WorldWideScience

Sample records for americium

  1. 1976 Hanford americium accident

    International Nuclear Information System (INIS)

    Heid, K.R.; Breitenstein, B.D.; Palmer, H.E.; McMurray, B.J.; Wald, N.

    1979-01-01

    This report presents the 2.5-year medical course of a 64-year-old Hanford nuclear chemical operator who was involved in an accident in an americium recovery facility in August 1976. He was heavily externally contaminated with americium, sustained a substantial internal deposition of this isotope, and was burned with concentrated nitric acid and injured by flying debris about the face and neck. The medical care given the patient, including the decontamination efforts and clinical laboratory studies, are discussed. In-vivo measurements were used to estimate the dose rates and the accumulated doses to body organs. Urinary and fecal excreta were collected and analyzed for americium content. Interpretation of these data was complicated by the fact that the intake resulted both from inhalation and from solubilization of the americium embedded in facial tissues. A total of 1100 μCi was excreted in urine and feces during the first 2 years following the accident. The long-term use of diethylenetriaminepentate (DTPA), used principally as the zinc salt, is discussed including the method, route of administration, and effectiveness. To date, the patient has apparently experienced no complications attributable to this extensive course of therapy, even though he has been given approximately 560 grams of DTPA. 4 figures, 1 table

  2. Chemistry of americium

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1976-01-01

    Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

  3. Americium in water and sediments

    International Nuclear Information System (INIS)

    Coughtrey, P.J.; Jackson, D.; Jones, C.H.; Thorne, M.C.

    1984-01-01

    Data for americium 241 in aquatic environments are presented derived from areas contaminated solely by global fallout, and also from areas contaminated by radioactive waste discharges. For several water bodies, in particular the Mediterranean, comprehensive data are given characterising the inputs, distribution, geochemical behaviour and biological availability of americium. Many data are also reported for concentrations of americium in North European coastal waters (e.g. English Channel, North Sea, Irish Sea, Baltic Sea, Barents Sea and the Eastern Atlantic). Much of the discussion in this section is in terms of the behaviour of americium relative to plutonium. (Auth.)

  4. Recycling of americium

    International Nuclear Information System (INIS)

    Hagstroem, Ingela

    1999-12-01

    Separation of actinides from spent nuclear fuel is a part of the process of recycling fissile material. Extracting agents for partitioning the high level liquid waste (HLLW) from conventional PUREX reprocessing is studied. The CTH-process is based on three consecutive extraction cycles. In the first cycle protactinium, uranium, neptunium and plutonium are removed by extraction with di-2-ethylhexyl-phosphoric acid (HDEHP) from a 6 M nitric acid HLLW solution. Distribution ratios for actinides, fission products and corrosion products between HLLW and 1 M HDEHP in an aliphatic diluent have been investigated. To avoid addition of chemicals the acidity is reduced by a tributylphosphate (TBP) extraction cycle. The distribution ratios of elements present in HLLW have been measured between 50 % TBP in an aliphatic diluent and synthetic HLLW in range 0.1-6 M nitric acid. In the third extraction cycle americium and curium are extracted. To separate trivalent actinides from lanthanides a method based on selective stripping of the actinides from 1 M HDEHP is proposed. The aqueous phase containing ammonia, diethylenetriaminepentaacetic acid (DTPA) and lactic acid is recycled in a closed loop after reextraction of the actinides into a second organic phase also containing 1 M HDEHP. Distribution ratios for americium and neodymium have been measured at varying DTPA and lactic acid concentrations and at varying pH. Nitrogen-donor reagents have been shown to have a potential to separate trivalent actinides from lanthanides. 2,2':6,2''-terpyridine as extractant follows the CHON-principle and can in synergy with 2-bromodecanoic acid separate americium from europium. Distribution ratios for americium and europium, in the range of 0.02-0.12 M nitric acid, between nitric acid and 0.02 M terpyridine with 1 M 2-bromodecanoic acid in tert-butylbenzene (TBB) was investigated. Comparison with other nitrogen-donor reagents show that increasing lipophilicity of the molecule, by substitution of

  5. Americium-241 - ED 4308

    International Nuclear Information System (INIS)

    Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Le Guen, B.; Pihet, P.; Rannou, A.; Vidal, E.

    2012-12-01

    This sheet presents the characteristics of Americium-241, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of wastes and effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the road transport of Americium-241, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

  6. Plutonium and americium separation from salts

    International Nuclear Information System (INIS)

    Hagan, P.G.; Miner, F.J.

    1976-01-01

    Salts or materials containing plutonium and americium are dissolved in hydrochloric acid, heated, and contacted with an alkali metal carbonate solution to precipitate plutonium and americium carbonates which are thereafter readily separable from the solution

  7. Transmutation of Americium in Fast Neutron Facilities

    OpenAIRE

    Zhang, Youpeng

    2011-01-01

    In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on c...

  8. Metabolism of americium-241 in dairy animals

    International Nuclear Information System (INIS)

    Sutton, W.W.; Patzer, R.G.; Mullen, A.A.; Hahn, P.B.; Potter, G.D.

    1978-10-01

    Groups of lactating cows and goats were used to examine americium-241 metabolism in dairy animals. Following either single oral or intravenous nuclide doses, samples of milk, urine, blood, and feces were taken over a 168-hr collection period and the americium concentrations were determined by gamma counting. Gastrointestinal uptake of americium by both cows and goats was estimated to be 0.014% of the respective oral doses. The cumulative percentage of oral dose transported to milk and urine was 4.4 x 10 -4 and 1.1 x 10 -3 respectively for cows and 4.4 x 10 -3 and 1.2 x 10 -3 respectively for goats. The relatively high americium concentrations noted in caprine milk following the oral doses are discussed. Plasma concentrations of americium decreased rapidly following all intravenous injections. The average percentage of injected americium transferred to milk, urine, and feces was 3, 6, and 2% respectively for cows and 2, 4, and 2% respectively for goats. In both intravenously dosed groups, approximately 30% of all americium released from the body was found in the urine during the first 24 hrs after injection. All animals were sacrificed 8 to 9 days after dosing. Bovine bone retained the greatest fraction of the administered dose followed by the liver. However, liver retained the greatest amount of americium in the goats following both oral and intravenous doses. Comparisons are presented between americium-241 and plutonium-238 transport in dairy cows

  9. Production of americium isotopes in France

    International Nuclear Information System (INIS)

    Koehly, G.; Bourges, J.; Madic, C.; Nguyen, T.H.; Lecomte, M.

    1984-12-01

    The program of productions of americium 241 and 243 isotopes is based respectively on the retreatment of aged plutonium alloys or plutonium dioxide and on the treatment of plutonium targets irradiated either in CELESTIN reactors for Pu-Al alloys or OSIRIS reactor for plutonium 242 dioxide. All the operations, including americium final purifications, are carried out in hot cells equipped with remote manipulators. The chemical processes are based on the use of extraction chromatography with hydrophobic SiO 2 impregnated with extracting agents. Plutonium targets and aged plutonium alloys are dissolved in nitric acid using conventional techniques while plutonium dioxide dissolutions are performed routine at 300 grams scale with electrogenerated silver II in 4M HNO 3 at room temperature. The separation between plutonium and americium is performed by extraction of Pu(IV) either on TBP/SiO 2 or TOAHNO 3 /SiO 2 column. Americium recovery from waste streams rid of plutonium is realized by chromatographic extraction of Am(III) using mainly TBP and episodically DHDECMP as extractant. The final purification of both americium isotopes uses the selective extraction of Am(VI) on HDDiBMP/SiO 2 column at 60 grams scale. Using the overall process a total amount of 1000 grams of americium 241 and 100 grams of americium 243 has been produced nowadays and the AmO 2 final product indicates a purity better than 98.5%

  10. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-22

    Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

  11. Formation of americium and europium humate complexes

    International Nuclear Information System (INIS)

    Minai, Y.; Tominaga, T.; Meguro, Y.

    1991-01-01

    Binding constants of americium and europium with a humic acid were determined to study if complex formation of trivalent actinide-humates affects dissolved species of the actinides in hydrosphere. The purified humic acid was characterized by means of UV-vis, IR, and pH titration, indicating high carboxylate capacity and low aromaticity. Binding constants of americium and europium humates were determined at pH 4.6 and 6.0 by solvent extraction using 241 Am or 152 Eu as a tracer. The binding constants for americium-humate obtained preliminarily suggest that complexes with humic acid are not negligible in speciation of trivalent actinides in hydrosphere. The obtained binding constants were nearly identical with those determined previously by the same procedures, but with humic acids of different origin and compositions. (author)

  12. Biosorption of americium by alginate beads

    International Nuclear Information System (INIS)

    Borba, Tania Regina de; Marumo, Julio Takehiro; Goes, Marcos Maciel de; Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi

    2009-01-01

    The use of biotechnology to remove heavy metals from wastes plays great potential in treatment of radioactive wastes and therefore the aim of this study was to evaluate the biosorption of americium by alginate beads. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. The calcium alginate beads as biosorbent were prepared and analyzed for americium uptaking. The experiments were performed in different solution activity concentrations, pH and exposure time. The results suggest that biosorption process is more efficient at pH 4 and for 75, 150, 300 Bq/mL and 120 minutes were necessary to remove almost 100% of the americium-241 from the solution. (author)

  13. New Fecal Method for Plutonium and Americium

    International Nuclear Information System (INIS)

    Maxwell, S.L. III

    2000-01-01

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin (Eichrom Industries), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin, which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Industries). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as thorium-228

  14. New fecal method for plutonium and americium

    International Nuclear Information System (INIS)

    Maxwell, S.L.; Fauth, D.J.; Nichols, S.T.

    2001-01-01

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin R (Eichrom Technologies), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin R , which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Technologies). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as 228 Th. (author)

  15. Transmutation of Americium in Fast Neutron Facilities

    International Nuclear Information System (INIS)

    Zhang, Youpeng

    2011-01-01

    In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on core's safety parameters. Applying the SAS4A/SASSYS transient analysis code, it is demonstrated that the power rating needs to be reduced by 6% for each percent additional americium introduction into the reference MOX fuel, maintaining 100 K margin to fuel melting, which is the most limiting failure mechanism. Safety analysis of a new Accelerator Driven System design with a smaller pin pitch-to-diameter ratio comparing to the reference EFIT-400 design, aiming at improving neutron source efficiency, was also performed by simulating performance for unprotected loss of flow, unprotected transient overpower, and protected loss-of-heat-sink transients, using neutronic parameters obtained from MCNP calculations. Thanks to the introduction of the austenitic 15/15Ti stainless steel with enhanced creep rupture resistance and acceptable irradiation swelling rate, the suggested ADS design loaded with nitride fuel and cooled by lead-bismuth eutectic could survive the full set of transients, preserving a margin of 130 K to cladding rupture during the most limiting transient. The thesis concludes that efficient transmutation of americium in a medium sized sodium cooled fast reactor loaded with MOX fuel is possible but leads to a severe power penalty. Instead, preserving transmutation rates of minor actinides up to 42 kg/TWh th , the suggested ADS design with enhanced proton source efficiency appears like a better option for americium transmutation

  16. Preparation of americium source for smoke detector

    International Nuclear Information System (INIS)

    Ramaswami, A.; Singh, R.J.; Manohar, S.B.

    1994-01-01

    This report describes the method developed for the preparation of 241 Am source for smoke detector. Americium was electrodeposited from iso-propyl alcohol medium on silver backing. Thin layer of gold (few hundred micro gram thick) was plated on the americium source to make it safe for handling. The thickness of plated gold was such that the alpha radiations from the 241 Am source could escape out of the gold layer and cause ionisation in the surrounding air. The performance of the prepared sources were checked in a smoke detector and was found to be satisfactory and comparable to the imported sources. (author). 1 refs., 2 figs., 1 tab

  17. Redox chemistry of americium in nitric acid media

    International Nuclear Information System (INIS)

    Picart, S.; Jobelin, I.; Armengol, G.; Adnet, JM.

    2004-01-01

    The redox properties of the actinides are very important parameters for speciation studies and spent nuclear fuel reprocessing based on liquid-liquid extraction of actinides at different oxidation states (as in the Purex or Sesame process). They are also very useful for developing analytical tools including coulometry and redox titration. This study addressed the americium(IV)/americium(III) and americium(VI)/americium(V) redox couples, focusing on exhaustive acquisition of the thermodynamic and kinetic parameters of americium oxidation at an electrode in a complexing nitric acid medium. (authors)

  18. 1976 Hanford americium exposure incident: psychological aspects

    International Nuclear Information System (INIS)

    Brown, W.R.

    1982-01-01

    Accidents involving exposure to radiation or radioactive materials may involve an unusual degree of emotional trauma. Methods that may be employed in dealing with such trauma are discussed in relation to a specific accident in which a radiation worker was injured and seriously contaminated with americium-241

  19. Americium migration in basalt and implications to repository risk analysis

    International Nuclear Information System (INIS)

    Rickert, P.G.

    1980-01-01

    Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH

  20. Procedure for the analysis of americium in complex matrices

    International Nuclear Information System (INIS)

    Knab, D.

    1978-02-01

    A radioanalytical procedure for the analysis of americium in complex matrices has been developed. Clean separations of americium can be obtained from up to 100 g of sample ash, regardless of the starting material. The ability to analyze large masses of material provides the increased sensitivity necessary to detect americium in many environmental samples. The procedure adequately decontaminates from rare earth elements and natural radioactive nuclides that interfere with the alpha spectrometric measurements

  1. The relative physiological and toxicological properties of americium and plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Carter, R.E.; Busch, E.; Johnson, O. [and others

    1951-11-15

    The relative physiological and toxicological properties of americium and plutonium have been studied following their intravenous administration to rats. The urinary and fecal excretion of americium was similar to that of plutonium administered as Pu(N0{sub 3}){sub 4}. The deposition of americium the tissues and organs of the rat was also similar to that observed for plutonium. The liver and the skeleton were the major sites of deposition. Zirconium citrate administered 15 minutes after injection of americium increased the urinary excretion of americium and decreased the amount found in the liver and the skeleton at 4 and 16 days. LD{sub 30}{sup 50} studies showed americium was slightly less toxic when given in the acute toxic range than was plutonium. The difference was, however, too slight to be important in establishing a larger tolerance does for americium. Survival studies, hematological observations, bone marrow observations, comparison of tumor incidence and the incidence of skeletal abnormalities indicated that americium and plutonium have essentially the same chronic toxicity when given on an equal {mu}c. basis. These studies support the conclusion that the tolerance values for americium should be essentially the same as those for Plutonium.

  2. Investigation of americium-241 metal alloys for target applications

    International Nuclear Information System (INIS)

    Conner, W.V.; Rockwell International Corp., Golden, CO

    1982-01-01

    Several 241 Am metal alloys have been investigated for possible use in the Lawrence Livermore National Laboratory Radiochemical Diagnostic Tracer Program. Several properties were desired for an alloy to be useful for tracer program applications. A suitable alloy would have a fairly high density, be ductile, homogeneous and easy to prepare. Alloys investigated have included uranium-americium, aluminium-americium, and cerium-americium. Uranium-americium alloys with the desired properties proved to be difficult to prepare, and work with this alloy was discontinued. Aluminium-americium alloys were much easier to prepare, but the alloy consisted of an aluminium-americium intermetallic compound (AmAl 4 ) in an aluminum matrix. This alloy could be cast and formed into shapes, but the low density of aluminum, and other problems, made the alloy unsuitable for the intended application. Americium metal was found to have a high solid solubility in cerium and alloys prepared from these two elements exhibited all of the properties desired for the tracer program application. Cerium-americium alloys containing up to 34 wt% americium have been prepared using both co-melting and co-reduction techniques. The latter technique involves co-reduction of cerium tetrafluoride and americium tetrafluoride with calcium metal in a sealed reduction vessel. Casting techniques have been developed for preparing up to eight 2.2 cm (0.87 in) diameter disks in a single casting, and cerium-americium metal alloy disks containing from 10 to 25 wt% 241 Am have been prepared using these techniques. (orig.)

  3. Surface complexation modeling of americium sorption onto volcanic tuff.

    Science.gov (United States)

    Ding, M; Kelkar, S; Meijer, A

    2014-10-01

    Results of a surface complexation model (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The model was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be modeled with two surface reactions involving an americium sulfate and an americium carbonate complex. It was assumed in applying the model to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface complexation constants, derived in this study, allow prediction of sorption of americium in a natural complex system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways. Published by Elsevier Ltd.

  4. Self-irradiation and oxidation effects on americium sesquioxide and Raman spectroscopy studies of americium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Horlait, Denis [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France); Caraballo, Richard [CEA, DEN, DTCD/SECM/LMPA, F-30207 Bagnols-sur-Cèze Cedex (France); Lebreton, Florent [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France); Jégou, Christophe [CEA, DEN, DTCD/SECM/LMPA, F-30207 Bagnols-sur-Cèze Cedex (France); Roussel, Pascal [Unité de Catalyse et Chimie du Solide, UMR 8012 CNRS, Ecole Nationale Supérieure de Chimie de Lille BP 90108, 59652 Villeneuve d’Ascq Cedex (France); Delahaye, Thibaud, E-mail: thibaud.delahaye@cea.fr [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France)

    2014-09-15

    Americium oxides samples were characterized by X-ray diffraction (XRD) and Raman spectroscopy, with an emphasis on their structural behavior under oxidation and self-irradiation. Raman spectra of americium dioxide (AmO{sub 2}) and sesquioxide (Am{sub 2}O{sub 3}) were obtained for the first time. With the help of literature data on isostructural oxides, Raman signatures of Ia-3 C-type Am{sub 2}O{sub 3} and P-3m1 A-type Am{sub 2}O{sub 3} are identified. For AmO{sub 2,} a clear band is noted at 390 cm{sup −1}. Its nature is compared to that of the other actinide dioxides. Am{sub 2}O{sub 3} evolution under ambient conditions and against {sup 241}Am α self-irradiation was monitored by powder XRD. The sample, initially composed of A-type Am{sub 2}O{sub 3} as major phase as well as C2/m B-type and C-type structures as minor phases, progressively oxidizes to Fm-3m AmO{sub 2−δ} over a few months. On the basis of diffractogram refinements, evolutions of unit cell volumes caused by self-irradiation are also determined and discussed. - Graphical abstract: The evolution of americium oxide under ambient conditions was monitored using XRD (X-ray diffraction) and Raman spectroscopy. After a thermal treatment under reducing conditions, a polyphasic sample mainly composed of A- and C-type americium sesquioxides is evidenced by XRD and Raman spectroscopy. The sample then evolves through two processes: oxidation and self-irradiation. The first one provokes the progressive appearance of F-type americium dioxide while the initial phases disappear, whereas the main effect of the second is a structural swelling with time. - Highlights: • The first Raman spectroscopy measurements on americium oxides were performed. • Observed Am{sub 2}O{sub 3} Raman bands were identified thanks to data on analogue compounds. • AmO{sub 2} assumed T{sub 2g} band presents a shift compared to the actinide dioxide series. • Am{sub 2}O{sub 3} evolution under self-irradiation and oxidation was also

  5. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-18

    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  6. Feasibility of the fabrication of americium targets

    International Nuclear Information System (INIS)

    Haas, D.; Somers, J.

    1999-01-01

    The paper compares the processes used at ITU for the fabrication of americium targets for transmutation: powder mixing process, sol-gel method and the infiltration by an active solution of inactive pellets. The advantages of the latter process, related mainly to the lower level of dust formation, are stressed. Moreover, the radiological constraints on the fabrication as a function of Am content and of selected fabrication process are evaluated. As conclusion, the feasibility of Am target fabrication has been demonstrated on a laboratory scale, based on experimental results evaluation. The penalties due to radiological constraints in a semi-industrial process are acceptable. The future developments consist in the construction of a laboratory fully dedicated to minor actinides fuel pins or targets fabrication. (author)

  7. Americium/Curium Disposition Life Cycle Planning Study

    International Nuclear Information System (INIS)

    Jackson, W.N.; Krupa, J.; Stutts, P.; Nester, S.; Raimesch, R.

    1998-01-01

    At the request of the Department of Energy Savannah River Office (DOE- SR), Westinghouse Savannah River Company (WSRC) evaluated concepts to complete disposition of Americium and Curium (Am/Cm) bearing materials currently located at the Savannah River Site (SRS)

  8. Plutonium and Americium Geochemistry at Hanford: A Site Wide Review

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Felmy, Andrew R.

    2012-08-23

    This report was produced to provide a systematic review of the state-of-knowledge of plutonium and americium geochemistry at the Hanford Site. The report integrates existing knowledge of the subsurface migration behavior of plutonium and americium at the Hanford Site with available information in the scientific literature regarding the geochemistry of plutonium and americium in systems that are environmentally relevant to the Hanford Site. As a part of the report, key research needs are identified and prioritized, with the ultimate goal of developing a science-based capability to quantitatively assess risk at sites contaminated with plutonium and americium at the Hanford Site and the impact of remediation technologies and closure strategies.

  9. Americium/Curium Disposition Life Cycle Planning Study

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, W.N. [Westinghouse Savannah River Company, AIKEN, SC (United States); Krupa, J.; Stutts, P.; Nester, S.; Raimesch, R.

    1998-04-30

    At the request of the Department of Energy Savannah River Office (DOE- SR), Westinghouse Savannah River Company (WSRC) evaluated concepts to complete disposition of Americium and Curium (Am/Cm) bearing materials currently located at the Savannah River Site (SRS).

  10. PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

    Science.gov (United States)

    Baybarz, R.D.; Lloyd, M.H.

    1963-02-26

    This invention relates to methods of separating americium and curium values from rare earth values. In accordance with the invention americium, curium, and rare earth values are sorbed on an anion exchange resin. A major portion of the rare earth values are selectively stripped from the resin with a concentrated aqueous solution of lithium chloride, and americium, curium, and a minor portion of rare earth values are then stripped from the resin with a dilute aqueous solution of lithium chloride. The americium and curium values are further purified by increasing the concentration of lithium chloride in the solution to at least 8 molar and selectively extracting rare earth values from the resulting solution with a monoalkylphosphoric acid. (AEC)

  11. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

  12. 1976 Hanford americium-exposure incident: external decontamination procedures

    International Nuclear Information System (INIS)

    Jech, J.J.; Berry, J.R.; Breitenstein, B.D.

    1982-01-01

    An accident resulted in the deposition on an injured workman's skin surfaces, in acid-burned areas and in lacerations, of something in excess of 6 mCi americium-241. The external decontamination procedures used, the change in americium content of the skin during the course of treatment, and some of the unusual problems encountered from the extrusion of foreign material and flaking of skin and scar tissue are described

  13. Preparation of americium metal of high purity and determination of the heat of formation of the hydrated trivalent americium ion

    International Nuclear Information System (INIS)

    Spirlet, J.C.

    1975-10-01

    In order to redetermine some physical and chemical properties of americium metal, several grams of Am-241 have been prepared by two independent methods: lanthanum reduction of the oxide and thermal dissociation of the intermetallic compound Pt 5 Am. After its separation from excess lanthanum or alloy constituent by evaporation, americium metal was further purified by sublimation at 1100 deg C and 10 -6 Torr. Irrespective of the method of preparation, the americium samples displayed the same d.h.c.p. crystal structure. As determined by vacuum hot extraction, the oxygen, nitrogen and hydrogen contents are equal to or smaller than 250, 50 and 20 ppm, respectively. The heats of solution of americium metal (d.c.h.p. structure) in aqueous hydrochloric acid solutions have been measured at 298.15+-0.05K. The standard enthalpy of formation of Am 3+ (aq) is obtained as -616.7+-1.2 kJ mol -1 [fr

  14. Citric complexes, neodymium citrate and americium citrate

    International Nuclear Information System (INIS)

    Bouhlassa, Saidati.

    1981-06-01

    The behaviour of neodymium and americium has been studied in citric aqueous medium by two methods: solvent extraction of elements at tracer scale as chelates and by potentiometry. So range of pH and concentrations of elements and citric acid never reached before have been explored: 10 -7 -1 M, 10 -10 -3 , Csub(H3 Cit) -1 M, 1 2 O; AmCit, xH 2 O; NdCit 2 Co(NH 3 ) 6 , 8H 2 O; AmCit 2 Co(NH 3 ) 6 , xH 2 O and Nd 3 (OH) 4 (Cit) 4 NH 4 (Co(NH 3 ) 6 ) 2 , 18H 2 O. Their spectroscopic and crystallographic characteristics have been listed and studied. The nephelauxetic effect has been estimated from citric complexes as well as from citrates of these elements. The structure of the complexes in solution has been discussed on the basis of analysis of hypersensitive transition in different complexes [fr

  15. Applicability of insoluble tannin to treatment of waste containing americium

    International Nuclear Information System (INIS)

    Matsumura, T.; Usuda, S.

    1998-01-01

    The applicability of insoluble tannin adsorbent to the treatment of aqueous waste contaminated with americium has been investigated. Insoluble tannin is considered highly applicable because it consists of only carbon, hydrogen and oxygen and so its volume can be easily reduced by incineration. This report describes measurements of the americium distribution coefficient in low concentration nitric acid. The americium distribution coefficients were found to decrease with increasing concentration of nitric acid and sodium nitrate, and with increasing temperature. At 25 C in 2.0 x 10 -3 M HNO 3 , the distribution coefficient was found to be 2000 ml g -1 . The adsorption capacity was determined by column experiments using europium as a simulant of americium, and found to be 7 x 10 -3 mmol g -1 -dried tannin in 0.01 M HNO 3 at 25 C, which corresponds to approximately 1.7 mg- 241 Am/g-adsorbent(dried). The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (orig.)

  16. A process for the recovery of americium from analytical wastes

    International Nuclear Information System (INIS)

    Brossard, P.; Kwinta, J.; Schwander, Y.

    1984-12-01

    The object of the present work is to define a procedure for the extraction of americium contained in hundreds of liters of liquid analytical wastes. The main objective is to produce wastes for which the americium concentration is lower than 0,5 mg/l, the operations being carried out in glove boxes. Dihexyl N, N-diethylcarbamylmethylene phosphonate (DHDECMP) is used for the extraction of americium. Experimental laboratory results and procedure design are described. Distribution coefficient, DHDECMP concentration, addition of TBP, influence of PH and temperature are studied. A bank of mixer-settlers appears to be the most appropriate laboratory equipment to handle large volume of solution with a good efficiency

  17. The selective extraction of americium from high level liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Adnet, J.M.; Donnet, L.; Brossard, P.; Bourges, J.

    1996-12-31

    One of the possible ways selected by CEA for the partitioning of minor actinides from solutions containing fission products is the selective extraction of the oxidized species. This papers deals with the latest developments in the electrochemical oxidation of americium in nitric media to the oxidation states (IV) and (VI). Oxidized americium is generated and stabilized through the use of poly anionic ligands such as the phospho tungstate. With in view the use of such ligands in the treatment of real liquid wastes, the complexation of several metallic ions has been investigated A first experiment done with a real liquid waste to prove the possibility to selectively extract the oxidized americium is presented. (authors). 8 refs.

  18. Synergistic extraction behaviour of americium from simulated acidic waste solutions

    International Nuclear Information System (INIS)

    Pathak, P.N.; Veeraraghavan, R.; Mohapatra, P.K.; Manchanda, V.K.

    1998-01-01

    The extraction behaviour of americium has been investigated with mixtures of 3-phenyl-4-benzoyl-5-isoxazolone (PBI) and oxodonors viz. tri-n-butyl phosphate (TBP), tri-n-octyl phosphine oxide (TOPO) and di-n-butyl octanamide (DBOA) using dodecane as the diluent from 1-6 M HNO 3 media. It is observed that D Am remains unaltered with PBI concentration (in the range 0.06-0.1 M) at 1.47 M TBP in the entire range of HNO 3 concentration. PBI and TBP in combination appears more promising compared to other synergistic systems. The possibility of using this mixture for americium removal from high level liquid waste solution has been explored. Extraction studies indicated that prior removal of uranium by 20% TBP in dodecane is helpful in the quantitative recovery of americium in three contacts. Effect of lanthanides on D Am is found to be marginal. (orig.)

  19. Covalency in Americium(III) Hexachloride.

    Science.gov (United States)

    Cross, Justin N; Su, Jing; Batista, Enrique R; Cary, Samantha K; Evans, William J; Kozimor, Stosh A; Mocko, Veronika; Scott, Brian L; Stein, Benjamin W; Windorff, Cory J; Yang, Ping

    2017-06-28

    Developing a better understanding of covalency (or orbital mixing) is of fundamental importance. Covalency occupies a central role in directing chemical and physical properties for almost any given compound or material. Hence, the concept of covalency has potential to generate broad and substantial scientific advances, ranging from biological applications to condensed matter physics. Given the importance of orbital mixing combined with the difficultly in measuring covalency, estimating or inferring covalency often leads to fiery debate. Consider the 60-year controversy sparked by Seaborg and co-workers ( Diamond, R. M.; Street, K., Jr.; Seaborg, G. T. J. Am. Chem. Soc. 1954 , 76 , 1461 ) when it was proposed that covalency from 5f-orbitals contributed to the unique behavior of americium in chloride matrixes. Herein, we describe the use of ligand K-edge X-ray absorption spectroscopy (XAS) and electronic structure calculations to quantify the extent of covalent bonding in-arguably-one of the most difficult systems to study, the Am-Cl interaction within AmCl 6 3- . We observed both 5f- and 6d-orbital mixing with the Cl-3p orbitals; however, contributions from the 6d-orbitals were more substantial. Comparisons with the isoelectronic EuCl 6 3- indicated that the amount of Cl 3p-mixing with Eu III 5d-orbitals was similar to that observed with the Am III 6d-orbitals. Meanwhile, the results confirmed Seaborg's 1954 hypothesis that Am III 5f-orbital covalency was more substantial than 4f-orbital mixing for Eu III .

  20. The ingestion of plutonium and americium by range cattle

    International Nuclear Information System (INIS)

    Blincoe, C.; Bohman, V.R.; Smith, D.D.

    1981-01-01

    The intake of plutonium and americium in the diet of cattle grazing on plutonium contaminated desert range was determined. Daily feed intake of the grazing animals was also determined so that the amount of nuclides ingested daily could be ascertained. Soil ingested by range cattle constituted the principal and possibly only source of ingested plutonium and americium and resulted in a daily intake of 3600-6600 pCi 238 Pu, 85,000-400,000 pCi 239 Pu, and 11,000-31,000 pCi 241 Am daily. Determining transuranic intake by direct measurement and from the composition and contamination of the diet gave identical results. (author)

  1. 1976 Hanford americium exposure incident: overview and perspective

    International Nuclear Information System (INIS)

    Thompson, R.C.

    1982-01-01

    Salient features of the 1976 Hanford americium exposure incident are discussed. Comparisons are made with previous human and animal exposure data, and conclusions drawn relative to the injured workman, to health physics practices, and to the adequacy of current exposure limits

  2. Determination of plutonium, americium and curium in the marine environment

    International Nuclear Information System (INIS)

    Grenaut, CLaude; Germain, Pierre; Miramand, Pierre.

    1982-01-01

    The method used in the Laboratory for plutonium, americium and curium determination in marine samples (water, sediments, animals, plants) is presented. It is a modification of a procedure based on adsorption on ion exchange resins developed by other authors. The preliminary preparation of the samples, the radiochemical procedures and electrodeposition are described so as to be used as a practical handbook [fr

  3. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  4. Kinetics and mechanism of oxidation of americium(III) to americium(VI) in dilute phosphoric acid solutions

    International Nuclear Information System (INIS)

    Milyukova, M.S.; Litvina, M.N.; Myasoedov, B.F.

    1980-01-01

    The reaction between trivalent americium and a mixture of silver with ammonium persulfate in 0.1-3M H 3 PO 4 solutions was studied. Hexavalent americium was found to be the product of interaction under these conditions. Americium oxidation is described with a first order equation with rate constants k=18.7 hr -1 and k=8.74 hr -1 for 0.1-0.5M and 1M H 3 PO 4 , respectively. The activation energy calculated from the temperature dependence of the rate of americium oxidation by a mixture of Ag 3 PO 4 with (NH 4 ) 2 S 2 O 8 is 9.1 kcal/mole. The stability of Am(VI) in 0.1-1M H 3 PO 4 was studied. No reduction of Am(VI) over a period of 30-40 hrs was observed; after that the reduction of Am(VI) follows a zero order law with the apparent rate constant k=0.0036 hr -1 . The mechanism of Am(III) oxidation with a mixture of silver and ammonium persulfate is discussed. (author)

  5. Americium extraction by alkylpyrocatechin from alkaline salt solutions

    International Nuclear Information System (INIS)

    Karalova, Z.K.; Rodionova, L.M.; Myasoedov, B.F.

    1984-01-01

    Effect of iron, aluminium, calcium, and sodium nitrates on americium extraction by 0.1 mol/l DOP solution [4-(α-α dioctylethyl) pyrocatechin] in toluene from a mixture of 2 mol/l NaOH with 0.1 mol/l EDTA has been investigated. It has been shown that americium extraction does not change essen-- tially in the presence of salts that permits to use DOP for Am extraction from alkaline solutions in the presence of outside salts. Verification of the above method of extraction of radioactive isotopes has been carried out. According to the data obtained double extraction provides a preparation of alkaline solutions practically free from radioactive isotopes. DOP application for Am extraction from alkaline salt solutions allows one to carry out repeated Am concentration and separation from accompanying elements. Conditions, under which Fe(3)-Am(3) pair separation coefficient achieves nx10 2 -10 4 , have been found out

  6. Contribution to the study of higher valency states of americium

    International Nuclear Information System (INIS)

    Langlet, Jean.

    1976-01-01

    Study of the chemistry of the higher valencies of americium in aqueous solutions and especially the autoreduction phenomenon. First a purification method of americium solutions is studied by precipitation, solvent extraction and ion exchange chromatography. Studies of higher valency states chemical properties are disturbed by the autoreduction phenomenon changing Am VI and Am V in Am III more stable. Stabilization of higher valency states, characterized by a steady concentration of Am VI in solution, can be done by complexation of Am VI and Am V ions or by a protecting effect of foreign ions. The original medium used has a complexing effect by SO 4 2- ions and a protecting effect by the system S 2 O 8 2- -Ag + consuming H 2 O 2 main reducing agent produced by water radiolysis. These effects are shown by the study of Am VI in acid and basic solutions. A mechanism of the stabilization effect is given [fr

  7. Method for removal of plutonium impurity from americium oxides and fluorides

    Science.gov (United States)

    FitzPatrick, J.R.; Dunn, J.G.; Avens, L.R.

    1987-02-13

    Method for removal of plutonium impurity from americium oxides and fluorides. AmF/sub 4/ is not further oxidized to AmF/sub 6/ by the application of O/sub 2/F at room temperature thereto, while plutonium compounds present in the americium sample are fluorinated to volatile PuF/sub 6/, which can readily be separated therefrom, leaving the purified americium oxides and/or fluorides as the solid tetrafluoride thereof.

  8. Research program on development of advanced treatment technology for americium-containing aqueous waste in NUCEF

    International Nuclear Information System (INIS)

    Mineo, Hideaki; Matsumura, Tatsuro; Tsubata, Yasuhiro

    1996-10-01

    A research program was prepared on the development of an advanced treatment process for the americium-containing concentrated aqueous waste in NUCEF, than allows americium recovery for the reuse and the reduction of TRU waste generation. A preliminary analysis was conducted on the separation requirements based on the components estimated for the waste. An R and D strategy was proposed from the view to reduce TRU waste generated in the processing that the highest priority is given on the control of TRU leakage such as americium into the effluent stream after americium recovery and the minimization of salt used in the separation over the decontamination of impurities from americium. The extraction chromatographic method was selected as a candidate technology for americium separation under the principle to use reagents that are functional in acidic conditions such as bidentate extractants of DHEDECMP, CMPO or diamides, considering the larger flexibilities in process modification and possible multi-component separation with compact equipment and the past achievements on the recovery of kg quantities of americium. Major R and D items extracted are screening and evaluation of extractants for americium and plutonium, optimization of separation conditions, selection of denitration method, equipment developments and development of solidification methods of discarded americium after reuse and of various kinds of separation residues. In order to cope these items, four steps of R and D program were proposed, i.e., fundamental experiment in beaker-scale on screening and evaluation of extractants, flowsheet study in bench-scale using simulated and small amount of americium aqueous waste solution to evaluate candidate process, americium recovery test in iron-shielded cell to be installed in NUCEF. It is objected to make recovery of 100g orders of americium used for research on fundamental TRU fuel properties. (J.P.N.)

  9. Ingestion Pathway Transfer Factors for Plutonium and Americium

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, A.

    1999-07-28

    Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site.

  10. 1976 Hanford americium-exposure incident: decontamination and treatment facility

    International Nuclear Information System (INIS)

    Berry, J.R.; McMurray, B.J.; Jech, J.J.; Breitenstein, B.D.; Quigley, E.J.

    1982-01-01

    An injured worker, contaminated with over 6 mCi of americium-241, required special treatment and housing for 4 months. This paper is a description of the design and management of the facility in which most of the treatment and housing occurred. The problems associated with contamination control, waste handling, supplies, and radiological concerns during the two-stage transfer of the patient from a controlled situation to his normal living environment are discussed in detail

  11. Americium-241: the most useful isotope of the actinide elements

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1984-01-01

    Used extensively in nuclear gauges and in many other areas, this man-made element (Atomic Number 95) was first isolated in weighable amounts during World War II. Americium is now a very useful by-product of the nuclear industry and is produced in kilogram amounts by appropriate recovery, separation and purification processes. A review will be presented of its discovery, nuclear and chemical properties, and uses, with emphasis on its production process and separations chemistry

  12. Extraction separation of americium and curium. A review

    International Nuclear Information System (INIS)

    Petrzilova, H.

    1976-11-01

    A survey is given of extraction systems suitable for transplutonium element separation and preparation as well as for the practical application of their nuclear properties. Methods are discussed in detail of separating the actinide and the lanthanide fractions from fission and corrosion products and of separating americium from curium. The description is completed with flowsheets showing the separation of transplutonium elements from irradiated targets and waste solutions after spent fuel reprocessing. (L.K.)

  13. Ingestion Pathway Transfer Factors for Plutonium and Americium

    International Nuclear Information System (INIS)

    Blanchard, A.

    1999-01-01

    Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site

  14. On the structure of thorium and americium adenosine triphosphate complexes

    International Nuclear Information System (INIS)

    Mostapha, Sarah; Berton, Laurence; Boubals, Nathalie; Zorz, Nicole; Charbonnel, Marie-Christine; Fontaine-Vive, Fabien; Den Auwer, Christophe; Solari, Pier Lorenzo

    2014-01-01

    The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electro-spray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes. (authors)

  15. On the structure of thorium and americium adenosine triphosphate complexes.

    Science.gov (United States)

    Mostapha, Sarah; Fontaine-Vive, Fabien; Berthon, Laurence; Boubals, Nathalie; Zorz, Nicole; Solari, Pier Lorenzo; Charbonnel, Marie Christine; Den Auwer, Christophe

    2014-11-01

    The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electrospray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes.

  16. The EFTTRA-T4 experiment on americium transmutation

    CERN Document Server

    Konings, R J M; Dassel, G; Pijlgroms, B J; Somers, J; Toscano, E

    2000-01-01

    In the EFTTRA-T4 experiment the irradiation behaviour of a target containing americium dispersed in MgAl sub 2 O sub 4 was studied. Pellets containing 10-12 wt% sup 2 sup 4 sup 1 Am were fabricated by the infiltration method. However, it was found that the americium, intended to be present as AmO sub 2 sub - sub x , formed a compound, probably AmAlO sub 3 , during sintering. The T4 target was irradiated in the High Flux Reactor (HFR) Petten from August 1996 to January 1998 (358.4 fpd's). Post-test burn-up calculations indicated that the sup 2 sup 4 sup 1 Am concentration is reduced to 4% of the initial value at the end of the irradiation. The fraction of the initial americium atoms that were fissioned is 28%. Non-destructive and destructive examinations of the target indicated that swelling of the target pellets occurred. This is attributed to accumulation of helium, produced by alpha decay of sup 2 sup 4 sup 2 Cm that occurs in the transmutation scheme of sup 2 sup 4 sup 1 Am.

  17. Gut uptake factors for plutonium, americium and curium

    International Nuclear Information System (INIS)

    Harrison, J.D.

    1982-01-01

    Data on estimates of the absorption of plutonium, americium and curium from the human gut based on measurements of uptake in other mammalian species are reviewed. It is proposed that for all adult members of the public ingesting low concentrations of plutonium in food and water, 0.05% would be an appropriate value of absorption except when the conditions of exposure are known and a lower value can be justified. For dietary intakes of americium and curium, the available data do not warrant a change from the ICRP value of 0.05%. For newborn children ingesting americium, curium and soluble forms of plutonium, a value of 1% absorption is proposed for the first 3 months of life during which the infant is maintained on a milk diet. It is proposed that a value of 0.5% should be used for the first year of life to take account of the gradual maturation of the gut. In considering the ingestion of insoluble oxides of plutonium by infants, it is proposed that absorption is taken as 0.1% for the first 3 months and 0.05% for the first year. (author)

  18. Extraction of pentavalent americium by di(2-ethylhexyl)phosphoric acid

    International Nuclear Information System (INIS)

    Molochnikova, N.P.; Myasoedov, B.F.; Frenkel, V.Ya.

    1983-01-01

    Conditions have been found for the extraction of americium(V) by HDEHP in octane from acetate buffer solutions at pH 4.5-5.0 in the presence of ammonium persulphate which was necessary to stabilize oxidized americium under these conditions. The effect of the nature of a solvent on the extraction coefficient of americium(V) was studied. Macroamounts of americium(V) were extracted by 0.5M HDEHP in octane. The absorption spectrum of americium(V) in the extract has been recorded. The stability of americium(V) in the organic phase was evaluated. The absence of interfering influence of the anions of phosphotungstic acids on the extraction of americium(V) by 0.5M HDEHP in octane makes it possible to separate americium(V) from trivalent actinides during one extraction from acetate solutions at pH 4.5-5.0 in the presence of 10 -3 M potassium phosphotungstate; the separation factor is about 10 3 . (author)

  19. Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1978-01-01

    Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

  20. Robotic sample preparation for radiochemical plutonium and americium analyses

    International Nuclear Information System (INIS)

    Stalnaker, N.; Beugelsdijk, T.; Thurston, A.; Quintana, J.

    1985-01-01

    A Zymate robotic system has been assembled and programmed to prepare samples for plutonium and americium analyses by radioactivity counting. The system performs two procedures: a simple dilution procedure and a TTA (xylene) extraction of plutonium. To perform the procedures, the robotic system executes 11 unit operations such as weighing, pipetting, mixing, etc. Approximately 150 programs, which require 64 kilobytes of memory, control the system. The system is now being tested with high-purity plutonium metal and plutonium oxide samples. Our studies indicate that the system can give results that agree within 5% at the 95% confidence level with determinations performed manually. 1 ref., 1 fig., 1 tab

  1. Implications of plutonium and americium recycling on MOX fuel fabrication

    International Nuclear Information System (INIS)

    Renard, A.; Pilate, S.; Maldague, Th.; La Fuente, A.; Evrard, G.

    1995-01-01

    The impact of the multiple recycling of plutonium in power reactors on the radiation dose rates is analyzed for the most critical stage in a MOX fuel fabrication plant. The limitation of the number of Pu recycling in light water reactors would rather stem from reactor core physics features. The case of recovering americium with plutonium is also considered and the necessary additions of shielding are evaluated. A comparison between the recycling of Pu in fast reactors and in light water reactors is presented. (author)

  2. Effect of 241-americium on bone marrow stroma

    International Nuclear Information System (INIS)

    Heuvel, R. van den

    1990-01-01

    The regulation of haemopoiesis occurs via complex interactions between the stroma and the haemopoietic cells. An attempt to further clarifying the mechanisms and the exact role of the stroma in the regulation was made in a study. Results revealed that the murine bone marrow stromal cells are highly radiosensitive after injection with 241-americium and can thus be considered as a target population after internal contamination. In addition, observations are made which may be important for risk estimation for the developing animal and during pregnancy. Contamination in utero and by lactation shows persistent damage up to 1 year after contamination at an average annual dose of 5 cGy. (author)

  3. Solubility of americium-241 in in vitro bovine ruminal-gastrointestinal fluids and predicted tissue retention and milk secretion of field-ingested americium-241

    International Nuclear Information System (INIS)

    Barth, J.

    1978-01-01

    The alimentary solubility and behavior of americium-241 were studied in an artificial rumen and simulated bovine gastrointestinal fluids. Rumen juice was augmented with americium-241 nitrate solution and incubated for 24 hours. This juice was successively converted by the addition of bile and enzymes and adjustment of the pH to simulate the digestive stages of the abomasum, duodenum, jejunum, and lower small intestine. Fluid samples were collected from each of these digestive stages and radioanalyzed for soluble americium-241. Shortly after the addition of americium-241 to rumen juice, an average of 15.3% remained soluble while 7.2% remained soluble following the incubation period. The solubility decreased to 5.3% following the abomasal period and increased to 11.6% and 20.0% when maintained at pH 4.0 and 5.0, respectively, in the duodenal phase. The solubility increased to 52% during the jejunal incubation period and was reduced to 44.8% during the lower intestinal incubation period. The sharp rise in americium-241 solubility during the jejunal incubation perid was found to be due mainly to the action of bile. Predictions of tissue retention and milk secretion of americium-241 ingested by grazing cattle at Area 13 of the Nevada Test Site are included

  4. Analysis of americium, plutonium and technetium solubility in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Seiji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-08-01

    Safety assessments for geologic disposal of radioactive waste generally use solubilities of radioactive elements as the parameter restricting the dissolution of the elements from a waste matrix. This study evaluated americium, plutonium and technetium solubilities under a variety of geochemical conditions using the geochemical model EQ3/6. Thermodynamic data of elements used in the analysis were provided in the JAERI-data base. Chemical properties of both natural groundwater and interstitial water in buffer materials (bentonite and concrete) were investigated to determine the variations in Eh, pH and ligand concentrations (CO{sub 3}{sup 2-}, F{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-}, NO{sub 3}{sup -} and NH{sub 4}{sup +}). These properties can play an important role in the complexation of radioactive elements. Effect of the groundwater chemical properties on the solubility and formation of chemical species for americium, plutonium and technetium was predicted based on the solubility analyses under a variety of geochemical conditions. The solubility and speciation of the radioactive elements were estimated, taking into account the possible range of chemical compositions determined from the groundwater investigation. (author)

  5. Plutonium and americium in the foodchain lichen-reindeer-man

    International Nuclear Information System (INIS)

    Jaakkola, T.; Hakanen, M.; Keinonen, M.; Mussalo, H.; Miettinen, J.K.

    1977-01-01

    The atmospheric nuclear tests have produced a worldwide fallout of transuranium elements. In addition to plutonium measurable concentrations of americium are to be found in terrestrial and aquatic environments. The metabolism of plutonium in reindeer was investigated by analyzing plutonium in liver, bone, and lung collected during 1963-1976. To determine the distribution of plutonium in reindeer all tissues of four animals of different ages were analyzed. To estimate the uptake of plutonium from the gastrointestinal tract in reindeer, the tissue samples of elk were also analyzed. Elk which is of the same genus as reindeer does not feed on lichen but mainly on deciduous plants, buds, young twigs, and leaves of trees and bushes. The composition of its feed corresponds fairly well to that of reindeer during the summer. Studies on behaviour of americium along the foodchain lichen-reindeer-man were started by determining the Am-241 concentrations in lichen and reindeer liver. The Am-241 results were compared with those of Pu-239,240. The plutonium contents of the southern Finns, whose diet does not contain reindeer tissues, were determined by analyzing autopsy tissue samples (liver, lung, and bone). The southern Finns form a control group to the Lapps consuming reindeer tissues. Plutonium analyses of the placenta, blood, and tooth samples of the Lapps were performed

  6. Uptake and recovery of americium and uranium by Anacystis biomass

    International Nuclear Information System (INIS)

    Liu, H.H.; Jiunntzong Wu

    1993-01-01

    The optimum conditions for the uptake of americium and uranium from wastewater solutions by Anacystis nidulans cells, and the recovery of these radionuclides were studied. The optimum pH range for both actinides was in the acidic region between 3.0 and 5.0. In a pH 3.5 solution with an algal biomass of 70 μg/mL, up to 95% of the Am and U were taken up by the cells. However, the uptake levels were lowered considerably when ethylene dinitrilotetraacetic acid (EDTA) or iron or calcium ions were present in the solutions. Most of the radionuclides taken up by the cells could also be desorbed by washing with salt solutions. Of nine salt solutions tested, ammonium carbonate was the most effective. Our experiments using algal biomass to remove radionuclides from wastewater showed that about 92% of americium and 85% of uranium in wastewater could be taken up by algal biomass, from which about 46% of the Am and 82% of the U originally present in the wastewater could be recovered by elution with a salt solution. 17 refs., 7 figs., 2 tabs

  7. Extraction of americium of different oxidation states in two-phase aqueous system based on polyethylene glycol

    International Nuclear Information System (INIS)

    Molochnikova, N.P.; Frenkel', V.Ya.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-01-01

    Americium extraction in different oxidation states in two-phase aqueous system based on polyethylene glycol is investigated. Conditions for quantitative extraction of americium (3) and americium (5) from ammonium sulfate solutions within pH=3-5 interval in the presence of arsenazo 3 are found. Composition of the produced americium complexes with reagent is determined; americium (3) interacts with arsenazo 3 in ammonium sulfate solutions with the formation of MeR and Me 2 R composition complexes. Absorption spectrum characteristics of americium (3) and- (5) complexes with arsenazo 3 in ammonium sulfate solutions and extracts based polyethylene glycol aqueous solutions are given. Molar extinction coefficients of americium complexes with arsenazo (3) in these solutions are determined

  8. Rare earth elements during diagenesis of abyssal sediments: analogies with a transuranic element americium

    International Nuclear Information System (INIS)

    Boust, D.

    1987-03-01

    One of the possibilities for the storage of high-level radioactive wastes consists in burying them into abyssal sediments, the sediments being supposed to barrier out radionuclides migration. The objective of the work was to estimate the efficiency of sediment barrier with respect to americium. As there is no americium in abyssal sediments, an indirect approach was used: the behaviour of the rare earth elements, the best natural analogs of americium. They were analysed in a 15 m long core, from the Cap Verde abyssal plateau. The terrigenous phase derived from the African continent was modified by short-term processes (1-1000 years); the intermediate rare earth elements were dissolved. Mineral coatings, enriched in rare earth appeared. After burial, the evolution continued at a much slower rate (10 5 - 10 6 years). The rare elements of the mineral coatings derived from the dissolution of the terrigenous phase and from an additional source, deeper in the sediment column. The fluxes of rare earth elements from sediment to water column were estimated. In suboxic sediments, the dissolved particulate equilibrium was related to redox conditions. The short-term reactivity of americium was studied in laboratory experiments. Simple americium migration models showed that the sediments barrier was totally efficient with respect to americium. In the conditions, neptunium 237 a daughter product of americium 241 could induce fluxes of 10 16 atoms per year per ton of stored waste (10 -8 Ci y-1), during millions years, towards the water column [fr

  9. Analysis of biological samples for americium and curium

    International Nuclear Information System (INIS)

    Miglio, J.J.

    1976-01-01

    A method of analyzing biological materials by liquid scintillation counting for americium and curium which greatly reduces the contribution from 40 K is described. The method employs an extractant liquid scintillation cocktail using N,N,N-trioctyl-N-methyl-ammonium chloride as the extractant. Instrument as well as tissue backgrounds are reduced. The lowered backgrounds allow picocurie level samples to be analyzed by liquid scintillation counting instead of alpha pulse height analysis. The samples are reduced to a carbon-free ash and then dissolved in 8M LiNo 3 which is also 10 -2 M in HNO 3 . An aliquot is placed in a liquid scintillation vial along with the extractant-scintillator, shaken and counted

  10. Pretreatment of americium/curium solutions for vitrification

    International Nuclear Information System (INIS)

    Rudisill, T.S.

    1996-01-01

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to the heavy isotope programs at Oak Ridge National Laboratory. Prior to vitrification, an in-tank oxalate precipitation and a series of oxalic/nitric acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Pretreatment development experiments were performed to understand the behavior of the lanthanides and the metal impurities during the oxalate precipitation and properties of the precipitate slurry. The results of these experiments will be used to refine the target glass composition allowing optimization of the primary processing parameters and design of the solution transfer equipment

  11. Determination of the oxygen-metal-ratio of uranium-americium mixed oxides

    International Nuclear Information System (INIS)

    Bartscher, W.

    1982-01-01

    During the dissolution of uranium-americium mixed oxides in phosphoric acid under nitrogen tetravalent uranium is oxidized by tetravalent americium. The obtained hexavalent uranium is determined by constant potential coulometry. The coulombs measured are equivalent to the oxygen in excess of the minimum composition of UO 2 x AmO 1 . 5 . The total uranium content of the sample is determined in a subsequent coulometric titration. The oxygen-metal ratio of the sample can be calculated for a given uranium-americium ratio. An excess of uranium dioxide is necessary in order to suppress the oxidation of water by tetravalent americium. The standard deviation of the method is 0.0017 O/M units. (orig.) [de

  12. In-line measurement of plutonium and americium in mixed solutions

    International Nuclear Information System (INIS)

    Li, T.K.

    1981-01-01

    A solution assay instrument (SAI) has been developed at the Los Alamos National Laboratory and installed in the plutonium purification and americium recovery process area in the Los Alamos Plutonium Processing Facility. The instrument is designed for accurate, timely, and simultaneous nondestructive analysis of plutonium and americium in process solutions that have a wide range of concentrations and Am/Pu ratios. For a 25-mL sample, the assay precision is 5 g/L within a 2000-s count time

  13. Biochemical fractionation and cellular distribution of americium and plutonium in the biomass of freshwater macrophytes

    International Nuclear Information System (INIS)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.Ya.

    2011-01-01

    Accumulation of americium ( 241 Am) and plutonium ( 238,242 Pu) and their distribution in cell compartments and biochemical components of the biomass of freshwater aquatic plants Elodea canadensis, Ceratophyllum demersum and Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory experiments. Americium and plutonium taken up from water by Elodea canadensis apical shoots were mainly absorbed by structural components of plant cells (90% for 241 Am; 89% for 238 Pu and 82-87% for 242 Pu). About 10-18% of isotope activity was recorded in the cytosol fraction. The major concentration (76-92%) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-24% of americium activity was registered in the fraction of proteins and carbohydrates, and just a minor concentration (<1%) in the lipid fraction. The distribution of plutonium in the biomass fractions of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides of cell walls of freshwater submerged macrophytes. (author)

  14. Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

    International Nuclear Information System (INIS)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA.

    2010-01-01

    Accumulation of uranium ( 238 U), americium ( 241 Am) and plutonium ( 242 Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

  15. Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2010-07-01

    Accumulation of uranium ({sup 238}U), americium ({sup 241}Am) and plutonium ({sup 242}Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

  16. Selective dissolution of americium by ferricyanide ions in basic aqueous solutions

    International Nuclear Information System (INIS)

    Meyer, D.; Fouchard, S.; Simoni, E.

    2000-01-01

    Americium exhibits a soluble form in aqueous alkaline media under oxidizing conditions which is not the case for the other Transplutonium Elements (TPE). This property can be exploited for High Level Liquid Waste (HLLW) treatment to extract Am, one of the main radionuclides responsible for the long term radiotoxicity of nuclear waste. The Soluble Am compound can be obtained by adding a concentrated basic solution of ferricyanide ions (Fe(CN) 6 3- ) to a trivalent americium hydroxide precipitate. The method allows complete and rapid extraction of americium via its soluble form in alkaline solutions. Under these conditions, other TPE and lanthanides remain in the solid state as precipitates of highly insoluble trivalent hydroxides. In the case of dissolution involving large amounts of americium, the formation of the soluble americium species is followed by the appearance of a reddish precipitate in the basic solution. Dissolution of the reddish solid in NaOH or NaOH/Fe(CN) 6 3- media demonstrated the existence of a media dependent solubility of the precipitate, and therefore the existence of at least two forms of soluble Am. Spectroscopic studies (UV-visible, EXAFS-XANES) of this reddish solid led to the determination of an Am oxidation state (pentavalent americium) and its possible formula (Na 2 AmVO 2 (OH) 3 .nH 2 O). Electrochemical studies show that the only possible oxidation reaction of trivalent americium in the working media yields the pentavalent form, and that the hexavalent state is unattainable. Stoichiometric and spectroscopic studies show that not all the ferricyanide ions required for complete dissolution of Am remain in the free Fe(CN) 6 3- form. This observation supports the view that this dissolution of Am(III) solid compound is much more complex than a simple oxidation by the ferricyanide ions. The existence of a molecular interaction between Am(V)O 2 + and ferricyanide ions is highly probable. This work demonstrates that the selective dissolution

  17. Effect of americium-241 on luminous bacteria. Role of peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrova, M., E-mail: maka-alexandrova@rambler.r [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Rozhko, T. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Vydryakova, G. [Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation); Kudryasheva, N. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation)

    2011-04-15

    The effect of americium-241 ({sup 241}Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of {sup 241}Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 {sup o}C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the {sup 241}Am is discussed. The effect of {sup 241}Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in {sup 241}Am solutions was demonstrated; and the similarity of {sup 241}Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions. - Highlights: {yields} Am-241 in water solutions (A = 0.16-6.7 kBq/L) suppresses bacterial growth.{yields} Am-241 (A = 0.16-6.7 kBq/L) stimulate bacterial luminescence. {yields} Peroxides, secondary radiolysis products, cause increase of bacterial luminescence.

  18. Americium/Curium Melter 2A Pilot Tests

    International Nuclear Information System (INIS)

    Smith, M.E.; Fellinger, A.P.; Jones, T.M.; Miller, C.B.; Miller, D.H.; Snyder, T.K.; Stone, M.E.; Witt, D.C.

