDU Reactor (ACR) could allow additional possibilities in the design of an IMF bundle, since the tighter lattice pitch and light-water coolant reduce or eliminate the need to suppress coolant void reactivity, allowing the center region of the bundle to include additional fissile material and to improve actinide burning. The ACR would provide flexibility for management of plutonium and MA from the existing LWR fleet, and would be complementary to the AFCI program in the U.S. Many of the fundamental principles concerning the use of IMF are nearly identical in LWRs and the ACR, including fuel

  20. Dispositional Hope and the Propensity to Cope: A Daily Diary Assessment of Minority Adolescents

    PubMed Central

    Roesch, Scott C.; Duangado, Kate M.; Vaughn, Allison A.; Aldridge, Arianna A.; Villodas, Feion

    2011-01-01

    The authors examined the predictive ability of dispositional hope components (pathways, agency) in explaining minority adolescents’ consistent use of daily coping strategies. Using daily diary methodology, 126 low socioeconomic status minority participants completed a multidimensional measure of dispositional hope and reported on subsequent stressful events that they experienced and the coping strategies that they employed over the course of a 5-day period. Multilevel modeling analyses revealed that hope–pathways was uniquely and positively related to direct problem solving, planning, positive thinking, religious coping, distracting action, and overall coping use. Hope–agency was uniquely and positively associated with instrumental support for actions. Discussion focuses on the role of hope as a protective factor for minority adolescents experiencing stress, and particularly the unique predictive ability of each hope component. PMID:20438157

  1. Analysis on fuel breeding capability of FBR core region based on minor actinide recycling doping

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Novitrian, Waris, Abdul; Ismail, Suzuki, Mitsutoshi; Saito, Masaki

    2014-09-01

    Nuclear fuel breeding based on the capability of fuel conversion capability can be achieved by convertion rasio 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 loding 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.

  2. Analysis on fuel breeding capability of FBR core region based on minor actinide recycling doping

    SciTech Connect

    Permana, Sidik; Novitrian,; Waris, Abdul; Ismail; Suzuki, Mitsutoshi; Saito, Masaki

    2014-09-30

    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.

  3. Irradiation Test of Fuel Containing Minor Actinides in the Experimental Fast Reactor Joyo

    NASA Astrophysics Data System (ADS)

    Soga, Tomonori; Sekine, Takashi; Tanaka, Kosuke; Kitamura, Ryoichi; Aoyama, Takafumi

    The mixed oxide containing minor actinides (MA-MOX) fuel irradiation program is being conducted using the experimental fast reactor Joyo of the Japan Atomic Energy Agency to research early thermal behavior of MA-MOX fuel. Two irradiation experiments were conducted in the Joyo MK-III 3rd operational cycle. Six prepared fuel pins included MOX fuel containing 3% or 5% americium (Am-MOX), MOX fuel containing 2% americium and 2% neptunium (Np/Am-MOX), and reference MOX fuel. The first test was conducted with high linear heat rates of approximately 430 W/cm maintained during only 10 minutes in order to confirm whether or not fuel melting occurred. After 10 minutes irradiation in May 2006, the test subassembly was transferred to the hot cell facility and an Am-MOX pin and a Np/Am-MOX pin were replaced with dummy pins including neutron dosimeters. The test subassembly loaded with the remaining four fuel pins was re-irradiated in Joyo for 24-hours in August 2006 at nearly the same linear power to obtain re-distribution data on MA-MOX fuel. Linear heat rates for each pin were calculated using MCNP accounting for both prompt and delayed heating components, and then adjusted using E/C for 10B (n, α) reaction rates measured in the MK-III core neutron field characterization test. Post irradiation examination of these pins to confirm the fuel melting and the local concentration under irradiation of NpO2-x or AmO2-x in the (U, Pu)O2-x fuel are underway. The test results are expected to reduce uncertainties on the design margin in the thermal design for MA-MOX fuel.

  4. Irradiation experiment on fast reactor metal fuels containing minor actinides up to 7 at.% burnup

    SciTech Connect

    Ohta, H.; Yokoo, T.; Ogata, T.; Inoue, T.; Ougier, M.; Glatz, J.P.; Fontaine, B.; Breton, L.

    2007-07-01

    Fast reactor metal fuels containing minor actinides (MAs: Np, Am, Cm) and rare earths (REs) have been irradiated in the fast reactor PHENIX. In this experiment, four types of fuel alloys, U-19Pu-10Zr, U-19Pu-10Zr-2MA-2RE, U-19Pu-10Zr-5MA-5RE and U-19Pu-10Zr-5MA (wt.%), are loaded into part of standard metal fuel stacks. The postirradiation examinations will be conducted at {approx}2.4, {approx}7 and {approx}11 at.% burnup. As for the low-burnup fuel pins, nondestructive postirradiation tests have already been performed and the fuel integrity was confirmed. Furthermore, the irradiation experiment for the intermediate burnup goal of {approx}7 at.% was completed in July 2006. For the irradiation period of 356.63 equivalent full-power days, the neutron flux level remained in the range of 3.5-3.6 x 10{sup 15} n/cm{sup 2}/s at the axial peak position. On the other hand, the maximum linear power of fuel alloys decreased gradually from 305-315 W/cm (beginning of irradiation) to 250-260 W/cm (end of irradiation). The discharged peak burnup was estimated to be 6.59-7.23 at.%. The irradiation behavior of MA-containing metal fuels up to 7 at.% burnup was predicted using the ALFUS code, which was developed for U-Pu-Zr ternary fuel performance analysis. As a result, it was evaluated that the fuel temperature is distributed between {approx}410 deg. C and {approx}645 deg. C at the end of the irradiation experiment. From the stress-strain analysis based on the preliminarily employed cladding irradiation properties and the FCMI stress distribution history, it was predicted that a cladding strain of not more than 0.9% would appear. (authors)

  5. Evaluation of Homogeneous Options: Effects of Minor Actinide Exclusion from Single and Double Tier Recycle in Sodium Fast Reactors

    SciTech Connect

    R. M. Ferrer; S. Bays; M. Pope

    2008-03-01

    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.

  6. Recovery of minor actinides from spent fuel using TPEN-immobilized gels

    SciTech Connect

    Koyama, S.; Suto, M.; Ohbayashi, H.; Oaki, H.; Takeshita, K.

    2013-07-01

    A series of separation experiments was performed in order to study the recovery process for minor actinides (MAs), such as americium (Am) and curium (Cm), from the actual spent fuel by using an extraction chromatographic technique. N,N,N',N'-tetrakis-(4-propenyloxy-2-pyridylmethyl) ethylenediamine (TPPEN) is an N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) analogue consisting of an incorporated pyridine ring that acts as not only a ligand but also as a site for polymerization and crosslinking of the gel. The TPPEN and N-isopropylacrylamide (NIPA) were dissolved into dimethylformamide (DMF, Wako Co., Ltd.) and a silica beads polymer, and then TTPEN was immobilized chemically in a polymer gel (so called TPEN-gel). Mixed oxide (MOX) fuel, which was highly irradiated up to 119 GWD/MTM in the experimental fast reactor Joyo, was used as a reference spent fuel. First, uranium (U) and plutonium (Pu) were separated from the irradiated fuel using an ion-exchange method, and then, the platinum group elements were removed by CMPO to leave a mixed solution of MAs and lanthanides. The 3 mol% TPPEN-gel was packed with as an extraction column (CV: 1 ml) and then rinsed by 0.1 M NaNO{sub 3}(pH 4.0) for pH adjustment. After washing the column by 0.01 M NaNO{sub 3} (pH 4.0), Eu was detected and the recovery rate reached 93%. The MAs were then recovered by changing the eluent to 0.01 M NaNO{sub 3} (pH 2.0), and the recovery rate of Am was 48 %. The 10 mol% TPPEN-gel was used to improve adsorption coefficient of Am and a condition of eluent temperature was changed in order to confirm the temperature swing effect on TPEN-gel for MA. More than 90% Eu was detected in the eluent after washing with 0.01 M NaNO{sub 3} (pH 3.5) at 5 Celsius degrees. Americium was backwardly detected and eluted continuously during the same condition. After removal of Eu, the eluent temperature was changed to 32 Celsius degrees, then Am was detected (pH 3.0). Finally remained Am could be stripped

  7. AECL/U.S. INERI - Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Power Reactors Fuel Requirements and Down-Select Report

    SciTech Connect

    William Carmack; Randy Fielding; Pavel Medvedev; Mitch Meyer

    2005-08-01

    This report documents the first milestone of the International Nuclear Energy Research Initiative (INERI) U.S./Euratom Joint Proposal 1.8 entitled “Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Light-Water Reactors.” The milestone represents the assessment and preliminary study of a variety of fuels that hold promise as transmutation and minor actinide burning fuel compositions for light-water reactors. The most promising fuels of interest to the participants on this INERI program have been selected for further study. These fuel compositions are discussed in this report.

  8. U.S./EURATOM INERI - Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in LWRs -- Fuel Requirements and Down-Select Report

    SciTech Connect

    William Carmack; Randy Fielding; Pavel Medvedev; Mitch Meyer

    2005-08-01

    This report documents the first milestone of the International Nuclear Energy Research Initiative (INERI) U.S./Canada Joint Proposal entitled “Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Power Reactors.” The milestone represents the assessment and preliminary study of a variety of fuels that hold promise as transmutation and minor actinide burning fuel compositions for light water reactors. The most promising fuels of interest to the participants on this INERI program have been selected for further study. These fuel compositions are discussed in this report.

  9. Evaluation of Heterogeneous Options: Effects of MgO versus UO2 Matrix Selection for Minor Actinide Targets in a Sodium Fast Reactor

    SciTech Connect

    M. Pope; S. Bays; R. Ferrer

    2008-03-01

    The primary focus of this work was to compare MgO with UO2 as target matrix material options for burning minor actinides in a transmutation target within a sodium fast reactor. This analysis compared the transmutation performance of target assemblies having UO2 matrix to those having specifically MgO inert matrix.

  10. Sigma Team for Minor Actinide Separation: PNNL FY 2010 Status Report

    SciTech Connect

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

    2010-08-24

    Work conducted at Pacific Northwest National Laboratory (PNNL) in FY 2010 addressed two lines of inquiry. The two hypotheses put forth were: 1. The extractants from the TRUEX( ) process (CMPO)( ) and from the TALSPEAK( ) process (HDEHP)( ) can be combined into a single process solvent to separate 1) the lanthanides and actinides from acidic high-level waste and 2) the actinides from the lanthanides in a single solvent extraction process. (Note: This combined process will hereafter be referred to as the TRUSPEAK process.) A series of empirical measurements performed (both at PNNL and Argonne National Laboratory) in FY 2009 supported this hypothesis, but also indicated some nuances to the chemistry. Lanthanide/americium separation factors of 12 and higher were obtained with a prototypic TRUSPEAK solvent when extracting the lanthanides from a citrate-buffered DTPA( ) solution. Although the observed separation factors are sufficiently high to design an actinide/lanthanide separation process, a better understanding of the chemistry is expected to lead to improved solvent formulations and improved process performance. Work in FY 2010 focused on understanding the synergistic extraction behavior observed for Nd(III) and Am(III) when extracted into mixtures of CMPO and HDEHP. The interaction between CMPO and HDEHP in dodecane was investigated by 31P NMR spectroscopy, and an adduct of the type CMPO•HDEHP was found to form. The formation of this adduct will reduce the effective extractant concentrations and must be taken into account when modeling metal ion extraction data in this system. Studies were also initiated to determine the Pitzer parameters for Nd(III) in lactate media. 2. Higher oxidation states (e.g., +5 and +6) of Am can be stabilized in solution by complexation with uranophilic ligands, and this chemistry can be exploited to separate Am from Cm. To test this hypothesis, the previously reported stereognostic uranophilic ligands NPB( ) and ETAC(e) were

  11. Fission cross-section measurements on 233U and minor actinides at the CERN n_TOF facility

    NASA Astrophysics Data System (ADS)

    Calviani, M.; Colonna, N.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Sesura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Ketlerov, V.; Kerveno, M.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krtička, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martínez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K.

    2009-10-01

    Neutron-induced fission cross-sections of minor actinides have been measured at the white neutron source n_TOF at CERN, Geneva. The studied isotopes include 233U, interesting for Th/U based nuclear fuel cycles, 241,243Am and 245Cm, relevant for transmutation and waste reduction studies in new generation fast reactors (Gen-IV) or Accelerator Driven Systems. The measurements take advantage of the unique features of the n_TOF facility, namely the wide energy range, the high instantaneous neutron flux and the low background. Results for the involved isotopes are reported from ~30 meV to around 1 MeV neutron enegy. The measurements have been performed with a dedicated Fission Ionization Chamber (FIC), relative to the standard cross-section of the 235U fission reaction, measured simultaneously with the same detector. Results are here reported.

  12. Granulation and infiltration processes for the fabrication of minor actinide fuels, targets and conditioning matrices

    NASA Astrophysics Data System (ADS)

    Nästren, C.; Fernandez, A.; Haas, D.; Somers, J.; Walter, M.

    2007-05-01

    The impact of Pu and Am, two elements that potentially pose a long term hazard for the disposal of spent nuclear fuel, can be abated by their reintroduction into the fuel cycle for transmutation. Such transmutation targets can be fabricated by a sol gel method for the production of porous inactive beads, which are then infiltrated by Am solutions. Following calcination, compaction into pellets and sintering, the product is obtained. At its heart, the sol gel process relies on an ammonia precipitation, so that it is not universally applicable. Therefore, an alternative is sought not just to overcome this chemical limitation, but also to simplify the process and reduce waste streams. The new concept utilises powder metallurgy routes (compaction, crushing and sieving) to produce porous, almost, dust free granules, which are infiltrated with the actinide nitrate. The method has been developed using yttria stabilised zirconia and alumina, and has been demonstrated for the production of Al2O3-AmO2 targets for neutron capture investigations. The results are very promising and meet light water reactor fuel specifications. In addition, the process is ideally suited for the production of ceramic matrices for conditioning actinides for geological disposal.

  13. Comparison of Aromatic Dithiophoshinic and Phosphinic Acid Derivatives for Minor Actinide Extraction

    SciTech Connect

    John R. Klaehn; Dean R. Peterman; Mason K. Harrup; Richard D. Tillotson; Mitchell R. Greenhalgh; Thomas A. Luther; Jack D. Law; Lee M. Daniels

    2008-03-01

    A new extractant for the separation of actinide(III) and lanthanide(III), bis(otrifluoromethylphenyl) phosphinic acid (O-PA) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(otrifluoromethylphenyl) dithiophosphinic acid (S-PA). Multinuclear NMR spectroscopy was used for elementary characterization of the new O-PA derivative. This new O-PA extractant was used to perform Am(III)/Eu(III) separations and the results were directly compared to those obtained in identical separation experiments using S-PA, an extractant that is known to exhibit separation factors of ~100,000 at low pH. The separations data are presented and discussed in terms comparing the nature of the oxygen atom as a donor to that of the sulfur atom in extractants that are otherwise identical.

  14. Comparison of Dithiophosphinic and Phosphinic Acid Derivatives for Minor Actinide Extraction

    SciTech Connect

    Mason K Harrup; Dean R. Peterman; Thomas A. Luther; Mitchell R. Greenhalgh; John R. Klaehn

    2008-03-01

    A new extractant for the separation of actinide(III) and lanthanide(III), bis(otrifluoromethylphenyl) phosphinic acid (O-PA) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(otrifluoromethylphenyl) dithiophosphinic acid (S-PA). Multinuclear NMR spectroscopy was used for elementary characterization of the new O-PA derivative. This new O-PA extractant was used to perform Am(III)/Eu(III) separations and the results were directly compared to those obtained in identical separation experiments using S-PA, an extractant that is known to exhibit separation factors of ~100,000 at low pH. The separations data are presented and discussed in terms comparing the nature of the oxygen atom as a donor to that of the sulfur atom in extractants that are otherwise identical.

  15. Progress of nitride fuel cycle research for transmutation of minor actinides

    SciTech Connect

    Arai, Yasuo; Akabori, Mitsuo; Minato, Kazuo

    2007-07-01

    Recent progress of nitride fuel cycle research for transmutation of MA is summarized. Preparation of MA-bearing nitride pellets, such as (Np,Am)N, (Am,Pu)N and (Np,Pu,Am,Cm)N, was carried out. Irradiation behavior of U-free nitride fuel was investigated by the irradiation test of (Pu,Zr)N and PuN+TiN fuels, in which ZrN and TiN were added as a possible diluent material. Further, pyrochemical process of spent nitride fuel was developed by electrorefining in a molten chloride salt and subsequent re-nitridation of actinides in liquid Cd cathode electro-deposits. Nitride fuel cycle for transmutation of MA has been demonstrated in a laboratory scale by the experimental study with MA and Pu. (authors)

  16. Computational Benchmark for Estimation of Reactivity Margin from Fission Products and Minor Actinides in PWR Burnup Credit

    SciTech Connect

    Wagner, J.C.

    2001-08-02

    This report proposes and documents a computational benchmark problem for the estimation of the additional reactivity margin available in spent nuclear fuel (SNF) from fission products and minor actinides in a burnup-credit storage/transport environment, relative to SNF compositions containing only the major actinides. The benchmark problem/configuration is a generic burnup credit cask designed to hold 32 pressurized water reactor (PWR) assemblies. The purpose of this computational benchmark is to provide a reference configuration for the estimation of the additional reactivity margin, which is encouraged in the U.S. Nuclear Regulatory Commission (NRC) guidance for partial burnup credit (ISG8), and document reference estimations of the additional reactivity margin as a function of initial enrichment, burnup, and cooling time. Consequently, the geometry and material specifications are provided in sufficient detail to enable independent evaluations. Estimates of additional reactivity margin for this reference configuration may be compared to those of similar burnup-credit casks to provide an indication of the validity of design-specific estimates of fission-product margin. The reference solutions were generated with the SAS2H-depletion and CSAS25-criticality sequences of the SCALE 4.4a package. Although the SAS2H and CSAS25 sequences have been extensively validated elsewhere, the reference solutions are not directly or indirectly based on experimental results. Consequently, this computational benchmark cannot be used to satisfy the ANS 8.1 requirements for validation of calculational methods and is not intended to be used to establish biases for burnup credit analyses.

  17. Actinides in the Geosphere

    NASA Astrophysics Data System (ADS)

    Runde, Wolfgang; Neu, Mary P.

    Since the 1950s actinides have been used to benefit industry, science, health, and national security. The largest industrial application, electricity generation from uranium and thorium fuels, is growing worldwide. Thus, more actinides are being mined, produced, used and processed than ever before. The future of nuclear energy hinges on how these increasing amounts of actinides are contained in each stage of the fuel cycle, including disposition. In addition, uranium and plutonium were built up during the Cold War between the United States and the Former Soviet Union for defense purposes and nuclear energy.

  18. One-group fission cross sections for plutonium and minor actinides inserted in calculated neutron spectra of fast reactor cooled with lead-208 or lead-bismuth eutectic

    SciTech Connect

    Khorasanov, G. L.; Blokhin, A. I.

    2012-07-01

    The paper is dedicated to one-group fission cross sections of Pu and MA in LFRs spectra with the aim to increase these values by choosing a coolant which hardens neutron spectra. It is shown that replacement of coolant from Pb-Bi with Pb-208 in the fast reactor RBEC-M, designed in Russia, leads to increasing the core mean neutron energy. As concerns fuel Pu isotopes, their one-group fission cross sections become slightly changed, while more dramatically Am-241 one-group fission cross section is changed. Another situation occurs in the lateral blanket containing small quantities of minor actinides. It is shown that as a result of lateral blanket mean neutron energy hardening the one-group fission cross sections of Np-237, Am-241 and Am-243 increases up to 8-11%. This result allows reducing the time of minor actinides burning in FRs. (authors)

  19. Neutronic Analysis for Transmutation of Minor Actinides and Long-Lived Fission Products in a Fusion-Driven Transmuter (FDT)

    NASA Astrophysics Data System (ADS)

    Yapıcı, Hüseyin; Demir, Nesrin; Genç, Gamze

    2006-12-01

    This study presents the transmutations of both the minor actinides (MAs: 237Np, 241Am, 243Am and 244Cm) and the long-lived fission products (LLFPs: 99Tc, 129I and 135Cs), discharged from high burn-up PWR-MOX spent fuel, in a fusion-driven transmuter (FDT) and the effects of the MA and LLFP volume fractions on their transmutations. The blanket configuration of the FDT is improved by analyzing various sample blanket design combinations with different radial thicknesses. Two different transmutation zones (TZMA and TZFP which contain the MA and LLFP nuclides, respectively) are located separately from each other. The volume fractions of the MA and the LLFP are raised from 10 to 20% stepped by 2% and from 10 to 80% stepped by 5%, respectively. The calculations are performed to estimate neutronic parameters and transmutation characteristics per D-T fusion neutron. The conversion ratios (CRs) for the whole of all MAs are about 65-70%. The transmutation rates of the LLFP nuclides increase linearly with the increase of volume fractions of the MA, and the 99Tc nuclide among them has the highest transmutation rate. The variations of their transmutation rate per unit volume in the radial direction are quasi-concave parabolic.

  20. Synthesis and structure of Ce1-xEuxPO4 solid solutions for minor actinides immobilization

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohuan; Teng, Yuancheng; Huang, Yi; Wu, Lang; Zeng, Pan

    2014-08-01

    Ce1-xEuxPO4 (x = 0-1) solid solutions were synthesized by the solid state reaction process using europium (Eu) as the surrogate for trivalent minor actinide americium (Am). The effects of calcination temperature, holding time and Eu content on the crystalline phase, microstructure and morphology of Ce1-xEuxPO4 (x = 0-1) were investigated. The monazite-type EuPO4 and CePO4 coexisted after being calcined at 1000 °C for 4 h, suggesting the CePO4 and EuPO4 phases would form initially separately. Pure and single-phase monazite-type Ce1-xEuxPO4 (x = 0-1) powders were obtained at 1300 °C for 4 h. The results of the XRD patterns Rietveld refinement and μ-Raman analysis confirmed the formation of a Ce1-xEuxPO4 (x = 0-1) continuous solid solution. The grain size of Ce0.5Eu0.5PO4 increased obviously as the holding time extended. The Ce, Eu, P and O elements were almost distributed homogeneously in the Ce0.5Eu0.5PO4 solid solution.

  1. Experimental Findings On Minor Actinide And Lanthanide Separations Using Ion Exchange

    SciTech Connect

    Hobbs, D. T.; Shehee, T. C.; Clearfield, A.

    2013-09-17

    This project seeks to determine if inorganic or hybrid inorganic ion-exchange materials can be exploited to provide effective americium and curium separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of the tested ion-exchange materials for actinide and lanthanide ions. During FY13, experimental work focused in the following areas: (1) investigating methods to oxidize americium in dilute nitric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium and (2) synthesis, characterization and testing of ion-exchange materials. Ion-exchange materials tested included alkali titanates, alkali titanosilicates, carbon nanotubes and group(IV) metal phosphonates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of Am(III). Experimental findings indicated that Pu(IV) is oxidized to Pu(VI) by peroxydisulfate, but there are no indications that the presence of plutonium affects the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used. Tests also explored the influence of nitrite on the oxidation of Am(III). Given the formation of Am(V) and Am(VI) in the presence of nitrite, it appears that nitrite is not a strong deterrent to the oxidation of Am(III), but may be limiting Am(VI) by quickly reducing Am(VI) to Am(V). Interestingly, additional absorbance peaks were observed in the UV-Vis spectra at 524 and 544 nm in both nitric acid and perchloric acid solutions when the peroxydisulfate was added as a solution. These peaks have not been previously observed and do not correspond to the expected peak locations for oxidized americium in solution. Additional studies are in progress to identify these unknown peaks. Three titanosilicate ion exchangers were synthesized using a microwave-accelerated reaction system (MARS) and determined to have high affinities

  2. Increasing the Acceptance of Spent Nuclear Fuel Disposal by the Transmutation of Minor Actinides Using an Accelerator

    NASA Astrophysics Data System (ADS)

    Sheffield, Richard L.

    2010-02-01

    The main challenge in nuclear fuel cycle closure is the reduction of the potential radiotoxicity of spent LWR nuclear fuel, or the length of time in which that potential hazard exists. Partitioning and accelerator-based transmutation in combination with geological disposal can lead to an acceptable societal solution for the nuclear spent fuel management problem. Nuclear fuel seems ideally suited for recycling. Only a small fraction of the available energy in the fuel is extracted in a single pass and the problem isotopes, consisting of the transuranic elements plutonium, neptunium, americium, curium and the long-lived fission products iodine and technetium, could be burned in fast-neutron spectrum reactors or sub-critical accelerator driven transmuters. Most of the remaining wastes have half-lives of a few hundred years and can be safely stored in man-made containment structures (casks or glass). The very small amount of remaining long-lived waste could be safely stored in a small geologic repository. The problem for the next 100 years is that a sufficient number of fast reactors are unlikely to be built by industry to burn its own waste and the waste from existing and new light water reactors (LWRs). So an interim solution is required to transition to a fast reactor economy. The goals of accelerator transmutation are some or all of the following: 1) to significantly reduce the impacts due to the minor actinides on the packing density and long-term radiotoxicity in the repository design, 2) preserve/use the energy-rich component of used nuclear fuel, and 3) reduce proliferation risk. Accelerator-based transmutation could lead to a greater percentage of our power coming from greenhouse-gas emission-free nuclear power and provide a long-term strategy enabling the continuation and growth of nuclear power in the U.S. )

  3. Zirconia Inert Matrix Fuel for Plutonium and Minor Actinides Management in Reactors and as an Ultimate Waste Form

    SciTech Connect

    Degueldre, Claude; Wiesenack, Wolfgang

    2008-07-01

    An yttria stabilised zirconia doped with plutonia and erbia has been selected as inert matrix fuel (IMF) at PSI. The results of experimental irradiation tests on yttria-stabilised zirconia doped with plutonia and erbia pellets in the Halden research reactor as well as a study of zirconia solubility are presented. Zirconia must be stabilised by yttria to form a solid solution such as MAz(Y,Er){sub y}Pu{sub x}Zr{sub 1-y}O{sub 2-{xi}} where minor actinides (MA) oxides are also soluble. (Er,Y,Pu,Zr)O{sub 2-{xi}} (with Pu containing 5% Am) was successfully prepared at PSI and irradiated in the Halden reactor. Emphasis is given on the zirconia- IMF properties under in-pile irradiation, on the fuel material centre temperatures and on the fission gas release. The retention of fission products in zirconia may be stronger at similar temperature, compared to UO{sub 2}. The outstanding behaviour of plutonia-zirconia inert matrix fuel is compared to the classical (U,Pu)O{sub 2} fuels. The properties of the spent fuel pellets are presented focusing on the once-through strategy. For this strategy, low solubility of the inert matrix is required for geological disposal. This parameter was studied in detail for a range of solutions corresponding to groundwater under near field conditions. Under these conditions the IMF solubility is about 109 times smaller than glass, several orders of magnitude lower than UO{sub 2} in oxidising conditions (Yucca Mountain) and comparable in reducing conditions, which makes the zirconia material very attractive for deep geological disposal. The behaviour of plutonia-zirconia inert matrix fuel is discussed within a 'burn and bury' strategy. (authors)

  4. Quantification of the Partitioning Ratio of Minor Actinide Surrogates between Zirconolite and Glass in Glass-Ceramic for Nuclear Waste Disposal.

    PubMed

    Liao, Chang-Zhong; Liu, Chengshuai; Su, Minhua; Shih, Kaimin

    2017-08-21

    Zirconolite-based glass-ceramic is considered a promising wasteform for conditioning minor actinide-rich nuclear wastes. Recent studies on this wasteform have sought to enhance the partitioning ratio (PR) of minor actinides in zirconolite crystal. To optimize the PR in the SiO2-Al2O3-CaO-TiO2-ZrO2 system, a novel conceptual approach, which can be derived from the chemical composition and quantity of zirconolite crystal in glass-ceramic, was introduced based on the results of Rietveld quantitative X-ray diffraction analysis and transmission electron microscopy energy dispersive X-ray spectroscopy. To verify this new conceptual approach, the influences of the crystallization temperature, the concentration of additives, and ionic radii on the PR of various surrogates (Ce, Nd, Gd, and Yb) in zirconolite were examined. The results reveal that the PR of Nd(3+) in zirconolite can be as high as 41%, but it decreases as the crystallization temperature increases. The quantities of all phases (including crystalline and amorphous) remained nearly constant when increasing the loading of Nd2O3 in glass-ceramic products crystallized at 1050 °C for 2 h. Correspondingly, the PR of Nd(3+) decreases in a linear fashion with the loading contents of Nd2O3. The radius of ions also has a great influence on the PR, and an increase in the ionic radius leads to a decrease in the PR. This new approach will be an important tool to facilitate the exploration of a glass-ceramic matrix for the disposal of minor actinide-rich nuclear wastes.

  5. Nuclear waste forms for actinides.

    PubMed

    Ewing, R C

    1999-03-30

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The "mineralogic approach" is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium.

  6. Bias estimates used in lieu of validation of fission products and minor actinides in MCNP Keff calculations for PWR burnup credit casks

    SciTech Connect

    Mueller, Don E.; Marshall, William J.; Wagner, John C.; Bowen, Douglas G.

    2015-09-01

    The U.S. Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation recently issued Interim Staff Guidance (ISG) 8, Revision 3. This ISG provides guidance for burnup credit (BUC) analyses supporting transport and storage of PWR pressurized water reactor (PWR) fuel in casks. Revision 3 includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MA). Based on previous work documented in NUREG/CR-7109, recommendation 4 of ISG-8, Rev. 3, includes a recommendation to use 1.5 or 3% of the FP&MA worth to conservatively cover the bias due to the specified FP&MAs. This bias is supplementary to the bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF and does not address extension to actinides and fission products beyond those identified herein. The work described in this report involves comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII based nuclear data and supports use of the 1.5% FP&MA worth bias when either SCALE or MCNP codes are used for criticality calculations, provided the other conditions of the recommendation 4 are met. The method used in this report may also be applied to demonstrate the applicability of the 1.5% FP&MA worth bias to other codes using ENDF/B V, VI or VII based nuclear data. The method involves use of the applicant s computational method to generate FP&MA worths for a reference SNF cask model using specified spent fuel compositions. The applicant s FP&MA worths are then compared to reference values provided in this report. The applicants FP&MA worths should not exceed the reference results by more than 1.5% of the reference FP&MA worths.

  7. Gadolinium speciation with Tetradentate, N-donor extractants for minor actinide/lanthanide separation: an XRD, mass spectrometry and EPR study

    SciTech Connect

    Whittaker, D.M.; Sharrad, C.A.; Sproules, S.

    2013-07-01

    The hydrophobic organic molecules CyMe{sub 4}-BTPhen (1) and CyMe{sub 4}-BTBP (2) have been developed and tuned over many years to be able to separate the trivalent actinides from the trivalent lanthanides (Ln) selectively in bi-phasic solvent extraction processes for the separation of the long-lived radio-toxic minor actinides from spent nuclear fuel. The ability of these N-donor ligands to perform this separation is poorly understood, as is their speciation with the metal ions when extracted into the organic phase. Our previous work has shown Ln{sup 3+} speciation to be largely 1:2 Ln:L in nature with another small molecule, either water or nitrate, occupying a cavity between the tetradentate bound N-donor ligands. The identity of the small molecule changes across the lanthanide series, and here we continue investigations into this speciation. Complexes of these N-donor ligands with Gd{sup 3+} have been synthesised and characterised by X-ray crystallography, mass spectrometry and EPR spectroscopy. We show that the N-donor ligands have no effect on the electronic configuration of Gd{sup 3+} and that the lanthanide contraction with the steric rigidity of the N-donor ligand appears to determine the size of the cavity between the coordinated ligands. This in turn appears to control the identity of the small molecule on the ninth site in the 1:2 Gd:L species. (authors)

  8. Atomistic Calculations of the Effect of Minor Actinides on Thermodynamic and Kinetic Properties of UO{sub 2{+-}x}

    SciTech Connect

    Deo, Chaitanya; Adnersson, Davis; Battaile, Corbett; uberuaga, Blas

    2012-10-30

    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

  9. Extending FEAST-METAL for analysis of low content minor actinide bearing and zirconium rich metallic fuels for sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın

    2011-07-01

    Computational models in FEAST-METAL fuel behaviour code have been upgraded to simulate minor actinide bearing zirconium rich metallic fuels for use in sodium fast reactors. Increasing the zirconium content to 20-40 wt.% causes significant changes in fuel slug microstructure affecting thermal, mechanical, chemical, and fission gas behaviour. Inclusion of zirconium rich phase reduces the fission gas swelling rate significantly in early irradiation. Above the threshold fission gas swelling, formation of micro-cracks, and open pores increase material compliancy enhance diffusivity, leading to rapid fuel gas swelling, interconnected porosity development and release of the fission gases and helium. Production and release of helium was modelled empirically as a function of americium content and fission gas production, consistent with previous Idaho National Laboratory studies. Predicted fuel constituent redistribution is much smaller compared to typical U-Pu-10Zr fuel operated at EBR-II. Material properties such as fuel thermal conductivity, modulus of elasticity, and thermal expansion coefficient have been approximated using the available database. Creep rate and fission gas diffusivity of high zirconium fuel is lowered by an order of magnitude with respect to the reference low zirconium fuel based on limited database and in order to match experimental observations. The new code is benchmarked against the AFC-1F fuel assembly post irradiation examination results. Satisfactory match was obtained for fission gas release and swelling behaviour. Finally, the study considers a comparison of fuel behaviour between high zirconium content minor actinide bearing fuel and typical U-15Pu-6Zr fuel pins with 75% smear density. The new fuel has much higher fissile content, allowing for operating at lower neutron flux level compared to fuel with lower fissile density. This feature allows the designer to reach a much higher burnup before reaching the cladding dose limit. On the other

  10. Actinides-1981

    SciTech Connect

    Not Available

    1981-09-01

    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.

  11. Uptake Mechanisms of Eu(III) on Hydroxyapatite: A Potential Permeable Reactive Barrier Backfill Material for Trapping Trivalent Minor Actinides.

