WorldWideScience

Sample records for americium 244

  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)

    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 239Pu containing 8-12% 240Pu (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 241Am 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 241Am, 243Am and 244Cm. 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 241Am 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. Preparation of americium amalgam

    International Nuclear Information System (INIS)

    The authors describe a method for the electrochemical preparation of an americium amalgam from americium dioxide and americium 241 and 243 for use in determining the physicochemical properties of the alloy. Moessbauer spectra were made using neptunium dioxide, in the neptunium 237 form, as an absorber. Results show that electrolysis produces a homogeneous amalgam that gives an unoxidized product on vacuum distillation at 200 degrees C

  3. Preparation of americium amalgam

    International Nuclear Information System (INIS)

    Using the method of NGR-spectroscopy with the aid of 241Am isotope chemical state of transuranium elements in the volume and on the surface of amalgams is studied. Amalgam preparation was realized in a simplified electrolytic cell. It is shown that in the process of amalgam preparation the first order of reaction as to actinide is observed; americium is distributed gradually over the volume and it is partially sorbed by the surface of glass capillary. NGR spectrum of dry residue after mercury distillation at 200 deg C points to the presence of americium-mercury intermetal compounds

  4. 1976 Hanford americium accident

    Energy Technology Data Exchange (ETDEWEB)

    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 ..mu..Ci 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.

  5. 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)

  6. The Biokinetic Model of Americium

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    To improve in vivo measurements for detecting internal exposure from transuranium radio nuclides, such as neptunium, plutonium, americium, the bioknetic model was studied. According to ICRP report (1993, 1995, 1997) and other research, the

  7. Americium product solidification and disposal

    International Nuclear Information System (INIS)

    The americium product from the TRUEX processing plant needs to be converted into a form suitable for ultimate disposal. An evaluation of the disposal based on safety, number of process steps, demonstrated operability of the processes, production of low-level alpha waste streams, and simplicity of maintenance with low radiation exposures to personnel during maintenance, has been made. The best process is to load the americium on a cation exchange resin followed by calcination or oxidation of the resin after loading

  8. Kilogram-scale purification of americium by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Wheelwright, E. J.

    1979-01-01

    Sequential anion and cation exchange processes have been used for the final purification of /sup 241/Am recovered during the reprocessing of aged plutonium metallurgical scrap. Plutonium was removed by absorption of Dowex 1, X-3.5 (30 to 50 mesh) anion exchange resin from 6.5 to 7.5 M HNO/sub 3/ feed solution. Following a water dilution to 0.75 to 1.0 M HNO/sub 3/, americium was absorbed on Dowex 50W, X-8 (50 to 100 mesh) cation exchange resion. Final purification was accomplished by elution of the absorbed band down 3 to 4 successive beds of the same resin, preloaded with Zn/sup 2 +/, with an NH/sub 4/OH buffered chelating agent. The recovery of mixed /sup 241/Am-/sup 243/Am from power reactor reprocessing waste has been demonstrated. Solvent extraction was used to recover a HNO/sub 3/ solution of mixed lanthanides and actinides from waste generated by the reprocessng of 13.5 tons of Shippingport Power Reactor blanket fuel. Sequential cation exchange band-displacement processes were then used to separate americium and curium from the lanthanides and then to separate approx. 60 g of /sup 244/Cm from 1000 g of mixed /sup 241/Am-/sup 243/Am.

  9. IT 244 UOP Tutorial Courses/ Uoptutorial

    OpenAIRE

    salman

    2015-01-01

    For more course tutorials visit www.uoptutorial.com   IT 244 Week 1 Assignment Principles of Security Paper   IT 244 Week 1 Checkpoint SmartScenario Information Security Security Policies   IT 244 Week 1 Assignment Introduction to the Information Security Policy Paper   IT 244 Week 2 Checkpoint Smart Scenario Trusted Computing Base   IT 244 Week 3 Smart Scenario: Business Continuity Disaster Recovery   IT 244 W...

  10. 8 CFR 244.2 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... immigrant except as provided under § 244.3; (e) Is not ineligible under § 244.4; and (f)(1) Registers for... relief from removal; (ii) The applicant has an application for change of status, adjustment of...

  11. Spectrochemical analysis of curium and americium samples

    International Nuclear Information System (INIS)

    Spectrochemical procedures have been developed to determine impurities in americium and curium samples. The simultaneous separation of many impurity elements from the base material (americium and curium) is carried out with extraction and extraction-chromatographic methods using di-2-ethylhexylphosphoric acid. It is shown that part of the elements are separated with extraction or sorption of americium and curium; the other part with the Talspeak process. Two fractions in the extraction chromatography and three fractions in the extraction separation of americium and curium, containing impurities, are analyzed separately by a.c. or d.c. arc spectrography. To increase the sensitivity of the spectrographic analysis and accelerate the burn-up of impurities from the crater of the carbon electrode bismuth fluoride and sodium chloride were used as chemically active substances. The extraction of impurities from weighed quantities of americium and curium samples of 5 to 10 mg permits the lower limit of determined impurity concentrations to be extended to 1 x 10-4 to 5 x 10-3% m/m. (author)

  12. 12 CFR 24.4 - Investment limits.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Investment limits. 24.4 Section 24.4 Banks and... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments...

  13. 8 CFR 244.9 - Evidence.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Evidence. 244.9 Section 244.9 Aliens and... OF DESIGNATED STATES § 244.9 Evidence. (a) Documentation. Applicants shall submit all documentation... affidavit or other credible evidence may be submitted. (1) Evidence of identity and nationality....

  14. 8 CFR 244.4 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  15. 8 CFR 244.15 - Travel abroad.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Travel abroad. 244.15 Section 244.15 Aliens... NATIONALS OF DESIGNATED STATES § 244.15 Travel abroad. (a) After the grant of Temporary Protected Status... to travel abroad. Permission to travel may be granted by the director pursuant to the...

  16. 8 CFR 244.6 - Application.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Application. 244.6 Section 244.6 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.6 Application. An application for Temporary Protected Status must be...

  17. Pyrochemical technology of plutonium and americium preparation and purification

    International Nuclear Information System (INIS)

    Pyrochemical tecnology of metallic plutonium and americium preparation and purification is considered. Investigations into plutonium dioxide reduction up to metal; plutonium electrolytic refining in molten salts; plutonium extraction from the molten salts and preparation of americium dioxide and metallic americium from its tetrafluoride are described

  18. 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.

  19. 1976 Hanford americium exposure incident: psychological aspects

    International Nuclear Information System (INIS)

    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

  20. Dicty_cDB: SLA244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available SL (Link to library) SLA244 (Link to dictyBase) - - - Contig-U16368-1 SLA244Z (Link... to Original site) - - SLA244Z 605 - - - - Show SLA244 Library SL (Link to library) Clone ID SLA244 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/SL/SLA2-B/SLA244Q.Seq.d/ Representative seq. ID SLA24...4Z (Link to Original site) Representative DNA sequence >SLA244 (SLA244Q) /CSM/SL/SLA2-B/SLA244Q.Seq.d/ XXXXX...CCACTTCATA AATAAAACTTTGATC sequence update 1997. 5. 7 Translated Amino Acid sequence ---QLCKVTQCPTDFSCKMIRGN

  1. 27 CFR 70.244 - Payroll period.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Payroll period. 70.244... Excise and Special (Occupational) Tax Limitations § 70.244 Payroll period. For purpose of determining the... established calendar period regularly used by the employer or other person levied upon for payroll or...

  2. Dicty_cDB: CFD244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CF (Link to library) CFD244 (Link to dictyBase) - - - Contig-U16511-1 CFD244P (Link to Original site) CFD...244F 686 CFD244Z 674 CFD244P 1360 - - Show CFD244 Library CF (Link to library) Clone ID CFD...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/CF/CFD2-B/CFD244Q.Seq.d/ Representative seq. ID CFD...244P (Link to Original site) Representative DNA sequence >CFD244 (CFD244Q) /CSM/CF/CFD2-B/CFD...FG6-D/SFG691Q.Seq.d/ 759 0.0 CFD244 (CFD244Q) /CSM/CF/CFD2-B/CFD244Q.Seq.d/ 759 0

  3. Incentives for transmutation of americium in thermal reactors

    International Nuclear Information System (INIS)

    This report describes possible benefits when americium is irradiated in a thermal reactor. If all plutonium is partitioned from spent fuel, americium is the main contributor to the radiotoxicity of spent fuel upto several thousands of years of storage. It is shown that americium can be transmuted to other nuclides upon irradiation in a thermal reactor, leading to a 50% reduction of the radiotoxicity of neptunium, which can be an important contributor to the dose due to leakage of nuclides after one million years of storage. The radiotoxicity of americium can be reduced considerably after irradiation for 3 to 6 years in a thermal reactor with thermal neutron flux of 1014 cm-2s-1. The strongly α and neutron emitting transmutation products can most probably not be recycled again, so a transmutation process is suggested in which americium is irradiated for 3 to 6 years and then put to final storage. It is shown that the radiotoxicity of the transmuation products after a storage time of about one hundred years can be considerably reduced compared to the radiotoxicity of the initial americium. The same holds for the α activity and heat emission of the transmutation products. Because plutonium in spent fuel contributes for about 80% to the radiotoxicity upto 105 years of storage, recycling and transmutation of plutonium has first priority. Transmutation of americium is only meaningful when the radiotoxicity of plutonium is reduced far below the radiotoxicity of americium. (orig.)

  4. 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.

  5. Electrochemical oxidation of americium in nitric medium: study of reaction mechanisms; Oxydation de l'americium par voie electrochimique: etude des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Picart, S.; Chartier, D.; Donnet, L.; Adnet, J.M. [CEA Valrho, (DCC/DRRV/SPHA), 30 - Marcoule (France)

    2000-07-01

    One alternative selected by the CEA for partitioning minor actinides from aqueous solutions containing fission products is the selective extraction of oxidized americium. This is the SESAME process (Selective Extraction and Separation of Americium by Means of Electrolysis) aimed to convert americium to oxidation state (VI) and then extract it with a specific extractant of high valences. This paper presents the study of the electrochemical oxidation of americium in nitric medium which represents an important stage of the process. The reaction can be divided into two main steps: oxidation of americium (III) to americium (IV), and then of americium (IV) to americium (VI). For the first oxidation step, a ligand L is needed to stabilize the intermediate species americium (IV) which disproportionates in its free form into americium (III) and (V). Phospho-tungstate or silico-tungstate are appropriate ligands because they are stable in concentrated nitric acid and show a great affinity for metallic cations at oxidation state (IV) (Table 1 lists the stability constants of americium (IV) complexes). The presence of the lacunary poly-anion lowers the potential of the americium (IV) / americium (Ill) redox pair (see Figure 5 for the diagram of the apparent formal potential of americium versus ligand concentration). This makes it thermodynamically possible to oxidize americium (III) into americium (IV) at the anode of an electrolyzer in nitric acid. For the second oxidation step, a strong oxidant redox mediator, like silver (II), is needed to convert complexed americium at oxidation state (IV) to oxidation state (V). The AmVL complex is then hydrolyzed to yield americyle (V) aqua ion. A spectroscopic Raman study with {sup 18}O labeled species showed that the oxygen atoms of the americyle moiety came from water. This indicates that water hydrolyzes the americium (V) complex to produce americyle (V) aqua ion, AmO{sub 2}{sup +}. This cation reacts with silver (Il) to give

  6. Extinct 244Pu in Ancient Zircons

    Science.gov (United States)

    Turner, Grenville; Harrison, T. Mark; Holland, Greg; Mojzsis, Stephen J.; Gilmour, Jamie

    2004-10-01

    We have found evidence, in the form of fissiogenic xenon isotopes, for in situ decay of 244Pu in individual 4.1- to 4.2-billion-year-old zircons from the Jack Hills region of Western Australia. Because of its short half-life, 82 million years, 244Pu was extinct within 600 million years of Earth's formation. Detrital zircons are the only known relics to have survived from this period, and a study of their Pu geochemistry will allow us to date ancient metamorphic events and determine the terrestrial Pu/U ratio for comparison with the solar ratio.

  7. 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

  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. Mixed chelation therapy for removal of plutonium and americium

    International Nuclear Information System (INIS)

    Iron-binding compounds, 2,3-dihydroxybenzoic acid (DHBA), 2-hydroxybenzoic acid (HBA), and 2-(acetyloxy)benzoic acid (ABA), were tested for their ability to remove americium and plutonium from rats following intraperitioneal injection of the radionuclides as citrates (pH 5). Treatments, 2 mmol/kg, were given on days 3, 6, 10, 12 and 14 following the actinide injection. DHBA and HBA caused about a 20% decrease in liver retention of americium compared to the control value, and DHB caused a similar effect for plutonium. The above agents, co-administered with 0.5 mmol polyaminopolycarboxylic acid (PAPCA)-type chelons, did not change tissue retention of americium and plutonium from that due to the PAPCAs alone. Administration of americium and plutonium to the same rats is useful for studying removal agents since the two actinides behave independently in their biological disposition and response to removal

  10. Gamma-sources on the basis of metallic americium-241

    International Nuclear Information System (INIS)

    A batch of gamma-radiation sources has been manufactured from metallic americium-241 of isotopic purity, its activity varying from 0.08 to 0.93 GBq. The cores of the sources are high-purity americium metal condensate on a tantalum or stainless steel substrate prepared by thermal decomposition of 241Pu-241Am alloy in a high vacuum. 7 refs., 1 tab

  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. Pyrochemical investigations into recovering plutonium from americium extraction salt residues

    International Nuclear Information System (INIS)

    Progress into developing a pyrochemical technique for separating and recovering plutonium from spent americium extraction waste salts has concentrated on selective chemical reduction with lanthanum metal and calcium metal and on the solvent extraction of americium with calcium metal. Both techniques are effective for recovering plutonium from the waste salt, although neither appears suitable as a separation technique for recycling a plutonium stream back to mainline purification processes. 17 refs., 13 figs., 2 tabs

  13. 244-AR Vault Interim Stabilization Project Plan

    International Nuclear Information System (INIS)

    The 244-AR Vault Facility, constructed between 1966 and 1968, was designed to provide lag storage and treatment for the Plutonium-Uranium Extraction Facility (PUREX) tank farm sludges. Tank farm personnel transferred the waste from the 244-AR Vault Facility to B Plant for recovery of cesium and strontium. B Plant personnel then transferred the treatment residuals back to the tank farms for storage of the sludge and liquids. The last process operations, which transferred waste supporting the cesium/strontium recovery mission, occurred in April 1978. After the final transfer in 1978, the 244-AR facility underwent a cleanout. However, 2,271 L (600 gal) of sludge were left in Tank 004AR from an earlier transfer from Tank 241-AX-104. When the cleanout was completed, the facility was placed in a standby status. The sludge had been transferred to Tank 004AR to support Pacific Northwest National Laboratory [PNNL] vitrification work. Documentation of waste transfers suggests that a portion of the sludge may have been moved from Tank 004AR to Tank 002AR in preparation for transfer back to the AX Tank Farm; however, quantities of the sludge that were moved to Tank 002AR from that transfer must be estimated

  14. Tank 244A tank characterization plan

    International Nuclear Information System (INIS)

    The Double-Shell Tank (DST) System currently receives waste from the Single-Shell Tank (SST) System in support of SST stabilization efforts or from other on-site facilities which generate or store waste. Waste is also transferred between individual DSTs. The mixing or commingling of potentially incompatible waste types at the Hanford Site must be addressed prior to any waste transfers into the DSTs. The primary goal of the Waste Compatibility Program is to prevent the formation of an Unreviewed Safety Question (USQ) as a result of improper waste management. Tank 244A is a Double Contained Receiver Tank (DCRT) which serves as any overflow tank for the East Area Farms. Waste material is able to flow freely between the underground storage tanks and tank 244A. Therefore, it is necessary to test the waste in tank 244A for compatibility purposes. Two issues related to the overall problem of waste compatibility must be evaluated: Assurance of continued operability during waste transfer and waste concentration and Assurance that safety problems are not created as a result of commingling wastes under interim storage. The results of the grab sampling activity prescribed by this Tank Characterization Plan shall help determine the potential for four kinds of safety problems: criticality, flammable gas accumulation, energetics, and corrosion and leakage

  15. Electrochemical oxidation of americium in nitric medium: study of reaction mechanisms

    International Nuclear Information System (INIS)

    One alternative selected by the CEA for partitioning minor actinides from aqueous solutions containing fission products is the selective extraction of oxidized americium. This is the SESAME process (Selective Extraction and Separation of Americium by Means of Electrolysis) aimed to convert americium to oxidation state (VI) and then extract it with a specific extractant of high valences. This paper presents the study of the electrochemical oxidation of americium in nitric medium which represents an important stage of the process. The reaction can be divided into two main steps: oxidation of americium (III) to americium (IV), and then of americium (IV) to americium (VI). For the first oxidation step, a ligand L is needed to stabilize the intermediate species americium (IV) which disproportionates in its free form into americium (III) and (V). Phospho-tungstate or silico-tungstate are appropriate ligands because they are stable in concentrated nitric acid and show a great affinity for metallic cations at oxidation state (IV) (Table 1 lists the stability constants of americium (IV) complexes). The presence of the lacunary poly-anion lowers the potential of the americium (IV) / americium (Ill) redox pair (see Figure 5 for the diagram of the apparent formal potential of americium versus ligand concentration). This makes it thermodynamically possible to oxidize americium (III) into americium (IV) at the anode of an electrolyzer in nitric acid. For the second oxidation step, a strong oxidant redox mediator, like silver (II), is needed to convert complexed americium at oxidation state (IV) to oxidation state (V). The AmVL complex is then hydrolyzed to yield americyle (V) aqua ion. A spectroscopic Raman study with 18O labeled species showed that the oxygen atoms of the americyle moiety came from water. This indicates that water hydrolyzes the americium (V) complex to produce americyle (V) aqua ion, AmO2+. This cation reacts with silver (Il) to give americyle (VI) ion. Figure

  16. 40 CFR 86.244-94 - Calculations; exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Calculations; exhaust emissions. 86.244-94 Section 86.244-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.244-94 Calculations;...

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

    International Nuclear Information System (INIS)

    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 HNO3, 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 HNO3 at 25 C, which corresponds to approximately 1.7 mg-241Am/g-adsorbent(dried). The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (orig.)

  18. Salvage of plutonium-and americium-contaminated metals

    International Nuclear Information System (INIS)

    Melt-slagging techniques were evaluated as a decontamination and consolidation step for metals contaminated with oxides of plutonium and americium. Experiments were performed in which mild steel, stainless steel, and nickel metals contaminated with oxides of plutonium and americium were melted in the presence of silicate slags of various compositions. The metal products were low in contamination, with the plutonium and americium strongly fractionated to the slags. Partition coefficients (plutonium in slag/plutonium in steel) of 7*10/sup 6/ with borosilicate slag and 3*10/sup 6/ for calcium, magnesium silicate slag were measured. Decontamination of metals containing as much as 14,000 p.p.m. plutonium appears to be as efficient as that of metals with plutonium levels of 400 p.p.m. Staged extraction, that is, a remelting of processed metal with clean slag, results in further decontamination of the metal. 10 refs

  19. 1976 Hanford americium exposure incident: overview and perspective

    International Nuclear Information System (INIS)

    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

  20. 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.

  1. Synthesis and characterization of uranium-americium mixed oxides

    International Nuclear Information System (INIS)

    Americium isotopes represent a significant part of high-level and long-lived nuclear waste in spent fuels. Among the envisaged reprocessing scenarios, their transmutation in fast neutron reactors using uranium-americium mixed-oxide pellets (U1-xAmxO2±δ) is a promising option which would help decrease the ecological footprint of ultimate waste repository sites. In this context, this thesis is dedicated to the study of such compounds over a wide range of americium contents (7.5 at.% ≤ Am/(U+Am) ≤ 70 at.%), with an emphasis on their fabrication from single-oxide precursors and the assessment of their structural and thermodynamic stabilities, also taking self-irradiation effects into account. Results highlight the main influence of americium reduction to Am(+III), not only on the mechanisms of solid-state formation of the U1-xAmxO2±δ solid solution, but also on the stabilization of oxidized uranium cations and the formation of defects in the oxygen sublattice such as vacancies and cub-octahedral clusters. In addition, the data acquired concerning the stability of U1-xAmxO2±δ compounds (existence of a miscibility gap, vaporization behavior) were compared to calculations based on new thermodynamic modelling of the U-Am-O ternary system. Finally, α-self-irradiation-induced structural effects on U1-xAmxO2±δ compounds were analyzed using XRD, XAS and TEM, allowing the influence of americium content on the structural swelling to be studied as well as the description of the evolution of radiation-induced structural defects. (author)

  2. Neptunium and americium control for international non-proliferation regime

    International Nuclear Information System (INIS)

    It was decided in the IAEA Board of Governors Meeting held in Sept. 1999 that Neptunium and Americium could be diverted for manufacturing nuclear weapon or explosives, so that appropriate measures should be taken for the prevention of proliferation of these materials. It is expected to take relatively long time for settling down the aligned system dealing with the above materials because the present regulatory statement was prepared on the basis of voluntary offers from the States concerned. The necessity of preventive measures is being convinced among Member States, but it would not be easy to take voluntary participation in detail because of their respective interests. It is expected that this paper could contribute to the effective response as to the international commitments as well as for protecting the domestic nuclear industry and R and D area through analysis on the IAEA's approach on Neptunium and Americium

  3. Thermophysical properties of americium-containing barium plutonate

    International Nuclear Information System (INIS)

    Polycrystalline specimens of americium-containing barium plutonate have been prepared by mixing the appropriate amounts of (Pu0.91Am0.09)O2 and BaCO3 powders followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. Elastic moduli were determined from longitudinal and shear sound velocities. Debye temperature was also determined from sound velocities and lattice parameter measurements. Thermal conductivity was calculated from measured density at room temperature, literature values of heat capacity and thermal diffusivity measured by laser flash method in vacuum. Thermal conductivity of americium-containing barium plutonate was roughly independent of temperature and registered almost the same magnitude as that of BaPuO3 and BaUO3. (author)

  4. 1976 Hanford americium-exposure incident: decontamination and treatment facility

    International Nuclear Information System (INIS)

    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

  5. 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.

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

    Science.gov (United States)

    FitzPatrick, John R.; Dunn, Jerry G.; Avens, Larry R.

    1987-01-01

    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, 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.

  7. Gut uptake factors for plutonium, americium and curium

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  9. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  10. Uncertainty analysis of doses from ingestion of plutonium and americium.

    Science.gov (United States)

    Puncher, M; Harrison, J D

    2012-02-01

    Uncertainty analyses have been performed on the biokinetic model for americium currently used by the International Commission on Radiological Protection (ICRP), and the model for plutonium recently derived by Leggett, considering acute intakes by ingestion by adult members of the public. The analyses calculated distributions of doses per unit intake. Those parameters having the greatest impact on prospective doses were identified by sensitivity analysis; the most important were the fraction absorbed from the alimentary tract, f(1), and rates of uptake from blood to bone surfaces. Probability distributions were selected based on the observed distribution of plutonium and americium in human subjects where possible; the distributions for f(1) reflected uncertainty on the average value of this parameter for non-specified plutonium and americium compounds ingested by adult members of the public. The calculated distributions of effective doses for ingested (239)Pu and (241)Am were well described by log-normal distributions, with doses varying by around a factor of 3 above and below the central values; the distributions contain the current ICRP Publication 67 dose coefficients for ingestion of (239)Pu and (241)Am by adult members of the public. Uncertainty on f(1) values had the greatest impact on doses, particularly effective dose. It is concluded that: (1) more precise data on f(1) values would have a greater effect in reducing uncertainties on doses from ingested (239)Pu and (241)Am, than reducing uncertainty on other model parameter values and (2) the results support the dose coefficients (Sv Bq(-1) intake) derived by ICRP for ingestion of (239)Pu and (241)Am by adult members of the public.

  11. Recovery of americium-241 from aged plutonium metal

    International Nuclear Information System (INIS)

    After separation and purification, both actinides were precipitated as oxalates and calcined. A large-scale process was developed using dissolution, separation, purification, precipitation, and calcination. Efforts were made to control corrosion, to avoid product contamination, to keep the volume of process and waste solutions manageable, and to denitrate solutions with formic acid. The Multipurpose Processing Facility (MPPF), designed for recovery of transplutonium isotopes, was used for the first time for the precipitation and calcination of americium. Also, for the first time,, large-scale formic acid denitration was performed in a canyon vessel at SRP

  12. Effect of 241-americium on bone marrow stroma

    International Nuclear Information System (INIS)

    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)

  13. Preferential decorporation of americium by pulmonary administration of DTPA dry powder after inhalation of aged PuO2 containing americium in rats

    International Nuclear Information System (INIS)

    After inhalation of plutonium oxides containing various percentages of americium in rats, we identified an acellular transient pulmonary compartment, the epithelial lining fluid (ELF), in which a fraction of actinide oxides dissolve prior to absorption and subsequent extrapulmonary deposit. Chelation therapy is usually considered to be poorly efficient after inhalation of actinide oxides. However, in the present study, prompt pulmonary administration of diethylenetriaminepentaacetic acid (DTPA) as a dry powder led to a decrease in actinide content in ELF together with a limitation of bone and liver deposits. Because americium is more soluble than plutonium, higher amounts of americium were found in ELF, extrapulmonary tissues and urine. Our results also demonstrated that the higher efficacy of DTPA on americium compared to plutonium in ELF induced a preferential inhibition of extrapulmonary deposit and a greater urinary excretion of americium compared to plutonium. All together, our data justify the use of an early and local DTPA treatment after inhalation of plutonium oxide aerosols in which americium can be in high proportion such as in aged compounds. (authors)

  14. Analytical performance of radiochemical method for americium determination in urine

    International Nuclear Information System (INIS)

    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 243Am 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-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)

  15. Development of separation techniques of americium from reprocessing solution

    International Nuclear Information System (INIS)

    Americium(Am) and neptunium(Np) finally transfer to the waste stream in the current PUREX reprocessing process. As an option, some methods have been developed to recover Am and Np from the waste stream to decrease long-term toxicity of the high level waste. The most stable valence state of Am is III, but TBP (tri-n-butyl phosphate) which is an extractant used in the PUREX reprocessing does not extract Am(III). Therefore, some special extractants have been developed to recover Am(III). However, they also extract rare-earth elements(REs), which necessitates the separation process for Am from REs. We have been developing a separation process which consists of valence control of Am to the VI state and its extraction with TBP. This process allows Am recovery from reprocessing solution and Am separation from REs simultaneously. Americium(III) is oxidized to Am(VI) by electrochemical oxidation and chemical oxidation using peroxodisulfate ammonium and silver nitrate. The latter was adopted here because the chemical oxidation reaction proceeds faster than the electrochemical method. Reaction mechanisms of oxidation and extraction were investigated. Based on the mechanisms, we found that extraction efficiency could be improved and waste generation could be minimized. (author)

  16. Selective leaching studies of deep-sea sediments loaded with americium, neptunium and plutonium

    International Nuclear Information System (INIS)

    A series of selective leaching experiments were undertaken to investigate the solid phase speciation and distribution of americium, neptunium and plutonium which had been experimentally loaded onto different marine sediment types. The chemical leaches employed showed rather poor selectivity but certain trends were evident. Adsorption was not by ion exchange. Americium showed a preferential affinity for carbonate and plutonium for organic matter. Neptunium appeared to have no preferential affinities. Americium was sorbed by acetic acid residues (CaCO3 removed) and by unleached carbonate-rich sediments with equal efficiency. This indicates that it is able to diversify its solid phase affinity/distribution depending upon which solid phases are available. (author)

  17. Pretreatment of americium/curium solutions for vitrification

    International Nuclear Information System (INIS)

    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

  18. Plutonium and americium in sediments of Lithuanian lakes

    International Nuclear Information System (INIS)

    The assessment of contribution of the global and the Chernobyl NPP (Nuclear Power Plant) accident plutonium and americium to plutonium pollution in sediments of Lithuanian lakes is presented. Theoretical evaluation of activity ratios of 238Pu/239+240Pu and 241Pu/239+240Pu in the reactor of unit 4 of the Chernobyl NPP before the accident was performed by means of the ORIGEN-ARP code from the SCALE 4.4A program package. Non-uniform distribution of radionuclides in depositions on the Lithuanian territory after nuclear weapon tests and the Chernobyl NPP accident is experimentally observed by measuring the lake sediment pollution with actinides. The activity concentration of sediments polluted with plutonium ranges from 2.0 ± 0.5 Bq/kg d.w. (dry weight) in Lake Asavelis to 14 ± 2 Bq/kg d.w. in Lake Juodis. The ratio of activity concentrations of plutonium isotopes 238Pu/239+240Pu measured by α-spectrometry in the 10-cm-thick upper layer of bottom sediment varies from 0.03 in Lake Juodis to 0.3 in Lake Zuvintas. The analysis of the ratio values shows that the deposition of the Chernobyl origin plutonium is prevailing in southern and south-western regions of Lithuania. Plutonium of nuclear weapon tests origin in sediments of lakes is observed on the whole territory of Lithuania, and it is especially distinct in central Lithuania. The americium activity due to 241Pu decay after the Chernobyl NPP accident and global depositions in bottom sediments of Lithuanian lakes has been evaluated to be from 0.9 to 5.7 Bq/kg. (author)

  19. 27 CFR 28.244 - Shipment to manufacturing bonded warehouse.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Shipment to manufacturing... Export Consignment § 28.244 Shipment to manufacturing bonded warehouse. Distilled spirits and wines withdrawn for shipment to a manufacturing bonded warehouse shall be consigned to the proprietor of...

  20. Kinetic parameters of transformation of americium and plutonium physicochemical forms in podsol soils

    International Nuclear Information System (INIS)

    Kinetic parameters of transformation of americium and plutonium physicochemical forms have been estimated and the prognosis of fixing and remobilization of these nuclides in podsol soils have been made on that basis in the work. (authors)

  1. Calibration procedures for in vivo sodium iodide spectrometry of plutonium and americium in the human lung

    International Nuclear Information System (INIS)

    This paper describes the calibration techniques and associated error analysis for the in vivo measurement by NaI spectrometry of heavy elements in the lung, specifically plutonium and americium. A very brief description of the instrumentation system is included

  2. Relativistic density functional theory modeling of plutonium and americium higher oxide molecules

    Science.gov (United States)

    Zaitsevskii, Andréi; Mosyagin, Nikolai S.; Titov, Anatoly V.; Kiselev, Yuri M.

    2013-07-01

    The results of electronic structure modeling of plutonium and americium higher oxide molecules (actinide oxidation states VI through VIII) by two-component relativistic density functional theory are presented. Ground-state equilibrium molecular structures, main features of charge distributions, and energetics of AnO3, AnO4, An2On (An=Pu, Am), and PuAmOn, n = 6-8, are determined. In all cases, molecular geometries of americium and mixed plutonium-americium oxides are similar to those of the corresponding plutonium compounds, though chemical bonding in americium oxides is markedly weaker. Relatively high stability of the mixed heptoxide PuAmO7 is noticed; the Pu(VIII) and especially Am(VIII) oxides are expected to be unstable.

  3. Double-contained receiver tank 244-TX, grab samples, 244TX-97-3 analytical results for the final report

    Energy Technology Data Exchange (ETDEWEB)

    Esch, R.A.

    1997-08-13

    This document is the final report for the double-contained receiver tank (DCRT) 244-TX grab samples. Three grabs samples were collected from riser 8 on May 29, 1997. Analyses were performed in accordance with the Compatibility Grab Sampling and Analysis Plan (TSAP) and the Data Quality Objectives for Tank Farms Waste Compatibility Program (DQO). The analytical results are presented in a table.

  4. 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)

  5. 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.

  6. 8 CFR 244.10 - Decision by the director or Administrative Appeals Unit (AAU).

    Science.gov (United States)

    2010-01-01

    ... exercise of discretion, consistent with the standards for eligibility in §§ 244.2, 244.3, and 244.4. (c... her right to appeal a decision denying Temporary Protected Status. To exercise such right, the alien... shall be given, in English and in the language of the designated foreign state or a language that...

  7. 8 CFR 244.11 - Renewal of application; appeal to the Board of Immigration Appeals.

    Science.gov (United States)

    2010-01-01

    ... of Immigration Appeals. 244.11 Section 244.11 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.11 Renewal of application; appeal to the Board of Immigration Appeals. If a charging document is served on the alien with...

  8. 48 CFR 1852.244-70 - Geographic participation in the aerospace program.

    Science.gov (United States)

    2010-10-01

    ... the aerospace program. 1852.244-70 Section 1852.244-70 Federal Acquisition Regulations System NATIONAL... Provisions and Clauses 1852.244-70 Geographic participation in the aerospace program. As prescribed in 1844.204-70, insert the following clause: Geographic Participation in the Aerospace Program (APR 1985)...

  9. 27 CFR 24.244 - Use of acid to stabilize standard wine.

    Science.gov (United States)

    2010-04-01

    ... standard wine. 24.244 Section 24.244 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.244 Use of acid to stabilize standard wine. Standard wine other than citrus wine, regardless of the...

  10. 10 CFR 32.57 - Calibration or reference sources containing americium-241 or radium-226: Requirements for license...

    Science.gov (United States)

    2010-01-01

    ... or radium-226: Requirements for license to manufacture or initially transfer. 32.57 Section 32.57... americium-241 or radium-226: Requirements for license to manufacture or initially transfer. An application... containing americium-241 or radium-226, for distribution to persons generally licensed under § 31.8 of...

  11. Operability test procedure for 244-U DCRT. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Erhart, M.F.

    1995-03-13

    This OPT will insure the operability of various systems and their general equipment, used in the operation of the 244-U DCRT. Systems that will be tested include the following: Leak Detection Systems; Heat Trace System; Vessel Temperature Measurement System; Dip Tube Water System; Weight Factor and Specific Gravity System; Instrument Air System; Vessel Liquid Level System; Vessel Liquid Transfer System; and Exhauster Differential Pressure Indicating Controller System. The tests will cover checks on equipment operation and electrical interlocks, but will not cover checks on associated annunciator alarms which are covered in a separate OTP.

  12. Separation and determination of americium in low-level alkaline waste of NPP origin

    Science.gov (United States)

    Todorov, B.; Djingova, R.; Nikiforova, A.

    2006-01-01

    The aim of this work is to develop a short and cost-saving procedure for the determination of 241Am in sludge sample of the alkaline low-level radioactive waste (LL LRAW) collected from Nuclear Power Plant “Kozloduy”. The determination of americium was a part of a complex analytical approach, where group actinide separation was achieved. An anion exchange was used for separation of americium from uranium, plutonium and iron. For the separation of americium extraction with diethylhexyl phosphoric acid (DEHPA) was studied. The final radioactive samples were prepared by micro co-precipitation with NdF3, counted by alpha and gamma spectrometry. The procedure takes 2 hours. The recovery yield of the procedure amounts to (95 ± 1.5)% and the detection limit is 53 mBq/kg 241Am (t=150 000 s). The analytical procedure was applied for actual liquid wastes and results were compared to standard procedure.

  13. Isotopic and elemental composition of plutonium/americium oxides influence pulmonary and extra-pulmonary distribution after inhalation in rats

    International Nuclear Information System (INIS)

    The biodistribution of plutonium and americium has been studied in a rat model after inhalation of two PuO2 powders in lungs and extra-pulmonary organs from 3 d to 3 mo. The main difference between the two powders was the content of americium (approximately 46% and 4.5% of total alpha activity). The PuO2 with a higher proportion of americium shows an accelerated transfer of activity from lungs to blood as compared to PuO2 with the lower americium content, illustrated by increased urinary excretion and higher bone and liver actinide retention. The total alpha activity measured reflects mostly the americium biological behavior. The activity contained in epithelial lining fluid, recovered in the acellular phase of broncho-alveolar lavages, mainly contains americium, whereas plutonium remains trapped in macrophages. Epithelial lining fluid could represent a transitional pulmonary compartment prior to translocation of actinides to the blood and subsequent deposition in extra-pulmonary retention organs. In addition, differential behaviors of plutonium and americium are also observed between the PuO2 powders with a higher dissolution rate for both plutonium and americium being obtained for the PuO2 with the highest americium content. Our results indicate that the biological behavior of plutonium and americium after translocation into blood differ two-fold: (1) for the two actinides for the same PuO2 aerosol, and (2) for the same actinide from the two different aerosols. These results highlight the importance of considering the specific behavior of each contaminant after accidental pulmonary intake when assessing extra-pulmonary deposits from the level of activity excreted in urine or for therapeutic strategy decisions. (authors)

  14. Isotopic and elemental composition of plutonium/americium oxides influence pulmonary and extra-pulmonary distribution after inhalation in rats.

    Science.gov (United States)

    Van der Meeren, A; Grémy, O

    2010-09-01

    The biodistribution of plutonium and americium has been studied in a rat model after inhalation of two PuO(2) powders in lungs and extra-pulmonary organs from 3 d to 3 mo. The main difference between the two powders was the content of americium (approximately 46% and 4.5% of total alpha activity). The PuO(2) with a higher proportion of americium shows an accelerated transfer of activity from lungs to blood as compared to PuO(2) with the lower americium content, illustrated by increased urinary excretion and higher bone and liver actinide retention. The total alpha activity measured reflects mostly the americium biological behavior. The activity contained in epithelial lining fluid, recovered in the acellular phase of broncho-alveolar lavages, mainly contains americium, whereas plutonium remains trapped in macrophages. Epithelial lining fluid could represent a transitional pulmonary compartment prior to translocation of actinides to the blood and subsequent deposition in extra-pulmonary retention organs. In addition, differential behaviors of plutonium and americium are also observed between the PuO(2) powders with a higher dissolution rate for both plutonium and americium being obtained for the PuO(2) with the highest americium content. Our results indicate that the biological behavior of plutonium and americium after translocation into blood differ two-fold: (1) for the two actinides for the same PuO(2) aerosol, and (2) for the same actinide from the two different aerosols. These results highlight the importance of considering the specific behavior of each contaminant after accidental pulmonary intake when assessing extra-pulmonary deposits from the level of activity excreted in urine or for therapeutic strategy decisions.

  15. 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)

    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 237Pu 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)

  16. Cesium-137 and americium-241 distribution by granulometric fractions of soil at Azgir test site grounds

    International Nuclear Information System (INIS)

    In measurements of radionuclide specific content in surface soil layer of contaminated territories it is important to determine in what agglomerations of soil particles there is the highest radionuclide concentration. For this purpose granulometric composition of soil at Azgir test site was studied and cesium-137 and americium-241 distribution by soil fractions was researched. (author)

  17. Apparatus for fabrication of americium- beryllium neutron sources prevents capsule contamination

    Science.gov (United States)

    Mohr, W. C.; Van Loom, J. A.

    1967-01-01

    Modified gloved enclosure is used to fill a capsule with a mixture of americium and beryllium radioactive powders to seal weld the opening, and to test it for leaks. It contains a horizontal partition, vortex mixer, mounting press, welder, test vessel, and radiation shielding to prevent surface contamination.

  18. 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...

  19. Effect of bone-status on retention and distribution of americium-241 in bones of small rodents

    International Nuclear Information System (INIS)

    Forced physical exercise before and after application of americium-241 resulted in only small changes in bone-structure and behaviour of the radionuclide in bone. Feeding of a low phosphorus or low calcium diet resulted in an increased excretion of americium from bone, whereby Zn-DTPA as chelating agent removed an additional fraction of the radionuclide from bone. Low calcium diet and simultaneous continuous infusion of pharmacological doses of vitamin D-hormones didn't increase the excretion of americium more than the low calcium diet alone. (orig.)

  20. 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

  1. Preparation of powdered CR244 adhesive type chloroprene rubber%CR244粘接型粉末氯丁橡胶的制备

    Institute of Scientific and Technical Information of China (English)

    朱家顺; 王炼石; 梁启浩

    2003-01-01

    用凝聚法制备出粉末粘接型氯丁橡胶(PCR244).研究了包覆剂性质对PCR244粒径分布的影响,并用SEM对所得PCR244的形貌及断面进行了观察分析.研究表明,在CR244粉末化体系中,包覆剂必须具有一定的交联程度才能起粉末化作用.在研究范围内,包覆剂的θg对粒径小于0.9mm产物的成粉率几乎无影响,均达到98.6%以上.SEM分析表明,PCR244宏观粒子表面粗糙,粒子内外均分布着大量空隙,其形成过程可分为三个主要阶段,即在包覆剂作用下,首先由胶乳初级粒子聚结成次级粒子,再由次级粒子凝聚成团粒,最后团粒相互结合成宏观粒子PCR244.