    1998-05-01

    Isotopes of americium (Am) and curium (Cm) were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. These highly radioactive and valuable isotopes have been stored in an SRS reprocessing facility for a number of years. Vitrification of this solution will allow the material to be more safely stored until it is transported to the DOE Oak Ridge Reservation for use in research and medical applications. To this end, the Am/Cm Melter 2A pilot system, a full-scale non- radioactive pilot plant of the system to be installed at the reprocessing facility, was designed, constructed and tested. The full- scale pilot system has a frit and aqueous feed delivery system, a dual zone bushing melter, and an off-gas treatment system. The main items which were tested included the dual zone bushing melter, the drain tube with dual heating and cooling zones, glass compositions, and the off-gas system which used for the first time a film cooler/lower melter plenum. Most of the process and equipment were proven to function properly, but several problems were found which will need further work. A system description and a discussion of test results will be given

  19. Density of simulated americium/curium melter feed solution

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.S.

    1997-09-22

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70{degrees} C. The measured density decreased linearly at a rate of 0.0007 g/cm3/{degree} C from an average value of 1.2326 g/cm{sup 3} at 20{degrees} C to an average value of 1.1973g/cm{sup 3} at 70{degrees} C.

  20. Density of simulated americium/curium melter feed solution

    International Nuclear Information System (INIS)

    Rudisill, T.S.

    1997-01-01

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70 degrees C. The measured density decreased linearly at a rate of 0.0007 g/cm3/degree C from an average value of 1.2326 g/cm 3 at 20 degrees C to an average value of 1.1973g/cm 3 at 70 degrees C

  1. Americium adsorption on the surface of macrophytic algae

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, F.P.; Fowler, S.W.

    1985-01-01

    Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring ..cap alpha..-emitter /sup 210/Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author).

  2. Americium adsorption on the surface of macrophytic algae

    International Nuclear Information System (INIS)

    Carvalho, F.P.; Fowler, S.W.

    1985-01-01

    Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring α-emitter 210 Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author)

  3. The rapid determination of americium curium, and uranium in urine by ultrafiltration

    International Nuclear Information System (INIS)

    Stradling, G.N.; Popplewell, D.S.; Ham, G.J.; Griffin, R.

    1975-01-01

    The rapid ultrafiltration method developed for the assay of plutonium has been extended to the determination of americium, curium and uranium in urine. The limits of detection for americium and curium, and uranium are 0.09 and 0.12 dm -1 l -1 respectively, and the analysis time excluding counting less than 2 hours. The method can therefor be effectively used as a rapid screening procedure. When the reference level for plutonium is exceeded, the α activity may require to be characterised. The single ultrafiltration technique must be modified for turbid urine samples. The method is inappropriate, except for uranium, when the urine contains DTPA. (author)

  4. Medical management after contamination and incorporation of americium in occupational exposure. Medizinische Massnahmen nach Kontamination und Inkorporation von Americium bei beruflicher Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Gensicke, F.; Stopp, G.; Scheler, R.; Klucke, H.; Czarwinski, R.; Naumann, M.; Hoelzer, F.; Ott, R.; Schmidt, I. (Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (Germany, F.R.). Abt. Strahlenschutzmedizin)

    1990-10-01

    In handling with an ampule of {sup 241}Am-nitrate solution one person received an contamination of the body surface, especially the face and the hairs, and an internal contamination of americium. The paper presents the results obtained in medical management to reduced the contamination of the skin and of the incorporated radionuclide. The radioactivity of the body surface could be reduced up to small local areas. After treatment with DTPA (Ditripentat) the internal exposure decrease about 83%. (orig.).

  5. Adsorption-desorption characteristics of plutonium and americium with sediment particles in the estuarine environment: studies using plutonium-237 and americium-241

    International Nuclear Information System (INIS)

    Murray, C.N.; Fukai, R.

    1975-01-01

    The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45 μm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

  6. Total and Compound Formation Cross Sections for Americium Nuclei: Recommendations for Coupled-Channels Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-11

    Calculations for total cross sections and compound-nucleus (CN) formation cross sections for americium isotopes are described, for use in the 2017 NA-22 evaluation effort. The code ECIS 2006 was used in conjunction with Frank Dietrich's wrapper `runtemplate'.

  7. Evaluation of the readsorption of plutonium and americium in dynamic fractionations of environmental solid samples

    DEFF Research Database (Denmark)

    Petersen, Roongrat; Hou, Xiaolin; Hansen, Elo Harald

    2008-01-01

    extractions. The degree of readsorption in dynamic and conventional batch extraction systems are compared and evaluated by using a double-spiking technique. A high degree of readsorption of plutonium and americium (>75%) was observed in both systems, and they also exhibited similar distribution patterns...

  8. Migration ability of plutonium and americium in the soils of Polessie State Radiation-Ecological Reserve

    International Nuclear Information System (INIS)

    Svetlana Ovsiannikova; Maryna Papenia; Katsiaryna Voinikava; Galina Sokolik; Sergey Svirschevsky; Justin Brown; Lindys Skipperud

    2010-01-01

    The physicochemical forms of radionuclides in soils determine the processes of their entry into the soil solutions, redistribution in the soil profile, soil-plant and soil-ground or surface waters transfer as well as spreading outside the contaminated area. The vertical distribution of plutonium and americium and their physicochemical forms in soils of Polessie State Radiation-Ecological Reserve (PSRER) were studied with the aim of establishing the potential for radionuclide migration. Samples of alluvial soddy-podzolic and peaty soils with a low (1-3%) and relatively high (∼80% of dry sample mass) content of organic matter have been selected for investigation. A method employing sequential selective extraction has been used for analysis of radionuclide physicochemical forms in the soils. Activity concentrations of 238 Pu, 239,240 Pu and 241 Am in the samples were determined via radiochemical analysis with alpha-spectrometric identification of radionuclides. The results indicate that the main proportion of plutonium and americium remains in the 0-20 cm soil layer. The inventories of mobile and biologically available forms of plutonium and americium, expressed as a percentage of the total radionuclide content in soil, lie in the ranges of 1.1-9.4 and 2.7-29% respectively. Greater proportions of mobile and biologically available forms of radionuclides appear to be associated with mineral soil as compared to organic soil. In both mineral and organic soils, the portion of mobile americium is higher than plutonium. The inventories of mobile forms of plutonium and americium increase with the depth of soils. (author)

  9. Interaction and diffusion transport of americium in soils

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Guinart, Oriol; Rigol, Anna; Vidal, Miquel [Analytical Chemistry department, Faculty of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028, Barcelona (Spain)

    2014-07-01

    The final disposal of High Level Radioactive Wastes (HLRW) is based on its long-term storage in underground facilities located in geological stable sites with a multi-barrier system, the so called Deep Geological Repositories (DGR), that will keep HLRW confined for >10.000 years. After this period of time, leachates rich in long-live radioisotopes might escape from DGR and start to transport towards the biosphere. There is still a lack of information concerning the interaction and transport in soils of some radionuclides present in HLRW, especially for radionuclides that present a high sorption, such as americium (Am). Having reliable information about the mobility of radionuclides in soils is crucial in order to develop risk assessment models and to take proper decisions in case of soil contamination. The aim of the present work was, by means of laboratory scale experiments, to study the interaction and, for first time, to evaluate the diffusion transport of {sup 241}Am in soils. The {sup 241}Am interaction in soils was assessed by applying sorption batch assays to 20 soil samples with contrasted edaphic properties which allowed us to quantify the solid-liquid distribution coefficient (K{sub d}) and desorption percentage. K{sub d} (Am) values ranged from 10{sup 3} to 10{sup 5} L kg{sup -1} and desorption percentages were always less than 2% which denoted a high capacity of the soil to incorporate the Am and a low reversibility of the sorption process. The influence of soil properties in {sup 241}Am interaction was studied by means of multiple linear and multivariate regressions. Although a single correlation between K{sub d} (Am) values and a soil property was not found, the main properties affecting {sup 241}Am interaction in soils were soil pH, carbonate and organic matter contents in the soil. Finally, additional batch assays at different controlled pH were done to study Am sorption as a function of the contact solution pH. A variation of the Am sorption

  10. Structural characterisations and mechanistic investigations of the selective dissolution of americium by the ferricyanide ions in alkaline media. Application for the partitioning americium curium

    International Nuclear Information System (INIS)

    Fouchard, Sebastien

    2000-01-01

    Americium exhibits a high solubility form in basic media under oxidant conditions, unlike the other Transplutonium elements (TPE). This property can be used in the frame of High Level Liquid Waste (HLLW) treatment in order to extract preferentially the americium element, the main responsible of the long term radiotoxicity of the nuclear waste. This soluble compound can be obtained by addition of a concentrated basic solution of Fe(CN) 6 3- ions on Am(OH) 3 precipitates. This technique enables a rapid extraction of Am by the synthesis of this soluble form in alkaline solutions. Under these conditions, the other TPE remain in the solid state as trivalent hydroxide solids, strongly insoluble. In the case of dissolutions involving large amounts of Am(OH) 3 , the formation of the soluble complex is concomitant with the appearance of a reddish precipitate in the basic solution. Dissolution experiments which were carried out on this solid in NaOH/Fe(CN) 6 3- have demonstrated the dependency of the solubility equilibria with the media. Spectroscopic studies (UV Visible, XAS) on the precipitate have enabled the determination of the chemical structure and the oxidation state of the americium in the solid: Na 2 Am(V)O 2 (OH) 3 ,nH 2 O. Electrochemical studies on the americium solution have confirmed that the oxidation of Am(OH) 3 by the Fe(CN) 6 3- ions in basic media could only lead to the pentavalent form. A stoichiometric study carries out between a AmO 2 + ion and one Fe(CN) 6 3- ion and the spectroscopic characterisation of this reaction have demonstrated that the Fe(CN) 6 3- ion didn't remain as an un-complexed form in solution after the alkaline mixing. These results tend to prove that this dissolution of Am(OH) 3 is much more complex than a simple oxidation by the Fe(CN) 6 3- ions. The existence of molecular interactions between AmO 2 + and Fe(CN) 6 3- has been postulated and a mechanistic scheme has been proposed in order to explain the appearance of the soluble

  11. Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

    DEFF Research Database (Denmark)

    Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

    1986-01-01

    of the Irish Sea) to Spitsbergen. 241Am found in Arctic waters probably originates from the decay of fallout 241Pu and, like Pu, tentatively has a residence time of the order of several years. Americium from Sellafield has an estimated mean residence time of 4–6 months in Scottish waters.......Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were...... collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of latitude 65°N, while for 238Pu a substantial fraction originates from European nuclear fuel reprocessing facilities. The 238Pu/239+240Pu isotope ratio provides clear evidence of the transport of effluent...

  12. Biochemical behaviour of plutonium and americium and geochemical modelling of the soil solution

    International Nuclear Information System (INIS)

    Bryan, N.D.; Livens, F.R.; Horrill, A.D.

    1994-01-01

    Field observations suggest that plutonium and americium in the environment are present in very different chemical forms in the interstitial waters of an intertidal sediment. Thermodynamic modelling using the PHREEQE code predicts that plutonium is present entirely in oxidation state (V) as the PuO 2 CO 3 - ion, whereas americium is present entirely in oxidation state (III), largely as the uncharged Am(OH)CO 3 species, but with significant concentrations of the Am 3+ and the AmSO 4 + ions. There are, however, differences between these predictions and others published for a very similar system which apparently arise from uncertainties in the thermodynamic data. Field data cannot resolve these differences unambiguously. (author) 29 refs.; 3 tabs

  13. High-purity germanium detection system for the in vivo measurement of americium and plutonium

    International Nuclear Information System (INIS)

    Tyree, W.H.; Falk, R.B.; Wood, C.B.; Liskey, R.W.

    1976-01-01

    A high-purity germanium (HPGe) array, photon-counting system has been developed for the Rocky Flats Plant Body-Counter Medical Facility. The newly improved system provides exceptional resolutions of low-energy X-ray and gamma-ray spectra associated with the in vivo deposition of plutonium and americium. Described are the operational parameters of the system and some qualitative results illustrating detector performance for the photon emissions produced from the decay of plutonium and americium between energy ranges from 10 to 100 kiloelectron volts. Since large amounts of data are easily generated with the system, data storage, analysis, and computer software developments continue to be an essential ingredient for processing spectral data obtained from the detectors. Absence of quantitative data is intentional. The primary concern of the study was to evaluate the effects of the various physical and electronic operational parameters before adding those related entirely to a human subject

  14. Electrodeposition of americium on a liquid cadmium cathode from a molten salt bath

    International Nuclear Information System (INIS)

    Laplace, A.; Lacquement, J.; Maillard, C.; Donner, L.

    2004-01-01

    A high-activity experiment involving the electrode position of americium on a liquid cadmium cathode from a LiCl-KCl eutectic with about 3 g of AmO 2 was conducted in a shielded cell in the ATALANTE complex. After describing the electrolyzer and the experimental conditions, the authors discuss the preparation of the LiCl-KCl-AmCl 3 solution and briefly review its electrochemical properties. It was clearly confirmed that Am(III) reduction on an inert solid cathode occurs in two steps forming Am(II) before Am(0), whereas only one reduction step was observed on liquid cadmium. The main results of this study concern americium electrode position on the liquid cadmium cathode (recovery yields, current densities, problems encountered). The solvent properties of cadmium for actinide/lanthanide separation are discussed. (authors)

  15. Determination of americium and plutonium in autopsy tissue: methods and problems

    International Nuclear Information System (INIS)

    Boyd, H.A.; Eutsler, B.C.; McInroy, J.F.

    1979-01-01

    The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average 242 Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average 242 Am tracer yield is 85 +- 7% for 40 determinations

  16. Final Radiological Assessment of External Exposure for CLEAR-Line Americium Recovery Operations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Adam C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Belooussova, Olga N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hetrick, Lucas Duane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-12

    Los Alamos National Laboratory is currently planning to implement an americium recovery program. The americium, ordinarily isotopically pure 241Am, would be extracted from existing Pu materials, converted to an oxide and shipped to support fabrication of americium oxide-beryllium neutron sources. These operations would occur in the currently proposed Chloride Extraction and Actinide Recovery (CLEAR) line of glove boxes. This glove box line would be collocated with the currently-operational Experimental Chloride Extraction Line (EXCEL). The focus of this document is to provide an in-depth assessment of the currently planned radiation protection measures and to determine whether or not further design work is required to satisfy design-goal and ALARA requirements. Further, this document presents a history of americium recovery operations in the Department of Energy and high-level descriptions of the CLEAR line operations to provide a basis of comparison. Under the working assumptions adopted by this study, it was found that the evaluated design appears to mitigate doses to a level that satisfies the ALARA-in-design requirements of 10 CFR 835 as implemented by the Los Alamos National Laboratory procedure P121. The analyses indicate that extremity doses would also meet design requirements. Dose-rate calculations were performed using the radiation transport code MCNP5 and doses were estimated using a time-motion study developed in consort with the subject matter expert. A copy of this report and all supporting documentation are located on the Radiological Engineering server at Y:\\Rad Engineering\\2013 PROJECTS\\TA-55 Clear Line.

  17. Quantitative determination of americium and curium in solutions using potassium tungstophosphate

    International Nuclear Information System (INIS)

    Chistyakov, V.M.; Baranov, A.A.; Erin, E.A.; Timoaeev, G.A.

    1990-01-01

    Two methods of americium (4) and curium (4) titration-replacement and redox ones - have been considered. According to the replacement method thorium nitrate solution was used as a titrant and the final point of titration was determined spectophotometrically. Using the method developed, on the basis of experimental data, the composition of thorium (4) complex with potassium tungstophosphate was determined. In case of the redox titration sodium nitrite was used, and the final titration point was indicated either spectrophotometrically or potentiometrically

  18. Medical management after contamination and incorporation of americium in occupational exposure

    International Nuclear Information System (INIS)

    Gensicke, F.; Stopp, G.; Scheler, R.; Klucke, H.; Czarwinski, R.; Naumann, M.; Hoelzer, F.; Ott, R.; Schmidt, I.

    1990-01-01

    In handling with an ampule of 241 Am-nitrate solution one person received an contamination of the body surface, especially the face and the hairs, and an internal contamination of americium. The paper presents the results obtained in medical management to reduced the contamination of the skin and of the incorporated radionuclide. The radioactivity of the body surface could be reduced up to small local areas. After treatment with DTPA (Ditripentat) the internal exposure decrease about 83%. (orig.) [de

  19. Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium

    International Nuclear Information System (INIS)

    2017-01-01

    This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl 2 and CaCl 2 brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl 2 solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

  20. Adsorption-Desorption Characteristics of Plutonium and Americium with Sediment Particles in the Estuarine Environment

    International Nuclear Information System (INIS)

    Murray, C.N.; Fukai, R.

    1976-01-01

    The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45pm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

  1. Bis(2-ethylhexyl)sulfoxide as an extractant for americium(III) from aqueous nitrate media

    International Nuclear Information System (INIS)

    Shukla, J.P.; Kedari, C.S.

    1992-01-01

    Solvent extraction separation of Am(III) from dilute aqueous nitrate media into n-dodecane by bis(2-ethylhexyl)sulfoxide (BESO) has been investigated over a wide range of experimental conditions. Very poor extractability of Am(III) necessitated the use of calcium nitrate as the salting-out agent. Effects of certain variables such as acidity, extractant concentration, salting-out agent concentration, organic diluents on the metal extraction by BESO have been examined in detail. By increasing the concentration of BESO in organic phase or calcium nitrate in aqueous phase, nearly quantitative extraction of americium even from moderate acidity is accomplished. Slope analyses applied to Am(III) distribution experiments from acidic nitrate solutions indicate predominant formation of the trisolvated organic phase complex, Am(NO 3 ) 3 *3BESO for which equilibrium constant is found to be, log K x = 1.99. Extraction behavior of Am(III) has also been evaluated in the presence of several water-miscible polar organic solvents to study their possible synergistic effects on its extraction. Extractability of americium increased 5 to 10-fold with increasing concentration of some of these additives, with maximum enhancement being observed in the presence of acetone or acetonitrile. Recovery of BESO from loaded americium is easily obtained using dilute nitric acid as the strippant. (author) 30 refs.; 2 figs.; 5 tabs

  2. Fabrication of uranium-americium mixed oxide pellet from microsphere precursors: Application of CRMP process

    Science.gov (United States)

    Remy, E.; Picart, S.; Delahaye, T.; Jobelin, I.; Lebreton, F.; Horlait, D.; Bisel, I.; Blanchart, P.; Ayral, A.

    2014-10-01

    Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Recently, several processes have been developed in order to validate fabrication flowchart in terms of material specifications such as density and homogeneity but also to suggest simplifications for lowering industrial costs and hazards linked to dust generation of highly contaminating and irradiating compounds. This study deals with the application of an innovative route using mixed oxide microspheres obtained from metal loaded resin bead calcination, called Calcined Resin Microsphere Pelletization (CRMP). The synthesis of mixed oxide microsphere precursor of U0.9Am0.1O2±δ is described as well as its characterisation. The use of this free-flowing precursor allows the pressing and sintering of one pellet of U0.9Am0.1O2±δ. The ceramic obtained was characterised and results showed that its microstructure is dense and homogeneous and its density attains 95% of the theoretical density. This study validates the scientific feasibility of the CRMP process applied to the fabrication of uranium and americium-containing materials.

  3. Influence of dissolved organic substances in groundwater on sorption behavior of americium and neptunium

    International Nuclear Information System (INIS)

    Boggs, S. Jr.; Seitz, M.G.

    1984-01-01

    Groundwaters typically contain dissolved organic carbon consisting largely of high molecular weight compounds of humic and fulvic acids. To evaluate whether these dissolved organic substances can enhance the tranport of radionuclides through the groundwater system, experiments were conducted to examine the sorption of americium and neptunium onto crushed basalt in the presence of dissolved humic- and fulvic-acid organic carbon introduced into synthetic groundwater. The partitioning experiments with synthetic groundwater show that increasing the concentration of either humic or fulvic acid in the water has a significant inhibiting effect on sorption of both americium and neptunium. At 22 0 C, adsorption of these radionuclides, as measured by distribution ratios (the ratio of nuclide sorbed onto the solid to nuclide in solution at the end of the experiment), decreased by 25% to 50% by addition of as little as 1 mg/L dissolved organic carbon and by one to two orders of magnitude by addition of 100 to 200 mg/L dissolved organic carbon. Distribution ratios measured in solutions reacted at 90 0 C similarly decreased with the addition of dissolved organic carbon but generally ranged from one to two orders of magnitude higher than those determined in the 22 0 C experiment. These results suggest that organic carbon dissolved in deep groundwaters may significantly enhance the mobility of radionuclides of americium and neptunium. 23 references, 5 figures, 11 tables

  4. Physics of plutonium and americium recycling in PWR using advanced fuel concepts

    International Nuclear Information System (INIS)

    Hourcade, E.

    2004-01-01

    PWR waste inventory management is considered in many countries including Frances as one of the main current issues. Pu and Am are the 2 main contents both in term of volume and long term radio-toxicity. Waiting for the Generation IV systems implementation (2035-2050), one of the mid-term solutions for their transmutation involves the use of advanced fuels in Pressurized Water Reactors (PWR). These have to require as little modification as possible of the core internals, the cooling system and fuel cycle facilities (fabrication and reprocessing). The first part of this paper deals with some neutronic characteristics of Pu and/or Am recycling. In a second part, 2 technical solutions MOX-HMR and APA-DUPLEX-84 are presented and the third part is devoted to the study of a few global strategies. The main neutronic parameters to be considered for Pu and Am recycling in PWR are void coefficient, Doppler coefficient, fraction of delayed neutrons and power distribution (especially for heterogeneous configurations). The modification of the moderation ratio, the opportunity to use inert matrices (targets), the optimisation of Uranium, Plutonium and Americium contents are the key parameters to play with. One of the solutions (APA-DUPLEX-84) presented here is a heterogeneous assembly with regular moderation ratio composed with both target fuel rods (Pu and Am embedded in an inert matrix) and standard UO 2 fuel rods. An EPR (European Pressurised Reactor) type reactor, loaded only with assemblies containing 84 peripheral targets, can reach an Americium consumption rate of (4.4; 23 kg/TWh) depending on the assembly concept. For Pu and Am inventories stabilisation, the theoretical fraction of reactors loaded with Pu + Am or Pu assemblies is about 60%. For Americium inventory stabilisation, the fraction decreases down to 16%, but Pu is produced at a rate of 18.5 Kg/TWh (-25% compared to one through UOX cycle)

  5. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2004-07-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

  6. Speciation of americium in seawater and accumulation in the marine sponge Aplysina cavernicola.

    Science.gov (United States)

    Maloubier, Melody; Michel, Hervé; Solari, Pier Lorenzo; Moisy, Philippe; Tribalat, Marie-Aude; Oberhaensli, François R; Dechraoui Bottein, Marie Yasmine; Thomas, Olivier P; Monfort, Marguerite; Moulin, Christophe; Den Auwer, Christophe

    2015-12-21

    The fate of radionuclides in the environment is a cause of great concern for modern society, seen especially in 2011 after the Fukushima accident. Among the environmental compartments, seawater covers most of the earth's surface and may be directly or indirectly impacted. The interaction between radionuclides and the marine compartment is therefore essential for better understanding the transfer mechanisms from the hydrosphere to the biosphere. This information allows for the evaluation of the impact on humans via our interaction with the biotope that has been largely undocumented up to now. In this report, we attempt to make a link between the speciation of heavy elements in natural seawater and their uptake by a model marine organism. More specifically, because the interaction of actinides with marine invertebrates has been poorly studied, the accumulation in a representative member of the Mediterranean coralligenous habitat, the sponge Aplysina cavernicola, was investigated and its uptake curve exposed to a radiotracer (241)Am was estimated using a high-purity Ge gamma spectrometer. But in order to go beyond the phenomenological accumulation rate, the speciation of americium(III) in seawater must be assessed. The speciation of (241)Am (and natural europium as its chemically stable surrogate) in seawater was determined using a combination of different techniques: Time-Resolved Laser-Induced Fluorescence (TRLIF), Extended X-ray Absorption Fine Structure (EXAFS) at the LIII edge, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy (SEM) and the resulting data were compared with the speciation modeling. In seawater, the americium(III) complex (as well as the corresponding europium complex, although with conformational differences) was identified as a ternary sodium biscarbonato complex, whose formula can be tentatively written as NaAm(CO3)2·nH2O. It is therefore this chemical form of americium that is

  7. Uptake of plutonium and americium by barley from two contaminated Nevada Test Site soils

    International Nuclear Information System (INIS)

    Schulz, R.K.; Tompkins, G.A.; Leventhal, L.; Babcock, K.L.

    1976-01-01

    Barley (Hordeum vulgare, Var. Atlas 68) plant uptake of Pu 239 , Pu 240 , and Am 241 was studied using two soil samples collected from widely separated areas of the Nevada Test Site. Each area had been previously contaminated with plutonium and americium as a result of a separate high explosive (nonnuclear) detonation of a device containing plutonium. The plants were grown on 3-kg soil samples in a controlled environment chamber. The plutonium concentration ratio (plutonium concentration in dry plant tissue/plutonium concentration in dry soil) was in the order of 10 -5 for plant vegetative material. The plutonium concentration ratio for the grain was 20 to 100 times lower than that in the vegetative material. Concentration ratios for americium were in the order of 10 -4 for vegetative growth and 25 to 75 times lower for the grain. These results imply that americium is more available to plants than plutonium. Plutonium-bearing particles were identified in a soil sample using an autoradiographic technique and then separated from the soil samples. The Pu 239 oxide equivalent diameters of plutonium-bearing particles could be described by a log-normal distribution function in the range of 0.2 to 0.7 μm. The actual diameters of the particles were 2 to 3 times the PuO 2 equivalent diameter. Microprobe analyses of the surface region of particles greater than 2 μm showed the following order of abundance: U, Pu is greater than O is greater than Al is greater than Si is greater than Fe is greater than Mg. Photographs obtained with a scanning electron microscope revealed that some of the particles are quite irregular and have large specific surface areas which might enhance solubility and plant uptake

  8. Fabrication of uranium–americium mixed oxide pellet from microsphere precursors: Application of CRMP process

    Energy Technology Data Exchange (ETDEWEB)

    Remy, E. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Picart, S., E-mail: sebastien.picart@cea.fr [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Delahaye, T. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Jobelin, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Lebreton, F.; Horlait, D. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Bisel, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Blanchart, P. [Heterogeneous Materials Research Group, Centre Européen de la Céramique, F-87068 Limoges (France); Ayral, A. [Institut Européen des Membranes, CNRS-ENSCM-UM2, CC47, University Montpellier 2, F-34095 Montpellier cedex 5 (France)

    2014-10-15

    Highlights: • Dust free process for (U,Am)O{sub 2} transmutation target fabrication. • Synthesis of U{sub 0.9}Am{sub 0.1}O{sub 2} mixed oxide microspheres from ion exchange resin. • Fabrication of dense U{sub 0.9}Am{sub 0.1}O{sub 2} pellet with 95% TD from mixed oxide microspheres. - Abstract: Mixed uranium–americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Recently, several processes have been developed in order to validate fabrication flowchart in terms of material specifications such as density and homogeneity but also to suggest simplifications for lowering industrial costs and hazards linked to dust generation of highly contaminating and irradiating compounds. This study deals with the application of an innovative route using mixed oxide microspheres obtained from metal loaded resin bead calcination, called Calcined Resin Microsphere Pelletization (CRMP). The synthesis of mixed oxide microsphere precursor of U{sub 0.9}Am{sub 0.1}O{sub 2±δ} is described as well as its characterisation. The use of this free-flowing precursor allows the pressing and sintering of one pellet of U{sub 0.9}Am{sub 0.1}O{sub 2±δ}. The ceramic obtained was characterised and results showed that its microstructure is dense and homogeneous and its density attains 95% of the theoretical density. This study validates the scientific feasibility of the CRMP process applied to the fabrication of uranium and americium-containing materials.

  9. Recovery of Americium-241 from lightning rod by the method of chemical treatment

    International Nuclear Information System (INIS)

    Cruz, W.H.

    2013-01-01

    About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ( 241 Am), fewer and Radium 226 ( 226 Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of 241 Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The 241 Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel 241 Am technique was used electrodeposition. (author)

  10. Comparison of acid leachate and fusion methods to determine plutonium and americium in environmental samples

    International Nuclear Information System (INIS)

    Smith, L.L.; Markun, F.; TenKate, T.

    1992-06-01

    The Analytical Chemistry Laboratory at Argonne National Laboratory performs radiochemical analyses for a wide variety of sites within the Department of Energy complex. Since the chemical history of the samples may vary drastically from site to site, the effectiveness of any analytical technique may also vary. This study compares a potassium fluoride-pyrosulfate fusion technique with an acid leachate method. Both normal and high-fired soils and vegetation samples were analyzed for both americium and plutonium. Results show both methods work well, except for plutonium in high-fired soils. Here the fusion method provides higher accuracy

  11. Influence of biofilms on migration of uranium, americium and europium in the environment

    International Nuclear Information System (INIS)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-01-01

    The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

  12. Rad Calc III: Radioanalysis calculation program for plutonium and americium determination

    International Nuclear Information System (INIS)

    Blackadar, J.M.; Wong, A.S.; Stalnaker, N.D.; Willerton, J.R.

    2000-01-01

    The radiochemistry team of the Analytical Chemistry Group has supported nuclear materials production and management programs at Los Alamos National Laboratory since the 1940s. Routinely, plutonium and americium contents in various matrices (such as metals, oxides, process solutions, and waste streams) are determined by direct alpha and gamma analyses. Over the years, analysts have written a number of computer programs to calculate analytical results. In 1999, the program was enhanced and upgraded to produce Rad Calc III. The new program, written in Visual Basic 4.0, corrects limitations of previous versions, offers enhanced features, and incorporates user suggestions to customize the program and make it more user friendly

  13. Recovery of americium from slag and crucible wastes and its purification

    International Nuclear Information System (INIS)

    Michael, K.M.; Dabholkar, G.M.; Vijayan, K.; Ramamoorthy, N.; Narayanan, C.V.; Jambunathan, U.; Kapoor, S.C.

    1990-01-01

    A method of recovery and purification of americium-241 from slag waste streams is described. Extraction of Am from slag solution of 0.16 M HNO 3 was carried out by tri-n-butyl phosphate. After stripping with acetic acid, Am was precipitated at pH 1. This was followed by metathesis to remove Ca. Final separation of Pu from Am solution was achieved by anion exchange method using Dowex 1x4 anion exchange resin. Details of large scale recovery of Am from slag are also described. (author). 12 refs., 11 tabs., 1 fig

  14. Distribution coefficients for plutonium and americium on particulates in aquatic environments

    International Nuclear Information System (INIS)

    Sanchez, A.L.; Schell, W.R.; Sibley, T.H.

    1982-01-01

    The distribution coefficients of two transuranic elements, plutonium and americium, were measured experimentally in laboratory systems of selected freshwater, estuarine, and marine environments. Gamma-ray emitting isotopes of these radionuclides, 237 Pu and 241 Am, were significantly greater than the sorption Ksub(d) values, suggesting some irreversibility in the sorption of these radionuclides onto sediments. The effects of pH and of sediment concentration on the distribution coefficients were also investigated. There were significant changes in the Ksub(d) values as these parameters were varied. Experiments using sterilized and nonsterilized samples for some of the sediment/water systems indicate possible bacterial effects on Ksub(d) values. (author)

  15. Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

    DEFF Research Database (Denmark)

    Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

    1986-01-01

    collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of latitude 65°N, while for 238Pu a substantial fraction originates from European nuclear fuel reprocessing facilities. The 238Pu/239+240Pu isotope ratio provides clear evidence of the transport of effluent...... of the Irish Sea) to Spitsbergen. 241Am found in Arctic waters probably originates from the decay of fallout 241Pu and, like Pu, tentatively has a residence time of the order of several years. Americium from Sellafield has an estimated mean residence time of 4–6 months in Scottish waters....

  16. Laboratory investigation of the role of desorption kinetics on americium transport associated with bentonite colloids.

    Science.gov (United States)

    Dittrich, Timothy Mark; Boukhalfa, Hakim; Ware, Stuart Douglas; Reimus, Paul William

    2015-10-01

    Understanding the parameters that control colloid-mediated transport of radionuclides is important for the safe disposal of used nuclear fuel. We report an experimental and reactive transport modeling examination of americium transport in a groundwater-bentonite-fracture fill material system. A series of batch sorption and column transport experiments were conducted to determine the role of desorption kinetics from bentonite colloids in the transport of americium through fracture materials. We used fracture fill material from a shear zone in altered granodiorite collected from the Grimsel Test Site (GTS) in Switzerland and colloidal suspensions generated from FEBEX bentonite, a potential repository backfill material. The colloidal suspension (100 mg L(-1)) was prepared in synthetic groundwater that matched the natural water chemistry at GTS and was spiked with 5.5 × 10(-10) M (241)Am. Batch characterizations indicated that 97% of the americium in the stock suspension was adsorbed to the colloids. Breakthrough experiments conducted by injecting the americium colloidal suspension through three identical columns in series, each with mean residence times of 6 h, show that more than 95% of the bentonite colloids were transported through each of the columns, with modeled colloid filtration rates (k(f)) of 0.01-0.02 h(-1). Am recoveries in each column were 55-60%, and Am desorption rate constants from the colloids, determined from 1-D transport modeling, were 0.96, 0.98, and 0.91 h(-1) in the three columns, respectively. The consistency in Am recoveries and desorption rate constants in each column indicates that the Am was not associated with binding sites of widely-varying strengths on the colloids, as one binding site with fast kinetics represented the system accurately for all three sequential columns. Our data suggest that colloid-mediated transport of Am in a bentonite-fracture fill material system is unlikely to result in transport over long distance scales because

  17. Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

    International Nuclear Information System (INIS)

    Guillou, P.

    1990-12-01

    The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

  18. Transmutation of americium and curium incorporated in zirconia-based host materials

    Energy Technology Data Exchange (ETDEWEB)

    Raison, P.E. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Combustibles; Haire, R.G. [Oak Ridge National Lab., TN (United States)

    2001-07-01

    Presented are studies involving the incorporation of americium and curium in zirconia-based materials. First explored was the pseudo ternary system AmO{sub 2}-ZrO{sub 2}-Y{sub 2}O{sub 3}. It was determined that selected Y-CSZ materials can incorporate significant quantities of americium oxide and remain cubic single-phase. The cell parameters of these fluorite-type products were established to be linear with the AmO{sub 2} content. The Cm{sub 2}O{sub 3}-ZrO{sub 2} system was also investigated. It was found that at 25 mol% of CmO{sub 1.5}, the Cm(III) stabilized zirconia in its cubic form (a = 5.21 {+-}0.01 Angstrom). At higher and lower concentrations, diphasic materials were encountered. At 50 mol% of CmO{sub 1.5}, a pyrochlore oxide - Cm{sub 2}Zr{sub 2}O{sub 7} - is formed (a = 10.63 {+-}0.02 Angstrom). (author)

  19. Fuel cycle covariance of plutonium and americium separations to repository capacity using information theoretic measures

    International Nuclear Information System (INIS)

    Scopatz, Anthony; Schneider, Erich; Li, Jun; Yim, Man-Sung

    2011-01-01

    A light water reactor, fast reactor symbiotic fuel cycle scenario was modeled and parameterized based on thirty independent inputs. Simultaneously and stochastically choosing different values for each of these inputs and performing the associated fuel cycle mass-balance calculation, the fuel cycle itself underwent Monte Carlo simulation. A novel information theoretic metric is postulated as a measure of system-wide covariance. This metric is the coefficient of variation of the set of uncertainty coefficients generated from 2D slices of a 3D contingency table. It is then applied to the fuel cycle, taking fast reactor used fuel plutonium and americium separations as independent variables and the capacity of a fully-loaded tuff repository as the response. This set of parameters is known from prior studies to have a strong covariance. When measured with all 435 other input parameters possible, the fast reactor plutonium and americium separations pair was found to be ranked the second most covariant. This verifies that the coefficient of variation metric captures the desired sensitivity of sensitivity effects in the nuclear fuel cycle. (author)

  20. Contribution to the prediction of americium, plutonium and neptunium behaviour in the geosphere: chemical data

    International Nuclear Information System (INIS)

    Robouch, P.

    1989-01-01

    An exhaustive bibliographic review on hydrolysis of americium gives the stability constants, at zero ionic strength. No evidence of Am(OH) 4 - formation was found by solubility studies up to pH 2 (CO 3 ) 3 characterised by its X-ray diffraction pattern is studied at a high ionic strength. All the published results on Am in carbonate media are reinterpreted using these stability constants (Am-OH-CO 3 complexes are not needed). No evidence of Am(CO 3 ) 4 5- formation was found by spectrophotometry up to 3M. Literature results are used to determine the formal redox potentials at pH = 9.4 and to calculate the formation constants, at zero ionic strength. The formation of complexes between americium and humic materials (purified fulvic and humic acids) has been studied by a spectrophotometric technique. The results are interpreted by the formation of a 1:1 complexe. Solubility of the solid PuO 2 (CO 3 ) is measured in bicarbonate media at high ionic strength, to obtain the solubility product and formation constants of the PuO 2 (CO 3 ) i 2-2i complexes [fr

  1. Production of a square geometry Americium standard source for use with photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Priscila; Geraldo, Bianca; Raele, Marcus P.; Marumo, Júlio T.; Vicente, Roberto; Zahn, Guilherme S.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    In the development of a thermal neutron detector using a square photodiode and a thin boron film, a radioactive calibration source with the same geometry was needed. An americium-243 standard source was produced by electrodeposition aiming at the calibration of a PIN-type silicon photodiode with a detection area of 10 x 10 mm{sup 2}. To produce the samples two tests were performed. In the first test, a square stainless steel plate (10 x 10 mm{sup 2}) was fixed on the surface of the conventional plate, which was removed after deposition. To reduce the loss of activity of the source, in the second test nail polish was applied on the silver plate leaving only an area of 10 x 10 mm{sup 2} without varnish coating. Once the electrodeposition process was completed, the activity concentration measurement was performed by alpha particle spectrometry. The first method presented a lower activity when compared to the total activity of Am-243 added initially. For the second method, the total activity was concentrate in the exposed square region (without nail polish). The results showed that it is possible to obtain a square geometry source; furthermore, the surrounding nail polish was not contaminated by {sup 243}Am. The comparison of these two approaches indicated that the second method was more efficient as it was possible to concentrate all the americium activity in the delimited square area. (author)

  2. Comparison of Americium-Beryllium neutron spectrum obtained using activation foil detectors and NE-213 spectrometer

    International Nuclear Information System (INIS)

    Sunny, Sunil; Subbaiah, K.V.; Selvakumaran, T.S.

    1999-01-01

    Neutron spectrum of Americium - Beryllium (α,n) source is measured with two different spectrometers vis-a-vis activation foils (foil detectors) and NE-213 organic scintillator. Activity induced in the foils is measured with 4π-β-γ sodium iodide detector by integrating counts under photo peak and the saturation activity is found by correcting to elapsed time before counting. The data on calculated activity is fed into the unfolding code, SAND-II to obtain neutron spectrum. In the case of organic scintillator, the pulse height spectrum is obtained using MCA and this is processed with unfolding code DUST in order to get neutron spectrum. The Americium - Beryllium (α,n) neutron spectrum thus obtained by two different methods is compared. It is inferred that the NE-213 scintillator spectrum is in excellent agreement with the values beyond 1MeV. Neutron spectrum obtained by activation foils depends on initial guess spectrum and is found to be in reasonable agreement with NE-213 spectrum. (author)

  3. The distribution of plutonium-239 and americium-241 in the Syrian hamster following its intravenous administration as citrate

    International Nuclear Information System (INIS)

    Rodwell, P.; Stather, J.W.

    1978-01-01

    Actinide distribution in various tissues and the skeleton of hamsters by liquid scintillation counting or isotope dilution. For plutonium 57% of activity was concentrated in the skeleton and more than 90% in the liver and skeleton after seven days. For americium the liver retained more than 50% of total activity and 25% was excreted in urine within seven days. (U.K.)

  4. Worldwide bioassay data resources for plutonium/americium internal dosimetry studies

    International Nuclear Information System (INIS)

    Miller, G.; Bertelli, L.; Little, T.; Guilmette, R.; Riddell, T.; Filipy, R.

    2005-01-01

    Full text: Biokinetic models are the scientific underpinning of internal dosimetry. These models describe how materials of interest taken into the body by various routes (for example inhalation) are transported through the body, allowing the modelling of bioassay measurements and the estimation of radiation dose. The International Commission on Radiation Protection (ICRP) publishes biokinetic models for use in internal dosimetry. These models represent the consensus judgement of a committee of experts, based on human and animal data. Nonetheless, it is important to validate biokinetic models using directly applicable data, in a scientifically transparent manner, especially for internal dosimetry research purposes (as opposed to radiation protection), as in epidemiology studies. Two major goals would be to determine individual variations of model parameters for the purpose of assessing this source of uncertainty in internal dose calculations, and to determine values of workplace specific parameters (such as particle solubility in lung fluids) for different representative workplaces. Furthermore, data on the observed frequency of intakes under various conditions can be used in the interpretation of bioassay data. All of the above may be couched in the terminology of Bayesian statistical analysis and amount to the determination of the Bayesian prior probability distributions needed in a Bayesian interpretation of bioassay data. The authors have direct knowledge of several significant databases of plutonium/americium bioassay data (including autopsy data). The purpose of this paper is to acquaint the worldwide community with these resources and to invite others who may know of other such databases to participate with us in a publication that would document the content, form, and the procedures for seeking access to these databases. These databases represent a tremendous scientific resource in this field. Examples of databases known to the authors include: the

  5. Complex formation of trivalent americium with salicylic acid at very low concentrations

    International Nuclear Information System (INIS)

    Melanie Mueller; Margret Acker; Steffen Taut; Gert Bernhard; Forschungszentrum Dresden-Rossendorf, Dresden

    2010-01-01

    For the first time, the complexation of americium(III) with salicylic acid was studied at trace metal concentrations using a 2.0 m Long Path Flow Cell for UV-vis spectroscopy. The detection limit of Am(III) in aqueous solution at pH 3.0 was found to be 5 x 10 -9 M. Two Am(III)-salicylate complexes were formed at pH 5.0 in 0.1 M NaClO 4 , indicated by a clear red shift of the absorption maximum. The absorption spectra obtained from spectrophotometric titration were analyzed by means of factor analysis and complex stabilities were calculated to be log β 110 = 2.56 ± 0.08 and log β 120 = 3.93 ± 0.19. (author)

  6. Plutonium and americium concentrations and vertical profiles in some Italian mosses used as bioindicators

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Meli, M.A.; Guerra, F.; Degetto, S.; Jia, G.; Gerdol, R.

    1998-01-01

    We have examined the uptake of actinide elements Am and Pu by different species of lichen and moss collected in two locations (Urbino, Central Italy; Alps region, North-east Italy). Plutonium and americium were separated and determined by extraction chromatography, electrodeposition and alpha-spectrometry. This paper summarizes our results with a special emphasis on the vertical profiles of these actinides in two different species of mosses. Several 1-2 cm depth sections were obtained and dated by 210 Pb method. A typical peak for 239,240 Pu and 241 Am was found in the very old moss species ('Sphagnum Compactum') at a depth corresponding to the period 1960-1970 which was the period characterized by the maximum nuclear weapon tests. In a younger moss species ('Neckeria Crispa') no peak was observed and the regression curves showed that Am is more mobile than 239,240 Pu and 238 Pu. (author)

  7. The uptake of plutonium-239, 240, americium-241, strontium-90 into plants

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Johnson, T.E.

    1984-01-01

    This report describes the results of measurements on the uptake of plutonium, americium, strontium-90 and caesium-137 into peas, beet, oats, sweet corn, tomatoes and vegetable marrow grown in tubs containing radioactively-contaminated silts. The silts had been taken from an area of West Cumbria commonly referred to as the Ravenglass estuary. The experiments are categorised as being carried out under non-standard conditions because of the manner in which the radioactivity came to be incorporated into the growth medium. The growth medium was representative of conditions which could arise when the estuarine silt moves inland under the influence of wind and tide and mixes with the adjacent farm land. The silt had been contaminated by radioactive effluents from the nuclear fuels reprocessing plant at Sellafield and this contamination had been brought about by natural means. (Auth.)

  8. Separation of trivalent americium and europium by purified Cyanex 301 immobilized in macro porous polymer

    International Nuclear Information System (INIS)

    Jing Chen; Veltkamp, A.C.; Booij, A.S.

    2002-01-01

    High separation ability of purified Cyanex 301 towards trivalent americium over europium in liquid-liquid extraction is confirmed. Solvent 2-nitrophenyl octyl ether (NPOE) lowered the partitioning of Am 3+ but remained the separation ability over europium. Solvent toluene and 3-octanone lowered the separation factor to ∼ 1000. It is feasible to separate Am 3+ from Eu 3+ by Cyanex 301 which was immobilized in the macro porous polymer (MPP). 3-Octanone is a suitable solvent for dissolving NH 4 OH-saponified Cyanex 301 and MPP is a suitable solid supported material for column operation. A five-step column experiment demonstrated the feasibility to separate Am 3+ from Eu 3+ in column which was packed with Cyanex 301-impregnated MPP. (author)

  9. Spectral properties of americium(III) in silicate matrices. Concentration-dependent up-conversion emission

    International Nuclear Information System (INIS)

    Assefa, Zerihun; Haire, R.G.; Stump, N.

    2002-01-01

    We have been pursuing the spectroscopic properties of actinide ions in silicate matrices. One facet of these studies involves the behavior of Stokes and anti-Stokes emissions exhibited by Am 3+ in these hosts. Several attributes have been found to influence the spectral profile, which include excitation wavelength, laser power, and dopant-concentration. Excitation with the 514.5 nm (19435 cm -1 ) line of argon laser provides anti-Stokes emissions at 21100 and ∼19920 cm -1 in the borosilicate matrices. This up-conversion was found to proceed through a multi-photon scheme, and the efficiency increases with increased dopant concentration. Based on our concentration-dependent studies, the up-conversion is suggested to involve a cross-relaxation process [( 5 D 1' , 7 F 0' ) ( 7 F 6' , 7 F 2' )] between neighboring americium ions. (author)

  10. Standard practice for The separation of americium from plutonium by ion exchange

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice describes the use of an ion exchange technique to separate plutonium from solutions containing low concentrations of americium prior to measurement of the 241Am by gamma counting. 1.2 This practice covers the removal of plutonium, but not all the other radioactive isotopes that may interfere in the determination of 241Am. 1.3 This practice can be used when 241Am is to be determined in samples in which the plutonium is in the form of metal, oxide, or other solid provided that the solid is appropriately sampled and dissolved (See Test Methods C758, C759, and C1168). 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  11. Magnesium ionophore II as an extraction agent for trivalent europium and americium

    Energy Technology Data Exchange (ETDEWEB)

    Makrlik, Emanuel [Czech Univ. of Life Sciences, Prague (Czech Republic). Faculty of Environmental Sciences; Vanura, Petr [Univ. of Chemistry and Technology, Prague (Czech Republic). Dept. of Analytical Chemistry

    2016-11-01

    Solvent extraction of microamounts of trivalent europium and americium into nitrobenzene by using a mixture of hydrogen dicarbollylcobaltate (H{sup +}B{sup -}) and magnesium ionophore II (L) was studied. The equilibrium data were explained assuming that the species HL{sup +}, HL{sup +}{sub 2}, ML{sup 3+}{sub 2}, and ML{sup 3+}{sub 3} (M{sup 3+} = Eu{sup 3+}, Am{sup 3+}; L=magnesium, ionophore II) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective magnesium ionophore II receptor for the Eu{sup 3+} and Am{sup 3+} cations could be considered as a potential extraction agent for nuclear waste treatment.

  12. Separation of oxidized americium from lanthanides by use of pillared metal(IV) phosphate-phosphonate hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Burns, J.D.; Clearfield, A. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Borkowski, M.; Reed, D.T. [Los Alamos National Laboratory, Carlsbad, NM (United States). Earth and Environmental Sciences Div.

    2012-07-01

    Closing the nuclear fuel cycle in the US poses many challenges, one of which is found in the waste streams, which contain both trivalent lanthanides and actinides. The separation of americium from the raffinate will dramatically reduce the long-term radiotoxicity of the waste. The sorption of americium in both the tri- and pentavalent oxidation states was observed for four M(IV) phosphate-phosphonate ion exchange materials in nitric acid at pH 2. High selectivity was observed for reduced Am(III) with K{sub d} values ca. 6 x 10{sup 5} mL/g, while the K{sub d} values for Am(V) were much lower. A new method of synthesizing and stabilizing AmO{sub 2}{sup +} to yield a lifetime of at least 24 h in acidic media using a combination of sodium persulfate and calcium hypochlorite will be described.

  13. Separation of oxidized americium from lanthanides by use of pillared metal(IV) phosphate-phosphonate hybrid materials

    International Nuclear Information System (INIS)

    Burns, J.D.; Clearfield, A.; Borkowski, M.; Reed, D.T.

    2012-01-01

    Closing the nuclear fuel cycle in the US poses many challenges, one of which is found in the waste streams, which contain both trivalent lanthanides and actinides. The separation of americium from the raffinate will dramatically reduce the long-term radiotoxicity of the waste. The sorption of americium in both the tri- and pentavalent oxidation states was observed for four M(IV) phosphate-phosphonate ion exchange materials in nitric acid at pH 2. High selectivity was observed for reduced Am(III) with K d values ca. 6 x 10 5 mL/g, while the K d values for Am(V) were much lower. A new method of synthesizing and stabilizing AmO 2 + to yield a lifetime of at least 24 h in acidic media using a combination of sodium persulfate and calcium hypochlorite will be described.

  14. Upper limits to americium concentration in large sized sodium-cooled fast reactors loaded with metallic fuel

    International Nuclear Information System (INIS)

    Zhang, Youpeng; Wallenius, Janne

    2014-01-01

    Highlights: • The americium transmutation capability of Integral Fast Reactor was investigated. • The impact from americium introduction was parameterized by applying SERPENT Monte Carlo calculations. • Higher americium content in metallic fuel leads to a power penalty, preserving consistent safety margins. - Abstract: Transient analysis of a large sized sodium-cooled reactor loaded with metallic fuel modified by different fractions of americium have been performed. Unprotected loss-of-offsite power, unprotected loss-of-flow and unprotected transient-over-power accidents were simulated with the SAS4A/SASSYS code based on the geometrical model of an IFR with power rating of 2500 MW th , using safety parameters obtained with the SERPENT Monte Carlo code. The Ti-modified austenitic D9 steel, having higher creep rupture strength, was considered as the cladding and structural material apart from the ferritic/martensitic HT9 steel. For the reference case of U–12Pu–1Am–10Zr fuel at EOEC, the margin to fuel melt during a design basis condition UTOP is about 50 K for a maximum linear rating of 30 kW/m. In order to maintain a margin of 50 K to fuel failure, the linear power rating has to be reduced by ∼3% and 6% for 2 wt.% and 3 wt.% Am introduction into the fuel respectively. Hence, an Am concentration of 2–3 wt.% in the fuel would lead to a power penalty of 3–6%, permitting a consumption rate of 3.0–5.1 kg Am/TW h th . This consumption rate is significantly higher than the one previously obtained for oxide fuelled SFRs

  15. Uptake of americium-241 by plants from contaminated Chernobyl exclusive zone test site soils

    International Nuclear Information System (INIS)

    Rashydov, N.M.

    2002-01-01

    Americium-241 was found to accumulate in soils and biological objects of the environment. Its concentration has increased many times after the Chernobyl disaster and can be expected to increase about 40 times in the future. This research concentrated on the contaminated exclusive Chernobyl zone polluted by trace radionuclides, their behavior and accumulation by various plant species. Special attention is devoted to the bioavailability of 241 Am to the plants Galium rivale, G. tinctorium, G. aparine, G. intermedium, Berteroa incana, Artemisia absinthium, A. vulgaris, Centaurea borysthenica, C. arenaria, Cirsium arvense, Succissa pratensis, Solidago virgaurea, Linaria vulgaris, Lepidium ruderale, Stenactis annua, Veronica maxima, Verbascum lychnitis, Euphorbia cyparissias, Genista tinctoria, Erigeron canadensis, Oenothera biennis, Betula pendula and Quercus robur, which were collected from the Chernobyl, Kopachi, and Yanov districts. The plant samples of Oenothera biennis, Betula pendula and Quercus robur were collected from the Yanov district, where the soil contamination by 241 Am and 137 Cs was at the level of 660 and 27 MBq/m 2 , respectively. Gamma spectroscopy and radiochemical methods were used to estimate the activity concentration of 137 Cs, 90 Sr, 238 Pu, 239+240 Pu, 241 Am. The radionuclides were measured in the dry green mass of the plant samples and in the dry soils. The contamination of the Oenothera biennis, Betula pendula and Quercus robur samples by 137 Cs was (5.8±1,5)x10 6 , (7.4±1.1)x10 5 , and (2.6±0.2)x10 6 Bq/kg dry mass, respectively, and contamination by 241 Am was 47±5, 45±3 and 3.2±0.2 Bq/kg, respectively. The soil-to-plant transfer ratio for 137 Cs ranged lay within the interval of 0.2 to 0.03 Bq/kg : Bq/m 2 , the the transfer ratio for 241 Am did not exceed 7x10 -5 Bq/kg : Bq/m 2 . The coefficient of the relative contents of the 241 Am/ 239+240 Pu radionuclides in the various plant samples varied from 3.2 to 8.3, while for soil from

  16. Contrasts between the marine and freshwater biological interactions of plutonium and americium

    International Nuclear Information System (INIS)

    Livingston, H.D.; Bowen, V.T.

    1975-01-01

    Whether in lakes or the oceans the transuranic elements plutonium and americium are taken up by marine organisms, with concentration factors that would class them as nice, typical heavy metals. There is no evidence for strong, widespread discrimination against the transuranics by either plant or animal absorptive surfaces. In both freshwater and marine situations the major reservoir of Pu and Am soon becomes the sediments, and organisms are more exposed to uptake of these nuclides the closer is their ecological involvement with the sediments. Although there is little evidence that this can be an ionic strength effect, it does appear that Pu may be somewhat more available, biologically, in marine environments, and Am, conversely, in fresh water. We incline to the belief that details of these behaviors are usually controlled by local availability of organic complexers. No compelling evidence exists of increase in Pu concentration at higher levels of food chains; in marine situations this appears true of Am as well, but a few data suggest that in fresh water fish there is a progressive increase, in higher trophic levels, in the ratio Am to Pu. Although marine and fresh water biogeochemistries of transuranics are much more similar than we had expected, it will generally be dangerous to extrapolate from one to the other. In both systems there appears to us no question that we are observing real element biogeochemistry, not the redistribution of inert, labelled, fallout fragments

  17. Multicompartment kinetic models for the metabolism of americium, plutonium and uranium in rats

    International Nuclear Information System (INIS)

    Sontag, W.

    1986-01-01

    To examine the kinetic behaviour of americium, plutonium and uranium in male and female rats, an extended mammillary model has been developed, composed of 10 compartments connected with 17 linear transfer coefficients. The 10 compartments describe the behaviour of the three nuclides in the blood, skeleton, liver and kidney; the remaining activity is assigned to one residual organ. Each organ is divided into two compartments, short- and long-term. In the skeleton the short-term compartment has been assumed to be the bone surface and marrow, and the long-term compartment the deep bone; in the liver, evidence suggests that the short-term compartment is physiologically associated with lysosomes and the long-term compartment identical with telolysosomes. Influence of age, sex and different nuclides on the transfer coefficients and the absorbed radiation dose are discussed. By using the transfer coefficients calculated for intravenous injection, the behaviour of the nuclides in skeleton and liver during continuous intake has been calculated. The behaviour of the three nuclides in skeleton and liver after intravenous injection has also been calculated with the additional assumption that from the fifth day the animals were treated continuously with a chelating agent. (UK)

  18. Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate

    Energy Technology Data Exchange (ETDEWEB)

    Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge

    2014-04-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.

  19. Speciation and bioavailability of Americium-241 in the fresh water environment

    International Nuclear Information System (INIS)

    Bierkens, J.

    1986-01-01

    Due to its anthropogenic origin, the transuranic americium 241 confronts physiologists with the intriguing question, which mechanisms are involved in the incorporation or elimination of such artificial elements in biological cycles. The investigations on the speciation and bioavailability of 241 Am in the freshwater environment aim to establish a relation between the behavior of 241 Am in freshwater ecosystems and its availability for biota. In the limnic environment, most often characterized by a high organic load and a low conductivity, the effect of complexation of 241 Am with humic acids and competition with trivalent cations such as A1 and Fe, were proven to be significant on the speciation of 241 Am. Based on the registration of the 241 Am uptake by a large number of freshwater organisms, the crayfish Astacus leptodactylus Eschscholtz was chosen to study the whole-body uptake of 241 Am, its corresponding organ distribution and its retention in the animal. The share of external fixation and ingestion in the global uptake, and the effect of speciation on it, were studied more carefully. Other aspects in this physiological part were: the kinetics of 241 Am in the hemolymph and the hepatopancreas, and its subcellular distribution in the digestive gland. Finally, by comparing the physiology of 241 Am with some other metals ( 240 Pu, 64 Cu, 198 Au) with analogous or contradictional properties, we tried to find out whether the behavior of 241 Am in organisms can be explained from its chemical characteristics

  20. Americium and plutonium in water, biota, and sediment from the central Oregon coast

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Reinald Dreas [Oregon State Univ., Corvallis, OR (United States)

    1982-06-01

    Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels.

  1. Americium and plutonium in water, biota, and sediment from the central Oregon coast

    International Nuclear Information System (INIS)

    Nielsen, R.D.

    1982-06-01

    Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels

  2. In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    William F. Bauer; Brian K. Schuetz; Gary M. Huestis; Thomas B. Lints; Brian K. Harris; R. Duane Ball; Gracy Elias

    2012-09-01

    Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dose estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.

  3. Removal of plutonium and Americium from hydrochloric acid waste streams using extraction chromatography

    International Nuclear Information System (INIS)

    Schulte, L.D.; FitzPatrick, J.R.; Salazar, R.R.; Schake, B.S.; Martinez, B.T.