    PubMed

    Xu, Lin; Zheng, Tao; Yang, Shitong; Zhang, Linjuan; Wang, Jianqiang; Liu, Wei; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2016-04-05

    The permeable reactive barrier (PRB) technique has attracted an increasing level of attention for the in situ remediation of contaminated groundwater. In this study, the macroscopic uptake behaviors and microscopic speciation of Eu(III) on hydroxyapatite (HAP) were investigated by a combination of theoretical modeling, batch experiments, powder X-ray diffraction (PXRD) fitting, and X-ray absorption spectroscopy (XAS). The underlying removal mechanisms were identified to further assess the application potential of HAP as an effective PRB backfill material. The macroscopic analysis revealed that nearly all dissolved Eu(III) in solution was removed at pH 6.5 within an extremely short reaction time of 5 min. In addition, the thermodynamic calculations, desorption experiments, and PXRD and XAS analyses definitely confirmed the formation of the EuPO4·H2O(s) phase during the process of uptake of dissolved Eu(III) by HAP via the dissolution-precipitation mechanism. A detailed comparison of the present experimental findings and related HAP-metal systems suggests that the relative contribution of precipitation to the total Eu(III) removal increases as the P:Eu ratio decreases. The dosage of HAP-based PRB for the remediation of groundwater polluted by Eu(III) and analogous trivalent actinides [e.g., Am(III) and Cm(III)] should be strictly controlled depending on the dissolved Eu(III) concentration to obtain an optimal P:M (M represents Eu, Am, or Cm) ratio and treatment efficiency.

  12. Synthesis, phase structure and microstructure of monazite-type Ce1-xPrxPO4 solid solutions for immobilization of minor actinide neptunium

    NASA Astrophysics Data System (ADS)

    Zeng, Pan; Teng, Yuancheng; Huang, Yi; Wu, Lang; Wang, Xiaohuan

    2014-09-01

    Praseodymium was used as the surrogate for trivalent minor actinide neptunium, and a complete series of pure monazite-type Ce1-xPrxPO4 (x = 0-1) solid solutions were successfully prepared by the solid state reaction. The effects of calcining temperature, holding time and Pr content on the structure of Ce1-xPrxPO4 solid solutions were investigated. The results show that although Pr6O11 (Pr23+Pr44+O11) exists two stabilized oxidation states, there has been no tetravalent praseodymium phosphate during the synthesis process. The optimized temperature for the synthesis of Ce0.8Pr0.2PO4 solid solution is more than 1100 °C, and a hypothetical reaction mechanism is also proposed. Besides, the crystalline grains coarsen as the increasing of holding time. The linear variation of unit cell parameters and a gradual hypsochromic shift in the Raman spectra are observed with the increase of Pr content, indicating that cerium is progressively replaced by praseodymium and Ce1-xPrxPO4 solid solutions were prepared.

  13. Basic Characteristics of Bis(2-ethylhexyl)phosphate-impregnated Adsorbent Used for Separation of Minor Actinides from FBR-Spent Fuel

    NASA Astrophysics Data System (ADS)

    Oda, Ryohei; Arai, Tsuyoshi; Nagayama, Katsuhisa; Watanabe, Sou; Sano, Yuichi; Myouchin, Munetaka

    FBR-spent nuclear fuel includes a great deal of minor actinides (MA: Am and Cm), which become febrile. Radioactive wastes including MA require a large area of ground for dumping and result in high cost. In Fast Reactor Cycel System Technology Development Project (FaCT) in Japan, we have been investigating extraction chromatography for separation of long-lived MA and specific fission products (FP) from high-level liquid wastes (HLLW). This method is expected to allow us to reduce an organic solvent use and to realize compact equipment. In this work, we have studied the static and dynamic adsorption behavior of representative FP contained in HLLW, Mo(VI), Zr(IV), Nd(III) and EU(III), on a bis(2-ethylhexyl)phosphate (HDEHP)-impregnated adsorbent. Such fundamental data should facilitate the efficient design of efficient MA recovery processes. Column adsorption experiments with the HDEHP-impregnated adsorbent have revealed that an increase in a flow rate results in a short breakthrough time and reduces the adsorption capacity of the column for all the elements tested. These results strongly suggest that a lower flow rate is preferable to enhance the adsorption capacity of the adsorbent.

  14. The carbon matrices made of pyrolyzed phthalocyanines as a base for encapsulation of the long-lived nuclides of iodine, technetium and minor actinides

    SciTech Connect

    Tikhonov, V.I.; Moskalev, P.N.; Kapustin, V.K.

    2007-07-01

    The creation and careful investigation of suitable materials and forms for transmutation of the long-lived radioactive waste (RW) is mainly in the starting stage. A new carbon material formed as a result of pyrolysis of bis-phthalocyanine, Pc2Me, gives a chance to solve this goal successfully. The pyrolysis takes place under an argon (Ar) atmosphere at temperature of 700 - 800 deg. C. The release of atoms encapsulated inside this carbon matrix occurs only at temperatures above 1200 deg. C, and a correlation between the efficiency of the atoms' release and their atomic radius has been revealed. It is caused with creation of closed micro-cavities in the carbon skeleton during pyrolysis of MeC 2. Due to inert features and high thermostability of carbon, an inculcation of the long-lived radionuclides in these micro-cavities by means of their phthalocyanines pyrolysis gives unique opportunities for both their transmutation and storage. The first results on encapsulation within matrixes of radionuclides of europium (Eu), technetium (Te), iodine (I) and 'minor actinides' are presented. The efficiency of encapsulation is close to 100% for all studied elements excluding iodine, for the last one, it is near 85-90%. The results on thermochemical stability, leaching and other tests of these matrixes are presented. (authors)

  15. Nuclear waste forms for actinides

    PubMed Central

    Ewing, Rodney C.

    1999-01-01

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The “mineralogic approach” is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium. PMID:10097054

  16. 33rd Actinide Separations Conference

    SciTech Connect

    McDonald, L M; Wilk, P A

    2009-05-04

    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.

  17. 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

    Timothy A. Hyde

    2012-06-01

    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.

  18. Transmutation of actinides in power reactors.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides.

  19. Actinide metal processing

    DOEpatents

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

    1992-03-24

    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.

  20. Actinide metal processing

    DOEpatents

    Sauer, Nancy N.; Watkin, John G.

    1992-01-01

    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.

  1. Hydrothermal Synthesis and Crystal Structures of Actinide Compounds

    NASA Astrophysics Data System (ADS)

    Runde, Wolfgang; Neu, Mary P.

    Since the 1950s actinides have been used to benefit industry, science, health, and national security. The largest industrial application, electricity generation from uranium and thorium fuels, is growing worldwide. Thus, more actinides are being mined, produced, used and processed than ever before. The future of nuclear energy hinges on how these increasing amounts of actinides are contained in each stage of the fuel cycle, including disposition. In addition, uranium and plutonium were built up during the Cold War between the United States and the Former Soviet Union for defense purposes and nuclear energy. These stockpiles have been significantly reduced in the last decade.

  2. Development of the Actinide-Lanthanide Separation (ALSEP) Process

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Niver, Cynthia M.; Gelis, Artem V.

    2014-09-30

    Separating the minor actinide elements (Am and Cm) from acidic high-level raffinates arising from the reprocessing of irradiated nuclear fuel is an important step in closing the nuclear fuel cycle. Most proposed approaches to this problem involve two solvent extraction steps: 1) co-extraction of the trivalent lanthanides and actinides, followed by 2) separation of the actinides from the lanthanides. The objective of our work is to develop a single solvent-extraction process for isolating the minor actinide elements. We report here a solvent containing N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) that can be used to separate the minor actinides in a single solvent-extraction process. T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid solution. Switching the aqueous phase chemistry to a citrate buffered solution of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus affecting separation of the actinides from the lanthanides. Separation factors between the lanthanides and actinides are approximately 20 in the pH range of 3 to 4, and the distribution ratios are not highly dependent on the pH in this system.

  3. Actinide-ion sensor

    DOEpatents

    Li, Shelly X; Jue, Jan-fong; Herbst, Ronald Scott; Herrmann, Steven Douglas

    2015-01-13

    An apparatus for the real-time, in-situ monitoring of actinide-ion concentrations. A working electrolyte is positioned within the interior of a container. The working electrolyte is separated from a reference electrolyte by a separator. A working electrode is at least partially in contact with the working electrolyte. A reference electrode is at least partially in contact with the reference electrolyte. A voltmeter is electrically connected to the working electrode and the reference electrode. The working electrolyte comprises an actinide-ion of interest. The separator is ionically conductive to the actinide-ion of interest. The separator comprises an actinide, Zr, and Nb. Preferably, the actinide of the separator is Am or Np, more preferably Pu. In one embodiment, the actinide of the separator is the actinide of interest. In another embodiment, the separator further comprises P and O.

  4. Actinide Spectroscopy Workshop

    SciTech Connect

    Tobin, J.G.; Shuh, D.K.

    2004-12-05

    Actinide materials present an extreme scientific challenge to the materials research community. The complex electronic structures of actinide materials result in many unusual and unique properties that have yet to be fully understood. The difficulties in handling, preparing, and characterizing actinide materials has frequently precluded investigations and has the limited the detailed understanding of these relevant, complex materials. However, modern experiments with actinide materials have the potential to provide key, fundamental information about many long-standing issues concerning actinide materials. This workshop focused on the scientific and technical challenges posed by actinide materials and the potential that synchrotron radiation approaches available at the ALS can contribute to improving the fundamental understanding of actinides materials. Fundamental experimental approaches and results, as well as theoretical modeling and computational simulations, were part of the workshop program.

  5. Actinide Lanthanide Separation Process – ALSEP

    SciTech Connect

    Gelis, Artem V.; Lumetta, Gregg J.

    2014-01-29

    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.

  6. Actinide extraction methods

    DOEpatents

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

    2010-09-21

    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.

  7. Research in actinide chemistry

    SciTech Connect

    Choppin, G.R.

    1993-01-01

    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

  8. Dispositional logic

    NASA Technical Reports Server (NTRS)

    Le Balleur, J. C.

    1988-01-01

    The applicability of conventional mathematical analysis (based on the combination of two-valued logic and probability theory) to problems in which human judgment, perception, or emotions play significant roles is considered theoretically. It is shown that dispositional logic, a branch of fuzzy logic, has particular relevance to the common-sense reasoning typical of human decision-making. The concepts of dispositionality and usuality are defined analytically, and a dispositional conjunctive rule and dispositional modus ponens are derived.

  9. Actinide recovery process

    DOEpatents

    Muscatello, Anthony C.; Navratil, James D.; Saba, Mark T.

    1987-07-28

    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.

  10. Actinide covalency measured by pulsed electron paramagnetic resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Formanuik, Alasdair; Ariciu, Ana-Maria; Ortu, Fabrizio; Beekmeyer, Reece; Kerridge, Andrew; Tuna, Floriana; McInnes, Eric J. L.; Mills, David P.

    2017-06-01

    Our knowledge of actinide chemical bonds lags far behind our understanding of the bonding regimes of any other series of elements. This is a major issue given the technological as well as fundamental importance of f-block elements. Some key chemical differences between actinides and lanthanides—and between different actinides—can be ascribed to minor differences in covalency, that is, the degree to which electrons are shared between the f-block element and coordinated ligands. Yet there are almost no direct measures of such covalency for actinides. Here we report the first pulsed electron paramagnetic resonance spectra of actinide compounds. We apply the hyperfine sublevel correlation technique to quantify the electron-spin density at ligand nuclei (via the weak hyperfine interactions) in molecular thorium(III) and uranium(III) species and therefore the extent of covalency. Such information will be important in developing our understanding of the chemical bonding, and therefore the reactivity, of actinides.

  11. Thermodynamic Properties of Actinides and Actinide Compounds

    NASA Astrophysics Data System (ADS)

    Konings, Rudy J. M.; Morss, Lester R.; Fuger, Jean

    The necessity of obtaining accurate thermodynamic quantities for the actinide elements and their compounds was recognized at the outset of the Manhattan Project, when a dedicated team of scientists and engineers initiated the program to exploit nuclear energy for military purposes. Since the end of World War II, both fundamental and applied objectives have motivated a great deal of further study of actinide thermodynamics. This chapter brings together many research papers and critical reviews on this subject. It also seeks to assess, to systematize, and to predict important properties of the actinide elements, ions, and compounds, especially for species in which there is significant interest and for which there is an experimental basis for the prediction.

  12. Synthesis and microstructure of fluorapatite-type Ca10-2xSmxNax(PO4)6F2 solid solutions for immobilization of trivalent minor actinide

    NASA Astrophysics Data System (ADS)

    Huang, Yi; Zhang, Haibin; Zhou, Xiaosong; Peng, Shuming

    2017-03-01

    Ca10-2xSmxNax(PO4)6F2 (x = 0.8-1.2) solid solutions were successfully synthesized by the solid state reaction method using samarium (Sm) as the surrogate for trivalent minor actinide neptunium (Np). The influences of calcining temperature, holding time and Sm doping content on the phase composition and microstructure of Ca10-2xSmxNax(PO4)6F2 were investigated. The results indicated that the optimized calcining temperature and holding time for preparing Ca10-2xSmxNax(PO4)6F2 were 1000 °C and 2 h. Ca10-2xSmxNax(PO4)6F2 were confirmed to be the discontinuous solid solutions and solid solubility limit of Sm in the Ca10-2xSmxNax(PO4)6F2 was 1.2 formula units. The rod-like grains of Ca10-2xSmxNax(PO4)6F2 had typical hexagonal characteristics with a diameter of 3-5 μm and a length of 10-20 μm. No significant changes on the microstructures of Ca10-2xSmxNax(PO4)6F2 were observed with the increase of Sm doping content. The Ca, Sm, Na, P, O and F elements were nearly distributed uniformly in the Ca8Sm1Na1(PO4)6F2 solid solution.

  13. Method for preparing actinide nitrides

    DOEpatents

    Bryan, G.H.; Cleveland, J.M.; Heiple, C.R.

    1975-12-01

    Actinide nitrides, and particularly plutonium and uranium nitrides, are prepared by reacting an ammonia solution of an actinide compound with an ammonia solution of a reactant or reductant metal, to form finely divided actinide nitride precipitate which may then be appropriately separated from the solution. The actinide nitride precipitate is particularly suitable for forming nuclear fuels.

  14. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  15. PREFACE: Actinides 2009

    NASA Astrophysics Data System (ADS)

    Rao, Linfeng; Tobin, James G.; Shuh, David K.

    2010-07-01

    This volume of IOP Conference Series: Materials Science and Engineering consists of 98 papers that were presented at Actinides 2009, the 8th International Conference on Actinide Science held on 12-17 July 2009 in San Francisco, California, USA. This conference was jointly organized by Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory. The Actinides conference series started in Baden-Baden, Germany (1975) and this first conference was followed by meetings at Asilomar, CA, USA (1981), Aix-en-Provence, France (1985), Tashkent, USSR (1989), Santa Fe, NM, USA (1993), Baden-Baden, Germany (1997), Hayama, Japan (2001), and Manchester, UK (2005). The Actinides conference series provides a regular venue for the most recent research results on the chemistry, physics, and technology of the actinides and heaviest elements. Actinides 2009 provided a forum spanning a diverse range of scientific topics, including fundamental materials science, chemistry, physics, environmental science, and nuclear fuels. Of particular importance was a focus on the key roles that basic actinide chemistry and physics research play in advancing the worldwide renaissance of nuclear energy. Editors Linfeng Rao Lawrence Berkeley National Laboratory (lrao@lbl.gov) James G Tobin Lawrence Livermore National Laboratory (tobin1@llnl.gov) David K Shuh Lawrence Berkeley National Laboratory (dkshuh@lbl.gov)

  16. Research in actinide chemistry

    SciTech Connect

    Not Available

    1991-01-01

    This report contains research results on studies of inorganic and organic complexes of actinide and lanthanide elements. Special attention is given to complexes of humic acids and to spectroscopic studies.

  17. PRODUCTION OF ACTINIDE METAL

    DOEpatents

    Knighton, J.B.

    1963-11-01

    A process of reducing actinide oxide to the metal with magnesium-zinc alloy in a flux of 5 mole% of magnesium fluoride and 95 mole% of magnesium chloride plus lithium, sodium, potassium, calcium, strontium, or barium chloride is presented. The flux contains at least 14 mole% of magnesium cation at 600-- 900 deg C in air. The formed magnesium-zinc-actinide alloy is separated from the magnesium-oxide-containing flux. (AEC)

  18. Actinide recovery process

    DOEpatents

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

    1985-06-13

    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.

  19. Thermochemistry of the actinides

    SciTech Connect

    Kleinschmidt, P.D.

    1993-10-01

    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.

  20. Subsurface Biogeochemistry of Actinides

    SciTech Connect

    Kersting, Annie B.; Zavarin, Mavrik

    2016-06-29

    A major scientific challenge in environmental sciences is to identify the dominant processes controlling actinide transport in the environment. It is estimated that currently, over 2200 metric tons of plutonium (Pu) have been deposited in the subsurface worldwide, a number that increases yearly with additional spent nuclear fuel (Ewing et al., 2010). Plutonium has been shown to migrate on the scale of kilometers, giving way to a critical concern that the fundamental biogeochemical processes that control its behavior in the subsurface are not well understood (Kersting et al., 1999; Novikov et al., 2006; Santschi et al., 2002). Neptunium (Np) is less prevalent in the environment; however, it is predicted to be a significant long-term dose contributor in high-level nuclear waste. Our focus on Np chemistry in this Science Plan is intended to help formulate a better understanding of Pu redox transformations in the environment and clarify the differences between the two long-lived actinides. The research approach of our Science Plan combines (1) Fundamental Mechanistic Studies that identify and quantify biogeochemical processes that control actinide behavior in solution and on solids, (2) Field Integration Studies that investigate the transport characteristics of Pu and test our conceptual understanding of actinide transport, and (3) Actinide Research Capabilities that allow us to achieve the objectives of this Scientific Focus Area (SFA and provide new opportunities for advancing actinide environmental chemistry. These three Research Thrusts form the basis of our SFA Science Program (Figure 1).

  1. Representing dispositions

    PubMed Central

    2011-01-01

    Dispositions and tendencies feature significantly in the biomedical domain and therefore in representations of knowledge of that domain. They are not only important for specific applications like an infectious disease ontology, but also as part of a general strategy for modelling knowledge about molecular interactions. But the task of representing dispositions in some formal ontological systems is fraught with several problems, which are partly due to the fact that Description Logics can only deal well with binary relations. The paper will discuss some of the results of the philosophical debate about dispositions, in order to see whether the formal relations needed to represent dispositions can be broken down to binary relations. Finally, we will discuss problems arising from the possibility of the absence of realizations, of multi-track or multi-trigger dispositions and offer suggestions on how to deal with them. PMID:21995952

  2. Actinide nuclear data for reactor physics calculations

    SciTech Connect

    Brady, M.C.; Wright, R.Q. ); England, T.R. )

    1991-07-01

    Calculational methodologies and data sources used to predict and recommend fission-product yields and delayed neutron and prompt neutron data for a number of actinide nuclides are presented and discussed. This compilation of nuclear data is the result of a nearly three-year effort under the Japan/US Actinide Program (JUSAP) at Oak Ridge National Laboratory to provide nuclear data supporting the preliminary design of an actinide burner reactor. In this type of reactor, minor actinides are the major components of the fuel. Nuclear data for these minor actinides are, therefore, essential in the design of such reactors. Fission yield, delayed neutron, and prompt neutron data are presented in the report for the following nuclides: Neptumium-237, Plutonium-238, -240, and -242, Americium-241 and -243, and Curium-242, -243, -244, -246, and -248. Additionally, prompt neutron data are also presented for these nuclides (except Plutonium-240, -242 and Curium-242) and for Curium-245 and -247. As in all compilations of nuclear data, the information in this report is subject to change as newer data become available. Most of the data presented here are based on calculational methodologies and should be revised as experimental data become available. The release of Version 6 of the Evaluated Nuclear Data Files (ENDF/B-6) is expected to be completed in 1991 and should replace this evaluation in areas of overlap although no serious discrepancies are expected between this compilation and ENDF/B-6. Because of the large amount of data comprising this compilation and limitations in publishing such a voluminous report, a complete listing of the explicit data is not included in this report. The data are, however, available from the authors on 5 {1/2}-in. high-density (1.2-Mbyte) diskettes. The file contents and formats are described in the text, and examples are given in the appendices. 34 refs., 18 tabs.

  3. Preparation of actinides and actinide compounds

    NASA Astrophysics Data System (ADS)

    Spirlet, J. C.; Vogt, O.

    1982-10-01

    Starting materials for actinide research are commercially available oxides. The metals are synthesized by the metallothermic reduction of oxides, halides or carbides. The metals are further refined by vacuum-melting, distillation, van Arkel process or electrorefining to 99.9% purity. Crystals of the metals and many compounds in mm sizes are grown by specifically adapted classical methods such as solution-growth, chemical transport, flux-growth, mineralization or melt-growth.

  4. Nonaqueous actinide hydride dissolution and production of actinide $beta$- diketonates

    DOEpatents

    Crisler, L.R.

    1975-11-11

    Actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a hydride of the actinide material in a mixture of carbon tetrachloride and methanol. (auth)

  5. Comparison of Processes of Transmutation of Long-Lived Actinides in Different Reactors

    SciTech Connect

    Bergelson, B.R.; Gerasimov, A.S.; Kiselev, G.V.; Tikhomirov, G.V.

    2002-07-01

    Efficiency of transmutation of actinides was compared for different types of reactors-transmuters: light water VVER-1000 type reactor, fast breeder BN-600 and Super-Phenix type reactors, as well as high-flux subcritical ADS-800 type facility. Feed with minor actinides extracted from the reactor of VVER-1000 type was supposed. (authors)

  6. 25 CFR 11.1012 - Dispositional alternatives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Dispositional alternatives. 11.1012 Section 11.1012 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1012 Dispositional alternatives. (a) If a minor...

  7. 25 CFR 11.1112 - Dispositional alternatives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Dispositional alternatives. 11.1112 Section 11.1112 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Minor-in-Need-of-Care Procedure § 11.1112 Dispositional alternatives. (a) If a...

  8. Actinide and lanthanide separation process (ALSEP)

    DOEpatents

    Guelis, Artem V.

    2013-01-15

    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).

  9. Microbial Transformations of Actinides and Other Radionuclides

    SciTech Connect

    Francis,A.J.; Dodge, C. J.

    2009-01-07

    Microorganisms can affect the stability and mobility of the actinides and other radionuclides released from nuclear fuel cycle and from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution in the environment and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been extensively investigated, we have only limited information on the effects of microbial processes and biochemical mechanisms which affect the stability and mobility of radionuclides. The mechanisms of microbial transformations of the major and minor actinides U, Pu, Cm, Am, Np, the fission products and other radionuclides such as Ra, Tc, I, Cs, Sr, under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.

  10. Teacher Dispositions and Student Achievement

    ERIC Educational Resources Information Center

    Vaughn, Kathleen Adams

    2012-01-01

    In an effort to close the achievement gap between students of minority and majority populations and between students in higher and lower economic circumstances, the National Council for the Accreditation of Teacher Education (NCATE) added instruction and evaluation of teacher dispositions to its requirements for credentialing prospective teachers.…

  11. Irradiaton of Metallic and Oxide Fuels for Actinide Transmutation in the ATR

    SciTech Connect

    Heather J. MacLean; Steven L. Hayes

    2007-09-01

    Metallic fuels containing minor actinides and rare earth additions have been fabricated and are prepared for irradiation in the ATR, scheduled to begin during the summer of 2007. Oxide fuels containing minor actinides are being fabricated and will be ready for irradiation in ATR, scheduled to begin during the summer of 2008. Fabrication and irradiation of these fuels will provide detailed studies of actinide transmutation in support of the Global Nuclear Energy Partnership. These fuel irradiations include new fuel compositions that have never before been tested. Results from these tests will provide fundamental data on fuel irradiation performance and will advance the state of knowledge for transmutation fuels.

  12. Actinide halide complexes

    SciTech Connect

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

    1991-02-07

    A compound of the formula MX{sub n}L{sub m} wherein M = Th, Pu, Np,or Am thorium, X = a halide atom, n = 3 or 4, 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 3 or 4 for monodentate ligands or is 2 for bidentate ligands, where n + m = 7 or 8 for monodentate ligands or 5 or 6 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.

  13. Novel Separation of Actinides

    SciTech Connect

    Mariella, R

    2011-02-17

    The separation of actinides and other elements of interest for nuclear forensics and threat reduction is currently performed using decades-old chemistries and ion-exchange columns. We propose to determine the technical feasibility of a novel method for separating actinide ions in solution. This method is based upon isotachophoresis (ITP), which has been applied in the purification of pharmaceuticals and other biochemical applications. This technique has the potential to separate inorganic ions more effectively than existing methods, which is key to analyzing very small samples. We will perform a quantitative assessment of the effectiveness of specific isotachophoretic approaches including predicting the physical and chemical properties, such as ion mobility, of inorganic ions under specific solvent conditions using a combination of ab initio calculations and semi-empirical methods. We expect to obtain a thorough understanding of the analytical systems parameters under which ITP is most effective for the separation of inorganic samples, including the influence of the double layer surrounding actinide ions, the Debye length for different ions and ion complexes, and Debye-Hueckel limits. Inorganic separations are key to nuclear forensics for countering terrorism and nuclear proliferation. If found to be feasible and potentially superior to currently used separation approaches, ITP could provide the conceptual basis for an improved means to separate samples of nuclear explosion debris for nuclear forensic analysis, in support of the Laboratory's missions in homeland and national security.

  14. Actinide management with commercial fast reactors

    SciTech Connect

    Ohki, Shigeo

    2015-12-31

    The capability of plutonium-breeding and minor-actinide (MA) transmutation in the Japanese commercial sodium-cooled fast reactor offers one of practical solutions for obtaining sustainable energy resources as well as reducing radioactive toxicity and inventory. The reference core design meets the requirement of flexible breeding ratio from 1.03 to 1.2. The MA transmutation amount has been evaluated as 50-100 kg/GW{sub e}y if the MA content in fresh fuel is 3-5 wt%, where about 30-40% of initial MA can be transmuted in the discharged fuel.

  15. Actinide management with commercial fast reactors

    NASA Astrophysics Data System (ADS)

    Ohki, Shigeo

    2015-12-01

    The capability of plutonium-breeding and minor-actinide (MA) transmutation in the Japanese commercial sodium-cooled fast reactor offers one of practical solutions for obtaining sustainable energy resources as well as reducing radioactive toxicity and inventory. The reference core design meets the requirement of flexible breeding ratio from 1.03 to 1.2. The MA transmutation amount has been evaluated as 50-100 kg/GWey if the MA content in fresh fuel is 3-5 wt%, where about 30-40% of initial MA can be transmuted in the discharged fuel.

  16. Potential role of ABC-assisted repositories in U.S. plutonium and high-level waste disposition

    SciTech Connect

    Berwald, D.; Favale, A.; Myers, T.

    1995-10-01

    This paper characterizes the issues involving deep geologic disposal of LWR spent fuel rods, then presents results of an investigation to quantify the potential role of Accelerator-Based Conversion (ABC) in an integrated national nuclear materials and high level waste disposition strategy. The investigation used the deep geological repository envisioned for Yucca Mt., Nevada as a baseline and considered complementary roles for integrated ABC transmutation systems. The results indicate that although a U.S. geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of plutonium, the minor actinides, and selected long-lived fission products can result in the following substantial benefits: plutonium burndown to near zero levels, a dramatic reduction of the long term hazard associated with geologic repositories, an ability to place several-fold more high level nuclear waste in a single repository, electricity sales to compensate for capital and operating costs.

  17. Potential role of ABC-assisted repositories in U.S. plutonium and high-level waste disposition

    NASA Astrophysics Data System (ADS)

    Berwald, David; Favale, Anthony; Myers, Timothy; McDaniel, Jerry

    1995-09-01

    This paper characterizes the issues involving deep geologic disposal of LWR spent fuel rods, then presents results of an investigation to quantify the potential role of Accelerator-Based Conversion (ABC) in an integrated national nuclear materials and high level waste disposition strategy. The investigation used the deep geological repository envisioned for Yucca Mt., Nevada as a baseline and considered complementary roles for integrated ABC transmutation systems. The results indicate that although a U.S. geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of plutonium, the minor actinides, and selected long-lived fission products can result in the following substantial benefits: plutonium burndown to near zero levels, a dramatic reduction of the long term hazard associated with geologic repositories, an ability to place several-fold more high level nuclear waste in a single repository, electricity sales to compensate for capital and operating costs.

  18. PROCESS OF PRODUCING ACTINIDE METALS

    DOEpatents

    Magel, T.T.

    1959-07-14

    The preparation of actinide metals in workable, coherent form is described. In general, the objects of the invention are achieved by heating a mixture of an oxide and a halide of an actinide metal such as uranium with an alkali metal on alkaline earth metal reducing agent in the presence of iodine.

  19. Actinide halide complexes

    DOEpatents

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

    1992-11-24

    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.

  20. Actinide halide complexes

    DOEpatents

    Avens, Larry R.; Zwick, Bill D.; Sattelberger, Alfred P.; Clark, David L.; Watkin, John G.

    1992-01-01

    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.

  1. Managing Inventories of Heavy Actinides

    SciTech Connect

    Wham, Robert M; Patton, Bradley D

    2011-01-01

    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.

  2. Actinide Burning in CANDU Reactors

    SciTech Connect

    Hyland, B.; Dyck, G.R.

    2007-07-01

    Actinide burning in CANDU reactors has been studied as a method of reducing the actinide content of spent nuclear fuel from light water reactors, and thereby decreasing the associated long term decay heat load. In this work simulations were performed of actinides mixed with natural uranium to form a mixed oxide (MOX) fuel, and also mixed with silicon carbide to form an inert matrix (IMF) fuel. Both of these fuels were taken to a higher burnup than has previously been studied. The total transuranic element destruction calculated was 40% for the MOX fuel and 71% for the IMF. (authors)

  3. Improved electrodeposited actinide layers

    NASA Astrophysics Data System (ADS)

    Ingelbrecht, C.; Moens, A.; Eykens, R.; Dean, A.

    1997-02-01

    Electrodeposition is a relatively simple and high-yielding method for producing actinide layers for nuclear targets. A new design of the cell has been used to deposit U, Pu, Np and Am onto metallic backings from isopropanol and onto carbon-coated polyimide films from isobutanol. The current density was 1-3 mA/cm 2. Deposition yields, determined by low geometry alpha-particle counting, were about 65% for Pu and about 90% for other elements. The same technique was used to investigate thickness homogeneity of 239Pu deposits, and it was observed that targets with mean thickness up to about 100 μg/cm 2 were thicker in the centre than at the edge, but for targets above 100 μg/cm 2, this profile was reversed. Modifications to the electrode shape were made in an attempt to improve the thickness uniformity.

  4. Environmental research on actinide elements

    SciTech Connect

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

    1987-08-01

    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)

  5. Actinide transmutation in nuclear reactors

    SciTech Connect

    Ganev, I.K.; Lopatkin, A.V.; Naumov, V.V.; Tocheny, L.V.

    1993-12-31

    Of some interest is the comparison between the actinide nuclide burning up (fission) rates such as americium 241, americium 242, curium 244, and neptunium 237, in the reactors with fast or thermal neutron spectra.

  6. Grouped actinide separation in advanced nuclear fuel cycles

    SciTech Connect

    Glatz, J.P.; Malmbeck, R.; Ougier, M.; Soucek, P.; Murakamin, T.; Tsukada, T.; Koyama, T.

    2013-07-01

    Aiming at cleaner waste streams (containing only the short-lived fission products) a partitioning and transmutation (P-T) scheme can significantly reduce the quantities of long-lived radionuclides consigned to waste. Many issues and options are being discussed and studied at present in view of selecting the optimal route. The choice is between individual treatment of the relevant elements and a grouped treatment of all actinides together. In the European Collaborative Project ACSEPT (Actinide recycling by Separation and Transmutation), grouped separation options derived from an aqueous extraction or from a dry pyroprocessing route were extensively investigated. Successful demonstration tests for both systems have been carried out in the frame of this project. The aqueous process called GANEX (Grouped Actinide Extraction) is composed of 2 cycles, a first one to recover the major part of U followed by a co-extraction of Np, Pu, Am, and Cm altogether. The pyro-reprocessing primarily applicable to metallic fuels such as the U-Pu-Zr alloy originally developed by the Argonne National Laboratory (US) in the mid 1980s, has also been applied to the METAPHIX fuels containing up to 5% of minor actinides and 5% of lanthanides (e.g. U{sub 60}Pu{sub 20}-Zr{sub 10}Am{sub 2}Nd{sub 3.5}Y{sub 0.5}Ce{sub 0.5}Gd{sub 0.5}). A grouped actinide separation has been successfully carried out by electrorefining on solid Al cathodes. At present the recovery of the actinides from the alloy formed with Al upon electrodeposition is under investigation, because an efficient P-T cycle requires multiple re-fabrication and re-irradiation. (authors)

  7. Dispositional greed.

    PubMed

    Seuntjens, Terri G; Zeelenberg, Marcel; van de Ven, Niels; Breugelmans, Seger M

    2015-06-01

    Greed is an important motive: it is seen as both productive (a source of ambition; the motor of the economy) and destructive (undermining social relationships; the cause of the late 2000s financial crisis). However, relatively little is known about what greed is and does. This article reports on 5 studies that develop and test the 7-item Dispositional Greed Scale (DGS). Study 1 (including 4 separate samples from 2 different countries, total N = 6092) provides evidence for the construct and discriminant validity of the DGS in terms of positive correlations with maximization, self-interest, envy, materialism, and impulsiveness, and negative correlations with self-control and life satisfaction. Study 2 (N = 290) presents further evidence for discriminant validity, finding that the DGS predicts greedy behavioral tendencies over and above materialism. Furthermore, the DGS predicts economic behavior: greedy people allocate more money to themselves in dictator games (Study 3, N = 300) and ultimatum games (Study 4, N = 603), and take more in a resource dilemma (Study 5, N = 305). These findings shed light on what greed is and does, how people differ in greed, and how greed can be measured. In addition, they show the importance of greed in economic behavior and provide directions for future studies.

  8. Kinetics of actinide complexation reactions

    SciTech Connect

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

    1997-09-01

    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.

  9. Actinides and Life's Origins

    NASA Astrophysics Data System (ADS)

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uranium- and thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3rd by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  10. Actinides and Life's Origins.

