WorldWideScience

Sample records for heaviest actinide targets

  1. Fusion probability and survivability in estimates of heaviest nuclei production

    International Nuclear Information System (INIS)

    Sagaidak, Roman

    2012-01-01

    . Examples of the P fus values derived with the capture-fission and ER cross-sections obtained recently for asymmetric projectile-target systems are shown. Data on the ER production in different fusion-evaporation reactions leading to the very heavy compound nuclei with ZCN ≥ 100 are considered and discussed in detail. Considering the fusion probability and survivability for the heaviest nuclei with Z > 108, one should bear in mind that the macroscopic component of fission barriers disappears as the shell-stabilized SHE region is approached. Thus the calculated survivability of nuclei produced in the 48 Ca reactions induced on actinide targets depends mainly on the microscopic (shell) corrections to nuclear masses used in calculations

  2. Incineration of actinide targets in a pressurized water reactor spin project

    International Nuclear Information System (INIS)

    Puill, A.; Bergeron, J.

    1993-01-01

    The ability of Pressurized Water Reactors (PWR) with uranium fuel to limit the inventory growth of minor actinides (237 neptunium, and americium) produced by the French nuclear powerplants is studied. Targets containing an actinide oxide mixed to an inert matrix are loaded in some reactors. After being irradiated along with the fuel, the target is specially reprocessed. The remaining actinide and the plutonium which is produced, added to fresh actinide, are recycled in new targets. The radiotoxicity balance, with and without incineration, is examined considering that only the losses coming from the target reprocessing treated as waste. A scenario arbitrarily based on 18 years of operation results in a reduction of the radiotoxicity of the waste by a factor between 10 and 20, depending on the actinide considered. 6 refs., 6 figs., 6 tabs

  3. Chemistry of the heaviest elements

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1996-01-01

    Studies of the chemical properties of the elements at the uppermost end of the periodic table are discussed. Some historical perspective is given, but major emphasis is on recent studies. Isotopes of these elements are short-lived and, therefore, must be studied near the site of production. They must be produced with charged-particle beams at accelerators rather than via neutron capture. The use of radioactive heavy actinide targets is often required and the number of atoms produced is so small that any chemistry to be performed must be done on an ''atom-at-a-time'' basis. Furthermore, a knowledge of their nuclear properties is required in order to identify and detect them. To date, both gas and aqueous phase properties of elements as heavy as element 104 (rutherfordium) and element 105 (hahnium) have been investigated, even though their longest-lived known isotopes have half-lives of only 65 and 35 seconds, respectively. The experimental results show that their chemical properties cannot be simply extrapolated from the known properties of their lighter homologs in the periodic table, emphasizing the importance of obtaining additional experimental information for the heaviest elements to compare with predictions and help assess the influence of relativistic effects. The feasibility of the extension of chemical studies to still heavier elements is also discussed. (orig.)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  5. Development of ion beam sputtering techniques for actinide target preparation

    Science.gov (United States)

    Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

    1985-06-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

  6. Fuels and targets for incineration and transmutation of actinides: the ITU programme

    International Nuclear Information System (INIS)

    Fernandez, A.; Glatz, J.P.; Haas, D.; Konings, R.J.M.; Somers, J.; Toscano, E.; Walker, C.T.; Wegen, D.

    2000-01-01

    The ITU programme for the development of fuels and targets for transmutation of actinides is presented. The fabrication of various types of oxide fuels/targets by dust-free processes is described. Selected results of post-irradiation examinations of irradiation experiments (SUPERFACT, TRABANT-1, EFTTRA-T4) are presented to demonstrate the irradiation behaviour of these fuels/targets. Finally, the future developments at ITU in this field are described, including the new shielded facility (the MA lab) for fabrication of minor actinide fuels. (authors)

  7. Fuels and targets for incineration and transmutation of actinides: the ITU programme

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.; Glatz, J.P.; Haas, D.; Konings, R.J.M.; Somers, J.; Toscano, E.; Walker, C.T.; Wegen, D. [Eurpean Commission, Joint Research Centre, Institute for Transuranium Elements, Kurlsruhe (Germany)

    2000-07-01

    The ITU programme for the development of fuels and targets for transmutation of actinides is presented. The fabrication of various types of oxide fuels/targets by dust-free processes is described. Selected results of post-irradiation examinations of irradiation experiments (SUPERFACT, TRABANT-1, EFTTRA-T4) are presented to demonstrate the irradiation behaviour of these fuels/targets. Finally, the future developments at ITU in this field are described, including the new shielded facility (the MA lab) for fabrication of minor actinide fuels. (authors)

  8. Actinide targets for fundamental research in nuclear physics

    Science.gov (United States)

    Eberhardt, K.; Düllmann, Ch. E.; Haas, R.; Mokry, Ch.; Runke, J.; Thörle-Pospiech, P.; Trautmann, N.

    2018-05-01

    Thin actinide layers deposited on various substrates are widely used as calibration sources in nuclear spectroscopy. Other applications include fundamental research in nuclear chemistry and -physics, e.g., the chemical and physical properties of super-heavy elements (SHE, Z > 103) or nuclear reaction studies with heavy ions. For the design of future nuclear reactors like fast-fission reactors and accelerator-driven systems for transmutation of nuclear waste, precise data for neutron absorption as well as neutron-induced fission cross section data for 242Pu with neutrons of different energies are of particular importance, requiring suitable Pu-targets. Another application includes studies of nuclear transitions in 229Th harvested as α-decay recoil product from a thin layer of its 233U precursor. For this, a thin and very smooth layer of 233U is used. We report here on the production of actinide layers mostly obtained by Molecular Plating (MP). MP is currently the only fabrication method in cases where the desired actinide material is available only in very limited amounts or possesses a high specific activity. Here, deposition is performed from organic solution applying a current density of 1-2 mA/cm2. Under these conditions target thicknesses of 500-1000 μg/cm2 are possible applying a single deposition step with deposition yields approaching 100 %. For yield determination α-particle spectroscopy, γ-spectroscopy and Neutron Activation Analysis is routinely used. Layer homogeneity is checked with Radiographic Imaging. As an alternative technique to MP the production of thin lanthanide and actinide layers by the so-called "Drop on Demand"-technique applied e.g., in ink-jet printing is currently under investigation.

  9. Development of ion beam sputtering techniques for actinide target preparation

    International Nuclear Information System (INIS)

    Aaron, W.S.; Zevenbergen, L.A.; Adair, H.L.

    1985-01-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed. (orig.)

  10. First ionization potential of the heaviest actinide lawrencium, element 103

    Directory of Open Access Journals (Sweden)

    Sato Tetsuya K.

    2016-01-01

    Full Text Available The first ionization potential (IP1 of element 103, lawrencium (Lr, has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP1 value is 4.9630.080.07 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15 eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s25f147p11/2, which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens the way for studies on atomic properties of heavy elements with atomic number Z > 100. Moreover, the present achievement has triggered a controversy on the position of lutetium (Lu and Lr in the Periodic Table of Elements.

  11. Preparation of actinide targets by molecular plating for Coulomb excitation studies at ATLAS

    International Nuclear Information System (INIS)

    Greene, J. P.

    1998-01-01

    Molecular plating is now routinely used to prepare sources and targets of actinide elements. Although the technique is simple and fairly reproducible, because of the radioactive nature of the target it is very useful to record various parameters in the preparation of such targets. At Argonne, ∼200 microg/cm 2 thick targets of Pu and Cm were required for Coulomb Excitation (COULEX) Studies with the Argonne-Notre Dame BGO gamma ray facility and later with the GAMMASPHERE. These targets were plated on 50 mg/cm 2 Au backing and were covered with 150 microg/cm 2 Au foil. Targets of 239 Pu, 240 Pu, 242 Pu, 244 Pu and 248 Cm were prepared by dissolving the material in isopropyl alcohol and electroplating the actinide ions by applying 600 volts. The amount of these materials on the target was determined by alpha particle counting and gamma ray counting. Details of the molecular plating and counting will be discussed

  12. Minor actinides transmutation scenario studies with PWRs, FRs and moderated targets

    International Nuclear Information System (INIS)

    Grouiller, J.P.; Pillon, S.; Saint Jean, C. de; Varaine, F.; Leyval, L.; Vambenepe, G.; Carlier, B.

    2003-01-01

    Using current technologies, we have demonstrated in this study that it is theoretically possible to obtain different minor actinide transmutation scenarios with a significant gain on the waste radiotoxicity inventory. The handling of objects with Am+Cm entails the significant increase of penetrating radiation sources (neutron and γ) whatever mixed scenario is envisioned; the PWR and FR scenario involving the recycling of Am + Cm in the form of targets results in the lowest flow. In the light of these outcomes, the detailed studies has allowed to design a target sub assembly with a high fission rate (90%) and define a drawing up of reprocessing diagram with the plant head, the minor actinide separation processes (PUREX, DIAMEX and SANEX). Some technological difficulties appear in manipulating curium, principally in manufacturing where the wet process ('sol-gel') is not acquired for (Am+Cm). (author)

  13. A new type of active actinide target for studying fission and (n,xn) reactions

    International Nuclear Information System (INIS)

    Belier, G.; Aupiais, J.; Varignon, C.; Vayre, S.

    2011-01-01

    A new type of active target for the detection of fission of actinides has been developed, it is based on α spectrometry through liquid scintillation. The target uses the liquid-liquid extraction in order to mix the actinide with the liquid organic scintillator. The actinide to be detected is inside the detector itself which maximises the efficiency of the detector. The use of an organic scintillator allows the identification of the particles emitted. Indeed, the time delay for the transfer of the energy deposited in the solvent towards the scintillating molecules depends on the type of the energy deposits: instantaneous fluorescence is obtained for direct excitation while delayed fluorescence is obtained for energy deposits through ionization. By discriminating the different slow and quick components of the photomultiplier signal it is then possible to identify the particle: beta, alpha or fission products. This target has been tested with Cf 252 irradiated with 18 MeV neutrons, the experimental data show different peaks corresponding to alpha decay (97%), spontaneous fission (3%), beta decay and recoil protons due to neutron emissions. (A.C.)

  14. Heterogeneous all actinide recycling in LWR all actinide cycle closure concept

    International Nuclear Information System (INIS)

    Tondinelli, Luciano

    1980-01-01

    A project for the elimination of transuranium elements (Waste Actinides, WA) by neutron transmutation is developed in a commercial BWR with U-Pu (Fuel Actinides, FA) recycle. The project is based on the All Actinide Cycle Closure concept: 1) closure of the 'back end' of the fuel cycle, U-Pu coprocessing, 2) waste actinide disposal by neutron transmutation. The reactor core consists of Pu-island fuel assemblies containing WAs in target pins. Two parallel reprocessing lines for FAs and WAs are provided. Mass balance, hazard measure, spontaneous activity during 10 recycles are calculated. Conclusions are: the reduction in All Actinide inventory achieved by Heterogeneous All Actinide Recycling is on the order of 83% after 10 recycles. The U235 enrichment needed for a constant end of cycle reactivity decreases for increasing number of recycles after the 4th recycle. A diffusion-burnup calculation of the pin power peak factors in the fuel assembly shows that design limits can be satisfied. A strong effort should be devoted to the solution of the problems related to high values of spontaneous emission by the target pins

  15. The effect of high pressures on actinide metals

    International Nuclear Information System (INIS)

    Benedict, U.

    1987-01-01

    The solid state properties of the actinides are controlled by the dualism of the localized and itinerant (delocalized) configuration of the 5f electrons. This dualism allows to define two main subgroups. At ambient pressures the first subgroup, of elements with atomic number 91 to 94, is characterized by 5f electrons in an itinerant state and the second subgroup, atomic number 95 to 98, by 5f electrons in a localized state. The latter means that these electrons have well defined energy levels and do not contribute to the metallic bond. The other two subgroups consist of thorium, as a subgroup of its own because its 5f levels are practically unoccupied in the ground state configuration, and of the five heaviest elements with atomic number 99 to 103. The most remarkable effect of pressure on the actinide metals is that due to closer contact between the lattice atoms, localized 5f electrons can become itinerant, hybridise with the conduction electrons and participate in the metallic bond. In this chapter the high-pressure structural behaviour of actinide metals is reviewed. Section 3 gives an introduction into the techniques of generating and measuring pressure and of determining various physical properties of the actinides under pressure and describes a few high-pressure devices and methods. Sections 4 to 7 treat the high-pressure results for each subgroup separately. In section 8 the results of the preceding sections are brought together in a graphical representation which consists of interconnecting binary phase diagrams of neighbouring actinide metals. 155 refs.; 14 figs.; 7 tabs. (H.W.)

  16. Preparation of actinide targets by molecular plating for coulomb excitation studies at ATLAS

    CERN Document Server

    Greene, J P; Ahmad, I

    1999-01-01

    Molecular plating is now routinely used to prepare sources and targets of actinide elements. Although the technique is simple and fairly reproducible, because of the radioactive nature of the targets, it is very useful to record various parameters in the preparation process. At Argonne, approx 200 mu g/cm sup 2 thick targets of Pu and Cm were required for Coulomb Excitation (COULEX) studies with the Argonne-Notre Dame boron germanate (BGO) gamma-ray facility and later with the GAMMASPHERE. These targets were plated on 50 mg/cm sup 2 Au backings and were covered with 150 mu g/cm sup 2 Au foil. Targets of sup 2 sup 3 sup 9 Pu, sup 2 sup 4 sup 0 Pu, sup 2 sup 4 sup 2 Pu, sup 2 sup 4 sup 4 Pu and sup 2 sup 4 sup 8 Cm were prepared by dissolving the material in isopropyl alcohol and electroplating the actinide ions by applying 600 V. The amount of these materials on the target was determined by alpha particle counting and gamma-ray counting. Details of the molecular plating and counting will be discussed.

  17. Thin layers in actinide research

    International Nuclear Information System (INIS)

    Gouder, T.

    1998-01-01

    Surface science research at the ITU is focused on the synthesis and surface spectroscopy studies of thin films of actinides and actinide compounds. The surface spectroscopies used are X-ray and ultra violet photoelectron spectroscopy (XPS and UPS, respectively), and Auger electron spectroscopy (AES). Thin films of actinide elements and compounds are prepared by sputter deposition from elemental targets. Alloy films are deposited from corresponding alloy targets and could be used, in principle, as replicates of these targets. However, there are deviations between alloy film and target composition, which depend on the deposition conditions, such as pressure and target voltage. Mastering of these effects may allow us to study stoichiometric film replicates instead of thick bulk compounds. As an example, we discuss the composition of U-Ni films prepared from a UNi 5 target. (orig.)

  18. Fusion barrier characteristics of actinides

    Science.gov (United States)

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

    2018-03-01

    We have studied fusion barrier characteristics of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations. After the calculation of fusion barrier heights and positions, we have searched for their parameterization. We have achieved the empirical formula for fusion barrier heights (VB), positions (RB), curvature of the inverted parabola (ħω) of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations (6 projectile target combinations. The values produced by the present formula are also compared with experiments. The present pocket formula produces fusion barrier characteristics of actinides with the simple inputs of mass number (A) and atomic number (Z) of projectile-targets.

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

    Science.gov (United States)

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

    2018-02-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    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.

  1. Preparation of minor actinides targets or blankets by the means of Ionic Exchange Resin

    Energy Technology Data Exchange (ETDEWEB)

    Picart, S.; Mokhtari, H.; Ramiere, I.; Jobelin, I. [CEA, Nuclear Energy Division, RadioChemistry and Process Department, Actinides Chemistry Laboratory, BP17171, Bagnols-sur-Ceze, 30207 (France)

    2009-06-15

    The objective of our R and D work is the elaboration by the use of ionic exchange resin of minor actinide precursors for target or blanket dedicated to their transmutation in sodium fast reactor. From the beginning, the resin process called WAR (acronym of Weak Acid Resin) was developed in the 70's at the ORNL for the making of uranium carbide kernels for the high temperature gas reactor [1] [2]. By now, our aim is to extend this concept to the manufacturing of minor actinides oxide mixed with uranium oxides [3]. More precisely, this process can be divided in two major steps: the loading of the resin and the thermal treatment of the fully loaded resin driving either to oxide or carbide phases depending on the gas atmosphere. The difficulty stems from the preparation of the loading solutions which must fulfill precise conditions of pH in presence of actinides cations prone to hydrolysis. Furthermore, the proportions of uranium and minor actinides in solutions must be adjusted to fit the right ratio in the solid. The study presented here will then focus on the experiments and tests which enable us to optimize the fixing of minor actinides on ionic exchange resin and their carbonization in oxide. [1] G. W. Weber, R. L. Beatty et V. J. Tennery, Nuclear Technology, 35, 217-226, (1977), 'Processing and composition control of weak-acid-resin derived fuel microspheres'. [2] K. J. Notz, P. A. Haas, J. H. Shaffer, Radiochimica Acta, 25, 153-160, (1978). 'The preparation of HTGR Fissile Fuel Kernels by Uranium Loading of Ion Exchange Resin'. [3] S. Picart, H. Mokhtari, I. Ramiere, 'Plutonium Futures, The Science 2008', 7-11 july 2008, Dijon, France. 'Modelling of the ionic Exchange between a weak acid resin in its ammonium form and a minor actinide'. (authors)

  2. Minor actinides incineration by loading moderated targets in fast reactor

    International Nuclear Information System (INIS)

    Wu Hongchun; Sato, Daisuke; Takeda, Toshikazu

    2000-01-01

    The effect of hydrogen concentration and loaded mass of minor actinides (MAs) in the target on the core performance and MAs transmutation rate was analyzed in this paper. An optimum core was proposed which has 96 MAs target assemblies of which MAs fuel pins per assembly is 38 with the composition ratio U/MA/Zr/H of 1/4/10/50. This optimized core offers good core performance and can transmute MAs very effectively, the transmutation rate was about 67% (939 kg) and the incinerate (transmute by fission) rate was about 35% (489 kg) through 3 years of reactor operation. It is about 2-3 times larger than current transmutation method that MAs are loaded homogeneously in the PWR and fast reactor core. (author)

  3. Fission properties of the heaviest elements

    International Nuclear Information System (INIS)

    Moller, P.; Nix, R.

    1995-01-01

    The authors discuss fission properties of the heaviest elements. In particular they focus on stability with respect to spontaneous fission and on the prospects of extending the region of known nuclei beyond the peninsula of currently known nuclides

  4. Target fuels for plutonium and minor actinide transmutation in pressurized water reactors

    International Nuclear Information System (INIS)

    Washington, J.; King, J.; Shayer, Z.

    2017-01-01

    Highlights: • We evaluate transmutation fuels for plutonium and minor actinide destruction in LWRs. • We model a modified AP1000 fuel assembly in SCALE6.1. • We evaluate spectral shift absorber coatings to improve transmutation performance. - Abstract: 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 nearer-term solution. This study considers a method for plutonium and minor actinide transmutation in existing light water reactors and evaluates a variety of transmutation fuels to provide a common basis for comparison and to determine if any single target fuel provides superior transmutation properties. A model developed using the NEWT module in the SCALE 6.1 code package provided performance data for the burnup of the target fuel rods in the present study. The target fuels (MOX, PuO_2, Pu_3Si_2, PuN, PuUZrH, PuZrH, PuZrHTh, and PuZrO_2) are evaluated over a 1400 Effective Full Power Days (EFPD) interval to ensure each assembly remained critical over the entire burnup period. The MOX (5 wt% PuO_2), Pu_0_._3_1ZrH_1_._6Th_1_._0_8, and PuZrO_2MgO (8 wt% Pu) fuels result in the highest rate of plutonium transmutation with the lowest rate of curium-244 production. This study selected eleven different burnable absorbers (B_4C, CdO, Dy_2O_3, Er_2O_3, Eu_2O_3, Gd_2O_3, HfO_2, In_2O_3, Lu_2O_3, Sm_2O_3, and TaC) for evaluation as spectral shift absorber coatings on the outside of the fuel pellets to determine if an absorber coating can improve the transmutation properties of the target fuels. The PuZrO_2MgO (8 wt% Pu) target fuel with a coating of Lu_2O_3 resulted in the highest rate of plutonium transmutation with the greatest reduction in curium

  5. Target fuels for plutonium and minor actinide transmutation in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Washington, J., E-mail: jwashing@gmail.com [Nuclear Science and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); King, J., E-mail: kingjc@mines.edu [Nuclear Science and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Shayer, Z., E-mail: zshayer@mines.edu [Department of Physics, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States)

    2017-03-15

    Highlights: • We evaluate transmutation fuels for plutonium and minor actinide destruction in LWRs. • We model a modified AP1000 fuel assembly in SCALE6.1. • We evaluate spectral shift absorber coatings to improve transmutation performance. - Abstract: 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 nearer-term solution. This study considers a method for plutonium and minor actinide transmutation in existing light water reactors and evaluates a variety of transmutation fuels to provide a common basis for comparison and to determine if any single target fuel provides superior transmutation properties. A model developed using the NEWT module in the SCALE 6.1 code package provided performance data for the burnup of the target fuel rods in the present study. The target fuels (MOX, PuO{sub 2}, Pu{sub 3}Si{sub 2}, PuN, PuUZrH, PuZrH, PuZrHTh, and PuZrO{sub 2}) are evaluated over a 1400 Effective Full Power Days (EFPD) interval to ensure each assembly remained critical over the entire burnup period. The MOX (5 wt% PuO{sub 2}), Pu{sub 0.31}ZrH{sub 1.6}Th{sub 1.08}, and PuZrO{sub 2}MgO (8 wt% Pu) fuels result in the highest rate of plutonium transmutation with the lowest rate of curium-244 production. This study selected eleven different burnable absorbers (B{sub 4}C, CdO, Dy{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Eu{sub 2}O{sub 3}, Gd{sub 2}O{sub 3}, HfO{sub 2}, In{sub 2}O{sub 3}, Lu{sub 2}O{sub 3}, Sm{sub 2}O{sub 3}, and TaC) for evaluation as spectral shift absorber coatings on the outside of the fuel pellets to determine if an absorber coating can improve the transmutation properties of the target fuels. The PuZrO{sub 2}MgO (8 wt% Pu) target

  6. Darmstadt: Heaviest of them all (so far)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The heaviest nuclei yet, with atomic numbers of 111 and 110, have been synthesized at the GSI (Gesellschaft fur Schwerionenforschung) heavy ion Laboratory, Darmstadt. The breakthrough was made by an international group (GSI/Dubna/ Bratislava/Jyvaeskylae) including Peter Armbruster and Sigurd Hofmann using the SHIP separator for heavy reaction products. This group has already discovered the elements 107, 108 and 109 at GSI. The element 110 experiment initially fused nickel 62 ions accelerated in the GSI UNILAC on a lead 208 target. The resulting nuclei were sorted by SHIP'S velocity filter and an alpha-decay chain could be unambiguously assigned to 269/110. In the Periodic Table, this new nucleus is a heavier cousin of nickel, palladium and platinum. Subsequently, irradiation of bismuth 209 with nickel 64 produced 272/111, exactly on the 25th anniversary of GSI's founding on 17 December 1969.

  7. Characterization and development of an active scintillating target for nuclear reaction studies on actinides

    Energy Technology Data Exchange (ETDEWEB)

    Belier, Gilbert, E-mail: gilbert.belier@cea.fr [CEA, DAM, DIF, DPTA, Centre du Grand Rue, 91297 Arpajon (France); Aupiais, Jean; Varignon, Cyril; Vayre, Sylvain [CEA, DAM, DIF, DPTA, Centre du Grand Rue, 91297 Arpajon (France)

    2012-02-01

    This article presents the development of a new kind of active actinide target, based on organic liquid scintillators containing the dissolved isotope. Amongst many advantages one can mention the very high detection efficiency, the Pulse Shape Discrimination capability, the fast response allowing high count rates and good time resolution and the ease of fabrication. The response of this target to fission fragments has been studied. The discrimination of alpha, fission and proton recoil events is demonstrated. The alpha decay and fission detection efficiencies are simulated and compared to measurements. Finally the use of such a target in the context of fast neutron induced reactions is discussed.

  8. Characterization and development of an active scintillating target for nuclear reaction studies on actinides

    International Nuclear Information System (INIS)

    Belier, Gilbert; Aupiais, Jean; Varignon, Cyril; Vayre, Sylvain

    2012-01-01

    This article presents the development of a new kind of active actinide target, based on organic liquid scintillators containing the dissolved isotope. Amongst many advantages one can mention the very high detection efficiency, the Pulse Shape Discrimination capability, the fast response allowing high count rates and good time resolution and the ease of fabrication. The response of this target to fission fragments has been studied. The discrimination of alpha, fission and proton recoil events is demonstrated. The alpha decay and fission detection efficiencies are simulated and compared to measurements. Finally the use of such a target in the context of fast neutron induced reactions is discussed.

  9. Transmutation of waste actinides in thermal reactors: survey calculations of candidate irradiation schemes

    International Nuclear Information System (INIS)

    Gorrell, T.C.

    1978-11-01

    Actinide recycle and transmutation calculations were made for twelve specific thermal reactor environments. The calculations included H 2 O-moderated reactor lattices with enriched U, recycled Pu, and 233 ' 235 U-Th. In addition two D 2 O reactor cases were calculated. When all actinides were recycled into 235 U-enriched fuel, about 10 percent of the transuranic actinides were fissioned per 3-year fuel cycle. About 9 percent of the actinides were fissioned per 3-year fuel cycle when waste actinides (no U or Pu) were irradiated in separate target rods in a U-fuel assembly. When actinides were recycled in separate target assemblies, the fission rate was strongly dependent on the specific loading of the target. Fission rates of 5 to 10 percent per 3-year fuel cycle were observed

  10. An optimization methodology for heterogeneous minor actinides transmutation

    Science.gov (United States)

    Kooyman, Timothée; Buiron, Laurent; Rimpault, Gérald

    2018-04-01

    In the case of a closed fuel cycle, minor actinides transmutation can lead to a strong reduction in spent fuel radiotoxicity and decay heat. In the heterogeneous approach, minor actinides are loaded in dedicated targets located at the core periphery so that long-lived minor actinides undergo fission and are turned in shorter-lived fission products. However, such targets require a specific design process due to high helium production in the fuel, high flux gradient at the core periphery and low power production. Additionally, the targets are generally manufactured with a high content in minor actinides in order to compensate for the low flux level at the core periphery. This leads to negative impacts on the fuel cycle in terms of neutron source and decay heat of the irradiated targets, which penalize their handling and reprocessing. In this paper, a simplified methodology for the design of targets is coupled with a method for the optimization of transmutation which takes into account both transmutation performances and fuel cycle impacts. The uncertainties and performances of this methodology are evaluated and shown to be sufficient to carry out scoping studies. An illustration is then made by considering the use of moderating material in the targets, which has a positive impact on the minor actinides consumption but a negative impact both on fuel cycle constraints (higher decay heat and neutron) and on assembly design (higher helium production and lower fuel volume fraction). It is shown that the use of moderating material is an optimal solution of the transmutation problem with regards to consumption and fuel cycle impacts, even when taking geometrical design considerations into account.

  11. Facilities for preparing actinide or fission product-based targets

    CERN Document Server

    Sors, M

    1999-01-01

    Research and development work is currently in progress in France on the feasibility of transmutation of very long-lived radionuclides such as americium, blended with an inert medium such as magnesium oxide and pelletized for irradiation in a fast neutron reactor. The process is primarily designed to produce ceramics for nuclear reactors, but could also be used to produce targets for accelerators. The Actinide Development Laboratory is part of the ATALANTE complex at Marcoule, where the CEA investigates reprocessing, liquid and solid waste treatment and vitrification processes. The laboratory produces radioactive sources; after use, their constituents are recycled, notably through R and D programs requiring such materials. Recovered americium is purified, characterized and transformed for an experiment known as ECRIX, designed to demonstrate the feasibility of fabricating americium-based ceramics and to determine the reactor transmutation coefficients.

  12. Reactor physics aspects of burning actinides in a nuclear reactor

    International Nuclear Information System (INIS)

    Hage, W.; Schmidt, E.

    1978-01-01

    A short review of the different recycling strategies of actinides other than fuel treated in the literature, is given along with nuclear data requirements for actinide build-up and transmutation studies. The effects of recycling actinides in a nuclear reactor on the flux distribution, the infinite neutron multiplication factor, the reactivity control system, the reactivity coefficients and the delayed neutron fraction are discussed considering a notional LWR or LMFBR as an Actinide Trasmutaton Reactor. Some operational problems of Actinide Transmutation reactors are mentioned, which are caused by the α-decay heat and the neutron sources of Actinide Target Elements

  13. A conceptual study of actinide transmutation system with proton accelerator, (2)

    International Nuclear Information System (INIS)

    Takizuka, T.; Takada, H.; Kanno, I.; Ogawa, T.; Nishida, T.; Kaneko, Y.

    1990-01-01

    This paper describes the thermal hydraulics of the accelerator-driven actinide incineration target system based on power distribution profiles to assess the maximum attainable power. In the case of Na cooling, the reference target operates at a thermal power of 404 MW and a beam current of 18.2 mA. The system transmutes 114 kg actinides per year, which implies that the annual actinide products from about 4.3 units of 3000 MWt pressurized water reactor (PWR) can be incinerated. The Pb-Bi cooled reference target operates at a thermal power of 163 MW and beam current of 5.4 mA. The system transmutes 42 kg actinides annually, and can serve about 1.8 units of PWR. The maximum thermal power can be increased by a factor of about 2 by introducing tungsten pins in the high flux region to flatten the power distribution. The Na cooled tungsten-loaded target operates at a thermal power of 691 MW and beam current of 22.6 mA. The system can serve about 7.6 PWRs. The tungsten-loaded target cooled by Pb-Bi operates at a thermal power of 343 MW at a 9.8 mA beam current. The system can process the actinide from about 3.8 PWRs. (N.K.)

  14. Feasibility studies of actinide recycle in LMFBRs as a waste management alternative

    International Nuclear Information System (INIS)

    Beaman, S.L.; Aitken, E.A.

    1976-01-01

    Actinide recycle in LMFBRs offers an attractive alternative on long-term storage of the actinides. The concept will not significantly affect the performance of the LMFBR, but will affect other parts of the nuclear fuel cycle. Assuming that hands-on maintenance will be allowed for Pu-recycle fuel fabrication facilities, the transplutonium actinides should be kept separate from the PuO 2 --UO 2 fuel. Thus, the ''reference'' recycle scheme should be defined as a scheme in which the actinides are recycled in target assemblies. The target assemblies should be reprocessed either in batches separate from spent-fuel batches or in a separate, relatively small, special purpose reprocessing plant. The target assemblies should be fabricated in a special purpose, remotely maintained facility

  15. Development of a plutonium ceramic target for the MASHA separator

    Energy Technology Data Exchange (ETDEWEB)

    Shaughnessy, D.A.; Moody, K.J.; Kenneally, J.M.; Wild, J.F.; Stoyer, M.A.; Lougheed, R.W.; Yeremin, A.V.; Oganessian, Yu.Ts

    2004-04-05

    We are participating in the development of the target for the MASHA (Mass Analyzer of Super Heavy Atoms) on-line mass separator in Dubna. Along with recent upgrades of the U400 cyclotron, MASHA will provide for at least a ten-fold increase in the production- and-detection rate for element 114 atoms, and will allow us to measure their atomic masses precisely. The MASHA separator will employ a thick Pu ceramic target capable of tolerating temperatures in the vicinity of 2000 C without vaporizing the actinide compound. Reaction products will diffuse out of the target and will drift to an ECR ion source after which they will be transported through the separator and will impinge on a position-sensitive focal-plane detector array. Furthermore, operation of the MASHA hot target/ion source combination will provide chemical volatility information that will support our assignment of an atomic number of 114 to these nuclei. Taken together, these experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments in which the chemical properties of the heaviest elements are studied.

  16. Development of a Plutonium Ceramic Target for the MASHA Separator

    Science.gov (United States)

    Shaughnessy, D. A.; Moody, K. J.; Kenneally, J. M.; Wild, J. F.; Stoyer, M. A.; Lougheed, R. W.; Yeremin, A. V.; Oganessian, Yu. Ts.

    2004-04-01

    We are participating in the development of the target for the MASHA (Mass Analyzer of Super Heavy Atoms) on-line mass separator in Dubna. Along with recent upgrades of the U400 cyclotron, MASHA will provide for at least a ten-fold increase in the production- and-detection rate for element 114 atoms, and will allow us to measure their atomic masses precisely. The MASHA separator will employ a thick Pu ceramic target capa- ble of tolerating temperatures in the vicinity of 2000 C without vaporizing the actinide compound. Reaction products will diffuse out of the target and will drift to an ECR ion source after which they will be transported through the separator and will impinge on a position-sensitive focal-plane detector array. Furthermore, operation of the MASHA hot target/ion source combination will provide chemical volatility information that will support our assignment of an atomic number of 114 to these nuclei. Taken together, these experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments in which the chemical properties of the heaviest elements are studied.

  17. Development of a plutonium ceramic target for the MASHA separator

    International Nuclear Information System (INIS)

    Shaughnessy, D.A.; Moody, K.J.; Kenneally, J.M.; Wild, J.F.; Stoyer, M.A.; Lougheed, R.W.; Yeremin, A.V.; Oganessian, Yu.Ts.

    2004-01-01

    We are participating in the development of the target for the MASHA (Mass Analyzer of Super Heavy Atoms) on-line mass separator in Dubna. Along with recent upgrades of the U400 cyclotron, MASHA will provide for at least a ten-fold increase in the production- and-detection rate for element 114 atoms, and will allow us to measure their atomic masses precisely. The MASHA separator will employ a thick Pu ceramic target capable of tolerating temperatures in the vicinity of 2000 C without vaporizing the actinide compound. Reaction products will diffuse out of the target and will drift to an ECR ion source after which they will be transported through the separator and will impinge on a position-sensitive focal-plane detector array. Furthermore, operation of the MASHA hot target/ion source combination will provide chemical volatility information that will support our assignment of an atomic number of 114 to these nuclei. Taken together, these experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments in which the chemical properties of the heaviest elements are studied

  18. Minor actinide transmutation using minor actinide burner reactors

    International Nuclear Information System (INIS)

    Mukaiyama, T.; Yoshida, H.; Gunji, Y.

    1991-01-01

    The concept of minor actinide burner reactor is proposed as an efficient way to transmute long-lived minor actinides in order to ease the burden of high-level radioactive waste disposal problem. Conceptual design study of minor actinide burner reactors was performed to obtain a reactor model with very hard neutron spectrum and very high neutron flux in which minor actinides can be fissioned efficiently. Two models of burner reactors were obtained, one with metal fuel core and the other with particle fuel core. Minor actinide transmutation by the actinide burner reactors is compared with that by power reactors from both the reactor physics and fuel cycle facilities view point. (author)

  19. Actinide production in 136Xe bombardments of 249Cf

    International Nuclear Information System (INIS)

    Gregorich, K.E.

    1985-08-01

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

  20. Studies on the properties of hard-spectrum, actinide fissioning reactors. Final report

    International Nuclear Information System (INIS)

    Nelson, J.B.; Prichard, A.W.; Schofield, P.E.; Robinson, A.H.; Spinrad, B.I.

    1980-01-01

    It is technically feasible to construct an operable (e.g., safe and stable) reactor to burn waste actinides rapidly. The heart of the concept is a driver core of EBR-II type, with a central radial target zone in which fuel elements, made entirely of waste actinides are exposed. This target fuel undergoes fission, as a result of which actinides are rapidly destroyed. Although the same result could be achieved in more conventionally designed LWR or LMFBR systems, the fast spectrum reactor does a much more efficient job, by virtue of the fact that in both LWR and LMFBR reactors, actinide fission is preceded by several captures before a fissile nuclide is formed. In the fast spectrum reactor that is called ABR (actinide burning reactor), these neutron captures are short-circuited

  1. Calculated investigation of actinide transmutation in the BOR-60 reactor

    International Nuclear Information System (INIS)

    Zhemkov, I.Yu.; Ishunina, O.V.; Yakovleva, I.V.

    2000-01-01

    One of the prospective actinide burner reactor type is the fast reactor with a 'hard' spectrum and small breeding factor, which is the BOR-60. The calculated investigations demonstrate that Loading up to 40% of minor-actinides to the BOR-60 reactor did not lead to the considerable change of neutron-physical characteristics. The performed calculations show that the BOR- 60 reactor possesses a high efficiency of the minor-actinide and plutonium bum-up (up to 37 kg/(TW · h)) hat is comparable with properties of the actinide burner-reactors under design. The BOR-60 reactor can provide a homogeneous minor-actinide Loading (minor-actinide addition to the standard fuel) to the core and heterogeneous Loading (as separate assemblies-targets with a high minor-actinide fraction) to the first rows of a radial blanket that allows the optimum usage of the reactor and its characteristics. (authors)

  2. Robust membrane systems for actinide separations

    International Nuclear Information System (INIS)

    Jarvinen, Gordon D.; McCleskey, T. Mark; Bluhm, Elizabeth A.; Abney, Kent D.; Ehler, Deborah S.; Bauer, Eve; Le, Quyen T.; Young, Jennifer S.; Ford, Doris K.; Pesiri, David R.; Dye, Robert C.; Robison, Thomas W.; Jorgensen, Betty S.; Redondo, Antonio; Pratt, Lawrence R.; Rempe, Susan L.

    2000-01-01

    Our objective in this project is to develop very stable thin membrane structures containing ionic recognition sites that facilitate the selective transport of target metal ions, especially the actinides

  3. Fabrication and characterisation of composite targets for the transmutation of actinides

    International Nuclear Information System (INIS)

    Naestren, C.; Haas, D.; Fernandez, A.; Somers, J.

    2006-01-01

    Transmutation of transuranic elements separated from spent fuel is a way to reduce the toxicity of long-lived nuclides in the waste before disposal. Plutonium and the minor actinides (MA) are reintroduced into the fuel cycle for further irradiation and incineration. Currently CERMET fuel forms, in which a ceramic actinide is dispersed in a matrix, are considered for MA transmutation. In a first step, PuO 2 beads are produced by a sol gel method in which a Pu nitrate solution is converted to solid, dust-free, particles. These porous beads are then infiltrated with an americium nitrate solution to the incipient wetness point and calcined to give the (PuAm)O 2 beads, which are blended with a metal matrix and compacted and sintered to form the final fuel pellet. The matrix used is molybdenum due to its high thermal conductivity and low neutron capture cross section, if it is enriched in 92 Mo. In this work, optimization of the bead porosity is investigated to achieve a higher Am content by infiltration. Addition of carbon to the mother solution in the sol gel step increases the bead porosity but it also changes both bead and final fuel pellet microstructure. A surrogate fuel, with cerium simulating the actinides has been fabricated and its mechanical stability and bead characteristics investigated as a function of carbon content and thermal treatment. The characterization of the surrogate fuel by ceramography, density, porosity, bead-quality, etc., is a necessary step in the process optimization, to be transferred to the production of the actinide samples. This process is now at an advanced stage and is being used for the production of fuels for irradiation tests in the Phenix (Futurix) and HFR-Petten (HELIOS) reactors. In parallel, studies on the dissolution of the fuel pellets, with the aim of dissolving the Mo-matrix while keeping the CeO 2 beads intact, have been initiated. Thus, Mo can be recycled for further fuel fabrication either from production scraps or from

  4. Production and properties of the heaviest elements. Status and perspectives

    International Nuclear Information System (INIS)

    Backe, H.; Hebberger, F.P.; Sewtz, M.; Turler, A.

    2007-01-01

    This article reviews the following topics which were discussed at the Workshop on the Atomic Properties of the Heaviest Elements held from September 25-27, 2006 in Chiemsee, Germany: (i) the recent progress in the production of the heaviest elements, the investigation of their nuclear structure, and prospects for direct mass measurements in Penning traps; (ii) recent studies of their chemical properties with the aid of volatile species and single-atom aqueous-phase chemistry; (iii) the current status and future prospects for the investigation of atomic and ionic properties such as optical spectroscopy in gas cells and ion traps, including fully relativistic calculations of the atomic level structure with predictions for the element nobelium; and (iv) ionic charge radii measurements in buffer gas filled drift cells, and ion chemical reactions in the gas phase. (authors)

  5. Preparation of minor actinides targets or blankets by means of ionic exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Picart, S.; Mokhtari, H.; Jobelin, I. [CEA Marcoule, Nucl Energy Div, RadioChem and Proc Dept, Actinides Chem and Convers, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    The conversion of minor actinides to fuel starting materials for transmutation in a closed nuclear cycle is a big challenge for the next decades and the development of Gen(IV) nuclear systems. Conversion routes are numerous, but one needs to prove that they can be adapted to handle minor actinides. One of them is called the resin process and is particularly attractive because it stands for a 'dustless' process as it produces microspheres of oxide or carbide after thermal treatment of the loaded resin. The study presented herein focuses on the experiments and tests which enable us to optimize the fixation of minor actinides onto ionic exchange resin and their carbonization into oxide type materials. (authors)

  6. Preparation of minor actinides targets or blankets by means of ionic exchange resin

    International Nuclear Information System (INIS)

    Picart, S; Mokhtari, H; Jobelin, I; Ramiere, I

    2010-01-01

    The conversion of minor actinides to fuel starting materials for transmutation in a closed nuclear cycle is a big challenge for the next decades and the development of Gen(IV) nuclear systems. Conversion routes are numerous, but one needs to prove that they can be adapted to handle minor actinides. One of them is called the resin process and is particularly attractive because it stands for a 'dustless' process as it produces microspheres of oxide or carbide after thermal treatment of the loaded resin. The study presented herein focuses on the experiments and tests which enable us to optimize the fixation of minor actinides onto ionic exchange resin and their carbonization into oxide type materials.

  7. Design, synthesis, and evaluation of polyhydroxamate chelators for selective complexation of actinides

    International Nuclear Information System (INIS)

    Gopalan, A.; Jacobs, H.; Koshti, N.; Stark, P.; Huber, V.; Dasaradhi, L.; Caswell, W.; Smith, P.; Jarvinen, G.

    1995-01-01

    Specific chelating polymers targeted for actinides have much relevance to problems involving remediation of nuclear waste. Goal is to develop polymer supported, ion specific extraction systems for removing actinides and other hazardous metal ions from wastewaters. This is part of an effort to develop chelators for removing actinide ions such as Pu from soils and waste streams. Selected ligands are being attached to polymeric backbones to create novel chelating polymers. These polymers and other water soluble and insoluble polymers have been synthesized and are being evaluated for ability to selectively remove target metal ions from process waste streams

  8. TUCS/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States)

    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.

  9. Actinide metal processing

    International Nuclear Information System (INIS)

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

    1992-01-01

    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

  10. Stopping powers and ranges for the heaviest atoms

    International Nuclear Information System (INIS)

    Sagaidak, Roman N.; Utyonkov, Vladimir K.; Dmitriev, Sergey N.

    2015-01-01

    Slowing down and stopping of the heaviest atoms, products of the fusion–evaporation nuclear reactions, during their passage through the Dubna gas-filled recoil separator has been studied using TRIM simulations. The study is important for experiments on the synthesis of super-heavy elements (SHEs) with atomic numbers around Z_P = 114 produced with accelerated heavy ion (HI) beams and extracted with a separator for their detection. The average Mylar stopping power (SP) values obtained with the simulations for HIs with 82 ⩽ Z_P ⩽ 92 reveal almost the same magnitudes, allowing extrapolation to the region of Z_P > 92. Similar extrapolation of the ranges in an He + Ar gas mixture leads to rather small values for the heaviest atoms (Z_P ⩾ 102) as compared to the range for U. The extrapolated values have large uncertainties and should be verified with different approaches. Available SP data obtained for HIs with 18 ⩽ Z_P ⩽ 92 at energies E < 20 MeV/u have been analysed within various semi-empirical approaches. The analysis has shown that existing parameterizations give Mylar SP values for Z_P ⩾ 82 that are very different from each other at energies of interest (around 0.1 MeV/u). We propose to use a general approach based on the HI effective charge parameterization obtained with available SP data for HIs and the hydrogen SP and effective charge corresponding to the same velocity and stopping medium as those for HIs. In this manner, the SPs of the gases H_2, He, C_4H_1_0, and Ar as well as those of the solids Mylar, C, Al, and Ti have been obtained for any atoms with Z_P ⩾ 18 (including the heaviest ones) at their reduced velocities 0.03 ⩽ V_r_e_d ⩽ 5.0. The SP values derived in such a way seem to be more reliable compared to the existing semi-empirical calculations and can be used in the conditioning of experiments on the synthesis of SHEs.

  11. Synthesis of tetravalent actinide chlorides. Versatile compounds for actinide chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Maerz, Juliane [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Chemistry of the F-Elements

    2016-07-01

    Anhydrous actinide tetrachlorides (AnCl{sub 4}) were synthesized under mild conditions to provide versatile compounds for actinide chemistry. They enable a direct access to actinide complexes with organic and inorganic ligands.

  12. Review of actinide nitride properties with focus on safety aspects

    Energy Technology Data Exchange (ETDEWEB)

    Albiol, Thierry [CEA Cadarache, St Paul Lez Durance Cedex (France); Arai, Yasuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    This report provides a review of the potential advantages of using actinide nitrides as fuels and/or targets for nuclear waste transmutation. Then a summary of available properties of actinide nitrides is given. Results from irradiation experiments are reviewed and safety relevant aspects of nitride fuels are discussed, including design basis accidents (transients) and severe (core disruptive) accidents. Anyway, as rather few safety studies are currently available and as many basic physical data are still missing for some actinide nitrides, complementary studies are proposed. (author)

  13. Actinide and fission product separation and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-07-01

    The second international information exchange meeting on actinide and fission product separation and transmutation, took place in Argonne National Laboratory in Illinois United States, on 11-13 November 1992. The proceedings are presented in four sessions: Current strategic system of actinide and fission product separation and transmutation, progress in R and D on partitioning processes wet and dry, progress in R and D on transmutation and refinements of neutronic and other data, development of the fuel cycle processes fuel types and targets. (A.L.B.)

  14. Actinide separation by electrorefining

    International Nuclear Information System (INIS)

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

    1995-01-01

    TRUMP-S is a pyrochemical process being developed for the recovery of actinides from PUREX wastes. This paper describes development of the electrochemical partitioning step for recovery of actinides in the TRUMP-S process. The objectives are to remove 99 % of each actinide from PUREX wastes, with a product that is > 90 % actinides. Laboratory tests indicate that > 99 % of actinides can be removed in the electrochemical partitioning step. A dynamic (not equilibrium) process model predicts that 90 wt % product actinide content can be achieved through 99 % actinide removal. Accuracy of model simulation results were confirmed in tests with rare earths. (authors)

  15. European Europart integrated project on actinide partitioning

    International Nuclear Information System (INIS)

    Madic, C.; Hudson, M.J.

    2005-01-01

    This poster presents the objectives of EUROPART, a scientific integrated project between 24 European partners, mostly funded by the European Community within the FP6. EUROPART aims at developing chemical partitioning processes for the so-called minor actinides (MA) contained in nuclear wastes, i.e. from Am to Cf. In the case of dedicated spent fuels or targets, the actinides to be separated also include U, Pu and Np. The techniques considered for the separation of these radionuclides belong to the fields of hydrometallurgy and pyrometallurgy, as in the previous FP5 programs named PARTNEW and PYROREP. The two main axes of research within EUROPART will be: The partitioning of MA (from Am to Cf) from high burn-up UO x fuels and multi-recycled MOx fuels; the partitioning of the whole actinide family for recycling, as an option for advanced dedicated fuel cycles (and in connection with the studies to be performed in the EUROTRANS integrated project). In hydrometallurgy, the research is organised into five Work Packages (WP). Four WP are dedicated to the study of partitioning methods mainly based on the use of solvent extraction methods, one WP is dedicated to the development of actinide co-conversion methods for fuel or target preparation. The research in pyrometallurgy is organized into four WP, listed hereafter: development of actinide partitioning methods, study of the basic chemistry of trans-curium elements in molten salts, study of the conditioning of the wastes, some system studies. Moreover, a strong management team will be concerned not only with the technical and financial issues arising from EUROPART, but also with information, communication and benefits for Europe. Training and education of young researchers will also pertain to the project. EUROPART has also established collaboration with US DOE and Japanese CRIEPI. (authors)

  16. Minor Actinide Laboratory at JRC-ITU: Fuel fabrication facility

    International Nuclear Information System (INIS)

    Fernandez, A.; McGinley, J.; Somers, J.

    2008-01-01

    The Minor Actinide Laboratory (MA-lab) of the Institute for Transuranium Elements is a unique facility for the fabrication of fuels and targets containing minor actinides (MA). It is of key importance for research on Partitioning and Transmutation in Europe, as it is one of the only dedicated facilities for the fabrication of MA containing materials, either for property measurements or for the production of test pins for irradiation experiments. In this paper a detailed description of the MA-Lab facility and the fabrication processes developed to fabricate fuels and samples containing high content of minor actinides is given. In addition, experience gained and improvements are also outlined. (authors)

  17. A new look at actinide recycle

    International Nuclear Information System (INIS)

    Burch, W.D.; Croff, A.G.; Rawlins, J.A.; Schulz, W.W.

    1991-01-01

    This paper will address the justification for reexamination of the value of recovering the minor actinides and certain fission products from spent light-water reactor fuels and describe some of the technical progress that has been made since the major studies of a decade ago. During this time, the US Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission have begun establishing detailed criteria and regulations for geologic repositories. An examination of the hazards of waste disposal relative to the EPA release standards reveals that removal of 99.9% of the actinides (Pu, Am, and Np) reduces these hazards quite close to the EPA standards after 300 years' decay of the strontium and cesium. It may be also useful to remove and separately manage and dispose of certain of the long-lived fission products, such as 99 Tc and 129 I. Much additional work is required to fully assess the appropriate target recoveries as the hazards and risks are more closely examined and as the standards are reworked and refined. The two decades before the projected start of the US repository may present a window of opportunity to introduce several better management practices that act to simplify the repository safety issues. From a technical standpoint, significant progress has been made on recovery of the actinides from aqueous wastes though use of the TRUEX process. Additional work is required to demonstrate the application of the process to spent LWR fuels, but it appears straightforward. In addition, work at the Argonne National Laboratory on the liquid-metal reactor metal fuel cycle shows the relative simplicity of recycle of the actinides in that fast reactor cycle. Much work remains to fully demonstrate that actinides from all secondary waste streams can be removed to the target levels from both the aqueous reprocessing of LWR fuel and the pyro processes for the metal-fueled fast reactor. 9 refs., 2 figs

  18. Rapid ion-exchange separations of actinides

    International Nuclear Information System (INIS)

    Usuda, Shigekazu

    1988-01-01

    For the purpose of studying short-lived actinide nuclides, three methods for rapid ion exchange separation of actinide elements with mineral acid-alcohol mixed media were developed: anion exchange with nitric acid-methyl alcohol mixed media to separate the transplutonium and rare earth elements from target material, U or Pu and Al catcher foils; anion exchange with hydrochloric acid-methyl alcohol media to separate Am+Cm, Bk and Cf+Fm from the target, catcher foils and major fission products; and cation exchange with hydrochloric acid-methyl alcohol media and with concentrated hydrochloric acid to separate the transplutonium elements as a group from the rare earths after eliminating the large amounts of U, Al, Cu, Fe etc. The methods enable one to perform rapid and effective separation at elevated temperature (90 deg C) and immediate source preparation for alpha-ray spectrometry. (author) 47 refs.; 10 figs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-01

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

  20. Identification of new neutron-rich actinide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Oura, Yasuji; Sakama, Minoru; Ohyama, T. [Tokyo Metropolitan Univ. (Japan)] [and others

    1999-10-01

    To advance research on new neutron-deficient actinide isotopes using an on-line isotope separator combined with a gas-jet injector installed in the JAERI Tandem accelerator, Tokai, performance test of the equipment was carried out. Efficiency of the product isotopes being transported from the target chamber to the measuring system was greatly improved by employing lead iodides (PbI{sub 2}) as the aerosol carrier. With the help of this technique, the authors succeeded in synthesizing and identifying actinide isotopes, {sup 235}Am and {sup 236}Am, and measured their alpha-decay half-life. (S. Ohno)

  1. Feasibility studies of actinide recycle in LMFBRs as a waste management alternative

    International Nuclear Information System (INIS)

    Beaman, S.L.; Aitken, E.A.