    1995-01-01

    Extraction chromatography is under development as a method to lower actinide activity levels in hydrochloric acid (HCl) effluent streams. Successful application of this technique for radioactive liquid waste treatment would provide a low activity feedstream for HCl recycle, reduce the loss of radioactivity to the environment in aqueous effluents, and lower the quantity and improve the form of solid waste generated. The extraction of plutonium and americium from HCl solutions was examined for several commercial and laboratory-produced sorbed resin materials. Polymer beads were coated with n-octyl(phenyl)-N,N-diisobutylcarbamoyl- methylphosphine oxide (CMPO) and either tributyl phosphate (TBP), or diamyl amylphosphonate (DAAP). Distribution coefficients for Pu and Am were measured by contact studies in 1-10 M HCl, while varying REDOX conditions, actinide loading levels, and resin formulations. Flow experiments were run to evaluate actinide loading and elution under varied conditions. Significant differences in the actinide distribution coefficients in contact experiments, and in actinide retention in flow experiments were observed as a function of resin formulation

  4. Cleanex process: a versatile solvent extraction process for recovery and purification of lanthanides, americium, and curium

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Collins, E.D.; King, L.J.

    1979-01-01

    At a concentration of 1 M in straight-chain hydrocarbon diluent, HDEHP will extract americium, curium, and other trivalent actinide and lanthanide elements from dilute acid or salt solutions. The solute is back-extracted with more concentrated acid, either nitric or hydrochloric. The process has been used in the continuous, countercurrent mode, but its greatest advantage arises in batch extractions where the excess acid can be titrated with NaOH to produce a final acidity of about 0.03 M. Under these conditions, 99% recovery can be achieved, usually in one stage. Cleanex was used on the 50-liter scale at the Transuranium Processing Plant at Oak Ridge for 12 years to provide a broad spectrum cleanup to transuranium elements before applying more sophisticated techniques for separating individual products. The process is also used routinely to recover excessive losses of curium and/or californium from plant waste streams. The solvent system is relatively resistant to radiation damage, being usable up to 200 W-h/liter

  5. Assessment of radiation doses from residential smoke detectors that contain americium-241

    International Nuclear Information System (INIS)

    O'Donnell, F.R.; Etnier, E.L.; Holton, G.A.; Travis, C.C.

    1981-10-01

    External dose equivalents and internal dose commitments were estimated for individuals and populations from annual distribution, use, and disposal of 10 million ionization chamber smoke detectors that contain 110 kBq (3 μCi) americium-241 each. Under exposure scenarios developed for normal distribution, use, and disposal using the best available information, annual external dose equivalents to average individuals were estimated to range from 4 fSv (0.4 prem) to 20 nSv (2 μrem) for total body and from 7 fSv to 40 nSv for bone. Internal dose commitments to individuals under post disposal scenarios were estimated to range from 0.006 to 80 μSv (0.0006 to 8 mrem) to total body and from 0.06 to 800 μSv to bone. The total collective dose (the sum of external dose equivalents and 50-year internal dose commitments) for all individuals involved with distribution, use, or disposal of 10 million smoke detectors was estimated

  6. Study of biosorbents application on the treatment of radioactive liquid wastes with americium-241

    International Nuclear Information System (INIS)

    Borba, Tania Regina de

    2010-01-01

    The use of nuclear energy for many different purposes has been intensified and highlighted by the benefits that it provides. Medical diagnosis and therapy, agriculture, industry and electricity generation are examples of its application. However, nuclear energy generates radioactive wastes that require suitable treatment ensuring life and environmental safety. Biosorption and bioaccumulation represent an emergent alternative for the treatment of radioactive liquid wastes, providing volume reduction and physical state change. This work aimed to study biosorbents for the treatment of radioactive liquid wastes contaminated with americium-241 in order to reduce the volume and change the physical state from liquid to solid. The biosorbents evaluated were Saccharomyces cerevisiae immobilized in calcium alginate beads, inactivated and free cells of Saccharomyces cerevisiae, calcium alginate beads, Bacillus subtilis, Cupriavidus metallidurans and Ochrobactrum anthropi. The results were quite satisfactory, achieving 100% in some cases. The technique presented in this work may be useful and viable for implementing at the Waste Management Laboratory of IPEN - CNEN/SP in short term, since it is an easy and low cost method. (author)

  7. Separation of neptunium, plutonium, americium and curium from uranium with di-(2-ethylhexyl)-phosphoric acid (HDEHP) for radiometric and ICP-MS analysis

    International Nuclear Information System (INIS)

    Ramebaeck, H.; Skaalberg, M.

    1998-01-01

    The possibility of using di-(2-ethylhexyl)-phosphoric acid (HDEHP) in solvent extraction for the separation of neptunium, plutonium, americium and curium from large amounts of uranium was studied. Neptunium, plutonium, americium and curium (as well as uranium) were extracted from HNO 3 , whereafter americium and curium were back-extracted with 5M HNO 3 . Thereafter was neptunium back-extracted in 1M HNO 3 containing hydroxylamine hydronitrate. Finally, plutonium was back-extracted in 3M HCl containing Ti(III). The method separates 238 Pu from 241 Am for α-spectroscopy. For ICP-MS analysis, the interferences from 238 U are eliminated: tailing from 238 U, for analysis of 237 Np, and the interference of 238 UH + for analysis of 239 Pu. The method has been used for the analysis of actinides in samples from a spent nuclear fuel leaching and radionuclide transport experiment. (author)

  8. Use of radioisotopes in the study of tetracycline analytical application. Extraction of compounds formed between tetracycline and neptunium and americium elements

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W. de

    1986-01-01

    The behavior of tetracycline as complexing agent, in solvent extraction studies of neptunium and americium, using benzyl alcohol as the organic phase, is presented. By using radioactive tracers of 239 Np and 2 4 1 Am the extraction percent of these elements were determined as a function of pH in the absence and in the presence of several masking agents. The influence of shaking time and the use of different types of supporting eletrolytes upon the extraction behavior was also studied. The extraction curves obtained using EDTA as masking agent show that tetracycline can be used for neptunium and americium separation. In this condition neptunium is extracted into the organic phase and americium remains in the aqueous phase. (Author) [pt

  9. Transport of plutonium, americium, and curium from soils into plants by roots

    International Nuclear Information System (INIS)

    Pimpl, M.; Schuettelkopf, H.

    1979-12-01

    For assessing the dose from radionuclides in agricultural products by ingestion it is necessary to know the soil to plant transfer factors. The literature was entirely investigated, in order to judge the size of the soil to plant transfer factors. In total, 92 publications - from 1948 to 1978 -have been evaluated. As result, transfer factors from 10 -9 to 10 -3 have been found for Plutonium, and from 10 -6 to 1 for Americium. For Curium only few data are available in literature. The considerable variation of the measured transfer factors is based on the dependence of these transfer factors from the ion exchange capacity of soils, from the amount of organic materials, from the pH-value, and from the mode of contamination. There are, in any case, contradictory data, although there has been detected a dependence of the transfer factors from these parameters. Chelating agenst increase the transfer factors to approximately 1300. As well, fertilizers have an influence on the size of the transfer factors - however, the relationships have been scarcely investigated. The distribution of actinides within the individual parts of plants has been investigated. The highest concentrations are in the roots; in the plant parts above ground the concentration of actinides decreases considerably. The most inferior transfer factors were measured for the respective seed or fruits. The soil to plant transfer factors of actinides are more dependend on the age of the plants within one growing period. At the beginning of the period, the transfer factor is considerably higher than at the end of this period. With respect to plants with a growing period of several years, correlations are unknown. (orig.) [de

  10. Experiments comparing the uptake of americium from chloride media using extraction chromatography

    International Nuclear Information System (INIS)

    FitzPatrick, J.R.; Schake, B.S.; Schulte, L.D.; Martinez, B.T.; Salazar, R.R.

    1995-01-01

    Clean-up of actinide effluent waste steams is of increasing importance at the Los Alamos Plutonium Facility, TA-55, and removing the actinide elements to very low levels allows less radioactivity to go the Los Alamos National Laboratory Water Treatment Facility, TA-50, thus reducing the number of drums of TRU waste. Americium (Am) is a difficult element to remove from chloride media because the +3 state is difficult to oxidize and chelating resins work better with elements such as plutonium which are more readily oxidized to the +4 and/or +6 state. Currently in hydrochloric acid (HC1) media, the acidic liquid waste is neutralized with potassium hydroxide to precipitate the metal hydroxides, before disposal to TA-50. This process is not very efficient. The removal of Am from chloride media was compared using a series of resins, some commercial and some made in our laboratory, using different percentages by weight of octyl(phenyl)-N,N-diiso- butylcarbamoyl-methylphosphine oxide (CMPO ) along with diamyl amylphosphonate (DAAP) or tributyl phosphate (TBP) as diluents. Resins were also made with no added diluent. Early comparisons using small-scale contact studies with 0.5 grams of resin in 0.1M-12M HC1, and subsequent small-scale flow experiments show a trend in which Am uptake is proportional to the amount of CMPO on the resins and the diluent plays a minor role in the uptake of Am from these solutions. Redox chemistry effects were also investigated. From these studies, it is possible to determine the best conditions for the removal of Am from HC1 media thus reducing the gross alpha content of the waste stream by a factor of 10-100 which reduces the number of barrels of waste produced at the Water Treatment Facility

  11. Concentration and vertical distribution of plutonium and americium in Italian mosses and lichens

    International Nuclear Information System (INIS)

    Jia, G.; Desideri, D.; Guerra, F.; Meli, M.A.; Testa, C.

    1997-01-01

    The plutonium and americium concentration and vertical distribution in some Italian mosses and lichens have been determined. The 239,240 Pu, 238 Pu and 241 Am concentration ranges in tree trunk lichens 0.83-1.87, 0.052-0.154 and 0.180-0.770 Bq/kg, respectively. The corresponding values in tree mosses are higher and more scattered ranging from 0.321 to 4.96, from 0.029 to 0.171 and from 0.200 to 1.93 Bq/kg. The mean 238 Pu/ 239,240 Pu and 241 Am/ 239,240 Pu ratios are 0.088±0.037 and 0.38 ± 0.13 in lichens and 0.091±0.072 and 0.54±0.16 in tree mosses. The Pu and Am concentrations are relatively low in terrestrial mosses. The 239,240 Pu, 238 Pu and 241 Am vertical distributions in a terrestrial moss core (Neckera Crispa) collected near Urbino (central Italy) show an exponential decrease with the height. On the contrary the 241 Am vertical distribution in another terrestrial moss core (Sphagnum Compactum) collected in the Alps (northern Italy) shows an interesting peak at 16 cm which corresponds to the deposition of fallout from the nuclear weapon tests in 1960's. The 241 Am movement upward and downward in the moss core is also studied. The results show once again that both mosses and lichens are very effective accumulators of Pu and Am and that they can be used as good biological indicators of the radionuclide airborne pollution from nuclear facilities and nuclear weapon tests. They can play a very important role in cycling naturally or artificially enhanced radionuclides in the atmosphere over long time scales. (author)

  12. Americium/Lanthanide Separations in Alkaline Solutions for Advanced Nuclear Fuel Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Goff, George S. [Los Alamos National Laboratory; Long, Kristy Marie [Los Alamos National Laboratory; Reilly, Sean D. [Los Alamos National Laboratory; Jarvinen, Gordon D. [Los Alamos National Laboratory; Runde, Wolfgang H. [Los Alamos National Laboratory

    2012-06-11

    Project goals: Can used nuclear fuel be partitioned by dissolution in alkaline aqueous solution to give a solution of uranium, neptunium, plutonium, americium and curium and a filterable solid containing nearly all of the lanthanide fission products and certain other fission products? What is the chemistry of Am/Cm/Ln in oxidative carbonate solutions? Can higher oxidation states of Am be stabilized and exploited? Conclusions: Am(VI) is kinetically stable in 0.5-2.0 M carbonate solutions for hours. Aliquat 336 in toluene has been successfully shown to extract U(VI) and Pu(VI) from carbonate solutions. (Stepanov et al 2011). Higher carbonate concentration gives lower D, SF{sub U/Eu} for = 4 in 1 M K{sub 2}CO{sub 3}. Experiments with Am(VI) were unsuccessful due to reduction by the organics. Multiple sources of reducing organics...more optimization. Reduction experiments of Am(VI) in dodecane/octanol/Aliquat 336 show that after 5 minutes of contact, only 30-40% of the Am(VI) has been reduced. Long enough to perform an extraction. Shorter contact times, lower T, and lower Aliquat 336 concentration still did not result in any significant extraction of Am. Anion exchange experiments using a strong base anion exchanger show uptake of U(VI) with minimal uptake of Nd(III). Experiments with Am(VI) indicate Am sorption with a Kd of 9 (10 minute contact) but sorption mechanism is not yet understood. SF{sub U/Nd} for = 7 and SF{sub U/Eu} for = 19 after 24 hours in 1 M K{sub 2}CO{sub 3}.

  13. Determination of americium and curium using ion-exchange in the nitric-acid-methanol medium for environmental analysis

    International Nuclear Information System (INIS)

    Holm, E.; Fukai, R.

    1976-01-01

    While transplutonic elements are only slightly sorbed to anion exchangers from hydrochloric or nitric acid media, the presence of alcohol enhances the anionic exchange of these elements, especially in nitric and sulfuric solutions. In the present work a method has been developed for determining americium and curium in environmental samples, on the basis of the difference between the sorption characteristics to anion exchangers in the acid-methanol system of these transplutonic elements and those of plutonium, polonium and thorium. The method also permits us to perform sequential determination of plutonium, when necessary

  14. Temperature and concentration dependences of the electrical resistivity for alloys of plutonium with americium under normal conditions

    Science.gov (United States)

    Tsiovkin, Yu. Yu.; Povzner, A. A.; Tsiovkina, L. Yu.; Dremov, V. V.; Kabirova, L. R.; Dyachenko, A. A.; Bystrushkin, V. B.; Ryabukhina, M. V.; Lukoyanov, A. V.; Shorikov, A. O.

    2010-01-01

    The temperature and concentration dependences of the electrical resistivity for alloys of americium with plutonium are analyzed in terms of the multiband conductivity model for binary disordered substitution-type alloys. For the case of high temperatures ( T > ΘD, ΘD is the Debye temperature), a system of self-consistent equations of the coherent potential approximation has been derived for the scattering of conduction electrons by impurities and phonons without any constraints on the interaction intensity. The definitions of the shift and broadening operator for a single-electron level are used to show qualitatively and quantitatively that the pattern of the temperature dependence of the electrical resistivity for alloys is determined by the balance between the coherent and incoherent contributions to the electron-phonon scattering and that the interference conduction electron scattering mechanism can be the main cause of the negative temperature coefficient of resistivity observed in some alloys involving actinides. It is shown that the great values of the observed resistivity may be attributable to interband transitions of charge carriers and renormalization of their effective mass through strong s-d band hybridization. The concentration and temperature dependences of the resistivity for alloys of plutonium and americium calculated in terms of the derived conductivity model are compared with the available experimental data.

  15. Osteosarcoma induction by plutonium-239, americium-241 and neptunium-237 : the problem of deriving risk estimates for man

    International Nuclear Information System (INIS)

    Taylor, D.M.

    1988-01-01

    Spontaneous bone cancer (osteosarcoma) represents only about 0.3% of all human cancers, but is well known to be inducible in humans by internal contamination with radium-226 and radium-224. plutonium-239, americium-241 and neptunium-237 form, or will form, the principal long-lived alpha particle emitting components of high activity waste and burnt-up nuclear fuel elements. These three nuclides deposit extensively in human bone and although, fortunately, no case of a human osteosarcoma induced by any of these nuclides is known, evidence from animal studies suggests that all three are more effective than radium-226 in inducing osteosarcoma. The assumption that the ratio of the risk factors, the number of osteosarcoma expected per 10000 person/animal Gy, for radium-226 and any other bone-seeking alpha-emitter will be independent of animal species has formed the basis of all the important studies of the radiotoxicity of actinide nuclides in experimental animals. The aim of this communication is to review the risk factors which may be calculated from the various animal studies carried out over the last thirty years with plutonium-237, americium-241 and neptunium-237 and to consider the problems which may arise in extrapolating these risk factors to homo sapiens

  16. The photoluminescence of crystallophosphors on the base of NaBi(WO4)2 activated by americium, plutonium and neptunium

    International Nuclear Information System (INIS)

    Gliva, V.R.; Novikov, Yu.P.; Myasoedov, B.F.

    1989-01-01

    The luminescence properties of crystallophosphors based on NaBi(WO 4 ) 2 activated by americium, plutonium and neptunium were studied. The synthesis of crystallophosphors is described. Crystallophosphors luminesce in the near infrared region. The excitation and luminescence spectra of crystallophosphors are considered. The dependence of luminescence yield is linear in the wide interval of activator concentration. (author) 3 refs.; 4 figs

  17. Peculiar Behavior of (U,Am)O(2-δ) Compounds for High Americium Contents Evidenced by XRD, XAS, and Raman Spectroscopy.

    Science.gov (United States)

    Lebreton, Florent; Horlait, Denis; Caraballo, Richard; Martin, Philippe M; Scheinost, Andreas C; Rossberg, Andre; Jégou, Christophe; Delahaye, Thibaud

    2015-10-19

    In U(1-x)Am(x)O(2±δ) compounds with low americium content (x ≤ 20 atom %) and oxygen-to-metal (O/M) ratios close to 2.0, Am(III+) cations are charge-balanced by an equivalent amount of U(V+) cations while the fluorite structure of pure U(IV+)O2 is maintained. Up to now, it is unknown whether this observation also holds for higher americium contents. In this study, we combined X-ray diffraction with Raman and X-ray absorption spectroscopies to investigate a U(0.5)Am(0.5)O(2±δ) compound. Our results indicate that americium is again only present as Am(III+), while U(V+) remains below the amount required for charge balance. Unlike lower americium contents, this leads to an overall oxygen hypostoichiometry with an average O/M ratio of 1.92(2). The cationic sublattice is only slightly affected by the coexistence of large amounts of reduced (Am(III+)) and oxidized (U(V+)) cations, whereas significant deviations from the fluorite structure are evidenced by both extended X-ray absorption fine structure and Raman spectroscopies in the oxygen sublattice, with the observation of both vacancies and interstitials, the latter being apparently consistent with the insertion of U6O12 cuboctahedral-type clusters (as observed in the U4O9 or U3O7 phases). These results thus highlight the specificities of uranium-americium mixed oxides, which behave more like trivalent lanthanide-doped UO2 than U(1-x)Pu(x)O(2±δ) MOX fuels.

  18. Chemical behaviour of trivalent and pentavalent americium in saline NaCl-solutions. Studies of transferability of laboratory data to natural conditions. Interim report. Reported period: 1.2.1993-31.12.1993; Chemisches Verhalten von drei- und fuenfwertigem Americium in Salinen NaCl-Loesungen. Untersuchung der Uebertragbarkeit von Labordaten auf natuerliche Verhaeltnisse. Zwischenbericht. Berichtszeitraum 1.2.1993-31.12.1993

    Energy Technology Data Exchange (ETDEWEB)

    Runde, W.; Kim, J.I.

    1994-09-15

    In order to clarify the chemical behaviour of Americium in saline aqueous systems relevant for final storage this study deals with the chemical reactions of trivalent and pentavalent Americium in NaCl-solutions under the influence of radiolysis from its own alpha radiation. The focus of the study was on investigating the geologically relevant reactions, such as hydrolysis or carbonate- and chloride complexing in solid-liquid equilibriums. Comprehensive measurements on solubility and spectroscopic studies in NaCl-solutions were carried out in a CO{sub 2}-free atmosphere and 10{sup -2} atm CO{sub 2} partial pressure. Identification and characterisation of the AM (III) and AM(V) solid phases were supplemented by structural research with the chemically analogue EU (III) and Np(V) compounds. The alpha-radiation induced radiolysis in saline NaCl solutions and the redox behaviour of Americium which was influenced thereby were spectroscopically quantified. (orig.) [Deutsch] Zur Klaerung des chemischen Verhaltens von Americium in endlagerrelevanten salinen aquatischen Systemen befasst sich die vorliegende Arbeit mit den chemischen Reaktionen des drei- und fuenfwertigen Americiums in NaCl-Loesungen unter dem Einfluss der Radiolyse durch die eigene {alpha}-Strahlung. Der Schwerpunkt dieser Arbeit lag auf der Untersuchung der geologisch relevanten Reaktionen, wie Hydrolyse sowie Carbonat- und Chloridkomplexierung in fest-fluessig Gleichgewichtssystemen. Hierzu wurden umfassende Loeslichkeitsmessungen und spektroskopische Untersuchungen in NaCl-Loesungen, sowohl unter CO{sub 2}-freier Atmosphaere als auch unter 10{sup -2} atm CO{sub 2}-Partialdruck, durchgefuehrt. Die Identifizierung und Charakterisierung der Am(III)- und Am(V)-Festphasen wurde ergaenzt durch strukturelle Untersuchungen mit den chemisch analogen Eu(III)- und Np(V)-Verbindungen. Die von der {alpha}-Strahlung induzierte Radiolyse in salinen NaCl-Loesungen und das dadurch beeinflusste Redoxverhalten von Americium

  19. Sequential separation method for the determination of Plutonium and Americium in fecal samples

    International Nuclear Information System (INIS)

    Raveendran, Nanda; Rao, D.D.; Yadav, J.R.; Baburajan, A.

    2014-01-01

    The estimation of internal contamination due to Plutonium and Americium of radiation workers of Advanced Fuel Fabrication Facility (AFFF) at Tarapur was carried out by the bioassay (Fecal sample) of the workers. Conventionally the separation of 'Pu' and 'Am' was carried out by alkali fusion followed by the anion exchange separation for Pu and cation exchange separation for Am. This paper deals with an alternative method in which initially the entire ash of the sample added with 236 Pu tracer (3-11 mBq) and 243 Am tracer (2.8-14.5 mBq) was acid leached and Pu was separated by anion exchange as per standard analytical procedure and Am by using TRU resin. In this work the extraction chromatography method using TRU resin procured from Eichrom,U.K. which contains N-N-di isobutyl carbanoyl methyl phosphine oxide (CMPO) as extractant, tri-n-butyl phosphate (TBP) as diluent absorbed on inert polymeric support has been used for the separation of Am from fecal sample. The 8N HNO 3 effluent from Pu separation step was dried and the residue was dissolved in 10 ml 1M Al(NO 3 ) 3 in 3M HNO 3 and pinch of Ascorbic acid was added and loaded on a TRU resin column (dia ∼ 4 mm and height 60 mm) preconditioned with 30 ml 1M Al(NO 3 ) 3 in 3 MHNO 3 . The column was washed with 5 ml 3M HNO 3 and 5 ml 2M HNO 3 . The nitrate concentration was lowered using addition of 10 ml 0.05 M HNO 3 . Am was eluted with 3 ml 9M HCl and 20 ml 2M HCl. The elute was dried and electrodeposited on a SS planchet in NH 4 (SO 4 ) 2 solution at pH 2.2 for two hours. Pu and Am activity estimated by counting in passivated ion implanted planner Silicon detector (PIPS) coupled to 8K channel alpha spectrometer. The sample was counted for duration of 3-4 lacs of seconds. In this study the numbers of samples analyzed are 25. The paper gives detail of analytical recoveries of Pu tracer varies from 55-90 % with a mean of 70% and std. deviation 9.9%. The Am tracer recovery was in the range of 20-89.3% with a mean of

  20. Crystallographic and Spectroscopic Characterization of Americium Complexes Containing the Bis[(phosphino)methyl]pyridine-1-oxide (NOPOPO) Ligand Platform

    Energy Technology Data Exchange (ETDEWEB)

    Corbey, Jordan F. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Rapko, Brian M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Wang, Zheming [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; McNamara, Bruce K. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Surbella, Robert G. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Pellegrini, Kristi L. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Schwantes, Jon M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States

    2018-02-06

    Abstract The crystal structures of americium species containing a common multi-functional phosphine oxide ligand, reported for its ability to extract f elements from acidic solutions, namely 2,6-[Ph2P(O)CH2]2C5H3-NO, L, have finally been determined after over three decades of separations studies involving these species and their surrogates. The molecular compounds Am(L)(NO3)3, Am 1:1, and [Am(L)2(NO3)][NO3]2, Am 2:1, along with their neodymium and europium analogs were synthesized and characterized using single-crystal X-ray crystallography, attenuated total reflectance Fourier transform infrared (ATR) spectroscopy and luminescence spectroscopy to provide a comprehensive comparison with new and known analogous complexes.

  1. Moessbauer spectroscopy of 237Np created by α-decay of 241Am in some compounds of americium

    International Nuclear Information System (INIS)

    Rebizant, Jean.

    1977-01-01

    The Moessbauer emission spectra of 237 Np impurities fed by α decay of 241 Am were measured in the following compounds: Am metal, AmPtsub(x) (x=1, 3, 5), AmAs, AmBi, Am 2 O 3 , AmO 2 , Lisub(x)AmOsub(x+1) (x=1, 2, 3, 4) and Li 6 AmO 6 . The studies concerned the consequences of the recoil and ionization effects, associated with the α-decay of 241 Am in the solid phase; these are analysed in situ and on a time scale of about 100 ns after the α emission; the dependence of these effects on the physico-chemical nature of the host and on the temperature; information about the electronic, magnetic and structural properties and, also, about the vibrational properties of the Np impurity in the investigated solid matrice as far as the previous effects do not hamper such conclusions. The existence itself of the Moessbauer effect shows that the Np ions are stabilized in well-defined lattice locations at the time of emission of the 59.5keV γ quanta (approximately 100ns), once this level is reached after the 241 Am decay. In Am metal and AmPtsub(x) alloys, the observation of a single charge state for neptunium indicates that the electronic effects associated with the α-decay are recovered in less than 100ns. In the americium oxide compounds and the monopnictides AmAs and AmBi, several charge states of neptunium recoil ions are observed; this shows unambiguously the importance of the ionization effects caused by the α-decay. Some informations about magnetic and electronic properties of the americium host matrices were obtained. The vibration modes of 237 Np impurities in the lattice of Am metal are described by means of the Debye model with a characteristic temperature thetasub(D)=115K [fr

  2. Separation of americium by liquid-liquid extraction using diglycol-amides water-soluble complexing agents

    Energy Technology Data Exchange (ETDEWEB)

    Chapron, S.; Marie, C.; Pacary, V.; Duchesne, M.T.; Miguirditchian, M. [CEA, Centre de Marcoule, Nuclear Energy Division, RadioChemistry and Processses Departement, 30207 Bagnols-sur-Ceze (France); Arrachart, G.; Pellet-Rostaing, S. [Institut de Chimie Separative de Marcoule, LTSM, Bat 426, F-30207 Bagnols-sur- Ceze (France)

    2016-07-01

    Recycling americium (Am) alone from spent nuclear fuels is an important option studied for the future nuclear cycle (Generation IV systems) since Am belongs to the main contributors of the long-term radiotoxicity and heat power of final waste. Since 2008, a liquid-liquid extraction process called EXAm has been developed by the CEA to allow the recovery of Am alone from a PUREX raffinate (a dissolution solution already cleared from U, Np and Pu). A mixture of DMDOHEMA (N,N'-dimethyl-N,N'-dioctyl-2-(2-(hexyloxy)ethyl)-malonamide) and HDEHP (di-2-ethylhexylphosphoric acid) in TPH is used as the solvent and the Am/Cm selectivity is improved using TEDGA (N,N,N',N'-tetraethyl-diglycolamide) as a selective complexing agent to maintain Cm and heavier lanthanides in the acidic aqueous phase (5 M HNO{sub 3}). Americium is then stripped selectively from light lanthanides at low acidity (pH=3) with a poly-aminocarboxylic acid. The feasibility of sole Am recovery was already demonstrated during hot tests in ATALANTE facility and the EXAm process was adapted to a concentrated raffinate to optimize the process compactness. The speciation of TEDGA complexes formed in the aqueous phase with Am, Cm and lanthanides was studied to better understand and model the behavior of TEDGA in the process. Some Ln-TEDGA species are extracted into the organic phase and this specific chemistry might play a role in the Am/Cm selectivity improvement. Hence the hydrophilicity-lipophilicity balance of the complexing agent is an important parameter. In this comprehensive study, new analogues of TEDGA were synthesized and tested in the EXAm process conditions to understand the relationship between their structure and selectivity. New derivatives of TEDGA with different N-alkyl chain lengths and ramifications were synthesized. The impact of lipophilicity on ligand partitioning and Am/Cm selectivity was investigated. (authors)

  3. Inspection report of unauthorized possession and use of unsealed americium-241 and subsequent confiscation, J.C. Haynes Company, Newark, Ohio

    International Nuclear Information System (INIS)

    1985-11-01

    This US Nuclear Regulatory Commission report documents the circumstances surrounding the March 26, 1985, confiscation and subsequent decontamination activities related to the use of unauthorized quantities of americium-241 at the John C. Haynes Company (licensee) of Newark, Ohio. It focuses on the period from early February to July 26, 1985. The incident started when NRC Region III recieved information that John C. Haynes possessed unauthorized quantities of americium-241 and was conducting unauthorized activities (diamond irradiation). By July 26, 1985, the decontamination activities at the licensee's laboratory were concluded. The licensee's actions with diamond irradiation resulted in contamination in restricted and unrestricted areas of the facility. The confiscation and decontamination activities required the combined efforts of NRC, Federal Bureau of Investigation, US Department of Energy, Oak Ridge Associated Universities, the State of Ohio, and the US Environmental Protection Agency. The report describes the factual information and significant findings associated with the confiscation and decontamination activities

  4. Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1991-12-01

    The Americium 241 radioelement accumulation and elimination rate and mechanisms in the lobster organism have been experimentally studied; incorporation and detoxification capacities of each organ are evaluated. The existence of various biological compartments is shown; the major role of the digestive gland in accumulation of the radioelement, its distribution towards the various organs, and its resorption is comprehensively described, with an analysis at the subcellular and molecular levels. 401 p., 65 fig., 43 tab., 428 ref

  5. An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1993-01-01

    An experimental study of americium-241 kinetics has been conducted in the lobster Homarus gammmarus. The investigations were conducted at all the levels from the whole body to the subcellular and molecular levels. The animals were contaminated by a single or chronic ingestion of 241 Am labelled mussels. Assessments of accumulation, elimination and distribution of the radionuclide were established on organisms kept in the laboratory; they made it possible to demonstrate the importance of the digestive gland in the radionuclide transfer pathways. The preliminary results led to structural then ultrastructural investigations of the digestive gland in association with radioautographic studies and cellular extractions methods. Four cellular types were demonstrated, only two of them being implied in the radionuclide retention, the former being responsible for americium intake and the latter for its long-term retention. By means of biochemical techniques, subcellular accumulation was studied and the organelles implied in the nuclide retention were specified. Finally, a method of cellular nuclei dissociation was developed; it made it possible to analyse the molecular nature of americium ligands and to demonstrate the function of the protein nuclear matrix in the nuclide retention

  6. Preliminary results from uranium/americium affinity studies under experimental conditions for cesium removal from NPP ''Kozloduy'' simulated wastes solutions

    International Nuclear Information System (INIS)

    Nikiforova, A.; Kinova, L.; Peneva, C.; Taskaeva, I.; Petrova, P.

    2005-01-01

    We use the approach described by Westinghouse Savannah River Company using ammonium molybdophosphate (AMP) to remove elevated concentrations of radioactive cesium to facilitate handling waste samples from NPP K ozloduy . Preliminary series of tests were carried out to determine the exact conditions for sufficient cesium removal from five simulated waste solutions with concentrations of compounds, whose complexing power complicates any subsequent processing. Simulated wastes solutions contain high concentrations of nitrates, borates, H 2 C 2 O 4 , ethylenediaminetetraacetate (EDTA) and Citric acid, according to the composition of the real waste from the NPP. On this basis a laboratory treatment protocol was created. This experiment is a preparation for the analysis of real waste samples. In this sense the results are preliminary. Unwanted removal of non-cesium radioactive species from simulated waste solutions was studied with gamma spectrometry with the aim to find a compromise between on the one hand the AMP effectiveness and on the other hand unwanted affinity to AMP of Uranium and Americium. Success for the treatment protocol is defined by proving minimal uptake of U and Am, while at the same time demonstrating good removal effectiveness through the use of AMP. Uptake of U and Am were determined as influenced by oxidizing agents at nitric acid concentrations, proposed by Savannah River National laboratory. It was found that AMP does not significantly remove U and Am when concentration of oxidizing agents is more than 0.1M for simulated waste solutions and for contact times inherent in laboratory treatment protocol. Uranium and Americium affinity under experimental conditions for cesium removal were evaluated from gamma spectrometric data. Results are given for the model experiment and an approach for the real waste analysis is chosen. Under our experimental conditions simulated wastes solutions showed minimal affinity to AMP when U and Am are most probably in

  7. Analytical utility of the M series x-ray emission lines applied to uranium, neptunium, plutonium, and americium

    International Nuclear Information System (INIS)

    Miller, A.G.

    1976-01-01

    Secondary emission x-ray analysis for actinide elements has usually meant utilizing the L series x-ray lines. The major disadvantage of these x-ray lines is that they fall in the region of high level Bremsstrahlung radiation, producing a high background and, subsequently, larger error and high detection limits. The utilization of the M series x-ray lines of actinide elements with wavelength dispersive x-ray spectrometers greatly minimizes these problems. Calibration curves for uranium, neptunium, plutonium, and americium were prepared by the ''coprex'' method, and the analytical characteristics of the L and M series compared. The Mα and β x-ray lines, under optimum conditions, are several times more sensitive than their L series counterparts. With the greater sensitivity in addition to the lower background, peak to background ratios for M lines up to 40 times greater than those for L lines were obtained. Detection limits can be lowered from about 0.7 μg using the Lα 1 line to 0.05 μg when M x-ray lines are used. The relative advantages and disadvantages of utilizing the L and M series x-ray lines for secondary emission x-ray analysis are discussed

  8. Use of radioanalytical methods for determination of uranium, neptunium, plutonium, americium and curium isotopes in radioactive wastes

    International Nuclear Information System (INIS)

    Geraldo, Bianca

    2012-01-01

    Activated charcoal is a common type of radioactive waste that contains high concentrations of fission and activation products. The management of this waste includes its characterization aiming the determination and quantification of the specific radionuclides including those known as Difficult-to-Measure Radionuclides (RDM). The analysis of the RDM's generally involves complex radiochemical analysis for purification and separation of the radionuclides, which are expensive and time-consuming. The objective of this work was to define a methodology for sequential analysis of the isotopes of uranium, neptunium, plutonium, americium and curium present in a type of radioactive waste, evaluating chemical yield, analysis of time spent, amount of secondary waste generated and cost. Three methodologies were compared and validated that employ ion exchange (TI + EC), extraction chromatography (EC) and extraction with polymers (ECP). The waste chosen was the activated charcoal from the purification system of primary circuit water cooling the reactor IEA-R1. The charcoal samples were dissolved by acid digestion followed by purification and separation of isotopes with ion exchange resins, extraction and chromatographic extraction polymers. Isotopes were analyzed on an alpha spectrometer, equipped with surface barrier detectors. The chemical yields were satisfactory for the methods TI + EC and EC. ECP method was comparable with those methods only for uranium. Statistical analysis as well the analysis of time spent, amount of secondary waste generated and cost revealed that EC method is the most effective for identifying and quantifying U, Np, Pu, Am and Cm present in charcoal. (author)

  9. Vertical transport of particulate-associated plutonium and americium in the upper water column of the Northeast Pacific

    International Nuclear Information System (INIS)

    Fowler, S.W.; Ballestra, S.; La Rosa, J.; Fukai, R.

    1983-01-01

    Concentrations of plutonium (Pu) and americium (Am) were determined in seawater, suspended particulate matter, sediment trap samples, and biogenic material collected at the VERTEX I site in the North Pacific off central California. From a vertical profile taken over the upper 1500 m, the presence of sub-surface maxima of sup(239+240)Pu and 241 Am were identified between 100 to 750 m and 250 to 750 m, respectively. A large fraction (32%) of the filterable sup(239+240)Pu in surface waters was associated with cells during a phytoplankton bloom; Pu:Am activity ratios in surface water and the suspended particles indicated that Pu was concentrated by the cells to a greater degree than Am. However, similar measurements beneath the surface layer showed an overall enrichment of Am over Pu on fine suspended particles with depth. Freshly produced zooplankton fecal pellets and large, fast sinking particles collected in PITS contained relatively high concentrations of Pu and Am. Both transuranic concentrations in trapped particles and transuranic flux tended to increase with depth down to 750 m, suggesting that their scavenging is in the upper water column. Am appeared to be scavenged by sinking biogenic particles to a greater extent than Pu. The results are discussed. (author)

  10. Molten salt extraction (MSE) of americium from plutonium metal in CaCl2-KCl-PuCl3 and CaCl2-PuCl3 salt systems

    International Nuclear Information System (INIS)

    Dodson, K.E.

    1992-01-01

    Molten salt extraction (MSE) of americium-241 from reactor-grade plutonium has been developed using plutonium trichloride salt in stationary furnaces. Batch runs with oxidized and oxide-free metal have been conducted at temperature ranges between 750 and 945C, and plutonium trichloride concentrations from one to one hundred mole percent. Salt-to-metal ratios of 0.10, 0.15, and 0 30 were examined. The solvent salt was either eutectic 74 mole percent CaCl 2 endash 26 mole percent KCl or pure CaCl 2 . Evidence of trivalent product americium, and effects of temperature, salt-to-metal ratio, and oxide contamination on the americium extraction efficiency are given. 24 refs, 20 figs, 13 tabs

  11. Observations on the redistribution of plutonium and americium in the Irish Sea sediments, 1978 to 1996: concentrations and inventories

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Denoon, D.C.; Woodhead, D.S.

    1999-01-01

    The distribution of plutonium and americium in the sub-tidal sediments of the Irish Sea is described following major surveys in 1978, 1983, 1988 and 1995. Concentrations in surface sediments have declined near the source at Sellafield since 1988. Time-series of inter-tidal surface sediment concentrations are presented from 1977 onwards, revealing the importance of sediment reworking and transport in controlling the evolution of the environmental signal. The surface and near-surface sediments, in the eastern Irish Sea 'mud-patch', are generally well mixed with respect to Pu (α) and 241 Am distributions but show increasing variability with depth - up to 4 orders of magnitude in concentration. The inventories of 239,240 Pu and 241 Am in the sub-tidal sediments have been estimated and compared with the reported decay-corrected discharges. These amounted to 360 and 545 TBq respectively, in 1995, about 60% of the total decay-corrected discharge. Part of the unaccounted fraction may be due to unrepresentative sampling of the seabed. It is speculated that some tens of TBq of plutonium and 241 Am reside undetected in the large volumes of coarse-grained, sub-tidal and inter-tidal sediment which characterise much of the Irish Sea. This has been due to the inability of the available corers to penetrate to the base of contamination in these mobile sediments. Further observations are needed to verify and quantify the missing amount. A budget of plutonium-α and 241 Am has been estimated based on published observations in the three main compartments: water column, sub-tidal and inter-tidal sediments. This amounts to 460-540 TBq and 575-586 TBq respectively, or 64-75% and 60-61%, of the decay-corrected reported discharge. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Picomolar traces of americium(III) introduce drastic changes in the structural chemistry of terbium(III). A break in the ''gadolinium break''

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Jan M. [TU Wien, Atominstitut, Vienna (Austria); Mueller, Danny; Knoll, Christian; Wilkovitsch, Martin; Weinberger, Peter [TU Wien, Institute of Applied Synthetic Chemistry, Vienna (Austria); Giester, Gerald [University of Vienna, Institute of Mineralogy and Crystallography, Vienna (Austria); Ofner, Johannes; Lendl, Bernhard [TU Wien, Institute of Chemical Technologies and Analytics, Vienna (Austria); Steinhauser, Georg [Leibniz Universitaet Hannover, Institute of Radioecology and Radiation Protection (Germany)

    2017-10-16

    The crystallization of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] (ZT) in the presence of trace amounts (ca. 50 Bq, ca. 1.6 pmol) of americium results in 1) the accumulation of the americium tracer in the crystalline solid and 2) a material that adopts a different crystal structure to that formed in the absence of americium. Americium-doped [Tb(Am)(H{sub 2}O){sub 7}ZT]{sub 2} ZT.10 H{sub 2}O is isostructural to light lanthanide (Ce-Gd) 5,5{sup '}-azobis[1H-tetrazol-1-ide] compounds, rather than to the heavy lanthanide (Tb-Lu) 5,5{sup '}-azobis[1H-tetrazol-1-ide] (e.g., [Tb(H{sub 2}O){sub 8}]{sub 2}ZT{sub 3}.6 H{sub 2}O) derivatives. Traces of Am seem to force the Tb compound into a structure normally preferred by the lighter lanthanides, despite a 10{sup 8}-fold Tb excess. The americium-doped material was studied by single-crystal X-ray diffraction, vibrational spectroscopy, radiochemical neutron activation analysis, and scanning electron microscopy. In addition, the inclusion properties of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] towards americium were quantified, and a model for the crystallization process is proposed. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Measurement of total alpha activity of neptunium, plutonium, and americium in highly radioactive Hanford waste by iron hydroxide precipitation and 2-heptanone solvent extraction

    International Nuclear Information System (INIS)

    Maiti, T.C.; Kaye, J.H.

    1992-06-01

    An improved method has been developed to concentrate the major alpha-emitting actinide elements neptunium, plutonium, and americium from samples with high salt content such as those resulting from efforts to characterize Hanford storage tank waste. Actinide elements are concentrated by coprecipitation of their hydroxides using iron carrier. The iron is removed by extraction from 8M HCI with 2-heptanone. The actinide elements remain in the aqueous phase free from salts, iron, and long-lived fission products. Recoveries averaged 98 percent

  14. Synthesis of zirconia sol stabilized by trivalent cations (yttrium and neodymium or americium): a precursor for Am-bearing cubic stabilized zirconia.

    Science.gov (United States)

    Lemonnier, Stephane; Grandjean, Stephane; Robisson, Anne-Charlotte; Jolivet, Jean-Pierre

    2010-03-07

    Recent concepts for nuclear fuel and targets for transmuting long-lived radionuclides (minor actinides) and for the development of innovative Gen-IV nuclear fuel cycles imply fabricating host phases for actinide or mixed actinide compounds. Cubic stabilized zirconia (Zr, Y, Am)O(2-x) is one of the mixed phases tested in transmutation experiments. Wet chemical routes as an alternative to the powder metallurgy are being investigated to obtain the required phases while minimizing the handling of contaminating radioactive powder. Hydrolysis of zirconium, neodymium (a typical surrogate for americium) and yttrium in aqueous media in the presence of acetylacetone was firstly investigated. Progressive hydrolysis of zirconium acetylacetonate and sorption of trivalent cations and acacH on the zirconia particles led to a stable dispersion of nanoparticles (5-7 nm) in the 6-7 pH range. This sol gels with time or with temperature. The application to americium-containing solutions was then successfully tested: a stable sol was synthesized, characterized and used to prepare cubic stabilized zirconia (Zr, Y, Am)O(2-x).

  15. Determining the americium transmutation rate and fission rate by post-irradiation examination within the scope of the ECRIX-H experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lamontagne, J., E-mail: jerome.lamontagne@cea.fr [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Pontillon, Y. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Esbelin, E. [CEA, DEN, DRCP, Marcoule, F-30207 Bagnols-sur-Cèze (France); Béjaoui, S.; Pasquet, B. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Bourdot, P. [CEA, DEN, DER, Cadarache, F-13108 St. Paul Lez Durance (France); Bonnerot, J.M. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France)

    2013-09-15

    The ECRIX-H experiment aims to assess the feasibility of transmuting americium micro-dispersed in an inert magnesia matrix under a locally moderated neutron flux in the Phénix reactor. A first set of examinations demonstrated that pellet behaviour was satisfactory with moderate swelling at the end of the irradiation. Additional post-irradiation examinations needed to be conducted to confirm the high transmutation rate so as to definitively conclude on the success of the ECRIX-H experiment. This article presents and discusses the results of these new examinations. They confirm the satisfactory behaviour of the MgO matrix not only during the basic irradiation but also during post-irradiation thermal transients. These examinations also provide additional information on the behaviour of fission products both in the americium-based particles and in the MgO matrix. These results particularly validate the transmutation rate predicted by the calculation codes using several different analytical techniques. The fission rate is also determined.

  16. Analytical performance of radiochemical method for americium determination in urine; Desempenho analitico do metodo radioquimico para determinacao de americio em urina

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Juliana Ferreira; Carneiro, Janete C.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ju_barreto@terra.com.br

    2005-07-01

    This paper presents an analytical method developed and adapted for separation and analysis of Plutonium (Pu) isotopes and Americium (Am) in urine samples. The proposed method will attend the demand of internal exposure monitoring program for workers involved mainly with dismantling rods and radioactive smoke detectors. In this experimental procedure four steps are involved as preparation of samples, sequential radiochemical separation, preparation of the source for electroplating and quantification by alpha spectrometry. In the first stage of radiochemical separation, plutonium is conventionally isolated employing the anion exchange technique. Americium isolation is achieved sequentially by chromatographic extraction (Tru.spec column) from the load and rinse solutions coming from the anion exchange column. The {sup 243}Am tracer is added into the sample as chemical yield monitors and to correct the results improving the precision and accuracy. The mean recovery obtained is 60%, and the detection limit for 24h urine sample is 1.0 mBq L{sup -1} in accordance with the literature. Based in the preliminary results, the method is appropriate to be used in monitoring programme of workers with a potential risk of internal contamination. (author)

  17. Inhaled americium dioxide

    International Nuclear Information System (INIS)

    Park, J.F.

    1982-01-01

    This project includes experiments to determine the effects of Zn-DTPA therapy on the retention, translocation and biological effects of inhaled 241 AmO 2 . Beagle dogs that received inhalation exposure to 241 AmO 2 developed leukopenia, clincial chemistry changes associated with hepatocellular damage, and were euthanized due to respiratory insufficiency caused by radiation pneumonitis 120 to 131 days after pulmonary deposition of 22 to 65 μCi 241 Am. Another group of dogs that received inhalation exposure to 241 AmO 2 and were treated daily with Zn-DTPA had initial pulmonary deposition of 19 to 26 μCi 241 Am. These dogs did not develop respiratory insufficiency, and hematologic and clinical chemistry changes were less severe than in the non-DTPA-treated dogs

  18. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    International Nuclear Information System (INIS)

    Groettheim, Siri

    2000-01-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m 3 , and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m 3 . In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m 3 , and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  19. Recovery of Americium-241 from lightning rod by the method of chemical treatment; Recuperacion del Americio-241 provenientes de los pararrayos por el metodo de tratamiento quimico

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, W.H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (GRRA/IPEN), Lima (Peru). Division de Gestion de Residuos Radiactivos

    2013-07-01

    About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ({sup 241}Am), fewer and Radium 226 ({sup 226}Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of {sup 241}Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The {sup 241}Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel {sup 241}Am technique was used electrodeposition. (author)

  20. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groettheim, Siri

    2000-07-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m{sub 3}, and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m{sub 3}. In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m{sub 3}, and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  1. Safe handling of kilogram amounts of fuel-grade plutonium and of gram amounts of plutonium-238, americium-241 and curium-244

    International Nuclear Information System (INIS)

    Louwrier, K.P.; Richter, K.

    1976-01-01

    During the past 10 years about 600 glove-boxes have been installed at the Institute for Transuranium Elements at Karlsruhe. About 80% of these glove-boxes have been designed and equipped for handling 100-g to 1-kg amounts of 239 Pu containing 8-12% 240 Pu (low-exposure plutonium). A small proportion of the glove-boxes is equipped with additional shielding in the form of lead sheet or lead glass for work with recycled plutonium. In these glove-boxes gram-amounts of 241 Am have also been handled for preparation of Al-Am targets using tongs and additional shielding inside the glove-boxes themselves. Water- and lead-shielded glove-boxes equipped with telemanipulators have been installed for routine work with gram-amounts of 241 Am, 243 Am and 244 Cm. A prediction of the expected radiation dose for the personnel is difficult and only valid for a preparation procedure with well-defined preparation steps, owing to the fact that gamma dose-rates depend strongly upon proximity and source seize. Gamma radiation dose measurements during non-routine work for 241 Am target preparation showed that handling of gram amounts leads to a rather high irradiation dose for the personnel, despite lead or steel glove-box shielding and shielding within the glove-boxes. A direct glove-hand to americium contact must be avoided. For all glove-handling of materials with gamma radiation an irradiation control of the forearms of the personnel by, for example, thermoluminescence dosimeters is necessary. Routine handling of americium and curium should be executed with master-slave equipment behind neutron and gamma shielding. (author)

  2. Preliminary application of 241-Americium calcaneus bone mineral density measurement in osteoporosis. Comparison with double X-ray densitometry of the lumber spine

    International Nuclear Information System (INIS)

    Guan Liang; Zhu Chengmo; Li Peiyong; Wang Hui; Pu Mingfang; Qiu Jigao

    2001-01-01

    Bone mineral density (BMD) of calcaneus in 54 normals, 45 Osteoporosis, 25 suspected osteoporosis and 16 other non-osteoporosis patients, a total of 140 cases were measured by HUAKE (HK-1) 241-Americium BMD absorpmetry, among them 43 were compared with that of lumber spine (L2 - L4) measured by Lunar Corporation's Expert-XL absorpmeter. BMD of normal group of calcaneus was (409.8 +- 79.4) mg/cm 2 . The BMD were decreased slowly with the increasing age. The BMD of osteoporosis, suspected osteoporosis and non-osteoporosis group were 230.3 +- 62.3, 395.7 +- 57.4 and 363.3 +- 51.9 mg/cm 2 respectively. The BMD of osteoporosis group was much lower than that of normal group, and also lower than that of the other two groups, among 26 patients (57.78%) had bone fracture, all was in accordance with the clinical diagnosis of osteoporosis. The BMD of suspected osteoporosis and non-osteoporosis had no significant difference with normal group. The coefficient variation (CV) of BMD in repeated measurement in calcaneus of 4 participants was less than 1.2%. The correlative coefficient (r) between BMD of calcaneus and lumber spine (L2 - L4) group was 0.6824. The correlative coefficient of normal young adult-matched percentage and T value in 2 groups were 0.6863 and 0.6755 respectively, whereas aged-matched percentage, Z value were 0.4614 and 0.5009 respectively. In conclusion 241-Americium calcaneus BMD absorpmetry has the advantage of low price, easy to operate, reliable and valuable in diagnosis osteoporosis. The correlations of calcaneus and lumber spine BMD, normal young adult-matched percentage and T value were rather good

  3. Correction factor K calculation for Americium-Beryllium neutron sources measured in a manganese sulfate bath; Calculo do fator de correcao K para fontes de neutrons de Americio-Berilio medida no banho de sulfato de manganes do LNMRI/IRD

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Sandro P.; Fonseca, Evaldo S. da; Patrao, Karla C.S.; Goncalves, Marcello G. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Neutrons; Pereira, Walsan W. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

    2005-03-15

    This paper simulates a manganese sulfate bath at the Ionizing Radiation Metrology National Laboratory for the calculation of K correction factor for the neutro emission ratio in some Americium-Beryllium sources.

  4. Actinide Oxidation State and O/M Ratio in Hypostoichiometric Uranium-Plutonium-Americium U0.750Pu0.246Am0.004O2-x Mixed Oxides.

    Science.gov (United States)

    Vauchy, Romain; Belin, Renaud C; Robisson, Anne-Charlotte; Lebreton, Florent; Aufore, Laurence; Scheinost, Andreas C; Martin, Philippe M

    2016-03-07

    Innovative americium-bearing uranium-plutonium mixed oxides U1-yPuyO2-x are envisioned as nuclear fuel for sodium-cooled fast neutron reactors (SFRs). The oxygen-to-metal (O/M) ratio, directly related to the oxidation state of cations, affects many of the fuel properties. Thus, a thorough knowledge of its variation with the sintering conditions is essential. The aim of this work is to follow the oxidation state of uranium, plutonium, and americium, and so the O/M ratio, in U0.750Pu0.246Am0.004O2-x samples sintered for 4 h at 2023 K in various Ar + 5% H2 + z vpm H2O (z = ∼ 15, ∼ 90, and ∼ 200) gas mixtures. The O/M ratios were determined by gravimetry, XAS, and XRD and evidenced a partial oxidation of the samples at room temperature. Finally, by comparing XANES and EXAFS results to that of a previous study, we demonstrate that the presence of uranium does not influence the interactions between americium and plutonium and that the differences in the O/M ratio between the investigated conditions is controlled by the reduction of plutonium. We also discuss the role of the homogeneity of cation distribution, as determined by EPMA, on the mechanisms involved in the reduction process.

  5. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan.

    Science.gov (United States)

    León Vintró, L; Mitchell, P I; Omarova, A; Burkitbayev, M; Jiménez Nápoles, H; Priest, N D

    2009-04-01

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that (241)Am, (239,240)Pu and (238)U concentrations in well waters within the study area are in the range 0.04-87mBq dm(-3), 0.7-99mBq dm(-3), and 74-213mBq dm(-3), respectively, and for (241)Am and (239,240)Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01mBq dm(-3), 0.08mBq dm(-3) and 0.32mBq dm(-3) for (241)Am, (239,240)Pu and (238)U, respectively. The (235)U/(238)U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42microSv (mean 21microSv). Presently, the ground water feeding these wells would not appear to be contaminated with

  6. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

    Leon Vintro, L. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)], E-mail: luis.leon@ucd.ie; Mitchell, P.I.; Omarova, A. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Burkitbayev, M. [Department of Inorganic Chemistry, Al-Faraby Kazakh National University, Almaty (Kazakhstan); Jimenez Napoles, H. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Priest, N.D. [School of Health and Social Sciences, Middlesex University, Enfield, EN3 4SA (United Kingdom)

    2009-04-15

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that {sup 241}Am, {sup 239,240}Pu and {sup 238}U concentrations in well waters within the study area are in the range 0.04-87 mBq dm{sup -3}, 0.7-99 mBq dm{sup -3}, and 74-213 mBq dm{sup -3}, respectively, and for {sup 241}Am and {sup 239,240}Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01 mBq dm{sup -3}, 0.08 mBq dm{sup -3} and 0.32 mBq dm{sup -3} for {sup 241}Am, {sup 239,240}Pu and {sup 238}U, respectively. The {sup 235}U/{sup 238}U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42 {mu}Sv (mean 21 {mu

  7. Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil; Etude theorique et experimentale du comportement biogeochimique de l'americium-241 en conditions rhizospheriques simplifiees. Application dans un sol agricole calcaire

    Energy Technology Data Exchange (ETDEWEB)

    Perrier, T

    2004-06-01

    Americium 241, is one of the most radio-toxic contaminant produced during the nuclear fuel cycle. It can be found in all environmental compartments, in particular the soils. The main goals of this study are to identify, quantify and model the effect of the main factors controlling the mobility of {sup 241}Am in the rhizosphere and the agricultural soils. The physico-chemical parameters of the soil and of the soil solution, the potential role of microorganisms on the sorption-desorption processes, and the speciation of americium in solution have been more particularly studied. {sup 241}Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with {sup 241}Am. The soil samples have been washed out in different hydrodynamic conditions by solutions with various compositions. The eluted solution has been analyzed (pH, conductivity, ionic composition, Fe{sub tot}, organic acids, {sup 241}Am) and its bacterial biomass content too. The overall results indicate that {sup 241}Am remobilization is contrasted and strongly linked with the condition under study (pH, ionic strength, glucose and/or citrate concentration). Therefore, a solution in equilibrium with the soil or containing small exudate concentrations (10{sup -4} M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of {sup 241}Am corresponds to a solid/liquid coefficient of partition (K{sub d}) of about 10{sup 5} L.kg{sup -1}. A significant addition of glucose induces an important dissolution of soil carbonates by the indirect action of microorganisms, but does not significantly favor the {sup 241}Am remobilization. On the other hand, the presence of strong citrate concentrations ({>=} 10{sup -2} M) allows 300 to 10000 time greater re-mobilizations by the complexing of {sup 241}Am released after the dissolution of the carrying phases. Finally, the colloidal

  8. Study of biosorbents application on the treatment of radioactive liquid wastes with americium-241; Estudo da aplicacao de biossorventes no tratamento de rejeitos radioativos liquidos contendo americio-241

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Tania Regina de

    2010-07-01

    The use of nuclear energy for many different purposes has been intensified and highlighted by the benefits that it provides. Medical diagnosis and therapy, agriculture, industry and electricity generation are examples of its application. However, nuclear energy generates radioactive wastes that require suitable treatment ensuring life and environmental safety. Biosorption and bioaccumulation represent an emergent alternative for the treatment of radioactive liquid wastes, providing volume reduction and physical state change. This work aimed to study biosorbents for the treatment of radioactive liquid wastes contaminated with americium-241 in order to reduce the volume and change the physical state from liquid to solid. The biosorbents evaluated were Saccharomyces cerevisiae immobilized in calcium alginate beads, inactivated and free cells of Saccharomyces cerevisiae, calcium alginate beads, Bacillus subtilis, Cupriavidus metallidurans and Ochrobactrum anthropi. The results were quite satisfactory, achieving 100% in some cases. The technique presented in this work may be useful and viable for implementing at the Waste Management Laboratory of IPEN - CNEN/SP in short term, since it is an easy and low cost method. (author)

  9. Diluent and extractant effects on the enthalpy of extraction of uranium(VI) and americium(III) nitrates by trialkyl phosphates

    International Nuclear Information System (INIS)

    Srinivasan, T.G.; Vasudeva Rao, P.R.; Sood, D.D.