    PubMed

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  11. Development of Metallic Fuels for Actinide Transmutation

    SciTech Connect

    Hayes, Steven Lowe; Fielding, Randall Sidney; Benson, Michael Timothy; Chichester, Heather Jean MacLean; Carmack, William Jonathan

    2015-09-01

    Research and development activities on metallic fuels are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is also a need for a near zero-loss fabrication process and a desire to demonstrate a multifold increase in burnup potential. The incorporation of Am and Np into the traditional U-20Pu-10Zr metallic fuel alloy was demonstrated in the US during the Integral Fast Reactor Program of the 1980’s and early 1990’s. However, the conventional counter gravity injection casting method performed under vacuum, previously used to fabricate these metallic fuel alloys, was not optimized for mitigating loss of the volatile Am constituent in the casting charge; as a result, approximately 40% of the Am casting charge failed to be incorporated into the as-cast fuel alloys. Fabrication development efforts of the past few years have pursued an optimized bottom-pour casting method to increase utilization of the melted charge to near 100%, and a differential pressure casting approach, performed under an argon overpressure, has been demonstrated to result in essentially no loss of Am due to volatilization during fabrication. In short, a path toward zero-loss fabrication of metallic fuels including minor actinides has been shown to be feasible. Irradiation testing of advanced metallic fuel alloys in the Advanced Test Reactor (ATR) has been underway since 2003. Testing in the ATR is performed inside of cadmium-shrouded positions to remove >99% of the thermal flux incident on the test fuels, resulting in an epi-thermal driven fuel test that is free from gross flux depression and producing an essentially prototypic radial temperature profile inside the fuel rodlets. To date, three irradiation test series (AFC-1,2,3) have been completed. Over 20 different metallic fuel alloys have been tested to burnups as high as 30% with constituent compositions of Pu up to 30%, Am up to 12%, Np up to 10%, and Zr between 10

  12. Actinide Thermodynamics at Elevated Temperatures

    SciTech Connect

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

    2007-11-16

    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

  13. Preliminary considerations concerning actinide solubilities

    SciTech Connect

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  14. Actinide chemistry in ionic liquids.

    PubMed

    Takao, Koichiro; Bell, Thomas James; Ikeda, Yasuhisa

    2013-04-01

    This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes.

  15. The Dispositions Improvement Process

    ERIC Educational Resources Information Center

    Brewer, Robin D.; Lindquist, Cynthia; Altemueller, Lisa

    2011-01-01

    Globally, teacher dispositions along with knowledge and skills continue to be the focal point of teacher education programs. Teachers influence children's development and therefore dispositions are a universal concern. For the past 20 years in the United States, teacher education programs have assessed dispositions. We, however, must now also use…

  16. SOLUBILIZATION OF ACTINIDE METAL-CONTAINING SLAG

    DOEpatents

    Hopkins, H.H. Jr.

    1959-08-01

    This patent relates to solubilization of the actinide rare earths valves contained in the slag materials resulting from the reduction of actinide salts, such as plutonium tetrafluoride. According to the invention the slag is subjected to a high temperature chloridizing roast, preferably from the reduction of actinide salts, such as plutonium tetrafluoride. According to the invention the slag is subjected to a high temperature chloridizing roast, preferably at about 700 deg C with gaseous hydrogen chloride, until the actinides within the slag are substantially convented to the chlorides. The resultant chlorinated actinides are then leached from the cooled roasted mass by treating with aqueous 0.01 M nitric acid.

  17. Trace Analysis of Actinides in Geological, Environmental, and Biological Matrices

    NASA Astrophysics Data System (ADS)

    Wolf, Stephen F.

    Actinide elements are ubiquitous in nature. Uranium and thorium are present in the Earth's crust with average concentrations of 1-10 μg g-1, making them more abundant than Ag, Sb, Cd, or Hg. While U and Th can even be found as major or minor mineral constituents in a variety of geochemical environments, typically they are highly dispersed and present only at trace or ultra-trace concentrations in most natural materials. Because 238U, 235U, and 232Th are the parents of the three naturally occurring non-extinct radioactive decay chains, they are always accompanied by lower concentrations of their radioactive progeny, many of which are also actinides (Table 30.1).

  18. Separations of actinides, lanthanides and other metals

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ensor, Dale D.

    1995-01-01

    An organic extracting solution comprised of a bis(acylpyrazolone or a substituted bis(acylpyrazolone) and an extraction method useful for separating certain elements of the actinide series of the periodic table having a valence of four from one other, and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also useful for separating hexavalent actinides from one or more of the substances in a group consisting of trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals.

  19. 33 CFR 52.62 - Minority report.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Minority report. 52.62 Section 52... CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Judgment and Disposition § 52.62 Minority report. In case of disagreement among Board members, a minority report may be submitted dissenting from or...

  20. 33 CFR 52.62 - Minority report.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Minority report. 52.62 Section 52... CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Judgment and Disposition § 52.62 Minority report. In case of disagreement among Board members, a minority report may be submitted dissenting from or...

  1. 33 CFR 52.62 - Minority report.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Minority report. 52.62 Section 52... CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Judgment and Disposition § 52.62 Minority report. In case of disagreement among Board members, a minority report may be submitted dissenting from or...

  2. 33 CFR 52.62 - Minority report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Minority report. 52.62 Section 52... CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Judgment and Disposition § 52.62 Minority report. In case of disagreement among Board members, a minority report may be submitted dissenting from or...

  3. 33 CFR 52.62 - Minority report.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Minority report. 52.62 Section 52... CORRECTION OF MILITARY RECORDS OF THE COAST GUARD Judgment and Disposition § 52.62 Minority report. In case of disagreement among Board members, a minority report may be submitted dissenting from or...

  4. Molecular models for actinide speciation

    SciTech Connect

    Clark, D.L.; Watkin, J.G.; Morris, D.E.; Berg, J.M.

    1994-06-01

    Much effort has been devoted to the development of sensitive spectroscopic techniques for the study of actinide speciation based on the sensitivity of f-f electronic absorption bands to oxidation state and ligation of the actinide ions. These efforts assume that data obtained in such studies will be interpretable in terms of changes in complexation of the metal center. However, the current understanding of 5f electronic structure is based on data from solid state doped single crystals. In those studies, the local coordination geometry about the central actinide ion is maintained in an almost perfect high-symmetry environment and will have little relevance for species in solution where deviations from perfect high symmetry tend to be the rule rather than the exception. The authors have developed a vigorous research program in the systematic preparation and spectroscopic characterization of synthetic actinide complexes (Th, U, Np, and Pu) in which they can control nuclearity, oxidation state, and molecular structure. These complexes have been used to determine how observable electronic transitions are perturbed in response to structural changes in the complex in solution. From the spectra obtained for these model complexes, the authors have found that the f-f transitions naturally fall into obvious groupings by coordination number and symmetry by which they can now differentiate between monomeric, dimeric, and trimeric species in solution. The study of radionuclide speciation is fundamentally important to the determination of radionuclide solubility in the groundwater at Yucca Mountain.

  5. Pyrometallurgical processes for recovery of actinide elements

    SciTech Connect

    Battles, J.E.; Laidler, J.J.; McPheeters, C.C.; Miller, W.E.

    1994-01-01

    A metallic fuel alloy, nominally U-20-Pu-lOZr, is the key element of the Integral Fast Reactor (IFR) fuel cycle. Metallic fuel permits the use of an innovative, simple pyrometallurgical process, known as pyroprocessing, (the subject of this report), which features fused salt electrorefining of the spent fuel. Electrorefining separates the actinide elements from fission products, without producing a separate stream of plutonium. The plutonium-bearing product is contaminated with higher actinides and with a minor amount of rare earth fission products, making it diversion resistant while still suitable as a fuel material in the fast spectrum of the IFR core. The engineering-scale demonstration of this process will be conducted in the refurbished EBR-II Fuel Cycle Facility, which has entered the start-up phase. An additional pyrometallurgical process is under development for extracting transuranic (TRU) elements from Light Water Reactor (LWR) spent fuel in a form suitable for use as a feed to the IFR fuel cycle. Four candidate extraction processes have been investigated and shown to be chemically feasible. The main steps in each process are oxide reduction with calcium or lithium, regeneration of the reductant and recycle of the salt, and separation of the TRU product from the bulk uranium. Two processes, referred to as the lithium and salt transport (calcium reductant) processes, have been selected for engineering-scale demonstration, which is expected to start in late 1993. An integral part of pyroprocessing development is the treatment and packaging of high-level waste materials arising from the operations, along with the qualification of these waste forms for disposal in a geologic repository.

  6. "Computational Modeling of Actinide Complexes"

    SciTech Connect

    Balasubramanian, K

    2007-03-07

    We will present our recent studies on computational actinide chemistry of complexes which are not only interesting from the standpoint of actinide coordination chemistry but also of relevance to environmental management of high-level nuclear wastes. We will be discussing our recent collaborative efforts with Professor Heino Nitsche of LBNL whose research group has been actively carrying out experimental studies on these species. Computations of actinide complexes are also quintessential to our understanding of the complexes found in geochemical, biochemical environments and actinide chemistry relevant to advanced nuclear systems. In particular we have been studying uranyl, plutonyl, and Cm(III) complexes are in aqueous solution. These studies are made with a variety of relativistic methods such as coupled cluster methods, DFT, and complete active space multi-configuration self-consistent-field (CASSCF) followed by large-scale CI computations and relativistic CI (RCI) computations up to 60 million configurations. Our computational studies on actinide complexes were motivated by ongoing EXAFS studies of speciated complexes in geo and biochemical environments carried out by Prof Heino Nitsche's group at Berkeley, Dr. David Clark at Los Alamos and Dr. Gibson's work on small actinide molecules at ORNL. The hydrolysis reactions of urnayl, neputyl and plutonyl complexes have received considerable attention due to their geochemical and biochemical importance but the results of free energies in solution and the mechanism of deprotonation have been topic of considerable uncertainty. We have computed deprotonating and migration of one water molecule from the first solvation shell to the second shell in UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}, UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}NpO{sub 2}(H{sub 2}O){sub 6}{sup +}, and PuO{sub 2}(H{sub 2}O){sub 5}{sup 2+} complexes. Our computed Gibbs free energy(7.27 kcal/m) in solution for the first time agrees with the experiment (7.1 kcal

  7. Sample results from the integrated salt disposition program macrobatch 6 tank 21H qualifications MST solids sample

    SciTech Connect

    Peters, T. B.

    2013-02-26

    Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Integrated Salt Disposition Program (ISDP) Batch 6 processing. As part of this qualification work, SRNL performed an Actinide Removal Process (ARP) test. From this test, the residual monosodium titanate (MST) was analyzed for radionuclide uptake. The results of these analyses are reported and are within historical precedent.

  8. One-electron physics of the actinides

    NASA Astrophysics Data System (ADS)

    Toropova, A.; Marianetti, C. A.; Haule, K.; Kotliar, G.

    2007-10-01

    We present a detailed analysis of the one-electron physics of the actinides. Various linear muffin-tin orbital basis sets are analyzed in order to determine a robust bare Hamiltonian for the actinides. The hybridization between f and spd states is compared with the f-f hopping in order to understand the Anderson-like and Hubbard-like contributions to itineracy in the actinides. We show that both contributions decrease strongly as one moves from the light actinides to the heavy actinides, while the Anderson-like contribution dominates in all cases. A real-space analysis of the band structure shows that nearest-neighbor hopping dominates the physics in these materials. Finally, we discuss the implications of our results to the delocalization transition as a function of atomic number across the actinide series.

  9. Actinide Recovery Method for Large Soil Samples

    SciTech Connect

    Maxwell, S.L. III; Nichols, S.

    1998-11-01

    A new Actinide Recovery Method has been developed by the Savannah River Site Central Laboratory to preconcentrate actinides in very large soil samples. Diphonix Resin(r) is used eliminate soil matrix interferences and preconcentrate actinides after soil leaching or soil fusion. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin(r). After the resin digestion, the actinides are recovered in a small volume of nitric acid which can be easily loaded onto small extraction-chromatography columns, such as TEVA Resin(r), U-TEVA Resin(r) or TRU Resin(r) (Eichrom Industries). This method enables the application of small, selective extraction-columns to recover actinides from very large soil samples with high selectivity, consistent tracer recoveries and minimal liquid waste.

  10. Actinide recovery techniques utilizing electromechanical processes

    SciTech Connect

    Westphal, B.R.; Benedict, R.W.

    1994-01-01

    Under certain conditions, the separation of actinides using electromechanical techniques may be an effective means of residue processing. The separation of granular mixtures of actinides and other materials discussed in this report is based on appreciable differences in the magnetic and electrical properties of the actinide elements. In addition, the high density of actinides, particularly uranium and plutonium, may render a simultaneous separation based on mutually complementary parameters. Both high intensity magnetic separation and electrostatic separation have been investigated for the concentration of an actinide waste stream. Waste stream constituents include an actinide metal alloy and broken quartz shards. The investigation of these techniques is in support of the Integral Fast Reactor (IFR) concept currently being developed at Argonne National Laboratory under the auspices of the Department of Energy.

  11. Process for recovering actinide values

    DOEpatents

    Horwitz, E. Philip; Mason, George W.

    1980-01-01

    A process for rendering actinide values recoverable from sodium carbonate scrub waste solutions containing these and other values along with organic compounds resulting from the radiolytic and hydrolytic degradation of neutral organophosphorous extractants such as tri-n butyl phosphate (TBP) and dihexyl-N,N-diethyl carbamylmethylene phosphonate (DHDECAMP) which have been used in the reprocessing of irradiated nuclear reactor fuels. The scrub waste solution is preferably made acidic with mineral acid, to form a feed solution which is then contacted with a water-immiscible, highly polar organic extractant which selectively extracts the degradation products from the feed solution. The feed solution can then be processed to recover the actinides for storage or recycled back into the high-level waste process stream. The extractant is recycled after stripping the degradation products with a neutral sodium carbonate solution.

  12. Actinide abundances in ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hagee, B.; Bernatowicz, T. J.; Podosek, F. A.; Johnson, M. L.; Burnett, D. S.

    1990-01-01

    Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also used to compare directly the Pu/U ratio with the earlier obtained ratio determined indirectly, as (Pu/Nd)x(Nd/U), assuming that Pu behaves chemically as a LREE. The data, combined with high-accuracy isotope-dilution data from the literature, show that the degree of gram-scale variability of the Th, U, and LREE abundances for equilibrated ordinary chondrites is a factor of 2-3 for absolute abundances and up to 50 percent for relative abundances. The observed variations are interpreted as reflecting the differences in the compositions and/or proportions of solar nebula components accreted to ordinary chondrite parent bodies.

  13. Advances in Metallic Fuels for High Burnup and Actinide Transmutation

    SciTech Connect

    Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.; Fielding, R. S.; Mariani, R. D.; Carmack, W. J.

    2016-10-01

    Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing an annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.

  14. Fall MRS 2003: Actinides Symposium

    SciTech Connect

    Tobin, J

    2003-11-24

    {lg_bullet} The focus was on fundamental actinide science and its role. {lg_bullet} History- none except the Nuclear Waste Management Symposia {lg_bullet} Joint Sessions- none but we are open to it in the future. {lg_bullet} Tutorials- none but we are open to it in the future. {lg_bullet} 3 days: 16 Invited talks; 36 Contributed Talks; 10 Posters

  15. Future nuclear fuel cycles: Prospect and challenges for actinide recycling

    NASA Astrophysics Data System (ADS)

    Warin, Dominique

    2010-03-01

    The global energy context pleads in favour of a sustainable development of nuclear energy since the demand for energy will likely increase, whereas resources will tend to get scarcer and the prospect of global warming will drive down the consumption of fossil fuel. In this context, nuclear power has the worldwide potential to curtail the dependence on fossil fuels and thereby to reduce the amount of greenhouse gas emissions while promoting energy independence. How we deal with nuclear radioactive waste is crucial in this context. In France, the public's concern regarding the long-term waste management made the French Governments to prepare and pass the 1991 and 2006 Acts, requesting in particular the study of applicable solutions for still minimizing the quantity and the hazardousness of final waste. This necessitates High Active Long Life element (such as the Minor Actinides MA) recycling, since the results of fuel cycle R&D could significantly change the challenges for the storage of nuclear waste. HALL recycling can reduce the heat load and the half-life of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste and thus aiding the "burying approach" in securing a "broadly agreed political consensus" of waste disposal in a geological repository. This paper presents an overview of the recent R and D results obtained at the CEA Atalante facility on innovative actinide partitioning hydrometallurgical processes. For americium and curium partitioning, these results concern improvements and possible simplifications of the Diamex-Sanex process, whose technical feasibility was already demonstrated in 2005. Results on the first tests of the Ganex process (grouped actinide separation for homogeneous recycling) are also discussed. In the coming years, next steps will involve both better in-depth understanding of the basis of these actinide partitioning processes and, for the new promising

  16. Analysis of large soil samples for actinides

    DOEpatents

    Maxwell, III; Sherrod, L [Aiken, SC

    2009-03-24

    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.

  17. Prompt fission neutron spectra of actinides

    SciTech Connect

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; Kornilov, N. V.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; Otuka, N.; Pronyaev, V. G.; Saxena, A.; Serot, O.; Shcherbakov, O. A.; Shu, N. -C.; Smith, D. L.; Talou, P.; Trkov, A.; Tudora, A. C.; Vogt, R.; Vorobyev, A. S.

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  18. Prompt fission neutron spectra of actinides

    DOE PAGES

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; ...

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  19. Prompt fission neutron spectrum of actinides

    SciTech Connect

    Capote, R.; Chen, Y. -J.; Hambsch, F. J.; Jurado, B.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; Otuka, N.; Pronyaev, V. G.; Saxena, A.; Schmidt, K. H.; Shcherbakov, O. A.; Shu, N. -C.; Smith, D. L.; Talou, P.; Trkov, A.; Tudora, A. C.; Vogt, R.; Vorobyev, A. S.

    2016-01-06

    Here, the energy spectrum of prompt neutron emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  20. Density functional theory investigations of the trivalent lanthanide and actinide extraction complexes with diglycolamides.

    PubMed

    Wang, Cong-Zhi; Lan, Jian-Hui; Wu, Qun-Yan; Zhao, Yu-Liang; Wang, Xiang-Ke; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-06-21

    At present, designing novel ligands for efficient actinide extraction in spent nuclear fuel reprocessing is extremely challenging due to the complicated chemical behaviors of actinides, the similar chemical properties of minor actinides (MA) and lanthanides, and the vulnerability of organic ligands in acidic radioactive solutions. In this work, a quantum chemical study on Am(III), Cm(III) and Eu(III) complexes with N,N,N',N'-tetraoctyl diglycolamide (TODGA) and N,N'-dimethyl-N,N'-diheptyl-3-oxapentanediamide (DMDHOPDA) has been carried out to explore the extraction behaviors of trivalent actinides (An) and lanthanides (Ln) with diglycolamides from acidic media. It has been found that in the 1 : 1 (ligand : metal) and 2 : 1 stoichiometric complexes, the carbonyl oxygen atoms have stronger coordination ability than the ether oxygen atoms, and the interactions between metal cations and organic ligands are substantially ionic. The neutral ML(NO3)3 (M = Am, Cm, Eu) complexes seem to be the most favorable species in the extraction process, and the predicted relative selectivities are in agreement with experimental results, i.e., the diglycolamide ligands have slightly higher selectivity for Am(III) over Eu(III). Such a thermodynamical priority is probably caused by the higher stabilities of Eu(III) hydration species and Eu(III)-L complexes in aqueous solution compared to their analogues. In addition, our thermodynamic analysis from water to organic medium confirms that DMDHOPDA has higher extraction ability for the trivalent actinides and lanthanides than TODGA, which may be due to the steric hindrance of the bulky alkyl groups of TODGA ligands. This work might provide an insight into understanding the origin of the actinide selectivity and a theoretical basis for designing highly efficient extractants for actinide separation.

  1. Actinide ion sensor for pyroprocess monitoring

    DOEpatents

    Jue, Jan-fong; Li, Shelly X.

    2014-06-03

    An apparatus for real-time, in-situ monitoring of actinide ion concentrations which comprises a working electrode, a reference electrode, a container, a working electrolyte, a separator, a reference electrolyte, and a voltmeter. The container holds the working electrolyte. The voltmeter is electrically connected to the working electrode and the reference electrode and measures the voltage between those electrodes. The working electrode contacts the working electrolyte. The working electrolyte comprises an actinide ion of interest. The reference electrode contacts the reference electrolyte. The reference electrolyte is separated from the working electrolyte by the separator. The separator contacts both the working electrolyte and the reference electrolyte. The separator is ionically conductive to the actinide ion of interest. The reference electrolyte comprises a known concentration of the actinide ion of interest. The separator comprises a beta double prime alumina exchanged with the actinide ion of interest.

  2. Interactions of microbial exopolymers with actinides

    NASA Astrophysics Data System (ADS)

    Johnson, Mitchell T.; Chitwood, Dawn J.; He, Lee; Neu, Mary P.

    2000-07-01

    The development of viable bioremediation strategies for radionuclide contaminated soils, sediments and ground waters at DOE sites is a formidable challenge. Ubiquitous microorganisms can absorb, oxidize, reduce and/or precipitate actinides and thereby affect the speciation, solubility, bioavailability, and migration of these toxic metals. Actinides can interact directly with microorganisms, i.e., via sorption to the cell wall, and indirectly via reaction with their byproducts, such as extracellular polymers. However, very little is known about the fundamental chemistry of any microbial-actinide interactions or their impact on environmental processes. Our goal is to fully characterize specific microbial-actinide interactions and determine how they may be exploited to effect environmental actinide mobility/immobility and remediation efforts.

  3. Exploring actinide materials through synchrotron radiation techniques.

    PubMed

    Shi, Wei-Qun; Yuan, Li-Yong; Wang, Cong-Zhi; Wang, Lin; Mei, Lei; Xiao, Cheng-Liang; Zhang, Li; Li, Zi-Jie; Zhao, Yu-Liang; Chai, Zhi-Fang

    2014-12-10

    Synchrotron radiation (SR) based techniques have been utilized with increasing frequency in the past decade to explore the brilliant and challenging sciences of actinide-based materials. This trend is partially driven by the basic needs for multi-scale actinide speciation and bonding information and also the realistic needs for nuclear energy research. In this review, recent research progresses on actinide related materials by means of various SR techniques were selectively highlighted and summarized, with the emphasis on X-ray absorption spectroscopy, X-ray diffraction and scattering spectroscopy, which are powerful tools to characterize actinide materials. In addition, advanced SR techniques for exploring future advanced nuclear fuel cycles dealing with actinides are illustrated as well. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Actinide abundances in ordinary chondrites

    USGS Publications Warehouse

    Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

    1990-01-01

    Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

  5. Separation of actinides from lanthanides

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

    1989-01-01

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  6. Separation of actinides from lanthanides

    SciTech Connect

    Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

    1989-09-19

    This patent describes an organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which include a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  7. Separation of actinides from lanthanides

    DOEpatents

    Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

    1988-03-31

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form is described. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4- dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  8. Energy-Dependent Fission Q Values Generalized for All Actinides

    SciTech Connect

    Vogt, R

    2008-09-25

    We generalize Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q values on incident neutron energy, E{sub n}, for all major and minor actinides. These Q(E{sub n}) parameterizations are included in the ENDL2008 release. This paper describes calculations of energy-dependent fission Q values based on parameterizations of the prompt energy release in fission [1], developed by Madland [1] to describe the prompt energy release in neutron-induced fission of {sup 235}U, {sup 238}U, and {sup 239}Pu. The energy release is then related to the energy deposited during fission so that experimentally measurable quantities can be used to obtain the Q values. A discussion of these specific parameterizations and their implementation in the processing code for Monte Carlo neutron transport, MCFGEN, [2] is described in Ref. [3]. We extend this model to describe Q(E) for all actinides, major and minor, in the Evaluated Nuclear Data Library (ENDL) 2008 release, ENDL2008.

  9. Experimental studies of actinides in molten salts

    SciTech Connect

    Reavis, J.G.

    1985-06-01

    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.

  10. Subsurface interactions of actinide species and microorganisms : implications for the bioremediation of actinide-organic mixtures.

    SciTech Connect

    Banaszak, J.E.; Reed, D.T.; Rittmann, B.E.

    1999-02-12

    By reviewing how microorganisms interact with actinides in subsurface environments, we assess how bioremediation controls the fate of actinides. Actinides often are co-contaminants with strong organic chelators, chlorinated solvents, and fuel hydrocarbons. Bioremediation can immobilize the actinides, biodegrade the co-contaminants, or both. Actinides at the IV oxidation state are the least soluble, and microorganisms accelerate precipitation by altering the actinide's oxidation state or its speciation. We describe how microorganisms directly oxidize or reduce actinides and how microbiological reactions that biodegrade strong organic chelators, alter the pH, and consume or produce precipitating anions strongly affect actinide speciation and, therefore, mobility. We explain why inhibition caused by chemical or radiolytic toxicities uniquely affects microbial reactions. Due to the complex interactions of the microbiological and chemical phenomena, mathematical modeling is an essential tool for research on and application of bioremediation involving co-contamination with actinides. We describe the development of mathematical models that link microbiological and geochemical reactions. Throughout, we identify the key research needs.

  11. Actinide removal from spent salts

    DOEpatents

    Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

    2002-01-01

    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.

  12. Joint Actinide Shock Physics Experimental Research - JASPER

    ScienceCinema

    None

    2016-07-12

    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.

  13. Joint Actinide Shock Physics Experimental Research - JASPER

    SciTech Connect

    2014-10-31

    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.

  14. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

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

    2012-03-21

    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.

  15. Overview of actinide chemistry in the WIPP

    SciTech Connect

    Borkowski, Marian; Lucchini, Jean - Francois; Richmann, Michael K; Reed, Donald T; Khaing, Hnin; Swanson, Juliet

    2009-01-01

    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

  16. PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

  17. Predictive Modeling in Actinide Chemistry and Catalysis

    SciTech Connect

    Yang, Ping

    2016-05-16

    These are slides from a presentation on predictive modeling in actinide chemistry and catalysis. The following topics are covered in these slides: Structures, bonding, and reactivity (bonding can be quantified by optical probes and theory, and electronic structures and reaction mechanisms of actinide complexes); Magnetic resonance properties (transition metal catalysts with multi-nuclear centers, and NMR/EPR parameters); Moving to more complex systems (surface chemistry of nanomaterials, and interactions of ligands with nanoparticles); Path forward and conclusions.

  18. Recent progress in actinide borate chemistry.

    PubMed

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-10-21

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB(5)O(6)(OH)(6)][BO(OH)(2)]·2.5H(2)O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO(4)(-). Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials.

  19. Rapid determination of actinides in seawater samples

    DOE PAGES

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

    2014-03-09

    A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti+3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used tomore » separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1–2 weeks and provide chemical yields of ~30–60 %. This new sample preparation method can be performed in 4–8 h with tracer yields of ~85–95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort.« less

  20. Rapid determination of actinides in seawater samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.; Utsey, Robin C.; McAlister, Daniel R.

    2014-03-09

    A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti+3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used to separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1–2 weeks and provide chemical yields of ~30–60 %. This new sample preparation method can be performed in 4–8 h with tracer yields of ~85–95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort.

  1. Recent progress in actinide borate chemistry

    SciTech Connect

    Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2011-01-01

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB₅O₆(OH)₆][BO(OH)₂]·2.5H₂O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO4- Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials.

  2. Actinide recovery method -- Large soil samples

    SciTech Connect

    Maxwell , S.L. III

    2000-04-25

    There is a need to measure actinides in environmental samples with lower and lower detection limits, requiring larger sample sizes. This analysis is adversely affected by sample-matrix interferences, which make analyzing soil samples above five-grams very difficult. A new Actinide-Recovery Method has been developed by the Savannah River Site Central Laboratory to preconcentrate actinides from large-soil samples. Diphonix Resin (Eichrom Industries), a 1994 R and D 100 winner, is used to preconcentrate the actinides from large soil samples, which are bound powerfully to the resin's diphosphonic acid groups. A rapid microwave-digestion technique is used to remove the actinides from the Diphonix Resin, which effectively eliminates interfering matrix components from the soil matrix. The microwave-digestion technique is more effective and less tedious than catalyzed hydrogen peroxide digestions of the resin or digestion of diphosphonic stripping agents such as HEDPA. After resin digestion, the actinides are recovered in a small volume of nitric acid which can be loaded onto small extraction chromatography columns, such as TEVA Resin, U-TEVA Resin or TRU Resin (Eichrom Industries). Small, selective extraction columns do not generate large volumes of liquid waste and provide consistent tracer recoveries after soil matrix elimination.

  3. Actinide speciation in relation to biological processes.

    PubMed

    Ansoborlo, Eric; Prat, Odette; Moisy, Philippe; Den Auwer, Christophe; Guilbaud, Philippe; Carriere, M; Gouget, Barbara; Duffield, John; Doizi, Denis; Vercouter, Thomas; Moulin, Christophe; Moulin, Valérie

    2006-11-01

    In case of accidental release of radionuclides into the environment, actinides represent a severe health risk to human beings following internal contamination (inhalation, ingestion or wound). For a better understanding of the actinide behaviour in man (in term of metabolism, retention, excretion) and in specific biological systems (organs, cells or biochemical pathways), it is of prime importance to have a good knowledge of the relevant actinide solution chemistry and biochemistry, in particular of the thermodynamic constants needed for computing actinide speciation. To a large extent, speciation governs bioavailability and toxicity of elements and has a significant impact on the mechanisms by which toxics accumulate in cell compartments and organs and by which elements are transferred and transported from cell to cell. From another viewpoint, speciation is the prerequisite for the design and success of potential decorporation therapies. The purpose of this review is to present the state of the art of actinide knowledge within biological media. It is also to discuss how actinide speciation can be determined or predicted and to highlight the areas where information is lacking with the aim to encourage new research efforts.

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

    SciTech Connect

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

    2001-03-01

    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.

  5. Long-term test results from a West Valley actinide-doped reference glass

    SciTech Connect

    Fortner, J.A.; Gerding, T.J.; Bates, J.K.

    1995-07-01

    Results from drip tests designed to simulate unsaturated conditions in the proposed Yucca Mountain Repository are reported for an actinide-doped glass (reference glass ATM-10) used as a model waste form. These tests have been ongoing for nearly 7 years, with data collected on solution composition (including transuranics), colloid formation and disposition, glass corrosion layers, and solid secondary phases. This test is unique because of its long elapsed time, high content of thorium and transuranics, use of actual groundwater from the proposed site area, use of contact between the glass and sensitized stainless steel in the test, and the variety of analytical procedures applied to the components. Some tests have been terminated, and scanning electron microscopy (SEM) and analytical transmission electron microscopy (AEM) were used to directly measure glass corrosion and identify secondary phases. Other tests remain ongoing, with periodic sampling of the water that had contacted the glass. The importance of integrated testing has been demonstrated, as complex interactions between the glass, the groundwater, and the sensitized stainless steel have been observed. Secondary phases include smectite clay, iron silicates, and brockite. Actinides, except neptunium, concentrate into stable secondary phases. The release of actinides is then controlled by the behavior of these phases.

  6. Some aspects of the use of ZrN as an inert matrix for actinide fuels

    NASA Astrophysics Data System (ADS)

    Burghartz, M.; Ledergerber, G.; Hein, H.; van der Laan, R. R.; Konings, R. J. M.

    2001-02-01

    The sodium compatibility and the nitric acid dissolution of (Zr 0.80U 0.20)N, prepared by carbothermic reduction of the oxide, were determined. No interaction with liquid sodium ( T=823 K) was observed. The material readily dissolved in nitric acid ( T=378-383 K). From these results it is concluded that ZrN is an attractive inert matrix in fast reactor fuels for the incineration of plutonium and minor actinides.

  7. Dispositions in Action: Do Dispositions Make a Difference in Practice?

    ERIC Educational Resources Information Center

    Thornton, Holly

    2006-01-01

    The discourse on teacher quality has centered on issues of teacher knowledge and teacher skill, yet a third element that is central to all professional standards is teacher dispositions. Although there is no consensus about a definition of teacher dispositions, there are several models in use regarding how dispositions are being addressed. Most…

  8. Sorption speciation of lanthanides/actinides on minerals by TRLFS, EXAFS and DFT studies: a review.

    PubMed

    Tan, Xiaoli; Fang, Ming; Wang, Xiangke

    2010-11-17

    Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory (DFT) is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the methods are concisely presented. Examples of recent research results of lanthanide/actinide speciation and local atomic structures using TRLFS, EXAFS and DFT are discussed. The interaction of lanthanides/actinides with oxides and minerals as well as their uptake are also of common interest in radionuclide chemistry. Especially the sorption and inclusion of radionuclides into several minerals lead to an improvement in knowledge of minor components in solids. In the solid-liquid interface, the speciation and local atomic structures of Eu(III), Cm(III), U(VI), and Np(IV/VI) in several natural and synthetic minerals and oxides are also reviewed and discussed. The review is important to understand the physicochemical behavior of lanthanides/actinides at a molecular level in the natural environment.

  9. Human factors and safety issues associated with actinide retrieval from spent light water reactor fuel assemblies

    SciTech Connect

    Spelt, P.F.

    1992-01-01

    A major problem in environmental restoration and waste management is the disposition of used fuel assemblies from the many light water reactors in the United States, which present a radiation hazard to those whose job is to dispose of them, with a similar threat to the general environment associated with long-term storage in fuel repositories around the country. Actinides resident in the fuel pins as a result of their use in reactor cores constitute a significant component of this hazard. Recently, the Department of Energy has initiated an Actinide Recycle Program to study the feasibility of using pyrochemical (molten salt) processes to recover actinides from the spent fuel assemblies of commercial reactors. This project concerns the application of robotics technology to the operation and maintenance functions of a plant whose objective is to recover actinides from spent fuel assemblies, and to dispose of the resulting hardware and chemical components from this process. Such a procedure involves a number of safety and human factors issues. The purpose of the project is to explore the use of robotics and artificial intelligence to facilitate accomplishment of the program goals while maintaining the safety of the humans doing the work and the integrity of the environment. This project will result in a graphic simulation on a Silicon Graphics workstation as a proof of principle demonstration of the feasibility of using robotics along with an intelligent operator interface. A major component of the operator-system interface is a hybrid artificial intelligence system developed at Oak Ridge National Laboratory, which combines artificial neural networks and an expert system into a hybrid, self-improving computer-based system interface. 10 refs.