  2. SKIN DOSIMETRY IN CONDITIONS OF ITS CONSTANT SURFACE CONTAMINATION WITH SOLUTIONS OF PLUTONIUM-239 AND AMERICIUM-241

    Directory of Open Access Journals (Sweden)

    E. B. Ershov

    2012-01-01

    Full Text Available The article considers, on the basis of experimental data, the issue of assessing dose burdens to the skin basal layer in conditions of its permanent contamination with solutions of plutonium-239 and americium-241 and subsequent decontamination.

  3. 8 CFR 244.5 - Temporary treatment benefits for eligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Temporary treatment benefits for eligible aliens. 244.5 Section 244.5 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... for eligible aliens. (a) Prior to the registration period. Prior to the registration...

  4. 49 CFR 244.11 - Contents of a Safety Integration Plan.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Contents of a Safety Integration Plan. 244.11... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS ON SAFETY INTEGRATION PLANS GOVERNING RAILROAD CONSOLIDATIONS, MERGERS, AND ACQUISITIONS OF CONTROL Safety Integration Plans § 244.11 Contents of a...

  5. 9 CFR 354.244 - Temperatures and cooling and freezing procedures.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Temperatures and cooling and freezing procedures. 354.244 Section 354.244 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... and cooling and freezing procedures. Temperatures and procedures which are necessary for cooling...

  6. Influence of biofilms on migration of uranium, americium and europium in the environment; Einfluss von Biofilmen auf das Migrationsverhalten von Uran, Americium und Europium in der Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-07-01

    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).

  7. Liquid-liquid extraction separation and sequential determination of plutonium and americium in environmental samples by alpha-spectrometry

    International Nuclear Information System (INIS)

    A procedure is described by which plutonium and americium can be determined in environmental samples. The sample is leached with nitric acid and hydrogen peroxide, and the two elements are co-precipitated with ferric hydroxide and calcium oxalate. The calcium oxalate is incinerated at 4500 and the ash is dissolved in nitric acid. Plutonium is extracted with tri-n-octylamine solution in xylene from 4M nitric acid and stripped with ammonium iodide/hydrochloric acid. Americium is extracted with thenoyltrifluoroacetone solution in xylene at pH 4 together with rare-earth elements and stripped with 1M nitric acid. Americium and the rare-earth elements thus separated are sorbed on Dowex 1 x 4 resin from 1M nitric acid in 93% methanol, the rare-earth elements are eluted with 0.1M hydrochloric acid/0.5M ammonium thiocyanate/80% methanol and the americium is finally eluted with 1.5M hydrochloric acid in 86% methanol. Plutonium and americium in each fraction are electro-deposited and determined by alpha-spectrometry. Overall average recoveries are 81% for plutonium and 59% for americium. (author)

  8. Involvement of CD244 in regulating CD4+ T cell immunity in patients with active tuberculosis.

    Directory of Open Access Journals (Sweden)

    Bingfen Yang

    Full Text Available CD244 (2B4 is a member of the signaling lymphocyte activation molecule (SLAM family of immune cell receptors and it plays an important role in modulating NK cell and CD8(+ T cell immunity. In this study, we investigated the expression and function of CD244/2B4 on CD4(+ T cells from active TB patients and latent infection individuals. Active TB patients had significantly elevated CD244/2B4 expression on M. tuberculosis antigen-specific CD4(+ T cells compared with latent infection individuals. The frequencies of CD244/2B4-expressing antigen-specific CD4(+ T cells were significantly higher in retreatment active TB patients than in new active TB patients. Compared with CD244/2B4-dull and -middle CD4(+ T cells, CD244/2B4-bright CD4(+ T cell subset had significantly reduced expression of IFN-γ, suggesting that CD244/2B4 expression may modulate IFN-γ production in M. tuberculosis antigen-responsive CD4(+ T cells. Activation of CD244/2B4 signaling by cross-linking led to significantly decreased production of IFN-γ. Blockage of CD244/2B4 signaling pathway of T cells from patients with active TB resulted in significantly increased production of IFN-γ, compared with isotype antibody control. In conclusion, CD244/2B4 signaling pathway has an inhibitory role on M. tuberculosis antigen-specific CD4(+ T cell function.

  9. Influence of environmental factors on the gastrointestinal absorption of plutonium and americium

    International Nuclear Information System (INIS)

    The absorption of plutonium and americium from the gastrointestinal tract was studied, using adult hamsters and rabbits. Both actinides were administered as inorganic compounds, as organic complexes with naturally occurring chelating agents, and in a biologically incorporated form in liver tissues. The absorption of the tetravalent and hexavalent forms of plutonium were compared and the effect of protracted administration at very low concentrations was investigated. In addition, plutonium uptake from contaminated sediments and grass, collected near a nuclear-fuel reprocessing plant, was measured. The results of these studies suggest that chronic exposure of man to plutonium and americium in food and water will not lead to any substantial increase in their gastrointestinal absorption above the values currently recommended by the International Commission on Radiological Protection to define the occupational exposure of workers

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

    International Nuclear Information System (INIS)

    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 AmO2 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-AmCl3 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)

  11. Analysis of americium-beryllium neutron source composition using the FRAM code

    Energy Technology Data Exchange (ETDEWEB)

    Hypes, P. A. (Philip A.); Bracken, D. S. (David S.); Sampson, Thomas E.; Taylor, W. A. (Wayne A.)

    2002-01-01

    The FRAM code was originally developed to analyze high-resolution gamma spectra from plutonium items. Its capabilities have since been expanded to include analysis of uranium spectra. The flexibility of the software also enables a capable spectroscopist to use FRAM to analyze spectra in which neither plutonium nor uranium is present in significant amounts. This paper documents the use of FRAM to determine the {sup 239}Pu/{sup 241}Am, {sup 243}Am/{sup 241}Am, {sup 237}Np/{sup 241}Am, and {sup 239}Np/{sup 241}Am ratios in americium-beryllium neutron sources. The effective specific power of each neutron source was calculated from the ratios determined by FRAM in order to determine the americium mass of each of these neutron sources using calorimetric assay. We will also discuss the use of FRAM for the general case of isotopic analysis of nonplutonium, nonuranium items.

  12. Experimental Insight into the Radiation Resistance of Zirconia-Based Americium Ceramics

    International Nuclear Information System (INIS)

    Our works shows that the americium pyrochlore 241Am2Zr2O7 undergoes a phase transition to a defect-fluorite structure along with an unusual volume contraction when subjected to internal radiation from α-emitting actinides. Disorder relaxation proceeds through the simultaneous formation of cation anti sites and oxygen Frenkel pairs. X-ray absorption spectroscopy at the Am-LII and the Zr-K edges reveals that Am-O polyhedra show an increasing disorder with increasing exposure. In contrast, the Zr-O polyhedral units remain highly ordered, while rotating along edges and corners, thereby reducing the structural strain imposed by the growing disorder around americium. We believe it is this particular property of the compound that provides the remarkable resistance to radiation (≥9.4 * 1018) α-decay events g-1 or 0.80 dpa). (authors)

  13. Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 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.

  14. Calcium and zinc DTPA administration for internal contamination with plutonium-238 and americium-241.

    Science.gov (United States)

    Kazzi, Ziad N; Heyl, Alexander; Ruprecht, Johann

    2012-08-01

    The accidental or intentional release of plutonium or americium can cause acute and long term adverse health effects if they enter the human body by ingestion, inhalation, or injection. These effects can be prevented by rapid removal of these radionuclides by chelators such as calcium or zinc diethylenetriaminepentaacetate (calcium or zinc DTPA). These compounds have been shown to be efficacious in enhancing the elimination of members of the actinide family particularly plutonium and americium when administered intravenously or by nebulizer. The efficacy and adverse effects profile depend on several factors that include the route of internalization of the actinide, the type, and route time of administration of the chelator, and whether the calcium or zinc salt of DTPA is used. Current and future research efforts should be directed at overcoming limitations associated with the use of these complex drugs by using innovative methods that can enhance their structural and therapeutic properties.

  15. 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.

  16. Table of radionuclides (Vol. 5 - A = 22 to 244)

    Energy Technology Data Exchange (ETDEWEB)

    Be, M.M.; Chiste, V.; Dulieu, C.; Mougeot, X.; Browne, E.; Chechev, V.; Kuzmenko, N.; Kondev, F.; Luca, A.; Galan, M.; Arinc, A.; Huang, X.

    2010-07-01

    have agreed on the methodologies to be used and the CD-ROM included with this monograph contains the evaluators' comments for each radionuclide in addition to the data tables included in the monograph. This volume includes the evaluation of the following radionuclides: {sup 22}Na, {sup 40}K, {sup 75}Se, {sup 124}Sb, {sup 207}Bi, {sup 211}Bi, {sup 217}At, {sup 222}Ra, {sup 225}Ac, {sup 228}Ra, {sup 231}Th, {sup 232}Th, {sup 233}Th, {sup 233}Pa, {sup 234}Th, {sup 235}U, {sup 237}U, {sup 238}Pu, {sup 240}Pu, {sup 241}Am, {sup 242}Pu, {sup 242}Am, {sup 243}Am, {sup 244}Am, {sup 244}Am{sup m}. Primary recommended data comprise half-lives, decay modes, X-rays, gamma-rays, electron emissions, alpha -and beta- particle transitions and emissions, and their uncertainties

  17. Bidentate organophosphorus extraction of americium and plutonium from Hanford Plutonium Reclamation Facility waste

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1974-09-01

    Applicability of bidentate organiphosphorus reagents to recovery of americium and plutonium from Hanford's Plutonium Reclamation Facility acid (approx. 2M HNO/sub 3/) waste stream (CAW solution) was studied. A solvent extraction process which employs a 30% DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate)-CCl/sub 4/ extractant was devised and successfully tested in mixer-settler runs with actual CAW solution. Substitution of DHDECMP for DBBP eliminates the need to perform careful neutralization of unbuffered CAW soluton and increases overall americium recovery from the present 60 to 80% level to greater than or equal to 90%. Disadvantages to such substitution include the high cost (approx. $50/liter) of DHDECMP and the need to purify it (by acid (6M HCl) hydrolysis and alkaline washing) from small amounts of an unidentified impurity which prevents stripping of americium with dilute HNO/sub 3/. Distribution data obtained in this study confirm Siddall's earlier contention that bidentate organophosphorus regents can be used to remove actinides from concentrated high-level Purex process acid waste; a conceptual flowsheet for such an extraction process is given.

  18. 49 CFR 244.15 - Subjects to be addressed in a Safety Integration Plan not involving an amalgamation of operations.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Subjects to be addressed in a Safety Integration Plan not involving an amalgamation of operations. 244.15 Section 244.15 Transportation Other... ACQUISITIONS OF CONTROL Safety Integration Plans § 244.15 Subjects to be addressed in a Safety Integration...

  19. 10 CFR 72.244 - Application for amendment of a certificate of compliance.

    Science.gov (United States)

    2010-01-01

    ... INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C WASTE Approval of Spent Fuel Storage Casks § 72.244 Application for amendment of a...

  20. Above-threshold structure in {sup 244}Cm neutron-induced fission cross section

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    The quasi-resonance structure appearing above the fission threshold in neutron-induced fission cross section of {sup 244}Cm(n,f) is interpreted. It is shown to be due to excitation of few-quasiparticle states in fissioning {sup 245}Cm and residual {sup 244}Cm nuclides. The estimate of quasiparticle excitation thresholds in fissioning nuclide {sup 245}Cm is consistent with pairing gap and fission barrier parameters. (author)

  1. Americium(3) coordination chemistry: An unexplored diversity of structure and bonding

    Energy Technology Data Exchange (ETDEWEB)

    Fedosseev, A.M.; Grigoriev, M.S.; Budantseva, N.A. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow (Russian Federation); Guillaumont, D.; Den Auwer, Ch.; Moisy, Ph. [CEA Marcoule, Nuclear Energy Division, RadioChemistry and Processes Department, 30 (France); Le Naour, C.; Simoni, E. [CNRS, University Paris-11 Orsay, IPN, 91 - Orsay (France)

    2010-06-15

    The comparison of the physicochemical behavior of the actinides with that of the lanthanides can be justified by the analogy of their electronic structure, as each of the series is made up of elements corresponding to the filling of a given (n)f atomic shell. However relatively few points of comparison are available, given the lack of available structure for trans-plutonium(III) elements and the additional difficulty of stabilizing coordination complexes of uranium(III) to plutonium(III). This contribution is a focal point of trans-plutonium(III) chemistry and, more specifically, of some americium compounds that have been recently synthesized, all related with hard acid oxygen donor ligands that may be involved in the reprocessing chain of nuclear fuel. After a brief review of the solid hydrates and aquo species for the lanthanide and actinide families, we discuss two types of ligands that have in common three carboxylic groups, namely the amino-tri-acetic acid and the citric acid anions. The additional roles of the nitrogen atom for the first one and of the hydroxy function for the second one are discussed. Accordingly, five new complexes with either americium or lanthanides elements are described: [Co(NH{sub 3}){sub 6}][M(NTA){sub 2}(H{sub 2}O)].8H{sub 2}O with M Nd, Yb and Am, and [Co(NH{sub 3}){sub 6}]{sub 2}K[M{sub 3}(Cit){sub 4}(H{sub 2}O){sub 3}].18H{sub 2}O with Nd and Am cations. In all cases the americium complexes are isostructural with their lanthanide equivalents. (authors)

  2. Americium(3) coordination chemistry: An unexplored diversity of structure and bonding

    International Nuclear Information System (INIS)

    The comparison of the physicochemical behavior of the actinides with that of the lanthanides can be justified by the analogy of their electronic structure, as each of the series is made up of elements corresponding to the filling of a given (n)f atomic shell. However relatively few points of comparison are available, given the lack of available structure for trans-plutonium(III) elements and the additional difficulty of stabilizing coordination complexes of uranium(III) to plutonium(III). This contribution is a focal point of trans-plutonium(III) chemistry and, more specifically, of some americium compounds that have been recently synthesized, all related with hard acid oxygen donor ligands that may be involved in the reprocessing chain of nuclear fuel. After a brief review of the solid hydrates and aquo species for the lanthanide and actinide families, we discuss two types of ligands that have in common three carboxylic groups, namely the amino-tri-acetic acid and the citric acid anions. The additional roles of the nitrogen atom for the first one and of the hydroxy function for the second one are discussed. Accordingly, five new complexes with either americium or lanthanides elements are described: [Co(NH3)6][M(NTA)2(H2O)].8H2O with M Nd, Yb and Am, and [Co(NH3)6]2K[M3(Cit)4(H2O)3].18H2O with Nd and Am cations. In all cases the americium complexes are isostructural with their lanthanide equivalents. (authors)

  3. MARIOS: Irradiation of UO{sub 2} containing 15% americium at well defined temperature

    Energy Technology Data Exchange (ETDEWEB)

    D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy - P.O. Box 2, 1755 ZG Petten (Netherlands); Hania, P.R. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Bejaoui, S. [Commissariat a l' Energie Atomique, DEC CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France); Sciolla, C.; Wyatt, T.; Hannink, M.H.C. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Herlet, N.; Jankowiak, A. [Commissariat a l' Energie Atomique DTEC CEA Marcoule, 30207 Bagnols sur Ceze Cedex (France); Klaassen, F.C. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Bonnerot, J.-M. [Commissariat a l' Energie Atomique, DEC CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer MARIOS is designed to check the behaviour of Minor Actinide Blanket Module concept. Black-Right-Pointing-Pointer Main requirement of the experiment is an accurate control of the temperature. Black-Right-Pointing-Pointer The swelling and the helium release will be the main output of the experiment. Black-Right-Pointing-Pointer A complementary experiment (DIAMINO), will be performed in the next future. - Abstract: Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. The MARIOS irradiation experiment is the latest of a series of experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS). MARIOS experiment is carried out in the framework of the 4-year project FAIRFUELS of the EURATOM 7th Framework Programme (FP7). During the past years of experimental work in the field of transmutation and tests of innovative nuclear fuel containing americium, the release or trapping of helium as well as swelling has shown to be the key issue for the design of such kinds of target. Therefore, the main objective of the MARIOS experiment is to study the in-pile behaviour of UO{sub 2} containing minor actinides (MAs) in order to gain knowledge on the role of the microstructure and of the temperature on the gas release and on fuel swelling. The MARIOS experiment will be conducted in the HFR (high flux reactor) in Petten (The Netherlands) and will start in the beginning of 2011. It has been planned that the experiment will last 11 cycles, corresponding to 11 months. This paper covers the description of the objective of the experiment, as well as a general description of the design of the experiment.

  4. 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

  5. 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

  6. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    International Nuclear Information System (INIS)

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg−1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (∼0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13− coordination environment (e.g. >90%) and no (III XAFS spectra recorded for the irradiated MOX sub-sample in the rim zone for a 300 μm×300 μm beam size area investigated over six scans of 4 h. The records remain constant during multi-scan. The analysis of the XAFS signal shows that Am is found as trivalent in the UO2 matrix. This analytical work shall open the door of very challenging analysis (speciation of fission product and actinides) in irradiated nuclear fuels. - Highlights: • Americium was characterized by microX-ray absorption spectroscopy in irradiated MOX fuel. • The americium redox state as determined from XAS data of irradiated fuel material was Am(III). • In the sample, the Am3+ face an AmO813− coordination environment in the (Pu,U)O2 matrix. • The americium dioxide is reduced by the uranium dioxide matrix

  7. 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.

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

    International Nuclear Information System (INIS)

    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).

  9. 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

    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...... plutonium from the latter to Spitsbergen waters. Fallout plutonium in Arctic waters has a residence time of the order of several years, while for Pu from Sellafield we estimate mean residence times of 11–15 months in Scottish waters and, tentatively, 1·5-3 y during transport from the North Channel (north...

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

    International Nuclear Information System (INIS)

    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. Purification of used scintillation liquids containing the alpha emitters americium and plutonium

    International Nuclear Information System (INIS)

    In Sweden, alpha radioactive waste liquids with an activity over some kBq per waste container cannot be sent for final storage. Therefore, in this work, a method for a purification of alpha active scintillation cocktails was developed. Until today (March, 2013) more than 20 L of scintillation liquids have successfully been purified from americium and plutonium. The products of the process are a solid fraction that can be sent to final storage and a practically non-radioactive liquid fraction that can be sent to municipal incineration. (author)

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

    International Nuclear Information System (INIS)

    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

  13. Anthropogenic plutonium-244 in the environment: Insights into plutonium’s longest-lived isotope

    Science.gov (United States)

    Armstrong, Christopher R.; Brant, Heather A.; Nuessle, Patterson R.; Hall, Gregory; Cadieux, James R.

    2016-02-01

    Owing to the rich history of heavy element production in the unique high flux reactors that operated at the Savannah River Site, USA (SRS) decades ago, trace quantities of plutonium with highly unique isotopic characteristics still persist today in the SRS terrestrial environment. Development of an effective sampling, processing, and analysis strategy enables detailed monitoring of the SRS environment, revealing plutonium isotopic compositions, e.g., 244Pu, that reflect the unique legacy of plutonium production at SRS. This work describes the first long-term investigation of anthropogenic 244Pu occurrence in the environment. Environmental samples, consisting of collected foot borne debris, were taken at SRS over an eleven year period, from 2003 to 2014. Separation and purification of trace plutonium was carried out followed by three stage thermal ionization mass spectrometry (3STIMS) measurements for plutonium isotopic content and isotopic ratios. Significant 244Pu was measured in all of the years sampled with the highest amount observed in 2003. The 244Pu content, in femtograms (fg = 10-15 g) per gram, ranged from 0.31 fg/g to 44 fg/g in years 2006 and 2003 respectively. In all years, the 244Pu/239Pu atom ratios were significantly higher than global fallout, ranging from 0.003 to 0.698 in years 2014 and 2003 respectively.

  14. Anthropogenic plutonium-244 in the environment: Insights into plutonium’s longest-lived isotope

    Science.gov (United States)

    Armstrong, Christopher R.; Brant, Heather A.; Nuessle, Patterson R.; Hall, Gregory; Cadieux, James R.

    2016-01-01

    Owing to the rich history of heavy element production in the unique high flux reactors that operated at the Savannah River Site, USA (SRS) decades ago, trace quantities of plutonium with highly unique isotopic characteristics still persist today in the SRS terrestrial environment. Development of an effective sampling, processing, and analysis strategy enables detailed monitoring of the SRS environment, revealing plutonium isotopic compositions, e.g., 244Pu, that reflect the unique legacy of plutonium production at SRS. This work describes the first long-term investigation of anthropogenic 244Pu occurrence in the environment. Environmental samples, consisting of collected foot borne debris, were taken at SRS over an eleven year period, from 2003 to 2014. Separation and purification of trace plutonium was carried out followed by three stage thermal ionization mass spectrometry (3STIMS) measurements for plutonium isotopic content and isotopic ratios. Significant 244Pu was measured in all of the years sampled with the highest amount observed in 2003. The 244Pu content, in femtograms (fg = 10−15 g) per gram, ranged from 0.31 fg/g to 44 fg/g in years 2006 and 2003 respectively. In all years, the 244Pu/239Pu atom ratios were significantly higher than global fallout, ranging from 0.003 to 0.698 in years 2014 and 2003 respectively. PMID:26898531

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

    International Nuclear Information System (INIS)

    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 (CO3)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-CO3 complexes are not needed). No evidence of Am(CO3)45- 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 PuO2(CO3) is measured in bicarbonate media at high ionic strength, to obtain the solubility product and formation constants of the PuO2(CO3)i2-2i complexes

  16. 胶态二氧化硅SYLOID244FP固化肉桂挥发油的研究%Study on solidifying volatile oil of cinnamon with colloidal silicon dioxide SYLOID244FP

    Institute of Scientific and Technical Information of China (English)

    蒋艳荣; 张振海; 胡绍英; 贾晓斌

    2013-01-01

    目的:评价胶态二氧化硅SYLOID244FP固化肉桂挥发油的特性.方法:采用SYLOID244FP固化肉桂挥发油,以桂皮醛收率为指标,优选SYLOID244FP用量;采用差示扫描量热法和扫描电镜法对固化粉末进行物相表征;考察SY-LOID244FP对肉桂挥发油中桂皮醛体外溶出和受热稳定性的影响.结果:SYLOID244FP与肉桂挥发油最佳固化比例1∶1,肉桂挥发油被固化之后,体外溶出速率加快,受热稳定性提高.结论:SYLOID244FP吸附固化中药挥发油值得进一步研究.%Objective:To evaluate the properties of solidifying volatile oil of cinnamon with colloidal silicon dioxide SYLOID244FP.Method:Volatile oil of cinnamon was solidified by SYLOID244FP.The amount of SYLOID244FP was optimized with the cinnamaldehyde yield as criteria.Curing powder was characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).The effects of SYLOID244FP on dissolution in vitro and thermal stability of cinnamaldehyde were studied.Result:The optimum solidification ratio of SYLOID244FP to volatile oil of cinnamon was 1 ∶ 1.Dissolution rate of cinnamaldehyde increasesd and its thermal stability improved after volatile oil of cinnamon was solidified.Conclusion:Solidifying herbal volatile oil with SY-LOID244FP deserves studying further.

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

    International Nuclear Information System (INIS)

    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.)

  18. EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of Americium in a USTUR leg phantom

    International Nuclear Information System (INIS)

    A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here. (authors)

  19. Anomalous aryl strengthening of americium and europium complexes during extraction by alkylenediphosphine dioxides from perchloric acid media

    International Nuclear Information System (INIS)

    Extraction of americium and europium from perchlorate environments by solutions of three types of methylenediphosphine dioxides, namely (C6H5)P(O)(CH2)sub(n)(O)P(C6H5)2, (C6H5)2P(O)CH2(O)P(C8H17)2 and (C8H17)2P(O)(CH2)sub(n)(O)P(C8H17)2 has been studied (n is 1 or 2 ) The diluents used have been dichlorethane and chloroform. In perchlorate environments the distribuiton coefficients of americium and europium have proved to be by about 3 orders of magnitude higher than in nitric acid environments, i.e. in perchlorate media the complexes are far more stable. Separation coefficients of americium and REE in perchloric acid soutions are much higher than in nitrate environments. The average value of Am/Eu separation coeffecient at 1-5 M acidity was about 6 (with dichlorethane as diluent) or about 7 (with chloroform as diluent). The complexes essentially exist as trisolvated. Americium complexes display anomalous stability increase upon being diluted: by about 2 orders of magnitude with dichlorethane and by up to 3 orders of magnitude with chloroform used as diluent

  20. Investigations of neutron characteristics for salt blanket models; integral fission cross section measurements of neptunium, plutonium, americium and curium isotopes

    International Nuclear Information System (INIS)

    Neutron characteristics of salt blanket micromodels containing eutectic mixtures of sodium, zirconium, and uranium fluorides were measured on FKBN-2M, BIGR and MAKET facilities. The effective fission cross sections of neptunium, plutonium, americium, and curium isotopes were measured on the neutron spectra formed by micromodels. (author)

  1. HAYNES 244 alloy – a new 760 ∘C capable low thermal expansion alloy

    Directory of Open Access Journals (Sweden)

    Fahrmann Michael G.

    2014-01-01

    Full Text Available HAYNES® 244TM alloy is a new 760∘C capable, high strength low thermal expansion (CTE alloy. Its nominal chemical composition in weight percent is Ni – 8 Cr – 22.5 Mo – 6 W. Recently, a first mill-scale heat of 244 alloy was melted by Haynes International, and processed to various product forms such as re-forge billet, plate, and sheet. This paper presents key attributes of this new alloy (CTE, strength, low-cycle fatigue performance, oxidation resistance, thermal stability as they pertain to the intended use in rings and seals of advanced gas turbines.

  2. On Pu-244 in lunar rocks from Fra Mauro and implications regarding their origin.

    Science.gov (United States)

    Marti, K.; Lightner, B. D.; Lugmair, G. W.

    1973-01-01

    The evidence for in situ produced fission xenon from Pu-244 in rock 14321 is presented. The inferred abundance ratio Pu-244/U-238 is found to be consistent with values observed in a meteorite. Data from a stepwise release of the xenon permits a characterization of the trapped component, which can be shown to be distinct from solar xenon. We discuss the evidence for the presence of fission gases and of uncorrelated radiogenic argon in this and in other Apollo 14 rocks and some implications regarding their origin.

  3. The measurement of prompt neutron spectrum in spontaneous fission of {sup 244}Cm

    Energy Technology Data Exchange (ETDEWEB)

    Batenkov, O.I.; Boykov, G.S.; Drapchinsky, L.V.; Majorov, M.Ju.; Trenkin, V.A. [V.G. Khlopin Radium Inst., Saint Petersburg (Russian Federation)

    1997-03-01

    Under the Program of Measurements of Prompt Fission Neutron Spectra of Minor Actinides for Transmutation Purposes the integral neutron spectrum in spontaneous fission of {sup 244}Cm has been measured by the time-of-flight method in the energy range of 0.1-15 MeV relative to the standard neutron spectrum in {sup 252}Cf spontaneous fission. Essential attention was paid to revealing of possible systematic errors. It is shown, that the {sup 244}Cm spectrum shape may be well described by using Mannhart evaluation with appropriate parameter of Maxwell temperature T{sub M} = 1.37 MeV. (author)

  4. Measurements of neutron cross section of the {sup 243}Am(n,{gamma}){sup 244}Am reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The effective thermal neutron cross section of {sup 243}Am(n,{gamma}){sup 244}Am reaction was measured by the activation method. Highly-purified {sup 243}Am target was irradiated in an aluminum capsule by using a research reactor JRR-3M. The tentative effective thermal neutron cross sections are 3.92 b, and 84.44 b for the production of {sup 244g}Am and {sup 244m}Am, respectively. (author)

  5. Purification of scintillation cocktails containing the alpha emitters americium and plutonium

    International Nuclear Information System (INIS)

    One efficient way of measuring alpha emitters is by the usage of liquid scintillation counting (LSC). A liquid sample is placed in a vial containing a scintillation cocktail. The alpha particles excite electrons in the surrounding liquid, and when they are de-excited photons are emitted. The photons are detected and the activity can be quantified. LSC has a high efficiency for alpha radiation and is therefore a fast and easy way for measuring alpha emitting samples. One drawback is that it does not differentiate very well between alpha energies; measurements of for example curium and plutonium simultaneously are impossible and demand other techniques. Another drawback is the production of a liquid alpha active waste. In Sweden alpha radioactive waste liquids with an activity over some kBq per waste container cannot be sent for final storage. If, however, the activity of the liquids could be reduced by precipitation of the actinides, it would be possible to send away the liquid samples to municipal incineration. In this work a method for a purification of alpha active scintillation cocktails was developed. The method was first tried on a lab scale, and then scaled up. Until today (March, 2013) more than 20 liters of scintillation liquids have successfully been purified from americium and plutonium at Chalmers University of Technology in Sweden. The four scintillation cocktails used were Emulsifier Safe®, Hionic-Fluor®, Ultima Gold AB® and Ultima Gold XR®. The scintillation cocktails could all be purified from americium with higher yield than 95%. The yield was kept when the liquids were mixed. Also plutonium could be precipitated with a yield over 95% in all cocktails except in Hionic-Fluor® (>55%). However, that liquid in particular could be purified (>95%) by mixing it with the three other cocktails. Up-scaling was performed to a batch size of 6-8 L of scintillation cocktail. In neither the americium nor the plutonium system, adverse effects of increasing the

  6. Inhalation toxicology of repeated exposures to 244CmO2

    International Nuclear Information System (INIS)

    Rats have been exposed to inhaled 244CmO2 at 70 and 280 days of age (IAD, approx. 350 nCi) and at ten 3-week intervals (IAD, approx. 35 nCi per exposure). Autoradiographs are being examined for lung, liver and bone microdosimetry

  7. 27 CFR 28.244a - Shipment to a customs bonded warehouse.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Shipment to a customs... Export Consignment § 28.244a Shipment to a customs bonded warehouse. Distilled spirits and wine withdrawn for shipment to a customs bonded warehouse shall be consigned in care of the customs officer in...

  8. A thermodynamic study of actinide oxide targets/fuels for americium transmutation

    International Nuclear Information System (INIS)

    A thermodynamic study was performed on the systems Am-O, AmOx-MgO, AmOx-MgAl2O4, Pu-Mg-O and U-Mg-O. Both experimental work (X-ray analyses, oxygen potential measurements etc.) and calculations on the phase diagrams involved were made. The reaction between americium oxide and spinel is expected to form the compound AmAlO3. Isothermal sections have been calculated for AmOx-(MgO, Al2O3), Pu-Mg-O and U-Mg-O at 2000 K using the software package ''Thermo-Calc''. Thermodynamic equilibrium data were used to predict the behaviour of actinide oxides in a reactor. The implication of the results for the technological application is discussed, with emphasis on the effects of the high oxygen potential of AmO2 as compared to the conventional fuel, i.e. UO2. (author)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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 NaClO4, 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 β110 = 2.56 ± 0.08 and log β120 = 3.93 ± 0.19. (author)

  11. 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.

  12. Transportability Class of Americium in K Basin Sludge under Ambient and Hydrothermal Processing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmitt, Bruce E.; Schmidt, Andrew J.

    2006-08-01

    This report establishes the technical bases for using a ''slow uptake'' instead of a ''moderate uptake'' transportability class for americium-241 (241Am) for the K Basin Sludge Treatment Project (STP) dose consequence analysis. Slow uptake classes are used for most uranium and plutonium oxides. A moderate uptake class has been used in prior STP analyses for 241Am based on the properties of separated 241Am and its associated oxide. However, when 241Am exists as an ingrown progeny (and as a small mass fraction) within plutonium mixtures, it is appropriate to assign transportability factors of the predominant plutonium mixtures (typically slow) to the Am241. It is argued that the transportability factor for 241Am in sludge likewise should be slow because it exists as a small mass fraction as the ingrown progeny within the uranium oxide in sludge. In this report, the transportability class assignment for 241Am is underpinned with radiochemical characterization data on K Basin sludge and with studies conducted with other irradiated fuel exposed to elevated temperatures and conditions similar to the STP. Key findings and conclusions from evaluation of the characterization data and published literature are summarized here. Plutonium and 241Am make up very small fractions of the uranium within the K Basin sludge matrix. Plutonium is present at about 1 atom per 500 atoms of uranium and 241Am at about 1 atom per 19000 of uranium. Plutonium and americium are found to remain with uranium in the solid phase in all of the {approx}60 samples taken and analyzed from various sources of K Basin sludge. The uranium-specific concentrations of plutonium and americium also remain approximately constant over a uranium concentration range (in the dry sludge solids) from 0.2 to 94 wt%, a factor of {approx}460. This invariability demonstrates that 241Am does not partition from the uranium or plutonium fraction for any characterized sludge matrix. Most

  13. The behaviour under irradiation of molybdenum matrix for inert matrix fuel containing americium oxide (CerMet concept)

    Science.gov (United States)

    D'Agata, E.; Knol, S.; Fedorov, A. V.; Fernandez, A.; Somers, J.; Klaassen, F.

    2015-10-01

    Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors or Accelerator Driven System (ADS, subcritical reactors dedicated to transmutation) of long-lived nuclides like 241Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. In order to safely burn americium in a fast reactor or ADS, it must be incorporated in a matrix that could be metallic (CerMet target) or ceramic (CerCer target). One of the most promising matrix to incorporate Am is molybdenum. In order to address the issues (swelling, stability under irradiation, gas retention and release) of using Mo as matrix to transmute Am, two irradiation experiments have been conducted recently at the High Flux Reactor (HFR) in Petten (The Netherland) namely HELIOS and BODEX. The BODEX experiment is a separate effect test, where the molybdenum behaviour is studied without the presence of fission products using 10B to "produce" helium, the HELIOS experiment included a more representative fuel target with the presence of Am and fission product. This paper covers the results of Post Irradiation Examination (PIE) of the two irradiation experiments mentioned above where molybdenum behaviour has been deeply investigated as possible matrix to transmute americium (CerMet fuel target). The behaviour of molybdenum looks satisfying at operating temperature but at high temperature (above 1000 °C) more investigation should be performed.

  14. Consideration of the effect of lymph-node deposition upon the measurement of plutonium and americium in the lungs

    International Nuclear Information System (INIS)

    Measurement of an inhaled radionuclide by external photon counting includes quantities which may be contained in lymph nodes, as well as quantities in the lungs. An overestimate of the lung burden can result, if a portion of the radionuclide were present in the lymph nodes. This problem is analyzed with respect to the measurement of inhaled plutonium containing plutonium-241 and americium-241, when americium-241 has been used as a tracer for the plutonium. Equations are derived which yield the amounts of americium and of plutonium in the lungs and in the lymph nodes as a function of time after exposure and for various translocation and retention parameters. Count histories (count profiles) of actual exposure cases are compared with calculated count profiles in order to gain insight into possible values of the translocation and retention parameters. Comparison is also made with calculated count profiles using values of translocation and retention parameters recommended by the International Commission on Radiological Protection (ICRP) for use with the Task Group Lung Model. The magnitude of the possible overestimate (error factor) was calculated for combinations o

  15. HELIOS: the new design of the irradiation of U-free fuels for americium transmutation

    Energy Technology Data Exchange (ETDEWEB)

    D' Agata, E. [European Commission, Joint Research Centre, Institute for Energy, P.O. Box 2, 1755 ZG Petten (Netherlands); Klaassen, F.; Sciolla, C. [Nuclear Research and Consultancy Group, Dept. Life Cycle and Innovations, P.O. Box 25 1755 ZG Petten (Netherlands); Fernandez-Carretero, A. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Bonnerot, J.M. [Commissariat a l' Energie Atomique, DEC/SESC/LC2I CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France)

    2009-06-15

    Americium is one of the radioactive elements that mostly contribute to the radiotoxicity of the nuclear spent fuel. Transmutation of long-lived nuclides like Americium is an option for the reduction of the mass, the radiotoxicity and the decay heat of nuclear waste. The HELIOS irradiation experiment is the last evolution in a series of experiments on americium transmutation. The previous experiments, EFTTRA-T4 and T4bis, have shown that the release or trapping of helium is the key issue for the design of such kind of target. In fact, the production of helium, which is characteristic of {sup 241}Am transmutation, is quite significant. The experiment is carried out in the framework of the 4-year project EUROTRANS of the EURATOM 6. Framework Programme (FP6). Therefore, the main objective of the HELIOS experiment is to study the in-pile behaviour of U-free fuels such as CerCer (Pu, Am, Zr)O{sub 2} and Am{sub 2}Zr{sub 2}O{sub 7}+MgO or CerMet (Pu, Am)O{sub 2}+Mo in order to gain knowledge on the role of the fuel microstructure and of the temperature on the gas release and on the fuel swelling. The experiment was planned to be conducted in the HFR (High Flux Reactor) in Petten (The Netherlands) starting the first quarter of 2007. Because of the innovative aspects of the fuel, the fabrication has had some delays as well as the final safety analyses of the original design showed some unexpected deviation. Besides, the HFR reactor has been unavailable since August 2008. Due to the reasons described above, the experiment has been postponed. HELIOS should start in the first quarter of 2009 and will last 300 full power days. The paper will cover the description of the new design of the irradiation experiment HELIOS. The experiment has been split in two parts (HELIOS1 and HELIOS2) which will be irradiated together. Moreover, due to the high temperature achieved in cladding and to the high amount of helium produced during transmutation the experiment previously designed for a

  16. Anomalous aryl strengthening of complexes at americium and europium extraction with alkylenediphospine dioxide from perchloric media

    International Nuclear Information System (INIS)

    Studied was the extraction of americium(3) and europium(3) from perchlorate solutions(0.001 M) with dioxides of alkylenediphosphines of three types: aryl Ph2P(O)CH2(O)PPh2(briefly 4P), and Ph2P(O)(CH2)2(O)PPh2, mixed Ph2P(O)CH2(O)P(C8H17)2 (or 2Ph2Oct) and alkyl (C8H17)2P(O)CH2(O)P(C8H17)2 (or 4 Oct). Trisolvates of MeS3x(ClO4)3 are predominantly formed but americium disolvates are also present upon dilution with dichloroethane. For 4Ph,2Ph2Oct and 4 Oct the concentration is, respectively, 1015, 2x1014, and 1013; for disolvates by 4 orders of magnitude lower which is, nevertheless, by 2 orders of magnitude higher than for nitric acid solutions. The separation coefficient of β Am/Eu for 4Ph attains 6-8. As in the case of nitrate solutions, an anomalous aryl strengthening of the complexes is observed: an increase in the distribution coefficients and extraction constants in the series of 4 Oct - 2Ph 2 Oct - 4Ph, in spite of the introduction of electronegative aryl substituents into the dioxide molecule, which reduce electron density on oxygen atoms and basicity of dioxides. In contrast to nitric acid solutions, observed is a nonlinear effect of a change in basicity on extraction properties upon dilution with dichloroethane (dioxide of 2Ph2 Oct does not occupy an intermediate position but is close to 4Ph). Upon dilution with chloroform the dependence is linear and anomalous effect rises due to a different nature of interactions of dioxides with chloroform. When the bridge increases up to ethylene, an anomalous strengthening of the complexes disappears. However, the distribution coefficients upon extraction with alkyl dioxide are considerably lower, which can be explained by a stronger extraction of perchloric acid

  17. 49 CFR 173.244 - Bulk packaging for certain pyrophoric liquids (Division 4.2), dangerous when wet (Division 4.3...

    Science.gov (United States)

    2010-10-01

    ... (Division 4.2), dangerous when wet (Division 4.3) materials, and poisonous liquids with inhalation hazards (Division 6.1). 173.244 Section 173.244 Transportation Other Regulations Relating to Transportation PIPELINE... Other Than Class 1 and Class 7 § 173.244 Bulk packaging for certain pyrophoric liquids (Division...