    1998-01-01

    The effect of various diluents such as n-hexane, n-heptane n-octane, isooctane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-hexadecane, cyclohexane, benzene, toluene, p-xylene, mesitylene and o-dichlorobenzene on the enthalpy of extraction of uranyl nitrate by tri-n-amyl phosphate (TAP) over the temperature range 283 K--333 K has been studied. The results indicate that the enthalpy of extraction does not vary significantly with the diluents studied. Also enthalpies of extraction of uranyl nitrate and americium(III) nitrate by neutral organo phosphorous extractants such as tri-n-butyl phosphate (TBP), tri-n-amyl phosphate (TAP), tri-sec-butyl phosphate (TsBP), tri-isoamyl phosphate (TiAP) and tri-n-hexyl phosphate (THP) have been studied. An attempt has been made to explain the trends, on the basis of the nature of the solvate formed and the different terms which contribute to the overall enthalpy change

  10. Human bones obtained from routine joint replacement surgery as a tool for studies of plutonium, americium and {sup 90}Sr body-burden in general public

    Energy Technology Data Exchange (ETDEWEB)

    Mietelski, Jerzy W., E-mail: jerzy.mietelski@ifj.edu.pl [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland); Golec, Edward B. [Traumatology and Orthopaedic Clinic, 5th Military Clinical Hospital and Polyclinic, Independent Public Healthcare Facility, Wroclawska 1-3, 30-901 Cracow (Poland); Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Department of Physical Therapy Basics, Faculty of Physical Therapy, Administration College, Bielsko-Biala (Poland); Tomankiewicz, Ewa [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland); Golec, Joanna [Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Physical Therapy Department, Institute of Physical Therapy, Faculty of Heath Science, Jagiellonian University, Medical College, Cracow (Poland); Nowak, Sebastian [Traumatology and Orthopaedic Clinic, 5th Military Clinical Hospital and Polyclinic, Independent Public Healthcare Facility, Wroclawska 1-3, 30-901 Cracow (Poland); Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Szczygiel, Elzbieta [Physical Therapy Department, Institute of Physical Therapy, Faculty of Heath Science, Jagiellonian University, Medical College, Cracow (Poland); Brudecki, Kamil [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland)

    2011-06-15

    The paper presents a new sampling method for studying in-body radioactive contamination by bone-seeking radionuclides such as {sup 90}Sr, {sup 239+240}Pu, {sup 238}Pu, {sup 241}Am and selected gamma-emitters, in human bones. The presented results were obtained for samples retrieved from routine surgeries, namely knee or hip joints replacements with implants, performed on individuals from Southern Poland. This allowed to collect representative sets of general public samples. The applied analytical radiochemical procedure for bone matrix is described in details. Due to low concentrations of {sup 238}Pu the ratio of Pu isotopes which might be used for Pu source identification is obtained only as upper limits other then global fallout (for example Chernobyl) origin of Pu. Calculated concentrations of radioisotopes are comparable to the existing data from post-mortem studies on human bones retrieved from autopsy or exhumations. Human bones removed during knee or hip joint surgery provide a simple and ethical way for obtaining samples for plutonium, americium and {sup 90}Sr in-body contamination studies in general public. - Highlights: > Surgery for joint replacement as novel sampling method for studying in-body radioactive contamination. > Proposed way of sampling is not causing ethic doubts. > It is a convenient way of collecting human bone samples from global population. > The applied analytical radiochemical procedure for bone matrix is described in details. > The opposite patient age correlations trends were found for 90Sr (negative) and Pu, Am (positive).

  11. Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

    Directory of Open Access Journals (Sweden)

    Geslot Benoit

    2017-01-01

    Full Text Available An experimental program, called AMSTRAMGRAM, was recently conducted in the Minerve low power reactor operated by CEA Cadarache within the frame of the CHANDA initiative (Solving CHAllenges in Nuclear Data. Its aim was to measure the integral capture cross section of 241Am in the thermal domain. Motivation of this work is driven by large differences in this actinide thermal point reported by major nuclear data libraries. The AMSTRAMGRAM experiment, that made use of well characterized EC-JRC americium samples, was based on the oscillation technique commonly implemented in the Minerve reactor. First results are presented and discussed in this article. A preliminary calculation scheme was used to compare measured and calculated results. It is shown that this work confirms a bias previously observed with JEFF-3.1.1 (C/E-1 = −10.5 ± 2%. On the opposite, the experiment is in close agreement with 241Am thermal point reported in JEFF-3.2 (C/E-1 = 0.5 ± 2%.

  12. Solubility of plutonium and americium-241 from rumen contents of cattle grazing on plutonium-contaminated desert vegetation in in vitro bovine gastrointestinal fluids - August 1975 to January 1977

    International Nuclear Information System (INIS)

    Barth, J.; Giles, K.R.; Brown, K.W.

    1985-01-01

    The alimentary solubility of plutonium and americium-241 ingested by cattle grazing at Area 13 of the Nevada Test Site and the Clean Slate II site on the Tonopah Test Range in Nevada was studied in a series of experiments. For each experiment, or trial, rumen contents collected from a fistulated steer or a normal animals at the time of sacrifice were incubated in simulated bovine gastrointestinal fluids, and the solubility of plutonium and americium was analyzed following the abomasal, duodenal, jejunal, and lower intestinal digestive states. For Area 13, the peak plutonium-238 solubilities ranged from 1.09 to 9.60 percent for animals grazing in the inner enclosure that surrounds ground zero (GZ); for animals grazing in the outer enclosure, the peaks ranged from 1.86 to 18.46%. The peak plutonium-239 solubilities ranged from 0.71 to 4.81% for animals from the inner enclosure and from 0.71 to 3.61% for animals from the outer enclosure. Plutonium-238 was generally more soluble than plutonium-239. Plutonium ingested by cattle grazing in the outer enclosure was usually more soluble than plutonium ingested by cattle grazing in the inner enclosure. The highest concentrations of plutonium in the rumen contents of cattle grazing in the inner enclosure were found in trials conducted during August and November 1975 and January 1976. These concentrations decreased during the February, May, and July 1976 trials. The decrease was followed by an increase in plutonium concentration during the November 1976 trial. The concentration of americium-241 followed the same trend. 13 references, 13 tables

  13. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    International Nuclear Information System (INIS)

    Ketelaer, Jens

    2010-01-01

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N ∝ 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of 241 Am could be measured directly for the first time. (orig.)

  14. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    Energy Technology Data Exchange (ETDEWEB)

    Ketelaer, Jens

    2010-06-14

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N {proportional_to} 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of {sup 241}Am could be measured directly for the first time. (orig.)

  15. Update of JAEA-TDB. Additional selection of thermodynamic data for solid and gaseous phases on nickel, selenium, zirconium, technetium, thorium, uranium, neptunium plutonium and americium, update of thermodynamic data on iodine, and some modifications

    International Nuclear Information System (INIS)

    Kitamura, Akira; Fujiwara, Kenso; Doi, Reisuke; Yoshida, Yasushi

    2012-07-01

    We additionally selected thermodynamic data for solid and gaseous phases of nickel, selenium, zirconium, technetium, thorium, uranium, neptunium, plutonium and americium to our thermodynamic database JAEA-TDB for geological disposal of radioactive waste of high-level and TRU wastes. We thermodynamically obtained equilibrium constant from addition and subtraction of Gibbs free energy of formation on nickel, selenium, zirconium, technetium, thorium, uranium, neptunium plutonium and americium, which were selected in the Thermochemical Database Project by the Nuclear Energy Agency in the Organisation for Economic Co-operation and Development. Furthermore, we collected and updated thermodynamic data on iodine, changed master species of technetium(IV), and added thermodynamic data on selenium due to improving reliability of the thermodynamic database. We prepared text files of the updated thermodynamic database (JAEA-TDB) for geochemical calculation programs of PHREEQC, EQ3/6 and Geochemist's Workbench. These text files are contained in the attached CD-ROM and will be available on our Website (http://migrationdb.jaea.go.jp/). (author)

  16. Determining the americium transmutation rate and fission rate by post-irradiation examination within the scope of the ECRIX-H experiment

    Science.gov (United States)

    Lamontagne, J.; Pontillon, Y.; Esbelin, E.; Béjaoui, S.; Pasquet, B.; Bourdot, P.; Bonnerot, J. M.

    2013-09-01

    The ECRIX-H experiment aims to assess the feasibility of transmuting americium micro-dispersed in an inert magnesia matrix under a locally moderated neutron flux in the Phénix reactor. A first set of examinations demonstrated that pellet behaviour was satisfactory with moderate swelling at the end of the irradiation. Additional post-irradiation examinations needed to be conducted to confirm the high transmutation rate so as to definitively conclude on the success of the ECRIX-H experiment. This article presents and discusses the results of these new examinations. They confirm the satisfactory behaviour of the MgO matrix not only during the basic irradiation but also during post-irradiation thermal transients. These examinations also provide additional information on the behaviour of fission products both in the americium-based particles and in the MgO matrix. These results particularly validate the transmutation rate predicted by the calculation codes using several different analytical techniques. The fission rate is also determined. Moderate pellet swelling under irradiation (6.7 vol.%), while only 23% of the produced He and 4% of the fission gases were released from the fuel. No interaction between the pellets and the cladding. Formation of bubbles due to the precipitation of fission gases and He mainly in bubbles located inside the americium-based particles. These bubbles are the main cause of macroscopic swelling in the pellets. Well-crystallised structure of the MgO matrix which shows no amorphisation after irradiation despite the presence of fission products. The absence of any reaction of MgO with the americium-based phase, Formation of a PuO2-type crystalline phase from AmO1.62 particles following the Am transmutation process. A shielded electron probe micro-analyser (EPMA) 'CAMECA' Camebax equipped to collect and exploit the measurements using the 'SAMx' system. A Philips XL30 scanning electron microscope (SEM). Field acquisitions were performed thanks to

  17. Fabrication of targets for transmutation of americium : synthesis of inertial matrix by sol-gel method. Procedure study on the infiltration of a radioactive solutions

    International Nuclear Information System (INIS)

    Fernandez Carretero, A.

    2002-01-01

    addition a new and unexpected phase formed by the reaction of americium with spinel during the high temperature synthesis process has been identified. This new phase could provide a unique menas to stabilise Am in one particular oxidation state. (Author)

  18. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  19. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

    Legarda, F.; Herranz, M.; Idoeta, R.; Abelairas, A.

    2010-01-01

    The adsorption of 241 Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241 Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241 Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  20. EURADOS action for determination of americium in skull measures in vivo and Monte Carlo simulation; Accion EURADOS para la determinacion de americio en craneo mediante medidas in-vivo y simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Ponte, M. A.; Navarro Amaro, J. F.; Perez Lopez, B.; Navarro Bravo, T.; Nogueira, P.; Vrba, T.

    2013-07-01

    From the Group of WG7 internal dosimetry of the EURADOS Organization (European Radiation Dosimetry group, e.V.) which It coordinates CIEMAT, international action for the vivo measurement of americium has been conducted in three mannequins type skull with detectors of Germanium by gamma spectrometry and simulation by Monte Carlo methods. Such action has been raised as two separate exercises, with the participation of institutions in Europe, America and Asia. Other actions similar precede this vivo intercomparison of measurement and modeling Monte Carlo1. The preliminary results and associated findings are presented in this work. The laboratory of the body radioactivity (CRC) of service counter of dosimetry staff internal (DPI) of the CIEMAT, it has been one of the participants in vivo measures exercise. On the other hand part, the Group of numerical dosimetry of CIEMAT is participant of the Monte Carlo2 simulation exercise. (Author)

  1. Critical and shielding parametric studies with the Monte Carlo code TRIPOLI to identify the key points to take into account during the transportation of blanket assemblies with high ratio of americium

    International Nuclear Information System (INIS)

    Gosmain, Cecile-Aline

    2011-01-01

    In the framework of French research program on Generation IV sodium cooled fast reactor, one possible option consists in burning minor actinides in this kind of Advanced Sodium Technological Reactor. Two types of transmutation mode are studied in the world : the homogeneous mode of transmutation where actinides are scattered with very low enrichment ratio in fissile assemblies and the heterogeneous mode where fissile core is surrounded by blanket assemblies filled with minor actinides with ratio of incorporated actinides up to 20%. Depending on which element is considered to be burnt and on its content, these minor actinides contents imply constraints on assemblies' transportation between Nuclear Power Plants and fuel cycle facilities. In this study, we present some academic studies in order to identify some key constraints linked to the residual power and neutron/gamma load of such kind of blanket assemblies. To simplify the approach, we considered a modeling of a 'model cask' dedicated to the transportation of a unique irradiated blanket assembly loaded with 20% of Americium and basically inspired from an existent cask designed initially for the damaged fissile Superphenix assembly transport. Thermal calculations performed with EDF-SYRTHES code have shown that due to thermal limitations on cladding temperature, the decay time to be considered before transportation is 20 years. This study is based on explicit 3D representations of the cask and the contained blanket assembly with the Monte Carlo code TRIPOLI/JEFF3.1.1 library and concludes that after such a decay time, the transportation of a unique Americium radial blanket is feasible only if the design of our model cask is modified in order to comply with the dose limitation criterion. (author)

  2. Selectivity of bis-triazinyl bipyridine ligands for americium(III) in Am/Eu separation by solvent extraction. Part 1. Quantum mechanical study on the structures of BTBP complexes and on the energy of the separation.

    Science.gov (United States)

    Narbutt, Jerzy; Oziminski, Wojciech P

    2012-12-21

    Theoretical studies were carried out on two pairs of americium and europium complexes formed by tetra-N-dentate lipophilic BTBP ligands, neutral [ML(NO(3))(3)] and cationic [ML(2)](3+) where M = Am(III) or Eu(III), and L = 6,6'-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (C2-BTBP). Molecular structures of the complexes have been optimized at the B3LYP/6-31G(d) level and total energies of the complexes in various media were estimated using single point calculations performed at the B3LYP/6-311G(d,p) and MP2/6-311G(d,p) levels of theory. In the calculations americium and europium ions were treated using pseudo-relativistic Stuttgart-Dresden effective core potentials and the accompanying basis sets. Selectivity in solvent extraction separation of two metal ions is a co-operative function of contributions from all extractable metal complexes, which depend on physico-chemical properties of each individual complex and on its relative amount in the system. Semi-quantitative analysis of BTBP selectivity in the Am/Eu separation process, based on the contributions from the two pairs of Am(III) and Eu(III) complexes, has been carried out. To calculate the energy of Am/Eu separation, a model of the extraction process was used, consisting of complex formation in water and transfer of the formed complex to the organic phase. Under the assumptions discussed in the paper, this simple two-step model results in reliable values of the calculated differences in the energy changes for each pair of the Am/Eu complexes in both steps of the process. The greater thermodynamic stability (in water) of the Am-BTBP complexes, as compared with the analogous Eu species, caused by greater covalency of the Am-N than Eu-N bonds, is most likely the main reason for BTBP selectivity in the separation of the two metal ions. The other potential reason, i.e. differences in lipophilic properties of the analogous complexes of Am and Eu, is less important with regard to this selectivity.

  3. Evaluation of neutron data for americium-241

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M.; Sukhovitskij, E.Sh.; Porodzinskij, Yu.V.; Klepatskij, A.B.; Morogovskij, G.B. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    The evaluation of neutron data for {sup 241}Am is made in the energy region from 10{sup -5} eV up to 20 MeV. The results of the evaluation are compiled in the ENDF/B-VI format. This work is performed under the Project Agreement CIS-03-95 with the International Science and Technology Center (Moscow). The Financing Party for the Project is Japan. The evaluation was requested by Y. Kikuchi (JAERI). (author). 60 refs.

  4. The proliferation potential of neptunium and americium

    International Nuclear Information System (INIS)

    An, J. S.; Shin, J. S.; Kim, J. S.; Kwack, E. H.; Kim, B. K.

    2000-05-01

    It is recognized that some trans-uranic elements other than plutonium, in particular Np and Am, if will be available in sufficient quantities, could be used for nuclear explosive devices. The spent fuel has been accumulating in number of nuclear power plant and operation of large scale commercial reprocessing plants. However, these materials are not covered by the definition of special fissionable material in the Agency Statute. At the time when the Statute was adopted, the availability of meaningful quantities of separated Np and Am was remote and they were not included in the definition of special fissionable material. Then, IAEA Board decided a measure for control of Np and Am on September 1999. This report contains the control method and the characteristic of Np and Am for using domestic nuclear industries, and it can be useful for understanding how to report and account of Np and Am. (author)

  5. Analysis procedure for americium in environmental samples

    International Nuclear Information System (INIS)

    Holloway, R.W.; Hayes, D.W.

    1982-01-01

    Several methods for the analysis of 241 Am in environmental samples were evaluated and a preferred method was selected. This method was modified and used to determine the 241 Am content in sediments, biota, and water. The advantages and limitations of the method are discussed. The method is also suitable for 244 Cm analysis

  6. Experiments of pyrochemical process with americium

    International Nuclear Information System (INIS)

    Hayashi, Hirokazu; Minato, Kazuo

    2004-01-01

    Experiments of pyrochemical process of minor actinide nitrides are scheduled. Experimental procedures of electrochemical study of the molten salts containing minor actinides (10-100mg) were established. Preliminary study with a rare earth element used as a surrogate was carried out in the hot cells using master-slave manipulators. (author)

  7. 1976 Hanford Americium exposure incident: hematologic effects

    International Nuclear Information System (INIS)

    Ragan, H.A.; Mahaffey, J.A.; Breitenstein, B.D.

    1982-05-01

    Hematologic evaluation of an individual with an initial systemic body burden of approx. 200 μCi 241 Am revealed a significant (P < 0.01) reduction of total leukocytes, neutrophils, and lymphocytes. This effect on total leukocytes and neutrophils was evident approx. 30 days after exposure, appeared to stabilize at about 3 months after exposure, and remained at this lower level thorugh a 52-months observation period. The effect on lymphocytes was apparent by 3 days after exposure, stabilizing at approx. 50% of pre-exposure values for about 7 months, with a return to pre-exposure levels in the following 4 y. There was a progressive and significant (P < 0.001) decline in platelet counts during the 52-months postexposure period. The pattern of response in erythrocyte parameters was complex. Immediately after the accident, these values were less than the pre-exposure mean level; they gradually increased (P < 0.001) for approx. 2 y and then began a progressive decline (P < 0.001)

  8. Americium-curium separation by means of selective extraction of hexavalent americium using a centrifugal contactor

    International Nuclear Information System (INIS)

    Musikas, C.; Germain, M.; Bathellier, A.

    1979-01-01

    This paper deals with Am (VI) - Cm (III) separation in nitrate media. The kinetics of oxidation of Am (III) by sodium persulfate in the presence of Ag + ions were reinvestigated by studying the effect of additions of small amounts of reagents which do not drastically change the distribution coefficients of Am (VI) or Cm (III) ions. Organo phosphorus solvents were selected because they are radiation resistant, possess weak reductant properties and that their affinity for hexavalent ion is high. The operating procedure was selected by consideration of the results of the two previous investigations. This can be done by using a centrifugal contactor enabling in to set organic-aqueous phase contact time in accordance with the kinetics of extraction of Am (VI), oxidation of Am (III) in aqueous phase, and reduction of Am (VI) in organic phase

  9. Fabrication of targets for transmutation of americium : synthesis of inertial matrix by sol-gel method. Procedure study on the infiltration of a radioactive solutions; Fabricacion de blancos para la transmutacion de americio: sintesis de matrices inertes por el metodo sol-gel. Estudio del procedimiento de infiltracion de disoluciones radiactivas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Carretero, A. [Universidad Complutense de Madrid (Spain)

    2002-07-01

    made. In addition a new and unexpected phase formed by the reaction of americium with spinel during the high temperature synthesis process has been identified. This new phase could provide a unique menas to stabilise Am in one particular oxidation state. (Author)

  10. Study of the electrochemical oxidation of Am with lacunary heteropolyanions and silver nitrate; Etude de l'oxydation electrochimique de l'americium en presence d'heteropolyanions lacunaires et de nitrate d'argent en milieu aqueux acide

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D

    1999-07-01

    Electrochemical oxidation of Am(III) with certain lacunary heteropolyanions (LHPA {alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}{sup 10-} or {alpha}SiW{sub 11}O{sub 39}{sup 8-}) and silver nitrate is an efficient way to prepare Am(VI). This document presents bibliographic data and an experimental study of the process. Thus, it has been established that Am(IV) is an intermediate species in the reaction and occurs in 1:1 (Amt{sup IV}LHPA) or 1:2 (Am {sup IV}(LHAP){sub 2}) complexes with the relevant LHPA. These 1:1 complexes of Am(IV) have been identified and isolated in this work whereas 1:2 complexes were known from previous studies. The reactivity of these complexes in oxidation shows that 1:1 complexes of Am(IV) are oxidised much more quickly than 1:2 complexes. Apparent stability constants of Am(III) and Am(IV) complexes with the relevant LHPA have been measured for a 1 M nitric acid medium. Thermodynamic data of the reaction are then assessed: redox potentials of Am pairs are computed for a 1 M nitric acid medium containing various amount of LHPA ligands. Those results show that the role of LHPA is to stabilize the intermediate species Am(IV) by lowering the Am(IV)/Am(III) pair potential of about 1 Volt. Nevertheless, if this stabilisation is too strong (i.e. of tungsto-silicate), the oxidation of Am(IV) requires high anodic potential (more than 2 V/ENH). Then, the faradic yield of the oxidation of americium is poor because of water oxidation. This study has also shown that the main role of silver is to catalyze the electrochemical oxidation of Am{sup IV}(LHPA){sub X} complexes. Indeed, these oxidations without silver are extremely slow. An oxygen tracer experiment has been performed during the oxidation of Am(III) in Am(VI). It has been shown that the oxygen atoms of Am(VI) (AMO{sub 2}{sup 2+}) come from water molecules of the solvent and not from the complexing oxygen atoms of the ligands. (author)

  11. Plutonium and americium behavior in coral atoll environments

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Eagle, R.J.

    1984-01-01

    Inventories of 239+240 Pu and 241 Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of 239+240 Pu and lesser amounts of 241 Am are continuously mobilizing from these sedimentary reservoirs. The amount of 239+240 Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized 239+240 Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of 239+240 Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of 241 Am to 239+240 Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of 239+240 Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables

  12. Gastrointestinal absorption of americium in rats: effect of citrate concentration

    International Nuclear Information System (INIS)

    Inaba, J.; Ishigure, N.; Oghiso, Y.; Sato, H.

    1994-01-01

    The gastrointestinal absorption of 241 Am was studied in relation to the amount of sodium citrate administered with it. Fasted Wistar strain female rats received 241 Am orally in sodium citrate solution of various concentrations and 5 days after administration animals were sacrificed and the retention and distribution of 241 Am was studied. The results indicated that the f 1 value was very high at about 10% of administered activity when 241 Am was given to fasted rats with a large amount of sodium citrate. (author)

  13. Further Studies of Plutonium and Americium at Thule, Greenland

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Dahlgaard, Henning; Nilsson, Karen Kristina

    1984-01-01

    further away from the impact point and at some locations the vertical distribution indicated a downward displacement of Pu in the sediment column since 1974. Seawater and seaplants showed no evidence of the presence of Pu from sources other than fallout; but Pu in benthos varied nearly proportionally...

  14. Uptake of plutonium and americium by plants from soils

    International Nuclear Information System (INIS)

    Schulz, R.K.; Tompkins, G.A.; Babcock, K.L.

    1975-01-01

    Plant uptake of 239 , 240 Pu and 241 Am was studied on two soil samples collected on the Nevada Test Site. These soils had each been previously contaminated with the radionuclides by high explosive detonation of devices containing plutonium. The 239 PuO 2 equivalent diameters of plutonium bearing particles present in the soil samples were determined and found to be log-normal in the range of 0.2 to 0.7 μm. Particles were examined by electronmicroscopy and found to be 2 to 3 times larger than the 239 PuO 2 equivalent diameter. Electron microprobe analysis showed that these particles consisted primarily of Pu, U, and O, with Al, Si, Fe and Mg present in much smaller amounts. The plutonium distribution ratio (D. R. = nuclide concentration in plant/nuclide concentration in soil) was in the order of 10 -5 for barley plant vegetation and was 20 to 100 times lower for barley grain. The D. R. for 241 Am was in the order of 10 -4 for vegetative growth and 25-75 times lower for the grain. In other uptake experiments three different soils were utilized: slightly acid forest soil, neutral valley soil, and calcareous alkaline soil. The 239 240 Pu and 241 Am were added to the soil as nitrate or chloride solution to facilitate the addition of Pu to soil in different oxidation states. Where Pu in the higher oxidation states (nitrate) was added to the alkaline calcareous soil, the highest plant uptake was observed. In uptake experiments with wheat the plutonium distribution ratio of the grain ranged from about 4 x 10 -8 to 4 x 10 -6 . The 241 Am D. R.'s ranged from 3 x 10 -7 to 3 x 10 -5 . (U.S.)

  15. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    International Nuclear Information System (INIS)

    Liao Jiali; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

    2004-01-01

    Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove 241 Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting 241 Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb 241 Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of 241 Am was removed from 241 Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of 241 Am. At this time, the total adsorption of 241 Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed 241 Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO 3

  16. Further Studies of Plutonium and Americium at Thule, Greenland

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Dahlgaard, Henning; Nilsson, Karen Kristina

    1984-01-01

    Eleven years after the accidental loss of nuclear weapons in 1968, the fourth scientific expedition to Thule occurred. The estimated inventory of 1 TBq 239,240Pu in the marine sediments was unchanged when compared with the estimate based on the 1974 data. Plutonium from the accident had moved...

  17. Europium (III) and americium (III) stability constants with humic acid

    International Nuclear Information System (INIS)

    Torres, R.A.; Choppin, G.R.

    1984-01-01

    The stability constants for tracer concentrations of Eu(III) and Am(III) complexes with a humic acid extracted from a lake-bottom sediment were measured using a solvent extraction system. The organic extractant was di(2-ethylhexyl)-phosphoric acid in toluene while the humate aqueous phase had a constant ionic strength of 0.1 M (NaClO 4 ). Aqueous humic acid concentrations were monitored by measuring uv-visible absorbances at approx.= 380 nm. The total carboxylate capacity of the humic acid was determined by direct potentiometric titration to be 3.86 +- 0.03 meq/g. The humic acid displayed typical characteristics of a polyelectrolyte - the apparent pKsub(a), as well as the calculated metal ion stability constants increased as the degree of ionization (α) increased. The binding data required a fit of two stability constants, β 1 and β 2 , such that for Eu, log β 1 = 8.86 α + 4.39, log β 2 = 3.55 α + 11.06 while for Am, log β 1 = 10.58 α + 3.84, log β 2 = 5.32 α + 10.42. With hydroxide, carbonate, and humate as competing ligands, the humate complex associated with the β 1 constant is calculated to be the dominant species for the trivalent actinides and lanthanides under conditions present in natural waters. (orig.)

  18. Ecological behavior of plutonium and americium in a freshwater pond

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

    1975-03-01

    A Pu processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior in this ecosystem. About 8.1 kg of Pu was reported to have been discharged into waste trenches leading to the pond. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, 0.61 for 241 Am to 238 Pu, and 0.49 for 241 Am to 239 240 Pu. Levels of Pu and Am in the interstitial water range from 0.5 to 13 pCi/g (dry wt. of sediment). For 238 Pu in pond water the mean concentration is 0.007 pCi/l, for 239 240 Pu it is 0.002 pCi/l, and for 241 Am it is 1.08 pCi/l. The remaining biota had Pu and Am levels which were generally well below those of the sediments. (U.S.)

  19. A bioassay method for americium and curium in feces

    International Nuclear Information System (INIS)

    Alexandre Gagne; Dominic Lariviere; Joel Surette; Sheila Kramer-Tremblay; Xiongxin Dai; Candice Didychuk

    2013-01-01

    Fecal radiobioassay is an essential and sensitive tool to estimate the internal intake of actinides after a radiological incident. A new fecal analysis method, based on lithium metaborate fusion of fecal ash for complete sample dissolution followed by sequential column chromatography separation of actinides, has been developed for the determination of low-level Am and Cm in a large size sample. Spiked synthetic fecal samples were analyzed to evaluate method performance against the acceptance criteria for radiobioassay as defined by ANSI N13.30; both satisfactory accuracy and repeatability were achieved. This method is a promising candidate for reliable dose assessment of low level actinide exposure to meet the regulatory requirements of routine radiobioassay for nuclear workers and the public. (author)

  20. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    Energy Technology Data Exchange (ETDEWEB)

    Liao Jiali E-mail: liaojiali@163.com; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

    2004-01-01

    Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove {sup 241}Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting {sup 241}Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb {sup 241}Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of {sup 241}Am was removed from {sup 241}Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of {sup 241}Am. At this time, the total adsorption of {sup 241}Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed {sup 241}Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO{sub 3}.

  1. High-Resolution Measurements of Neutron Energy Spectra from Americium-Beryllium and Americium-Boron Neutron Sources

    Science.gov (United States)

    Marsh, James W.

    Available from UMI in association with The British Library. A Helium-3 sandwich spectrometer incorporating two semiconductor detectors was designed and constructed to enable the measurement of high resolution neutron energy spectra in the energy range from 100 keV to 15 MeV. The instrument is novel in respect of the inclusion of an anode wire which enables the gas chamber to function as a gas proportional counter. Few similar instruments have been constructed and no similar instrument is known to be currently (1990) in use in the UK. The efficiency of the spectrometer was determined experimentally, using a Californium-252 spontaneous fission source, in the low-scatter facility of the National physical Laboratory. A Monte Carlo code has been written to determine the absolute efficiency over an energy range from 81 keV to 20 MeV. The calculated values were used to extrapolate the measured efficiency to higher energies. Furthermore the Monte Carlo code was used to determine certain operating parameters to optimise the efficiency of the spectrometer. The neutron energy spectra from two different size standard Am-Be neutron sources and a standard Am-B neutron source available at NPL were measured. Although these types of neutron sources have been subject to energy spectra measurements elsewhere, the present work improves considerably on the previous poorer energy resolution and energy range. The new data indicates for the three neutron sources studied that the ambient dose equivalent, H*(10) per unit fluence, for each, were identical, being within 2% of 3.70 E-10 Sv cm^2.

  2. Investigation of the retention and distribution of americium-241 in the baboon and the enhanced removal of americium-241 from the body by diethylenetriaminepentaacetic acid (DTPA)

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Cohen, N.; Wrenn, M.E.

    1975-01-01

    Experiments were performed to study the metabolism and distribution of intravenously administered 241 Am in the adult and juvenile baboon; in addition, decorporation therapy using Na 3 -CaDTPA was performed on selected baboons to assess the efficacy of this drug in removing systemic burdens of 241 Am from this primate species. Determination of the kinetics of 241 Am was accomplished principally by in vivo methodologies and by radiochemical analysis of 241 Am activity of biological material. The use of Na 3 -CaDTPA as a therapeutic agent for the removal of 241 Am from the body proved to be an effective form of treatment in the case of early administration. (U.S.)

  3. Rapid selective separation of americium/curium from simulated nuclear forensic matrices using triazine ligands

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, Matthew A.; Livens, Francis R.; Heath, Sarah L. [Manchester Univ. (United Kingdom). Centre for Radiochemistry Research; Thompson, Paul; Marsden, Olivia J. [AWE, Aldermaston, Reading (United Kingdom); Harwood, Laurence M.; Hudson, Michael J. [Reading Univ. (United Kingdom). Dept. of Chemistry; Lewis, Frank W. [Reading Univ. (United Kingdom). Dept. of Chemistry; Northumbria Univ., Newcastle upon Tyne (United Kingdom). Dept. of Chemical and Forensic Sciences

    2015-07-01

    In analysis of complex nuclear forensic samples containing lanthanides, actinides and matrix elements, rapid selective extraction of Am/Cm for quantification is challenging, in particular due the difficult separation of Am/Cm from lanthanides. Here we present a separation process for Am/Cm(III) which is achieved using a combination of AG1-X8 chromatography followed by Am/Cm extraction with a triazine ligand. The ligands tested in our process were CyMe{sub 4}-BTPhen, CyMe{sub 4}-BTBP, CA-BTP and CA-BTPhen. Our process allows for purification and quantification of Am and Cm (recoveries 80% - 100%) and other major actinides in < 2 d without the use of multiple columns or thiocyanate. The process is unaffected by high level Ca(II)/Fe(III)/Al(III) (10 mg mL{sup -1}) and thus requires little pre-treatment of samples.

  4. Criteria Considered in Selecting Feed Items for Americium-241 Oxide Production Operations

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Louis D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-30

    The analysis in this document serves the purpose of defining a number of attributes in selection of feed items to be utilized in recovery/recycle of Pu and also production operations of 241AmO2 material intended to meet specification requirements. This document was written in response to a specific request on the part of the 2014 annual program review which took place over the dates of October 28-29, 2014. A number of feed attributes are noted including: (1) Non-interference with existing Pu recovery operations; (2) Content of sufficient 241Am to allow process efficiency in recovery operations; (3) Absence of indications that 243Am might be mixed in with the Pu/241Am material; (4) Absence of indications that Cm might be mixed in with the Pu/241Am material; (5) Absence of indications of other chemical elements that would present difficulty in chemical separation from 241Am; (6) Feed material not expected to present difficulty in dissolution; (7) Dose issues; (8) Process efficiency; (9) Size; (10) Hazard associated with items and package configuration in the vault; (11) Within existing NEPA documentation. The analysis in this document provides a baseline of attributes considered for feed materials, but does not presume to replace the need for technical expertise and judgment on the part of individuals responsible for selecting the material feed to be processed. This document is not comprehensive as regards all attributes that could prove to be important. The value of placing a formal QA hold point on accepting feed items versus more informal management of feed items is discussed in the summation of this analysis. The existing planned QA hold points on 241AmO2 products produced and packaged may be adequate as the entire project is based on QA of the product rather than QA of the process. The probability of introduction of items that would inherently cause the241AmO2 products produced to be outside of specification requirements appears to be rather small.

  5. Role of americium interference in analysis of samples containing rare earths

    International Nuclear Information System (INIS)

    Mohapatra, P.K.; Adya, V.C.; Thulasidas, S.K.; Bhattacharyya, A.; Kumar, Mithlesh; Godbole, S.V.; Manchanda, V.K.

    2007-01-01

    Quality control of nuclear fuel samples requires precise estimation of rare earths which have high neutron absorption cross sections and act as neutron poisons. Am is generated by nuclear decay where as lanthanides may be present as impurities picked up during reprocessing/fuel fabrication. Precise estimation of the rare earths by ICP-AES method in presence of 241 Am is a challenging task due to the likelihood of spectral interference of the latter. Rare earths impurities in the purified Am sample were estimated by ICP-AES method. Known amounts of the rare earths viz. Sm, Eu, Dy and Gd were used as synthetic sample and the interference due to Am was investigated. (author)

  6. Extraction of Americium and Europium by Diphosphine Dioxides and Their Mixtures with Chlorinated Cobalt Dicarbollide

    International Nuclear Information System (INIS)

    R. Scott Herbst; Dean R. Peterman; Terry A. Todd

    2005-01-01

    Extraction of Am and Eu using mixtures of diphosphine dioxides (DPDO, e.g., (R1)2P(O)(CH2)nP(O)(R2)2 where R1, R2 = Ph, Bu; n = 1,2), with and without chlorinated cobalt dicarbollide (CCD) in the polar diluents 1,2-dichloroethane (DCE), meta-nitrobenzotrifluoride (F-3), bis-tetrafluoropropyl ether of diethylene glycol (F-8) and phenyltrifluoromethyl sulfone (FS-13) from HNO3, HClO4, LiNO3 and LiClO4 solutions has been investigated. The anomalous aryl strengthening (AAS) effect, i.e. the anomalous increase of extraction ability of methylene bridged diphosphine dioxides due to substitution of aromatic (i.e., phenyl) for alkyl (e.g., butyl or octyl) moieties (DAm increases by three to four orders of magnitude), is only observed during the extraction of Am and Eu from acidic media. In salt media the AAS effect is weakly observed, and is practically absent in such diluents as F-3 and FS-13. The extraction isotherm in the case of DPDO with an observed AAS effect indicates the distribution coefficients of Eu decrease by a factor of two to three, even at the concentration ratio of DPDO:Eu = 50:1; however, these values decrease only by 10% for the DPDO that do not indicate an observed AAS effect. It is proposed that the presence of water in the diluent is necessary for manifestation of the AAS effect. The synergistic effects of adding chlorinated cobalt dicarbollide (CCD) with the DPDO that has been reported for other systems was also found to prevail in several of the systems investigated in this study. On addition of CCD with the DPDO, a considerable synergistic effect is observed (DAm increases by three to four orders of magnitude) during Am and Eu extraction from nitrate media. In perchlorate media the synergistic effect is absent. The most probable reason for synergism in the presence of CCD is the higher hydrophobicity of the CCD anion as compared to the nitrate anion. The results of this work will be of utility in understanding existing and developing new extraction systems designed for the simultaneous removal of multiple radionuclides from acidic streams

  7. Multi-recycling of plutonium and incineration of americium, curium, and technetium in PWRs

    International Nuclear Information System (INIS)

    Golfier, H.; Bergeron, J.; Puill, A.; Rohart, M.

    2000-01-01

    The future of nuclear power requires a clear strategy for radwaste and Plutonium management. Pressurized water reactors (PWR) and the associated fuel cycle installations represent the largest part of the French power plants (and are partly paid off). The reactors in service produce an annual 10 tons of Pu, 1.4 tons of minor actinides (MA), and 3.8 tons of long-lived fission products (LLFP). The spent fuel is reprocessed in La Hague plant to recover the energetic elements U and Pu. The latter was initially dedicated to power Fast Breeder Reactors that converted the depleted and reprocessed, thus ensuring a significant part of the French national energy resources. The shut-down of Super-Phenix, the postponement of building of Fast Breeder Reactors (FBR) and the relaxed need for stretching natural U resources raise the issue of Pu management. In fact, the Pu mono-recycling practiced in France since 1987 (St Laurent B1) only slows down the Pu accumulation in spent nuclear fuel, yet it is unable to stabilize the Pu inventory. Beyond the cooperation with its industrial partners, CEA investigates solutions for short and medium term Pu management thus contributing to research required for keeping nuclear power as an energy option. The range of these investigations shall cover both adaptations for light water reactors to facilitate Pu recycling and more innovative solutions concerning reactors, fuel and fuel cycle. The aim of using Pu more efficiently in PWR has led, not only for economic and non-proliferation reasons, but also for considerations related to the optimization of Pu and MA management. The mastery of Pu inventory is a requirement for all long-lived radwaste management methods. In this context, the potential of innovative PWRs has been investigated to control the Pu fluxes and to make them a milestone on the way to clean nuclear power. This paper presents the most recent results related to Pu utilization and MA and LLFP incineration like (Am+Cm) and Tc. To determine the influence of the Pu fluxes, a 1450 MWe PWR with one standard and one innovative concept (code named APA for Advanced Plutonium fuel Assembly) have been performed. A multi-recycling scenario is simulated with a 400 TWhe power plant park. (authors)

  8. Fundamental chemistry and materials science of americium in selected immobilization glasses

    Energy Technology Data Exchange (ETDEWEB)

    Haire, R.G. [Oak Ridge National Lab., TN (United States); Stump, N.A. [Winston-Salem State Univ., NC (United States). Dept. of Physical Sciences

    1996-12-01

    We have pursued some of the fundamental chemistry and materials science of Am in 3 glass matrices, two being high-temperature (850 and 1400 C mp) silicate-based glasses and the third a sol-gel glass. Optical spectroscopy was the principal tool. One aspect of this work was to determine the oxidation state exhibited by Am in these matrices, as well as factors that control or may alter this state. A correlation was noted between the oxidation state of the f-elements in the two high-temperature glasses with their high-temperature oxide chemistries. One exception was Am: although AmO{sub 2} is the stable oxide encountered in air, when this dioxide was incorporated into the high-temperature glasses, only trivalent Am was found in the products. When Am(III) was used to prepare the sol-gel glasses at ambient temperature, and after these products were heated in air to 800 C, only Am(III) was observed. Potential explanations for the unexpected Am behavior is offered in the context of its basic chemistry. Experimental spectra, spectroscopic assignments, etc. are discussed.

  9. Plutonium, americium and 90Sr in bones of the some wild animals living in Poland

    International Nuclear Information System (INIS)

    Mietelski, J.W.; Kitowski, I.; Tomankiewicz, E.; Gaca, P.; Blazej, S.

    2006-01-01

    Bones of the wild foxes (Vulpes vulpes), roe deer (Capreolus capreolus), deer (Cervus elaphus), wild boars (Sus scorf), mooses (Alces alces), as well as of certain kinds of rodents and insectivorous animals were ashed and milled prior to the radioactivity measurement in the γ-spectrometer. 238 Pu, 239,240 Pu, 241 Am and 90 Sr contents were determined. The results are presented in terms of the kind and origin of the animals. North-east, central-east and south-est parts of Poland were taken into an account

  10. Kinetics of the oxidation-reduction reactions of uranium, neptunium, plutonium, and americium in aqueous solutions

    International Nuclear Information System (INIS)

    Newton, T.W.

    1975-01-01

    This is a review with about 250 references. Data for 240 reactions are cataloged and quantitative activation parameters are tabulated for 79 of these. Some empirical correlations are given. Twelve typical reactions are discussed in detail, along with the effects of self-irradiation and ionic strength. (U.S.)

  11. Treatment of selected primary gynecologic and pelvic malignancies with 241Americium

    International Nuclear Information System (INIS)

    Chung, Joyce Y.; Peschel, Richard E.; Kacinski, Barry; Nath, Ravinder; Pourang, Rauman; Roberts, Kenneth; Fischer, Diana; Chambers, Joseph; Schwartz, Peter E.; Wilson, Lynn

    1995-01-01

    Purpose: To evaluate the efficacy of encapsulated 241 Am in the treatment of primary gynecological malignancies and in previously irradiated patients with recurrent disease in the pelvis. Materials and Methods: Encapsulated 241 Am primarily emits 60keV photons which are effectively shielded by thin layers of high atomic number materials. Dose distributions in water are similar to those produced by Cs-137 photons but with a half-value layer that is considerably less. Cases of 28 patients (12-primary, 16-recurrent) who have been treated with 241 Am at the Yale University School of Medicine since 1986 were retrospectively reviewed. Data concerning dosimetry, disease site, prior treatment, recurrence, disease-free survival, overall survival, and complications were evaluated. Results: Median follow up for the 12 patients with primary gynecological tumors was 19 months (7mo-51mo). There were 6 vulvar, 3 vaginal, 2 cervical and 1 endometrial carcinomas. Median surface dose of 241 Am was 42.2 Gy (23.3Gy-106.6Gy). As part of their initial therapy 11 received pelvic external beam radiation therapy, 6 underwent surgery and 2 received other forms of intracavitary brachytherapy. Of these 12 patients, 11 achieved a complete response (CR) with the duration of CR ranging from 7 to 51 months. Actuarial disease-free survival at 3 years was 66% (S.E.=.16) and actuarial overall survival at 3 years was 91% (S.E.=.08). Median follow up for the 16 patients with recurrent pelvic malignancies was 72 months (20mo-99mo). There were 9 cases of endometrial, 3 vulvar, 3 colorectal, and 1 cervical carinomas. Fifteen of 16 received some form of surgery and radiotherapy prior to their treatment with 241 Am. Median surface dose of 241 Am was 40.3 (17.6Gy-141.7Gy). Of these 16 patients, 10 achieved a CR with the duration of CR ranging from 3 to 88 months. Actuarial disease-free survival at 5 years was 51% (S.E.=.16) and actuarial overall survival at 5 years was 43% (S.E.=.14). Complications were observed in 1 primarily treated patient (soft tissue necrosis) and in 3 patients with recurrent disease (colonic obstruction, rectal fissure, and GI bleed, respectively). Conclusion: The unique dosimetric characteristics of 241 Am allow effective and safe treatment of selected primary gynecological malignancies and in previously irradiated patients with recurrent pelvic malignancies

  12. Fabrication of uranium-americium mixed oxide fuels: thermodynamical modeling and materials properties

    International Nuclear Information System (INIS)

    Prieur, D.

    2011-01-01

    Fuel irradiation in pressurized water reactors lead to the formation of fission products and minor actinides (Np, Am, Cm) which can be transmuted in fast neutrons reactors. In this context, the aim of this work was to study the fabrication conditions of the U 1-y Am y O 2+x fuels which exhibit particular thermodynamical properties requiring an accurate monitoring of the oxygen potential during the sintering step. For this reason, a thermodynamical model was developed to assess the optimum sintering conditions for these materials. From these calculations, U 1-y Am y O 2+x (y=0.10; 0.15; 0.20; 0.30) were sintered in two range of atmosphere. In hyper-stoichiometric conditions at low temperature, porous and multiphasic compounds are obtained whereas in reducing conditions at high temperature materials are dense and monophasic. XAFS analyses were performed in order to obtain additional experimental data for the thermodynamical modeling refinement. These characterizations also showed the reduction of Am(+IV) to Am(+III) and the partial oxidation of U(+IV) to U(+V) due to a charge compensation mechanism occurring during the sintering. Finally, taking into account the high - activity of Am, self-irradiation effects were studied for two types of microstructures and two Am contents (10 and 15%). For each composition, a lattice parameter increase was observed without structural change coupled with a macroscopic swelling of the pellet diameter up to 1.2% for the dense compounds and 0.6% for the tailored porosity materials. (author) [fr

  13. Thermochemistry of selected trivalent lanthanide and americium compounds: orthorhombic and hexagonal hydroxycarbonates

    International Nuclear Information System (INIS)

    Rorif, F.; Fuger, J.; Desreux, J.F.

    2005-01-01

    The molar enthalpies of dissolution of a number of well-characterized hexagonal hydroxycarbonates Ln(OH)CO 3 (hex) (Ln = La, Nd, Sm, Eu) in 6.00 mol dm -3 HCl were measured at 298.15K. A new sealed solution micro-calorimeter was developed for this purpose. It was made of an 18-carat gold alloy in order to improve the performances of a calorimeter previously built in our laboratory. The following standard molar enthalpies of formation, Δ f H m [Ln(OH)CO 3 , hex], in kJ mol -1 , were calculated: -(1627.8±1.6), -(1614.8±1.9), -(1613.4±1.6), and -(1523.0±3.0), for the La, Nd, Sm, and Eu compounds, respectively. These results allowed an extrapolation to Δ f H m [Eu(OH)CO 3 .0.5H 2 O, orth] = -(1653.4±3.6) kJ mol -1 and to Δ f H m [Am(OH)CO 3 , hex] = -(1552.5±3.3) kJ mol -1 . Using auxiliary data and estimated entropies, the solubility products of the hexagonal hydroxycarbonates were calculated. They are compared here with values deduced from solubility and calorimetric measurements for the corresponding orthorhombic hydroxycarbonates. Our approach generally leads to values similar to those deduced from solubility studies. The orthorhombic form is found to be metastable with respect to the hexagonal form. (orig.)

  14. Distribution of plutonium and americium in whole bodies donated to the United States Transuranium Registry

    International Nuclear Information System (INIS)

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

    1989-01-01

    Radiochemical analysis of whole body donations from six former nuclear industry workers 30 or more years post-exposure revealed about 45% of the total body deposition of 239 Pu and 35% of the 241 Am in the respiratory tract of the four cases with inhalation exposure. These proportions are greater than predicted by the current ICRP lung model. Exclusive of the respiratory tract, the mean fractional systemic deposition of 239 Pu in the tissues of five whole bodies was: liver 35.4% ± 12.5%; skeleton 53.7% ± 12.5%; striated muscle 6.5% ± 1.8% and all other organs and tissues 4.4% ± 1.7%. For 241 Am, the comparable values in four cases were liver 6.5% ± 4.8%; skeleton 73.5% ± 12.4%; muscle 14.3% ± 7.6%; and all other tissues and organs 6.65% ± 4.2%. The systemic distribution of 239 Pu was generally consistent with ICRP Publication 30. A significant fraction of both nuclides was retained in the muscle and other soft tissues which serve as long-term storage depots. Initial fractionation of 241 Am between skeleton and liver is consistent with the 50:30 ratio proposed in ICRP Publication 48 assuming an effective clearance half-time from the liver of about 2 y. Estimates of 239 Pu deposition made on the basis of urinalysis results in vivo were typically greater than the observed deposition measured in the tissues of the whole body after death. (author)

  15. Controlling Hexavalent Americium – A Centerpiece to a Compact Nuclear Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Shafer/Braley, Jenifer; Nash, Kenneth L; Lumetta, Gregg; McCann, Kevin; Sinkov, Sergey I

    2014-10-01

    Closing the nuclear fuel cycle could be simplified by recovering the actinides U through Am as a group. This could be achieved by converting U, Np, Pu and Am to the hexavalent state. Uranium, Np and Pu are readily oxidized to the hexavalent state. Generation of hexavalent Am in acidic solutions is more difficult, as the standard reduction potential of the Am(VI) /Am(III) couple (+1.68 V in 1 M HClO4) is well outside of the electrochemical stability window of water. While the oxidation and separation of Am has been demonstrated under laboratory conditions, several issues could plague scale up and implementation of this separation with used fuel. Two primary concerns are considered. The first issue concerns the stability of the oxidized Am. The second involves the undesirable co-extraction of tetravalent f-elements with the hexavalent actinides. To address the first concern regarding Am redox instability, Am reduction will be monitored under a variety of different conditions to establish the means of improving the stability of Am(VI) in the organic phase. Identifying the components contributing most significantly to its reduction will allow thoughtful modification of the process. To address the second concern, we propose to apply branched chain extractants to separate hexavalent actinides from tetravalent f-elements. Both branched monoamide and organophosphorus extractants have demonstrated significant selectivity for UO22+ versus Th4+, with separation factors generally on the order of 100. The efforts of this two-pronged research program should represent a significant step forward in the development of aqueous separations approaches designed to recover the U-Am actinides based on the availability of the hexavalent oxidation state. For the purposes of this proposal, separations based on this approach will be called SAn(VI) separations, indicating the Separation of An(VI).

  16. Separation of americium from lanthanides in nitric acid medium by DPTP in octanol-dodecane

    International Nuclear Information System (INIS)

    Tang Hongbin; Ye Guoan; Cheng Qifu; Ye Yuxing; Jiang Dexiang; Zhu Wenbin; Chen Hui; Zhang Hu; He Hui; Li Gaoliang

    2008-01-01

    Considering the good solubility of 2,6-bis(5,6-di-n-propyl-1,2,4-triazin-3-yl)- pyridine (DPTP) and avoiding the third phase formation, octanol-dodecane (ODOD) with a volume fraction of 30% was selected as the diluent. The distribution ratios of Am(III) and Eu(III) were studied as a function of a number of parameters such as con- tact time, nitrate ion and the nitric acid concentration in aqueous phase, the concentration of DPTP in the organic phase. A counter-current cascade (10 mL glass tube with plug) extraction experiment was carried out with 0.04 mol/L DPTP/ODOD. In the experiments, the flow rate ratios are as following: F:X:S=1:0.63:0.25, BF:BX=1:1; the feed solution, Eu(III) + Am(III) in 1.0 mol/L HNO 3 solution; scrubbing solution, 1.0 mol/L HNO 3 solution; stripping reagent, 0.01 mol/L HNO 3 . The results show that the recovery of Am is 98.42%, only containing Am/Eu is 45, SF Eu/Am is more than 10 3 . (authors)

  17. A consistent set of thermodynamic constants for americium (III) species with hydroxyl and carbonate

    International Nuclear Information System (INIS)

    Kerrisk, J.F.; Silva, R.J.

    1986-01-01

    A consistent set of thermodynamic constants for aqueous species, and compounds of Am(III) with hydroxyl and carbonate ligands has been developed. The procedure used to develop these constants involved establishing a value for one formation constant at a time in a sequential order, starting with the hydrolysis products and hydroxide solids, and then proceeding to carbonate species. The EQ3NR chemical-equilibrium model was used to test the constants developed. These constants are consistent with most of the experimental data that form their basis; however, considerable uncertainty still exists in some aspects of the Am(III) data

  18. Optimization of TRPO process parameters for americium extraction from high level waste

    International Nuclear Information System (INIS)

    Chen Jing; Wang Jianchen; Song Chongli

    2001-01-01

    The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35 mol/L for the feed and 0.5 mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given

  19. Separation of americium (III) and strontium (II) using TEHDGA and 18-crown-6

    Energy Technology Data Exchange (ETDEWEB)

    Sinharoy, Prithwish; Khan, Pasupati Nath; Nair, Deepika; Jagasia, Poonam; Dhami, P.S.; Kaushik, C.P.; Banerjee, Kalyan [Bhabha Atomic Research Centre, Mumbai (India). Nuclear Recycle Group; Anitha, M. [Bhabha Atomic Research Centre, Mumbai (India). Rare Earth Development Section; Sharma, J.N. [Bhabha Atomic Research Centre, Mumbai (India). Process Development Div.

    2017-06-01

    This work describes extraction of Am(III) and Sr(II) together with tetra(2-ethylhexyl) diglycolamide (TEHDGA) and selective back-extraction of strontium with a strontium complexant, 18-crown-6, leading to their separation from each other. 0.3 M TEHDGA+5% isodecyl alcohol/n-dodecane was used to extract Am(III) and Sr(II) from 4 M nitric acid into organic phase with very high D (D{sub Am}=1000, D{sub Sr}=22) and 0.1 M 18-crown-6 dissolved in 4 M nitric acid is used for selective stripping of Sr(II) from loaded extract phase. Am(III) left in the extract phase was then stripped with 0.01 M nitric acid. Stripping of Sr(II) was found to increase with increase in 18-crown-6 concentration, at 0.1 M 18-crown-6 dissolved in 4 M nitric acid, 83% of the loaded strontium (D{sub Sr}=0.20) was back-extracted in a single contact while loss of Am(III) was 0.8% (D{sub Am}=122.45). Stoichiometry limit of 1:1 was observed between strontium and 18-crown-6. Strontium was precipitated and separated from the complexant by Na{sub 2}SO{sub 4} or Na{sub 2}CO{sub 3}. This process was tested with simulated solution of high level waste and found suitable for quantitative recovery of strontium with high purity.

  20. Fundamental chemistry and materials science of americium in selected immobilization glasses

    International Nuclear Information System (INIS)

    Haire, R.G.; Stump, N.A.

    1996-01-01

    We have pursued some of the fundamental chemistry and materials science of Am in 3 glass matrices, two being high-temperature (850 and 1400 C mp) silicate-based glasses and the third a sol-gel glass. Optical spectroscopy was the principal tool. One aspect of this work was to determine the oxidation state exhibited by Am in these matrices, as well as factors that control or may alter this state. A correlation was noted between the oxidation state of the f-elements in the two high-temperature glasses with their high-temperature oxide chemistries. One exception was Am: although AmO 2 is the stable oxide encountered in air, when this dioxide was incorporated into the high-temperature glasses, only trivalent Am was found in the products. When Am(III) was used to prepare the sol-gel glasses at ambient temperature, and after these products were heated in air to 800 C, only Am(III) was observed. Potential explanations for the unexpected Am behavior is offered in the context of its basic chemistry. Experimental spectra, spectroscopic assignments, etc. are discussed

  1. Standard test method for the radiochemical determination of americium-241 in soil by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This method covers the determination of americium–241 in soil by means of chemical separations and alpha spectrometry. It is designed to analyze up to ten grams of soil or other sample matrices that contain up to 30 mg of combined rare earths. This method allows the determination of americium–241 concentrations from ambient levels to applicable standards. The values stated in SI units are to be regarded as standard. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precaution statements, see Section 10.

  2. Photochemical oxidation of americium(3) in bicarbonate-carbonate solutions saturated with N2O

    International Nuclear Information System (INIS)

    Shilov, V.P.; Yusov, A.B.

    1993-01-01

    The influence of UV radiation on 1.1x10 -4 mol/l Am(3) in bicarbonate-carbonate solutions of sodium and potassium saturated with N 2 O was studied by spectrographic method. In all the cases Am(4) was formed as a primary product. Initial rate of Am(4) accumulation remains stable in solutions up to HCO 3 - or HCO 3 - +CO 3 2- concentration of approximately 1.5 mol/l, but it decreases in case of their higher concentration. In solutions with pH 8.4-10 Am(4) disproportionates at a slow rate and the method suggested permits attaining practically 100% yield of it

  3. Sorption of carbon, cobalt, nickel, strontium, iodine, cesium, americium and neptumium in rocks and minerals

    International Nuclear Information System (INIS)

    Pinnoja, S.; Jaakkola, T.; Kaemaeraeinen, E.L.; Koskinen, A.; Lindberg, A.