    1976-01-01

    A strategy of actinide burnup in LMFBRs is being investigated as a waste management alternative to long term storage of high level nuclear waste. This strategy is being evaluated because many of the actinides in the waste from spent-fuel reprocessing have half-lives of thousands of years and an alternative to geological storage may be desired. From a radiological viewpoint, the actinides and their daughters dominate the waste hazard for decay times beyond about 400 years. Actinide burnup in LMFBRs may be an attractive alternative to geological storage because the actinides can be effectively transmuted to fission products which have significantly shorter half-lives. Actinide burnup in LMFBRs rather than LWRs is preferred because the ratio of fission reaction rate to capture reaction rate for the actinides is higher in an LMFBR, and an LMFBR is not so sensitive to the addition of the actinide isotopes. An actinide target assembly recycle scheme is evaluated to determine the effects of the actinides on the LMFBR performance, including local power peaking, breeding ratio, and fissile material requirements. Several schemes are evaluated to identify any major problems associated with reprocessing and fabrication of recycle actinide-containing assemblies. The overall efficiency of actinide burnout in LMFBRs is evaluated, and equilibrium cycle conditions are determined. It is concluded that actinide recycle in LMFBRs offers an attractive alternative to long term storage of the actinides, and does not significantly affect the performance of the host LMFBR. Assuming a 0.1 percent or less actinide loss during reprocessing, a 0.1 percent loss of less during fabrication, and proper recycle schemes, virtually all of the actinides produced by a fission reactor economy could be transmuted in fast reactors

  2. Actinide oxide photodiode and nuclear battery

    Energy Technology Data Exchange (ETDEWEB)

    Sykora, Milan; Usov, Igor

    2017-12-05

    Photodiodes and nuclear batteries may utilize actinide oxides, such a uranium oxide. An actinide oxide photodiode may include a first actinide oxide layer and a second actinide oxide layer deposited on the first actinide oxide layer. The first actinide oxide layer may be n-doped or p-doped. The second actinide oxide layer may be p-doped when the first actinide oxide layer is n-doped, and the second actinide oxide layer may be n-doped when the first actinide oxide layer is p-doped. The first actinide oxide layer and the second actinide oxide layer may form a p/n junction therebetween. Photodiodes including actinide oxides are better light absorbers, can be used in thinner films, and are more thermally stable than silicon, germanium, and gallium arsenide.

  3. Thermodynamic Properties of Actinides and Actinide Compounds

    Science.gov (United States)

    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.

  4. From alchemy to super-actinides. The preparation, physical-chemical properties and the limits of the Periodic Table

    International Nuclear Information System (INIS)

    Kuruc, J.

    2016-01-01

    In this review a brief history of the discovery of the periodic law, discoveries of elements from the epoch of alchemy to the synthesis of actinides and transactinides is described. The preparation of transactinides (elements with Z ≥ 104 to Z = 118) is discussed, using already proposed names of the elements with Z = 113, 115, 117 and 118: nihonium, moscovium, tennessine and oganesson. The Periodic Tables are presented in short form, the long 18-column and 32-column form. The periodic table containing elements of 8"t"h and 9"t"h periods and its possible range is discussed. By extrapolation of decay half-time of the heaviest isotopes of elements from thorium up to oganesson decay half-time of unbihexium (Z = 126) was predicted about 378 seconds. (author

  5. Measurement of actinide neutron cross sections

    International Nuclear Information System (INIS)

    Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald

    2003-01-01

    The maintenance of strong scientific expertise is critical to the U.S. nuclear attribution community. It is particularly important to train students in actinide chemistry and physics. Neutron cross-section data are vital components to strategies for detecting explosives and fissile materials, and these measurements require expertise in chemical separations, actinide target preparation, nuclear spectroscopy, and analytical chemistry. At the University of California, Berkeley and the Lawrence Berkeley National Laboratory we have trained students in actinide chemistry for many years. LBNL is a leader in nuclear data and has published the Table of Isotopes for over 60 years. Recently, LBNL led an international collaboration to measure thermal neutron capture radiative cross sections and prepared the Evaluated Gamma-ray Activation File (EGAF) in collaboration with the IAEA. This file of 35, 000 prompt and delayed gamma ray cross-sections for all elements from Z=1-92 is essential for the neutron interrogation of nuclear materials. LBNL has also developed new, high flux neutron generators and recently opened a 1010 n/s D+D neutron generator experimental facility

  6. Actinides-1981

    International Nuclear Information System (INIS)

    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

  7. Actinides-1981

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

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

    1999-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Chemistry of the heaviest elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    1992-08-01

    The experimentally known chemical properties of elements 103,104, and 105, and the experimental techniques to obtain these properties on a one-atom- at-a-time base, are summarized. The chemical properties are compared with the lighter group 3,4 and 5 homologs and with the expected behaviour as obtained from theoretical calculations. In this transition region from the last actinide element to the beginning of the transactinide series one may expect to find evidence for increasingly strong relativistic effects altering the chemical behaviour. (orig.)

  11. High transfer cross sections from reactions with 254Es

    International Nuclear Information System (INIS)

    Schaedel, M.; Bruechle, W.; Bruegger, M.; Gaeggeler, H.; Moody, J.; Schardt, D.; Suemmerer, K.; Hulet, E.K.; Dougan, A.D.; Dougan, R.J.; Landrum, J.H.; Lougheed, R.W.; Wild, J.F.; O'Kelly, G.D.

    1985-08-01

    We report radiochemically determined cross sections for the heaviest known actinides produced in transfer reactions of 101 MeV 16 O, 98 MeV 18 O and 127 MeV 22 Ne with 254 Es as a target. A comparison with data for similar transfers from 248 Cm targets is made. Transfer cross sections are extrapolated for the production of unknown, neutron-rich isotopes of elements 101 through 105, and the unique potential of 254 Es as a target to make these exotic nuclei accessible is demonstrated. (orig.)

  12. Subsurface interactions of actinide species and microorganisms. Implications for the bioremediation of actinide-organic mixtures

    International Nuclear Information System (INIS)

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

    1999-01-01

    By reviewing how microorganisms interact with actinides in subsurface environments, the way how bioremediation controls the fate of actinides is assessed. 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. The way 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 is described. Why inhibition caused by chemical or radiolytic toxicities uniquely affects microbial reactions is explained. 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. Development of mathematical models that link microbiological and geochemical reactions is described. Throughout, the key research needs are identified. (author)

  13. Actinide colloid generation in groundwater

    International Nuclear Information System (INIS)

    Kim, J.I.

    1990-05-01

    The progress made in the investigation of actinide colloid generation in groundwaters is summarized and discussed with particular examples relevant to an understanding of the migration behaviour of actinides in natural aquifer systems. The first part deals with the characterization of colloids: groundwater colloids, actinide real-colloids and actinide pseudocolloids. The second part concentrates on the generation processes and migration behaviour of actinide pseudocolloids, which are discussed with some notable experimental examples. Importance is stressed more on the chemical aspects of the actinide colloid generation in groundwater. This work is a contribution to the CEC project MIRAGE II, particularly, to research area: complexation and colloids. (orig.)

  14. Partitioning and Transmutation of minor actinides

    International Nuclear Information System (INIS)

    Koch, L.; Wellum, R.

    1991-01-01

    The partitioning of minor actinides from spent fuels and their transmutation into short-lived fission products has been the topic of two dedicated meetings organized jointly by the European Commission and the OECD. The conclusion of the last meeting in 1980, in short, was that partitioning and transmutation of minor actinides, especially in fast reactors, seemed possible. However, the incentive, which would be a reduction of the radiological hazard to the public, was too small if long-lived fission products were not included. Furthermore this meeting showed that minor actinide targets or possible nuclear fuels containing minor actinides for transmutation had not yet been developed. The European Institute for Transuranium Elements took up this task and has carried it out as a small activity for several years. Interests expressed recently by an expert meeting of the OECD/NEA (Paris, 25 April 1989), which was initiated by the proposed Japanese project Omega, led us to the conclusion that the present state of knowledge should be looked at in a workshop environment. Since the Japanese proposal within the project Omega is based on a broader approach we needed this evaluation to assess the relevance of our present activity and wanted to identifiy additional studies which might be needed to cover possible future demands from the public. This workshop was therefore organized, and participants active in the field from EC countries, the USA and Japan were invited

  15. Advances in chemical investigations of the heaviest elements

    Directory of Open Access Journals (Sweden)

    Türler Andreas

    2016-01-01

    Full Text Available Although somewhat in the shadow of the discoveries of new elements, experimental chemical investigations of the heaviest elements have made tremendous progress in the last decades. Indeed, it was possible to experimentally determine thermochemical properties of heavy transactinide elements such as copernicium or flerovium. But will it be possible to chemically study all currently known elements of the periodic table up to element 118? While it is experimentally feasible to work with single atoms, the short half-lives of even the longest currently known isotopes of elements 115 through 118 call for new experimental approaches.

  16. Research in actinide chemistry

    International Nuclear Information System (INIS)

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

  17. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    Energy Technology Data Exchange (ETDEWEB)

    Cassayre, L., E-mail: cassayre@chimie.ups-tlse.fr [Laboratoire de Genie Chimique (LGC), Departement Procedes Electrochimiques, CNRS-UMR 5503, Universite de Toulouse III - Paul Sabatier, 31062 Toulouse (France); Soucek, P.; Mendes, E.; Malmbeck, R.; Nourry, C.; Eloirdi, R.; Glatz, J.-P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany)

    2011-07-01

    Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl{sub 3}. A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl{sub 3} alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl{sub 2}/UAl{sub 3} molar ratio, providing complete chlorination of the alloy without formation of volatile UCl{sub 5} and UCl{sub 6}. The results showed high efficient chlorination at a temperature of 150 deg. C.

  18. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    International Nuclear Information System (INIS)

    Cassayre, L.; Soucek, P.; Mendes, E.; Malmbeck, R.; Nourry, C.; Eloirdi, R.; Glatz, J.-P.

    2011-01-01

    Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl 3 . A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl 3 alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl 2 /UAl 3 molar ratio, providing complete chlorination of the alloy without formation of volatile UCl 5 and UCl 6 . The results showed high efficient chlorination at a temperature of 150 deg. C.

  19. Chemistry of the heaviest elements--one atom at a time

    International Nuclear Information System (INIS)

    Hoffman, Darleane C.; Lee, Diana M.

    2000-01-01

    In keeping with the goal of the Viewpoint series of the Journal of Chemical Education, this article gives a 75-year perspective of the chemistry of the heaviest elements, including a 50-year retrospective view of past developments, a summary of current research achievements and applications, and some predictions about exciting, new developments that might be envisioned within the next 25 years. A historical perspective of the importance of chemical separations in the discoveries of the transuranium elements from neptunium (Z=93) through mendelevium (Z=101) is given. The development of techniques for studying the chemical properties of mendelevium and still heavier elements on the basis of measuring the radioactive decay of a single atom (''atom-at-a-time'' chemistry) and combining the results of many separate experiments is reviewed. The influence of relativistic effects (expected to increase as Z 2 ) on chemical properties is discussed. The results from recent atom-at-a-time studies of the chemistry of the heaviest elements through seaborgium (Z=106) are summarized and show that their properties cannot be readily predicted based on simple extrapolation from the properties of their lighter homologues in the periodic table. The prospects for extending chemical studies to still heavier elements than seaborgium are considered and appear promising

  20. Actinides

    International Nuclear Information System (INIS)

    Martinot, L.; Fuger, J.

    1985-01-01

    The oxidation behavior of the actinides is explained on the basis of their electronic structure. The actinide elements, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and laurencium are included. For all except the last three elements, the points of discussion are oxidation states, Gibbs energies and potentials, and potential diagram for the element in acid solution; and thermodynamic properties of these same elements are tabulated. References are cited following discussion of each element with a total of 97 references being cited. 13 tables

  1. Behavior of actinides in the Integral Fast Reactor fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, J.C. [Louisiana State Univ., Baton Rouge, LA (United States). Nuclear Science Center; Lineberry, M.J. [Argonne National Lab., Idaho Falls, ID (United States). Technology Development Div.

    1994-06-01

    The Integral Fast Reactor (IFR) under development by Argonne National Laboratory uses metallic fuels instead of ceramics. This allows electrorefining of spent fuels and presents opportunities for recycling minor actinide elements. Four minor actinides ({sup 237}Np, {sup 240}Pu, {sup 241}Am, and {sup 243}Am) determine the waste storage requirements of spent fuel from all types of fission reactors. These nuclides behave the same as uranium and other plutonium isotopes in electrorefining, so they can be recycled back to the reactor without elaborate chemical processing. An experiment has been designed to demonstrate the effectiveness of the high-energy neutron spectra of the IFR in consuming these four nuclides and plutonium. Eighteen sets of seven actinide and five light metal targets have been selected for ten day exposure in the Experimental Breeder Reactor-2 which serves as a prototype of the IFR. Post-irradiation analyses of the exposed targets by gamma, alpha, and mass spectroscopy are used to determine nuclear reaction-rates and neutron spectra. These experimental data increase the authors` confidence in their ability to predict reaction rates in candidate IFR designs using a variety of neutron transport and diffusion programs.

  2. Actinide behavior in the Integral Fast Reactor. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, J.C.

    1994-11-01

    The Integral Fast Reactor (IFR) under development by Argonne National Laboratory uses metallic fuels instead of ceramics. This allows electrorefining of spent fuels and presents opportunities for recycling minor actinide elements. Four minor actinides ({sup 237}Np, {sup 240}Pu, {sup 241}Am, and {sup 243}Am) determine the waste storage requirements of spent fuel from all types of fission reactors. These nuclides behave the same as uranium and other plutonium isotopes in electrorefining, so they can be recycled back to the reactor without elaborate chemical processing. An experiment has been designed to demonstrate the effectiveness of the high-energy neutron spectra of the IFR in consuming these four nuclides and weapons grade plutonium. Eighteen sets of seven actinide and five light metal targets have been selected for seven day exposure in the Experimental Breeder Reactor-II which serves as a prototype of the IFR. Post-irradiation analyses of the exposed targets by gamma, alpha, and mass spectroscopy are used to determine nuclear reaction rates and neutron spectra. These experimental data increase the authors confidence in their ability to predict reaction rates in candidate IFR designs using a variety of neutron transport and diffusion programs.

  3. Actinide behavior in the Integral Fast Reactor. Final project report

    International Nuclear Information System (INIS)

    Courtney, J.C.

    1994-11-01

    The Integral Fast Reactor (IFR) under development by Argonne National Laboratory uses metallic fuels instead of ceramics. This allows electrorefining of spent fuels and presents opportunities for recycling minor actinide elements. Four minor actinides ( 237 Np, 240 Pu, 241 Am, and 243 Am) determine the waste storage requirements of spent fuel from all types of fission reactors. These nuclides behave the same as uranium and other plutonium isotopes in electrorefining, so they can be recycled back to the reactor without elaborate chemical processing. An experiment has been designed to demonstrate the effectiveness of the high-energy neutron spectra of the IFR in consuming these four nuclides and weapons grade plutonium. Eighteen sets of seven actinide and five light metal targets have been selected for seven day exposure in the Experimental Breeder Reactor-II which serves as a prototype of the IFR. Post-irradiation analyses of the exposed targets by gamma, alpha, and mass spectroscopy are used to determine nuclear reaction rates and neutron spectra. These experimental data increase the authors confidence in their ability to predict reaction rates in candidate IFR designs using a variety of neutron transport and diffusion programs

  4. Behavior of actinides in the Integral Fast Reactor fuel cycle

    International Nuclear Information System (INIS)

    Courtney, J.C.; Lineberry, M.J.

    1994-01-01

    The Integral Fast Reactor (IFR) under development by Argonne National Laboratory uses metallic fuels instead of ceramics. This allows electrorefining of spent fuels and presents opportunities for recycling minor actinide elements. Four minor actinides ( 237 Np, 240 Pu, 241 Am, and 243 Am) determine the waste storage requirements of spent fuel from all types of fission reactors. These nuclides behave the same as uranium and other plutonium isotopes in electrorefining, so they can be recycled back to the reactor without elaborate chemical processing. An experiment has been designed to demonstrate the effectiveness of the high-energy neutron spectra of the IFR in consuming these four nuclides and plutonium. Eighteen sets of seven actinide and five light metal targets have been selected for ten day exposure in the Experimental Breeder Reactor-2 which serves as a prototype of the IFR. Post-irradiation analyses of the exposed targets by gamma, alpha, and mass spectroscopy are used to determine nuclear reaction-rates and neutron spectra. These experimental data increase the authors' confidence in their ability to predict reaction rates in candidate IFR designs using a variety of neutron transport and diffusion programs

  5. Actinide and fission product partitioning and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The third international information exchange meeting on actinide and fission product partitioning and transmutation, took place in Cadarache France, on 12-14 December 1994. The proceedings are presented in six sessions : an introduction session, the major programmes and international cooperation, the systems studies, the reactors fuels and targets, the chemistry and a last discussions session. (A.L.B.)

  6. Actinide recycle

    Energy Technology Data Exchange (ETDEWEB)

    Till, C; Chang, Y [Argonne National Laboratory, Argonne, IL (United States)

    1990-07-01

    A multitude of studies and assessments of actinide partitioning and transmutation were carried out in the late 1970s and early 1980s. Probably the most comprehensive of these was a study coordinated by Oak Ridge National Laboratory. The conclusions of this study were that only rather weak economic and safety incentives existed for partitioning and transmuting the actinides for waste management purposes, due to the facts that (1) partitioning processes were complicated and expensive, and (2) the geologic repository was assumed to contain actinides for hundreds of thousands of years. Much has changed in the few years since then. A variety of developments now combine to warrant a renewed assessment of the actinide recycle. First of all, it has become increasingly difficult to provide to all parties the necessary assurance that the repository will contain essentially all radioactive materials until they have decayed. Assurance can almost certainly be provided to regulatory agencies by sound technical arguments, but it is difficult to convince the general public that the behavior of wastes stored in the ground can be modeled and predicted for even a few thousand years. From this point of view alone there would seem to be a clear benefit in reducing the long-term toxicity of the high-level wastes placed in the repository.

  7. Actinide recycle

    International Nuclear Information System (INIS)

    Till, C.; Chang, Y.

    1990-01-01

    A multitude of studies and assessments of actinide partitioning and transmutation were carried out in the late 1970s and early 1980s. Probably the most comprehensive of these was a study coordinated by Oak Ridge National Laboratory. The conclusions of this study were that only rather weak economic and safety incentives existed for partitioning and transmuting the actinides for waste management purposes, due to the facts that (1) partitioning processes were complicated and expensive, and (2) the geologic repository was assumed to contain actinides for hundreds of thousands of years. Much has changed in the few years since then. A variety of developments now combine to warrant a renewed assessment of the actinide recycle. First of all, it has become increasingly difficult to provide to all parties the necessary assurance that the repository will contain essentially all radioactive materials until they have decayed. Assurance can almost certainly be provided to regulatory agencies by sound technical arguments, but it is difficult to convince the general public that the behavior of wastes stored in the ground can be modeled and predicted for even a few thousand years. From this point of view alone there would seem to be a clear benefit in reducing the long-term toxicity of the high-level wastes placed in the repository

  8. EUROPART: an European integrated project on actinide partitioning

    International Nuclear Information System (INIS)

    Madic, C.; Baron, P.; Hudson, M.J.

    2006-01-01

    Full text of publication follows: The EUROPART project is a scientific integrated project between 24 European partners, from 10 countries, mostly funded by the European Community within the FP6, together with CRIEPI from Japan and ANSTO from Australia. EUROPART aims at developing chemical partitioning processes for the so-called minor actinides (MA) contained in nuclear wastes, i.e. from Am to Cf. In the case of the treatment of dedicated spent fuels or targets, the actinides to be separated also include U, Pu and Np. The techniques considered for the separation of these radionuclides belong to the fields of hydrometallurgy and pyrometallurgy, as in the previous European FP5 programs named PARTNEW, CALIXPART and PYROREP, respectively. The two main axes of research within EUROPART are: 1/ the partitioning of MA (from Am to Cf) from wastes issuing from the reprocessing of high burn-up UOX fuels and multi-recycled MOX fuels, 2/ the partitioning of the whole actinide family of elements for recycling, as an option for advanced dedicated fuel cycles (this work will be connected to the studies to be performed within the EUROTRANS European integrated project). In hydrometallurgy, the research is organized in five Work Packages (WP). Four are dedicated to the study of partitioning methods mainly based on the use of solvent extraction methods and of solid extractants, one WP is dedicated to the development of actinide co-conversion methods for fuel or target preparations. The research in pyrometallurgy is organized into four WPs, listed hereafter: (i) study of the basic chemistry of transuranium elements and of some fission products in molten salts (chlorides, fluorides), (ii) development of actinide partitioning methods, (iii) study of the conditioning of the salt wastes, (iv) system studies. Moreover, a strong management team is concerned not only with the technical and financial issues arising from EUROPART, but also with information, communication and benefits for Europe

  9. Recent development in computational actinide chemistry

    International Nuclear Information System (INIS)

    Li Jun

    2008-01-01

    Ever since the Manhattan project in World War II, actinide chemistry has been essential for nuclear science and technology. Yet scientists still seek the ability to interpret and predict chemical and physical properties of actinide compounds and materials using first-principle theory and computational modeling. Actinide compounds are challenging to computational chemistry because of their complicated electron correlation effects and relativistic effects, including spin-orbit coupling effects. There have been significant developments in theoretical studies on actinide compounds in the past several years. The theoretical capabilities coupled with new experimental characterization techniques now offer a powerful combination for unraveling the complexities of actinide chemistry. In this talk, we will provide an overview of our own research in this field, with particular emphasis on applications of relativistic density functional and ab initio quantum chemical methods to the geometries, electronic structures, spectroscopy and excited-state properties of small actinide molecules such as CUO and UO 2 and some large actinide compounds relevant to separation and environment science. The performance of various density functional approaches and wavefunction theory-based electron correlation methods will be compared. The results of computational modeling on the vibrational, electronic, and NMR spectra of actinide compounds will be briefly discussed as well [1-4]. We will show that progress in relativistic quantum chemistry, computer hardware and computational chemistry software has enabled computational actinide chemistry to emerge as a powerful and predictive tool for research in actinide chemistry. (authors)

  10. ACTINET: a European Network for Actinide Sciences

    International Nuclear Information System (INIS)

    Bernard Boullis; Pascal Chaix

    2006-01-01

    Full text of publication follows: The research in Actinide sciences appear as a strategic issue for the future of nuclear systems. Sustainability issues are clearly in connection with the way actinide elements are managed (either addressing saving natural resource, or decreasing the radiotoxicity of the waste). The recent developments in the field of minor actinide P and T offer convincing indications of what could be possible options, possible future processes for the selective recovery of minor actinides. But they point out, too, some lacks in the basic understanding of key-issues (such as for instance the control An versus Ln selectivity, or solvation phenomena in organic phases). Such lacks could be real obstacles for an optimization of future processes, with new fuel compounds and facing new recycling strategies. This is why a large and sustainable work appears necessary, here in the field of basic actinide separative chemistry. And similar examples could be taken from other aspects of An science, for various applications (nuclear fuel or transmutation targets design, or migration issues,): future developments need a strong, enlarged, scientific basis. The Network ACTINET, established with the support of the European Commission, has the following objectives: - significantly improve the accessibility of the major actinide facilities to the European scientific community, and form a set of pooled facilities, as the corner-stone of a progressive integration process, - improve mobility between the member organisations, in particular between Academic Institutions and National Laboratories holding the pooled facilities, - merge part of the research programs conducted by the member institutions, and optimise the research programs and infrastructure policy via joint management procedures, - strengthen European excellence through a selection process of joint proposals, and reduce the fragmentation of the community by putting critical mass of resources and expertise on

  11. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    Koenig, Z.M.; Ruhter, W.D.; Gunnink, R.

    1990-01-01

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  12. Actinide recovery techniques utilizing electromechanical processes

    International Nuclear Information System (INIS)

    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 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

  13. Criteria for achieving actinide reduction goals

    International Nuclear Information System (INIS)

    Liljenzin, J.O.

    1996-01-01

    In order to discuss various criteria for achieving actinide reduction goals, the goals for actinide reduction must be defined themselves. In this context the term actinides is interpreted to mean plutonium and the so called ''minor actinides'' neptunium, americium and curium, but also protactinium. Some possible goals and the reasons behind these will be presented. On the basis of the suggested goals it is possible to analyze various types of devices for production of nuclear energy from uranium or thorium, such as thermal or fast reactors and accelerator driven system, with their associated fuel cycles with regard to their ability to reach the actinide reduction goals. The relation between necessary single cycle burn-up values, fuel cycle processing losses and losses to waste will be defined and discussed. Finally, an attempt is made to arrange the possible systems on order of performance with regard to their potential to reduce the actinide inventory and the actinide losses to wastes. (author). 3 refs, 3 figs, 2 tabs

  14. Nuclear Structure of the Heaviest Elements – Investigated at SHIP-GSI

    Directory of Open Access Journals (Sweden)

    Heßberger Fritz Peter

    2014-03-01

    Full Text Available The quest for the heaviest nuclei that can exist is a basic topic in natural science as their stability is characterized by a delicate interplay of short range nuclear forces acting between the nucleons (protons and neutrons and long-range Coulomb forces acting solely between charged particles, i.e. the protons. As the stability of a nucleus is strongly correlated to its structure, understanding the nuclear structure of heaviest nuclei is presently a main challenge of experimental and theoretical investigations concerning the field of Superheavy Elements. At the velocity filter SHIP at GSI Darmstadt an extensive program on nuclear structure investigations has been started about a decade ago. The project covered both as well systematic investigations of single particle levels in odd-mass isotopes populated by α-decay as investigation of two- or fourquasi-particle states forming K isomers and was supplemented by direct mass measurements at SHIPTRAP and investigation of spontaneous fission properties. Recent experimental studies allowed to extend the systematics of low lying levels in N = 151 and N = 153 up to 255Rf and 259Sg, investigation of possible relations between nuclear structure and fission properties of odd-mass nuclei and investigation of shell strengths at N = 152 and towards N = 162.

  15. Actinides: why are they important biologically

    International Nuclear Information System (INIS)

    Durbin, P.W.

    1978-01-01

    The following topics are discussed: actinide elements in energy systems; biological hazards of the actinides; radiation protection standards; and purposes of actinide biological research with regard to toxicity, metabolism, and therapeutic regimens

  16. Actinide recovery techniques utilizing electromechanical processes

    International Nuclear Information System (INIS)

    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

  17. Research on the chemical speciation of actinides

    International Nuclear Information System (INIS)

    Jung, Euo Chang; Park, K. K.; Cho, H. R.

    2010-04-01

    A demand for the safe and effective management of spent nuclear fuel and radioactive waste generated from nuclear power plant draws increasing attention with the growth of nuclear power industry. The objective of this project is to establish the basis of research on the actinide chemistry by using advanced laser-based highly sensitive spectroscopic systems. Researches on the chemical speciation of actinides are prerequisite for the development of technologies related to nuclear fuel cycles, especially, such as the safe management of high level radioactive wastes and the chemical examination of irradiated nuclear fuels. For supporting these technologies, laser-based spectroscopies have been performed for the chemical speciation of actinide in an aqueous solutions and the quantitative analysis of actinide isotopes in spent nuclear fuels. In this report, results on the following subjects have been summarized. (1) Development of TRLFS technology for chemical speciation of actinides, (2) Development of LIBD technology for measuring solubility of actinides, (3) Chemical speciation of plutonium complexes by using a LWCC system, (4) Development of LIBS technology for the quantitative analysis of actinides, (5) Development of technology for the chemical speciation of actinides by CE, (6) Evaluation on the chemical reactions between actinides and humic substances, (7) Chemical speciation of actinides adsorbed on metal oxides surfaces, (8) Determination of actinide source terms of spent nuclear fuel

  18. Sensitivity analysis of minor actinides transmutation to physical and technological parameters

    International Nuclear Information System (INIS)

    Kooyman, T.; Buiron, L.

    2015-01-01

    Minor actinides transmutation is one of the 3 main axis defined by the 2006 French law for management of nuclear waste, along with long-term storage and use of a deep geological repository. Transmutation options for critical systems can be divided in two different approaches: (a) homogeneous transmutation, in which minor actinides are mixed with the fuel. This exhibits the drawback of 'polluting' the entire fuel cycle with minor actinides and also has an important impact on core reactivity coefficients such as Doppler Effect or sodium void worth for fast reactors when the minor actinides fraction increases above 3 to 5% depending on the core; (b) heterogeneous transmutation, in which minor actinides are inserted into transmutation targets which can be located in the center or in the periphery of the core. This presents the advantage of decoupling the management of the minor actinides from the conventional fuel and not impacting the core reactivity coefficients. In both cases, the design and analyses of potential transmutation systems have been carried out in the frame of Gen IV fast reactor using a 'perturbation' approach in which nominal power reactor parameters are modified to accommodate the loading of minor actinides. However, when designing such a transmutation strategy, parameters from all steps of the fuel cycle must be taken into account, such as spent fuel heat load, gamma or neutron sources or fabrication feasibility. Considering a multi-recycling strategy of minor actinides, an analysis of relevant estimators necessary to fully analyze a transmutation strategy has been performed in this work and a sensitivity analysis of these estimators to a broad choice of reactors and fuel cycle parameters has been carried out. No threshold or percolation effects were observed. Saturation of transmutation rate with regards to several parameters has been observed, namely the minor actinides volume fraction and the irradiation time. Estimators of interest that have been

  19. Actinide Separation Demonstration Facility, Tarapur

    International Nuclear Information System (INIS)

    Vishwaraj, I.

    2017-01-01

    Partitioning of minor actinide from high level waste could have a substantial impact in lowering the radio toxicity associated with high level waste as well as it will reduce the burden on geological repository. In Indian context, the partitioned minor actinide could be routed into the fast breeder reactor systems scheduled for commissioning in the near period. The technological breakthrough in solvent development has catalyzed the partitioning programme in India, leading to the setting up and hot commissioning of the Actinide Separation Demonstration Facility (ASDF) at BARC, Tarapur. The engineering scale Actinide Separation Demonstration Facility (ASDF) has been retrofitted in an available radiological hot cell situated adjacent to the Advanced Vitrification Facility (AVS). This location advantage ensures an uninterrupted supply of high-level waste and facilitates the vitrification of the high-level waste after separation of minor actinides

  20. Subsurface Biogeochemistry of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, Annie B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Univ. Relations and Science Education; Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.

    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. Ten years of experience in extraction chromatographic processes for the recovery, separation and purification of actinides elements

    International Nuclear Information System (INIS)

    Madic, C.; Bourges, J.; Koehly, G.

    1984-06-01

    Ten years ago the extraction chromatographic technique was developed for preparative purposes and is now applied for all chemicals separations needed for the production of actinides isotopes. That technique appears to be simple and flexible. It can be used for the production of microgram to kilogram amounts of actinide isotopes. This paper focuses on the experience gained and describes some peculiar production of actinide isotopes solved by using extraction chromatographic technique. After a review of extracting molecules and equipment, treatment of irradiated targets (preparation of Pu 238 and removal of neptunium, production of Am 243 and Cm 244), recovery of actinides from alpha aqueous wastes (preparation of Am 241) and recovery of decay products from aged actinide stocks (recovery of Am 241 from Pu stocks, of U 234 from Pu 238 stocks) are described

  2. Concentration of actinides in the food chain

    International Nuclear Information System (INIS)

    Bulman, R.A.

    1976-06-01

    Considerable concern is now being expressed over the discharge of actinides into the environment. This report presents a brief review of the chemistry of the actinides and examines the evidence for interaction of the actinides with some naturally-occurring chelating agents and other factors which might stimulate actinide concentration in the food chain of man. This report also reviews the evidence for concentration of actinides in plants and for uptake through the gastrointestinal tract. (author)

  3. Thermal-hydraulics of actinide burner reactors

    International Nuclear Information System (INIS)

    Takizuka, Takakazu; Mukaiyama, Takehiko; Takano, Hideki; Ogawa, Toru; Osakabe, Masahiro.

    1989-07-01

    As a part of conceptual study of actinide burner reactors, core thermal-hydraulic analyses were conducted for two types of reactor concepts, namely (1) sodium-cooled actinide alloy fuel reactor, and (2) helium-cooled particle-bed reactor, to examine the feasibility of high power-density cores for efficient transmutation of actinides within the maximum allowable temperature limits of fuel and cladding. In addition, calculations were made on cooling of actinide fuel assembly. (author)

  4. BWR Assembly Optimization for Minor Actinide Recycling

    International Nuclear Information System (INIS)

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

    2010-01-01

    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). A top-level objective of the Advanced Fuel Cycle Systems Analysis program element of the DOE NERI program is to investigate spent fuel treatment and recycling options for current light water reactors (LWRs). Accordingly, this project targets to expand the traditional scope of nuclear fuel management optimization into the following two complementary specific objectives: (1) To develop a direct coupling between the pin-by-pin within-bundle loading control variables and core-wide (bundle-by-bundle) optimization objectives, (2) to extend the methodology developed to explicitly encompass control variables, objectives, and constraints designed to maximize minor actinide incineration in BWR bundles and cycles. The first specific objective is projected to 'uncover' dormant thermal margin made available by employing additional degrees of freedom within the optimization process, while the addition of minor actinides is expected to 'consume' some of the uncovered thermal margin. Therefore, a key underlying goal of this project is to effectively invest some of the uncovered thermal margin into achieving the primary objective.

  5. Actinide colloid generation in groundwater. Part 2

    International Nuclear Information System (INIS)

    Kim, J.I.

    1991-01-01

    The progress made in the investigation of actinide colloid generation in groundwater is summarized and discussed with particular examples relevant to an understanding of the migration behaviour of actinides in natural aquifer systems. The first part deals with the characterization of colloids: groundwater colloids, actinide real-colloids and actinide pseudocolloids. The second part concentrates on the generation processes and migration behaviour of actinide pseudo colloids, which are discussed with some notable experimental examples. Importance is stressed more on the chemical aspects of the actinide colloid generation in groundwater. This work is a contribution to the CEC Mirage II project, in particular the complexation and colloids research area

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

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.

    1988-10-01

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

  7. Actinide cation-cation complexes

    International Nuclear Information System (INIS)

    Stoyer, N.J.; Seaborg, G.T.

    1994-12-01

    The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO 2 + ) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO 2 + ; therefore, cation-cation complexes indicate something unique about AnO 2 + cations compared to actinide cations in general. The first cation-cation complex, NpO 2 + ·UO 2 2+ , was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO 2 + species, the cation-cation complexes of NpO 2 + have been studied most extensively while the other actinides have not. The only PuO 2 + cation-cation complexes that have been studied are with Fe 3+ and Cr 3+ and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO 2 + ·UO 2 2+ , NpO 2 + ·Th 4+ , PuO 2 + ·UO 2 2+ , and PuO 2 + ·Th 4+ at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ∼0.8 M -1

  8. Actinide production in the reaction of heavy ions with curium-248

    International Nuclear Information System (INIS)

    Moody, K.J.

    1983-07-01

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

  9. Extraction chromatogrpahy of actinides, ch. 7

    International Nuclear Information System (INIS)

    Mueller, W.

    1975-01-01

    This review on extraction chromatography of actinides emphasizes the important usage of neutral (Tributylphosphate), basic (substituted ammonium salts), and acidic (HDEHP) extractants, and their application to separations of actinides in the di-to hexavalent oxidation state. Furthermore, the actinide extraction by ketones, ethers, alcohols and β-diketones is discussed

  10. Utilization of fast reactor excess neutrons for burning minor actinides and long lived FPs

    International Nuclear Information System (INIS)

    Kawashima, K.; Kobayashi, K.; Kaneto, K.

    1995-01-01

    An evaluation is made on a large MOX fuel fast reactor's capability of burning minor actinides and long lived fission products (FPs) without imposing penalties on core nuclear and safety characteristics. The excess neutrons generated in the fast reactor core are fully utilized not only to generate the fissile material but also to transmute the minor actinides and long lived FPs. The FP target assemblies which consist of Tc-99 and I-129 are loaded into the selected blanket positions whereas the minor actinides are loaded to the rest of the blanket. A long term FP accumulation scenario is also considered in the mix of FP burner fast reactor and non-burner LWRs. (author)

  11. Cross Sections for Neutron-induced Reactions on Actinide Targets Extracted from Surrogate Experiments: A Status Report

    International Nuclear Information System (INIS)

    Escher, J.E.; Burke, J.T.; Dietrich, F.S.; Lesher, S.R.; Scielzo, N.D.; Thompson, I.J.; Younes, W.

    2009-01-01

    The Surrogate nuclear reactions method, an indirect approach for determining cross sections for compound-nuclear reactions involving difficult-to-measure targets, is reviewed. Focusing on cross sections for neutron-induced reactions on actinides, we review the successes of past and present applications of the method and assess its uncertainties and limitations. The approximations used in the analyses of most experiments work reasonably well for (n,f) cross sections for neutron energies above 1-2 MeV, but lead to discrepancies for low-energy (n,f) reactions, as well as for (n,γ) applications. Correcting for some of the effects neglected in the approximate analyses leads to improved (n,f) results. We outline steps that will further improve the accuracy and reliability of the Surrogate method and extend its applicability to reactions that cannot be approached with the present implementation of the method.

  12. Cross Sections for Neutron-induced Reactions on Actinide Targets Extracted from Surrogate Experiments: A Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Lesher, S R; Scielzo, N D; Thompson, I J; Younes, W

    2009-10-01

    The Surrogate nuclear reactions method, an indirect approach for determining cross sections for compound-nuclear reactions involving difficult-to-measure targets, is reviewed. Focusing on cross sections for neutron-induced reactions on actinides, we review the successes of past and present applications of the method and assess its uncertainties and limitations. The approximations used in the analyses of most experiments work reasonably well for (n,f) cross sections for neutron energies above 1-2 MeV, but lead to discrepancies for low-energy (n,f) reactions, as well as for (n,{gamma}) applications. Correcting for some of the effects neglected in the approximate analyses leads to improved (n,f) results. We outline steps that will further improve the accuracy and reliability of the Surrogate method and extend its applicability to reactions that cannot be approached with the present implementation of the method.

  13. Minor actinide transmutation on PWR burnable poison rods

    International Nuclear Information System (INIS)

    Hu, Wenchao; Liu, Bin; Ouyang, Xiaoping; Tu, Jing; Liu, Fang; Huang, Liming; Fu, Juan; Meng, Haiyan

    2015-01-01

    Highlights: • Key issues associated with MA transmutation are the appropriate loading pattern. • Commercial PWRs are the only choice to transmute MAs in large scale currently. • Considerable amount of MA can be loaded to PWR without disturbing k eff markedly. • Loading MA to PWR burnable poison rods for transmutation is an optimal loading pattern. - Abstract: Minor actinides are the primary contributors to long term radiotoxicity in spent fuel. The majority of commercial reactors in operation in the world are PWRs, so to study the minor actinide transmutation characteristics in the PWRs and ultimately realize the successful minor actinide transmutation in PWRs are crucial problem in the area of the nuclear waste disposal. The key issues associated with the minor actinide transmutation are the appropriate loading patterns when introducing minor actinides to the PWR core. We study two different minor actinide transmutation materials loading patterns on the PWR burnable poison rods, one is to coat a thin layer of minor actinide in the water gap between the zircaloy cladding and the stainless steel which is filled with water, another one is that minor actinides substitute for burnable poison directly within burnable poison rods. Simulation calculation indicates that the two loading patterns can load approximately equivalent to 5–6 PWR annual minor actinide yields without disturbing the PWR k eff markedly. The PWR k eff can return criticality again by slightly reducing the boric acid concentration in the coolant of PWR or removing some burnable poison rods without coating the minor actinide transmutation materials from PWR core. In other words, loading minor actinide transmutation material to PWR does not consume extra neutron, minor actinide just consumes the neutrons which absorbed by the removed control poisons. Both minor actinide loading patterns are technically feasible; most importantly do not need to modify the configuration of the PWR core and

  14. Actinide speciation in the environment

    International Nuclear Information System (INIS)

    Choppin, G.R.

    2007-01-01

    Nuclear test explosions and nuclear reactor wastes and accidents have released large amounts of radioactivity into the environment. Actinide ions in waters often are not in a state of thermodynamic equilibrium and their solubility and migration behavior is related to the form in which the nuclides are introduced into the aquatic system. Chemical speciation, oxidation state, redox reactions, and sorption characteristics are necessary in predicting solubility of the different actinides, their migration behaviors and their potential effects on marine biota. The most significant of these variables is the oxidation state of the metal ion as the simultaneous presence of more than one oxidation state for some actinides in a solution complicates actinide environmental behavior. Both Np(V)O 2 + and Pu(V)O 2 + , the most significant soluble states in natural oxic waters, are relatively noncomplexing and resistant to hydrolysis and subsequent precipitation. The solubility of NpO 2 + can be as high as 10 -4 M while that of PuO 2 + is much more limited by reduction to the insoluble tetravalent species, Pu(OH) 4 , (pK sp ≥56) but which can be present in the pentavalent form in aqautic phases as colloidal material. The solubility of hexavalent UO 2 2+ in sea water is relatively high due to formation of carbonate complexes. The insoluble trivalent americium hydroxocarbonate, Am(OH)(CO 3 ) is the limiting species for the solubility of Am(III) in sea water. Thorium(IV) is present as Th(OH) 4 , in colloidal form. The chemistry of actinide ions in the environment is reviewed to show the spectrum of reactions that can occur in natural waters which must be considered in assessing the environmental behavior of actinides. Much is understood about sorption of actinides on surfaces, the mode of migration of actinides in such waters and the potential effects of these radioactive species on marine biota, but much more understanding of the behavior of the actinides in the environment is

  15. Research on the chemical speciation of actinides

    International Nuclear Information System (INIS)

    Jung, Euo Chang; Park, K. K.; Cho, H. R.

    2012-04-01

    A demand for the safe and effective management of spent nuclear fuel and radioactive waste generated from nuclear power plant draws increasing attention with the growth of nuclear power industry. The objective of this project is to establish the basis of research on the actinide chemistry by using highly sensitive and advanced laser-based spectroscopic systems. Researches on the chemical speciation of actinides are prerequisite for the development of technologies related to nuclear fuel cycles, especially, such as the safe management of high level radioactive wastes and the chemical examination of irradiated nuclear fuels. For supporting these technologies, laser-based spectroscopies have been applied for the chemical speciation of actinide in aqueous solutions and the quantitative analysis of actinide isotopes in spent nuclear fuels. In this report, results on the following subjects have been summarized. Development of TRLFS technology for the chemical speciation of actinides, Development of laser-induced photo-acoustic spectroscopy (LPAS) system, Application of LIBD technology to investigate dynamic behaviors of actinides dissolution reactions, Development of nanoparticle analysis technology in groundwater using LIBD, Chemical speciation of plutonium complexes by using a LWCC system, Development of LIBS technology for the quantitative analysis of actinides, Evaluation on the chemical reactions between actinides and humic substances, Spectroscopic speciation of uranium-ligand complexes in aqueous solution, Chemical speciation of actinides adsorbed on metal oxides surfaces

  16. Sequestering agents for the removal of actinides from waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, K.N.; White, D.J.; Xu, Jide; Mohs, T.R. [Univ. of California, Berkeley, CA (United States)

    1997-10-01

    The goal of this project is to take a biomimetic approach toward developing new separation technologies for the removal of radioactive elements from contaminated DOE sites. To achieve this objective, the authors are investigating the fundamental chemistry of naturally occurring, highly specific metal ion sequestering agents and developing them into liquid/liquid and solid supported actinide extraction agents. Nature produces sideophores (e.g., Enterobactin and Desferrioxamine B) to selectivity sequester Lewis acidic metal ions, in particular Fe(III), from its surroundings. These chelating agents typically use multiple catechols or hydroxamic acids to form polydentate ligands that chelate the metal ion forming very stable complexes. The authors are investigating and developing analogous molecules into selective chelators targeting actinide(IV) ions, which display similar properties to Fe(III). By taking advantage of differences in charge, preferred coordination number, and pH stability range, the transition from nature to actinide sequestering agents has been applied to the development of new and highly selective actinide extraction technologies. Additionally, the authors have shown that these chelating ligands are versatile ligands for chelating U(VI). In particular, they have been studying their coordination chemistry and fundamental interactions with the uranyl ion [UO{sub 2}]{sup 2+}, the dominant form of uranium found in aqueous media. With an understanding of this chemistry, and results obtained from in vivo uranium sequestration studies, it should be possible to apply these actinide(IV) extraction technologies to the development of new extraction agents for the removal of uranium from waste streams.

  17. Safe actinide disposition in molten salt reactors

    International Nuclear Information System (INIS)

    Gat, U.

    1997-01-01

    Safe molten salt reactors (MSR) can readily accommodate the burning of all fissile actinides. Only minor compromises associated with plutonium are required. The MSRs can dispose safely of actinides and long lived isotopes to result in safer and simpler waste. Disposing of actinides in MSRs does increase the source term of a safety optimized MSR. It is concluded that the burning and transmutation of actinides in MSRs can be done in a safe manner. Development is needed for the processing to handle and separate the actinides. Calculations are needed to establish the neutron economy and the fuel management. 9 refs

  18. Optimization of Actinide Quantification by Electron Probe Microanalysis

    International Nuclear Information System (INIS)

    Moy, A.; Merlet, C.; Llovet, X.; Dugne, O.

    2013-06-01

    Conventional quantitative electron probe microanalysis of actinides requires the use of reference standard samples. However, for such elements, standards are generally not available. To overcome this difficulty, standard-less methods of analysis are used, in which the x-ray intensity emitted by the standard is calculated. To be reliable, such calculations require accurate knowledge of physical data such as the x-ray production cross section. However, experimental data of this quantity are not always available for actinide elements. In the present work, experimental L and M x-ray production cross sections were measured for elements uranium and lead. Measurements were performed with two electron microprobes using wavelength-dispersive spectrometers using thin self-supporting targets. Experimental results are compared with calculated cross sections obtained from different analytical formulae, and, whenever possible, with experimental data obtained from the literature. (authors)

  19. Minor actinide transmutation in accelerator driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Friess, Friederike [IANUS, TU Darmstadt (Germany)

    2015-07-01

    Transmutation of radioactive waste, the legacy of nuclear energy use, gains rising interest. This includes the development of facilities able to transmute minor actinides (MA) into stable or short-lived isotopes before final disposal. The most common proposal is to use a double-strata approach with accelerator-driven-systems (ADS) for the efficient transmutation of MA and power reactors to dispose plutonium. An ADS consists of a sub-critical core that reaches criticality with neutrons supplied by a spallation target. An MCNP model of the ADS system Multi Purpose Research Reactor for Hightech Applications will be presented. Depletion calculations have been performed for both standard MOX fuel and transmutation fuel with an increased content of minor actinides. The resulting transmutation rates for MAs are compared to published values. Special attention is given to selected fission products such as Tc-99 and I-129, which impact the radiation from the spent fuel significantly.

  20. Study of nuclear energy systems and double strata scenarios for minor actinides transmutation in ADS

    International Nuclear Information System (INIS)

    Clavel, J.B.

    2012-01-01

    The French law of 28 June 2006 regarding advanced nuclear waste management requires a scientific assessment to define future industrial strategies. The present PhD thesis was carried in this framework and concerns specifically the research axis of minor actinides transmutation. A high power Accelerator Driven System (ADS) concept is developed at SUBATECH for this purpose. A 1 GeV proton beam feeds three liquid lead-bismuth spallation targets. The Multiple Spallation Target (MUST) ADS reaches the thermal powers up to 1 GW with a high specific power. A nuclear reactor dimensioning method has been developed and applied to different double strata scenarios. In these scenarios, SFR (Sodium Fast Reactors) or PWR (Pressurized Water Reactors) power reactors produce minor actinides that will be transmuted into ADS. In each core (SFR and ADS), the plutonium multi-reprocessing strategy is performed while ADS subcritical core also multi-reprocesses minor actinides. To limit the core reactivity and improve the fuel thermal conductivity, the minor actinides fuel is mixed with MgO inert matrix. Nuclear branches with lead and sodium coolants for the ADS, have been studied for different irradiation times and two transmutation strategies have been assessed: whether whole minor actinides, whether americium only is transmuted. The thesis presents precisely the MUST ADS design methodology and the calculations to get a fuel composition at equilibrium. Then a one cycle evolution is performed and analysed for the fuel and the multiplication factor. Radiotoxicity and thermal power of the waste produced are then compared. Finally, the study of double strata scenarios is performed to analyse the plutonium and minor actinides inventories in cycle and also the waste produced according to the transmutation strategies applied and the first stratum evolution. (author)

  1. Actinides burnup in a sodium fast reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-15

    The burnup of actinides in a nuclear reactor is been proposed as part of an advanced nuclear fuel cycle, this process would close the fuel cycle recycling some of the radioactive material produced in the open nuclear fuel cycle. These actinides are found in the spent nuclear fuel from nuclear power reactors at the end of their burnup in the reactor. Previous studies of actinides recycling in thermal reactors show that would be possible reduce the amounts of actinides at least in 50% of the recycled amounts. in this work, the amounts of actinides that can be burned in a fast reactor is calculated, very interesting results surge from the calculations, first, the amounts of actinides generated by the fuel is higher than for thermal fuel and the composition of the actinides vector is different as in fuel for thermal reactor the main isotope is the {sup 237}Np in the fuel for fast reactor the main isotope is the {sup 241}Am, finally it is concluded that the fast reactor, also generates important amounts of waste. (Author)

  2. Burning actinides in very hard spectrum reactors

    International Nuclear Information System (INIS)

    Robinson, A.H.; Shirley, G.W.; Prichard, A.W.; Trapp, T.J.

    1978-01-01

    The major unresolved problem in the nuclear industry is the ultimate disposition of the waste products of light water reactors. The study demonstrates the feasibility of designing a very hard spectrum actinide burner reactor (ABR). A 1100 MW/sub t/ ABR design fueled entirely with actinides reprocessed from light water reactor (LWR) wastes is proposed as both an ultimate disposal mechanism for actinides and a means of concurrently producing usable power. Actinides from discharged ABR fuel are recycled to the ABR while fission products are routed to a permanent repository. As an integral part of a large energy park, each such ABR would dispose of the waste actinides from 2 LWRs

  3. Actinide separative chemistry

    International Nuclear Information System (INIS)

    Boullis, B.

    2004-01-01

    Actinide separative chemistry has focused very heavy work during the last decades. The main was nuclear spent fuel reprocessing: solvent extraction processes appeared quickly a suitable, an efficient way to recover major actinides (uranium and plutonium), and an extensive research, concerning both process chemistry and chemical engineering technologies, allowed the industrial development in this field. We can observe for about half a century a succession of Purex plants which, if based on the same initial discovery (i.e. the outstanding properties of a molecule, the famous TBP), present huge improvements at each step, for a large part due to an increased mastery of the mechanisms involved. And actinide separation should still focus R and D in the near future: there is a real, an important need for this, even if reprocessing may appear as a mature industry. We can present three main reasons for this. First, actinide recycling appear as a key-issue for future nuclear fuel cycles, both for waste management optimization and for conservation of natural resource; and the need concerns not only major actinide but also so-called minor ones, thus enlarging the scope of the investigation. Second, extraction processes are not well mastered at microscopic scale: there is a real, great lack in fundamental knowledge, useful or even necessary for process optimization (for instance, how to design the best extracting molecule, taken into account the several notifications and constraints, from selectivity to radiolytic resistivity?); and such a need for a real optimization is to be more accurate with the search of always cheaper, cleaner processes. And then, there is room too for exploratory research, on new concepts-perhaps for processing quite new fuels- which could appear attractive and justify further developments to be properly assessed: pyro-processes first, but also others, like chemistry in 'extreme' or 'unusual' conditions (supercritical solvents, sono-chemistry, could be

  4. Actinides integral measurements on FCA assemblies

    International Nuclear Information System (INIS)

    Mukaiyama, Takehiko; Okajima, Shigeaki

    1984-01-01

    Actinide integral measurements were performed on eight assemblies of FCA where neutron energy spectra were shifted systematically from soft to hard in order to evaluate and modify the nuclear cross section data of major actinides. Experimental values on actinide fission rates and sample reactivity worths are compared with the calculated values using JENDL-2 and ENDF/B-V (or IV) data sets. (author)

  5. Actinide burning and waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Pigford, T H [University of California, Berkeley, CA (United States)

    1990-07-01

    Here we review technical and economic features of a new proposal for a synergistic waste-management system involving reprocessing the spent fuel otherwise destined for a U.S. high-level waste repository and transmuting the recovered actinides in a fast reactor. The proposal would require a U.S. fuel reprocessing plant, capable of recovering and recycling all actinides, including neptunium americium, and curium, from LWR spent fuel, at recoveries of 99.9% to 99.999%. The recovered transuranics would fuel the annual introduction of 14 GWe of actinide-burning liquid-metal fast reactors (ALMRs), beginning in the period 2005 to 2012. The new ALMRs would be accompanied by pyrochemical reprocessing facilities to recover and recycle all actinides from discharged ALMR fuel. By the year 2045 all of the LWR spent fuel now destined f a geologic repository would be reprocessed. Costs of constructing and operating these new reprocessing and reactor facilities would be borne by U.S. industry, from the sale of electrical energy produced. The ALMR program expects that ALMRs that burn actinides from LWR spent fuel will be more economical power producers than LWRs as early as 2005 to 2012, so that they can be prudently selected by electric utility companies for new construction of nuclear power plants in that era. Some leaders of DOE and its contractors argue that recovering actinides from spent fuel waste and burning them in fast reactors would reduce the life of the remaining waste to about 200-300 years, instead of 00,000 years. The waste could then be stored above ground until it dies out. Some argue that no geologic repositories would be needed. The current view expressed within the ALMR program is that actinide recycle technology would not replace the need for a geologic repository, but that removing actinides from the waste for even the first repository would simplify design and licensing of that repository. A second geologic repository would not be needed. Waste now planned

  6. Actinide burning and waste disposal

    International Nuclear Information System (INIS)

    Pigford, T.H.