  18. Americium-based oxides: Dense pellet fabrication from co-converted oxalates

    Energy Technology Data Exchange (ETDEWEB)

    Horlait, Denis; Lebreton, Florent [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France); Gauthé, Aurélie [CEA, DEN, DRCP/SERA/LCAR, 30207 Bagnols-sur-Cèze (France); Caisso, Marie [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France); Arab-Chapelet, Bénédicte; Picart, Sébastien [CEA, DEN, DRCP/SERA/LCAR, 30207 Bagnols-sur-Cèze (France); Delahaye, Thibaud, E-mail: thibaud.delahaye@cea.fr [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France)

    2014-01-15

    Mixed oxides are used as nuclear fuels and are notably envisaged for future fuel cycles including plutonium and minor actinide recycling. In this context, processes are being developed for the fabrication of uranium–americium mixed-oxide compounds for transmutation. The purpose of these processes is not only the compliance with fuel specifications in terms of density and homogeneity, but also the simplification of the process for its industrialization as well as lowering dust generation. In this paper, the use of a U{sub 0.85}Am{sub 0.15}O{sub 2±δ} powder synthesized by oxalate co-conversion as a precursor for dense fuel fabrications is assessed. This study notably focuses on sintering, which yielded pellets up to 96% of the theoretical density, taking advantage of the high reactivity and homogeneity of the powder. As-obtained pellets were further characterized to be compared to those obtained via processes based on the UMACS (Uranium Minor Actinide Conventional Sintering) process. This comparison highlights several advantages of co-converted powder as a precursor for simplified processes that generate little dust.

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

    International Nuclear Information System (INIS)

    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)

  20. Mutual separation of americium(III) and europium(III) using glycolamic acid and thioglycolamic acid

    Energy Technology Data Exchange (ETDEWEB)

    Suneesh, A.S.; Venkatesan, K.A.; Syamala, K.V.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2012-07-01

    The extractants, bis(2-ethylhexyl)diglycolamicacid (HDEHDGA) and bis(2-ethylhexy)thiodiglycolamic acid (HDEHSDGA) were synthesized and characterized by {sup 1}H and {sup 13}C NMR, mass and IR spectroscopy. The extraction behaviour of {sup (152+154})Eu(III) and {sup 241}Am(III) from nitric acid medium by a solution of HDEHDGA (or HDEHSDGA) in n-dodecane (n-DD) was studied for the mutual separation of actinides and lanthanides. The effect of various parameters such as the pH, concentrations of HDEHDGA, HDEHSDGA, sodium nitrate, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and diethylenetriaminepentaacetic acid (DTPA) on the separation factor (SF) of americium(III) over europium(III) and vice versa was studied, and the conditions needed for the preferential separation were optimised. The results show that HDEHDGA exhibits higher extraction for {sup (152+154)}Eu(III) and HDEHSDGA shows the superior selectivity for {sup 241}Am(III). (orig.)

  1. Determination of plutonium americium and curium in soil samples by solvent extraction with trioctylphosphine oxide

    International Nuclear Information System (INIS)

    A method of Pu, Am and Cm determination in soil samples, which was developed for analyzing samples from territories subjected to radioactive contamination as a result of the Chernobyl accident is described. After preliminary treatment the samples were leached by solution of 7 mol/l HNO23+0.3 mol/l KBrO3 during heating. Pu was isolated by extraction with 0.05 mol TOPO from 7 mol/l HNO3. 144Ce and partially remaining in water phase isotopes of Zr, U and Th were isolated in an extraction-chromatographic column with TOPO and PbO2. Then Am and Cm were extracted by 0.2 mol/l TOPO from solution 1 mol/l HLact+0.07 mol/l DTPA+1 mol/l Al(NO3)3. Alpha-activity of both extracted products was determined in liquid scintillation counter. Chemical yield of plutonium counted to 85±10%, that of americium and curium -75±10%. 17 refs

  2. 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.

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

    International Nuclear Information System (INIS)

    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 241Am in the freshwater environment aim to establish a relation between the behavior of 241Am 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 241Am with humic acids and competition with trivalent cations such as A1 and Fe, were proven to be significant on the speciation of 241Am. Based on the registration of the 241Am uptake by a large number of freshwater organisms, the crayfish Astacus leptodactylus Eschscholtz was chosen to study the whole-body uptake of 241Am, 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 241Am in the hemolymph and the hepatopancreas, and its subcellular distribution in the digestive gland. Finally, by comparing the physiology of 241Am with some other metals (240Pu, 64Cu, 198Au) with analogous or contradictional properties, we tried to find out whether the behavior of 241Am in organisms can be explained from its chemical characteristics

  4. Solution speciation of plutonium and Americium at an Australian legacy radioactive waste disposal site.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Harrison, Jennifer J; Thiruvoth, Sangeeth; Wilsher, Kerry; Wong, Henri K Y; Johansen, Mathew P; Waite, T David; Payne, Timothy E

    2014-09-01

    During the 1960s, radioactive waste containing small amounts of plutonium (Pu) and americium (Am) was disposed in shallow trenches at the Little Forest Burial Ground (LFBG), located near the southern suburbs of Sydney, Australia. Because of periodic saturation and overflowing of the former disposal trenches, Pu and Am have been transferred from the buried wastes into the surrounding surface soils. The presence of readily detected amounts of Pu and Am in the trench waters provides a unique opportunity to study their aqueous speciation under environmentally relevant conditions. This study aims to comprehensively investigate the chemical speciation of Pu and Am in the trench water by combining fluoride coprecipitation, solvent extraction, particle size fractionation, and thermochemical modeling. The predominant oxidation states of dissolved Pu and Am species were found to be Pu(IV) and Am(III), and large proportions of both actinides (Pu, 97.7%; Am, 86.8%) were associated with mobile colloids in the submicron size range. On the basis of this information, possible management options are assessed. PMID:25126837

  5. Solution speciation of plutonium and Americium at an Australian legacy radioactive waste disposal site.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Harrison, Jennifer J; Thiruvoth, Sangeeth; Wilsher, Kerry; Wong, Henri K Y; Johansen, Mathew P; Waite, T David; Payne, Timothy E

    2014-09-01

    During the 1960s, radioactive waste containing small amounts of plutonium (Pu) and americium (Am) was disposed in shallow trenches at the Little Forest Burial Ground (LFBG), located near the southern suburbs of Sydney, Australia. Because of periodic saturation and overflowing of the former disposal trenches, Pu and Am have been transferred from the buried wastes into the surrounding surface soils. The presence of readily detected amounts of Pu and Am in the trench waters provides a unique opportunity to study their aqueous speciation under environmentally relevant conditions. This study aims to comprehensively investigate the chemical speciation of Pu and Am in the trench water by combining fluoride coprecipitation, solvent extraction, particle size fractionation, and thermochemical modeling. The predominant oxidation states of dissolved Pu and Am species were found to be Pu(IV) and Am(III), and large proportions of both actinides (Pu, 97.7%; Am, 86.8%) were associated with mobile colloids in the submicron size range. On the basis of this information, possible management options are assessed.

  6. Type B investigation report of curium-244 exposure at the ORNL TRU Facility, January 15, 1986

    Energy Technology Data Exchange (ETDEWEB)

    Love, G.L.; Butler, H.M.; Duncan, D.T.; Oakes, T.W.

    1986-04-01

    This Type B Investigative Report provides an evaluation of relevant events and activities that led to, were a part of, or resulted from the release of curium-244 in the Building 7920 facility at ORNL in January 1986. Impacts have been evaluated with respect to employee exposures and the costs and loss of productivity resulting from increased bioassay analyses and activities of investigative committees. Management systems evaluated include (1) training of employees performing lab analyses, (2) adherence to procedures, and (3) response to unusual circumstances.

  7. Infrared Line Emission in the Interacting Region of Arp 244 (the Antennae) Colliding Molecular Cloud Complexes ?

    CERN Document Server

    Liang, M C; Lo, K Y; Kim, D C

    2001-01-01

    We report velocity-resolved spectroscopy of infrared hydrogen recombination lines in the interacting region of the Antennae galaxies (NGC 4038/4039). It generally has been assumed that the active star formation found there is due to the interaction of the disks of the two galaxies and \\citet{lee01} have observed two molecular cloud complexes, separated in velocity by $\\sim$100 km s$^{-1}$, in the southern part of this region. Our measurements imply that the two cloud complexes are moving away from each other. This result poses interesting questions about the physical mechanisms leading to starbursts in Arp 244 and other interacting galaxies.

  8. Type B investigation report of curium-244 exposure at the ORNL TRU Facility, January 15, 1986

    International Nuclear Information System (INIS)

    This Type B Investigative Report provides an evaluation of relevant events and activities that led to, were a part of, or resulted from the release of curium-244 in the Building 7920 facility at ORNL in January 1986. Impacts have been evaluated with respect to employee exposures and the costs and loss of productivity resulting from increased bioassay analyses and activities of investigative committees. Management systems evaluated include (1) training of employees performing lab analyses, (2) adherence to procedures, and (3) response to unusual circumstances

  9. Kuluttajakäyttäytymisen hyödyntäminen verkkokaupan markkinoinnissa : Case: 244

    OpenAIRE

    Kylä-Kaila, Tero; Kylä-Kaila, Kaisa

    2013-01-01

    Opinnäytetyön toimeksiantajana oli kirjoittajien vuonna 2011 perustama yritys, 244. Yritys on vaatteita ja asusteita myyvä verkkokauppa. Opinnäytetyö tehtiin vauhdittamaan verkkokaupan myyntiä luomalla markkinointistrategia. Opinnäytetyöllä oli kaksi tavoitetta: ensimmäinen tavoite oli tutkia ja todistaa erityisesti sosiaalisten tekijöiden vaikutusta ihmisten verkkokauppakäyttäytymiseen muodin ostamisessa. Toinen tavoite oli löytää ja luoda keinoja markkinoida yritystä tutkimuksista saatujen ...

  10. Population and decay of a Kπ=8- two-quasineutron isomer in 244Pu

    Science.gov (United States)

    Hota, S. S.; Tandel, S. K.; Chowdhury, P.; Ahmad, I.; Carpenter, M. P.; Chiara, C. J.; Greene, J. P.; Hoffman, C. R.; Jackson, E. G.; Janssens, R. V. F.; Kay, B. P.; Khoo, T. L.; Kondev, F. G.; Lakshmi, S.; Lalkovski, S.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Moran, K.; Peterson, D.; Shirwadkar, U.; Seweryniak, D.; Stefanescu, I.; Toh, Y.; Zhu, S.

    2016-08-01

    The decay of a Kπ=8- isomer in 244Pu and the collective band structures populating the isomer were studied using deep inelastic excitations with 47Ti and 208Pb beams, respectively. Precise measurements of M 1 /E 2 branching ratios in the band confirm a 9 /2-[734] ν⊗7 /2+[624] ν configuration assignment for the isomer, validating the systematics of Kπ=8- , two-quasineutron isomers observed in even-Z , N =150 isotones. These isomers around the deformed shell gap at N =152 provide critical benchmarks for theoretical predictions of single-particle energies in this gateway region to superheavy nuclei.

  11. A study of plutonium and americium concentrations in seaspray on the southern Scottish coast

    International Nuclear Information System (INIS)

    Seaspray and seawater have been collected from the southern Scottish coast and, for comparison, Cumbria in northwest England during 1989 and 1991. The occurrence of sea-to-land transfer of the actinides plutonium and americium in seaspray was observed on these coasts using muslin screens (a semi-quantitative technique most efficient for collecting large spray droplets) and high volume conventional air samplers. The actinides and fine particulate in the spray were present in relatively higher concentrations than measured in the adjacent seawater, i.e. the spray was enriched in particulate actinides. The net efficiency of the muslim screens in collecting airborne plutonium isotopes and 241Am generally appeared to be about 20%. A review of earlier published concentrations of 239+240Pu and 241Am measured in aerosol and deposition for over a year several tens of metres inland was carried out. This suggested that airborne activities are up to a factor of 5 times higher in Cumbria than southern Scotland. However, neither the new data collected in 1989 and 1991 nor this older data suggests any enhancement of seaspray actinide enrichment in southern Scotland compared to Cumbria. This finding contrasts with earlier, more limited, comparisons that have been carried out which suggested such a difference. There is clear evidence of considerable localised spatial and temporal variability in aerosol actinide enrichment over the beaches in both areas. Enrichments varies between 20 and 500 relative to the adjacent surf zone waters. However, the average enrichment in spray based on the continuous measurements made further inland is likely to be at the lower end of this range. (author)

  12. Biosorption of Americium-242 by saccharomyces cerevisiae: preliminary evaluation and mechanism

    International Nuclear Information System (INIS)

    As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high radiation toxicity and long half-life. In this experiment, the biosorption of 241Am from solution by a fungus, Saccharomyces cerevisiae (S. cerevisiae), and the effects of various experimental conditions on the biosorption and the mechanism were explored. The preliminary results showed that S. cerevisiae is a very efficient biosorbent. An average of more than 99% of the total 241Am could be removed by S. cerevisiae of 2.1g/L (dry weight) from 241Am solutions of 2.22MBq/L -555 MBq/L (Co). The adsorption equilibrium was achieved within 1 hour and the optimum pH ranged 1-3. The culture times of more than 16 hours were suitable and the efficient adsorption of 241Am by the S. cerevisiae could be noted. The biosorption of 241Am by the decomposed cell wall, protoplasm or cell membrane of S. cerevisiae was same efficient as by the intact fungus, but the some components of S. cerevisiae, such as protein and acylation group had obvious effect on adsorption. When the concentrations of coexistent Eu3+, Nd3+ were 100 times more than that of 241Am, the adsorption rates would drop to 65%. However, most of the investigated acidic ions have no significant influence on the 241Am adsorption but minute change of pH value, while the saturated EDTA can strong inhibit the biosorption of 241Am.. (authors)

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

    International Nuclear Information System (INIS)

    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.)

  14. The treatment of liquid radioactive waste containing Americium by using a cation exchange method

    International Nuclear Information System (INIS)

    A research in the treatment of a liquid radioactive waste containing americium has been done. The liquid radioactive waste used in this research was standard solution of U dan Ce with the initial activity of 100 ppm. The experimental investigation is aimed at a study of the effects of the waste pH, the column dimension of IR-120 cation exchanger which is expressed as L/D, the flow rate of a liquid waste and the influence of thiocyanate as a complex agent against the efficiency of a decontamination for uranium and cerium element. The experiment was done by passing downward the feed of uranium and cerium solution into an IR-120 type of cation exchanger with the L/D of 11.37. From the experimental parameters done in this research where the influence of waste pH was varied from 3 - 8, the geometric column (L/D) 11.37, the liquid flow rate was from 2.5 - 10 ml/m and the thiocyanate concentration was between 100 ppm-500 ppm can be concluded that the optimum operational condition for the ion exchange achieved were the waste pH for uranium = 4 and the waste pH for cerium = 6, the flow rate = 2.5 ml/men. From the given maximum value of DF for uranium = 24 (DE = 95.83%) and of DF for cerium = 40 (DE = 97.5%), it can also be concluded that this investigation is to be continued in order that the greater value of DF/DE can be achieved

  15. 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)

    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 239Np and 241Am 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)

  16. Effect of a long-term release of plutonium and americium into an estuarine and coastal sea ecosystem

    International Nuclear Information System (INIS)

    This paper discusses the general problem of speciation of plutonium and americium in aquatic ecosystems and the implications relative to their fate in those systems. The following conclusions were reached: several oxidation states of plutonium coexist in the natural environment; the effect of environmental changes such as pH and Esub(h) values and complexes are probably the cause of these various oxidation states; a clearer definition of the 'concentration factor' should be given in view of the important role the sediments play in supplying plutonium for transfer through the food web. (author)

  17. EFFECT OF COMPOSITION OF SELECTED GROUNDWATERS FROM THE BASIN AND RANGE PROVINCE ON PLUTONIUM, NEPTUNIUM, AND AMERICIUM SPECIATION.

    Science.gov (United States)

    Rees, Terry F.; Cleveland, Jess M.; Nash, Kenneth L.

    1984-01-01

    The speciation of plutonium, neptunium, and americium was determined in groundwaters from four sources in the Basin and Range Province: the lower carbonate aquifer, Nevada Test Site (NTS) (Crystal Pool); alluvial fill, Frenchman Flat, NTS (well 5C); Hualapai Valley, Arizona (Red Lake south well); and Tularosa Basin, New Mexico (Rentfrow well). The results were interpreted to indicate that plutonium and, to a lesser extent, neptunium are least soluble in reducing groundwaters containing a large concentration of sulfate ion and a small concentration of strongly complexing anions. The results further emphasize the desirability of including studies such as this among the other site-selection criteria for nuclear waste repositories.

  18. Microstructure and elemental distribution of americium-containing MOX fuel under the short-term irradiation tests

    International Nuclear Information System (INIS)

    In order to investigate the effect of americium addition to MOX fuels on the irradiation behavior, the 'Am-1' program is being conducted in JAEA. The Am-1 program consists of two short-term irradiation tests of 10-minute and 24-hour irradiations and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post irradiation examinations (PIEs) are in progress. The PIEs for Am-containing MOX fuels focused on the microstructural evolution and redistribution behavior of Am at the initial stage of irradiation and the results to date are reported. (author)

  19. Isotopic yield in cold binary fission of even-even $^{244-258}$Cf isotopes

    CERN Document Server

    Santhosh, K P; Krishnan, Sreejith

    2016-01-01

    The cold binary fission of even-even 244-258Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. The favorable fragment combinations are obtained from the cold valley plot (plot of driving potential vs. mass number of fragments) and by calculating the yield for charge minimized fragments. It is found that highest yield for 244,246,248Cf isotopes are for the fragments with isotope of Pb (Z=82) as one fragment, whereas for 250Cf and 252Cf isotopes the highest yield is for the fragments with isotope of Hg (Z=80) as one fragment. In the case of 254,256,258Cf isotopes the highest yield is for the fragments with Sn (Z=50) as one fragment. Thus, the fragment combinations with maximum yield reveal the role of doubly magic and near doubly magic nuclei in binary fission. It is found that asymmetric splitting is favoured for Cf isotopes with mass number A 252. In the case of Cf isotope with A=252, there is an equal probability for asymmetric and symmetric splitti...

  20. New limit of $^{244}$Pu on Earth points to rarity of actinide nucleosynthesis

    CERN Document Server

    Wallner, A; Feige, J; Feldstein, C; Knie, K; Korschinek, G; Kutschera, W; Ofan, A; Paul, M; Quinto, F; Rugel, G; Steier, P

    2015-01-01

    Half of the heavy elements including all actinides are produced in r-process nucleosynthesis whose sites and history still remain a mystery. If continuously produced, the Interstellar Medium (ISM) is expected to build up a quasi-steady state of abundances of short-lived nuclides (with half-lives <100My), including actinides produced in r-process nucleosynthesis. Their existence in today's ISM would serve as a radioactive clock and would establish that their production was recent. In particular $^{244}$Pu, a radioactive actinide nuclide (81 My half-life), can place strong constraints on recent r-process frequency and production yield. Here we report on the detection of live interstellar $^{244}$Pu, archived in Earth's deep-sea floor during the last 25 My, at abundances lower by about two orders of magnitude than expected from continuous production in the Galaxy. This large discrepancy may signal a rarity of actinide r-process nucleosynthesis sites, compatible with neutron-star mergers or with a small subset...

  1. Stability of 244-260Fm isotopes against alpha and cluster radioactivity

    Indian Academy of Sciences (India)

    K P Santhosh; R K Biju; Sabina Sahadevan

    2009-12-01

    Taking Coulomb and proximity potentials as the interacting barrier we have studied the cold valley in the radioactive decay of 244-260Fm isotopes. It is found that in addition to alpha particle minima, other minima occur at S, Ar and Ca clusters. We have computed the half-lives and other characteristics of different clusters emitted from these parents treating parent, daughter and emitted cluster as spheres. Our study reveals that most of these parents are unstable against alpha and heavy cluster (46Ar, 48,50Ca) emissions and stable against light cluster emission, except 8Be from 244-248Fm isotopes. The most probable clusters from these parents are predicted to be 46Ar, 48,50Ca which indicate the role of doubly or near doubly magic clusters ( = 20, = 28) and also stress the role of doubly magic 208Pb daughter. The computed half-lives for alpha decay are in good agreement with the experimental data. It is found that the presence of neutron excess in the parent nuclei slows down the cluster decay process. The effect of quadrupole (2) and hexadecapole (4) deformations of parent and fragments on half-lives are also studied. It is found that inclusion of 2 and 4 reduces the height and shape of the barrier (increases barrier penetrability) and hence the half-life decreases.

  2. 244CmO2/nat.-UO2 hybrid blanket with flat fission power production

    International Nuclear Information System (INIS)

    In the present study, 244CmO2 is mixed with nat.-UO2 for the purpose of power flattening in a hybrid blanket with a reasonably high energy multiplication factor. Also, the temporal variations of the fission power density (FPD) are observed during an 18-month plant operation period. The main conclusion drawn from this work is that it became possible to keep a flat fission power profile (FPP) over a very long plant operation period of 18 months by simply omitting the beryllium multiplier in the blanket and keeping the neutron spectrum fairly unchanged throughout the fission zone. This reduced the efforts for fuel management to a minimum. A further observation focused on only minor variations of the integral neutronic data over longer plant operation periods. Among others, the fission power generation increase is also very modest. This results in an optimum investment for the nonnuclear island. The blanket burns up high-level nuclear waste 244Cm effectively, with efficient electricity production and breeding of a new type of nuclear fuel 245Cm with very superior nuclear properties. Finally, a warning should be issued for the careful international safeguarding of such a hybrid plant due to the extremely high quality of the bred plutonium fuel

  3. Development of a methodology for the determination of americium and thorium by ICP-AES and their inter-element effect

    International Nuclear Information System (INIS)

    Due to the scarcity of good quality uranium resources, the growth of nuclear technology in India is dependent on the utilization of the vast thorium resources. Therefore, Advance Heavy Water Reactor is going to acquire significant role in the scenario of Indian nuclear technology, where (Th, Pu)O2 will be utilized as fuel in the outermost ring of the reactor core. This will lead to a complex matrix containing thorium as well as americium, which is formed due to β-decay of plutonium. The amount of americium is dependent on the burn up and the storage time of the Pu based fuels. In the present case, attempt was made to develop a method for the determination of americium as well as thorium by ICP-AES. Two emission lines of americium were identified and calibration curves were established for determination of americium. Though the detection limit of 283.236 nm line (5 ng mL-1) of americium was found to be better than that of 408.930 nm (11 ng mL-1), the former line is significantly interfered by large amount of thorium. Three analytical lines (i.e. 283.242, 283.730 and 401.913 nm) of thorium were identified and calibration curves were established along with their detection limits. It was observed that 283.242 and 401.913 nm line are having similar detection limits (18 and 13 ng mL-1, respectively) which are better than that of 283.730 nm (60 ng mL-1). This can be attributed to the high background of 283.273 nm channel of thorium. The spectral interference study revealed that even small amount of americium has significant contribution on 283.242 nm channel of thorium while the other two channels remain practically unaffected. Considering both these facts, spectral interference and analytical performance (detection limits and sensitivity), it was concluded that 401.913 nm line is the best analytical line out of the three lines for determination of thorium in presence of americium. (author)

  4. Effect of radiolysis on leachability of plutonium and americium from 76-101 glass. [Glass containing 2 mole % plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L.; Fried, S.; Friedman, A.M.; Susak, N.; Rickert, P.; Sullivan, J.C.; Karim, D.P.; Lam, D.J.

    1982-01-01

    One aspect of the leachability of actinide-bearing glass which has not been adequately addressed is the effect of radiolysis of the system (glass-water) on the amount of actinides liberated from the glass. In the present study, we have investigated the leaching of plutonium and americium from 76-101 glass samples (containing 2 mole % plutonium) in the presence of a one megaRad/hour gamma-radiation field. The presence of the radiation field was found to increase the leaching rate of both plutonium and americium by a factor of five. Speciation studies of the plutonium in the leachate indicate that the plutonium is present predominantly in the higher oxidation states, Pu(V) and Pu(VI) and that it is significantly associated with colloidal particles. Examination of the glass surfaces with x-ray photoemission spectroscopy, XPS, both before and after leaching was carried out; these studies showed lower surface concentrations of plutonium in the samples of glass leached in the radiation field. 1 figure, 3 tables.

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

    International Nuclear Information System (INIS)

    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

  6. Preparation of powdered polychloroprene rubber-244 and comparison with lump polychloroprene rubber%粉末氯丁橡胶-244的制备及与块状氯丁橡胶的比较

    Institute of Scientific and Technical Information of China (English)

    魏绪玲; 龚光碧; 高阳光; 郑聚成; 赵志超; 梁滔; 白竞冰; 艾纯金

    2011-01-01

    以氯丁胶乳为原料,采用直接凝聚法制备粉末氯丁橡胶(PCR-244),研究了体系pH值、凝聚剂和隔离剂用量、凝聚温度、搅拌转速对PCR-244凝聚效果的影响,并与块状氯丁橡胶进行了对比.结果表明,在体系pH值为11~13、凝聚剂和隔离剂用量分别为20份和10~15份以及凝聚温度为20~25℃、搅拌转速为80~100 r/min的条件下,能得到平均粒径小于0.80 mm、成粉率达100%的PCR.相同条件下,PCR比块状氯丁橡胶的溶解速率大大提高,但二者溶解后的溶液黏度和剥离强度相近.PCR-244仅仅改变了氯丁橡胶的形态,其内部主要结构与块状氯丁橡胶相似.%The powdered polychloroprene rubber (PCR-244) was prepared by direct coacervation with neoprene latex as material. The effects of pH value, the amount of coagulant and antiadhesion agent, the coacervation temperature, stirring speed on the powdering were investigated, and the comparison was carried out with lump polychloroprene rubber (CR-244). The results showed that PCR of the diameter less than 0.80 mm and powder ratio of 100% could be obtained when pH value was 11 - 13 in the system, the amounts of coagulant and antiadhesion agent were 20 phr and 10 - 15 phr respectively, coacervation temperature was 20 - 25 ℃, stirring speed was 80 - 100 r/min. Under the same conditions, the dissolution rate of PCR-244 increased greatly, while solution viscosity and peeling strength were similar compared with lump CR-244.So the preparation processs of PCR-244 only changed the geometric form of the latter, but not changed its main internal structure.

  7. Experimental Study on Behavior of Americium in Pyrochemical Process of Nitride Fuel Cycle

    International Nuclear Information System (INIS)

    R and D on the transmutation of long-lived minor actinides (MA) by the accelerator-driven system (ADS) using nitride fuels is underway at JAEA. In regard to reprocessing technology, pyrochemical process has several advantages in case of treating spent fuel with large decay heat and fast neutron emission, and recovering highly enriched N-15. In the pyrochemical reprocessing, plutonium and MA are dissolved in LiCl-KCl eutectic melts and selectively recovered into liquid cadmium (Cd) cathode by molten salt electrorefining. The electrochemical behavior in LiCl-KCl eutectic melts and the subsequent nitride formation behavior of plutonium and MA recovered in liquid Cd cathode are investigated. In this paper, recent results on electrochemical study of americium (Am) on electrolyses of AmN in LiCl-KCl eutectic melts and nitride formation of Am recovered in the liquid Cd cathode are presented. Electrochemical behavior of Am on anodic dissolution of AmN and recovery of Am into a liquid Cd cathode by electrolyses in LiCl-KCl eutectic melts was investigated by transient electrochemical techniques. The formal standard potential of Am(III)/Am(0) obtained with the liquid Cd electrode is more positive than that calculated for the solid metal electrode. The potential shift is considered to be attributed to the lowering of the activity of Am by the formation of the intermetallic compound with Cd. Potentiostatic electrolyses of AmN in LiCl-KCl eutectic melts containing AmCl3 at 773 K were carried out. Nitrogen gas generated by the anodic dissolution of AmN was observed, and the current efficiency was obtained from the ratio of the amount of released nitrogen gas and the passed electric charge to be 20 - 28 %. Am was recovered as Am-Cd alloy in the liquid Cd cathode, in which AmCd6 type phase was identified besides Cd phase. The recovered Am was converted to AmN by the nitridation-distillation combined method, in which the Am-Cd alloy was heated in nitrogen gas stream at 973 K. These

  8. Filaments and Ionized Gas in the Vicinity of 3C 244.1

    CERN Document Server

    Feinstein, C; Martel, A R; Sparks, W B; Feinstein, Carlos; Martel, Andre R.; Sparks, William B.

    2001-01-01

    We present results of Hubble Space Telescope observations of the radio galaxy 3C 244.1. The broadband F702W (R) and F555W (V) images (WFPC2/PC) show an elliptical galaxy and gaseous filaments and blobs surrounding it. In the narrow-band ramp filter, dominated by [OIII]lambda5007, these filaments are bright and have the same morphology as the broad band images. To the south, the filaments have a cone-shaped structure and the radio jet is located at the center of this cone. To the north of the galaxy, the structure is found near the nucleus of the galaxy within its elliptical profile. From the photometry, the two brighter structures seem to be extended narrow line emission regions (ENLRs). The comparison with diagnostic line ratios shows that the observed emission is consistent with interactions between the expanding radio-jet and the local denser medium.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-18

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze a mixed actinide fuel pellet containing 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2}. The preliminary data shown here is the first report of LIBS analysis of a mixed actinide fuel pellet, to the authors knowledge. The LIBS spectral data was acquired in a plutonium facility at Los Alamos National Laboratory where the sample was contained within a glove box. The initial installation of the glove box was not intended for complete ultraviolet (UV), visible (VIS) and near infrared (NIR) transmission, therefore the LIBS spectrum is truncated in the UV and NIR regions due to the optical transmission of the window port and filters that were installed. The optical collection of the emission from the LIBS plasma will be optimized in the future. However, the preliminary LIBS data acquired is worth reporting due to the uniqueness of the sample and spectral data. The analysis of several actinides in the presence of each other is an important feature of this analysis since traditional methods must chemically separate uranium, plutonium, neptunium, and americium prior to analysis. Due to the historic nature of the sample fuel pellet analyzed, the provided sample composition of 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2} cannot be confirm without further analytical processing. Uranium, plutonium, and americium emission lines were abundant and easily assigned while neptunium was more difficult to identify. There may be several reasons for this observation, other than knowing the exact sample composition of the fuel pellet. First, the atomic emission wavelength resources for neptunium are limited and such techniques as hollow cathode discharge lamp have different dynamics than the plasma used in LIBS which results in different emission spectra. Secondly, due to the complex sample of four actinide elements, which all have very dense electronic energy levels, there may be reactions and

  10. Preconcentration of low levels of americium and plutonium from waste waters by synthetic water-soluble metal-binding polymers with ultrafiltration

    International Nuclear Information System (INIS)

    A preconcentration approach to assist in the measurement of low levels of americium and plutonium in waste waters has been developed based on the concept of using water-soluble metal-binding polymers in combination with ultrafiltration. The method has been optimized to give over 90% recovery and accountability from actual waste water. (author)

  11. 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

    First-principles calculations have been performed for americium (Am) metal using the generalized gradient approximation + orbital-dependent onsite Coulomb repulsion via Hubbard interaction (GGA+U) and hybrid density functional theory (HYB-DFT) methods to investigate various ground state propertie...

  12. Separation of Americium from Fission Product Lanthanides Using Cyanex 301 Extraction

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongjun; CHEN Jing

    2001-01-01

    The extraction behavior of bis (2,4,4-trimethylpentyl)dithiophosphinic acid (HBTMPDTP),purified from Cyanex 301,was studied for extracting Am3+ and trivalent lanthanides (Lns).HBTMPDTP shows very high selectivity for Am.Separation factor(SF)of Am and Eu,SF Am/Eu,(trace amount)reaches a high value of 5.9×103 and SF Am/(Pr+Nd) (macro amount)is about 2×103.The mathematical model for the distribution ratios and process parameters calculated for HBTMPDTP extraction was established and the calculated results were verified experimentally.In a five-stage countercurrent process,the extraction rates of Am and Lns were >99.999% and 0.14%,respectively,to fulfill the separation requirements.The efficiency of this process was also verified in a cross-flow extraction experiment using a genuine Am-FPLns fraction.In the presence of TBP,the extraction of Am and Eu is enhanced,but their separation is reduced to some extent.A fairly good separation was achieved in a fractional extraction process using a mixture of HBTMPDTP and TBP in kerosene at low pH.

  13. Representation of perfectly reconstructed octave decomposition filter banks with set of decimators {2,4,4} via tree structure

    OpenAIRE

    Ling, Wing-Kuen; Tam, P K

    2003-01-01

    In this letter, we prove that a filter bank with set of decimators {2,4,4} achieves perfect reconstruction if and only if it can be represented via a tree structure and each branch of the tree structure achieves perfect reconstruction.

  14. 19 CFR 24.4 - Optional method for payment of estimated import taxes on alcoholic beverages upon entry, or...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Optional method for payment of estimated import... THE TREASURY CUSTOMS FINANCIAL AND ACCOUNTING PROCEDURE § 24.4 Optional method for payment of... been given to me to use such procedure. (d) Use of deferred payment method. (1) The port director...

  15. 29 CFR 779.244 - “Covered enterprises” of interest to retailers of goods or services.

    Science.gov (United States)

    2010-07-01

    ... retail and service industry, section 3(s)(1) of the Act as amended in 1966 may apply to any enterprise. This part is concerned only with retail or service establishments and enterprises. Enterprises... Apply; Enterprise Coverage Covered Retail Enterprise § 779.244 “Covered enterprises” of interest...

  16. Direct nuclear magnetic resonance observation of odorant binding to mouse odorant receptor MOR244-3.

    Science.gov (United States)

    Burger, Jessica L; Jeerage, Kavita M; Bruno, Thomas J

    2016-06-01

    Mammals are able to perceive and differentiate a great number of structurally diverse odorants through the odorant's interaction with odorant receptors (ORs), proteins found within the cell membrane of olfactory sensory neurons. The natural gas industry has used human olfactory sensitivity to sulfur compounds (thiols, sulfides, etc.) to increase the safety of fuel gas transport, storage, and use through the odorization of this product. In the United States, mixtures of sulfur compounds are used, but the major constituent of odorant packages is 2-methylpropane-2-thiol, also known as tert-butyl mercaptan. It has been fundamentally challenging to understand olfaction and odorization due to the low affinity of odorous ligands to the ORs and the difficulty in expressing a sufficient number of OR proteins. Here, we directly observed the binding of tert-butyl mercaptan and another odiferous compound, cis-cyclooctene, to mouse OR MOR244-3 on living cells by saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. This effort lays the groundwork for resolving molecular mechanisms responsible for ligand binding and resulting signaling, which in turn will lead to a clearer understanding of odorant recognition and competition.

  17. Stability of penta- and hexavalent americium in the solutions of sodium peroxydisulfate and sodium bromate at intensive internal α-irradiation

    International Nuclear Information System (INIS)

    The spectrometric method has been used for studying the dependence of the rates of radiolytic reduction of Am(5) and (6) on the initial concentration of sodium persulfate and bromate, Am(5) and (6), acidity, and the dose rate of inner alpha-irradiation of the solutions. The high dose rates of inner alpha-irradiation of solutions (up to 3.25x1021 eV/lxmin-250Ci/l) have been attained with the aid of curium isotopes. The stability of americium (6) ions towards the action of ionizing radiation in solutions of sodium persulfate and bromate has been shown to be considerable lower than that of americium (5). The chemical difference has been shown in radiolytic behaviour between Am(5) and Am(6) ions in solutions of sodium persulfate and bromate. The equations have been derived showing the dependence of the rates of Am(6) and Am(5) reduction of different variables

  18. Comparative XRPD and XAS study of the impact of the synthesis process on the electronic and structural environments of uranium-americium mixed oxides

    Science.gov (United States)

    Prieur, D.; Lebreton, F.; Martin, P. M.; Caisso, M.; Butzbach, R.; Somers, J.; Delahaye, T.

    2015-10-01

    Uranium-americium mixed oxides are potential compounds to reduce americium inventory in nuclear waste via a partitioning and transmutation strategy. A thorough assessment of the oxygen-to-metal ratio is paramount in such materials as it determines the important underlying electronic structure and phase relations, affecting both thermal conductivity of the material and its interaction with the cladding and coolant. In 2011, various XAS experiments on U1-xAmxO2±δ samples prepared by different synthesis methods have reported contradictory results on the charge distribution of U and Am. This work alleviates this discrepancy. The XAS results confirm that, independently of the synthesis process, the reductive sintering of U1-xAmxO2±δ leads to the formation of similar fluorite solid solution indicating the presence of Am+III and U+V in equimolar proportions.

  19. THE FIRST ISOLATION OF AMERICIUM IN THE FORM OF PURE COMPOUNDS - THE SPECIFIC ALPHA-ACTIVITY AND HALF-LIFE OF Am241

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, B.B.; Asprey, L.B.

    1950-07-20

    The microgram scale isolation and preparation of pure compounds of americium is described. Data are presented to show that the alpha-half-life of the isotope Am{sup 241} is 490 {+-} 14 years. The absorption spectrum of Am(III) in 1M nitric acid in the range 3500-8000 mu is given. The wave lengths of 10 of the most prominent lines in the copper spark emission spectrum of americium are given to the nearest 0.01 {angstrom}. Evidence is presented to show that the potential for the Am(III)-Am(IV) couple in acid solution is more negative than -2v and that the potential for the Am(II)-Am(III) couple is more positive than +0.9v.

  20. Al-26, Pu-244, Ti-50, REE, and trace element abundances in hibonite grains from CM and CV meteorites

    Science.gov (United States)

    Fahey, A. J.; Mckeegan, K. D.; Zinner, E.; Goswami, J. N.

    1987-01-01

    Hibonites from the CM meteorites Murchison, Murray, and Cold Bokkeveld, and hibonites and Ti-rich pyroxene from the CV chondrite Allende are studied. Electron microprobe measurements of major element concentrations and track and ion probe measurements of Mg and Ti isotopic ratios, rare earth elements (REEs), and trace element abundances are analyzed. Correlations between isotopic anomalies in Ti, Al-26, Pu-244, and Mg-26(asterisk) are examined. Ti isotopic anomalies are compared with REE and trace element abundance patterns. Reasons for the lack of Al-26 in the hibonites are investigated and discussed. It is observed that there is no correlation between the Ti isotopic compositions, and the presence of Mg-26(asterisk), Pu-244, and REE and trace element patterns in individual hibonite samples. The data reveal that hibonites are not interstellar dust grains but formed on a short time scale and in localized regions of the early solar system.

  1. The statistical model calculation of prompt neutron spectra from spontaneous fission of {sup 244}Cm and {sup 246}Cm

    Energy Technology Data Exchange (ETDEWEB)

    Gerasimenko, B.F. [V.G. Khlopin Radium Inst., Saint Peterburg (Russian Federation)

    1997-03-01

    The calculations of integral spectra of prompt neutrons of spontaneous fission of {sup 244}Cm and {sup 246}Cm were carried out. The calculations were done by the Statistical Computer Code Complex SCOFIN applying the Hauser-Feschbach method as applied to the description of the de-excitation of excited fission fragments by means of neutron emission. The emission of dipole gamma-quanta from these fragments was considered as a competing process. The average excitation energy of a fragment was calculated by two-spheroidal model of tangent fragments. The density of levels in an excited fragment was calculated by the Fermi-gas model. The quite satisfactory agreement was reached between theoretical and experimental results obtained in frames of Project measurements. The calculated values of average multiplicities of neutron number were 2,746 for {sup 244}Cm and 2,927 for {sup 246}Cm that was in a good accordance with published experimental figures. (author)

  2. A Density Functional Study of Atomic Hydrogen and Oxygen Chemisorption on the Relaxed (0001) Surface of Double Hexagonal Close Packed Americium

    OpenAIRE

    Dholabhai, P. P.; Atta-Fynn, R.; A.K. Ray

    2009-01-01

    Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the adlayer str...

  3. 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)

    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

  4. Utilisation of micro-plant and reactive distillation for the production of 2-methoxy-2,4,4-trimethylpentane

    OpenAIRE

    Mustapha, Kehinde

    2014-01-01

    The micro-plant and reactive distillation concepts have been researched in this thesis. The aim of the project is to invent a technique for the production of pure 2-methoxy-2,4,4-trimethylpentane (TOME). After the production, physical property of interest of the chemical compound would be determined. The first phase of this project relates to the production of TOME with the micro-plant constructed by Aalto University chemical engineering research group. In the second section, TOME was man...

  5. Problem Assessment for a Formal Decision on the Future of the 244-S Double Contained Receiver Tank (DCRT)

    Energy Technology Data Exchange (ETDEWEB)

    SEDERBURG, J.P.