    1984-09-01

    Sorption of the radionuclides C-14, Co-58, Ni-63, I-125, Sr-85, Cs-134, Am-241 and Np-237, which are important in nuclear waste, were studied in rock by autoradiographic method. Samples were selected to represent common rocks and minerals in Finnish bedrock: rapakivi granite, tonalite, mica gneiss, granodiorite, biotite, quartz, plagioclase, K feldspar and hornblende. Polished thin sections were used to determine the contributions of different minerals to the sorption of the radionuclides. Sawn rock pieces (1.2 x 1.2 x 1.6 cm) were used to determine the Ksub(a)-values for rough rock surfaces where penetration into the rock matrix was found. The sorption order of the elements determined with the rock pieces was Ksub(a)sup(Cs)>Ksub(a)sup(Ni)>Ksub(a)sup(Co)>Ksub(a)sup(Sr)>Ksub(a)sup(C)>Ksub(a)sup(I). The same order of sorption was determined with thin sections for all nuclides except carbon, which was not sorbed on thin sections. Wide differences in the Ksub(a)-values for different minerals were found for Cs and Sr. The sorption mechanism for these elements is presumed to be ion exchange. The Ksub(a)-values of Cs varied between 0.1 x 10 -4 and 600 x 10 -4 m 3 /m 2 and those for Sr between 0.01 x 10 -4 and 10 x 10 -4 m 3 /m 2 . The lowest values were determined for quartz and the highest for biotite. Radionuclides having a tendency to form pseudocolloids and hydroxide precipitates (Am, Np, Ni) were sorbed on thin sections with only small variation in Ksub(a)-values: all values were between 1 x 10 -4 and 10 x 10 -4 and 100 x 10 -4 m 3 /m 2 . A very good agreement was found between experimental and calculated Ksub(a)-values for rock thin sections. Ksub(a)-values were calculated by multiplying the percentages of individual minerals in the rock by the Ksub(a)-values of the corresponding pure minerals and summing the results. Calculated Ksub(a)-values were occasionally up to 50% smaller than the experimental ones, owing to the low contents of some high adsorbing minerals not included in the calculations

  4. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    International Nuclear Information System (INIS)

    Albrecht-Schmitt, Thomas Edward

    2013-01-01

    The past three years of support by the Heavy Elements Chemistry Program have been highly productive in terms of advanced degrees awarded, currently supported graduate students, peer-reviewed publications, and presentations made at universities, national laboratories, and at international conferences. Ph.D. degrees were granted to Shuao Wang and Juan Diwu, who both went on to post-doctoral appointments at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory with Jeff Long and Ken Raymond, respectively. Pius Adelani completed his Ph.D. with me and is now a post-doc with Peter C. Burns. Andrea Alsobrook finished her Ph.D. and is now a post-doc at Savannah River with Dave Hobbs. Anna Nelson completed her Ph.D. and is now a post-doc with Rod Ewing at the University of Michigan. As can be gleaned from this list, students supported by the Heavy Elements Chemistry grant have remained interested in actinide science after leaving my program. This follows in line with previous graduates in this program such as Richard E. Sykora, who did his post-doctoral work at Oak Ridge National Laboratory with R. G. Haire, and Amanda C. Bean, who is a staff scientist at Los Alamos National Laboratory, and Philip M. Almond and Thomas C. Shehee, who are both staff scientists at Savannah River National Laboratory, Gengbang Jin who is a staff scientist at Argonne National Lab, and Travis Bray who has been a post-doc at both LBNL and ANL. Clearly this program is serving as a pipe-line for students to enter into careers in the national laboratories. About half of my students depart the DOE complex for academia or industry. My undergraduate researchers also remain active in actinide chemistry after leaving my group. Dan Wells was a productive undergraduate of mine, and went on to pursue a Ph.D. on uranium and neptunium chalcogenides with Jim Ibers at Northwestern. After earning his Ph.D., he went directly into the nuclear industry

  5. A Study of the Translocation of Plutonium and Americium from Wounds

    Energy Technology Data Exchange (ETDEWEB)

    Watters, R. L. [Colorado State Univ., Fort Collins, CO (United States); Lebel, Jacques L. [Colorado State Univ., Fort Collins, CO (United States); Johnson, LaMar J. [Colorado State Univ., Fort Collins, CO (United States); Bull, Emory H. [Colorado State Univ., Fort Collins, CO (United States)

    1968-12-15

    The technological feasibility and economic advantages of the use of plutonium in power reactors and in other plutoniumfueled systems have been widely explored and demonstrated (1). As the use of plutonium and other transuranic nuclides has increased, the chance of their deposition within the human body has increased. A relatively complete review of the literature regarding the modes of entry, distribution, excretion, and means of evaluating plutonium within living systems has been recently published (2, 3).

  6. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht-Schmitt, Thomas Edward

    2013-09-14

    The past three years of support by the Heavy Elements Chemistry Program have been highly productive in terms of advanced degrees awarded, currently supported graduate students, peer-reviewed publications, and presentations made at universities, national laboratories, and at international conferences. Ph.D. degrees were granted to Shuao Wang and Juan Diwu, who both went on to post-doctoral appointments at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory with Jeff Long and Ken Raymond, respectively. Pius Adelani completed his Ph.D. with me and is now a post-doc with Peter C. Burns. Andrea Alsobrook finished her Ph.D. and is now a post-doc at Savannah River with Dave Hobbs. Anna Nelson completed her Ph.D. and is now a post-doc with Rod Ewing at the University of Michigan. As can be gleaned from this list, students supported by the Heavy Elements Chemistry grant have remained interested in actinide science after leaving my program. This follows in line with previous graduates in this program such as Richard E. Sykora, who did his post-doctoral work at Oak Ridge National Laboratory with R. G. Haire, and Amanda C. Bean, who is a staff scientist at Los Alamos National Laboratory, and Philip M. Almond and Thomas C. Shehee, who are both staff scientists at Savannah River National Laboratory, Gengbang Jin who is a staff scientist at Argonne National Lab, and Travis Bray who has been a post-doc at both LBNL and ANL. Clearly this program is serving as a pipe-line for students to enter into careers in the national laboratories. About half of my students depart the DOE complex for academia or industry. My undergraduate researchers also remain active in actinide chemistry after leaving my group. Dan Wells was a productive undergraduate of mine, and went on to pursue a Ph.D. on uranium and neptunium chalcogenides with Jim Ibers at Northwestern. After earning his Ph.D., he went directly into the nuclear industry.

  7. Subsurface Behavior of Plutonium and Americium at Non-Hanford Sites and Relevance to Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Riley, Robert G.

    2008-02-01

    Seven sites where Pu release to the environment has raised significant environmental concerns have been reviewed. A summary of the most significant hydrologic and geochemical features, contaminant release events and transport processes relevant to Pu migration at the seven sites is presented.

  8. Neutron activation analysis: Modelling studies to improve the neutron flux of Americium Beryllium source

    OpenAIRE

    Didi, Abdessamad; Dadouch, A.; Jaï, O.; Tajmouati, J.; El Bekkouri, H.

    2017-01-01

    Americium–beryllium (Am-Be; n, γ) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: pr...

  9. Radioanalytical determination of plutonium and americium using ion exchange and extraction chromatography technique in urine

    International Nuclear Information System (INIS)

    Santhanakrishnan, V.; Sreedevi, K.R.; Rajaram, S.; Ravi, P.M.

    2011-01-01

    The use of anion exchange chromatography for the separation of Pu and extraction chromatography technique for the separation of Am from urine samples was studied. In the earlier method, Pu separation was carried out by anion exchange chromatography followed by Am separation by cation exchange chromatography. The chemical recovery of Am obtained by cation exchange separation method was inconsistent and low in the range 30-70%. In this study, the average Pu recovery obtained using anion exchange chromatography was 89.2 with standard deviation of 10.4 and the average Am recovery obtained using extraction chromatography with TRU resin was 77.4 with standard deviation of 14.8. Moreover, Am separation could be completed within three hours using the TRU column compared to two days that were required for the cation exchange chromatography. (author)

  10. Computer modelling of the chemical speciation of Americium (III) in human body fluids

    International Nuclear Information System (INIS)

    Jiang, Shu-bin; Lei, Jia-rong; Wang, He-yi; Zhong, Zhi-jing; Yang, Yong; Du, Yang

    2008-01-01

    A multi-phase equilibrium model consisted of multi-metal ion and low molecular mass ligands in human body fluid has been constructed to discuss the speciation of Am 3+ in gastric juice, sweat, interstitial fluid, intracellular fluid and urine of human body, respectively. Computer simulations indicated that the major Am(III)P Species were Am 3+ , [Am Cl] 2+ and [AmH 2 PO 4 ] 2+ at pH 4 became dominant with higher pH value when [Am] = 1 x 10 -7 mol/L in gastric juice model and percentage of AmPO 4 increased with [Am]. in sweat system, Am(III) existed with soluble species at pH 4.2∼pH 7.5 when [Am] = 1 x 10 -7 mol/L and Am(III) existed with Am 3+ and [Am OH] 2+ at pH 6.5 when [Am] -10 mol/L or [Am] > 5 x 10 -8 mol/L . With addition of EDTA, the Am(III) existed with soluble [Am EDTA] - whereas the Am(III) existed with insoluble AmPO 4 when [Am] > 1 x 10 -12 mol/L at interstitial fluid. The major Am(III) species was AmPO 4 at pH 7.0 and [Am]=4 x 10 -12 mol/L in intracellular fluid, which implied Am(III) represented strong cell toxicity. The percentage of Am(III) soluble species increased at lower pH hinted that the Am(III), in the form of aerosol, ingested by macrophage, could released into interstitial fluid and bring strong toxicity to skeleton system. The soluble Am(III) species was dominant when pH 4 when pH > 4.5 when [Am] = 1 x 10 -10 Pmol/L in human urine, so it was favorable to excrete Am(III) from kidney by taking acid materials. (author)

  11. Neutron activation analysis: Modelling studies to improve the neutron flux of Americium-Beryllium source

    Energy Technology Data Exchange (ETDEWEB)

    Didi, Abdessamad; Dadouch, Ahmed; Tajmouati, Jaouad; Bekkouri, Hassane [Advanced Technology and Integration System, Dept. of Physics, Faculty of Science Dhar Mehraz, University Sidi Mohamed Ben Abdellah, Fez (Morocco); Jai, Otman [Laboratory of Radiation and Nuclear Systems, Dept. of Physics, Faculty of Sciences, Tetouan (Morocco)

    2017-06-15

    Americium–beryllium (Am-Be; n, γ) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

  12. Plutonium, americium, and uranium concentrations in Nevada Test Site soil profiles

    International Nuclear Information System (INIS)

    Essington, E.H.; Gilbert, R.O.; Eberhardt, L.L.; Fowler, E.B.

    1975-01-01

    Many soil profile samples were collected by the Nevada Applied Ecology Group from five nuclear safety test sites on the Nevada Test Site and Tonopah Test Range in Nevada, U.S.A. The profile samples were analyzed for 239 Pu, 240 Pu, 241 Am, and in some cases 235 U and 238 U, in order to estimate the depth of radionuclide penetration and level of contamination at specific sampling depths after an extended period of time since deposition on the surface. Nearly 70 individual profiles were examined. About one-half of the profiles exhibited a smooth leaching pattern with more than 95 percent of the plutonium in the top 5 cm. Other profile patterns are discussed relative to mechanical disturbance of the profile after the initial deposition, accumulation of plutonium in specific zones within the soil profile, and occurrence of large amounts of plutonium in the deepest parts of the soil profile. The implications of these observations are discussed with respect to redistribution of radioactivity by wind, water, and burrowing animals, ingestion by burrowing and grazing animals, uptake by vegetation, and cleanup operations. (auth)

  13. Assessment of Neptunium, Americium, and Curium in the Savannah River Site Environment

    International Nuclear Information System (INIS)

    Carlton, W.H.

    1997-01-01

    A series of documents has been published in which the impact of various radionuclides released to the environment by Savannah River Site (SRS) operations has been assessed. The quantity released, the disposition of the radionuclides in the environment, and the dose to offsite individuals has been presented for activation products, carbon cesium, iodine, plutonium, selected fission products, strontium, technetium, tritium, uranium, and the noble gases. An assessment of the impact of nonradioactive mercury also has been published.This document assesses the impact of radioactive transuranics released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are 239Np, 241Am, and 244Cm

  14. Effect of solvent on in vitro dissolution: Summary of results for uranium, americium, and cobalt aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Hoover, M.D.

    1995-12-01

    The revised 10 CFR Part 20 has adopted the ICRP Publication 30 method for calculating the committed effective dose equivalent from intakes of radionuclides. This dosimetry scheme requires knowledge or assumptions about the chemical form of the radionuclide, its particle size, and its known or assumed solubility. The solubility is classified as being either D (relatively soluble), W, or Y (relatively insoluble), depending on whether the material dissolves over periods of days, weeks, or years. Although Nuclear Regulatory Commission licensees may wish to take advantage of material-specific knowledge in order to adjust annual limits on intake and derived air concentrations, relatively few radioactive materials to which workers and the general population may be exposed have been adequately characterized either in terms of physicochemical form or solubility. Experimental measurement of solubility using some type of in vitro dissolution measurement system is therefore needed. However, there is currently no clear consensus regarding the appropriate design of in vitro dissolution systems, particularly when considering the range of different radionuclides to be studied, and the complexity of the biological mechanisms involved in the retention and clearance of inhaled deposited radioactive particles. The purpose of this study was to evaluate the effect of the several solvents on the dissolution of four test aerosols ({sup 57}Co{sub 3}O{sub 4}, {sup 241}AmO{sub 2}, ammonium diuranate [ADU], and U{sub 3}O{sub 8}) selected to encompass a variety of chemical and biochemical properties in vivo. The results of this study provide some guidance on the usefulness of in vitro dissolution tests for estimating the solubility of unknown radionuclide particles within the context of a simple model such as the class D, W, and Y formulation of ICRP 30.

  15. Determination and speciation of plutonium, americium, uranium, thorium, potassium and 137Cs in a Venice canal sediment sample

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Guerra, F.; Meli, M.A.; Roselli, C.; Degetto, S.

    1998-01-01

    A sequential extraction method consisting of six operationally-defined fractions has been developed for determining the geochemical partitioning of natural (U, Th, 40 K) and anthropogenic (Pu, Am, 137 Cs) radionuclides in a 40-50 cm deep sediment sample collected in a Venice canal. Extraction chromatography was used for the chemical separation of a single radionuclide; the final recoveries were calculated by adding 232 U, 228 Th, 242 Pu and 243 Am as the yield tracers. After electrodeposition the alpha spectrometry was carried out. 137 Cs and 40 K were measured by gamma spectrometry. The total concentrations in the wet sample, obtained by a complete disgregation of the matrix by NaOH fusion, were the following: 239+240 Pu = 610 ± 80 mBq/kg, 238 Pu = 13 ± 5mBq/kg, 241 Am 200 ± 30 mBq/kg, 137 Cs = 6.9 ± 1.1 Bq/kg, U = 1.33 ± 0.14 ppm, Th = 2.69 ± 0.26 ppm, K = 0.72 ± 0.04 %. The mean ratio 238 Pu/ 239+240 Pu ( 0.02) shows a contamination due essentially to fall-out and U and Th alpha spectra indicate the natural origin of two elements. The absence of 134 Cs proves that the sediment was not affected by the Chernobyl fall-out. For the speciation, the following fractions were considered: water soluble, carbonates, Fe-Mn oxides, organic matter, acid soluble, residue. Pu (about 65%) and Am (about 90%) were present predominantly in the carbonate fraction; U was more distributed and about 30% appeared both in the carbonate fraction and in the residue; the majority of Th was present in the residue (about 67%); 40 K was totally present in the residue; and 137 Cs was found mostly in the acid soluble fraction (about 46%) and in the residue (about 40%)

  16. A Review of Subsurface Behavior of Plutonium and Americium at the 200-PW-1/3/6 Operable Units

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Riley, Robert G.

    2008-01-31

    This report begins with a brief summary of the history and current status of 200-PW-1/3/6 OUs in section 2.0. This is followed by a description of our concentual model of Pu/Am migration at the 200-PW-1/3/6 OUs, during both past artificial recharge conditions and current natural recharge condictions (section 3.0). Section 4.0 discusses data gaps and information needs. The final section (section 5.0) provides recommendations for futher work to address the data gaps and information needs identified in section 4.0.

  17. A highly efficient solvent system containing functionalized diglycolamides and an ionic liquid for americium recovery from radioactive wastes

    NARCIS (Netherlands)

    Sengupta, A; Mohapatra, P.K.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2012-01-01

    Three room temperature ionic liquids (RTILs), viz. C4mim+·PF6−, C6mim+·PF6− and C8mim+·PF6−, were evaluated as diluents for the extraction of Am(III) by N,N,N′,N′-tetraoctyl diglycolamide (TODGA). At 3 M HNO3, the DAm-values by 0.01 M TODGA were found to be 102, 34 and 74 for C4mim+·PF6−,

  18. The extraction of americium and strontium by P,P'-Di(2-ethylhexyl) benzene-1,2- diphosphonic acid

    International Nuclear Information System (INIS)

    Otu, E.O.; Chiarizia, R.; Rickert, P.G.; Nash, K.L.

    2002-01-01

    A new acidic organophosphorus extractant, P,P'-di(2-ethylhexyl) benzene-1,2-diphosphonic acid (H2DEH[1,2-BzDP]), has been synthesized. Though the extractant proved unstable with respect to acid hydrolysis upon storage at room temperature, it was sufficiently stable in o-xylene solution under refrigeration to determine its aggregation and extraction properties for Sr 2+ and Am 3+ between 25 and 60 C. Slope analysis of radioanalytical data and the results of osmometric measurements indicate that the dominant extraction reaction for both metal ions is M n+ +n HL(l e quilibrium)ML n +n H + where n=2 for Sr(II) and 3 for Am(III). In the Sr system there is also evidence for the extraction of SrNO 3 + . As the extractant aggregation and extraction stoichiometries do not change significantly with temperature, it was possible to derive enthalpies and entropies of extraction from the temperature dependence of the metal extraction equilibrium constants between 25.0 and 60.0 C. The extraction of both metal ions is driven by an exothermic enthalpy and opposed by unfavorable entropies. The thermodynamic data are discussed in comparison with earlier data on the thermodynamics of extraction of these metal ions by analogous ligands containing aliphatic alkyl linkages between the functional groups and other data from the literature.

  19. Salicylic acid failed to increase the efficacy of Ca-DTPA in the decorporation of plutonium and americium

    International Nuclear Information System (INIS)

    Jones, C.W.; Lloyd, R.D.; Mays, C.W.

    1979-01-01

    Male and female C57BL/Do mice were each given a single i.p. injection of 237+239 Pu + 241 Am as the citrate complex at 45 days of age. Twice weekly i.p. injecctions of either 500 μmol/kg Ca-DTPA or 500 μmol/kg Ca-DTPA, mixed just before injection with 2000 μmol/kg salicylic acid (SA), were begun 3 days after nuclide administration and continued for 5 weeks. Control mice were injected each time with isotonic saline. Nuclide retention was determined by in vivo counting using NaI(T1) spectrometry. At the end of treatment, total-body retention of Pu or Am in the mice given Ca-DTPA was significantly lower (P < 0.001) than in the control animals. Mice treated with Ca-DTPA + SA were statistically indistinguishable from mice treated with Ca-DTPA

  20. Theoretical investigation of pressure-induced structural transitions in americium using GGA+U and hybrid density functional theory methods

    DEFF Research Database (Denmark)

    Verma, Ashok K.; Modak, P.; Sharma, Surinder M.

    2013-01-01

    and pressure-induced structural transitions. Both methods yield equilibrium volume and bulk modulus in good agreement with the experimental results. The GGA+spin orbit coupling+U method reproduced all structural transitions under pressure correctly, but the HYB-DFT method failed to reproduce the observed Am......-I to Am-II transition. Good agreement was found between calculated and experimental equations of states for all phases, but the first three phases need larger U (α) parameters (where α represents the fraction of Hartree-Fock exchange energy replacing the DFT exchange energy) than the fourth phase in order...... to match the experimental data. Thus, neither the GGA+U nor the HYB-DFT methods are able to describe the energetics of Am metal properly in the entire pressure range from 0 GPa to 50 GPa with a single choice of their respectiveU and α parameters. Low binding-energy peaks in the experimental photoemission...

  1. Evaluation of thermal neutron cross-sections and resonance integrals of protactinium, americium, curium, and berkelium isotopes

    International Nuclear Information System (INIS)

    Belanova, T.S.

    1994-12-01

    Data on the thermal neutron fission and capture cross-sections as well as their corresponding resonance integrals are reviewed and analysed. The data are classified according to the form of neutron spectra under investigation. The weighted mean values of the cross-sections and resonance integrals for every type of neutron spectra were adopted as evaluated data. (author). 87 refs, 2 tabs

  2. Thermodynamic properties of chemical species in nuclear waste: Topical report: The solubilities of crystalline neodymium and americium trihydroxides

    International Nuclear Information System (INIS)

    Silva, R.J.

    1982-12-01

    The solubilities of crystalline Nd(OH) 3 and Am(OH) 3 were measured at 25 +- 1 0 C in aqueous solutions of 0.1 M NaClO 4 under argon as a function of pH by determination of the solution concentrations of Nd and Am. Prior to use in the solubility measurements, the solid materials were characterized through their x-ray powder patterns. Analyses of the solubility data with the computer code MINEQL allowed estimates of the solubility product constants, K/sub s10/, and the second and third hydrolysis constants, K 12 and K 13 , for Nd 3+ and Am 3+ . Upper limits for the fourth hydrolysis constants were also estimated. For Nd, they are: log K/sub s10/ = 16.0 +- .2, log K 12 = -15.8 +- .5, log K 13 = -23.9 +- .2 and log K 14 12 = -16.0 +- .7, log K 13 = -24.3 +- .3 and log K 14 3 was found to be a factor of 100 to 300 less soluble than predicted from previously reported thermodynamic data over much of the pH range of environmental interest. The measured solubility of crystalline Am(OH) 3 was also considerably less than predicted from the previously estimated solubility product constant, i.e., a factor of about 600. For Am, the solubility of the crystalline material was a factor of about 30 less than the amorphous material. The solubilities of crystalline Nd(OH) 3 and Am(OH) 3 as a function of pH were found to be very similar and Nd(OH) 3 should be a good analog compound for Am(OH) 3

  3. LITERATURE REVIEW ON THE SORPTION OF PLUTONIUM, URANIUM, NEPTUNIUM, AMERICIUM AND TECHNETIUM TO CORROSION PRODUCTS ON WASTE TANK LINERS

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Kaplan, D.

    2012-02-29

    The Savannah River Site (SRS) has conducted performance assessment (PA) calculations to determine the risk associated with closing liquid waste tanks. The PA estimates the risk associated with a number of scenarios, making various assumptions. Throughout all of these scenarios, it is assumed that the carbon-steel tank liners holding the liquid waste do not sorb the radionuclides. Tank liners have been shown to form corrosion products, such as Fe-oxyhydroxides (Wiersma and Subramanian 2002). Many corrosion products, including Fe-oxyhydroxides, at the high pH values of tank effluent, take on a very strong negative charge. Given that many radionuclides may have net positive charges, either as free ions or complexed species, it is expected that many radionuclides will sorb to corrosion products associated with tank liners. The objective of this report was to conduct a literature review to investigate whether Pu, U, Np, Am and Tc would sorb to corrosion products on tank liners after they were filled with reducing grout (cementitious material containing slag to promote reducing conditions). The approach was to evaluate radionuclides sorption literature with iron oxyhydroxide phases, such as hematite ({alpha}-Fe{sub 2}O{sub 3}), magnetite (Fe{sub 3}O{sub 4}), goethite ({alpha}-FeOOH) and ferrihydrite (Fe{sub 2}O{sub 3} {center_dot} 0.5H{sub 2}O). The primary interest was the sorption behavior under tank closure conditions where the tanks will be filled with reducing cementitious materials. Because there were no laboratory studies conducted using site specific experimental conditions, (e.g., high pH and HLW tank aqueous and solid phase chemical conditions), it was necessary to extend the literature review to lower pH studies and noncementitious conditions. Consequently, this report relied on existing lower pH trends, existing geochemical modeling, and experimental spectroscopic evidence conducted at lower pH levels. The scope did not include evaluating the appropriateness of K{sub d} values for the Fe-oxyhydroxides, but instead to evaluate whether it is a conservative assumption to exclude this sorption process of radionuclides onto tank liner corrosion products in the PA model. This may identify another source for PA conservatism since the modeling did not consider any sorption by the tank liner.

  4. Studies on the binding and transport processes of americium-241 hydroxide polymers in rat lung and bovine alveolar macrophages

    International Nuclear Information System (INIS)

    Taya, A.

    1986-03-01

    The binding of Am-241 hydroxide polymers to the cell components of rat lung was investigated using differential centrifugation, density gradient centrifugation with different media, gel chromatography, free flow electrophoresis and electron microscopic autoradiography with Pu-241. The bovine alveolar macrophage cultures were introduced as an in vitro test system for Am-241 uptake. Form the biochemical and electron microscopic studies it can be concluded that Am-241 is taken up by pulmonary macrophages, where its first storage site is probably the lysosome. Then the Am-241 seems to be solubilized in the lysosomes and to be bound to the cytosolic ferritin of macrophages. Am-241 might be released from the cells and crosses the alveolar membranes as bound to transferrin or as low molecular weight form. (orig.) [de

  5. Handling of a glove box accident. Surgical treatment of a wound contaminated by a mixture of plutonium-239 and americium

    International Nuclear Information System (INIS)

    Lalu, P.

    1977-01-01

    An employee of the Valduc Centre (France) suffered an injury to his right thumb when working in a glove-box on a pipeline which had contained a solution of 239 Pu and Am. The lesion was slight but attempts at decontamination were fruitless. The contamination was deep-seated (activity of not less than 18nCi). DTPA was injected intravenously, and it was decided to excise the lesion surgically. Thanks to the quality of its physical facilities and the professional quality of its radiation medicine and surgery team, the Valduc Centre was able to carry out the operation successfully. The result was excellent, and the contamination was eliminated to the satisfaction of both the patient and the physician. (author)

  6. Selective extraction of americium(III) over europium(III) ions with pyridylpyrazole ligands. Structure-property relationships

    Energy Technology Data Exchange (ETDEWEB)

    Su, Dongping; Liu, Ying; Li, Shimeng; Ding, Songdong; Jin, Yongdong; Wang, Zhipeng; Hu, Xiaoyang; Zhang, Lirong [Department of chemistry, Sichuan University, Chengdu (China)

    2017-01-18

    To clarify the structure-property relationships of pyridylpyrazole ligands and provide guidance for the design of new and more efficient ligands for the selective extraction of actinides over lanthanides, a series of alkyl-substituted pyridylpyrazole ligands with different branched chains at different positions of the pyrazole ring were synthesized. Extraction experiments showed that the pyridylpyrazole ligands exhibited good selective extraction abilities for Am{sup III} ions, and the steric effects of the branched chain had a significant impact on the distribution ratios of Am{sup III} and Eu{sup III} ions as well as the separation factor. Moreover, both slope analyses and UV/Vis spectrometry titrations indicated the formation of a 1:1 complex of 2-(1-octyl-1H-pyrazol-3-yl)pyridine (C8-PypzH) with Eu{sup III} ions. The stability constant (log K) for this complex obtained from the UV/Vis titration was 4.45 ± 0.04. Single crystals of the complexes of 3-(2-pyridyl)pyrazole (PypzH) with Eu(NO{sub 3}){sub 3} and Sm(NO{sub 3}){sub 3} were obtained; PypzH acts as a bidentate ligand in the crystal structures, and the N atom with a bound H atom did not participate in the coordination. In general, this study revealed some interesting findings on the effects of the alkyl-chain structure and the special complexation between pyridylpyrazole ligands and Ln{sup III} ions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Measurements of Plutonium and Americium in Soil Samples from Project 57 using the Suspended Soil Particle Sizing System (SSPSS)

    International Nuclear Information System (INIS)

    John L. Bowen; Rowena Gonzalez; David S. Shafer

    2001-01-01

    As part of the preliminary site characterization conducted for Project 57, soils samples were collected for separation into several size-fractions using the Suspended Soil Particle Sizing System (SSPSS). Soil samples were collected specifically for separation by the SSPSS at three general locations in the deposited Project 57 plume, the projected radioactivity of which ranged from 100 to 600 pCi/g. The primary purpose in focusing on samples with this level of activity is that it would represent anticipated residual soil contamination levels at the site after corrective actions are completed. Consequently, the results of the SSPSS analysis can contribute to dose calculation and corrective action-level determinations for future land-use scenarios at the site

  8. UNDERSTANDING VARIATION IN PARTITION COEFFICIENT KD, VALUES, VOLUME III: AMERICIUM, ARSENIC, CURIUM, IODINE, NEPTUNIUM, RADIUM, AND TECHNETIUM

    Science.gov (United States)

    This report describes the conceptualization, measurement, and use of the partition (or distribution) coefficient, Kd, parameter, and the geochemical aqueous solution and sorbent properties that are most important in controlling adsorption/retardation behavior of selected contamin...

  9. Treatment with Ca-DTPA of internal contaminations by plutonium and americium: Recommendations for writing protocols in Cea and AREVA centers

    International Nuclear Information System (INIS)

    Grappin, L.; Legoff, J.P.; Andre, F.; Carbone, L.; Agrinier, A.L.; Courtay, C.; Aninat, M.; Amabile, J.C.; Florin, A.

    2009-01-01

    The purpose of this document is to provide physicians working in a B.N.F. (Basic Nuclear Facility) with recommendations for the drafting of Ca-DTPA treatment protocols for internal contamination by actinides. These recommendations are based on the results of injections carried out by Cea and AREVA doctors in a working group, with the collaboration of the Army Radiation Protection Service. The study focused on Ca-DTPA IV injection. Other dosage forms, routes of administration as well as adjuvant treatments are also mentioned. For cases of contaminated wounds and inhalation, indicators for treatment with Ca-DTPA, particularly its initialization, the dosage, duration, frequency of administration, the criteria for ending the treatment, then its efficiency and dosimetry gain are covered. A guide for the prescription of the radio toxicological monitoring necessary for the treatment and the dosimetric evaluation is proposed. (authors)

  10. Liquid-liquid extraction of americium(III) by bis (2-ethylhexyl) sulfoxide from aqueous nitrate media (Preprint no. SSC-16)

    International Nuclear Information System (INIS)

    Shukla, J.P.; Kedari, C.S.

    1991-01-01

    Extraction of Am(III) was studied from acidic nitrate media into n-dodecane by bis (2-ethylhexyl) sulfoxide (BESO). Ca(NO 3 ) 2 was used as the salting-out agent. Effect of several water-miscible polar organic solvents was examined for their possible synergistic effects on its extraction. Slope analysis revealed a predominant formation of the trisolvated organic phase complex, Am(NO 3 ) 3 .3BESO. (author). 2 refs., 1 tab

  11. Proceedings of the specialists' meeting on nuclear data of plutonium and americium isotopes for reactor applications. [BNL, Nov. 20-21, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Chrien, R E [ed.

    1979-05-01

    Separate abstracts were prepared for 17 of the papers in these Proceedings. The remaining six have already been cited in ERA, and can be located by referring to the entry CONF-781174-- in the Report Number Index. (RWR)

  12. Simulation of loading conditions for a type A package containing Americium-241 involved in an airplane crash at Detroit Metro Airport in January 1983

    International Nuclear Information System (INIS)

    Maxfield, B.W.; Woo, H.H.

    1983-10-01

    On January 11, 1983, a United Airlines DC-8F cargo aircraft crashed shortly after takeoff from Detroit Metro Airport. A lower rear cargo pit had a type A package containing 10,000 241 Am solid-form sources, each of 1.5-μCi strength, used in smoke detectors. Although burned and somewhat battered, the 1-gal metal can holding all these sources was recovered completely intact with no release of radioactive material to the environment or loss of any sources. This report describes Lawrence Livermore National Laboratory's attempt to reconstruct, as closely as practical, the mechanical and thermal environments experienced by this can during and immediately after the accident. Mechanical loading of the metal can in a shipping carton was simulated by impacts from a 16-lb pendulum mass falling through vertical displacements of up to 6 ft. Internal damage ranged from imperceptible to sufficient to demolish internal plastic jars and to produce major deformation of the metal can. The thermal environment was best reproduced by the simple burning of the outer shipping carton. 6 references, 27 figures

  13. Separation of americium(III) and europium(III) from nitrate medium using a binary mixture of Cyanex-301 with neutral donor ligands

    International Nuclear Information System (INIS)

    Bhattacharyya, A.; Mohapatra, P.K.; Manchanda, V.K.

    2005-01-01

    Separation behaviour of Am 3+ and Eu 3+ was investigated from aqueous nitrate medium using a binary mixture of Cyanex-301 (bis(2,4,4- trimethylpentyl) dithiophosphinic acid) and several N, O or S donor ligands such as 1,10-phenanthroline (phen), TPTZ (2,4,6- tri(2-pyridyl)- 1,3,5- triazine), 2,2'-bipyridyl(bipy), hexa thia 18 crown 6 (S 6 18C6), TBP (tri-n-butyl phosphate), TBTP (tri-n-butyl thiophosphate) in toluene. The S.F. values of >40,000 obtained with bipy and phen are the highest reported to date. (author)

  14. The role of natural organic matter in the migration behaviour of americium in the Boom clay - Part II: analysis of migration experiments

    International Nuclear Information System (INIS)

    Hicks, T.; Bennett, D.; Maes, N.; Wang, L.; Warwick, P.; Hall, T.; Walker, G.; Dierckx, A.

    2005-01-01

    Full text of publication follows: In demonstrating the suitability of Boom Clay as a potential site for the disposal of radioactive waste in Belgium, the role of the relatively high amount of Natural Organic Matter (NOM) present in the Boom Clay on the mobility of critical radionuclides needs investigation. Trivalent actinides and lanthanides form strong complexes with humic substances. Complexation of these trivalent radionuclides with NOM present in the Boom Clay may have opposing effects. If complexed by the aqueous phase (mobile) NOM, radionuclide transport will be governed by the mobility of these dissolved radionuclide-NOM species. If complexed by the solid phase (immobile) NOM, migration will be retarded. One of the aims of the EC projects TRANCOM-Clay and TRANCOM-II was to investigate the role of mobile NOM as radionuclide carrier with the objective of deriving conceptual models that can be implemented in repository performance assessment (PA) models. A separate paper describes the results of column migration experiments involving the transport of 241 Am- 14 C-NOM complexes through Boom Clay cores. This paper describes the transport model, POPCORN, that was developed to describe and evaluate the influence of NOM on radionuclide transport in clay, taking into account attachment/detachment rates of NOM to clay surfaces and the kinetics of RN complexation to, and destabilization from, NOM. The POPCORN model was used to evaluate diffusion experiments involving injection of 14 C-labelled NOM in Boom Clay cores. Model fits were obtained by varying the rates of filtration of NOM by attachment to the surface of the clay matrix. POPCORN was then used to analyse the 241 Am- 14 C-NOM migration experiments. The stability properties of the 241 Am-NOM were characterised by kinetic constants, and good matches to the migration data were achieved for the experiments. The findings suggest that a small sub-population of the original 241 Am-OM is the most stable, and that this sub-population has specific transport characteristics, including low dispersivity and a potential for filtering. Such characteristics may be representative of larger, more stable, but less mobile 241 Am-OM complexes. In summary, the key processes governing 241 Am migration are the rate of 241 Am-OM destabilization and the rates of attachment and detachment of OM on the clay surfaces. Correlations between different transport parameters have been identified, and these findings offer means of extrapolating parameter values for application of the model to larger-scale problems. (authors)

  15. Sorption and diffusion of cobalt, strontium, cesium and americium in natural fissure surfaces and drill core cups studied by autoradiography, 1

    International Nuclear Information System (INIS)

    Pinnioja, S.; Kaemaeraeinen, E.L.; Jaakkola, T.; Siitari, M.; Muuronen, S.; Lindberg, A.

    1985-06-01

    A method based on autoradiography was developed to determine the diffusion of radionuclides into the rock matrix. To investigate the diffusion the samples, which has been in contact with radioactive tracer solution up to 6 months, were splitted by sawing. From the autoradiograms of the cross sections the penetration depths of radionuclides were determined and the apparent diffusion coefficient Dsup(a) calculated. The filled and unfilled natural fissure surfaces chosen to this study were bars of drilling cores and drill core cups of tonalite, mica gneiss and rapakivi granite. After contact time of 3 months the highest penetration depths of cesium were observed for natural fissure surface sample of rapakivi granite up to 2.5 mm and of mica gneiss up to 3.7 mm. For strontium the penetration depths of 6 mm and 11 mm for unfilled and filled natural fissure samples of rapakivi granite were found. Dsup(a)-values for cesium varied between 1.5 x 10 -15 and 3.2 x 10 -14 , for strontium between 3.5 x 10 -14 and 2.1 x 10 -13 m 2 /s. D-value obtained for cobalt (drill core cup sample, tonalite) was 5.4 x 10 -17 m 2 /s. 241 Am was only sorbed on the surface of the sample and thus no apparent diffusion coefficient could be calculated. Filling materials, chlorite and secondary minerals in tonalite and rapakivi granite increased diffusion into the mother rock. Radionuclides were sorbed both into the filling material and through fillers into the rock matrix. Cs and Sr penetrated though calcite filling material in mica gneiss into the mother rock. Calcite didn't influence on diffusion of radionuclides. Penetration depths of Cs and Sr were about the same for filled and unfilled samples

  16. Chemical speciation of strontium, americium, and curium in high level waste: Predictive modeling of phase partitioning during tank processing. Annual progress report, October 1996--September 1997

    International Nuclear Information System (INIS)

    Choppin, G.; Felmy, A.R.

    1997-01-01

    'The program at Florida State University was funded to collaborate with Dr. A. Felmy (PNNL) on speciation in high level wastes and with Dr. D. Rai (PNNL) on redox of Pu under high level waste conditions. The funding provided support for 3 research associates (postdoctoral researchers) under Professor G. R. Choppin as P.I. Dr. Kath Morris from U. Manchester (Great Britain), Dr. Dean Peterman and Dr. Amy Irwin (both from U. Cincinnati) joined the laboratory in the latter part of 1996. After an initial training period to become familiar with basic actinide chemistry and radiochemical techniques, they began their research. Dr. Peterman was assigned the task of measuring Th-EDTA complexation prior to measuring Pu(IV)-EDTA complexation. These studies are associated with the speciation program with Dr. Felmy. Drs. Morris and Irwin initiated research on redox of plutonium with agents present in the Hanford Tanks as a result of radiolysis or from use in separations. The preliminary results obtained thus far are described in this report. It is expected that the rate of progress will continue to increase significantly as the researchers gain more experience with plutonium chemistry.'

  17. Experimental studies and thermodynamic modelling of volatilities of uranium, plutonium, and americium from their oxides and from their oxides interacted with ash

    Energy Technology Data Exchange (ETDEWEB)

    Krikorian, O.H.; Ebbinghaus, B.B.; Adamson, M.G.; Fontes, A.S. Jr.; Fleming, D.L.

    1993-09-15

    The purpose of this study is to identify the types and amounts of volatile gaseous species of U, Pu, and Am that are produced in the combustion chamber offgases of mixed waste oxidation processors. Primary emphasis is on the Rocky Flats Plant Fluidized Bed Incinerator. Transpiration experiments have been carried out on U{sub 3}O{sub 8}(s), U{sub 3}O{sub 8} interacted with various ash materials, PuO{sub 2}(s), PuO{sub 2} interacted with ash materials, and a 3%PuO{sub 2}/0.06%AmO{sub 2}/ash material, all in the presence of steam and oxygen, and at temperatures in the vicinity of 1,300 K. UO{sub 3}(g) and UO{sub 2}(OH){sub 2}(g) have been identified as the uranium volatile species and thermodynamic data established for them. Pu and Am are found to have very low volatilities, and carryover of Pu and Am as fine dust particulates is found to dominate over vapor transport. The authors are able to set upper limits on Pu and Am volatilities. Very little lowering of U volatility is found for U{sub 3}O{sub 8} interacted with typical ashes. However, ashes high in Na{sub 2}O (6.4 wt %) or in CaO (25 wt %) showed about an order of magnitude reduction in U volatility. Thermodynamic modeling studies were carried out that show that for aluminosilicate ash materials, it is the presence of group I and group II oxides that reduces the activity of the actinide oxides. K{sub 2}O is the most effective followed by Na{sub 2}O and CaO for common ash constituents. A more major effect in actinide activity lowering could be achieved by adding excess group I or group II oxides to exceed their interaction with the ash and lead to direct formation of alkali or alkaline earth uranates, plutonates, and americates.

  18. Separation of americium and neodymium by selective stripping and subsequent extraction with HDEHP using DTPA-lactic acid solution in a closed loop

    International Nuclear Information System (INIS)

    Svantesson, I.; Hangstroem, I.; Persson, G.; Liljenzin, J.O.

    1979-01-01

    A method for the separation of trivalent actinides and lanthanides is proposed. The method is based on selective stripping of the actinides from 1M HDEHP into an aqueous phase containing ammonia, DTPA and lactic acid followed by subsequent extraction into a second organic phase also containing 1M HDEHP. The aqueous phase is recycled in a closed loop, thereby reducing the amounts of secondary waste. Distribution ratios for Am and Nd have been measured at varying DTPA and lactic acid concentrations and at varying pH. The distribution of ammonia was also measured. (author)

  19. An insight into the complexation of trivalent americium vis-a-vis lanthanides with bis(1,2,4-triazinyl)bipyridine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Arunasis; Mohapatra, Manoj; Mohapatra, Prasanta K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Radiochemistry Div.; Gadly, Trilochan; Ghosh, Sunil K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Bioorganic Div.; Manna, Debashree; Ghanty, Tapan K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Theoretical Chemistry Section; Rawat, Neetika; Tomar, Bhupendra S. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Radioanalytical Chemistry Div.

    2017-01-26

    Complexation of Am{sup 3+} and Ln{sup 3+} (La{sup 3+}, Eu{sup 3+}, and Er{sup 3+}) with two bis(1,2,4-triazinyl)bipyridine (C{sub 2}BTBP, C{sub 5}BTBP) derivatives has been studied in acetonitrile medium with use of various experimental techniques such as electrospray ionization mass spectrometry (ESI-MS), time-resolved fluorescence spectroscopy (TRFS), UV/Vis spectrophotometry, and solution calorimetry. Metal-ligand stoichiometries and conditional stability constants of these complexes were determined. To the best of our knowledge, this is the first report on the complexation of Am{sup 3+} with any of the BTBP derivatives with use of UV/Vis spectrophotometric titration to determine the conditional stability constants. Density functional theory (DFT) calculations are carried out on the An{sup 3+} (U{sup 3+} and Am{sup 3+}) and Ln{sup 3+} (La{sup 3+}, Nd{sup 3+}, Eu{sup 3+}, Er{sup 3+}, and Lu{sup 3+}) complexes of BTBP in order to understand the difference between the bonding in actinide and lanthanide complexes. The results indicate a stronger covalent interaction in the An-N bonds as compared to the Ln-N bonds, which leads to an actinide selectivity of this class of ligands. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Americium, Cesium, and Plutonium Colloid-Facilitated Transport in a Groundwater/Bentonite/Fracture Fill Material System: Column Experiments and Model Results

    Science.gov (United States)

    Dittrich, T. M.; Boukhalfa, H.; Reimus, P. W.

    2014-12-01

    The objective of this study was to investigate and quantify the effects of desorption kinetics and colloid transport on radionuclides with different sorption affinities. We focused on quantifying transport mechanisms important for upscaling in time and distance. This will help determine the long-term fate and transport of radionuclides to aid in risk assessments. We selected a fractured/weathered granodiorite at the Grimsel Test Site (GTS) in Switzerland as a model crystalline rock repository system because the system has been thoroughly studied and field experiments involving radionuclides have already been conducted. Working on this system provides a unique opportunity to compare lab experiments with field-scale observations. Weathered fracture fill material (FFM) and bentonite used as backfill at the GTS were characterized (e.g., BET, SEM/EDS, QXRD), and batch and breakthrough column experiments were conducted. Solutions were prepared in synthetic groundwaters that matched the natural water chemistry. FFM samples were crushed, rinsed, sieved (150-355 μm), and equilibrated with synthetic groundwater. Bentonite was crushed, sodium-saturated, equilibrated with synthetic groundwater, and settled to yield a stable suspension. Suspensions were equilibrated with Am, Cs, or Pu. All experiments were conducted with Teflon®materials to limit sorption to system components. After radionuclide/colloid injections reached stability, radionuclide-free solutions were injected to observe the desorption and release behavior. Aliquots of effluent were measured for pH, colloid concentration, and total and dissolved radionuclides. Unanalyzed effluent from the first column was then injected through a second column of fresh material. The process was repeated for a third column and the results of all three breakthrough curves were modeled with a multi-site/multi-rate MATLAB code to elucidate the sorption rate coefficients and binding site densities of the bentonite colloids and fracture fill material. Nearly 50% of the sorbed Am was exchanged from the colloids to the fracture filling material in each of the three columns; whereas, less Cs and Pu was desorbed with each pass through a new column. Using a two-site kinetic model allowed for interrogation of desorption rates and dominant transport parameters.

  1. Methodology for the Inventory and Assessment of Americium Contamination Level in 1987 in an Area of Palomares Contaminated with Plutonium Weapon Grade

    International Nuclear Information System (INIS)

    Espinosa, A.; Aragon, A.; Cruz de la, B.

    2001-01-01

    This paper presents a methodology applied for the assessment of the ''241 Am coming from the decay of ''241 Pu isotope content in a contaminated area of Palomares, where the clean-up work done in 1966, given the negligible agricultural importance of such area at the time and its geographical characteristics, was not of the same magnitude as for the rest of the region. (Author) 4 refs

  2. Investigation of the chemical explosion of an ion exchange resin column and resulting americium contamination of personnel in the 242-Z building, August 30, 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-10-19

    As a result of an explosion in the Waste Treatment Facility, 242-Z Building, 200 West Area of the Hanford Reservation on August 30, 1976, the Manager of the Richland Operations Office (RL), Energy Research and Development Administration (ERDA), appointed an ERDA Committee to conduct a formal investigation and to prepare a report on their findings of this occurrence. The Committee was instructed to conduct the investigation in accordance with ERDAMC 0502, insofar as circumstances would permit, to cover and explain technical elements of the casual sequence(s) of the occurrence, and to describe management systems which should have or could have prevented the occurrence. This report is the result of the investigation and presents the conclusions of the review.

  3. Determination of Neptunium, Americium and Curium in Spent Nuclear Fuel Samples by Alpha Spectrometry Using 239Np and 243Am as a Spike and a Tracer

    International Nuclear Information System (INIS)

    Jeo, Kih-Soo; Song, Byung-Chul; Kim, Young-Bok; Han, Sun-Ho; Jeon, Young-Shin; Jung, Euo-Chang; Jee, Kwang-Yong

    2007-01-01

    Determination of actinide elements and fission products in spent nuclear fuels is of importance for a burnup determination and source term evaluation. Especially, the amounts of uranium and plutonium isotopes are used for the evaluation of a burnup credit in spent nuclear fuels. Additionally, other actinides such as Np, Am and Cm in spent nuclear fuel samples is also required for the purposes mentioned above. In this study, 237 Np, 241 Am and 244 Cm were determined by an alpha spectrometry for the source term data for high burnup spent nuclear fuels ranging from 37 to 62.9 GWD/MtU as a burnup. Generally, mass spectrometry has been known as the most powerful method for isotope determinations such as high concentrations of uranium and plutonium. However, in the case of minor actinides such as Np, Am and Cm, alpha spectrometry would be recommended instead. Determination of the transuranic elements in spent nuclear fuel samples is different from that for environmental samples because the amount of each nuclide in the spent fuel samples is higher and the relative ratios between each nuclide are also different from those for environmental samples. So, it is important to select an appropriate tracer and an optimum sample size depending on the nuclides and analytical method. In this study 237 Np was determined by an isotope dilution alpha(gamma) spectrometry using 239 Np as a spike, and 241 Am and curium isotopes were determined by alpha spectrometry using 243 Am as a tracer. The content of each nuclide was compared with that by the Origen-2 code

  4. Neutron-Induced Fission Cross Section of Uranium, Americium and Curium Isotopes. Progress report - Research Contract 14485, Coordinated Research Project on Minor Actinide Neutron Reaction Data (MANREAD)

    International Nuclear Information System (INIS)

    Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

    2009-12-01

    This report contains brief description of the Lead Slowing Down Spectrometer and results of measurements of neutron-induced fission cross sections for 236 U, 242m Am, 243 Cm, 244 Cm, 245 Cm and 246 Cm done at this spectrometer. The work was partially supported through the IAEA research contract RC-14485-RD in the framework of the IAEA Coordinated Research Project 'Minor Actinide Neutron Reaction Data (MANREAD)'. The detailed description of the experimental set up, measurements procedure and data treatment can be found in the JIA-1182 (2007) and JIA-1212 (2009) reports from the Institute of Nuclear Research of the Russian Academy of Science published in Russian. Part 1 contains the first year report of the research contract and part 2 the second year report. (author)

  5. Design of Alpha Voltaic Power Source Using Americium 241 (241Am) and Diamond with a Power Density of 10 mW/cm3

    Science.gov (United States)

    2017-10-19

    detectors) is one of the most widely available and affordable sources of alpha radiation. 241Am has a half-life of 432 years, enabling long- lived ...mobility. The next step will be to fabricate a diamond vertical or quasi-vertical diode and irradiate it. This experiment will give important insights for...distribution is unlimited. NOTICES Disclaimers The findings in this report are not to be construed as an official Department of the Army

  6. Removal of plutonium and americium from the rat using 3,4,3-LIHOPO and DTPA after simulated wound contamination: effect of delayed administration and mass of plutonium

    International Nuclear Information System (INIS)

    Gray, S.A.; Stradling, G.N.; Pearce, M.J.; Wilson, I.; Moody, J.C.; Burgada, R.; Durbin, P.W.; Raymond, K.N.

    1994-01-01

    The comparative efficacies of treatment with 3,4,3-LIHOPO and DTPA have been investigated in the rat after their subcutaneous intramuscular injection. Commencement of treatment was delayed 30 min, 6 h or 1 d and the animals killed at 7 d. Under all conditions, 3,4,3-LIHOPO was considerably more effective than DTPA, although the efficacy of both ligands and their relative effectiveness decreased rapidly with their delay in administration. After early treatment of the intramuscular deposit of Pu and Am with 3,4,3-LIHOPO, the body content of Pu and Am was about 1% of those in untreated animals and about 30 times less than when using the same treatment regimen with DTPA. The value for Pu increased to 5% of controls when the amount deposited increased from 1.5 ng to 0.9 mg.kg -1 body mass. (author)

  7. Treatment with Ca-DTPA of internal contaminations by plutonium and americium: Recommendations for writing protocols in Cea and AREVA centers; Traitement par le Ca-DTPA des contaminations internes par le plutonium et l'americium: recommandations pour la redaction de protocoles dans les centres CEA et AREVA

    Energy Technology Data Exchange (ETDEWEB)

    Grappin, L. [CEA Cadarache, DEN, Service de Sante au Travail, 13 - Saint-Paul-lez-Durance (France); Legoff, J.P.; Andre, F. [CEA Valduc, Service de Sante au Travail, 21 - Is-sur-Tille (France); Carbone, L.; Agrinier, A.L. [CEA Marcoule, DEN, Service de Sante au Travail, 30 (France); Courtay, C.; Aninat, M. [AREVA, Service de Sante au Travail, La Hague, 50 - Beaumont-Hague (France); Amabile, J.C. [SPRA, HIA Percy, 92 - Clamart (France); Florin, A. [CEA Saclay, SDM Service de Sante au Travail, 91 - Gif-sur-Yvette (France)

    2009-10-15

    The purpose of this document is to provide physicians working in a B.N.F. (Basic Nuclear Facility) with recommendations for the drafting of Ca-DTPA treatment protocols for internal contamination by actinides. These recommendations are based on the results of injections carried out by Cea and AREVA doctors in a working group, with the collaboration of the Army Radiation Protection Service. The study focused on Ca-DTPA IV injection. Other dosage forms, routes of administration as well as adjuvant treatments are also mentioned. For cases of contaminated wounds and inhalation, indicators for treatment with Ca-DTPA, particularly its initialization, the dosage, duration, frequency of administration, the criteria for ending the treatment, then its efficiency and dosimetry gain are covered. A guide for the prescription of the radio toxicological monitoring necessary for the treatment and the dosimetric evaluation is proposed. (authors)

  8. Interaction and transport of actinides in natural clay rock with consideration of humic substances and clay organics. Characterization and quantification of the influence of clay organics on the interaction and diffusion of uranium and americium in the clay. Joint project

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, Gert [Helmholtz-Zentrum Dresden-Rossendorf e.V. (Germany). Inst. of Radiochemistry; Schmeide, Katja; Joseph, Claudia; Sachs, Susanne; Steudtner, Robin; Raditzky, Bianca; Guenther, Alix

    2011-07-01

    The objective of this project was the study of basic interaction processes in the systems actinide - clay organics - aquifer and actinide - natural clay - clay organics - aquifer. Thus, complexation, redox, sorption and diffusion studies were performed. To evaluate the influence of nitrogen, phosphorus and sulfur containing functional groups of humic acid (HA) on the complexation of actinides in comparison to carboxylic groups, the Am(III) and U(VI) complexation by model ligands was studied by UV-Vis spectroscopy and TRLFS. The results show that Am(III) is mainly coordinated via carboxylic groups, however, probably stabilized by nitrogen groups. The U(VI) complexation is dominated by carboxylic groups, whereas nitrogen and sulfur containing groups play a minor role. Phosphorus containing groups may contribute to the U(VI) complexation by HA, however, due to their low concentration in HA they play only a subordinate role compared to carboxylic groups. Applying synthetic HA with varying sulfur contents (0 to 6.9 wt.%), the role of sulfur functionalities of HA for the U(VI) complexation and Np(V) reduction was studied. The results have shown that sulfur functionalities can be involved in U(VI) humate complexation and act as redox-active sites in HA for the Np(V) reduction. However, due to the low content of sulfur in natural HA, its influence is less pronounced. In the presence of carbonate, the U(VI) complexation by HA was studied in the alkaline pH range by means of cryo-TRLFS (-120 C) and ATR FT-IR spectroscopy. The formation of the ternary UO{sub 2}(CO{sub 3}){sub 2}HA(II){sup 4-} complex was detected. The complex formation constant was determined with log {beta}{sub 0.1} M = 24.57 {+-} 0.17. For aqueous U(VI) citrate and oxalate species, luminescence emission properties were determined by cryo-TRLFS and used to determine stability constants. The existing data base could be validated. The U(VI) complexation by lactate, studied in the temperature range 7 to 65 C, was found to be endothermic and entropy-driven. In contrast, the complex stability constants determined for U(VI) humate complexation at 20 and 40 C are comparable, however, decrease at 60 C. For aqueous U(IV) citrate, succinate, mandelate and glycolate species stability constants were determined. These ligands, especially citrate, increase solubility and mobility of U(IV) in solution due to complexation. The U(VI) sorption onto crushed Opalinus Clay (OPA, Mont Terri, Switzerland) was studied in the absence and presence of HA or low molecular weight organic acids, in dependence on temperature and CO2 presence using OPA pore water as background electrolyte. Distribution coefficients (K{sub d}) were determined for the sorption of U(VI) and HA onto OPA with (0.0222 {+-} 0.0004) m{sup 3}/kg and (0.129 {+-} 0.006) m{sup 3}/kg, respectively. The U(VI) sorption is not influenced by HA ({<=}50 mg/L), however, decreased by low molecular weight organic acids ({>=} 1 x 10{sup -5} M), especially by citrate and tartrate. With increasing temperature, the U(VI) sorption increases both in the absence and in the presence of clay organics. The U(VI) diffusion in compacted OPA is not influenced by HA at 25 and 60 C. Predictions of the U(VI) diffusion show that an increase of the temperature to 60 C does not accelerate the migration of U(VI). With regard to uranium-containing waste, it is concluded that OPA is suitable as host rock for a future nuclear waste repository since OPA has a good retardation potential for U(VI). (orig.)

  9. Interaction and transport of actinides in natural clay rock with consideration of humic substances and clay organics. Characterization and quantification of the influence of clay organics on the interaction and diffusion of uranium and americium in the clay. Joint project

    International Nuclear Information System (INIS)

    Bernhard, Gert; Schmeide, Katja; Joseph, Claudia; Sachs, Susanne; Steudtner, Robin; Raditzky, Bianca; Guenther, Alix

    2011-01-01

    The objective of this project was the study of basic interaction processes in the systems actinide - clay organics - aquifer and actinide - natural clay - clay organics - aquifer. Thus, complexation, redox, sorption and diffusion studies were performed. To evaluate the influence of nitrogen, phosphorus and sulfur containing functional groups of humic acid (HA) on the complexation of actinides in comparison to carboxylic groups, the Am(III) and U(VI) complexation by model ligands was studied by UV-Vis spectroscopy and TRLFS. The results show that Am(III) is mainly coordinated via carboxylic groups, however, probably stabilized by nitrogen groups. The U(VI) complexation is dominated by carboxylic groups, whereas nitrogen and sulfur containing groups play a minor role. Phosphorus containing groups may contribute to the U(VI) complexation by HA, however, due to their low concentration in HA they play only a subordinate role compared to carboxylic groups. Applying synthetic HA with varying sulfur contents (0 to 6.9 wt.%), the role of sulfur functionalities of HA for the U(VI) complexation and Np(V) reduction was studied. The results have shown that sulfur functionalities can be involved in U(VI) humate complexation and act as redox-active sites in HA for the Np(V) reduction. However, due to the low content of sulfur in natural HA, its influence is less pronounced. In the presence of carbonate, the U(VI) complexation by HA was studied in the alkaline pH range by means of cryo-TRLFS (-120 C) and ATR FT-IR spectroscopy. The formation of the ternary UO 2 (CO 3 ) 2 HA(II) 4- complex was detected. The complex formation constant was determined with log β 0.1 M = 24.57 ± 0.17. For aqueous U(VI) citrate and oxalate species, luminescence emission properties were determined by cryo-TRLFS and used to determine stability constants. The existing data base could be validated. The U(VI) complexation by lactate, studied in the temperature range 7 to 65 C, was found to be endothermic and entropy-driven. In contrast, the complex stability constants determined for U(VI) humate complexation at 20 and 40 C are comparable, however, decrease at 60 C. For aqueous U(IV) citrate, succinate, mandelate and glycolate species stability constants were determined. These ligands, especially citrate, increase solubility and mobility of U(IV) in solution due to complexation. The U(VI) sorption onto crushed Opalinus Clay (OPA, Mont Terri, Switzerland) was studied in the absence and presence of HA or low molecular weight organic acids, in dependence on temperature and CO2 presence using OPA pore water as background electrolyte. Distribution coefficients (K d ) were determined for the sorption of U(VI) and HA onto OPA with (0.0222 ± 0.0004) m 3 /kg and (0.129 ± 0.006) m 3 /kg, respectively. The U(VI) sorption is not influenced by HA (≤50 mg/L), however, decreased by low molecular weight organic acids (≥ 1 x 10 -5 M), especially by citrate and tartrate. With increasing temperature, the U(VI) sorption increases both in the absence and in the presence of clay organics. The U(VI) diffusion in compacted OPA is not influenced by HA at 25 and 60 C. Predictions of the U(VI) diffusion show that an increase of the temperature to 60 C does not accelerate the migration of U(VI). With regard to uranium-containing waste, it is concluded that OPA is suitable as host rock for a future nuclear waste repository since OPA has a good retardation potential for U(VI). (orig.)

  10. Monitored Natural Attenuation of Inorganic Contaminants in Ground Water Volume 3 Assessment for Radionuclides IncludingTritium, Radon, Strontium, Technetium, Uranium, Iodine, Radium, Thorium, Cesium, and Plutonium-Americium

    Science.gov (United States)

    The current document represents the third volume of a set of three volumes that address the technical basis and requirements for assessing the potential applicability of MNA as part of a ground-water remedy for plumes with nonradionuclide and/or radionuclide inorganic contamina...