    1990-01-01

    Here we review technical and economic features of a new proposal for a synergistic waste-management system involving reprocessing the spent fuel otherwise destined for a U.S. high-level waste repository and transmuting the recovered actinides in a fast reactor. The proposal would require a U.S. fuel reprocessing plant, capable of recovering and recycling all actinides, including neptunium americium, and curium, from LWR spent fuel, at recoveries of 99.9% to 99.999%. The recovered transuranics would fuel the annual introduction of 14 GWe of actinide-burning liquid-metal fast reactors (ALMRs), beginning in the period 2005 to 2012. The new ALMRs would be accompanied by pyrochemical reprocessing facilities to recover and recycle all actinides from discharged ALMR fuel. By the year 2045 all of the LWR spent fuel now destined f a geologic repository would be reprocessed. Costs of constructing and operating these new reprocessing and reactor facilities would be borne by U.S. industry, from the sale of electrical energy produced. The ALMR program expects that ALMRs that burn actinides from LWR spent fuel will be more economical power producers than LWRs as early as 2005 to 2012, so that they can be prudently selected by electric utility companies for new construction of nuclear power plants in that era. Some leaders of DOE and its contractors argue that recovering actinides from spent fuel waste and burning them in fast reactors would reduce the life of the remaining waste to about 200-300 years, instead of 00,000 years. The waste could then be stored above ground until it dies out. Some argue that no geologic repositories would be needed. The current view expressed within the ALMR program is that actinide recycle technology would not replace the need for a geologic repository, but that removing actinides from the waste for even the first repository would simplify design and licensing of that repository. A second geologic repository would not be needed. Waste now planned

  7. Chemistry of actinides and fission products

    International Nuclear Information System (INIS)

    Pruett, D.J.; Sherrow, S.A.; Toth, L.M.

    1988-01-01

    This task is concerned primarily with the fundamental chemistry of the actinide and fission product elements. Special efforts are made to develop research programs in collaboration with researchers at universities and in industry who have need of national laboratory facilities. Specific areas currently under investigation include: (1) spectroscopy and photochemistry of actinides in low-temperature matrices; (2) small-angle scattering studies of hydrous actinide and fission product polymers in aqueous and nonaqueous solvents; (3) kinetic and thermodynamic studies of complexation reactions in aqueous and nonaqueous solutions; and (4) the development of inorganic ion exchange materials for actinide and lanthanide separations. Recent results from work in these areas are summarized here

  8. Study of actinide paramagnetism in solution

    International Nuclear Information System (INIS)

    Autillo, Matthieu

    2015-01-01

    The physiochemical properties of actinide (An) solutions are still difficult to explain, particularly the behavioral differences between An(III) and Ln(III). The study of actinide paramagnetic behavior may be a 'simple' method to analyze the electronic properties of actinide elements and to obtain information on the ligand-actinide interaction. The objective of this PhD thesis is to understand the paramagnetic properties of these elements by magnetic susceptibility measurements and chemical shift studies. Studies on actinide electronic properties at various oxidation states in solution were carried out by magnetic susceptibility measurements in solution according to the Evans method. Unlike Ln(III) elements, there is no specific theory describing the magnetic properties of these ions in solution. To obtain accurate data, the influence of experimental measurement technique and radioactivity of these elements was analyzed. Then, to describe the electronic structure of their low energy states, the experimental results were complemented with quantum chemical calculations from which the influence of the ligand field was studied. Finally, these interpretations were applied to better understand the variations in the magnetic properties of actinide cations in chloride and nitrate media. Information about ligand-actinide interactions may be determined from an NMR chemical shift study of actinide complexes. Indeed, modifications induced by a paramagnetic complex can be separated into two components. The first component, a Fermi contact contribution (δ_c) is related to the degree of covalency in coordination bonds with the actinide ions and the second, a dipolar contribution (δ_p_c) is related to the structure of the complex. The paramagnetic induced shift can be used only if we can isolate these two terms. To achieve this study on actinide elements, we chose to work with the complexes of dipicolinic acid (DPA). Firstly, to characterize the geometrical parameters, a

  9. Catalytic Organic Transformations Mediated by Actinide Complexes

    Directory of Open Access Journals (Sweden)

    Isabell S. R. Karmel

    2015-10-01

    Full Text Available This review article presents the development of organoactinides and actinide coordination complexes as catalysts for homogeneous organic transformations. This chapter introduces the basic principles of actinide catalysis and deals with the historic development of actinide complexes in catalytic processes. The application of organoactinides in homogeneous catalysis is exemplified in the hydroelementation reactions, such as the hydroamination, hydrosilylation, hydroalkoxylation and hydrothiolation of alkynes. Additionally, the use of actinide coordination complexes for the catalytic polymerization of α-olefins and the ring opening polymerization of cyclic esters is presented. The last part of this review article highlights novel catalytic transformations mediated by actinide compounds and gives an outlook to the further potential of this field.

  10. Evidence for bimodal fission in the heaviest elements

    International Nuclear Information System (INIS)

    Hulet, E.K.; Wild, J.F.; Lougheed, R.W.

    1987-08-01

    We have measured the mass and kinetic-energy partitioning in the spontaneous fission of five heavy nuclides: 258 Fm, 259 Md, 260 Md 258 No, and 260 [104]. Each was produced by heavy-ion reactions with either 248 Cm, 249 Bk, or 254 Es targets. Energies of correlated fragments from the isotopes with millisecond half lives, 258 No and 260 [104], were measured on-line by a special rotating-wheel instrument, while the others were determined off-line after mass separation. All fissioned with mass distributions that were symmetric. Total-kinetic-energy distributions peaked near either 200 or 235 MeV. Surprisingly, because only a single Gaussian energy distribution had been observed previously in actinide fission, these energy distributions were skewed upward or downward from the peak in each case, except for 260 [104], indicating a composite of two energy distributions. We were able to fit accurately two Gaussian curves to the gross energy distributions from the four remaining nuclides. From the multiple TKE distributions and the shapes of the mass distributions, we conclude that there is a low-energy fission component with liquid-drop characteristics which is admixed with a much higher-energy component due to closed fragment shells. We now have further evidence for this conclusion from measurements of the neutron multiplicity in the spontaneous fission of 260 Md. 25 refs., 9 figs

  11. Burn of actinides in MOX fuel cells

    International Nuclear Information System (INIS)

    Martinez C, E.; Ramirez S, J. R.; Alonso V, G.

    2017-09-01

    The spent fuel from nuclear reactors is stored temporarily in dry repositories in many countries of the world. However, the main problem of spent fuel, which is its high radio-toxicity in the long term, is not solved. A new strategy is required to close the nuclear fuel cycle and for the sustain ability of nuclear power generation, this strategy could be the recycling of plutonium to obtain more energy and recycle the actinides generated during the irradiation of the fuel to transmute them in less radioactive radionuclides. In this work we evaluate the quantities of actinides generated in different fuels and the quantities of actinides that are generated after their recycling in a thermal reactor. First, we make a reference calculation with a regular enriched uranium fuel, and then is changed to a MOX fuel, varying the plutonium concentrations and determining the quantities of actinides generated. Finally, different amounts of actinides are introduced into a new fuel and the amount of actinides generated at the end of the fuel burn is calculated, in order to determine the reduction of minor actinides obtained. The results show that if the concentration of plutonium in the fuel is high, then the production of minor actinides is also high. The calculations were made using the cell code CASMO-4 and the results obtained are shown in section 6 of this work. (Author)

  12. Minor actinide transmutation - a waste management option

    International Nuclear Information System (INIS)

    Koch, L.

    1986-01-01

    The incentive to recycle minor actinides results from the reduction of the long-term α-radiological risk rather than from a better utilization of the uranium resources. Nevertheless, the gain in generated electricity by minor actinide transmutation in a fast breeder reactor can compensate for the costs of their recovery and make-up into fuel elements. Different recycling options of minor actinides are discussed: transmutation in liquid metal fast breeder reactors (LMFBRs) is possible as long as plutonium is not recycled in light water reactors (LWRs). In this case a minor actinide burner with fuel of different composition has to be introduced. The development of appropriate minor actinide fuels and their properties are described. The irradiation experiments underway or planned are summarized. A review of minor actinide partitioning from the PUREX waste stream is given. From the present constraints of LMFBR technology a reduction of the long-term α-radiological risk by a factor of 200 is deduced relative to that from the direct storage of spent LWR fuel. Though the present accumulation of minor actinides is low, nuclear transmutation may be needed when nuclear energy production has grown. (orig.)

  13. Few atom chemistry of the trans actinide element rutherfordium (Rf)

    International Nuclear Information System (INIS)

    Nagame, Y.

    2002-01-01

    Studies of chemical properties of the trans actinide elements - starting with element 104 (Rf) - offer the unique opportunity to obtain information about trends in the Periodic Table at the limits of nuclear stability and to assess the magnitude of the influence of relativistic effects on chemical properties. To explore experimentally the influence of relativistic effects of electron shell structure, we study the chemical properties of the trans actinide elements. So far, we have developed some experimental apparatuses for the study of chemical properties of the trans actinide elements: a beam-line safety system for the usage of the gas-jet coupled radioactive 248 Cm target chamber for the production of trans actinides, a rotating wheel catcher apparatus for the measurement of α particles and spontaneous fission decay of trans actinides and an automated rapid chemical separation apparatus based on high performance liquid chromatography. The trans actinide nuclide, the element 104, 261 Rf (t 1/2 = 78 s) has been successfully produced via the reactions of 248 Cm( 18 O,5n) at the JAERI (Japan Atomic Energy Research Institute) tandem accelerator. The evaluated production cross section was about 10 nb, indicating that the production rate was approximately 2 atoms per min. Because of the short half-life and the low production rate of Rf, each atom produced decays before a new atom is synthesized. It means that any chemistry to be performed must be done on an 'atom-at-a-time' basis. Therefore rapid, very efficient and selective chemical procedures are indispensable to isolate the desired trans actinide 261 Rf. To perform fast and repetitive ion-exchange separation of Rf, we have developed the apparatus AIDA (Automated Ion exchange separation system coupled with the Detection apparatus for Alpha spectroscopy). Recently, ion-exchange behavior of Rf in acidic solutions has been studied with AIDA, and the results indicate that anion-exchange behavior of Rf is quite similar

  14. Moessbauer effect studies with actinides

    International Nuclear Information System (INIS)

    Stone, J.A.

    1966-01-01

    Moessbauer resonance studies in the actinide elements offer a new technique for measuring solid-state properties to a region of the periodic chart where such information is relatively sparse. It is well known that the actinides, the elements with atomic numbers from 90 to 103, form a transition series due to filling of the 5f electron shell, analogous to the rare-earth series in which the 4f shell is filled. Like the rare earths, the actinide metals and compounds are expected to exhibit a variety of interesting magnetic properties, but, unlike the rare earths, there have been few studies of the magnetic behaviour of actinides, and these properties are largely unknown. The chemical properties of the actinides have been studied somewhat more extensively, and, in contrast to the rare earths, form a multiplicity of stable valence states, especially in the lighter members of the series. It is just these properties, magnetic and chemical, for which the Moessbauer effect is a valuable probe, sensitive to the magnetic and electric environment of an atom. The rare-earth series has been a particularly fruitful region in terms of the number of elements which have been shown to exhibit the Moessbauer effect, and for this reason the exploitation of the Moessbauer effect to yield new solid-state and chemical information on the rare earths is a highly active field of research today. There is every reason to believe that the actinides can be similarly studied by the Moessbauer effect. 43 refs, 6 figs, 4 tabs

  15. Evaluation of actinide partitioning and transmutation

    International Nuclear Information System (INIS)

    1982-01-01

    After a few centuries of radioactive decay the long-lived actinides, the elements of atomic numbers 89-103, may constitute the main potential radiological health hazard in nuclear wastes. This is because all but a very few fission products (principally technetium-99 and iodine-129) have by then undergone radioactive decay to insignificant levels, leaving the actinides as the principal radionuclides remaining. It was therefore at first sight an attractive concept to recycle the actinides to nuclear reactors, so as to eliminate them by nuclear fission. Thus, investigations of the feasibility and potential benefits and hazards of the concept of 'actinide partitioning and transmutation' were started in numerous countries in the mid-1970s. This final report summarizes the results and conclusions of technical studies performed in connection with a four-year IAEA Co-ordinated Research Programme, started in 1976, on the ''Environmental Evaluation and Hazard Assessment of the Separation of Actinides from Nuclear Wastes followed by either Transmutation or Separate Disposal''. Although many related studies are still continuing, e.g. on waste disposal, long-term safety assessments, and waste actinide management (particularly for low and intermediate-level wastes), some firm conclusions on the overall concept were drawn by the programme participants, which are reflected in this report

  16. Concept and experimental studies on fuel and target for minor actinides and fission products transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Prunier, C; Guerin, Y [CEA Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d` Etudes des Combustibles; Salvatores, M [CEA Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Direction des Reacteurs Nucleaires; Zaetta, A [CEA Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d` Etudes des Reacteurs

    1994-12-31

    High activity long-lived radionuclides in nuclear wastes, namely minor actinides (americium and neptunium) are in large amount generated by current nuclear reactive. The destruction of these radionuclides is a part of the French SPIN (Partitioning and Burning) program consistent with the determination to send a minimum amount of harmful products for final storage. Transmutation concepts are defined for neptunium and americium taking into account fuel cycle strategies. Neptunium destruction does not pose any major problems. It`s a by-product of uranium consumption, as plutonium and in despite of a slight gamma activity due to the protactinium 233 it`s quite easy to handle. Diluting neptunium in the mixed oxide fuels (MOX) should not be an obstacle for fabrication, in-pile behaviour and reprocessing either. Consequently we make the proposal of homogeneous mode of neptunium in MOX which should be soon explored in the experimental OSIRIS reactor and in the Phenix and Superphenix reactors. The analysis is more complex for the multi isotope americium. Its destruction is difficult because of gamma radioactivity which complicates fabrication. Experiments in Phenix and calculation showed that Phenix reactor offers a good potential for americium incineration, but similar data do not exist for PWR. It will remain a well known difficulty for fabrication and reprocessing. In this case we have to put a real new face to the fabrication flow-sheet of americium compounds and we propose to develop the heterogeneous mode. Targets choice are defined in term of: -safety, considering fuel reaction with cladding and water sodium, -transmutation rate, limited by target behaviour, in FR`s (Phenix), PWR`s (OSIRIS) and HFR (Petten), -reprocessing, checking the solubility of such targets by Purex process. So, at the beginning of our program the account has been on improving fuel and targets properties related to safety and fuel cycle. (authors). 4 figs.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  18. Actinide nanoparticle research

    International Nuclear Information System (INIS)

    Kalmykov, Stepan N.; Denecke, Melissa A.

    2011-01-01

    This is the first book to cover actinide nano research. It is of interest both for fundamental research into the chemistry and physics of f-block elements as well as for applied researchers such as those studying the long-term safety of nuclear waste disposal and developing remediation strategies. The authors cover important issues of the formation of actinide nano-particles, their properties and structure, environmental behavior of colloids and nanoparticles related to the safe disposal of nuclear wastes, modeling and advanced methods of characterization at the nano-scale. (orig.)

  19. Burning minor actinides in a HTR energy spectrum

    International Nuclear Information System (INIS)

    Pohl, Christoph; Rütten, H. Jochem

    2012-01-01

    Highlights: ► Burn-up analysis for varying plutonium/minor actinide fuel compositions. ► The influence of varying heavy metal fuel element loads is investigated. ► Significant burn-up via radiative capture and subsequently fission is observed. ► Difference observed between fuel element burn-up and total actinide burning rate. - Abstract: The generation of nuclear energy by means of the existing nuclear reactor systems is based mainly on the fission of U-235. But this comes along with the capture of neutrons by the U-238 faction and results in a build-up of plutonium isotopes and minor actinides as neptunium, americium and curium. These actinides are dominant for the long time assessment of the radiological risk of a final disposal therefore a minimization of the long living isotopes is aspired. Burning the actinides in a high temperature helium cooled graphite moderated reactor (HTR) is one of these options. The use of plutonium isotopes to sustain the criticality of the system is intended to avoid on the one hand highly enriched uranium because of international regulations and on the other hand low enriched uranium because of the build up of new actinides from neutron capture in the U-238 fraction. Because initial minor actinide isotopes are typically not fissionable by thermal neutrons the idea is to fission instead the intermediate isotopes generated by the first neutron capture. This paper comprises calculations for plutonium/minor actinides/thorium fuel compositions and their correlated final burn-up for a generic pebble bed HTR based on the reference design of the 400 MW PBMR. In particular the cross sections and the neutron balance of the different minor actinide isotopes in the higher thermal energy spectrum of a HTR will be discussed. For a fuel mixture of plutonium and minor actinides a significant burn-up of these actinides up to 20% can be achieved but at the expense of a higher residual fraction of plutonium in the burned fuel. Combining

  20. Actinides reduction by recycling in a thermal reactor

    International Nuclear Information System (INIS)

    Ramirez S, J. R.; Martinez C, E.; Balboa L, H.

    2014-10-01

    This work is directed towards the evaluation of an advanced nuclear fuel cycle in which radioactive actinides could be recycled to remove most of the radioactive material; firstly a production reference of actinides in standard nuclear fuel of uranium at the end of its burning in a BWR reactor is established, after a fuel containing plutonium is modeled to also calculate the actinides production in MOX fuel type. Also it proposes a design of fuel rod containing 6% of actinides in a matrix of uranium from the tails of enrichment, then four standard uranium fuel rods are replaced by actinides rods to evaluate the production and transmutation thereof, the same procedure was performed in the fuel type MOX and the end actinide reduction in the fuel was evaluated. (Author)

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

    International Nuclear Information System (INIS)

    Moeller, P.; Nix, J.R.

    1993-01-01

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

  2. PRODUCTION OF ACTINIDE METAL

    Science.gov (United States)

    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)

  3. ACSEPT-Partitioning technologies and actinide science: Towards pilot facilities in Europe

    International Nuclear Information System (INIS)

    Bourg, S.; Hill, C.; Caravaca, C.; Rhodes, C.; Ekberg, C.; Taylor, R.; Geist, A.; Modolo, G.; Cassayre, L.; Malmbeck, R.; Harrison, M.; Angelis, G. de; Espartero, A.; Bouvet, S.; Ouvrier, N.

    2011-01-01

    Highlights: → ACSEPT works at developing actinide separation processes for advanced fuel cycles. → ACSEPT develops both aqueous and pyrochemical actinide separation processes. → Homogeneous and heterogeneous recycling strategies are both considered in ACSEPT. → Training and education in actinide chemistry are important issues addressed by ACSEPT. - Abstract: Actinide recycling by separation and transmutation is considered worldwide and particularly in several European countries as one of the most promising strategies to reduce the inventory of radioactive waste and to optimise the use of natural resources. With its multidisciplinary consortium of 34 partners from 12 European countries plus Australia and Japan, the European Research Project ACSEPT (Actinide reCycling by SEParation and Transmutation) aims at contributing to the development of this strategy by studying both hydrometallurgical and pyrochemical partitioning routes. ACSEPT is organised into three technical domains: (i)Considering technically mature aqueous separation processes, ACSEPT works to optimise and select the most promising ones dedicated either to actinide partitioning (for the heterogeneous recycling of actinides in ADS target or specific actinide bearing blanket fuels in fast reactor) or to grouped actinide separation (for the homogeneous recycling of the actinides in fast reactor fuels). In addition, dissolution and conversion studies are underway taking into account the specific requirements of these specific fuels. (ii)Concerning pyrochemical separation processes, ACSEPT focuses on the enhancement of the two reference cores processes selected within FP6-EUROPART. R and D efforts are also devoted to key scientific and technical issues compulsory to set up a complete separation process (head-end steps, salt treatment for recycling and waste management). (iii)By integrating all the experimental results in engineering and system studies, both in hydro and pyro domains, ACSEPT will

  4. Potential carcinogenic effects of actinides in the environment

    International Nuclear Information System (INIS)

    Harley, N.H.; Pasternack, B.S.

    1979-01-01

    Inhalation of alpha emitting actinides delivers a dose to critical cancer sites in the human body. These sites are the bronchial epithelium and cells near bone surfaces. Inhalation of the naturally occurring actinides uranium and thorium in resuspended soil in the air results in a continuous exposure for the global population of about 0.1 fCi/m 3 for each of these actinides. The highest dose is from the natural actinide 230 Th. Over 50 yr, the dose to bronchial epithelium is 0.05 mrad and to bone surfaces 0.4 mrad. In the case of accidental environmental contamination (e.g. near a nuclear fuel reprocessing plant) the man-made actinides plutonium, americium and curium could deliver about the same alpha dose to these sites if the soil is contaminated to the same level as the natural actinides (approximately 1 pCi/g). Two nuclear accidents have already produced contamination of about this level. Exposures in this case, however, are to small local populations compared with global exposure for the natural actinides. Significant enhancement of the natural radioactive actinide pollution by combustion of all types of fossil fuel is suspected but not enough data are available to estimate total population doses. (author)

  5. End point control of an actinide precipitation reactor

    International Nuclear Information System (INIS)

    Muske, K.R.

    1997-01-01

    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

  6. On the suitability of lanthanides as actinide analogs

    International Nuclear Information System (INIS)

    Raymond, Kenneth; Szigethy, Geza

    2008-01-01

    With the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries. (authors)

  7. Review of actinide decorporation with chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Ansoborlo, E. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/CETAMA), 30 - Marcoule (France); Amekraz, B.; Moulin, Ch. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC/SECR), 91 - Gif sur Yvette (France); Moulin, V. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares (DEN/DDIN/MR), 91 - Gif Sur Yvette (France); Taran, F. [CEA Saclay (DSV/DBJC/SMMCB), 91 - Gif-sur-Yvette (France); Bailly, Th.; Burgada, R. [Centre National de la Recherche Scientifique (CNRS/LCSB/UMR 7033), 93 - Bobigny (France); Henge-Napoli, M.H. [CEA Valrho, Site de Marcoule (INSTN), 30 (France); Jeanson, A.; Den Auwer, Ch.; Bonin, L.; Moisy, Ph. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DRCP/SCPS), 30 - Marcoule (France)

    2007-10-15

    In case of accidental release of radionuclides in a nuclear facility or in the environment, internal contamination (inhalation, ingestion or wound) with actinides represents a severe health risk to human beings. It is therefore important to provide effective chelation therapy or decorporation to reduce acute radiation damage, chemical toxicity, and late radiation effects. Speciation governs bioavailability and toxicity of elements and it is a prerequisite tool for the design and success of new ligands or chelating agents. The purpose of this review is to present the state-of-the-art of actinide decorporation within biological media, to recall briefly actinide metabolism, to list the basic constraints of actinide-ligand for development, to describe main tools developed and used for decorporation studies, to review mainly the chelating agents tested for actinides, and finally to conclude on the future trends in this field. (authors)

  8. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    International Nuclear Information System (INIS)

    Clark, David L.; Fedosseev, Alexander M.

    2001-01-01

    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

  9. Transmutation of waste actinides in light water reactors

    International Nuclear Information System (INIS)

    Gorrell, T.C.

    1979-04-01

    Actinide recycle and transmutation calculations were made for three irradiation options of a light water reactor (LWR). The cases considered were: all actinides recycled in regular uranium fuel assemblies; transuranic actinides recycled in separate MOX assemblies with 235 U enrichment of uranium; and transuranic actinides recycled in separate MOX assemblies with plutonium enrichment of natural uranium. When all actinides were recycled in a uniform lattice, the transuranic inventory after ten recycles was 38% of the inventory accumulated without recycle. When the transuranics from two regular uranium assemblies were combined with those recycled from a MOX assembly, the transuranic inventory was reduced 50% after five recycles

  10. Chemical compatibility of HLW borosilicate glasses with actinides

    International Nuclear Information System (INIS)

    Walker, C.T.; Scheffler, K.; Riege, U.

    1978-11-01

    During liquid storage of HLLW the formation of actinide enriched sludges is being expected. Also during melting of HLW glasses an increase of top-to-bottom actinide concentrations can take place. Both effects have been studied. Besides, the vitrification of plutonium enriched wastes from Pu fuel element fabrication plants has been investigated with respect to an isolated vitrification process or a combined one with the HLLW. It is shown that the solidification of actinides from HLLW and actinide waste concentrates will set no principal problems. The leaching of actinides has been measured in salt brine at 23 0 C and 115 0 C. (orig.) [de

  11. Synthesis and structural characterisation of mixed An(IV)-An(III) actinide oxalates used as precursors for dedicated fuel or target

    International Nuclear Information System (INIS)

    Tamain, Christelle; Grandjean, Stephane; Arab Chapelet, Benedicte; Abraham, Francis

    2010-01-01

    Oxalic co-conversion process plays an important role by producing mixed-actinide compounds used as starting materials as they are particularly suitable precursors of actinide oxide solid solutions. In these oxalate compounds, a mixed crystallographic site which accommodates both elements in spite of their different oxidation states has been established. The charge compensation is ensured by monovalent cations present in the acidic solution. This communication reviews the various mixed-actinide oxalates obtained by crystallization from acidic solution. First, crystallographic structures determined by X-ray diffraction from single crystals are described. Then completing data obtained by powder X-ray diffraction are presented on various systems. The different supramolecular arrangements underline the complexity of An(IV)-An(III)/Ln(III) oxalate system and the need to pursue studies on single crystals. (authors)

  12. Advances in computational actinide chemistry in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongqi; Wu, Jingyi; Chai, Zhifang [Chinese Academy of Sciences, Beijing (China). Multidisciplinary Initiative Center; Su, Jing [Chinese Academy of Sciences, Shanghai (China). Div. of Nuclear Materials Science and Engineering; Li, Jun [Tsinghua Univ., Beijing (China). Dept. of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering

    2014-04-01

    The advances in computational actinide chemistry made in China are reviewed. Several areas relevant to chemistry of actinides in gas, liquid, and solid phases have been explored. However, we limit the scope to selected contributions in the chemistry of molecular actinide systems in gas and liquid phases. These studies may be classified into two categories: treatment of relativistic effects, which cover the development of two- and four-component Hamiltonians and the optimization of relativistic pseudopotentials, and the applications of theoretical methods in actinide chemistry. The applications include (1) the electronic structures of actinocene, noble gas complexes, An-C multiple bonding compounds, uranyl and its isoelectronic species, fluorides and oxides, molecular systems with metal-metal bonding in their isolated forms (U{sub 2}, Pu{sub 2}) and in fullerene (U{sub 2} rate at C{sub 60}), and the excited states of actinide complexes; (2) chemical reactions, including oxidation, hydrolysis of UF{sub 6}, ligand exchange, reactivities of thorium oxo and sulfido metallocenes, CO{sub 2}/CS{sub 2} functionalization promoted by trivalent uranium complex; and (3) migration of actinides in the environment. A future outlook is discussed. (orig.)

  13. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    International Nuclear Information System (INIS)

    Sypula, Michal

    2013-01-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF Ln/Am obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as a Zr

  14. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Energy Technology Data Exchange (ETDEWEB)

    Sypula, Michal

    2013-07-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

  15. Transmutation of minor actinide using thorium fueled BWR core

    International Nuclear Information System (INIS)

    Susilo, Jati

    2002-01-01

    One of the methods to conduct transmutation of minor actinide is the use of BWR with thorium fuel. Thorium fuel has a specific behaviour of producing a little secondary minor actinides. Transmutation of minor actinide is done by loading it in the BWR with thorium fuel through two methods, namely close recycle and accumulation recycle. The calculation of minor actinide composition produced, weigh of minor actinide transmuted, and percentage of reminder transmutation was carried SRAC. The calculations were done to equivalent cell modeling from one fuel rod of BWR. The results show that minor actinide transmutation is more effective using thorium fuel than uranium fuel, through both close recycle and accumulation recycle. Minor actinide transmutation weight show that the same value for those recycle for 5th recycle. And most of all minor actinide produced from 5 unit BWR uranium fuel can transmuted in the 6 t h of close recycle. And, the minimal value of excess reactivity of the core is 12,15 % Δk/k, that is possible value for core operation

  16. Actinide recovery from waste and low-grade sources

    International Nuclear Information System (INIS)

    Navratil, J.D.; Schulz, W.W.

    1982-01-01

    Actinide and nuclear fuel cycle operations generate a variety of process waste streams. New methods are needed to remove and recover actinides. More interest is also being expressed in recovering uranium from oceans, phosphoric acid, and other low grade sources. To meet the need for an up-to-date status report in the area of actinide recovery from waste and low grade sources, these papers were brought together. The papers provide an authoritative, in-depth coverage of an important area of nuclear and industrial and engineering chemistry which cover the following topics: uranium recovery from oceans and phosphoric acid; recovery of actinides from solids and liquid wastes; plutonium scrap recovery technology; and other new developments in actinide recovery processes

  17. Transmutation of LWR waste actinides in thermal reactors

    International Nuclear Information System (INIS)

    Gorrell, T.C.

    1979-01-01

    Recycle of actinides to a reactor for transmutation to fission products is being considered as a possible means of waste disposal. Actinide transmutation calculations were made for two irradiation options in a thermal (LWR) reactor. The cases considered were: all actinides recycled in regular uranium fuel assemblies, and transuranic actinides recycled in separate mixed oxide (MOX) assemblies. When all actinides were recycled in a uranium lattice, a reduction of 62% in the transuranic inventory was achieved after 10 recycles, compared to the inventory accumulated without recycle. When the transuranics from 2 regular uranium assemblies were combined with those recycled from a MOX assembly, the transuranic inventory was reduced 50% after 5 recycles

  18. Actinide science. Fundamental and environmental aspects

    International Nuclear Information System (INIS)

    Choppin, Gregory R.

    2005-01-01

    Nuclear test explosions and reactor wastes have deposited an estimated 16x10 15 Bq of plutonium into the world's aquatic systems. However, plutonium concentration in open ocean waters is orders of magnitude less, indicating that most of the plutonium is quite insolvable in marine waters and has been incorporated into sediments. Actinide ions in waters often are not in a state of thermodynamic equilibrium and their solubility and migration behavior is related to the form in which the nuclides were introduced into the aquatic system. Actinide solubility depends on such factors as pH(hydrolysis), E H (oxidation state), reaction with complexants (e.g. carbonate, phosphate, humic acid, etc.) sorption to surfaces of minerals and/or colloids, etc., in the water. The most significant of these variables is the oxidation sate of the metal ion. The simultaneous presence of more than one oxidation state for some actinides (e.g. plutonium) in a solution complicates actinide environmental behavior. Both Np(V)O 2 + and Pu(V)O 2 + , the most significant soluble states in natural oxic waters are relatively noncomplexing and resistant to hydrolysis and subsequent precipitation but can undergo reduction to the Pu(IV) oxidation state with its different elemental behavior. The solubility of NpO 2 + can be as high as 10 -4 M while that of PuO 2 + is more limited by reduction to the insoluble tetravalent species, Pu(OH) 4 , (pK SP - 56). The net solubility of hexavalent UO 2 2+ in sea water is also limited by hydrolysis; however, it has a relatively high concentration due to formation of carbonate complexes. The insoluble trivalent americium hydroxocarbonate, Am(CO) 3 (OH), is the limiting species for the solubility of Am(III) in sea water. Thorium is found exclusively as the tetravalent species and its solubility is limited by the formation of quite insoluble Th(OH) 4 . The chemistry of actinide ions in the environment is reviewed to show the spectrum of reactions that can occur in

  19. Solubility of actinides and surrogates in nuclear glasses

    International Nuclear Information System (INIS)

    Lopez, Ch.

    2003-01-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO 2 at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  20. Nuclear waste forms for actinides

    Science.gov (United States)

    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

  1. Programme and Abstracts. 38. Journees des Actinides together with the 7. School on the Physics and Chemistry of the Actinides

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Journees des Actinides (JdA) is a traditional informal actinide forum, including physics, chemistry, and materials research. It regularly brings together experts from fields involved, taking place in a very informal way, emphasizing exchanges and discussions on current issues in actinide science. At the 38{sup th} JdA (10-15 April 2008; Wroclaw, Poland) scientific communications on the following topics on physics and chemistry of the actinides were presented: (a) inorganic and organometallic chemistry; (b) strongly correlated behaviour, superconductivity, quantum criticality; (c) materials science; (d) theory, electronic structure; (e) nuclear fuel cycle, environment.

  2. Programme and Abstracts. 38. Journees des Actinides together with the 7. School on the Physics and Chemistry of the Actinides

    International Nuclear Information System (INIS)

    2008-01-01

    Journees des Actinides (JdA) is a traditional informal actinide forum, including physics, chemistry, and materials research. It regularly brings together experts from fields involved, taking place in a very informal way, emphasizing exchanges and discussions on current issues in actinide science. At the 38 th JdA (10-15 April 2008; Wroclaw, Poland) scientific communications on the following topics on physics and chemistry of the actinides were presented: (a) inorganic and organometallic chemistry; (b) strongly correlated behaviour, superconductivity, quantum criticality; (c) materials science; (d) theory, electronic structure; (e) nuclear fuel cycle, environment

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

    International Nuclear Information System (INIS)

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

    1994-01-01

    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 panelclose quotes model for mobile actinide concentrations is not defensible; and, although it is extremely conservative, the open-quotes inventory limitsclose 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 concentrationsclose 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 limitsclose quotes model

  4. Limitations of actinide recycle and waste disposal consequences

    International Nuclear Information System (INIS)

    Baetsle, L.H.; Raedt, C. de

    1994-01-01

    The paper emphasizes the impact of Light Water Reactor - Mixed Oxides introduction on the subsequent actinide management and fate of reprocessed and depleted uranium. The spent fuel from LWR-MOX contains in principle 75% of the initially produced plutonium. This new source term has to be considered together with the minor actinides from the conventional reprocessing. Subsequent LWR-MOX reprocessing in the first step in a very long term Pu + minor actinides management. Recycling of Pu + minor actinides in fast reactors to significantly reduce the Pu and minor actinides inventory (e.g. a factor of 10) is a very slow process which requires the development and operation of a large park of actinide burner reactors during an extended period of time. The overall feasibility of the P and T option will greatly depend on the massive introduction during the next century of fast neutron reactors as a replacement to the present LWR generation of nuclear power plants. (authors). 11 refs., 6 tabs., 2 figs

  5. 33rd Actinide Separations Conference

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 33rd Actinide Separations Conference

    International Nuclear Information System (INIS)

    McDonald, L.M.; Wilk, P.A.

    2009-01-01

    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.

  7. Hydrothermal decomposition of actinide(IV oxalates: a new aqueous route towards reactive actinide oxide nanocrystals

    Directory of Open Access Journals (Sweden)

    Walter Olaf

    2016-01-01

    Full Text Available The hydrothermal decomposition of actinide(IV oxalates (An= Th, U, Pu at temperatures between 95 and 250 °C is shown to lead to the production of highly crystalline, reactive actinide oxide nanocrystals (NCs. This aqueous process proved to be quantitative, reproducible and fast (depending on temperature. The NCs obtained were characterised by X-ray diffraction and TEM showing their size to be smaller than 15 nm. Attempts to extend this general approach towards transition metal or lanthanide oxalates failed in the 95–250 °C temperature range. The hydrothermal decomposition of actinide oxalates is therefore a clean, flexible and powerful approach towards NCs of AnO2 with possible scale-up potential.

  8. Research for actinides extractants from various wastes

    International Nuclear Information System (INIS)

    Musikas, C.; Cuillerdier, C.; Condamines, N.

    1990-01-01

    This paper is an overview of the actinides solvent extraction research undertaken in Fontenay-aux-Roses. Two kinds of extractants are investigated; those usable for the improvement of the nowadays nuclear fuels reprocessing and those necessary for advanced fuels cycles which include the minor actinides (Np, Am) recovery for a further elimination through nuclear reactions. In the first class the mono and diamides, alternative to the organophosphorus extractants, TBP and polyfunctional phosphonates, showed promising properties. The main results are discussed. For the future efficient extractants for trivalent actinides-lanthanides group separations are suitable. The point about the actinides (III) - lanthanides (III) group separation chemistry and the development of some of these extractants are given

  9. ACTINET - EU network of excellence for actinide sciences

    International Nuclear Information System (INIS)

    Gompper, K.

    2006-01-01

    ACTINET, the Network of Excellence for Actinide Sciences within the 6th EU Framework Program, was launched in March 2004 for an initial period of four years. A number of tools are available in ACTINET to serve the purposes of the project, i.e. stimulate and coordinate actinide research in Europe, promote integration, train young scientists and, in this way, ensure and enhance European competence. The large European actinide laboratories with their unique experimental and analytical equipment are available to scientists from Europe as so-called 'pool facilities' within the framework of joint research projects. Setting up a 'theoretical user lab' has turned out to be a promising way of exploiting the synergies of theory and experiment in various fields of actinide science. Joint research projects are supported within the network, working with actinides being made possible in the pool facilities. Training and instruction are ensured by seminars, workshops, and schools organized annually. In familiarizing young scientists with actinide work, ACTINET exercises training functions and contributes to ensuring and enhancing European competence in the field on the medium and long term. Even after only half of its term, ACTINET is developing into a live network, thus decisively contributing towards promoting, coordinating and integrating European actinide research. As actinides play a key role in the use of nuclear power, this benefits European industries, research centers, operators of nuclear power plants and nuclear facilities as well as licensing and regulatory authorities. (orig.)

  10. Superconductivity in the actinides

    International Nuclear Information System (INIS)

    Smith, J.L.; Lawson, A.C.

    1985-01-01

    The trends in the occurrence of superconductivity in actinide materials are discussed. Most of them seem to show simple transition metal behavior. However, the superconductivity of americium proves that the f electrons are localized in that element and that ''actinides'' is the correct name for this row of elements. Recently the superconductivity of UBe 13 and UPt 3 has been shown to be extremely unusual, and these compounds fall in the new class of compounds now known as heavy fermion materials

  11. Molecular and electronic structure of actinide hexa-cyanoferrates; Structure moleculaire et electronique des hexacyanoferrates d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Bonhoure, I

    2001-07-01

    The goal of this work is to improve our knowledge on the actinide-ligand bond properties. To this end, the hexacyanoferrate entities have been used as pre-organized ligand. We have synthesized, using mild chemistry, the following series of complexes: An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Th, U, Np, Pu); Am{sup III}[Fe{sup III}(CN){sub 6}].xH{sub 2}O; Pu {sup III}[Co{sup III}(CN){sub 6}].xH{sub 2}O and K(H?)An{sup III}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Pu, Am). The metal oxidation states have been obtained thanks to the {nu}{sub CN}, stretching vibration and to the actinide L{sub III} absorption edge studies. As Prussian Blue, the An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Np, Pu) are class II of Robin and Day compounds. X-ray Diffraction has shown besides that these complexes crystallize in the P6{sub 3}/m space group, as the isomorphic LaKFe(CN){sub 6}.4H{sub 2}O complex used as structural model. The EXAFS oscillations at the iron K edge and at the An L{sub III} edge allowed to determine the An-N, An-O, Fe-C and Fe-N distances. The display of the multiple scattering paths for both edges explains the actinide contribution absence at the iron edge, whereas the iron signature is present at the actinide edge. We have shown that the actinide coordination sphere in actinides hexa-cyanoferrates is comparable to the one of lanthanides. However, the actinides typical behavior towards the lanthanides is brought to the fore by the An{sup IV} versus Ln{sup III} ions presence in this family of complexes. Contrarily to the 4f electrons, the 5f electrons influence the electronic properties of the compounds of this family. However, the gap between the An-N and Ln-N distances towards the corresponding metals ionic radii do not show any covalence bond evolution between the actinide and lanthanide series. (author)

  12. Actinide chemistry in the far field

    International Nuclear Information System (INIS)

    Livens, F.R.; Morris, K.; Parkman, R.; Moyes, L.

    1996-01-01

    The environmental chemistry of the actinides is complicated due both to the extensive redox and coordination chemistry of the elements and also to the complexity of the reactive phases encountered in natural environments. In the far field, interactions with reactive surfaces, coatings and colloidal particles will play a crucial role in controlling actinide mobility. By virtue of both their abundance and reactivity; clays and other layer aluminosilicate minerals, hydrous oxides and organic matter (humic substances) are all identified as having the potential to react with actinide ions and some possible modes of interaction are described, together with experimental evidence for their occurrence. (author)

  13. Separations chemistry for actinide elements: Recent developments and historical perspective

    International Nuclear Information System (INIS)

    Nash, K.L.; Choppin, G.R.

    1997-01-01

    With the end of the cold war, the principal mission in actinide separations has changed from production of plutonium to cleanup of the immense volume of moderately radioactive mixed wastes which resulted from fifty years of processing activities. In order to approach the cleanup task from a proper perspective, it is necessary to understand how the wastes were generated. Most of the key separations techniques central to actinide production were developed in the 40's and 50's for the identification and production of actinide elements. Total actinide recovery, lanthanide/actinide separations, and selective partitioning of actinides from inert constituents are currently of primary concern. To respond to the modern world of actinide separations, new techniques are being developed for separations ranging from analytical methods to detect ultra-trace concentrations (for bioassay and environmental monitoring) to large-scale waste treatment procedures. In this report, the history of actinide separations, both the basic science and production aspects, is examined and evaluated in terms of contemporary priorities

  14. 1981 Annual Status Report. Plutonium fuels and actinide programme

    International Nuclear Information System (INIS)

    1981-01-01

    In this 1981 report the work carried out by the European Institute for Transuranium elements is reviewed. Main topics are: operation limits of plutonium fuels: swelling of advanced fuels, oxide fuel transients, equation of state of nuclear materials; actinide cycle safety: formation of actinides (FACT), safe handling of plutonium fuel (SHAPE), aspects of the head-end processing of carbide fuel (RECARB); actinide research: crystal chemistry, solid state studies, applied actinide research

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

    Science.gov (United States)

    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.

  16. Extraction chromatography of actinides

    International Nuclear Information System (INIS)

    Muller, W.

    1978-01-01

    Extraction chromatography of actinides in the oxidation state from 2 to 6 is reviewed. Data on using neutral (tbp), basic (substituted ammonium salts) and acidic [di-(2-ethylhexyl)-phosphoric acid (D2EHPA)] extracting agents ketones, esters, alcohols and β-diketones in this method are given. Using the example of actinide separation using D2EHPA, discussed are factors influencing the efficiency of their chromatography separation (nature and particle size of the carrier materials, extracting agents amount on the carrier, temperature and elution rate)

  17. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Transmutation of fission products and actinide waste at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, L.L.; Pitcher, E.J.; Russell, G.J. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    The authors studied the neutronics of an ATW system for the transmutation of the fission products ({sup 99}Tc in particular) and the type of actinide waste stored in several tanks at Hanford. The heart of the system is a highly-efficient neutron production target. It is surrounded by a blanket containing a moderator/reflector material, as well as the products to be transmuted. The fission products are injected into the blanket in the form of an aqueous solution in heavy water, whereas an aqueous actinides slurry is circulated in the outer part of the blanket. For the sake of definiteness, the authors focussed on {sup 99}Tc (the most difficult fission product to transmute), and {sup 239}Pu, {sup 237}Np, and {sup 241}Am. Because of the low thermal neutron absorption cross-section of {sup 99}Tc, considerable care and effort must be devoted to the design of a very efficient neutron source.

  19. PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

    Science.gov (United States)

    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)

  20. Actinide isotopes in the marine environment

    International Nuclear Information System (INIS)

    Holm, E.; Fukai, R.

    1986-01-01

    Studies of actinide isotopes in the environment are important not only from the viewpoint of their radiological effects on human life, but also from the fact that they act as excellent biochemical and geochemical tracers especially in the marine environment. For several of the actinide isotopes there is still a lack of basic data on concentration levels and further investigations on their chemical and physical speciation are required to understand their behaviour in the marine environment. The measured and estimated activity concentration levels of artificial actinides are at present in general a few orders of magnitude lower than those of the natural ones and their concentration factors in biota are relatively low, except in a few species of macroalgae and phytoplankton. The contribution from seafood to total ingestion of actinides by the world population is a few per cent and, therefore, the dose to man from these long-lived radionuclides caused by seafood ingestion is usually low. (orig.)

  1. The R-process: supernovae and other sources of the heaviest elements

    International Nuclear Information System (INIS)

    Thielemann, F.-K.; Moceli, D.; Panov, I.

    2007-01-01

    Rapid neutron capture in stellar explosions is responsible for the heaviest elements in nature, up to Th, U and beyond. This nucleosynthesis process, the r-process, is unique in the sense that a combination of nuclear physics far from stability (masses, half-lives, neutron-capture and photodisintegration, neutron-induced and beta-delayed fission and last but not least neutrino-nucleus interactions) is intimately linked to ejecta from astrophysical explosions (core collapse supernovae or other neutron star related events). The astrophysics and nuclear physics involved still harbor many uncertainties, either in the extrapolation of nuclear properties far beyond present experimental explorations or in the modeling of multidimensional, general relativistic (neutrino-radiation) hydrodynamics with rotation and possibly required magnetic fields. Observational clues about the working of the r-process are mostly obtained from solar abundances and from the abundance evolution of the heaviest elements as a function of galactic age, as witnessed in old extremely metal-poor stars. They contain information whether the r-process is identical for all stellar events, how abundance features develop with galactic time and whether the frequency of r-process events is comparable to that of average core collapse supernovae - producing oxygen through titanium, as well as iron-group nuclei. The theoretical modeling of the r-process has advanced from simple approaches, where the use of static neutron densities and temperatures can aid to test the influence of nuclear properties far from stability on abundance features, to more realistic expansions with a given entropy, global neutron/proton ratio and expansion timescales, as expected from explosive astrophysical events. The direct modeling in astrophysical events such as supernovae still faces the problem whether the required conditions can be met. (author)

  2. Actinide recycle in LMFBRs as a waste management alternative

    International Nuclear Information System (INIS)

    Beaman, S.L.

    1979-01-01

    A strategy of actinide burnup in fast reactor systems has been investigated as an approach for reducing the long term hazards and storage requirements of the actinide waste elements and their decay daughters. The actinide recycle studies also included plutonium burnup studies in the event that plutonium is no longer required as a fuel. Particular emphasis was placed upon the timing of the recycle program, the requirements for separability of the waste materials, and the impact of the actinides on the reactor operations and performance. It is concluded that actinide recycle and plutonium burnout are attractive alternative waste management concepts. 25 refs., 14 figs., 34 tabs

  3. Rapid determination of actinides in seawater samples

    International Nuclear Information System (INIS)

    Maxwell, S.L.; Culligan, B.K.; Hutchison, J.B.; Utsey, R.C.; McAlister, D.R.

    2014-01-01

    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. (author)

  4. Radiochemistry and actinide chemistry

    International Nuclear Information System (INIS)

    Guillaumont, R.; Peneloux, A.

    1989-01-01

    The analysis of trace amounts of actinide elements by means of radiochemistry, is discussed. The similarities between radiochemistry and actinide chemistry, in the case of species amount by cubic cm below 10 12 , are explained. The parameters which allow to define what are the observable chemical reactions, are given. The classification of radionuclides in micro or macrocomponents is considered. The validity of the mass action law and the partition function in the definition of the average number of species for trace amounts, is investigated. Examples illustrating the results are given

  5. Interaction between actinides and protein: the calmodulin

    International Nuclear Information System (INIS)

    Brulfert, Florian

    2016-01-01

    Considering the environmental impact of the Fukushima nuclear accident, it is fundamental to study the mechanisms governing the effects of the released radionuclides on the biosphere and thus identify the molecular processes generating the transport and deposition of actinides, such as neptunium and uranium. However, the information about the microscopic aspect of the interaction between actinides and biological molecules (peptides, proteins...) is scarce. The data being mostly reported from a physiological point of view, the structure of the coordination sites remains largely unknown. These microscopic data are indeed essential for the understanding of the interdependency between structural aspect, function and affinity.The Calmodulin (CaM) (abbreviation for Calcium-Modulated protein), also known for its affinity towards actinides, acts as a metabolic regulator of calcium. This protein is a Ca carrier, which is present ubiquitously in the human body, may also bind other metals such as actinides. Thus, in case of a contamination, actinides that bind to CaM could avoid the protein to perform properly and lead to repercussions on a large range of vital functions.The complexation of Np and U was studied by EXAFS spectroscopy which showed that actinides were incorporated in a calcium coordination site. Once the thermodynamical and structural aspects studied, the impact of the coordination site distortion on the biological efficiency was analyzed. In order to evaluate these consequences, a calorimetric method based on enzyme kinetics was developed. This experiment, which was conducted with both uranium (50 - 500 nM) and neptunium (30 - 250 nM) showed a decrease of the heat produced by the enzymatic reaction with an increasing concentration of actinides in the medium. Our findings showed that the Calmodulin actinide complex works as an enzymatic inhibitor. Furthermore, at higher neptunium (250 nM) and uranium (500 nM) concentration the metals seem to have a poison

  6. On the hazard accumulation of actinide waste in a Pu-fueled LMFBR power economy with and without by-product actinide recycling

    International Nuclear Information System (INIS)

    Anselmi, L.; Caruso, K.; Hage, W.; Schmidt, E.

    1979-01-01

    The actinide waste arisings in terms of hazard potential for ingestion and inhalation are given for a Pu-fueled LMFBR Power Economy as function of decay time. The data were assessed for two simplified fuel cycles, one considering the recycling of by-product actinides and the other their complete discharge to the high-level waste. Two durations of nuclear power and several loss fractions of actinides to the waste were considered. The major contributors in form of chemical elements or isotopes to the actinide waste hazard built up during the nuclear power duration were identified for various decay intervals

  7. Selective extraction of actinides from high level liquid wastes. Study of the possibilities offered by the Redox properties of actinides

    International Nuclear Information System (INIS)

    Adnet, J.M.

    1991-07-01

    Partitioning of high level liquid wastes coming from nuclear fuel reprocessing by the PUREX process, consists in the elimination of minor actinides (Np, Am, and traces of Pu and U). Among the possible processes, the selective extraction of actinides with oxidation states higher than three is studied. First part of this work deals with a preliminary step; the elimination of the ruthenium from fission products solutions using the electrovolatilization of the RuO4 compound. The second part of this work concerns the complexation and oxidation reactions of the elements U, Np, Pu and Am in presence of a compound belonging to the insaturated polyanions family: the potassium phosphotungstate. For actinide ions with oxidation state (IV) complexed with phosphotungstate anion the extraction mechanism by dioctylamine was studied and the use of a chromatographic extraction technic permitted successful separations between tetravalents actinides and trivalents actinides. Finally, in accordance with the obtained results, the basis of a separation scheme for the management of fission products solutions is proposed

  8. Structural characterization of the Actinides (III) and (IV) - DOTA complexes

    International Nuclear Information System (INIS)

    Audras, Matthieu

    2014-01-01

    The polyamino-carboxylate anions have been identified as compounds of interest in the operations of actinide separation, in actinide migration in the environment and in human radio-toxicology. The structural characterization of complexes formed between actinides and polyamino-carboxylates ligands is essential for a better understanding of actinide-ligands interactions. Among the polyamino-carboxylate anions, the DOTA ligand (1,4,7,10-tetraaza-cyclododecane tetraacetic acid) is described as a very strong complexing agent of the lanthanides(III), but has been little studied with actinides. The objective of this thesis is to describe the complexes formed between the actinides (III) and (IV) and the DOTA ligand, and compare them with the lanthanide complexes. For this, an approach has been introduced to characterize the complexes by complementary analytical techniques (spectrophotometry, electro-spray ionization mass spectrometry, NMR, EXAFS, electrochemistry), but also by calculations of theoretical chemistry to help the interpretation of the experimental data. The formation of a 1:1 complex is observed with the actinides(III) (plutonium and americium) as for lanthanides(III): rapid formation of intermediate species which evolves slowly towards the formation of a limit complex. Within this complex, the cation is located inside the cavity formed by the ligand. Four nitrogen atoms and four oxygen atoms from the carboxylate functions are involved in the coordination sphere of the cation. However, differences were observed in the bond lengths formed between the cation and the nitrogen atoms (the bonds are somewhat shorter in the case of actinide complexes) as well as the complexation kinetics, which is slightly faster for the actinides(III) than for lanthanide(III) ions of equivalent radius. The same behavior was observed in solution upon complexation of actinides(IV) (uranium, plutonium and neptunium): slow formation of a 1:1 complex (actinide(IV):ligand) in wherein the

  9. Actinide Capture and Fission Cross Section Measurements Within the Mini-Inca Project

    International Nuclear Information System (INIS)

    Letourneau, A.