    2000-04-03

    This document describes the background, concerns, and issues associated with continued use of the 244-S DCRT. A problem statement is defined such that management may in the future make a decision about the preferred path forward on this DCRT. Influences and potential answers are outlined and presented such that costs, waste volume projections, projects (such as W-314), and other facilities (such as 222-S and PFP) are accurately represented.

  6. Short-lived $^{244}$Pu Points to Compact Binary Mergers as Sites for Heavy r-process Nucleosynthesis

    CERN Document Server

    Hotokezaka, Kenta; Paul, Michael

    2015-01-01

    Measurements of the radioactive $^{244}$Pu abundances can break the degeneracy between high-rate/low-yield and low-rate/high-yield scenarios for the production of heavy $r$-process elements. The first corresponds to production by core collapse supernovae (cc-SNe) while the latter corresponds to production by e.g. compact binary mergers. The estimated $^{244}$Pu abundance in the current interstellar medium inferred from deep-sea measurements (Wallner et al. 2015) is significantly lower than that corresponding Early Solar System abundances (Turner et al 2007). We estimate the expected median value of the $^{244}$Pu abundances and fluctuations around this value in both models. We show that while the current and Early Solar System abundances are naturally explained within the low-rate/high-yield (e.g. merger) scenario, they are incompatible with the high-rate/low-yield (cc-SNe) model. The inferred event rate remarkably agrees with compact binary merger rates estimated from Galactic neutron star binaries and from ...

  7. {\\alpha}-accompanied cold ternary fission of $^{238-244}$Pu isotopes in equatorial and collinear configuration

    CERN Document Server

    Santhosh, K P; Priyanka, B

    2015-01-01

    The cold ternary fission of $^{238}$Pu, $^{240}$Pu, $^{242}$Pu and $^{244}$Pu isotopes, with $^{4}$He as light charged particle, in equatorial and collinear configuration has been studied within the Unified ternary fission model (UTFM). The fragment combination $^{100}$Zr+$^{4}$He+$^{134}$Te possessing the near doubly magic nuclei $^{134}$Te (N=82, Z=52) gives the highest yield in the alpha accompanied ternary fission of $^{238}$Pu. For the alpha accompanied ternary fission of $^{240}$Pu, $^{242}$Pu and $^{244}$Pu isotopes, the highest yield was found for the fragment combination with doubly magic nuclei $^{132}$Sn (N=82, Z=50) as the heavier fragment. The deformation and orientation of fragments have also been taken into account for the alpha accompanied ternary fission of $^{238-244}$Pu isotopes, and it has been found that in addition to closed shell effect, ground state deformation also plays an important role in determining the isotopic yield in the ternary fission process. The emission probability and ki...

  8. The emission probabilities of long range alpha particles from even-even 244-252Cm isotopes

    CERN Document Server

    Santhosh, K P; Priyanka, B

    2014-01-01

    The alpha accompanied cold ternary fission of even-even 244Cm, 246Cm, 248Cm, 250Cm and 252Cm isotopes have been studied by taking the interacting barrier as the sum of Coulomb and proximity potential with the fragments in equatorial configuration. The favorable fragment combinations are obtained from the cold reaction valley plot and by calculating the relative yield for the charge minimized fragments. In the alpha accompanied ternary fission of 244Cm isotope, the highest yield is found for the fragment combination 110Ru+4He+130Sn, which possess near doubly magic nuclei 130Sn. For the ternary fission of 246Cm, 248Cm, 250Cm and 252Cm isotopes with 4He as light charged particle, the highest yield is obtained for the fragment combination with doubly magic nuclei 132Sn as the heavier fragment. The emission probabilities and kinetic energies of long range alpha particle have been computed for the 242,244,246,248Cm isotopes and are found to be in good agreement with the experimental data. The relative yields for th...

  9. A new method for the determination of plutonium and americium using high pressure microwave digestion and alpha-spectrometry or ICP-SMS

    International Nuclear Information System (INIS)

    Plutonium and americium are radionuclides particularly difficult to measure in environmental samples because they are a-emitters and therefore necessitate a careful separation before any measurement, either using radiometric methods or ICP-SMS. Recent developments in extraction chromatography resins such as EichromR TRU and TEVA have resolved many of the analytical problems but drawbacks such as low recovery and spectral interferences still occasionally occur. Here, we report on the use of the new EichromR DGA resin in association with TEVA resin and high pressure microwave acid leaching for the sequential determination of plutonium and americium in environmental samples. The method results in average recoveries of 83 ± 15% for plutonium and 73 ± 22% for americium (n = 60), and a less than 10% deviation from reference values of four IAEA reference materials and three samples from intercomparisons exercises. The method is also suitable for measuring 239Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement. (author)

  10. 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)

    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

  11. Comparative XRPD and XAS study of the impact of the synthesis process on the electronic and structural environments of uranium–americium mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Prieur, D., E-mail: dam.prieur@gmail.com [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Lebreton, F. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France); Martin, P.M. [CEA, DEN, DEC/SESC/LLCC, 13108 Saint-Paul-Lez-Durance cedex (France); Caisso, M. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France); Butzbach, R. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Radiochemistry, P.O. Box 10119, 01314 Dresden (Germany); Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Delahaye, T. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France)

    2015-10-15

    Uranium–americium mixed oxides are potential compounds to reduce americium inventory in nuclear waste via a partitioning and transmutation strategy. A thorough assessment of the oxygen-to-metal ratio is paramount in such materials as it determines the important underlying electronic structure and phase relations, affecting both thermal conductivity of the material and its interaction with the cladding and coolant. In 2011, various XAS experiments on U{sub 1−x}Am{sub x}O{sub 2±δ} samples prepared by different synthesis methods have reported contradictory results on the charge distribution of U and Am. This work alleviates this discrepancy. The XAS results confirm that, independently of the synthesis process, the reductive sintering of U{sub 1−x}Am{sub x}O{sub 2±δ} leads to the formation of similar fluorite solid solution indicating the presence of Am{sup +III} and U{sup +V} in equimolar proportions. - Graphical abstract: Formation of (U{sup IV/V},Am{sup III})O{sup 2} solid solution by sol–gel and by powder metallurgy. - Highlights: • Uranium–americium mixed oxides were synthesized by sol–gel and powder metallurgy. • Fluorite solid solutions with similar local environment have been obtained. • U{sup V} and Am{sup III} are formed in equimolar proportions.

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

    International Nuclear Information System (INIS)

    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)

  13. Intramolecular sensitization of americium luminescence in solution: shining light on short-lived forbidden 5f transitions.

    Science.gov (United States)

    Sturzbecher-Hoehne, M; Yang, P; D'Aléo, A; Abergel, R J

    2016-06-14

    The photophysical properties and solution thermodynamics of water soluble trivalent americium (Am(III)) complexes formed with multidentate chromophore-bearing ligands, 3,4,3-LI(1,2-HOPO), Enterobactin, and 5-LIO(Me-3,2-HOPO), were investigated. The three chelators were shown to act as antenna chromophores for Am(III), generating sensitized luminescence emission from the metal upon complexation, with very short lifetimes ranging from 33 to 42 ns and low luminescence quantum yields (10(-3) to 10(-2)%), characteristic of Near Infra-Red emitters in similar systems. The specific emission peak of Am(III) assigned to the (5)D1 → (7)F1 f-f transition was exploited to characterize the high proton-independent stability of the complex formed with the most efficient sensitizer 3,4,3-LI(1,2-HOPO), with a log β110 = 20.4 ± 0.2 value. In addition, the optical and solution thermodynamic features of these Am(III) complexes, combined with density functional theory calculations, were used to probe the influence of electronic structure on coordination properties across the f-element series and to gain insight into ligand field effects.

  14. Nano-cerium vanadate: a novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste.

    Science.gov (United States)

    Banerjee, Chayan; Dudwadkar, Nilesh; Tripathi, Subhash Chandra; Gandhi, Pritam Maniklal; Grover, Vinita; Kaushik, Chetan Prakash; Tyagi, Avesh Kumar

    2014-09-15

    Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides (233)U (4.82 MeV α) and (241)Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr(2+), Ru(3+), Fe(3+), etc., in the uptake process indicated CeVO4 nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions.

  15. Distribution of plutonium, americium, and several rare earth fission product elements between liquid cadmium and LiCl-KCl eutectic

    International Nuclear Information System (INIS)

    Separation factors were measured that describe the partition between molten cadmium and molten LiCl-KCl eutectic of plutonium, americium, praseodymium, neodymium, cerium, lanthanum, gadolinium, dysprosium, and yttrium. The temperature range was 753-788 K, and the range of concentrations was that allowed by the sensitivity of the chemical analysis methods. Mean separation factors were derived for Am-Pu, Nd-Am, Nd-Pu, Nd-Pr, Gd-La, Dy-La, La-Ce, La-Nd, Y-La, and Y-Nd. Where previously published data were available, agreement was good. For convenience, the following series of separation factors relative to plutonium was derived by combining the measured separation factors: Pu, 1.00 (basis); Am, 1.54; Pr, 22.0; Nd, 23.4; Ce, 26; La, 70; Gd, 77; Dy, 270; Y, 3000. These data are used in calculating the distribution of the actinide and rare earth elements in the prochemical reprocessing of spent fuel from the Integral Fast Reactor. (orig.)

  16. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    International Nuclear Information System (INIS)

    Routine counting methods and ICP-MS are unable to directly measure the new US Department of Energy (DOE) regulatory level for discharge waters containing alpha-emitting radionuclides of 30 pCi/L total alpha or the 0.05 pCi/L regulatory level for Pu or Am activity required for surface waters at the Rocky Flats site by the State of Colorado. This inability indicates the need to develop rapid, reliable, and robust analytical techniques for measuring actinide metal ions, particularly americium and plutonium. Selective separation or preconcentration techniques would aid in this effort. Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for 241Am(III) and 238Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4

  17. Characteristics of plutonium and americium contamination at the former U.K. atomic weapons test ranges at Maralinga and Emu

    International Nuclear Information System (INIS)

    Physico-chemical studies on environmental plutonium are described, which provide data integral to an assessment of dose for the inhalation of artificial actinides by Australian Aborigines living a semi-traditional lifestyle at Maralinga and Emu, sites of U.K. atomic weapons tests between 1953 and 1963. The most significant area, from a radiological perspective, is the area contaminated by plutonium in a series of ''one point'' safety trials in which large quantities of plutonium were dispersed explosively at a location known as Taranaki. The activity distribution of plutonium and americium with particle size is quite different from the mass distribution, as a considerably higher proportion of the activity is contained in the finer (inhalable) fraction than of the mass. Except in areas which were disturbed through ploughing during a cleanup in 1967, most the activity remains in the top 1 cm of the surface. Much of the activity is in particulate form, even at distances > 20 km from the firing sites, and discrete particles have been located even at distances beyond 100 km. Data are presented which permit the assessment of annual committed doses through the inhalation pathway, for Aborigines living a semi-traditional lifestyle in the areas affected by the Taranaki firings in particular. (author)

  18. A multi-channel 24.4 ps bin size Time-to-Digital Converter for HEP applications

    CERN Document Server

    Mester, C; Morira, P

    2008-01-01

    A multi-channel time-tagging Time-to-Digital Converter (TDC) ASIC with a resolution of 24.4 ps (bin size) has been implemented and fabricated in a 130 nm CMOS technology. An on-chip PLL is used to generate an internal timing reference from an external 40 MHz clock source. The circuit is based on a 32 element Delay Locked Loop (DLL) which performs the time interpolation. The 32 channel architecture of the TDC is suitable for both triggered and non-triggered applications. The prototype contains test structures such as a substrate noise generator. The paper describes the circuit architecture and its principles of operation.

  19. 小学教师244名预防儿童虐待知识态度分析%Knowledge and attitudes toward child maltreatment in 244 teachers of elementary schools

    Institute of Scientific and Technical Information of China (English)

    罗晓玲; 陈晶琦; 孔艳秋; 李向梅; 张文静; 李景壹; 赵晓侠; 冯亚男

    2013-01-01

    目的 了解小学教师预防儿童虐待的知识和态度,为开展以学校为基础的预防儿童虐待工作提供参考依据.方法 于2012年11月,对方便抽取的辽宁省某市6所小学244名小学教师进行不记名问卷调查.结果 在被调查的244名小学教师中,分别只有32.0%和38.5%认为父母因为孩子吸烟、说脏话而非常用力地打孩子是对儿童的虐待;53.3%认为用“愚蠢”、“丑陋”、“笨”等词来责骂孩子是儿童虐待;92.6%的教师认为有必要学习预防儿童虐待课程.结论 教师预防儿童虐待知识有限,应重视学校教师预防儿童虐待知识培训,普及预防儿童虐待基本知识.

  20. The role of natural organic matter in the migration behaviour of americium in the Boom Clay - Part 1: migration experiments

    International Nuclear Information System (INIS)

    Full text of publication follows: In demonstrating the suitability of Boom Clay as reference site for studying the disposal of radioactive waste, the role of the relatively high amount of Natural Organic Matter (NOM) present in the Boom Clay on the mobility of critical radionuclides needs to be investigated thoroughly. It is generally accepted that trivalent actinides and lanthanides form strong complexes with humic substances. Complexation of these trivalent radionuclides with NOM present in the Boom Clay may therefore have two opposite effects. If complexed by the aqueous phase NOM (the mobile NOM), the radionuclide transport will be governed by the mobility of these dissolved radionuclide- NOM species. If complexed by the solid phase NOM (the immobile NOM) the 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 in order to develop a conceptual model for inclusion in a performance assessment (PA) model. The migration behaviour of Americium (used as an analogue for the critical radionuclide Pu) was investigated by complexing 241Am with radiolabelled (14C-labelled) NOM before passing through undisturbed Boom Clay cores contained in columns. The use of two different radionuclides, allows the migration behaviour of both the NOM and the Am to be followed. The results of the migration experiments showed that the Am-NOM complexes dissociated when they came into contact with Boom Clay and that the bulk of Am became immobilised (either as Am complexed to immobile NOM or sorbed to the mineral phase). Only a small percentage of the complex persisted as 'stabilised' Am-OM complex which exhibited slow dissociation kinetics upon moving through the Boom Clay. When the applied radionuclide source also contains Am in the form of an inorganic solid phase (when Am is applied above the solubility limit), a continuous source of Am exists to form 'temporarily stabilised' Am

  1. Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Nano-cerium vanadate: A novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Chayan; Dudwadkar, Nilesh [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tripathi, Subhash Chandra, E-mail: sctri001@gmail.com [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gandhi, Pritam Maniklal [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Grover, Vinita [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kaushik, Chetan Prakash [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, Avesh Kumar, E-mail: aktyagi@barc.gov.in [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2014-09-15

    Highlights: • Template free, low temperature synthesis of CeVO{sub 4} nanopowders. • Thermodynamically and kinetically favourable uptake of Am(III) and U(VI) exhibited. • K{sub d} and ΔG° values for Am(III) and U(VI) uptake in pH 1–6 are reported. • Interdiffusion coefficients and zeta potential values in pH 1–6 are reported. • Possible application in low level aqueous nuclear waste remediation. - Abstract: Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides {sup 233}U (4.82 MeV α) and {sup 241}Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3 h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr{sup 2+}, Ru{sup 3+}, Fe{sup 3+}, etc., in the uptake process indicated CeVO{sub 4} nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions.

  3. Plutonium, americium and radiocaesium in the marine environment close to the Vandellos I nuclear power plant before decommissioning

    International Nuclear Information System (INIS)

    The Vandellos nuclear power plant (NPP), releasing low-level radioactive liquid waste to the Mediterranean Sea, is the first to be decommissioned in Spain, after an incident which occurred in 1989. The presence, distribution and uptake of various artificial radionuclides (radiocaesium, plutonium and americium) in the environment close to the plant were studied in seawater, bottom sediments and biota, including Posidonia oceanica, fish, crustaceans and molluscs. Seawater, sediments and Posidonia oceanica showed enhanced levels in the close vicinity of the NPP, although the effect was restricted to its near environment. Maximum concentrations in seawater were 11.6±0.5 Bq m-3 and 16.9±1.2 mBq m-3 for 137Cs and 239,240Pu, respectively. When sediment concentrations were normalized to excess 210Pb, they showed both the short-distance transport of artificial radionuclides from the Vandellos plant and the long-distance transport of 137Cs from the Asco NPP. Posidonia oceanica showed the presence of various gamma-emitters attributed to the impact of the Chernobyl accident, on which the effect of the NPP was superimposed. Seawater, sediment and Posidonia oceanica collected near the plant also showed an enhancement of the plutonium isotopic ratio above the fallout value. The uptake of these radionuclides by marine organisms was detectable but limited. Pelagic fish showed relatively higher 137Cs concentrations and only in the case of demersal fish was the plutonium isotopic ratio increased. The reported levels constitute a set of baseline values against which the impact of the decommissioning operations of the Vandellos I NPP can be studied

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

    International Nuclear Information System (INIS)

    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 CaCl2 endash 26 mole percent KCl or pure CaCl2. 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

  5. Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea.

    Science.gov (United States)

    Hunt, G J

    1998-06-01

    Our previous studies have indicated lower values of the gut transfer factor ('f1 values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Carastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 h samples of urine and faeces. Urine samples indicated f1 values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7 x 10(-4) with an arithmetic mean in the range (2-3) x 10(-4), and for americium up to 2.6 x 10(-4) with an arithmetic mean of 1.2 x 10(-4). Limited data based on volunteers eating cockles from the Solway suggest that f1 values for americium may be greater at distance from Sellafield. The measured values compare with 5 x 10(-4) used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f1 value in the region of 0.2, twice the value currently used by ICRP. For 137Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f1 = 1.0. Technetium-99 gave f1 values up to about 0.6, in reasonable conformity with the ICRP value of 0.5.

  6. Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.J. [CEFAS Laboratory, Lowestoft, Suffolk NR33 0HT (United Kingdom)

    1998-06-01

    Our previous studies have indicated lower values of the gut transfer factor ('f{sub L} values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Cerastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 samples of urine and faeces. Urine samples indicated f{sub L} values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7x10{sup -4} with an arithmetic mean in the range (2-3)x10{sup -4}, and for americium up to 2.6x10{sup -4} with an arithmetic mean of 1.2x10{sup -4}. Limited data based on volunteers eating cockles from the Solway suggest that f{sub L} values for americium may be greater at distance from Sellafield. The measured values compare with 5x10{sup -4} used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f{sub L} value in the region of 0.2, twice the value currently used by ICRP. For {sup 137}Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f{sub L}=1.0. Technetium-99 gave f{sub L} values up to about 0.6, in reasonable conformity with the ICRP value of 0.5. (author)

  7. Deformation effects in the alpha accompanied cold ternary fission of even-even $^{244-260}$Cf isotopes

    CERN Document Server

    Santhosh, K P

    2016-01-01

    Within the Unified ternary fission model (UTFM), the alpha accompanied ternary fission of even-even $^{244-260}$Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. For the alpha accompanied ternary fission of 244^Cf isotope, the highest yield is obtained for the fragment combination 108^Ru+4^He+132^Te, which contain near doubly magic nuclei 132^Te (N=80, Z=52). In the case of 246^Cf and 248^Cf isotopes, the highest yield is obtained for the fragment combinations with near doubly magic nuclei 134^Te (N=82, Z=52) as the heavier fragment. The highest yield obtained for 250^Cf, 252^Cf, 254^Cf, 256^Cf, 258^Cf and 260^Cf isotopes is for the fragment combination with doubly magic nuclei 132^Sn (N=82, Z=50) as the heavier fragment. We have included the effect of deformation and orientation of fragments and this has revealed that in addition to closed shell effect, ground state deformation also plays an important role in the calculation of relative yield of fav...

  8. When the non-contrast-enhanced phase is unnecessary in abdominal computed tomography scans? A retrospective analysis of 244 cases

    International Nuclear Information System (INIS)

    Objective: to evaluate the necessity of the non contrast-enhanced phase in abdominal computed tomography scans. Materials and Methods: A retrospective, cross-sectional, observational study was developed, evaluating 244 consecutive abdominal computed tomography scans both with and without contrast injection. Initially, the contrast-enhanced images were analyzed (first analysis). Subsequently, the observers had access to the non-contrast-enhanced images for a second analysis. The primary and secondary diagnoses were established as a function of the clinical indications for each study (such as tumor staging, acute abdomen, investigation for abdominal collection and hepatocellular carcinoma, among others). Finally, the changes in the diagnoses resulting from the addition of the non-contrast-enhanced phase were evaluated. Results: Only one (0.4%; p > 0.999; non-statistically significant) out of the 244 reviewed cases had the diagnosis changed after the reading of non-contrast-enhanced images. As the secondary diagnoses are considered, 35 (14%) cases presented changes after the second analysis, as follows: nephrolithiasis (10%), steatosis (3%), adrenal nodule (0.7%) and cholelithiasis (0.3%). Conclusion: For the clinical indications of tumor staging, acute abdomen, investigation of abdominal collections and hepatocellular carcinoma, the non-contrast-enhanced phase can be excluded from abdominal computed tomography studies with no significant impact on the diagnosis. (author)

  9. Radioactive air emissions notice of construction use of a portable exhauster at 244-AR vault. Revision 2

    International Nuclear Information System (INIS)

    This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.96, a portable exhauster at the 244-AR Vault. The exhauster would be used during air jetting of accumulated liquids from the cell sumps into the tanks and to make transfers among the tanks within the vault when needed. The 244-AR Vault is considered to be a double-contained receiver tank (OCRT) based on its functional characteristics, although it is not listed as one of the five designated DCRTs in the 200 Area Tank Farm systems. Process operations at the vault have been inactive since 1978 and the vault's two stacks have not operated since 1993. Since cessation of vault operations an extremely large amount of rain water and snow melt have accumulated in the cell sumps. The water level in the sumps is substantially above their respective operating levels and there is concern for leakage to the environment through containment failure due to corrosion from backed-up sump liquid. Active ventilation is required to provide contamination control during air jetting operations within the vault. It has been determined that it would not be cost effective to repair the existing exhaust systems to an operational condition; thus, a portable exhauster will be used to support the intermittent operations

  10. When the non-contrast-enhanced phase is unnecessary in abdominal computed tomography scans? A retrospective analysis of 244 cases

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Danilo Manuel Cerqueira; Salvadori, Priscila Silveira; Monjardim, Rodrigo da Fonseca; Bretas, Elisa Almeida Sathler; Torres, Lucas Rios; Caldana, Rogerio Pedreschi; Shigueoka, David Carlos; Medeiros, Regina Bitelli; D' ippolito, Giuseppe, E-mail: giuseppe_dr@uol.com.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Departamento de Diagnostico por Imagem

    2013-06-15

    Objective: to evaluate the necessity of the non contrast-enhanced phase in abdominal computed tomography scans. Materials and Methods: A retrospective, cross-sectional, observational study was developed, evaluating 244 consecutive abdominal computed tomography scans both with and without contrast injection. Initially, the contrast-enhanced images were analyzed (first analysis). Subsequently, the observers had access to the non-contrast-enhanced images for a second analysis. The primary and secondary diagnoses were established as a function of the clinical indications for each study (such as tumor staging, acute abdomen, investigation for abdominal collection and hepatocellular carcinoma, among others). Finally, the changes in the diagnoses resulting from the addition of the non-contrast-enhanced phase were evaluated. Results: Only one (0.4%; p > 0.999; non-statistically significant) out of the 244 reviewed cases had the diagnosis changed after the reading of non-contrast-enhanced images. As the secondary diagnoses are considered, 35 (14%) cases presented changes after the second analysis, as follows: nephrolithiasis (10%), steatosis (3%), adrenal nodule (0.7%) and cholelithiasis (0.3%). Conclusion: For the clinical indications of tumor staging, acute abdomen, investigation of abdominal collections and hepatocellular carcinoma, the non-contrast-enhanced phase can be excluded from abdominal computed tomography studies with no significant impact on the diagnosis. (author)

  11. When the non-contrast-enhanced phase is unnecessary in abdominal computed tomography scans? A retrospective analysis of 244 cases

    Directory of Open Access Journals (Sweden)

    Danilo Manuel Cerqueira Costa

    2013-07-01

    Full Text Available Objective: To evaluate the necessity of the non contrast-enhanced phase in abdominal computed tomography scans. Materials and Methods: A retrospective, cross-sectional, observational study was developed, evaluating 244 consecutive abdominal computed tomography scans both with and without contrast injection. Initially, the contrast-enhanced images were analyzed (first analysis. Subsequently, the observers had access to the non-contrast-enhanced images for a second analysis. The primary and secondary diagnoses were established as a function of the clinical indications for each study (such as tumor staging, acute abdomen, investigation for abdominal collection and hepatocellular carcinoma, among others. Finally, the changes in the diagnoses resulting from the addition of the non-contrast-enhanced phase were evaluated. Results: Only one (0.4%; p > 0.999; non-statistically significant out of the 244 reviewed cases had the diagnosis changed after the reading of non-contrast-enhanced images. As the secondary diagnoses are considered, 35 (14% cases presented changes after the second analysis, as follows: nephrolithiasis (10%, steatosis (3%, adrenal nodule (0.7% and cholelithiasis (0.3%. Conclusion: For the clinical indications of tumor staging, acute abdomen, investigation of abdominal collections and hepatocellular carcinoma, the non-contrast-enhanced phase can be excluded from abdominal computed tomography studies with no significant impact on the diagnosis.

  12. Determination by gamma-ray spectrometry of the plutonium and americium content of the Pu/Am separation scraps. Application to molten salts; Determination par spectrometrie gamma de la teneur en plutonium et en americium de produits issus de separation Pu/Am. Application aux bains de sels

    Energy Technology Data Exchange (ETDEWEB)

    Godot, A. [CEA Valduc, Dept. de Traitement des Materiaux Nucleaires, 21 - Is-sur-Tille (France); Perot, B. [CEA Cadarache, Dept. de Technologie Nucleaire, Service de Modelisation des Transferts et Mesures Nucleaires, 13 - Saint-Paul-lez-Durance (France)

    2005-07-01

    Within the framework of plutonium recycling operations in CEA Valduc (France), americium is extracted from molten plutonium metal into a molten salt during an electrolysis process. The scraps (spent salt, cathode, and crucible) contain extracted americium and a part of plutonium. Nuclear material management requires a very accurate determination of the plutonium content. Gamma-ray spectroscopy is performed on Molten Salt Extraction (MSE) scraps located inside the glove box, in order to assess the plutonium and americium contents. The measurement accuracy is influenced by the device geometry, nuclear instrumentation, screens located between the sample and the detector, counting statistics and matrix attenuation, self-absorption within the spent salt being very important. The purpose of this study is to validate the 'infinite energy extrapolation' method employed to correct for self-attenuation, and to detect any potential bias. We present a numerical study performed with the MCNP computer code to identify the most influential parameters and some suggestions to improve the measurement accuracy. A final uncertainty of approximately 40% is achieved on the plutonium mass. (authors)

  13. An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

    Energy Technology Data Exchange (ETDEWEB)

    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 {sup 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.

  14. Dissertation on the computer-based exploitation of a coincidence multi parametric recording. Application to the study of the disintegration scheme of Americium 241

    International Nuclear Information System (INIS)

    After having presented the meaning of disintegration scheme (alpha and gamma emissions, internal conversion, mean lifetime), the author highlights the benefits of the use of multi-parametric chain for the recording of correlated parameters, and of the use of a computer for the analysis of bi-parametric information based on contour lines. Using the example of Americium 241, the author shows how these information are obtained (alpha and gamma spectrometry, time measurement), how they are chosen, coded, analysed and stored, and then processed by contour lines

  15. The smart home system based on S3C244OA and ZigBee technology%基于S3C244OA和ZigBee技术的智能家居系统

    Institute of Scientific and Technical Information of China (English)

    汪玉凤; 冯泽中

    2010-01-01

    本文介绍一种基于ZigBee技术的网络化智能家居系统的设计和实现方案.系统硬件上以S3C244OA为控制核心,利用CC2430组建家庭内部网络来采集家庭设备的数字信号,用USB camera采集家庭内部的视频信号.软件上利用嵌入式Web服务器和CGI技术实现家庭内网和Internet相连,达到远程监控的目的.通过实际测试证明系统功能强大,运行稳定,满足了家庭信息网络化的要求.

  16. Tolerance Analysis and Control on L4 Length for 244.5 mm BC Casing%244.5mm管偏梯形螺纹接头L4长度公差分析及控制

    Institute of Scientific and Technical Information of China (English)

    吕拴录; 姬丙寅; 杨成新; 文志明; 张锋; 徐永康; 樊文刚

    2012-01-01

    某油田在检验一批244.5 mm偏梯形螺纹接头套管时发现,管端至螺纹消失点的长度L4比公称值小25.22 mm.虽然API SPEC 5B对套管偏梯形外螺纹接头L4没有规定公差,但依据APISPEC 5CT和油田规定的外径公差可以推算结果,L4的上偏差为39.11 mm(7.7扣),下偏差为一17.39 mm(3.42扣).分析结果表明:该批套管L4实际公差已经超过推算出的L4负公差,使套管接头密封性能降低22.0%,并降低了螺纹连接强度.%It was found that the total length end of pipe to vanish point L4 is less 25. 22 mm of casing connection than that of the normal dimension specified in API SPEC 5B for 244. 5mm buttress thread casing during inspection in one oil field. Though L4 tolerance is not specified in API SPEC 5B,but it is considered that L4 tolerance can be deduced per outside diameter tolerance in accordance with API SPEC 5CT and the oil field specification, the calculation result is that the upper deviation and lower deviation of L, is +39.11mm (7. 7 thread) and ?7. 39mm (3. 42 thread) .respectively. The actual L, is shorter than the lower deviation that will decrease 22% of seal performance of casing connection,and reduce the tension strength of casing connection.

  17. Shu-mei Shih, Visuality and Identity. Sinophone Articulation across the Pacific, Berkeley, University Press of California, 2007, 244 p.

    OpenAIRE

    Lincot, Emmanuel

    2008-01-01

    Professeur de littérature comparée à l’université de Californie de Los Angeles (UCLA), spécialiste des « gender studies », Shu-mei Shih aborde d’une manière originale, dans ce nouvel ouvrage, la question de l’identité dans le monde sinophone actuel. Long de 244 pages, Visuality and Identity. Sinophone Articulations across the Pacific, est composé d’une introduction et de six parties : la première porte sur la globalisation et ses effets sur les minorités, la deuxième sur le cas, plus précis, ...

  18. Production of new superheavy Z=108-114 nuclei with $^{238}$U, $^{244}$Pu and $^{248,250}$Cm targets

    CERN Document Server

    Feng, Zhao-Qing; Li, Jun-Qing

    2009-01-01

    Within the framework of the dinuclear system (DNS) model, production cross sections of new superheavy nuclei with charged numbers Z=108-114 are analyzed systematically. Possible combinations based on the actinide nuclides $^{238}$U, $^{244}$Pu and $^{248,250}$Cm with the optimal excitation energies and evaporation channels are pointed out to synthesize new isotopes which lie between the nuclides produced in the cold fusion and the $^{48}$Ca induced fusion reactions experimentally, which are feasible to be constructed experimentally. It is found that the production cross sections of superheavy nuclei decrease drastically with the charged numbers of compound nuclei. Larger mass asymmetries of the entrance channels enhance the cross sections in 2n-5n channels.

  19. Deformation effects in the alpha accompanied cold ternary fission of even-even {sup 244-260}Cf isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P.; Krishnan, Sreejith [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

    2016-04-15

    Within the unified ternary fission model (UTFM), the alpha accompanied ternary fission of even-even {sup 244-260}Cf isotopes has been studied by taking the interacting barrier as the sum of Coulomb and proximity potential. For the alpha accompanied ternary fission of the {sup 244}Cf isotope, the highest yield is obtained for the fragment combination {sup 108}Ru + {sup 4}He + {sup 132}Te, which contains the near doubly magic nucleus {sup 132}Te (N = 80, Z = 52). In the case of {sup 246}Cf and {sup 248}Cf isotopes, the highest yield is obtained for the fragment combinations with the near doubly magic nucleus {sup 134}Te (N = 82, Z = 52) as the heaviest fragment. The highest yield obtained for {sup 250}Cf, {sup 252}Cf, {sup 254}Cf, {sup 256}Cf, {sup 258}Cf and {sup 260}Cf isotopes is for the fragment combination with the doubly magic nucleus {sup 132}Sn (N = 82), Z = 50 as the heaviest fragment. We have included the effect of deformation and orientation of fragments and this has revealed that in addition to the closed shell effect, ground-state deformation also plays an important role in the calculation of the relative yield of favorable fragment combinations. The computed isotopic yields for the alpha accompanied ternary fission of the {sup 252}Cf isotope are found to be in agreement with the experimental data. The emission probability and kinetic energy of the long-range alpha particle is calculated for the various isotopes of Cf and are found to be in good agreement with the experimental data. (orig.)

  20. Statistical evaluation of lung, bone, and liver tumors in rats exposed to aerosols of 238PuO2, 239PuO2, and 244CmO2

    International Nuclear Information System (INIS)

    The Mantel--Haenszel procedure was applied to the evaluation of tumor data from exposures to aerosols of 238PuO2, 239PuO2, and 244CmO2. Significance was evident for lung tumors for all three transuranics, for osteosarcomas in animals exposed to 244CmO2, and was suggested for liver tumors in animals exposed to 244CmO2

  1. Inhaled americium dioxide

    International Nuclear Information System (INIS)

    This project includes experiments to determine the effects of Zn-DTPA therapy on the retention, translocation and biological effects of inhaled 241AmO2. Beagle dogs that received inhalation exposure to 241AmO2 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 241Am. Another group of dogs that received inhalation exposure to 241AmO2 and were treated daily with Zn-DTPA had initial pulmonary deposition of 19 to 26 μCi 241Am. These dogs did not develop respiratory insufficiency, and hematologic and clinical chemistry changes were less severe than in the non-DTPA-treated dogs

  2. Drospirenone/ethinylestradiol 3mg/20microg (24/4 day regimen): a review of its use in contraception, premenstrual dysphoric disorder and moderate acne vulgaris.

    Science.gov (United States)

    Fenton, Caroline; Wellington, Keri; Moen, Marit D; Robinson, Dean M

    2007-01-01

    Drospirenone 3mg with ethinylestradiol 20microg (Yaz) is a low-dose combined oral contraceptive (COC) administered in a regimen of 24 days of active tablets followed by a short hormone-free interval (4 days; 24/4 regimen). Drospirenone, unlike other synthetic progestogens used in COCs, is a 17alpha-spirolactone derivative and a 17alpha-spironolactone analogue with antimineralocorticoid and antiandrogenic properties. Drospirenone/ethinylestradiol 3mg/20microg (24/4) is approved in the US for the prevention of pregnancy in women, for the treatment of the symptoms of premenstrual dysphoric disorder (PMDD) and for the treatment of moderate acne vulgaris in women who wish to use an oral contraceptive for contraception.Drospirenone/ethinylestradiol 3mg/20microg (24/4) provided 99% contraceptive protection over 1 year of treatment in two large studies. The same treatment regimen over three treatment cycles also significantly improved the emotional and physical symptoms associated with PMDD, and improved moderate acne vulgaris over six treatment cycles in double-blind trials. It was generally well tolerated, with adverse events generally typical of those experienced with other COCs and which were most likely to occur in the first few cycles. Clinical trials indicate that drospirenone/ethinylestradiol 3mg/20microg (24/4) is a good long-term contraceptive option, and additionally offers relief of symptoms that characterise PMDD and has a favourable effect on moderate acne vulgaris. PMID:17683173

  3. 77 FR 27082 - StarTek USA, Inc., 244 Dundee Avenue, Greeley, CO; StarTek USA, Inc., 1250 H Street, Greeley, CO...

    Science.gov (United States)

    2012-05-08

    ... December 28, 2010, applicable to workers and former workers of StarTek USA, Inc., Greeley, Colorado. The Department's notice of determination was published in the Federal Register on January 14, 2011 (76 FR 2717... Employment and Training Administration StarTek USA, Inc., 244 Dundee Avenue, Greeley, CO; StarTek USA,...

  4. Oxidation-reduction properties of americium, curium, berkelium, californium, einsteinium and fermium, and thermodynamic consequences for the 5f series

    International Nuclear Information System (INIS)

    The amalgamation of 5f elements from Am to Fm has been studied by using 241Am, 244Cm, 249Bk, 249Cf, 252Cf, 253Es, 254Es, 252Fm and 255Fm with two electrochemical methods, radiocoulometry and radiopolarography, perfectly adapted to investigate extremely diluted solutions when the concentration of electroactive species is as low as 10-16M. The theory of radiocoulometry has been developed in the general cases of reversible and irreversible electrode process. It has been used to interpret the experimental data on the kinetic curves of amalgamation, and to estimate the standard rate constant of the electrode process in complexing medium (citric). On the other hand the radiopolarographic method has been applied to study the mechanism of reduction at the dropping mercury electrode of cations M3+ in aqueous medium to the metal M with formation of amalgam. The results are exploited into two directions: 1- Acquisition of some data concerning the oxidation-reduction properties of elements from Am to Fm. Therefore the standard electrode E0 [M(III-0)] potentials for Bk, Cf and Es, and the standard electrode E0 [M(II-0)] potential for Fm are estimated and the relative stability of each oxidation state (from II to VII) of 5f elements is discussed; 2- Acquisition of unknown thermodynamic data on transcalifornium elements. Correlations between 4f and 5f elements are precised and some divergences appear for the second half of 4f and 5f series (i.e. for 65<=Z<=71 and 97<=Z<=103)

  5. 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)

  6. Partitioning studies in China and the separation of americium and fission product rare earths with dialkyl phosphinic acid and its thio-substituted derivatives

    International Nuclear Information System (INIS)

    Studies on the TRPO extractions process for recovering actinides from highly active waste (HAW) and its application to the pretreatment of Chinese HAW are described. The removal of Sr by di-cyclohexyl 18 crown 6 and the removal of Cs by spherical titanium ferrous hexa-cyanate from acidic waste are also described. Results of the extraction of trivalent americium and fission product rare earths (FPREs) by dialkyl-phosphinic, dialkyl-mono-thio-phosphinic and dialkyl-di-thio-phosphinic acids are reported. Dialkyl-thio-phosphinic acid (commercial product Cyanex 301, alkyl =2, 4, 4-methyl-pentyl) shows very high selectivity towards Am. Using 1M Cyanex 301 -kerosene as extractant, 99.9 % Am can be separated from 0.5M(Pr+Nd)(NO3)3 solution with 3-4 extraction stages and 3-4 scrubbing stages. (authors)

  7. Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil

    International Nuclear Information System (INIS)

    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 241Am 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. 241Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with 241Am. 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, Fetot, organic acids, 241Am) and its bacterial biomass content too. The overall results indicate that 241Am 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 (10-4 M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of 241Am corresponds to a solid/liquid coefficient of partition (Kd) of about 105 L.kg-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 241Am remobilization. On the other hand, the presence of strong citrate concentrations (≥ 10-2 M) allows 300 to 10000 time greater re-mobilizations by the complexing of 241Am released after the dissolution of the carrying phases. Finally, the colloidal transport of 241Am has been systematically observed in a limited but significant extend and

  8. Fragmentation of 200 and 244 MeV/u carbon beams in thick tissue-like absorbers

    International Nuclear Information System (INIS)

    Stacks consisting of thin CR-39 sheets sandwiched between thick lucite and water absorbers were perpendicularly bombarded by 12C ions at 200 and 244 MeV/u. Track radius distributions representing the charge composition of the fragmented beams were automatically measured by a particle track analysis system. After analysis of the nuclear charge distributions, the total charge removal cross-sections and elemental production cross-sections of fragments with atomic numbers from 5 to 3, were obtained down to the lower energies (∼50 and 100 MeV/u, respectively). It has been found that the measured total charge removal cross-section agrees with theoretical predictions within ∼10% and very well with previous experiments in corresponding energy regions. Two model calculations for production of B fragment are in good agreement with our measured data while a third model overestimates it by ∼12%. Theoretical cross-sections for Be and Li fragments differ strongly among the different models and from measured values

  9. Evolving role of 2B4/CD244 in T and NK cell responses during virus infection

    Directory of Open Access Journals (Sweden)

    Stephen Noel Waggoner

    2012-12-01

    Full Text Available The signaling lymphocyte activation molecule (SLAM family receptor, 2B4/CD244, was first implicated in anti-viral immunity by the discovery that mutations of the SLAM-associated protein, SAP/SH2D1A, impaired 2B4-dependent stimulation of T and natural killer (NK cell anti-viral functions in X-linked lymphoproliferative (XLP syndrome patients with uncontrolled Epstein-Barr virus (EBV infections. Engagement of 2B4 has been variably shown to either activate or inhibit lymphocytes which express this receptor. While SAP expression is required for stimulatory functions of 2B4 on lymphocytes, it remains unclear whether inhibitory signals derived from 2B4 can predominate even in the presence of SAP. Regardless, mounting evidence suggests that 2B4 expression by NK and CD8 T cells is altered by virus infection in mice as well as in humans, and 2B4-mediated signaling may be an important determinant of effective immune control of chronic virus infections. In this review, recent findings regarding the expression and function of 2B4 as well as SAP on T and NK cells during virus infection is discussed, with a focus on the role of 2B4-CD48 interactions in crosstalk between innate and adaptive immunity.