  11. Americium and plutonium in phosphates of trigonal structure (NZP type) Am1/3[Zr2(PO4)3] and Pu1/4[Zr2(PO4)3

    International Nuclear Information System (INIS)

    Bykov, D.M.; Orlova, A.I.; Tomilin, S.V.; Lizin, A.A.; Lukinykh, A.N.

    2006-01-01

    Am 1/3 [Zr 2 (PO 4 ) 3 ] and Pu 1/4 [Zr 2 (PO 4 ) 3 ] phosphates are synthesized and are investigated by X-ray diffraction method. Compounds have triclinic lattices and lattice parameters are determined. Possibility of actinide inclusion into hollows of framework of NZP type is shown for the first time. It is proposed that inclusion of Pu and Am highly-charged cations into framework hollows decreases crystal structure symmetry up to primitive trigonal one. Rate of Pu leaching from ceramics on Pu 1/4 [Zr 2 (PO 4 ) 3 ] basis are measured [ru

  12. Neutron-induced Fission Cross Sections of Am and Cm isotopes (Final Report of Research Contract 14485). Resonance and Fast Neutron Induced Fission Cross Sections of Americium and Curium Nuclides (Third-year Progress Report of Research Contract 14485)

    International Nuclear Information System (INIS)

    Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Egorov, A.S.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

    2012-01-01

    The neutron induced fission cross sections of Am and Cm isotopes were measured relative to 239 Pu in the neutron energy range from 1 eV to 20 keV at the INR RAS lead slowing down spectrometer LSDS-100. The fission resonance integrals were also estimated using the measured cross section data. The results have been compared with the available experimental and evaluated data. This analysis has shown the present status of the measured fission cross sections and the necessity to revise the evaluated cross sections libraries for the minor actinides. (author)

  13. Supported liquid inorganic membranes for nuclear waste separation

    Science.gov (United States)

    Bhave, Ramesh R; DeBusk, Melanie M; DelCul, Guillermo D; Delmau, Laetitia H; Narula, Chaitanya K

    2015-04-07

    A system and method for the extraction of americium from radioactive waste solutions. The method includes the transfer of highly oxidized americium from an acidic aqueous feed solution through an immobilized liquid membrane to an organic receiving solvent, for example tributyl phosphate. The immobilized liquid membrane includes porous support and separating layers loaded with tributyl phosphate. The extracted solution is subsequently stripped of americium and recycled at the immobilized liquid membrane as neat tributyl phosphate for the continuous extraction of americium. The sequestered americium can be used as a nuclear fuel, a nuclear fuel component or a radiation source, and the remaining constituent elements in the aqueous feed solution can be stored in glassified waste forms substantially free of americium.

  14. 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....

  15. On the transmutation of Am in a fast lead-cooled system

    Indian Academy of Sciences (India)

    For one year of operation, 61 kg of americium is destroyed, and due to increased 238Pu content, americium is mainly converted to fission products. Thus in a ... of about 50%. Application of similar strategy for ADS with a sub-criticality level ≈ 0.96–0.98 can essentially relax safety problems related to positive void effects.

  16. Chemistry research and development progress report, May-October, 1978

    International Nuclear Information System (INIS)

    Miner, F.J.

    1979-01-01

    Work in progress includes: calorimetry and thermodynamics of nuclear materials; americium recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten salt extraction residues, photochemical separations of actinides; advanced ion exchange materials and techniques; secondary actinide recovery; removal of plutonium from lathe coolant oil; evaluation of tributyl phosphate-impregnated sorbent for plutonium-uranium separations; plutonium recovery in advance size reduction facility; plutonium peroxide precipitation; decontamination of Rocky Flats soil; soil decontamination at other Department of Energy sites; recovery of actinides from combustible wastes; induction-heated, tilt-pour furnace; vacuum melting; determination of plutonium and americium in salts and alloys by calorimetry; plutonium peroxide precipitation process; silica removal study; a comparative study of annular and Raschig ring-filled tanks; recovery of plutonium and americium from a salt cleanup alloy; and process development for recovery of americium from vacuum melt furnace crucibles

  17. The behaviour of Eu, Pu, Am radionuclide at burning radioactive graphite in an oxygen atmosphere. Computer experiments

    Directory of Open Access Journals (Sweden)

    Kolbin T.S.

    2015-01-01

    Full Text Available Be means of the method of computer thermodynamic simulation we studied the behaviour of the europium, plutonium and americium from the combustion of radioactive graphite in oxygen. Europe is in the form of condensed EuOCl, Eu2O3 and vapour EuO. Pluto is in the form of condensed vapour PuO2 and PuO2. Americium is a condensed AmO2, Am2O3 and vapour Am. The basic reactions occurring compounds with europium, plutonium and americium. Equilibrium constants of the reactions have been determined.

  18. Low-level determination of transuranic elements in marine environment samples

    International Nuclear Information System (INIS)

    Ballestra, S.; Holm, E.; Fukai, R.

    1978-01-01

    The procedures developed and currently employed in the Monaco Laboratory for determining transuranic elements in seawater, marine sediments and organisms are described and discussed. While the standard anion-exchange procedure from the hydrochloric acid medium is used for the separation of plutonium isotopes from americium, purification of americium and curium is achieved by an ion-exchange sorption from the methanol-nitric acid medium, followed by an elution with the methanol-hydrochloric acid mixture. Satisfactory clean-up of plutonium as well as americium and curium can be achieved by applying the described procedures. (author)

  19. Methodology for the Inventory and Assessment of Americium Contamination Level in 1987 in an Area of Palomares Contaminated with Plutonium Weapon Grade; Estimacion del Contenido de Americio Existente en el Ano 1987 en una Zona de Palomares Contaminada en 1966 por Material de Plutonio Grado Bomba

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, A.; Aragon, A.; Cruz de la, B.

    2001-07-01

    This paper presents a methodology applied for the assessment of the ''241 Am coming from the decay of ''241 Pu isotope content in a contaminated area of Palomares, where the clean-up work done in 1966, given the negligible agricultural importance of such area at the time and its geographical characteristics, was not of the same magnitude as for the rest of the region. (Author) 4 refs.

  20. Study of the properties of the Am-O system in view of the transmutation of Am 241 in fast reactors; Etude des proprietes du systeme Am-O en vue de la transmutation de l`americium 241 en reacteur a neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Casalta, S.

    1996-04-01

    To reduce the long term toxicity of Am 241 it was considered to transmute this isotope in fast reactor. The first part of this thesis is an introduction at this problem. In the second part we give the experimental techniques used for the realisation of an AmO{sub 2}-MgO target (powder metallurgy under inert, oxidizing or reducing atmosphere). The properties of the Am-O system has been analyzed by X diffraction, thermodynamic and ceramography, in the Am{sub 2}O{sub 3}-AmO{sub 2} field. In the third part we study the external exposure risk created by the manufacturing of this target and in the last part the behavior of this target in a fast reactor. 66 refs., 28 figs., 25 tabs., 1 append.

  1. An investigation into radiological health and safety at the Ministry of Defence (Procurement Executive) Atomic Weapons Research Establishment, Aldermaston

    International Nuclear Information System (INIS)

    Pochin, E.

    1978-01-01

    The report is in sections, as follows: introduction; radiation exposure (sources of radiation exposure, monitoring methods, protection criteria, plutonium, uranium, americium, tritium, external exposure, environmental releases, general); problems of staffing; buildings; conclusions. (U.K.)

  2. Chemistry of pyroprocessing for nuclear waste transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, J.P. [Argonne National Laboratory, IL (United States)

    1995-10-01

    Pyrochemical treatment of spent nuclear fuel is an attractive approach for separating the transuranium (TRU) elements neptunium, plutonium, americium, and curium because of its simplicity, diversion resistance, and potentially low cost.

  3. Solubility of AmOHCO3 in aqueous solution under atmospheric conditions

    International Nuclear Information System (INIS)

    Nitsche, H.

    1987-12-01

    Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO 2 . The solubility of crystalline 243 AmOHCO 3 has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO 4 at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis

  4. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

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

    1984-01-01

    A new process for recovery of plutonium and americium from pyrochemical waste has been demonstrated. It is based on chloride solution anion exchange at low acidity, which eliminates corrosive HCl fumes. Developmental experiments of the process flowsheet concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 = from high chloride-low acid solution. Americium and other metals are washed from the ion exchange column with 1N HNO 3 -4.8M NaCl. The plutonium is recovered, after elution, via hydroxide precipitation, while the americium is recovered via NaHCO 3 precipitation. All filtrates from the process are discardable as low-level contaminated waste. Production-scale experiments are now in progress for MSE residues. Flow sheets for actinide recovery from electrorefining and direct oxide reduction residues are presented and discussed

  5. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

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

    1985-05-01

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

  6. Potassium Iodide (KI)

    Science.gov (United States)

    ... to Mass Casualties Screening People for External Contamination Use of Radiation Detection, Measuring, and Imaging Instruments Virtual Community Reception Center (vCRC) Community Reception Center (CRC) Simulation Tools Isotopes Americium-241 (Am-241) Cesium-137 (Cs-137) ...

  7. Prussian Blue

    Science.gov (United States)

    ... to Mass Casualties Screening People for External Contamination Use of Radiation Detection, Measuring, and Imaging Instruments Virtual Community Reception Center (vCRC) Community Reception Center (CRC) Simulation Tools Isotopes Americium-241 (Am-241) Cesium-137 (Cs-137) ...

  8. Acute Radiation Syndrome

    Science.gov (United States)

    ... to Mass Casualties Screening People for External Contamination Use of Radiation Detection, Measuring, and Imaging Instruments Virtual Community Reception Center (vCRC) Community Reception Center (CRC) Simulation Tools Isotopes Americium-241 (Am-241) Cesium-137 (Cs-137) ...

  9. Filgrastim (Neupogen)

    Science.gov (United States)

    ... to Mass Casualties Screening People for External Contamination Use of Radiation Detection, Measuring, and Imaging Instruments Virtual Community Reception Center (vCRC) Community Reception Center (CRC) Simulation Tools Isotopes Americium-241 (Am-241) Cesium-137 (Cs-137) ...

  10. Rubbia proposes a speedier voyage to Mars and back

    CERN Multimedia

    Abbott, A

    1999-01-01

    Carlo Rubbia has designed a propulsion engine that uses fission fragments of americium to directly heat a propulsion gas. He estimates it would allow a manned trip to Mars and back in around a year (8 paragraphs).

  11. 10 CFR 110.23 - General license for the export of byproduct material.

    Science.gov (United States)

    2010-01-01

    ...) Actinium-225 and -227, americium-241 and -242m, californium-248, -249, -250, -251, -252, -253, and -254, curium-240, -241, -242, -243, -244, -245, -246 and -247, einsteinium-252, -253, -254 and -255, fermium...

  12. Raman spectra of the transplutonium orthophosphates and trimetaphosphates

    International Nuclear Information System (INIS)

    Hobart, D.E.; Begun, G.M.; Haire, R.G.; Hellwege, H.E.

    1983-01-01

    Raman spectra have been obtained from multimicrogram samples of crystalline transplutonium (americium through einsteinium) orthophosphates. Spectra were also obtained for americium, curium, and californium trimetaphosphates. Assignments of the major Raman bands and confirmation of the compounds' stoichiometry were made by comparison with spectra obtained in previous studies on the lanthanide phosphates. The variation of transplutonium orthophosphate vibrational frequencies as a function of atomic number was found to be smaller in magnitude than that established for the lanthanide orthophosphates. (author)

  13. Radionuclides in rodents

    International Nuclear Information System (INIS)

    Taylor, G.N.

    1985-01-01

    Studies are being conducted in mice comparing the toxicity of radium-226, plutonium-239, americium-241, californium-249 and californium-252 in C57B1/Do (albino) mice and the toxicity of americium-241, plutonium-239 and radium-226 in deer mice (Peromyscus maniculatus) and grasshopper mice (Onychomys leucogaster). These experiments will ultimately enable comparison of the toxicity of the above actinide toxicity in man to be made using radium toxicity as the baseline

  14. Extraction of transplutonium elements from carbonate solutions by alkylpyrocatechol

    International Nuclear Information System (INIS)

    Karalova, Z.K.; Myasoedov, B.F.; Rodionova, L.M.; Kuznetsova, V.S.

    1983-01-01

    Extraction of americium, berkelium as well as Ce, Eu, Th, U, Zr, Cs, Fe with solution of 4(α, α-dioctylethyl)pyrocatechol (DOP) in toluene from carbonate solutions to determine conditions of their separation has been studied. It is established that americium extraction is quite sensitive to the changes of potassium carbonate concentration. The maximum extraction of americium (R >90%) is observed in the case of 0.1-0.5 mol/l of K 2 CO 3 solutions and the minimum one (R=2.5%) - in the case of 8 mol/l K 2 CO 3 . Americium extraction increases sharply when sodium hydroxide is introduced in carbonate solutions. It is shown that varying sodium hydroxide concentration it is possible to achieve qualitative extraction of americium even from saturated solution of potassium carbonate. Reextraction of TPE is easily realized with 3 mol/l HCl solution. The system K 2 CO 3 (KOH)-DOP proved to be perspective for Am separation from Bk, Ce, Cs, actinoid elements as well as from Fe

  15. Electrochemical determination of the oxidation potentials and the thermodynamic stability of the valence states of the transuranium elements in aqueous alkaline media

    International Nuclear Information System (INIS)

    Peretrukhin, V.F.; Spitsyn, V.I.

    1982-01-01

    The oxidation potentials of neptunium, plutonium, and americium in the valance states from (III) to (VII) have been determined experimentally in 0.1-15 M NaOH. Heptavalent plutonium and americium are thermodynamically able to oxidize water with the evolution of oxygen in 0.1-15 M NaOH, neptunium(VII) in 0.1-7 M NaOH. All valance states of plutonium resist disproportionation in alkaline solutions; in the case of neptunium and americium only one disproportionation reaction is possible; of the hexavalent state in to penta- and heptavalent states. The degree of completion of the reaction can be calculated accurately from the oxidation potentials determined

  16. 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.

  17. Materials Science and Technology (MST) Division, Nuclear Materials Process Technology Group (MST-12), chemical process research and development report

    International Nuclear Information System (INIS)

    Clifton, D.G.

    1984-04-01

    A process for the recovery of plutonium and americium from molten salt extraction (MSE) salt residues has been demonstrated. It is based upon a new chloride anion-exchange process at low acidity that eliminates corrosive HCl fumes. The Los Alamos americium oxide production line has been improved to give more product with a concurrent lowering of personnel radiation exposure. A cost study has been made for the disposal of americium-contaminated calcium metal buttons that were obtained by pyrochemical recovery of plutonium from MSE salts. The waste form used in the study conforms to WIPP-Facility standards and current state-of-the-art radioactive waste disposal. The cost estimate is approx. $300/g 241 Am. Plutonium decontamination factors of approx. 300 have been obtained from lead-platinum alloy dissolution experiments carried out in alumina crucibles using lead oxide slag to getter the plutonium

  18. Application of insoluble tannin adsorbent to alpha aqueous waste treatment in NUCEF

    International Nuclear Information System (INIS)

    Matsumura, Tatsuro; Usuda, Shigekazu; Mineo, Hideaki; Nishizawa, Ichio; Takeshita, Isao

    1997-01-01

    The use of insoluble tannin adsorbent has been investigated as a means to reduce the volume of aqueous waste contaminated with americium. This work is aimed at reducing the volume of TRU waste generated within NUCEF where experiments related to back end of the nuclear fuel cycle are performed. Insoluble tannin adsorbent is a gelled material consisting of C, H and O which can be easily incinerated. The distribution coefficient and adsorption capacity of americium in insoluble tannin have been investigated and found to be 1000 ml/g in 0.02 M HNO 3 and 0.013 mmol/g-dried tannin, respectively. The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (author)

  19. The influence of temperature on migration of radionuclides in deep-sea sediments: Simulation experiments concerning sorption and heat flow related to deep-sea disposal of high-level radioactive waste

    International Nuclear Information System (INIS)

    Geldermalsen, L.A. van

    1985-02-01

    This report presents the results of a study on the effects of temperatures up to 90 0 C on the migration of the radionuclides plutonium, neptunium and americium through marine sediments in the near field of a canister with radioactive waste. Topics entered were; (i) the influence of temperature on the distribution coefficients of the transuranics plutonium, americium and neptunium, (ii) the effect of temperature on the composition and characteristics of interstitial water and (iii) the effects of a point heat source on the temperature distributions and flow velocities in interstitial water of sediments. (Auth.)

  20. Simple method for preparation of secondary amides of phosphorylacetic acids and their use for actinide extraction and sorption from nitric acid solutions

    International Nuclear Information System (INIS)

    Artyushin, O.I.; Sharova, E.V.; Odinets, I.L.; Lenevich, S.V.; Mastruykova, T.A.; Morgalyuk, V.P.; Tananaev, I.G.; Pribylova, G.V.; Myasoedova, G.V.; Myasoedov, B.F.

    2004-01-01

    An effective method of synthesis of secondary alkylamides of phosphorylacetic acids (APA), based on amidation of ethyl esters of phosphorylacetic acids with primary aliphatic amines, was developed. Extraction of americium(III) complexes with APA solutions in dichloroethane and uranium(VI) sorption by sorbents with non-covalently fixed APA from nitric acid solutions were studied. In the course of americium(III) extraction there is no correlation between Am III distribution factor and APA structure, whereas during uranium(VI) sorption a dependence of U VI extraction degree on the complexing agent structure is observed [ru

  1. Colloid formation during waste form reaction: Implications for nuclear waste disposal

    Science.gov (United States)

    Bates, J. K.; Bradley, J.; Teetsov, A.; Bradley, C. R.; Buchholtz ten Brink, Marilyn R.

    1992-01-01

    Insoluble plutonium- and americium-bearing colloidal particles formed during simulated weathering of a high-level nuclear waste glass. Nearly 100 percent of the total plutonium and americium in test ground water was concentrated in these submicrometer particles. These results indicate that models of actinide mobility and repository integrity, which assume complete solubility of actinides in ground water, underestimate the potential for radionuclide release into the environment. A colloid-trapping mechanism may be necessary for a waste repository to meet long-term performance specifications.

  2. Plutonium isotopes in the environment

    International Nuclear Information System (INIS)

    Holm, E.

    1977-12-01

    Determination of plutonium and americium by ion exchange and alpha-spectrometry. Deposition of global fall-out and accumulated area-content of 238 Pu, 239 Pu, 240 Pu, 241 Pu, 242 Pu and 241 Am in central Sweden (62.3 deg N, 12.4 deg E), by using the lichen species Cladonia alpestris as bioindicator. Retention and distribution of plutonium in carpets of lichen and soil. Transfer of plutonium from lichen to reindeer and man. Absorbed dose in reindeer and man from plutonium. Basic studies of plutonium and americium in the western Mediterranean surface waters, with emphases on particulate form of the transuranics. (author)

  3. The EFTTRA experiment on irradiation of Am targets

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, J.-F. [Commission of the European Communities, Karlsruhe (Germany). European Inst. for Transuranium Elements; Conrad, R. [European Commission, Joint Research Centre, Institute for Advanced Materials, P.O. Box 2, 1755 ZG Petten (Netherlands); Konings, R.J.M. [Netherlands Energy Research Foundation ECN, P.O. Box 1, 1755 ZG Petten (Netherlands); Muehling, G. [Forschungszentrum Karlsruhe, Projekt Nukleare Sicherheitsforschung, Postfach 3640, 76021 Karlsruhe (Germany); Salvatores, M. [CEA, DRN, CE/Cadarache, 13108 Saint-Paul-Lez-Durance Cedex (France); Vambenepe, G. [EDF/SEPTEN, 12-14, avenue Dutrievoz, 69628 Villeurbanne Cedex (France)

    1998-06-12

    The EFTTRA European collaboration (experimental feasibility of targets for transmutation), started in 1992, analyzes material problems related to the possibility of transmuting long-lived radioactive nuclides. One of the EFTTRA activities concerns the development of targets for the transmutation of americium in a matrix (heterogeneous cycle). The irradiation in the HFR of a sample of americium oxide embedded in a spinel matrix, the EFTTRA-T4 experiment, containing 11.2 wt.% of Am-241, was started in September 1996. (orig.) 4 refs.

  4. The Methods Sampling, Measurement and Analysis in Impression of Environment Radioactivity

    International Nuclear Information System (INIS)

    Aycik, A.; Onat, B.; Ertuerk, K.; Topcuoglu, S.; Koeksal, G.; Yasar, S.; Guengoer, N.

    2000-01-01

    This document relates to radionuclides, analytic methods, analytic quality control, equipment and person el necessities for laboratories, gamma-ray spectroscopic method, radiostrontium and strontium-90, standard test method for tritium, strontium-89 and strontium-90, plutonium and americium, systems of international unit

  5. British Nuclear Fuels - a dirty business

    International Nuclear Information System (INIS)

    Bunyard, P.

    1983-01-01

    The radioactive discharges from British Nuclear Fuels Sellafield, Cumbria, reprocessing plant to the sea are discussed. Statements that have been made by various individuals and groups about the contamination of the sea, the coast and places inland, and the biological effects of plutonium and americium, are discussed in detail. Particular stress is placed on statements about increased incidence of cancers. (U.K.)

  6. Radiological analysis of materials sampled on the old nuclear test site of In Ekker (Algeria)

    International Nuclear Information System (INIS)

    Chareyron, Bruno

    2010-01-01

    After having recalled the context of the French nuclear test campaign in Algeria between 1961 and 1966, this document reports and comments radiological measurements performed on the site of In Ekker, and also results of analysis performed in laboratory (contamination by cesium 137, americium 241, plutonium); recommendations are given

  7. Preservation and restoration of works-of-art via nuclear technology

    International Nuclear Information System (INIS)

    Coeure, Ph.

    1999-01-01

    This paper presents the techniques using gamma rays for preservation and restoration of our cultural patrimony. Developed at CEA and by ARC-Nucleart, these techniques, which use mainly Cobalt 60 and Americium 241 sources, allow disinfection and strengthening of the various materials which make up the objects (wood, paper, bone, stone, plaster, etc), together with radiography of wood and stone. (author)

  8. Historical review of californium-252 discovery and development

    International Nuclear Information System (INIS)

    Stoddard, D.H.

    1985-01-01

    This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving 252 Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed

  9. Study of sugar cooking degree to sugar obtention using gamma attenuation

    International Nuclear Information System (INIS)

    Holanda Cavalcanti, J. de.

    1984-01-01

    The application of gamma radiation attenuation methodology in the determination of sugar cooking degree is studied. Several experiments with samples of vacuum equipment during the cooking were made, based on beam intensity variations of a radioactive source of Americium 241. One sensible difference between the sirup emergent radiation and the cooked mass was observed. (M.A.C.) [pt

  10. 77 FR 75610 - Foreign-Trade Zone 22-Chicago, IL, Notification of Proposed Production Activity, Abbott...

    Science.gov (United States)

    2012-12-21

    ... trials; radioactive elements and isotopes and compounds other than those of subheadings 2844.10, 2844.20... elements; isotopes or compounds; radioactive residues; elements, isotopes and compounds with cobalt-60 radioactivity only; and other elements, isotopes and compounds: Americium-241, californium-252, curium-244...

  11. Mock iodine-125 radiation source

    International Nuclear Information System (INIS)

    Coffey, D.L.

    1976-01-01

    An intimate mixture of americium-241 and iodine-129 provides an energy spectrum that reliably simulates the spectrum of iodine-125 in a well-type detector. As such, it may be used as a long-lived standard to calibrate instruments such as well scintillation spectrometers in which measurements are to be made involving iodine-125

  12. Radiological analysis of materials sampled on the old nuclear test site of In Ekker (Algeria); Analyses radiologiques de materiaux preleves sur l'ancien site d'essais nucleaires d'In Ekker (Algerie)

    Energy Technology Data Exchange (ETDEWEB)

    Chareyron, Bruno

    2010-02-11

    After having recalled the context of the French nuclear test campaign in Algeria between 1961 and 1966, this document reports and comments radiological measurements performed on the site of In Ekker, and also results of analysis performed in laboratory (contamination by cesium 137, americium 241, plutonium); recommendations are given

  13. 10 years Efttra: 1992-2001

    Energy Technology Data Exchange (ETDEWEB)

    Warin, D.; Martin, P. [CEA Cadarache, 13 - Saint Paul lez Durance (France); Conrad, R. [European Commission JRC, Institute for Advanced Material, Petten (Netherlands); Haas, R.; Konings, R.J.M. [European Commission, JRC, Institute fuer Transuranium Elements, Karlsruhe (Germany); Heusener, G. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Schram, R.P.C. [NRG Petten (Netherlands); Vambenepe, G. [Electricite de France EDF, SEPTEN, 69 - Villeurbanne (France)

    2001-07-01

    An overview is given of the achievements of the EFTTRA programme in the period 1992-2001. The results of the irradiation tests of transmutation of technetium, iodine and americium will be presented and the plans for the coming years will be discussed shortly. (author)

  14. Report on the scientifical feasibility of advanced separation

    International Nuclear Information System (INIS)

    2001-01-01

    The advanced separation process Purex has been retained for the recovery of neptunium, technetium and iodine from high level and long lived radioactive wastes. Complementary solvent extraction processes will be used for the recovery of americium, curium and cesium from the high activity effluents of the spent fuel reprocessing treatment. This document presents the researches carried out to demonstrate the scientifical feasibility of the advanced separation processes: the adaptation of the Purex process would allow the recovery of 99% of the neptunium, while the association of the Diamex and Sanex (low acidity variant) processes, or the Paladin concept (single cycle with selective de-extraction of actinides) make it possible the recovery of 99.8% of the actinides III (americium and curium) with a high lanthanides decontamination factor (greater than 150). The feasibility of the americium/curium separation is demonstrated with the Sesame process (extraction of americium IV after electrolytic oxidation). Iodine is today recovered at about 99% with the Purex process and the dissolved fraction of technetium is also recovered at 99% using an adaptation of the Purex process. The non-dissolved fraction is retained by intermetallic compounds in dissolution residues. Cesium is separable from other fission products with recovery levels greater than 99.9% thanks to the use of functionalized calixarenes. The scientifical feasibility of advanced separation is thus demonstrated. (J.S.)

  15. Exploratory Research on Radioisotope Thermoelectric Generators for Deep Space Missions

    Directory of Open Access Journals (Sweden)

    Freis D.

    2017-01-01

    The new exploratory research project will be introduced together with an overview on the available facilities and capabilities of JRC in this domain. Alternative americium forms with potential improved stability versus the oxides are discussed and innovative thermoelectric materials based on actinides are introduced.

  16. 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.

  17. Determination of 241Am and 244Cm in environmental samples

    International Nuclear Information System (INIS)

    Bonino, N.O.; Grinman, A.D.R.; Serdeiro, N.H.

    1998-01-01

    The present technique describes a method to separate, purify and measure low levels of americium and curium in different environmental samples such as sediments, soils, water, vegetables, and air filters. The determination of radionuclides in theses environmental matrices have analytical problems, since a simple method doesn't exist for the purification, which is indispensable for its later measuring alpha spectrometry. The developed technique consist on taking an aliquot of the sample to analyze, to add tracer as americium 243 and curium 242, and to dissolve the matrix in a such way to have a clear solution. For the isolation of the americium and curium of the other actinides ar used as separation techniques: precipitation with Fe 3+ , anionic and cationic exchange, and extraction with a appropriate organic solvent. The purification of the americium and curium is followed by the electrodeposition habitually used. The measurement is carried out by alpha spectrometry with a detector of implanted ion. The detection limit for this techniques is of 0,002 Bq/l or 0,2 mBq in the case of filters. (author)

  18. Radionuclides distribution in internal organs of wild animals in alienation zone of Chernobyl NPP

    International Nuclear Information System (INIS)

    Gorbatova, T.A.; Kudryashov, V.P.; Mironov, V.P.

    2002-01-01

    Activities of caesium 137, strontium 90, plutonium isotopes and americium 241 are experimentally defined in the internal organs of bearer and wolf alienation zone of Chernobyl NPP. Radionuclides distribution in the internal organs of wild animals is defined by destruction of nuclear fuel particles

  19. Sorption of radionuclides on geological samples from the Bradwell, Elstow, Fulbeck and Killingholme site investigations

    International Nuclear Information System (INIS)

    Berry, J.A.; Coates, H.A.; Green, A.; Littleboy, A.K.

    1988-06-01

    The sorption of chloride, caesium, calcium, nickel and americium on geological samples collected during the site investigations at Bradwell, Elstow, Fulbeck and Killingholme has been studied. Through-diffusion and batch sorption techniques were used and experiments were designed to give a direct comparison between the sorptive behaviour of material from each site. (author)

  20. Pyrochemical properties of actinides elements

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Hayashi, Hirokazu; Minato, Kazuo

    2005-01-01

    The present status of research works on pyrochemical processing is introduced in view of: 1) the process concept; 2) R and D progress; 3) new experimental facilities in NUCEF. Basic laboratory studies with rare-earth elements have almost been completed and hot tests with americium have been started at the TRU-HITEC facility in NUCEF. (author)

  1. Experimental findings on actinide recovery utilizing oxidation by peroxydisulfate followed by ion exchange: Fuel cycle research & development

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shehee, T. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-31

    Our research seeks to determine if inorganic ion-exchange materials can be exploited to provide effective minor actinide (Am, Cm) separation from lanthanides. Previous work has established that a number of inorganic and UMOF ion-exchange materials exhibit varying affinities for actinides and lanthanides, which may be exploited for effective separations. During FY15, experimental work focused on investigating methods to oxidize americium in dilute nitric and perchloric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium in dilute nitric acid. Ion-exchange materials tested included a variety of alkali titanates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of AmIII. Experimental findings indicated that CeIII, NpV, and RuII are oxidized by peroxydisulfate, but there are no indications that the presence of CeIII, NpV, and RuII affected the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used.

  2. Recommendations for ionization chamber smoke detectors for commercial and industrial fire protection systems (1988)

    International Nuclear Information System (INIS)

    1989-01-01

    Ionization chamber smoke detectors (ICSDs) utilising a radioactive substance as the source of ionization are used to detect the presence of smoke and hence give early warning of a fire. These recommendations are intended to ensure that the use of ICSDs incorporating radium-226 and americium-241 in commercial/industrial fire protection systems does not give rise to any unnecessary radiation exposure

  3. Historical Review of Californium-252 Discovery and Development

    Science.gov (United States)

    Stoddard, D. H.

    1985-01-01

    This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed. (PLG)

  4. Uranium and transuranium analysis

    International Nuclear Information System (INIS)

    Regnaud, F.

    1989-01-01

    Analytical chemistry of uranium, neptunium, plutonium, americium and curium is reviewed. Uranium and neptunium are mainly treated and curium is only briefly evoked. Analysis methods include coulometry, titration, mass spectrometry, absorption spectrometry, spectrofluorometry, X-ray spectrometry, nuclear methods and radiation spectrometry [fr

  5. Mobilities of radionuclides in fresh and fractured crystalline rock

    International Nuclear Information System (INIS)

    Torstenfelt, B.; Ittner, T.; Allard, B.; Andersson, K.; Olofsson, U.

    1982-12-01

    Sorption and migration of technetium, cesium and americium on fracture surfaces and fresh surfaces of granites taken from drilling cores from the Finnsjoen and Studsvik areas and the Stripa mine are reported. The three elements were used as reference elements with different chemistry and behaviour in water; under the conditions used in the experiments technetium exists as the heptavalent TcO -4 -ion, cesium as the non-complexed monovalent cation Cs + and americium as the strongly hydrolysed Am(OH)super (3-x) (x-1-4). The waters used were synthetic groundwaters representative of waters from the drilling holes. After the exposure of the fracture samples to spiked groundwater solutions for a period of three up to six months the penetration depths and concentration profiles were analysed and autoradiographs of cesium and americium distribution vs depth were taken. The sorption of technetium was found to be negligible. The transport of TcO -4 depends on accessibility to fractures and micro-fissures in the rock. Cesium is sorbed through an ion-exchange process. Migration of cesium depends not only on the transport in water into fractures and micro-fissures, but also on migration through mineral veins with a high CEC. Americium is strongly sorbed on most solid surfaces and did not migrate significantly during the contact time of three months. The diffusivity in granite was found to be around 10 - 13 m 2 /s for cesium; preliminary values for technetium and americium were 10 - 12 m 2 /s and less than 10 - 16 m 2 /s, respectively. (Authors)

  6. Removal of inhaled industrial mixed oxide aerosols from Beagle dogs by lung lavage and chelation therapy

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Eidson, A.F.; Guilmette, R.A.

    1978-01-01

    An experiment was conducted in 15 adult Beagle dogs to evaluate lung lavage and chelation therapy for the removal of inhaled particles of mixed actinide oxides. The dogs were divided into three groups of five dogs each. Each group was exposed to an aerosol from a different industrial process. Group 1 was exposed to mixed oxide material which had been calcined at 750 0 C collected from a ball milling process. Group 2 was exposed to mixed oxide material from a centerless grinding operation which had been previously heat treated to 1750 0 C. The third group was exposed to 239 PuO 2 not containing uranium from a V-blending procedure which had been heat treated at 850 0 C. After exposure, three dogs in each group were given ten lung lavages and 18 intravenous injections of calcium trisodium diethylenetriaminepentaacetate (DTPA). All dogs were sacrificed 64 days after inhalation exposure. The tissues were radioanalyzed for plutonium and americium. Fluorimetric analyses for uranium in the tissues are in progress. The urine, feces and lavage fluid are also being analyzed for plutonium, americium and uranium. The distribution of plutonium and americium expressed as percentages of the sacrifice body burden was similar in the tissues of the treated and unteated dogs. The lungs contained most of the radionuclides with a small amount in the liver, skeleton and tracheobronchial lymph nodes. The percentage of the sacrifice body burden of americium and plutonium that was present in the lung was less in the treated dogs and was higher in the TBLN's and skeleton than in the untreated dogs. The ratio of Pu/Am was higher in the lungs than in the original material obtained from the industrial sites suggesting a shorter retention time for americium than plutonium to 64 days in the dog

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-17

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

  8. Electrochemical oxidation of 243Am(III) in nitric acid by a terpyridyl-derivatized electrode

    Energy Technology Data Exchange (ETDEWEB)

    Dares, C. J.; Lapides, A. M.; Mincher, B. J.; Meyer, T. J.

    2015-11-05

    A high surface area, tin-doped indium oxide electrode surface-derivatized with a terpyridine ligand has been applied to the oxidation of trivalent americium to Am(V) and Am(VI) in nitric acid. Potentials as low as 1.8 V vs. the saturated calomel electrode are used, 0.7 V lower than the 2.6 V potential for one-electron oxidation of Am(III) to Am(IV) in 1 M acid. This simple electrochemical procedure provides, for the first time, a method for accessing the higher oxidation states of Am in non-complexing media for developing the coordination chemistries of Am(V) and Am(VI) and, more importantly, for separation of americium from nuclear waste streams.

  9. Advanced plutonium management in PWR - complementarity of thorium and uranium cycles

    International Nuclear Information System (INIS)

    Ernoult, Marc

    2014-01-01

    In order to study the possibility of advanced management of plutonium in existing reactors, 8 strategies for plutonium multi-recycling in PWRs are studied. Following equilibrium studies, it was shown that, by using homogeneous assemblies, the use of thorium cannot reduce the plutonium inventory of equilibrium cycle or production of americium. By distributing the different fuel types within the same assembly, some thoriated strategies allow however lower inventories and lower production americium best strategies using only the uranium cycle. However, in all cases, low fuel conversion theories in PWRs makes it impossible to lower resource consumption more than a few percent compared to strategies without thorium. To study the transition, active participation in development of the scenario code CLASS has been taken. It led to the two simulation scenarios among those studied in equilibrium with CLASS. These simulations have shown discrepancies with previously simulated scenarios. The major causes of these differences were identified and quantified. (author)

  10. A radiochemical procedure for a low-level measurement of ''241Am in environmental samples using a supported functional organo phosphorus extractant

    International Nuclear Information System (INIS)

    Gasco, C.; Anton, M. P.; Alvarez, A.; Navarro, N.; Salvador, S.

    1994-01-01

    The transuranides analysis in environmental samples is carried out by CIEMAT using standardized methods based on sequential separation with ionic-exchange resins. The americium fraction is purified through a two-layer ion exchange column and lately in an anion-exchange column in nitric acid methanol medium. The technique is time consuming and the results are not completely satisfactory (low recovery and loss of a-resolution) for some samples. The chemical compound CMPO (octyl(phenyl)-N,N-diisobutyl carbomoylmethyiphosphine oxide) dissolved in TPB (tributyl phosphate) and supported on an inert substrate has been tested directly for ''241Am analysis by a large number of laboratories. A new method that combines both procedures has been developed. The details of the improved procedure are described in this paper. The advantages of its application to environmental samples (urine, faeces and sediments) are discussed. The utilization of standard samples, with americium certified concentrations confirms the reliability of our measurements. (Author) 8 refs

  11. A radiochemical procedure for a low-level measurement of ''241 Am in environmental samples using a supported functional organo phosphorus extractant

    International Nuclear Information System (INIS)

    Gasco, C.; Anton, M.A.; Alvarez, A.; Navarro, N.; Salvador, S.

    1994-01-01

    The transuranides analysis in environmental samples is carried out by CIEMAT using standardized methods based on sequential separation with ionic-exchange resins. The americium fraction is purified through a two-layer ion exchange column and lately in an anion-exchange column in nitric acid methanol medium. The technique is time-consuming and the results are not completely satisfactory (low recovery and loss of alpha-resolution) for some samples. The chemical compound CMPO (octyl(phenyl).N,N-diisobutyl carbomoylmethyiphosphine oxide) dissolved in TPB (tributyl phosphate) and supported on an inert substrate has been tested directly for ''241 Am analysis by a large number of laboratories. A new method that combines both procedures has been developed. The details of the improved procedure are described in this paper. The advantages of its application to environmental samples (urine, faeces and sediments) are discussed. The utilization of standard, with americium certified concentrations confirms the reliability of our measurements

  12. TRUEX Radiolysis Testing Using the INL Radiolysis Test Loop: FY-2012 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Dean R. Peterman; Lonnie G. Olson; Richard D. Tillotson; Rocklan G. McDowell; Jack D. Law

    2012-09-01

    The INL radiolysis test loop has been used to evaluate the affect of radiolytic degradation upon the efficacy of the strip section of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. The nominal composition of the TRUEX solvent used in this study is 0.2 M CMPO and 1.4 M TBP dissolved in n-dodecane and the nominal composition of the TRUEX strip solution is 1.5 M lactic acid and 0.050 M diethylenetriaminepentaacetic acid. Gamma irradiation of a mixture of TRUEX process solvent and stripping solution in the test loop does not adversely impact flowsheet performance as measured by stripping americium ratios. The observed increase in americium stripping distribution ratios with increasing absorbed dose indicates the radiolytic production of organic soluble degradation compounds.

  13. Safety analysis report: packages. Pu oxide and Am oxide shipping cask (Packaging of fissile and other radioactive materials). Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1980-05-01

    The PuO 2 cask or SP 5320-2 and 3 cask is designed for surface shipment of americium or plutonium. The cask design was physically tested to demonstrate that it met the criteria specified in US ERDA Manual Chapter 0529, and Chapter I, Interstate Commerce Commission. The package has been assessed for transport of up to 357 grams of plutonium (403 grams PuO 2 powder) and up to 176 grams of americium (200 grams AmO 2 powder), having a maximum decay heat of 203 watts. Criticality evaluation alone would allow the shipment as Fissile Class II but the radiation level of the cask, measured at the time of shipment, may exceed 50 mrem/h at the surface and require shipment as Fissile Class III. Sample calculations address only the more restrictive of the two materials, which in most cases is 238 PuO 2

  14. Core physics aspects and possible loadings for actinide recycling in light water reactors

    International Nuclear Information System (INIS)

    Maldague, Th.; Renard, A.; Harislur, A.; Mouney, H.; Rome, M.; PIlate, S.

    1995-01-01

    The long-term activity and toxicity of nuclear waste is mainly due to plutonium with an important contribution from americium. The studies presented here assume a future recovery of americium at reprocessing and the possible existence of fuel fabrication chains devoted to Am target pins. Core physics calculations with standard design methods have considered Am targets being recycled in a 900-MWe PWR according to 3 possibilities: removable clusters on guide tube positions; dedicated assemblies at core periphery; target pins pins on MOX assembly corners. Concept No. 3 appears most promising for implementation; it corresponds to high Am transmutation rates (about 80 %). Concept No. 2 is also attractive as it can probably be improved. Both are recommended for further detailed studies. (authors)

  15. Behaviour of actinide elements in the lithium reduction process. 1. Feasibility of the Li reduction process to UO2 and PuO2

    International Nuclear Information System (INIS)

    Usami, Tuyoshi; Kurata, Masateru; Yuda, Ryoichi; Kato, Tetsuya; Inoue, Tadashi; Sims, Howard; Jenkins, Jon

    2000-01-01

    Lithium reduction process has been developed to apply pyrochemical recycle process for oxide fuels. This process uses lithium metal as a reductant to convert oxides of actinide elements to metal. Lithium oxide generated in the reduction is to be dissolved in a molten lithium chloride bath to enhance reduction. The authors have measured the solubility of lithium oxide in lithium chloride, and then reduced uranium dioxide and plutonium dioxide. The solubility measured at 923 K was 8.8 wt.%. The uranium dioxide was completely reduced with no intermediate products and formed porous metal. Plutonium dioxide including 3% of americium dioxide was also reduced completely and formed molten metal. Even lithium oxide was just under saturation , plutonium could be reduced to metal. Shown from this result was easier reduction than predicted from thermodynamic data. Americium dioxide was also reduced at 1.8 wt% lithium oxide, but was not reduced at 8.8 wt.%. (author)

  16. Rapid determination of 239,240Pu, 238Pu, 241Am and 90Sr in high contaminated samples waste using combined SPE sorbents AnaLigR Pu-02, AnaLigR Sr-01 and DGAR Resin

    International Nuclear Information System (INIS)

    Silvia Dulanska; Igor Antalik; Miroslav Labaska; Boris Remenec; Andrej Matel

    2013-01-01

    A rapid separation method has been developed which allows measurement of plutonium, americium and strontium isotopes in the high active sample from CBRN Training and Testing Centre in Zemianske Kostolany (Slovakia) with high chemical recoveries and effective removal of matrix interferences. This method uses different commercial products stacked AnaLig R Pu-02, AnaLig R Sr-01 and DGA R Resin cartridges from IBC Advanced Technologies and Eichrom Technologies. The method allows rapid separation of plutonium, strontium and americium using a single multi-stage column in the vacuum box (cartridge technology) with rapid flow rates to minimize sample separation time. The 239,240 Pu, 23 8Pu and 241 Am were determined by alpha spectroscopy, 90 Sr was counted on TRICARB 2900 TR by Cherenkov counting of its progeny 90 Y. (author)

  17. ECN contributions to global `97. International conference on future nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Kloosterman, J.L.; Bende, E.E.; Konings, R.J.M.; Gruppelaar, H.; Bakker, K.; Boshoven, J.G.; Hein, H.; Huntelaar, M.E.; Zhang, H. [Netherlands Energy Research Foundation ECN, Petten (Netherlands); Kiefhaber, E.; Muehling, G. [Forschungszentrum Karlsruhe FZK, Karlsruhe (Germany); Rome, M. [Electricite de France EdF, Lyon (France); Tommasi, J.; Delpech, M.; Cocuaud, N.; Picard, E.; Conti, A.; Salvatores, M. [Commissariat a l`Energie Atomique CEA, Cadarache (France); Chawla, R.; Paratte, J.M.; Kasemeyer, U. [Paul Scherrer Institute PSI, Villigen (Switzerland); Akie, H.; Takano, H. [Japan Atomic Energy Research Institute JAERI, Ibaraki-ken (Japan); Lombardi, C.; Mazzola, A. [Polytechnic of Milan POLIMI, Milano (Italy); Matzke, H.; Babelot, J.F. [Institute for Transuranium Elements ITU, Karlsruhe (Germany); Conrad, R. [Joint Research Centre Institute for Advanced Materials JRC/IAM, Petten (Netherlands); Vambenepe, G. [Electricite de France, EDF SEPTEN, Villeurbanne (France); Meeldijk, J.D.; Woensdregt, C.F. [Faculty of Earth Sciences, Department of Petrology, Utrecht University, Utrecht (Netherlands)

    1997-08-01

    The six papers in this report, which are presented during the title conference, deal with the following subjects: (1) Strategies for the transmutation of americium; (2) Transmutation of plutonium in pebble bed type high temperature reactors; (3) Benchmark comparisons of calculations of LWR fuel cells with uranium-free fuels; (4) Inert matrices, uranium-free plutonium fuels and americium targets. Synthesis of CAPRA (`Consommation Accrue de Plutonium dans les Rapides`), SPIN (`Separation et Incineration`) and EFTTRA (Experimental Feasibility of Targets for Transmutation) studies; (5) Development of fuels for the transmutation in the frame of the EFTTRA European collaboration; and (6) On the use of spinel-based nuclear fuels for the transmutation of actinides. 16 figs., 23 tabs., 65 refs.

  18. Ingot formation using uranium dendrites recovered by electrolysis in LiCl-KCl-PuCl3-UCl3 melt

    International Nuclear Information System (INIS)

    Mineo Fukushima; Akira Nakayoshi; Shinichi Kitawaki; Masaki Kurata; Noboru Yahagi

    2008-01-01

    Products on solid cathodes recovered by the metal pyrochemical processing were processed to obtain uranium ingot. Studies on process conditions of uranium formation, assay recovered uranium products and by-products and evaluation of mass balance were carried out. In these tests, it is confirmed that uranium ingots can be obtained with heating the products more than melting temperature of metal uranium under atmospheric pressure because adhered salt cover the uranium not to oxidize it during uranium cohering. Covered salt can be removed after ingot formation. Inside the ingot, there were a lump of uranium and dark brown colored dross was observed. Material balance of uranium is 77 ∼ 96%, that of plutonium is 71 ∼ 109%, and that of americium that is a volatile substance more than uranium and plutonium become 79 ∼ 119%. Volatilization of americium is very small under the condition of high temperature. (authors)

  19. Removal of actinides from high-level wastes generated in the reprocessing of commercial fuels

    International Nuclear Information System (INIS)

    Bond, W.D.; Leuze, R.E.

    1975-09-01

    Progress is reported on a technical feasibility study of removing the very long-lived actinides (uranium, neptunium, plutonium, americium, and curium) from high-level wastes generated in the commercial reprocessing of spent nuclear fuels. The study was directed primarily at wastes from the reprocessing of light water reactor (LWR) fuels and specifically to developing satisfactory methods for reducing the actinide content of these wastes to values that would make 1000-year-decayed waste comparable in radiological toxicity to natural uranium ore deposits. Although studies are not complete, results thus far indicate the most promising concept for actinide removal includes both improved recovery of actinides in conventional fuel reprocessing and secondary processing of the high-level wastes. Secondary processing will be necessary for the removal of americium and curium and perhaps some residual plutonium. Laboratory-scale studies of separations methods that appear most promising are reported and conceptual flowsheets are discussed. (U.S.)

  20. Emergence of californium as the second transitional element in the actinide series

    Science.gov (United States)

    Cary, Samantha K.; Vasiliu, Monica; Baumbach, Ryan E.; Stritzinger, Jared T.; Green, Thomas D.; Diefenbach, Kariem; Cross, Justin N.; Knappenberger, Kenneth L.; Liu, Guokui; Silver, Mark A.; DePrince, A. Eugene; Polinski, Matthew J.; Van Cleve, Shelley M.; House, Jane H.; Kikugawa, Naoki; Gallagher, Andrew; Arico, Alexandra A.; Dixon, David A.; Albrecht-Schmitt, Thomas E.

    2015-01-01

    A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, and show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. The metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence. PMID:25880116

  1. Assessment of environment survey (2005-2009). Synthesis of results and comments - 'ACROnic du nucleaire' nr 91, December 2010

    International Nuclear Information System (INIS)

    2010-12-01

    This document presents and comments radioactivity level measurements performed by the Citizen Observatory of radioactivity in the environment which has been created by the ACRO (Association for the Control of Radioactivity in the West). As several nuclear installations are present in this part of France (power station, reprocessing plants, waste storage centre, military harbour), measurements have been made during five years (2005-2009) along the coasts of Normandy and in some waterways and lands. Several topics are addressed: marine environment (radioactivity measurements in species and algae), sediments on the coast (cobalt 60, americium-241, caesium-137), sea water (tritium activity), radiological status of brooks around La Hague (detection of 5 isotopes: cobalt 60, americium-241, caesium-137, iodine-129 and ruthenium-rhodium-106). A focus is made on tritium

  2. 2014 AFCI Glovebox Event Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Joseph Lenard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    One of the primary INL missions is to support development of advanced fuels with the goal of creating reactor fuels that produce less waste and are easier to store. The Advanced Fuel Cycle Initiative (AFCI) Glovebox in the Fuel Manufacturing Facility (FMF) is used for several fuel fabrication steps that involve transuranic elements, including americium. The AFCI glove box contains equipment used for fuel fabrication, including an arc melter – a small, laboratory-scale version of an electric arc furnace used to make new metal alloys for research – and an americium distillation apparatus. This overview summarizes key findings related to the investigation into the releases of airborne radioactivity that occurred in the AFCI glovebox room in late August and early September 2014. The full report (AFCI Glovebox Radiological Release – Evaluation, Corrective Actions and Testing, INL/INL-15-36996) provides details of the identified issues, corrective actions taken as well as lessons learned

  3. Extraction of Am, Pu and U by dicyclohexano-18-crown-6/1-octanol from HNO3 solution and simulated HLLW

    International Nuclear Information System (INIS)

    Wang Xinghai; Wang Jianchen; Liu Xiuqin; Song Chongli

    1999-01-01

    The extraction of americium, plutonium and uranium by dicyclohexano-18-crown-6 (DCH18C6)/1-octanol from HNO 3 solution and simulated HLLW are studied. The influences of acidity and dilution factor of simulated HLLW are studied. At low HNO 3 concentration and dilution factor above 2, 0.1 mol/L DCH18C6/1-octanol extracts very little americium, plutonium and uranium. the distribution ratios of Am, Pu and U increase with the increase of HNO 3 concentration in aqueous phase, and decrease with increasing of dilution factor of HLLW. The distribution ratio of extraction of Pu(IV) increases with the increase of extractant concentration

  4. An Aerial Radiological Survey of the Nevada Test Site - Area 10 Corrective Action Unit 367

    International Nuclear Information System (INIS)

    Lyons, Craig

    2010-01-01

    A series of aerial radiological surveys were conducted over the Sedan, Uncle, and Ess ground zero areas in Area 10. The surveys were performed in November 2009 utilizing a large array of helicopter mounted sodium iodide detectors. The purpose of the survey was to update the previous radiological survey levels of the environment and surrounding areas of the ground zeros. Gross Counts, inferred exposure rates, man-made activity, and Americium-241 activity, as calculated from the aerial data are presented in the form of isopleth maps superimposed on imagery of the surveyed areas. In addition, spectral products are included that identify Cesium-137, Americium-241 and Cobalt-60 as the primary radionuclides present within the survey area.

  5. Radioisotopes of the U, Th, Pu, Am in the mushrooms

    International Nuclear Information System (INIS)

    Galanda, D.; Matel, L.

    2001-01-01

    The present work is devoted the estimation of the data about radioactive contamination in different species of mushrooms with the aim to analyzing the influence of soil properties. The radioactive plutonium, uranium, thorium and americium was assayed in the dried mushrooms collected in areas of East and West Slovakia in 1998 -2000, and examined the effectiveness of this mushroom as a possible indicator of radioactive contamination of environment due to nuclear contamination of biosphere. Were determined the mushrooms of canes: Suillus, Leccinum, Baletus, Armillariella, Xerocomus and Craterellus. The mushrooms were dried and prepared by liquid extraction with Aliquat 336. The samples were measured by α-barrier spectrometry. The results of specific activity of plutonium, thorium, uranium and americium in the mushrooms and the layers of forest litter were summarized. (authors)

  6. Sorption studies of radioelements on geological materials

    International Nuclear Information System (INIS)

    Berry, John A.; Yui, Mikazu; Kitamura, Akira

    2007-11-01

    Batch sorption experiments have been carried out to study the sorption of uranium, technetium, curium, neptunium, actinium, protactinium, polonium, americium and plutonium onto bentonite, granodiorite and tuff. Mathematical modelling using the HARPHRQ program and the HATCHES database was carried out to predict the speciation of uranium and technetium in the equilibrated seawater, and neptunium, americium and plutonium in the rock equilibrated water. Review of the literature for thermodynamic data for curium, actinium, protactinium and polonium was carried out. Where sufficient data were available, predictions of the speciation and solubility were made. This report is a summary report of the experimental work conducted by AEA Technology during April 1991-March 1998, and the main results have been presented at Material Research Society Symposium Proceedings and published as proceedings of them. (author)

  7. Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    These analytical procedures are designed to show whether a given material meets the purchaser's specifications as to plutonium content, effective fissile content, and impurity content. The following procedures are described in detail: plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron(II); free acid by titration in an oxalate solution; free acid by iodate precipitation-potentiometric titration method; uranium by Arsenazo I spectrophotometric method; thorium by thorin spectrophotometric method; iron by 1,10-phenanthroline spectrophotometric method; chloride by thiocyanate spectrophotometric method; fluoride by distillation-spectrophotometric method; sulfate by barium sulfate turbidimetric method; isotopic composition by mass spectrometry; americium-241 by extraction and gamma counting; americium-241 by gamma counting; gamma-emitting fission products, uranium, and thorium by gamma-ray spectroscopy; rare earths by copper spark spectrochemical method; tungsten, niobium (columbium), and tantalum by spectrochemical method; simple preparation by spectrographic analysis for general impurities

  8. Incineration by accelerator

    International Nuclear Information System (INIS)

    Cribier, M.; FIoni, G.; Legrain, R.; Lelievre, F.; Leray, S.; Pluquet, A.; Safa, H.; Spiro, M.; Terrien, Y.; Veyssiere, Ch.

    1997-01-01

    The use MOX fuel allows to hope a stabilization of plutonium production around 500 tons for the French park. In return, the flow of minor actinides is increased to several tons. INCA (INCineration by Accelerator), dedicated instrument, would allow to transmute several tons of americium, curium and neptunium. It could be able to reduce nuclear waste in the case of stopping nuclear energy use. This project needs: a protons accelerator of 1 GeV at high intensity ( 50 m A), a window separating the accelerator vacuum from the reactor, a spallation target able to produce 30 neutrons by incident proton, an incineration volume where a part of fast neutrons around the target are recovered, and a thermal part in periphery with flows at 2.10 15 n/cm 2 .s; a chemical separation of elements burning in thermal (americium) from the elements needing a flow of fast neutrons. (N.C.)

  9. Technical Improvements to an Absorbing Supergel for Radiological Decontamination in Tropical Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Michael D. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, Carol J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kivenas, Nadia [Argonne National Lab. (ANL), Argonne, IL (United States); demmer, Rick [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    Argonne National Laboratory (Argonne) developed a superabsorbing gel-based process (SuperGel) for the decontamination of cesium from concrete and other porous building materials. Here, we report on results that tested the gel decontamination technology on specific concrete and ceramic formulations from a coastal city in Southeast Asia, which may differ significantly from some U.S. sources. Results are given for the evaluation of americium and cesium sequestering agents that are commercially available at a reasonable cost; the evaluation of a new SuperGel formulation that combines the decontamination properties of cesium and americium; the variation of the contamination concentration to determine the effects on the decontamination factors with concrete, tile, and brick samples; and pilot-scale testing (0.02–0.09 m2 or 6–12 in. square coupons).

  10. R and D on Transmutation at CEA: Recent Results

    International Nuclear Information System (INIS)

    Royet, V.; Delahaye, T.; Lebreton, F.; Picart, S.; Caisso, M.; Gauthe, A.; Ode, D.; Tronche, E.; Bayle, J.P; Warin, D.; Bejaoui, S.; Delage, F.

    2015-01-01

    In the field of minor actinide transmutation in future Generation IV SFR reactor, CEA investigates in priority the recycling of Americium (Am) in the radial blankets located in the outer core area (AmBB: Americium Bearing Blankets). This paper gives an overview of the recent outcomes of the R and D programme carried out at CEA in the different fields of research: from powder elaboration to experimental irradiation. Concerning the powder elaboration, several batches have been produced by the oxalic co-conversion route as well as by the Calcined Resin Microsphere Pelletizing. Different tests have been then performed for the fabrication of pellets according to the current specifications of AmBB. For these two processes, different additional developments of innovative technologies have been achieved well adapted with the processes constraints and hot cell operating. Information on irradiation programmes (MARIOS in HFR and ongoing DIAMINO in Osiris) are presented. The next steps of the programme will then be tackled. (authors)

  11. Ingot formation using uranium dendrites recovered by electrolysis in LiCl-KCl-PuCl{sub 3}-UCl{sub 3} melt

    Energy Technology Data Exchange (ETDEWEB)

    Mineo Fukushima; Akira Nakayoshi; Shinichi Kitawaki [Japan Atomic Energy Agency (JAEA), 4-33 Muramatsu Tokai-mura Naka-gun, Ibaraki, 319-1194 (Japan); Masaki Kurata; Noboru Yahagi [Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwadokita Komae-shi, Tokyo, 201-8511 (Japan)

    2008-07-01

    Products on solid cathodes recovered by the metal pyrochemical processing were processed to obtain uranium ingot. Studies on process conditions of uranium formation, assay recovered uranium products and by-products and evaluation of mass balance were carried out. In these tests, it is confirmed that uranium ingots can be obtained with heating the products more than melting temperature of metal uranium under atmospheric pressure because adhered salt cover the uranium not to oxidize it during uranium cohering. Covered salt can be removed after ingot formation. Inside the ingot, there were a lump of uranium and dark brown colored dross was observed. Material balance of uranium is 77 {approx} 96%, that of plutonium is 71 {approx} 109%, and that of americium that is a volatile substance more than uranium and plutonium become 79 {approx} 119%. Volatilization of americium is very small under the condition of high temperature. (authors)

  12. Determination of the first ionization potential of actinides by resonance ionization mass spectroscopy

    International Nuclear Information System (INIS)

    Koehler, S.; Albus, F.; Dibenberger, R.; Erdmann, N.; Funk, H.; Hasse, H.; Herrmann, G.; Huber, G.; Kluge, H.; Nunnemann, M.; Passler, G.; Rao, P.M.; Riegel, J.; Trautmann, N.; Urban, F.