  10. Human factors and safety issues associated with actinide retrieval from spent light water reactor fuel assemblies

    SciTech Connect

    Spelt, P.F.

    1992-08-01

    A major problem in environmental restoration and waste management is the disposition of used fuel assemblies from the many light water reactors in the United States, which present a radiation hazard to those whose job is to dispose of them, with a similar threat to the general environment associated with long-term storage in fuel repositories around the country. Actinides resident in the fuel pins as a result of their use in reactor cores constitute a significant component of this hazard. Recently, the Department of Energy has initiated an Actinide Recycle Program to study the feasibility of using pyrochemical (molten salt) processes to recover actinides from the spent fuel assemblies of commercial reactors. This project concerns the application of robotics technology to the operation and maintenance functions of a plant whose objective is to recover actinides from spent fuel assemblies, and to dispose of the resulting hardware and chemical components from this process. Such a procedure involves a number of safety and human factors issues. The purpose of the project is to explore the use of robotics and artificial intelligence to facilitate accomplishment of the program goals while maintaining the safety of the humans doing the work and the integrity of the environment. This project will result in a graphic simulation on a Silicon Graphics workstation as a proof of principle demonstration of the feasibility of using robotics along with an intelligent operator interface. A major component of the operator-system interface is a hybrid artificial intelligence system developed at Oak Ridge National Laboratory, which combines artificial neural networks and an expert system into a hybrid, self-improving computer-based system interface. 10 refs.

  11. Lithium actinide recycle process demonstration

    SciTech Connect

    Johnson, G.K.; Pierce, R.D.; McPheeters, C.C.

    1995-10-01

    Several pyrochemical processes have been developed in the Chemical Technology Division of Argonne Laboratory for recovery of actinide elements from LWR spent fuel. The lithium process was selected as the reference process from among the options. In this process the LWR oxide spent fuel is reduced by lithium at 650{degrees}C in the presence of molten LiCl. The Li{sub 2}O formed during the reduction process is soluble in the salt. The spent salt and lithium are recycled after the Li{sub 2}O is electrochemically reduced. The oxygen is liberated as CO{sub 2} at a carbon anode or oxygen at an inert anode. The reduced metal components of the LWR spent fuel are separated from the LiCL salt phase and introduced into an electrorefiner. The electrorefining step separates the uranium and transuranium (TRU) elements into two product streams. The uranium product, which comprises about 96% of the LWR spent fuel mass, may be enriched for recycle into the LWR fuel cycle, stored for future use in breeder reactors, or converted to a suitable form for disposal as waste. The TRU product can be recycled as fast reactor fuel or can be alloyed with constituents of the LWR cladding material to produce a stable waste form.

  12. Actinide recovery from pyrochemical residues

    SciTech Connect

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.

    1985-05-01

    We demonstrated a new process for recovering plutonium and americium from pyrochemical waste. The method is based on chloride solution anion exchange at low acidity, or acidity that eliminates corrosive HCl fumes. Developmental experiments of the process flow chart concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained <500 ppM americium and <2500 ppM magnesium. The process operates by sorbing PuCl/sub 6//sup 2 -/ from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO/sub 3/-4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO/sub 3/ precipitation. All filtrates from the process can be discardable as low-level contaminated waste. Production-scale experiments are in progress for MSE residues. Flow charts for actinide recovery from electro-refining and direct oxide reduction residues are presented and discussed.

  13. A Disposition for Benevolence

    ERIC Educational Resources Information Center

    O'Shea, Joseph

    2011-01-01

    This article presents the first half of an address at the 2011 Jon C. Dalton Institution on College Student Values. Drawing on personal reflections regarding his higher education experiences, the author argues that cultivating a robust disposition for benevolence requires a synthesis of intellectual engagement, critical self-reflection, and…

  14. A Disposition for Benevolence

    ERIC Educational Resources Information Center

    O'Shea, Joseph

    2011-01-01

    This article presents the first half of an address at the 2011 Jon C. Dalton Institution on College Student Values. Drawing on personal reflections regarding his higher education experiences, the author argues that cultivating a robust disposition for benevolence requires a synthesis of intellectual engagement, critical self-reflection, and…

  15. Five Dispositions for Personalization

    ERIC Educational Resources Information Center

    Carter, Kim

    2017-01-01

    The author reviews various ways personalized learning has come to be interpreted and asserts that rather than requiring we create individualized learning plans for each student, true personalization requires that teachers give learners the tools, knowledge, skills, and dispositions to manage themselves and their learning environment. Teachers…

  16. SAMPLE RESULTS FROM THE INTEGRATED SALT DISPOSITION PROGRAM MACROBATCH 5 TANK 21H QUALIFICATION MST, ESS AND PODD SAMPLES

    SciTech Connect

    Peters, T.; Fink, S.

    2012-04-24

    Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Integrated Salt Disposition Program (ISDP) Batch 5 processing. This qualification material was a composite created from recent samples from Tank 21H and archived samples from Tank 49H to match the projected blend from these two tanks. Additionally, samples of the composite were used in the Actinide Removal Process (ARP) and extraction-scrub-strip (ESS) tests. ARP and ESS test results met expectations. A sample from Tank 21H was also analyzed for the Performance Objectives Demonstration Document (PODD) requirements. SRNL was able to meet all of the requirements, including the desired detection limits for all the PODD analytes. This report details the results of the Actinide Removal Process (ARP), Extraction-Scrub-Strip (ESS) and Performance Objectives Demonstration Document (PODD) samples of Macrobatch (Salt Batch) 5 of the Integrated Salt Disposition Program (ISDP).

  17. Nonaqueous method for dissolving lanthanide and actinide metals

    DOEpatents

    Crisler, L.R.

    1975-11-11

    Lanthanide and actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a lanthanide or actinide element in the elemental metallic state in a mixture of carbon tetrachloride and methanol.

  18. TUCS/phosphate mineralization of actinides

    SciTech Connect

    Nash, K.L.

    1997-10-01

    This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

  19. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOEpatents

    Miller, Steven M.

    1988-01-01

    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.

  20. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOEpatents

    Miller, S.M.

    1983-10-31

    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.

  1. Sample results from the interim salt disposition program macrobatch 8 tank 21H qualification MST solids sample

    SciTech Connect

    Peters, T. B.; Washington, A. L.

    2015-02-01

    Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for Interim Salt Disposition Program (ISDP) processing. As part of this qualification work, SRNL performed an Actinide Removal Process (ARP) and several Extraction, Scrub, Strip (ESS) tests. This document reports characterization of the monosodium titanate (MST) solids from the ARP test. The results of these analyses are reported and are within historical precedent.

  2. RECOVERY OF ACTINIDES FROM AQUEOUS NITRIC ACID SOLUTIONS

    DOEpatents

    Ader, M.

    1963-11-19

    A process of recovering actinides is presented. Tetravalent actinides are extracted from rare earths in an aqueous nitric acid solution with a ketone and back-extracted from the ketone into an aqueous medium. The aqueous actinide solution thus obtained, prior to concentration by boiling, is sparged with steam to reduce its ketone to a maximum content of 3 grams per liter. (AEC)

  3. The Actinide-Lanthanide Separation Process

    SciTech Connect

    Lumetta, Gregg J.; Gelis, Artem V.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-02-21

    The Actinide-Lanthanide SEParation (ALSEP) process is described. The process uses an extractant phase consisting of either N,N,N',N'-tetraoctyldiglycolamide (TODGA) or N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). The neutral TODGA or T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid media. Switching the aqueous phase chemistry to a citrate buffered diethylenetriaminepentaacetic acid (DTPA) solution at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus resulting in separation of these two groups of elements.

  4. Sigma Team for Advanced Actinide Recycle FY2015 Accomplishments and Directions

    SciTech Connect

    Moyer, Bruce A.

    2015-09-30

    The Sigma Team for Minor Actinide Recycle (STAAR) has made notable progress in FY 2015 toward the overarching goal to develop more efficient separation methods for actinides in support of the United States Department of Energy (USDOE) objective of sustainable fuel cycles. Research in STAAR has been emphasizing the separation of americium and other minor actinides (MAs) to enable closed nuclear fuel recycle options, mainly within the paradigm of aqueous reprocessing of used oxide nuclear fuel dissolved in nitric acid. Its major scientific challenge concerns achieving selectivity for trivalent actinides vs lanthanides. Not only is this challenge yielding to research advances, but technology concepts such as ALSEP (Actinide Lanthanide Separation) are maturing toward demonstration readiness. Efforts are organized in five task areas: 1) combining bifunctional neutral extractants with an acidic extractant to form a single process solvent, developing a process flowsheet, and demonstrating it at bench scale; 2) oxidation of Am(III) to Am(VI) and subsequent separation with other multivalent actinides; 3) developing an effective soft-donor solvent system for An(III) selective extraction using mixed N,O-donor or all-N donor extractants such as triazinyl pyridine compounds; 4) testing of inorganic and hybrid-type ion exchange materials for MA separations; and 5) computer-aided molecular design to identify altogether new extractants and complexants and theory-based experimental data interpretation. Within these tasks, two strategies are employed, one involving oxidation of americium to its pentavalent or hexavalent state and one that seeks to selectively complex trivalent americium either in the aqueous phase or the solvent phase. Solvent extraction represents the primary separation method employed, though ion exchange and crystallization play an important role. Highlights of accomplishments include: Confirmation of the first-ever electrolytic oxidation of Am(III) in a

  5. Elevated concentrations of actinides in mono lake.

    PubMed

    Anderson, R F; Bacon, M P; Brewer, P G

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  6. Systematization of actinides using cluster analysis

    SciTech Connect

    Kopyrin, A.A.; Terent`eva, T.N.; Khramov, N.N.

    1994-11-01

    A representation of the actinides in multidimensional property space is proposed for systematization of these elements using cluster analysis. Literature data for their atomic properties are used. Owing to the wide variation of published ionization potentials, medians are used to estimate them. Vertical dendograms are used for classification on the basis of distances between the actinides in atomic-property space. The properties of actinium and lawrencium are furthest removed from the main group. Thorium and mendelevium exhibit individualized properties. A cluster based on the einsteinium-fermium pair is joined by californium.

  7. Strong correlations in actinide redox reactions

    NASA Astrophysics Data System (ADS)

    Horowitz, S. E.; Marston, J. B.

    2011-02-01

    Reduction-oxidation (redox) reactions of the redox couples An(VI)/An(V), An(V)/An(IV), and An(IV)/An(III), where An is an element in the family of early actinides (U, Np, and Pu), as well as Am(VI)/Am(V) and Am(V)/Am(III), are modeled by combining density functional theory with a generalized Anderson impurity model that accounts for the strong correlations between the 5f electrons. Diagonalization of the Anderson impurity model yields improved estimates for the redox potentials and the propensity of the actinide complexes to disproportionate.

  8. The gastrointestinal absorption of the actinide elements.

    PubMed

    Harrison, J D

    1991-03-01

    The greatest uncertainty in dose estimates for the ingestion of long-lived, alpha-emitting isotopes of the actinide elements is in the values used for their fractional absorption from the gastrointestinal tract (f1 values). Recent years have seen a large increase in the available data on actinide absorption. Human data are reviewed here, together with animal data, to illustrate the effect on absorption of chemical form, incorporation into food materials, fasting and other dietary factors, and age at ingestion. The f1 values recommended by the International Commission on Radiological Protection, by an Expert Group of the Nuclear Energy Agency and by the National Radiological Protection Board are discussed.

  9. Elevated concentrations of actinides in Mono Lake

    SciTech Connect

    Anderson, R.F.; Bacon, M.P.; Brewer, P.G.

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  10. Strong correlations in actinide redox reactions.

    PubMed

    Horowitz, S E; Marston, J B

    2011-02-14

    Reduction-oxidation (redox) reactions of the redox couples An(VI)/An(V), An(V)/An(IV), and An(IV)/An(III), where An is an element in the family of early actinides (U, Np, and Pu), as well as Am(VI)/Am(V) and Am(V)/Am(III), are modeled by combining density functional theory with a generalized Anderson impurity model that accounts for the strong correlations between the 5f electrons. Diagonalization of the Anderson impurity model yields improved estimates for the redox potentials and the propensity of the actinide complexes to disproportionate.

  11. Actinide ion extraction using room temperature ionic liquids: opportunities and challenges for nuclear fuel cycle applications.

    PubMed

    Mohapatra, Prasanta Kumar

    2017-02-14

    Studies on the extraction of actinide ions from radioactive feeds have great relevance in nuclear fuel cycle activities, mainly in the back end processes focused on reprocessing and waste management. Room temperature ionic liquid (RTIL) based diluents are becoming increasingly popular due to factors such as more efficient extraction vis-à-vis molecular diluents, higher metal loading, higher radiation resistance, etc. The fascinating chemistry of the actinide ions in RTIL based solvent systems due to complex extraction mechanisms makes it a challenging area of research. By the suitable tuning of the cationic and anionic parts of the ionic liquids, their physical properties such as density, dielectric constant and viscosity can be changed which are considered key parameters in metal ion extraction. Aqueous solubility of the RTILs, which can lead to significant loss in the solvent inventory, can be avoided by appending the extractant moieties onto the ionic liquid. While the low vapour pressure and non-flammability of the ionic liquids make them appear as 'green' diluents, their aqueous solubility raises concerns of environmental hazards. The present article gives a summary of studies carried out on actinide ion extraction and presents perspectives of its applications in the nuclear fuel cycle. The article discusses various extractants used for actinide ion extraction and at many places, comparison is made vis-à-vis molecular diluents which includes the nature of the extracted species and the mechanism of extraction. Results of studies on rare earth elements are also included in view of their similarities with the trivalent minor actinides.

  12. Disposition of intravenous radioactive acyclovir

    SciTech Connect

    de Miranda, P.; Good, S.S.; Laskin, O.L.; Krasny, H.C.; Connor, J.D.; Lietman, P.S.

    1981-11-01

    The kinetic and metabolic disposition of (8-14C)acyclovir (ACV) was investigated in five subjects with advanced malignancy. The drug was administered by 1-hr intravenous infusion at doses of 0.5 and 2.5 mg/kg. Plasma and blood radioactivity-time, and plasma concentration-time data were defined by a two-compartment open kinetic model. There was nearly equivalent distribution of radioactivity in blood and plasma. The overall mean plasma half-life and total body clearance +/- SD of ACV were 2.1 +/- 0.5 hr and 297 +/- 53 ml/min/1.73 m2. Binding of ACV to plasma proteins was 15.4 +/- 4.4%. Most of the radioactive dose excreted was recovered in the urine (71% to 99%) with less than 2% excretion in the feces and only trace amounts in the expired Co2. Analyses by reverse-phase high-performance liquid chromatography indicated that 9-(carboxymethoxymethyl)guanine was the only significant urinary metabolite of ACV, accounting for 8.5% to 14.1% of the dose. A minor metabolite (less than 0.2% of dose) had the retention time of 8-hydroxy-9-((2-hydroxyethoxy)methyl)guanine. Unchanged urinary ACV ranged from 62% to 91% of the dose. There was no indication of ACV cleavage to guanine. Renal clearance of ACV was approximately three times the corresponding creatinine clearances.

  13. Teachers' Dispositions: Supporting Democracy or Forcing Indoctrination

    ERIC Educational Resources Information Center

    Norris, Dale

    2008-01-01

    Teacher education programs have become increasingly aware of the need to consider appropriate professional dispositions. This article addresses several potentially uncomfortable questions surrounding teacher dispositions including a true meaning of disposition(s), assessing dispositions and the research base of what is known concerning…

  14. Positron Spectroscopy of Hydrothermally Grown Actinide Oxides

    DTIC Science & Technology

    2014-03-27

    In this method, the powdered material is placed in a solution which contains extremely powerful mineralizers, such as cesium fluoride for actinide...the isotope that acts as a positron source is sodium -22, which has a relatively short half-life (2.6 y) and emits a characteristic gamma photon (at

  15. Rapid determination of actinides in asphalt samples

    DOE PAGES

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

    2014-01-12

    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 organicsmore » 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.« less

  16. Semi-empirical models of actinide alloying

    NASA Astrophysics Data System (ADS)

    Gibson, John K.; Haire, Richard G.; Ogawa, Toru

    1999-07-01

    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 237Np, 241Am and other actinide isotopes as significant, long-lived and highly radiotoxic nuclear waste components, and particularly the roles of metallic materials in new handling/separations and remediation technologies, demands that this paucity of information concerning alloy behaviors be addressed. An additional interest in these materials 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 diagrams. 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.

  17. Actinide measurements by AMS using fluoride matrices

    NASA Astrophysics Data System (ADS)

    Cornett, R. J.; Kazi, Z. H.; Zhao, X.-L.; Chartrand, M. G.; Charles, R. J.; Kieser, W. E.

    2015-10-01

    Actinides can be measured by alpha spectroscopy (AS), mass spectroscopy or accelerator mass spectrometry (AMS). We tested a simple method to separate Pu and Am isotopes from the sample matrix using a single extraction chromatography column. The actinides in the column eluent were then measured by AS or AMS using a fluoride target matrix. Pu and Am were coprecipitated with NdF3. The strongest AMS beams of Pu and Am were produced when there was a large excess of fluoride donor atoms in the target and the NdF3 precipitates were diluted about 6-8 fold with PbF2. The measured concentrations of 239,240Pu and 241Am agreed with the concentrations in standards of known activity and with two IAEA certified reference materials. Measurements of 239,240Pu and 241Am made at A.E. Lalonde AMS Laboratory agree, within their statistical uncertainty, with independent measurements made using the IsoTrace AMS system. This work demonstrated that fluoride targets can produce reliable beams of actinide anions and that the measurement of actinides using fluorides agree with published values in certified reference materials.

  18. Rapid determination of actinides in asphalt samples

    SciTech Connect

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

    2014-01-12

    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.

  19. Trends in actinide processing at Hanford

    SciTech Connect

    Harmon, H.D.

    1993-09-01

    In 1989, the mission at the Hanford Site began a dramatic and sometimes painful transition. The days of production--as we used to know it--are over. Our mission officially has become waste management and environmental cleanup. This mission change didn`t eliminate many jobs--in fact, budgets have grown dramatically to support the new mission. Most all of the same skilled crafts, engineers, and scientists are still required for the new mission. This change has not eliminated the need for actinide processing, but it has certainly changed the focus that our actinide chemists and process engineers have. The focus used to be on such things as increasing capacity, improving separations efficiency, and product purity. Minimizing waste had become a more important theme in recent years and it is still a very important concept in the waste management and environmental cleanup arena. However, at Hanford, a new set of words dominates the actinide process scene as we work to deal with actinides that still reside in a variety of forms at the Hanford Site. These words are repackage, stabilize, remove, store and dispose. Some key activities in each of these areas are described in this report.

  20. DEVELOPMENT OF GLASS AND CRYSTALLINE CERAMIC FORMS FOR DISPOSITION OF EXCESS PLUTONIUM

    SciTech Connect

    Marra, James; Cozzi, A; Crawford, C.; Herman, C.; Marra, John; Peeler, D.

    2009-09-10

    In the aftermath of the Cold War, the United States Department of Energy (DOE) has identified up to 50 metric tons of excess plutonium that needs to be dispositioned. The bulk of the material is slated to be blended with uranium and fabricated into a Mixed Oxide (MOX) fuel for subsequent burning in commercial nuclear reactors. Excess plutonium-containing impurity materials making it unsuitable for fabrication into MOX fuel will need to be dispositioned via other means. Glass and crystalline ceramics have been developed and studied as candidate forms to immobilize these impure plutonium feeds. A titanate-based ceramic was identified as an excellent actinide material host. This composition was based on Synroc compositions previously developed for nuclear waste immobilization. These titanate ceramics were found to be able to accommodate extremely high quantities of fissile material and exhibit excellent aqueous durability. A lanthanide borosilicate (LaBS) glass was developed to accommodate high concentrations of plutonium and to be very tolerant of impurities yet still maintain good aqueous durability. Recent testing of alkali borosilicate compositions showed promise of using these compositions to disposition lower concentrations of plutonium using existing high level waste vitrification processes. The developed waste forms all appear to be suitable for Pu disposition. Depending on the actual types and concentrations of the Pu residue streams slated for disposition, each waste form offers unique advantages.

  1. Plutonium Futures -- The Science. Topical Conference on Plutonium and Actinides. AIP Conference Proceedings, No. 532 [APCPCS

    SciTech Connect

    Pillay, K.K.S.; Kim, K.C.

    2000-12-31

    Presentations at this conference covered the topics of materials science/nuclear fuels, condensed matter physics, actinides in the environment/separation and analysis, actinides/processing, actinides/TRU wastes, materials science, TRU waste forms, nuclear fuels/isotopes, separations and process chemistry, actinides in the environment, detection and analysis, Pu and Pu compounds, actinide compounds and complexes.

  2. Adventures in Actinide Chemistry: A Year of Exploring Uranium and Thorium in Los Alamos

    SciTech Connect

    Pagano, Justin

    2016-01-08

    The first part of this collection of slides is concerned with considerations when working with actinides. The topics discussed in the document as a whole are the following: Actinide chemistry vs. transition metal chemistry--tools we can use; New synthetic methods to obtain actinide hydrides; Actinide metallacycles: synthesis, structure, and properties; and Reactivity of actinide metallacycles.

  3. An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses: Criticality (keff) Predictions

    DOE PAGES

    Scaglione, John M.; Mueller, Don E.; Wagner, John C.

    2014-12-01

    One of the most important remaining challenges associated with expanded implementation of burnup credit in the United States is the validation of depletion and criticality calculations used in the safety evaluation—in particular, the availability and use of applicable measured data to support validation, especially for fission products (FPs). Applicants and regulatory reviewers have been constrained by both a scarcity of data and a lack of clear technical basis or approach for use of the data. In this study, this paper describes a validation approach for commercial spent nuclear fuel (SNF) criticality safety (keff) evaluations based on best-available data and methodsmore » and applies the approach for representative SNF storage and transport configurations/conditions to demonstrate its usage and applicability, as well as to provide reference bias results. The criticality validation approach utilizes not only available laboratory critical experiment (LCE) data from the International Handbook of Evaluated Criticality Safety Benchmark Experiments and the French Haut Taux de Combustion program to support validation of the principal actinides but also calculated sensitivities, nuclear data uncertainties, and limited available FP LCE data to predict and verify individual biases for relevant minor actinides and FPs. The results demonstrate that (a) sufficient critical experiment data exist to adequately validate keff calculations via conventional validation approaches for the primary actinides, (b) sensitivity-based critical experiment selection is more appropriate for generating accurate application model bias and uncertainty, and (c) calculated sensitivities and nuclear data uncertainties can be used for generating conservative estimates of bias for minor actinides and FPs. Results based on the SCALE 6.1 and the ENDF/B-VII.0 cross-section libraries indicate that a conservative estimate of the bias for the minor actinides and FPs is 1.5% of their worth within the

  4. Spent Nuclear Fuel Disposition

    SciTech Connect

    Wagner, John C.

    2016-05-22

    One interdisciplinary field devoted to achieving the end-state of used nuclear fuel (UNF) through reuse and/or permanent disposal. The reuse option aims to make use of the remaining energy content in UNF and reduce the amount of long-lived radioactive materials that require permanent disposal. The planned approach in the U.S., as well as in many other countries worldwide, is direct permanent disposal in a deep geologic repository. Used nuclear fuel is fuel that has been irradiated in a nuclear reactor to the point where it is no longer capable of sustaining operational objectives. The vast majority (by mass) of UNF is from electricity generation in commercial nuclear power reactors. Furthermore, the other main source of UNF in the U.S. is the Department of Energy’s (DOE) and other federal agencies’ operation of reactors in support of federal government missions, such as materials production, nuclear propulsion, research, testing, and training. Upon discharge from a reactor, UNF emits considerable heat from radioactive decay. Some period of active on-site cooling (e.g., 2 or more years) is typically required to facilitate efficient packaging and transportation to a disposition facility. Hence, the field of UNF disposition broadly includes storage, transportation and ultimate disposition. See also: Nuclear Fission (content/nuclear-fission/458400), Nuclear Fuels (/content/nuclear-fuels/458600), Nuclear Fuel Cycle (/content/nuclear-fuel-cycle/458500), Nuclear Fuels Reprocessing (/content/nuclear-fuels-reprocessing/458700), Nuclear Power (/content/nuclear-power/459600), Nuclear Reactor (/content/nuclear-reactor/460100), Radiation (/content/radiation/566300), and Radioactive Waste Management (/content/radioactive-waste-management/568900).

  5. Spent Nuclear Fuel Disposition

    DOE PAGES

    Wagner, John C.

    2016-05-22

    One interdisciplinary field devoted to achieving the end-state of used nuclear fuel (UNF) through reuse and/or permanent disposal. The reuse option aims to make use of the remaining energy content in UNF and reduce the amount of long-lived radioactive materials that require permanent disposal. The planned approach in the U.S., as well as in many other countries worldwide, is direct permanent disposal in a deep geologic repository. Used nuclear fuel is fuel that has been irradiated in a nuclear reactor to the point where it is no longer capable of sustaining operational objectives. The vast majority (by mass) of UNFmore » is from electricity generation in commercial nuclear power reactors. Furthermore, the other main source of UNF in the U.S. is the Department of Energy’s (DOE) and other federal agencies’ operation of reactors in support of federal government missions, such as materials production, nuclear propulsion, research, testing, and training. Upon discharge from a reactor, UNF emits considerable heat from radioactive decay. Some period of active on-site cooling (e.g., 2 or more years) is typically required to facilitate efficient packaging and transportation to a disposition facility. Hence, the field of UNF disposition broadly includes storage, transportation and ultimate disposition. See also: Nuclear Fission (content/nuclear-fission/458400), Nuclear Fuels (/content/nuclear-fuels/458600), Nuclear Fuel Cycle (/content/nuclear-fuel-cycle/458500), Nuclear Fuels Reprocessing (/content/nuclear-fuels-reprocessing/458700), Nuclear Power (/content/nuclear-power/459600), Nuclear Reactor (/content/nuclear-reactor/460100), Radiation (/content/radiation/566300), and Radioactive Waste Management (/content/radioactive-waste-management/568900).« less

  6. Synthesis of actinide nitrides, phosphides, sulfides and oxides

    DOEpatents

    Van Der Sluys, William G.; Burns, Carol J.; Smith, David C.

    1992-01-01

    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.

  7. Revisiting Professional Dispositions: Research Redux

    ERIC Educational Resources Information Center

    Bush, Gail; Jones, Jami L.

    2011-01-01

    As the authors progressed through their research agenda last year, they contributed an article to "School Library Monthly" entitled "Forecasting Professional Dispositions of School Librarians" (January 2011, 54-56) wherein they described a Delphi study they conducted in the fall of 2009 that identified professional dispositions based on responses…

  8. Revisiting Professional Dispositions: Research Redux

    ERIC Educational Resources Information Center

    Bush, Gail; Jones, Jami L.

    2011-01-01

    As the authors progressed through their research agenda last year, they contributed an article to "School Library Monthly" entitled "Forecasting Professional Dispositions of School Librarians" (January 2011, 54-56) wherein they described a Delphi study they conducted in the fall of 2009 that identified professional dispositions based on responses…

  9. Leadership: Dispositional and Situational. Revision

    DTIC Science & Technology

    1988-11-01

    Situations, Traits , Contexts, Multiple levels of analysis, Managerial practice, (over) 19. ABSTRACT (Continue on reverse if necessary and ’dentify by...block number) For over four decades, leadership research has examined the issue of whether internal dispositions ( traits ), situational characteristics...leadership research has examined the issue of whether internal dispositions ( traits ), situational characteristics (contexts), or some combination of

  10. Electrorecovery of actinides at room temperature

    SciTech Connect

    Stoll, Michael E; Oldham, Warren J; Costa, David A

    2008-01-01

    There are a large number of purification and processing operations involving actinide species that rely on high-temperature molten salts as the solvent medium. One such application is the electrorefining of impure actinide metals to provide high purity material for subsequent applications. There are some drawbacks to the electrodeposition of actinides in molten salts including relatively low yields, lack of accurate potential control, maintaining efficiency in a highly corrosive environment, and failed runs. With these issues in mind we have been investigating the electrodeposition of actinide metals, mainly uranium, from room temperature ionic liquids (RTILs) and relatively high-boiling organic solvents. The RTILs we have focused on are comprised of 1,3-dialkylimidazolium or quaternary ammonium cations and mainly the {sup -}N(SO{sub 2}CF{sub 3}){sub 2} anion [bis(trif1uoromethylsulfonyl)imide {equivalent_to} {sup -}NTf{sub 2}]. These materials represent a class of solvents that possess great potential for use in applications employing electrochemical procedures. In order to ascertain the feasibility of using RTILs for bulk electrodeposition of actinide metals our research team has been exploring the electron transfer behavior of simple coordination complexes of uranium dissolved in the RTIL solutions. More recently we have begun some fundamental electrochemical studies on the behavior of uranium and plutonium complexes in the organic solvents N-methylpyrrolidone (NMP) and dimethylsulfoxide (DMSO). Our most recent results concerning electrodeposition will be presented in this account. The electrochemical behavior of U(IV) and U(III) species in RTILs and the relatively low vapor pressure solvents NMP and DMSO is described. These studies have been ongoing in our laboratory to uncover conditions that will lead to the successful bulk electrodeposition of actinide metals at a working electrode surface at room temperature or slightly elevated temperatures. The RTILs we

  11. Thiamphenicol disposition in pigs.

    PubMed

    Castells, G; Prats, C; El Korchi, G; Pérez, B; Arboix, M; Cristòfol, C; Martì, G

    1999-06-01

    Pharmacokinetic parameters of thiamphenicol (TAP) were determined after intravenous (i.v.) and intramuscular (i.m.) administration of 30 mg kg-1 of TAP in pigs. Plasma drug concentrations were determined by high performance liquid chromatography (HPLC) Intravenous TAP kinetics were fitted to a bi-exponential equation, with a first rapid disposition phase followed by a slower disposition phase. Elimination half-life was short, at 59.3 (29.4) minutes; volume of distribution at steady state was 0.62 (0.24) 1 kg-1; and plasma clearance was 13.4 (4.5) ml min-1 kg-1. After i.m. administration, the peak plasma concentration (Cmax= 4.1 microg ml-1) was reached in about 60 minutes; these concentrations are lower than those reported in other species. The TAP elimination half-life after i.m. administration, 250.2 (107.1) minutes was longer after than i.v. administration, probably due to the slow rate of absorption from the muscle. The mean bioavailability value for i.m. administration was 76 (12) per cent.

  12. Plutonium Disposition Now!

    SciTech Connect

    Buckner, M.R.

    1995-05-24

    A means for use of existing processing facilities and reactors for plutonium disposition is described which requires a minimum capital investment and allows rapid implementation. The scenario includes interim storage and processing under IAEA control, and fabrication into MOX fuel in existing or planned facilities in Europe for use in operating reactors in the two home countries. Conceptual studies indicate that existing Westinghouse four-loop designs can safety dispose of 0.94 MT of plutonium per calendar year. Thus, it would be possible to consume the expected US excess stockpile of about 50 MT in two to three units of this type, and it is highly likely that a comparable amount of the FSU excess plutonium could be deposed of in a few VVER-1000`s. The only major capital project for this mode of plutonium disposition would be the weapons-grade plutonium processing which could be done in a dedicated international facility or using existing facilities in the US and FSU under IAEA control. This option offers the potential for quick implementation at a very low cost to the governments of the two countries.

  13. Review Article: The Effects of Radiation Chemistry on Solvent Extraction 3: A Review of Actinide and Lanthanide Extraction

    SciTech Connect

    Bruce J. Mincher; Giuseppe Modolo; Stephen P. Mezyk

    2009-12-01

    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.

  14. Actinide Isotopes for the Synthesis of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    Recent research resulting in the synthesis of isotopes of new elements 113-118 has demonstrated the importance of actinide targets in superheavy element research. Oak Ridge National Laboratory (ORNL) has unique facilities for the production and processing of actinide target materials, including the High Flux Isotope Reactor (HFIR) and the Radiochemical Engineering Development Center (REDC). These facilities have provided actinide target materials that have been used for the synthesis of all superheavy (SHE) elements above Copernicium (element 112). In this paper, the use of actinide targets for SHE research and discovery is described, including recent results for element 117 using 249Bk target material from ORNL. ORNL actinide capabilities are reviewed, including production and separation/purification, availabilities of actinide materials, and future opportunities including novel target materials such as 251Cf.

  15. Actinide phosphonate complexes in aqueous solutions

    SciTech Connect

    Nash, K.L.

    1993-10-01

    Complexes formed by actinides with carboxylic acids, polycarboxylic acids, and aminopolycarboxylic acids play a central role in both the basic and process chemistry of the actinides. Recent studies of f-element complexes with phosphonic acid ligands indicate that new ligands incorporating doubly ionizable phosphonate groups (-PO{sub 3}H{sub 2}) have many properties which are unique chemically, and promise more efficient separation processes for waste cleanup and environmental restoration. Simple diphosphonate ligands form much stronger complexes than isostructural carboxylates, often exhibiting higher solubility as well. In this manuscript recent studies of the thermodynamics and kinetics of f-element complexation by 1,1 and 1,2 diphosphonic acid ligands are described.

  16. Chemistry of the actinide elements. Second edition

    SciTech Connect

    Katz, J.J.; Seaborg, G.T.; Morss, L.R.

    1987-01-01

    This is an exhaustive, updated discourse on the chemistry of Actinides, Volume 1 contains a systematic coverage of the elements Ac, Th, Pa, U, Np, and Pu, which constitutes Part 1 of the work. The characterization of each element is discussed in terms of its nuclear properties, occurrence, preparation, atomic and metallic properties, chemistry of specific compounds, and solution chemistry. The first part of Volume 2 follows the same format as Volume 1 but is confined to the elements Am, Cm, Bk, Cf, and Es, plus a more condensed coverage of the Transeinsteinium elements (Fm, Md, No, Lw, and 104-109). Part 2 of this volume is devoted to a discussion of the actinide elements in general, with a specific focus on electronic spectra, thermodynamic and magnetic properties, the metallic state, structural chemistry, solution kinetics, organometallic chemistry for /sigma/- and /pi/-bonded compounds, and some concluding remarks on the superheavy elements.

  17. QUANTIFICATION OF ACTINIDE ALPHA-RADIATION DAMAGE IN MINERALS AND CERAMICS

    SciTech Connect

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

    2007-01-11

    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.