  10. Synergistic extraction of rare earths with bis(2,4,4-trimethyl pentyl) dithiophosphinic acid and trialkyl phosphine oxide.

    Science.gov (United States)

    Reddy, M L; Bosco Bharathi, J R; Peter, S; Ramamohan, T R

    1999-08-23

    Synergistic extraction of trivalent rare earths from nitrate solutions using mixtures of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301=HX) and trialkyl phosphine oxide (Cyanex 923=TRPO) in xylene has been investigated. The results demonstrate that these trivalent metal ions are extracted into xylene as MX(3).3HX with Cyanex 301 alone. In the presence of Cyanex 923, La(III) and Nd(III) are found to be extracted as MX(2).NO(3).TRPO. On the other hand, Eu(III), Y(III) and heavier rare earths are found to be extracted as MX(3).HX.2TRPO. The addition of a trialkylphosphine oxide to the metal extraction system not only enhances the extraction efficiency of these metal ions but also improves the selectivities significantly, especially between yttrium and heavier lanthanides. The separation factors between these metal ions were calculated and compared with that of commercially important extraction systems like di-2-ethylhexyl phosphoric acid.

  11. Resíduos de glifosato e ácido aminometilfosfônico e teores de isoflavonas em soja BRS 244 RR e BRS 154 Residues of glyphosate and aminomethylphosphonic acid and levels of isoflavones in BRS 244 RR and BRS 154 soybean

    Directory of Open Access Journals (Sweden)

    Giani Mariza Bärwald Bohm

    2008-12-01

    Full Text Available A principal forma de controle das plantas daninhas durante o cultivo de soja geneticamente modificada (GM RR BRS 244 RR é o uso de glifosato. Porém, existem dúvidas quanto à segurança desse herbicida, à qualidade dos grãos e do solo da soja GM RR cultivada em Planossolo. Resíduos da molécula do glifosato e do metabólito ácido aminometilfosfônico (AMPA podem estar presentes nos grãos, bem como, podem afetar a concentração de isoflavonas. Por isso, avaliaram-se as sojas BRS 244 RR e BRS 154 cultivadas nos seguintes tratamentos: T1 - soja BRS 244 RR, sem aplicação de herbicida, com capina manual aos 28 dias após o plantio (dap; T2 - soja BRS 154 sem aplicação de herbicida, com capina manual também aos 28 dap; T3 - soja BRS 244 RR com uma aplicação de glifosato a 960 g ia ha-1 aos 28 dap; T4 - soja BRS 244 RR com duas aplicações de glifosato a 960 g ia ha-1 aos 28 e 56 dap; T5 - soja BRS 244 RR com uma aplicação de herbicida imazetapir a 100 g ia ha-1 aos 28 dap; T6 - soja BRS 154 com uma aplicação de herbicida imazetapir a 100 g ia ha-1 aos 28 dap. Verificou-se que a aplicação de glifosato no controle de plantas daninhas resultou em teores elevados de glifosato e ácido aminometilfosfônico no solo. Nos grãos, o teor de isoflavonas não parece ser significativamente afetado pela aplicação de glifosato, mas os resíduos desse herbicida foram superiores ao permitido pela legislação vigente, que é de 10 mg.kg-1.The use of Glyphosate is the best way to control weed growing when cultivating genetically modified soybean (GMRR BRS 244 RR. However, there have been doubts about the safety of this herbicide use concerning its effects on the quality of grains and on the soil of Albaqualf cultivated GMRR soybean. Glyphosate and the metabolite aminomethylphosphonic acid (AMPA residues can be present in the grains and affect the isoflavones concentration. Therefore, BRS 244 RR and BRS 154 soybeans with the following

  12. Studying of distribution of 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm according to the organic acids fractions of the alienation zone soils

    International Nuclear Information System (INIS)

    The paper deals with data of research on the distribution of the radionuclides 137Cs, 90Sr, 239+240Pu, 241Am and 244Cm of ''the Chornobyl rains'' by the fractions of the organic matters of derno-podzolic sandy, derno-meadow and peat soils sampled in the alienation zone of the Chornobyl NPP. Functioning of organic matters was carried according to Tyurin's method. It is stressed that, independently on soil type, 137Cs is connected with the mineral contituent by 80-95%. It is found out that, independently on the soil type, 50-70% 137Sr and 15-45% 241Am are associated with fulvic acid fractions. The 241Am and 244Cm distribution according to organic acids taking into account deviations while carrying out determinations is unambiguous. It is found out that in all the soils tested the main quality of 239+24Pu is connected with humic acids

  13. A Study of Personality and Family- and School Environment and Possible Interactional Effects in 244 Swedish Children—A Multiple Regression Analysis

    OpenAIRE

    Persson, Bertil

    2014-01-01

    The aim of the study was to examine relationships between psychosocial family- and school environment and personality as assessed by the Junior Eysenck Personality Questionnaire (EPQ-J) and possible personality interactional effects. The study was based on 244 Swedish girls and boys, 10-19 years old, who filled in the Family- and School Psychosocial Environment (FSPE) questionnaire and the EPQ-J. A multiple regression analysis showed that the FSPE-factor Family conflicts and school discipline...

  14. 2-[4-(4-Methoxyphenylcarbonyloxy)benzylidene]-6-dimethylaminomethyl cyclohexanone hydrochloride: a Mannich base which inhibits the growth of some drug-resistant strains of Mycobacterium tuberculosis.

    Science.gov (United States)

    Das, S; Das, U; Bandy, B; Gorecki, D K J; Dimmock, J R

    2010-11-01

    2-[4-(4-Methoxyphenylcarbonyloxy)benzylidene]-6-dime-thylaminomethyl cyclohexanone hydrochloride 1 has a MIC value of 0.78 microg/mL towards Mycobacterium tuberculosis H37Rv and displays similar or identical MIC figures towards various drug-resistant strains of this microorganism. The enone 1 along with a partial structure 2-dimethylaminomethylcyclohexanone hydrochloride 3 affected respiration in isolated rat liver mitochondria differently which may contribute to the variation in toxicity to both normal cells and M. tuberculosis.

  15. The effect of occupational stress on depression symptoms among 244 policemen in a city%某市244名警察职业紧张对抑郁症状发生的影响

    Institute of Scientific and Technical Information of China (English)

    谷桂珍; 余善法; 吴辉; 周文慧

    2015-01-01

    Objective To explore the influence of occupational stress related factors on depression symptoms among 244 policemen in a city in China. Methods In May 2011, 287 policemen from a city public security bureau were recruited to this survey by cluster sampling method. We deleted questionnaires which include missing variables on demographic characteristics and factors associated with occupational stress questionnaires which include over 3 missing items. 244 policemen were included in this study. Depression symptoms and occupational stressors were measured using Chinese version of depression self-reported questionnaire, job content questionnaire,Chinese version of effort-reward imbalances questionnaire,job hazard scale and occupational stress inventory. Depression symptom scores and the relationship between the variables and occupational stress were analyzed by Spearman correlation analysis and multiple regression analysis. Results The Median (P25-P75) of depression symptom scores of all respondents was 16.50 (11.00-25.00). 144 were policemen with no depression symptoms and 100 were with depression symptoms. The median (P25-P75) of depression symptoms scores among policemen with length of serves<10, 10-19, 20-29 and≥30 was 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively. The difference of scores was significant among length of serves groups (χ2=9.52,P=0.023). The scores of psychological demands, sleep disorder , daily life stress and negative affectivity among policemen with depression symptoms were 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively, which were higher than those with no depression symptoms (24.00 (22.00-25.00),8.00 (5.00-13.00),8.00 (6.00-10.00),1.00 (0-2.75)), and the differences were significant (Z=3.82, 5.39, 5.15, 6.41,P<0.001). Spearman correlation analysis revealed that depression symptoms score was positively related to sleep disorder, commitment

  16. 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

    2016-03-01

    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. PMID:26907589

  17. Awareness of occupational low back pain: a survey of 244 midwives%助产士对职业性下背痛认知的调查

    Institute of Scientific and Technical Information of China (English)

    叶朝; 郭路; 张清梅; 耿志洁; 尚晓娣; 李星

    2014-01-01

    目的 了解助产士对职业性下背痛的认知、预防和保健的知识,调查该人群职业性下背痛的发生率.方法 应用调查问卷和中文版Roland-Morris功能障碍调查表(CRMDQ),对某市二、三级医院随机抽取的244名助产士进行问卷调查,并对相关指标进行统计分析.结果 参与调查的244名助产士中,了解职业性下背痛的概念、发生机制及危害的仅分别占18.4%、28.3%和54.1%,掌握一种职业性下背痛预防和保健方法的占9.4%~85.2%;能否正确应用人体力学与是否出现职业性下背痛情况密切相关(P<0.01),244名助产士对应用人体力学原理操作的需求率较高,最高达99.2%; CRMDQ腰痛量表的24个项目均有得分,最低为1分,最高为24分,总得分平均值为(8.5±7.2)分.结论 本次调查的244名助产士对职业性下背痛的认知度较低,而职业性下背痛在助产士中有较高的发生率,并对助产士的身体健康及正常执业构成了不同程度的影响.%Objective To investigate the awareness of occupational low back pain and knowledge of related prevention and healthcare measures among midwives,and to determine the incidence of low back pain among them.Methods A questionnaire survey was carried out with the use of Roland-Morris Disability Questionnaire (Chinese version) (CRMDQ) among 244 midwives from second-and third-class hospitals in Tianjin,China.Related indices were statistically analyzed.Results Among 244 midwives who participated in the survey,only 18.4% knew the definition of occupational low back pain,28.3% knew the pathogenic mechanism,and 54.1% knew its harm.About 9.4%~85.2% of midwives mastered at least one method for prevention and health care against occupational low back pain.Proper or improper use of human body mechanics was closely related to the development of occupational low back pain (P<0.01).There was a high proportion of midwives with a demand for application of human

  18. 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)

    Separation behaviour of Am3+ and Eu3+ 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 (S618C6), 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)

  19. Biological, chemical and other data collected aboard the THOMAS G. THOMPSON during cruise TN244 in the Coastal Waters of SE Alaska from 2009-12-05 to 2009-12-08 (NODC Accession 0117395)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0117395 includes biological, chemical, optical and physical data collected aboard the THOMAS G. THOMPSON during cruise TN244 in the Coastal Waters of...

  20. 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).

  1. The recycling of the actinides neptunium, americium and curium in a fast power reactor to reduce the long term activity in a final store

    International Nuclear Information System (INIS)

    The starting point for the considerations and calculations given in this dissertation is the inevitable production of radioactive materials in the use of nuclear energy, which creates a considerable potential danger in a final store for a very long period. As one possibility of alleviating this problem, a concept for recycling the waste actinides neptunium, americium and curium was proposed. The waste actinides are separated in the reprocessing of burnt-up fuel elements and reach a further irradiation circuit. There they pass through the stages 'manufacture of irradiation elements', 'use in a fast power reactor' and reprocessing of irradiation elements' several times. In each irradiation and subsequent storage, about 17% of the waste actinides are removed by fission or by conversion into nuclides which can be reused as fuel, so that during the life of 40 years of the fast recycling reacor, the waste actinides can be reduced in mass by one half. In order to determine this mass reduction effect, a model calculation was developed, which includes the representation of the neutron physics and thermal properties of the reactor core and the storage and reprocessing of the irradiation elements. (orig./RB)

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

    International Nuclear Information System (INIS)

    The paper presents a new sampling method for studying in-body radioactive contamination by bone-seeking radionuclides such as 90Sr, 239+240Pu, 238Pu, 241Am 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 238Pu 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 90Sr 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).

  3. The estimation of reactions of hematopoietic systems of organisms to the effect, caused by americium and plutonium, of nuclear industry workers

    Energy Technology Data Exchange (ETDEWEB)

    Gasteva, G. N.; Ivanova, T. A.; Gordeeva, A. A.; Suvorova, L. A.; Molokanov, A. A.; Badine, I.

    2004-07-01

    Object of research are the workers having in an organism radioactive substance (Am-241 and Pu-239). The purpose of work was the estimation of reaction hemopoietic systems of an organism on influence of americium and plutonium at workers of the nuclear industry. At the surveyed contingent of persons the determined effects caused by total influence Am-241 and Pu-239 are ascertained; chronic radiation disease with development, besides diffusive a pneumoscleoris and a chronic toxic-chemical radiating bronchitis, reactions of system of blood, jet hepatopathy which frequency accrued with increase doses loadings and essentially did not depend on age. In peripheral blood on the foreground jet changes act: hyperglobulia, the tendency to neutrophilus leukocytosis, monocytosis, increase ESR, decrease (reduction ?/G of factor reflecting weight and processing of defeat bronchus and pulmonary of system. Stable downstroke in number thrombocytes and reticulocytes in peripheral blood, their direct dependence on a doze of an irradiation, reflect hypoplastic a background hemogenesis, caused by long influence incorporatedin a bone and a bone brain of radioactive substances. At cytologic research punctate a bone brain jet changes which are expressed in increase of functional activity erythro-and myelopoiesiscome to light and provide compensatory reaction of peripheral blood. At histologic research of a bone brain and a bone fabric attributes of development atrophic process which is expressed in reduction of volume parenchyma a bone brain (a fatty atrophy) and dysplasia to a bone fabric are observed.

  4. Magnetic thermal hysteresis due to paramagnetic-antiferromagnetic transition in Fe-24.4Mn-5.9Si-5.1Cr alloy

    Directory of Open Access Journals (Sweden)

    L. Wang

    2013-08-01

    Full Text Available Magnetic thermal hysteresis (MTH associated with a paramagnetic (PM-antiferromagnetic (AFM phase transition was found in an Fe-24.4Mn-5.9Si-5.1Cr shape-memory alloy. Aside from the magnetic field (H, the driving rate (v can also tune the critical temperature of the magnetic transition and cause an increase in MTH. The magnetic phase diagram obtained is discussed. The equation for MTH was deduced based on the Landau model for a PM-AFM transition that includes H and v dependence, which gives a reasonable account of the experimental results.

  5. Liquid-Liquid Extraction and Separation of Co (II) and Ni(II) from Chloride Medium by bis (2,4,4-trimethylpentyl) dithio phosphinic acid in Kerosene

    International Nuclear Information System (INIS)

    The extraction of Co(II) and Ni(II) from chloride solutions using bis (2,4,4-trimethylpentyl) dithio phosphinic acid (CYANEX 301) in kerosene has been investigated. The various factors affecting the extraction process of Co(II) and Ni(II) by the investigated extractant such as contact time, ph, extractant and metal ion concentration as well as temperature, are separately investigated. The stripping of the extracted metal ions from loaded organic solutions is also carried out using different stripping reagents. The results were used to assess the conditions for maximum Co(II)/Ni(II) separation from chloride medium using CYANEX 301

  6. Crystal Structure and Magnetic Property of a Two-dimensional Manganese Compound [Mn(PhCOO)2(4,4'-bipyridine)]n

    Institute of Scientific and Technical Information of China (English)

    CHEN Hui; WANG Wen-Guo; MA Cheng-Bing; CHEN Chang-Neng; LIU Qiu-Tian; LIAO Dai-Zheng; LI Li-Cun

    2007-01-01

    A new two-dimensional polymeric manganese compound [Mn(PhCOO)2(4,4'-bipyridine)]n 1 has been prepared and structurally characterized by X-ray diffraction. The complex crystallizes in space group Pbcn with a = 18.7158(2), b = 11.6919(3), c = 9.4799(2)(A), V = 2074.42(7)(A)3, Z = 4, Mr = 453.34, Dc = 1.452 g/cm3, μ = 0.670 mm-1 and F(000) = 932. The final refinement gave R = 0.0458 and wR = 0.1439 for 1358 observed reflections with Ⅰ> 2σ(Ⅰ). The complex consists of repeating units of Mn(PhCOO)2(4,4'-bipyridine). Each Mn center is sixcoordinated by four carboxylate O atoms of four benzoate anions and two pyridyl N atoms from bipy ligands to furnish a slightly distorted octahedral geometry. The two adjacent Mn atoms are connected by a pair of μ1,3-carboxylate groups to form infinite chains, which are further interlinked by bipy to complete a 2D grid network. The magnetic property of the polymeric complex has also been investigated.

  7. 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.)

  8. 6,6 '-bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo 1,2,4 triazine-3-yl) 2,2 ' bipyridine, an effective extracting agent for the separation of americium(III) and curium(III) from the lanthanides

    International Nuclear Information System (INIS)

    The extraction of americium(III), curium(III), and the lanthanides(III) from nitric acid by 6,6'- bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo[1,2,4]triazine-3-yl)-[2,2'] bipyridine (CyMe4-BTBP) has been studied. Since the extraction kinetics were slow, N,N'-dimethyl-N,N'-di-octyl-2-(2-hexyl-oxy-ethyl)malonamide (DMDOHEMA) was added as a phase transfer reagent. With a mixture of 0.01 M CyMe4-BTBP + 0.25 M DMDOHEMA in n -octanol, extraction equilibrium was reached within 5 min of mixing. At a nitric acid concentration of 1 M, an americium(III) distribution ratio of approx. 10 was achieved. Americium(III)/lanthanide(III) separation factors between 50 (dysprosium) and 1500 (lanthanum) were obtained. Whereas americium(III) and curium(III) were extracted as di-solvates, the stoichiometries of the lanthanide(III) complexes were not identified unambiguously, owing to the presence of DMDOHEMA. In the absence of DMDOHEMA, both americium(III) and europium(III) were extracted as di-solvates. Back-extraction with 0.1 M nitric acid was thermodynamically possible but rather slow. Using a buffered glycolate solution of pH=4, an americium(III) distribution ratio of 0.01 was obtained within 5 min of mixing. There was no evidence of degradation of the extractant, for example, the extraction performance of CyMe4-BTBP during hydrolysis with 1 M nitric acid did not change over a two month contact. (authors)

  9. Mesures magnétiques d'aimants dipôles de type MBA révisés (MBA 005, 244, 297, 375)

    CERN Document Server

    Dutour, J

    2000-01-01

    Dans l'anneau SPS, les dipôles MBA et MBB sont installés depuis 1975 (assemblés au CERN, Réf. 1 et 2). Lorsque certains de ces aimants sont défectueux, ils sont révisés: changement de chambre, isolation, etc. Après révision, il est nécessaire de contrôler leurs caractéristiques magnétiques. De même, sont contrôlés aussi les aimants de réserve stockes dans le hall 867. C'est le cas des dipôles MBA 005, 244, 297, 375.

  10. Impact of the cation distribution homogeneity on the americium oxidation state in the U0.54Pu0.45Am0.01O2-x mixed oxide

    Science.gov (United States)

    Vauchy, Romain; Robisson, Anne-Charlotte; Martin, Philippe M.; Belin, Renaud C.; Aufore, Laurence; Scheinost, Andreas C.; Hodaj, Fiqiri

    2015-01-01

    The impact of the cation distribution homogeneity of the U0.54Pu0.45Am0.01O2-x mixed oxide on the americium oxidation state was studied by coupling X-ray diffraction (XRD), electron probe micro analysis (EPMA) and X-ray absorption spectroscopy (XAS). Oxygen-hypostoichiometric Am-bearing uranium-plutonium mixed oxide pellets were fabricated by two different co-milling based processes in order to obtain different cation distribution homogeneities. The americium was generated from β- decay of 241Pu. The XRD analysis of the obtained compounds did not reveal any structural difference between the samples. EPMA, however, revealed a high homogeneity in the cation distribution for one sample, and substantial heterogeneity of the U-Pu (so Am) distribution for the other. The difference in cation distribution was linked to a difference in Am chemistry as investigated by XAS, with Am being present at mixed +III/+IV oxidation state in the heterogeneous compound, whereas only Am(IV) was observed in the homogeneous compound. Previously reported discrepancies on Am oxidation states can hence be explained by cation distribution homogeneity effects.

  11. 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)

    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)

  12. Sorption and diffusion of cobalt, nickel, strontium, iodine, cesium and americium in natural fissure surfaces and drill core cups studied by autoradiography, 3

    International Nuclear Information System (INIS)

    This report summarizes the studies on sorption and diffusion of Cs, Sr, Co, Ni, Am and I in common rocks in Finnish bedrock carried out in laboratory experiments. Samples used in these studies were sections of drill cores containing filled and unfilled natural fracture surfaces and drill cores with a diamond drilled longitudinal cavity in the middle of the sample (drill core cups). Samples originated from the two nuclear power plant sites in Finland: tonalite and mica gneiss from Olkiluoto in Eurajoki and rapakivi granite from Haestholmen in Loviisa. The water used in the experiments was synthetic groundwater spiked at a time with one of the radionuclides: Cs-134, Sr-90, Co-60, Ni-63, Am-241 and I-125. Contact times from one week to one year were used to evaluate time dependence of diffusion. An autoradiographic method was used for determination of the penetration depths and diffusion pathways of elements. For determination of diffusion coefficients a quantitative computerized autoradiographic method was used to get the concentration profiles of the radionuclides in the drill cores. Sorption on natural fracture surfaces was more effective than on freshly drilled core samples. Filling materials on natural fracture surfaces, except calcite, increased sorption. The distribution coefficients for drill core cups were about the same as those for unfilled natural fracture surfaces after a contact time of one week and the sorption tendency of radionuclides was: Ka(Cs) > Ka(Co) > Ka(Am) > Ka(Ni) > Ka(Sr) > Ka(I). Radionuclides were observed to penetrate into fissures of the rock matrix and high-capacity minerals. Strontium was found as far as 35 mm in a filled natural fracture surface sample of rapakivi granite after a contact time of one year. The corresponding values were 3.0 mm for cesium, 2.1 mm for cobalt and 2.6 mm for nickel. For americium no diffusion could be observed (a-values for strontium was 6.6 x 10-16-1.1 x 10-13 m2/s, for cesium 4.7 x 10-16-7.2 x 10-15 m2/s

  13. Separation by sequential chromatography of americium, plutonium and neptunium elements: application to the study of trans-uranian elements migration in a European lacustrine system

    International Nuclear Information System (INIS)

    The nuclear tests carried out in the atmosphere in the Sixties, the accidents and in particular that to the power station of Chernobyl in 1986, were at the origin of the dispersion of a significant quantity of transuranic elements and fission products. The study of a lake system, such that of the Blelham Tarn in Great Britain, presented in this memory, can bring interesting answers to the problems of management of the environment. The determination of the radionuclides in sediment cores made it possible not only to establish the history of the depositions and consequently the origin of the radionuclides, but also to evaluate the various transfers which took place according to the parameters of the site and the properties of the elements. The studied transuranic elements are plutonium 238, 239-240, americium 241 and neptunium 237. Alpha emitting radionuclides, their determination requires complex radiochemical separations. A method was worked out to successively separate the three radioelements by using a same chromatographic column. Cesium 137 is the studied fission product, its determination is done by direct Gamma spectrometry. Lead 210, natural radionuclide, whose atmospheric flow can be supposed constant. makes it possible to obtain a chronology of the various events. The detailed vertical study of sediment cores showed that the accumulation mode of the studied elements is the same one and that the methods of dating converge. The cesium, more mobile than transuranic elements in the atmosphere, was detected in the 1963 and 1986 fallout whereas an activity out of transuranic elements appears only for the 1963 fallout. The activity of the 1963 cesium fallout is of the same order of magnitude as that of 1986. The calculation of the diffusion coefficients of the elements in the sediments shows an increased migration of cesium compared to transuranic elements. An inventory on the whole of the lake made it possible to note that the atmospheric fallout constitute the

  14. A randomised study comparing the effect on ovarian activity of a progestogen-only pill (POP) containing desogestrel and a new POP containing drospirenone in a 24/4 regimen

    DEFF Research Database (Denmark)

    Duijkers, Ingrid J M; Heger-Mahn, Doris; Drouin, Dominique;

    2015-01-01

    pattern. A new POP containing 4 mg drospirenone has been developed with a 24/4 intake regimen which may improve the bleeding pattern. The objectives of this study were to investigate ovulation inhibition with the new drospirenone-only pill in comparison with the desogestrel-only pill and, in addition...

  15. 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.

  16. 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)

  17. Synthesis and Crystal Structure of Cobalt(II) Complex [Co(H2O)2(bpe)(OAc)2](4,4'-dpdo

    Institute of Scientific and Technical Information of China (English)

    赵琦华; 李惠琼; 方瑞斌

    2004-01-01

    The reaction of Co(OAc)2 with bpe and 4,4'-dpdo in an aqueous-alcohol solution affords the formation of red crystals of [Co(H2O)2(bpe)(OAc)2](4,4'-dpdo (bpe = trans-1,2-bis(4- pyridyl)ethylene, 4,4'-dpdo = 4,4'-dipyridyl N,N'-oxide). The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P with a = 7.6146(9), b = 8.6691(11), c = 10.344011 A, α = 88.311(3), β = 76.992(3), γ = 75.809(3)°, V = 644.7613 A3, Z = 1, C26H28CoN4O8, Mr = 583.45, Dc = 1.503 g/cm3, μ = 0.724 mm-1, F(000) = 303, T = 223(2) K, the final R = 0.0477 and wR = 0.1177 for 3199 observed reflections with I > 2σ(I). In the crystal the cobalt atom is six-coordinated by oxygen atoms from two carboxylic molecules, two nitrogen atoms from the bpe ligands and two water molecules, completing an octahedral geometry. The structure of the title complex consists of neutral chains containing cobalt(II) ions bridged by mutually trans bpe molecules. The adjacent chains are connected through weak hydrogen bonds to form a two-dimensional structure.

  18. Synthesis and Crystal Structure of {Cu2(pdc)2(4,4′-bipy)(H2O)·(3H2O}2

    Institute of Scientific and Technical Information of China (English)

    温一航; 张健; 覃业燕; 李兆基; 康遥; 陈玉标; 程建开; 姚元根

    2004-01-01

    The title compound {Cu2(pdc)2(4,4′-bipy)(H2O)(3H2O}2 1 (H2pdc = pyridine-2,6- dicarboxylic acid, also known as dipicolinic acid; 4,4′-bipy = 4,4′-bipyridine) has been synthesized by the hydrothermal reaction and its structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pī with a = 7.2278(3), b = 10.6259(4), c = 17.7614(6)A, α= 79.5990(10), β = 83.6300(10), γ = 71.8280(10)o, V = 1272.60(8)A3, C48H44Cu4N8O24, Mr = 1371.07, Z = 1, Dc = 1.789 g/cm3, μ = 1.747 mm-1, F(000) = 696, R = 0.0397 and wR = 0.1137 for 3938 observed reflections (I > 2σ(I)). There are two kinds of Cu coordination environments, and each central copper(II) atom is five-coordinated in a distorted square-based pyramidal coordination geo- metry. Four copper(II) atoms are linked by four pdc and two 4,4′-bipy ligands to form an annular rectangle structure. Extensive hydrogen-bonding interactions involving carboxylate O atoms as well as coordinated and free water molecules lead to the formation of a three-dimensional network struc- ture.

  19. Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Mn(NAA)2(4,4'-bipy)(H2O)4]n

    Institute of Scientific and Technical Information of China (English)

    YANG Ying-Qun; LI Chang-Hong; LI Wei; KUANG Yun-Fei

    2008-01-01

    A novel one-dimensional chain coordination polymer [Mn(NAA)2(4,4'-bipy)(H2O)4]n has been synthesized with α-naphthaleneacetic acid, 4,4'-bipy and manganese(Ⅱ) sulfate as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a = 1.1421(2), b=1.6337(3), c=0.94177(19) nm, β = 112.15(3)°, V= 1.6275(6) nm3, Dc = 1.407 g/cm3, Z = 2,μ(MoKα) = 0.467 mm-1, F(000) = 722, S = 1.007, R= 0.0412 and wR = 0.1022. The crystal structure shows that two neighboring manganese(Ⅱ) ions are linked together by one 4,4'-bipy molecule, and the whole complex molecule forms a one-dimensional chain structure. Each manganese(Ⅱ) ion is coordinated with two oxygen atoms of two α-naphthaleneacetic acid molecules, two nitrogen atoms of two 4,4'-bipy molecules and two oxygen atoms from two water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were also analyzed.

  20. Synergistic extraction of uranium(VI) by bis(2,4,4-trimethylpentyl) phosphinic acid in the presence of neutral oxo-donors

    Energy Technology Data Exchange (ETDEWEB)

    Meera, R.; Reddy, M.L.P. [Inorganic and Analytical Chemistry Unit, Regional Research Lab. (CSIR), Trivandrum (India)

    2002-07-01

    The extraction behavior of uranium(VI) from nitric acid solutions has been investigated using mixtures of bis(2,4,4-trimethylpentyl)phosphinic acid (HBTMPP) and trialkylphosphine oxide (Cyanex 923 = TRPO), triphenylphosphine oxide (TPhPO) or tributylphosphate (TBP). The results demonstrate that uranium(VI) is extracted into xylene as UO{sub 2}(BTMPP){sub 2} with HBTMPP alone and as UO{sub 2}(BTMPP){sub 2}.S (where S = TRPO, TPhPO or TBP) in the presence of neutral oxo-donors. The extraction equilibrium constants of the above extracted complexes have been deduced by non-linear regression analysis with the aid of suitable chemically based model developed taking into account aqueous phase complexation of metal ion with inorganic ligands and all plausible complexes extracted into the organic phase. The addition of a neutral oxo-donor to the metal chelate system significantly enhances the extraction efficiency of uranium(VI). Complexation strength of uranium(VI) with neutral oxo-donors follows the order: TRPO > TPhPO > TBP, which is also the basicity sequence of these ligands. The IR spectral studies of the extracted complexes were used to further clarify the nature of the extracted complexes. (orig.)

  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)

    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. 社区卫生服务中心门诊腹痛患者244例诊治情况分析%Analysis of diagnosis and treatment of 244 cases of patients with abdominal pain in outpatient services of community health service center

    Institute of Scientific and Technical Information of China (English)

    胡勇军

    2014-01-01

    目的:分析某社区卫生服务中心门诊腹痛患者伴随症状及病因,探索门诊腹痛诊治过程中的注意事项及腹痛诊断思维。方法:2013年1-12月收治腹痛患者244例,回顾性分析其临床资料。结果:244例腹痛患者中,102例伴恶心呕吐,86例伴腹泻,28例伴反跳痛,5例伴牵涉痛,19例有发热。腹痛病因最后确诊为急性胃肠炎等18种疾病,病例数及百分比排在前5位的疾病有急性胃肠炎92例(38.70%)、胆囊炎及胆结石34例(13.92%)、急性阑尾炎17例(6.97%)、泌尿系结石及感染12例(4.92%)、急性盆腔炎11例(4.51%)。另有腹痛患者诊断为心肌梗死、心肌炎和癫痫等。结论:腹痛病因较为复杂,社区门诊医师应完善自己的知识结构,打破固有的思维定势,进一步扩大腹痛病因诊断方面的知识面,以减少误诊和漏诊。%Objective:To analyze the associated symptoms and etiology of patients with abdominal pain in outpatient services of community health service center,to explore the matters needing attention in the course of diagnosis and treatment of abdominal pain and abdominal pain diagnosis thinking.Methods:244 patients with abdominal pain were selected from January to December 2013.The clinical data were retrospectively analyzed.Results:In 244 cases of patients with abdominal pain,102 cases accompanied with nausea and vomiting;86 cases had diarrhea;28 cases had rebound pain;5 cases had referred pain;19 cases had fever.The cause of abdominal pain finally diagnosed as acute gastroenteritis and other 18 kinds of diseases.The case number and percentage of the top five diseases were acute gastroenteritis in 92 cases(38.70% ),cholecystitis and gallstones in 34 cases(13.92% ),17 cases(6.97%) of acute appendicitis,urinary calculi and infection in 12 cases(4.92%),11 cases(4.51%) of acute pelvic inflammatory disease.In addition,some abdominal pain were diagnosed with myocardial infarction

  3. In silico enhanced restriction enzyme based methylation analysis of the human glioblastoma genome using Agilent 244K CpG Island microarrays

    Directory of Open Access Journals (Sweden)

    Anh Tran

    2010-01-01

    Full Text Available Genome wide methylation profiling of gliomas is likely to provide important clues to improving treatment outcomes. Restriction enzyme based approaches have been widely utilized for methylation profiling of cancer genomes and will continue to have importance in combination with higher density microarrays. With the availability of the human genome sequence and microarray probe sequences, these approaches can be readily characterized and optimized via in silico modeling. We adapted the previously described HpaII/MspI based Methylation Sensitive Restriction Enzyme (MSRE assay for use with two-color Agilent 244K CpG island microarrays. In this assay, fragmented genomic DNA is digested in separate reactions with isoschizomeric HpaII (methylation-sensitive and MspI (methylation-insensitive restriction enzymes. Using in silico hybridization, we found that genomic fragmentation with BfaI was superior to MseI, providing a maximum effective coverage of 22,362 CpG islands in the human genome. In addition, we confirmed the presence of an internal control group of fragments lacking HpaII/MspI sites which enable separation of methylated and unmethylated fragments. We used this method on genomic DNA isolated from normal brain, U87MG cells, and a glioblastoma patient tumor sample and confirmed selected differentially methylated CpG islands using bisulfite sequencing. Along with additional validation points, we performed a receiver operating characteristics (ROC analysis to determine the optimal threshold (p ≤ 0.001. Based on this threshold, we identified ~2400 CpG islands common to all three samples and 145 CpG islands unique to glioblastoma. These data provide more general guidance to individuals seeking to maximize effective coverage using restriction enzyme based methylation profiling approaches.

  4. Soil washing in combination with homogeneous Fenton-like oxidation for the removal of 2,4,4'-trichlorodiphenyl from soil contaminated with capacitor oil.

    Science.gov (United States)

    Ma, Xiao-Hong; Zhao, Ling; Lin, Zhi-Rong; Dong, Yuan-Hua

    2016-04-01

    Detoxification by chemical oxidation of polychlorinated biphenyls (PCBs) in contaminated soils is very difficult and inefficient because PCBs typically associate with the solid phase or exist as non-aqueous-phase liquids due to their low solubility and slow desorption rates, and thus, they are difficult to remove from soils by using traditional, water-based elution techniques. Surfactant can enhance washing efficiency of PCBs from contaminated soils. This study used Brij 58, Brij 30, Tween 80, and 2-hydroxypropyl-β-cyclodextrin (HPCD) to solubilize 2,4,4'-trichlorodiphenyl (PCB28) from soil contaminated with capacitor oil into solution. The feasibility of PCB28 oxidation in soil washing wastewater through a Fe(3+)-catalyzed Fenton-like reaction was subsequently examined. Washing with 10 g L(-1) Brij 58 solution showed the highest extraction efficiency (up to 61.5 %) compared with that of the three other surfactants. The total concentration of PCB28 in contaminated soil at 25 °C after 48-h extraction was 286 mg L(-1). In contrast to conditions in which no washing agent was added, addition of the four washing agents decreased the efficiency of PCB28 degradation by the Fenton-like reaction, with the decrease due to addition of 10 g L(-1) Brij 58 solution being the smallest. The optimal concentration of H2O2 for preventing its useless decomposition was found to be 50 mM. The efficiency of PCB28 removal was lower when the initial concentration of PCB28 treated in the Fenton-like reaction was higher. The degradation efficiencies of PCB28 at initial concentrations of 0.1, 10, and 176 mg L(-1) in 10 g L(-1) Brij 58 solution at 25 °C and pH 3.0 and 9 h of reaction using 50 mM H2O2 were 64.1, 42.0, and 34.6 %, respectively. This result indicates that soil washing combined with Fenton-like oxidation may be a practical approach for the remediation of PCB-contaminated soil.

  5. Soil washing in combination with homogeneous Fenton-like oxidation for the removal of 2,4,4'-trichlorodiphenyl from soil contaminated with capacitor oil.

    Science.gov (United States)

    Ma, Xiao-Hong; Zhao, Ling; Lin, Zhi-Rong; Dong, Yuan-Hua

    2016-04-01

    Detoxification by chemical oxidation of polychlorinated biphenyls (PCBs) in contaminated soils is very difficult and inefficient because PCBs typically associate with the solid phase or exist as non-aqueous-phase liquids due to their low solubility and slow desorption rates, and thus, they are difficult to remove from soils by using traditional, water-based elution techniques. Surfactant can enhance washing efficiency of PCBs from contaminated soils. This study used Brij 58, Brij 30, Tween 80, and 2-hydroxypropyl-β-cyclodextrin (HPCD) to solubilize 2,4,4'-trichlorodiphenyl (PCB28) from soil contaminated with capacitor oil into solution. The feasibility of PCB28 oxidation in soil washing wastewater through a Fe(3+)-catalyzed Fenton-like reaction was subsequently examined. Washing with 10 g L(-1) Brij 58 solution showed the highest extraction efficiency (up to 61.5 %) compared with that of the three other surfactants. The total concentration of PCB28 in contaminated soil at 25 °C after 48-h extraction was 286 mg L(-1). In contrast to conditions in which no washing agent was added, addition of the four washing agents decreased the efficiency of PCB28 degradation by the Fenton-like reaction, with the decrease due to addition of 10 g L(-1) Brij 58 solution being the smallest. The optimal concentration of H2O2 for preventing its useless decomposition was found to be 50 mM. The efficiency of PCB28 removal was lower when the initial concentration of PCB28 treated in the Fenton-like reaction was higher. The degradation efficiencies of PCB28 at initial concentrations of 0.1, 10, and 176 mg L(-1) in 10 g L(-1) Brij 58 solution at 25 °C and pH 3.0 and 9 h of reaction using 50 mM H2O2 were 64.1, 42.0, and 34.6 %, respectively. This result indicates that soil washing combined with Fenton-like oxidation may be a practical approach for the remediation of PCB-contaminated soil. PMID:26762933

  6. 232Th、233U、238Pu、240Pu、242Pu、241Am、242Cm、243Cm和244Cm的裂变释放热能研究%Thermal Energy Released in Fission of 232 Th,233 U,238 Pu, 240 Pu,242 Pu,241 Am,242 Cm,243 Cm and 244 Cm

    Institute of Scientific and Technical Information of China (English)

    赵艳飞; 马续波; 陈义学

    2013-01-01

    In the nuclear reactor design ,the precise calculation of thermal fission energy is of great significance .In the pressurized water reactor ,high energy neutron-induced fission rarely occurs ,the isotopes including 233 U ,241 Am and 243 Cm are mostly induced by thermal neutrons ,while the other isotopes such as 232Th ,238Pu ,240Pu ,242Pu ,242Cm and 244 Cm are by fast neutron . In order to carry out this work , the nuclear data extracted from the latest evaluated nuclear data file (ENDF/B-Ⅶ ) were adopted ,and the energy-conservation law for the calculation of total fission energy were used , meanw hile ,with the consideration of capture energy and the correction of βand γ ,the thermal fission energy of nine isotopes was obtained .Compared with the data excerpted from IAEA issued WIMS-D database ,the results are reasonable .The thermal fission energy and its uncertainties of the nine isotopes are :(193.939 ± 0.176) MeV for 232 Th , (200.063 ± 0.084) MeV for 233 U ,(208.786 ± 1.133 ) MeV for 238 Pu ,(211.266 ± 0.220 ) MeV for 240 Pu ,(213.862 ± 0.299 ) MeV for 242 Pu ,(215.077 ± 0.210 ) MeV for 241 Am ,(218.821 ± 0.159) MeV for 242Cm ,(218.525 ± 0.388) MeV for 243Cm ,and (220.067 ± 0.131) MeV for 244 Cm ,respectively .%在核反应堆设计中,对每次裂变释放热能进行精确计算具有重要意义。在压水堆内,高能中子诱发核裂变份额很小,233 U、241 Am、243 Cm主要由热中子诱发裂变,232 T h、238 Pu、240 Pu、242 Pu、242 Cm、244 Cm主要由快中子诱发裂变。本文采用最新的核评价数据库 ENDF/B-Ⅶ,利用质量守恒法计算裂变释放总能,同时研究了中微子带走的能量,中子俘获能及β、γ修正项,最终给出了9种核素裂变释放热能。与IAEA颁布的WIMS-D格式数据库中的裂变释放热能数据的对比表明,本文所用方法计算结果合理。9种核素每次裂变释放热能分别为:232 Th ,(193.939±0.176) MeV ;233 U ,(200.063

  7. SILICATE, WATER TEMPERATURE, FLUORESCENCE, PHOTOSYNTHETIC ACTIVE RADIATION (PAR) and other profile and discrete sample data collected in the Gulf of Alaska on the ALPHA HELIX cruises HX242, HX244 and others as part of the NEP project from 2001-04-18 to 2003-08-11 (NODC Accession 0113348)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113348 includes profile, discrete sample, biological, chemical and physical data collected aboard the ALPHA HELIX during cruises HX242, HX244,...