    1995-01-01

    Resonance ionization mass spectroscopy (RIMS) is used for the precise determination of the first ionization potential of transuranium elements. The first ionization potentials (IP) of americium and curium have been measured for the first time to IP Am =5.9738(2) and IP Cm =5.9913(8) eV, respectively, using only 10 12 atoms of 243 Am and 248 Cm. The same technique was applied to thorium, neptunium, and plutonium yielding IP T H =6.3067(2), IP N P =6.2655(2), and IP Pu =6.0257(8) eV. The good agreement of our results with the literature data proves the precision of the method which was additionally confirmed by the analysis of Rydberg seris of americium measured by RIMS. copyright American Institute of Physics 1995

  13. ECN contributions to global '97. International conference on future nuclear systems

    International Nuclear Information System (INIS)

    Kloosterman, J.L.; Bende, E.E.; Konings, R.J.M.; Gruppelaar, H.; Bakker, K.; Boshoven, J.G.; Hein, H.; Huntelaar, M.E.; Zhang, H.; Kiefhaber, E.; Muehling, G.; Rome, M.; Tommasi, J.; Delpech, M.; Cocuaud, N.; Picard, E.; Conti, A.; Salvatores, M.; Chawla, R.; Paratte, J.M.; Kasemeyer, U.; Akie, H.; Takano, H.; Lombardi, C.; Mazzola, A.; Matzke, H.; Babelot, J.F.; Conrad, R.; Vambenepe, G.; Meeldijk, J.D.; Woensdregt, C.F.

    1997-08-01

    The six papers in this report, which are presented during the title conference, deal with the following subjects: (1) Strategies for the transmutation of americium; (2) Transmutation of plutonium in pebble bed type high temperature reactors; (3) Benchmark comparisons of calculations of LWR fuel cells with uranium-free fuels; (4) Inert matrices, uranium-free plutonium fuels and americium targets. Synthesis of CAPRA ('Consommation Accrue de Plutonium dans les Rapides'), SPIN ('Separation et Incineration') and EFTTRA (Experimental Feasibility of Targets for Transmutation) studies; (5) Development of fuels for the transmutation in the frame of the EFTTRA European collaboration; and (6) On the use of spinel-based nuclear fuels for the transmutation of actinides. 16 figs., 23 tabs., 65 refs

  14. On possibility of transuranium element by the method of transport reactions

    International Nuclear Information System (INIS)

    Sinitsyna, G.S.; Krashenitsyn, G.N.; Shestakov, B.I.

    1983-01-01

    A possibility to use chemical transport reaction for separation of uranium, plutonium and some transplutonium elements is shown. The method is based on the use of the known plutonium property to form tetrachloride existing only in the gaseous phase in chlorine atmosphere, which is transported ever the temperature gradiept. Two ways of transport reaction realization - the method of flow and the method of diffusion in closed volume are tested. The experiments are made using specially synthesized plutonium dioxide, containing uranium, americium, curium, lanthanum, terbium, barium. Chlorination is realized by the mixture of chlorine and carbon tetrachloride at temperatures 723-953 K. Plutonium trichloride is deposited in the range 613-653 K, uranium - in the range 473-523 K, curium, americium, lanthanum, terbium, barium remain in the start zone if its temperature does not exceed 873 K

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

    Energy Technology Data Exchange (ETDEWEB)

    Marcalo, Joaquim; Gibson, John K.

    2009-08-10

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

  16. Radionuclide concentrations in honey bees from Area G at TA-54 during 1997. Progress report

    International Nuclear Information System (INIS)

    Haarmann, T.K.; Fresquez, P.R.

    1998-07-01

    Honey bees were collected from two colonies located at Los Alamos National Laboratory's Area G, Technical Area 54, and from one control (background) colony located near Jamez Springs, NM. Samples were analyzed for the following: cesium ( 137 Cs), americium ( 241 Am), plutonium ( 238 Pu and 239,240 Pu), tritium ( 3 H), total uranium, and gross gamma activity. Area G sample results from both colonies were higher than the upper (95%) level background concentration for 238 Pu and 3 H

  17. 2H Evaporator CP class instrumentation uncertainties evaluations

    International Nuclear Information System (INIS)

    Hwang, E.

    1994-01-01

    The Evaporator Pot Temperature Instrumentations and the Steam Condensate Gamma Monitors are two instrumentation systems in the 2H Evaporator facilities that are classified as the critical protection. The temperature high alarm and interlock circuit and the temperature recorder circuit of the pot temperature instrumentation loop are described. From the gamma monitor loop, the high gamma alarm and interlock circuit, failure alarm and interlock circuit, cesium activity recorder circuit, and americium activity recorder circuit are described

  18. 2H Evaporator CP class instrumentation uncertainties evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, E.

    1994-02-10

    The Evaporator Pot Temperature Instrumentations and the Steam Condensate Gamma Monitors are two instrumentation systems in the 2H Evaporator facilities that are classified as the critical protection. The temperature high alarm and interlock circuit and the temperature recorder circuit of the pot temperature instrumentation loop are described. From the gamma monitor loop, the high gamma alarm and interlock circuit, failure alarm and interlock circuit, cesium activity recorder circuit, and americium activity recorder circuit are described. (GHH)

  19. Characterisation of contaminaiton in Maralinga and Emu soils

    International Nuclear Information System (INIS)

    Williams, G.A.; Wilks, M.J.; Burns, P.A.; Cooper, M.B.

    1990-01-01

    A range of Maralinga and Emu soils have been characterised by means of sieving and microparticle classification, yielding mass and activity distribution of plutonium and americium with respect to size. The activity distribution is quite different from the mass distribution and much more variable from sample to sample. While the 241 Am activities >0.1 Bq, extends at least 100 km from the firing sites at Taranaki. 19 refs., 17 tabs., 4 figs

  20. State-of-art technology of fuels for burning minor actinides. An OECD/NEA study

    International Nuclear Information System (INIS)

    Ogawa, Toru; Konings, R.J.M.; Pillon, S.; Schram, R.P.C.; Verwerft, M.; Wallenius, J.

    2005-01-01

    At OECD/NEA, Working Party on Scientific Issues in Partitioning and Transmutation was formed for 2000-2004, which studied the status and trends of scientific issues in Partitioning and Transmutation (P and T). The study included the scientific and technical issues of fuels and materials, which are related to dedicated systems for transmutation. This paper summarizes the state-of-art technology of the fuels for burning minor actinides (neptunium, americium and curium). (author)

  1. Evaluation of the neutral comet assay for detection of alpha-particle induced DNA-double-strand-breaks

    International Nuclear Information System (INIS)

    Hofbauer, Daniela

    2010-01-01

    Aim of this study was to differentiate DNA-double-strand-breaks from DNA-single-strand-breaks on a single cell level, using the comet assay after α- and γ-irradiation. Americium-241 was used as a alpha-irradiation-source, Caesium-137 was used for γ-irradiation. Because of technical problems with both the neutral and alkaline comet assay after irradiation of gastric cancer cells and human lymphocytes, no definite differentiation of DNA-damage was possible.

  2. Bibliography of PNL publications in management of radioactive wastes, subject-indexed (alphabetically) and listed chronologically (latest issues first)

    International Nuclear Information System (INIS)

    Powell, J.A.

    1976-07-01

    The citations are arranged under: actinides, alpha particles, americium, beta particles, calcination, cements, ceramics, cesium, containers, decontamination, evaporation, fluidized bed, glass, ground release, high-level wastes, incinerators, liquid wastes, marine disposal, melting, nonradioactive waste disposal, Pu, radiation doses, radiation protection, disposal, processing, radionuclide migration, Ru, safety, separation processes, soils, solidification, solid wastes, stack disposal, temperature, thermal conductivity, transmutation, tritium, underground disposal, U, volatility, and waste disposal/management/processing/storage/transportation

  3. Nuclear densimeter of soil simulated in MCNP-4C code

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Mario R.M.S.S.; Penna, Rodrigo; Vasconcelos, Danilo C.; Pereira, Claubia; Guerra, Bruno T., E-mail: mario@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Silva, Clemente J.G.C., E-mail: clementecarneito@yahoo.com.b [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas

    2009-07-01

    The Monte Carlo code (MCNPX) was used to simulate a nuclear densimeter for measuring soil density. An Americium source (E = 60 keV) and a NaI (Tl) detector were placed on soil surface. Results from MCNP shown that scattered photon fluxes may be used to determining soil density. Linear regressions between scattered photons fluxes and soil density were calculated and shown correlation coefficients near unity. (author)

  4. Waste management of actinide contaminated soil

    International Nuclear Information System (INIS)

    Navratil, J.D.; Thompson, G.H.; Kochen, R.L.

    1978-01-01

    Waste management processes have been developed to reduce the volume of Rocky Flats soil contaminated with plutonium and americium and to prepare the contaminated fraction for terminal storage. The primary process consists of wet-screening. The secondary process uses attrition scrubbing and wet screening with additives. The tertiary process involves volume reduction of the contaminated fraction by calcination, or fixation by conversion to glass. The results of laboratory scale testing of the processes are described

  5. Development of a Temperature Compensation Method for the Radiation Detector of a Radiation Monitoring System

    International Nuclear Information System (INIS)

    Park, Ki Sun; Jeong, Jae Jun

    2014-01-01

    Americium, which has been used to date for the assessment of integrity and efficiency of the radiation detector, was replaced by an LED to resolve these problems. However, while americium is negligibly affected by the temperature and the surrounding environment, the LED is significantly affected by the temperature. Accordingly, a method to resolve this issue is needed. In this study, a temperature-compensated preamplifier was developed, where the reference luminous output of the LED affecting on temperatures is constantly maintained to be uniform by controlling the current and the PMT gain difference is compensated by controlling the high voltage from a comparison of the input and output pulse values. After setting up the experimental apparatus, the validity of the preamplifier was verified through radiation measurement experiments where the temperature was varied from 10 .deg. C to 60 .deg. C. The output signals of the scintillation detector of the RMS are intricately related to the temperature. In particular, the output signal value is greatly affected by the thermal equilibrium in the process of converting electro-magnetic energy to light energy and back to electrical energy. To compensate for these temperature characteristics, the americium standard source is used, since it is not affected by temperature, or a temperature compensation method using an LED optical-pulse as a reference value is used. In this study, instead of the americium standard source, an LED and a temperature detector were used to develop a temperature compensation device for the PMT amplification factor. To verify the validity of the developed method, a reference temperature of 25 .deg. C and a reference current of a 60μA LED optical-pulse were used to experimentally measure the radiation while varying the temperature from 10 .deg. C to 60 .deg. C using a Cs-137 standard source. The experiment results showed that the measurement error is reduced by approximately 83.3 % by using the

  6. Research in radiobiology. Annual report of work in progress in the internal irradiation program

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-31

    The toxicity, retention, biological effects, distribution, decorporation and measuring techniques of radionuclides are discussed. Calculations of trabecular bone formation rates from tetracycline labeling is included. The characteristics of trabecular bone in the Rhesus monkey are discussed. Studies on the early retention and distribution of radium 224 in beagles are included. Studies on the decorporation of plutonium and americium in dogs by DTPA and salicylic acid are presented.

  7. Simulating measures of wood density through the surface by Compton scattering

    International Nuclear Information System (INIS)

    Penna, Rodrigo; Oliveira, Arno H.; Braga, Mario R.M.S.S.; Vasconcelos, Danilo C.; Carneiro, Clemente J.G.; Penna, Ariane G.C.

    2009-01-01

    Monte Carlo code (MCNP-4C) was used to simulate a nuclear densimeter for measuring wood densities nondestructively. An Americium source (E = 60 keV) and a NaI (Tl) detector were placed on a wood block surface. Results from MCNP shown that scattered photon fluxes may be used to determining wood densities. Linear regressions between scattered photons fluxes and wood density were calculated and shown correlation coefficients near unity. (author)

  8. Recent solvent extraction experience at Savannah River

    International Nuclear Information System (INIS)

    Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

    1986-01-01

    Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

  9. Separation of Californium from other Actinides

    Science.gov (United States)

    Mailen, J C; Ferris, L M

    1973-09-25

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

  10. Determination of actinides in urine and fecal samples

    Science.gov (United States)

    McKibbin, Terry T.

    1993-01-01

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

  11. Electronic structure of Pu-Ce(-Ga) and Pu-Am(-Ga) alloys, stabilized in the {delta} phase; Structure electronique d'alliages Pu-Ce(-Ga) et Pu-Am(-Ga) stabilises en phase {delta}

    Energy Technology Data Exchange (ETDEWEB)

    Dormeval, M

    2001-09-01

    The behaviour of {delta}-plutonium, stable between 319 and 451 deg C, exhibits numerous singularities which are still a mystery for both physicists and metallurgists. This is due to its complex electronic structure, and in particular to the 5f electrons, which are at the edge between localization and delocalization. The stability domain of the {delta} phase can be extended down to room temperature by alloying with so called 'deltagen atoms' such as gallium (Ga), aluminum (A1), cerium (Ce) or americium (Am). The present work deals, one the one hand, with the influence of cerium and americium solutes regarding the localization of the 5f electrons of {delta}-plutonium, in binary Pu-Ce and Pu-Am alloys. On the other hand, the effect of two different deltagen solutes, simultaneously present, on the stability of the {delta} phase has been studied in ternary Pu-Am-Ga and Pu-Ce-Ga alloys. The electronic structure being strongly related to the crystalline organization, characterization methods such as X-Ray diffraction and EXAFS measurements were used together with electrical resistivity and magnetic susceptibility experiments. These showed that the roles of cerium and americium, supposed to be similar at the beginning of this investigation, are actually very different. Moreover, the additive effect of cerium and gallium, and, americium and gallium, has been demonstrated. Studying plutonium alloys, which are radioactive, also means following their evolution in time. The characteristics of the alloys have then been followed which allowed to detect, in Pu-Ce(-Ga) alloys, a destabilization of the {delta} phase and, to observe, in Pu-Am(-Ga) alloys, the influence of self-irradiation defects on the magnetic response. (author)

  12. 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

  13. Determination of formal potential of Amsup((4))/Amsup((3)) pair in phosphoric-acid solutions

    International Nuclear Information System (INIS)

    Mikhajlov, V.M.; Myasoedov, B.F.

    1977-01-01

    Values of formal potentials of the system Amsup((4))/Amsup((3)) in 12 and 15 M phosphoric acid at 20+-2 deg C are determined by potentiometric method. The effect is studied of metallic platinum on the process of self-reduction of tetravalent americium, and the optimum conditions are found for potentiostatic oxidation of Amsup((3)) to Amsup((4)) in 12 M phosphoric acid

  14. Gas-Phase Energetics of Actinide Oxides: An Assessment of Neutral and Cationic Monoxides and Dioxides from Thorium to Curium

    Science.gov (United States)

    Marçalo, Joaquim; Gibson, John K.

    2009-09-01

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

  15. Reevaluation of the average prompt neutron emission multiplicity (nubar) values from fission of uranium and transuranium nuclides

    International Nuclear Information System (INIS)

    Holden, N.E.; Zucker, M.S.

    1984-01-01

    In response to a need of the safeguards community, we have begun an evaluation effort to upgrade the recommended values of the prompt neutron emission multiplicity distribution, P/sub nu/ and its average value, nubar. This paper will report on progress achieved thus far. The evaluation of the uranium, plutonium, americium and curium nuclide's nubar values will be presented. The recommended values will be given and discussed. 61 references

  16. Radioisotopes of the U, Th, Pu, Am in the mushrooms

    International Nuclear Information System (INIS)

    Galanda, D.; Matel, L.

    2002-01-01

    The radioactive plutonium, uranium, thorium and americium were assayed in the dried mushrooms collected in areas of East and West Slovakia in 1998 -2000, and examined the effectiveness of this mushroom as a possible indicator of radioactive contamination of environment due to nuclear contamination of biosphere. The mushrooms were dried and prepared by liquid extraction with Aliquat 336. The samples were measured by α-barrier spectrometry. (author)

  17. Extractant Design by Covalency

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olson, Angela Christine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kozimor, Stosh Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cross, Justin Neil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Batista, Enrique Ricardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Macor, Joe [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Illinois, Urbana-Champaign, IL (United States); Peterman, Dean R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Grimes, Travis [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-21

    This project aims to provide an electronic structure-to-function understanding of extractants for actinide selective separation processes. The research entails a multi-disciplinary approach that integrates chemical syntheses, structural determination, K-edge X-ray Absorption Spectroscopy (XAS), and Density Functional Theory (DFT) calculations. In FY15, the project reached the final stage of testing the extraction performance of a new ligand design and preparing an americium-extractant complex for analysis.

  18. Applicability of microautoradiography to sorption studies

    International Nuclear Information System (INIS)

    Thompson, J.L.; Wolfsberg, K.

    1979-01-01

    The technique of microautoradiography was applied to the study of the sorption of uranium and americium on five rock types which exist at the Nevada Test Site. It was found that autoradiograms could be prepared in a few days which would allow the specific minerals responsible for sorption to be identified. Furthermore, the state of aggregation of the sorbed species was clearly indicated. It was concluded that microautoradiography was a useful adjunct to currently used methods for studying sorption of certain radionuclides

  19. Analytical evaluation of actinide sensitivities

    International Nuclear Information System (INIS)

    Sola, A.

    1977-01-01

    The analytical evaluation of the sensitivities of actinides to various parameters such as cross sections, decay constants, flux and time is presented. The formulae are applied to isotopes of the Uranium, Neptunium, Plutonium and Americium series. The agreement between analytically obtained and computer evaluated sensitivities being always good, it is throught that the formulation includes all the important parameters entering in the evaluation of sensitivities. A study of the published data is made

  20. Online high sensitivity measurement system for transuranic aerosols

    International Nuclear Information System (INIS)

    Kordas, J.F.; Phelps, P.L.

    1976-01-01

    A measurement system for transuranic aerosols has been designed that will be able to withstand the corrosive nature of stack effluents and yet have extremely high sensitivity. It will be capable of measuring 1 maximum permissible concentration (MPC) of plutonium or americium in 30 minutes with a fractional standard deviation of less than 0.33. Background resulting from 218 Po is eliminated by alpha energy discrimination and a decay scheme analysis. A microprocessor controls all data acquisition, data reduction, and instrument calibration

  1. Radioecology

    International Nuclear Information System (INIS)

    Kienzl, K.; Kralik, M.; Bossew, P.

    2001-01-01

    This chapter of the environmental control report deals with the radioactivity measurement and monitoring in Austria. The geographical distribution and the depth distribution of the cesium, plutonium and americium isotope content of the soil is given. The radionuclide migration in soil, hydrosphere, forests and the whole ecosystem is studied. The tritium content in atmospheric precipitation is monitored. The European map of cesium-137 deposition of the year 1996 and the actual positions of nuclear power stations around Austria is given. (a.n.)

  2. The uptake of radionuclides by plants

    International Nuclear Information System (INIS)

    Cawse, P.A.; Turner, G.S.

    1982-02-01

    A review of the literature, since 1970, on the research into the uptake of radionuclides by plants, with references to earlier soil and plant studies on the fate of nuclear weapons fallout. Experimental data on the uptake of plutonium isotopes, americium 241, cesium 137, radium 226, curium 244 and neptunium 237 and details of the chemical form of the radionuclide, soil type and plant growth period are tabulated. (U.K.)

  3. Evaluation of the neutral comet assay for detection of alpha-particle induced DNA-double-strand-breaks; Evaluation des Comet Assays bei neutralem pH zur Detektion von α-Partikel induzierten DNA-Doppelstrangbruechen

    Energy Technology Data Exchange (ETDEWEB)

    Hofbauer, Daniela

    2010-10-20

    Aim of this study was to differentiate DNA-double-strand-breaks from DNA-single-strand-breaks on a single cell level, using the comet assay after α- and γ-irradiation. Americium-241 was used as a alpha-irradiation-source, Caesium-137 was used for γ-irradiation. Because of technical problems with both the neutral and alkaline comet assay after irradiation of gastric cancer cells and human lymphocytes, no definite differentiation of DNA-damage was possible.

  4. Size dispersion and colloid mediated radionuclide transport in a synthetic porous media.

    Science.gov (United States)

    Delos, A; Walther, C; Schäfer, T; Büchner, S

    2008-08-01

    Size dispersion effects during the migration of natural submicron bentonite colloids (model predictions and earlier findings with carboxylated polystyrene spheres. By addition of trace amounts of americium(III) and plutonium(IV), colloid mediated transport of these radionuclides is studied. The peak arrival times of Pu-244 and Am-241, as measured by ICP-MS, match the bentonite colloid breakthrough and occur significantly prior to the conservative tracer (HTO) indicating the colloid-borne migration of tri- and tetravalent radionuclides.

  5. Nuclear densimeter of soil simulated in MCNP-4C code

    International Nuclear Information System (INIS)

    Braga, Mario R.M.S.S.; Penna, Rodrigo; Vasconcelos, Danilo C.; Pereira, Claubia; Guerra, Bruno T.; Silva, Clemente J.G.C.

    2009-01-01

    The Monte Carlo code (MCNPX) was used to simulate a nuclear densimeter for measuring soil density. An Americium source (E = 60 keV) and a NaI (Tl) detector were placed on soil surface. Results from MCNP shown that scattered photon fluxes may be used to determining soil density. Linear regressions between scattered photons fluxes and soil density were calculated and shown correlation coefficients near unity. (author)

  6. Isotopic distributions, element ratios, and element mass fractions from enrichment-meter-type gamma-ray measurements of MOX

    International Nuclear Information System (INIS)

    Close, D.A.; Parker, J.L.; Haycock, D.L.; Dragnev, T.

    1991-01-01

    The gamma-ray spectra from ''infinitely'' thick mixed oxide samples have been measured. The plutonium isotopics, the U/Pu ratio, the high-Z mass fractions (assuming only plutonium, uranium, and americium), and the low-Z mass fraction (assuming the matrix is only oxygen) can be determined by carefully analyzing the data. The results agree well with the chemical determination of these parameters. 8 refs., 3 figs., 3 tabs

  7. An investigation of the characteristics of humic acid and of its effects on the chemistry of the near field of a radioactive waste repository

    International Nuclear Information System (INIS)

    Bates, C.I.; Bayliss, S.; Gardiner, M.P.; Hobley, J.; Smith, A.J.; Williams, S.J.

    1993-01-01

    The work described in this report attempts to assess the possible effects of humic substances in the near field of a radioactive waste repository. Two samples of humic acid were studied by analytical ultracentrifugation. It was found to be an advantage to reduce sample polydispersity before carrying out molecular weight determinations. Ultrafiltration experiments showed that calcium concentrations of greater than 10 -3 M were sufficient to cause precipitation of humic acid. Boom clay extracts in sodium hydroxide solution were able to maintain high concentrations of americium in the aqueous phase. Extracts of Boom clay in cement-equilibrated water showed less ability to increase americium concentrations. The sorption of americium on BFS/OPC was studied. Distribution ratios of 600 ml g -1 in the absence of humic acid and 500 ml g -1 in its presence were obtained. Size distribution studies on americium showed that humic acid had little effect on the concentration of the radioelement in solutions passed through filters with up to 2 μm pore size. However, size distribution studies on plutonium revealed that more plutonium was associated with each filtered fraction in the experiments which contained Boom clay extract than in those which used cement-equilibrated water. Measurements of the sorption of neptunium on cements showed that this radioelement was strongly sorbed onto both 9:1 BFS/OPC and the Nirex reference backfill. The presence of humic acid extracted from Boom clay did not cause any discernible decrease in the sorption of this radioelement on cement. Thermodynamic calculations, using a simple model, illustrate the important role which calcium could play in controlling the concentrations of actinide humates in the near-field porewater. 31 refs., 19 figs., 12 tabs

  8. An investigation of the characteristics of humic acid and of its effects on the chemistry of the near field of a radioactive waste repository

    International Nuclear Information System (INIS)

    Bates, C.I.; Bayliss, S.; Gardiner, M.P.; Hobley, J.; Smith, A.J.; Williams, S.J.

    1992-07-01

    The work described in this report attempts to assess the possible effects of humic substances in the near field of a radioactive waste repository. Two samples of humic acid were studied by analytical ultracentrifugation. It was found to be an advantage to reduce sample polydispersity before carrying out molecular weight determinations. Ultrafiltration experiments showed that calcium concentrations of greater than 10 -3 M were sufficient to cause precipitation of humic acid. Boom clay extracts in sodium hydroxide solution were able to maintain high concentrations of americium in the aqueous phase. Extracts of Boom clay in cement-equilibrated water showed less ability to increase americium concentrations. The sorption of americium on BFS/OPC was studied. Distribution ratios of 600 ml g -1 in the absence of humic acid and 500 ml g -1 in its presence were obtained. Size distribution studies on americium showed that humic acid had little effect on the concentration of the radioelement in solutions passed through filters with up to 2 μm pore size. However, size distribution studies on plutonium revealed that more plutonium was associated with each filtered fraction in the experiments which contained Boom clay extract than in those which used cement-equilibrated water. Measurements of the sorption of neptunium on cements showed that this radioelement was strongly sorbed onto both 9:1 BFS/OPC and the Nirex reference backfill. The presence of humic acid extracted from Boom clay did not cause any discernible decrease in the sorption of this radioelement on cement. Thermodynamic calculations, using a simple model, illustrate the important role which calcium could play in controlling the concentrations of actinide humates in the near-field porewater. (author)

  9. Neutron-Activated Gamma-Emission: Technology Review

    Science.gov (United States)

    2012-01-01

    complex in implementation. The lower energy neutrons from californium - 252 (0.7–4 MeV) and deuterium-on-deuterium (D-D) electronic neutron generators (ENG...for production of californium is centered at Oak Ridge National Laboratory (ORNL) high-flux- reactor (HIFR). Californium is used to start up new power...achievable Am americium API associated particle imaging B boron Be beryllium BNCT boron neutron capture therapy C carbon Cf californium Cl

  10. Determination of plutoniumn and transplutonium elements in the environment

    International Nuclear Information System (INIS)

    Willemot, J.M.; Verry, M.; Jeanmaire, L.

    1988-01-01

    Environmental samples made of many different stable elements and natural emitting radionuclides must undergo chemical analysis allowing to prepare quality sources. Plutonium and americium sources with a good resolution can be obtained from environmental samples by successive operations of co-precipitation ion-exchange separation and solvent extraction. Spectral analysis is then simple and consequently plutonium and transplutonium elements are determined easily in such samples. 15 refs [fr

  11. Extraction of Plutonium From Spiked INEEL Soil Samples Using the Ligand-Assisted Supercritical Fluid Extraction (LA-SFE) Technique

    International Nuclear Information System (INIS)

    Fox, R.V.; Mincher, B.J.; Holmes, R.G.G.

    1999-01-01

    In order to investigate the effectiveness of ligand-assisted supercritical fluid extraction for the removal of transuranic contaminations from soils an Idaho National Engineering and Environmental Laboratory (INEEL) silty-clay soil sample was obtained from near the Radioactive Waste Management Complex area and subjected to three different chemical preparations before being spiked with plutonium. The spiked INEEL soil samples were subjected to a sequential aqueous extraction procedure to determine radionuclide portioning in each sample. Results from those extractions demonstrate that plutonium consistently partitioned into the residual fraction across all three INEEL soil preparations whereas americium partitioned 73% into the iron/manganese fraction for soil preparation A, with the balance partitioning into the residual fraction. Plutonium and americium were extracted from the INEEL soil samples using a ligand-assisted supercritical fluid extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction efficiencies ranging from 14% to 19%. After a second round wherein the initial extraction parameters were changed, the plutonium extraction efficiencies increased to 60% and as high as 80% with the americium level in the post-extracted soil samples dropping near to the detection limits. The third round of experiments are currently underway. These results demonstrate that the ligand-assisted supercritical fluid extraction technique can effectively extract plutonium from the spiked INEEL soil preparations

  12. Routine radiochemical method for the determination of 90Sr, 238Pu, 239+240Pu, 241Am and 244Cm in environmental samples

    International Nuclear Information System (INIS)

    Ageyev, V.A.; Sajeniouk, A.D.

    2005-01-01

    Routine analytical procedures have been developed for the reliable simultaneous determination of 90 Sr, 238 Pu, 239+240 Pu, 241 Am and 242-244 Cm, Chernobyl derived radioisotopes and fallout after nuclear weapon tests in a wide range of environmental samples: soil (100-200 g), sediments, aerosols, water and vegetation. This procedure has been applied to thousands of soil and sediment samples and hundreds of biological and water samples taken in the exclusive zone of Chernobyl NPP and different regions of Ukraine from 1989 to the present. After the sample has been properly prepared and isotopic tracers added, plutonium, americium and curium are precipitated with calcium oxalate and then lanthanum fluoride. Plutonium is separated from americium and curium by anion-exchange. Americium and curium are separated from rare earths by cation-exchange with gradient elute α-hydroxy-iso-butyric acid. During projects by AQCS IAEA 'Evaluation of Methods for 90 Sr in a Mineral Matrix' and 'Proficiency Test for 239 Pu, 241 Pu and 241 Am Measurement in a Mineral Matrix' accuracy and precision for 90 Sr, 239 Pu and 241 Am by present procedure was evaluated. Advantages, difficulties and limitations of the method are discussed. (author)

  13. Accumulation of {sup 241}Am by suspended matter, diatoms and aquatic weeds of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A., E-mail: t_zotina@ibp.r [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Bolsunovsky, A.Ya.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk 660036 (Russian Federation)

    2010-02-15

    In this work we experimentally estimated the capacities of the key components of the Yenisei River (Russia): particulate suspended matter (seston), diatom microalgae, and submerged macrophytes for accumulating {sup 241}Am from water. In our experiments large particles of seston (>8 mum), comparable in size with diatoms, took up most of americium from water. The accumulation of americium by isolated diatom algae (Asterionella formosa and Diatoma vulgare) was lower than by total seston. The concentration factors (CFs) of {sup 241}Am for seston of the Yenisei River in our experiments were (2.8-6.9).10{sup 5}; for diatoms - (1.5-4.2).10{sup 4}. The CFs for aquatic plant Elodea canadensis were within the same order of magnitude as those for diatoms. Activity concentration and CFs of {sup 241}Am were nearly the same in experiments under dark and light conditions. This is indicative of an energy independent mechanism of americium uptake from the water by diatoms and submerged macrophytes.

  14. Theoretical and experimental evaluation of waste transport in selected rocks: 1977 annual report of LBL Contract No. 45901AK. Waste Isolation Safety Assessment Program: collection and generation of transport data

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.A.; Benson, L.V.; Lucas, J.; Mathur, A.K.; Tsao, L.

    1977-09-01

    During fiscal year 1977, the following subtasks were performed. (1) Thermodynamic data were tabulated for those aqueous complexes and solid phases of plutonium, neptunium, americium, and curium likely to form in the environment. (2) Eh-pH diagrams were computed and drafted for plutonium, neptunium, americium and curium at 25/sup 0/C and one atmosphere. (3) The literature on distribution coefficients of plutonium, neptunium, americium, and curium was reviewed. (4) Preliminary considerations were determined for an experimental method of measuring radionuclide transport in water-saturated rocks. (5) The transport mechanisms of radionuclides in water-saturated rocks were reviewed. (6) A computer simulation was attempted of mass transfer involving actinides in water-saturated rocks. Progress in these tasks is reported. Subtasks 1, 2, 3, and 4 are complete. The progress made in subtask 5 is represented by an initial theoretical survey to define the conditions needed to characterize the transport of radionuclides in rocks. Subtask 6 has begun but is not complete.

  15. Actinide recovery from combustible waste: the Ce(IV)-NHO3 system. Final report

    International Nuclear Information System (INIS)

    Thompson, G.H.; Childs, E.L.; Kochen, R.L.; Schmunk, R.H.; Smith, C.M.

    1979-01-01

    Actinides in ash can be leached effectively by refluxing with Ce(IV) in HNO 3 ; solubilization of actinide in ash was greater than or equal to 95% at ash concentrations to 30 g/l in stirred leachant. Plutonium and americium were the actinides present in the ash. Solubilized plutonium and americium were recovered from Ce(IV)-HNO 3 solution by solvent extraction. Extraction of plutonium into 30% tributyl phosphate in n-dodecane gave 99.99% recovery. The plutonium-depleted solution was then extracted with 30% dihexyl-N,N-diethylcarbamolylmethylenephosphonate (DHDECMP). Americium recovery was 99.64%. The Ce(IV)-HNO 3 system was compared with the HF-HNO 3 system now in common use. Advantages of the former included less equipment corrosion, no volatilization of silica, safe oxidation of carbon residues, minimal secondary waste (Ce is recycled), and better solubilization of actinide in the initial contact. However, additional contacts do not significantly improve solubilization, and a small fraction of actinide is not solubilized with Ce(IV)-HNO 3 that can be solubilized by HF-HNO 3 . The effect of the fission product ruthenium on the dissolution of actinides in the Ce(IV)-HNO 3 system was investigated briefly, and a method for removing the ruthenium electrolytically was developed. Several process flowsheets were also considered. Actinide recovery requirements will suggest which of these might best be used. 6 figures, 7 tables

  16. Development of ultrafiltration and adsorbents: October 1978--March 1979

    International Nuclear Information System (INIS)

    Herald, W.R.; Roberts, R.C.

    1979-01-01

    Studies were conducted to determine the feasibility of using a bone char adsorption column or a reverse osmosis (RO) unit as a treatment secondary to ultrafiltration for Mound aqueous waste. Results showed RO to be much more effective than bone char as a secondary treatment. Tests were performed to determine whether RO would also remove americium-241 from a waste stream. (Plutonium was removed in previous tests.) The results of these tests showed nearly complete removal of americium-241. Data collected from almost 2 yr of operation show that the M-type ultrafiltration membranes are more suitable than D membranes for use in a full-scale system. A literature search is being conducted to find adsorbents for the removal of fission products from waste streams. Adsorbers for cesium have been identified and testing to determine their effectiveness has started. The literature identified by computer search for iodine and cobalt adsorbers is now being studied. Engineering column decontamination factors for americium-241 removal from waste streams with pH of 3, 7, and 10 were determined. A cross reference of adsorbents was compiled in a series of tables so that data from waste treatment reports can be compared

  17. Actinide recovery from combustible waste: the Ce(IV)-NHO/sub 3/ system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, G. H.; Childs, E. L.; Kochen, R. L.; Schmunk, R. H.; Smith, C. M.

    1979-09-14

    Actinides in ash can be leached effectively by refluxing with Ce(IV) in HNO/sub 3/; solubilization of actinide in ash was greater than or equal to 95% at ash concentrations to 30 g/l in stirred leachant. Plutonium and americium were the actinides present in the ash. Solubilized plutonium and americium were recovered from Ce(IV)-HNO/sub 3/ solution by solvent extraction. Extraction of plutonium into 30% tributyl phosphate in n-dodecane gave 99.99% recovery. The plutonium-depleted solution was then extracted with 30% dihexyl-N,N-diethylcarbamolylmethylenephosphonate (DHDECMP). Americium recovery was 99.64%. The Ce(IV)-HNO/sub 3/ system was compared with the HF-HNO/sub 3/ system now in common use. Advantages of the former included less equipment corrosion, no volatilization of silica, safe oxidation of carbon residues, minimal secondary waste (Ce is recycled), and better solubilization of actinide in the initial contact. However, additional contacts do not significantly improve solubilization, and a small fraction of actinide is not solubilized with Ce(IV)-HNO/sub 3/ that can be solubilized by HF-HNO/sub 3/. The effect of the fission product ruthenium on the dissolution of actinides in the Ce(IV)-HNO/sub 3/ system was investigated briefly, and a method for removing the ruthenium electrolytically was developed. Several process flowsheets were also considered. Actinide recovery requirements will suggest which of these might best be used. 6 figures, 7 tables.

  18. Review of iron oxides for water treatment

    International Nuclear Information System (INIS)

    Navratil, J. D.

    2001-01-01

    Many processes have utilized iron oxides for the treatment of liquid wastes containing radioactive and hazardous metals. These processes have included adsorption, precipitation and other chemical and physical techniques. For example, a radioactive wastewater precipitation process includes addition of a ferric hydroxide floc to scavenge radioactive contaminants, such as americium, plutonium and uranium. Some adsorption processes for wastewater treatment have utilized ferrites and a variety of iron containing minerals. Various ferrites and natural magnetite were used in batch modes for actinide and heavy metal removal from wastewater. Supported magnetite was also used in a column mode, and in the presence of an external magnetic field, enhanced capacity was found for removal of plutonium and americium from wastewater. These observations were explained by a nano-level high gradient magnetic separation effect, as americium, plutonium and other hydrolytic metals are known to form colloidal particles at elevated pHs. Recent modeling work supports this assumption and shows that the smaller the magnetite particle the larger the induced magnetic field around the particle from the external field. Other recent studies have demonstrated the magnetic enhanced removal of arsenic, cobalt and iron from simulated groundwater. (author)

  19. Localization in f-shell metals

    International Nuclear Information System (INIS)

    Harrison, W.A.

    1984-01-01

    Anderson's theory of local moments is applied to the f-shell metals with the use of parameters for the electronic structure given earlier. A criterion for localization (abrupt in this theory) of Z/sub f/ levels per atom is that the resonance width be less than 2U sin 2 (πZ/sub f//14), with U the intra-atomic repulsion associated with s-f transfer. Americium and the heavier actinides satisfy this criterion, as do all the rare earths except cerium; plutonium is borderline. The traditional term ''localized state'' is used here though ''correlated state'' would be more appropriate. For the cases considered the localized states are found to have net spin (or moment) but that is not a necessary condition. They are found to contribute to the f-band pressure on the crystal, but reduced by a factor of about W/sub f//3U, equal to 0.09 for americium, where W/sub f/ is the itinerant f-band width. The localized f levels may themselves be thought to form bands, but with reduced width, and they may even have Fermi surface, though that was not found for the systems considered. A comparison of this state with band ferromagnetism is made. An approximate calculation of the total energy of the localized and delocalized states as a function of volume correctly predicted the large volume and localization for americium

  20. Fetoplacental transfer of plutonium and the effects on fetal hematopoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Yoshihisa; Takahashi, Sentaro [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    Investigations into links between childhood leukemias and radionuclide exposure in the vicinity of nuclear sites in the UK have focused attention on the need for fetal dosimetric models and risk estimation of embryo/fetus contaminated with radionuclides such as isotopes of plutonium and americium. Thereafter, extensive studies have been performed to elucidate in detail the fetoplacental transfer and distribution of plutonium and americium and their effects, particularly on fetal hematopoietic tissues. Some of these studies showed that maternal contamination with plutonium or americium at the early or mid-term gestation resulted in hematopoietic damage to the fetal liver or bone marrow of offspring. We demonstrated the effect of {sup 239}Pu administered on day 4 of gestation on the number of CFU-S (spleen-colony forming units) in the fetal liver on day 17 of gestation was markedly different between C3H and BDF1 mice. There were no significant differences in the distribution and concentration of {sup 239}Pu between the fetoplacental units of these two strains, suggesting a strain difference in the effect of {sup 239}Pu {alpha}-irradiation on the development of the fetal hematopoietic systems in the mouse. (author)

  1. Radioecological zoning of territories of carrying out of underground nuclear explosions in conditions of Yakutia

    International Nuclear Information System (INIS)

    Yakovleva, V.D.; Stepanov, V.E.

    2005-01-01

    Full text: In territory of Yakutia on period 1974 - 1987 years in the industrial purposes 12 peace underground nuclear explosions (UNE) have been made seven from which is carried out on Average-Botuobinsk a deposit with the purpose of an intensification of an oil recovery and inflow of gas (a chink No. 42, 43, 47, 66, 61, 68) and one (No. 101) - for creation of underground capacity - storehouses of the oil, four explosions - for seismic sounding an earth's crust ('Kimberlit', 'Horizon - 4', 'Kraton-4', 'Kraton-3'), and one 'Crystal' - for creation of a dam by loosening of breeds. From them 'Crystal' and 'Kraton-3' are emergency where the dead woods forming impact zones were formed. Impact zones are the sites dated for places with attributes of changes of an environment from influence of radiation. Differently, impact zone can be characterized as a zone of shock influence of the radiating factor on an environment allocated on the basis of seen damages of a vegetative cover. On Average-Botuobinsk 'air-blast cleaning' a deposit are available local radioactive a stain, formed (educated) at 'air-blast cleaning' chinks 42, 43, 47, 68 after end of chisel works and opening potted component which is taking place under the cement bridge. As a result of it has taken place teknogen change of a radiating background as a local stain the area approximately from 4 up to 25 m 2 , adjoining to mouth blowing lines (in approximately 100 m from a mouth of chinks). As a result of radioecological researches on vicinities of objects UNE conclusions which further can be a basis of the concept are received. 1. radioactive pollution of objects UNE have spotty character, are found out: on emergency UNE - a) cesium - 137, americium - 241, cobalt - 60; 6) cesium - 134, antimony - 125, europium - 155; a) objects kamuflet cesium - 137 and americium -241. 2. Definition impact zones on objects UNE is based on attributes- a) the vegetative cover is damaged; the level of a scale - background is

  2. Study on the contamination of transuranides in Pulmonata gastropoda collected in Palomares (Spain)

    International Nuclear Information System (INIS)

    Aragon, A.; Espinosa, A.; Anton, M.P.

    2006-01-01

    A study on the contamination levels and distribution of plutonium and americium in gastropods collected in Palomares (south-east Spain) was performed. This region is partially contaminated with actinides following the 1966 nuclear accident. The existence of plutonium and americium in gastropods (Helix albicans and Theba pisana), along with their great gastronomic interest in the area, reinforces the concern in studying the incorporation of these radioelements to a trophic level of the alimentary chain. In this work, plutonium concentration levels have been determined in the excrements, washing waters, flesh and shell of different types of gastropods collected in various sampling campaigns. Pretreatment of the snail samples for further transuranics analyses was based on culinary customs of the region. First, the gastropods had a biological rest, allowing the removal of the non-adsorbed or non-retained ingested material, and then the excrements were collected by washing the snails. Water with excrements was filtered using different filters and analyzed separately. Once rinsed, the snails were dipped into salty water to eliminate the slime, finally, after boiling, the soft tissue was separated from the shell. Plutonium and americium analyses have been carried out sequentially, following normalized procedures for the determination of these radionuclides. The results show the distribution of plutonium in washing and boiling water, excrements, soft tissues and shell of the snails. Autoradiographies performed to soft tissues made evident that the contamination was incorporated into the gastropods as radioactive particles. In addition, it has been estimated that the consumption of one kilogram of snails collected in the most contaminated area of Palomares could reach 1/3 of the effective dose (due to ingestion) to the inhabitants of the area. (author)

  3. Plutonium in the desert environment of the Nevada Test Site and the Tonopah Test Range

    International Nuclear Information System (INIS)

    Romney, E.M.; Essington, E.H.; Fowler, E.B.; Tamura, T.; Gilbert, R.O.

    1987-01-01

    Several safety shot tests were conducted in the desert environment of the Nevada Test Site and the Tonopah Test Range during the period 1955 to 1963. Follow-up studies were conducted in fallout areas resulting from these tests to investigate the distribution in soils and the availability to animals and plants of plutonium (and americium) after residence times of 10 to 20 years. Soil profile studies disclosed that more than 95% of the plutonium (and americium) dispersed as fallout to the environment had remained in the top 5 cm of soil in undisturbed areas. Significant amounts had been redistributed into blow-sand mounds formed underneath clumps of vegetation. That redistribution should be expected because the contaminant was associated primarily with the coarse silt and fine sand particle size fractions. Resuspension factors were calculated that varied from 9.1 x 10 -11 m -1 to 5.4 x 10 -9 m -1 with geometric mean and arithmetic averages of 2.9 x 10 -10 m -1 and 6.8 x 10 -10 m -1 , respectively; however, the plutonium essentially remained in place when the soil surface was left undisturbed. Vegetation in the fallout areas was contaminated primarily by resuspendable material deposited on the surface of plant foliage; plutonium concentration ratios ranged from 10 -3 to 10 0 . Carcass samples of small vertebrate animals collected from fallout areas contained only trace amounts of plutonium compared to the environmental exposure levels. Furthermore, only trace amounts of plutonium (and americium) were found in muscle and organ tissues of grazing cattle during a 3-year on-site residence experiment. 36 references, 4 figures

  4. Fabrication of uranium-based ceramics using internal gelation for the conversion of trivalent actinides; Herstellung uranbasierter Keramiken mittel interner Gelierung zur Konversion trivalenter Actinoiden

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Henrik

    2012-07-01

    Alternative to today's direct final waste disposal strategy of long-lived radionuclides, for example the minor actinides neptunium, americium, curium and californium, is their selective separation from the radioactive wastestream with subsequent transmutation by neutron irradiation. Hereby it is possible to obtain nuclides with a lower risk-potential concerning their radiotoxicity. 1 neutron irradiation can be carried out either with neutron sources or in the next generation of nuclear reactors. Before the treatment, the minor actinides need to be converted in a suitable chemical and physical form. Internal gelation offers a route through which amorphous gel-spheres can be obtained directly from a metal-salt solution. Due to the presence of different types of metal ions as well as changing pH-values in a stock solution, a complex hydrolysis behaviour of these elements before and during gelation occurs. Therefore, investigations with uranium and neodymium as a minor actinide surrogate were carried out. As a result of suitable gelation-parameters, uraniumneodymium gel-spheres were successfully synthesised. The spheres also stayed intact during the subsequent thermal treatment. Based upon these findings, uranium-plutonium and uranium-americium gels were successfully created. For theses systems, the determined parameters for the uraniumneodymium gelation could also be applied. Additionally, investigations to reduce the acidity of uranium-based stock solutions for internal gelation were carried out. The necessary amount of urea and hexamethylenetetramine to induce gelation could hereby be decreased. This lead to a general increase of the gel quality and made it possible to carry out uranium-americium gelation in the first place. To investigate the stability of urea and hexamethylenetetramine, solutions of these chemicals were irradiated with different radiation doses. These chemicals showed a high stability against radiolysis in aqueous solutions.

  5. Cleaning up the Legacy of the Cold War: Plutonium Oxides and the Role of Synchrotron Radiation Research

    Energy Technology Data Exchange (ETDEWEB)

    Clark, David Lewis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-21

    The deceptively simple binary formula of AnO2 belies an incredibly complex structural nature, and propensity to form mixed-valent, nonstoichiometric phases of composition AnO2±x. For plutonium, the very formation of PuO2+x has challenged a long-established dogma, and raised fundamental questions for long-term storage and environmental migration. This presentation covers two aspects of Los Alamos synchrotron radiation studies of plutonium oxides: (1) the structural chemistry of laboratory-prepared AnO2+x systems (An = U, Pu; 0 ≤ x ≤ 0.25) determined through a combination of x-ray absorption fine structure spectroscopy (XAFS) and x-ray scattering of laboratory prepared samples; and (2) the application of synchrotron radiation towards the decontamination and decommissioning of the Rocky Flats Environmental Technology Site. Making the case for particle transport mechanisms as the basis of plutonium and americium mobility, rather than aqueous sorption-desorption processes, established a successful scientific basis for the dominance of physical transport processes by wind and water. The scientific basis was successful because it was in agreement with general theory on insolubility of PuO2 in oxidation state IV, results of ultrafiltration analyses of field water/sediment samples, XAFS analyses of soil, sediment, and concrete samples, and was also in general agreement with on-site monitoring data. This understanding allowed Site contractors to rapidly move to application of soil erosion and sediment transport models as the means of predicting plutonium and americium transport, which led to design and application of site-wide soil erosion control technology to help control downstream concentrations of plutonium and americium in streamflow.

  6. New Developments in Actinides Burning with Symbiotic LWR-HTR-GCFR Fuel Cycles

    International Nuclear Information System (INIS)

    Bomboni, Eleonora

    2008-01-01

    The long-term radiotoxicity of the final waste is currently the main drawback of nuclear power production. Particularly, isotopes of Neptunium and Plutonium along with some long-lived fission products are dangerous for more than 100000 years. 96% of spent Light Water Reactor (LWR) fuel consists of actinides, hence it is able to produce a lot of energy by fission if recycled. Goals of Generation IV Initiative are reduction of long-term radiotoxicity of waste to be stored in geological repositories, a better exploitation of nuclear fuel resources and proliferation resistance. Actually, all these issues are intrinsically connected with each other. It is quite clear that these goals can be achieved only by combining different concepts of Gen. IV nuclear cores in a 'symbiotic' way. Light-Water Reactor - (Very) High Temperature Reactor ((V)HTR) - Fast Reactor (FR) symbiotic cycles have good capabilities from the viewpoints mentioned above. Particularly, HTR fuelled by Plutonium oxide is able to reach an ultra-high burn-up and to burn Neptunium and Plutonium effectively. In contrast, not negligible amounts of Americium and Curium build up in this core, although the total mass of Heavy Metals (HM) is reduced. Americium and Curium are characterised by an high radiological hazard as well. Nevertheless, at least Plutonium from HTR (rich in non-fissile nuclides) and, if appropriate, Americium can be used as fuel for Fast Reactors. If necessary, dedicated assemblies for Minor Actinides (MA) burning can be inserted in Fast Reactors cores. This presentation focuses on combining HTR and Gas Cooled Fast Reactor (GCFR) concepts, fuelled by spent LWR fuel and depleted uranium if need be, to obtain a net reduction of total mass and radiotoxicity of final waste. The intrinsic proliferation resistance of this cycle is highlighted as well. Additionally, some hints about possible Curium management strategies are supplied. Besides, a preliminary assessment of different chemical forms of

  7. Chemical equilibria in actinide carbonate systems

    International Nuclear Information System (INIS)

    Grenthe, I.; Robouch, P.; Vitorge, P.

    1986-01-01

    By spectrophotometric and potentiometric methods it is shown that trimers are formed in media of high ionic strength (3 M NaClO 4 ) and total concentrations of hexavalent actinides higher than 10 -3 M. The equilibrium constants for the reactions 3 MO 2 (CO 3 ) 3 4- ↔ (MO 2 ) 3 (CO 3 ) 6 6- + 3 CO 3 2- are lg K(U)=-11.3±0.1; lg K(NP)=-10.1±0.1; lg K(Pu)=-7.4±0.2. It is demonstrated that one of the cations of the trimer can be exchanged with another actinide cation: the equilibrium constants for the reactions 2 UO 2 (CO 3 ) 3 4- + MO 2 (CO 3 ) 3 4- ↔ (UO 2 ) 2 MO 2 (CO 3 ) 6 6- + 3 CO 3 3- are lg K=-11.3±0.1, -10.0±0.2 and -8.8 respectively for M=U, Np, Pu. Thus, polynuclear complexes can be efficient solution ''carriers'' for other hexavalent actinides in waste disposal. Some properties of the solid phases MO 2 CO 3 (s) are discussed. Experimental studies of chemical equilibria of americium (III, IV) are reviewed: in carbonate media americium(III) species are AmCO 3 + , Am(CO 3 ) 2 - , Am(CO 3 ) 3 3- , (Am 2 (CO 3 ) 3 ) 6 and (NaAm(CO 3 ) 2 ) s ; for americium-(IV) lg β 5 ≅ 40. In 3 M NaClO 4 solubility measurements of neptunium(V) show that lg β 1 =5.09, lg β 2 =8.15, lg β 3 =10.46, lg Ks(NaNpO 2 CO 3 )=10.56 and lg Ks(Na 3 NpO 2 (CO 3 ) 2 )=12.44; ionic strength corrections are proposed on the basis of these results. (orig.)

  8. Investigation on n/γ discrimination methods for liquid scintillator detector

    International Nuclear Information System (INIS)

    Li Kuinian; Li Yang; Zhang Mei; Zhang Zhongbing; Li Binkang; Zhang Xiaodong; Liu Jun; Zhang Xianpeng

    2014-01-01

    To obtain the n/γ discrimination ability of different digital pulse shape discrimination methods, four methods (rising time method, charge comparison method, pulse gradient analysis and frequency gradient analysis) in americium-beryllium mixed radiation fields were demonstrated. The signals from EJ-301 and BC501A scintillator detectors were digitized using oscilloscope. A comparison was taken among the four discrimination methods. The discrimination results of the four methods in liquid scintillator detectors show that the rising time method is the best and it provides a good choice in real-time n/γ discrimination system. (authors)

  9. Impact of MST on the Rheology of the Neutralized Am/Cm Slurry

    International Nuclear Information System (INIS)

    Lambert, D.P.

    2001-01-01

    The americium (Am) and curium (Cm) solution, currently stored in F-Canyon Tank 17.1 will be neutralized and diluted prior to addition to High Level Waste (HLW) sludge batch 3 to eliminate the cost and uncertainty of processing and vitrifying this solution. One of the processing alternatives involves the addition of monosodium titanate (MST) to adsorb any soluble Am, Cm or Pu present in the slurry. This paper discusses the impact of the MST on the rheology of the neutralized Am/Cm slurry

  10. Study of the physico-chemical behavior of transuranian elements in radioactive waste repositories

    International Nuclear Information System (INIS)

    Vitorge, P.; Billon, A.; Dautel, C.; Michau, O.; Quevrin, M.; Delorme, P.; Berthoud, T.; Mauchien, P.

    1986-01-01

    Transuranian chemistry is being studied in the geochemical context of the geological disposal of radioactive waste. The transuranians considered are plutonium, neptunium and americium. The first part, devoted to the chemistry of these elements in aqueous solutions, consists of a critical compilation of literature data with a view to resulting in producing the E h -pH diagrams of transuranians in a complexing environment. The study of the retention by constituents of artificial clay barriers (bentonite and attapulgite) is the subject of the second part. The third part concerns the development of a measurement technique for transuranian elements at trace levels by the thermal lensing method

  11. Radiometric measurements on the fabrication of non-destructive assay standards for WIPP-Performance Demonstration Program

    International Nuclear Information System (INIS)

    Wong, A.S.; Marshall, R.S.

    1997-04-01

    The Inorganic Elemental Analysis Group of LANL has prepared several different sets of working reference materials (WRMs). These WRMs are prepared by blending quantities of nuclear materials (plutonium, americium, and enriched uranium) with diatomaceous earth. The blends are encapsulated in stainless steel cylinders. These WRMs are being measured as blind controls in neutron and gamma based non-destructive assay (NDA) instruments. Radiometric measurements on the blending homogeneity and verification on a set of sixty three plutonium based WRMs are discussed in this paper

  12. Research and development on nuclear waste future management: partition and transmutation

    International Nuclear Information System (INIS)

    Vergnes, J.

    1997-01-01

    The first area of the French Law of December 30, 1991 on long-lived nuclear waste management is devoted to finding solutions for waste partitioning and transmutation. Within this framework, multi-recycling feasibility studies in reactor were performed, concerning plutonium and minor actinides such as neptunium, americium, and curium. FBBs are the most efficient. In PWRs and with today's practices, the number of recycling would be limited to safety reasons. To solve this problem, either modified reactors or different fuels would be required. (authors)

  13. Technical basis for internal dosimetry at Hanford

    International Nuclear Information System (INIS)

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1989-04-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products ( 58 Co, 60 Co, 54 Mn, and 59 Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation; and bioassay follow-up treatment. 64 refs., 42 figs., 118 tabs

  14. Composition containing transuranic elements for use in the homeopathic treatment of aids

    International Nuclear Information System (INIS)

    Lustig, D.

    1996-01-01

    A homeopathic remedy consisting of a composition containing one or more transuranic elements, particularly plutonium, for preventing and treating acquired immunodeficiency syndrome (AIDS) in humans, as well as seropositivity for human immunodeficiency virus (HIV). Said composition is characterized in that it uses any chemical or isotopic form of one or more transuranic elements (neptunium, plutonium, americium, curium, berkelium, californium or einsteinium), particularly plutonium, said form being diluted and dynamized according to conventional homeopathic methods, particularly the so-called Hahnemann and Korsakov methods, and provided preferably but not exclusively in the form of lactose and/or saccharose globules or granules impregnated with the active principle of said composition. (author)

  15. Safety Analysis Report: Packages, Pu oxide and Am oxide shipping cask: Packaging of fissile and other radioactive materials: Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1984-12-01

    The PuO 2 cask or 5320-3 cask is designed for shipment of americium or plutonium by surface transportation modes. The cask design was physically tested to demonstrate that it met the criteria specified in US ERDA Manual Chapter 0529, dated 12/21/76, which invokes Title 10 Code of Federal Regulations, Part 71 (10 CFR 71) ''Packaging of Radioactive Materials for Transport,'' and Title 49 CFR Parts 171.179 ''Hazardous Materials Regulations.'' (US DOE Order 4580.1A, Chapter III, superseded manual chapter 0529 effective May 1981, but it retained the same 10 CFR 71 and 49 CFR 171-179 references

  16. Assay of low-level plutonium effluents

    International Nuclear Information System (INIS)

    Hsue, S.T.; Hsue, F.; Bowersox, D.F.

    1981-01-01

    In the plutonium recovery section at the Los Alamos National Laboratory, an effluent solution is generated that contains low plutonium concentration and relatively high americium concentration. Nondestructive assay of this solution is demonstrated by measuring the passive L x-rays following alpha decay. Preliminary results indicate that an average deviation of 30% between L x-ray and alpha counting can be achieved for plutonium concentrations above 10 mg/L and Am/Pu ratios of up to 3; for plutonium concentrations less than 10 mg/L, the average deviation is 40%. The sensitivity of the L x-ray assay is approx. 1 mg Pu/L

  17. Last improvements of the DTC 1000 spectrophotometer

    International Nuclear Information System (INIS)

    Blanc, F.