  18. Conjugates of magnetic nanoparticle-actinide specific chelator for radioactive waste separation.

    PubMed

    Kaur, Maninder; Zhang, Huijin; Martin, Leigh; Todd, Terry; Qiang, You

    2013-01-01

    A novel nanotechnology for the separation of radioactive waste that uses magnetic nanoparticles (MNPs) conjugated with actinide specific chelators (MNP-Che) is reviewed with a focus on design and process development. The MNP-Che separation process is an effective way of separating heat generating minor actinides (Np, Am, Cm) from spent nuclear fuel solution to reduce the radiological hazard. It utilizes coated MNPs to selectively adsorb the contaminants onto their surfaces, after which the loaded particles are collected using a magnetic field. The MNP-Che conjugates can be recycled by stripping contaminates into a separate, smaller volume of solution, and then become the final waste form for disposal after reusing number of times. Due to the highly selective chelators, this remediation method could be both simple and versatile while allowing the valuable actinides to be recovered and recycled. Key issues standing in the way of large-scale application are stability of the conjugates and their dispersion in solution to maintain their unique properties, especially large surface area, of MNPs. With substantial research progress made on MNPs and their surface functionalization, as well as development of environmentally benign chelators, this method could become very flexible and cost-effective for recycling used fuel. Finally, the development of this nanotechnology is summarized and its future direction is discussed.

  19. Preparation, properties, and some recent studies of the actinide metals

    SciTech Connect

    Haire, R.G.

    1985-01-01

    The actinide elements form a unique series of metals. The variation in their physial properties combined with the varying availability of the different elements offers a challenge to the preparative scientist. This article provides a brief review of selected methods used for preparing ..mu..g to kg amounts of the actinide metals and the properties of these metals. In addition, some recent studies on selected actinide metals are discussed. 62 refs.

  20. In vitro removal of actinide (IV) ions

    DOEpatents

    Weitl, Frederick L.; Raymond, Kenneth N.

    1982-01-01

    A compound of the formula: ##STR1## wherein X is hydrogen or a conventional electron-withdrawing group, particularly --SO.sub.3 H or a salt thereof; n is 2, 3, or 4; m is 2, 3, or 4; and p is 2 or 3. The present compounds are useful as specific sequestering agents for actinide (IV) ions. Also described is a method for the 2,3-dihydroxybenzamidation of azaalkanes.

  1. Separation of Californium from other Actinides

    DOEpatents

    Mailen, J C; Ferris, L M

    1973-09-25

    A method is provided for separating californium from a fused fluoride composition containing californium and at least one element selected from the group consisting of plutonium, americium, curium, uranium, thorium, and protactinium which comprises contacting said fluoride composition with a liquid bismuth phase containing sufficient lithium or thorium to effect transfer of said actinides to the bismuth phase and then contacting the liquid bismuth phase with molten LiCl to effect selective transfer of californium to the chloride phase.

  2. Surrogate Reactions in the Actinide Region

    SciTech Connect

    Burke, J T; Bernstein, L A; Scielzo, N D; Bleuel, D L; Lesher, S R; Escher, J; Ahle, L; Dietrich, F S; Hoffman, R D; Norman, E B; Sheets, S A; Phair, L; Fallon, P; Clark, R M; Gibelin, J; Jewett, C; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Wiedeking, M; Lyles, B F; Beausang, C W; Allmond, J M; Ai, H; Cizewski, J A; Hatarik, R; O'Malley, P D; Swan, T

    2008-01-30

    Over the past three years we have studied various surrogate reactions (d,p), ({sup 3}He,t), ({alpha},{alpha}{prime}) on several uranium isotopes {sup 234}U, {sup 235}U, {sup 236}U, and {sup 238}U. An overview of the STARS/LIBERACE surrogate research program as it pertains to the actinides is discussed. A summary of results to date will be presented along with a discussion of experimental difficulties encountered in surrogate experiments and future research directions.

  3. Surrogate Reactions in the Actinide Region

    SciTech Connect

    Burke, J. T.; Bernstein, L. A.; Scielzo, N. D.; Bleuel, D. L.; Lesher, S. R.; Escher, J.; Ahle, L.; Dietrich, F. S.; Hoffman, R. D.; Norman, E. B.; Sheets, S. A.; Phair, L.; Fallon, P.; Clark, R. M.; Gibelin, J.; Jewett, C.; Lee, I. Y.; Macchiavelli, A. O.; McMahan, M. A.; Moretto, L. G.

    2008-04-17

    Over the past three years we have studied various surrogate reactions (d,p), ({sup 3}He,t), ({alpha},{alpha}{sup '}) on several uranium isotopes {sup 234}U, {sup 235}U, {sup 236}U, and {sup 238}U. An overview of the STARS/LIBERACE surrogate research program as it pertains to the actinides is discussed. A summary of results to date will be presented along with a discussion of experimental difficulties encountered in surrogate experiments and future research directions.

  4. Actinide behavior in a freshwater pond

    SciTech Connect

    Trabalka, J.R.; Bogle, M.A.; Scott, T.G.

    1983-01-01

    Long-term investigations of solution chemistry in an alkaline freshwater pond have revealed that actinide oxidation state behavior, particularly that of plutonium, is complex. The Pu(V,VI) fraction was predominant in solution, but it varied over the entire range reported from other natural aquatic environments, in this case, as a result of intrinsic biological and chemical cycles (redox and pH-dependent phenomena). A strong positive correlation between plutonium (Pu), but not uranium (U), and hydroxyl ion over the observation period, especially when both were known to be in higher oxidation states, was particularly notable. Coupled with other examples of divergent U and Pu behavior, this result suggests that Pu(V), or perhaps a mixture of Pu(V,VI), was the prevalent oxidation state in solution. Observations of trivalent actinide sorption behavior during an algal bloom, coupled with the association with a high-molecular weight (nominally 6000 to 10,000 mol wt) organic fraction in solution, indicate that solution-detritus cycling of organic carbon, in turn, may be the primary mechanism in amercium-curium (Am-Cm) cycling. Sorption by sedimentary materials appears to predominate over other factors controlling effective actinide solubility and may explain, at least partially, the absence of an expected strong positive correlation between carbonate and dissolved U. 49 references, 6 figures, 12 tables.

  5. Bidentate organophosphorus solvent extraction process for actinide recovery and partition

    DOEpatents

    Schulz, Wallace W.

    1976-01-01

    A liquid-liquid extraction process for the recovery and partitioning of actinide values from acidic nuclear waste aqueous solutions, the actinide values including trivalent, tetravalent and hexavalent oxidation states is provided and includes the steps of contacting the aqueous solution with a bidentate organophosphorous extractant to extract essentially all of the actinide values into the organic phase. Thereafter the respective actinide fractions are selectively partitioned into separate aqueous solutions by contact with dilute nitric or nitric-hydrofluoric acid solutions. The hexavalent uranium is finally removed from the organic phase by contact with a dilute sodium carbonate solution.

  6. 24 CFR 290.15 - Disposition plan.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Disposition plan. 290.15 Section... MORTGAGES Disposition of Multifamily Projects § 290.15 Disposition plan. (a) In general. Before disposing of a HUD-owned multifamily housing project, HUD will develop an initial and a final disposition plan...

  7. 12 CFR 1081.212 - Dispositive motions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 8 2013-01-01 2013-01-01 false Dispositive motions. 1081.212 Section 1081.212... Initiation of Proceedings and Prehearing Rules § 1081.212 Dispositive motions. (a) Dispositive motions. This section governs the filing of motions to dismiss and motions for summary disposition. The filing of any...

  8. 24 CFR 290.15 - Disposition plan.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Disposition plan. 290.15 Section... MORTGAGES Disposition of Multifamily Projects § 290.15 Disposition plan. (a) In general. Before disposing of a HUD-owned multifamily housing project, HUD will develop an initial and a final disposition...

  9. 24 CFR 290.15 - Disposition plan.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Disposition plan. 290.15 Section... MORTGAGES Disposition of Multifamily Projects § 290.15 Disposition plan. (a) In general. Before disposing of a HUD-owned multifamily housing project, HUD will develop an initial and a final disposition...

  10. The Validation of the Administrator Dispositions Index

    ERIC Educational Resources Information Center

    Schulte, Laura E.; Kowal, Penny

    2005-01-01

    The purpose of this study was to validate the instrument, Administrator Dispositions Index (ADI), that measures the dispositions of effective school leaders. The ADI could be used to assess administrator candidate dispositions and to integrate dispositions of effective school leaders into the curricula of administrator preparation programs.…

  11. 7 CFR 1000.3 - Route disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Route disposition. 1000.3 Section 1000.3 Agriculture... Definitions § 1000.3 Route disposition. Route disposition means a delivery to a retail or wholesale outlet (except a plant), either directly or through any distribution facility (including disposition from a plant...

  12. 19 CFR 147.42 - Disposition generally.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Disposition generally. 147.42 Section 147.42... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.42 Disposition generally. (a) Kinds of disposition. Any article entered for a fair under this part may be entered for...

  13. 7 CFR 1000.3 - Route disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Route disposition. 1000.3 Section 1000.3 Agriculture... Definitions § 1000.3 Route disposition. Route disposition means a delivery to a retail or wholesale outlet (except a plant), either directly or through any distribution facility (including disposition from a plant...

  14. 19 CFR 147.42 - Disposition generally.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Disposition generally. 147.42 Section 147.42... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.42 Disposition generally. (a) Kinds of disposition. Any article entered for a fair under this part may be entered for...

  15. 24 CFR 290.15 - Disposition plan.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Disposition plan. 290.15 Section... DEVELOPMENT HUD-OWNED PROPERTIES DISPOSITION OF MULTIFAMILY PROJECTS AND SALE OF HUD-HELD MULTIFAMILY MORTGAGES Disposition of Multifamily Projects § 290.15 Disposition plan. (a) In general. Before disposing of...

  16. 17 CFR 10.91 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Summary disposition. 10.91... Disposition Without Full Hearing § 10.91 Summary disposition. (a) Filing of motions, answers. Any party who... decision as a matter of law may move for a summary disposition in his favor of all or any part of the...

  17. 24 CFR 290.15 - Disposition plan.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Disposition plan. 290.15 Section... DEVELOPMENT HUD-OWNED PROPERTIES DISPOSITION OF MULTIFAMILY PROJECTS AND SALE OF HUD-HELD MULTIFAMILY MORTGAGES Disposition of Multifamily Projects § 290.15 Disposition plan. (a) In general. Before disposing of...

  18. 17 CFR 10.91 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Summary disposition. 10.91... Disposition Without Full Hearing § 10.91 Summary disposition. (a) Filing of motions, answers. Any party who... decision as a matter of law may move for a summary disposition in his favor of all or any part of the...

  19. 7 CFR 1000.3 - Route disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Route disposition. 1000.3 Section 1000.3 Agriculture... Definitions § 1000.3 Route disposition. Route disposition means a delivery to a retail or wholesale outlet (except a plant), either directly or through any distribution facility (including disposition from a plant...

  20. 19 CFR 147.42 - Disposition generally.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Disposition generally. 147.42 Section 147.42... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.42 Disposition generally. (a) Kinds of disposition. Any article entered for a fair under this part may be entered for...

  1. 7 CFR 1000.3 - Route disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Route disposition. 1000.3 Section 1000.3 Agriculture... Definitions § 1000.3 Route disposition. Route disposition means a delivery to a retail or wholesale outlet (except a plant), either directly or through any distribution facility (including disposition from a plant...

  2. 7 CFR 1000.3 - Route disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Route disposition. 1000.3 Section 1000.3 Agriculture... Definitions § 1000.3 Route disposition. Route disposition means a delivery to a retail or wholesale outlet (except a plant), either directly or through any distribution facility (including disposition from a plant...

  3. 19 CFR 147.42 - Disposition generally.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Disposition generally. 147.42 Section 147.42... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.42 Disposition generally. (a) Kinds of disposition. Any article entered for a fair under this part may be entered for...

  4. Trivalent Lanthanide/Actinide Separation Using Aqueous-Modified TALSPEAK Chemistry

    SciTech Connect

    Travis S. Grimes; Richard D. Tillotson; Leigh R. Martin

    2014-05-01

    TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln3+) from minor actinides (MAs) Am3+ and Cm3+. Traditional TALSPEAK organic phase is comprised of a monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous phase contains a soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) in a concentrated (1.0-2.0 M) lactic acid (HL) buffer with the aqueous acidity typically adjusted to pH 3.0. TALSPEAK balances the selective complexation of the actinides by DTPA against the electrostatic attraction of the lanthanides by the HDEHP extractant to achieve the desired trivalent lanthanide/actinide group separation. Although TALSPEAK is considered a successful separations scheme, recent fundamental studies have highlighted complex chemical interactions occurring in the aqueous and organic phases during the extraction process. Previous attempts to model the system have shown thermodynamic models do not accurately predict the observed extraction trends in the p[H+] range 2.5-4.8. In this study, the aqueous phase is modified by replacing the lactic acid buffer with a variety of simple and longer-chain amino acid buffers. The results show successful trivalent lanthanide/actinide group separation with the aqueous-modified TALSPEAK process at pH 2. The amino acid buffer concentrations were reduced to 0.5 M (at pH 2) and separations were performed without any effect on phase transfer kinetics. Successful modeling of the aqueous-modified TALSPEAK process (p[H+] 1.6-3.1) using a simplified thermodynamic model and an internally consistent set of thermodynamic data is presented.

  5. Disposition of citral in male Fischer rats

    SciTech Connect

    Diliberto, J.J.; Usha, G.; Birnbaum, L.S.

    1988-09-01

    The disposition of citral, an essential oil occurring in many foods and fragrances, was studied in male Fischer rats after iv, po, and dermal treatments. The pattern of distribution and elimination was the same after iv or oral exposure. Urine was the major route of elimination of citral-derived radioactivity, followed by feces, /sup 14/CO/sub 2/, and expired volatiles. However, after dermal exposure, relatively less of the material was eliminated in the urine and more in the feces, suggesting a role for first-pass metabolism through the skin. Citral was almost completely absorbed orally; due to its extreme volatility, much of an applied dermal dose was lost. The citral remaining on the skin was fairly well absorbed. No effect of oral dose, from 5 to 500 mg/kg, was detected on disposition. Although the feces was a minor route of excretion, approximately 25% of the administered dose was eliminated via the bile within 4 hr of an iv dose. The metabolism of citral was both rapid and extensive. Within 5 min of an iv dose, no unmetabolized citral could be detected in the blood. Repeated exposure to citral resulted in an increase in biliary elimination, without any significant change in the pattern of urinary, fecal, or exhaled excretion. This suggests that citral may induce at least one pathway of its own metabolism. The rapid metabolism and excretion of this compound suggest that significant bioaccumulation of citral would not occur.

  6. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

    Nash, Ken; Martin, Leigh; Lumetta, Gregg

    2015-04-02

    One of the most challenging aspects of advanced processing of used nuclear fuel is the separation of transplutonium actinides from fission product lanthanides. This separation is essential if actinide transmutation options are to be pursued in advanced fuel cycles, as lanthanides compete with actinides for neutrons in both thermal and fast reactors, thus limiting efficiency. The separation is difficult because the chemistry of Am3+ and Cm3+ is nearly identical to that of the trivalent lanthanides (Ln3+). The prior literature teaches that two approaches offer the greatest probability of devising a successful group separation process based on aqueous processes: 1) the application of complexing agents containing ligand donor atoms that are softer than oxygen (N, S, Cl-) or 2) changing the oxidation state of Am to the IV, V, or VI state to increase the essential differences between Am and lanthanide chemistry (an approach utilized in the PUREX process to selectively remove Pu4+ and UO22+ from fission products). The latter approach offers the additional benefit of enabling a separation of Am from Cm, as Cm(III) is resistant to oxidation and so can easily be made to follow the lanthanides. The fundamental limitations of these approaches are that 1) the soft(er) donor atoms that interact more strongly with actinide cations than lanthanides form substantially weaker bonds than oxygen atoms, thus necessitating modification of extraction conditions for adequate phase transfer efficiency, 2) soft donor reagents have been seen to suffer slow phase transfer kinetics and hydro-/radiolytic stability limitations and 3) the upper oxidation states of Am are all moderately strong oxidants, hence of only transient stability in media representative of conventional aqueous separations systems. There are examples in the literature of both approaches having been described. However, it is not clear at present that any extant process is sufficiently robust for application at the scale

  7. Progress toward accurate high spatial resolution actinide analysis by EPMA

    NASA Astrophysics Data System (ADS)

    Jercinovic, M. J.; Allaz, J. M.; Williams, M. L.

    2010-12-01

    High precision, high spatial resolution EPMA of actinides is a significant issue for geochronology, resource geochemistry, and studies involving the nuclear fuel cycle. Particular interest focuses on understanding of the behavior of Th and U in the growth and breakdown reactions relevant to actinide-bearing phases (monazite, zircon, thorite, allanite, etc.), and geochemical fractionation processes involving Th and U in fluid interactions. Unfortunately, the measurement of minor and trace concentrations of U in the presence of major concentrations of Th and/or REEs is particularly problematic, especially in complexly zoned phases with large compositional variation on the micro or nanoscale - spatial resolutions now accessible with modern instruments. Sub-micron, high precision compositional analysis of minor components is feasible in very high Z phases where scattering is limited at lower kV (15kV or less) and where the beam diameter can be kept below 400nm at high current (e.g. 200-500nA). High collection efficiency spectrometers and high performance electron optics in EPMA now allow the use of lower overvoltage through an exceptional range in beam current, facilitating higher spatial resolution quantitative analysis. The U LIII edge at 17.2 kV precludes L-series analysis at low kV (high spatial resolution), requiring careful measurements of the actinide M series. Also, U-La detection (wavelength = 0.9A) requires the use of LiF (220) or (420), not generally available on most instruments. Strong peak overlaps of Th on U make highly accurate interference correction mandatory, with problems compounded by the ThMIV and ThMV absorption edges affecting peak, background, and interference calibration measurements (especially the interference of the Th M line family on UMb). Complex REE bearing phases such as monazite, zircon, and allanite have particularly complex interference issues due to multiple peak and background overlaps from elements present in the activation

  8. FS65 Disposition Option Report

    SciTech Connect

    Wenz, Tracy R.

    2015-09-25

    This report outlines the options for dispositioning the MOX fuel stored in FS65 containers at LANL. Additional discussion regarding the support equipment for loading and unloading the FS65 transport containers is included at the end of the report.

  9. The Forced Evacuation of the Japanese Minority During World War II

    ERIC Educational Resources Information Center

    Miyamoto, S. Frank

    1973-01-01

    Attempts to explain in extremely abbreviated form what caused the evacuation and how the Japanese minority reacted to their exclusion and rejection, focusing on three general causes: collective dispositions, situational factors, and collective interaction. (Author/JM)

  10. The OSMOSE program for the qualification of integral cross sections of actinides: Preliminary results in a PWR-UOx spectrum

    SciTech Connect

    Hudelot, J. P.; Antony, M.; Bernard, D.; Fougeras, P.

    2006-07-01

    The need for improved nuclear data for minor actinides has been stressed by various organizations throughout the world - especially for studies relating to plutonium management, waste incineration, transmutation of waste, and Pu burning in future nuclear concepts. Several international programs have indicated a strong desire to obtain accurate integral reaction rate data for improving the major and minor actinides cross sections. Data on major actinides (i.e. {sup 235}U, {sup 236}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu and {sup 241}Am) are reasonably well-known and available in the Evaluated Nuclear Data Files (JEFF, JENDL, ENDF-BX However information on the minor actinides (i.e. {sup 232}Th, {sup 233}U, {sup 237}Np, {sup 238}Pu, {sup 242}Am, {sup 243}Am, {sup 243}Cm, {sup 235}Cm, {sup 244}Cm, {sup 245}Cm, {sup 246}Cm and {sup 247}Cm) is less well-known and considered to be relatively poor in some cases, having to rely on model and extrapolation of few data points. In this framework, the ambitious OSMOSE program between the Commissariat a l'Energie Atomique (CEA), Electricite de France (EDF) and the U.S. Dept. of Energy (DOE) has been undertaken with the aim of measuring the integral absorption rate parameters of actinides in the MINERVE experimental facility located at the CEA Cadarache Research Center. The OSMOSE Program (Oscillation in Minerve of isotopes in 'Eupraxic' Spectra) includes a complete analytical program associated with the experimental measurement program and aims at understanding and resolving potential discrepancies between calculated and measured values. In the OSMOSE program, the reactivity worth of samples containing separated actinides are measured in different neutron spectra using an oscillation technique with an overall expected accuracy better than 3%. Reactivity effects of less than 10 pcm (0.0001 or approximately 1.5 cents) are measured and compared with calibrations to determine the differential reactivity

  11. On the valence fluctuation in the early actinide metals

    SciTech Connect

    Soderlind, P.; Landa, A.; Tobin, J. G.; Allen, P.; Medling, S.; Booth, C. H.; Bauer, E. D.; Cooley, J. C.; Sokaras, D.; Weng, T. -C.; Nordlund, D.

    2015-12-15

    In this study, recent X-ray measurements suggest a degree of valence fluctuation in plutonium and uranium intermetallics. We are applying a novel scheme, in conjunction with density functional theory, to predict 5f configuration fractions of states with valence fluctuations for the early actinide metals. For this purpose we perform constrained integer f-occupation calculations for the α phases of uranium, neptunium, and plutonium metals. For plutonium we also investigate the δ phase. The model predicts uranium and neptunium to be dominated by the f3 and f4 configurations, respectively, with only minor contributions from other configurations. For plutonium (both α and δ phase) the scenario is dramatically different. Here, the calculations predict a relatively even distribution between three valence configurations. The δ phase has a greater configuration fraction of f6 compared to that of the α phase. The theory is consistent with the interpretations of modern X-ray experiments and we present resonant X-ray emission spectroscopy results for α-uranium.

  12. On the valence fluctuation in the early actinide metals

    DOE PAGES

    Soderlind, P.; Landa, A.; Tobin, J. G.; ...

    2015-12-15

    In this study, recent X-ray measurements suggest a degree of valence fluctuation in plutonium and uranium intermetallics. We are applying a novel scheme, in conjunction with density functional theory, to predict 5f configuration fractions of states with valence fluctuations for the early actinide metals. For this purpose we perform constrained integer f-occupation calculations for the α phases of uranium, neptunium, and plutonium metals. For plutonium we also investigate the δ phase. The model predicts uranium and neptunium to be dominated by the f3 and f4 configurations, respectively, with only minor contributions from other configurations. For plutonium (both α and δmore » phase) the scenario is dramatically different. Here, the calculations predict a relatively even distribution between three valence configurations. The δ phase has a greater configuration fraction of f6 compared to that of the α phase. The theory is consistent with the interpretations of modern X-ray experiments and we present resonant X-ray emission spectroscopy results for α-uranium.« less

  13. Process for making a ceramic composition for immobilization of actinides

    DOEpatents

    Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen; Armantrout, Guy A.; Herman, Connie Cicero; Hobson, Beverly F.; Herman, David Thomas; Curtis, Paul G.; Farmer, Joseph

    2001-01-01

    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.

  14. Improved method for extracting lanthanides and actinides from acid solutions

    DOEpatents

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

    1983-07-26

    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.

  15. Process for Making a Ceramic Composition for Immobilization of Actinides

    SciTech Connect

    Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen; Armantrout, Guy A.; Curtis, Paul G.; Hobson, Beverly F.; Farmer, Joseph; Herman, Connie Cicero; Herman, David Thomas

    1999-06-22

    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.

  16. Study of actinide chemistry in saturated potassium fluoride solution

    NASA Technical Reports Server (NTRS)

    Cohen, D.; Thalmayer, C. E.

    1969-01-01

    Study concerning the chemistry of actinides in saturated KF solution included work with neptunium, uranium, and americium. Solubilities, absorption spectra, oxidation-reduction reactions, and solid compounds which can be produced in KF solution were examined. The information is used for preparation of various materials from salts of the actinides.

  17. POTENTIAL BENCHMARKS FOR ACTINIDE PRODUCTION IN HANFORD REACTORS

    SciTech Connect

    PUIGH RJ; TOFFER H

    2011-10-19

    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.

  18. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    SciTech Connect

    Dr. David L. Clark; Dr. Alexander M. Fedosseev

    2001-12-21

    Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier.

  19. Actinides and Rare Earths Topical Conference (Code AC)

    SciTech Connect

    Tobin, J G

    2009-11-24

    Actinide and the Rare Earth materials exhibit many unique and diverse physical, chemical and magnetic properties, in large part because of the complexity of their f electronic structure. This Topical Conference will focus upon the chemistry, physics and materials science in Lanthanide and Actinide materials, driven by 4f and 5f electronic structure. Particular emphasis will be placed upon 4f/5f magnetic structure, surface science and thin film properties. For the actinides, fundamental actinide science and its role in resolving technical challenges posed by actinide materials will be stressed. Both basic and applied experimental approaches, including synchrotron-radiation-based investigations, as well as theoretical modeling and computational simulations, are planned to be part of the Topical Conference. Of particular importance are the issues related to the potential renaissance in Nuclear Fuels, including synthesis, oxidation, corrosion, intermixing, stability in extreme environments, prediction of properties via benchmarked simulations, separation science, environmental impact and disposal of waste products.

  20. Separation of actinides from lanthanides utilizing molten salt electrorefining

    SciTech Connect

    Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.; Gay, R.L.; Krueger, C.L.; Storvick, T.S.; Inoue, T.; Hijikata, T.; Takahashi, N.

    1996-10-01

    TRUMP-S (TRansUranic Management through Pyropartitioning Separation) is a pyrochemical process being developed to separate actinides form fission products in nuclear waste. A key process step involving molten salt electrorefining to separate actinides from lanthanides has been studied on a laboratory scale. Electrorefining of U, Np, Pu, Am, and lanthanide mixtures from molten cadmium at 450 C to a solid cathode utilizing a molten chloride electrolyte resulted in > 99% removal of actinides from the molten cadmium and salt phases. Removal of the last few percent of actinides is accompanied by lowered cathodic current efficiency and some lanthanide codeposition. Actinide/lanthanide separation ratios on the cathode are ordered U > Np > Pu > Am and are consistent with predictions based on equilibrium potentials.

  1. Research in actinide chemistry. Progress report, 1990--1993

    SciTech Connect

    Choppin, G.R.

    1993-04-01

    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}}, CO{sub 3}{sup 2{minus}}, PO{sub 4}{sup 3{minus}}, humates). The research undertakes fundamental studies of actinide complexes which can increase understanding of the environmental behavior of these elements.

  2. Chemistry of lower valent actinide halides

    SciTech Connect

    Lau, K.H.; Hildenbrand, D.L.

    1992-01-01

    This research effort was concerned almost entirely with the first two members of the actinide series, thorium and uranium, although the work was later extended to some aspects of the neptunium-fluorine system in a collaborative program with Los Alamos National Laboratory. Detailed information about the lighter actinides will be helpful in modeling the properties of the heavier actinide compounds, which will be much more difficult to study experimentally. In this program, thermochemical information was obtained from high temperature equilibrium measurements made by effusion-beam mass spectrometry and by effusion-pressure techniques. Data were derived primarily from second-law analysis so as to avoid potential errors in third-law calculations resulting from uncertainties in spectroscopic and molecular constants. This approach has the additional advantage of yielding reaction entropies that can be checked for consistency with various molecular constant assignments for the species involved. In the U-F, U-Cl, and U-Br systems, all of the gaseous species UX, UX{sub 2}, UX{sub 3}, UX{sub 4}, and UX{sub 5}, where X represents the halogen, were identified and characterized; the corresponding species ThX, ThX{sub 2}, ThX{sub 3}, and ThX{sub 4} were studied in the Th-F, Th-Cl, and Th-Br systems. A number of oxyhalide species in the systems U-0-F, U-0-Cl, Th-0-F, and Th-O-Cl were studied thermochemically. Additionally, the sublimation thermodynamics of NpF{sub 4}(s) and NpO{sub 2}F{sub 2}(s) were studied by mass spectrometry.

  3. Plutonium Disposition by Immobilization

    SciTech Connect

    Gould, T.; DiSabatino, A.; Mitchell, M.

    2000-03-07

    The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D&T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D&T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D&T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency.

  4. Status of nuclear data for actinides

    SciTech Connect

    Guzhovskii, B.Y.; Gorelov, V.P.; Grebennikov, A.N.

    1995-10-01

    Nuclear data required for transmutation problem include many actinide nuclei. In present paper the analysis of neutron fission, capture, (n,2n) and (n,3n) reaction cross sections at energy region from thermal point to 14 MeV was carried out for Th, Pa, U, Np, Pu, Am and Cm isotops using modern evaluated nuclear data libraries and handbooks of recommended nuclear data. Comparison of these data indicates on substantial discrepancies in different versions of files, that connect with quality and completeness of original experimental data.

  5. Vapor pressure and thermodynamics of actinide metals

    SciTech Connect

    Ward, J.W.; Kleinschmidt, P.D.; Haire, R.G.; Brown, D.

    1980-01-01

    Precise vapor pressure measurements by target collection/mass spectrometric Knudsen effusion techniques were combined with crystal entropy estimates to produce self-consistent free-enrgy functions, permitting calculation of heats, entropies and free energies from 298/sup 0/K to the highest temperatures of measurement. The vapor pressures and thermodyamics of vaporization of americium, curium, berkelium, and californium are compared in terms of electronic structure and bonding trends in the trans-plutonium elements. These resuslts are contrasted with the behavior of the early actinides, with attention to energy states and possible effects of f-electron bonding. 9 figures, 4 tables.

  6. Actinide removal from nitric acid waste streams

    SciTech Connect

    Muscatello, A.C.; Navratil, J.D.

    1986-01-01

    Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydrolytic polymer. Partial neutralization and solid supported liquid membrane transfer removes americium for sorption on discardable inorganic ion exchangers, potentially allowing for non-TRU waste disposal.

  7. Multicoordinate ligands for actinide/lanthanide separations.

    PubMed

    Dam, Henk H; Reinhoudt, David N; Verboom, Willem

    2007-02-01

    In nuclear waste treatment processes there is a need for improved ligands for the separation of actinides (An(III)) and lanthanides (Ln(III)). Several research groups are involved in the design and synthesis of new An(III) ligands and in the confinement of these and existing An(III) ligands onto molecular platforms giving multicoordinate ligands. The preorganization of ligands considerably improves the An(III) extraction properties, which are largely dependent on the solubility and rigidity of the platform. This tutorial review summarizes the most important An(III) ligands with emphasis on the preorganization strategy using (macrocyclic) platforms.

  8. Actinide electronic structure and atomic forces

    NASA Astrophysics Data System (ADS)

    Albers, R. C.; Rudin, Sven P.; Trinkle, Dallas R.; Jones, M. D.

    2000-07-01

    We have developed a new method[1] of fitting tight-binding parameterizations based on functional forms developed at the Naval Research Laboratory.[2] We have applied these methods to actinide metals and report our success using them (see below). The fitting procedure uses first-principles local-density-approximation (LDA) linear augmented plane-wave (LAPW) band structure techniques[3] to first calculate an electronic-structure band structure and total energy for fcc, bcc, and simple cubic crystal structures for the actinide of interest. The tight-binding parameterization is then chosen to fit the detailed energy eigenvalues of the bands along symmetry directions, and the symmetry of the parameterization is constrained to agree with the correct symmetry of the LDA band structure at each eigenvalue and k-vector that is fit to. By fitting to a range of different volumes and the three different crystal structures, we find that the resulting parameterization is robust and appears to accurately calculate other crystal structures and properties of interest.

  9. Evaluation of actinide biosorption by microorganisms

    SciTech Connect

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  10. Seniority of Emergency Physician, Patient Disposition and Outcome Following Disposition.

    PubMed

    Li, Chao-Jui; Syue, Yuan-Jhen; Kung, Chia-Te; Hung, Shih-Chiang; Lee, Chien-Hung; Wu, Kuan-Han

    2016-06-01

    The relationship between the seniority of emergency physicians (EPs) and disposition decision-making is not well defined. As most responsibility by EPs involves developing an appropriate disposition plan, this study aimed to examine the influence of EP seniority on decisions regarding patient dispositions in the emergency department (ED). This retrospective, 1-year, cohort study was conducted in 3 EDs including all day-shift nontraumatic adult patients. The outcome involves patient dispositions at the end of the shift, patient final dispositions and patient 72-hour ED return. The EPs were categorized into the following 3 groups according to seniority: junior group (≤5 years of work experience), intermediate group (6-10 years) and senior group (>10 years). The dispositions of 68,333 ED patients as determined by the 59 full-time EPs were studied. Compared to junior and intermediate EPs, senior EPs kept more patients in the ED (2.7% more than junior EP, 2.3% more than intermediate EP); they had the lowest patient mortality rate especially in first triage patients (3.4% fewer than junior EP, 1.3% fewer than intermediate EP); they took more time for patient discharge (0.2 more hours than junior EP, 0.1 more hours than intermediate EP); they had fewer patients return to the ED within 72 hours after discharge (0.5% fewer than junior EP, 0.3% fewer than intermediate EP). Senior EPs had the best quality of care (lowest mortality, fewest 72-hour returns). This best quality of care is accompanied with a slightly longer length of stay. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  11. Silent Minority.

    ERIC Educational Resources Information Center

    Kramer, Beth, Ed.

    Discussed in the booklet are approaches for citizens to use in helping the silent minority--mentally retarded (MR) children and adults--attain their rights to life, liberty, and the pursuit of happiness. The MR person is described to be one of 6 million retarded Americans, to benefit from education although his ability to learn is limited, to have…

  12. Gas core reactors for actinide transmutation. [uranium hexafluoride

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.; Wan, P. T.; Chow, S.

    1979-01-01

    The preliminary design of a uranium hexafluoride actinide transmutation reactor to convert long-lived actinide wastes to shorter-lived fission product wastes was analyzed. It is shown that externally moderated gas core reactors are ideal radiators. They provide an abundant supply of thermal neutrons and are insensitive to composition changes in the blanket. For the present reactor, an initial load of 6 metric tons of actinides is loaded. This is equivalent to the quantity produced by 300 LWR-years of operation. At the beginning, the core produces 2000 MWt while the blanket generates only 239 MWt. After four years of irradiation, the actinide mass is reduced to 3.9 metric tonnes. During this time, the blanket is becoming more fissile and its power rapidly approaches 1600 MWt. At the end of four years, continuous refueling of actinides is carried out and the actinide mass is held constant. Equilibrium is essentially achieved at the end of eight years. At equilibrium, the core is producing 1400 MWt and the blanket 1600 MWt. At this power level, the actinide destruction rate is equal to the production rate from 32 LWRs.