  8. SALINITY, WATER TEMPERATURE, FLUORESCENCE, PHOTOSYNTHETIC ACTIVE RADIATION (PAR) and other profile data collected in the Gulf of Alaska on the ALPHA HELIX cruises HX242, HX244 and others as part of the NEP project from 2001-04-18 to 2003-08-11 (NODC Accession 0115255)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115255 includes profile, biological and physical data collected aboard the ALPHA HELIX during cruises HX242, HX244, HX247, HX271 and HX275 in the...

  9. CHLOROPHYLL A, growth rate and graze rate (or grazing rate) site samples data collected in the Gulf of Alaska on the ALPHA HELIX cruises HX242, HX244 and others as part of the NEP project from 2001-04-18 to 2003-08-10 (NODC Accession 0114241)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0114241 includes site samples and biological data collected aboard the ALPHA HELIX during cruises HX242, HX244, HX247, HX271 and HX275 in the Gulf of...

  10. Use of radioactive methods for determination of uranium, neptunium, plutonium, americium and curium isotopes in waste radioactive; Utilizacao de metodos radioanaliticos para determinacao de isotopos de uranio, netunio, plutonio, americio e curio em rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Bianca

    2012-07-01

    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)

  11. AG Turbo, Turbotech II, project 1.244. Experimental investigations of rotary instabilities in axial compressors and their effects in terms of compressor stability. Final report; AG Turbo, Turbotech II, Vorhaben 1.244. Experimentelle Untersuchungen rotierender Instabilitaeten in Axialverdichtern und ihr Einfluss auf die Verdichterstabilitaet. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Holste, F.; Haukap, C.; Kameier, F.

    2000-07-10

    The physical phenomena of rotary instabilities in industrial compressors and high-pressure aircraft compressors were investigated, which may be a cause of compressor blade fracture. The investigations were carried out by Duesseldorf Technical University on behalf of Rolls-Royce Deutschland GmbH at the new four-stage low-pressure compressor test stand of TU Dresden University. Extensive measurements were made both in the rotary and stationary system in the third compressor stage. Rotary instabilities could be detected by increasing the clearance between the blade tip and compressor wall. Modal analyses yielded a rate of about 30 for 63 blades, i.e. a characteristic wavelength of about twice the length of a blade. So far, an accurate description of the physical mechanism was impossible. Investigations using a Snubber model showed no significant influence on the rotary instabilities. [German] Im Turbotech II Forschungsvorhaben 1.244 wurden die physikalischen Vorgaenge der rotierenden Instabilitaet untersucht, die sowohl in industriellen Verdichtern als auch in Hochdruckverdichtern von Flugtriebwerken auftreten koennen. Diese Instabilitaeten stellen eine zusaetzliche Belastung fuer die Verdichterblaetter dar und koennen damit die Ursache fuer Blattbrueche sein. Im Auftrag von Rolls-Royce Deutschland wurden die Untersuchungen von der Faachhochschule Duesseldorf durchgefuehrt. Testobjekt war der neu aufgebaute vier stufige Niedergeschwindigkeitsverdichter der TU Dresden. In enger Kooperation mit den Vorhaben 1.243 und 1.246 wurden umfangreiche Messungen sowohl im rotierenden als auch im festen System an der dritten Stufe des Verdichters durchgefuehrt. Durch Vergroesserung des Spaltes zwischen Schaufelspitze und Verdichterwandung konnten rotierenden Instabilitaeten nachgewiesen werden. Modenanalysen ergaben Umfangsordnungen von ungefaehr 30 bei einer Blattzahl von 63, wodurch die charakteristische Wellenlaenge etwa zwei Schaufelwellenlaengen entspricht. Eine exakte

  12. Solubility and speciation studies of waste radionuclides pertinent to geologic disposal at Yucca Mountain: Results on neptunium, plutonium and americium in J-13 groundwater; Letter report (R707): Reporting period, October 1, 1985--September 30, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, H.; Standifer, E.M.; Lee, S.C.; Gatti, R.C.; Tucker, D.B.

    1988-01-01

    We have studied the solubilities of neptunium, plutonium, and americium in J-13 groundwater from Yucca Mountain (Nevada) at three temperatures and hydrogen ion concentrations. They are 25{degree}, 60{degree}C, and 90{degree}C and pH 5.9, 7.0, and 8.5. The results for 25{degree}C are from a study which we did during FY 1984. We included these previous results in the tables to give more information on the solubility temperature dependence; they were, however, done at only one pH (7.0). The solubilities were studied from oversaturation. The nuclides were added at the beginning of each experiment as NpO{sub 2}{sup +}, Pu{sup 4+}, and Am{sup 3+}. The neptunium solubility decreased with increasing temperature and with increasing pH. The soluble neptunium did not change oxidation state at steady state. The pentavalent neptunium was increasingly complexed by carbonate with increasing pH. All solids were crystalline and contained carbonate, except the solid formed at 90{degree}C and pH 5.9. We identified this solid as crystalline Np{sub 2}P{sub 5}. The 25{degree}C, pH 7 solid was Na{sub 3}NpO{sub 2}(CO{sub 3}){sub 2} {center_dot} nH{sub 2}O. Plutonium concentrations decreased with increasing temperature and showed no trend with pH. Pu(V) and Pu(VI) were the dominant oxidation states in the supernatant solution; as the amount of Pu(V) increased with pH, Pu(VI) decreed. The steady-state solids were mostly amorphous, although some contained a crystalline component. They contained Pu(IV) polymer and unknown carbonates.

  13. Facile synthesis of new nano sorbent for magnetic solid-phase extraction by self assembling of bis-(2,4,4-trimethyl pentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles: Characterization and application

    International Nuclear Information System (INIS)

    Graphical abstract: Self assembling of bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles and application of it for solid phase extraction of PAHs. Highlights: ► A novel sorbent for magnetic solid-phase extraction of PAHs was introduced. ► Silver was coated on Fe3O4 nanoparticles (MNPs) by reduction of AgNO3 with NaBH4. ► Bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid self-assembled on silver coated MNPs. ► Size, morphology, composition and properties of the nanoparticles were characterized. ► Extraction efficiency of the sorbent was investigated by extraction of five PAHs. - Abstract: A novel sorbent for magnetic solid-phase extraction by self-assembling of organosulfur compound, (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid), onto the silver-coated Fe3O4 nanoparticles was introduced. Due to the formation of covalent bond of S-Ag, the new coating on the silver surface was very stable and showed high thermal stability (up to 320 °C). The size, morphology, composition, and properties of the prepared nanoparticles have also been characterized and determined using scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), dynamic light scattering (DLS), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). Extraction efficiency of the new sorbent was investigated by extraction of five polycyclic aromatic hydrocarbons (PAHs) as model compounds. The optimum extraction conditions for PAHs were obtained as of extraction time, 20 min; 50 mg sorbent from 100 mL of the sample solution, and elution with 100 μL of 1-propanol under fierce vortex for 2 min. Under the optimal conditions, the calibration curves were obtained in the range of 0.05–100 μg L−1 (R2 > 0.9980) and the LODs (S/N = 3) were obtained in the range of 0.02–0.10 μg L−1. Relative standard deviations (RSDs) for intra- and inter-day precision were 2.6–4.2% and 3.6–8.3%, respectively. In

  14. Saturation mutagenesis on Arg244 of the tryptophan C4-prenyltransferase FgaPT2 leads to enhanced catalytic ability and different preferences for tryptophan-containing cyclic dipeptides.

    Science.gov (United States)

    Fan, Aili; Li, Shu-Ming

    2016-06-01

    FgaPT2 from Aspergillus fumigatus catalyzes a Friedel-Crafts alkylation at C-4 of L-tryptophan and is involved in the biosynthesis of the ergot alkaloids fumigaclavines. Several tryptophan-containing cyclic dipeptides had also been prenylated by FgaPT2, but the turnover rate (k cat) was low. Here, we report the generation of FgaPT2 mutants by saturation mutagenesis at the amino acid residue Arg244 to improve its catalytic efficiency toward cyclic dipeptides. Thirteen mutated enzymes demonstrated up to 76-fold higher turnover number toward seven cyclic dipeptides than the non-mutated FgaPT2. More importantly, the mutated enzymes exhibited different preferences toward these substrates. This study provides a convenient approach for creation of new biocatalysts for production of C4-prenylated cyclic dipeptides. PMID:26875876

  15. Adsorption of gases and vapors on nanoporous Ni2(4,4'-Bipyridine)3(NO3)4 metal-organic framework materials templated with methanol and ethanol: structural effects in adsorption kinetics.

    Science.gov (United States)

    Fletcher, Ashleigh J; Cussen, Edmund J; Bradshaw, Darren; Rosseinsky, Matthew J; Thomas, K Mark

    2004-08-11

    Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks. PMID:15291578

  16. Psychological Empowerment of Contract Nurses and Its Influencing Factors%244名合同制护士心理授权及其影响因素分析

    Institute of Scientific and Technical Information of China (English)

    郭青; 覃巍; 何红燕; 程嘉莉; 胡华琼; 张小虹

    2012-01-01

    Objective To understand the status quo and the potential influencing factors of psychological empowerment of contract nurses and to provide reference for nursing managers to take psychological empowerment and improve contract nurses ' psychological empowerment. Methods Psychological Empowerment Scale (PES) was used to survey 244 contract nurses. Results The score of PES of contract nurses was (40.70±4.96), and there was no statistically significant difference in terms of different ages, marriages, work length, educational background, professional titles and departments. However, statistically significant difference was found in the factor of different working purposes (P<0.01). Conclusion Psychological empowerment of contract nurses needs to be improved. The recognition of importance of psychological empowerment, and the devotion to nursing will contribute to the improvement of psychological empowerment of contract nurses.%目的 了解合同制护士心理授权状况,探讨潜在的影响因素,为护理管理者实施心理授权提供依据,以有效提高合同制护士心理授权水平.方法 采用中文版心理授权量表对湖北省襄阳市3 所三级甲等综合性医院的244 名合同制护士进行调查.结果 合同制护士心理授权问卷总分(40.70±4.96)分,不同年龄、婚姻状态、护龄、学历、职称、科室的合同制护士心理授权总分差异无统计学意义,而工作目的 不同的合同制护士心理授权总分差异有统计学意义(P<0.01).结论 合同制护士的心理授权水平有待提高,认识合同制护士心理授权的重要性,培养合同制护士热爱护理专业有助于提高合同制护士心理授权水平.

  17. Adsorption dynamics of gases and vapors on the nanoporous metal organic framework material Ni2(4,4'-bipyridine)3(NO3)4: guest modification of host sorption behavior.

    Science.gov (United States)

    Fletcher, A J; Cussen, E J; Prior, T J; Rosseinsky, M J; Kepert, C J; Thomas, K M

    2001-10-17

    This study combines measurements of the thermodynamics and kinetics of guest sorption with powder X-ray diffraction measurements of the nanoporous metal organic framework adsorbent (host) at different adsorptive (guest) loadings. The adsorption characteristics of nitrogen, argon, carbon dioxide, nitrous oxide and ethanol and methanol vapors on Ni2(4,4'-bipyridine)3(NO3)4 were studied over a range of temperatures as a function of pressure. Isotherm steps were observed for both carbon dioxide and nitrous oxide adsorption at approximately 10-20% of the total pore volume and at approximately 70% of total pore volume for methanol adsorption. The adsorption kinetics obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. At high surface coverage, both methanol and ethanol adsorption follow a combined barrier resistance/diffusion model. The rates of adsorption in the region of both the carbon dioxide and methanol isotherm steps were significantly slower than those observed either before or after the step. X-ray diffraction studies at various methanol loadings showed that the host structure disordered initially but underwent a structural change in the region of the isotherm step. These isotherm steps are ascribed to discrete structural changes in the host adsorbent that are induced by adsorption on different sites. Isotherm steps were not observed for ethanol adsorption, which followed a Langmuir isotherm. Previous X-ray crystallography studies have shown that all the sites are equivalent for ethanol adsorption on Ni2(4,4'-bipyridine)3(NO3)4, with the host structure undergoing a scissoring motion and the space group remaining unchanged during adsorption. The activation energies and preexponential factors for methanol and ethanol adsorption were calculated for each pressure increment at which the linear driving force model was obeyed. There was a good correlation between activation energy and ln(preexponential factor), indicating a

  18. The proliferation potential of neptunium and americium

    Energy Technology Data Exchange (ETDEWEB)

    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)

  19. Delocalization and new phase in Americium: theory

    Energy Technology Data Exchange (ETDEWEB)

    Soderlind, P

    1999-04-23

    Density-functional electronic structure calculations have been used to investigate the high pressure behavior of Am. At about 80 kbar (8 GPa) calculations reveal a monoclinic phase similar to the ground state structure of plutonium ({alpha}-Pu). The experimentally suggested {alpha}-U structure is found to be substantially higher in energy. The phase transition from fcc to the low symmetry structure is shown to originate from a drastic change in the nature of the electronic structure induced by the elevated pressure. A calculated volume collapse of about 25% is associated with the transition. For the low density phase, an orbital polarization correction to the local spin density (LSD) theory was applied. Gradient terms of the electron density were included in the calculation of the exchange/correlation energy and potential, according to the generalized gradient approximation (GGA). The results are consistent with a Mott transition; the 5f electrons are delocalized and bonding on the high density side of the transition and chemically inert and non-bonding (localized) on the other. Theory compares rather well with recent experimental data which implies that electron correlation effects are reasonably modeled in our orbital polarization scheme.

  20. 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.

  1. Cutting edge: The adapters EAT-2A and -2B are positive regulators of CD244- and CD84-dependent NK cell functions in the C57BL/6 mouse.

    Science.gov (United States)

    Wang, Ninghai; Calpe, Silvia; Westcott, Jill; Castro, Wilson; Ma, Chunyan; Engel, Pablo; Schatzle, John D; Terhorst, Cox

    2010-11-15

    EWS/FLI1-activated transcript 2 (EAT-2)A and EAT-2B are single SH2-domain proteins, which bind to phosphorylated tyrosines of signaling lymphocyte activation molecule family receptors in murine NK cells. While EAT-2 is a positive regulator in human cells, a negative regulatory role was attributed to the adapter in NK cells derived from EAT-2A-deficient 129Sv mice. To evaluate whether the genetic background or the presence of a selection marker in the mutant mice could influence the regulatory mode of these adapters, we generated EAT-2A-, EAT-2B-, and EAT-2A/B-deficient mice using C57BL/6 embryonic stem cells. We found that NK cells from EAT-2A- and EAT-2A/B-deficient mice were unable to kill tumor cells in a CD244- or CD84-dependent manner. Furthermore, EAT-2A/B positively regulate phosphorylation of Vav-1, which is known to be implicated in NK cell killing. Thus, as in humans, the EAT-2 adapters act as positive regulators of signaling lymphocyte activation molecule family receptor-specific NK cell functions in C57BL/6 mice.

  2. Formation of W/O microemulsions in the extraction of Nd(iii) by bis(2,4,4-trimethylpentyl)dithiophosphinic acid and its effects on Nd(iii) coordination.

    Science.gov (United States)

    Sun, Taoxiang; Xu, Chao; Chen, Jing

    2016-01-21

    The formation of water-in-oil (W/O) microemulsions during the extraction of Nd(iii) by bis(2,4,4-trimethylpentyl)dithiophosphinic acid (also known as purified Cyanex 301, denoted as HC301) was studied. Results from the measurement of the concentration of Nd(iii), Na(+) and NO3(-) in the organic phase, IR spectroscopy, and dynamic light scattering (DLS) all indicated that W/O microemulsions could form as the ratio of the neutralized ligand to Nd(iii) in the aqueous phase is over 3 : 1. The coordination environment of Nd(iii) in the extracted complexes was monitored by absorption spectroscopy and extended X-ray absorption fine structure (EXAFS) and was found to vary significantly with the formation of W/O microemulsions. When only 10% of HC301 was neutralized, with no formation of W/O microemulsions, the inner coordination shell of Nd(iii) in the organic phase was occupied dominantly by sulfur atoms from HC301. As HC301 was further neutralized, the coordinated sulfur atoms around Nd(iii) were replaced gradually by the oxygen atoms from water. This work provides further insights into the extraction mechanism in the extraction system using purified Cyanex 301 as an extractant. PMID:26660060

  3. Synthesis, Crystal Structure and Electrochemical Properties of One-dimensional Chain Coordination Polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4'-bipy)(H2O)5]n

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A one-dimensional chain coordination polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4'-bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4'-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a - 1.1481(3), b =1.1230(2), c = 1.1759(3) nm, β = 97.054(4)°, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z= 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(Ⅱ) ions are linked together by one 4,4'-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(Ⅱ) ion is coordinated with two nitrogen atoms from two 4,4'-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure.

  4. 48 CFR 1652.244-70 - Subcontracts.

    Science.gov (United States)

    2010-10-01

    ... under FAR 52.215-2 “Audit and Records—Negotiations” if based on cost analysis or 48 CFR 1646.301 and... all FEHB Program contracts based on cost analysis (experience-rated): Subcontracts (JUL 2005) (a) The... price analysis; (5) The subcontractor's current, complete, and accurate cost or pricing data and...

  5. 15 CFR 24.4 - Applicability.

    Science.gov (United States)

    2010-01-01

    ... under the Public Health Services Act (Section 1921), Alcohol and Drug Abuse Treatment and Rehabilitation Block Grant and Part C of Title V, Mental Health Service for the Homeless Block Grant). (3) Entitlement... (Community Services; Preventive Health and Health Services; Alcohol, Drug Abuse, and Mental Health...

  6. 17 CFR 244.101 - Definitions.

    Science.gov (United States)

    2010-04-01

    ... applicable to the registrant. (b) GAAP. GAAP refers to generally accepted accounting principles in the United... prepared in accordance with non-U.S. generally accepted accounting principles, GAAP refers to the... with U.S. generally accepted accounting principles, GAAP refers to U.S. generally accepted...

  7. 27 CFR 24.4 - Related regulations.

    Science.gov (United States)

    2010-04-01

    ... Part 16—Alcoholic Beverage Health Warning Statement 27 CFR Part 18—Production of Volatile Fruit-Flavor... the Virgin Islands. 27 CFR Part 27—Importation of Distilled Spirits, Wines and Beer. 27 CFR Part 28... listed below: 26 CFR Part 301—Procedure and Administration. 27 CFR Part 1—Basic Permit Requirements...

  8. 50 CFR 216.244 - Mitigation.

    Science.gov (United States)

    2010-10-01

    ... Training Handbook (NAVEDTRA, 12968-D). (iv) Lookout training shall include on-the-job instruction under the...). (v) Lookouts shall be trained in the most effective means to ensure quick and effective communication... Lookout Training Handbook (NAVEDTRA 12968-D). Surface lookouts should scan the water from the ship to...

  9. 49 CFR 244.9 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... deflator formula) from time to time. Corporate culture means the totality of the commitments, written and... regulations of the Surface Transportation Board (49 CFR part 1201; General Instructions 1-1), as those... an amalgamation of operations, or by a railroad or a corporate parent of a Class I railroad...

  10. Efficacy and safety of an oral contraceptive containing ethinylestradiol 20 µg/drospirenone 3 mg (24/4 regimen in three indications in the People's Republic of China: a comparison with international studies

    Directory of Open Access Journals (Sweden)

    Marr J

    2015-07-01

    Full Text Available Joachim Marr,1 Zirong Huang,2 Baoxi Wang,3 Hongyan Zhang,4 Katrin Roth1 1Bayer Pharma AG, Berlin, Germany; 2Obstetrics and Gynecology Hospital of Fudan University, Shanghai, 3Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, Jiangsu, 4Peking University Sixth Hospital, Peking University Institute of Mental Health, Ministry of Health (Peking University, Beijing, People's Republic of China Abstract: While combined oral contraceptives are a popular choice in developed Western countries, they are used by only 1% of women who are married or in a relationship in the People's Republic of China. The purpose of this review is to describe the efficacy and safety of the combined oral contraceptive containing ethinylestradiol (EE 20 µg/drospirenone 3 mg taken in a 24/4 regimen (YAZ®; Bayer HealthCare Pharmaceuticals, Berlin, Germany by Chinese women and to compare these results with those in women assessed in the international studies. Studies of EE 20 µg/drospirenone 3 mg in three different indications (contraception, acne, and premenstrual dysphoric disorder [PMDD] have been conducted in Chinese women. The results of these three studies indicate that the EE 20 µg/drospirenone 3 mg combined oral contraceptive is a good long-term contraceptive option in Chinese women, providing 99% contraceptive protection over the observed 1-year treatment period, and additionally had a favorable effect on moderate acne vulgaris and relieved the symptoms of PMDD. The contraceptive efficacy, improvement in acne, and relief from PMDD symptoms observed in these studies did not differ from the effects observed in other international studies of EE 20 µg/drospirenone 3 mg, indicating that EE 20 µg/drospirenone 3 mg is as effective in Chinese women as in other ethnicities. Further, EE 20 µg/drospirenone 3 mg demonstrated a similar safety and tolerability profile in women enrolled in the Chinese and international trials, with no unexpected adverse

  11. Facile synthesis of new nano sorbent for magnetic solid-phase extraction by self assembling of bis-(2,4,4-trimethyl pentyl)-dithiophosphinic acid on Fe{sub 3}O{sub 4}-Ag core-shell nanoparticles: Characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Tahmasebi, Elham [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yamini, Yadollah, E-mail: yyamini@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2012-12-05

    Graphical abstract: Self assembling of bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid on Fe{sub 3}O{sub 4}-Ag core-shell nanoparticles and application of it for solid phase extraction of PAHs. Highlights: Black-Right-Pointing-Pointer A novel sorbent for magnetic solid-phase extraction of PAHs was introduced. Black-Right-Pointing-Pointer Silver was coated on Fe{sub 3}O{sub 4} nanoparticles (MNPs) by reduction of AgNO{sub 3} with NaBH{sub 4}. Black-Right-Pointing-Pointer Bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid self-assembled on silver coated MNPs. Black-Right-Pointing-Pointer Size, morphology, composition and properties of the nanoparticles were characterized. Black-Right-Pointing-Pointer Extraction efficiency of the sorbent was investigated by extraction of five PAHs. - Abstract: A novel sorbent for magnetic solid-phase extraction by self-assembling of organosulfur compound, (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid), onto the silver-coated Fe{sub 3}O{sub 4} nanoparticles was introduced. Due to the formation of covalent bond of S-Ag, the new coating on the silver surface was very stable and showed high thermal stability (up to 320 Degree-Sign C). The size, morphology, composition, and properties of the prepared nanoparticles have also been characterized and determined using scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), dynamic light scattering (DLS), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). Extraction efficiency of the new sorbent was investigated by extraction of five polycyclic aromatic hydrocarbons (PAHs) as model compounds. The optimum extraction conditions for PAHs were obtained as of extraction time, 20 min; 50 mg sorbent from 100 mL of the sample solution, and elution with 100 {mu}L of 1-propanol under fierce vortex for 2 min. Under the optimal conditions, the calibration curves were obtained in the range of 0.05-100 {mu}g L{sup -1} (R{sup 2} > 0.9980) and the

  12. 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)

  13. Historical review of californium-252 discovery and development

    International Nuclear Information System (INIS)

    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 252Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed

  14. 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)

  15. 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)

  16. Preparation of americium targets for nuclear chemistry experiments at DANCE

    International Nuclear Information System (INIS)

    Using 1 gram of 241Am from LANL stocks, the purification steps required to obtain a solution of 241Am from the original material are described. Part of the purified solution was submitted for purity analysis by mass spectrometry, radiochemistry and trace metals analysis. The impurities were expected to be 239Pu and 237Np. A second fraction of this material was used for electroplating three samples onto titanium disks that were suitable for insertion into an instrument package to be placed into the DANCE detector. The purification methods used, the electroplating setup and the solutions to various problems that were encountered in making these targets are discussed. The analytical results are discussed as well as the yields from the electrodeposition process. Comparison of these yields with those from similar experiments utilizing 235U and 243Am are also discussed. (author)

  17. Americium separation from nuclear fuel dissolution using higher oxidation states.

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher

    2009-09-01

    Much of the complexity in current AFCI proposals is driven by the need to separate the minor actinides from the lanthanides. Partitioning and recycling Am, but not Cm, would allow for significant simplification because Am has redox chemistry that may be exploited while Cm does not. Here, we have explored methods based on higher oxidation states of Am (AmV and AmVI) to partition Am from the lanthanides. In a separate but related approach we have also initiated an investigation of the utility of TRUEX Am extraction from thiocyanate solution. The stripping of loaded TRUEX by Am oxidation or SCN- has not yet proved successful; however, the partitioning of inextractable AmV by TRUEX shows promise.

  18. Recovery of neptunium, plutonium, and americium from highly active waste

    International Nuclear Information System (INIS)

    Trialkylphosphine oxides (TRPO) (alkyl is 6c-C8) were chosen as the extractant for the recovery of Np, Pu, and Am from highly active waste (HAW) because of its extraction ability, excellent solvent behavior, high radiolytic stability, and low cost. Process chemistry based on 30 vol % TRPO-kerosene as solvent is presented. Extraction of Am in the presence of macro amounts of neodymium, adjustment of Np valence by electrolytic reduction, selective stripping of actinides from loaded organic phase, and loading capacity of the solvent are included. Process parameters of multistage countercurrent extraction and stripping and the results of experimental verification are given. From HAW with ∼1 M nitric acid concentration, recovery of actinides is higher than 99.9%. The actinides extracted can be stripped out separately into Am, Np-Pu, and U fractions. The behavior of nonactinide HAW constituents, including Tc, is discussed

  19. Property Data for Simulated Americium/Curium Glasses

    International Nuclear Information System (INIS)

    The authors studied the properties of mixed lanthanide-alumino-borosilicate glasses. Fifty-five glasses were designed to augment a previous, Phase I, study by systematically varying the composition of Ln2O3 and the concentrations of Ln2O3, SiO2, B2O3, Al2O3, and SrO in glass. These glasses were designed and fabricated at the Savannah River Technology Center and tested at the Pacific Northwest National Laboratory. The properties measured include the high-temperature viscosity (η) as a function of temperature (T) and the liquidus temperature (TL) of Phase II test glasses

  20. The vapour pressure of americium(III) chloride

    International Nuclear Information System (INIS)

    Based on the method described by Fischer, an ultramicro-size appratus was developed for static determination of the saturation vapour pressure of highly radioactive materials. The apparatus was tested with MgCl2, MnCl2, HoCl3 and ScF3. The vapour pressure curves of MgCl2 and MnCl2 were in good agreement with other publications and thus proved the efficiency of the apparatus in spite of its difficulties of handling. The values measured for HoCl3 and ScF3 differed from those of earlier publications. However, these deviations have been observed before and may be the result of the different measuring principles of static and dynamic methods. For AmCl3, the following vapour pressure equation was established: log psub(Torr)=-(11826/T)+10.7. The thermodynamic parameters of the evaporation process were calculated on this basis, and the values for AmBr3 and PnCl3 were determined by extrapolation. (orig.)

  1. 1976 Hanford americium-exposure incident: accident description

    International Nuclear Information System (INIS)

    An accident is described, involving the explosion of an ion-exchange column containing about 100 g of 241Am. A chemical operator was injured in this accident, receiving acid burns and superficial cuts on the upper part of his body. From 1 to 5 curies of 241Am is estimated to have been deposited on the injured worker and on his clothing

  2. 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...

  3. Dicty_cDB: CHE244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ing in prelim test: 0 Number of HSP's gapped (non-prelim): 0 length of query: 176 length of database: 80,480,566 effective... HSP length: 17 effective length of query: 159 effective length of database: 78,821,179 effe...ctive search space: 12532567461 effective search space used: 12532567461 T: 0 A: 0 ... of query: 176 length of database: Z,811,932,929 effective HSP length: 22 effective length of query: 154 effective... length of database: Y,960,467,611 effective search space: 6461912012094 effective

  4. Dicty_cDB: SHF244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available t WO0168911. 38 2e-04 4 BD460610 |BD460610.1 Diagnosis of Diseases Associated with Cell Cycle.... 38 2e-04 4 BD452532 |BD452532.1 Diagnosis of Diseases Associated with Cell Cycle. 38 2e-04 4 A

  5. Dicty_cDB: SHL244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available YDEMLKYNYSQY*iqyqylc*wsilycsnfpi*i*inn*l**k*virisk *nvyryccnynifsinflcy*ntg*kiy*reksqksi*is**sts*ts*etcc*nr*...hf yq*sl*wkeylmimvvi*ls--- ---LTCNVTNYDEMLKYNYSQY*iqyqylc*wsilycsnfpi*i*inn*l**k*viris

  6. Dicty_cDB: VHE244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 038.1 Dictyostelium dimigraformum 18S rRNA gene, isolate AR5b. 1146 0.0 1 AM168039 |AM168039.1 Dictyostelium...1 Dictyostelium discoideum 18S rRNA gene, isolate NC4. 1154 0.0 1 AM168038 |AM168

  7. Dicty_cDB: VFH244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available resident chaperone calreticulin mRNA, complete cds. 56 6e-04 1 CB937139 |CB937139.1 IpCGJ...x13_12_E07_23 IpCGJx13 Ictalurus punctatus cDNA clone IpCGJx13_12_E07 5', mRNA sequence. 56 6e-04 1

  8. Fuzzy Itand#244; Integral Driven by a Fuzzy Brownian Motion

    OpenAIRE

    Didier Kumwimba Seya; Rostin Mabela Makengo; Marcel Rémon; Walo Omana Rebecca

    2015-01-01

    In this paper we take into account the fuzzy stochastic integral driven by fuzzy Brownian motion. To define the metric between two fuzzy numbers and to take into account the limit of a sequence of fuzzy numbers, we invoke the Hausdorff metric. First this fuzzy stochastic integral is constructed for fuzzy simple stochastic functions, then the construction is done for fuzzy stochastic integrable functions.

  9. 48 CFR 52.244-6 - Subcontracts for Commercial Items.

    Science.gov (United States)

    2010-10-01

    ... clauses in subcontracts for commercial items: (i) 52.203-13, Contractor Code of Business Ethics and... Recovery Act. (iii) 52.219-8, Utilization of Small Business Concerns (MAY 2004) (15 U.S.C. 637(d)(2) and (3... subcontracts to small business concerns) exceeds $650,000 ($1.5 million for construction of any public...

  10. Dicty_cDB: SHD244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available BAC clone RP11-487E13 from 4, complete sequence. 48 0.52 1 AJ410884 |AJ410884.1 Influenza A virus (swine/Cotes d'Armor/1515/99 (H1N1...Influenza A virus (swine/Cotes d'Armor/1482/99 (H1N1)) partial N1NA gene for Neur

  11. Dicty_cDB: SHK244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available uence. 48 0.52 1 AJ410884 |AJ410884.1 Influenza A virus (swine/Cotes d'Armor/1515/99 (H1N1)) partial N1NA ge...us (swine/Cotes d'Armor/1482/99 (H1N1)) partial N1NA gene for Neuraminidase, genomic RNA. 42 0.97 2 CJ477883

  12. Dicty_cDB: AHA244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available one) Pichia stipitis CBS 6054 chromos... 35 4.8 EU095850_1( EU095850 |pid:none) Turkey coronavirus isolate M...G10, c... 35 4.8 EU095850_2( EU095850 |pid:none) Turkey coronavirus isolate MG10, c... 35 4.8 CP000094_2730(

  13. Dicty_cDB: VSC244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available gene for cytochrome c, partial sequence, country:Japan:Okinawa. 30 0.12 3 BQ476583 |BQ476583.1 curculio2h12....g Curculio glandium cDNA Curculio glandium cDNA clone curculio2h12 3', mRNA seque

  14. 1935 15' Quad #244 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  15. Dicty_cDB: CHK244 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CK273593 |CK273593.1 EST719671 potato abiotic stress cDNA library Solanum tuberosum cDNA clone POADC22 5' en...5234 An expressed sequence tag database for abiotic stressed leaves of Vitis vinifera var. Chardonnay Vitis ...VB066D06_332552 An expressed sequence tag database for abiotic stressed leaves of Vitis vinifera var. Chardo...An expressed sequence tag database for abiotic stressed leaves of Vitis vinifera var. Chardonnay Vitis vinif

  16. Poweo 2006 consolidated revenue at euro 244 million, up 121%

    International Nuclear Information System (INIS)

    POWEO, the leading independent energy operator in France, presents in this document its key business indicators for the 4. quarter of 2006 and the full year: POWEO records again a strong rise of its annual revenue, exceeding its euro 220 million target. This progression relates to all the business components. The particularly soft climatic conditions recorded in France at the end of the year did not result in a significant fall of revenue compared to initial forecasts. The number of customer sites amounts to 80.300 at December 31, 2006, in progression of 23% compared to the end of 2005. The customer base remained overall stable during the second half of 2006, POWEO limiting voluntarily the acquisition of customers in electricity during the preparation of the opening to competition of the residential market due to take place on July 1, 2007. The gas customer base for its part more than doubled compared to end June 2006, with more than 5.000 customer sites transferred as at December 31, 2006. The Energy Management net margin, realised or un-realised, amounted to euro 49.7 million in 2006, recognised as revenue under IFRS standards. This includes the euro 22 million exceptional capital gain mentioned in previous financial releases in 2006, as well as a euro 7.9 million un-realised capital gain resulting from the transfer of some contracts into the Energy Management portfolio further to the capacity swap agreement with EDF announced publicly on January 3, 2007. The services provided by POWEO to its customers enjoy a high level of acceptance and represented revenue of euro 2.9 million in 2006. As from 2007, the revenue realised through these services will be presented separately from other components of revenue in order to better reflect its expected growth. The services offering will be indeed a key element of the marketing strategy of POWEO in the years to come, with a potentially significant impact on the results taking into account their level of gross margin which is structurally high. POWEO announced on January 3, 2007 to have concluded with EDF a long-term industrial agreement relating to a power generation capacity exchange, which will allow POWEO to have access from 2007 to 2021 to base-load electricity generated by EDF nuclear power plants. POWEO actively prepares the launch of its offering to residential customers, with in particular a communication campaign planned from next March to June in order to increase its notoriety and to create the conditions necessary to its commercial success on this segment. In parallel POWEO will dedicate specific sales resources to the acquisition of large accounts in industry and services. The public opinion poll carried out in the 4. quarter 2006 by BVA at the request of the Commission of Regulation of the Energy (CRE), and whose results have been just published, indicates that POWEO is already enjoying a global notoriety of 24% near companies only consuming electricity and 37% near companies consuming both electricity and gas. In addition, according to a TNS Sofres study ordered by POWEO, the assisted notoriety of the company near the specific segment of residential customers targeted by POWEO amounts to 13%. These results make POWEO feel confident in its ability to grow significantly its customer base in 2007

  17. The uptake of radionuclides by plants

    International Nuclear Information System (INIS)

    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.)

  18. 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)

    Experiments were performed to study the metabolism and distribution of intravenously administered 241Am in the adult and juvenile baboon; in addition, decorporation therapy using Na3-CaDTPA was performed on selected baboons to assess the efficacy of this drug in removing systemic burdens of 241Am from this primate species. Determination of the kinetics of 241Am was accomplished principally by in vivo methodologies and by radiochemical analysis of 241Am activity of biological material. The use of Na3-CaDTPA as a therapeutic agent for the removal of 241Am from the body proved to be an effective form of treatment in the case of early administration. (U.S.)

  19. Poweo 2006 consolidated revenue at euro 244 million, up 121%; Poweo chiffre d'affaires 2006 de 244 millions euro, en hausse de 121%

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-01-15

    POWEO, the leading independent energy operator in France, presents in this document its key business indicators for the 4. quarter of 2006 and the full year: POWEO records again a strong rise of its annual revenue, exceeding its euro 220 million target. This progression relates to all the business components. The particularly soft climatic conditions recorded in France at the end of the year did not result in a significant fall of revenue compared to initial forecasts. The number of customer sites amounts to 80.300 at December 31, 2006, in progression of 23% compared to the end of 2005. The customer base remained overall stable during the second half of 2006, POWEO limiting voluntarily the acquisition of customers in electricity during the preparation of the opening to competition of the residential market due to take place on July 1, 2007. The gas customer base for its part more than doubled compared to end June 2006, with more than 5.000 customer sites transferred as at December 31, 2006. The Energy Management net margin, realised or un-realised, amounted to euro 49.7 million in 2006, recognised as revenue under IFRS standards. This includes the euro 22 million exceptional capital gain mentioned in previous financial releases in 2006, as well as a euro 7.9 million un-realised capital gain resulting from the transfer of some contracts into the Energy Management portfolio further to the capacity swap agreement with EDF announced publicly on January 3, 2007. The services provided by POWEO to its customers enjoy a high level of acceptance and represented revenue of euro 2.9 million in 2006. As from 2007, the revenue realised through these services will be presented separately from other components of revenue in order to better reflect its expected growth. The services offering will be indeed a key element of the marketing strategy of POWEO in the years to come, with a potentially significant impact on the results taking into account their level of gross margin which is structurally high. POWEO announced on January 3, 2007 to have concluded with EDF a long-term industrial agreement relating to a power generation capacity exchange, which will allow POWEO to have access from 2007 to 2021 to base-load electricity generated by EDF nuclear power plants. POWEO actively prepares the launch of its offering to residential customers, with in particular a communication campaign planned from next March to June in order to increase its notoriety and to create the conditions necessary to its commercial success on this segment. In parallel POWEO will dedicate specific sales resources to the acquisition of large accounts in industry and services. The public opinion poll carried out in the 4. quarter 2006 by BVA at the request of the Commission of Regulation of the Energy (CRE), and whose results have been just published, indicates that POWEO is already enjoying a global notoriety of 24% near companies only consuming electricity and 37% near companies consuming both electricity and gas. In addition, according to a TNS Sofres study ordered by POWEO, the assisted notoriety of the company near the specific segment of residential customers targeted by POWEO amounts to 13%. These results make POWEO feel confident in its ability to grow significantly its customer base in 2007.

  20. Americium-Curium Stabilization - 5'' Cylindrical Induction Melter System Design Basis

    Energy Technology Data Exchange (ETDEWEB)

    Witt, D.C.

    1999-11-08

    Approximately 11,000 liters (3,600) gallons of solution containing isotopes of Am and Cm are currently stored in F-Canyon Tank 17.1. These isotopes were recovered during plutonium-242 production campaigns in the mid- and late-1970s. Experimental work for the project began in 1995 by the Savannah River Technology Center (SRTC). Details of the process are given in the various sections of this document.

  1. Biosorption of radionuclide Americium-241 by A. niger spore and hyphae

    International Nuclear Information System (INIS)

    The biosorption of radionuclide 241Am from solution was studied by a. niger spore and hyphae, and the effects of the operational conditions on the treatment were investigated. The results showed the treatment by A. niger spore and hyphae were very efficient. An average of 96% of the total 241Am was removed from 241Am solutions of 5.6-111 MBq/L (C0), with adsorption capacities (W) of 7.2-142.4 MBq/g biomass, 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 h and the optimum pH value ranged 3-0.1 mol/L HNO3 and 3-2 for spore and hyphae of A. niger, respectively. No significant effects on 241Am biosorption were observed at 15 degree C-45 degree C, or challenged with containing Au3+ or Ag+, even 2000 times above 241Am amount. the index relationship between concentrations and adsorption capacities of 241Am indicated that the 241Am biosorption by A. niger spore and hyphae obey to Freundlich adsorption equation. The adsorption behavior of A. niger spore and hyphae were basically coincident

  2. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    Science.gov (United States)

    Sato, I.; Suto, M.; Miwa, S.; Hirosawa, T.; Koyama, S.