    2006-01-01

    Full text of publication follows: The Mini-INCA project is devoted to precise description of the transmutation chain of Actinides within high thermal neutron fluxes. It uses the High Flux Reactor of ILL (Laue Langevin Institute) as an intense thermal neutron source to measure capture and fission cross sections. Two irradiation channels are dedicated for those measurements offering a diversity of fluxes ranging from pure thermal neutrons to 15% epithermal neutrons with intensities as high as 1*10 15 n/cm 2 /s. Standard nuclear techniques for measurements, such as α and γ-spectroscopy of irradiated samples, have been extended in order to stand all constraints due to the irradiation in high fluxes. In particular new types of fission micro-chambers have been developed to follow online the evolution of one actinide and to measure its fission cross section in reference to 235 U(n,F) standard reaction. This type of neutron detector will be used within the MEGAPIE target to on-line characterise the neutron flux and to study the potentiality of such target in terms of incineration. (author)

  10. Recent progress in actinide and lanthanide solvent extraction

    International Nuclear Information System (INIS)

    Musikas, C.; Hubert, H.; Benjelloun, N.; Vitorge, P.; Bonnin, M.; Forchioni, A.; Chachaty, C.

    1983-04-01

    Work in progress on actinide solvent extraction is briefly reviewed in this paper. 1 H and 31 P NMR are used to elucidate several fundamental unsolved problems concerning organophosphorous extractants often used in actinides extraction: determination of site of dialkylthiophosphate protonation and addition of basic phosphine oxide to dibutylthiophosphoric acid dimer. Extraction of Am III and Eu from high radioactivity level wastes by tetrasubsituted methylene diamides is investigated. Trivalent actinide-lanthanide group are separated by solvent extraction using soft donor ligand complexes which are more stable. The synergism of dinonylnaphtalene sulfonic acid (HDNNS) associated with several neutral donors like TBP, TOPO, amides are examined in the trivalent and tetravalent actinide extraction

  11. Actinide removal from aqueous solution with activated magnetite

    International Nuclear Information System (INIS)

    Kochen, R.L.; Thomas, R.L.

    1987-01-01

    An actinide aqueous waste treatment process using activated magnetite has been developed at Rocky Flats. The use and effectiveness of various magnetites in lowering actinide concentrations in aqueous solution are described. Experiments indicate that magnetite particle size and pretreatment (activation of the magnetite surface with hydroxyl ions greatly influence the effective use of magnetite as an actinide adsorbent. With respect to actinide removal, Ba(OH) 2 -activated magnetite was more effective over a broader pH range than was NaOH-activated magnetite. About 50% less Ba(OH) 2 -activated magnetite was required to lower plutonium concentration from 10 -4 to 10 -8 g/l. 7 refs., 8 tabs

  12. Formation of actinides in irradiated HTGR fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    dos Santos, A. M.

    1976-03-15

    Actinide nuclide concentrations of 11 spent AVR fuel elements were determined experimentally. The burnup of the spheres varied in the range between 10% and 100% fifa, the Th : U ratio was 5 : 1. The separation procedures for an actinide isolation were tested with highly irradiated ThO/sub 2/. Separation and decontamination factors are presented. Build-up of /sup 232/U was discussed. The AVR breeding rate was ascertained to be 0.5. The hazard potential of high activity waste was calculated. Actinide recovery factors were proposed in order to reduce the hazard potential of the waste by an actinide removal under consideration of the reprocessing technology which is available presently.

  13. Ground-state electronic structure of actinide monocarbides and mononitrides

    DEFF Research Database (Denmark)

    Petit, Leon; Svane, Axel; Szotek, Z.

    2009-01-01

    The self-interaction corrected local spin-density approximation is used to investigate the ground-state valency configuration of the actinide ions in the actinide monocarbides, AC (A=U,Np,Pu,Am,Cm), and the actinide mononitrides, AN. The electronic structure is characterized by a gradually increa...

  14. ALICE’s wonderland reveals the heaviest antimatter ever observed

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Producing and observing antiparticles is part of everyday life for many physics laboratories around the world, including CERN. However, recreating and observing the anti-nuclei of complex atoms is a much more difficult task. Analysing data collected in a run of just one month, ALICE has recently found evidence of the formation of four anti-nuclei of Helium 4, the heaviest antimatter ever created in a laboratory.   The STAR experiment at RHIC came first and published the result in March: they presented evidence of 18 anti-nuclei of Helium 4 collected over several years of data taking. “ALICE came second but it's amazing to see how fast the results came,” exclaims Paolo Giubellino, the experiment’s spokesperson. “We were able to confirm the observation of 4He anti-nuclei with data collected in November 2010.” Scientists agree on the fact that antimatter was created in the Big Bang together with matter. However, today we do not observe antimatter outsid...

  15. LEMA facility and equipments for minor actinides compounds fabrication and characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Donnet, L. [Commissariat a l' Energie Atomique - CEA, CEA/DEN/VRH/DTEC/SDTC/LEMA (France)

    2008-07-01

    The LEMA (Actinide based materials study laboratory) is mainly involved in minor actinides materials development and fabrication, from raw materials choice and synthesis to finished products including pin assembly. The aim of the technological analyses is to establish choices of raw materials and manufacturing techniques. The LEMA is located in the ATALANTE facility in Marcoule. It consists in two shielded chains (one specific for neutrons) and three hot laboratories. The laboratory has various apparatuses in hot cells such as: ball mills, press, dilatometer, TGA (thermo-gravimetry analyser), calcination and sintering furnaces (2000 deg. C). The laboratory has also characterisation apparatuses such as XRD and SEM (scanning electron microscopy) dedicated to structural and microstructural studies. Thanks to the diversity of its equipment, the LEMA has well established worldwide collaborations and takes part in international fuels/target fabrication and irradiation experiments. (author)

  16. LEMA facility and equipments for minor actinides compounds fabrication and characterisation

    International Nuclear Information System (INIS)

    Donnet, L.

    2008-01-01

    The LEMA (Actinide based materials study laboratory) is mainly involved in minor actinides materials development and fabrication, from raw materials choice and synthesis to finished products including pin assembly. The aim of the technological analyses is to establish choices of raw materials and manufacturing techniques. The LEMA is located in the ATALANTE facility in Marcoule. It consists in two shielded chains (one specific for neutrons) and three hot laboratories. The laboratory has various apparatuses in hot cells such as: ball mills, press, dilatometer, TGA (thermo-gravimetry analyser), calcination and sintering furnaces (2000 deg. C). The laboratory has also characterisation apparatuses such as XRD and SEM (scanning electron microscopy) dedicated to structural and microstructural studies. Thanks to the diversity of its equipment, the LEMA has well established worldwide collaborations and takes part in international fuels/target fabrication and irradiation experiments. (author)

  17. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Neutron nuclear data evaluation for actinide nucleic

    International Nuclear Information System (INIS)

    Chen Guochang; Yu Baosheng; Duan Junfeng; Ge Zhigang; Cao Wentian; Tang Guoyou; Shi Zhaomin; Zou Yubin

    2010-01-01

    The nuclear data with high accuracy for minor actinides are playing an important role in nuclear technology applications, including reactor design and operation, fuel cycle concepts, estimation of the amount of minor actinides in high burn-up reactors and the minor actinides transmutation. Through describe the class of nuclear data and nuclear date library, and introduce the procedure of neutron nuclear data evaluation. 234 U(n, f) and 237 Np(n, 2n) reaction experimental data evaluation was evaluated. The fission nuclear data are updated and improved. (authors)

  19. Experimental studies of actinides in molten salts

    International Nuclear Information System (INIS)

    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

  20. Fission in the landscape of heaviest elements: Some recent examples

    International Nuclear Information System (INIS)

    Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch.E.; Ackermann, D.; Andersson, L.-L.; Block, M.; Brand, H.; Even, J.; Forsberg, University; Hartmann, W.; Herzberg, R.-D.; Heßberger, F.P.; Hoffmann, J.; Hübner, A.; Jäger, E.; Jeppsson, J.; Kindler, B.; Kratz, J.V.; Krier, J.; Kurz, N.; Lommel, B.; Maiti, M.; Minami, S.; Rudolph, D.; Runke, J.; Sarmiento, L.G.; Schädel, M.; Schausten, B.; Steiner, J.; Heidenreich, T. Torres De; Uusitalo, J.; Wiehl, N.; Yakusheva, V.

    2016-01-01

    The fission process still remains a main factor that determines the stability of the atomic nucleus of heaviest elements. Fission half-lives vary over a wide range, 10"−"1"9−10"2"4 s. Present experimental techniques for the synthesis of the superheavy elements that usually measure α-decay chains are sensitive only in a limited range of half-lives, often 10"−"5−10"3 s. In the past years, measurement techniques for very short-lived and very long-lived nuclei were significantly improved at the gas-filled recoil separator TASCA at GSI Darmstadt. Recently, several experimental studies of fission-related phenomena have successfully been performed. In this paper, results on "2"5"4"−"2"5"6Rf and "2"6"6Lr are presented and corresponding factors for retarding the fission process are discussed.

  1. Band structure studies of actinide systems

    International Nuclear Information System (INIS)

    Koelling, D.D.

    1976-01-01

    The nature of the f-orbitals in an actinide system plays a crucial role in determining the electronic properties. It has long been realized that when the actinide separation is small enough for the f-orbitals to interact directly, the system will exhibit itinerant electron properties: an absence of local moment due to the f-orbitals and sometimes even superconductivity. However, a number of systems with the larger actinide separation that should imply local moment behavior also exhibit intinerant properties. Such systems (URh 3 , UIr 3 , UGe 3 , UC) were examined to learn something about the other f-interactions. A preliminary observation made is that there is apparently a very large and ansiotropic mass enhancement in these systems. There is very good reason to believe that this is not solely due to large electron--electron correlations but to a large electron--phonon interaction as well. These features of the ''non-magnetic'', large actinide separation systems are discussed in light of our results to date. Finally, the results of some recent molecular calculations on actinide hexafluorides are used to illustrate the shielding effects on the intra-atomic Coulomb term U/sub f-f/ which would appear in any attempt to study the formation of local moments. As one becomes interested in materials for which a band structure is no longer an adequate model, this screened U/sub ff/ is the significant parameter and efforts must be made to evaluate it in solid state systems

  2. Properties of minor actinide nitrides

    International Nuclear Information System (INIS)

    Takano, Masahide; Itoh, Akinori; Akabori, Mitsuo; Arai, Yasuo; Minato, Kazuo

    2004-01-01

    The present status of the research on properties of minor actinide nitrides for the development of an advanced nuclear fuel cycle based on nitride fuel and pyrochemical reprocessing is described. Some thermal stabilities of Am-based nitrides such as AmN and (Am, Zr)N were mainly investigated. Stabilization effect of ZrN was cleary confirmed for the vaporization and hydrolytic behaviors. New experimental equipments for measuring thermal properties of minor actinide nitrides were also introduced. (author)

  3. ALMR potential for actinide consumption

    International Nuclear Information System (INIS)

    Cockey, C.L.; Thompson, M.L.

    1992-01-01

    The Advanced Liquid Metal Reactor (ALMR) is a US Department of Energy (DOE) sponsored fast reactor design based on the Power Reactor, Innovative Small Module (PRISM) concept originated by General Electric. This reactor combines a high degree of passive safety characteristics with a high level of modularity and factory fabrication to achieve attractive economics. The current reference design is a 471 MWt modular reactor fueled with ternary metal fuel. This paper discusses actinide transmutation core designs that fit the design envelope of the ALMR and utilize spent LWR fuel as startup material and for makeup. Actinide transmutation may be accomplished in the ALMR core by using either a breeding or burning configuration. Lifetime actinide mass consumption is calculated as well as changes in consumption behavior throughout the lifetime of the reactor. Impacts on system operational and safety performance are evaluated in a preliminary fashion. Waste disposal impacts are discussed. (author)

  4. On the use of spinel-based nuclear fuels for the transmutation of actinides

    International Nuclear Information System (INIS)

    Konings, R.J.M.; Bakker, K.; Boshoven, J.G.; Hein, H.; Huntelaar, M.E.; Zhang, H.; Meeldijk, J.D.; Woensdregt, C.F.

    1997-01-01

    The properties of spinel-based nuclear fuels for the transmutation of actinides are investigated. The results of laboratory experiments, thermodynamic calculations and irradiations in the High Flux Reactor (HFR) at Petten are presented, and allow us to evaluate the potential of spinel as an inert matrix for fuels and targets for transmutation. (author)

  5. Actinide recycle potential in the integral fast reactor

    International Nuclear Information System (INIS)

    Chang, Y.I.

    1993-01-01

    The Integral Fast Reactor (IFR) fuel cycle holds promise for substantial improvements in economics, diversion-resistance, and waste management. In the IFR pyroprocessing, minor actinides accompany plutonium product stream, and therefore, actinide recycle occurs naturally. The fast neutron spectrum of the IFR makes it an ideal actinide burner, as well. This paper discusses technical features of the IFR fuel cycle, its technical progress, the development status, and potential implications on long-term waste management

  6. The radiological impact of actinides discharged to the Irish Sea

    International Nuclear Information System (INIS)

    Hunt, G.J.; Smith, B.D.

    1999-01-01

    This paper describes the radiological effects of releases of actinides to the Irish Sea from Sellafield, the major source. Exposure pathways to man since the commencement of discharges in 1952 are reviewed; the importance of actinides began to increase with increased discharges in the 1970s. With the demise of the porphyra/laverbread pathway due to transport difficulties, the pathway due to fish and shellfish consumption became critical, particularly for actinides through molluscan shellfish. A reassessment on the current basis of effective dose shows that peak exposures to the critical group of about 2 mSv yr -1 were received in the mid-1970s, about 30% of which was due to actinides. Effective doses have since reduced but the relative importance of actinides is greater, due to the interplay of discharges of radionuclides from Sellafield and their behaviour in the environment. Additive doses through sea food due to releases of natural radionuclides from the Marchon phosphate plant at Whitehaven are also considered, although the actinide component from this source has been small. Exposures due to actinides from Sellafield via other pathways are shown to be much lower than those involving sea food. Collective doses are also considered; these peaked at about 300 man-Sv to the European population (including the UK) in 1979, with only a few percent due to actinides. As in the case of critical group doses, the relative importance of actinides has increased in recent years within the decreasing total collective dose. For both critical group and collective doses, therefore, the actinide component needs to be kept under review. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Environmental chemistry of the actinide elements

    International Nuclear Information System (INIS)

    Rao Linfeng

    1986-01-01

    The environmental chemistry of the actinide elements is a new branch of science developing with the application of nuclear energy on a larger and larger scale. Various aspects of the environmental chemistry of the actinide elements are briefly reviewed in this paper, such as its significance in the nuclear waste disposal, its coverage of research fields and possible directions for future study

  8. Actinide separations by supported liquid membranes

    International Nuclear Information System (INIS)

    Danesi, P.R.; Horwitz, E.P.; Rickert, P.; Chiarizia, R.

    1984-01-01

    The work has demonstrated that actinide removal from synthetic waste solutions using both flat-sheet and hollow-fiber SLM's is a feasible chemical process at the laboratory scale level. The process is characterized by the typical features of SLM's processes: very small quantities of extractant required; the potential for operations with high feed/strip volume ratios, resulting in a corresponding concentration factor of the actinides; and simplicity of operation. Major obstacles to the implementation of the SLM technology to the decontamination of liquid nuclear wastes are the probable low resistance of polypropylene supports to high radiation fields, which may prevent the application to high-level nuclear wastes; the unknown lifetime of the SLM; and the high Na content of the separated actinide solution

  9. Analysis of large soil samples for actinides

    Science.gov (United States)

    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.

  10. Spin and orbital moments in actinide compounds

    DEFF Research Database (Denmark)

    Lebech, B.; Wulff, M.; Lander, G.H.

    1991-01-01

    The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single...... experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced...

  11. Evaluating the efficacy of a minor actinide burner

    International Nuclear Information System (INIS)

    Dobbin, K.D.; Kessler, S.F.; Nelson, J.V.; Omberg, R.P.; Wootan, D.W.

    1993-06-01

    The efficacy of a minor actinide burner can be evaluated by comparing safety and economic parameters to the support ratio. Minor actinide mass produced per unit time in this number of Light Water Reactors (LWRs) can be burned during the same time period in one burner system. The larger the support ratio for a given set of safety and economic parameters, the better. To illustrate this concept, the support ratio for selected Liquid Metal Reactor (LMR) burner core designs was compared with corresponding coolant void worths, a fundamental safety concern following the Chernobyl accident. Results can be used to evaluate the cost in reduced burning of minor actinides caused by LMR sodium void reduction efforts or to compare with other minor actinide burner systems

  12. Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Vénéroni variational principle

    Directory of Open Access Journals (Sweden)

    Kedziora David J.

    2011-10-01

    Full Text Available Collisions of actinide nuclei form, during very short times of few zs (10−21 s, the heaviest ensembles of interacting nucleons available on Earth. Such collisions are used to produce super-strong electric fields by the huge number of interacting protons to test spontaneous positron-electron pair emission (vacuum decay predicted by the quantum electrodynamics (QED theory. Multi-nucleon transfer in actinide collisions could also be used as an alternative way to fusion in order to produce neutron-rich heavy and superheavy elements thanks to inverse quasifission mechanisms. Actinide collisions are studied in a dynamical quantum microscopic approach. The three-dimensional time-dependent Hartree-Fock (TDHF code tdhf3d is used with a full Skyrme energy density functional to investigate the time evolution of expectation values of one-body operators, such as fragment position and particle number. This code is also used to compute the dispersion of the particle numbers (e.g., widths of fragment mass and charge distributions from TDHF transfer probabilities, on the one hand, and using the BalianVeneroni variational principle, on the other hand. A first application to test QED is discussed. Collision times in 238U+238U are computed to determine the optimum energy for the observation of the vacuum decay. It is shown that the initial orientation strongly affects the collision times and reaction mechanism. The highest collision times predicted by TDHF in this reaction are of the order of ~ 4 zs at a center of mass energy of 1200 MeV. According to modern calculations based on the Dirac equation, the collision times at Ecm > 1 GeV are sufficient to allow spontaneous electron-positron pair emission from QED vacuum decay, in case of bare uranium ion collision. A second application of actinide collisions to produce neutron-rich transfermiums is discussed. A new inverse quasifission mechanism associated to a specific orientation of the nuclei is proposed to

  13. Production and measurement of minor actinides in the commercial fuel cycle

    International Nuclear Information System (INIS)

    Stanbro, W.D.

    1997-03-01

    The minor actinide elements, particularly neptunium and americium, are produced as a normal byproduct of the operation of thermal power reactors. Because of the existence of long-lived isotopes of these elements, they constitute the major sources of the residual radiation in spent fuel or in wastes resulting from reprocessing. This has led to examinations by some countries of the possibility of separating the minor actinides from waste products. The papers found in this report address the production of minor actinides in common thermal power reactors as well as approaches to measure these materials in various media. The first paper in this volume, open-quotes Production of Minor Actinides in the Commercial Fuel Cycle,close quotes uses calculations with the ORIGEN2 reactor and decay code to estimate the amounts of minor actinides in spent fuel and separated plutonium as a function of reactor irradiation and the time after discharge. The second paper, open-quotes Destructive Assay of Minor Actinides,close quotes describes a number of promising approaches for the chemical analysis of minor actinides in the various forms in which they are found at reprocessing plants. The next paper, open-quotes Hybrid KED/XRF Measurement of Minor Actinides in Reprocessing Plants,close quotes uses the results of a simulation model to examine the possible applications of the hybrid KED/XRF instrument to the determination of minor actinides in some of the solutions found in reprocessing plants. In open-quotes Calorimetric Assay of Minor Actinides,close quotes the authors show some possible extensions of this powerful technique beyond the normal plutonium assays to include the minor actinides. Finally, the last paper in this volume, open-quotes Environment Measurements of Transuranic Nuclides,close quotes discusses what is known about the levels of the minor actinides in the environment and ways to analyze for these materials in environmental matrices

  14. Trends in actinide processing at Hanford

    International Nuclear Information System (INIS)

    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

  15. Subcritical limits for special fissile actinides

    International Nuclear Information System (INIS)

    Clark, H.K.

    1980-01-01

    Critical masses and subcritical mass limits in oxide-water mixtures were calculated for actinide nuclides other than /sup 233/U, /sup 235/U, and /sup 239/Pu that have an odd number of neutrons in the nucleus; S/sub n/ transport theory was used together with cross sections, drawn from the GLASS multigroup library, developed to provide accurate forecasts of actinide production at Savannah River

  16. Transmutation of actinides in power reactors.

    Science.gov (United States)

    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.

  17. Separation of actinides and their transmutation

    International Nuclear Information System (INIS)

    Bouchard, M.; Bathelier, M.; Cousin, M.

    1978-08-01

    Neutron irradiation of long-half-life actinides for transmutation into elements with shorter half-life is investigated as a means to reduce the long-term hazards of these actinides. The effectiveness of the method is analysed by applying it to fission product solutions from the first extraction cycle of fuel reprocessing plants. Basic principles, separation techniques and transmutation efficiencies are studied and discussed in detail

  18. Study on remain actinides recovery in pyro reprocessing

    International Nuclear Information System (INIS)

    Suharto, Bambang

    1996-01-01

    The spent fuel reprocessing by dry process called pyro reprocessing have been studied. Most of U, Pu and MA (minor actinides) from the spent fuel will be recovered and be fed back to the reactor as new fuel. Accumulation of remain actinides will be separated by extraction process with liquid cadmium solvent. The research was conducted by computer simulation to calculate the stage number required. The calculation's results showed on the 20 stages extractor more than 99% actinides can be separated. (author)

  19. CACAO facility. Radioactive targets at Orsay

    International Nuclear Information System (INIS)

    Bacri, C.O.; Petitbon-Thevenet, V.; Mottier, J.; Lefort, H.; Durnez, A.; Fortuna, F.

    2014-01-01

    CACAO, Chimie des Actinides et Cibles radioActives a Orsay (actinide chemistry and radioactive targets at Orsay), is a new laboratory dedicated to the fabrication and characterization of radioactive targets. It is supported by the radiochemistry group and the stable target service of the IPNO. The recurring needs of physicists working in the nuclear fuel cycle physics and the growing difficulties to obtain radioactive targets elsewhere were the main motivating factors behind the construction of this new laboratory. The first targets of 235,238 U and 232 Th have already been prepared although the full operating licenses still need to be obtained. In this paper, the installation and the equipment of CACAO will be described. An extensive study of a U test target fabricated by the CACAO laboratory has been performed and results are reported here. The different techniques used to characterize the deposit are presented and the outcome is discussed. (author)

  20. Use of fast-spectrum reactors for actinide burning

    International Nuclear Information System (INIS)

    Chang, Yoon I.

    1991-01-01

    Finally, Integral Fast Reactor (IFR) pyroprocessing has been developed only in recent years and it appears to have potential as a relatively uncomplicated, effective actinide recovery process. In fact, actinide recycling occurs naturally in the IFR fuel cycle. Although still very much developmental, the entire IFR fuel cycle will be demonstrated on prototype-scale in conjunction with the EBR-II and its refurbished Fuel Cycle Facility starting in late 1991. A logical extension to this work, therefore, is to establish whether this IFR pyrochemical processing can be applied to extracting actinides from LWR spent fuel. This paper summarizes current thinking on the rationale for actinide recycle, its ramifications on the geologic repository and the current high-level waste management plans, and the necessary development programs. 4 figs., 4 tabs

  1. The effect of corrosion product colloids on actinide transport

    International Nuclear Information System (INIS)

    Gardiner, M.P.; Smith, A.J.; Williams, S.J.

    1992-01-01

    The near field of the proposed UK repository for ILW/LLW will contain containers of conditioned waste in contact with a cementious backfill. It will contain significant quantities of iron and steel, Magnox and Zircaloy. Colloids deriving from their corrosion products may possess significant sorption capacity for radioelements. If the colloids are mobile in the groundwater flow, they could act as a significant vector for activity transport into the far field. The desorption of plutonium and americium from colloidal corrosion products of iron and zirconium has been studied under chemical conditions representing the transition from the near field to the far field. Desorption R d values of ≥ 5 x 10 6 ml g -1 were measured for both actinides on these oxides and hydroxides when actinide sorption took place under the near-field conditions and desorption took place under the far-field conditions. Desorption of the actinides occurred slowly from the colloids under far-field conditions when the colloids had low loadings of actinide and more quickly at high loadings of actinide. Desorbed actinide was lost to the walls of the experimental vessel. (author)

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

    International Nuclear Information System (INIS)

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

    1994-01-01

    The disposition of actinide elements released from high-level waste glasses into a tuff groundwater in laboratory tests at 90 degrees C at various glass surface area/leachant volume ratios (S/V) between dissolved, suspended, and sorbed fractions has been measured. While the maximum release of actinides is controlled by the corrosion rate of the glass matrix, their solubility and sorption behavior affects the amounts present in potentially mobile phases. Actinide solubilities are affected by the solution pH and the presence of complexants released from the glass, such as sulfate, phosphate, and chloride, radiolytic products, such as nitrate and nitrite, and carbonate. Sorption onto inorganic colloids formed during lass corrosion may increase the amounts of actinides in solution, although subsequent sedimentation of these colloids under static conditions leads to a significant reduction in the amount of actinides in solution. The solution chemistry and observed actinide behavior depend on the S/V of the test. Tests at high S/V lead to higher pH values, greater complexant concentrations, and generate colloids more quickly than tests at low S/V. The S/V also affects the rate of glass corrosion

  3. Research on the actinide chemistry in Nuclear Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyseok; Park, Yong Joon; Cho, Young Hwan; and others

    2012-04-15

    Fundamental technique to measure chemical behaviors and properties of lanthanide and actinide in radioactive waste is necessary for the development of pryochemical process. First stage, the electrochemical/spectroscopic integrated measurement system was designed and set up for spectro-electrochemical measurements of lanthanide and actinide ions in high temperature molten salt media. A compact electrochemical cell and electrode system was also developed for the minimization of reactants, and consequently minimization of radioactive waste generation. By applying these equipments, oxidation and reduction behavior of lanthanide and actinide ions in molten salt media have been made. Also, thermodynamic parameter values are determined by interpreting the results obtained from electrochemical measurements. Several lanthanide ions exhibited fluorescence properties in molten salt. Also, UV-VIS measurement provided the detailed information regarding the oxidation states of lanthanide and actinide ions in high temperature molten salt media. In the second stage, measurement system for physical properties at pyrochemical process such as viscosity, melting point and conductivity is established, and property database at different compositions of lanthanide and actinide is collected. And, both interactions between elements and properties with different potential are measured at binary composition of actinide-lanthanide in molten salt using electrochemical/spectroscopic integrated measurement system.

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

    Science.gov (United States)

    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.

  5. Nonaqueous method for dissolving lanthanide and actinide metals

    International Nuclear Information System (INIS)

    Crisler, L.R.

    1975-01-01

    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

  6. A Plutonium Ceramic Target for MASHA

    International Nuclear Information System (INIS)

    Wilk, P A; Shaughnessy, D A; Moody, K J; Kenneally, J M; Wild, J F; Stoyer, M A; Patin, J B; Lougheed, R W; Ebbinghaus, B B; Landingham, R L; Oganessian, Y T; Yeremin, A V; Dmitriev, S N

    2004-01-01

    We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments where the chemical properties of the heaviest elements are studied

  7. Biotransformation of uranium and other actinides in radioactive wastes

    International Nuclear Information System (INIS)

    Francis, A.J.

    1998-01-01

    Microorganisms affect the solubility, bioavailability, and mobility of actinides in radioactive wastes. Under appropriate conditions, actinides are solubilized or stabilized by the direct enzymatic or indirect nonenzymatic actions of microorganisms. Biotransformation of various forms of uranium (ionic, inorganic, and organic complexes) by aerobic and anaerobic microorganisms has been extensively studied, whereas limited information is available on other important actinides (Th, Np, Pu, and Am). Fundamental information on the mechanisms of biotransformation of actinides by microbes under various environmental conditions will be useful in predicting the long-term performance of waste repositories and in developing strategies for waste management and remediation of contaminated sites. (orig.)

  8. Strategies for minority actinides transmutation in fast reactors

    International Nuclear Information System (INIS)

    Perez-Martin, S.; Martin-Fuertes, F.; Alvarez-Velarde, F.

    2010-01-01

    Presentation of the strategies that can be followed in fast reactors designed for the fourth generation to reduce the inventory of minority actinides generated in current light water reactors, as the actinides generation in fast reactor.

  9. Actinide-handling experience for training and education of future expert under J-ACTINET

    International Nuclear Information System (INIS)

    Osaka, Masahiko; Sato, Isamu; Miwa, Shuhei; Konashi, Kenji; Li, Dexin; Homma, Yoshiya; Yamamura, Tomoo; Hayashi, Hirokazu; Minato, Kazuo; Sekimoto, Syun; Kubota, Takumi; Fukutani, Satoshi; Hori, Junichi; Okumura, Ryo; Uehara, Akihiro; Fujii, Toshiyuki; Yamana, Hajimu; Kurosaki, Ken; Muta, Hiroaki; Ohishi, Yuji; Yamanaka, Shinsuke; Uno, Masayoshi; Yaita, Tsuyoshi

    2011-01-01

    Summer schools for future experts have successfully been completed under Japan Actinide Network (J-ACTINET) for the purpose of development of human resources who are expected to be engaged in every areas of actinide-research/engineering. The first summer school was held in Ibaraki-area in August 2009, followed by the second one in Kansai-area in August 2010. Two summer schools have focused on actual experiences of actinides in actinide-research fields for university students and young researchers/engineers as an introductory course of actinide-researches. Many efforts were made to awaken interests into actinide-researches inside the participants during short periods of schools, 3 to 4 days. As actinides must be handled inside special apparatuses such as an air-tight globe-box with well-trained and qualified technicians, programs were optimized for effective experiences of actinides-handling. Several quasi actinide-handling experiences at the actinide-research fields have attracted attentions of participants at the first school in Ibaraki-area. The actual experiments using actinides-containing solutions have been carried out at the second school in Kansai-area. Future summer schools will be held every year for the sustainable human resource development in various actinide-research fields, together with other training and education programs conducted by the J-ACTINET. (author)

  10. Actinide separation chemistry in nuclear waste streams and materials

    International Nuclear Information System (INIS)

    1997-12-01

    The separation of actinide elements from various waste materials, produced either in nuclear fuel cycles or in past nuclear weapons production, represents a significant issue facing developed countries. Improvements in the efficiencies of the separation processes can be expected to occur as a result of better knowledge of the elements in these complex matrices. The Nuclear Science Committee of the OECD/NEA has established a task force of experts in actinide separation chemistry to review current and developing separation techniques and chemical processes. The report consist of eight chapters. In Chapter 1 the importance of actinide separation chemistry in the fields of waste management and its background are summarized.In Chapter 2 the types of waste streams are classified according to their relative importance, by physical form and by source of actinides. The basic data of actinide chemical thermodynamics, such as oxidation states, hydrolysis, complexation, sorption, Gibbs energies of formation, and volatility, were collected and are presented in Chapter 3. Actinide analyses related to separation processes are also mentioned in this chapter. The state of the art of actinide separation chemistry is classified in three groups, including hydrometallurgy, pyrochemical process and process based on fields, and is described in Chapter 4 along with the relationship of kinetics to separations. In Chapter 5 basic chemistry research needs and the inherent limitation on separation processes are discussed. Prioritization of research and development is discussed in Chapter 6 in the context of several attributes of waste management problems. These attributes include: mass or volume of waste; concentration of the actinide in the waste; expected difficulty of treating the wastes; short-term hazard of the waste; long-term hazard of the waste; projected cost of treatment; amount of secondary waste. Based on the priority, recommendations were made for the direction of future research

  11. Actinide separation chemistry in nuclear waste streams and materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The separation of actinide elements from various waste materials, produced either in nuclear fuel cycles or in past nuclear weapons production, represents a significant issue facing developed countries. Improvements in the efficiencies of the separation processes can be expected to occur as a result of better knowledge of the elements in these complex matrices. The Nuclear Science Committee of the OECD/NEA has established a task force of experts in actinide separation chemistry to review current and developing separation techniques and chemical processes. The report consist of eight chapters. In Chapter 1 the importance of actinide separation chemistry in the fields of waste management and its background are summarized.In Chapter 2 the types of waste streams are classified according to their relative importance, by physical form and by source of actinides. The basic data of actinide chemical thermodynamics, such as oxidation states, hydrolysis, complexation, sorption, Gibbs energies of formation, and volatility, were collected and are presented in Chapter 3. Actinide analyses related to separation processes are also mentioned in this chapter. The state of the art of actinide separation chemistry is classified in three groups, including hydrometallurgy, pyrochemical process and process based on fields, and is described in Chapter 4 along with the relationship of kinetics to separations. In Chapter 5 basic chemistry research needs and the inherent limitation on separation processes are discussed. Prioritization of research and development is discussed in Chapter 6 in the context of several attributes of waste management problems. These attributes include: mass or volume of waste; concentration of the actinide in the waste; expected difficulty of treating the wastes; short-term hazard of the waste; long-term hazard of the waste; projected cost of treatment; amount of secondary waste. Based on the priority, recommendations were made for the direction of future research

  12. Performance of the Lead-Alloy Cooled Concept Balanced for Actinide Burning and Electricity Production

    International Nuclear Information System (INIS)

    Pavel Hejzlar; Cliff Davis

    2004-01-01

    A lead-bismuth-cooled fast reactor concept targeted for a balanced mission of actinide burning and low-cost electricity production is proposed and its performance analyzed. The design explores the potential benefits of thorium-based fuel in actinide-burning cores, in particular in terms of the reduction of the large reactivity swing and enhancement of the small Doppler coefficient typical of fertile-free actinide burners. Reduced electricity production cost is pursued through a longer cycle length than that used for fertile-free burners and thus a higher capacity factor. It is shown that the concept can achieve a high transuranics destruction rate, which is only 20% lower than that of an accelerator-driven system with fertile-free fuel. The small negative fuel temperature reactivity coefficient, small positive coolant temperature reactivity coefficient, and negative core radial expansion coefficient provide self-regulating characteristics so that the reactor is capable of inherent shutdown during major transients without scram, as in the Integral Fast Reactor. This is confirmed by thermal-hydraulic analysis of several transients without scram, including primary coolant pump trip, station blackout, and reactivity step insertion, which showed that the reactor was able to meet all identified thermal limits. However, the benefits of high actinide consumption and small reactivity swing can be attained only if the uranium from the discharged fuel is separated and not recycled. This additional uranium separation step and thorium reprocessing significantly increase the fuel cycle costs. Because the higher fuel cycle cost has a larger impact on the overall cost of electricity than the savings from the higher capacity factor afforded through use of thorium, this concept appears less promising than the fertile-free actinide burners

  13. Impact of minor actinide recycling on sustainable fuel cycle options

    Energy Technology Data Exchange (ETDEWEB)

    Heidet, F.; Kim, T. K.; Taiwo, T. A.

    2017-11-01

    The recent Evaluation and Screening study chartered by the U.S. Department of Energy, Office of Nuclear Energy, has identified four fuel cycle options as being the most promising. Among these four options, the two single-stage fuel cycles rely on a fast reactor and are differing in the fact that in one case only uranium and plutonium are recycled while in the other case minor actinides are also recycled. The two other fuel cycles are two-stage and rely on both fast and thermal reactors. They also differ in the fact that in one case only uranium and plutonium are recycled while in the other case minor actinides are also recycled. The current study assesses the impact of recycling minor actinides on the reactor core design, its performance characteristics, and the characteristics of the recycled material and waste material. The recycling of minor actinides is found not to affect the reactor core performance, as long as the same cycle length, core layout and specific power are being used. One notable difference is that the required transuranics (TRU) content is slightly increased when minor actinides are recycled. The mass flows are mostly unchanged given a same specific power and cycle length. Although the material mass flows and reactor performance characteristics are hardly affected by recycling minor actinides, some differences are observed in the waste characteristics between the two fuel cycles considered. The absence of minor actinides in the waste results in a different buildup of decay products, and in somewhat different behaviors depending on the characteristic and time frame considered. Recycling of minor actinides is found to result in a reduction of the waste characteristics ranging from 10% to 90%. These results are consistent with previous studies in this domain and depending on the time frame considered, packaging conditions, repository site, repository strategy, the differences observed in the waste characteristics could be beneficial and help improve

  14. Proceedings of the symposium Actinides 2006 - Basic Science, Applications and Technology

    International Nuclear Information System (INIS)

    Blobaum, Kerri J.M.; Chandler, Elaine A.; Havela, Ladislav; Maple, M. Brian; Neu, Mary P.

    2007-01-01

    These proceedings from the September 2006 symposium includes papers presented on experimental and modeling work with the intention of broadening understanding of the field of actinide research. Actinides have gained attention recently because of their roles in the threat of nuclear terrorism (e.g., 'dirty bombs') and the use of nuclear power to offset fossil fuel consumption. Actinide science is the study of the elements with atomic numbers in the range of 90 to 103, which includes uranium and plutonium. Beyond the well-known nuclear reactions of these heavy radioactive metals, the large electron clouds with 5f electrons in the outer shell yield fascinating and complex chemistries, crystal structures, and physical properties. Traditionally, actinide research has been divided among three scientific disciplines: chemistry (nuclear chemistry and radiochemistry); physics (condensed matter physics and electronic structure); and materials science (metallurgy). Modern actinide research, however, has become an interdisciplinary blend of these traditional fields, and it also incorporates developing fields such as environmental chemistry and superconductivity. Improved scientific understanding of actinides is needed for development of materials for actinide detection and nuclear fuels, and for safer management of nuclear waste. Recently, there has been a resurgence of actinide science at national laboratories and universities. The current multidisciplinary approach to actinide science lays the groundwork for understanding the connection between the 5f electronic structure and observed chemical reactions and physical properties such as structural phase transformations and novel ground states. This work provides many opportunities for new researchers in actinide science. These proceedings gather 25 selected papers among the 53 presentations given at this symposium

  15. Casting of metallic fuel containing minor actinide additions

    International Nuclear Information System (INIS)

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

    1992-01-01

    A significant attribute of the Integral Fast Reactor (IFR) concept is the transmutation of long-lived minor actinide fission products. These isotopes require isolation for thousands of years, and if they could be removed from the waste, disposal problems would be reduced. The IFR utilizes pyroprocessing of metallic fuel to separate auranium, plutonium, and the minor actinides from nonfissionable constituents. These materials are reintroduced into the fuel and reirradiated. Spent IFR fuel is expected to contain low levels of americium, neptunium, and curium because the hard neutron spectrum should transmute these isotopes as they are produced. This opens the possibility of using an IFR to trnasmute minor actinide waste from conventional light water reactors (LWRs). A standard IFR fuel is based on the alloy U-20% Pu-10% Zr (in weight percent). A metallic fuel system eases the requirements for reprocessing methods and enables the minor actinide metals to be incorporated into the fuel with simple modifications to the basic fuel casting process. In this paper, the authors report the initial casting experience with minor actinide element addition to an IFR U-Pu-Zr metallic fuel

  16. Prospects of subcritical molten salt reactor for minor actinides incineration in closed fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, Pavel N.; Balanin, Andrey L.; Dudnikov, Anatoly A.; Fomichenko, Petr A.; Nevinitsa, Vladimir A.; Frolov, Aleksey A.; Lubina, Anna S.; Sedov, Aleksey A.; Subbotin, Aleksey S.; Blandinsky, Viktor Yu. [Nuclear Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2015-09-15

    A subcritical molten salt reactor is proposed for minor actinides (separated from spent fuel VVER-1000 light water reactor) incineration and for {sup 233}U conversion from {sup 232}Th. Here the subcritical molten salt reactor with fuel composition of heavy nuclide fluorides in molten LiF - NaF - KF salt and with external neutron source, based on 1 GeV proton accelerator and molten salt cooled tungsten target is considered. The paper presents the results of parametrical analysis of equilibrium nuclide composition of molten salt reactor with minor actinides feed in dependence of core dimensions, average neutron flux and external neutron source intensity. Reactor design is defined; requirements to external neutron source are posed; heavy nuclides equilibrium and fuel cycle main parameters are calculated.

  17. Calculated Atomic Volumes of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, H.; Andersen, O. K.; Johansson, B.

    1979-01-01

    The equilibrium atomic volume is calculated for the actinide metals. It is possible to account for the localization of the 5f electrons taking place in americium.......The equilibrium atomic volume is calculated for the actinide metals. It is possible to account for the localization of the 5f electrons taking place in americium....

  18. Citrate based ''TALSPEAK'' lanthanide-actinide separation process

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ''geological'' periods of time. The costs of building, maintaining, and operating a ''geological TRU repository'' can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ''TALSPEAK'' process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced

  19. Research on Actinides in Nuclear Fuel Cycles

    International Nuclear Information System (INIS)

    Song, Kyu Seok; Park, Yong Joon; Cho, Young Hwan

    2010-04-01

    The electrochemical/spectroscopic integrated measurement system was designed and set up for spectro-electrochemical measurements of lanthanide and actinide ions in high temperature molten salt media. A compact electrochemical cell and electrode system was also developed for the minimization of reactants, and consequently minimization of radioactive waste generation. By applying these equipment, oxidation and reduction behavior of lanthanide and actinide ions in molten salt media have been made. Also, thermodynamic parameter values are determined by interpreting the results obtained from electrochemical measurements. Several lanthanide ions exhibited fluorescence properties in molten salt. Also, UV-VIS measurement provided the detailed information regarding the oxidation states of lanthanide and actinide ions in high temperature molten salt media

  20. Research on Actinides in Nuclear Fuel Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyu Seok; Park, Yong Joon; Cho, Young Hwan

    2010-04-15

    The electrochemical/spectroscopic integrated measurement system was designed and set up for spectro-electrochemical measurements of lanthanide and actinide ions in high temperature molten salt media. A compact electrochemical cell and electrode system was also developed for the minimization of reactants, and consequently minimization of radioactive waste generation. By applying these equipment, oxidation and reduction behavior of lanthanide and actinide ions in molten salt media have been made. Also, thermodynamic parameter values are determined by interpreting the results obtained from electrochemical measurements. Several lanthanide ions exhibited fluorescence properties in molten salt. Also, UV-VIS measurement provided the detailed information regarding the oxidation states of lanthanide and actinide ions in high temperature molten salt media

  1. Proposal for experiments with actinide elements

    International Nuclear Information System (INIS)

    Sanchez, R.G.

    1994-01-01

    An analytical study was conducted in which critical masses for some actinide isotopes were calculated with the Monte Carlo Neutron Photon (MCNP) Transport computer code. Different spherical computer models were used for even- and odd-neutron nuclides. Critical masses obtained are tabulated for Np-237, Pu-242, Am-241, Am-243, Pu-241, and Am-242m, together with indirect experimental data. Experimental data are needed for actinides with odd number of neutrons

  2. Actinide science with soft x-ray synchrotron radiation

    International Nuclear Information System (INIS)

    Shuh, D.

    2002-01-01

    Several workshops, some dating back more than fifteen years, recognised both the potential scientific impact and opportunities that would be made available by the capability to investigate actinide materials in the vacuum ultraviolet (VUV)/soft X-ray region of the synchrotron radiation (SR) spectrum. This spectral region revolutionized the approach to surface materials chemistry and physics nearly two decades ego. The actinide science community was unable to capitalize on these SR methodologies for the study of actinide materials until recently because of radiological safety concerns. ,The Advanced Light Source (ALS) at LBNL is a third-generation light source providing state-of-the-art performance in the VUV/soft X-ray region. Along with corresponding improvements in detector and vacuum technology, the ALS has rendered experiments with small amounts of actinide materials possible. In particular, it has been the emergence and development of micro-spectroscopic techniques that have enabled investigations of actinide materials at the ALS. 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 photo-emission is capable of resolving the 5f electron contributions to actinide bonding and can be used to characterise the electronic structure of actinide materials. This technique is clearly a most important methodology afforded by the tunable SR source. Core level and valence band photoelectron spectroscopies are valuable for the characterisation of the electronic properties of actinide materials, as well as for general analytical purposes. High-resolution core-level photo-emission and resonant photo-emission measurements from the a (monoclinic) and δ (FCC) allotropic phases of plutonium metal have been collected on beam line 7.0 at the ALS and the spectra show

  3. J-ACTINET activities of training and education for actinide science research

    International Nuclear Information System (INIS)

    Miato, Kazuo; Konashi, Kenji; Yamana, Hajimu; Yamanaka, Shinsuke; Nagasaki, Shinya; Ikeda, Yasuhisa; Sato, Seichi; Arita, Yuji; Idemitsu, Kazuya; Koyama, Tadafumi

    2011-01-01

    Actinide science research is indispensable to maintain sustainable development of innovative nuclear technology, especially advanced fuels, partitioning/reprocessing, and waste management. For actinide science research, special facilities with containment and radiation shields are needed to handle actinide materials since actinide elements are γ-, α- and neutron-emitters. The number of facilities for actinide science research has been decreased, especially in universities, due to the high maintenance cost. J-ACTINET was established in 2008 to promote and facilitate actinide science research in close cooperation with the facilities and to foster many of young scientists and engineers to be actively engaged in the fields of actinide science. The research program was carried out, through which young researchers were expected to learn how to make experiments with advanced experimental tools and to broaden their horizons. The summer schools and computational science school were held to provide students, graduate students, and young researchers with the opportunities to come into contact with actinide science research. In these schools, not only the lectures, but also the practical exercises were made as essential part. The overseas dispatch program was also carried out, where graduate students and young researchers were sent to the international summer schools and conferences. (author)

  4. Protactinium and the intersection of actinide and transition metal chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Richard E.; De Sio, Stephanie; Vallet, Valérie

    2018-02-12

    The role of the 5f and 6d orbitals in the chemistry of the actinide elements has been of considerable interest since their discovery and synthesis. Relativistic effects cause the energetics of the 5f and 6d orbitals to change as the actinide series is traversed left to right imparting a rich and complex chemistry. The 5f and 6d atomic states cross in energy at protactinium (Pa), making it a potential intersection between transition metal and actinide chemistries. Herein, we report the synthesis of a Pa-peroxo cluster, A(6)(Pa4O(O-2)(6)F-12) [A = Rb, Cs, (CH3)(4)N], formed in pursuit of an actinide polyoxometalate. Quantum chemical calculations at the density functional theory level demonstrate equal 5f and 6d orbital participation in the chemistry of Pa and increasing 5f orbital participation for the heavier actinides. Periodic changes in orbital character to the bonding in the early actinides highlights the influence of the 5f orbitals in their reactivity and chemical structure.

  5. Actinide removal from molten salts by chemical oxidation and salt distillation

    Energy Technology Data Exchange (ETDEWEB)

    McNeese, J.A.; Garcia, E.; Dole, V.R. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-10-01

    Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed.

  6. Actinide removal from molten salts by chemical oxidation and salt distillation

    International Nuclear Information System (INIS)

    McNeese, James A.; Garcia, Eduardo; Dole, Vonda R.; Griego, Walter J.

    1995-01-01

    Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed

  7. Complexation studies of actinides (U, Pu, Am) with linear polyamino-carboxylate ligands and sidero-chelates

    International Nuclear Information System (INIS)

    Nguyen, L.V.

    2010-01-01

    As part of our research endeavour aimed at developing and improving decontamination processes of wastewater containing alpha emitters, physico-chemical complexation studies of actinides (U, Pu, Am) with organic open-chain ligands such as poly-aminocarboxylic acids (H 4 EDTA) and sidero-chelates (di-hydroxamic acids and desferrioxamine B) have been carried out. Gaining a clear understanding of the coordination properties of the targeted actinides is an essential step towards the selection of the most appropriate chelating agents that will exhibit high uptake efficiencies. EXAFS (Extended X-ray Absorption Fine Structure) measurements at the ESRF synchrotron enabled to elucidate the coordination scheme of uranium and plutonium complexes. Solution thermodynamic investigations were intended to provide valuable information about the nature and the stability of the uranium(VI) and americium(III) complexes prevailing at a given pH in solution. The set of stability constants determined from potentiometric and UV-visible spectrophotometric titrations, allowed to predict the speciation of the selected actinides in presence of the aforementioned ligands and to determine the pH range required for achieving 'ultimate' decontamination. (author) [fr

  8. Use of fast reactors for actinide transmutation

    International Nuclear Information System (INIS)

    1993-03-01

    The management of radioactive waste is one of the key issues in today's discussions on nuclear energy, especially the long term disposal of high level radioactive wastes. The recycling of plutonium in liquid metal fast breeder reactors (LMFBRs) would allow 'burning' of the associated extremely long life transuranic waste, particularly actinides, thus reducing the required isolation time for high level waste from tens of thousands of years to hundreds of years for fission products only. The International Working Group on Fast Reactors (IWGFR) decided to include the topic of actinide transmutation in liquid metal fast breeder reactors in its programme. The IAEA organized the Specialists Meeting on Use of Fast Breeder Reactors for Actinide Transmutation in Obninsk, Russian Federation, from 22 to 24 September 1992. The specialists agree that future progress in solving transmutation problems could be achieved by improvements in: Radiochemical partitioning and extraction of the actinides from the spent fuel (at least 98% for Np and Cm and 99.9% for Pu and Am isotopes); technological research and development on the design, fabrication and irradiation of the minor actinides (MAs) containing fuels; nuclear constants measurement and evaluation (selective cross-sections, fission fragments yields, delayed neutron parameters) especially for MA burners; demonstration of the feasibility of the safe and economic MA burner cores; knowledge of the impact of maximum tolerable amount of rare earths in americium containing fuels. Refs, figs and tabs

  9. The chemistry of the actinide elements. Volume I

    International Nuclear Information System (INIS)

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

    1986-01-01

    The Chemistry of the Actinide Elements is a comprehensive, contemporary and authoritative exposition of the chemistry and related properties of the 5f series of elements: actinium, thorium, protactinium, uranium and the first eleven. This second edition has been completely restructured and rewritten to incorporate current research in all areas of actinide chemistry and chemical physics. The descriptions of each element include accounts of their history, separation, metallurgy, solid-state chemistry, solution chemistry, thermo-dynamics and kinetics. Additionally, separate chapters on spectroscopy, magnetochemistry, thermodynamics, solids, the metallic state, complex ions and organometallic compounds emphasize the comparative chemistry and unique properties of the actinide series of elements. Comprehensive lists of properties of all actinide compounds and ions in solution are given, and there are special sections on such topics as biochemistry, superconductivity, radioisotope safety, and waste management, as well as discussion of the transactinides and future elements

  10. Thermochemical and thermophysical properties of minor actinide compounds

    International Nuclear Information System (INIS)

    Minato, Kazuo; Takano, Masahide; Otobe, Haruyoshi; Nishi, Tsuyoshi; Akabori, Mitsuo; Arai, Yasuo

    2009-01-01

    Burning or transmutation of minor actinides (MA: Np, Am, Cm) that are classified as the high-level radioactive waste in the current nuclear fuel cycle is an option for the advanced nuclear fuel cycle. Although the thermochemical and thermophysical properties of minor actinide compounds are essential for the design of MA-bearing fuels and analysis of their behavior, the experimental data on minor actinide compounds are limited. To support the research and development of the MA-bearing fuels, the property measurements were carried out on minor actinide nitrides and oxides. The lattice parameters and their thermal expansions were measured by high-temperature X-ray diffractometry. The specific heat capacities were measured by drop calorimetry and the thermal diffusivities by laser-flash method. The thermal conductivities were determined by the specific heat capacities, thermal diffusivities and densities. The oxygen potentials were measured by electromotive force method.

  11. Lattice effects in the light actinides

    International Nuclear Information System (INIS)

    Lawson, A.C.; Cort, B.; Roberts, J.A.; Bennett, B.I.; Brun, T.O.; Dreele, R.B. von; Richardson, J.W. Jr.

    1998-01-01

    The light actinides show a variety of lattice effects that do not normally appear in other regions of the periodic table. The article will cover the crystal structures of the light actinides, their atomic volumes, their thermal expansion behavior, and their elastic behavior as reflected in recent thermal vibration measurements made by neutron diffraction. A discussion of the melting points will be given in terms of the thermal vibration measurements. Pressure effects will be only briefly indicated

  12. Non-compound nucleus fission in actinide and pre-actinide regions

    Indian Academy of Sciences (India)

    Data on the evaporation residue cross-sections, in addition to those on mass and angular distributions, are necessary for better understanding of the contribution from non-compound nucleus fission in the pre-actinide region. Measurement of mass-resolved angular distribution of fission products in 20Ne+232Th reaction ...

  13. Special actinide nuclides: Fuel or waste?

    International Nuclear Information System (INIS)

    Srinivasan, M.; Rao, K.S.; Dingankar, M.V.

    1989-01-01

    The special actinide nuclides such as Np, Cm, etc. which are produced as byproducts during the operation of fission reactors are presently looked upon as 'nuclear waste' and are proposed to be disposed of as part of high level waste in deep geological repositories. The potential hazard posed to future generations over periods of thousands of years by these long lived nuclides has been a persistent source of concern to critics of nuclear power. However, the authors have recently shown that each and every one of the special actinide nuclides is a better nuclear fuel than the isotopes of plutonium. This finding suggests that one does not have to resort to exotic neutron sources for transmuting/incinerating them as proposed by some researchers. Recovery of the special actinide elements from the waste stream and recycling them back into conventional fission reactors would eliminate one of the stigmas attached to nuclear energy

  14. Neutron scattering studies of the actinides

    International Nuclear Information System (INIS)

    Lander, G.H.