  13. End point control of an actinide precipitation reactor

    SciTech Connect

    Muske, K.R.; Palmer, M.J.

    1997-10-01

    The actinide precipitation reactors in the nuclear materials processing facility at Los Alamos National Laboratory are used to remove actinides and other heavy metals from the effluent streams generated during the purification of plutonium. These effluent streams consist of hydrochloric acid solutions, ranging from one to five molar in concentration, in which actinides and other metals are dissolved. The actinides present are plutonium and americium. Typical actinide loadings range from one to five grams per liter. The most prevalent heavy metals are iron, chromium, and nickel that are due to stainless steel. Removal of these metals from solution is accomplished by hydroxide precipitation during the neutralization of the effluent. An end point control algorithm for the semi-batch actinide precipitation reactors at Los Alamos National Laboratory is described. The algorithm is based on an equilibrium solubility model of the chemical species in solution. This model is used to predict the amount of base hydroxide necessary to reach the end point of the actinide precipitation reaction. The model parameters are updated by on-line pH measurements.

  14. Spectroscopic investigation of actinide speciation in concentrated chloride solution

    SciTech Connect

    Runde, W.; Neu, M.P.; Conradson, S.D.; Clark, D.L.; Palmer, P.D.; Reilly, S.D.; Scott, B.L.; Tait, C.D.

    1997-12-31

    The proposed disposal of nuclear waste in geological salt formations, e.g., the Waste Isolation Pilot Plant (USA) and the Gorleben site (Germany), raises a fundamental question: To what degree actinides will be solubilized and mobilized upon interaction with chloride ions? Actinide solubilities in highly concentrated chloride solutions are about one order of magnitude higher than in similar inert electrolyte (NaClO{sub 4}) solutions. This increased solubility is due to interactions between actinide and chloride ions. Contradictory results exist regarding the interaction mechanism between actinide and chloride ions. Specifically, both inner-sphere complex formation and ion pair association have been implicated in the interpretation of spectrophotometric and extraction data. To address this controversy, the authors investigated the interaction between actinide ions in the (III), (IV), (V) and (VI) oxidation states and chloride ions using a multi-method approach. Spectroscopic techniques (TRLFS, Raman, UV-Vis absorption, EXAFS) were used to distinguish between changes in the inner coordination sphere of the actinide ion and effects of ion pairing, X-ray absorption spectroscopy and single crystal X-ray diffraction were used to determine structural details of the actinide chloro complexes formed in solution and solid states.

  15. 39 CFR 954.3 - Informal dispositions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.3 Informal dispositions. These rules do not preclude the informal dispositions of Periodicals mailing privilege matters before or after institution of...

  16. 39 CFR 954.3 - Informal dispositions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.3 Informal dispositions. These rules do not preclude the informal dispositions of Periodicals mailing privilege matters before or after institution of...

  17. 39 CFR 954.3 - Informal dispositions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.3 Informal dispositions. These rules do not preclude the informal dispositions of Periodicals mailing privilege matters before or after institution of...

  18. 39 CFR 952.3 - Informal dispositions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REPRESENTATION AND LOTTERY ORDERS § 952.3 Informal dispositions. This part does not preclude the disposition of any matter by agreement between the parties either before or after the filing of a complaint when...

  19. 48 CFR 1850.103-6 - Disposition.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Disposition. 1850.103-6 Section 1850.103-6 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.103-6 Disposition. ...

  20. 48 CFR 1850.103-6 - Disposition.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Disposition. 1850.103-6 Section 1850.103-6 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.103-6 Disposition. ...

  1. 48 CFR 1850.103-6 - Disposition.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Disposition. 1850.103-6 Section 1850.103-6 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.103-6 Disposition. ...

  2. Crystal growth methods dedicated to low solubility actinide oxalates

    SciTech Connect

    Tamain, C.; Arab-Chapelet, B.; Rivenet, M.; Grandjean, S.; Abraham, F.

    2016-04-15

    Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am{sub 2}(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 3}·xH{sub 2}O, Th(C{sub 2}O{sub 4}){sub 2}·6H{sub 2}O, M{sub 2+x}[Pu{sup IV}{sub 2−x}Pu{sup III}{sub x}(C{sub 2}O{sub 4}){sub 5}]·nH{sub 2}O and M{sub 1−x}[Pu{sup III}{sub 1−x}Pu{sup IV}{sub x}(C{sub 2}O{sub 4}){sub 2}·H{sub 2}O]·nH{sub 2}O. It is the first time that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV–visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds. - Graphical abstract: Two new single crystal growth methods dedicated to actinide oxalate compounds. - Highlights: • Use of diester as oxalate precursor for crystal growth of actinide oxalates. • Use of actinide oxide as precursor for crystal growth of actinide oxalates. • Crystal growth of Pu(III) and Am(III) oxalates. • Crystal growth of mixed Pu(III)/Pu(IV) oxalates.

  3. Actinide and Xenon reactivity effects in ATW high flux systems

    SciTech Connect

    Woosley, M.; Olson, K.; Henderson, D.L.

    1995-10-01

    In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

  4. Chemistry of tetravalent actinide phosphates-Part I

    SciTech Connect

    Brandel, V. . E-mail: vbrandel@neuf.fr; Dacheux, N. . E-mail: dacheux@ipno.in2p3.fr

    2004-12-01

    The chemistry and crystal structure of phosphates of tetravalent cations, including that of actinides was reviewed several times up to 1985. Later, new compounds were synthesized and characterized. In more recent studies, it was found that some of previously reported phases, especially those of thorium, uranium and neptunium, were wrongly identified. In the light of these new facts an update review and classification of the tetravalent actinide phosphates is proposed in the two parts of this paper. Their crystal structure and some chemical properties are also compared to non-actinide cation phosphates.

  5. Process to remove actinides from soil using magnetic separation

    DOEpatents

    Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

    1996-01-01

    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.

  6. Engineering-Scale Distillation of Cadmium for Actinide Recovery

    SciTech Connect

    J.C. Price; D. Vaden; R.W. Benedict

    2007-10-01

    During the recovery of actinide products from spent nuclear fuel, cadmium is separated from the actinide products by a distillation process. Distillation occurs in an induction-heated furnace called a cathode processor capable of processing kilogram quantities of cadmium. Operating parameters have been established for sufficient recovery of the cadmium based on mass balance and product purity. A cadmium distillation rate similar to previous investigators has also been determined. The development of cadmium distillation for spent fuel treatment enhances the capabilities for actinide recovery processes.

  7. An emergency bioassay method for actinides in urine.

    PubMed

    Dai, Xiongxin; Kramer-Tremblay, Sheila

    2011-08-01

    A rapid bioassay method has been developed for the sequential measurements of actinides in human urine samples. The method involves actinide separation from a urine matrix by co-precipitation with hydrous titanium oxide (HTiO), followed by anion exchange and extraction chromatography column purification, and final counting by alpha spectrometry after cerium fluoride micro-precipitation. The minimal detectable activities for the method were determined to be 20 mBq L(-1) or less for plutonium, uranium, americium and curium isotopes, with an 8-h sample turn-around time. Spike tests showed that this method would meet the requirements for actinide bioassay following a radiation emergency.

  8. Separations and Actinide Science -- 2005 Roadmap

    SciTech Connect

    Not Available

    2005-09-01

    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

  9. 19 CFR 147.42 - Disposition generally.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.42 Disposition generally. (a) Kinds of disposition. Any article entered for a fair under this part may be entered for consumption, for warehouse, or under any other provision of the Customs laws, or for another fair, or may be...

  10. Social Justice and Dispositions for Adult Education

    ERIC Educational Resources Information Center

    Holst, John D.

    2010-01-01

    The article identifies dispositions from a thematic investigation of the pedagogical practice of Ernesto Che Guevara and various social movements in the United States. The article outlines and places these dispositions within the context of debates over social justice and dispositions for education program accreditation in the United States that…

  11. 25 CFR 11.1011 - Dispositional hearing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Dispositional hearing. 11.1011 Section 11.1011 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER COURTS OF INDIAN OFFENSES AND LAW AND ORDER CODE Juvenile Offender Procedure § 11.1011 Dispositional hearing. (a) A dispositional hearing...

  12. Teaching Dispositions: Shared Understanding for Teacher Preparation

    ERIC Educational Resources Information Center

    DeMuth, Lynn

    2012-01-01

    This qualitative phenomenological study explored the perceptions of 16 high-performing teachers related to teaching dispositions, effects of dispositions on teaching and learning, and recommendations for assessment of teaching dispositions during teacher preparation. Participants' perceptions were gathered using six guided interview questions…

  13. Disposition: A Superfluous Construct in Teacher Education

    ERIC Educational Resources Information Center

    Murray, Frank B.

    2007-01-01

    Unlike the literature on some dispositions, like field dependence-independence, in psychology, the dispositions cited in the teacher education literature (e.g., INTASC) have almost no explanatory value and very little meaning at the present time. This conclusion stems from an analysis of the cited teacher dispositions in terms of Underwood's…

  14. Social Justice and Dispositions for Adult Education

    ERIC Educational Resources Information Center

    Holst, John D.

    2010-01-01

    The article identifies dispositions from a thematic investigation of the pedagogical practice of Ernesto Che Guevara and various social movements in the United States. The article outlines and places these dispositions within the context of debates over social justice and dispositions for education program accreditation in the United States that…

  15. 12 CFR 109.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Summary disposition. 109.29 Section 109.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 109.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  16. 12 CFR 263.29 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Summary disposition. 263.29 Section 263.29... RULES OF PRACTICE FOR HEARINGS Uniform Rules of Practice and Procedure § 263.29 Summary disposition. (a... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  17. 16 CFR 2.34 - Disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Disposition. 2.34 Section 2.34 Commercial... Consent Order Procedure § 2.34 Disposition. (a) Acceptance of proposed consent agreement. The Commission... further actions leading to final disposition of the matter. (b) Effectiveness of hold-separate or asset...

  18. 12 CFR 1209.34 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Summary disposition. 1209.34 Section 1209.34... PROCEDURE Rules of Practice and Procedure § 1209.34 Summary disposition. (a) In general. The presiding officer shall recommend that the Director issue a final order granting a motion for summary disposition if...

  19. 17 CFR 12.207 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Summary disposition. 12.207... REPARATIONS Rules Applicable to Summary Decisional Proceedings § 12.207 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time until the parties have concluded their...

  20. 12 CFR 747.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Summary disposition. 747.29 Section 747.29... of Practice and Procedure § 747.29 Summary disposition. (a) In general. The administrative law judge shall recommend that the NCUA Board issue a final order granting a motion for summary disposition if the...

  1. 10 CFR 2.1205 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Summary disposition. 2.1205 Section 2.1205 Energy NUCLEAR... Adjudications § 2.1205 Summary disposition. (a) Unless the presiding officer or the Commission directs otherwise, motions for summary disposition may be submitted to the presiding officer by any party no later than 45...

  2. 16 CFR 2.34 - Disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Disposition. 2.34 Section 2.34 Commercial... Consent Order Procedure § 2.34 Disposition. (a) Acceptance of proposed consent agreement. The Commission... further actions leading to final disposition of the matter. (b) Effectiveness of hold-separate or asset...

  3. 12 CFR 390.58 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Summary disposition. 390.58 Section 390.58... Proceedings § 390.58 Summary disposition. (a) In general. The administrative law judge shall recommend that the Board of Directors issue a final order granting a motion for summary disposition if the undisputed...

  4. 7 CFR 70.92 - Disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Disposition. 70.92 Section 70.92 Agriculture... Disposition. The original and a copy of each grading certificate, issued pursuant to §§ 70.90 through 70.93... shall be filed and retained in accordance with the disposition schedule for grading program records. [71...

  5. 39 CFR 952.3 - Informal dispositions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Informal dispositions. 952.3 Section 952.3 Postal... REPRESENTATION AND LOTTERY ORDERS (EFF. UNTIL 7-22-2011) § 952.3 Informal dispositions. These rules do not preclude the disposition of any matter by agreement between the parties either before or after the filing...

  6. 12 CFR 308.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Summary disposition. 308.29 Section 308.29... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.29 Summary disposition. (a) In general... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  7. 17 CFR 12.310 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Summary disposition. 12.310... REPARATIONS Rules Applicable to Formal Decisional Proceedings § 12.310 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time before a determination is made by the...

  8. 17 CFR 12.310 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Summary disposition. 12.310... REPARATIONS Rules Applicable to Formal Decisional Proceedings § 12.310 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time before a determination is made by the...

  9. 48 CFR 250.103-6 - Disposition.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Disposition. 250.103-6... Contractual Actions 250.103-6 Disposition. For requests denied or approved below the Secretarial level, follow the disposition procedures at PGI 250.103-6. ...

  10. 39 CFR 952.3 - Informal dispositions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Informal dispositions. 952.3 Section 952.3 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.3 Informal dispositions. This part does not preclude the disposition of...

  11. 39 CFR 952.3 - Informal dispositions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Informal dispositions. 952.3 Section 952.3 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.3 Informal dispositions. These rules do not preclude the disposition of...

  12. 12 CFR 1209.34 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 9 2013-01-01 2013-01-01 false Summary disposition. 1209.34 Section 1209.34... PROCEDURE Rules of Practice and Procedure § 1209.34 Summary disposition. (a) In general. The presiding officer shall recommend that the Director issue a final order granting a motion for summary disposition if...

  13. 12 CFR 308.29 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Summary disposition. 308.29 Section 308.29... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.29 Summary disposition. (a) In general... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  14. 17 CFR 12.207 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Summary disposition. 12.207... REPARATIONS Rules Applicable to Summary Decisional Proceedings § 12.207 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time until the parties have concluded their...

  15. 16 CFR 2.34 - Disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Disposition. 2.34 Section 2.34 Commercial... Consent Order Procedure § 2.34 Disposition. (a) Acceptance of proposed consent agreement. The Commission... further actions leading to final disposition of the matter. (b) Effectiveness of hold-separate or asset...

  16. 12 CFR 747.29 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Summary disposition. 747.29 Section 747.29... of Practice and Procedure § 747.29 Summary disposition. (a) In general. The administrative law judge shall recommend that the NCUA Board issue a final order granting a motion for summary disposition if the...

  17. 12 CFR 390.58 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Summary disposition. 390.58 Section 390.58... Proceedings § 390.58 Summary disposition. (a) In general. The administrative law judge shall recommend that the Board of Directors issue a final order granting a motion for summary disposition if the undisputed...

  18. 7 CFR 765.304 - Unapproved disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Unapproved disposition. 765.304 Section 765.304... disposition. (a) If a borrower disposes of chattel security without Agency approval, or misuses proceeds, the... disposition or use information to enable the Agency to consider post-approval within 30 days of Agency...

  19. 12 CFR 308.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Summary disposition. 308.29 Section 308.29... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.29 Summary disposition. (a) In general... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  20. 10 CFR 2.1205 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Summary disposition. 2.1205 Section 2.1205 Energy NUCLEAR... Hearing Procedures for NRC Adjudications § 2.1205 Summary disposition. (a) Unless the presiding officer or the Commission directs otherwise, motions for summary disposition may be submitted to the presiding...

  1. 17 CFR 12.207 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Summary disposition. 12.207... REPARATIONS Rules Applicable to Summary Decisional Proceedings § 12.207 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time until the parties have concluded their...

  2. 12 CFR 747.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Summary disposition. 747.29 Section 747.29... of Practice and Procedure § 747.29 Summary disposition. (a) In general. The administrative law judge shall recommend that the NCUA Board issue a final order granting a motion for summary disposition if the...

  3. 7 CFR 765.304 - Unapproved disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Unapproved disposition. 765.304 Section 765.304... disposition. (a) If a borrower disposes of chattel security without Agency approval, or misuses proceeds, the... disposition or use information to enable the Agency to consider post-approval within 30 days of Agency...

  4. 12 CFR 509.29 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Summary disposition. 509.29 Section 509.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  5. 12 CFR 19.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Summary disposition. 19.29 Section 19.29 Banks... Uniform Rules of Practice and Procedure § 19.29 Summary disposition. (a) In general. The administrative... disposition if the undisputed pleaded facts, admissions, affidavits, stipulations, documentary evidence...

  6. 17 CFR 12.310 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Summary disposition. 12.310... REPARATIONS Rules Applicable to Formal Decisional Proceedings § 12.310 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time before a determination is made by the...

  7. 48 CFR 250.103-6 - Disposition.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Disposition. 250.103-6... Contractual Actions 250.103-6 Disposition. For requests denied or approved below the Secretarial level, follow the disposition procedures at PGI 250.103-6. ...

  8. 12 CFR 19.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Summary disposition. 19.29 Section 19.29 Banks... Uniform Rules of Practice and Procedure § 19.29 Summary disposition. (a) In general. The administrative... disposition if the undisputed pleaded facts, admissions, affidavits, stipulations, documentary evidence...

  9. 12 CFR 19.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Summary disposition. 19.29 Section 19.29 Banks... Uniform Rules of Practice and Procedure § 19.29 Summary disposition. (a) In general. The administrative... disposition if the undisputed pleaded facts, admissions, affidavits, stipulations, documentary evidence...

  10. 7 CFR 70.92 - Disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Disposition. 70.92 Section 70.92 Agriculture... Disposition. The original and a copy of each grading certificate, issued pursuant to §§ 70.90 through 70.93... shall be filed and retained in accordance with the disposition schedule for grading program records. [71...

  11. 7 CFR 765.304 - Unapproved disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Unapproved disposition. 765.304 Section 765.304... disposition. (a) If a borrower disposes of chattel security without Agency approval, or misuses proceeds, the... disposition or use information to enable the Agency to consider post-approval within 30 days of Agency...

  12. 12 CFR 263.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Summary disposition. 263.29 Section 263.29... disposition. (a) In general. The administrative law judge shall recommend that the Board issue a final order granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  13. 39 CFR 952.3 - Informal dispositions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Informal dispositions. 952.3 Section 952.3 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.3 Informal dispositions. This part does not preclude the disposition of...

  14. 7 CFR 765.304 - Unapproved disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Unapproved disposition. 765.304 Section 765.304... disposition. (a) If a borrower disposes of chattel security without Agency approval, or misuses proceeds, the... disposition or use information to enable the Agency to consider post-approval within 30 days of Agency...

  15. 12 CFR 109.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Summary disposition. 109.29 Section 109.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 109.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  16. 7 CFR 70.92 - Disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Disposition. 70.92 Section 70.92 Agriculture... Disposition. The original and a copy of each grading certificate, issued pursuant to §§ 70.90 through 70.93... shall be filed and retained in accordance with the disposition schedule for grading program records. ...

  17. 7 CFR 70.92 - Disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Disposition. 70.92 Section 70.92 Agriculture... Disposition. The original and a copy of each grading certificate, issued pursuant to §§ 70.90 through 70.93... shall be filed and retained in accordance with the disposition schedule for grading program records. ...

  18. 12 CFR 509.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Summary disposition. 509.29 Section 509.29 Banks... IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.29 Summary disposition. (a... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  19. 12 CFR 1780.31 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Summary disposition. 1780.31 Section 1780.31... Summary disposition. (a) In general. The presiding officer shall recommend that the Director issue a final order granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  20. 7 CFR 765.304 - Unapproved disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Unapproved disposition. 765.304 Section 765.304... disposition. (a) If a borrower disposes of chattel security without Agency approval, or misuses proceeds, the... disposition or use information to enable the Agency to consider post-approval within 30 days of Agency...

  1. 12 CFR 509.29 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Summary disposition. 509.29 Section 509.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  2. 12 CFR 908.51 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Summary disposition. 908.51 Section 908.51... disposition. (a) In general. The presiding officer shall recommend that the Board of Directors issue a final order granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  3. 12 CFR 509.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Summary disposition. 509.29 Section 509.29 Banks... IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.29 Summary disposition. (a... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  4. 12 CFR 1209.34 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 9 2012-01-01 2012-01-01 false Summary disposition. 1209.34 Section 1209.34... PROCEDURE Rules of Practice and Procedure § 1209.34 Summary disposition. (a) In general. The presiding officer shall recommend that the Director issue a final order granting a motion for summary disposition if...

  5. 10 CFR 2.1205 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Summary disposition. 2.1205 Section 2.1205 Energy NUCLEAR... Adjudications § 2.1205 Summary disposition. (a) Unless the presiding officer or the Commission directs otherwise, motions for summary disposition may be submitted to the presiding officer by any party no later than 45...

  6. 12 CFR 308.29 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Summary disposition. 308.29 Section 308.29... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.29 Summary disposition. (a) In general... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  7. 16 CFR 2.34 - Disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Disposition. 2.34 Section 2.34 Commercial... Consent Order Procedure § 2.34 Disposition. (a) Acceptance of proposed consent agreement. The Commission... further actions leading to final disposition of the matter. (b) Effectiveness of hold-separate or asset...

  8. 12 CFR 509.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Summary disposition. 509.29 Section 509.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  9. 16 CFR 2.34 - Disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Disposition. 2.34 Section 2.34 Commercial... Consent Order Procedure § 2.34 Disposition. (a) Acceptance of proposed consent agreement. The Commission... further actions leading to final disposition of the matter. (b) Effectiveness of hold-separate or asset...

  10. 10 CFR 2.1205 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Summary disposition. 2.1205 Section 2.1205 Energy NUCLEAR... Hearing Procedures for NRC Adjudications § 2.1205 Summary disposition. (a) Unless the presiding officer or the Commission directs otherwise, motions for summary disposition may be submitted to the presiding...

  11. 12 CFR 390.58 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Summary disposition. 390.58 Section 390.58... Proceedings § 390.58 Summary disposition. (a) In general. The administrative law judge shall recommend that the Board of Directors issue a final order granting a motion for summary disposition if the undisputed...

  12. 48 CFR 250.103-6 - Disposition.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Disposition. 250.103-6... Contractual Actions 250.103-6 Disposition. For requests denied or approved below the Secretarial level, follow the disposition procedures at PGI 250.103-6. ...

  13. 48 CFR 250.103-6 - Disposition.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Disposition. 250.103-6... Contractual Actions 250.103-6 Disposition. For requests denied or approved below the Secretarial level, follow the disposition procedures at PGI 250.103-6. ...

  14. 12 CFR 747.29 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Summary disposition. 747.29 Section 747.29... of Practice and Procedure § 747.29 Summary disposition. (a) In general. The administrative law judge shall recommend that the NCUA Board issue a final order granting a motion for summary disposition if the...

  15. 12 CFR 263.29 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Summary disposition. 263.29 Section 263.29... RULES OF PRACTICE FOR HEARINGS Uniform Rules of Practice and Procedure § 263.29 Summary disposition. (a... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  16. 12 CFR 19.29 - Summary disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Summary disposition. 19.29 Section 19.29 Banks... Uniform Rules of Practice and Procedure § 19.29 Summary disposition. (a) In general. The administrative... disposition if the undisputed pleaded facts, admissions, affidavits, stipulations, documentary evidence...

  17. 12 CFR 747.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Summary disposition. 747.29 Section 747.29... of Practice and Procedure § 747.29 Summary disposition. (a) In general. The administrative law judge shall recommend that the NCUA Board issue a final order granting a motion for summary disposition if the...

  18. 12 CFR 308.29 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Summary disposition. 308.29 Section 308.29... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.29 Summary disposition. (a) In general... a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  19. 17 CFR 12.207 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Summary disposition. 12.207... REPARATIONS Rules Applicable to Summary Decisional Proceedings § 12.207 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time until the parties have concluded their...

  20. 12 CFR 263.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Summary disposition. 263.29 Section 263.29... disposition. (a) In general. The administrative law judge shall recommend that the Board issue a final order granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  1. 48 CFR 250.103-6 - Disposition.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Disposition. 250.103-6... Contractual Actions 250.103-6 Disposition. For requests denied or approved below the Secretarial level, follow the disposition procedures at PGI 250.103-6. ...

  2. 7 CFR 70.92 - Disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Disposition. 70.92 Section 70.92 Agriculture... Disposition. The original and a copy of each grading certificate, issued pursuant to §§ 70.90 through 70.93... shall be filed and retained in accordance with the disposition schedule for grading program records. [71...

  3. 17 CFR 12.310 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Summary disposition. 12.310... REPARATIONS Rules Applicable to Formal Decisional Proceedings § 12.310 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time before a determination is made by the...

  4. 17 CFR 12.310 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Summary disposition. 12.310... REPARATIONS Rules Applicable to Formal Decisional Proceedings § 12.310 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time before a determination is made by the...

  5. 12 CFR 109.29 - Summary disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Summary disposition. 109.29 Section 109.29... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 109.29 Summary disposition... granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  6. 10 CFR 2.1205 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Summary disposition. 2.1205 Section 2.1205 Energy NUCLEAR... Hearing Procedures for NRC Adjudications § 2.1205 Summary disposition. (a) Unless the presiding officer or the Commission directs otherwise, motions for summary disposition may be submitted to the presiding...

  7. 17 CFR 12.207 - Summary disposition.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Summary disposition. 12.207... REPARATIONS Rules Applicable to Summary Decisional Proceedings § 12.207 Summary disposition. (a) Filing of... proceeding may file a motion for summary disposition at any time until the parties have concluded their...

  8. 12 CFR 19.29 - Summary disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Summary disposition. 19.29 Section 19.29 Banks... Uniform Rules of Practice and Procedure § 19.29 Summary disposition. (a) In general. The administrative... disposition if the undisputed pleaded facts, admissions, affidavits, stipulations, documentary evidence...

  9. 12 CFR 263.29 - Summary disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Summary disposition. 263.29 Section 263.29... disposition. (a) In general. The administrative law judge shall recommend that the Board issue a final order granting a motion for summary disposition if the undisputed pleaded facts, admissions, affidavits...

  10. Teaching Thinking Dispositions: From Transmission to Enculturation.

    ERIC Educational Resources Information Center

    Tishman, Shari; And Others

    1993-01-01

    Describes a dispositional conception of thinking, presenting a view of what good thinking dispositions look like and what they are made of. The article compares different models of teaching (teaching as transmission and as enculturation) and examines the extent to which they provide adequate guidelines for teaching thinking dispositions. (SM)

  11. Teaching Dispositions: Shared Understanding for Teacher Preparation

    ERIC Educational Resources Information Center

    DeMuth, Lynn

    2012-01-01

    This qualitative phenomenological study explored the perceptions of 16 high-performing teachers related to teaching dispositions, effects of dispositions on teaching and learning, and recommendations for assessment of teaching dispositions during teacher preparation. Participants' perceptions were gathered using six guided interview questions…

  12. An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses: Criticality (keff) Predictions

    SciTech Connect

    Scaglione, John M.; Mueller, Don E.; Wagner, John C.

    2014-12-01

    One of the most important remaining challenges associated with expanded implementation of burnup credit in the United States is the validation of depletion and criticality calculations used in the safety evaluation—in particular, the availability and use of applicable measured data to support validation, especially for fission products (FPs). Applicants and regulatory reviewers have been constrained by both a scarcity of data and a lack of clear technical basis or approach for use of the data. In this study, this paper describes a validation approach for commercial spent nuclear fuel (SNF) criticality safety (keff) evaluations based on best-available data and methods and applies the approach for representative SNF storage and transport configurations/conditions to demonstrate its usage and applicability, as well as to provide reference bias results. The criticality validation approach utilizes not only available laboratory critical experiment (LCE) data from the International Handbook of Evaluated Criticality Safety Benchmark Experiments and the French Haut Taux de Combustion program to support validation of the principal actinides but also calculated sensitivities, nuclear data uncertainties, and limited available FP LCE data to predict and verify individual biases for relevant minor actinides and FPs. The results demonstrate that (a) sufficient critical experiment data exist to adequately validate keff calculations via conventional validation approaches for the primary actinides, (b) sensitivity-based critical experiment selection is more appropriate for generating accurate application model bias and uncertainty, and (c) calculated sensitivities and nuclear data uncertainties can be used for generating conservative estimates of bias for minor actinides and FPs. Results based on the SCALE 6.1 and the ENDF/B-VII.0 cross-section libraries indicate that a conservative estimate of the bias for the minor actinides and FPs is 1.5% of their worth

  13. Magnetic response functions in actinide compounds

    SciTech Connect

    Lander, G.H.

    1986-01-01

    A brief review is given of neutron inelastic scattering experiments on actinide (5f) systems. Only a few compounds exhibit sharp crystal-field levels so that analogies with 4f compounds are rarely straight forward. In the systems that order magnetically, we do find well-defined magnetic excitations, although in many cases the strong interaction with the conduction electrons gives rise to overdamped modes. Finally, in the strongly enhanced paramagnets and heavy-fermion systems the response is essentially featureless in ..-->..Q space and can be characterized by a single Lorentzian with full-width at half-maximum of GAMMA. Attempts to relate this quantity GAMMA to other physical properties, particularly the coefficient of the electronic specific heat ..gamma.., have not been too successful. 22 refs., 5 figs.

  14. Theoretical atomic volumes of the light actinides

    SciTech Connect

    Jones, M. D.; Boettger, J. C.; Albers, R. C.; Singh, D. J.

    2000-02-15

    The zero-pressure zero-temperature equilibrium volumes and bulk moduli are calculated for the light actinides Th through Pu using two independent all-electron, full-potential, electronic-structure methods: the full-potential linear augmented-plane-wave method and the linear combinations of Gaussian-type orbitals-fitting function method. The results produced by these two distinctly different electronic-structure techniques are in good agreement with each other, but differ significantly from previously published calculations using the full-potential linear muffin-tin-orbital (FP-LMTO) method. The theoretically calculated equilibrium volumes are in some cases nearly 10% larger than the previous FP-LMTO calculations, bringing them much closer to the experimentally observed volumes. We also discuss the anomalous upturn in equilibrium volume seen experimentally for {alpha}-Pu. (c) 2000 The American Physical Society.

  15. Complexation of actinides with derivatives of oxydiaceticacid

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin

    2006-01-04

    Complexation of Np(V), U(VI) and Nd(III) with dimethyl-3-oxa-glutaramic acid (DMOGA) and tetramethyl-3-oxa-glutaramide (TMOGA) was studied in comparison with the complexation with oxydiacetic acid (ODA). Stability constants and enthalpy of complexation were determined by potentiometry, spectrophotometry and calorimetry. Thermodynamic parameters, in conjunction with structural information of solid compounds, indicate that DMOGA and TMOGA form tridentate complexes with the ether-oxygen participating in bonding with actinide/lanthanide ions. The trends in the stability constants, enthalpy and entropy of complexation are discussed in terms of the difference in the hydration of the amide groups and carboxylate groups and the difference in the charge density of the metal ions.

  16. Archetypes for actinide-specific chelating agents

    SciTech Connect

    Smith, W.L.

    1980-01-01

    The complexes of uranium and thorium with monomeric hydroxamic acids can serve as archetypes for an optimized macrochelate designed for tetravalent actinides. The eight-coordinate complexes, Th(i-PrN(O)C(O)R)/sub 4/, where R = tert-butyl or R = neopentyl, have been synthesized and their structures have been determined by x-ray diffraction. The bulky alkyl substituents impart remarkable volatility and hydrocarbon solubility to these complexes, and the steric interactions of these substituents largely determine the structures. When R = tert-butyl, the substituents occupy the corners of a tetrahedron and force the complex into a distorted cubic geometry with crystallographic S/sub 4/ symmetry. Insertion of a methylene group between the carbonyl carbon and the tert-butyl group relaxes the steric requirements, and the coordination polyhedron of the neopentyl derivative is close to the mmmm isomer of the trigonal-faced dodecahedron. Uranium tetrachloride was quantitatively oxidized via an oxygen transfer reaction with two equivalents of N-phenylbenzohydroxamic acid anion (PBHA) in tetrahydrofuran (THF) to form UO/sub 2/ Cl(PBHA)(THF)/sub 2/ and benzanilide. The structure of the uranyl complex has been determined from x-ray diffraction data; the linear uranyl ion is surrounded by a planar pentagonal array composed of two hydroxamate oxygen atoms, a chloride ion and two THF oxygens, such that the chloride ion is opposite the hydroxamate group. That the THF and phenyl rings are twisted from this equatorial plane limits the molecular geometry to that of the C/sub 1/ point group. Some aspects of the chemistry of hydroxamic acids and of their incorporation into molecules that may serve as precursors of tetravalent actinide specific sequestering agents have also been investigated.

  17. Actinides in HD 101065 (Przybylski's Star)

    NASA Astrophysics Data System (ADS)

    Cowley, C. R.; Hubrig, S.; Bord, D. J.

    2003-05-01

    There are many strange things about the abundances in Przybylski's star (HD 101065). The most recent study (MN, 217, 299, 2000) finds that among the elements through copper, the abundances scatter with no apparent pattern. The largest deviations from solar are found for magnesium, which may be deficient by somewhat more than 1 dex, and cobalt, which appears to be in excess by about the same amount. The heavier elements especially those beyond barium, and continuing through the actinides uranium and thorium, show a clear pattern and a remarkable coherence. We plot solar and stellar abundances on a logarithmic plot vs. atomic number Z, and displace the solar points upward by some 3 dex. While individual points do not overlap, there is a remarkable similarity in the overall trends from Z = 58-80, including the maxima caused in the solar case by the third r-process peak. Points for the displaced solar actinides fall near their stellar counterparts. The processes that produced the large enhancements of these heavy elements have not caused large fractionations of adjacent elements. We have new spectra from the ESO UVES spectrograph on UT2. Resolution is 80,000 (blue) and 110,000 (red), with S/N > 300. This material, and new oscillator strengths (AA 381, 1090,2002; AA 382, 368, 2002), allow a more complete analysis of U and Th. We find abundances near +2.5 for both elements (log(H) = 12), but uncertainties at the moment are surely +/- 0.3 dex. We are currently working to improve the accuracy. Current errors preclude the use of these observations for accurate cosmochronometry, even if the chemical differentiation were not relevant. If a U/Th ratio of unity could be taken at face value, it would imply an r-process event some 103 years ago. Thanks to B. Pfeiffer help and advice.