    2013-06-01

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10-4 min-1 and 1.60 × 10-4 min-1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure.

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

    International Nuclear Information System (INIS)

    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 U1-yAmyO2+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, U1-yAmyO2+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)

  4. Chemical behaviour of americium in natural aquatic solutions: Hydrolysis, radiolysis and redox reactions

    International Nuclear Information System (INIS)

    Hydrolysis and redox reactions of the Am(III) and Am(V) ions have been investigated in NaClO4 and NaCl solutions as well as in natural saline groundwaters. The hydrolysis constants of Am(OH)n3-n species and the solubility product of Am(OH)3(s) have been determined in 0.1 M NaClO4, 0.1 M NaCl and 0.6 M NaCl solutions. As observed in concentrated NaCl solutions (> 3 M), the α-radiation induces the radiolytic oxidation of the Cl--ion to produce Cl2, HClO, ClO- and other oxidized species, which result in a strongly oxidizing medium. Consequently Am(III) is oxidized to Am(V). Under these conditions the hydrolysis constants of AmO2(OH)n1-n species and the solubility product are also determined. The α-radiation induced radiolysis reactions in NaCl solution and the subsequent oxidation reaction of Am(III) have been systematically investigated by varying pH, NaCl concentration and specific α-activity. Also included in the investigation are a few selected groundwaters of relatively high salinity from the Gorleben aquifer systems. (orig.)

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

    International Nuclear Information System (INIS)

    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 (57Co3O4, 241AmO2, ammonium diuranate [ADU], and U3O8) 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

  6. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Zakir H. [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Cornett, Jack R., E-mail: jack.cornett@uottawa.ca [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Zhao, Xaiolei; Kieser, Liam [Department of Physics, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada)

    2014-06-01

    Highlights: • Am and Pu were adsorbed and separated using a single extraction chromatography DGA column. • Pu was eluted from the column completely using on-column reduction of Pu(IV) to Pu(III). • ²⁴¹Am and 239,240Pu measurements by accelerator mass spectrometry (AMS) agree with the certified values in two SRMs. Abstract: A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8 M HNO₃ with 0.05 M NaNO₂ before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO₃, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl₃ facilitated the complete desorption of Pu. Interferences (e.g. Ca²⁺, Fe³⁺) were washed off from the resin bed with excess HNO₃. Using NdF₃, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7 ± 5.3% and 95.5 ± 4.6% for ²⁴¹Am and ²⁴²Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1 ± 6.0 and 96.8 ± 5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1–100 Bq kg⁻¹. The single column separation of Pu and Am saves reagents, separation time, and cost.

  7. 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.

  8. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    Science.gov (United States)

    Jandel, M.; Bredeweg, T. A.; Stoyer, M. A.; Wu, C. Y.; Fowler, M. M.; Becker, J. A.; Bond, E. M.; Couture, A.; Haight, R. C.; Haslett, R. J.; Henderson, R. A.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2009-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for 241Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for 243Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on 242mAm will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,γ) events from (n,f) events. The first direct observation of neutron capture on 242mAm in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  9. Plutonium and americium in air on the coasts of the Irish Sea

    International Nuclear Information System (INIS)

    Measurements of artificial radionuclides in air, deposition and seawater were carried out at coastal and inland locations in Cumbria, south-west Scotland, Northern Ireland and North Wales. The measurements were undertaken to determine the distribution of artificial radionuclides in the coastal environment attributable to discharges from Sellafield and to investigate the mechanisms responsible for the increased radionuclide concentration in the marine aerosol and their subsequent transfer to land. A number of different sampling methods were used and the contribution each method could make to the understanding of the marine aerosol was assessed. Measurements of the size distribution of the marine aerosol was also undertaken. The measurements demonstrated that the actinide concentrations measured in the air and deposition at coastal locations could be related to near shore sea water concentrations, but that no direct proportionality existed. It was also determined that a significant proportion of the material transferred from sea to land was associated with larger particulate present in the marine aerosol during conditions of above average onshore winds. (author)

  10. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Jandel, Marian [Los Alamos National Laboratory

    2008-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  11. Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Steven J [Los Alamos National Laboratory; Oldham, Warren J [Los Alamos National Laboratory; Murrell, Michael T [Los Alamos National Laboratory; Katzman, Danny [Los Alamos National Laboratory

    2010-12-07

    We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both {sup 242}Pu and {sup 151}Sm normalizations, although the errors for the {sup 151}Sm correction are currently larger due to the greater uncertainty of their measurements. Additional efforts to develop a concordant {sup 241}Pu-{sup 241}Am dating method for environmental collections are underway with emphasis on soil cores.

  12. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    International Nuclear Information System (INIS)

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for 241Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for 243Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on 242mAm will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,γ) from (n,f) events. The first evidence of neutron capture on 242mAm in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  13. Mean squared slowing-down distance and age of americium-beryllium neutrons in perspex

    International Nuclear Information System (INIS)

    THe mean squared slowing-down distance 2>, and the age to thermal capture (Migration Area), M2, are direct measures of the slowing.down, and the spreading out, processes of neutrons in a medium. They also enter directly into reactor calculations. These parameters have been determined experimentally for Am-Be neutrons (mean energy 4.46 MeV), in a block of perspex, using the activities induced in thin indium foils from the 115In(n,γ)116In reactions. (author) 13 refs.; 5 figs.; 2 tabs

  14. Americium-Curium Stabilization - 5'' Cylindrical Induction Melter System Design Basis

    International Nuclear Information System (INIS)

    Approximately 11,000 liters (3,600) gallons of solution containing isotopes of Am and Cm are currently stored in F-Canyon Tank 17.1. These isotopes were recovered during plutonium-242 production campaigns in the mid- and late-1970s. Experimental work for the project began in 1995 by the Savannah River Technology Center (SRTC). Details of the process are given in the various sections of this document

  15. 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.

  16. Distribution of plutonium and americium in human and animal tissues after chronic exposures

    International Nuclear Information System (INIS)

    The distribution of plutonium in the tissues of a group of southern Finns was determined. Their Pu intake had been solely from fallout via inhalation. A group of northern Finns was also studied. They obtain most of the Pu from inhalation, but also some from their diet which is rich in reindeer liver. Reindeer obtain large amounts of transuranium elements in their natural winter diet, which mainly consists of lichen. Pu-239, 240 and Am-241 were also analyzed in elk because it is closely related to reindeer but does not feed on lichen. It was found that much of the Am-241 in reindeer tissues is due to ingrowth from Pu-241 in the animal. The aim of this study to establish whether this situation is also true for the human bone. (H.K.)

  17. Separation of americium(III) from lanthanides(III) by nanofiltration-complexation in aqueous medium

    International Nuclear Information System (INIS)

    The separation of Am(III) from a mixture of lanthanides(III) was performed in aqueous medium by nanofiltration combined with a complexation step using a DTPA derivative as selective complexing agent. (author)

  18. Optimization of TRPO Process Parameters for Americium Extraction from High Level Waste

    Institute of Scientific and Technical Information of China (English)

    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.1750 L/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. Functional sorbents for selective capture of plutonium, americium, uranium, and thorium in blood.

    Science.gov (United States)

    Yantasee, Wassana; Sangvanich, Thanapon; Creim, Jeffery A; Pattamakomsan, Kanda; Wiacek, Robert J; Fryxell, Glen E; Addleman, R Shane; Timchalk, Charles

    2010-09-01

    Self-assembled monolayer on mesoporous supports (SAMMS) are hybrid materials created from attachment of organic moieties onto very high surface area mesoporous silica. SAMMS with surface chemistries including three isomers of hydroxypyridinone, diphosphonic acid, acetamide phosphonic acid, glycinyl urea, and diethylenetriamine pentaacetate (DTPA) analog were evaluated for chelation of actinides ((239)Pu, (241)Am, uranium, thorium) from blood. Direct blood decorporation using sorbents does not have the toxicity or renal challenges associated with traditional chelation therapy and may have potential applications for critical exposure cases, reduction of nonspecific dose during actinide radiotherapy, and for sorbent hemoperfusion in renal insufficient patients, whose kidneys clear radionuclides at a very slow rate. Sorption affinity (K(d)), sorption rate, selectivity, and stability of SAMMS were measured in batch contact experiments. An isomer of hydroxypyridinone (3,4-HOPO) on SAMMS demonstrated the highest affinity for all four actinides from blood and plasma and greatly outperformed the DTPA analog on SAMMS and commercial resins. In batch contact, a fifty percent reduction of actinides in blood was achieved within minutes, and there was no evidence of protein fouling or material leaching in blood after 24 h. The engineered form of SAMMS (bead format) was further evaluated in a 100-fold scaled-down hemoperfusion device and showed no blood clotting after 2 h. A 0.2 g quantity of SAMMS could reduce 50 wt.% of 100 ppb uranium in 50 mL of plasma in 18 min and that of 500 dpm mL(-1) in 24 min. 3,4-HOPO-SAMMS has a long shelf-life in air and at room temperature for at least 8 y, indicating its feasibility for stockpiling in preparedness for an emergency. The excellent efficacy and stability of SAMMS materials in complex biological matrices suggest that SAMMS can also be used as orally administered drugs and for wound decontamination. By changing the organic groups of SAMMS, they can be used not only for actinides but also for other radionuclides. By using the mixture of these SAMMS materials, broad spectrum decorporation of radionuclides is very feasible.

  20. Sorption of americium in tuff and pure minerals using synthetic and natural groundwaters

    International Nuclear Information System (INIS)

    The distribution of Am between selected solid and liquid phases has been studied using initial 241Am solutions with a molarity smaller than 1 x 10-11. The synthetic and natural groundwaters used have pH values in the 7--8 range and a total alkalinity of approximately 1 mN which is mainly due to bicarbonate. Mass spectrometric isotope dilution was utilized to determine the amount of Am in the solution phase initially and after equilibrium was attained. Using this sensitive technique, 7 x 108 atoms of 241Am were accurately measured. Our results indicate that the percent of Am lost to the walls of the container in the absence of geologic material varies from 35 to 84. The Am sorption coefficient determined is on the order of 103 ml/g for clinoptilolite, 104 ml/g for tuff consisting mainly of alkali feldspar and cristobalite, and 105 ml/g for romanechite. 12 refs

  1. Americium-241 and plutonium-237 turnover in mussels ( Mytilus galloprovincialis) living in field enclosures

    Science.gov (United States)

    Guary, J. C.; Fowler, S. W.

    1981-02-01

    Loss of 241Am and 237Pu from contaminated mussels ( Mytilus galloprovincialis) living in situ in the Mediterranean Sea is described as the sum of three exponential functions. In the case of 241Am, two short-lived compartments representing a total of 80% of the incorporated radionuclide turned over rapidly with biological half-lives of 2 and 3 weeks. The remaining fraction of 241Am, associated with a long-lived compartment, was lost at an extremely slow rate ( Tb1/2=1·3 years). Plutonium-237 turnover in the two short-lived compartments (containing 70% of the Pu) was more rapid ( Tb1/2=1-2 days and 2 weeks) than that of 241Am; however, there was some indication that subsequent loss rates of the two radionuclides in long-lived compartments may be similar if determined over comparable periods of time. Loss rates of 241Am differed for the various tissues, with the most rapid rates occurring in gill, viscera and shell. Abrupt changes in loss observed in muscle and mantle suggested a translocation of 241Am to muscle and mantle during depuration. Whole shell contained by far the largest fraction (˜90%) of both 241Am and 237Pu taken up; in addition, these radionuclides are not irreversibly bound to mussel shell but readily leach into the water. These observations suggest that mollusc shell may influence the biogeochemistry of transuranic elements in littoral zones.

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

    International Nuclear Information System (INIS)

    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

  3. Combined procedure using radiochemical separation of plutonium, americium and uranium radionuclides for alpha-spectrometry

    International Nuclear Information System (INIS)

    Radiochemical separation of Pu, Am and U was tested from synthetic solutions and evaporator concentrate samples from nuclear power plants for isolation of each of them for alpha-spectrometry analysis. The separation was performed by anion-exchange chromatography, extraction chromatography, using TRU resin, and precipitation techniques. The aim of the study was to develop a sensitive analytical procedure for the sequential determination of 242Pu, 238Pu, 239+240Pu, 241Am and 235,238U in radioactive wastes. 238Pu, 242Pu, 243Am and 232U were used as tracers. The measurements of α emitting radionuclides were performed by semiconductor detector that is used especially when spectrometric information is needed. For synthetic solutions the chemical recovery was based on associated iron concentration and was about 93%. (author)

  4. Study on the uptake of Americium using PC88A - impregnated macroporous polymeric beads

    International Nuclear Information System (INIS)

    The prime objective of radioactive waste treatment in nuclear industry is to minimize the waste volume by efficient process without generating secondary radioactive waste for its final disposal. Among the currently available technologies, for separation and recovery of metal ions, solvent extraction, ion-exchange, membrane based technologies and solid sorbent materials are more popular means. Though, all these technologies play major role in all the bulk separation processes, their marked limitations force the separation scientists to think of advance, more efficient and technically feasible alternatives. The extractant impregnated polymeric beads (EIMPBs), impregnated with metal-specific extractants, exhibit reliable separation performances under column operation, and hence bridge the gap between solvent extraction and ion exchange techniques. In the present work, PC88A impregnated PES beads are prepared and the sorption of Am (III) from aqueous waste solutions is investigated. The synthesized EIMPBs were characterized by FTIR, TGA and SEM techniques. The physiochemical strength of the beads was found to be excellent. The sorption study of Am (III), using these beads, was carried out by batch equilibration method and the effect of various parameters, like pH, equilibration time, Am (III) concentration, etc., on the sorption process, was investigated. The synthesized polymeric beads presented fairly higher sorption capacity for Am (III) at pH 3. The kinetics of extraction is very fast. The saturation of sorption is achieved in about 60 minutes of equilibration. The sorption kinetics data fits well in the pseudo second-order model, indicating that the sorption is dominated by chemisorptions. The sorption of Am (III) is observed to follow Langmuir isotherm and the monolayer capacity was calculated as 2.498 mg/g. The quantitative stripping of the extracted Am (III) can be achieved by using 0.1M oxalic acid. The blank polymeric beads, without PC88A,have shown negligible sorption of Am (III) under the similar experimental conditions

  5. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    International Nuclear Information System (INIS)

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10−4 min−1 and 1.60 × 10−4 min−1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure

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

    International Nuclear Information System (INIS)

    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.)

  7. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry.

    Science.gov (United States)

    Kazi, Zakir H; Cornett, Jack R; Zhao, Xaiolei; Kieser, Liam

    2014-06-01

    A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8M HNO3 with 0.05 M NaNO2 before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO3, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl3 facilitated the complete desorption of Pu. Interferences (e.g. Ca(2+), Fe(3+)) were washed off from the resin bed with excess HNO3. Using NdF3, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7±5.3% and 95.5±4.6% for (241)Am and (242)Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1±6.0 and 96.8±5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1-100 Bq kg(-1). The single column separation of Pu and Am saves reagents, separation time, and cost. PMID:24856406

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

    International Nuclear Information System (INIS)

    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 CyMe4-BTPhen, CyMe4-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-1) and thus requires little pre-treatment of samples.

  9. 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.

  10. 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.

  11. Neutron Nuclear Data Evaluation of Actinoid Nuclei for CENDL-3.1

    CERN Document Server

    Guo-Chang, Chen; Bao-Sheng, Yu; Guo-You, Tang; Zhao-Min, Shi; Xi, Tao

    2011-01-01

    New evaluations for several actinoids of the third version of China Evaluated Nuclear Data Library (CENDL-3.1) have been completed during the period between 2000 and 2005. The evaluations are for all neutron induced reactions with Uranium, Neptunium, Plutonium and Americium in the mass range A=232-241, 236-239, 236-246 and 240-244, respectively, and cover the incident neutron energy up to 20 MeV. In present evaluation, much more efforts were devoted to improve reliability of nuclide for available new measured data, especially scarce experimental data. A general description for the evaluation of several actinoids data were presented.

  12. 7 CFR 2.44 - Administrator, Risk Management Agency and Manager, Federal Crop Insurance Corporation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Administrator, Risk Management Agency and Manager... Secretary for Farm and Foreign Agricultural Services to the Administrator, Risk Management Agency, and... for the transaction of the business of the Federal Crop Insurance Corporation and the Risk...

  13. 40 CFR 98.244 - Monitoring and QA/QC requirements.

    Science.gov (United States)

    2010-07-01

    ... Measurement of Fluid Flow by Means of Coriolis Mass Flowmeters (incorporated by reference, see § 98.7). (viii... the minimum frequency specified by the manufacturer. (2) Operate and maintain all flow meters for gas... procedures specified by the flow meter manufacturer or § 98.3(i). Recalibrate each flow meter...

  14. PETROCHINA PLACED US$2.44 B IN NEW H SHARES

    Institute of Scientific and Technical Information of China (English)

    Qu Lan

    2005-01-01

    @@ Following a request made by PetroChina, China's largest oil and gas producer, Hong Kong-listed, to the Stock Exchange of Hong Kong Limited, trading in the Company's H shares had been suspended with effect from 9:30 a.m. on 31 August 2005. The Company issued a formal announcement concerning about a placing of H shares under the general mandate granted to the Board of Directors at the annual general meeting of the Company on 26 May 2005 to issue up to 20% of the aggregate nominal amount of the Company's H shares in issue on that date, being not exceeding 3,516,483,600 H shares.

  15. Crystal structure of (E-2-[4-(4-hydroxyphenylbutan-2-ylidene]hydrazine-1-carbothioamide

    Directory of Open Access Journals (Sweden)

    Adriano Bof de Oliveira

    2015-01-01

    Full Text Available The title compound, C11H15N3OS, is a thiosemicarbazone derivative of the raspberry ketone rheosmin [systematic name: 4-(4-hydroxyphenylbutane-2-one]. The molecule deviates from planarity, with the bridging C—C—C=N torsion angle equal to −101.3 (2°. The maximum deviation from the mean plane of the non-H atoms of the thiosemicarbazone fragment [C=N—N—C(= S—N] is 0.085 (5 Å for the Schiff base N atom, and the dihedral angle between this mean plane and the aromatic ring is 50.31 (8°. In the crystal, molecules are linked by N—H...O, N—H...S and O—H...S hydrogen bonds, forming a three-dimensional structure, with the molecules stacked along [011].

  16. Radiocaesium, plutonium and americium partitioning and solid speciation in sized, inter-tidal sediments from Strangford Lough

    International Nuclear Information System (INIS)

    Fine-grained surface (0-2 cm) sediment was collected at an inter-tidal site (Mahee Island) in Strangford Lough, on the NE coast of Ireland in September 1997. The sediment was wet-sieved into standard sized fractions using Endecott test sieves and the fractions assayed for 137Cs, 239,240Pu and 241Am content. Sub-samples of each fraction were measured with a Malvern 2600 laser diffraction analyser, which confirmed that >90% of the particles in each fraction was in the defined size range

  17. Speciation of plutonium and americium in the soils affected by Kraton-3 accidental underground nuclear explosion in Yakutia (Russia)

    International Nuclear Information System (INIS)

    In calcareous soils from Yakutia only 0.1 % or less 239Pu and 241Am exist in water-soluble form, i.e., the mobility of these radionuclides is relatively low. In the top humus-containing layer (0-4 cm) 239Pu and 241Am are distributed uniformly between organic and inorganic soil components. In the bottom soil layer (20-30 cm) the radionuclides are present mainly in inorganic soil components. The estimation of the radionuclide mobility demonstrates that 241Am is potentially a more mobile element than 239Pu. In the considered calcareous soils collected from the top layer 239Pu and 241Am exist both in humic and fulvic acids (FA). 241Am is much stronger bound to the group of mobile FA than 239Pu. In the bottom soil layer 239Pu and 241Am have been found mainly in FA. (author)

  18. 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.

  19. 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.

  20. Study of plutonium and americium contamination in agricultural area, radiological impact caused by consumption of vegetables of this area

    International Nuclear Information System (INIS)

    The transuranide concentration has been studied for 30 years in vegetable production, crops in wide extensions and in private-owned farms, all of them situated within the Pu-contaminated area of Palomares due to an air accident in 1966. Based on these studies, a preliminary estimation of the radiological risk caused by the consumption of these products by the inhabitants was possible. The results show that most of the fruits present a surface contamination, which disappears or is significantly reduced when they are washed. The contamination present in edible parts of the vegetables, as well as the contamination of other products included in the diet, has facilitated the estimation of the effective dose for ingestion and the committed effective dose for 50 years for the inhabitants. The main conclusions are: those plants, whose cultivation period is less than a year, present a low level of contamination; the green parts of the plants have a higher contamination than the fruits; the Pu soil to plant transfer factor is very low. In general, those plants that have remained in the contaminated land for several years present a high contamination level; the ingestion of products from Palomares does not represent an important risk for the population, even in the case that the products were totally consumed by a critical group.( author)

  1. The determination of alpha-emitting nuclides of plutonium, americium and curium in environmental materials: Pt. 1

    International Nuclear Information System (INIS)

    Within the Aquatic Environment Protection Division of the Directorate of Fisheries Research (DFR), the Radioanalytical Group routinely analyses a wide range of environmental materials for a substantial number of radionuclides. A wide variety of radiochemical procedures have been developed at different laboratories but there are no 'standard' methods because the methods are continually developing. Nevertheless, it is useful, as in this present series, periodically to draw together the methods which are in routine use at a laboratory and to discuss their development and application. (author)

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

    International Nuclear Information System (INIS)

    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.)

  3. Effects of americium-241 and humic substances on Photobacterium phosphoreum: Bioluminescence and diffuse reflectance FTIR spectroscopic studies

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Selivanova, Maria A.; Tarantilis, Petros A.; Polissiou, Moschos G.; Kudryasheva, Nadezhda S.

    The integral bioluminescence (BL) intensity of live Photobacterium phosphoreum cells (strain 1883 IBSO), sampled at the stationary growth stage (20 h), was monitored for further 300 h in the absence (control) and presence of 241Am (an α-emitting radionuclide of a high specific activity) in the growth medium. The activity concentration of 241Am was 2 kBq l-1; [241Am] = 6.5 × 10-11 M. Parallel experiments were also performed with water-soluble humic substances (HS, 2.5 mg l-1; containing over 70% potassium humate) added to the culture medium as a possible detoxifying agent. The BL spectra of all the bacterial samples were very similar (λmax = 481 ± 3 nm; FWHM = 83 ± 3 nm) showing that 241Am (also with HS) influenced the bacterial BL system at stages prior to the formation of electronically excited states. The HS added per se virtually did not influence the integral BL intensity. In the presence of 241Am, BL was initially activated but inhibited after 180 h, while the system 241Am + HS showed an effective activation of BL up to 300 h which slowly decreased with time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, applied to dry cell biomass sampled at the stationary growth phase, was used to control possible metabolic responses of the bacteria to the α-radioactivity stress (observed earlier for other bacteria under other stresses). The DRIFT spectra were all very similar showing a low content of intracellular poly-3-hydroxybutyrate (at the level of a few percent of dry biomass) and no or negligible spectroscopic changes in the presence of 241Am and/or HS. This assumes the α-radioactivity effect to be transmitted by live cells mainly to the bacterial BL enzyme system, with negligible structural or compositional changes in cellular macrocomponents at the stationary growth phase.

  4. Assessment of americium and curium transmutation in magnesia based targets in different spectral zones of an experimental accelerator driven system

    Science.gov (United States)

    Haeck, W.; Malambu, E.; Sobolev, V. P.; Aït Abderrahim, H.

    2006-06-01

    The potential to incinerate minor actinides (MA) in a sub-critical accelerator-driven system (ADS) is a subject of study in several countries where nuclear power plants are present. The performance of the MYRRHA experimental ADS, as to the transmutation of Am and Cm in the inert matrix fuel (IMF) samples consisting of 40 vol.% (Cm0.1Am0.5Pu0.4)O1.88 fuel and 60 vol.% MgO matrix with a density of 6.077 g cm-3 in three various spectrum regions, were analysed at the belgian nuclear research centre SCK · CEN. The irradiation period of 810 effective full power days (EFPD) followed by a storage period of 2 years was considered. The ALEPH code system currently under development at SCK · CEN was used to carry out this study. The total amount of MA is shown to decrease in all three considered cases. For Am, the decrease is the largest in the reflector (89% decrease) but at the cost of a net Cm production (92% increase). In the two other positions (inside the core region), 20-30% of Am has disappeared but with a lower production of Cm (between 7% and 11%). In the reflector, a significant build-up of long-lived 245Cm, 246Cm, 247Cm and 248Cm was also observed while the production of these isotopes is 10-1000 times smaller in the core. The reduction of the Pu content is also the highest in the reflector position (41%). In the other positions the incinerated amount of Pu is much smaller: 1-5%.

  5. 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...

  6. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    International Nuclear Information System (INIS)

    Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for 241Am(III) and 238Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4. (author)

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

    International Nuclear Information System (INIS)

    Male and female C57BL/Do mice were each given a single i.p. injection of 237+239Pu + 241Am 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

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

    International Nuclear Information System (INIS)

    Male and female C57BL/Do mice were each given a single ip injection of /sup 237 + 239/Pu + 241Am as the citrate complex at 45 days of age. Twice-weekly ip injections of either 500 μmole/kg Ca-DTPA or 500 μmole/kg Ca-DTPA mixed just before injection with 2000 μmole/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 γ-ray counting using a NaI(Tl) crystal spectrometer. 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 that in the control animals. Mice treated with Ca-DTPA plus SA were statistically indistinguishable from mice treated with Ca-DTPA alone

  9. 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)

    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 239Pu 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)

  10. Effects of Hanford high-level waste components on the solubility and sorption of cobalt, strontium, neptunium, plutonium, and americium

    International Nuclear Information System (INIS)

    High-level radioactive defense waste solutions, originating from plutonium recovery and waste processing operations at the U.S. Department of Energy's Hanford Site, currently are stored in mild steel-lined concrete tanks located in thick sedimentary beds of sand and gravel. Statistically designed experiments were used to identify the effects of 12 major chemical components of Hanford waste solution on radionuclide solubility and sorption. The chemical components with the most effect on radioelement solubility and sorption were NaOH, NaAl0/sub 2/, EDTA, and HEDTA. The EDTA and HEDTA increased Co, Sr, and Am solubility and decreased sorption for almost all radioelements studied. Sodium hydroxide and NaAlO/sub 2/ increased Pu solubility and decreased Np and Pu sorption. Sodium nitride decreased Np solubility, while Na/sub 2/CO/sub 3/ and HEDTA increased it. These observations give evidence for the formation of radioelement complexes which are soluble and are not strongly sorbed by the sediments near the waste tanks

  11. Oscar H. Aelo, El peronismo en la provincia de Buenos Aires (1946-1955), Caseros, Eduntref, 2012, 244 p.

    OpenAIRE

    Hémeury, Lucie

    2013-01-01

    Fenómeno fundamental en la historia de la Argentina del siglo XX, el peronismo sigue siendo un tema central de la historiografía argentina. Como suele ocurrir en el caso de movimientos de tal amplitud, caracterizados tanto por su longevidad como por la importancia de ciertas transformaciones en el campo político, social, cultural y económico, la bibliografía enfoca algunos de estos aspectos en perjuicio de otros. En su libro El peronismo en la provincia de Buenos Aires, fruto de una tesis de ...

  12. Metabolites of 2,4,4'-tribrominated diphenyl ether (BDE-28) in pumpkin after in vivo and in vitro exposure.

    Science.gov (United States)

    Yu, Miao; Liu, Jiyan; Wang, Thanh; Sun, Jianteng; Liu, Runzeng; Jiang, Guibin

    2013-01-01

    There is currently limited knowledge on PBDE metabolism in plants although they could play an important role in the environmental transformation of these persistent organic pollutants. In this study, pumpkin (Cucurbita maxima × C. moschata) was chosen as the model to understand the fate of BDE-28 in plants. MeO-tri-BDEs, OH-tri-BDEs, and OH-tri-BDEs were found as metabolites in plant samples of both in vivo hydroponic and in vitro tissue culture exposure. Three MeO-tri-BDEs were further identified as para-substituted metabolites. MeO-BDEs and OH-BDEs, respectively, accounted for about 1.6% and 1.5% (recovery corrected) of initial amount of BDE-28 according to the semiquantitative results. Other PBDEs, especially less brominated PBDEs as impurities in the standard of BDE-28, were also detected. The impurities and evaporation of the standard must be considered when trace metabolites are studied in exposure experiments.

  13. 25 CFR 162.244 - How will BIA decide whether to approve a leasehold mortgage under an agricultural lease?

    Science.gov (United States)

    2010-04-01

    ... the tenant's interest in the leased premises, and no unrelated collateral; (3) The loan being secured... find no compelling reason to withhold our approval in order to protect the best interests of the...

  14. Ines Lei Corvette, L'ita iano regionale di Sardegna, Fenomeni Linguistici num. 3, Bologna, Zanichelli 1983, IV + 244 pp.

    Directory of Open Access Journals (Sweden)

    Pavao Tekavčić

    1983-01-01

    Full Text Available L'Autrice del volume, professore associate di linguistica presso la Facoltà di Magistero dell'Università di Cagliari, ci ha dato già in precedenza alcuni notevoli contributi allo studio della complessa situazione linguistica in Sardegna (La metafonesi ne l'italiano regionale di Sardegna, "Lingua e stile" X/1975/; Neutralizzazione e ridondanza fonologiaa nei dialetti sardi, "Lingua e stile" XII/1977/; Dittonghi e iato nel campidanese, "Rivista italiana di dialettologia" IV/1979-1980/; Variétés et minorités linguistiques en Sardaigne, "Peuples Méditerranéens" XIII/1980/, dedicandosi nel contempo anche adaltri temi (l'arabo, i disturbi del linguaggio, la semantica del linguaggio della letteratura ecc.. Malgrado questa larghezza di interessi scientifici il dominic principale dell'Autrice re­sta la Sardegna, e anche l'opera qui recensita è una specie di sintesi dei suoi studi linguistici sardi condotti finora. Il tema è l'italiano regionale di Sardegna(IRS, nei suoi molteplici rapporti con i principali dialetti(D sardi da un late, con l'italiano standard (IS dall'altro. Oggigiorno in Italia, un'opera simile non può non essere impostata principalmente dal punta di vista sociolinguistico, non soltanto perché la sociolinguistica è uno degli indirizzi linguistici più attuali, rna anche e soprattutto perché in Italia, terra di mille e uno dia­ letti, studi sull'italiano regionale, sull'italiano standard, sull'educazione linguistica ecc. senza l'angolazione sociolinguistica semplicemente non sono possibili.

  15. Notice of construction work in tank farm waste transfer pit 244-TX double contained receiver-tank

    International Nuclear Information System (INIS)

    The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions and Defense Waste Section as a notice of construction (NOC) in accordance with Washington Administrative Code (WAC) 246-247, Radiation Protection - Air Emissions. WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A,'' Appendix A (WAC 246-247-1 10) lists the requirements that must be addressed. Additionally, the following description, attachments, and references are provided to the U.S. Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40 Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide less than 0.1 millired year total effective dose equivalent to the hypothetical offsite maximally exposed individual, and commencement is needed within a short time. Therefore, this application also is intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in 40 CFR 61.09(a)(1), and it is requested that approval of this application also will constitute EPA acceptance of this initial startup notification. Written notification of the actual date of initial startup, in accordance with the requirement listed in 40 CFR 61.09(a)(2), will be provided later. The activities described in this NOC are estimated to provide a potential offsite (unabated) total effective dose equivalent (TEDE) to the hypothetical maximally exposed individual (MEI) of 2.36 E-02 millirem per year

  16. NA22 Model Cities Project - LL244T An Intelligent Transportation System-Based Radiation Alert and Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Peglow, S

    2004-02-24

    The purpose of this project was twofold: first, provide an understanding of the technical foundation and planning required for deployment of Intelligent Transportation System (ITS)-based system architectures for the protection of New York City from a terrorist attack using a vehicle-deployed nuclear device; second, work with stakeholders to develop mutual understanding of the technologies and tactics required for threat detection/identification and establish guidelines for designing operational systems and procedures. During the course of this project we interviewed and coordinated analysis with people from the New Jersey State Attorney General's office, the New Jersey State Police, the Port Authority of New York/New Jersey, the Counterterrorism Division of the New York City Police Department, the New Jersey Transit Authority, the State of New Jersey Department of Transportation, TRANSCOM and a number of contractors involved with state and federal intelligent transportation development and implementation. The basic system architecture is shown in the figure below. In an actual system deployment, radiation sensors would be co-located with existing ITS elements and the data will be sent to the Traffic Operations Center. A key element of successful system operation is the integration of vehicle data, such as license plate, EZ pass ID, vehicle type/color and radiation signature. A threat data base can also be implemented and utilized in cases where there is a suspect vehicle identified from other intelligence sources or a mobile detector system. Another key aspect of an operational architecture is the procedures used to verify the threat and plan interdiction. This was a major focus of our work and discussed later in detail. In support of the operational analysis, we developed a detailed traffic simulation model that is described extensively in the body of the report.

  17. Comparison of photosensitivity in germanium doped silica fibers using 244 nm and 266 nm continuous wave lasers

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo; Varming, Poul; Liu, B.;

    2001-01-01

    Diode pumped continuous-wave UV lasers offer an interesting alternative to frequency doubled argon-ion lasers. We report the first photosensitivity comparison using these lasers on deuterium loaded standard telecommunication fibers and unloaded experimental fibers....

  18. Health-hazard evaluation report HETA-88-244-1951, Orrville Bronze and Aluminum Company, Orrville, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Montopoli, M.; Seligman, P.; O' Brien, D.; Zaebst, D.

    1989-03-01

    An investigation was made of possible hazardous working conditions at the Orrville Bronze and Aluminum Company, Orrville, Ohio. Medical screening at the site had recently discovered a worker with a blood lead level in excess of 100 micrograms/deciliter (microg/dl) and seven workers with blood lead levels in excess of 40 microg/dl. The facility was a nonferrous foundry specializing in small- to medium-sized bronze, brass, and copper castings. Lead concentrations in six personal breathing-zone samples ranged from 38 to 520 micrograms/cubic meter (microg/m{sup 3}). Airborne copper levels ranged from 26 to 2601 microg/m{sup 3}. Airborne zinc concentrations ranged from 291 to 3165 microg/m{sup 3}. Three of 18 workers had blood lead levels in excess of 60 microg/m{sup 3}, the OSHA level which requires immediate medical removal protection. The report concludes that lead and copper exposures represented a serious health hazard to workers. Measures to reduce exposures, including engineering controls, work practices, and housekeeping are recommended.

  19. Metabolites of 2,4,4'-tribrominated diphenyl ether (BDE-28) in pumpkin after in vivo and in vitro exposure.

    Science.gov (United States)

    Yu, Miao; Liu, Jiyan; Wang, Thanh; Sun, Jianteng; Liu, Runzeng; Jiang, Guibin

    2013-01-01

    There is currently limited knowledge on PBDE metabolism in plants although they could play an important role in the environmental transformation of these persistent organic pollutants. In this study, pumpkin (Cucurbita maxima × C. moschata) was chosen as the model to understand the fate of BDE-28 in plants. MeO-tri-BDEs, OH-tri-BDEs, and OH-tri-BDEs were found as metabolites in plant samples of both in vivo hydroponic and in vitro tissue culture exposure. Three MeO-tri-BDEs were further identified as para-substituted metabolites. MeO-BDEs and OH-BDEs, respectively, accounted for about 1.6% and 1.5% (recovery corrected) of initial amount of BDE-28 according to the semiquantitative results. Other PBDEs, especially less brominated PBDEs as impurities in the standard of BDE-28, were also detected. The impurities and evaporation of the standard must be considered when trace metabolites are studied in exposure experiments. PMID:24191731

  20. 49 CFR 244.13 - Subjects to be addressed in a Safety Integration Plan involving an amalgamation of operations.

    Science.gov (United States)

    2010-10-01

    ... transaction: (a) Corporate culture. Each applicant shall: (1) Identify and describe differences for each safety-related area between the corporate cultures of the railroads involved in the transaction; (2... step-by-step measures, the integration of these corporate cultures and the manner in which it...

  1. INL DPAH STAAR 2015 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterman, Dean Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-15

    Research conducted at the INL has demonstrated the synergistic extraction of americium using solvents comprised of bis(o,o-(trifluoromethyl)phenyl) dithiophosphinic acid (DPAH “1”) and trioctylphosphine oxide (TOPO), butyl bis(2,4,4-trimethylpentyl) phosphinate (BuCy272), or dibutyl butylphosphonate (DBBP). One potential drawback of this separations scheme is that soft metals such as silver, cadmium, or palladium and fission products such as zirconium are well extracted by these solvents. Several potential scrubbing reagents were examined. Of the scrubbing reagents studied, cysteine and methione exhibited some ability to scrub soft metals from the loaded solvent. More conventional scrub reagents such as ammonium fluoride or oxalic acid were not effective. Reagents like Bimet and CDTA were not soluble at the acidities used in these studies. Unfortunately, these results indicate that the identification of effective scrubbing reagents for use in a flowsheet based upon the INL DPAH is going to be very difficult.

  2. Environmental, safety, and health plan for the remedial investigation of Waste Area Grouping 10, Operable Unit 3, at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This document outlines the environmental, safety, and health (ES&H) approach to be followed for the remedial investigation of Waste Area Grouping (WAG) 10 at Oak at Ridge National Laboratory. This ES&H Plan addresses hazards associated with upcoming Operable Unit 3 field work activities and provides the program elements required to maintain minimal personnel exposures and to reduce the potential for environmental impacts during field operations. The hazards evaluation for WAG 10 is presented in Sect. 3. This section includes the potential radiological, chemical, and physical hazards that may be encountered. Previous sampling results suggest that the primary contaminants of concern will be radiological (cobalt-60, europium-154, americium-241, strontium-90, plutonium-238, plutonium-239, cesium-134, cesium-137, and curium-244). External and internal exposures to radioactive materials will be minimized through engineering controls (e.g., ventilation, containment, isolation) and administrative controls (e.g., procedures, training, postings, protective clothing).

  3. Neutron nuclear data evaluation of actinide nuclei for CENDL-3.1

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-Chang; CAO Wen-Tian; YU Bao-Sheng; TANG Guo-You; SHI Zhao-Min; TAO Xi

    2012-01-01

    New evaluations for several actinide nuclei of the third version of Chinese Evaluated Nuclear Data Library for Neutron Reaction Data (CENDL-3.1) have been completed and released.The evaluation is for all neutron induced reactions with uranium,neptunium,plutonium and americium in the mass range A=232-241,236-239,236-246 and 240-244,respectively,and cover the incident neutron energy up to 20 MeV.In the present evaluation,much more effort was devoted to improving the reliability of the evaluated nuclear data for available new measured data,especially scarce or absent experimental data.A general description for the evaluation of several actinides' data is presented.