    1979-01-01

    The electronic structure of actinide materials presents a unique example of the interplay between localized and band electrons. Together with a variety of other techniques, especially magnetization and the Mossbauer effect, neutron studies have helped us to understand the systematics of many actinide compounds that order magnetically. A direct consequence of the localization of 5f electrons is the spin-orbit coupling and subsequent spin-lattice interaction that often leads to strongly anisotropic behavior. The unusual phase transition in UO 2 , for example, arises from interactions between quadrupole moments. On the other hand, in the monopnictides and monochalcogenides, the anisotropy is more difficult to understand, but probably involves an interaction between actinide and anion wave functions. A variety of neutron experiments, including form-factor studies, critical scattering and measurements of the elementary excitations have now been performed, and the conceptual picture emerging from these studies will be discussed

  15. Successive change regularity of actinide properties with atomic number

    International Nuclear Information System (INIS)

    Yang Xuexian

    1990-08-01

    The development and achievements on chemistry of actinide elements are summarised. The relations of properties of actinides to their electronic configurations of valence electronic shells are discussed. Some anomalies of solid properties, the radius contraction, the stable state effect of f 7n -orbits (n = 0, 1, 2) and the tetrad effect of oxidation states, etc., with atomic number (Z) are described. 31 figures appended show directly the successive change regularity of actinide properties with Z

  16. Soft X-ray synchrotron radiation investigations of actinide materials systems utilizing X-ray emission spectroscopy and resonant inelastic X-ray scattering

    International Nuclear Information System (INIS)

    Shuh, D.K.; Butorin, S.M.; Guo, J.-H.; Nordgren, J.

    2004-01-01

    Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies

  17. ORNL actinide materials and a new detection system for superheavy nuclei

    Directory of Open Access Journals (Sweden)

    Rykaczewski Krzysztof P.

    2016-01-01

    Full Text Available The actinide resources and production capabilities at Oak Ridge National Laboratory (ORNL are reviewed, including potential electromagnetic separation of rare radioactive materials. The first experiments at the Dubna Gas Filled Recoil Separator (DGFRS with a new digital detection system developed at ORNL and University of Tennessee Knoxville (UTK are presented. These studies used 240Pu material provided by ORNL and mixed-Cf targets made at ORNL. The proposal to use an enriched 251Cf target and a large dose of 58Fe beam to reach the N = 184 shell closure and to observe new elements with Z = 124, 122 and 120 is discussed.

  18. A Summary of Actinide Enrichment Technologies and Capability Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Bradley D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robinson, Sharon M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    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.

  19. Extraction of Trivalent Actinides and Lanthanides from Californium Campaign Rework Solution Using TODGA-based Solvent Extraction System

    Energy Technology Data Exchange (ETDEWEB)

    Benker, Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dryman, Joshua Cory [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    This report presents the studies carried out to demonstrate the possibility of quantitatively extracting trivalent actinides and lanthanides from highly acidic solutions using a neutral ligand-based solvent extraction system. These studies stemmed from the perceived advantage of such systems over cationexchange- based solvent extraction systems that require an extensive feed adjustment to make a low-acid feed. The targeted feed solutions are highly acidic aqueous phases obtained after the dissolution of curium targets during a californium (Cf) campaign. Results obtained with actual Cf campaign solutions, but highly diluted to be manageable in a glove box, are presented, followed by results of tests run in the hot cells with Cf campaign rework solutions. It was demonstrated that a solvent extraction system based on the tetraoctyl diglycolamide molecule is capable of quantitatively extracting trivalent actinides from highly acidic solutions. This system was validated using actual feeds from a Cf campaign.

  20. Performance of the Lead-Alloy-Cooled Reactor Concept Balanced for Actinide Burning and Electricity Production

    International Nuclear Information System (INIS)

    Hejzlar, Pavel; Davis, Cliff B.

    2004-01-01

    A lead-bismuth-cooled fast reactor concept targeted for a balanced mission of actinide burning and low-cost electricity production is proposed and its performance analyzed. The design explores the potential benefits of thorium-based fuel in actinide-burning cores, in particular in terms of the reduction of the large reactivity swing and enhancement of the small Doppler coefficient typical of fertile-free actinide burners. Reduced electricity production cost is pursued through a longer cycle length than that used for fertile-free burners and thus a higher capacity factor. It is shown that the concept can achieve a high transuranics destruction rate, which is only 20% lower than that of an accelerator-driven system with fertile-free fuel. The small negative fuel temperature reactivity coefficient, small positive coolant temperature reactivity coefficient, and negative core radial expansion coefficient provide self-regulating characteristics so that the reactor is capable of inherent shutdown during major transients without scram, as in the Integral Fast Reactor. This is confirmed by thermal-hydraulic analysis of several transients without scram, including primary coolant pump trip, station blackout, and reactivity step insertion, which showed that the reactor was able to meet all identified thermal limits. However, the benefits of high actinide consumption and small reactivity swing can be attained only if the uranium from the discharged fuel is separated and not recycled. This additional uranium separation step and thorium reprocessing significantly increase the fuel cycle costs. Because the higher fuel cycle cost has a larger impact on the overall cost of electricity than the savings from the higher capacity factor afforded through use of thorium, this concept appears less promising than the fertile-free actinide burners

  1. a Plutonium Ceramic Target for Masha

    Science.gov (United States)

    Wilk, P. A.; Shaughnessy, D. A.; Moody, K. J.; Kenneally, J. M.; Wild, J. F.; Stoyer, M. A.; Patin, J. B.; Lougheed, R. W.; Ebbinghaus, B. B.; Landingham, R. L.; Oganessian, Yu. Ts.; Yeremin, A. V.; Dmitriev, S. N.

    2005-09-01

    We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 °C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments where the chemical properties of the heaviest elements are studied.

  2. Nuclear fuel cycle-oriented actinides separation in China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing; He, Xihong; Wang, Jianchen [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology

    2014-04-01

    In the last decades, the separation of actinides was widely and continuously studied in China. A few kinds of salt-free reductants to adjust Pu and Np valences have been investigated. N,N-dimethylhydroxylamine is a good reductant with high reduction rate constants for the co-reduction of Pu(IV) and Np(VI), and monomethylhydrazine is a simple compound for the individual reduction of Np(VI). Advanced PUREX based on Organic Reductants (APOR) was proposed. Trialkylphosphine oxide (TRPO) with a single functional group was found to possess strong affinity to tri-, tetra- and hexa-valent actinides. TRPO process has been first explored in China for actinides partitioning from high level waste and the good partitioning performance was demonstrated by the hot test. High extraction selectivity for trivalent actinides over lanthanides by dialkyldithiophosphinic acids was originally found in China. A separation process based on purified Cyanex 301 for the separation of Am from lanthanides was presented and successfully tested in a battery of miniature centrifugal contactors. (orig.)

  3. Development and testing of metallic fuels with high minor actinide content

    International Nuclear Information System (INIS)

    Meyer, M.K.; Hayes, S.L.; Kennedy, J.R.; Keiser, D.D.; Hilton, B.A.; Frank, S.M.; Kim, Y.-S.; Chang, G.; Ambrosek, R.G.

    2003-01-01

    Metallic alloys are promising candidates for use as fuels for transmutation and in advanced closed nuclear cycles. Metallic alloys have high heavy metal atom density, relatively high thermal conductivity, favorable gas release behavior, and lend themselves to remote recycle processes. Both non-fertile and uranium-bearing metal fuels containing minor actinide are under consideration for use as transmutation fuels by the U.S. Advanced Fuel Cycle (AFC) program, however, little irradiation performance data exists for fuel forms containing significant fractions of minor actinides. The first irradiation tests of non-fertile high-actinide-content fuels are scheduled to begin in early 2003 in the Advanced Test Reactor (ATR). The irradiation test matrix was designed to provide basic information on the irradiation behavior of binary Pu-Zr alloy fuel and the effect of the minor actinides americium and neptunium on alloy fuel behavior, together and separately. Five variants of transuranic containing zirconium-based alloy fuels are included in the AFC-1 irradiation test matrix. These are (in wt.%) Pu-40Zr, Pu-60Zr, Pu-12Am-40Zr, Pu-10Np-40Zr and Pu-10Np-10Am-40Zr. PuN-ZrN based fuels containing Am and Np are also included. All five of the fuel alloys have been fabricated in the form of cylindrical fuel slugs by arc-casting. Short melt times, on the order or 5-20 seconds, prevent the volatilization of significant quantities of americium metal, despite the high melt temperatures characteristic of the arc-melting process. Alloy microstructure have been characterized by x-ray diffraction and scanning electron microscopy. Thermal analysis has also been performed. The AFC-1 irradiation experiment configuration consists of twenty-four sodium bonded fuel specimens sealed in helium filled secondary capsules. The first capsule has a design burnup to 7 at.% 239 Pu; goal peak burnup of the second capsule is ∼18 at%. Capsule assemblies are placed within an aluminum flow-through basket

  4. Actinides in irradiated graphite of RBMK-1500 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Plukienė, R., E-mail: rita@ar.fi.lt; Plukis, A.; Barkauskas, V.; Gudelis, A.; Gvozdaitė, R.; Duškesas, G.; Remeikis, V.

    2014-10-01

    Highlights: • Activation of actinides in the graphite of the RBMK-1500 reactor was analyzed. • Numerical modeling using SCALE 6.1 and MCNPX was used for actinide calculation. • Measurements of the irradiated graphite sample were used for model validation. • Results are important for further decommissioning process of the RBMK type reactors. - Abstract: The activation of graphite in the nuclear power plants is the problem of high importance related with later graphite reprocessing or disposal. The activation of actinide impurities in graphite due to their toxicity determines a particular long term risk to waste management. In this work the activation of actinides in the graphite constructions of the RBMK-1500 reactor is determined by nuclear spectrometry measurements of the irradiated graphite sample from the Ignalina NPP Unit I and by means of numerical modeling using two independent codes SCALE 6.1 (using TRITON-VI sequence) and MCNPX (v2.7 with CINDER). Both models take into account the 3D RBMK-1500 reactor core fragment with explicit graphite construction including a stack and a sleeve but with a different simplification level concerning surrounding graphite and construction of control roads. The verification of the model has been performed by comparing calculated and measured isotope ratios of actinides. Also good prediction capabilities of the actinide activation in the irradiated graphite have been found for both calculation approaches. The initial U impurity concentration in the graphite model has been adjusted taking into account the experimental results. The specific activities of actinides in the irradiated RBMK-1500 graphite constructions have been obtained and differences between numerical simulation results, different structural parts (sleeve and stack) as well as comparison with previous results (Ancius et al., 2005) have been discussed. The obtained results are important for further decommissioning process of the Ignalina NPP and other RBMK

  5. Solubility of actinides and surrogates in nuclear glasses; Solubilite des actinides et de leurs simulants dans les verres nucleaires. Limites d'incorporation et comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Ch

    2003-07-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO{sub 2} at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  6. Self-interaction corrected local spin density calculations of actinides

    DEFF Research Database (Denmark)

    Petit, Leon; Svane, Axel; Szotek, Z

    2010-01-01

    We use the self-interaction corrected local spin-density approximation in order to describe localization-delocalization phenomena in the strongly correlated actinide materials. Based on total energy considerations, the methodology enables us to predict the ground-state valency configuration...... of the actinide ions in these compounds from first principles. Here we review a number of applications, ranging from electronic structure calculations of actinide metals, nitrides and carbides to the behaviour under pressure of intermetallics, and O vacancies in PuO2....

  7. Separation and preconcentration of actinides from acidic media by extraction chromatography

    International Nuclear Information System (INIS)

    Horwitz, E. Philip; Chiarizia, Renato; Dietz, Mark L.; Diamond, Herbert; Nelson, Donald M.

    1993-01-01

    A systematic examination of the effect of nitric and hydrochloric acid concentrations and of macro levels of selected elements on the sorption of actinide ions by a novel extraction chromatographic resin comprised of a solution of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide in tri-n-butyl phosphate supported on an inert polymeric substrate is described. Actinide sorption is demonstrated to be most efficient at high (>1 M) nitric acid concentrations, although tetra- and hexavalent actinides are strongly retained even from dilute (e.g., 0.05 M) nitric acid solutions. Macro concentrations of several common anions (e.g., PO 4 3- and SO 4 2- ) or complexing agents (e.g., oxalic acid) are shown not to adversely affect the sorption of trivalent actinides, while reducing the sorption of tetravalents. Such effects, together with oxidation state adjustments, are shown to provide a basis for the sequential elution of individual actinides and for actinide isolation from environmental and biological matrices

  8. The electronic structure of the lanthanides and actinides, a comparison

    International Nuclear Information System (INIS)

    Edelstein, N.M.

    1998-01-01

    Full text: Optical spectra of the two f-element series (the lanthanides and actinides) are comparable in many respects. For the trivalent ions isolated in single crystals, both series exhibit rich, narrow line spectra. These data can be analysed in terms of a parametric model based on a free-ion Hamiltonian plus the addition of a crystal field Hamiltonian. For most systems the agreement between the calculated and experimental energy levels is quite good. In the actinide series there appears to be a correlation between the magnitude of the crystal field and the inadequacy of the fits. The early actinides exhibit multiple oxidation states for which there is no precedent in the lanthanide series. The parametric model mentioned earlier has been utilized for some tetravalent actinide systems with reasonably good results. A selective survey of results describing the similarities and differences of various lanthanide and actinide systems will be given

  9. Actinide distribution in the human skeleton

    International Nuclear Information System (INIS)

    Kathren, R.L.; McInroy, J.F.; Swint, M.J.

    1985-05-01

    Radiochemical analysis of two half skeletons donated to the United States Transuranium Registry, one from an individual with an occupationally incurred deposition of 241 Am and the other with a deposition of 239 Pu, revealed an inverse linear relationship between the concentration of actinide in the bone ash and the fraction of ash. Two distinct relationships were noted, one for the cranium and the other for the remainder of the skeleton. The results suggest that the actinide content of the skeleton as a whole, Q, can be obtained with an uncertainty of +-50% from analysis of a single sample of any bone (except the cranium) by Q = [(830 C/sub sample/)/(0.61 - f/sub sample/)], in which C/sub sample/ refers to the actinide content per g of ash and f/sub sample/ the fraction of ash (i.e., ratio of dry to wet weight) in the sample. 5 figs., 3 tabs

  10. Mixer-settler performance evaluation in actinide extraction

    International Nuclear Information System (INIS)

    Camilo, R.L.; Goncalves, M.A.; Carvalho, E.I.; Nakazone, A.K.; Araujo, B.F. de; Araujo, J.A.

    1988-07-01

    This paper deals with four conceptions of mixer-settlers used for actinide purification and recovery. By means of the uranium concentration profiles in the organic and aqueous phases, the evaluation of each mixer-settler was made. The main purpose of this work is the data acquisition, for adapting the different contactor types to actinide recovery by liquid-liquid extraction, in the nuclear fuel cycle. (autor) [pt

  11. Synergistic extraction of actinides : Part I. Hexa-and pentavalent actinides

    International Nuclear Information System (INIS)

    Patil, S.K.; Ramakrishna, V.V.

    1980-01-01

    A detailed discussion on the reported literature on the synergistic extraction of hexa- and pentavalent actinide ions, by different combinations of extractants and from different aqueous media, is presented. Structural aspects of the various complexes involved in synergism also are reviewed. A short account of the applications based on synergistic extraction is also given. (author)

  12. Latest Results on Top Quark Properties: \\\\ Deciphering the DNA of the heaviest quark

    CERN Document Server

    Gallinaro, Michele

    2017-01-01

    The top quark, the heaviest known elementary particle discovered at the Fermilab Tevatron more than twenty years ago, has taken a central role in the study of fundamental interactions. Due to its large mass, the top quark provides a unique environment for tests of the standard model. With a cumulative luminosity of more than 100~fb$^{-1}$ collected at $\\sqrt{s}=7,8,13$~TeV by each of the ATLAS and CMS experiments at the Large Hadron Collider in the first ten years of operation, top quark physics is probing uncharted territories in precision and rare measurements with sensitivity to New Physics processes. This document summarizes the latest experimental measurements and studies of top quark properties.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pagano, Justin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  14. Scissors strength in the quasi-continuum of actinides

    Directory of Open Access Journals (Sweden)

    Guttormsen M.

    2014-03-01

    Full Text Available The M1-scissors resonance has been measured for the first time in the quasi-continuum of actinides. The strength and position of the resonances in 231,232,233Th were determined by particle-γ coincidences using deuteron induced reactions on a 232Th target. The residual nuclei show a strong integrated strength of BM1 = 9 − 11 µn2 in the Eγ = 1.0 − 3.5 MeV region. The presence of the scissors resonance modifies significantly the (n,γ cross section, which has impact on fuel-cycle simulations of fast nuclear reactors and nucleosynthesis in explosive stellar environments.

  15. Preliminary considerations concerning actinide solubilities

    International Nuclear Information System (INIS)

    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

  16. Orbital effects in actinide systems

    International Nuclear Information System (INIS)

    Lander, G.H.

    1983-01-01

    Actinide magnetism presents a number of important challenges; in particular, the proximity of 5f band to the Fermi energy gives rise to strong interaction with both d and s like conduction electrons, and the extended nature of the 5f electrons means that they can interact with electron orbitals from neighboring atoms. Theory has recently addressed these problems. Often neglected, however, is the overwhelming evidence for large orbital contributions to the magnetic properties of actinides. Some experimental evidence for these effects are presented briefly in this paper. They point, clearly incorrectly, to a very localized picture for the 5f electrons. This dichotomy only enhances the nature of the challenge

  17. Formation of actinides in irradiated HTGR fuel elements

    International Nuclear Information System (INIS)

    Santos, A.M. dos.

    1976-03-01

    Actinide nuclide concentrations of 11 spent AVR fuel elements were determined experimentally. The burnup of the spheres varied in the range between 10% and 100% fifa, the Th : U ratio was 5 : 1. The separation procedures for actinide isolation were tested with highly irradiated ThO 2 . Separation and decontamination factors are presented. Actinide nuclide formation can be described by exponential functions of the type ln msub(nuclide) = A + B x % fifa. The empirical factors A and B were calculated performing a least squares analysis. Build-up of 232 U was discussed. According to the experimental results, 232 U is mainly produced from 230 Th, a certain amount (e.g. about 20% at a 10 5 MWd/t burnup) originated from a (n,2n) reaction of 233 U; a formation from 233 Th by a (n,2n) followed by a (n,γ) reaction was not observed. The AVR breeding rate was ascertained to be 0.5. The hazard potential of high activity waste was calculated. After a 1,000 years' storage time, the elements Pa, Am and Cm will no longer influence the total hazard index. Actinide recovery factors were proposed in order to reduce the hazard potential of the waste by an actinide removal in consideration of the reprocessing technology which is available presently. (orig.) [de

  18. Technical requirements for the actinide source-term waste test program

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-10-01

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

  19. Technical requirements for the actinide source-term waste test program

    International Nuclear Information System (INIS)

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

    1993-10-01

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

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

    International Nuclear Information System (INIS)

    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 μg 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

  1. Accelerator-based transmuter-breeder and energy producer from transuranic actinides and thorium

    Energy Technology Data Exchange (ETDEWEB)

    Batskikh, G.I.; Fedotov, A.P.; Murin, B.P. [Moscow Radiotechnical Institute (Russian Federation)

    1995-10-01

    A concept of an accelerator-driven subcritical blanket with Pb or molten salt (heavy chloride) as the primary target, a graphite moderator-reflector to produce high-density thermal neutron fluxes and a fluid fuel carrying TUA actinides and Th-U, is being studied at MRTI. A driver is CW H{sup +}/H{sup {minus}} linac: 1 GeV, 200 mA, SIU-DTL-D&W structure energized by regotron as RF power supply.

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

    Science.gov (United States)

    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.

  3. What fits best minor actinides as a die material?

    International Nuclear Information System (INIS)

    Hinfray, J.

    2003-01-01

    Zirconolite might be the die material used to confine actinides definitively. Cea's teams have been investigating the ability of zirconolite to trap actinide atoms in its own crystal structure. These studies have been performed with 239 Pu that presents the same ability to set chemical links with the constituents of the die as 3 minor actinides do. Crystal materials like zirconolite are more sensitive to self irradiation than glass. The next step of the characterization of zirconolite is to evaluate its capacity to sustain self alpha irradiation. In order to do so, 238 Pu is used since its relatively short period (T = 87 years) allows an acceleration of the process : damages cumulated in the die material in 2 years will be equivalent to those produced by minor actinides for millions years. The results will be known in 2004. (A.C.)

  4. Possible existence of backbending in actinide nuclei

    International Nuclear Information System (INIS)

    Dudek, J.; Nazarewicz, W.; Szymanski, Z.

    1982-01-01

    The possibilities for the backbending effect to occur in actinide nuclei are studied using the pairing-self-consistent independent quasiparticle method. The Hamiltonian used is that of the deformed Woods-Saxon potential plus monopole pairing term. The results of the calculations explain why there is no backbending in most actinide nuclei and simultaneously suggest that in some light neutron deficient nuclei around Th and 22 Ra a backbending effect may occur

  5. Positron Spectroscopy of Hydrothermally Grown Actinide Oxides

    Science.gov (United States)

    2014-03-27

    actinide oxides . The work described here is an attempt to characterize the quality of crystals using positron annihilation spectroscopy (PALS). The...Upadhyaya, R. V. Muraleedharan, B. D. Sharma and K. G. Prasad, " Positron lifetime studies on thorium oxide powders," Philosohical Magazine A, vol. 45... crystals . A strong foundation for actinide PALS studies was laid, but further work is required to build a more effective system. Positron Spectroscopy

  6. The removal of actinide metals from solution

    International Nuclear Information System (INIS)

    Hancock, R.D.; Howell, I.V.

    1980-01-01

    A process is specified for removing actinide metals (e.g. uranium) from solutions. The solution is contacted with a substrate comprising the product obtained by reacting an inorganic solid containing surface hydroxyl groups (e.g. silica gel) with a compound containing a silane grouping, a nitrogen-containing group (e.g. an amine) and other specified radicals. After treatment, the actinide metal is recovered from the substrate. (U.K.)

  7. Biological pathways and chemical behavior of plutonium and other actinides in the environment

    International Nuclear Information System (INIS)

    Dahlman, R.C.; Bondietti, E.A.; Eyman, L.D.

    1976-01-01

    The principal long-lived actinide elements that may enter the environment from either U or Pu fuel cycles are Pu, Am, Cm, and Np. Approximately 25% of the alpha activity estimated to be released to the atmosphere from the LMFBR fuel cycle will be contributed by 241 Am, 242 Cm, and 244 Cm. The balance of the alpha activity will come from Pu isotopes. Activities of 242 Cm, 244 Cm, 241 Am, 243 Am, and 237 Np in waste may exceed concentrations of Pu isotopes in waste after various periods of decay. Thorium and uranium isotopes may also be released by operations of the thorium fuel cycle. Environmental actinides are discussed under the following headings: sources of man-made actinide elements; pathways of exposure; environmental chemistry of actinides; uptake of actinides by plants; distribution of actinides in components of White Oak Lake; entry of actinides into terrestrial food chains; relationship between chemical behavior and uptake of actinides by organisms; and behavior of Pu in freshwater and marine food chains

  8. Reduction of minor actinides for recycling in a light water reactor

    International Nuclear Information System (INIS)

    Martinez C, E.; Ramirez S, J. R.; Alonso V, G.

    2015-09-01

    The aim of actinide transmutation from spent nuclear fuel is the reduction in mass of high-level waste which must be stored in geological repositories and the lifetime of high-level waste; these two achievements will reduce the number of repositories needed, as well as the duration of storage. The present work is directed towards the evaluation of an advanced nuclear fuel cycle in which the minor actinides (Np, Am and Cm) could be recycled to remove most of the radioactive material; a reference of actinides production in standard nuclear fuel of uranium at the end of its burning in a BWR is first established, after a design of fuel rod containing 6% of minor actinides in a matrix of uranium from the enrichment lines is proposed, then 4 fuel rods of standard uranium are replaced by 4 actinides bars to evaluate the production and transmutation of them and finally the minor actinides reduction in the fuel is evaluated. In the development of this work the calculation tool are the codes: Intrepin-3, Casmo-4 and Simulate-3. (Author)

  9. Electrochemical separation of actinides and fission products in molten salt electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Gay, R.L.; Grantham, L.F.; Fusselman, S.P. [Rockwell International/Rocketdyne Division, Canoga Park, CA (United States)] [and others

    1995-10-01

    Molten salt electrochemical separation may be applied to accelerator-based conversion (ABC) and transmutation systems by dissolving the fluoride transport salt in LiCl-KCl eutectic solvent. The resulting fluoride-chloride mixture will contain small concentrations of fission product rare earths (La, Nd, Gd, Pr, Ce, Eu, Sm, and Y) and actinides (U, Np, Pu, Am, and Cm). The Gibbs free energies of formation of the metal chlorides are grouped advantageously such that the actinides can be deposited on a solid cathode with the majority of the rare earths remaining in the electrolyte. Thus, the actinides are recycled for further transmutation. Rockwell and its partners have measured the thermodynamic properties of the metal chlorides of interest (rare earths and actinides) and demonstrated separation of actinides from rare earths in laboratory studies. A model is being developed to predict the performance of a commercial electrochemical cell for separations starting with PUREX compositions. This model predicts excellent separation of plutonium and other actinides from the rare earths in metal-salt systems.

  10. Aqueous actinide complexes: A thermochemical assessment

    International Nuclear Information System (INIS)

    Fuger, J.; Khodakovsky, I.L.; Medvedev, V.A.; Navratil, J.D.

    1979-01-01

    The scope and purpose of an assessment of the thermodynamic properties of the aqueous actinide complexes are presented. This work which, at present, is limited to inorganic ligands and three selected organic ligands (formate, acetate and oxalate), is part of an effort established by the International Atomic Energy Agency to assess the thermodynamic properties of the actinides and their compounds. The problems involved in this work are illustrated by discussing the present status of the assessment as related to a few complex species, (hydroxyl-, fluoride-, carbonate complexes). (orig.) [de

  11. Molecular dynamics studies of actinide nitrides

    International Nuclear Information System (INIS)

    Kurosaki, Ken; Uno, Masayoshi; Yamanaka, Shinsuke; Minato, Kazuo

    2004-01-01

    The molecular dynamics (MD) calculation was performed for actinide nitrides (UN, NpN, and PuN) in the temperature range from 300 to 2800 K to evaluate the physical properties viz., the lattice parameter, thermal expansion coefficient, compressibility, and heat capacity. The Morse-type potential function added to the Busing-Ida type potential was employed for the ionic interactions. The interatomic potential parameters were determined by fitting to the experimental data of the lattice parameter. The usefulness and applicability of the MD method to evaluate the physical properties of actinide nitrides were studied. (author)

  12. A worldwide perspective on actinide burning

    International Nuclear Information System (INIS)

    Burch, W.D.

    1991-01-01

    Worldwide interest has been evident over the past few years in reexamining the merits of recovering the actinides from spent light-water reactor (LWR) fuel and transmuting them in fast reactors to reduce hazards in geologic repositories. This paper will summarize some of the recent activities in this field. Several countries are embarked on programs of reprocessing and vitrification of present wastes, from which removal of the actinides is largely precluded. The United States is assessing the ideas related to the fast reactor program and the potential application to defense wastes. 18 refs., 2 figs

  13. Spin–orbit coupling in actinide cations

    DEFF Research Database (Denmark)

    Bagus, Paul S.; Ilton, Eugene S.; Martin, Richard L.

    2012-01-01

    The limiting case of Russell–Saunders coupling, which leads to a maximum spin alignment for the open shell electrons, usually explains the properties of high spin ionic crystals with transition metals. For actinide compounds, the spin–orbit splitting is large enough to cause a significantly reduced...... spin alignment. Novel concepts are used to explain the dependence of the spin alignment on the 5f shell occupation. We present evidence that the XPS of ionic actinide materials may provide direct information about the angular momentum coupling within the 5f shell....

  14. The INE-Beamline for Actinide Research at ANKA

    Science.gov (United States)

    Brendebach, Boris; Denecke, Melissa A.; Rothe, Jörg; Dardenne, Kathy; Römer, Jürgen

    2007-02-01

    The INE-Beamline for actinide research at the synchrotron source ANKA is now fully operational. This beamline was designed, built, and commissioned by the Institut für Nukleare Entsorgung (INE) at the Forschungszentrum Karlsruhe (FZK), Germany. It is dedicated to actinide speciation investigations related to nuclear waste disposal as well as applied and basic actinide research. Experiments on radioactive samples with activities up to 106 times the limit of exemption inside a safe and flexible double containment concept are possible. The close proximity of the beamline to INE's active laboratories is unique in Europe. Currently, experiments can be performed in an X-ray energy range from around 2.15 keV (P K edge) to 24.35 keV (Pd K edge). The INE-Beamline design is optimized for spectroscopy with emphasis on surface sensitive techniques. A microfocus option is presently being installed at the INE-Beamline. Access to the INE-Beamline is possible through cooperation with INE, through the ANKA proposal system and via the European Network of Excellence for Actinide Sciences (ACTINET).

  15. The actinides and the man in its environment

    International Nuclear Information System (INIS)

    Metivier, H.; Colle, C.; Germain, P.

    1996-01-01

    The actinides have generally a long and superior to the human life span radioactive period. When they are incorporated in the man, they can stay during the human whole life. For this reason and because of their radiotoxicity, it is absolutely necessary to attend to their development in the environment in order to be able to estimate the consequences on people of their presence in the natural medium. The study of the actinides behaviour and their effects in the organism is also primordial to ensure the nuclear workers protection. The actinides sources, their localization and their transfers in the environment, the human transfers and their biological effects are more particularly described. (O.L.). 9 figs

  16. Actinide behavior in the integral fast reactor

    International Nuclear Information System (INIS)

    Courtney, J.C.

    1993-05-01

    Goal of this project is to determine the consumption of Np-237, Pu-240, Am-241, and Am-243 in the Integral Fast Reactor (IFR) fuel cycle. These four actinides set the long term waste management criteria for spent nuclear fuel; if it can be demonstrated that they can be efficiently consumed in the IFR, then requirements for nuclear waste repositories can be much less demanding. Irradiations in the Experimental Breeder Reactor II (EBR-II) at Argonne National Laboratory's site near Idaho Falls, Idaho, will be conducted to determine fission and transmutation rates for the four nuclides. The experimental effort involves target package design, fabrication, quality assurance, and irradiation. Post irradiation analyses are required to determine the fission rates and neutron spectra in the EBR-II core

  17. Removal of actinides from selected nuclear fuel reprocessing wastes

    International Nuclear Information System (INIS)

    Navratil, J.D.; Thompson, G.H.

    1979-01-01

    The US Department of Energy awarded Oak Ridge National Laboratory a program to develop a cost-risk-benefit analysis of partitioning long-lived nuclides from waste and transmuting them to shorter lived or stable nuclides. Two subtasks of this program were investigated at Rocky Flats. In the first subtask, methods for solubilizing actinides in incinerator ash were tested. Two methods appear to be preferable: reaction with ceric ion in nitric acid or carbonate-nitrate fusion. The ceric-nitric acid system solubilizes 95% of the actinides in ash; this can be increased by 2 to 4% by pretreating ash with sodium hydroxide to solubilize silica. The carbonate-nitrate fusion method solubilizes greater than or equal to 98% of the actinides, but requires sodium hydroxide pretreatment. Two additional disadvantages are that it is a high-temperature process, and that it generates a lot of salt waste. The second subtask comprises removing actinides from salt wastes likely to be produced during reactor fuel fabrication and reprocessing. A preliminary feasibility study of solvent extraction methods has been completed. The use of a two-step solvent extraction system - tributyl phosphate (TBP) followed by extraction with a bidentate organophosphorous extractant (DHDECMP) - appears to be the most efficient for removing actinides from salt waste. The TBP step would remove most of the plutonium and > 99.99% of the uranium. The second step using DHDECMP would remove > 99.91% of the americium and the remaining plutonium (> 99.98%) and other actinides from the acidified salt waste. 8 figures, 11 tables

  18. The actinides

    International Nuclear Information System (INIS)

    Bagnall, K.W.

    1987-01-01

    This chapter of coordination compound chemistry is devoted to the actinides and starts with a general survey. Most of the chapter relates to thorium and uranium but protactinium, neptunium and plutonium are included. There are sections on nitrogen, phosphorus, sulfur, selenium, tellurium and halogen ligands of the metals in their +3, +4, +5 and +6 oxidation states and of the transplutonium elements in their +2, +3, +4, and +5 oxidation states. (UK)

  19. Value of burnup credit beyond actinides

    International Nuclear Information System (INIS)

    Lancaster, D.; Fuentes, E.; Kang, Chi.

    1997-01-01

    DOE has submitted a topical report to the NRC justifying burnup credit based only on actinide isotopes (U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241). When this topical report is approved, it will allow a great deal of the commercial spent nuclear fuel to be transported in significantly higher capacity casks. A cost savings estimate for shipping fuel in 32 assembly (burnup credit) casks as opposed to 24 assembly (non-burnup credit) casks was previously presented. Since that time, more detailed calculations have been performed using the methodology presented in the Actinide-Only Burnup Credit Topical Report. Loading curves for derated casks have been generated using actinide-only burnup credit and are presented in this paper. The estimates of cost savings due to burnup credit for shipping fuel utilizing 32, 30, 28, and 24 assembly casks where only the 24 assembly cask does not burnup credit have been created and are discussed. 4 refs., 2 figs

  20. Critical masses for the even-neutron-numbered transuranium actinides

    International Nuclear Information System (INIS)

    Westfall, R.M.

    1981-01-01

    As part of a standards effort of the American Nuclear Society to establish subcritical mass limits for the transuranium actinides, critical masses were calculated for seven actinides, critical masses were calculated for seven actinide elements in bare, water-reflected, and steel-reflected metal systems. For the nuclides /sup 242/Pu and /sup 241/Am, values obtained with ENDF/B-V cross-section data were in much better agreement with values inferred from experimental measurement than were initial values calculated with ENDF/B-IV data. A brief description of the analytical methods employed is followed by a presentation of the results. 10 refs

  1. ENDF/B-V actinides

    International Nuclear Information System (INIS)

    Kocherov, N.; Lemmel, H.D.

    1981-01-01

    This document summarizes the contents of the actinides part of the ENDF/B-V nuclear data library released by the US National Nuclear Data Center. This library or selective retrievals of it, are available from the IAEA Nuclear Data Section. (author)

  2. The actinides-a beautiful ending of the Periodic Table

    International Nuclear Information System (INIS)

    Johansson, Boerje; Li, Sa

    2007-01-01

    The 5f elements, actinides, show many properties which have direct correspondence to the 4f transition metals, the lanthanides. The remarkable similarity between the solid state properties of compressed Ce and the actinide metals is pointed out in the present paper. The α-γ transition in Ce is considered as a Mott transition, namely, from delocalized to localized 4f states. An analogous behavior is also found for the actinide series, where the sudden volume increase from Pu to Am can be viewed upon as a Mott transition within the 5f shell as a function of the atomic number Z. On the itinerant side of the Mott transition, the earlier actinides (Pa-Pu) show low symmetry structures at ambient conditions; while across the border, the heavier elements (Am-Cf) present the dhcp structure, an atomic arrangement typical for the trivalent lanthanide elements with localized 4f magnetic moments. The reason for an isostructural Mott transition of the f electron in Ce, as opposed to the much more complicated cases in the actinides, is identified. The strange appearance of the δ-phase (fcc) in the phase diagram of Pu is another consequence of the border line behavior of the 5f electrons. The path leading from δ-Pu to α-Pu is identified

  3. Actinide partitioning-transmutation program final report. III. Transmutation studies

    International Nuclear Information System (INIS)

    Wachter, J.W.; Croff, A.G.

    1980-07-01

    Transmutation of the long-lived nuclides contained in fuel cycle wastes has been suggested as a means of reducing the long-term toxicity of the wastes. A comprehensive program to evaluate the feasibility and incentives for recovering the actinides from wastes (partitioning) and transmuting them to short-lived or stable nuclides has been in progress for 3 years under the direction of Oak Ridge National Laboratory (ORNL). This report constitutes the final assessment of transmutation in support of this program. Included are (1) a summary of recent transmutation literature, (2) a generic evaluation of actinide transmutation in thermal, fast, and other transmutation devices, (3) a preliminary evaluation of 99 Tc and 129 I transmutation, and (4) a characterization of a pressurized-water-reactor fuel cycle with and without provisions for actinide recovery and transmutation for use in other parts of the ORNL program. The principal conclusion of the report is that actinide transmutation is feasible in both thermal and fast reactors, subject to demonstrating satisfactory fuel performance, with relatively little impact on the reactor. It would also appear that additional transmutation studies are unwarranted until a firm decision to proceed with actinide transmutation has been made by the responsible authorities

  4. Status of the French research programme for actinides and fission products partitioning and transmutation

    International Nuclear Information System (INIS)

    Warin, D.

    2003-01-01

    The paper focus on separation and transmutation research and development programme and main results over these ten last years. The massive research programme on enhanced separation, conducted by CEA and supported by broad international cooperation, has recently achieved some vital progress. Based on real solutions derived from the La Hague process, the CEA demonstrated the lab-scale feasibility of extracting minor actinides and some fission products (I, Cs and Tc) using an hydrometallurgical process that can be extrapolated on the industrial scale. The CEA also conducted programmes proving the technical feasibility of the elimination of minor actinides and fission products by transmutation: fabrication of specific targets and fuels for transmutation tests in the HFR and Phenix reactors, neutronics and technology studies for ADS developments in order to support the MEGAPIE, TRADE and MYRRHA experiments and the future 100 MW international ADS demonstrator. Scenarios studies aimed at stabilizing the inventory with long-lived radionuclides, plutonium, minor actinides and certain long-lived fission products in different nuclear power plant parks and to verify the feasibility at the level of the cycle facilities and fuels involved in those scenarios. Three French Research Groups CEA-CNRS carry out partitioning (PRACTIS) and transmutation (NOMADE and GEDEON) more basic studies. (author)

  5. Characterization of actinide targets by low solid-angle alpha particle counting

    CERN Document Server

    Denecke, B; Pauwels, J; Robouch, P; Gilliam, D M; Hodge, P; Hutchinson, J M R; Nico, J S

    1999-01-01

    Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine sup 2 sup 3 sup 3 UF sub 4 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi propo...

  6. Study on the leaching behavior of actinides from nuclear fuel debris

    Science.gov (United States)

    Kirishima, Akira; Hirano, Masahiko; Akiyama, Daisuke; Sasaki, Takayuki; Sato, Nobuaki

    2018-04-01

    For the prediction of the leaching behavior of actinides contained in the nuclear fuel debris generated by the Fukushima Daiichi nuclear power plant accident in Japan, simulated fuel debris consisting of a UO2-ZrO2 solid solution doped with 137Cs, 237Np, 236Pu, and 241Am tracers was synthesized and investigated. The synthesis of the debris was carried out by heat treatment at 1200 °C at different oxygen partial pressures, and the samples were subsequently used for leaching tests with Milli-Q water and seawater. The results of the leaching tests indicate that the leaching of actinides depends on the redox conditions under which the debris was generated; for example, debris generated under oxidative conditions releases more actinide nuclides to water than that generated under reductive conditions. Furthermore, we found that, as Zr(IV) increasingly substituted U(IV) in the fluorite crystal structure of the debris, the actinide leaching from the debris decreased. In addition, we found that seawater leached more actinides from the debris than pure water, which seems to be caused by the complexation of actinides by carbonate ions in seawater.

  7. Predictive Modeling in Actinide Chemistry and Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  8. Synroc tailored waste forms for actinide immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, Daniel J.; Vance, Eric R. [Australian Nuclear Science and Technology Organisation, Kirrawee (Australia). ANSTOsynroc, Inst. of Materials Engineering

    2017-07-01

    Since the end of the 1970s, Synroc at the Australian Nuclear Science and Technology Organisation (ANSTO) has evolved from a focus on titanate ceramics directed at PUREX waste to a platform waste treatment technology to fabricate tailored glass-ceramic and ceramic waste forms for different types of actinide, high- and intermediate level wastes. The particular emphasis for Synroc is on wastes which are problematic for glass matrices or existing vitrification process technologies. In particular, nuclear wastes containing actinides, notably plutonium, pose a unique set of requirements for a waste form, which Synroc ceramic and glass-ceramic waste forms can be tailored to meet. Key aspects to waste form design include maximising the waste loading, producing a chemically durable product, maintaining flexibility to accommodate waste variations, a proliferation resistance to prevent theft and diversion, and appropriate process technology to produce waste forms that meet requirements for actinide waste streams. Synroc waste forms incorporate the actinides within mineral phases, producing products which are much more durable in water than baseline borosilicate glasses. Further, Synroc waste forms can incorporate neutron absorbers and {sup 238}U which provide criticality control both during processing and whilst within the repository. Synroc waste forms offer proliferation resistance advantages over baseline borosilicate glasses as it is much more difficult to retrieve the actinide and they can reduce the radiation dose to workers compared to borosilicate glasses. Major research and development into Synroc at ANSTO over the past 40 years has included the development of waste forms for excess weapons plutonium immobilization in collaboration with the US and for impure plutonium residues in collaboration with the UK, as examples. With a waste loading of 40-50 wt.%, Synroc would also be considered a strong candidate as an engineered waste form for used nuclear fuel and highly

  9. Electrorecovery of actinides at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Michael E [Los Alamos National Laboratory; Oldham, Warren J [Los Alamos National Laboratory; Costa, David A [Los Alamos National Laboratory

    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

  10. Actinide recycling in reactors

    International Nuclear Information System (INIS)

    Kuesters, H.; Wiese, H.W.; Krieg, B.

    1995-01-01

    The objective is an assessment of the transmutation of long-lived actinides and fission products and the incineration of plutonium for reducing the risk potential of radioactive waste from reactors in comparison to direct waste disposal. The contribution gives an interim account on homogeneous and heterogeneous recycling of 'risk nuclides' in thermal and fast reactors. Important results: - A homogeneous 5 percent admixture of minor actinides (MA) from N4-PWRs to EFR fuel would allow a transmutation not only of the EFR MA, but in addition of the MA from 5 or 6 PWRs of equal power. However, the incineration is restricted by safety considerations. - LWR have only a very low MA incineration potential, due to their disadvantageous neutron capture/fission ratio. - In order to keep the Cm inventory at a low level, it is advantageous to concentrate the Am heterogeneously in particular fuel elements or rods. (orig./HP)

  11. Sequential determination of actinides in a variety of matrices

    International Nuclear Information System (INIS)

    Olsen, S.C.

    2002-01-01

    A large number of analytical procedures for the actinides have been published, each catering for a specific need. Due to the bioassay programme in our laboratory, a need arose for a method to determine natural (Th and U) and anthropogenic actinides (Np, Pu and Am/Cm) together in a variety of samples. The method would have to be suitable for routine application: simple, inexpensive, rapid and robust. In some cases, the amount of material available is not sufficient for the determination of separate groups of actinides, and a sequential separation and measurement of the analytes would therefore be required. The types of matrices vary from aqueous samples to radiological surveillance (urine and faeces) to environmental studies (soil, sediment and fish), but the separation procedure should be able to service all of these. The working range of the method would have to cater for lower levels of the transuranium actinides in particular sample types containing higher levels of the natural actinides (U and Th). The first analytical problem to be discussed, is how to get the different sample types into the same loading solution required by a single separation approach. This entails sample dissolution or decomposition in some cases, and pre-concentration or pre-separation in others. A separation scheme is presented for the clean separation of all the actinides in a form suitable for alpha spectrometry. The development of a single column separation of the analytes of interest are looked at, as well as observations made during the development of the separation scheme, such as concentration effects. Results for test samples and certified reference materials are be presented. (author)

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

    International Nuclear Information System (INIS)

    Soderquist, Chuck Z.; Weaver, Jamie L.

    2015-01-01

    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 99m Tc 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 99 Mo 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 99 Mo and 99m Tc 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.

  13. Actinides and environmental interfaces: striving for molecular-level understanding

    International Nuclear Information System (INIS)

    Heino Nitsche

    2005-01-01

    Actinides can undergo a variety of complex chemical reactions in the environment. In addition to the formation of solid precipitates, colloids and dissolved solution species common to aqueous systems, actinide ions can interact with the surrounding geo and biomedia to change oxidation states or sorb on surfaces and colloids. The rate of migration is determined by aqueous solubility, and interactions with solid surfaces such as minerals, soils, natural organic matter, and soil microorganisms Sorption of aqueous actinide species on biological and geological matrices can be quantitatively described by a surface complexation or site-binding model. The disadvantage of this model is the difficulty in the experimental determination of the model parameters and surface reaction constants. Usually, a set of surface reactions and species are proposed based on knowledge of the solution speciation of the solute, and the reaction constants are usually derived by fitting computer-calculated absorption curves to experimental data. Because this process typically involves a large number of potentially adjustable parameters, it is likely to lead to non-unique parameter fitting and does not always result in a consistent set of parameters for the same systems. A fundamental molecular-level understanding of sorption processes of actinides on environmental surfaces is required to better understand and predict their transport behavior in nature. Several different surface spectroscopic techniques have been applied to the characterization of the adsorbed species and surface reactions and a direct determination of the sorbed species and surface reactions has become possible. The non-linear optical techniques of second harmonic and sum frequency generation (SHG and SFG) are ideally suited to study surfaces and interfaces of mineral oxides, biosurfactants and biopolymers, organic adlayers adsorbed on solid/mineral surfaces and soil organic matter, including humic and fulvic acids. Resonant

  14. General survey of applications which require actinide nuclear data

    International Nuclear Information System (INIS)

    Raman, S.

    1976-01-01

    This review paper discusses the actinide waste problem, the buildup of toxic isotopes in the fuel, the neutron activity associated with irradiated fuel, the 252 Cf buildup problem, and the production of radioisotope power sources as broad areas that require actinide cross-section data. Decay data enter into the area of radiological safety and health physics. This paper also discusses a few cross-section measurements in progress at the Oak Ridge Electron Linear Accelerator. The availability of actinide samples through the Transuranium Program at Oak Ridge is discussed in considerable detail. The present data status with respect to the various applications is reviewed along with recommendations for improving the data base

  15. Status report on actinide and fission product transmutation studies

    International Nuclear Information System (INIS)

    1997-06-01

    The management of radioactive waste is one of the key issues in today's political and public discussions on nuclear energy. One of the fields that looks into the future possibilities of nuclear technology is the neutronic transmutation of actinides and of some most important fission products. Studies on transmutation of actinides are carried out in various countries and at an international level. This status report which gives an up-to-date general overview of current and planned research on transmutation of actinides and fission products in non-OECD countries, has been prepared by a Technical Committee meeting organized by the IAEA in September 1995. 168 refs, 16 figs, 34 tabs

  16. Radioactive decay pattern of actinides present in waste from Mo-99 production

    Energy Technology Data Exchange (ETDEWEB)

    Hiromoto, Goro; Dellamano, José Claudio, E-mail: hiromoto@ipen.br, E-mail: jcdellam@ipen.br [Instituto de PesquisasEnergéticas e Nucleares (GRR/IPEN/CNEN-SP), São Paulo, SP (Brazil). Gerência de Rejeitos Radioativos

    2017-07-01

    Brazil is currently planning to produce {sup 99}Mo from fission of LEU targets to meet the present national demand of {sup 99m}Tc. The {sup 99}Mo activity planned at the end of irradiation is 5000 Ci (185 TBq) per weekly cycle, in order to meet the present demand of 1000 Ci (37 TBq) per week, after target cooling and processing. To predict the activities that will be handled in the waste treatment facility, the computational code SCALE 6.0 was used to simulate the irradiation of the uranium targets and the decay of radioactive products. This study presents the findings of this research, mainly focused on the actinides activity that will be present in the waste and the respective radioactive decay pattern over a period of one hundred thousand years. (author)

  17. Optimization of plutonium and minor actinide transmutation in an AP1000 fuel assembly via a genetic search algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Washington, J., E-mail: jwashing@gmail.com; King, J., E-mail: kingjc@mines.edu

    2017-01-15

    Highlights: • We model a modified AP1000 fuel assembly in SCALE6.1. • We couple the NEWT module of SCALE to the MOGA module of DAKOTA. • Transmutation is optimized based on choice of coating and fuel. • Greatest transmutation achieved with PuZrO{sub 2}MgO fuel pins coated with Lu{sub 2}O{sub 3}. - Abstract: The average nuclear power plant produces twenty metric tons of used nuclear fuel per year, which contains approximately 95 wt% uranium, 1 wt% plutonium, and 4 wt% fission products and transuranic elements. Fast reactors are the 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. Previous simulation work demonstrated the potential to transmute transuranic elements in a modified light water reactor fuel pin. This study optimizes a quarter-assembly containing target fuels coated with spectral shift absorbers for the transmutation of plutonium and minor actinides in light water reactors. The spectral shift absorber coating on the target fuel pin tunes the neutron energy spectrum experienced by the target fuel. A coupled model developed using the NEWT module from SCALE 6.1 and a genetic algorithm module from the DAKOTA optimization toolbox provided performance data for the burnup of the target fuel pins in the present study. The optimization with the coupled NEWT/DAKOTA model proceeded in three stages. The first stage optimized a single-target fuel pin per quarter-assembly adjacent to the central instrumentation channel. The second stage evaluated a variety of quarter-assemblies with multiple target fuel pins from the first stage and the third stage re-optimized the pins in the optimal second stage quarter-assembly. An 8 wt% PuZrO{sub 2}MgO inert matrix fuel pin with a 1.44 mm radius and a 0.06 mm Lu{sub 2}O{sub 3} coating in a five target fuel pin per quarter-assembly configuration represents the optimal combination for the

  18. The prediction of minor actinides amounts accumulated in the spent fuel in China

    International Nuclear Information System (INIS)

    Zhou Peide

    2000-01-01

    The amounts of the Minor Actinides accumulated in the spent fuel are predicted according to the Nuclear Power Plant development plan envisaged in China. The Minor Actinides generated in the spent fuel unloaded from a typical PWR per year are calculated. The decay characteristics of the Minor Actinides during storage and cooling period are also calculated. At last, the Minor Actinides amounts accumulated in all spent fuel which were unloaded before sometime are given

  19. Literature review of intrinsic actinide colloids related to spent fuel waste package release rates

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, P.; Steward, S.A.

    1997-01-01

    Existence of actinide colloids provides an important mechanism in the migration of radionuclides and will be important in performance of a geologic repository for high-level nuclear waste. Actinide colloids have been formed during long-term unsaturated dissolution of spent fuel by groundwater. This article summarizes a literature search of actinide colloids. This report emphasizes the formation of intrinsic actinide colloids, because they would have the opportunity to form soon after groundwater contact with the spent fuel and before actinide-bearing groundwater reaches the surrounding geologic formations.

  20. Literature review of intrinsic actinide colloids related to spent fuel waste package release rates

    International Nuclear Information System (INIS)

    Zhao, P.; Steward, S.A.

    1997-01-01

    Existence of actinide colloids provides an important mechanism in the migration of radionuclides and will be important in performance of a geologic repository for high-level nuclear waste. Actinide colloids have been formed during long-term unsaturated dissolution of spent fuel by groundwater. This article summarizes a literature search of actinide colloids. This report emphasizes the formation of intrinsic actinide colloids, because they would have the opportunity to form soon after groundwater contact with the spent fuel and before actinide-bearing groundwater reaches the surrounding geologic formations

  1. Neutronics design study on a minor actinide burner for transmuting spent fuel

    International Nuclear Information System (INIS)

    Choi, Hang Bok

    1998-08-01

    A liquid metal reactor was designed for the primary purpose of burning the minor actinide waste from commercial light water reactors. The design was constrained to maintain acceptable safety performance as measured by the burnup reactivity swing, the doppler coefficient, and the sodium void worth. Sensitivity studies were performed for homogeneous and decoupled core designs, and a minor actinide burner design was determined to maximize actinide consumption and satisfy safety constraints. One of the principal innovations was the use of two core regions, with a fissile plutonium outer core and an inner core consisting only of minor actinides. The physics studies performed here indicate that a 1200 MWth core is able to transmute the annual minor actinide inventory of about 16 LWRs and still exhibit reasonable safety characteristics. (author). 34 refs., 22 tabs., 14 figs

  2. Phoenix type concepts for transmutation of LWR waste minor actinides

    International Nuclear Information System (INIS)

    Segev, M.