    1988-01-01

    The DTC 1000 spectrophotometer, based on optical fibers and photodiode array was developed for Pu(IV) measurement in fuel reprocessing. The apparatus takes advantage of experience acquired in optical fibers instrumentation and of the study of gamma radiation effects on fibers. This paper give the complete evolution of these last months (memory, hardware, software, background noise). But the principle of the apparatus and examples of results obtained on americium and plutonium on a previous version of the apparatus are recalled. 17 figs., 6 refs [fr

  18. Polyacrylonitrile based composite materials with extracting agents containing chemically bonded CMPO groups for separation of actinoids

    International Nuclear Information System (INIS)

    Jan Kamenik; Ferdinand Sebesta; Jan John

    2015-01-01

    Composite materials made from polyacrylonitrile binding polymer and solid extracting agents with functional groups of diphenyl-carbamoylmethylphosphine oxide bonded to a platform of calix[4]arenes and cobalt bis(dicarbollide) cluster anion were tested for application in column chromatography. They exhibited high affinity for americium, plutonium, uranium, and europium ions in nitric acid solutions. However, europium distribution isotherm in 3 M HNO 3 indicated low capacity and unsatisfactory employment of the functional groups. Similar material with octyl(phenyl)-N,N'-diisobutylcarbamoylmethylphosphine oxide extracting agent had both high affinity and uptake capacity. (author)

  19. An Aerial Radiological Survey of the Nevada Test Site - Areas 18 and 20 Corrective Action Unit 372

    International Nuclear Information System (INIS)

    Lyons, Craig

    2010-01-01

    A series of aerial radiological surveys were conducted over the Little Feller I and II ground zero areas in Area 18 and the Palanquin and Cabriolet ground zero areas in Area 20. The surveys were performed in October and November 2009 utilizing a large array of helicopter mounted sodium iodide detectors. The purpose of the survey was to update the previous radiological survey levels of the environment and surrounding areas of the ground zeros. Gross Counts, inferred exposure rates, man-made activity, and Americium-241 activity, as calculated from the aerial data are presented in the form of isopleth maps superimposed on imagery of the surveyed areas.

  20. The bioavailability of the transuranic elements 237Pu and 241Am for the pond snail, Lymnaea stagnalis L., and their behaviour in selected natural surface waters

    International Nuclear Information System (INIS)

    Thiels, G.M.

    1983-01-01

    An attempt was made to characterise the bioavailability of 237 Pu and 241 Am for the pond snail Lymnaea stagnalis L. in selected surface waters. The uptake, distribution and retention patterns were studied through the contamination route water-snail. The effects of a number of parameters, such as seasonal variation, water type (pH, conductivity, ionic composition) and presence of food, on the bioavailability of the transuranics were evaluated. Finally, an assessment was made concerning the chemical speciation of plutonium and americium in the selected freshwaters

  1. Apparatus for measuring moisture in moving bulk material using a lithium-7 radiation source

    International Nuclear Information System (INIS)

    Ashe, J.B.

    1976-01-01

    A nucleonic device is described for measuring the moisture content of bulk materials using a radioisotopic fast-neutron source such as lithium-7 admixed with an alpha-particle emitter such as americium-241 as a means of minimizing the thickness of the layer of bulk material required proximate to the moisture sensor for a neutron-reflection moisture gauge for proper operation of said gauge. Minimization of the required thickness of the bulk material permits use of a neutron-reflection moisture gauge for measurements of bulk materials on lightly-loaded belts and other types of conveyors where measurements have previously been impracticable

  2. The Minister Council decree about intervention level values for particular types of intervention activity and about criteria of recall this activity of 27 April 2004

    International Nuclear Information System (INIS)

    Miller, L.

    2004-01-01

    The decree refers to intervention level values for particular types of intervention activity, such as evacuation, order to leave in closed rooms, application of preparations containing stabile iodine, prohibition or limiting to consume contaminated food or water, temporary or permanent displacement. The intervention level values refer to contamination level values refer to contamination with strontium 90, iodine 131, plutonium 239, americium 241, cesium 134 and cesium 137 of drinking water, milk and food for men and domestic animals. The decree replaces the decrees of 6 August 2002 (Dz. U. no 145, item 1218, 2002 and no 151, item 1463, 2003)

  3. An in situ survey of Clean Slate 1, 2, and 3, Tonopah Test Range, Central Nevada. Date of survey: September--November 1993

    International Nuclear Information System (INIS)

    1995-08-01

    A ground-based in situ radiological survey was conducted downwind of the Clean Slate 1, 2, and 3 nuclear safety test sites at the Tonopah Test Range in central Nevada from September through November 1993. The purpose of the study was to corroborate the americium-241 ( 241 Am) soil concentrations that were derived from the aerial radiological survey of the Clean Slate areas, which was conducted from August through October 1993. The presence of 241 Am was detected at 140 of the 190 locations, with unrecoverable or lost data accounting for fifteen (15) of the sampling points. Good agreement was obtained between the aerial and in situ results

  4. Thermodynamics of carbothermic synthesis of actinide mononitrides

    International Nuclear Information System (INIS)

    Ogawa, T.; Shirasu, Y.; Minato, K.; Serizawa, H.

    1997-01-01

    Carbothermic synthesis will be further applied to the fabrication of nitride fuels containing minor actinides (MA) such as neptunium, americium and curium. A thorough understanding of the carbothermic synthesis of UN will be beneficial in the development of the MA-containing fuels. Thermodynamic analysis was carried out for conditions of practical interest in order to better understand the recent fabrication experiences. Two types of solution phases, oxynitride and carbonitride phases, were taken into account. The Pu-N-O ternary isotherm was assessed for the modelling of M(C, N, O). With the understanding of the UN synthesis, the fabrication problems of Am-containing nitrides are discussed. (orig.)

  5. Modifying radionuclide effects

    International Nuclear Information System (INIS)

    Sasser, L.B.

    1983-01-01

    This project involves a study of the relationship of physiological and environmental factors to the metabolism and effects of radionuclides. We have studied placental transfer and suckling as pathways of americium entry into the newborn or juvenile rat. Rats were injected intravenously with 5 μCi of 241 Am while nulliparous (30 days prior to mating), pregnant (day 19 of gestation), or lactating (1 day after parturition), and subsequent litters were killed to determine 241 Am retention. A deficit in reproductive performance was observed in the group injected before mating, as evidenced by reduced number and weight of offspring

  6. Artificial radioactivity in Lough Foyle

    International Nuclear Information System (INIS)

    Cunningham, J.D.; Ryan, T.P.; Lyons, S.; Smith, V.; McGarry, A.; Mitchell, P.I.; Leon Vintro, L.; Larmour, R.A.; Ledgerwood, F.K.

    1996-04-01

    The purpose of this study was to assess the extent to which the marine environment of Lough Foyle, situated on the north coast of Ireland, has been affected by artificial radioactivity released from Sellafield. Although traces of plutonium, americium and radiocaesium from Sellafield are detectable in Lough Foyle, the concentrations in various marine media are significantly lower than those found along the NE coast of Ireland and in the western Irish Sea. The minute quantities of artificial radioactivity found in Lough Foyle are of negligible radiological significance

  7. Determination of U, Pu and Am isotopes in Irish Sea sediment by a combination of AMS and radiometric methods.

    Science.gov (United States)

    Srncik, M; Hrnecek, E; Steier, P; Wallner, G

    2011-04-01

    Samples from a marine sediment core from the Irish Sea (54.416 N, 3.563 W) were analyzed for the isotopic composition of uranium, plutonium and americium by a combination of radiometric methods and AMS. The radiochemical procedure consisted of a Pu separation step by anion exchange, subsequent U separation by extraction chromatography using UTEVA® and finally Am separation with TRU® Resin. Additionally to radiometric determination of these isotopes by alpha spectrometry, the separated samples were also used for the determination of (236)U/(238)U and plutonium isotope ratios by Accelerator Mass Spectrometry (AMS) at the VERA facility. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Test plan for demonstrating plutonium extraction from 10-L solutions using EIChrom extraction chromatographic resins

    International Nuclear Information System (INIS)

    Barney, G.S.

    1994-01-01

    Corrosive plutonium solutions stored in 10-L containers at the Plutonium Finishing Plant must be treated to convert the plutonium to a safe, solid form for storage and to remove the americium so that radiation exposure can be reduced. Extraction chromatographic resins will be tested for separating plutonium from these solutions in the laboratory. Separation parameters will be developed during the testing for large scale processing of the 10-L solutions and solutions of similar composition. Use of chromatographic resins will allow plutonium separation with minimum of chemical addition to the feed and without the need for plutonium valence adjustment. The separated plutonium will be calcined to plutonium oxide by direct solution calcination

  9. Development of fuels for the transmutation in the frame of the EFTTRA European collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, J.F. [European Commission, Joint Research Centre, Inst. for Transuranium Elements, Karlsruhe (Germany); Conrad, R.; Gruppelaar, H.; Muehling, G.; Salvatores, M.; Vambenepe, G.

    1997-12-31

    The EFTTRA collaboration (Experimental Feasibility of Targets for Transmutation) between CEA (France), ECN (The Netherlands), EDF (France), FZK (Germany), IAM and ITU (European Commission), launched in 1992, has now reached its cruising speed: joint experiments for the study of materials for the transmutation have started in parallel in the Phenix fast reactor in France, and in the high flux thermal reactor HFR in the Netherlands. One of these experiments, concerning technetium and iodine, has been completed and the results published. The EFTTRA activities are described, in particular one experiment concerning the irradiation of a spinel matrix with 10% americium content. (author)

  10. Speciation of radionuclides in natural groundwaters: Annual report for the period October 1986 through September 1987

    International Nuclear Information System (INIS)

    Doxtader, M.M.; Beitz, J.V.; Reed, D.T.; Bates, J.K.

    1988-02-01

    Two ultrasensitive laser techniques, laser photoacoustic spectroscopy (LPAS) and laser-induced fluorescence (LIF), are being developed for the detection and speciation of trace levels of actinides in solutions typical of those expected in a high-level waste repository. An LPAS system was set up for these studies. Experiments were carried out to determine the detection limits of plutonium and americium in solution. Concurrently with the LPAS work, LIF studies were carried out on uranyl ion and curium in solution. 32 refs., 35 figs., 8 tabs

  11. Schubert Review 2017 2-page summary of AmBe project

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-04

    Accelerator-based neutron sources to replace Americium Beryllium (AmBe) radiological sources used for oil well logging are needed for safety and security purposes. DT neutron generators have successfully been used in the past for some measurements, but are less sensitive to rock porosity than the AmBe spectrum is. Additionally, the well-logging industry has decades of data calibrated to the AmBe neutron spectrum. Ideally, if this industry were required to use an accelerator source, they would like a similar neutron spectrum to the AmBe source, with a yield of at least 1×107 n/s.

  12. Electronic Structure of the Actinide Metals

    DEFF Research Database (Denmark)

    Johansson, B.; Skriver, Hans Lomholt

    1982-01-01

    Some recent experimental photoelectron spectroscopic results for the actinide metals are reviewed and compared with the theoretical picture of the basic electronic structure that has been developed for the actinides during the last decade. In particular the experimental data confirm the change from...... itinerant to localized 5f electron behaviour calculated to take place between plutonium and americium. From experimental data it is shown that the screening of deep core-holes is due to 5f electrons for the lighter actinide elements and 6d electrons for the heavier elements. A simplified model for the full...

  13. An overview of results obtained in intercomparison exercises for determination of actinides.

    Science.gov (United States)

    Benedik, L

    2013-11-01

    In recent years the Jožef Stefan Institute participated in numerous intercomparison exercises for determination of natural and man-made radionuclides. The reported values were mostly in good agreement with the resulting reference values. This paper describes an analysis of the measurement results obtained in intercomparison exercises for determination of actinides in the period from 2009 to 2011, organised by the National Physical Laboratory and the Bundesamt für Strahlenschutz. The review covers neptunium, plutonium and americium radioisotopes over this period. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. An emergency bioassay method for actinides in urine.

    Science.gov (United States)

    Dai, Xiongxin; Kramer-Tremblay, Sheila

    2011-08-01

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

  15. Correlation properties of delayed neutrons from fast neutron induced fission

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Isaev, S.G.

    1998-01-01

    The experimental studies of the energy dependence of the delayed neutron parameters for various fissioning systems has shown that the behavior of a some combination of delayed neutron parameters (group relative abundances a i and half lives T i ) has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. Below we will present the preliminary results which were obtained during this study omitting the physics interpretation of the results. (author)

  16. Systematic of delayed neutron parameters

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  17. The Citizen Observatory of Radioactivity - Assessment for 2010 of radioactivity survey in the environment at the scale of Normandy (coast and waterways) - Results of measurement of gamma emitters and of Tritium in water

    International Nuclear Information System (INIS)

    2012-01-01

    This document proposes a set of tables containing different information and data regarding measurements of gamma radioactivity and of the presence of tritium made during 2010 in different marine and water environments (algae, sands, sea water, molluscs, sediments, water mosses, vegetal) in different locations: a bay close to the AREVA plant in La Hague, different locations on the Normandy coast, around the AREVA plant in La Hague, and in waterways in Normandy. These tables contain information about the sampling (date, location, quantity, analysed fraction, and so on) and results of measurements of artificial (isotopes of cobalt, ruthenium-rhodium, silver, iodine, caesium, americium, europium) and natural (potassium, beryllium, lead, bismuth, etc.) radionuclides

  18. Radionuclide concentrations in honey bees from Area G at TA-54 during 1997. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Haarmann, T.K.; Fresquez, P.R.

    1998-07-01

    Honey bees were collected from two colonies located at Los Alamos National Laboratory`s Area G, Technical Area 54, and from one control (background) colony located near Jamez Springs, NM. Samples were analyzed for the following: cesium ({sup 137}Cs), americium ({sup 241}Am), plutonium ({sup 238}Pu and {sup 239,240}Pu), tritium ({sup 3}H), total uranium, and gross gamma activity. Area G sample results from both colonies were higher than the upper (95%) level background concentration for {sup 238}Pu and {sup 3}H.

  19. Novel extractant calixcrown used in high-level liquid waste. Pt.3: Extraction capability of bis(2-propyloxy)calix[4]crown-6/n-octanol

    International Nuclear Information System (INIS)

    Zhu Xiaowen; Wang Jianchen; Song Chongli

    2004-01-01

    The extraction capability of bis(2-propyloxy)-calix[4]crown-6/n-octanol was studied. The D(Cs) is strongly affected by acidity and dilution factor of simulated high-level liquid waste (SHLLW). There are little influences of other common ions except potassium. There is little change for D(Cs) in the range of the radiation dose 10 4 -10 5 Gy. The distribution ratios of actinides are very low when aqueous phase is nitric acid. They distinctly increase when the aqueous phase is SHLLW except americium and technetium. (authors)

  20. Technical basis for internal dosimetry at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1989-04-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products (/sup 58/Co, /sup 60/Co, /sup 54/Mn, and /sup 59/Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation; and bioassay follow-up treatment. 64 refs., 42 figs., 118 tabs.

  1. Technical basis for internal dosimetry at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1991-07-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products ({sup 58}Co, {sup 60}Co, {sup 54}Mn, and {sup 59}Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium,. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation and bioassay follow-up treatment. 78 refs., 35 figs., 115 tabs.

  2. Remediation of ultra low level of transuranics from potable water using hybrid materials

    International Nuclear Information System (INIS)

    Singhal, R.K.; Basu, H.; Reddy, A.V.R.

    2015-01-01

    In case of nuclear accidents like Daiichi Nuclear Power Plant (NPP) Fukushima, Japan (11 March, 2011) and nuclear accidents like Chernobyl, USSR (March, 1986), where large amount of activity spread in public domain necessitate the need of development of new material which can efficiently remove transuranic from potable water without disturbing its water quality. Three different types of natural sorbents were developed using natural siliceous material, sodium alginate and impregnation of goethite in alginate matrix. Experiments were carried out for decontamination of americium and plutonium by using Calcium Alginate (Cal-Alg) and Goethite impregnated Cal-Alg (Geo-Cal-Alg) respectively

  3. Complexes of actinides with naturally occuring organic substances - Literature survey

    International Nuclear Information System (INIS)

    Olofsson, U.; Allard, B.

    1983-02-01

    Properties of naturally occurring humic and fulvic acids and their formation of actinide complexes are reviewed. Actinides in all the oxdation states III, IV, V and VI would form complexes with many humic and fulvic acids, comparable in strength to the hydroxide and carbonate complexes. Preliminary experiments have shown, that the presence of predominantly humic acid complexes would significantly reduce the sorption of americium on geologic media. This does not, however, necessarily lead to a potentially enhanced mobility under environmental conditions, since humic and fulvic acids carrying trace metals also would be strongly bound to e.g. clayish material. (author)

  4. Radiotoxicological analyses of {sup 239+240}Pu and {sup 241}Am in biological samples by anion-exchange and extraction chromatography: a preliminary study for internal contamination evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Ridone, S.; Arginelli, D.; Bortoluzzi, S.; Canuto, G.; Montalto, M.; Nocente, M.; Vegro, M. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), Research Centre of Saluggia, Radiation Protection Institute, Saluggia, VC (Italy)

    2006-07-01

    Many biological samples (urines and faeces) have been analysed by means of chromatographic extraction columns, utilising two different resins (AG 1-X2 resin chloride and T.R.U.), in order to detect the possible internal contamination of {sup 239{sup +}}{sup 240}Pu and {sup 241}Am, for some workers of a reprocessing nuclear plant in the decommissioning phase. The results obtained show on one hand the great suitability of the first resin for the determination of plutonium, and on the other the great selectivity of the second one for the determination of americium.

  5. Monte Carlo modelling of Germanium detectors for the measurement of low energy photons in internal dosimetry: Results of an international comparison

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Ros, J.M. [CIEMAT, Av. Complutense 22, E-28040 Madrid (Spain)], E-mail: jm.gomezros@ciemat.es; Carlan, L. de [CEA DRT/LIST/DETECS/LNHB/LMD, Bat 534, F-91191 Gif sur Yvette, Cedex (France); IRSN DRPH/SDI/LEDI, BP6, F-92262, Fontenay-aux-Roses, Cedex (France); Franck, D. [IRSN DRPH/SDI/LEDI, BP6, F-92262, Fontenay-aux-Roses, Cedex (France); Gualdrini, G. [ENEA ION-IRP, Via dei Colli 16, I-40136 Bologna (Italy); Lis, M.; Lopez, M.A.; Moraleda, M. [CIEMAT, Av. Complutense 22, E-28040 Madrid (Spain); Zankl, M. [GSF - National Research Center for Environment and Health, D-85764 Neuherberg (Germany); Badal, A. [Institut de Tecniques Energetiques, UPC, Diagonal 647, 08028 Barcelona (Spain); Capello, K. [Human Monitoring Laboratory (Canada); Cowan, P. [Serco Assurance, Bld. A32, Winfrith Tech. Centre Winfrith, Dorchester, Dorset DT2 8DH (United Kingdom); Ferrari, P. [ENEA ION-IRP, Via dei Colli 16, I-40136 Bologna (Italy); Heide, B. [Forschungszentrum Karlsruhe, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Henniger, J. [Technical University of Dresden, 01062 Dresden (Germany); Hooley, V. [Serco Assurance, Bld. A32, Winfrith Tech. Centre Winfrith, Dorchester, Dorset DT2 8DH (United Kingdom); Hunt, J. [IRD, Av. Salvador Allende, s/n, Recreio, Rio de Janeiro (Brazil); Kinase, S. [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Kramer, G.H. [Human Monitoring Laboratory (Canada); Loehnert, D. [Technical University of Dresden, 01062 Dresden (Germany); Lucas, S. [LARN Laboratory, University of Namur, Rue de Bruxelles 61, B-5000 Namur (Belgium)] (and others)

    2008-02-15

    This communication summarizes the results concerning the Monte Carlo (MC) modelling of Germanium detectors for the measurement of low energy photons arising from the 'International comparison on MC modelling for in vivo measurement of Americium in a knee phantom' organized within the EU Coordination Action CONRAD (Coordinated Network for Radiation Dosimetry) as a joint initiative of EURADOS working groups 6 (computational dosimetry) and 7 (internal dosimetry). MC simulations proved to be an applicable way to obtain the calibration factor that needs to be used for in vivo measurements.

  6. 238Pu based energy micro-generation sources for medical applications

    International Nuclear Information System (INIS)

    Boucher, Rene

    1968-10-01

    Pace-makers are frequently implanted in the human body. The existing apparatus are, actually, equipped with chemical piles with a lifetime of about 15 months. The use of 238 Pu will provide a pace-maker with an autonomy of 10 years at least. Principal problems of security due to the use of plutonium are considered. It is advisable to improve the properties of pure plutonium by small additions of elements such as cerium, scandium, indium, gallium or americium. A number of the most important properties for a pace-maker source are presented. Finally, the fabrication and canning of the source are surveyed. (author) [fr

  7. Sorption-desorption studies on tuff III. A continuation of studies with samples from Jackass Flats and Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Wolfsberg, K.; Aguilar, R.D.; Bayhurst, B.P.

    1981-05-01

    This report is the third in a series of reports describing studies of sorption and migration of radionuclides in tuff. The investigations were extended to lithologies of tuff not previously studied. Continuing experiments with uranium, plutonium, and americium are described. The dependence of sorption on the concentration of the sorbing element and on the solution-to-solid ratio was investigated for a number of nuclides and two lithologies. A circulating system was designed for measuring sorption ratios. Values obtained from this system, batch measurements, and column elutions are compared. Progress on measuring and controlling Eh is described

  8. Use of two-phase aqueous systems based on water-soluble polymers in thin-layer and extraction chromatography for recovery and separtion of actinides

    International Nuclear Information System (INIS)

    Molochnikova, N.P.; Shkinev, V.M.; Myasoedov, B.F.

    1995-01-01

    The feasibility has been demonstrated of using two-phase aqueous systems based on water-soluble polymers, polyethylene glycol and dextran sulfate, in thin-layer and extraction chromatography for recovery and separation of actinides. A convenient method has been proposed for continuous recovery of 239 Np from 243 Am, originating from differences in sorption of tri- and pentavalent actinides from sulfate solutions containing potassium phosphotungstate by silica gel impregnated with polyethylene glycol. New plates for thin-layer chromatography using water-soluble polymers have been developed. These plates were used to study behavior of americium in various oxidation states in thin sorbent layers

  9. Problems and progress in the preparation of sources for the alpha spectrometry of plutonium

    International Nuclear Information System (INIS)

    Miguel, M.; Deron, S.; Swietly, H.; Heinonen, O.J.

    1981-01-01

    The interpretation of non-destructive measurements of plutonium materials require more accurate determinations of the isotopic abundance of Pu-238 than conventional chemical assays. The requirements of calorimetry, passive neutron and conventional chemical assays are presented and compared. When Pu-238 is measured by alpha spectrometry, these requirements define how well the plutonium must be separated from americium, and what should be the accuracy of the spectrometry. The latter can strongly depend upon the resolution of the alpha spectrum. The authors describe a procedure to produce sources by drop deposition which ensure a resolution of 17 keV with commercial instrumentation

  10. Calculated Bulk Properties of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.

    1978-01-01

    Self-consistent relativistic calculations of the electronic properties for seven actinides (Ac-Am) have been performed using the linear muffin-tin orbitals method within the atomic-sphere approximation. Exchange and correlation were included in the local spin-density scheme. The theory explains...... the variation of the atomic volume and the bulk modulus through the 5f series in terms of an increasing 5f binding up to plutonium followed by a sudden localisation (through complete spin polarisation) in americium...

  11. CANDU - a versatile reactor for plutonium disposition or actinide burning

    International Nuclear Information System (INIS)

    Chan, P.S.W.; Gagnon, M.J.N.; Boczar, P.G.; Ellis, R.J.; Verrall, R.A.

    1997-10-01

    High neutron economy, on-line refuelling, and a simple fuel-bundle design result in a high degree of versatility in the use of the CANDU reactor for the disposition of weapons-derived plutonium and for the annihilation of long-lived radioactive actinides, such as plutonium, neptunium, and americium isotopes, created in civilian nuclear power reactors. Inherent safety features are incorporated into the design of the bundles carrying the plutonium and actinide fuels. This approach enables existing CANDU reactors to operate with various plutonium-based fuel cycles without requiring major changes to the current reactor design. (author)

  12. Elimination of man-made radionuclides from natural waters by applying a standard coagulation-flocculation process

    International Nuclear Information System (INIS)

    Baeza, A.; Miro, C.; Salas, A.; Fernandez, M.; Herranz, M.; Legarda, F.

    2004-01-01

    Effectiveness of potable water treatment processes that consist of the stages of coagulation-flocculation-decantation, using iron-based coagulants, in eliminating gamma-emitting man-made radioisotopes of cesium, strontium, and americium from two natural waters with different degrees of mineralization was studied. The resulting decontamination was found to depend on the chemical behavior of each of the radionuclides considered, on the pH at which the process of coagulation is carried out, and on the concentration of the other stable cations present. (author)

  13. Numerical Analysis of Particle Interactions with Nuclei in the Framework of Quantum Molecular Dynamic Model

    CERN Document Server

    Amirkhanov, I V; Zemlyanaya, E V; Polanski, A; Puzynina, T P; Uzhinsky, V V

    2004-01-01

    Combinations of the QMD model with various models of nuclear residual de-excitation are considered. The QMD model parameters are fitted; neutron spectra in hadron-nucleus interactions are calculated. The numerical results were compared with analogous calculations by the cascade-evaporation model and with experimental data. The comparison shows that the numerical results are in agreement between each other and with the experimental data for the energies of projectile particles lower than 200-300 MeV for fast neutrons. Cross-sections of isotope yields in the neutron interactions with radioactive iodine, americium, plutonium and others isotopes have been calculated.

  14. Eutectic reaction analysis between TRU-50%Zr alloy fuel and HT-9 cladding, and temperature prediction of eutectic reaction under steady-state

    International Nuclear Information System (INIS)

    Hwang, Woan; Lee, Byoung Oon; Lee, Bong Sang; Park, Won Seok

    2001-02-01

    Blanket fuel assembly for HYPER contains a bundle of pins arrayed in triangular pitch, which has hexagonal bundle structure. The reference blanket fuel pin consists of the fuel slug of TRU-50wt%Zr alloy and the cladding material of ferritic martensite steel, HT-9. Chemical interaction between fuel slug and cladding is one of the major concerns in metallic fuel rod design. The contact of metallic fuel slug and stainless steel cladding in a fuel rod forms a complex multi-component diffusion couple at elevated temperatures. The potential problem of inter-diffusion of fuel and cladding components is essentially two-fold weakening of cladding mechanical strength due to the formation of diffusion zones in the cladding, and the formation of comparatively low melting point phases in the fuel/cladding interface to develop eutectic reaction. The main components of fuel slug are composed of zirconium alloying element in plutonium matrix, including neptunium, americium and uranium additionally. Therefore basic eutectic reaction change of Pu-Fe binary system can be assessed, while it is estimated how much other elements zirconium, uranium, americium and neptunium influence on plutonium phase stability. Afterwards it is needed that eutectic reaction is verified through experimental necessarily

  15. Gamma detector for use with luggage X-ray systems

    International Nuclear Information System (INIS)

    McHugh, H.; Quam, W.

    1998-01-01

    A new gamma radiation sensor has been designed for installation on several types of luggage x-ray machines and mobile x-ray vans operated by the U.S. Customs Service and the U.S. Department of State. The use of gamma detectors on x-ray machines imposed difficulties not usually encountered in the design of gamma detectors because the spectrum of scattered x-rays, which varied from machine to machine, extended to energies significantly higher than those of the low-energy isotopic emissions. In the original design, the lower level discriminator was raised above the x-ray end point energy resulting in the loss of the americium line associated with plutonium. This reduced the overall sensitivity to unshielded plutonium by a factor of approximately 100. An improved method was subsequently developed wherein collimation was utilized in conjunction with a variable counting threshold to permit accommodation of differing conditions of x-ray scattering. This design has been shown to eliminate most of the problems due to x-ray scattering while still capturing the americium emissions. The overall sensitivity has remained quite high, though varying slightly from one model of x-ray machine to another, depending upon the x-ray scattering characteristics of each model. (author)

  16. Treatment of alpha active organic liquid scintillator waste with ion exchange resins-column studies

    International Nuclear Information System (INIS)

    Venugopal Chetty, K.; Vaidya, V.N.; Venugopal, V.; Rao, P.R.V.

    2002-01-01

    The distribution ratios and percentage extraction for americium and total alpha due to plutonium and americium were determined using mixture of resins from the simulated alpha active organic liquid scintillator waste solution. Macroporous Bifunctional Phosphinic Acid (MPBPA) resin along with Amberlite IR-120 or AG 50WX8 in the ratios 1 : 1 to 1 : 6 were studied and the percentage extraction of better than 97% and distribution ratio of more than 480 were obtained. The data indicated the usefulness of these resins to remove alpha activity from these organic waste solutions. The column experiments were carried out using the active organic liquid scintillator waste with and without dilution with alcohol, and only alcoholic waste generated in the laboratory during the washing of the used liquid scintillator vials. The column containing either single MPBPA resin or with additional resin bed of Amberlite IR-120 were used for the treatment of the wastes. In the case of alcoholic waste after removal of activity it was reused for rinsing of the used vials. (author)

  17. Thermodynamic approach of the poly-azine - f element ions interaction in aqueous conditions

    International Nuclear Information System (INIS)

    Miguirditchian, M.; Guillaumont, D.; Moisy, P.; Guillaneux, D.; Madic, C.

    2004-01-01

    2-Amino-4,6-di-(pyridine-2-yl)-1,3,5-triazine (Adptz) was considered as a model compound for selective aromatic nitrogen extractants (poly-azines) of minor actinides. Thermodynamic data ( ΔG 0 , ΔH 0 , ΔS 0 ) were systematically acquired for the complexation of lanthanide(III) ions as well as yttrium(III) and americium(III) in hydro-alcoholic medium. Two complementary experimental approaches were followed. Stability constants for the formation of the 1:1 complexes were evaluated from UV-visible spectrophotometry titration experiments, whereas enthalpies and entropies of reaction were obtained consistently from either temperature dependence experiments or micro-calorimetry. The interaction of Adptz with lanthanide(III) and yttrium(III) ions was found to be essentially ionic and dependent upon the hydration and size of the ion. As for americium(III) ion, stability constant and enthalpy of complexation was significantly larger. This was attributed to a partial electronic transfer from the ligand to empty orbitals of the cation. DFT calculations support this interpretation. (authors)

  18. Behavior of 241Am in fast reactor systems - a safeguards perspective

    International Nuclear Information System (INIS)

    Beddingfield, David H.; Lafleur, Adrienne M.

    2009-01-01

    Advanced fuel-cycle developments around the world currently under development are exploring the possibility of disposing of 241 Am from spent fuel recycle processes by burning this material in fast reactors. For safeguards practitioners, this approach could potentially complicate both fresh- and spent-fuel safeguards measurements. The increased (α,n) production in oxide fuels from the 241 Am increases the uncertainty in coincidence assay of Pu in MOX assemblies and will require additional information to make use of totals-based neutron assay of these assemblies. We have studied the behavior of 241 Am-bearing MOX fuel in the fast reactor system and the effect on neutron and gamma-ray source-terms for safeguards measurements. In this paper, we will present the results of simulations of the behavior of 241 Am in a fast breeder reactor system. Because of the increased use of MOX fuel in thermal reactors and advances in fuel-cycle designs aimed at americium disposal in fast reactors, we have undertaken a brief study of the behavior of americium in these systems to better understand the safeguards impacts of these new approaches. In this paper we will examine the behavior of 241 Am in a variety of nuclear systems to provide insight into the safeguards implications of proposed Am disposition schemes.

  19. Inert matrix advantages in the transmutation balance of minor actinides

    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; Zaetta, A.; Tommasi, J. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Reacteurs

    1995-12-31

    The results of experimental irradiation in relation to the homogeneous concept (UO{sub 2} fuel) with a limited burn-up of 4.5 atom. % have shown that the percentage of the minor actinides Am and Np incinerated reached values of around 25% to 30% - values confirmed by calculations - for irradiation in the Phenix reactor (FR). The calculation and analysis of the quantity of nuclides formed by transmutation, especially plutonium isotopes, are also in close agreement. Using these experimental results, which are supported by the calculations, research on the incineration of minor actinides has been extended to compare the production of plutonium isotopes. Two minor actinide supports are used for this comparison: - a fuel (UO{sub 2} oxide), - an inert matrix (magnesia MgO). In both cases, a content of 45% of minor actinides (Np or Am) by weight is used to represent the heterogeneous recycling mode. Comparison shows the advantage of inert matrices relative to UO{sub 2} fuel to greatly reduce the production of plutonium for the same consumption of minor actinides. A particularly interesting case is that of heterogeneous recycling, which implements americium-based targets (magnesia with 45% americium in the form of AmO{sub 2}), placed on the periphery of the FR core (first row of blankets). (authors). 9 refs., 2 figs., 11 tabs.

  20. The United States Transuranium and Uranium Registries: overview and recent progress

    International Nuclear Information System (INIS)

    Kathren, R.L.

    1989-01-01

    This paper describes the organisation, activities and recent scientific accomplishments of the United States Transuranium and Uranium Registries. Through voluntary donations of tissue obtained at autopsies, the Registries carry out studies of the concentration, distribution and biokinetics of actinides in occupationally exposed persons. Findings from tissue analyses from more than 200 autopsies include the following: a greater proportion of the americium intake, as compared with plutonium, is found in the skeleton; the half-time of americium in liver is significantly shorter than that of plutonium; the concentration of actinide in the skeleton is inversely proportional to the calcium and ash content of the bone; only a small percentage of the total skeletal deposition of plutonium is found in the marrow, implying a smaller risk from irradiation of the marrow relative to the bone surfaces; estimates of plutonium body burden made from urinalysis typically exceed those made from autopsy data; pathologists are unable to discriminate between a group of uranium workers and persons without known occupational exposure on the basis of evaluation of microscopic kidney slides; the skeleton is an important long-term depot for uranium and its fractional uptake by both skeleton and kidney may be greater than indicated by current models. These and other findings and current studies are discussed in depth. (author)

  1. Waste Isolation Pilot Plant Salt Decontamination Testing

    Energy Technology Data Exchange (ETDEWEB)

    Demmer, Ricky Lynn [Idaho National Laboratory; Reese, Stephen Joseph [Idaho National Laboratory

    2015-03-01

    On February 14, 2014, americium and plutonium contamination was released in the Waste Isolation Pilot Plant (WIPP) salt caverns. Several practical, easily deployable methods of decontaminating WIPP salt, using a surrogate contaminant and americium (241Am), were developed and tested. The effectiveness of the methods is evaluated qualitatively, and to the extent practical, quantitatively. Of the methods tested (dry brushing, vacuum cleaning, water washing, mechanical grinding, strippable coatings, and fixative barriers), the most practical seems to be water washing. Effectiveness is very high, and water washing is easy and rapid to deploy. The amount of wastewater produced (~2 L/m2) would be substantial and may not be easy to manage, but the method is the clear winner from a usability perspective. Removable surface contamination levels (smear results) from water washed coupons found no residual removable contamination. Thus, whatever contamination is left is likely adhered to (or trapped within) the salt. The other option that shows promise is the use of a fixative barrier. Bartlett Nuclear, Inc.’s Polymeric Barrier System proved the most durable of the coatings tested. The coatings were not tested for contaminant entrapment, only for coating integrity and durability.

  2. Preparation and certification of plutonium standards

    International Nuclear Information System (INIS)

    1978-11-01

    The Commissariat a l'Energie Atomique has prepared plutonium metal reference samples of guaranteed mass, ranging from 300 to 900 mg, and plutonium content (99.977%). Purification then fragmentization into beads were performed by electrorefining in fused salt baths. The high-precision weighings in a glove box required special equipment and extemely careful handling to achieve a +- 42 μg dubiousness on the mass determination of each sample. Packaging in glass ampoules was carried out under secondary vacuum. Many of the residual impurities were detected by spark mass spectrometry while carbon, nitrogen, hydrogen, oxygen and americium were determined by specific methods. The discovery of an americium segregation necessitated a γ spectrometric sorting to eliminate samples containing abnormal amounts of the element. The plutonium content was determined from the results of direct analyses carried out in five laboratories by five different methods. An extensive statistical treatment guarantees the plutonium mass in each sample with a maximum dubiousness of +- 0.052 % at the probability level 0.95. A certificate of guarantee gives instructions for use of the standards [fr

  3. Characterization of radiolytically generated degradation products in the strip section of a TRUEX flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Peterman, Dean R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, Lonnie G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Groenewold, Gary S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); McDowell, Rocklan G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tillotson, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-08-01

    This report presents a summary of the work performed to meet the FCRD level 2 milestone M3FT-13IN0302053, “Identification of TRUEX Strip Degradation.” The INL radiolysis test loop has been used to identify radiolytically generated degradation products in the strip section of the TRUEX flowsheet. These data were used to evaluate impact of the formation of radiolytic degradation products in the strip section upon the efficacy of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. The nominal composition of the TRUEX solvent used in this study is 0.2 M CMPO and 1.4 M TBP dissolved in n-dodecane and the nominal composition of the TRUEX strip solution is 1.5 M lactic acid and 0.050 M diethylenetriaminepentaacetic acid. Gamma irradiation of a mixture of TRUEX process solvent and stripping solution in the test loop does not adversely impact flowsheet performance as measured by stripping americium ratios. The observed increase in americium stripping distribution ratios with increasing absorbed dose indicates the radiolytic production of organic soluble degradation compounds.

  4. Design, construction and characterization of a dosimeter for neutron radiation

    International Nuclear Information System (INIS)

    Souto, Eduardo de Brito

    2007-01-01

    An individual dosimeter for neutron-gamma mixed field dosimetry was design and developed aiming monitoring the increasing number of workers potentially exposed to neutrons. The proposed dosimeter was characterized to an Americium-Beryllium source spectrum and dose range of radiation protection interest (up to 20 mSv). Thermoluminescent albedo dosimetry and nuclear tracks dosimetry, traditional techniques found in the international literature, with materials of low cost and national production, were used. A commercial polycarbonate, named SS-1, was characterized for solid state tack detector application. The chemical etching parameters and the methodology of detectors evaluation were determined. The response of TLD-600, TLD-700 and SS-1 were studied and algorithms for dose calculation of neutron and gamma radiation of Americium- Beryllium sources were proposed. The ratio between thermal, albedo and fast neutrons responses, allows analyzing the spectrum to which the dosimeter was submitted and correcting the track detector response to variations in the radiation incidence angle. The new dosimeter is fully characterized, having sufficient performance to be applied as neutron dosimeter in Brazil. (author)

  5. A system to control contamination during retrieval of buried TRU waste

    International Nuclear Information System (INIS)

    Loomis, G.G.; Menkhaus, D.E.; Scott, D.W.

    1990-01-01

    This paper discusses design features of a contamination control system for use during retrieval of buried transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL). Between 1952 and 1970 over 56,000m 3 of primarily Rocky Mats Plant (RFP) generated TRU waste was stored at the INEL in shallow land filled pits and trenches, which consisted of sludges, cloth, paper, metal, wood, concrete, and asphalt contaminated with micron-sized, oxidized particles of plutonium and americium. Retrieval for final disposal is one of the options being considered for this buried waste. This contamination control system is an important subsystem of an overall retrieval system design involving containment buildings, remotely controlled excavators and transporters, separation systems, and final disposal options. The main contaminants to be controlled are plutonium and americium compounds associated with the TRU waste. The contamination control system is comprised of the Dust Suppression System (DSS) and a Rapid Monitoring System (RMS). The DSS is a grouping of subsystems including: (a) the inner building laminar flow ventilation system (b) the Lifting and Moving System (LAMS) which provides mobility for (c) the Contamination Suppression System (CSS). The RMS consists of state-of-the-art air monitors and detection systems for measuring loose contamination. To complement and guide the design effort, engineering background experimental studies were performed on the DSS and RMS. The results of these studies are summarized along with a discussion of the general design features. 6 refs., 1 fig

  6. Radiation technique in density and strength testing of coniferous structural timber

    International Nuclear Information System (INIS)

    Dzbenski, W.; Krzosek, S.

    1998-01-01

    The control process of intermediate and final wood products manufacturing is more and more frequently assisted by flow detectors. In radiation devices cesium isotope 137 Cs is replaced by less harmful americium 241 Am. Americium 241 Am was used in the measuring device made in The Academy of Mining and Metallurgy in Cracow. The device was applied in Warsaw Agricultural University (SGGW) in research on Polish structural timber. Negative influence of anatomical defects (knots, compression wood, resinasis, slope of grain, decay) was estimated by gammascopy method. Botanical species (pine, spruce), position in a stem (sapwood, heartwood), anatomical direction (radial, tangential) and moisture content were taken into account. The method of determination a critical place in timber were density is the lowest value (what is an obligatory criterion of stress graded structural timber according to EN standards) was developed. The practical implementation of the method can be reached when sawmills producing structural timber (especially for export) will be more interested in using miniaturized isotope densitometers. (author)

  7. Comparative studies of natural and artificial α-emitters (actinides) in the lichen-reindeer-man food chain

    International Nuclear Information System (INIS)

    Holm, E.; Persson, B.R.R.

    1981-01-01

    Fallout of actinide elements has been investigated by studying samples of lichen collected at different places in Scandinavia. Maximum-activity concentrations of plutonium isotopes in lichen were found in 1965. Americium-241 has been formed in situ from the decay of 241 Pu, and the maximum-activity concentration found in lichen is 35 PCi/kg. In reindeer, the activity concentrations of 239+240 Pu, 241 Pu, and 241 Am have been studied in liver and bone. The fraction of Pu activity ingested and retained in reindeer liver is about two to three times higher than that of Am. Investigations of Pu and Am in human food chains raise the question of comparisons with the natural α-emitting radionuclides uranium, thorium, and their daughters. Americium and thorium exhibit very similar biophysical behavior in the environement. The fraction of activity that is absorbed by gastrointestinal ingestion seems to be of the same order of magnitude. High concentrations of uranium in reindeer tissues probably depend on a high intake from drinking water and other foodstuffs than lichen

  8. Synthesis and characterization of hybrid silicon based complexing materials: extraction of transuranic elements from high level liquid waste; Synthese et caracterisation de gels hybrides de silice a proprietes complexantes: applications a l'extraction des transuraniens des effluents aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Conocar, O

    1999-07-01

    Hybrid organic/inorganic silica compounds with extractive properties have been developed under an enhanced decontamination program for radioactive aqueous nitric acid waste in nuclear facilities. The materials were obtained by the sol-gel process through hydrolysis and poly-condensation of complexing organo-tri-alkoxy-silanes with the corresponding tetra-alkoxy-silane. Hybrid silica compounds were initially synthesized and characterized from mono- and bis-silyl precursors with malonamide or ethylenediamine patterns. Solids with different specific areas and pore diameters were obtained depending on the nature of the precursor, its functionality and its concentration in the tetra-alkoxy-silane. These compounds were then considered and assessed for use in plutonium and americium extraction. Excellent results-partitioning coefficients and capacities have been obtained with malonamide hybrid silica. The comparison with silica compounds impregnated or grafted with the same type of organic group is significant in this respect. Much of the improved performance obtained with hybrid silica may be attributed to the large quantity of complexing groups that can be incorporated in these materials. The effect of the solid texture on the extraction performance was also studied. Although the capacity increased with the specific area, little effect was observed on the distribution coefficients -notably for americium- indicating that the most favorable complexation sites are found on the outer surface. Macroporous malonamide hybrid silica compounds were synthesized to study the effects of the pore diameter, but the results have been inconclusive to date because of the unexpected molecular composition of the materials. (author)

  9. Pyrochemical reduction of uranium dioxide and plutonium dioxide by lithium metal

    International Nuclear Information System (INIS)

    Usami, T.; Kurata, M.; Inoue, T.; Sims, H.E.; Beetham, S.A.; Jenkins, J.A.

    2002-01-01

    The lithium reduction process has been developed to apply a pyrochemical recycle process for oxide fuels. This process uses lithium metal as a reductant to convert oxides of actinide elements to metal. Lithium oxide generated in the reduction would be dissolved in a molten lithium chloride bath to enhance reduction. In this work, the solubility of Li 2 O in LiCl was measured to be 8.8 wt% at 650 deg. C. Uranium dioxide was reduced by Li with no intermediate products and formed porous metal. Plutonium dioxide including 3% of americium dioxide was also reduced and formed molten metal. Reduction of PuO 2 to metal also occurred even when the concentration of lithium oxide was just under saturation. This result indicates that the reduction proceeds more easily than the prediction based on the Gibbs free energy of formation. Americium dioxide was also reduced at 1.8 wt% lithium oxide, but was hardly reduced at 8.8 wt%

  10. Eutectic reaction analysis between TRU-50%Zr alloy fuel and HT-9 cladding, and temperature prediction of eutectic reaction under steady-state

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Woan; Lee, Byoung Oon; Lee, Bong Sang; Park, Won Seok

    2001-02-01

    Blanket fuel assembly for HYPER contains a bundle of pins arrayed in triangular pitch, which has hexagonal bundle structure. The reference blanket fuel pin consists of the fuel slug of TRU-50wt%Zr alloy and the cladding material of ferritic martensite steel, HT-9. Chemical interaction between fuel slug and cladding is one of the major concerns in metallic fuel rod design. The contact of metallic fuel slug and stainless steel cladding in a fuel rod forms a complex multi-component diffusion couple at elevated temperatures. The potential problem of inter-diffusion of fuel and cladding components is essentially two-fold weakening of cladding mechanical strength due to the formation of diffusion zones in the cladding, and the formation of comparatively low melting point phases in the fuel/cladding interface to develop eutectic reaction. The main components of fuel slug are composed of zirconium alloying element in plutonium matrix, including neptunium, americium and uranium additionally. Therefore basic eutectic reaction change of Pu-Fe binary system can be assessed, while it is estimated how much other elements zirconium, uranium, americium and neptunium influence on plutonium phase stability. Afterwards it is needed that eutectic reaction is verified through experimental necessarily.

  11. A radiochemical procedure for a low-level measurement of ''241Am in environmental samples using a supported functional organo phosphorus extractant; Metodo analitico para la determinacion de ''241Am en muestras biologicas y sedimentos marinos mediante uso de una columna con extractante organico

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Anton, M. P.; Alvarez, A.; Navarro, N.; Salvador, S.

    1994-07-01

    The transuranides analysis in environmental samples is carried out by CIEMAT using standardized methods based on sequential separation with ionic-exchange resins. The americium fraction is purified through a two-layer ion exchange column and lately in an anion-exchange column in nitric acid methanol medium. The technique is time consuming and the results are not completely satisfactory (low recovery and loss of a-resolution) for some samples. The chemical compound CMPO (octyl(phenyl)-N,N-diisobutyl carbomoylmethyiphosphine oxide) dissolved in TPB (tributyl phosphate) and supported on an inert substrate has been tested directly for ''241Am analysis by a large number of laboratories. A new method that combines both procedures has been developed. The details of the improved procedure are described in this paper. The advantages of its application to environmental samples (urine, faeces and sediments) are discussed. The utilization of standard samples, with americium certified concentrations confirms the reliability of our measurements. (Author) 8 refs.

  12. Preparation and certification of plutonium standards

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The Commissariat a l'Energie Atomique has prepared plutonium metal reference samples of guaranteed mass, ranging from 300 to 900 mg, and plutonium content (99.977%). Purification then fragmentization into beads were performed by electrorefining in fused salt baths. The high-precision weighings in a glove box required special equipment and extremely careful handling to achieve a +- 42 μg dubiousness on the mass determination of each sample. Packaging in glass ampoules was carried out under secondary vacuum. Many of the residual impurities were detected by spark mass spectrometry while carbon, nitrogen, hydrogen, oxygen and americium were determined by specific methods. The discovery of an americium segregation necessitated a γ spectrometric sorting to eliminate samples containing abnormal amounts of the element. The plutonium content was determined from the results of direct analyses carried out in five laboratories by five different methods. An extensive statistical treatment guarantees the plutonium mass in each sample with a maximum dubiousness of +- 0.052% at the probability level 0.95. A certificate of guarantee gives instructions for use of the standards [fr

  13. Studies of selected transuranium and lanthanide tri-iodides under pressure using absorption spectrophotometry

    International Nuclear Information System (INIS)

    Haire, R.G.; Young, J.P.; Peterson, J.R.; Tennessee Univ., Knoxville; Benedict, U.

    1987-01-01

    The anhydrous tri-iodides of plutonium, americium and curium under pressure have been investigated using absorption spectrophotometry. These initial studies on plutonium and curium tri-iodides together with the published data for americium tri-iodide show that the rhombohedral form of these compounds (BiI 3 -type structure) can be converted to the orthorhombic form (PuBr 3 -type structure) by applying pressure at room temperature. Absorption spectrophotometry can often differentiate between two crystallographic forms of a material and has been used in the present high-pressure studies to monitor the effects of pressure on the tri-iodides. A complication in these studies of the tri-iodides is a significant shift of their absorption edges with pressure from the near UV to the visible spectral region. With curium tri-iodide this shift causes interference with the major f-f absorption peaks and precludes identification by absorption spectrophotometry of the high pressure phase of CmI 3 . (orig.)

  14. Study of the U/Am separation with supported calix[6]arene in the aim of urinary actinides analysis.

    Science.gov (United States)

    Poriel, L; Boulet, B; Cossonnet, C; Bouvier-Capely, C

    2007-01-01

    The aim of this work is to propose an alternative radiochemical procedure for the analysis of U, Pu and Am in urine, which is one of the controls used to monitor workers exposed to risk of internal contamination with actinides. Previous studies have demonstrated the extraction efficiency of these molecules towards uranium and plutonium, the affinity of calix[6]arenes bearing hydroxamic acid groups (LHH3) and carboxylic groups (LCH3) towards americium were studied in this paper by solvent extraction. The results showed that LHH3 and LCH3 have a very good affinity for americium and enhance the possibility of separating Pu from U and Am. Experiments were performed to perfect the separation of U/Am. The immobilisation of these calixarenes on polymer supports was also investigated for routine applications. Supported calixarenes LCH3 and LHH3 presented the same performances as those obtained in a liquid-liquid system and, hence, are a promising system for the analysis of actinides. These molecules and their uses have been protected (patent pending).

  15. A novel malonamide grafted polystyrene-divinyl benzene resin for extraction, pre-concentration and separation of actinides.

    Science.gov (United States)

    Ansari, S A; Mohapatra, P K; Manchanda, V K

    2009-01-30

    A new chelating polymeric extraction chromatographic resin was prepared by chemical anchoring of N,N'-dimethyl-N,N'-dibutyl malonamide (DMDBMA) with chloromethylated Merrifield resin((R)). The grafted resin exhibited stronger binding for hexavalent and tetravalent actinides such as U(VI), Th(IV) and Pu(IV) over trivalent actinides, viz. Am(III) and Pu(III). Batch studies on solid phase extraction performed over a wide range of acid solution (0.01-6M HNO(3)) revealed that ternary mixer of uranium, americium and plutonium or thorium, americium and plutonium could be separated from each other at 1M HNO(3). Desorption of U(VI), Pu(IV) and Am(III) from the loaded resin was efficiently carried out using 0.1M alpha-HIBA, 0.25M oxalic acid and 0.01M EDTA, respectively. Quantitative pre-concentration of actinide ions such as Th(IV) and U(VI) was possible from 3M HNO(3) solution. The practical utility of the grafted resin was evaluated by uranium sorption measurements in several successive cycles. The sorption efficiency of the resin with respect to uranyl ion remained unchanged even after 30 days of continuous use. The surface morphology of the resin was monitored with the help of scanning electron microscopy (SEM) technique.

  16. The EBR-II X501 Minor Actinide Burning Experiment

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  17. Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation

    Energy Technology Data Exchange (ETDEWEB)

    Peter R Zalupski; Leigh R Martin; Ken Nash; Yoshinobu Nakamura; Masahiko Yamamoto

    2009-07-01

    The ingenious combination of lactate and diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention has been devoted to the understanding of the basic thermodynamic features of the complex fluids responsible for the separation. The available thermochemical information of both lactate and DTPA protonation and metal complexation reactions are representative of the behavior of these ions under idealized conditions. Our previous studies of medium effects on lactate protonation suggest that significant departures from the speciation predicted based on reported thermodynamic values should be expected in the TALSPEAK aqueous environment. Thermodynamic parameters describing the separation chemistry of this process thus require further examination at conditions significantly removed from conventional ideal systems commonly employed in fundamental solution chemistry. Such thermodynamic characterization is the key to predictive modelling of TALSPEAK. Improved understanding will, in principle, allow process technologists to more efficiently respond to off-normal conditions during large scale process operation. In this report, the results of calorimetric and potentiometric investigations of the effects of aqueous electrolytes on the thermodynamic parameters for lactate protonation and lactate complexation of americium and neodymium will be presented. Studies on the lactate protonation equilibrium will clearly illustrate distinct thermodynamic variations between strong electrolyte aqueous systems and buffered lactate environment.

  18. NEW METHOD FOR DETERMINATION OF ACTINIDES AND STRONTIUM IN ANIMAL TISSUE

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S; Jay Hutchison, J; Don Faison, D

    2007-05-07

    The analysis of actinides in animal tissue samples is very important for environmental monitoring. There is a need to measure actinide isotopes with very low detection limits in animal tissue samples, including fish, deer, hogs, beef and shellfish. A new, rapid actinide separation method has been developed and implemented that allows the measurement of plutonium, neptunium, uranium, americium, curium and strontium isotopes in large animal tissue samples (100-200 g) with high chemical recoveries and effective removal of matrix interferences. This method uses stacked TEVA Resin{reg_sign}, TRU Resin{reg_sign} and DGA-Resin{reg_sign} cartridges from Eichrom Technologies (Darien, IL, USA) that allows the rapid separation of plutonium (Pu), neptunium (Np), uranium (U), americium (Am), and curium (Cm) using a single multi-stage column combined with alpha spectrometry. Sr-90 is collected on Sr Resin{reg_sign} from Eichrom Technologies (Darien, IL, USA). After acid digestion and furnace heating of the animal tissue samples, the actinides and Sr-89/90 are separated using column extraction chromatography. This method has been shown to be effective over a wide range of animal tissue matrices. By using vacuum box cartridge technology with rapid flow rates, sample preparation time is minimized.

  19. Effects of soluble organic complexants and their degradation products on the removal of selected radionuclides from high-level waste. Part II: Distributions of Sr, Cs, Tc, and Am onto 32 absorbers from four variations of Hanford tank 101-SY simulant solution

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, S.F. [Sandia National Labs., Albuquerque, NM (United States); Svitra, Z.V.; Bowen, S.M. [Los Alamos National Lab., NM (United States)

    1995-04-01

    Many of the radioactive waste storage tanks at U.S. Department of Energy facilities contain organic compounds that have been degraded by radiolysis and chemical reactions during decades of storage. In this second part of our three-part investigation of the effects of soluble organic complexants and their degradation products, we measured the sorption of strontium, cesium, technetium, and americium onto 32 absorbers that offer high sorption of these elements in the absence of organic complexants. The four solutions tested were (1) a simulant for a 3:1 dilution of Hanford Tank 101-SY contents that initially contained ethylenediaminetetraacetic acid (EDTA), (2) this simulant after gamma-irradiation to 34 Mrads, (3) the unirradiated simulant after treatment with a hydrothermal organic-destruction process, and (4) the irradiated simulant after hydrothermal processing. For each of 512 element/absorber/solution combinations, we measured distribution coefficients (Kds) twice for each period for dynamic contact periods of 30 min, 2 h, and 6 h to obtain information about sorption kinetics. On the basis of our 3,072 measured Kd values, the sorption of strontium and americium is significantly decreased by the organic components of the simulant solutions, whereas the sorption of cesium and technetium appears unaffected by the organic components of the simulant solutions.

  20. Investigation of the sintering mechanisms for (U,Am)O{sub 2} pellets obtained by CRMP process

    Energy Technology Data Exchange (ETDEWEB)

    Caisso, M. [CEA, Centre de Marcoule, DEN, DTEC/SECA/LFC, F-30207 Bagnols-sur-Ceze (France); CEA, Centre de Marcole, DEN, DRCP/SERA/LCAR, F-30207 Bagnols-sur-Ceze (France); Institut Europeen des Membranes, UMR 5635 CNRS-ENSCM-UM, CC047, Campus Triolet, Universite de Montpellier, F-34095 Montpellier Cedex 5 (France); Boulesteix, R.; Maitre, A. [SPCTS, UMR 7315 CNRS-Universite de Limoges-ENSCI, Centre Europeen de la Ceramique, 12 Rue Atlantis, F-87068 Limoges (France); Picart, S.; Delahaye, T. [CEA, Centre de Marcole, DEN, DRCP/SERA/LCAR, F-30207 Bagnols-sur-Ceze Cedex (France); Ayral, A. [Institut Europeen des Membranes, UMR 5635 CNRS-ENSCM-UM, CC047, Campus Triolet Universite de Montpellier, F-34095 Montpellier Cedex 5 (France)

    2016-07-01

    The use of CRMP (Calcined Resin Microsphere Pelletization) process for AmBB (Americium Bearing Blankets) fabrication is today a key research axis in americium transmutation domain, where its very high activity requires minimization of powder dissemination. In this aim, the use of oxide microspheres as compaction precursors is a promising clean alternative to powder metallurgy. Understanding the different steps of densification during CRMP pellet sintering thus appears as fundamental to obtain final materials with the specific features required for AmBB. The densification curve recorded in dynamic conditions shows different sintering steps. A first decrease of shrinkage rate happens at low temperature, around 1100 K. This phenomenon is not normally observed in the sintering of conventional powders. Chemical and microstructural studies were performed on (U,Am)O{sub 2} and also on (Ce,Gd)O{sub 2} surrogate compound to highlight the causes of this low-temperature sintering step. Multi-scale reorganization finally appears as the sole explanation, through the sintering of nano-metric aggregate present in the green pellet and related to the morphology of the starting microspheres employed as pelletization precursors. (authors)