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

    SciTech Connect

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; Ezold, Julie G.; Felker, Leslie Kevin; Rykaczewski, Krzysztof Piotr; Hogle, Susan L.

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

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

    DOE PAGES

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; ...

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing themore » production of rare actinides including 249Bk, 251Cf, and 254Es are described.« less

  1. Quantification of actinide alpha-radiation damage in minerals and ceramics.

    PubMed

    Farnan, Ian; Cho, Herman; Weber, William J

    2007-01-11

    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 consensus that actinides that have been separated from spent nuclear fuel should be immobilized within mineral-based ceramics rather than glass because of their superior aqueous durability and lower risk of accidental criticality. However, in 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. At present, this number is estimated to be 1,000-2,000 atoms/alpha in zircon. Here we report nuclear magnetic resonance, spin-counting experiments that measure close to 5,000 atoms/alpha in radiation-damaged natural zircons. New radiological nuclear magnetic resonance measurements on highly radioactive, 239Pu zircon show damage similar to that caused by 238U and 232Th in mineral zircons at the same dose, indicating no significant effect of half-life or loading levels (dose rate). On the basis of these measurements, the initially crystalline structure of a 10 weight per cent 239Pu zircon would be amorphous after only 1,400 years in a geological repository (desired immobilization timescales are of the order of 250,000 years). These measurements establish a basis for assessing the long-term structural durability of actinide-containing ceramics in terms of an atomistic understanding of the fundamental damage event.

  2. Advanced Analytic Cognition: Thinking Dispositions

    DTIC Science & Technology

    2013-09-01

    anticipate and avoid situations where there is likely chance I will have to think in depth about something. 6. I find satisfaction in deliberating hard...34 Harvard Graduate School of Education Alumni Bulletin, Vol. 39, No. 1, 1994, pp. 7-9. Tishman, S. "Added Value: A Dispositional Perspective on

  3. Plutonium disposition and storage model

    SciTech Connect

    Krupa, J.F.

    2000-03-01

    An EXTEND/SDI-Industry model of DOE plutonium disposition and storage has been created which can easily accommodate changes in scenarios by changing input parameters. It matches well with hand-crafted spreadsheet analyses, and has the advantage that it shows system logic and can be documented easily.

  4. Plutonium disposition and storage model

    SciTech Connect

    Krupa, J.F.

    1999-12-06

    An EXTEND/SDI-Industry model of DOE plutonium disposition and storage has been created which can easily accommodate changes in scenarios by changing input parameters. It matches well with hand-crafted spreadsheet analyses, and has the advantage that it shows system logic and can be documented easily.

  5. Sex Differences in Drug Disposition

    PubMed Central

    Soldin, Offie P.; Chung, Sarah H.; Mattison, Donald R.

    2011-01-01

    Physiological, hormonal, and genetic differences between males and females affect the prevalence, incidence, and severity of diseases and responses to therapy. Understanding these differences is important for designing safe and effective treatments. This paper summarizes sex differences that impact drug disposition and includes a general comparison of clinical pharmacology as it applies to men and women. PMID:21403873

  6. Whatever Happened to Productive Disposition?

    ERIC Educational Resources Information Center

    Grady, Maureen

    2016-01-01

    In 2001, Kilpatrick, Swafford, and Findell proposed a new way to look at what it means for students to be mathematically proficient. They described mathematical proficiency as comprising five intertwined strands: procedural fluency, conceptual understanding, adaptive reasoning, strategic competence, and productive disposition. The vision is that…

  7. Signs, dispositions, and semiotic scaffolding.

    PubMed

    Fernández, Eliseo

    2015-12-01

    In theoretical work we distinguish living beings from inanimate objects on the basis of some paramount attributes, such as agency and autonomy. These abstract features are not directly accessible to our scrutiny, but we surmise their nature through observation of the purpose-oriented behavior of organisms. I intend to show that organismal purposefulness springs from the intrinsic, constitutive kind of finality that is the hallmark of all semiotic transactions. To this aim I develop a dispositionalist account of organismal causation based on a distinction between two kinds of causal dispositions: fixed (efficient) dispositions and traveling dispositions. Fixed dispositions are rigidly attached to physical structures and processes; these are the dispositions regularly invoked in current discussions of causal explanation. Traveling dispositions are able to move freely from one location to another by becoming embodied into suitable supporting media. I introduce these notions to articulate a view of semiosis I deem best suited to the life sciences, and contend that sign tokens are vehicles of traveling dispositions. This account places the origin of purposive behavior at the interaction of physical and semiotic causation. To properly motivate the discussion I briefly review some recent developments in the philosophy of science concerning various forms of causation invoked by scientists across disciplines to frame explanations and make predictions. The ensuing discussion gives particular prominence to mechanistic (as distinct from mechanicist) explanatory accounts of biological phenomena. This review is followed by a brief characterization of a "nomological machine," a comprehensive schema introduced and developed by Nancy Cartwright with the goal of explaining causal mechanisms in a general setting. By capitalizing on this model's heuristic virtues I seek to formulate a compelling view of the interactions between physical and semiotic causation at play in semiotic

  8. Actinide Source Term Program, position paper. Revision 1

    SciTech Connect

    Novak, C.F.; Papenguth, H.W.; Crafts, C.C.; Dhooge, N.J.

    1994-11-15

    The Actinide Source Term represents the quantity of actinides that could be mobilized within WIPP brines and could migrate with the brines away from the disposal room vicinity. This document presents the various proposed methods for estimating this source term, with a particular focus on defining these methods and evaluating the defensibility of the models for mobile actinide concentrations. The conclusions reached in this document are: the 92 PA {open_quotes}expert panel{close_quotes} model for mobile actinide concentrations is not defensible; and, although it is extremely conservative, the {open_quotes}inventory limits{close_quotes} model is the only existing defensible model for the actinide source term. The model effort in progress, {open_quotes}chemical modeling of mobile actinide concentrations{close_quotes}, supported by a laboratory effort that is also in progress, is designed to provide a reasonable description of the system and be scientifically realistic and supplant the {open_quotes}Inventory limits{close_quotes} model.

  9. Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.

    1977-01-01

    Design power plant studies were carried out for two applications of the plasma core reactor: (1) As a breeder reactor, (2) As a reactor able to transmute actinides effectively. In addition to the above applications the reactor produced electrical power with a high efficiency. A reactor subsystem was designed for each of the two applications. For the breeder reactor, neutronics calculations were carried out for a U-233 plasma core with a molten salt breeding blanket. A reactor was designed with a low critical mass (less than a few hundred kilograms U-233) and a breeding ratio of 1.01. The plasma core actinide transmutation reactor was designed to transmute the nuclear waste from conventional LWR's. The spent fuel is reprocessed during which 100% of Np, Am, Cm, and higher actinides are separated from the other components. These actinides are then manufactured as oxides into zirconium clad fuel rods and charged as fuel assemblies in the reflector region of the plasma core actinide transmutation reactor. In the equilibrium cycle, about 7% of the actinides are directly fissioned away, while about 31% are removed by reprocessing.

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

    SciTech Connect

    Perkasa, Y. S.; Waris, A. Kurniadi, R. Su'ud, Z.

    2014-09-30

    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.

  11. Decreased Salinity and Actinide Mobility: Colloid-Facilitated Transport or pH Change?

    PubMed

    Haliena, Brian; Zheng, Hangping; Melson, Nathan; Kaplan, Daniel I; Barnett, Mark O

    2016-01-19

    Colloids have been implicated in influencing the transport of actinides and other adsorbed contaminants in the subsurface, significantly increasing their mobility. Such colloid-facilitated transport can be induced by changes in groundwater chemistry that occur, for example, when high ionic strength contaminant plumes are displaced by infiltrating rainwater. We studied the transport and mobility of Th(IV), as an analogue for Pu(IV) and other tetravalent actinides [An(IV)], in saturated columns packed with a natural heterogeneous subsurface sandy sediment. As expected, decreases in ionic strength both promoted the mobilization of natural colloids and enhanced the transport of previously adsorbed Th(IV). However, colloid-facilitated transport played only a minor role in enhancing the transport of Th(IV). Instead, the enhanced transport of Th(IV) was primarily due to the pH-dependent desorption of Th(IV) caused by the change in ionic strength. In contrast, the adsorption of Th(IV) had a marked impact on the surface charge of the sandy sediment, significantly affecting the mobility of the colloids. In the absence of Th(IV), changes in ionic strength were ineffective at releasing colloids while in the presence of Th(IV), decreases in ionic strength liberated significant concentrations of colloids. Therefore, under the conditions of our experiments which mimicked acidic, high ionic strength groundwater contaminant plumes, Th(IV) had a much greater effect on colloid transport than colloids had on Th(IV) transport.

  12. Ab Initio Enhanced calphad Modeling of Actinide-Rich Nuclear Fuels

    SciTech Connect

    Morgan, Dane; Yang, Yong Austin

    2013-10-28

    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.

  13. Selective sorption of actinides by titania nanoparticles covalently functionalized with simple organic ligands.

    PubMed

    Veliscek-Carolan, Jessica; Jolliffe, Katrina A; Hanley, Tracey L

    2013-11-27

    Although current and proposed reprocessing of used nuclear fuel is performed predominantly by solvent extraction processes, solid phase sorbent materials have many advantages including the ability to avoid production of large volumes of organic waste. Therefore, three titania nanoparticle based sorbent materials have been developed, functionalized with organic ligands designed to impart selectivity for elements relevant to important separations at the back end of the nuclear fuel cycle. A novel, simplified method of covalent functionalization to the titania surface has been utilized, and the resulting materials have been shown to be hydrolytically stable at pH 2. The sorption behavior of these organofunctionalized titania materials was investigated over a wide pH range with a selection of elements including fission products and actinides. Titania nanoparticles functionalized with an amine or phosphate moiety were able to demonstrate exclusive extraction of uranium under optimized conditions. Titania nanoparticles functionalized with a picolinamide moiety exhibited superior minor actinide sorption properties, in terms of both efficiency and selectivity, to solvent extraction processes using similar organic moieties. As such, organo-functionalized titania materials as solid phase sorbents show promise as a future alternative to solvent extraction processes for nuclear separations.

  14. Disposition of nuclear waste using subcritical accelerator-driven systems

    SciTech Connect

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-01

    Studies have shown that the repository long-term radiological risk is from the long-lived transuranics and the fission products Tc-99 and I-129, thermal loading concerns arise mainly form the short-lived fission products Sr-90 and Cs-137. In relation to the disposition of nuclear waste, ATW is expected to accomplish the following: (1) destroy over 99.9% of the actinides; (2) destroy over 99.9% of the Tc and I; (3) separate Sr and Cs (short half-life isotopes); (4) separate uranium; (5) produce electricity. In the ATW concept, spent fuel would be shipped to a ATW site where the plutonium, other transuranics and selected long-lived fission products would be destroyed by fission or transmutation in their only pass through the facility. This approach contrasts with the present-day reprocessing practices in Europe and Japan, during which high purity plutonium is produced and used in the fabrication of fresh mixed-oxide fuel (MOX) that is shipped off-site for use in light water reactors.

  15. Thin extractive membrane for monitoring actinides in aqueous streams.

    PubMed

    Chavan, Vivek; Paul, Sumana; Pandey, Ashok K; Kalsi, P C; Goswami, A

    2013-09-15

    Alpha spectrometry and solid state nuclear track detectors (SSNTDs) are used for monitoring ultra-trace amount of alpha emitting actinides in different aqueous streams. However, these techniques have limitations i.e. alpha spectrometry requires a preconcentration step and SSNTDs are not chemically selective. Therefore, a thin polymer inclusion membrane (PIM) supported on silanized glass was developed for preconcentraion and determination of ultra-trace concentration of actinides by α-spectrometry and SSNTDs. PIMs were formed by spin coating on hydrophobic glass slide or solvent casting to form thin and self-supported membranes, respectively. Sorption experiments indicated that uptakes of actinides in the PIM were highly dependent on acidity of solution i.e. Am(III) sorbed up to 0.1 molL(-1) HNO₃, U(VI) up to 0.5 molL(-1) HNO₃ and Pu(IV) from HNO₃ concentration as high as 4 molL(-1). A scheme was developed for selective sorption of target actinide in the PIM by adjusting acidity and oxidation state of actinide. The actinides sorbed in PIMs were quantified by alpha spectrometry and SSNTDs. For SSNTDs, neutron induced fission-fragment tracks and α-particle tracks were registered in Garware polyester and CR-39 for quantifications of natural uranium and α-emitting actinides ((241)Am/(239)Pu/(233)U), respectively. Finally, the membranes were tested to quantify Pu in 4 molL(-1) HNO3 solutions and synthetic urine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. The disposition of coralyne sulphoacetate in rodents.

    PubMed

    Plowman, J; Cysyk, R L; Adamson, R H

    1976-05-01

    1. The disposition of (14C) coralyne sulphoacetate has been examined in the mouse and rat at three dose levels. 2. In both species the major route of excretion is biliary following either intraperitoneal or intravenous administration. In rats, 18-24% of the 14C is eliminated in the bile in the first 24 h and only 1-2% in the urine. Transport into bile appears to be active and the transport system saturable at the doses employed. 3. The majority of the biliary 14C in the rats is unchanged parent compound and a minority is associated with a metabolite. The maximum amount of metabolite is 12% at 10-30 min following the administered dose. 4. The initial plasma decay of (14C) coralyne following intravenous administration is rapid. Half-life values are 12-3, 16-2 and 2-41 min after doses of 13, 26 and 52 mg/kg respectively. 5. No sex differences were found in the rat in the parameters studied.

  17. 19 CFR 174.22 - Accelerated disposition of protest.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Accelerated disposition of protest. 174.22 Section... OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.22 Accelerated disposition of protest. (a) Request for accelerated disposition. Accelerated disposition of a protest filed in...

  18. 19 CFR 174.22 - Accelerated disposition of protest.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Accelerated disposition of protest. 174.22 Section... OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.22 Accelerated disposition of protest. (a) Request for accelerated disposition. Accelerated disposition of a protest filed in...

  19. Microbial transformations of actinides in the environment

    NASA Astrophysics Data System (ADS)

    Livens, F. R.; Al-Bokari, M.; Fomina, M.; Gadd, G. M.; Geissler, A.; Lloyd, J. R.; Renshaw, J. C.; Vaughan, D. J.

    2010-03-01

    The diversity of microorganisms is still far from understood, although many examples of the microbial biotransformation of stable, pollutant and radioactive elements, involving Bacteria, Archaea and Fungi, are known. In estuarine sediments from the Irish Sea basin, which have been labelled by low level effluent discharges, there is evidence of an annual cycle in Pu solubility, and microcosm experiments have demonstrated both shifts in the bacterial community and changes in Pu solubility as a result of changes in redox conditions. In the laboratory, redox transformation of both U and Pu by Geobacter sulfurreducens has been demonstrated and EXAFS spectroscopy has been used to understand the inability of G. sufurreducens to reduce Np(V). Fungi promote corrosion of metallic U alloy through production of a range of carboxylic acid metabolites, and are capable of translocating the dissolved U before precipitating it externally to the hyphae, as U(VI) phosphate phases. These examples illustrate the far-reaching but complex effects which microorganisms can have on actinide behaviour.

  20. Correlation and relativistic effects in actinide ions

    SciTech Connect

    Safronova, U. I.; Safronova, M. S.

    2011-11-15

    Wavelengths, line strengths, and transition rates are calculated for the multipole (E1, M1, E2, M2, E3, and M3) transitions between the excited 6s{sup 2}6p{sup 5}nl and 6s6p{sup 6}nl states and the ground 6s{sup 2}6p{sup 6} state in Ac{sup 3+}, Th{sup 4+}, and U{sup 6+} Rn-like ions. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate energies and transition rates for multipole transitions in these hole-particle systems. The RMBPT method agrees with multiconfigurational Dirac-Fock (MCDF) calculations in lowest order, includes all second-order correlation corrections, and includes corrections from negative-energy states. The calculations start from a [Xe]4f{sup 14}5d{sup 10}6s{sup 2}6p{sup 6} Dirac-Fock potential. First-order perturbation theory is used to obtain intermediate-coupling coefficients, and second-order RMBPT is used to determine the matrix elements. Evaluated multipole matrix elements for transitions from excited states to the ground states are used to determine the line strengths, transition rates, and multipole polarizabilities. This work provides a number of yet unmeasured properties of these actinide ions for various applications and for benchmark tests of theory and experiment.

  1. Synthesis of crystalline ceramics for actinide immobilisation

    SciTech Connect

    Burakov, B.; Gribova, V.; Kitsay, A.; Ojovan, M.; Hyatt, N.C.; Stennett, M.C.

    2007-07-01

    Methods for the synthesis of ceramic wasteforms for the immobilization of actinides are common to those for non-radioactive ceramics: hot uniaxial pressing (HUP); hot isostatic pressing (HIP); cold pressing followed by sintering; melting (for some specific ceramics, such as garnet/perovskite composites). Synthesis of ceramics doped with radionuclides is characterized with some important considerations: all the radionuclides should be incorporated into crystalline structure of durable host-phases in the form of solid solutions and no separate phases of radionuclides should be present in the matrix of final ceramic wasteform; all procedures of starting precursor preparation and ceramic synthesis should follow safety requirements of nuclear industry. Synthesis methods that avoid the use of very high temperatures and pressures and are easily accomplished within the environment of a glove-box or hot cell are preferable. Knowledge transfer between the V. G. Khlopin Radium Institute (KRI, Russia) and Immobilisation Science Laboratory (ISL, UK) was facilitated in the framework of a joint project supported by UK Royal Society. In order to introduce methods of precursor preparation and ceramic synthesis we selected well-known procedures readily deployable in radiochemical processing plants. We accounted that training should include main types of ceramic wasteforms which are currently discussed for industrial applications. (authors)

  2. Derivation of plutonium-239 materials disposition categories

    SciTech Connect

    Brough, W.G.

    1995-04-27

    At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report.

  3. A Summary of Actinide Enrichment Technologies and Capability Gaps

    SciTech Connect

    Patton, Bradley D.; Robinson, Sharon M.

    2017-01-01

    The evaluation performed in this study indicates that a new program is needed to efficiently provide a national actinide radioisotope enrichment capability to produce milligram-to-gram quantities of unique materials for user communities. This program should leverage past actinide enrichment, the recent advances in stable isotope enrichment, and assessments of the future requirements to cost effectively develop this capability while establishing an experience base for a new generation of researchers in this vital area. Preliminary evaluations indicate that an electromagnetic isotope separation (EMIS) device would have the capability to meet the future needs of the user community for enriched actinides. The EMIS technology could be potentially coupled with other enrichment technologies, such as irradiation, as pre-enrichment and/or post-enrichment systems to increase the throughput, reduce losses of material, and/or reduce operational costs of the base EMIS system. Past actinide enrichment experience and advances in the EMIS technology applied in stable isotope separations should be leveraged with this new evaluation information to assist in the establishment of a domestic actinide radioisotope enrichment capability.

  4. Gas core reactors for actinide transmutation and breeder applications

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.

    1978-01-01

    This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

  5. Recovery and chemical purification of actinides at JRC, Karlsruhe

    NASA Astrophysics Data System (ADS)

    Bokelund, H.; Apostolidis, C.; Glatz, J.-P.

    1989-07-01

    The application of actinide elements in research and in technology is many times subject to rather stringent purity requirements; often a nuclear grade quality is specified. The additional possible demand for a high isotopic purity is a special feature in the handling of these elements. The amount of actinide elements contained in or adhering to materials declared as waste should be low for safety reasons and out of economic considerations. The release of transuranium elements to the environment must be kept negligible. For these and for other reasons a keen interest in the separation of actinides from various materials exists, either for a re-use through recycling, or for their safe confinement in waste packages. This paper gives a short review of the separation methods used for recovery and purification of actinide elements over the past years in the European Institute for Transuranium Elements. The methods described here involve procedures based on precipitation, ion exchange or solvent extraction; often used in a combination. The extraction methods were preferably applied in a Chromatographie column mode. The actinide elements purified and/or separated from each other by the above methods include uranium, neptunium, plutonium, americium, curium, and californium. For the various elements the work was undertaken with different aims, ranging from reprocessing and fabrication of nuclear fuels on a kilogramme scale, over the procurement of alpha-free waste, to the preparation of neutron sources of milligramme size.

  6. Rapid determination of alpha emitters using Actinide resin.

    PubMed

    Navarro, N; Rodriguez, L; Alvarez, A; Sancho, C

    2004-01-01

    The European Commission has recently published the recommended radiological protection criteria for the clearance of building and building rubble from the dismantling of nuclear installations. Radionuclide specific clearance levels for actinides are very low (between 0.1 and 1 Bq g(-1)). The prevalence of natural radionuclides in rubble materials makes the verification of these levels by direct alpha counting impossible. The capability of Actinide resin (Eichrom Industries, Inc.) for extracting plutonium and americium from rubble samples has been tested in this work. Besides a strong affinity for actinides in the tri, tetra and hexavalent oxidation states, this extraction chromatographic resin presents an easy recovery of absorbed radionuclides. The retention capability was evaluated on rubble samples spiked with certified radionuclide standards (239Pu and 241Am). Samples were leached with nitric acid, passed through a chromatographic column containing the resin and the elution fraction was measured by LSC. Actinide retention varies from 60% to 80%. Based on these results, a rapid method for the verification of clearance levels for actinides in rubble samples is proposed.

  7. Crystal growth methods dedicated to low solubility actinide oxalates

    NASA Astrophysics Data System (ADS)

    Tamain, C.; Arab-Chapelet, B.; Rivenet, M.; Grandjean, S.; Abraham, F.

    2016-04-01

    Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am2(C2O4)3(H2O)3·xH2O, Th(C2O4)2·6H2O, M2+x[PuIV2-xPuIIIx(C2O4)5]·nH2O and M1-x[PuIII1-xPuIVx(C2O4)2·H2O]·nH2O. It is the first time that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV-visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds.

  8. Siderocalin-mediated recognition, sensitization, and cellular uptake of actinides

    PubMed Central

    Allred, Benjamin E.; Rupert, Peter B.; Gauny, Stacey S.; An, Dahlia D.; Ralston, Corie Y.; Sturzbecher-Hoehne, Manuel; Strong, Roland K.; Abergel, Rebecca J.

    2015-01-01

    Synthetic radionuclides, such as the transuranic actinides plutonium, americium, and curium, present severe health threats as contaminants, and understanding the scope of the biochemical interactions involved in actinide transport is instrumental in managing human contamination. Here we show that siderocalin, a mammalian siderophore-binding protein from the lipocalin family, specifically binds lanthanide and actinide complexes through molecular recognition of the ligands chelating the metal ions. Using crystallography, we structurally characterized the resulting siderocalin–transuranic actinide complexes, providing unprecedented insights into the biological coordination of heavy radioelements. In controlled in vitro assays, we found that intracellular plutonium uptake can occur through siderocalin-mediated endocytosis. We also demonstrated that siderocalin can act as a synergistic antenna to sensitize the luminescence of trivalent lanthanide and actinide ions in ternary protein–ligand complexes, dramatically increasing the brightness and efficiency of intramolecular energy transfer processes that give rise to metal luminescence. Our results identify siderocalin as a potential player in the biological trafficking of f elements, but through a secondary ligand-based metal sequestration mechanism. Beyond elucidating contamination pathways, this work is a starting point for the design of two-stage biomimetic platforms for photoluminescence, separation, and transport applications. PMID:26240330

  9. Laboratory studies of actinide metal-silicate fractionation

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Burnett, D. S.

    1980-01-01

    Actinide and Sm partition coefficients between silicate melt and several metallic phases have been measured. Under reducing conditions Si, Th, U and Pu can be reduced to metals from silicate melts and alloyed with a platinum-gold alloy. U and Pu enter a molten Pt-Si alloy with roughly equal affinity but U strongly partitions into the solid Pt. Th behaves qualitatively the same as Pu but is much less readily reduced than U, and Sm appears to remain unreduced. Experiments with Fe metal have shown that the partition coefficients of the actinides between Fe and silicate liquid are extremely low, suggesting a very low actinide concentration in planetary cores. Experiments show that platinum metals can efficiently fractionate actinides and fractionate actinides from lanthanides and this process may be relevant to the condensation behavior of these elements from the solar nebula. Pt-metal grains in Allende Ca-Al-rich inclusions appear to be U-poor, although the sub-class of Zr-bearing Pt metals may have high U contents.

  10. Theoretical investigation on multiple bonds in terminal actinide nitride complexes.

    PubMed

    Wu, Qun-Yan; Wang, Cong-Zhi; Lan, Jian-Hui; Xiao, Cheng-Liang; Wang, Xiang-Ke; Zhao, Yu-Liang; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-09-15

    A series of actinide (An) species of L-An-N compounds [An = Pa-Pu, L = [N(CH2CH2NSiPr(i)3)3](3-), Pr(i) = CH(CH3)2] have been investigated using scalar relativistic density functional theory (DFT) without considering spin-orbit coupling effects. The ground state geometric and electronic structures and natural bond orbital (NBO) analysis of actinide compounds were studied systematically in neutral and anionic forms. It was found that with increasing actinide atomic number, the bond length of terminal multiple An-N1 bond decreases, in accordance with the actinide contraction. The Mayer bond order of An-N1 decreases gradually from An = Pa to Pu, which indicates a decrease in bond strength. The terminal multiple bond for L-An-N compounds contains one σ and two π molecular orbitals, and the contributions of the 6d orbital to covalency are larger in magnitude than the 5f orbital based on NBO analysis and topological analysis of electron density. This work may help in understanding of the bonding nature of An-N multiple bonds and elucidating the trends and electronic structure changes across the actinide series. It can also shed light on the construction of novel An-N multiple bonds.

  11. Siderocalin-mediated recognition, sensitization, and cellular uptake of actinides.

    PubMed

    Allred, Benjamin E; Rupert, Peter B; Gauny, Stacey S; An, Dahlia D; Ralston, Corie Y; Sturzbecher-Hoehne, Manuel; Strong, Roland K; Abergel, Rebecca J

    2015-08-18

    Synthetic radionuclides, such as the transuranic actinides plutonium, americium, and curium, present severe health threats as contaminants, and understanding the scope of the biochemical interactions involved in actinide transport is instrumental in managing human contamination. Here we show that siderocalin, a mammalian siderophore-binding protein from the lipocalin family, specifically binds lanthanide and actinide complexes through molecular recognition of the ligands chelating the metal ions. Using crystallography, we structurally characterized the resulting siderocalin-transuranic actinide complexes, providing unprecedented insights into the biological coordination of heavy radioelements. In controlled in vitro assays, we found that intracellular plutonium uptake can occur through siderocalin-mediated endocytosis. We also demonstrated that siderocalin can act as a synergistic antenna to sensitize the luminescence of trivalent lanthanide and actinide ions in ternary protein-ligand complexes, dramatically increasing the brightness and efficiency of intramolecular energy transfer processes that give rise to metal luminescence. Our results identify siderocalin as a potential player in the biological trafficking of f elements, but through a secondary ligand-based metal sequestration mechanism. Beyond elucidating contamination pathways, this work is a starting point for the design of two-stage biomimetic platforms for photoluminescence, separation, and transport applications.

  12. Removal of actinides from nuclear reprocessing wastes: a pilot plant study using non-radioactive simulants

    SciTech Connect

    Maxey, H.R.; McIsaac, L.D.; Chamberlain, D.B.; McManus, G.J.

    1980-01-01

    Nuclear fuel reprocessing wastes generated at the ICPP contain small amounts of actinides, primarily Pu and Am. Removal of these actinides reduces the long term storage hazards of the waste. The development of a flowsheet to remove trivalent actinides is discussed in this paper. Pilot plant studies used actinide simulants. As a result of these studies, the Height of a Transfer Unit (HTU) was selected as the better measure of pulse column separation efficiency.

  13. 7 CFR 984.456 - Disposition of reserve walnuts and walnuts used for reserve disposition credit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Disposition of reserve walnuts and walnuts used for..., Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Administrative Rules and Regulations § 984.456 Disposition of reserve walnuts and walnuts used for reserve disposition credit. (a)...

  14. 7 CFR 984.456 - Disposition of reserve walnuts and walnuts used for reserve disposition credit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Disposition of reserve walnuts and walnuts used for..., Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Administrative Rules and Regulations § 984.456 Disposition of reserve walnuts and walnuts used for reserve disposition credit. (a)...

  15. 7 CFR 984.456 - Disposition of reserve walnuts and walnuts used for reserve disposition credit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Disposition of reserve walnuts and walnuts used for..., NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Administrative Rules and Regulations § 984.456 Disposition of reserve walnuts and walnuts used for reserve disposition credit. (a)...

  16. 7 CFR 984.456 - Disposition of reserve walnuts and walnuts used for reserve disposition credit.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Disposition of reserve walnuts and walnuts used for..., NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Administrative Rules and Regulations § 984.456 Disposition of reserve walnuts and walnuts used for reserve disposition credit. (a)...

  17. 7 CFR 984.456 - Disposition of reserve walnuts and walnuts used for reserve disposition credit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Disposition of reserve walnuts and walnuts used for..., Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Administrative Rules and Regulations § 984.456 Disposition of reserve walnuts and walnuts used for reserve disposition credit. (a)...

  18. The Difficulty of Teacher Dispositions: Considering Professional Dispositions for Preservice English Teachers

    ERIC Educational Resources Information Center

    Shoffner, Melanie; Sedberry, Tiffany; Alsup, Janet; Johnson, Tara Star

    2014-01-01

    This article explores the place of teacher dispositions in English teacher preparation by contextualizing the issue of dispositions in English teacher preparation. This allows consideration for the importance of developing professional dispositions during English teacher preparation by recognizing that various stakeholders (teacher educators,…

  19. The Difficulty of Teacher Dispositions: Considering Professional Dispositions for Preservice English Teachers

    ERIC Educational Resources Information Center

    Shoffner, Melanie; Sedberry, Tiffany; Alsup, Janet; Johnson, Tara Star

    2014-01-01

    This article explores the place of teacher dispositions in English teacher preparation by contextualizing the issue of dispositions in English teacher preparation. This allows consideration for the importance of developing professional dispositions during English teacher preparation by recognizing that various stakeholders (teacher educators,…

  20. Sample Results from the Interim Salt Disposition Program Macrobatch 8 Tank 21H Qualification Samples

    SciTech Connect

    Peters, T. B.; Washington, A. L.

    2015-01-01

    Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for the Interim Salt Disposition Program (ISDP). An Actinide Removal Process (ARP) and several Extraction-Scrub- Strip (ESS) tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). No issues with the projected Salt Batch 8 strategy are identified. A demonstration of the monosodium titanate (MST) (0.2 g/L) removal of strontium and actinides provided acceptable average decontamination factors for plutonium of 2.62 (4 hour) and 2.90 (8 hour); and average strontium decontamination factors of 21.7 (4 hour) and 21.3 (8 hour). These values are consistent with results from previous salt batch ARP tests. The two ESS tests also showed acceptable performance with extraction distribution ratios (D(Cs)) values of 52.5 and 50.4 for the Next Generation Solvent (NGS) blend (from MCU) and NGS (lab prepared), respectively. These values are consistent with results from previous salt batch ESS tests. Even though the performance is acceptable, SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed in order to improve our predictive capabilities for the ESS tests.

  1. Sample results from the Interim Salt Disposition Program Macrobatch 8 Tank 21H qualification samples

    SciTech Connect

    Peters, T. B.; Washington, II, A. L.

    2015-01-13

    Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for the Interim Salt Disposition Program (ISDP). An Actinide Removal Process (ARP) and several Extraction-Scrub-Strip (ESS) tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). No issues with the projected Salt Batch 8 strategy are identified. A demonstration of the monosodium titanate (MST) (0.2 g/L) removal of strontium and actinides provided acceptable average decontamination factors for plutonium of 2.62 (4 hour) and 2.90 (8 hour); and average strontium decontamination factors of 21.7 (4 hour) and 21.3 (8 hour). These values are consistent with results from previous salt batch ARP tests. The two ESS tests also showed acceptable performance with extraction distribution ratios (D(Cs)) values of 52.5 and 50.4 for the Next Generation Solvent (NGS) blend (from MCU) and NGS (lab prepared), respectively. These values are consistent with results from previous salt batch ESS tests. Even though the performance is acceptable, SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed in order to improve our predictive capabilities for the ESS tests.

  2. Systematic view of optical absorption spectra in the actinide series

    SciTech Connect

    Carnall, W.T.

    1985-01-01

    In recent years sufficient new spectra of actinides in their numerous valence states have been measured to encourage a broader scale analysis effort than was attempted in the past. Theoretical modelling in terms of effective operators has also undergone development. Well established electronic structure parameters for the trivalent actinides are being used as a basis for estimating parameters in other valence states and relationships to atomic spectra are being extended. Recent contributions to our understanding of the spectra of 4+ actinides have been particularly revealing and supportive of a developing general effort to progress beyond a preoccupation with modelling structure to consideration of the much broader area of structure-bonding relationships. We summarize here both the developments in modelling electronic structure and the interpretation of apparent trends in bonding. 60 refs., 9 figs., 1 tab.

  3. Actinide science with soft x-ray synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Shuh, David K.

    2000-07-01

    The primary methods for the experimental investigation of actinide materials in the VUV/soft x-ray region are the complementary photoelectron spectroscopies, near-edge x-ray absorption fine structure (NEXAFS), and x-ray emission spectroscopy (XES) techniques. Resonant photoemission techniques capable of resolving the 5f electron contributions to actinide bonding along with angle-resolving measurements for band structure and surface structure determinations, have clear and immediate applications. Venerable angle-integrating core and valence band photoelectron spectroscopy are valuable for characterization and analytical purposes. Combined with results from NEXAFS measurements, these techniques will provide the information needed to develop improved understandings of the electronic structure of actinide materials and their surface chemistries/physics.

  4. A new opportunity: coincident spectroscopy in neutron-deficient actinides

    NASA Astrophysics Data System (ADS)

    Gothe, Oliver; Gates, J. M.; Gregorich, K. E.; Baartman, B.; Fallon, P.; Esker, N. E.; Kwarsick, J.; Machiavelli, A. O.; Mudder, P. R.; Olive, D. T.; Pang, G.; Rissanen, J.; Nitsche, H.