    1994-01-01

    A number of variations on the original Phoenix theme were studied. The basic rationale of the Phoenix incinerator is making oxide fuel of the LWR waste minor actinides, loading it in an FFTF-like subcritical core, then bombarding the core with the high current beam accelerated protons to generate considerable energy through spallation and fission reactions. As originally assessed, if the machine is fed with 1600 MeV protons in a 102 mA current, then 8 core modules are driven to transmute the yearly minor actinides waste of 75 1000 MW LWRs into Pu 238 and fission products; in a 2 years cycle the energy extracted is 100000 MW d/T. This performance cannot be substantiated in a rigorous analysis. A calculational consistent methodology, based on a combined execution of the Hermes, NCNP, and Korigen codes, shows, nonetheless that changes in the original Phoenix parameters can upgrade its performance.The original Phoenix contains 26 tons minor actinides in 8 core modules; 1.15 m 3 module is shaped for 40% neutron leakage; with a beam of 102 mA the 8 modules are driven to 100000 MW/T in 10.5 years, burning out the yearly minor actinide waste of 15 LWRs; the operation must be assisted by grid electricity. If the 1.15 m 3 module is shaped to allow only 28% leakage, then a beam of 102 mA will drive the 8 modules to 100000 MW/T in 3.5 years, burning out the yearly minor actinides waste of 45 LWRs. Some net grid electricity will be generated. If 25 tons minor actinides are loaded into 5 modules, each 1.72 m 3 in volume and of 24% leakage, then a 97 mA beam will drive the module to 100000 MW/T in 2.5 years, burning out the yearly minor actinides waste of 70 LWRs. A considerable amount of net grid electricity will be generated. If the lattice is made of metal fuel, and 26 tons minor actinides are loaded into 32 small modules, 0.17 m 3 each, then a 102 mA beam will drive the modules to 100000 MW/T in 2 years, burning out the yearly minor actinides waste of 72 LWRs. A considerable

  3. Factors affecting actinide solubility in a repository for spent fuel, 1

    International Nuclear Information System (INIS)

    Snellman, Margit

    1986-07-01

    The main tasks in the study were to get information on the chemical conditions in a repository for spent fuel and information on factors affecting releases of actinides from spent fuel and solubility of actinides in a repository for spent fuel. The work in this field started at the Reactor Laboratory of the Technical Research Centre of Finland (VTT) in 1982. This is a report on the effects on the main parameters, Eh, pH, carbonate, organic compounds, colloids, microbes and radiation on the actinide solubility in the nearfield of the repository. Another task has been to identify available models and reported experience from actinide solubility calculations with different codes. 167 refs

  4. Monazite as a suitable actinide waste form

    Energy Technology Data Exchange (ETDEWEB)

    Schlenz, Hartmut; Heuser, Julia; Schmitz, Stephan; Bosbach, Dirk [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie und Klimaforschung (IEK), Nukleare Entsorgung und Reaktorsicherheit (IEK-6); Neumann, Andreas [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie und Klimaforschung (IEK), Nukleare Entsorgung und Reaktorsicherheit (IEK-6); RWTH Aachen Univ. (Germany). Inst. for Crystallography

    2013-03-01

    The conditioning of radioactive waste from nuclear power plants and in some countries even of weapons plutonium is an important issue for science and society. Therefore the research on appropriate matrices for the immobilization of fission products and actinides is of great interest. Beyond the widely used borosilicate glasses, ceramics are promising materials for the conditioning of actinides like U, Np, Pu, Am, and Cm. Monazite-type ceramics with general composition LnPO{sub 4} (Ln = La to Gd) and solid solutions of monazite with cheralite or huttonite represent important materials in this field. Monazite appears to be a promising candidate material, especially because of its outstanding properties regarding radiation resistance and chemical durability. This article summarizes the most recent results concerning the characterization of monazite and respective solid solutions and the study of their chemical, thermal, physical and structural properties. The aim is to demonstrate the suitability of monazite as a secure and reliable waste form for actinides. (orig.)

  5. Interaction of actinides with natural microporous materials

    International Nuclear Information System (INIS)

    Misaelides, P.; Godelirsas, A.

    1998-01-01

    The existing studies mainly concern the sorption of thorium, uranium, neptunium, plutonium and americium from aqueous media by clay minerals and zeolites as well as the determination of the corresponding chemical processes taking place at the mineral-water interface. The investigation techniques applied for this purpose include, except the conventional wet-chemical and radiochemical methods, advanced spectroscopic methods such as extended X-ray absorption fine structure spectroscopy (EXAFS), Rutherford Backscattered Spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. These techniques significantly contribute to the characterization of the reacted mineral waters and to the explanation of the structural and compositional characteristics of the sorbed actinide species. Theoretical models regarding the aqueous chemistry and speciation of the actinides have also been developed aiming the elucidation of the complex actinide sorption mechanisms. This contribution will critically review of the existing literature, present recently obtained unpublished results and discuss the necessity of future work in the field. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-24

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

  7. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    International Nuclear Information System (INIS)

    Rydberg, J.

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs

  8. Interaction of actinides with natural microporous materials: a review

    International Nuclear Information System (INIS)

    Misaelides, P.; Godelitsas, A.

    1998-01-01

    Natural microporous materials include several types of minerals such as zeolites, clay minerals, micas, iron- and manganese-oxides/hydroxides/oxyhydroxides present in various geological environments and soil formations. The transport of the actinide elements in the environment is mainly performed through aquatic pathways (streams, rivers, underground waters) and their mobility is strongly related to the interaction of their dissolved species with geological materials and especially with the highly sorptive microporous minerals. The existing studies mainly concern the sorption of Th, U, Np, Pu and Am from aqueous media by clay minerals and zeolites as well as the determination of the corresponding chemical processes taking place at the mineral-water interface. The investigation techniques also include advanced spectroscopic methods such as Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS), Rutherford Backscattered Spectroscopy (RBS), X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. These techniques significantly contribute to the characterization of the reacted mineral surfaces and to the explanation of the structural and compositional characteristics of the sorbed actinide species. Theoretical models regarding the aqueous chemistry and speciation of the actinides have also been developed aiming the elucidation of the complex actinide sorption mechanisms. Finally, this contribution also includes some recently obtained data concerning the interaction of actinides with todorokite (a naturally occurring microporous manganese-oxide of technological importance) and granitic micas (biotite) correlated with the nuclear waste disposal in geological formations

  9. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

  10. Synthesis of selective extractor for minor actinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seung [Konyang University, Nonsan (Korea); Cho, Moon Hwan [Kangwon National University, Chunchon (Korea)

    1998-04-01

    To selectively co-separate the lanthanide and actinide elements (MA) such as Am or Cm ion from radioactive waste, synthesis of diamide derivatives has been accomplished. In addition, picoline amide derivatives were also synthesized for selectively separate the minor actinide elements from lanthanide elements. The content of research has don are as follows: (1) synthesis of diamide as co-extractant (2) introduction of n-tetradecyl to increase the lipophilicity (3) Picolyl chloride, intermediate of the final product, was synthesized by improved method rather than reported method. (4) The length of alkyl side chain was adjusted to increase the lipophilicity of free ligand and its derivatives able to selectively separate the actinide metal from lanthanide metal ions was successfully synthesized and determined their purity by analytical instruments. (author). 12 refs., 28 figs.

  11. Fuels and targets for the transmutation of high activity long lived radioactive wastes

    International Nuclear Information System (INIS)

    Pillon, S.; Warin, D.

    2010-01-01

    The authors present and comment the different strategies which can be adopted to transmute minor actinides (concerned reactors, in fast breeder reactors, in accelerator driven systems or ADS), and the chemical composition of transmutation fuels (actinide compounds, inert matrices, fuels and targets). They describe the behaviour of refractory ceramic fuels during their service life under irradiation with their different damage origins (neutrons, fission by-products, alpha particles), the fabrication of transmutation fuels and targets through different processes (metallurgical, co-precipitate, sol-gel, wax, infiltration of radioactive materials, VIPAC/SPHEREPAC) and the reprocessing or recycling of these transmutation fuels and targets

  12. Characterization Of Actinides In Simulated Alkaline Tank Waste Sludges And Leachates

    International Nuclear Information System (INIS)

    Nash, Kenneth L.

    2008-01-01

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

  13. CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Kenneth L.

    2008-11-20

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

    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

  16. Actinide and xenon reactivity effects in ATW high flux systems

    International Nuclear Information System (INIS)

    Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C.

    1995-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, M. [Univ. of Virginia, Charlottesville, VA (United States); Olson, K.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)] [and others

    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.

  18. Research needs in metabolism and dosimetry of the actinides

    International Nuclear Information System (INIS)

    Richmond, C.R.

    1978-01-01

    The following topics are discussed: uranium mine and mill tailings; environmental standards; recommendations of NCRP and ICRP; metabolic models and health effects; life-time exposures to actinides and other alpha emitters; high-specific-activity actinide isotopes versus naturally occurring isotopic mixtures of uranium isotopes; adequacy of the n factor; and metabolism and dosimetry;

  19. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Bondietti, E.A.; Bogle, M.A.; Brantley, J.N.

    1979-01-01

    Progress is reported on the following research projects: water-sediment interactions of U, Pu, Am, and Cm; relative availability of actinide elements from abiotic to aquatic biota; comparative uptake of transuranic elements by biota bordering Pond 3513; metabolic reduction of 239 Np from Np(V) to Np(IV) in cotton rats; evaluation of hazards associated with transuranium releases to the biosphere; predicting Pu in bone; adsorption--solubility--complexation phenomena in actinide partitioning between sorbents and solution; comparative soil extraction data; and comparative plant uptake data

  20. Handbook on the physics and chemistry of the actinides. V. 3

    International Nuclear Information System (INIS)

    Freeman, A.J.; Keller, C.

    1985-01-01

    It is the purpose of the Handbook to describe in detail the present understanding of the actinides by means of comprehensive, critical, broad and up to date reviews covering both physics and chemistry of these exotic elements. Volume 3 is the first of two volumes to cover the more chemical, physico-chemical, structural and environmental aspects of the actinide elements. Leading scientists from Europe, USA and P.R. China present critical reviews on important aspects of the behaviour of this radioactive group of elements. In contrast to most other elements radioactivity has, to a degree, a profound influence on the chemical behaviour of the actinides. The unusual behaviour of the 5f-elements - delocalization of the electrons for the light actinides versus localization for the heavier ones - makes them an outstanding tool for the scientist, which can be seen by the variety of oxidation states ranging from +1 to +7. Special laboratory techniques must be developed to deal with the problem of the transcurium elements only being available in small amounts (nanograms to micrograms) or only in the tracer scale. Special emphasis is also placed on the fate of actinides released in the environment, e.g. their reaction to carbonate and organic complexing agents in aquatic systems. In contrast to volumes 1 and 2 which deal mainly with the less radioactive actinides, this volume and the forthcoming volume 4 cover all actinides, in particular those which can be prepared in weighable quantities (up to fermium, element 100). refs.; figs.; tabs

  1. Photochemistry of the actinides

    International Nuclear Information System (INIS)

    Toth, L.M.; Bell, J.T.; Friedman, H.A.

    1979-01-01

    It has been found that all three major actinides have a useful variety of photochemical reactions which could be used to achieve a separations process that requires fewer reagents. Several features merit enumerating: (1) Laser photochemistry is not now as uniquely important in fuel reprocessing as it is in isotopic enrichment. The photochemistry can be successfully accomplished with conventional light sources. (2) The easiest place to apply photo-reprocessing is on the three actinides U, Pu, and Np. The solutions are potentially cleaner and more amenable to photoreactions. (3) Organic-phase photoreactions are probably not worth much attention because of the troublesome solvent redox chemistry associated with the photochemical reaction. (4) Upstream process treatment on the raffinate (dissolver solution) may never be too attractive since the radiation intensity precludes the usage of many optical materials and the nature of the solution is such that light transmission into it might be totally impossible

  2. Rare earths and actinides

    International Nuclear Information System (INIS)

    Coqblin, B.

    1982-01-01

    This paper reviews the different properties of rare-earths and actinides, either as pure metals or as in alloys or compounds. Three different cases are considered: (i) First, in the case of 'normal' rare-earths which are characterized by a valence of 3, we discuss essentially the magnetic ordering, the coexistence between superconductivity and magnetism and the properties of amorphous rare-earth systems. (ii) Second, in the case of 'anomalous' rare-earths, we distinguish between either 'intermediate-valence' systems or 'Kondo' systems. Special emphasis is given to the problems of the 'Kondo lattice' (for compounds such as CeAl 2 ,CeAl 3 or CeB 6 ) or the 'Anderson lattice' (for compounds such as TmSe). The problem of neutron diffraction in these systems is also discussed. (iii) Third, in the case of actinides, we can separate between the d-f hybridized and almost magnetic metals at the beginning of the series and the rare-earth like the metals after americium. (orig.)

  3. Actinide phosphonate complexes in aqueous solutions

    International Nuclear Information System (INIS)

    Nash, K.L.

    1993-01-01

    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 3 H 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

  4. Fusion probability and survivability in estimates of heaviest nuclei production

    Directory of Open Access Journals (Sweden)

    Sagaidak Roman N.

    2012-02-01

    Full Text Available Production of the heavy and heaviest nuclei (from Po to the region of superheavy elements close to Z=114 and N=184 in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing model coupled with the statistical model (SM of de-excitation of a compound nucleus (CN. Excitation functions for fission and evaporation residues (ER measured in very asymmetric combinations can be described rather well. One can scale and fix macroscopic (liquid-drop fission barriers for nuclei involved in the calculation of survivability with SM. In less asymmetric combinations, effects of fusion suppression caused by quasi-fission (QF are starting to appear in the entrance channel of reactions. QF effects could be semi-empirically taken into account using fusion probabilities deduced as the ratio of measured ER cross sections to the ones obtained in the assumption of absence of the fusion suppression in corresponding reactions. SM parameters (fission barriers obtained at the analysis of a very asymmetric combination leading to the production of (nearly the same CN should be used for this evaluation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weaver, Jamie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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.

  6. Program and presentations of the 33th Actinide Days

    International Nuclear Information System (INIS)

    2003-04-01

    The 'Journees des Actinides' (JDA) is an annual conference which provides a forum for discussions on all aspects related to the chemical and physical properties of the actinides. At the 2003 meeting, mainly the following properties were discussed of actinides and a number of actinide compounds and complexes: crystal structure, crystal-phase transformations and transformation temperatures; electrical properties including superconductivity and superconducting transition temperatures; magnetic properties; specific heat and other thermodynamic properties; electronic structure, especially in condensed matter; chemical and physico-chemical properties. The relevant experimental techniques were also dealt with, such as neutron diffraction; X-ray diffraction, in particular using synchrotron radiation; photoemission techniques, electron microscopy and spectroscopy, etc. Altogether 96 contributions were presented, of which 42 were oral presentations and 54 poster presentations. A program of the meeting and texts of both type of presentations were published in electronic form in the PDF format. All contributions were inputted to INIS; the full text of the program and the presentations has been incorporated into the INIS collection of non-conventional literature on CD-ROM. (A.K.)

  7. Valence instabilities as a source of actinide system inconsistencies

    International Nuclear Information System (INIS)

    Sandenaw, T.A.

    1979-01-01

    Light actinide elements alone, and in some of their alloys, may exist as a static or dynamic mixture of two configurations. Such a state can explain both a resistivity maximum and lack of magnetic order observed in so many actinide materials, and still be compatible with the existence of f-electrons in narrow bands. Impurity elements may stabilize slightly different intermediate valence states in U, Np, and Pu, thus contributing to inconsistencies in published results. The physical property behavior of mixed-valence, rare-earth compounds is very much like that observed in development of antiphase (martensitic) structures. Martensitic transformations in U, Np, and Pu, from high-temperature b. c. c. to alpha phase, may be a way of ordering an alloy-like metal of mixed or intermediate valence. The relative stability of each phase structure may depend upon its electron-valence ratio. A Hubbard model for electron correlations in a narrow energy band has been invoked in most recent theories for explaining light actinide behavior. Such a model may also be applicable to crystal symmetry changes in martensitic transformations in actinides

  8. Experimental Evaluation of Actinide Transport in a Fractured Granodiorite

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Laboratory; Reimus, Paul W. [Los Alamos National Laboratory

    2015-03-16

    The objective of this study was to demonstrate and evaluate new experimental methods for quantifying the potential for actinide transport in deep fractured crystalline rock formations. We selected a fractured granodiorite at the Grimsel Test Site (GTS) in Switzerland as a model system because field experiments have already been conducted with uranium and additional field experiments using other actinides are planned at the site. Thus, working on this system provides a unique opportunity to compare lab experiment results with fieldscale observations. Rock cores drilled from the GTS were shipped to Los Alamos National Laboratory, characterized by x-ray diffraction and microscopy, and used in batch sorption and column breakthrough experiments. Solutions with pH 6.8 and 8.8 were tested. Solutions were switched to radionuclide-free synthetic Grimsel groundwater after near-steady actinide/colloid breakthrough occurred in column experiments. We are currently evaluating actinide adsorption/desorption rates as a function of water chemistry (initial focus on pH), with future testing planned to evaluate the influence of carbonate concentrations, flow rates, and mineralogy in solutions and suspensions with bentonite colloids. (auth)

  9. Review of the treatment of actinides-bearing radioactive wastes

    International Nuclear Information System (INIS)

    Krause, H.

    1983-01-01

    Actinides bearing wastes are produced above all in the course of irradiated nuclear fuel reprocessing and during fabrication of mixed oxide fuel elements. Particular attention in research and development work must be paid to this type of waste, mainly on account of its longevity. In practical application, the specific character of the actinides bearing wastes has been largely recognized. Nevertheless, definitions and methods of treatment generally accepted worldwide are still missing today. This has no bearing as yet on present day treatment of radioactive wastes. But by the time of application of the breeder technology at the latest a special treatment concept should be available which complies with the high actinide contents and short precooling periods of the wastes

  10. Supercritical fluid carbon dioxide extraction of actinides

    International Nuclear Information System (INIS)

    Rao, Ankita; Tomar, B.S.

    2016-01-01

    Supercritical fluid extraction (SFE) is a process akin to liquid-liquid or solvent extraction where a Supercritical fluid (SCF) is contacted with a solid/ liquid matrix for the purpose of separating the component of interest from the original matrix. Carbon dioxide is a preferred choice as supercritical fluid (SCF) owing to its moderate critical parameter (P c = 7.38 MPa and T c = 304.1K) coupled with radiation and chemical stability, non toxic nature and low cost. Despite widespread applications for extraction of organic compounds and associated advantages especially liquid waste minimization, the SFE of metal ions was left unexplored for quite some time, as direct metal ion extraction is inefficient due charge neutralization requirement and weak solute-solvent interaction. Neutral SCF soluble metal-ligand complexation is imperative and SFE of actinides was reported only in 1994. Several studies have been carried out on SFE of uranium, thorium and plutonium from nitric acid medium employing different sets of ligands (organophosphorus, diketones, amides). Especially attractive is the possibility of direct dissolution and extraction of actinides employing ligand-acid adducts (like TBP.HNO 3 adduct) from solid matrices of different stages of nuclear fuel cycle viz. ores, spent nuclear fuels and radioactive wastes. Also, partitioning of actinides from fission products has been explored in spent nuclear fuel. These studies on supercritical fluid extraction of actinides indicate a more efficient and environmentally sustainable technology. (author)

  11. Basic research on solvent extraction of actinide cations with diamide compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Yuji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-11-01

    Newly synthesized 4 diamide compounds were tested for solvent extraction of actinide cations. It is obvious that N,N`-dimethyl-N,N`-dihexyl-3-oxapentanediamide (DMDHOPDA) can extract Eu(III), Th(IV), U(VI), Np(V), and Am(III) into organic solvent. Other 3 diamides hardly extract actinide ions, which is supposed that the reasons come from the difference of their chemical structures. In the synergistic extraction with a diamide and thenoyltrifluoroacetone (TTA), all diamides work as a extractant. Furthermore, by examining extracted species, it was confirmed that there are 4 kinds of chemical species of actinides with diamide and TTA. Finally, the mutual separation method of actinide (III), (IV), (V) and (VI) ions by solvent extraction using DMDHOPDA and TTA were developed. (author). 147 refs.

  12. The INE-Beamline for actinide science at ANKA

    Science.gov (United States)

    Rothe, J.; Butorin, S.; Dardenne, K.; Denecke, M. A.; Kienzler, B.; Löble, M.; Metz, V.; Seibert, A.; Steppert, M.; Vitova, T.; Walther, C.; Geckeis, H.

    2012-04-01

    Since its inauguration in 2005, the INE-Beamline for actinide research at the synchrotron source ANKA (KIT North Campus) provides dedicated instrumentation for x-ray spectroscopic characterization of actinide samples and other radioactive materials. R&D work at the beamline focuses on various aspects of nuclear waste disposal within INE's mission to provide the scientific basis for assessing long-term safety of a final nuclear waste repository. The INE-Beamline is accessible for the actinide and radiochemistry community through the ANKA proposal system and the European Union Integrated Infrastructure Initiative ACTINET-I3. Experiments with activities up to 1 × 10+6 times the European exemption limit are feasible within a safe but flexible containment concept. Measurements with monochromatic radiation are performed at photon energies varying between ˜2.1 keV (P K-edge) and ˜25 keV (Pd K-edge), including the lanthanide L-edges and the actinide M- and L3-edges up to Cf. The close proximity of the INE-Beamline to INE controlled area labs offers infrastructure unique in Europe for the spectroscopic and microscopic characterization of actinide samples. The modular beamline design enables sufficient flexibility to adapt sample environments and detection systems to many scientific questions. The well-established bulk techniques x-ray absorption fine structure (XAFS) spectroscopy in transmission and fluorescence mode have been augmented by advanced methods using a microfocused beam, including (confocal) XAFS/x-ray fluorescence detection and a combination of (micro-)XAFS and (micro-)x-ray diffraction. Additional instrumentation for high energy-resolution x-ray emission spectroscopy has been successfully developed and tested.

  13. The INE-Beamline for actinide science at ANKA

    International Nuclear Information System (INIS)

    Rothe, J.; Dardenne, K.; Denecke, M. A.; Kienzler, B.; Loeble, M.; Metz, V.; Steppert, M.; Vitova, T.; Geckeis, H.; Butorin, S.; Seibert, A.; Walther, C.

    2012-01-01

    Since its inauguration in 2005, the INE-Beamline for actinide research at the synchrotron source ANKA (KIT North Campus) provides dedicated instrumentation for x-ray spectroscopic characterization of actinide samples and other radioactive materials. R and D work at the beamline focuses on various aspects of nuclear waste disposal within INE's mission to provide the scientific basis for assessing long-term safety of a final nuclear waste repository. The INE-Beamline is accessible for the actinide and radiochemistry community through the ANKA proposal system and the European Union Integrated Infrastructure Initiative ACTINET-I3. Experiments with activities up to 1 x 10 +6 times the European exemption limit are feasible within a safe but flexible containment concept. Measurements with monochromatic radiation are performed at photon energies varying between ∼2.1 keV (P K-edge) and ∼25 keV (Pd K-edge), including the lanthanide L-edges and the actinide M- and L3-edges up to Cf. The close proximity of the INE-Beamline to INE controlled area labs offers infrastructure unique in Europe for the spectroscopic and microscopic characterization of actinide samples. The modular beamline design enables sufficient flexibility to adapt sample environments and detection systems to many scientific questions. The well-established bulk techniques x-ray absorption fine structure (XAFS) spectroscopy in transmission and fluorescence mode have been augmented by advanced methods using a microfocused beam, including (confocal) XAFS/x-ray fluorescence detection and a combination of (micro-)XAFS and (micro-)x-ray diffraction. Additional instrumentation for high energy-resolution x-ray emission spectroscopy has been successfully developed and tested.

  14. Actinide extractants for the nuclear industry of the future

    International Nuclear Information System (INIS)

    Musikas, C.; Morisseau, J.C.; Hoel, P.; Guillaume, B.

    1987-06-01

    Non organo-phosphorus extractants properties regarding the extractions of actinides in nuclear fuels reprocessing are presented. N,N-dialkylamides are proposed as alternatives to TBP.N,N'-tetraalkylamides or pentaalkyl propane diamides properties are reported. They show that those bidentate extractants are alternatives to bidentate organophosphorus extractants for actinides (III) extraction from concentrated nitric acid. 11 figs, 15 refs

  15. Sequential analysis of selected actinides in urine

    International Nuclear Information System (INIS)

    Kramer, G.H.

    1980-07-01

    The monitoring of personnel by urinalysis for suspected contamination by actinides necessitated the development and implementation of an analytical scheme that will separate and identify alpha emitting radionuclides of these elements. The present work deals with Pu, Am, and Th. These elements are separated from an ashed urine sample by means of coprecipitation and ion exchange techniques. The final analysis is carried out by electroplating the actinides and counting in a α-spectrometer. Mean recoveries of these elements from urine are: Pu 64%, Am 74% and Th 69%. (auth)

  16. Significance of actinide chemistry for the long-term safety of waste disposal

    International Nuclear Information System (INIS)

    Kim, Jae Il

    2006-01-01

    A geochemical approach to the long-term safety of waste disposal is discussed in connection with the significance of actinides, which shall deliver the major radioactivity inventory subsequent to the relatively short-term decay of fission products. Every power reactor generates transuranic (TRU) elements: plutonium and minor actinides (Np, Am, Cm), which consist chiefly of long-lived nuclides emitting alpha radiation. The amount of TRU actinides generated in a fuel life period is found to be relatively small (about 1 wt% or less in spent fuel) but their radioactivity persists many hundred thousands years. Geological confinement of waste containing TRU actinides demands, as a result, fundamental knowledge on the geochemical behavior of actinides in the repository environment for a long period of time. Appraisal of the scientific progress in this subject area is the main objective of the present paper. Following the introductory discussion on natural radioactivities, the nuclear fuel cycle is briefly brought up with reference to actinide generation and waste disposal. As the long-term disposal safety concerns inevitably with actinides, the significance of the aquatic actinide chemistry is summarized in two parts: the fundamental properties relevant to their aquatic behavior and the geochemical reactions in nanoscopic scale. The constrained space of writing allows discussion on some examples only, for which topics of the primary concern are selected, e.g. apparent solubility and colloid generation, colloid-facilitated migration, notable speciation of such processes, etc. Discussion is summed up to end with how to make a geochemical approach available for the long-term disposal safety of nuclear waste or for the Performance Assessment (PA) as known generally

  17. Measurement of fast neutron induced fission cross section of minor-actinide

    International Nuclear Information System (INIS)

    Hirakawa, Naohiro

    2000-06-01

    In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron accelerator in Tohoku University. The followings were performed in this fiscal year; (1) Research of nuclear data of MA, (2) Sample preparation and sample mass assay, (3) Investigation of neutron sources with the energy of several 10 keV, (4) Preliminary measurement of fission cross section using Dynamitron accelerator. As the result, four 237 Np samples were prepared and the sample mass were measured using alpha-spectrometry with the accuracy of 1.2%. Then, it was confirmed that a neutron source via 7 Li(p,n) 7 Be reaction using a Li-thick target is suitable for measuring fission cross section of MA in the energy region of several 10 keV. Furthermore, it was verified by the preliminary measurement that the measurement of fission cross section of MA is available using a fission chamber and electronics developed in this study. (author)

  18. Factors influencing the transport of actinides in the groundwater environment. Final report

    International Nuclear Information System (INIS)

    Sheppard, J.C.; Kittrick, J.A.

    1983-01-01

    This report summarizes investigations of factors that significantly influence the transport of actinide cations in the groundwater environment. Briefly, measurements of diffusion coefficients for Am(III), Cm(III), and Np(V) in moist US soils indicated that diffusion is negligible compared to mass transport in flowing groundwater. Diffusion coefficients do, however, indicate that, in the absence of flowing water, actinide elements will migrate only a few centimeters in a thousand years. The remaining investigations were devoted to the determination of distribution ratios (K/sub d/s) for representative US soils, factors influencing them, and chemical and physical processes related to transport of actinides in groundwaters. The computer code GARD was modified to include complex formation to test the importance of humic acid complexing on the rate of transport of actinides in groundwaters. Use of the formation constant and a range of humic acid, even at rather low concentrations of 10 -5 to 10 -6 molar, significantly increases the actinide transport rate in a flowing aquifer. These computer calculations show that any strong complexing agent will have a similar effect on actinide transport in the groundwater environment. 32 references, 9 figures

  19. Report of the panel on practical problems in actinide biology

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Practical problems are classified as the need to make operational decisions, the need for regulatory assessment either of individual facilities or of generic actions, and the overt appearance of radiobiological effects in man or radioactivity in man or the environment. Topics discussed are as follows: simulated reactor accident; long term effects of low doses; effects of repeated exposures to actinides; inhaled uranium mine air contaminants; metabolism and dosimetry; environmental equilibrium models; patterns of alpha dosimetry; internal dose calculations; interfaces between actinide biology and environmental studies; removal of actinides deposited in the body; and research needs related to uranium isotopes

  20. Fabrication of U-Pu-Zr metallic fuel containing minor actinides

    International Nuclear Information System (INIS)

    Kurata, Masaki; Sasahara, Akihiro; Inoue, Tadashi; Betti, M.; Babelot, J.F.; Spirlet, J.C.; Koch, L.

    1997-01-01

    Rods of UPuZr alloy containing 5% minor actinides, 2% minor actinides and 2% rare-earth elements, and 5% minor actinides and 5% rare-earth elements have been fabricated by casting in yttria molds. Parts of the ingots were cut off for quantitative analysis and the rods characterized to the required extent, which included measurement of length, weight, diameter, and bending. For selected samples, metallographic study was carried out to examine the dispersion of the various phases contained in the alloy. Finally, the rods were encapsulated in stainless steel pin with the UPuZr reference after sodium bonding for the irradiation study. (author)

  1. Elimination of waste actinides by recycling them to nuclear reactors

    International Nuclear Information System (INIS)

    McKay, H.A.C.

    1981-01-01

    After a few centuries of radioactive decay the long-lived actinides, the elements of atomic numbers 89-103, may constitute the main potential radiological health hazard in nuclear wastes. This is because all but a very few fission products (principally technetium-99 and iodine-129) have by then decayed to insignificant levels, leaving the actinides as the principal hazardous species remaining. It is therefore at first sight an attractive idea to recycle the actinides in nuclear reactors, so as to eliminate them by nuclear fission. There are good reasons for examining the idea in detail, and studies have been carried out in a number of countries. These have culminated recently in international conferences at the European Joint Research Centre at Ispra in Italy and at Austin, Texas in the USA as well as in the issue of an IAEA Technical Report entitled An Evaluation of Actinide Partitioning and Transmutation, a product of a four-year IAEA Co-ordinated Research Programme, on which the present article is based. The term partitioning refers to the separation of the actinides from nuclear fuel cycle wastes, a necessary preliminary step to their introduction into reactors for transmutation by nuclear fission. The complete scheme will be referred to as P-T, i.e. partitioning-transmutation

  2. Actinide production from xenon bombardments of curium-248

    International Nuclear Information System (INIS)

    Welch, R.B.

    1985-01-01

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

  3. Homogeneous Minor Actinide Transmutation in SFR: Neutronic Uncertainties Propagation with Depletion

    International Nuclear Information System (INIS)

    Buiron, L.; Plisson-Rieunier, D.

    2015-01-01

    In the frame of next generation fast reactor design, the minimisation of nuclear waste production is one of the key objectives for current R and D. Among the possibilities studied at CEA, minor actinides multi-recycling is the most promising industrial way achievable in the near-term. Two main management options are considered: - Multi-recycling in a homogeneous way (minor actinides diluted in the driver fuel). If this solution can help achieving high transmutation rates, the negative impact of minor actinides on safety coefficients allows only a small fraction of the total heavy mass to be loaded in the core (∼ few %). - Multi-recycling in heterogeneous way by means of Minor Actinide Bearing Blanket (MABB) located at the core periphery. This solution offers more flexibility than the previous one, allowing a total minor actinides decoupled management from the core fuel. As the impact on feedback coefficient is small larger initial minor actinide mass can be loaded in this configuration. Starting from a breakeven Sodium Fast Reactor designed jointly by CEA, Areva and EdF teams, the so called SFR V2B, transmutation performances have been studied in frame on the French fleet for both options and various specific isotopic management (all minor actinides, americium only, etc.). Using these results, a sensitivity study has been performed to assess neutronic uncertainties (i.e coming from cross section) on mass balance on the most attractive configurations. This work in based on a new implementation of sensitivity on concentration with depletion in the ERANOS code package. Uncertainties on isotopes masses at the end of irradiation using various variance-covariance is discussed. (authors)

  4. Projected benefits of actinide partitioning

    International Nuclear Information System (INIS)

    Braun, C.; Goldstein, M.

    1976-05-01

    Possible benefits that could accrue from actinide separation and transmutations are presented. The time frame for implementing these processes is discussed and the expected benefits are qualitatively described. These benefits are provisionally quantified in a sample computation

  5. Environmental research on actinide elements

    International Nuclear Information System (INIS)

    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

  6. Assessment of Partitioning Processes for Transmutation of Actinides

    International Nuclear Information System (INIS)

    2010-04-01

    To obtain public acceptance of future nuclear fuel cycle technology, new and innovative concepts must overcome the present concerns with respect to both environmental compliance and proliferation of fissile materials. Both these concerns can be addressed through the multiple recycling of all transuranic elements (TRUs) in fast neutron reactor. This is only possible through a process known as partitioning and transmutation scheme (P and T) as this scheme is expected to reduce the long term radio-toxicity as well as the radiogenic heat production of the nuclear waste. Proliferation resistance of separated plutonium could further be enhanced by mixing with self-generated minor actinides. In addition, P and T scheme is expected to extend the nuclear fuel resources on earth about 100 times because of the recycle and reuse of fissile actinides. Several Member States are actively pursuing the research in the field of P and T and consequently several IAEA publications have addressed this topic. The present coordinated research project (CRP) focuses on the potentials in minimizing the residual TRU inventories of the discharged nuclear waste and in enhancing the proliferation resistance of the future civil nuclear fuel cycle. Partitioning approaches can be grouped into aqueous- (hydrometallurgical) and pyroprocesses. Several aqueous processes based on sequential separation of actinides from spent nuclear fuel have been developed and tested at pilot plant scale. In view of the proliferation resistance of the intermediate and final products of a P and T scheme, a group separation of all actinides together is preferable. The present CRP has gathered experts from different organisations and institutes actively involved in developing P and T scheme as mentioned in the list of contributors and also taken into consideration the studies underway in France and the UK. The scientific objectives of the CRP are: To minimize the environmental impact of actinides in the waste stream; To

  7. Mathematical modeling of the effects of aerobic and anaerobic chelate biodegradation on actinide speciation

    International Nuclear Information System (INIS)

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

    1998-01-01

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and, hence, the mobility of actinides in subsurface environments. We combined mathematical modeling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bio-utilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modeling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems

  8. Mathematical modelling of the effects of aerobic and anaerobic chelate biodegradation on actinide speciation

    International Nuclear Information System (INIS)

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

    1998-01-01

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and hence, the mobility of actinides in subsurface environments. We combined mathematical modelling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bioutilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modelling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems. (orig.)

  9. Calculated /alpha/-induced thick target neutron yields and spectra, with comparison to measured data

    International Nuclear Information System (INIS)

    Wilson, W.B.; Bozoian, M.; Perry, R.T.

    1988-01-01

    One component of the neutron source associated with the decay of actinide nuclides in many environments is due to the interaction of decay /alpha/ particles in (/alpha/,n) reactions on low Z nuclides. Measurements of (/alpha/,n) thick target neutron yields and associated neutron spectra have been made for only a few combinations of /alpha/ energy and target nuclide or mixtures of actinide and target nuclides. Calculations of thick target neutron yields and spectra with the SOURCES code require /alpha/-energy-dependent cross sections for (/alpha/,n) reactions, as well as branching fractions leading to the energetically possible levels of the product nuclides. A library of these data has been accumulated for target nuclides of Z /le/ 15 using that available from measurements and from recent GNASH code calculations. SOURCES, assuming neutrons to be emitted isotopically in the center-of-mass system, uses libraries of /alpha/ stopping cross sections, (/alpha/,n) reaction cross reactions, product nuclide level branching fractions, and actinide decay /alpha/ spectra to calculate thick target (/alpha/,n) yields and neutron spectra for homogeneous combinations of nuclides. The code also calculates the thick target yield and angle intergrated neutron spectrum produced by /alpha/-particle beams on targets of homogeneous mixtures of nuclides. Illustrative calculated results are given and comparisons are made with measured thick target yields and spectra. 50 refs., 1 fig., 2 tabs

  10. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Ken [Washington State Univ., Pullman, WA (United States); Martin, Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lumetta, Gregg [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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

  11. Theoretical Studies of the Electronic Structure of the Compounds of the Actinide Elements

    International Nuclear Information System (INIS)

    Kaltsoyannis, Nikolas; Hay, P.J.; Li, Jun; Blaudeau, Jean-Philippe; Bursten, Bruce E.

    2006-01-01

    In this chapter, we will present an overview of the theoretical and computational developments that have increased our understanding of the electronic structure of actinide-containing molecules and ions. The application of modern electronic structure methodologies to actinide systems remains one of the great challenges in quantum chemistry; indeed, as will be discussed below, there is no other portion of the periodic table that leads to the confluence of complexity with respect to the calculation of ground- and excited-state energies, bonding descriptions, and molecular properties. But there is also no place in the periodic table in which effective computational modeling of electronic structure can be more useful. The difficulties in creating, isolating, and handling many of the actinide elements provide an opportunity for computational chemistry to be an unusually important partner in developing the chemistry of these elements. The importance of actinide electronic structure begins with the earliest studies of uranium chemistry and predates the discovery of quantum mechanics. The fluorescence of uranyl compounds was observed as early as 1833, a presage of the development of actinometry as a tool for measuring photochemical quantum yields. Interest in nuclear fuels has stimulated tremendous interest in understanding the properties, including electronic properties, of small actinide-containing molecules and ions, especially the oxides and halides of uranium and plutonium. The synthesis of uranocene in 1968 led to the flurry of activity in the organometallic chemistry of the actinides that continues today. Actinide organometallics (or organoactinides) are nearly always molecular systems and are often volatile, which makes them amenable to an arsenal of experimental probes of molecular and electronic structure (Marks and Fischer, 1979). Theoretical and computational studies of the electronic structure of actinide systems have developed in concert with the experimental

  12. Chemical factors controlling actinide sorption in the environment

    International Nuclear Information System (INIS)

    Beall, G.W.; Allard, B.

    1979-01-01

    The solid geologic media and the aqueous phase are of equal importance for the retention of actinides in the environment. The composition of the water is largely determined by the mineralogical composition of the rock that it is in equilibrium with. The chemical form of the actinides and their sorption, are highly dependent on the composition of the water with respect to pH, redox potential, and concentration of anions like carbonate, phosphate, fluoride, and organic acids

  13. Crystal structure of actinide metals at high compression

    International Nuclear Information System (INIS)

    Fast, L.; Soederlind, P.

    1995-08-01

    The crystal structures of some light actinide metals are studied theoretically as a function of applied pressure. The first principles electronic structure theory is formulated in the framework of density functional theory, with the gradient corrected local density approximation of the exchange-correlation functional. The light actinide metals are shown to be well described as itinerant (metallic) f-electron metals and generally, they display a crystal structure which have, in agreement with previous theoretical suggestions, increasing degree of symmetry and closed-packing upon compression. The theoretical calculations agree well with available experimental data. At very high compression, the theory predicts closed-packed structures such as the fcc or the hcp structures or the nearly closed-packed bcc structure for the light actinide metals. A simple canonical band picture is presented to explain in which particular closed-packed form these metals will crystallize at ultra-high pressure

  14. Invisible structures in the X-ray absorption spectra of actinides

    NARCIS (Netherlands)

    Kvashnina, Kristina O.; De Groot, Frank M F

    The X-ray absorption spectra of actinides are discussed with an emphasis on the fundamental effects that influence their spectral shape, including atomic multiplet theory, charge transfer theory and crystal field theory. Many actinide spectra consist of a single peak and it is shown that the use of

  15. Proceedings of the Workshop on Experimental and theoretical problems around actinides for future reactors

    International Nuclear Information System (INIS)

    Kerveno, Maelle; Dupuis, Marc; Bauge, E.; Hilaire, S.; Romain, P.; Morillon, B.; Delaroche, J.P.; Dupuis, M.; Peru, S.; Belier, G.; Bonnet, T.; Laborie, J.M.; Laurent, B.; Ledoux, X.; Varignon, C.; Meot, V.; Bernard, David; Capote, Roberto; Kawano, T.; Bond, E.; Vieira, D.J.; Wilhelmy, J.B.; Raynal, J.; Plompen, Arjan J.M.; Drohe, J.C.; Nankov, N.; Nyman, M.; Rouki, C.; Bacquias, A.; Dessagne, Ph.; Henning, G.; Karam, H.; Kerveno, M.; Rudolf, G.; Thiry, J.C.; Borcea, C.; Negret, A.; Stanoiu, M.; Bucurescu, D.; Deleanu, D.; Filipescu, D.; Ghita, D.; Glodariu, T.; Marginean, N.; Marginean, R.; Mihai, C.; Olacel, A.; Pascu, S.; Sava, T.; Stroe, L.; Goriely, S.; Pavlik, A.; Jericha, E.; Ledoux, X.; Becker, J.A.; Macri, R.; Authier, N.; Hyneck, D.; Jansen, Y.; Legendre, J.; Jacquet, X.; Gunsing, Frank; Henning, Greg

    2014-03-01

    cross sections. As it is impossible to observe experimentally all the 7 transitions, model predictions are required to provide missing information. Few years ago, a collaboration between experimentalists and theoreticians has been engaged on actinides studies. It has recently led to a joint publication in which it was shown that specific theoretical work is needed to obtain better agreement between code predictions and measured cross sections. New sets of experimental data are now available and provide new severe constraints. Deeper theoretical studies could thus start. The first results have emphasized that improvements of the knowledge of nuclei structure parameters are required. Studies on reaction mechanism models have also shown that more realistic model, based on a microscopic description of the target's spectrum, could be used to noticeably improve the quality of the predictions. For actinides, as measurements could be very difficult or even impossible to implement due to target activity it would be very useful to have a nuclear reaction code with a real predictive power and in which we could have confidence. In summary, the goals of the project are 1. to gather theoreticians, evaluators and experimentalists who are working in the inelastic scattering on actinides field; 2. to present the last results concerning (n,xn) and (n,xn γ) measurements performed on actinides; 3. to present the last theoretical developments; 4. to compare experimental and theoretical results; 5. to discuss and highlight which are the possible improvements concerning theoretical models as well as new measurements; 6. to discuss other issues related to experimental and theoretical studies around actinides. This document brings together the presentations (slides) given at this workshop. Content: - Introduction (M. Kerveno, M. Dupuis); - The basics of modeling (n,xn) cross-sections for actinides (E. Bauge et al.); - Importance of the neutron slowing down through 238 U(n,n') for reactor

  16. Basic actinide chemistry and physics research in close cooperation with hot laboratories: ACTILAB

    International Nuclear Information System (INIS)

    Minato, K; Konashi, K; Fujii, T; Uehara, A; Nagasaki, S; Ohtori, N; Tokunaga, Y; Kambe, S

    2010-01-01

    Basic research in actinide chemistry and physics is indispensable to maintain sustainable development of innovative nuclear technology. Actinides, especially minor actinides of americium and curium, need to be handled in special facilities with containment and radiation shields. To promote and facilitate actinide research, close cooperation with the facilities and sharing of technical and scientific information must be very important and effective. A three-year-program B asic actinide chemistry and physics research in close cooperation with hot laboratories , ACTILAB, was started to form the basis of sustainable development of innovative nuclear technology. In this program, research on actinide solid-state physics, solution chemistry and solid-liquid interface chemistry is made using four main facilities in Japan in close cooperation with each other, where basic experiments with transuranium elements can be made. The 17 O-NMR measurements were performed on (Pu 0.91 Am 0.09 )O 2 to study the electronic state and the chemical behaviour of Am and Cm ions in electrolyte solutions was studied by distribution experiments.

  17. Investigations of actinides in the context of final disposal of high-level radioactive waste. Trivalent actinides in aqueous solution

    International Nuclear Information System (INIS)

    Banik, N.L.; Boris Brendebach; Marquardt, Ch.M.

    2014-01-01

    The speciation of redox sensitive trivalent actinides Pu(III), Np(III), and U(III) has been studied in aqueous solution. The redox preparation, stabilization, and speciation of these trivalent actinides in aqueous systems are discussed here. The reductants investigated were rongalite, hydroxylamine hydrochloride, and acetohydroxamic acid and the An(III) species have been characterized by UV-Vis and XANES spectroscopy. The results show that the effectiveness of stabilization decreases generally in the order Pu(III) > Np(III) > U(III) and that the effectiveness of each reducing agent depends on the experimental conditions. More than 80 % of Pu(III) aquo species have been stabilized up to pH 5.5, whereas the Np(III) aquo ion could be stabilized in a pH range 0-2.5, and U(III) aquo ion is sufficiently stable at pH 1.0 and below over time periods suitable for experiments. However, this study gives a basis for the characterisation of the trivalent lighter actinides involved in complexation, sorption, and solid formation reactions in the future. (author)

  18. Comparison calculations for an accelerator-driven minor actinide burner

    International Nuclear Information System (INIS)

    2002-01-01

    International interest in accelerator-driven systems (ADS) has recently been increasing in view of the important role that these systems may play as efficient minor actinide and long-lived fission-product (LLFP) burners and/or energy producers with an enhanced safety potential. However, the current methods of analysis and nuclear data for minor actinide and LLFP burners are not as well established as those for conventionally fuelled reactor systems. Hence, in 1999, the OECD/NEA Nuclear Science Committee organised a benchmark exercise for an accelerator-driven minor actinide burner to check the performances of reactor codes and nuclear data for ADS with unconventional fuel and coolant. The benchmark model was a lead-bismuth-cooled subcritical system driven by a beam of 1 GeV protons. This report provides an analysis of the results supplied by seven participants from eight countries. The analysis reveals significant differences in important neutronic parameters, indicating a need for further investigation of the nuclear data, especially minor actinide data, as well as the calculation methods. This report will be of particular interest to reactor physicists and nuclear data evaluators developing nuclear systems for nuclear waste management. (authors)

  19. Application of dynamic pseudo fission products and actinides for accurate burnup calculations

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E.; Leege, P.F.A. de [Technische Univ. Delft (Netherlands). Interfacultair Reactor Inst.; Kloosterman, J.L.

    1996-09-01

    The introduction of pseudo fission products for accurate fine-group spectrum calculations during burnup is discussed. The calculation of the density of the pseudo nuclides is done before each spectrum calculation from the actual densities and their cross sections of all nuclides to be lumped into a pseudo fission product. As there are also many actinides formed in the fuel during its life cycle, a pseudo actinide with fission cross section is also introduced. From a realistic burnup calculation it is demonstrated that only a few fission products and actinides need to be included explicitly in a spectrum calculation. All other fission products and actinides can be accurately represented in the pseudo nuclides. (author)

  20. Organophosphorus reagents in actinide separations: Unique tools for production, cleanup and disposal

    International Nuclear Information System (INIS)

    Nash, K. L.

    2000-01-01

    Interactions of actinide ions with phosphate and organophosphorus reagents have figured prominently in nuclear science and technology, particularly in the hydrometallurgical processing of irradiated nuclear fuel. Actinide interactions with phosphorus-containing species impact all aspects from the stability of naturally occurring actinides in phosphate mineral phases through the application of the bismuth phosphate and PUREX processes for large-scale production of transuranic elements to the development of analytical separation and environment restoration processes based on new organophosphorus reagents. In this report, an overview of the unique role of organophosphorus compounds in actinide production, disposal, and environment restoration is presented. The broad utility of these reagents and their unique chemical properties is emphasized

  1. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-07-28

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  2. Actinide biocolloid formation in brine by halophilic bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.B.; Papenguth, H.W.

    1998-01-01

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  3. Actinide biocolloid formation in brine by halophilic bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-01-01

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  4. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-01-01

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  5. Synthesis and structural characterization of actinide oxalate compounds

    International Nuclear Information System (INIS)

    Tamain, C.

    2011-01-01

    Oxalic acid is a well-known reagent to recover actinides thanks to the very low solubility of An(IV) and An(III) oxalate compounds in acidic solution. Therefore, considering mixed-oxide fuel or considering minor actinides incorporation in ceramic fuel materials for transmutation, oxalic co-conversion is convenient to synthesize mixed oxalate compounds, precursors of oxide solid solutions. As the existing oxalate single crystal syntheses are not adaptable to the actinide-oxalate chemistry or to their manipulation constrains in gloves box, several original crystal growth methods were developed. They were first validate and optimized on lanthanides and uranium before the application to transuranium elements. The advanced investigations allow to better understand the syntheses and to define optimized chemical conditions to promote crystal growth. These new crystal growth methods were then applied to a large number of mixed An1(IV)-An2(III) or An1(IV)-An2(IV) systems and lead to the formation of the first original mixed An1(IV)-An2(III) and An1(IV)-An2(IV) oxalate single crystals. Finally thanks to the first thorough structural characterizations of these compounds, single crystal X-ray diffraction, EXAFS or micro-RAMAN, the particularly weak oxalate-actinide compounds structural database is enriched, which is essential for future studied nuclear fuel cycles. (author) [fr

  6. Thermally unstable complexants/phosphate mineralization of actinides

    International Nuclear Information System (INIS)

    Nash, K.

    1996-01-01

    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

  7. Static and dynamic deformations of actinide nuclei

    International Nuclear Information System (INIS)

    Rozmej, P.

    1985-09-01

    The zero-point quadrupole-hexadecapole vibrations have been taken into account to calculate dynamical deformations for even-even actinide nuclei. The collective and intrinsic motions are separated according to the Born-Oppenheimer approximation. The collective Hamiltonian is constructed using the macroscopic-microscopic method in the potential energy part and the cranking model in the kinetic energy part. The BCS theory with a modified oscillator potential is applied to describe the intrinsic motion of nucleons. A new set of Nilsson potential parameters, which produces a much better description of the properties of light actinide nuclei, has also been found. (orig.)

  8. Environmental research on actinide elements

    Energy Technology Data Exchange (ETDEWEB)

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

    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)

  9. On the influence of the americium isotopic vector on the cooling time of minor actinides bearing blankets in fast reactors

    Directory of Open Access Journals (Sweden)

    Kooyman Timothée

    2018-01-01

    Full Text Available In the heterogeneous minor actinides transmutation approach, the nuclei to be transmuted are loaded in dedicated targets often located at the core periphery, so that long-lived heavy nuclides are turned into shorter-lived fission products by fission. To compensate for low flux level at the core periphery, the minor actinides content in the targets is set relatively high (around 20 at.%, which has a negative impact on the reprocessing of the targets due to their important decay heat level. After a complete analysis of the main contributors to the heat load of the irradiated targets, it is shown here that the choice of the reprocessing order of the various feeds of americium from the fuel cycle depends on the actual limit for fuel reprocessing. If reprocessing of hot targets is possible, it is more interesting to reprocess first the americium feed with a high 243Am content in order to limit the total cooling time of the targets, while if reprocessing of targets is limited by their decay heat, it is more interesting to wait for an increase in the 241Am content before loading the americium in the core. An optimization of the reprocessing order appears to lead to a decrease of the total cooling time by 15 years compared to a situation where all the americium feeds are mixed together when two feeds from SFR are considered with a high reprocessing limit.

  10. Swedish-German actinide migration experiment at ÄSPÖ hard rock laboratory

    Science.gov (United States)

    Kienzler, B.; Vejmelka, P.; Römer, J.; Fanghänel, E.; Jansson, M.; Eriksen, T. E.; Wikberg, P.

    2003-03-01

    Within the scope of a bilateral cooperation between Svensk Kärnbränslehantering (SKB) and Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgung (FZK-INE), an actinide migration experiment is currently being performed at the Äspö Hard Rock Laboratory (HRL) in Sweden. This paper covers laboratory and in situ investigations on actinide migration in single-fractured granite core samples. For the in situ experiment, the CHEMLAB 2 probe developed by SKB was used. The experimental setup as well as the breakthrough of inert tracers and of the actinides Am, Np and Pu are presented. The breakthrough curves of inert tracers were analyzed to determine hydraulic properties of the fractured samples. Postmortem analyses of the solid samples were performed to characterize the flow path and the sorbed actinides. After cutting the cores, the abraded material was analyzed with respect to sorbed actinides. The slices were scanned optically to visualize the flow path. Effective volumes and inner surface areas were measured. In the experiments, only breakthrough of Np(V) was observed. In each experiment, the recovery of Np(V) was ≤40%. Breakthrough of Am(III) and Pu(IV) as well as of Np(IV) was not observed.

  11. Actinide partitioning-transmutation program final report. I. Overall assessment

    International Nuclear Information System (INIS)

    Croff, A.G.; Blomeke, J.O.; Finney, B.C.

    1980-06-01

    This report is concerned with an overall assessment of the feasibility of and incentives for partitioning (recovering) long-lived nuclides from fuel reprocessing and fuel refabrication plant radioactive wastes and transmuting them to shorter-lived or stable nuclides by neutron irradiation. The principal class of nuclides considered is the actinides, although a brief analysis is given of the partitioning and transmutation (P-T) of 99 Tc and 129 I. The results obtained in this program permit us to make a comparison of the impacts of waste management with and without actinide recovery and transmutation. Three major conclusions concerning technical feasibility can be drawn from the assessment: (1) actinide P-T is feasible, subject to the acceptability of fuels containing recycle actinides; (2) technetium P-T is feasible if satisfactory partitioning processes can be developed and satisfactory fuels identified (no studies have been made in this area); and (3) iodine P-T is marginally feasible at best because of the low transmutation rates, the high volatility, and the corrosiveness of iodine and iodine compounds. It was concluded on the basis of a very conservative repository risk analysis that there are no safety or cost incentives for actinide P-T. In fact, if nonradiological risks are included, the short-term risks of P-T exceed the long-term benefits integrated over a period of 1 million years. Incentives for technetium and iodine P-T exist only if extremely conservative long-term risk analyses are used. Further RD and D in support of P-T is not warranted

  12. Thermal neutron actinide data

    International Nuclear Information System (INIS)

    Tellier, H.

    1992-01-01

    During the 70's, the physicists involved in the cross section measurements for the low energy neutrons were almost exclusively interested in the resonance energy range. The thermal range was considered as sufficiently known. In the beginning of the 80's, reactor physicists had again to deal with the delicate problem of the power reactor temperature coefficient, essentially for the light water reactors. The measured value of the reactivity temperature coefficient does not agree with the computed one. The later is too negative. For obvious safety reasons, it is an important problem which must be solved. Several causes were suggested to explain this discrepancy. Among all these causes, the spectral shift in the thermal energy range seems to be very important. Sensibility calculations shown that this spectral shift is very sensitive to the shape of the neutron cross sections of the actinides for energies below one electron-volt. Consequently, reactor physicists require new and accurate measurements in the thermal and subthermal energy ranges. A part of these new measurement results were recently released and reviewed. The purpose of this study is to complete the preceding review with the new informations which are now available. In reactor physics the major actinides are the fertile nuclei, uranium 238, thorium 232 and plutonium 240 and the fissile nuclei, uranium 233, uranium 235 and plutonium 239. For the fertile nuclei the main datum is the capture cross section, for the fissile nuclei the data of interest are nu-bar, the fission and capture cross sections or a combination of these data such as η or α. In the following sections, we will review the neutron data of the major actinides for the energy below 1 eV

  13. Thermodynamics proposes, kinetics decides, speciation dares: speciation of actinides in biological media

    International Nuclear Information System (INIS)

    Ansoborlo, E.

    2005-06-01

    After having recalled the content and purpose of his research thesis, the author proposes a detailed overview of the research works he performed thereafter in the field of the speciation of actinides at the level of the organism entry gates and in target tissues. These works therefore concern four important areas of research in radioprotection: bio-kinetic, toxicology, decorporation, and dosimetry studies. The author outlines how speciation studies can be useful for these different areas, and to better understand and describe, and therefore foresee, the biokinetics and toxicity of radionuclides

  14. Potential radiation dose from eating fish exposed to actinide contamination

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K.

    1980-01-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-Pond, a nuclear waste pond on the Hanford Site. It has concentrations of 238 U, 238 Pu, /sup 239,240/Pu and 241 Am that are approximately three orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated by assuming that actinide behavior in their bodies was similar to that defined for Standard Man by the International Commission on Radiological Protection. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (∼1 lb) of these fillets every day for 70 years. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources. 34 refs., 5 figs., 4 tabs

  15. Coprecipitation of aluminium with hydroxides of tetra-, penta- and hexavalent actinides

    International Nuclear Information System (INIS)

    Yusov, A.B.; Budantseva, N.A.; Anan'ev, A.V.; Fedoseev, A.M.

    2000-01-01

    By the methods of IR spectroscopy and powder x-ray diffractometry precipitates formed in alkaline medium by actinide (4, 5, 6) in the presence of aluminium are studied. It is shown that in studied conditions formation of actinide aluminates not occurs. In the same time in the process of precipitation interaction of aluminium hydroxocomplexes with U(6) and Th(4) ions probably takes place. Hypothesis is expressed that possibility of aluminium hydroxocomplexes interaction with actinides in different oxidation state is depended on peculiarities of hydrolytic behaviour of the lasts [ru

  16. Removal of actinide elements from high level radioactive waste by trialkylphosphine oxide (TRPO)

    International Nuclear Information System (INIS)

    Song Chongli; Yang Dazhu; He Longhai; Xu Jingming; Zhu Yongjun

    1992-03-01

    The modified TRPO process for removing actinide elements from synthetic solution, which was taken from reprocessing of power reactor nuclear fuel, was verified by cascade experiment. Neptunium valence was adjusted in the process for improving neptunium removing efficiency. At 1 mol/L concentration of HNO 3 of feed solution and after a few stages of extraction with 30% t=TRPO kerosene, over 99.9% of Am, Pu, Np and U could be removed from HAW (high level radioactive waste) solution. The stripping of actinides loaded in TRPO are accomplished by high concentration nitric acid, oxalic acid and sodium carbonate instead of amino carboxylic complexing agents used in previous process. The actinides stripped were divided into three groups, which are Am + RE, Np + Pu, and U, and the cross contamination between them is small. Behaviours of F.P. elements are divided into three types which are not extracted, little extracted and extracted elements. The extracted elements are rare earth and Pd, Zr and Mo which are co-extracted with actinides. The separation factor between actinides and other two types of F.P.elements will increase if more scrubbing sections are added in the process. The relative concentration profile of actinide elements and Tc in various stages as well as the distribution of actinides and F.P. elements in the process stream solutions are also presented

  17. Mechanisms for the reduction of actinide ions by Geobacter sulfurreducens

    International Nuclear Information System (INIS)

    Renshaw, J.C.; Livens, F.R.; May, I.; Lloyd, J.R.

    2005-01-01

    Full text of publication follows: Three of the most problematic radioactive contaminants are the actinide elements uranium, neptunium and plutonium. All three pose considerable long-term environmental risks. The most stable environmental oxidation states of uranium and neptunium are VI and V, respectively, as the di-oxo cations [UO 2 ] 2+ and [NpO 2 ] + ; both are highly soluble and so are relatively mobile and biologically available in the environment. In similar conditions, plutonium mainly exists as Pu(IV), which forms a highly insoluble hydrous oxide, although is also environmentally stable in the more soluble III, V and VI oxidation states. The bio-reduction of U(VI) by anaerobic subsurface microorganisms has been the focus of much recent interest. Both Fe(III)- and sulfate-reducing bacteria have been shown to reduce soluble [U VI O 2 ] 2+ to insoluble U IV O 2 , with c-type cytochromes involved in electron transfer to the actinide. Such transformations offer a strategy for the bio-remediation of uranium contaminated groundwater and a potential mechanism for the bio-deposition of uranium ores. The mechanism of U(VI). reduction has important implications for the potential microbial reduction of transuranic elements with environmentally stable lower oxidation states. Reduction of mobile 237 Np(V) to Np(IV) and subsequent precipitation may be advantageous whilst remobilization of immobile Pu(IV) as more soluble Pu(III) species could have important environmental implications. Conversely, selective reduction might allow targeting of particular radionuclide species. The model anaerobic bacterium Geobacter sulfurreducens is typical of those found in contaminated subsurface environments and has been shown to reduce soluble [U VI O 2 ] 2+ to insoluble U IV O 2 . In the course of this study we use X-ray absorption spectroscopy (XAS) to show that G. sulfurreducens reduces U(VI) by a one-electron reduction, forming an unstable [UO 2 ] + species which subsequently

  18. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances

    International Nuclear Information System (INIS)

    Kim, J.I.; Rhee, D.S.; Wimmer, H.; Buckau, G.; Klenze, R.; Decambox, P.; Moulin, C.; Moulin, V.; Tits, J.; Marquardt, C.; Herrmann, G.; Trautmann, N.; Dierckx, A.; Vancluysen, J.; Maes, A.

    1992-09-01

    The aim of the present research programme is to study the complexation behaviour of actinide ions with humic substances in natural aquifer systems and hence to quantify the effect of humic substances on the actinide migration. Aquatic humic substances commonly found in all groundwaters in different concentrations have a strong tendency towards complexation with actinide ions. This is one of the major geochemical reactions but hitherto least quantified. Therefore, the effect of humic substances on the actinide migration is poorly understood. In the present research programme the complexation of actinide ions with humic substances will be described thermodynamically. This description will be based on a model being as simple as possible to allow an easy introduction of the resulting constants into geochemical modelling of the actinide migration. (orig.)

  19. Actinides, the narrowwest bands

    International Nuclear Information System (INIS)

    Smith, J.L.; Riseborough, P.S.

    1984-01-01

    A table of elements is shown that demonstrates the crossover from superconductivity to magnetism as well as regions of mixed valence. In particular, the actinides must eventually show 4f-electron like mixed valence, after the 5f-electrons become localized. There also seems to be an adiabatic continuation between heavy fermion and mixed valence behavior

  20. Separation of macro-quantities of actinide elements at Savannah River by high-pressure cation exchange

    International Nuclear Information System (INIS)

    Burney, G.A.

    1980-01-01

    Large-scale separation of actinides from fission products and from each other by pressurized cation exchange chromatography at Savannah River is reviewed. Several kilograms of 244 Cm have been separated, with each run containing as much as 150 g of 244 Cm. Dowex 50W-X8 (Dow Chemical Co.) cation resin, graded to 30-70 micron size range, is used, and separation is made by eluting with 0.05M diethylenetriamine pentaacetic acid (DTPA) at a pH of 3. The effluent from the column is continuously monitored by a BF 3 detector, a NaI detector, and a lithium-drifted germanium detector and gamma spectrometer to guide collection of product fractions. Operating the columns at 300 to 1000 psi pressure eliminates resin bed disruption caused by radiolytically produced gases, and operating at increased flow rates decreases the radiolytic degradation of the resin per unit of product processed. A portion of the hot canyon of a production radiochemical separation plant was converted from a remote crane-operated facility to a master-slave manipulator-operated facility for separation and purification of actinide elements by pressurized cation exchange. It also contains an evaporator, furnaces, a calorimeter, and several precipitators and associated tanks. Actinide processing from target dissolution to packaging of purified product is planned in this facility

  1. Seventeen-coordinate actinide helium complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kaltsoyannis, Nikolas [School of Chemistry, The University of Manchester (United Kingdom)

    2017-06-12

    The geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations are explored computationally using density functional and coupled cluster theories. A new record coordination number is established, as AcHe{sub 17}{sup 3+}, ThHe{sub 17}{sup 4+}, and PaHe{sub 17}{sup 4+} are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide. Analysis of AcHe{sub n}{sup 3+} (n=1-17) using the quantum theory of atoms in molecules (QTAIM) confirms these systems as having closed shell, charge-induced dipole bonding. Excellent correlations (R{sup 2}>0.95) are found between QTAIM metrics (bond critical point electron densities and delocalization indices) and the average Ac-He distances, and also with the incremental He binding energies. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Chemical aspects of actinides in the geosphere: towards a rational nuclear materials management

    International Nuclear Information System (INIS)

    Allen, P; Sylwester, E

    2001-01-01

    A complete understanding of actinide interactions in the geosphere is paramount for developing a rational Nuclear and Environmental Materials Management Policy. One of the key challenges towards understanding the fate and transport of actinides is determining their speciation (i.e., oxidation state and structure). Since an element's speciation directly dictates physical properties such as toxicity and solubility, this information is critical for evaluating and controlling the evolution of an actinide element through the environment. Specific areas within nuclear and environmental management programs where speciation is important are (1) waste processing and separations; (2) wasteform materials for long-term disposition; and (3) aqueous geochemistry. The goal of this project was to develop Actinide X-ray Absorption Spectroscopy ( U S ) as a core capability at LLNL and integrate it with existing facilities, providing a multi-technique approach to actinide speciation. XAS is an element-specific structural probe which determines the oxidation state and structure for most atoms. XAS can be more incisive than other spectroscopies because it originates from an atomic process and the information is always attainable, regardless of an element's speciation. Despite the utility, XAS is relatively complex due to the need for synchrotron radiation and significant expertise with data acquisition and analysis. The coupling of these technical hurdles with the safe handling of actinides at a general user synchrotron facility such as the Stanford Synchrotron Radiation Facility (SSRL) make such experiments even more difficult. As a result, XAS has been underutilized by programs that could benefit by its application. We achieved our project goals by implementing key state-of-the-art Actinide XAS instrumentation at SSRL (Ge detector and remote positioning equipment), and by determining the chemical speciation of actinides (Th, U, and Np) in aqueous solutions, wasteform cements, and

  3. Review and needs in actinide chemistry in relation with biological purposes

    Energy Technology Data Exchange (ETDEWEB)

    Ansoborlo, E.; Moulin, V.; Bion, L.; Doizi, D.; Moulin, C.; Cote, G.; Madic, C.; Van der Lee, J

    2004-07-01

    In case of accidental release of radionuclides in the environment, actinides could occur and may present an healthy risk for human beings. In order to study their behavior in human organism (metabolism, retention, excretion), it is of prime importance to know solution actinide chemistry, and more particularly thermodynamic constants, which will allow to determine their speciation: speciation governs biological availability and toxicity of elements and is also of great interest for decorporation purposes. In this framework, a CEA working group on speciation has been created in order to share data both on thermodynamic constants and on speciation analytical methods, interesting chemists, environmentalists and biologists. It has been focused, in a first time, on actinides. The purpose of this paper is to present the state of the art on actinide speciation within biological media and to focus on the lack of information in order to orientate future research. (authors)

  4. Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Dorhout, Jacquelyn Marie [Univ. of Nevada, Las Vegas, NV (United States)

    2017-11-28

    This dissertation covers several distinct projects relating to the fields of nuclear forensics and basic actinide science. Post-detonation nuclear forensics, in particular, the study of fission products resulting from a nuclear device to determine device attributes and information, often depends on the comparison of fission products to a library of known ratios. The expansion of this library is imperative as technology advances. Rapid separation of fission products from a target material, without the need to dissolve the target, is an important technique to develop to improve the library and provide a means to develop samples and standards for testing separations. Several materials were studied as a proof-of-concept that fission products can be extracted from a solid target, including microparticulate (< 10 μm diameter) dUO2, porous metal organic frameworks (MOFs) synthesized from depleted uranium (dU), and other organicbased frameworks containing dU. The targets were irradiated with fast neutrons from one of two different neutron sources, contacted with dilute acids to facilitate the separation of fission products, and analyzed via gamma spectroscopy for separation yields. The results indicate that smaller particle sizes of dUO2 in contact with the secondary matrix KBr yield higher separation yields than particles without a secondary matrix. It was also discovered that using 0.1 M HNO3 as a contact acid leads to the dissolution of the target material. Lower concentrations of acid were used for future experiments. In the case of the MOFs, a larger pore size in the framework leads to higher separation yields when contacted with 0.01 M HNO3. Different types of frameworks also yield different results.

  5. INERT-MATRIX FUEL: ACTINIDE ''BURNING'' AND DIRECT DISPOSAL

    International Nuclear Information System (INIS)

    Rodney C. Ewing; Lumin Wang

    2002-01-01

    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

  6. Fermi surface measurements in actinide metals and compounds

    International Nuclear Information System (INIS)

    Arko, A.J.; Schirber, J.E.

    1978-01-01

    The various techniques of measuring Fermi Surface parameters are briefly discussed in terms f application to actinide systems. Particular emphasis is given the dHvA effect. Some general results found in the dHvA studies of actinide compounds are given. The dHvA effect has been measured in α-U and is presented in detail. None of the observed frequencies corresponds to closed surfaces. Results are compared to the calculations of Freeman, Koelling and Watson-Yang where qualitative agreement is observed

  7. Studies of thermal-hydraulics and plant systems for actinide burning fast reactor concept

    International Nuclear Information System (INIS)

    Yamazaki, Seiichiro; Misumi, Masahiro; Izaki, Makoto; Koike, Hiroyuki; Tanaka, Ryokichi

    1984-01-01

    As one of the methods to dispose long life actinide nuclides, the actinide burning fast reactor using only actinide wastes as the fuel has been proposed. Kawasaki Heavy Industries Ltd. carried out the conceptual examination on the ABFR cooled with helium gas, cooperating with Japan Atomic Energy Research Institute, and its feasibility and problems were clarified. In this report, the setting-up of various fundamental dimensions by the parameter survey of the thermal and flowing performance of the core, the examination of the thermal and flowing characteristics of the core based on the detailed power distribution, and the examination of the plant system centering around the main cooling system are outlined. The fuel is composed of actinide oxide and diluent MgO. The diluent is used for obtaining proper excess reactivity, and MgO has been taken up also in foreign countries, considering the compatibility with actinide oxide, the easiness of reprocessing and manufacture. The fuel element is of pin type, and actinide oxide and MgO pellets are in a SUS 316 cladding tube. This ABFR can treat the wastes from ten 1000 MWe power reactors, and has the power output of about 1000 MWt. (Kako, I.)

  8. Actinide burning in the integral fast reactor

    International Nuclear Information System (INIS)

    Chang, Y.I.

    1993-01-01

    During the past few years, Argonne National Laboratory has been developing the integral fast reactor (IFR), an advanced liquid-metal reactor concept. In the IFR, the inherent properties of liquid-metal cooling are combined with a new metallic fuel and a radically different refining process to allow breakthroughs in passive safety, fuel cycle economics, and waste management. A key feature of the IFR concept is its unique pyroprocessing. Pyroprocessing has the potential to radically improve long-term waste management strategies by exploiting the following attributes: 1. Minor actinides accompany plutonium product stream; therefore, actinide recycling occurs naturally. Actinides, the primary source of long-term radiological toxicity, are removed from the waste stream and returned to the reactor for in situ burning, generating useful energy. 2. High-level waste volume from pyroprocessing call be reduced substantially as compared with direct disposal of spent fuel. 3. Decay heat loading in the repository can be reduced by a large factor, especially for the long-term burden. 4. Low-level waste generation is minimal. 5. Troublesome fission products, such as 99 Tc, 129 I, and 14 C, are contained and immobilized. Singly or in combination, the foregoing attributes provide important improvements in long-term waste management in terms of the ease in meeting technical performance requirements (perhaps even the feasibility of demonstrating that technical performance requirements can be met) and perhaps also in ultimate public acceptance. Actinide recycling, if successfully developed, could well help the current repository program by providing an opportunity to enhance capacity utilization and by deferring the need for future repositories. It also represents a viable technical backup option in the event unforeseen difficulties arise in the repository licensing process

  9. Actinide cross section data and inertial confinement fusion for long term waste disposal

    International Nuclear Information System (INIS)

    Meldner, H.

    1979-01-01

    Actinide cross section data at thermonuclear neutron energies are needed for the calculation of ICF pellet center burnup of fission reactor waste, viz. 14 MeV neutron fission of the very long-lived actinides that pose storage problems. A major advantage of pellet center burnup is safety: only milligrams of highly toxic and active material need to be present in the fusion chamber, whereas blanket burnup requires the continued presence of tons of actinides in a small volume. The actinide data tables required for Monte Carlo calculations of the burnup of 241 Am and 243 Am are discussed in connection with typical burnup reactor fusion and fission spectra. 2 figures

  10. Recovery of actinides from TBP-Na2Co3 scrub-waste solutions: the ARALEX process

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Bloomquist, C.A.A.; Mason, G.W.; Leonard, R.A.; Ziegler, A.A.

    1979-08-01

    A flowsheet for the recovery of actinides from TBP-Na 2 CO 3 scrub-waste solutions has been developed, based on batch extraction data, and tested, using laboratory-scale countercurrent extraction techniques. The process, called the ARALEX process, uses 2-ethyl-1-hexanol (2-EHOH) to extract the TBP degradation products (HDBP and H 2 MBP) from acidified Na 2 CO 3 scrub waste leaving the actinides in the aqueous phase. Dibutyl and monobutyl phosphoric acids are attached to the 2-EHOH molecules through hydrogen bonds, which also diminish the ability of the HDBP and H 2 MBP to complex actinides. Thus all actinides remain in the aqueous raffinate. Dilute sodium hydroxide solutions can be used to back-extract the dibutyl and monobutyl phosphoric acid esters as their sodium salts. The 2-EHOH can then be recycled. After extraction of the acidified carbonate waste with 2-EHOH, the actinides may be readily extracted from the raffinate with DHDECMP or, in the case of tetra- and hexavalent actinides, with TBP. The ARALEX process can also be applied to other actinide waste streams which contain appreciable concentrations of polar organic compounds (e.g., detergents) that interfere with conventional actinide ion exchange and liquid-liquid extraction procedures. 20 figures, 6 tables

  11. Preliminary design and neutronic analysis of a laser fusion driven actinide waste burning hybrid reactor

    International Nuclear Information System (INIS)

    Berwald, D.H.; Duderstadt, J.J.

    1979-01-01

    The laser fusion driven actinide waste burner (LDAB) system investigated uses partitioned fission power reactor generated actinide wastes dissolved in a molten tin alloy as feed material (or fuel). A novel fuel processing concept based on the high-temperature precipitation of ''actinide--nitrides'' from a liquid tin solution is proposed. This concept will allow for fission product removal to be performed entirely within the device at high burnup. No attempt has been made to optimize this system, but potential performance is impressive. The equilibrium LDAB design consumes 7.6 MT/y of actinide waste. This corresponds to the waste output from 136 light water reactors [1000 MW (electric)]. The mean life of an actinide atom in the LDAB is only 4.5 y; and actinides, once charged to the LDAB, might be reprocessed fewer times during irradiation than in previously proposed systems

  12. Structural organization and spectroscopy of peptide-actinide(IV) complexes

    International Nuclear Information System (INIS)

    Dahou, S.

    2010-01-01

    The contamination of living organisms by actinide elements is at the origin of both radiological and chemical toxicity that may lead to severe dysfunction. Most of the data available on the actinide interaction with biological systems are macroscopic physiological measurements and are lacking a molecular description of the systems. Because of the intricacy of these systems, classical biochemical methods are difficult to implement. Our strategy consisted in designing simplified biomimetic peptides, and describing the corresponding intramolecular interactions with actinides. A carboxylic pentapeptide of the form DDPDD has been at the starting point of this work in order to further assess the influence of the peptide sequence on the topology of the complexes.To do so, various linear (Asp/Ala permutations, peptoids) and cyclic analogues have been synthesized. Furthermore, in order to include the hydroxamic function (with a high affinity for Fe(III)) in the peptide, both desferrioxamine and acetohydroxamic acid have been investigated. However because of difficulties in synthesis, we have not been able to test these peptides. Three actinide cations have been considered at oxidation state +IV (Th, Np, Pu) and compared to Fe(III), often considered as a biological surrogate of Pu(IV). The spatial arrangement of the peptide around the cation has been probed by spectrophotometry and X-ray Absorption Spectroscopy. The spectroscopic data and EXAFS data adjustment lead us to rationalize the topology of the complexes as a function of the peptide sequence: mix hydroxy polynuclear species for linear and cyclic peptides, mononuclear for the desferrioxamine complexes. Furthermore, significant differences have appeared between Fe(III) and actinide(IV), related to differences of reactivity in aqueous medium. (author)

  13. Nuclear transmutation of actinides other than fuel as a radioactive waste management scheme

    International Nuclear Information System (INIS)

    Cecille, L.; Hage, W.; Hettinger, H.; Mannone, F.; Mousty, F.; Schmidt, E.; Sola, A.; Huber, B.; Koch, L.

    1977-01-01

    The bulk of fission products in the high-level waste (HLW) decays to innocuous hazard levels within about 600 years. Actinide waste and a few fission products however represent a potential risk up to some hundreds of thousand of years. An alternative to the disposal of the whole HLW in geological formations is its fractionation, a nuclear transmutation of long-lived isotopes in fission reactors and a geological disposal of the other components. This solution would decrease the potential long-term risks of the geological waste disposal and would also accomodate to the demand of public opinion. The results of studies related to this management scheme are outlined with special reference to areas, where additional effort is required for realistic cost/benefit evaluations. Reactor physics calculations demonstrated the feasibility of actinide incineration in thermal and fast reactors. Obtained transmutation rates are sufficiently high to garantee acceptably small actinide inventories in the reactor in the case of self-generated actinide recycling. It appears that fast breeders could be used as transmutation devices without major additional reactor devlopment work. The thermal power rating of actinide fuel elements and the contribution of actinides and of minor amounts of lanthanide impurities to the neutron economy of the reactor has been evaluated. Sensitivity studies indicated that the results are dependent on the reactor operation mode and on the accuracy of the nuclear data. These calculations permitted the identification of isotopes for which cross section masurements and improved theoretical methods are required. The chemical separation of actinides from the HLW with the envisaged decontamination factors is being studied by solvent extraction and precipitation techniques using waste simulates and samples of high activity waste from European reprocessing plants. Up to now, the obtained results do not yet allow a definitive judgement on the feasibility of actinides

  14. Review of the sorption of actinides on natural minerals

    International Nuclear Information System (INIS)

    Beall, G.W.

    1981-01-01

    Over the past few years, a large body of data concerning sorption of actinides on geologic media has been built in connection with high-level-waste disposal. The primary aim of the work has been to allow predictions of the migration behavior of these radionuclides in the case of a breach of the repository that allowed groundwater flow through the repository. As a result of this work, some new backfill materials specifically tailored for the actinides have also been designed. Several major mechanisms of sorption that appear to dominate the sorption of actinides have emerged from these studies. These mechanisms can be divided into solution reactions dominated by hydrolysis, chemisorption reactions, and oxidation-reduction reactions. Each of these mechanisms will be discussed in detail, with experimental examples. Surprisingly, one mechanism, cation exchange, does not play an important role; why it fails to operate in any significant way in the environmental pH region will be discussed. The implications of the sorption mechanisms for waste forms and backfill materials will be discussed in detail. These discussions will center primarily around the valence state of the actinide in various waste forms and the effect of various anions on leachability from waste forms and backfill materials

  15. Cerium compounds in the fashion of the light actinides

    International Nuclear Information System (INIS)

    Koelling, D.D.

    1984-01-01

    Researchers familiar with the light actinides easily recognize in cerium compounds a microcosm of the rich variety of properties seen in the light actinides. The parallelism seen between comparable cerium and actinide compounds strongly suggests that the same physical models are applicable. The most significant is the relative size of the f-orbital. Localization is generally tighter in Ce compounds than uranium compounds, making Ce roughly analogous to Np through Am. A way to see the actinide parallelism is to compare Hill plots. Compounds in the different regions of the plots (representing different physics) are isostructural compounds with the same companion (B) elements. The most common materials exhibiting a direct f-f interaction are the cubic Laves compounds. Accordingly, we have determined the band structures of CeRu 2 , CeRh 2 , CeIr 2 , CeOs 2 , and CeNi 2 . Compounds illustrative of the interaction of f-orbitals with ligand orbitals are the Cu 3 Au structured materials. Materials calculated in this class are CeRh 3 , CePd 3 , and CeSn 3 - the materials of much interest as mixed valent. Although the focus is on the Ce compounds, calculations performed on uranium isomorphs are used to highlight the interesting physics

  16. Hydrothermal processing of actinide contaminated organic wastes

    International Nuclear Information System (INIS)

    Worl, A.; Buelow, S.J.; Le, L.A.; Padilla, D.D.; Roberts, J.H.

    1997-01-01

    Hydrothermal oxidation is an innovative process for the destruction of organic wastes, that occurs above the critical temperature and pressure of water. The process provides high destruction and removal efficiencies for a wide variety of organic and hazardous substances. For aqueous/organic mixtures, organic materials, and pure organic liquids hydrothermal processing removes most of the organic and nitrate components (>99.999%) and facilitates the collection and separation of the actinides. We have designed, built and tested a hydrothermal processing unit for the removal of the organic and hazardous substances from actinide contaminated liquids and solids. Here we present results for the organic generated at the Los Alamos National Laboratory Plutonium Facility

  17. Gas core reactors for actinide transmutation and breeder applications. Annual report

    International Nuclear Information System (INIS)

    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

  18. Adsorption of actinides by chelating agents containing benzene rings, fixed on charcoal

    International Nuclear Information System (INIS)

    Valentini Ganzerli, M.T.; Crespi Caramella, V.; Maggi, L.

    1999-01-01

    The focus of this paper is on the analysis of the actinides in the hydrosphere to study their environmental dispersion. The 8-hydroxyquinoline family and the benzohydroxamic acid have a complexing ability towards the actinides, even if in different oxidation states. Taking advantage of this ability, their salts with some organic acids or bases were prepared. In this way compounds were obtained easily incorporated into active charcoal. Only a small amount of the prepared adsorber may be equilibrated with large sample volumes. Subsequently it can be recovered by filtration. The adsorbed ions may be then re-dissolved with a small volume of the appropriate eluting solution. The 8-hydroxy-quinolines and the 8-hydroxyquinoline produced salts with the benzilic acid. These compounds similarly behave and show wide adsorption coefficients for solutions of pH higher than 3. The adsorption takes place by means of the formation of a complex of the actinide ion with the hydroxyquinoline moiety and also with the benzilic anion. Provided that the active extracting agent is not dissolved in a medium but fixed into a solid phase, the whole adsorption process may be regarded as a solvent extraction reaction. The benzohydroxamic acid was treated with the diphenylamine or with the tribenzylamine to obtain salts, later adsorbed into the charcoal. The adsorption of actinide ions seems to take place by means of a precipitation mechanism of the actinide ions with the hydroxamate ions for solution of pH higher than 3.5. Also in this case high values were obtained for the distribution coefficients. The actinide ions act similarly in the +4 or +6 oxidation state towards the prepared adsorber series. Therefore, it is possible to use only one adsorber to concentrate all actinides. Methods of analysis of actinides in the environment may be suitably set up and the concentration step based on these new prepared adsorber may improve the whole procedure. (authors)

  19. The complex formation of selected actinides (U, Np, Cm) with microbial ligands

    International Nuclear Information System (INIS)

    Glorius, Maja

    2009-01-01

    One of the urgent tasks in the field of nuclear technology is the final storage of radioactive substances. As a part of the safety requirements the protection of humans and the environment from the danger of radioactive substances in case of the release from the final storage is essential. For performing long-term safety calculations the detailed understanding of the physico-chemical effects and influences which cause the mobilisation and transport of actinides are necessary. The presented work was a discrete part of a project, which was focused on the clarification of the influence of microorganisms on the migration of actinides in case of the release of actinides from a final storage. The influence of microbial produced substances on the mobilisation of selected actinides was studied thereby. The microbial produced substances studied in this project were synthesized by bacteria from the Pseudomonas genus under special conditions. Fluorescent Pseudomonads secrete bacterial pyoverdin-type siderophores with a high potential to complex and transport metals, especially iron(III). The aim of the project was to determine how and under which conditions the bioligands are able to complex also radioactive substances and therefore to transport them. For this work the alpha-emitting actinides uranium, curium and neptunium were chosen because their long-life cycle and their radiotoxicity are a matter of particular interest. This work dealed with the interaction of the actinides U(VI), Np(V) and Cm(III) with model ligands simulating the functionality of the pyoverdins. So, such bioligands can essentially influence the behaviour of actinides in the environment. The results of this work contribute to a better understanding and assessment of the influence of the microbial ligands to the mobilisation and migration of the radionuclides. The outcomes could be used to quantify the actinide-mobilising effect of the bioligands, which are released, for example, in the vicinity of a

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

    International Nuclear Information System (INIS)

    Wills, John M.; Mattsson, Ann E.

    2012-01-01

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

  1. Actinide-pnictide (An-Pn) bonds spanning non-metal, metalloid, and metal combinations (An=U, Th; Pn=P, As, Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Rookes, Thomas M.; Wildman, Elizabeth P.; Gardner, Benedict M.; Wooles, Ashley J.; Gregson, Matthew; Tuna, Floriana; Liddle, Stephen T. [School of Chemistry, The University of Manchester (United Kingdom); Balazs, Gabor; Scheer, Manfred [Institute of Inorganic Chemistry, University of Regensburg (Germany)

    2018-01-26

    The synthesis and characterisation is presented of the compounds [An(Tren{sup DMBS}){Pn(SiMe_3)_2}] and [An(Tren{sup TIPS}){Pn(SiMe_3)_2}] [Tren{sup DMBS}=N(CH{sub 2}CH{sub 2}NSiMe{sub 2}Bu{sup t}){sub 3}, An=U, Pn=P, As, Sb, Bi; An=Th, Pn=P, As; Tren{sup TIPS}=N(CH{sub 2}CH{sub 2}NSiPr{sup i}{sub 3}){sub 3}, An=U, Pn=P, As, Sb; An=Th, Pn=P, As, Sb]. The U-Sb and Th-Sb moieties are unprecedented examples of any kind of An-Sb molecular bond, and the U-Bi bond is the first two-centre-two-electron (2c-2e) one. The Th-Bi combination was too unstable to isolate, underscoring the fragility of these linkages. However, the U-Bi complex is the heaviest 2c-2e pairing of two elements involving an actinide on a macroscopic scale under ambient conditions, and this is exceeded only by An-An pairings prepared under cryogenic matrix isolation conditions. Thermolysis and photolysis experiments suggest that the U-Pn bonds degrade by homolytic bond cleavage, whereas the more redox-robust thorium compounds engage in an acid-base/dehydrocoupling route. (copyright 2018 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  2. Measurement of fast neutron induced fission cross section of minor-actinide

    International Nuclear Information System (INIS)

    Hirakawa, Naohiro

    1997-03-01

    In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron Accelerator in Tohoku University. The experimental method and the samples, which were developed or introduced during the last year, were improved in this fiscal year: (1) Development of a sealed fission chamber, (2) Intensification of Li neutron target, (3) Improvement of time-resolution of Time-of-Flight (TOF) electronic circuit, (4) Introduction of Np237 samples with large sample mass and (5) Introduction of a U235 sample with high purity. Using these improved tools and samples, the fission cross section ratio of Np237 relative to U235 was measured between 5 to 100 keV, and the fission cross section of Np237 was deduced. On the other hand, samples of Am241 and Am243 were obtained from Japan Atomic Energy Research Institute (JAERI) after investigating fission cross section of two americium isotopes (Am241 and Am 243) which are important for core physics calculation of fast reactors. (author)

  3. Study of actinides fission induced by multi-nucleon transfer reactions in inverse kinematics

    International Nuclear Information System (INIS)

    Derkx, X.

    2010-10-01

    The study of actinide fission encounters two major issues. On one hand, measurements of the fission fragment distributions and the fission probabilities allow a better understanding of the fission process itself and the discrimination among the models of nuclear structure and dynamics. On the other hand, new measurements are required to improve nuclear data bases, which are a key component for the design of new generation reactors and radio-toxic waste incinerators. This thesis is in line with different French and American experimental projects using the surrogate method, i.e. transfer reactions leading to the same compound nuclei as in neutron irradiation, allowing the study of fission of actinides which are inaccessible by conventional techniques, whereas they are important for applications. The experiment is based on multi-nucleon transfer reactions between a 238 U beam and a 12 C target, using the inverse kinematics technique to measure, for each transfer channel, the complete isotopic distributions of the fission fragments with the VAMOS spectrometer. The work presented in this dissertation is focused on the identification of the transfer channels and their properties, as their angular distributions and the distributions of the associated excitation energy, using the SPIDER telescope to identify the target recoil nuclei. This work of an exploratory nature aims to generalize the surrogate method to heavy transfers and to measure, for the first time, the fission probabilities in inverse kinematics. The obtained results are compared with available direct kinematics and neutron irradiation measurements. (author)

  4. Recovery actinide values

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Delphin, W.H.; Mason, G.W.

    1979-01-01

    A process is described for partitioning and recovering actinide values from acidic waste solutions resulting from reprocessing of irradiated nuclear fuels by adding hydroxylammonium nitrate and hydrazine to the waste solution to adjust the valence of the neptunium and plutonium values in the solution to the +4 oxidation state, thus forming a feed solution and contacting the feed solution with an extractant of di-hexoxyethyl phosphoric acid in an organic diluent whereby the actinide values, most of the rare earth values and some fission product values are taken up by the extractant. Separation is achieved by contacting the loaded extractant with two aqueous strip solutions, a nitric acid solution to selectively strip the americium, curium and rare earth values and an oxalate solution of tetramethylammonium hydrogen oxalate and oxalic acid or trimethylammonium hydrogen oxalate to selectively strip the neptunium, plutonium and fission product values. Uranium values remain in the extractant and may be recovered with a phosphoric acid strip. The neptunium and plutonium values are recovered from the oxalate by adding sufficient nitric acid to destroy the complexing ability of the oxalate, forming a second feed, and contacting the second feed with a second extractant of tricaprylmethylammonium nitrate in an inert diluent whereby the neptunium and plutonium values are selectively extracted. The values are recovered from the extractant with formic acid. (author)

  5. Burn of actinides in MOX fuel cells; Quemado de actinidos en celdas de combustible MOX

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-15

    The spent fuel from nuclear reactors is stored temporarily in dry repositories in many countries of the world. However, the main problem of spent fuel, which is its high radio-toxicity in the long term, is not solved. A new strategy is required to close the nuclear fuel cycle and for the sustain ability of nuclear power generation, this strategy could be the recycling of plutonium to obtain more energy and recycle the actinides generated during the irradiation of the fuel to transmute them in less radioactive radionuclides. In this work we evaluate the quantities of actinides generated in different fuels and the quantities of actinides that are generated after their recycling in a thermal reactor. First, we make a reference calculation with a regular enriched uranium fuel, and then is changed to a MOX fuel, varying the plutonium concentrations and determining the quantities of actinides generated. Finally, different amounts of actinides are introduced into a new fuel and the amount of actinides generated at the end of the fuel burn is calculated, in order to determine the reduction of minor actinides obtained. The results show that if the concentration of plutonium in the fuel is high, then the production of minor actinides is also high. The calculations were made using the cell code CASMO-4 and the results obtained are shown in section 6 of this work. (Author)

  6. Actinides and the environment: what we know and what we need to know

    International Nuclear Information System (INIS)

    Nitsche, H.

    1998-01-01

    In order to design methods for the cleanup of contaminated sites, predict the transport behavior in the environment, perform safety assessment studies to determine the ability of repositories to adequately contain them, and design ways to retard their release and migration rates, it is essential to understand the chemical behavior and forms of actinides under environmental conditions. Excluding gaseous and airborne transport, actinides can migrate in the environment mostly via aqueous media such as groundwater and surface, river, lake and sea water. Models predicting the hydrological transport through the environment require as input an actinide concentration, the true amount that is actually available for transport. It is defined as the actinide source term and not as true solubility, because it may be a combination of dissolved and colloidal material. Three major processes define the actinide source term: (1) solubility, (2) organic interaction, and (3) sorption. They are dependent on each other and each individual process is the result of several sub-processes. Also, colloid formation plays a major role in the actinide source term, and it is common to each of the three main processes. The current state of knowledge of these processes will be discussed and areas will be outlined where additional information is required

  7. Simulations of the Thermodynamic and Diffusion Properties of Actinide Oxide Fuel Materials

    International Nuclear Information System (INIS)

    Becker, Udo

    2013-01-01

    Spent nuclear fuel from commercial reactors is comprised of 95-99 percent UO 2 and 1-5 percent fission products and transuranic elements. Certain actinides and fission products are of particular interest in terms of fuel stability, which affects reprocessing and waste materials. The transuranics found in spent nuclear fuels are Np, Pu, Am, and Cm, some of which have long half- lives (e.g., 2.1 million years for 237 Np). These actinides can be separated and recycled into new fuel matrices, thereby reducing the nuclear waste inventory. Oxides of these actinides are isostructural with UO 2 , and are expected to form solid solutions. This project will use computational techniques to conduct a comprehensive study on thermodynamic properties of actinide-oxide solid solutions. The goals of this project are to: Determine the temperature-dependent mixing properties of actinide-oxide fuels; Validate computational methods by comparing results with experimental results; Expand research scope to complex (ternary and quaternary) mixed actinide oxide fuels. After deriving phase diagrams and the stability of solid solutions as a function of temperature and pressure, the project team will determine whether potential phase separations or ordered phases can actually occur by studying diffusion of cations and the kinetics of potential phase separations or ordered phases. In addition, the team will investigate the diffusion of fission product gases that can also have a significant influence on fuel stability. Once the system has been established for binary solid solutions of Th, U, Np, and Pu oxides, the methodology can be quickly applied to new compositions that apply to ternaries and quaternaries, higher actinides (Am, Cm), burnable poisons (B, Gd, Hf), and fission products (Cs, Sr, Tc) to improve reactivity

  8. Quantum Chemical Studies of Actinides and Lanthanides: From Small Molecules to Nanoclusters

    Science.gov (United States)

    Vlaisavljevich, Bess

    Research into actinides is of high interest because of their potential applications as an energy source and for the environmental implications therein. Global concern has arisen since the development of the actinide concept in the 1940s led to the industrial scale use of the commercial nuclear energy cycle and nuclear weapons production. Large quantities of waste have been generated from these processes inspiring efforts to address fundamental questions in actinide science. In this regard, the objective of this work is to use theory to provide insight and predictions into actinide chemistry, where experimental work is extremely challenging because of the intrinsic difficulties of the experiments themselves and the safety issues associated with this type of chemistry. This thesis is a collection of theoretical studies of actinide chemistry falling into three categories: quantum chemical and matrix isolation studies of small molecules, the electronic structure of organoactinide systems, and uranyl peroxide nanoclusters and other solid state actinide compounds. The work herein not only spans a wide range of systems size but also investigates a range of chemical problems. Various quantum chemical approaches have been employed. Wave function-based methods have been used to study the electronic structure of actinide containing molecules of small to middle-size. Among these methods, the complete active space self consistent field (CASSCF) approach with corrections from second-order perturbation theory (CASPT2), the generalized active space SCF (GASSCF) approach, and Moller-Plesset second-order perturbation theory (MP2) have been employed. Likewise, density functional theory (DFT) has been used along with analysis tools like bond energy decomposition, bond orders, and Bader's Atoms in Molecules. From these quantum chemical results, comparison with experimentally obtained structures and spectra are made.

  9. Actinide AMS at DREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Khojasteh, Nasrin B.; Merchel, Silke; Rugel, Georg; Scharf, Andreas; Ziegenruecker, Rene [HZDR, Dresden (Germany); Pavetich, Stefan [HZDR, Dresden (Germany); ANU, Canberra (Australia)

    2016-07-01

    Radionuclides such as {sup 236}U and {sup 239}Pu were introduced into the environment by atmospheric nuclear weapon tests, reactor accidents (Chernobyl, Fukushima), releases from nuclear reprocessing facilities (Sellafield, La Hague), radioactive waste disposal, and accidents with nuclear devices (Palomares, Thule) [1]. Accelerator Mass Spectrometry (AMS) is the most sensitive method to measure these actinides. The DREsden AMS (DREAMS) facility is located at a 6 MV accelerator, which is shared with ion beam analytics and implantation users, preventing major modifications of the accelerator and magnetic analyzers. DREAMS was originally designed for {sup 10}Be, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, and {sup 129}I. To modify the system for actinide AMS, a Time-of-Flight (TOF) beamline at the high-energy side has been installed and performance tests are on-going. Ion beam and detector simulations are carried out to design a moveable ionization chamber. Especially, the detector window and anode dimensions have to be optimized. This ionization chamber will act as an energy detector of the system and its installation is planned as closely as possible to the stop detector of the TOF beamline for highest detection efficiency.

  10. Leaching of actinides from nuclear waste glass: French experience

    International Nuclear Information System (INIS)

    Vernaz, E.Y.; Godon, N.

    1991-01-01

    The activity concentration versus time of a typical LWR glass shows that after 300 years most of the activity is attributable to three actinides (Np, Pu and Am) and to 99 Tc. This activity decreases slowly, and some 50.000 years are necessary before the activity concentration drops to the level of the richest natural ores. This paper reviews the current state of knowledge concerning the kinetics of actinide release from glass subjected to aqueous leaching

  11. Co-deposition of metallic actinides on a solid cathode

    Energy Technology Data Exchange (ETDEWEB)

    Limmer, S. J.; Williamson, M. A.; Willit, J. L. [Argonne National Laboratory, Argonne (United States)

    2008-08-15

    The amount of rare earth contamination that will be found in a co-deposit of actinides is a function of the type of cathode used. A non-alloying solid cathode will result in a significantly lower rare earth contamination in the actinide co-deposit than a liquid cadmium cathode. With proper control of the cathode potential vs. a stable reference electrode, co-deposition of uranium with other more electroactive metals has been demonstrated using a non-alloying solid cathode.

  12. Co-deposition of metallic actinides on a solid cathode

    International Nuclear Information System (INIS)

    Limmer, S. J.; Williamson, M. A.; Willit, J. L.

    2008-01-01

    The amount of rare earth contamination that will be found in a co-deposit of actinides is a function of the type of cathode used. A non-alloying solid cathode will result in a significantly lower rare earth contamination in the actinide co-deposit than a liquid cadmium cathode. With proper control of the cathode potential vs. a stable reference electrode, co-deposition of uranium with other more electroactive metals has been demonstrated using a non-alloying solid cathode

  13. Strength of Coriolis Coupling in actinide nuclei

    International Nuclear Information System (INIS)

    Peker, L.K.; Rasmussen, J.O.; Hamilton, J.H.

    1982-01-01

    Coriolis Coupling V/sub cor/ plays an important role in deformed nuclei. V/sub cor/ is proportional to h 2 /J[j (j + 1) -Ω (Ω + 1)]/sup 1/2/ and therefore is particularly significant in the nuclei with large j and low Ω Nilsson levels close to Fermi surface: n(i/sub 13/2/) in A = 150 to 170 rare-earth nuclei and p(i/sub 13/2/) and n(j/sub 15/2/) in A greater than or equal to 224 actinide nuclei. Because of larger j (n(j/sub 15/2/) versus n(i/sub 13/2/)) and smaller deformations (β approx. = 0.22 versus β 0.28) it was reasonable to expect that in actinide nuclei Coriolis effects are stronger than in the rare earth nuclei. Recently it was realized that the strength of observed Coriolis effects depends not only on the genuine Coriolis Coupling but also on the interplay between Coriolis ad pairing forces which leads to an interference between the wave functions of two mixing rotational bands. As a consequence the effective interaction V/sub eff/ of both bands is an oscillating function of the degree of shell filling (or chemical potential lambda F). It was shown that in the rare earth nuclei this interference strongly influenced conclusions about the trends in the Coriolis coupling strength and explained many of the observed band-mixing features (the sharpness of back banding curves, details of the blocking effect etc.). From theoretical analysis it was concluded that in the majority of actinide nuclei the effective interaction V/sub eff/ is strong, and therefore the Coriolis band-mixing have to be very strong. In this paper we would like to demonstrate that contrary to these predictions experimental data suggest that Coriolis band mixing in studied actinide nuclei is relatively weak and possibly significantly weaker than in rare earth nuclei

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

    International Nuclear Information System (INIS)

    Nash, K.L.

    2013-01-01

    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 - ). 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)

  15. The Lawrence Livermore National Laboratory Intelligent Actinide Analysis System

    International Nuclear Information System (INIS)

    Buckley, W.M.; Carlson, J.B.; Koenig, Z.M.

    1993-01-01

    The authors have developed an Intelligent Actinide Analysis System (IAAS) for Materials Management to use in the Plutonium Facility at the Lawrence Livermore National Laboratory. The IAAS will measure isotopic ratios for plutonium and other actinides non-destructively by high-resolution gamma-ray spectrometry. This system will measure samples in a variety of matrices and containers. It will provide automated control of many aspects of the instrument that previously required manual intervention and/or control. The IAAS is a second-generation instrument, based on experience in fielding gamma isotopic systems, that is intended to advance non-destructive actinide analysis for nuclear safeguards in performance, automation, ease of use, adaptability, systems integration and extensibility to robotics. It uses a client-server distributed monitoring and control architecture. The IAAS uses MGA as the isotopic analysis code. The design of the IAAS reduces the need for operator intervention, operator training, and operator exposure

  16. Evaluation of thorium based nuclear fuel. Actinide waste

    International Nuclear Information System (INIS)

    Wichers, V.A.

    1995-06-01

    Use of thorium based fuel has recently been proposed as a possible way to reduce the amount of actinide waste from nuclear power. To examine this possibility, burnup calculations were done of five once-through Thorium Heavy Water Reactor (THWR) systems, and three THWR systems with uranium recycle. The natural uranium once-through system was adopted as reference. The studied THWR fuel systems differed in the choice of fissile makeup fuel and exit burnup. The HWR was chosen because of its good neutron economy. Actinide waste production (in mass per GW e a) and radiotoxicity (in ALI per GW e a) for storage times up to 10 6 a were calculated for each system. The study shows that the THWR system with uranium recycle and High Enriched Uranium (U-235) makeup fuel performed best, producing both the lowest amount of plutonium and actinide waste with the lowest radiotoxicity. Relative to the natural uranium in HWR once-through system, radiotoxicity is reduced by a factor varying between 2 and 50 for the full range of storage times up to 10 6 a. (orig.)

  17. Process analytical chemistry applied to actinide waste streams

    International Nuclear Information System (INIS)

    Day, R.S.

    1994-01-01

    The Department of Energy is being called upon to clean up it's legacy of waste from the nuclear complex generated during the cold war period. Los Alamos National Laboratory is actively involved in waste minimization and waste stream polishing activities associated with this clean up. The Advanced Testing Line for Actinide Separations (ATLAS) at Los Alamos serves as a developmental test bed for integrating flow sheet development of nitric acid waste streams with process analytical chemistry and process control techniques. The wastes require processing in glove boxes because of the radioactive components, thus adding to the difficulties of making analytical measurements. Process analytical chemistry methods provide real-time chemical analysis in support of existing waste stream operations and enhances the development of new waste stream polishing initiatives. The instrumentation and methods being developed on ATLAS are designed to supply near-real time analyses on virtually all of the chemical parameters found in nitric acid processing of actinide waste. These measurements supply information on important processing parameters including actinide oxidation states, free acid concentration, interfering anions and metal impurities

  18. Potential radiation dose from eating fish exposed to actinide contamination

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K.

    1981-01-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-pond, a nuclear waste pond on the Hanford Site. It has concentrations of 238 U, 238 Pu, sup(239,240)Pu and 241 Am that are approx. 3 orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-Pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (of the order of 1 lb) of these fillets every day for 70 yr. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources. (author)

  19. Reversible optical sensor for the analysis of actinides in solution

    International Nuclear Information System (INIS)

    Lesage, B.; Picard, S.; Serein-Spirau, F.; Lereporte, J.P.

    2007-01-01

    In this work is presented a concept of reversible optical sensor for actinides. It is composed of a p doped conducing polymer support and of an anion complexing the actinides. The chosen conducing polymer is the thiophene-2,5-di-alkoxy-benzene whose solubility and conductivity are perfectly known. The actinides selective ligand is a lacunar poly-oxo-metallate such as P 2 W 17 O 61 10- or SiW 11 O 39 8- which are strong anionic complexing agents of actinides at the oxidation state (IV) even in a very acid medium. The sensor is prepared by spin coating of the composite mixture 'polymer + ligand' on a conducing glass electrode and then tested towards its optical and electrochemical answer in presence of uranium (IV). The absorption change due to the formation of cations complexes by poly-oxo-metallate reveals the presence of uranium (IV). After the measurement, the sensor is regenerated by anodic polarization of the support and oxidation of the uranium (IV) into uranium (VI) which weakly interacts with the poly-oxo-metallate and is then released in solution. (O.M.)

  20. Studies of Actinides Reduction on Iron Surfaces by Means of Resonant Inelastic X-ray Scattering

    International Nuclear Information System (INIS)

    Kvashnina, K.O.; Butorin, S.M.; Shuh, D.K.; Ollila, K.; Soroka, I.; Guo, J.-H.; Werme, L.; Nordgren, J.

    2006-01-01

    The interaction of actinides with corroded iron surfaces was studied using resonant inelastic x-ray scattering (RIXS) spectroscopy at actinide 5d edges. RIXS profiles, corresponding to the f-f excitations are found to be very sensitive to the chemical states of actinides in different systems. Our results clearly indicate that U(VI) (as soluble uranyl ion) was reduced to U(IV) in the form of relatively insoluble uranium species, indicating that the iron presence significantly affects the mobility of actinides, creating reducing conditions. Also Np(V) and Pu (VI) in the ground water solution were getting reduced by the iron surface to Np(IV) and Pu (IV) respectively. Studying the reduction of actinides compounds will have an important process controlling the environmental behavior. Using RIXS we have shown that actinides, formed by radiolysis of water in the disposal canister, are likely to be reduced on the inset corrosion products and prevent release from the canister

  1. Operating procedures for the manufacture of radioactive SYNROC in the actinide laboratory

    International Nuclear Information System (INIS)

    Western, K.F.

    1986-03-01

    The purpose of this manual is to acquaint the operator with the procedures required to manufacture SYNROC-containing radioactive materials in the SYNROC actinide laboratory, Lucas Heights Research Laboratories. The actinide-doped SYNROC production facility is a series of four interconnected glove boxes and one free-standing glove box. The samples of radioactive SYNROC produced in the actinide laboratory are used to carry out physical testing of the product at various laboratories on site, e.g. leach testing, auto-radiographic examination, electron-microscopc examination, atomic absorption spectrophotometry and analysis

  2. Experimental measurements and integrated modelling studies of actinide sorption onto cement

    International Nuclear Information System (INIS)

    Sugiyama, Daisuke; Fujita, Tomonari; Baston, G.M.N.