    2014-09-01

    Due to high γ-ray background rates heavy element production facilities are usually not sensitive to the electron capture decay of neutron deficient actinides. We have developed new capabilities at the Berkeley Gas Filled Separator (BGS) that allow us to study these isotopes. The highly selective and efficient separation of compound nucleus evaporation residue products using the BGS couple with a rapid delivery to a low-background detector facility, opens up many new possibilities for nuclear decay and structure studies in the neutron deficient actinides. The decay of these actinides produces vacancies in the K-shell resulting in x-rays uniquely identifying the Z of the decay products. We present the first results of this new methodology in studying the nuclear structure of fermium-254 by observing the gamma rays in coincidence with fermium x-rays. Coincident gamma-decay spectroscopy gives us a new tool to study the nuclear structure of previously inaccessible systems.

  5. FY2010 Annual Report for the Actinide Isomer Detection Project

    SciTech Connect

    Warren, Glen A.; Francy, Christopher J.; Ressler, Jennifer J.; Erikson, Luke E.; Miller, Erin A.; Hatarik, R.

    2011-01-01

    This project seeks to identify a new signature for actinide element detection in active interrogation. This technique works by exciting and identifying long-lived nuclear excited states (isomers) in the actinide isotopes and/or primary fission products. Observation of isomers in the fission products will provide a signature for fissile material. For the actinide isomers, the decay time and energy of the isomeric state is unique to a particular isotope, providing an unambiguous signature for Special Nuclear Materials (SNM). Future work will include a follow-up measurement scheduled for December 2010 at LBNL. Lessons learned from the July 2010 measurements will be incorporated into these new measurements. Analysis of both the July and December experiments will be completed in a few months. A research paper to be submitted to a peer-reviewed journal will be drafted if the conclusions from the measurements warrant publication.

  6. X-ray and electron microscopy of actinide materials.

    PubMed

    Moore, Kevin T

    2010-06-01

    Actinide materials demonstrate a wide variety of interesting physical properties in both bulk and nanoscale form. To better understand these materials, a broad array of microscopy techniques have been employed, including transmission electron microscopy (TEM), electron energy-loss spectroscopy (EELS), energy dispersive X-ray spectroscopy (EDXS), high-angle annular dark-field imaging (HAADF), scanning electron microscopy (SEM), wavelength dispersive X-ray spectroscopy (WDXS), electron back scattered diffraction (EBSD), scanning tunneling microscopy (STM), atomic force microscopy (AFM), and scanning transmission X-ray microscopy (STXM). Here these techniques will be reviewed, highlighting advances made in the physics, materials science, chemistry, and biology of actinide materials through microscopy. Construction of a spin-polarized TEM will be discussed, considering its potential for examining the nanoscale magnetic structure of actinides as well as broader materials and devices, such as those for computational magnetic memory. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Actinide Dioxides in Water: Interactions at the Interface

    SciTech Connect

    Alexandrov, Vitaly; Shvareva, Tatiana Y.; Hayun, Shmuel; Asta, Mark; Navrotsky, Alexandra

    2011-12-15

    A comprehensive understanding of chemical interactions between water and actinide dioxide surfaces is critical for safe operation and storage of nuclear fuels. Despite substantial previous research, understanding the nature of these interactions remains incomplete. In this work, we combine accurate calorimetric measurements with first-principles computational studies to characterize surface energies and adsorption enthalpies of water on two fluorite-structured compounds, ThO₂ and CeO₂, that are relevant for understanding the behavior of water on actinide oxide surfaces more generally. We determine coverage-dependent adsorption enthalpies and demonstrate a mixed molecular and dissociative structure for the first hydration layer. The results show a correlation between the magnitude of the anhydrous surface energy and the water adsorption enthalpy. Further, they suggest a structural model featuring one adsorbed water molecule per one surface cation on the most stable facet that is expected to be a common structural signature of water adsorbed on actinide dioxide compounds.

  8. Actinide chemistry in Allende Ca-Al-rich inclusions

    NASA Astrophysics Data System (ADS)

    Murrell, M. T.; Burnett, D. S.

    1987-04-01

    Fission track radiography is used to investigate the U and Th microscale distribution in a set of Allende-meteorite Ca-Al-rich inclusions. In the Type B inclusions, the major phases melilite and fassaite are important actinide host phases, and on the rims of Type B inclusions and throughout all other inclusions studied, perovskite is the dominant actinide host phase. Results suggest that neither alteration nor loss or gain of an actinide-rich phase appears to have been an important Th/U fractionation mechanism, and that volatility differences may be the dominant factor. Th/U and rare earth element abundance patterns for the spinel and perovskite rim suggest rim formation by volatilization of interior material, and within the constraints of the brief time scale required for this heating, several mechanisms for spinel-perovskite rim formation are possible.

  9. Determination of actinides at the radiological and environmental sciences laboratory

    NASA Astrophysics Data System (ADS)

    Williams, R. L.; Grothaus, G. E.

    1984-06-01

    This article briefly describes some of the techniques and procedures that have been developed at the Radiological and Environmental Sciences Laboratory (RESL) to determine the actinides in environmental and biological samples. Dried or ashed samples are totally decomposed in high temperature fusions or with an acid dissolution method. Actinides of interest are coprecipitated from the sample matrix with barium sulfate, cerium fluoride, or a combination of ferrous phosphate and calcium fluoride precipitations. The precipitates are dissolved in perchloric acid and extracted with bis(2-ethylhexyl)phosphoric acid (HDEHP) or dissolved in acidic aluminum nitrate and extracted with Aliquat-336. Actinides in the stripped fractions are coprecipitated with 50 μg of cerium as cerium fluoride, filtered onto membrane filters and counted by alpha spectrometry. The described procedures enable an experienced analyst to prepare sixteen 1 g soil or twelve 5 g faecal ash samples for alpha spectrometry in 14 to 16 working-hours.

  10. Electronic, structural, and thermodynamic properties of actinide dioxides

    NASA Astrophysics Data System (ADS)

    Ma, Li; Atta-Fynn, Raymond; Ray, Asok K.

    2010-03-01

    As a continuation of our studies of pure actinide metals using hybrid density functional theory,footnotetextR. Atta-Fynn and A. K. Ray, Europhysics Letters, 85, 27008-p1- p6 (2009); Chemical Physics Letters, 482, 223-227 (2009). we present here a systematic study of the electronic and geometric structure properties of the actinide dioxides, UO2, PuO2 and AmO2, using both density functional and hybrid density functional theories. For the hybrid density functionals, the fractions of exact Hartree-Fock exchange used were 25% and 40%. Each compound has been studied at the nonmagnetic, ferromagnetic and antiferromagnetic configurations, with and without spin-orbit coupling (SOC). The influence of SOC on the properties of the actinide dioxides will be discussed. Thermodynamic properties such as phonon dispersion curves, heat capacity, entropy, internal energy and free energy have been calculated by a coupling of first-principles calculations and lattice dynamics.

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

    SciTech Connect

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

    2009-09-01

    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.

  12. Advancing the scientific basis of trivalent actinide-lanthanide separations

    SciTech Connect

    Nash, K.L.

    2013-07-01

    For advanced fuel cycles designed to support transmutation of transplutonium actinides, several options have been demonstrated for process-scale aqueous separations for U, Np, Pu management and for partitioning of trivalent actinides and fission product lanthanides away from other fission products. The more difficult mutual separation of Am/Cm from La-Tb remains the subject of considerable fundamental and applied research. The chemical separations literature teaches that the most productive alternatives to pursue are those based on ligand donor atoms less electronegative than O, specifically N- and S-containing complexants and chloride ion (Cl{sup -}). These 'soft-donor' atoms have exhibited usable selectivity in their bonding interactions with trivalent actinides relative to lanthanides. In this report, selected features of soft donor reagent design, characterization and application development will be discussed. The roles of thiocyanate, aminopoly-carboxylic acids and lactate in separation processes are detailed. (authors)

  13. Actinide chemistry in Allende Ca-Al-rich inclusions

    NASA Technical Reports Server (NTRS)

    Murrell, M. T.; Burnett, D. S.

    1987-01-01

    Fission track radiography is used to investigate the U and Th microscale distribution in a set of Allende-meteorite Ca-Al-rich inclusions. In the Type B inclusions, the major phases melilite and fassaite are important actinide host phases, and on the rims of Type B inclusions and throughout all other inclusions studied, perovskite is the dominant actinide host phase. Results suggest that neither alteration nor loss or gain of an actinide-rich phase appears to have been an important Th/U fractionation mechanism, and that volatility differences may be the dominant factor. Th/U and rare earth element abundance patterns for the spinel and perovskite rim suggest rim formation by volatilization of interior material, and within the constraints of the brief time scale required for this heating, several mechanisms for spinel-perovskite rim formation are possible.

  14. Prompt Fission Neutron Spectra of Actinides

    SciTech Connect

    Capote, R; Chen, Y J; Hambsch, F J; Kornilov, N V; Lestone, J P; Litaize, O; Morillon, B; Neudecker, D; Oberstedt, S; Ohsawa, T; Smith, D. L.

    2016-01-01

    The energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) “Evaluation of Prompt Fission Neutron Spectra of Actinides”was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei. The following technical areas were addressed: (i) experiments and uncertainty quantification (UQ): New data for neutron-induced fission of 233U, 235U, 238U, and 239Pu have been measured, and older data have been compiled and reassessed. There is evidence from the experimental work of this CRP that a very small percentage of neutrons emitted in fission are actually scission neutrons; (ii) modeling: The Los Alamos model (LAM) continues to be the workhorse for PFNS evaluations. Monte Carlo models have been developed that describe the fission phenomena microscopically, but further development is needed to produce PFNS evaluations meeting the uncertainty targets; (iii) evaluation methodologies: PFNS evaluations rely on the use of the least-squares techniques for merging experimental and model data. Considerable insight was achieved on how to deal with the problem of too small uncertainties in PFNS evaluations. The importance of considering that all experimental PFNS data are “shape” data was stressed; (iv) PFNS evaluations: New evaluations, including covariance data, were generated for major actinides including 1) non-model GMA evaluations of the 235U(nth,f), 239Pu(nth,f), and 233U(nth,f) PFNS based exclusively on experimental data (0.02 ≤ E ≤ 10 MeV), which resulted in PFNS average energies E of 2.00±0.01, 2.073±0.010, and 2.030±0.013 MeV, respectively; 2) LAM evaluations of neutron-induced fission spectra on uranium and plutonium targets with improved UQ for incident energies from thermal up to 30 MeV; and 3) Point-by-Point calculations for 232Th, 234U and 237Np targets; and (v) data

  15. In pursuit of homoleptic actinide alkyl complexes.

    PubMed

    Seaman, Lani A; Walensky, Justin R; Wu, Guang; Hayton, Trevor W

    2013-04-01

    This Forum Article describes the pursuit of isolable homoleptic actinide alkyl complexes, starting with the pioneering work of Gilman during the Manhattan project. The initial reports in this area suggested that homoleptic uranium alkyls were too unstable to be isolated, but Wilkinson demonstrated that tractable uranium alkyls could be generated by purposeful "ate" complex formation, which serves to saturate the uranium coordination sphere and provide the complexes with greater kinetic stability. More recently, we reported the solid-state molecular structures of several homoleptic uranium alkyl complexes, including [Li(THF)4][U(CH2(t)Bu)5], [Li(TMEDA)]2[UMe6], [K(THF)]3[K(THF)2][U(CH2Ph)6]2, and [Li(THF)4][U(CH2SiMe3)6], by employing Wilkinson's strategy. Herein, we describe our attempts to extend this chemistry to thorium. The treatment of ThCl4(DME)2 with 5 equiv of LiCH2(t)Bu or LiCH2SiMe3 at -25 °C in THF affords [Th(CH2(t)Bu)5] (1) and [Li(DME)2][Th(CH2SiMe3)5 (2), respectively, in moderate yields. Similarly, the treatment of ThCl4(DME)2 with 6 equiv of K(CH2Ph) produces [K(THF)]2[Th(CH2Ph)6] (3), in good yield. Complexes 1-3 have been fully characterized, while the structures of 1 and 3 were confirmed by X-ray crystallography. Additionally, the electronic properties of 1 and 3 were explored by density functional theory.

  16. Modeling actinide chemistry with ASPEN PLUS

    SciTech Connect

    Grigsby, C.O.

    1995-12-31

    When chemical engineers think of chemical processing, they often do not include the US government or the national laboratories as significant participants. Compared to the scale of chemical processing in the chemical process, petrochemical and pharmaceutical industries, the government contribution to chemical processing is not large. However, for the past fifty years, the US government has been, heavily involved in chemical processing of some very specialized materials, in particular, uranium and plutonium for nuclear weapons. Individuals and corporations have paid taxes that, in part have been used to construct and to maintain a series of very expensive laboratories and production facilities throughout the country. Even ignoring the ongoing R & D costs, the price per pound of enriched uranium or of plutonium exceeds that of platinum by a wide margin. Now, with the end of the cold war, the government is decommissioning large numbers of nuclear weapons and cleaning up the legacy of radioactive wastes generated over the last fifty years. It is likely that the costs associated with the build-down and clean-up of the nuclear weapons complex will exceed the investment of the past fifty years of production. Los Alamos National Laboratory occupies a special place in the history of nuclear weapons. The first weapons were designed and assembled at Los Alamos using uranium produced in Oak Ridge, Tennessee or plutonium produced in Richland, Washington. Many of the thermophysical and metallurgical properties of actinide elements have been investigated at Los Alamos. The only plutonium processing facility currently operating in the US is in Los Alamos, and the Laboratory is striving to capture and maintain the uranium processing technology applicable to the post-cold war era. Laboratory researchers are actively involved in developing methods for cleaning up the wastes associated with production of nuclear weapons throughout the US.

  17. Actinide consumption: Nuclear resource conservation without breeding

    SciTech Connect

    Hannum, W.H.; Battles, J.E.; Johnson, T.R.; McPheeters, C.C.

    1991-01-01

    A new approach to the nuclear power issue based on a metallic fast reactor fuel and pyrometallurgical processing of spent fuel is showing great potential and is approaching a critical demonstration phase. If successful, this approach will complement and validate the LWR reactor systems and the attendant infrastructure (including repository development) and will alleviate the dominant concerns over the acceptability of nuclear power. The Integral Fast Reactor (IFR) concept is a metal-fueled, sodium-cooled pool-type fast reactor supported by a pyrometallurgical reprocessing system. The concept of a sodium cooled fast reactor is broadly demonstrated by the EBR-II and FFTF in the US; DFR and PFR in the UK; Phenix and SuperPhenix in France; BOR-60, BN-350, BN-600 in the USSR; and JOYO in Japan. The metallic fuel is an evolution from early EBR-II fuels. This fuel, a ternary U-Pu-Zr alloy, has been demonstrated to be highly reliable and fault tolerant even at very high burnup (160-180,000 MWd/MT). The fuel, coupled with the pool type reactor configuration, has been shown to have outstanding safety characteristics: even with all active safety systems disabled, such a reactor can survive a loss of coolant flow, a loss of heat sink, or other major accidents. Design studies based on a small modular approach show not only its impressive safety characteristics, but are projected to be economically competitive. The program to explore the feasibility of actinide recovery from spent LWR fuel is in its initial phase, but it is expected that technical feasibility could be demonstrated by about 1995; DOE has not yet committed funds to achieve this objective. 27 refs.

  18. Measurement of Actinides in Molybdenum-99 Solution Analytical Procedure

    SciTech Connect

    Soderquist, Chuck Z.; Weaver, Jamie L.

    2015-11-01

    This document is a companion report to a previous report, PNNL 24519, Measurement of Actinides in Molybdenum-99 Solution, A Brief Review of the Literature, August 2015. In this companion report, we report a fast, accurate, newly developed analytical method for measurement of trace alpha-emitting actinide elements in commercial high-activity molybdenum-99 solution. Molybdenum-99 is widely used to produce 99mTc for medical imaging. Because it is used as a radiopharmaceutical, its purity must be proven to be extremely high, particularly for the alpha emitting actinides. The sample of 99Mo solution is measured into a vessel (such as a polyethylene centrifuge tube) and acidified with dilute nitric acid. A gadolinium carrier is added (50 µg). Tracers and spikes are added as necessary. Then the solution is made strongly basic with ammonium hydroxide, which causes the gadolinium carrier to precipitate as hydrous Gd(OH)3. The precipitate of Gd(OH)3 carries all of the actinide elements. The suspension of gadolinium hydroxide is then passed through a membrane filter to make a counting mount suitable for direct alpha spectrometry. The high-activity 99Mo and 99mTc pass through the membrane filter and are separated from the alpha emitters. The gadolinium hydroxide, carrying any trace actinide elements that might be present in the sample, forms a thin, uniform cake on the surface of the membrane filter. The filter cake is first washed with dilute ammonium hydroxide to push the last traces of molybdate through, then with water. The filter is then mounted on a stainless steel counting disk. Finally, the alpha emitting actinide elements are measured by alpha spectrometry.

  19. Selection of actinide chemical analogues for WIPP tests

    SciTech Connect

    Villarreal, R.; Spall, D.

    1995-07-05

    The Department of Energy must demonstrate the effectiveness of the Waste Isolation Pilot Plant (WIPP) as a permanent repository for the disposal of transuranic (TRU) waste. Performance assessments of the WIPP require that estimates of the transportability and outcome of the radionuclides (actinides) be determined from disposal rooms that may become either partially or completely filled with brine. Federal regulations limit the amount of radioactivity that may be unintentionally released to the accessible environment by any mechanism during the post closure phase up to 10,000 years. Thermodynamic models have been developed to predict the concentrations of actinides in the WIPP disposal rooms under various situations and chemical conditions. These models are based on empirical and theoretical projections of the chemistry that might be present in and around the disposal room zone for both near and long-term periods. The actinides that are known to be present in the TRU wastes (and are included in the model) are Th, U, Np, Pu, and Am. Knowledge of the chemistry that might occur in the disposal rooms when the waste comes in contact with brine is important in understanding the range of oxidation states that might be present under different conditions. There is a need to establish the mechanisms and resultant rate of transport, migration, or effective retardation of actinides beyond the disposal rooms to the boundary of the accessible environment. The influence of the bulk salt rock, clay sediments and other geologic matrices on the transport behavior of actinides must be determined to establish the overall performance and capability of the WIPP in isolating waste from the environment. Tests to determine the capabilities of the WIPP geologic formations in retarding actinide species in several projected oxidation states would provide a means to demonstrate the effectiveness of the WIPP in retaining TRU wastes.

  20. Actinide and metal toxicity to prospective bioremediation bacteria.

    PubMed

    Ruggiero, Christy E; Boukhalfa, Hakim; Forsythe, Jennifer H; Lack, Joseph G; Hersman, Larry E; Neu, Mary P

    2005-01-01

    Bacteria may be beneficial for alleviating actinide contaminant migration through processes such as bioaccumulation or metal reduction. However, sites with radioactive contamination often contain multiple additional contaminants, including metals and organic chelators. Bacteria-based bioremediation requires that the microorganism functions in the presence of the target contaminant, as well as other contaminants. Here, we evaluate the toxicity of actinides, metals and chelators to two different bacteria proposed for use in radionuclide bioremediation, Deinococcus radiodurans and Pseudomonas putida, and the toxicity of Pu(VI) to Shewanella putrefaciens. Growth of D. radiodurans was inhibited at metal concentrations ranging from 1.8 microM Cd(II) to 32 mM Fe(III). Growth of P. putida was inhibited at metal concentrations ranging from 50 microM Ni(II) to 240 mM Fe(III). Actinides inhibited growth at mM concentrations: chelated Pu(IV), U(VI) and Np(V) inhibit D. radiodurans growth at 5.2, 2.5 and 2.1 mM respectively. Chelated U(VI) inhibits P. putida growth at 1.7 mM, while 3.6 mM chelated Pu(IV) inhibits growth only slightly. Pu(VI) inhibits S. putrefaciens growth at 6 mM. These results indicate that actinide toxicity is primarily chemical (not radiological), and that radiation resistance does not ensure radionuclide tolerance. This study also shows that Pu is less toxic than U and that actinides are less toxic than other types of metals, which suggests that actinide toxicity will not impede bioremediation using naturally occurring bacteria.

  1. Magnetic exchange coupling in actinide-containing molecules.

    PubMed

    Rinehart, Jeffrey D; Harris, T David; Kozimor, Stosh A; Bartlett, Bart M; Long, Jeffrey R

    2009-04-20

    Recent progress in the assembly of actinide-containing coordination clusters has generated systems in which the first glimpses of magnetic exchange coupling can be recognized. Such systems are of interest owing to the prospects for involving 5f electrons in stronger magnetic exchange than has been observed for electrons in the more contracted 4f orbitals of the lanthanide elements. Here, we survey the actinide-containing molecules thought to exhibit magnetic exchange interactions, including multiuranium, uranium-lanthanide, uranium-transition metal, and uranium-radical species. Interpretation of the magnetic susceptibility data for compounds of this type is complicated by the combination of spin-orbit coupling and ligand-field effects arising for actinide ions. Nevertheless, for systems where analogues featuring diamagnetic replacement components for the non-actinide spin centers can be synthesized, a data subtraction approach can be utilized to probe the presence of exchange coupling. In addition, methods have been developed for employing the resulting data to estimate lower and upper bounds for the exchange constant. Emphasis is placed on evaluation of the linear clusters (cyclam)M[(mu-Cl)U(Me(2)Pz)(4)](2) (M = Co, Ni, Cu, Zn; cyclam = 1,4,8,11-tetraazacyclotetradecane; Me(2)Pz(-) = 3,5-dimethylpyrazolate), for which strong ferromagnetic exchange with 15 cm(-1) < or = J < or = 48 cm(-1) is observed for the Co(II)-containing species. Owing to the modular synthetic approach employed, this system in particular offers numerous opportunities for adjusting the strength of the magnetic exchange coupling and the total number of unpaired electrons. To this end, the prospects of such modularity are discussed through the lens of several new related clusters. Ultimately, it is hoped that this research will be of utility in the development of electronic structure models that successfully describe the magnetic behavior of actinide compounds and will perhaps even lead to new

  2. Bonding in tris(. eta. sup 5 -cyclopentadienyl) actinide complexes. 5. A comparison of the bonding in Np, Pu, and transplutonium compounds with that in lanthanide compounds and a transition-metal analogue

    SciTech Connect

    Strittmatter, R.J.; Bursten, B.E. )

    1991-01-16

    Cp{sub 3}An (An = U, Np, Pu, Am, Cm, Bk, Cf) compounds have been investigated via X{alpha}-SW molecular orbital calculations with quasi-relativistic corrections. The 5f-orbital energy drops across the series while the 6d-orbital energy rises. Due to the greater radial extension of the 6d orbitals, the metal 6d orbitals are more important in bonding the Cp ligands than the 5f orbitals. Comparison of the actinide compounds with the lanthanide series reveals some minor differences. The 4f orbitals and 6s orbital of the lanthanides are not as effective at bonding the Cp ligands as the 5f orbitals and 7s orbital of the actinides. Also, the semicore 5p orbitals of the lanthanides have a greater antibonding influence on the Cp ligands than do the 6p orbitals of the actinides. Comparison of the actinide compounds with ({eta}{sup 5}-Cp){sub 3}Zr shows some major differences. The 4d orbitals of zirconium are much more effective at bonding the Cp ligands than the 6d orbitals of the actinides.

  3. Drug Disposition in Pathophysiological Conditions

    PubMed Central

    Gandhi, Adarsh; Moorthy, Bhagavatula; Ghose, Romi

    2014-01-01

    Expression and activity of several key drug metabolizing enzymes (DMEs) and transporters are altered in various pathophysiological conditions, leading to altered drug metabolism and disposition. This can have profound impact on the pharmacotherapy of widely used clinically relevant medications in terms of safety and efficacy by causing inter-individual variabilities in drug responses. This review article highlights altered drug disposition in inflammation and infectious diseases, and commonly encountered disorders such as cancer, obesity/diabetes, fatty liver diseases, cardiovascular diseases and rheumatoid arthritis. Many of the clinically relevant drugs have a narrow therapeutic index. Thus any changes in the disposition of these drugs may lead to reduced efficacy and increased toxicity. The implications of changes in DMEs and transporters on the pharmacokinetics/pharmacodynamics of clinically-relevant medications are also discussed. Inflammation-mediated release of pro-inflammatory cytokines and activation of toll-like receptors (TLRs) are known to play a major role in down-regulation of DMEs and transporters. Although the mechanism by which this occurs is unclear, several studies have shown that inflammation-associated cell-signaling pathway and its interaction with basal transcription factors and nuclear receptors in regulation of DMEs and transporters play a significant role in altered drug metabolism. Altered regulation of DMEs and transporters in a multitude of disease states will contribute towards future development of powerful in vitro and in vivo tools in predicting the drug response and opt for better drug design and development. The goal is to facilitate a better understanding of the mechanistic details underlying the regulation of DMEs and transporters in pathophysiological conditions. PMID:22746301

  4. Physics studies of higher actinide consumption in an LMR

    SciTech Connect

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

    1990-01-01

    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.

  5. Thermally unstable complexants/phosphate mineralization of actinides

    SciTech Connect

    Nash, K.

    1996-10-01

    In situ immobilization is an approach to isolation of radionuclides from the hydrosphere that is receiving increasing attention. Rather than removing the actinides from contaminated soils, this approach transforms the actinides into intrinsically insoluble mineral phases resistant to leaching by groundwater. The principal advangates of this concept are the low cost and low risk of operator exposure and/or dispersion of the radionuclides to the wider environment. The challenge of this approach is toe accomplish the immobilization without causing collateral damage to the environment (the cure shouldn`t be worse than the disease) and verification of system performance.

  6. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    DOEpatents

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  7. The US/UK Actinides Experiment at the Dounreay PFR

    SciTech Connect

    Raman, S., Walker, R.L., Dickens, J.K., Murphy, B.D.

    1997-01-01

    The United States and the United Kingdom have been engaged in a joint research program in which samples of higher actinides were irradiated in the 600-MW Dounreay Prototype Fast Reactor in Scotland. Analytical results using mass spectrometry and radiometry for actinides and fission products are now available for the samples in Fuel Pins 1 and 2, which were irradiated for 63 full-power days, and for the samples in Fuel Pin 4, which were irradiated for 492 full-power days. Results from these three fuel pins are providing estimates of integral cross sections and fission yields.

  8. Method for extracting lanthanides and actinides from acid solutions

    DOEpatents

    Horwitz, E. Philip; Kalina, Dale G.; Kaplan, Louis; Mason, George W.

    1985-01-01

    A process for the recovery of actinide and lanthanide values from aqueous acidic solutions with an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms. 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.

  9. Analogue Study of Actinide Transport at Sites in Russia

    SciTech Connect

    Novikov, A P; Simmons, A M; Halsey, W G

    2003-02-12

    The U. S. Department of Energy (DOE) and the Russian Academy of Sciences (RAS) are engaged in a three-year cooperative study to observe the behavior of actinides in the natural environment at selected disposal sites and/or contamination sites in Russia. The purpose is to develop experimental data and models for actinide speciation, mobilization and transport processes in support of geologic repository design, safety and performance analyses. Currently at the mid-point of the study, the accomplishments to date include: evaluation of existing data and data needs, site screening and selection, initial data acquisition, and development of preliminary conceptual models.

  10. Actinide geochemistry: from the molecular level to the real system.

    PubMed

    Geckeis, Horst; Rabung, Thomas

    2008-12-12

    Geochemical processes leading to either mobilization or retention of radionuclides in an aquifer system are significantly influenced by their interaction with rock, sediment and colloid surfaces. Therefore, a sound safety assessment of nuclear waste disposal requires the elucidation and quantification of those processes. State-of-the-art analytical techniques as e.g. laser- and X-ray spectroscopy are increasingly applied to study solid-liquid interface reactions to obtain molecular level speciation insight. We have studied the sorption of trivalent lanthanides and actinides onto aluminium oxides, hydroxides and purified clay minerals by the time-resolved laser fluorescence spectroscopy and X-ray-absorption spectroscopy. Chemical constitution and structure of surface bound actinides are proposed based on spectroscopic information. Open questions still remain with regard to the exact nature of mineral surface ligands and the mineral/water interface. Similarities of spectroscopic data obtained for M(III) sorbed onto gamma-alumina, and clay minerals suggest the formation of very comparable inner-sphere surface complexes such as S-O-An(III)(OH)x(2-x)(H2O)5-x at pH > 5. Those speciation data are found consistent with those predicted by surface complexation modelling. The applicability of data obtained for pure mineral phases to actinide sorption onto heterogeneously composed natural clay rock is examined by experiments and by geochemical modelling. Good agreement of experiment and model calculations is found for U(VI) and trivalent actinide/lanthanide sorption to natural clay rock. The agreement of spectroscopy, geochemical modelling and batch experiments with natural rock samples and purified minerals increases the reliability in model predictions. The assessment of colloid borne actinide migration observed in various laboratory and field studies calls for detailed information on actinide-colloid interaction. Kinetic stabilization of colloid bound actinides can be due

  11. New cubic structure compounds as actinide host phases

    NASA Astrophysics Data System (ADS)

    Stefanovsky, S. V.; Yudintsev, S. V.; Livshits, T. S.

    2010-03-01

    Various compounds with fluorite (cubic zirconia) and fluorite-derived (pyrochlore, zirconolite) structures are considered as promising actinide host phases at immobilization of actinide-bearing nuclear wastes. Recently some new cubic compounds — stannate and stannate-zirconate pyrochlores, murataite and related phases, and actinide-bearing garnet structure compounds were proposed as perspective matrices for complex actinide wastes. Zirconate pyrochlore (ideally Gd2Zr2O7) has excellent radiation resistance and high chemical durability but requires high temperatures (at least 1500 °C) to be produced by hot-pressing from sol-gel derived precursor. Partial Sn4+ substitution for Zr4+ reduces production temperature and the compounds REE2ZrSnO7 may be hot-pressed or cold pressed and sintered at ~1400 °C. Pyrochlore, A2B2O7-x (two-fold elementary fluorite unit cell), and murataite, A3B6C2O20-y (three-fold fluorite unit cell), are end-members of the polysomatic series consisting of the phases whose structures are built from alternating pyrochlore and murataite blocks (nano-sized modules) with seven- (2C/3C/2C), five- (2C/3C), eight- (3C/2C/3C) and three-fold (3C — murataite) fluorite unit cells. Actinide content in this series reduces in the row: 2C (pyrochlore) > 7C > 5C > 8C > 3C (murataite). Due to congruent melting murataite-based ceramics may be produced by melting and the firstly segregated phase at melt crystallization is that with the highest fraction of the pyrochlore modules in its structure. The melts containing up to 10 wt. % AnO2 (An = Th, U, Np, Pu) or REE/An fraction of HLW form at crystallization zoned grains composed sequentially of the 5C → 8C → 3C phases with the highest actinide concentration in the core and the lowest — in the rim of the grains. Radiation resistance of the "murataite" is comparable to titanate pyrochlores. One more promising actinide hosts are ferrites with garnet structure. The matrices containing sometime complex fluorite

  12. INERT-MATRIX FUEL: ACTINIDE ''BURINGIN'' AND DIRECT DISPOSAL

    SciTech Connect

    Rodney C. Ewing; Lumin Wang

    2002-10-30

    Excess actinides result from the dismantlement of nuclear weapons (Pu) and the reprocessing of commercial spent nuclear fuel (mainly 241 Am, 244 Cm and 237 Np). In Europe, Canada and Japan studies have determined much improved efficiencies for burnup of actinides using inert-matrix fuels. This innovative approach also considers the properties of the inert-matrix fuel as a nuclear waste form for direct disposal after one-cycle of burn-up. Direct disposal can considerably reduce cost, processing requirements, and radiation exposure to workers.

  13. Thermodynamic constants for actinide oxides and oxyhydroxides relevant to actinide volatility calculations for thermal oxidation processes

    SciTech Connect

    Ebbinghaus, B.B.; Krikorian, O.H.

    1993-10-27

    The purpose of this report is to provide input of thermodynamic data on actinide volatilities to EERC for use in their computer code for modeling of metal volatilities in incinerators. It is also anticipated that the data may be documented later in an EPA sponsored ``Metals Bible.`` It should be noted that only upper limits for the volatility of PuO{sub 2}(s) due to PuO{sub 3}(g) and PuO{sub 2}(OH){sub 2}(g) and the volatility of AmO{sub 2} in PuO{sub 2}(s) due to AmO{sub 3}(g) and AmO{sub 2}(OH){sub 2}(g) could be set. The data on the americium vapor species are intended for calculations where AmO{sub 2} is present as a solid solution in PuO{sub 2}(s).

  14. Overview of surplus weapons plutonium disposition

    SciTech Connect

    Rudy, G.

    1996-05-01

    The safe disposition of surplus weapons useable plutonium is a very important and urgent task. While the functions of long term storage and disposition directly relate to the Department`s weapons program and the environmental management program, the focus of this effort is particularly national security and nonproliferation.

  15. Knowledge, Skills, and Dispositions for Diversity

    ERIC Educational Resources Information Center

    Jones, Anne

    2011-01-01

    The purposes of this research are to explore how currently assessed diversity knowledge, diversity skills, and diversity dispositions of pre-service teachers (PST) relate to each other and further to surmise if the presence of diversity knowledge, diversity skills, and diversity dispositions manifests in cultural efficacy and a general cultural…

  16. Culturally Responsive Dispositions in Prospective Mathematics Teachers

    ERIC Educational Resources Information Center

    Williams, Desha L.; Edwards, Belinda; Kuhel, Karen A.; Lim, Woong

    2016-01-01

    Sustaining teachers in culturally and linguistically diverse schools has been a prominent issue for years. This qualitative study focused on the impact of an enhanced preparation program on the cultural dispositions of five pre-service mathematics teachers. It is postulated that if positive cultural dispositions are developed in teacher…

  17. 9 CFR 2.80 - Records, disposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Records, disposition. 2.80 Section 2.80 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Records § 2.80 Records, disposition. (a) No dealer, exhibitor, broker...

  18. 9 CFR 2.80 - Records, disposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Records, disposition. 2.80 Section 2.80 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Records § 2.80 Records, disposition. (a) No dealer, exhibitor, broker...

  19. 9 CFR 2.80 - Records, disposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Records, disposition. 2.80 Section 2.80 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Records § 2.80 Records, disposition. (a) No dealer, exhibitor, broker...

  20. 9 CFR 2.80 - Records, disposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Records, disposition. 2.80 Section 2.80 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Records § 2.80 Records, disposition. (a) No dealer, exhibitor, broker...