    2003-01-01

    An Integrated Cement Sorption Model (ICSM) for actinides onto Ordinary Portland Cement (OPC) is developed. The experimental measurements using the batch sorption technique for actinides onto cement and constituent minerals, which were considered in the modelling calculations, are also described. The actinide elements studied (thorium, uranium, neptunium, plutonium and americium) were strongly sorbed onto OPC. An initial comparison of the experimental data relating the sorption values of actinides onto cement-component phases with those onto OPC is carried out. The results suggest that the Calcium Silicate Hydrate (C-S-H) phases were found to be the most likely candidates to be the dominant-sorbing phases in order to describe the sorption of a actinides onto OPC. An approach to develop the integrated cement sorption model, based on a thermodynamic surface complexation model, is described with discussions on the possible mineralogy and phase distribution of OPC. Another approach than sorption, assuming that co-precipitation on the surface of the cement phase dominates 'sorption', is proposed and discussed. A scoring system is introduced to assess the applicability of the proposed ICSMs. It is suggested that the thermodynamic sorption model is recommended for the sorption of ionic species and the surface co-precipitation model is recommended for the sorption of neutral species though the sorption model is still recommended to be used to model OPC-based systems. (author)

  3. Analytical chemistry of actinides

    International Nuclear Information System (INIS)

    Chollet, H.; Marty, P.

    2001-01-01

    Different characterization methods specifically applied to the actinides are presented in this review such as ICP/OES (inductively coupled plasma-optical emission spectrometry), ICP/MS (inductively coupled plasma spectroscopy-mass spectrometry), TIMS (thermal ionization-mass spectrometry) and GD/OES (flow discharge optical emission). Molecular absorption spectrometry and capillary electrophoresis are also available to complete the excellent range of analytical tools at our disposal. (authors)

  4. Actinides compounds for the transmutation: scientific contributions of american and japanese collaborations; Composes d'actinides pour la transmutation: apports scientifiques de collaborations americaines et japonaises

    Energy Technology Data Exchange (ETDEWEB)

    Raison, Ph.; Albiot, T

    2000-07-01

    This paper deals with the minor actinides transmutation and the scientific contribution of the ORNL and the JAERI. It presents researches on the Am-Zr-Y-O system in the framework of the heterogeneous reprocessing, the curium and pyrochlore structures, with the ORNL contribution and phase diagrams, data of Thermodynamics, actinides nitrides, with the JAERI. (A.L.B.)

  5. Cerium compounds in the fashion of the light actinides

    International Nuclear Information System (INIS)

    Koelling, D.D.

    1985-01-01

    Researchers familiar with the light actinides easily recognize in cerium compounds a microcosm of the rich variety of properties seen in the light actinides. The parallelism seen between comparable cerium and actinide compounds strongly suggests that the same physical models are applicable. The most significant is the relative size of the f-orbital. Localization is generally tighter in Ce compounds than uranium compounds, making Ce roughly analogous to Np through Am. A way to see the actinide parallelism is to compare Hill plots. Compounds in the different regions of the plots (representing different physics) are isostructural compounds with the same companion (B) elements. The most common materials expected to exhibit direct f-f interaction are the cubic Laves compounds. Accordingly, we have determined the band structures of CeRu 2 , CeRh 2 , CeIr 2 , and CeNi 2 . Surprisingly, it was found that an f-d interaction overshadows any direct f-f interaction in these systems. Compounds illustrative of the interaction of f-orbitals with ''ligand'' orbitals are the Cu 3 Au structured materials. Materials calculated in this class are CeRh 3 , CePd 3 , and CeSn 3 - the materials of much interest as ''mixed valent''. Although the focus is on the Ce compounds, calculations performed on uranium isomorphs are used to highlight the interesting physics. (orig.)

  6. Actinides and fission products partitioning from high level liquid waste

    International Nuclear Information System (INIS)

    Yamaura, Mitiko

    1999-01-01

    The presence of small amount of mixed actinides and long-lived heat generators fission products as 137 Cs and 90 Sr are the major problems for safety handling and disposal of high level nuclear wastes. In this work, actinides and fission products partitioning process, as an alternative process for waste treatment is proposed. First of all, ammonium phosphotungstate (PWA), a selective inorganic exchanger for cesium separation was chosen and a new procedure for synthesizing PWA into the organic resin was developed. An strong anionic resin loaded with tungstate or phosphotungstate anion enables the precipitation of PWA directly in the resinous structure by adding the ammonium nitrate in acid medium (R-PWA). Parameters as W/P ratio, pH, reactants, temperature and aging were studied. The R-PWA obtained by using phosphotungstate solution prepared with W/P=9.6, 9 hours digestion time at 94-106 deg C and 4 to 5 months aging time showed the best capacity for cesium retention. On the other hand, Sr separation was performed by technique of extraction chromatography, using DH18C6 impregnated on XAD7 resin as stationary phase. Sr is selectively extracted from acid solution and >99% was recovered from loaded column using distilled water as eluent. Concerning to actinides separations, two extraction chromatographic columns were used. In the first one, TBP(XAD7) column, U and Pu were extracted and its separations were carried-out using HNO 3 and hydroxylamine nitrate + HNO 3 as eluent. In the second one, CMP0-TBP(XAD7) column, the actinides were retained on the column and the separations were done by using (NH 4 ) 2 C 2 O 4 , DTPA, HNO 3 and HCl as eluent. The behavior of some fission products were also verified in both columns. Based on the obtained data, actinides and fission products Cs and Sr partitioning process, using TBP(XAD7) and CMP0-TBP(XAD7) columns for actinides separation, R-PWA column for cesium retention and DH18C6(XAD7) column for Sr isolation was performed

  7. Alpha decay and cluster decay of some neutron-rich actinide nuclei

    Indian Academy of Sciences (India)

    2017-02-09

    Feb 9, 2017 ... Abstract. Nuclei in the actinide region are good in exhibiting cluster radioactivity. In the present work, the half-lives of α-decay and heavy cluster emission from certain actinide nuclei have been calculated using cubic plus Yukawa plus exponential model (CYEM). Our model has a cubic potential for the ...

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  9. Managing Zirconium Chemistry and Phase Compatibility in Combined Process Separations for Minor Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Nathalie [Washington State Univ., Pullman, WA (United States); Nash, Ken [Washington State Univ., Pullman, WA (United States); Martin, Leigh [Washington State Univ., Pullman, WA (United States)

    2017-03-17

    In response to the NEUP Program Supporting Fuel Cycle R&D Separations and Waste Forms call DEFOA- 0000799, this report describes the results of an R&D project focusing on streamlining separation processes for advanced fuel cycles. An example of such a process relevant to the U.S. DOE FCR&D program would be one combining the functions of the TRUEX process for partitioning of lanthanides and minor actinides from PUREX(UREX) raffinates with that of the TALSPEAK process for separating transplutonium actinides from fission product lanthanides. A fully-developed PUREX(UREX)/TRUEX/TALSPEAK suite would generate actinides as product(s) for reuse (or transmutation) and fission products as waste. As standalone, consecutive unit-operations, TRUEX and TALSPEAK employ different extractant solutions (solvating (CMPO, octyl(phenyl)-N,Ndiisobutylcarbamoylmethylphosphine oxide) vs. cation exchanging (HDEHP, di-2(ethyl)hexylphosphoric acid) extractants), and distinct aqueous phases (2-4 M HNO3 vs. concentrated pH 3.5 carboxylic acid buffers containing actinide selective chelating agents). The separate processes may also operate with different phase transfer kinetic constraints. Experience teaches (and it has been demonstrated at the lab scale) that, with proper control, multiple process separation systems can operate successfully. However, it is also recognized that considerable economies of scale could be achieved if multiple operations could be merged into a single process based on a combined extractant solvent. The task of accountability of nuclear materials through the process(es) also becomes more robust with fewer steps, providing that the processes can be accurately modeled. Work is underway in the U.S. and Europe on developing several new options for combined processes (TRUSPEAK, ALSEP, SANEX, GANEX, ExAm are examples). There are unique challenges associated with the operation of such processes, some relating to organic phase chemistry, others arising from the

  10. On the solvation of actinide ions

    International Nuclear Information System (INIS)

    Hagberg, D.

    2007-01-01

    Complete text of publication follows: Simulation of the universal ions in water solution is a standardized tool commonly used today. The route to simulation of actinide ions is normally tough because the evaluation of the simulation parameters are normally not given empirically and standard Hartree-Fock calculations are not accurate enough. We use multiconfigurational quantum chemical calculations when deriving the parameters for actinide ion-water potential [1]. The parameters are then simulated using classical molecular dynamics. A case study of the Cm 3+ ion will be presented on the poster. Results from the simulations will be also be discussed, e.g. the radial distribution functions and the coordination number. [1] D. Hagberg, G. Karlstrom, B.O. Roos and L. Gagliardi The coordination of uranyl in water: a combined quantum chemical and molecular simulation study J. Am. Chem. Soc. 127, 14250-14256 (2005)

  11. Numerical analysis on reduction of radioactive actinides by recycling of nuclear fuel

    International Nuclear Information System (INIS)

    Balboa L, H. E.

    2014-01-01

    Worldwide, human growth has reached unparalleled levels historically, this implies a need for more energy, and just in 2007 was consumed in the USA 4157 x 10 9 kWh of electricity and there were 6 x 10 9 metric tons of carbon dioxide, which causes a devastating effect on our environment. To this problem, a solution to the demand for non-fossil energy is nuclear energy, which is one of the least polluting and the cheapest among non-fossil energy; however, a problem remains unresolved the waste generation of nuclear fuels. In this work the option of a possible transmutation of actinides in a nuclear reactor of BWR was analyzed, an example of this are the nuclear reactors at the Laguna Verde nuclear power plant, which have generated spent fuel stored in pools awaiting a decision for final disposal or any other existing alternative. Assuming that the spent fuel was reprocessed to separate useful materials and actinides such as plutonium and uranium remaining, could take these actinides and to recycle them inside the same reactor that produced them, so il will be reduced the radiotoxicity of spent fuel. The main idea of this paper is to evaluate by means of numeric simulation (using the Core Management System (CMS)) the reduction of minor actinides in the case of being recycled in fresh fuel of the type BWR. The actinides were introduced hypothetically in the fuel pellets to 6% by weight, and then use a burned in the range of 0-65 G Wd/Tm, in order to have a better panorama of their behavior and thus know which it is the best choice for maximum reduction of actinides. Several cases were studied, that is to say were used as fuels; the UO 2 and MOX. Six different cases were also studied to see the behavior of actinides in different situations. The CMS platform calculation was used for the analysis of the cases presented. Favorable results were obtained, having decreased from a range of 35% to 65% of minor actinides initially introduced in the fuel rods, reducing the

  12. Nuclear fuel activity with minor actinides after their useful life in a BWR

    International Nuclear Information System (INIS)

    Martinez C, E.; Ramirez S, J. R.; Alonso V, G.

    2016-09-01

    Nuclear fuel used in nuclear power reactors has a life cycle, in which it provides energy, at the end of this cycle is withdrawn from the reactor core. This used fuel is known as spent nuclear fuel, a strong problem with this fuel is that when the fuel was irradiated in a nuclear reactor it leaves with an activity of approximately 1.229 x 10 15 Bq. The aim of the transmutation of actinides from spent nuclear fuel is to reduce the activity of high level waste that must be stored in geological repositories and the lifetime of high level waste; these two achievements would reduce the number of necessary repositories, as well as the duration of storage. The present work is aimed at evaluating the activity of a nuclear fuel in which radioactive actinides could be recycled to remove most of the radioactive material, first establishing a reference of actinides production in the standard nuclear fuel of uranium at end of its burning in a BWR, and a fuel rod design containing 6% of actinides in an uranium matrix from the enrichment tails is proposed, then 4 standard uranium fuel rods are replaced by 4 actinide bars to evaluate the production and transmutation of the same, finally the reduction of actinide activity in the fuel is evaluated. (Author)

  13. X-ray study of chemical bonding in actinides(IV) and lanthanides(III) hexa-cyanoferrates

    International Nuclear Information System (INIS)

    Dumas, T.

    2011-01-01

    Bimetallic cyanide molecular solids derived from Prussian blue are well known to foster long-range magnetic ordering and show an intense inter-valence charge transfer band resulting from an exchange interaction through the cyanide-bridge. For those reasons the ferrocyanide and ferricyanide building blocks have been chosen to study electronic delocalization and covalent character in actinide bonding using an experimental and theoretical approach based on X-ray absorption spectroscopy. In 2001, the actinide (IV) and early lanthanides (III) hexacyanoferrate have been found by powder X-ray diffraction to be isostructural (hexagonal, P6 3 /m group). Here, extended X-ray Absorption Fine Structure (EXAFS) at the iron K-edge and actinide L 3 -edge have been undertaken to probe the local environment of both actinides and iron cations. In an effort to describe the cyano bridge, a double edge fitting procedure including both iron and actinide edges and based on multiple scattering approach has been developed. We have also investigated the electronic properties of these molecular solids. Low energy electronic transitions have been used iron L 2,3 edge, nitrogen and carbon K-edge and also actinides N 4,5 edge to directly probe the valence molecular orbitals of the complex. Using a phenomenological approach, a clear distinctive behaviour between actinides and lanthanides has been shown. Then a theoretical approach using quantum chemistry calculation has shown more specifically the effect of covalency in the actinide-ferrocyanide bond. More specifically, π interactions were underlined by both theoretical and experimental methods. Finally, in agreement with the ionic character of the lanthanide bonding no inter-valence charge transfer has been observed in the corresponding optical spectra of these compounds. On the contrary, optical spectra for actinides adducts (except for thorium) show an intense inter-valence charge transfer band like in the transition metal cases which is

  14. The Lawrence Livermore National Laboratory Intelligent Actinide Analysis System

    International Nuclear Information System (INIS)

    Buckley, W.M.; Carlson, J.B.; Koenig, Z.M.

    1993-07-01

    The authors have developed an Intelligent Actinide Analysis System (IAAS) for Materials Management to use in the Plutonium Facility at the Lawrence Livermore National Laboratory. The IAAS will measure isotopic ratios for plutonium and other actinides non-destructively by high-resolution gamma-ray spectrometry. This system will measure samples in a variety of matrices and containers. It will provide automated control of many aspects of the instrument that previously required manual intervention and/or control. The IAAS is a second-generation instrument, based on the authors' experience in fielding gamma isotopic systems, that is intended to advance non-destructive actinide analysis for nuclear safeguards in performance, automation, ease of use, adaptability, systems integration and extensibility to robotics. It uses a client-server distributed monitoring and control architecture. The IAAS uses MGA 3 as the isotopic analysis code. The design of the IAAS reduces the need for operator intervention, operator training, and operator exposure

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

    International Nuclear Information System (INIS)

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

    1994-01-01

    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

  16. Preparation of higher-actinide burnup and cross section samples

    International Nuclear Information System (INIS)

    Adair, H.L.; Kobisk, E.H.; Quinby, T.C.; Thomas, D.K.; Dailey, J.M.

    1981-01-01

    A joint research program involving the United States and the United Kingdom was instigated about four years ago for the purpose of studying burnup of higher actinides using in-core irradiation in the fast reactor at Dounreay, Scotland. Simultaneously, determination of cross sections of a wide variety of higher actinide isotopes was proposed. Coincidental neutron flux and energy spectral measurements were to be made using vanadium encapsulated dosimetry materials in the immediate region of the burnup and cross section samples. The higher actinide samples chosen for the burnup study were 241 Am and 244 Cm in the forms of Am 2 O 3 , Cm 2 O 3 , and Am 6 Cm(RE) 7 O 21 , where (RE) represents a mixture of lanthanide sesquioxides. It is the purpose of this paper to describe technology development and its application in the preparation of the fuel specimens and the cross section specimens that are being used in this cooperative program

  17. Colloidal products and actinide species in leachate from spent nuclear fuel

    International Nuclear Information System (INIS)

    Finn, P.A.; Buck, E.C.; Gong, M.; Hoh, J.C.; Emery, J.W.; Hafenrichter, L.D.; Bates, J.K.

    1993-01-01

    Two well-characterized types of spent nuclear fuel (ATM-103 and ATM-106) were subjected to unsaturated leach tests with simulated groundwater at 90 degrees C. The actinides present in the leachate were determined at the end of two successive periods of ∼60 days and after an acid strip done at the end of the second period. Both colloidal and soluble actinide species were detected in the leachates which had pHs ranging from 4 to 7. The uranium phases identified in the colloids were schoepite and soddyite. In addition, the actinide release behavior of the two fuels appeared to be different for both the total amount of material released and the relative amount of each isotope released. This paper will focus on the detection and identification of the colloidal species observed in the leachate that was collected after each of the first two successive testing periods of approximately 60 days each. In addition, preliminary values for the total actinide release for these two periods are reported

  18. Actinides complexes in solvent extraction. The amide type of extractants

    International Nuclear Information System (INIS)

    Musikas, C.; Condamines, N.; Charbonnel, M.C.; Hubert, H.

    1989-01-01

    The N,N-dialkylamides and the N,N'-tetraalkyl. 2-alkyl 1,3-diamide propane are two promising classes of extractants which could replace advantageously the organophosphorus molecules for the separations of the actinide. The main advantages of the amides lie in their complete incinerability and the small interference of their radiolytic and hydrolytic degradation products for the processes. The actinide extraction chemistry with various amides is reviewed in this paper

  19. Design of unique pins for irradiation of higher actinides in a fast reactor

    International Nuclear Information System (INIS)

    Basmajian, J.A.; Birney, K.R.; Weber, E.T.; Adair, H.L.; Quinby, T.C.; Raman, S.; Butler, J.K.; Bateman, B.C.; Swanson, K.M.

    1982-03-01

    The actinides produced by transmutation reactions in nuclear reactor fuels are a significant factor in nuclear fuel burnup, transportation and reprocessing. Irradiation testing is a primary source of data of this type. A segmented pin design was developed which provides for incorporation of multiple specimens of actinide oxides for irradiation in the UK's Prototype Fast Reactor (PFR) at Dounreay Scotland. Results from irradiation of these pins will extend the basic neutronic and material irradiation behavior data for key actinide isotopes

  20. Gastrointestinal absorption of actinides: a review with special reference to primate data

    International Nuclear Information System (INIS)

    Burkart, W.

    1984-01-01

    Large scale geological burial of transuranic wastes from fission power production may expose segments of future generations to trace amounts of actinides in water and food, which, via gastrointestinal absorption, could result in internal doses of alpha radiation. Gastrointestinal absorption of actinide elements is a poorly understood process. Experimental studies, primarily using rodents, often produce ambiguous results with order of magnitude fluctuations in estimates of GI absorption. Since experimental conditions like the chemical form of the fed actinides or reducing and complexing capacity of the stomach content, influence the GI transfer factor in seemingly unpredictable ways, only a better understanding of events at the molecular level will enable more reliable predictions to be made of the organ burdens resulting from actinides passing through the digestive tract. From a review of the existing literature it is apparent that in vitro research data in the area of GI uptake mechanisms (i.e. transport mediated by ion carriers in body fluids and across cell membranes) are virtually non-existant. In view of the uncertainties linked to in vivo uptake experiment, models which approximate man, i.e. derived from non-human primate studies, should be the best choice of experimental systems in which to determine reliable estimates for gastrointestinal transfer factors of actinide elements. (Auth.)

  1. Minor Actinides Recycling in PWRs

    International Nuclear Information System (INIS)

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

    2006-01-01

    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)

  2. Contribution to the physical modeling of the actinide characterization by electron probe microanalysis

    International Nuclear Information System (INIS)

    Moy, Aurelien

    2014-01-01

    Electron probe microanalysis (EPMA) is used to quantify with a high accuracy the amount of different elements present on a sample of unknown composition. EPMA is largely used to quantify the amount of actinides present in fresh and irradiated fuels, to manage waste disposal and to date rocks. However, quantitative EPMA is not always possible to achieve for these materials due to the lack of suitable reference standards for the radionuclides. To overcome this difficulty, standard-less methods of analysis are employed with mean of virtual calculated standards. These calculated standards are generally obtained from empirical formulae based on experimental extrapolations or from theoretical calculations that require physical parameters which are poorly known as it is the case for the X-ray production cross section. The accurate knowledge of these cross sections is required in many applications such as in particle transport code and in Monte Carlo simulations. The computer simulations are widely used in the medical field and particularly in medical imaging and in electron beam therapy. In the field of astronomy, these data are used to perform simulations that predict the compositions of stars and galactic clouds, and the formation of planetary systems. In the present work, L- and M-shell absolute x-ray production cross sections were determined experimentally for elements lead, thorium and uranium by electron impact using ultrathin self-supporting targets with thickness varying from 0.2 to 8 nm. The measured cross sections have been compared, with the distorted-wave Born approximation (DWBA) calculated by Bote et al. and with the predictions of analytical formulae widely used in practical applications. For the conversion of inner-shell ionization cross sections into x-ray production cross sections, atomic relaxation parameters were extracted from the literature. The predictions of the DWBA calculations are in excellent agreement with our measured x-ray production cross

  3. Actinide uptake by transferrin and ferritin metalloproteins

    International Nuclear Information System (INIS)

    Den Auwer, C.; Llorens, I.; Moisy, Ph.; Vidaud, C.; Goudard, F.; Barbot, C.; Solari, P.L.; Funke, H.

    2005-01-01

    In order to better understand the mechanisms of actinide uptake by specific biomolecules, it is essential to explore the intramolecular interactions between the cation and the protein binding site. Although this has long been done for widely investigated transition metals, very few studies have been devoted to complexation mechanisms of actinides by active chelation sites of metalloproteins. In this field, X-ray absorption spectroscopy has been extensively used as a structural and electronic metal cation probe. The two examples that are presented here are related to two metalloproteins in charge of iron transport and storage in eukaryote cells: transferrin and ferritin. U(VI)O 2 2+ , Np(IV) and Pu(IV) have been selected because of their possible role as contaminant from the geosphere. (orig.)

  4. Fusion-driven actinide burner design study. Second quarterly progress report

    International Nuclear Information System (INIS)

    Chi, J.W.H.; Gold, R.E.; Holman, R.R.

    1975-11-01

    The Second Quarterly Progress Report summarizes the status at the mid-point of the conceptual design effort. The fusion driver continues to pose some of the principal design problems due to the necessity of advancing plasma engineering and technology for long pulse, high duty cycle operation. The development of credible design solutions to these problems is one of the major objectives of the study. The TF and OH coil designs have been modified to provide a more compact arrangement in the nose region of the TF coils and to ensure fully cryostable operation. A unique concept has been developed to effectively shield the TF coils from the poloidal fields. A vacuum vessel concept which separates the functions for sustaining the differential pressure load and for sealing the vacuum system is described. The thickness of the blanket has been decreased to reduce the power density and the actinide inventory. Determination and presentation of actinide depletion characteristics represents a major element thus far in the study and is a principal objective. Evaluation of the changes in the hazard only during irradiation proved to be an inadequate measure of the reduction in long term hazards due to the importance of radioactive daughter products which appear much later in time. Therefore, comparisons have been made of long term decay characteristics before and after irradiation in the actinide burner. It has also been noted that some of the actinides that are produced during irradiation have beneficial applications as radioisotopic power sources. These and other considerations suggest that alternate approaches to assessing the waste management problem be considered to develop a meaningful perspective on long term hazards from the actinides

  5. Fusion-driven actinide burner design study. Second quarterly progress report

    Energy Technology Data Exchange (ETDEWEB)

    Chi, J.W.H.; Gold, R.E.; Holman, R.R.

    1975-11-01

    The Second Quarterly Progress Report summarizes the status at the mid-point of the conceptual design effort. The fusion driver continues to pose some of the principal design problems due to the necessity of advancing plasma engineering and technology for long pulse, high duty cycle operation. The development of credible design solutions to these problems is one of the major objectives of the study. The TF and OH coil designs have been modified to provide a more compact arrangement in the nose region of the TF coils and to ensure fully cryostable operation. A unique concept has been developed to effectively shield the TF coils from the poloidal fields. A vacuum vessel concept which separates the functions for sustaining the differential pressure load and for sealing the vacuum system is described. The thickness of the blanket has been decreased to reduce the power density and the actinide inventory. Determination and presentation of actinide depletion characteristics represents a major element thus far in the study and is a principal objective. Evaluation of the changes in the hazard only during irradiation proved to be an inadequate measure of the reduction in long term hazards due to the importance of radioactive daughter products which appear much later in time. Therefore, comparisons have been made of long term decay characteristics before and after irradiation in the actinide burner. It has also been noted that some of the actinides that are produced during irradiation have beneficial applications as radioisotopic power sources. These and other considerations suggest that alternate approaches to assessing the waste management problem be considered to develop a meaningful perspective on long term hazards from the actinides.

  6. Determination of actinides using ICP-SFMS

    International Nuclear Information System (INIS)

    Nygren, Ulrika

    2006-01-01

    Interest in the determination of the actinides using ICP-MS has steadily increased with the development of systems capable of more sensitive and precise measurements. However, the analysis of less abundant actinides such as Pu and Am is not straightforward due to the need for chemical separation of these elements prior to determination. In many applications of mass-spectrometric actinide analysis, isotope ratio measurements are important, either for the analysis of the isotopic composition of, e.g., U or Pu in the sample, or for quantitative determinations using isotope dilution mass spectrometry. In order to achieve high precision and accuracy in an isotope ratio measurement, corrections for instrumentally induced systematic errors, e.g., due to dead-time and mass bias, need to be considered. In this thesis, different aspects of actinide analysis using ICP-SFMS have been addressed. In Papers I and III, separation procedures based on solid phase extraction for Pu, Am and U were developed and evaluated with respect to chemical yield and separation from elements causing spectral interferences. Applications of the analytical procedures developed comprised measurement of the 240 Pu/ 2 3 9Pu ratio in environmental reference materials, and age determination of Pu based on the 241 Pu/ 241 Am and 240 Pu/ 236 U ratios. In the application of different separation procedures for Pu, previously unidentified spectral interferences were discovered. In Paper II, these interferences were identified as lanthanide phosphate ions and the composition and formation of these species with respect to different instrumental parameters were further examined. Due to the importance of precise and accurate isotope ratio determination, a thorough investigation of the instrumental dead time of an ICP-SFMS system was performed. The dead time was evaluated via both isotope ratio and electronic measurements of the output from the detector amplifier. It was found that the overall uncertainty in ratio

  7. Preliminary Study for Inventories of Minor Actinides in Thorium Molten Salt Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Wie; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    It has different characteristic with the conventional reactors which use a solid fuel. It can continually supply the fuel by online refueling and reprocessing of minor actinides so that those can be separated and eliminated from the reactor. The MSR maintains steady state except initial stage and the reactor becomes stable. In this research, considering online refueling, bubbling and reprocessing, the basic concept for evaluation of the inventory of minor actinide in the molten salt reactor is driven using the Bateman equation. The simulation results, where REM and MCNP code from CNRS (Centre National de la Recherche Scientifique) applied to the concept equation are analyzed. The analysis of the basic concept was carried out for evaluation of the inventory of the minor actinides in MSR. It was thought that the inventories of the minor actinides should be evaluated by solving the modified Bateman equation due to the MSR characteristic of online refueling, chemical reprocessing and bubbling.

  8. Preliminary Study for Inventories of Minor Actinides in Thorium Molten Salt Reactor

    International Nuclear Information System (INIS)

    Lee, Choong Wie; Kim, Hee Reyoung

    2015-01-01

    It has different characteristic with the conventional reactors which use a solid fuel. It can continually supply the fuel by online refueling and reprocessing of minor actinides so that those can be separated and eliminated from the reactor. The MSR maintains steady state except initial stage and the reactor becomes stable. In this research, considering online refueling, bubbling and reprocessing, the basic concept for evaluation of the inventory of minor actinide in the molten salt reactor is driven using the Bateman equation. The simulation results, where REM and MCNP code from CNRS (Centre National de la Recherche Scientifique) applied to the concept equation are analyzed. The analysis of the basic concept was carried out for evaluation of the inventory of the minor actinides in MSR. It was thought that the inventories of the minor actinides should be evaluated by solving the modified Bateman equation due to the MSR characteristic of online refueling, chemical reprocessing and bubbling

  9. Actinides reduction by recycling in a thermal reactor; Reduccion de actinidos por reciclado en un reactor termico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Martinez C, E.; Balboa L, H., E-mail: ramon.ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    This work is directed towards the evaluation of an advanced nuclear fuel cycle in which radioactive actinides could be recycled to remove most of the radioactive material; firstly a production reference of actinides in standard nuclear fuel of uranium at the end of its burning in a BWR reactor is established, after a fuel containing plutonium is modeled to also calculate the actinides production in MOX fuel type. Also it proposes a design of fuel rod containing 6% of actinides in a matrix of uranium from the tails of enrichment, then four standard uranium fuel rods are replaced by actinides rods to evaluate the production and transmutation thereof, the same procedure was performed in the fuel type MOX and the end actinide reduction in the fuel was evaluated. (Author)

  10. High flux transmutation of fission products and actinides

    International Nuclear Information System (INIS)

    Gerasimov, A.; Kiselev, G.; Myrtsymova, L.

    2001-01-01

    Long-lived fission products and minor actinides accumulated in spent nuclear fuel of power reactors comprise the major part of high level radwaste. Their incineration is important from the point of view of radwaste management. Transmutation of these nuclides by means of neutron irradiation can be performed either in conventional nuclear reactors, or in specialized transmutation reactors, or in ADS facilities with subcritical reactor and neutron source with application of proton accelerator. Different types of transmutation nuclear facilities can be used in order to insure optimal incineration conditions for radwaste. The choice of facility type for optimal transmutation should be based on the fundamental data in the physics of nuclide transformations. Transmutation of minor actinides leads to the increase of radiotoxicity during irradiation. It takes significant time compared to the lifetime of reactor facility to achieve equilibrium without effective transmutation. High flux nuclear facilities allow to minimize these draw-backs of conventional facilities with both thermal and fast neutron spectrum. They provide fast approach to equilibrium and low level of equilibrium mass and radiotoxicity of transmuted actinides. High flux facilities are advantageous also for transmutation of long-lived fission products as they provide short incineration time

  11. Safe management of actinides in the nuclear fuel cycle: Role of mineralogy; La gestion des actinides dans le cycle du combustible nucleaire: le role de la mineralogie

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C. [Department of Nuclear Engineering and Radiological Sciences, Department of Geological Sciences, Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States)

    2011-02-15

    During the past 60 years, more than 1800 metric tonnes of Pu, and substantial quantities of the 'minor' actinides, such as Np, Am and Cm, have been generated in nuclear reactors. Some of these transuranium elements can be a source of energy in fission reactions (e.g., {sup 239}Pu), a source of fissile material for nuclear weapons (e.g., {sup 239}Pu and {sup 237}Np), and of environmental concern because of their long-half lives and radiotoxicity (e.g., {sup 239}Pu and {sup 237}Np). There are two basic strategies for the disposition of these heavy elements: (1) to 'burn' or transmute the actinides using nuclear reactors or accelerators; (2) to 'sequester' the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of actinide-bearing minerals, especially isometric pyrochlore, A{sub 2}B{sub 2}O{sub 7} (A rare earths; B = Ti, Zr, Sn, Hf), for the immobilization of actinides, particularly plutonium, both as inert matrix fuels and nuclear waste forms. Systematic studies of rare-earth pyrochlores have led to the discovery that certain compositions (B = Zr, Hf) are stable to very high doses of alpha-decay event damage. Recent developments in our understanding of the properties of heavy element solids have opened up new possibilities for the design of advanced nuclear fuels and waste forms. (author)

  12. Electronic structure and properties of rare earth and actinide intermetallics

    International Nuclear Information System (INIS)

    Kirchmayr, H.R.

    1984-01-01

    There are 188 contributions, experimental and theoretical, a few on rare earth and actinide elements but mostly on rare earth and actinide intermetallic compounds and alloys. The properties dealt with include 1) crystal structure, 2) magnetic properties and magnetic structure, 3) magnetic phase transformations and valence fluctuations, 4) electrical properties and superconductivity and their temperature, pressure and magnetic field dependence. A few papers deal with crystal growth and novel measuring methods. (G.Q.)

  13. Hydration numbers of trivalent lanthanide and actinide ions

    International Nuclear Information System (INIS)

    David, F.; Fourest, B.; Duplessis, J.

    1987-01-01

    Investigations on the structure of actinide aquo ions and determination of hydration numbers have to be studied, essentially, through radiochemical methods. They measured the transport numbers, diffusion coefficient D by the open end capillary method and ionic mobility u by electrophoresis. Both methods show a discontinuity in the transport number corresponding to the crystallographic radius of Eu 3+ or Bk 3+ ion. They deduced the volume of the actinide aquo ions, and the coordination number in the primary sphere. From calculations of the electrostriction phenomenon in the vicinity of central ion, they obtained effective volume of the water molecules and the dynamic hydration number corresponding to the second hydration sphere

  14. Observation of large scissors resonance strength in actinides.

    Science.gov (United States)

    Guttormsen, M; Bernstein, L A; Bürger, A; Görgen, A; Gunsing, F; Hagen, T W; Larsen, A C; Renstrøm, T; Siem, S; Wiedeking, M; Wilson, J N

    2012-10-19

    The orbital M1 scissors resonance has been measured for the first time in the quasicontinuum of actinides. Particle-γ coincidences are recorded with deuteron and (3)He-induced reactions on (232)Th. The residual nuclei (231,232,233)Th and (232,233) Pa show an unexpectedly strong integrated strength of B(M1)=11-15μ(n)(2) in the E(γ)=1.0-3.5 MeV region. The increased γ-decay probability in actinides due to scissors resonance is important for cross-section calculations for future fuel cycles of fast nuclear reactors and may also have an impact on stellar nucleosynthesis.

  15. Actinide Partitioning and Transmutation Program. Progress report, April 1--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Tedder, D. W.; Blomeke, J. O. [comps.

    1977-10-01

    Experimental work on the 16 tasks comprising the Actinide Partitioning and Transmutation Program was continued. Summaries of work are given on Purex Process modifications, actinide recovery, Am-Cm recovery, radiation effects on ion exchangers, LMFBR transmutation studies, thermal reactor transmutation studies, fuel cycle studies, and partitioning-transmutation evaluation. (JRD)

  16. Photochemical reactions of actinide ions

    International Nuclear Information System (INIS)

    Tomiyasu, Hiroshi

    1995-01-01

    This paper reviews the results of photochemical studies of actinide ions, which have been performed in our research group for past several years as follows: I) behavior of the excited uranyl(VI) ion; II) photo-reductions of the uranyl ion with organic and inorganic compounds; III) photo-oxidations of uranium(IV) and plutonium(III) in nitric acid solutions. (author)

  17. Angular overlap model in actinides

    International Nuclear Information System (INIS)

    Gajek, Z.; Mulak, J.

    1991-01-01

    Quantitative foundations of the Angular Overlap Model in actinides based on ab initio calculations of the crystal field effect in the uranium (III) (IV) and (V) ions in various crystals are presented. The calculations justify some common simplifications of the model and fix up the relations between the AOM parameters. Traps and limitations of the AOM phenomenology are discussed

  18. Angular overlap model in actinides

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, Z.; Mulak, J. (Polska Akademia Nauk, Wroclaw (PL). Inst. Niskich Temperatur i Badan Strukturalnych)

    1991-01-01

    Quantitative foundations of the Angular Overlap Model in actinides based on ab initio calculations of the crystal field effect in the uranium (III) (IV) and (V) ions in various crystals are presented. The calculations justify some common simplifications of the model and fix up the relations between the AOM parameters. Traps and limitations of the AOM phenomenology are discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    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

  20. In vivo measurement of actinides in the human lung

    International Nuclear Information System (INIS)

    Anderson, A.L.; Campbell, G.W.; Griffith, R.V.

    1979-01-01

    The problems associated with the in vivo detection and measurement of actinides in the human lung are discussed together with various measurement systems currently in use. In particular, the methods and calibration procedures employed at the Lawrence Livermore Laboratory, namely, the use of twin Phoswich detectors and a new, more realistic, tissue-equivalent phantom, are described. Methods for the measurement of chest-wall thickness, fat content, and normal human background counts are also discussed. Detection-efficiency values and minimum detectable activity estimates are given for three common actinides, 238 Pu, 239 Pu, and 241 Am

  1. Physics studies of higher actinide consumption in an LMR

    International Nuclear Information System (INIS)

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

    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

  2. Experimental studies of narrow band effects in the actinides

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, M.B.

    1976-01-01

    In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds.

  3. Experimental studies of narrow band effects in the actinides

    International Nuclear Information System (INIS)

    Brodsky, M.B.

    1976-01-01

    In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds

  4. Physics studies of higher actinide consumption in an LMR

    International Nuclear Information System (INIS)

    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. Safe management of actinides in the nuclear fuel cycle: Role of mineralogy

    International Nuclear Information System (INIS)

    Ewing, R.C.

    2011-01-01

    During the past 60 years, more than 1800 metric tonnes of Pu, and substantial quantities of the 'minor' actinides, such as Np, Am and Cm, have been generated in nuclear reactors. Some of these transuranium elements can be a source of energy in fission reactions (e.g., 239 Pu), a source of fissile material for nuclear weapons (e.g., 239 Pu and 237 Np), and of environmental concern because of their long-half lives and radiotoxicity (e.g., 239 Pu and 237 Np). There are two basic strategies for the disposition of these heavy elements: (1) to 'burn' or transmute the actinides using nuclear reactors or accelerators; (2) to 'sequester' the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of actinide-bearing minerals, especially isometric pyrochlore, A 2 B 2 O 7 (A rare earths; B = Ti, Zr, Sn, Hf), for the immobilization of actinides, particularly plutonium, both as inert matrix fuels and nuclear waste forms. Systematic studies of rare-earth pyrochlores have led to the discovery that certain compositions (B = Zr, Hf) are stable to very high doses of alpha-decay event damage. Recent developments in our understanding of the properties of heavy element solids have opened up new possibilities for the design of advanced nuclear fuels and waste forms. (author)

  6. Extraction of tetravalent and hexavalent actinide ions by tetraheptylammonium nitrate

    International Nuclear Information System (INIS)

    Swarup, Rajendra; Patil, S.K.

    1977-01-01

    Extraction of Th(IV), Np(IV), Pu(IV), U(VI), Np(VI), and Pu(VI) by tetraheptylammonium nitrate in Solvesso-100 has been studied from nitric acid medium. Attempts were made to identify the complex species in the organic phase by studying the dependence of the distribution coefficient of the actinide on amine concentration and taking the absorption spectra of the organic phase containing actinide ions. A compound tetraheptylammonium trinitratodioxouranate (VI) has been isolated and characterised. (author)

  7. Methods for separating actinides from reprocessing and refabrication plant wastes

    International Nuclear Information System (INIS)

    Tedder, D.W.; Finney, B.C.; Blomeke, J.O.

    1979-01-01

    Chemical processing flowsheets have been developed to partition actinides from all actinide-bearing LWR fuel reprocessing and refabrication plant wastes. These wastes include high-activity-level liquids, scrap recovery liquors, HEPA filters and incinerator ashes, and chemical salt wastes such as sodium carbonate scrub solutions, detergent cleanup streams, and alkaline off-gas scrubber liquors. The separations processes that were adopted for this study are based on solvent extraction, cation exchange chromatography, and leaching with Ce 4+ -HNO 3 solution

  8. Semi-microdetermination of nitrogen in actinide compounds by Dumas method

    International Nuclear Information System (INIS)

    Nagar, M.S.; Ruikar, P.B.; Subramanian, M.S.

    1986-01-01

    This report describes the application of the Dumas method for the semi-micro determination of nitrogen in actinide compounds and actinide complexes with organic ligands. The usual set up has been modified to make it adaptable for glove box operations. The carbon dioxide generator and nitrometer assemblies were located outside the glove box while the reaction tube and combustion furnaces were housed inside. The nitrogen gas collected in the nitrometer was read with the help of a travelling microscope with a vernier attachment fitted in front of the nitrometer burette. The set up was standardised using acetanilide and employed for the determination of nirtogen in various substances such as uranium nitride, and a variety of substituted quinoline and pyrazolone derivatives of actinides as well as some ternary uranium-PMBR-sulphoxide complexes. Full details of the technique and the analytical data obtained are contained in this report. (author)

  9. Actinide concentrations in tissues from cattle grazing a contaminated range

    International Nuclear Information System (INIS)

    Smith, D.D.; Bernhardt, D.E.

    1977-01-01

    Actinide concentrations in the tissues of beef animals periodically sacrificed and sampled during a 3-year grazing study on a plutonium-contaminated range of the Nevada Test Site are discussed. Actinide concentrations in the skeletons of the cows originally introduced into the study areas showed little increase with increased time of exposure, while those of animals born in the study areas showed a continued upward trend with time. Plutonium-239/americium-241 ratios in tissues and ingesta suggest little differentiation in the uptake of these radionuclides. However, the plutonium-239/plutonium-238 ratios indicate that plutonium-238 is more readily absorbed. The gonadal concentrations of the actinides were significantly higher than those of blood and muscle and approached those of bone. These data indicate that consideration should be given to the plutonium-239 dose to gonads as well as that to bone, liver, and lungs of man

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

    Science.gov (United States)

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

    1984-08-01

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

  11. The thermodynamic functions of gaseous actinide elements

    International Nuclear Information System (INIS)

    Rand, M.H.

    1979-01-01

    The actinide gases have large number of unobserved energy states - up to 3 x 10 6 for Pu(g) - which could contribute to the partition function and its derivatives, from which the thermal functions of these gases are calculated. Existing compilations have simply ignored these levels. By making reasonable assumptions as to the distribution of these energy states, their effect on the functions can be calculated. It is concluded that the existing compilations will be inadequate above approximately 2000K. The effect is particularly marked on the heat capacity. For example, when unobserved levels for Pu(g) are included, the heat capacity of Pu(g) reaches a maximum value of more than 12R at 3200K. Similar considerations will apply to the gaseous actinide ions. (orig.) [de

  12. Synthesis and Evaluation of new Polyfunctional Molecules for Group Actinide Extraction

    International Nuclear Information System (INIS)

    Marie, C.

    2009-10-01

    The aim of this project is to design new extracting molecules for spent nuclear fuel reprocessing. In order to minimize the long-term residual radiotoxicity of the waste, the GANEX process is an option based on homogeneous recycling of actinides. All actinides (U, Np, Pu, Am, Cm), present in a highly acidic aqueous solution, would be extracted together and separated from fission products (especially from lanthanides) using liquid-liquid extraction. In this context, twenty new bi-topic ligands constituted of a nitrogen poly-aromatic unit functionalized by amide groups were synthesized. Liquid-liquid extraction tests with these ligands dissolved alone in the organic phase show that N, N, N', N'-tetra-alkyl-6, 6''(2, 2':6', 2''-terpyridine)-diamides are able to selectively extract actinides at different oxidation states (Np(V et VI), U(VI), Pu(IV), Am(III), Cm(III)) from an aqueous solution 3M HNO 3 . Nevertheless, actinides(III) are poorly extracted. According to crystallographic structures of complexes with Nd(III) and U(VI) determined by X-rays diffraction, these ligands are penta-dentate. In solution (methanol), complexes stoichiometries (1:1) of Nd(III), U(VI) and Pu(IV) were determined by electro-spray ionization mass spectrometry. Stability constants, evaluated by UV-visible spectrophotometry in MeOH/H 2 O solutions, confirm the selectivity of ligands toward actinides(III) with respect to lanthanides(III). Associate to nuclear magnetic resonance experiments and DFT calculations (Density Functional Theory), a better knowledge of their coordination mode was achieved. (author)

  13. Zirconium behaviour during electrorefining of actinide-zirconium alloy in molten LiCl-KCl on aluminium cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Meier, R. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Heidelberg University, Institute of Physical Chemistry, Im Neuenheimer Feld 253, Heidelberg 69120 (Germany); Souček, P., E-mail: Pavel.Soucek@ec.europa.eu [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Malmbeck, R.; Krachler, M.; Rodrigues, A.; Claux, B.; Glatz, J.-P. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Fanghänel, Th. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Heidelberg University, Institute of Physical Chemistry, Im Neuenheimer Feld 253, Heidelberg 69120 (Germany)

    2016-04-15

    A pyrochemical electrorefining process for the recovery of actinides from metallic nuclear fuel based on actinide-zirconium alloys (An–Zr) in a molten salt is being investigated. In this process actinides are group-selectively recovered on solid aluminium cathodes as An–Al alloys using a LiCl–KCl eutectic melt at a temperature of 450 °C. In the present study the electrochemical behaviour of zirconium during electrorefining was investigated. The maximum amount of actinides that can be oxidised without anodic co-dissolution of zirconium was determined at a selected constant cathodic current density. The experiment consisted of three steps to assess the different stages of the electrorefining process, each of which employing a fresh aluminium cathode. The results indicate that almost a complete dissolution of the actinides without co-dissolution of zirconium is possible under the applied experimental conditions. - Highlights: • Recovery of actinides was shown by electrorefining of U/Pu–Zr alloys in LiCl–KCl. • Constant current density of 20 mA/cm{sup 2} is applied. • Most of the actinides were dissolved avoiding zirconium co-dissolution. • Deterioration of the deposit quality by a small amount of co-deposited Zr is not observed.

  14. Photoionization cross-sections of ground and excited valence levels of actinides

    Directory of Open Access Journals (Sweden)

    Yarzhemsky Victor G.

    2012-01-01

    Full Text Available The photoionization cross-sections of ground and excited atomic states of actinide atoms were calculated by the Dirac-Fock-Slater method for two excitation energies of X-ray radiation (1253.6 eV and 1486.6 eV. These data are required for calculations of intensities of X-ray photoelectron spectra of actinide compound valence bands and interpretation of experimental spectra.

  15. Crystalline matrices for the immobilization of plutonium and actinides

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, E.B.; Burakov, E.E.; Galkin, Ya.B.; Starchenko, V.A.; Vasiliev, V.G. [V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    1996-05-01

    The management of weapon plutonium, disengaged as a result of conversion, is considered together with the problem of the actinide fraction of long-lived high level radioactive wastes. It is proposed to use polymineral ceramics based on crystalline host-phases: zircon ZrSiO{sub 4} and zirconium dioxide ZrO{sub 2}, for various variants of the management of plutonium and actinides (including the purposes of long-term safe storage or final disposal from the human activity sphere). It is shown that plutonium and actinides are able to form with these phases on ZrSiO{sub 4} and ZrO{sub 2} was done on laboratory level by the hot pressing method, using the plasmochemical calcination technology. To incorporate simulators of plutonium into the structure of ZrSiO{sub 4} and ZrO{sub 2} in the course of synthesis, an original method developed by the authors as a result of studying the high-uranium zircon (Zr,U) SiO{sub 4} form Chernobyl {open_quotes}lavas{close_quotes} was used.

  16. The actinide beamline - A new AMS facility at ANTARES

    International Nuclear Information System (INIS)

    Hotchkis, M.A.C.; Lee, P.J.; Mino, N.

    1998-01-01

    At the ANTARES accelerator a new beamline has been commissioned, incorporating new magnetic and electrostatic analysers, to optimise the efficiency for Actinides detection by Accelerator Mass Spectrometry. The detection of Actinides, particularly the isotopic ratios of uranium and plutonium, provide unique signatures for nuclear safeguards purposes. We are currently engaged in a project to evaluate the application of AMS to the measurement of Actinides in environmental samples for nuclear safeguards. Measurement of 236 U is of particular interest as a means of tracing the anthropogenic component of uranium. 236 U is expected to be present in natural samples at an extremely low level ( 236 U: 238 U ratio ∼10 -10 ). It has recently been demonstrated that AMS has sufficient sensitivity to detect 236 U at this level. The principal components of the new beamline include: an electrostatic quadrupole, a 12 deg electrostatic deflector, a 90 deg electrostatic analyser, a multi-isotope detection system including ion counters and Faraday cups. The beamline was completed in September 1998 and initial tests have been performed with iodine samples

  17. Electronic structure and correlation effects in actinides

    International Nuclear Information System (INIS)

    Albers, R.C.

    1998-01-01

    This report consists of the vugraphs given at a conference on electronic structure. Topics discussed are electronic structure, f-bonding, crystal structure, and crystal structure stability of the actinides and how they are inter-related

  18. The reprocessing-recycling of spent nuclear fuel. Actinides separation - Application to wastes management; Le traitement-recyclage du combustible nucleaire use. La separation des actinides - Application a la gestion des dechets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    After its use in the reactor, the spent fuel still contains lot of recoverable material for an energetic use (uranium, plutonium), but also fission products and minor actinides which represent the residues of nuclear reactions. The reprocessing-recycling of the spent fuel, as it is performed in France, implies the chemical separation of these materials. The development and the industrial implementation of this separation process represent a major contribution of the French science and technology. The reprocessing-recycling allows a good management of nuclear wastes and a significant saving of fissile materials. With the recent spectacular rise of uranium prices, this process will become indispensable with the development of the next generation of fast neutron reactors. This book takes stock of the present and future variants of the chemical process used for the reprocessing of spent fuels. It describes the researches in progress and presents the stakes and recent results obtained by the CEA. content: the separation of actinides, a key factor for a sustainable nuclear energy; the actinides, a discovery of the 20. century; the radionuclides in nuclear fuels; the aquo ions of actinides; some redox properties of actinides; some complexing properties of actinide cations; general considerations about treatment processes; some characteristics of nuclear fuels in relation with their reprocessing; technical goals and specific constraints of the PUREX process; front-end operations of the PUREX process; separation and purification operations of the PUREX process; elaboration of finite products in the framework of the PUREX process; management and treatment of liquid effluents; solid wastes of the PUREX process; towards a joint management of uranium and plutonium: the COEX{sup TM} process; technical options of treatment and recycling techniques; the fuels of generation IV reactors; front-end treatment processes of advanced fuels; hydrometallurgical processes for future fuel

  19. Calculation of binary phase diagrams between the actinide elements, rare earth elements, and transition metal elements

    International Nuclear Information System (INIS)

    Selle, J.E.

    1992-01-01

    Attempts were made to apply the Kaufman method of calculating binary phase diagrams to the calculation of binary phase diagrams between the rare earths, actinides, and the refractory transition metals. Difficulties were encountered in applying the method to the rare earths and actinides, and modifications were necessary to provide accurate representation of known diagrams. To calculate the interaction parameters for rare earth-rare earth diagrams, it was necessary to use the atomic volumes for each of the phases: liquid, body-centered cubic, hexagonal close-packed, and face-centered cubic. Determination of the atomic volumes of each of these phases for each element is discussed in detail. In some cases, empirical means were necessary. Results are presented on the calculation of rare earth-rare earth, rare earth-actinide, and actinide-actinide diagrams. For rare earth-refractory transition metal diagrams and actinide-refractory transition metal diagrams, empirical means were required to develop values for the enthalpy of vaporization for rare earth elements and values for the constant (C) required when intermediate phases are present. Results of using the values determined for each element are presented

  20. Search for proton emission in {sup 54}Ni and multi-nucleon transfer reactions in the actinide region

    Energy Technology Data Exchange (ETDEWEB)

    Geibel, Kerstin

    2012-06-15

    The first part of the thesis presents the investigation of fusion-evaporation reactions in order to verify one-proton emission from the isomeric 10{sup +} state in the proton rich nucleus {sup 54}Ni. Between the years 2006 and 2009 a series of experimental studies were performed at the Tandem accelerator in the Institut fuer Kernphysik (IKP), University of Cologne. These experiments used fusion-evaporation reactions to populate {sup 54}Ni via the two-neutron-evaporation channel of the compound nucleus {sup 56}Ni. The cross section for the population of the ground state of {sup 54}Ni was predicted to be in orders of microbarn. This required special care with respect to the sensitivity of the experimental setup, which consisted of a double-sided silicon-strip detector (DSSSD), a neutron-detector array and HPGe detectors. In two experiments the excitation functions of the reactions ({sup 32}S+{sup 24}Mg) and ({sup 28}Si+{sup 28}Si) were determined to find the optimal experimental conditions for the population of {sup 54}Ni. A final experiment employed a {sup 28}Si beam at an energy of 70 MeV, impinging on a {sup 28}Si target. With a complex analysis it is possible to obtain a background-free energy spectrum of the DSSSD. An upper cross section limit for the population of the 10{sup +} state in {sup 54}Ni is established at σ({sup 54}Ni(10{sup +})) ≤ (13.9 ± 7.8) nbarn. In the second part of the thesis the population of actinide nuclei by multi-nucleon transfer reactions is investigated. Two experiments, performed in 2007 and 2008 at the CLARA-PRISMA setup at the Laboratori Nazionali di Legnaro, are analyzed with respect to the target-like reaction products. In both experiments {sup 238}U was used as target. A {sup 70}Zn beam with 460 MeV and a {sup 136}Xe beam with 926 MeV, respectively, impinged on the target, inducing transfer reactions. Kinematic correlations between the reaction partners are used to obtain information on the unobserved target-like reaction