  4. Measurements of the neutron capture cross sections and incineration potentials of minor-actinides in high thermal neutron fluxes: Impact on the transmutation of nuclear wastes

    International Nuclear Information System (INIS)

    This thesis comes within the framework of minor-actinide nuclear transmutation studies. First of all, we have evaluated the impact of minor actinide nuclear data uncertainties within the cases of 241Am and 237Np incineration in three different reactor spectra: EFR (fast), GT-MHR (epithermal) and HI-HWR (thermal). The nuclear parameters which give the highest uncertainties were thus highlighted. As a result of fact, we have tried to reduce data uncertainties, in the thermal energy region, for one part of them through experimental campaigns in the moderated high intensity neutron fluxes of ILL reactor (Grenoble). These measurements were focused onto the incineration and transmutation of the americium-241, the curium-244 and the californium-249 isotopes. Finally, the values of 12 different cross sections and the 241Am isomeric branching ratio were precisely measured at thermal energy point. (author)

  5. Environmental, safety, and health plan for the remedial investigation of Waste Area Grouping 10, Operable Unit 3, at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    This document outlines the environmental, safety, and health (ES ampersand H) approach to be followed for the remedial investigation of Waste Area Grouping (WAG) 10 at Oak at Ridge National Laboratory. This ES ampersand H Plan addresses hazards associated with upcoming Operable Unit 3 field work activities and provides the program elements required to maintain minimal personnel exposures and to reduce the potential for environmental impacts during field operations. The hazards evaluation for WAG 10 is presented in Sect. 3. This section includes the potential radiological, chemical, and physical hazards that may be encountered. Previous sampling results suggest that the primary contaminants of concern will be radiological (cobalt-60, europium-154, americium-241, strontium-90, plutonium-238, plutonium-239, cesium-134, cesium-137, and curium-244). External and internal exposures to radioactive materials will be minimized through engineering controls (e.g., ventilation, containment, isolation) and administrative controls (e.g., procedures, training, postings, protective clothing)

  6. Measurements of the neutron capture cross sections and incineration potentials of minor-actinides in high thermal neutron fluxes: Impact on the transmutation of nuclear wastes; Mesures des sections efficaces de capture et potentiels d'incineration des actinides mineurs dans les hauts flux de neutrons: Impact sur la transmutation des dechets

    Energy Technology Data Exchange (ETDEWEB)

    Bringer, O

    2007-10-15

    This thesis comes within the framework of minor-actinide nuclear transmutation studies. First of all, we have evaluated the impact of minor actinide nuclear data uncertainties within the cases of {sup 241}Am and {sup 237}Np incineration in three different reactor spectra: EFR (fast), GT-MHR (epithermal) and HI-HWR (thermal). The nuclear parameters which give the highest uncertainties were thus highlighted. As a result of fact, we have tried to reduce data uncertainties, in the thermal energy region, for one part of them through experimental campaigns in the moderated high intensity neutron fluxes of ILL reactor (Grenoble). These measurements were focused onto the incineration and transmutation of the americium-241, the curium-244 and the californium-249 isotopes. Finally, the values of 12 different cross sections and the {sup 241}Am isomeric branching ratio were precisely measured at thermal energy point. (author)

  7. Production and investigation of thin films of metal actinides (Pu, Am, Cm, Bk, Cf)

    Science.gov (United States)

    Radchenko, V. M.; Ryabinin, M. A.; Stupin, V. A.

    2010-03-01

    Under limited availability of transplutonium metals some special techniques and methods of their production have been developed that combine the process of metal reduction from a chemical compound and preparation of a sample for examination. In this situation the evaporation and condensation of metal onto a substrate becomes the only possible technology. Thin film samples of metallic 244Cm, 248Cm and 249Bk were produced by thermal reduction of oxides with thorium followed by deposition of the metals in the form of thin layers on tantalum substrates. For the production of 249Cf metal in the form of a thin layer the method of thermal reduction of oxide with lanthanum was used. 238Pu and 239Pu samples in the form of films were prepared by direct high temperature evaporation and condensation of the metal onto a substrate. For the production of 241Am films a gram sample of plutonium-241 metal was used containing about 18 % of americium at the time of production. Thermal decomposition of Pt5Am intermetallics in vacuum was used to produce americium metal with about 80% yield. Resistivity of the metallic 249Cf film samples was found to decrease exponentially with increasing temperature. The 249Cf metal demonstrated a tendency to form preferably a DHCP structure with the sample mass increasing. An effect of high specific activity on the crystal structure of 238Pu nuclide thin layers was studied either.

  8. Production and investigation of thin films of metal actinides (Pu, Am, Cm, Bk, Cf)

    International Nuclear Information System (INIS)

    Under limited availability of transplutonium metals some special techniques and methods of their production have been developed that combine the process of metal reduction from a chemical compound and preparation of a sample for examination. In this situation the evaporation and condensation of metal onto a substrate becomes the only possible technology. Thin film samples of metallic 244Cm, 248Cm and 249Bk were produced by thermal reduction of oxides with thorium followed by deposition of the metals in the form of thin layers on tantalum substrates. For the production of 249Cf metal in the form of a thin layer the method of thermal reduction of oxide with lanthanum was used. 238Pu and 239Pu samples in the form of films were prepared by direct high temperature evaporation and condensation of the metal onto a substrate. For the production of 241Am films a gram sample of plutonium-241 metal was used containing about 18 % of americium at the time of production. Thermal decomposition of Pt5Am intermetallics in vacuum was used to produce americium metal with about 80% yield. Resistivity of the metallic 249Cf film samples was found to decrease exponentially with increasing temperature. The 249Cf metal demonstrated a tendency to form preferably a DHCP structure with the sample mass increasing. An effect of high specific activity on the crystal structure of 238Pu nuclide thin layers was studied either.

  9. Luminescence study on solvation of americium(III), curium(III) and several lanthanide(III) ions in nonaqueous and binary mixed solvents

    International Nuclear Information System (INIS)

    The luminescence lifetimes of An(III) and Ln(III) ions [An=Am and Cm; Ln=Nd, Sm, Eu, Tb and Dy] were measured in dimethyl sulfoxide(DMSO), N,N-dimethylformamide(DMF), methanol(MeOH), water and their perdeuterated solvents. Nonradiative decay rates of the ions were in the order of H2O > MeOH > DMF > DMSO, indicating that O-H vibration is more effective quencher than C-H, C=O, and S=O vibrations in the solvent molecules. Maximal lifetime ratios τD/τH were observed for Eu(III) in H2O, for Sm(III) in MeOH and DMF, and for Sm(III) and Dy(III) in DMSO. The solvent composition in the first coordination sphere of Cm(III) and Ln(III) in binary mixed solvents was also studied by measuring the luminescence lifetime. Cm(III) and Ln(III) were preferentially solvated by DMSO in DMSO-H2O, by DMF in DMF-H2O, and by H2O in MeOH-H2O over the whole range of the solvent composition. The order of the preferential solvation, i.e., DMSO > DMF > H2O > MeOH, correlates with the relative basicity of these solvents. The Gibbs free energy of transfer of ions from water to nonaqueous solvents was further estimated from the degree of the preferential solvation. (orig.)

  10. Studies on the feasibility of using completely incinerable reagents for the single-cycle separation of americium(III) from simulated high-level liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, P.K.; Kumaresan, R.; Venkatesan, K.A.; Subramanian, G.G.S.; Prathibha, T.; Syamala, K.V.; Selvan, B. Robert; Rajeswari, S.; Antony, M.P.; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.; Chaurasia, Shivkumar; Bhanage, B.M. [Institute of Chemical Technology, Mumbai (India)

    2015-06-01

    The extraction and stripping behavior of various metal ions present in the fast reactor simulated high-level liquid waste (FR-SHLLW) was studied using a solvent phase composed of a neutral extractant, N,N,-didodecyl-N',N'-dioctyl-3-oxapentane-1,5-diamide (D{sup 3}DODGA) and an acidic extractant, di-2-ethylhexyl diglycolamic acid (HDEHDGA) in n-dodecane (n-DD). The third phase formation behavior of the solvent formulation D{sup 3}DODGA + HDEHDGA/n-DD, was studied when it was contacted with FR-SHLLW, and the concentration of neutral and acidic extractant needed to avoid the third phase formation was optimized. The distribution ratio of various metal ions present in FR-SHLLW was measured in a solution of 0.1 M D{sup 3}DODGA + 0.2 M HDEHDGA/n-DD. The extraction of Am(III) was accompanied by the co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Y(III), and Pd(II). A procedure was developed to minimize the extraction of unwanted metal ions by using aqueous soluble complexing agents in FR-SHLLW. Based on those results, the counter-current mixer-settler run was performed in a 20-stage mixer-settler. Quantitative extraction of Am(III), Ln(III), Y(III), and Sr(II) in 0.1 M D{sup 3}DODGA + 0.2 M HDEHDGA/n-DD was observed. The recovery of Am(III) from the loaded organic phase was carried out by the optimized aqueous formulation composed of 0.01 M diethylenetriaminepentaacetic acid (DTPA) + 0.5 M citric acid (CA) at pH 1.5. The stripping of Am(III) was accompanied by co-stripping of some early lanthanides. However the later lanthanides (Eu(III) and beyond) were not back extracted to Am(III) product. Therefore, the studies foresee the possibility of intra-lanthanides as well as lanthanide-actinide separation in a single-processing cycle.

  11. 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

    Energy Technology Data Exchange (ETDEWEB)

    Felmy, A.R. [Pacific Northwest National Lab., Richland, WA (US); Choppin, G. [Florida State Univ., Tallahassee, FL (US)

    1997-12-31

    '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.'

  12. 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.

  13. 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)

    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 m2/s. D-value obtained for cobalt (drill core cup sample, tonalite) was 5.4 x 10-17 m2/s. 241Am 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

  14. Sorption and diffusion of cobalt, nickel, strontium, iodine, cesium and americium in natural fissure surfaces and drill core cups studied by autoradiography, 2

    International Nuclear Information System (INIS)

    Theoretical studies on geological disposal of radioactive waste in fractured crystalline rock and migration of radionuclides in groundwater circulating through the fractured zones have indicated the importance of diffusion into the rock matrix. Samples chosen for this study were filled and unfilled natural fracture surfaces and drill cores having a central drilled cavity ('drill core cups'). Samples originated from the two nuclear power plant sites in Finland: mica gneiss and tonalite from Olkiluoto and rapakivi granite from Haestholmen in Loviisa. An autoradiographic method was used for determination of the penetration depths and calculation of diffusion coefficients of Cs-134, Sr-90, Co-60, Ni-63, I-125 and Am-241. Emphasis was also directed to testing the quantitative autoradiographic method for diffusion coefficient measurements. After one year's contact time the penetration depths of strontium in tonalite were 15 mm and 10 mm for the filled and unfilled natural fracture surface samples and 5 mm for drill core cups. In the filled natural fracture surface sample of rapakivi granite the penetration depth of strontium was 35 mm. For cesium penetration depths in tonalite from 2.0 mm (unfilled natural surface) to 3.0 mm (drill core cup) were observed. For cobalt a penetration depth of 0.9 mm was found in the drill core cup sample of tonalite after contact time of one year and 1.5 mm in the filled natural fracture surface of rapakivi granite after contact time of six months. The range of Da-values of strontium was 1.4 x 10-14 - 1.1 x 10-13 m2/s. The Da-values for cesium and cobalt in tonalite (drill core cup samples) were 7 x 10-15 m2/s and 5 x 10-16 m2/s, respectively

  15. Sequential isotopic determination of plutonium, thorium, americium and uranium in the air filter and drinking water samples around the WIPP site

    International Nuclear Information System (INIS)

    The simultaneous determination of actinides in air filter and water samples around the WIPP site have been demonstrated. The analytical method is based on the selective separation and purification by anion exchange and Eichrome-TEVA, TRU and DGA-resin followed by determination of actinides by alpha spectrometry. Counting sources for alpha spectrometric measurements were prepared by microcoprecipitation on neodymium fluoride (NdF3). Radiochemical yields were determined using 242Pu, 229Th, 243Am and 232U as tracers. The validation of the method is performed through the analysis of reference materials or participating in laboratory intercomparison programs. The plutonium concentrations in aerosols varied seasonally, being highest in spring and summer due to the spring-time enhanced wind-storm transportation of radioactive aerosols from the stratosphere to the troposphere. The 238Pu/239+240Pu activity ratio in the aerosol samples is typically close to that of global fallout from historic above-ground nuclear weapons testing. The results presented here indicate that the source of plutonium in the WIPP environment results mainly from global nuclear fallout and there is no evidence of increases in radiological contaminants in the region that could be attributed to releases from the WIPP. (author)

  16. Americium(III) oxidation by copper(III) periodate in nitric acid solution as compared with the action of Bi(V) compounds of sodium, lithium, and potassium

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Lumetta, Gregg J. [Pacific Northwest National Laboratory, Radiochemical Processing Lab., Richland, WA (United States)

    2015-07-01

    The oxidative action of a Cu(III) periodate compound toward Am(III) in nitric acid was studied. The extent of oxidation of Am(III) to Am(VI) was investigated using a constant initial Cu(III)-to-Am(III) molar ratio of 10:1 and varying nitric acid concentrations from 0.25 to 3.5 mol/L. From 0.25 to 3 mol/L HNO3, more than 98% of the Am(III) was oxidized to Am(VI); however, at 3.5 mol/L HNO{sub 3}, the conversion to Am(VI) was only 80%. Increasing the Cu(III)-to-Am(III) molar ratio to 20:1 in 3.5 mol/L HNO{sub 3} resulted in 98% conversion to Am(VI). For comparison, oxidation of Am(III) with NaBiO{sub 3} was studied at 3.5 mol/L HNO{sub 3} and the same stoichiometric excess of Bi(V) oxidant over Am(III) (stoichiometric ratio of 3.33:1). With NaBiO{sub 3}, the extent of Am(III) conversion to Am(VI) was only 19%, while with the Cu(III) compound this value was found to be about 4 times higher under otherwise identical conditions. Similar results were obtained with other Bi(V) salts. These results show that the Cu(III) periodate compound is a superior oxidant to NaBiO{sub 3}, yielding rapid conversion to Am(VI) in a homogeneous acidic solution, and is, therefore, an excellent candidate for further development of Am separation systems.

  17. I. Nuclear Production Reaction and Chemical Isolation Procedure for Americium-240 II. New Superheavy Element Isotopes: Plutonium-242(Calcium-48,5n)(285)114

    Science.gov (United States)

    Ellison, Paul Andrew

    2011-12-01

    Part I discusses the study of a new nuclear reaction and chemical separation procedure for the production of 240Am. Thin 242Pu, natTi, and natNi targets were coincidently activated with protons from the 88-Inch Cyclotron, producing 240Am, 48V, and 57Ni, respectively. The radioactive decay of these isotopes was monitored using high-purity Ge gamma ray detectors in the weeks following irradiation. The excitation function for the 242 Pu(p, 3n)240Am nuclear reaction was measured to be lower than theoretical predictions, but high enough to be the most viable nuclear reaction for the large-scale production of 240 Am. Details of the development of a chemical separation procedure for isolating 240Am from proton-irradiated 242Pu are discussed. The separation procedure, which includes two anion exchange columns and two extraction chromatography columns, was experimentally investi- gated using tracer-level 241Am, 239Pu, and model proton-induced fission products 95Zr, 95Nb, 125Sb, and 152Eu. The separation procedure was shown to have an Am/Pu separation factor of >2x10 7 and an Am yield of ˜70%. The separation procedure was found to purify the Am sample from >99.9% of Eu, Zr, Nb, and Sb. The procedure is well suited for the processing of ˜1 gram of proton-irradiated 242Pu to produce a neutron-induced fission target consisting of tens of nanograms of 240Am. Part II describes the use of the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron for the study of the 242Pu(48Ca,5n)285114 nuclear re- action. The new, neutron-deficient, superheavy element isotope 285114 was produced in 48Ca irradiations of 242Pu targets at a center-of-target beam energy of 256 MeV ( E* = 50 MeV). The alpha decay of 285114 was followed by the sequential alpha decay of four daughter nuclides, 281Cn, 277Ds, 273Hs, and 269 Sg. 265Rf was observed to decay by spontaneous fission. The measured alpha-decay Q-values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The 242Pu(48Ca, 5n)285114 cross section was 0.6-0.2 +1.3 pb.

  18. 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)

    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

  19. DEVELOPMENT OF FUNDAMENTAL DATA ON CHEMICAL SPECIATION AND SOLUBILITY FOR STRONTIUM AND AMERICIUM IN HIGH LEVEL WASTE: PREDICTIVE MODELING OF PHASE PARTITIONING DURING TANK PROCESSING

    Science.gov (United States)

    Current strategies for reducing the total volume of radioactive tank waste requiring disposal at Hanford and other DOE sites call for the development of methods to selectively dissolve and remove non-radioactive elements such as Al, P, and Cr while retaining or precipitating the ...

  20. Studies on the feasibility of using completely incinerable reagents for the single-cycle separation of americium(III) from simulated high-level liquid waste

    International Nuclear Information System (INIS)

    The extraction and stripping behavior of various metal ions present in the fast reactor simulated high-level liquid waste (FR-SHLLW) was studied using a solvent phase composed of a neutral extractant, N,N,-didodecyl-N',N'-dioctyl-3-oxapentane-1,5-diamide (D3DODGA) and an acidic extractant, di-2-ethylhexyl diglycolamic acid (HDEHDGA) in n-dodecane (n-DD). The third phase formation behavior of the solvent formulation D3DODGA + HDEHDGA/n-DD, was studied when it was contacted with FR-SHLLW, and the concentration of neutral and acidic extractant needed to avoid the third phase formation was optimized. The distribution ratio of various metal ions present in FR-SHLLW was measured in a solution of 0.1 M D3DODGA + 0.2 M HDEHDGA/n-DD. The extraction of Am(III) was accompanied by the co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Y(III), and Pd(II). A procedure was developed to minimize the extraction of unwanted metal ions by using aqueous soluble complexing agents in FR-SHLLW. Based on those results, the counter-current mixer-settler run was performed in a 20-stage mixer-settler. Quantitative extraction of Am(III), Ln(III), Y(III), and Sr(II) in 0.1 M D3DODGA + 0.2 M HDEHDGA/n-DD was observed. The recovery of Am(III) from the loaded organic phase was carried out by the optimized aqueous formulation composed of 0.01 M diethylenetriaminepentaacetic acid (DTPA) + 0.5 M citric acid (CA) at pH 1.5. The stripping of Am(III) was accompanied by co-stripping of some early lanthanides. However the later lanthanides (Eu(III) and beyond) were not back extracted to Am(III) product. Therefore, the studies foresee the possibility of intra-lanthanides as well as lanthanide-actinide separation in a single-processing cycle.

  1. Solubility limits of radionuclides in interstitial water. Americium in cement. Task 3. Characterization of radioactive waste forms. A series of final reports (1985-89). No 34

    International Nuclear Information System (INIS)

    The migration of actinides inside cement (or concrete) is very slow, even when the material is saturated with water: precipitation of actinide hydroxide explains this retention phenomenon. The aim of this work is to measure Am solubility in aqueous solutions equilibrated with CPA55 cement to: (i) compare it with thermodynamic predictions; and (ii) correlate it to (future) migration measurements of Am through cement discs. 12 figs.; 8 tabs.; 3 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. Bis(2-ethylhexyl)diglycolamic acid for the mutual separation of Europium (III) and Americium (III) from citric acid - nitric acid medium

    International Nuclear Information System (INIS)

    High-level liquid waste arises from fast reactor fuel reprocessing contains significant quantities of lanthanides and trivalent minor actinides. Recently, the partitioning of minor actinides from fast reactor-high active waste (FR-HAW) using a TRUEX solvent, composed of a solution of 0.2 M octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO)-1.2 M tri-n-butylphosphate (TBP) in n-dodecane is demonstrated. A new stripping formulation composed of a solution of 0.1 M citric acid in 0.1 M nitric acid was employed for back extraction of trivalents from the loaded TRUEX solvent. Thus the mutual separation lanthanides and actinides requires a suitable extractant for separating them from citric acid medium

  4. 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)

    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 241Am-14C-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 14C-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 241Am-14C-NOM migration experiments. The stability properties of the 241Am-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 241Am-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 241Am-OM complexes. In summary, the key processes governing 241Am migration are the rate of 241Am-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)

  5. Aqueous complexation of citrate with neodymium(III) and americium(III): a study by potentiometry, absorption spectrophotometry, microcalorimetry, and XAFS.

    Science.gov (United States)

    Brown, M Alex; Kropf, A Jeremy; Paulenova, Alena; Gelis, Artem V

    2014-05-01

    The aqueous complexation of Nd(III) and Am(III) with anions of citrate was studied by potentiometry, absorption spectrophotometry, microcalorimetry, and X-ray absorption fine structure (XAFS). Using potentiometric titration data fitting the metal-ligand (L) complexes that were identified for Nd(III) were NdHL, NdL, NdHL2, and NdL2; a review of trivalent metal-citrate complexes is also included. Stability constants for these complexes were calculated from potentiometric and spectrophotometric titrations. Microcalorimetric results concluded that the entropy term of complex formation is much more dominant than the enthalpy. XAFS results showed a dependence in the Debye-Waller factor that indicated Nd(iii)-citrate complexation over the pH range of 1.56-6.12.

  6. 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)

    '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.'

  7. 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.

  8. Uncertainty induced by chest wall thickness assessment methods on lung activity estimation for plutonium and americium: a large population-based study

    International Nuclear Information System (INIS)

    In vivo lung counting aims at assessing the retained activity in the lungs. The calibration factor relating the measured counts to the worker’s specific retained lung activity can be obtained by several means and strongly depends on the chest wall thickness. Here we compare, for 374 male nuclear workers, the activity assessed with a reference protocol, where the material equivalent chest wall thickness is known from ultrasound measurements, with two other protocols. The counting system is an array of four germanium detectors. It is found that non site-specific equations for the assessment of the chest wall thickness induce large biases in the assessment of activity. For plutonium isotopes or 241Am the proportion of workers for whom the retained activity is within ± 10% of the reference one is smaller than 10%. The use of site-specific equations raises this proportion to 20% and 58% for plutonium and 241Am, respectively. Finally, for the studied population, when site-specific equations are used for the chest wall thickness, the standard uncertainties for the lung activity are 42% and 12.5%, for plutonium and 241Am, respectively. Due to the relatively large size of the studied population, these values are a relatively robust estimate of the uncertainties due to the assessment of the chest wall thickness for the current practice at this site. (paper)

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

    OpenAIRE

    Ketelaer, J.

    2010-01-01

    Kernmassen sind eine wichtige Größe zur Untersuchung der Kernstruktur, da sie die Summe aller Wechselwirkungen im Atomkern widerspiegeln. Es gibt viele Möglichkeiten zur präzisen Massenmessung unter denen die Penningfalle die höchste Präzision erreicht. Darüber hinaus können damit absolute Massenmessungen unter Verwendung des atomaren Massenstandards Kohlenstoff als Referenz durchgeführt werden. Im Rahmen dieser Arbeit wurde das neue Doppel-Penningfallen-Massenspektrometer TRIGA-TRAP aufgebau...

  10. 8 CFR 1240.21 - Suspension of deportation and adjustment of status under section 244(a) of the Act (as in effect...

    Science.gov (United States)

    2010-01-01

    ... 240A(b) of the Act for certain nonpermanent residents. (a) Applicability of annual cap on suspension of deportation or cancellation of removal. (1) As used in this section, the term cap means the numerical... described in section 309(c)(5)(C)(i) of the Illegal Immigration Reform and Immigrant Responsibility...

  11. 8 CFR 240.21 - Suspension of deportation and adjustment of status under section 244(a) of the Act (as in effect...

    Science.gov (United States)

    2010-01-01

    ... nonpermanent residents. (a) Applicability of annual cap on suspension of deportation or cancellation of removal. (1) As used in this section, the term cap means the numerical limitation of 4,000 grants of...)(i) of the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA), as amended...

  12. El control territorial de la administración ugarítica: el ‘catastro’ TU 4.244

    OpenAIRE

    Zamora, José-Ángel

    2003-01-01

    Estudio ugarítico, y de aspectos de la administración ugarítica que de él se deducen, haciendo uso de los instrumentos informáticos que el homenajeado, Jesús-Luis Cunchillos, proporcionó a la especialidad.

  13. Distribution of sup 137 Cs, sup 90 Sr, sup 238 Pu, sup 239 Pu, sup 241 Am and sup 244 Cm in Pond B, Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, F.W. (Colorado State Univ., Fort Collins, CO (USA)); Pinder, J.E. III; Bowling, J.W. (Savannah River Ecology Lab., Aiken, SC (USA)); Alberts, J.J. (Georgia Univ., Sapelo Island, GA (USA). Marine Inst.); Brisbin, I.L. Jr. (Savannah River Ecology Lab., Aiken, SC (USA))

    1989-05-01

    The gradual senescence of present-day operating nuclear facilities, and resultant contamination of aquatic and terrestrial ecosystems, emphasize the importance of understanding the behavior of radionuclides in the environment. Observations and deductions concerning mechanisms of radionuclide transport can contribute significantly to knowledge of fundamental ecological processes. This study emphasized the ecosystem-level distribution of several long-lived radionuclides in an abandoned reactor cooling impoundment after a twenty year period of chemical and biological equilibration. 90 refs., 14 figs., 5 tabs.

  14. Integrated plant safety assessment systematic evaluation program. R.E. Ginna Nuclear Power Plant, Rochester Gas and Electric Corporation, Docket No. 50-244

    International Nuclear Information System (INIS)

    The Systematic Evaluation Program was initiated in February 1978 by the US Nuclear Regulatory Commission to review the designs of older operating nuclear reactor plants to reconfirm and document their safety. The review provides (1) an assessment of how these plants compare with current licensing safety requirements relating to selected issues, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety. This report documents the review of the R.E. Ginna Nuclear Power Plant (located in Wayne County near Rochester, NY), one of ten plants reviewed under Phase II of this program, and indicates how 137 topics selected for review under Phase I of the program were addressed. Equipment and procedural changes have been identified as a result of the review. It is expected that this report will be one of the bases in considering the issuance of a full-term operating license in place of the existing provisional operating license

  15. Large-Scale Wind Turbine Testing in the NASA 24.4m (80) by 36.6m(120) Wind Tunnel

    Science.gov (United States)

    Zell, Peter T.; Imprexia, Cliff (Technical Monitor)

    2000-01-01

    The 80- by 120-Foot Wind Tunnel at NASA Ames Research Center in California provides a unique capability to test large-scale wind turbines under controlled conditions. This special capability is now available for domestic and foreign entities wishing to test large-scale wind turbines. The presentation will focus on facility capabilities to perform wind turbine tests and typical research objectives for this type of testing.

  16. SU-E-J-244: Development and Validation of a Knowledge Based Planning Model for External Beam Radiation Therapy of Locally Advanced Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: The study aims to develop and validate a knowledge based planning (KBP) model for external beam radiation therapy of locally advanced non-small cell lung cancer (LA-NSCLC). Methods: RapidPlan™ technology was used to develop a lung KBP model. Plans from 65 patients with LA-NSCLC were used to train the model. 25 patients were treated with VMAT, and the other patients were treated with IMRT. Organs-at-risk (OARs) included right lung, left lung, heart, esophagus, and spinal cord. DVH and geometric distribution DVH were extracted from the treated plans. The model was trained using principal component analysis and step-wise multiple regression. Box plot and regression plot tools were used to identify geometric outliers and dosimetry outliers and help fine-tune the model. The validation was performed by (a) comparing predicted DVH boundaries to actual DVHs of 63 patients and (b) using an independent set of treatment planning data. Results: 63 out of 65 plans were included in the final KBP model with PTV volume ranging from 102.5cc to 1450.2cc. Total treatment dose prescription varied from 50Gy to 70Gy based on institutional guidelines. One patient was excluded due to geometric outlier where 2.18cc of spinal cord was included in PTV. The other patient was excluded due to dosimetric outlier where the dose sparing to spinal cord was heavily enforced in the clinical plan. Target volume, OAR volume, OAR overlap volume percentage to target, and OAR out-of-field volume were included in the trained model. Lungs and heart had two principal component scores of GEDVH, whereas spinal cord and esophagus had three in the final model. Predicted DVH band (mean ±1 standard deviation) represented 66.2±3.6% of all DVHs. Conclusion: A KBP model was developed and validated for radiotherapy of LA-NSCLC in a commercial treatment planning system. The clinical implementation may improve the consistency of IMRT/VMAT planning

  17. SU-E-J-244: Development and Validation of a Knowledge Based Planning Model for External Beam Radiation Therapy of Locally Advanced Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Kennedy, A [Sarah Cannon, Nashville, TN (United States); Larsen, E; Hayes, C; Grow, A [North Florida Cancer Center, Gainesville, FL (United States); Bahamondes, S.; Zheng, Y; Wu, X [JFK Comprehensive Cancer Institute, Lake Worth, FL (United States); Choi, M; Pai, S [Good Samaritan Hospital, Los Gatos, CA (United States); Li, J [Doctors Hospital of Augusta, Augusta, GA (United States); Cranford, K [Trident Medical Center, Charleston, SC (United States)

    2015-06-15

    Purpose: The study aims to develop and validate a knowledge based planning (KBP) model for external beam radiation therapy of locally advanced non-small cell lung cancer (LA-NSCLC). Methods: RapidPlan™ technology was used to develop a lung KBP model. Plans from 65 patients with LA-NSCLC were used to train the model. 25 patients were treated with VMAT, and the other patients were treated with IMRT. Organs-at-risk (OARs) included right lung, left lung, heart, esophagus, and spinal cord. DVH and geometric distribution DVH were extracted from the treated plans. The model was trained using principal component analysis and step-wise multiple regression. Box plot and regression plot tools were used to identify geometric outliers and dosimetry outliers and help fine-tune the model. The validation was performed by (a) comparing predicted DVH boundaries to actual DVHs of 63 patients and (b) using an independent set of treatment planning data. Results: 63 out of 65 plans were included in the final KBP model with PTV volume ranging from 102.5cc to 1450.2cc. Total treatment dose prescription varied from 50Gy to 70Gy based on institutional guidelines. One patient was excluded due to geometric outlier where 2.18cc of spinal cord was included in PTV. The other patient was excluded due to dosimetric outlier where the dose sparing to spinal cord was heavily enforced in the clinical plan. Target volume, OAR volume, OAR overlap volume percentage to target, and OAR out-of-field volume were included in the trained model. Lungs and heart had two principal component scores of GEDVH, whereas spinal cord and esophagus had three in the final model. Predicted DVH band (mean ±1 standard deviation) represented 66.2±3.6% of all DVHs. Conclusion: A KBP model was developed and validated for radiotherapy of LA-NSCLC in a commercial treatment planning system. The clinical implementation may improve the consistency of IMRT/VMAT planning.

  18. Phenotype and 244k array-CGH characterization of chromosome 13q deletions: an update of the phenotypic map of 13q21.1-qter

    DEFF Research Database (Denmark)

    Kirchhoff, Maria; Bisgaard, Anne-Marie; Stoeva, Radka;

    2009-01-01

    breakpoints in 14 patients with partial deletions of this region. Subsequently, we linked the genotype to the patient's phenotype. Using this approach, we were able to refine the smallest deletion region linked to short stature (13q31.3: 89.5-91.6 Mb), microcephaly (13q33.3-q34), cortical development...

  19. Impact of environmental curium on plutonium migration and isotopic signatures.

    Science.gov (United States)

    Kurosaki, Hiromu; Kaplan, Daniel I; Clark, Sue B

    2014-12-01

    Plutonium (Pu), americium (Am), and curium (Cm) activities were measured in sediments from a former radioactive waste disposal basin located on the Savannah River Site, South Carolina, and in subsurface aquifer sediments collected downgradient from the basin. In situ Kd values (Pu concentration ratio of sediment/groundwater) derived from this field data and previously reported groundwater concentration data compared well to laboratory Kd values reported in the literature. Pu isotopic signatures confirmed multiple sources of Pu contamination. The ratio of (240)Pu/(239)Pu was appreciably lower for sediment samples compared to the associated groundwater. This isotopic ratio difference may be explained by the following: (1) (240)Pu produced by decay of (244)Cm may exist predominantly in high oxidation states (Pu(V)O2(+) and Pu(VI)O2(2+)) compared to Pu derived from the disposed waste effluents, and (2) oxidized forms of Pu sorb less to sediments than reduced forms of Pu. Isotope-specific Kd values calculated from measured Pu activities in the sediments and groundwater indicated that (240)Pu, which is derived primarily from the decay of (244)Cm, had a value of 10 ± 2 mL g(-1), whereas (239)Pu originating from the waste effluents discharged at the site had a value of 101 ± 8 mL g(-1). One possible explanation for the isotope-specific sorption behavior is that (240)Pu likely existed in the weaker sorbing oxidation states, +5 or +6, than (239)Pu, which likely existed in the +3 or +4 oxidation states. Consequently, remediation strategies for radioactively contaminated systems must consider not only the discharged contaminants but also their decay products. In this case, mitigation of Cm as well as Pu will be required to completely address Pu migration from the source term. PMID:25350948

  20. Radiological and Environmental Research Division annual report, January-December 1981: ecology

    Energy Technology Data Exchange (ETDEWEB)

    1982-07-01

    Highlights of progress accomplished during the year ending December 1981 are presented. Some of the subjects discussed are: the effects of acid deposition on crop-soil systems; the effects of energy-related pollutants on crops, including field corn, which was found to be quite resistant to both O/sub 3/ and SO/sub 2/; the synergistic effects of SO/sub 2/ and NO/sub x/ on soybean productivity; the impact of acid rain on food crops and the dependence of these effects on the chemical composition of rain; the effects of acid rain on soil systems; /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 243/ /sup 244/Am in a core from the Saquenay Fjord, Quebec; rate of removal of natural thorium isotopes from Lake Michigan water; influence of colloidal dissolved organic carbon on the sorption of plutonium on natural sediments; the behavior of americium in natural waters; and near-bottom currents and sediment resuspension in Lake Michigan. Separate abstracts have been prepared for 12 reports for inclusion in the Energy Data Base. (RJC)

  1. Type B accident investigation board report of the July 2, 1997 curium intake by shredder operator at Building 513 Lawrence Livermore National Laboratory, Livermore, California. Final report

    International Nuclear Information System (INIS)

    On July 2, 1997 at approximately 6:00 A.M., two operators (Workers 1 and 2), wearing approved personal protective equipment (PPE), began a shredding operation of HEPA filters for volume reduction in Building 513 (B-513) at Lawrence Livermore National Laboratory (LLNL). The waste requisitions indicated they were shredding filters containing ≤ 1 μCi of americium-241 (Am-241). A third operator (Worker 3) provided support to the shredder operators in the shredding area (hot area) from a room that was adjacent to the shredding area (cold area). At Approximately 8:00 A.M., a fourth operator (Worker 4) relieved Worker 2 in the shredding operation. Sometime between 8:30 A.M. and 9:00 A.M., Worker 3 left the cold area to make a phone call and set off a hand and foot counter in Building 514. Upon discovering the contamination, the shredding operation was stopped and surveys were conducted in the shredder area. Surveys conducted on the workers found significant levels of contamination on their PPE and the exterior of their respirator cartridges. An exit survey of Worker 1 was conducted at approximately 10:05 A.M., and found contamination on his PPE, as well as on the exterior and interior of his respirator. Contamination was also found on his face, chest, back of neck, hair, knees, and mustache. A nose blow indicated significant contamination, which was later determined to be curium-244

  2. Effect of transplutonium doping on approach to long-life core in uranium-fueled PWR

    Energy Technology Data Exchange (ETDEWEB)

    Peryoga, Yoga; Saito, Masaki; Artisyuk, Vladimir [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors; Shmelev, Anatolii [Moscow Engineering Physics Institute, Moscow (Russian Federation)

    2002-08-01

    The present paper advertises doping of transplutonium isotopes as an essential measure to improve proliferation-resistance properties and burnup characteristics of UOX fuel for PWR. Among them {sup 241}Am might play the decisive role of burnable absorber to reduce the initial reactivity excess while the short-lived nuclides {sup 242}Cm and {sup 244}Cm decay into even plutonium isotopes, thus increasing the extent of denaturation for primary fissile {sup 239}Pu in the course of reactor operation. The doping composition corresponds to one discharged from a current PWR. For definiteness, the case identity is ascribed to atomic percentage of {sup 241}Am, and then the other transplutonium nuclide contents follow their ratio as in the PWR discharged fuel. The case of 1 at% doping to 20% enriched uranium oxide fuel shows the potential of achieving the burnup value of 100 GWd/tHM with about 20% {sup 238}Pu fraction at the end of irradiation. Since so far, americium and curium do not require special proliferation resistance measures, their doping to UOX would assist in introducing nuclear technology in developing countries with simultaneous reduction of accumulated minor actinides stockpiles. (author)

  3. Determination of Am and Cm in spent nuclear fuels by isotope dilution inductively coupled plasma mass spectrometry and isotope dilution thermal ionization mass spectrometry after separation by high-performance liquid chromatography

    International Nuclear Information System (INIS)

    Elemental and isotopic determination of americium and curium in spent nuclear fuels is necessary to validate neutronic calculation codes and for nuclear waste disposal purposes. Prior to mass spectrometric analysis, it is mandatory to perform separations in order to eliminate isobaric interferences between U, Pu, Am and Cm. In the spent fuels samples analyzed, a separation of U and Pu has been first realized with an anion-exchange resin. Then a rapid Am/Cm separation has been developed by high-performance liquid chromatography (HPLC) with an on-line detection using the Am and Cm α-emission. The influence of the different parameters on the chromatographic separation are described and discussed. Inductively coupled plasma mass spectrometry (ICP-MS) and thermal-ionization mass spectrometry (TIMS) have been used to measure the isotopic composition of U, Am and Cm and to determine the 241Am/238U and 244Cm/238U ratios with the double spike isotope dilution method. The measurement procedures and the accuracy and precision of the results obtained with a quadrupole ICP-MS on different spent fuels samples are discussed and compared with those obtained by TIMS, used as a reference technique. (orig.)

  4. Sorption of americium(III) and europium(III) from nitric acid solutions by a novel diglycolamide-grafted silica-based resins. Pt. 2. Sorption isotherms, column and radiolytic stability studies

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Seraj A.; Mohapatra, Prasanta K. [Bahabha Atomic Research Centre, Trombay, Mumbai (India). Radiochemistry Div.; Iqbal, Mudassir; Huskens, Jurriaan; Verboom, Willem [Twente Univ. (Netherlands). Lab. of Molecular Nanofabrication

    2014-07-01

    Two novel diglycolamide-grafted silica-based resins (DGSRs) were used for the sorption of trivalent actinides and lanthanides from 3 M nitric acid solutions. The sorption of Am(III) onto the resin containing one diglycolamide (DGA) moiety (DGSR-I) was less efficient than the resin containing two DGA moieties (DGSR-II) with Lagergren first order rate constants of (1.20 ± 0.03) x 10{sup -3}s{sup -1} and (2.01 ± 0.05) x 10{sup -3}s{sup -1}, respectively. The maximum sorption of Eu(III) (used as a representative of the trivalent lanthanide/actinide ions in radioactive wastes) was 10.4 ± 1.1 mg g{sup -1} and 13.9 ± 1.3 mg g{sup -1} by the DGSR-I and DGSR-II, respectively. The sorption of Eu(III) on the grafted silica resins followed the Langmuir monolayer sorption phenomenon with sorption energies of 16.5 ± 2.05 and 17.8 ± 1.6 kJ mol{sup -1} for DGSR-I and DGSR-II, respectively. Column experiments revealed that the breakthrough capacity of Eu(III) on the DGSR-II column was higher than that on the DGSR-I column. Efficient elution could be achieved with a 0.01 M EDTA solution. The radiolytic stability of the resins was ascertained by exposing the resins to a gamma ray dose up to 1030 kGy resulting in a decrease of the K{sub d} values with about 50%; at doses <500 kGy the K{sub d} values remained unaffected.

  5. Study of plutonium and americium contamination in agricultural area, radiological impact caused by consumption of vegetables of this area; Estudio de la contaminacion de plutonio y americio en un area agricola, impacto radiologico ocasionado por consumo de vegetales contaminados

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, Assuncion; Aragon, Antonio; Cruz, Berta de la; Gutierrez, Jose [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid (Spain). Dept. de Impacto Ambiental de la Energia

    2001-07-01

    The transuranide concentration has been studied for 30 years in vegetable production, crops in wide extensions and in private-owned farms, all of them situated within the Pu-contaminated area of Palomares due to an air accident in 1966. Based on these studies, a preliminary estimation of the radiological risk caused by the consumption of these products by the inhabitants was possible. The results show that most of the fruits present a surface contamination, which disappears or is significantly reduced when they are washed. The contamination present in edible parts of the vegetables, as well as the contamination of other products included in the diet, has facilitated the estimation of the effective dose for ingestion and the committed effective dose for 50 years for the inhabitants. The main conclusions are: those plants, whose cultivation period is less than a year, present a low level of contamination; the green parts of the plants have a higher contamination than the fruits; the Pu soil to plant transfer factor is very low. In general, those plants that have remained in the contaminated land for several years present a high contamination level; the ingestion of products from Palomares does not represent an important risk for the population, even in the case that the products were totally consumed by a critical group.( author)

  6. 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.)

  7. 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...

  8. Radiochemical determination of Np-237 in soil samples contaminated with weapon grade plutonium

    International Nuclear Information System (INIS)

    The Palomares terrestrial ecosystem (Andalusia, southwestern Spain) is known to constitute a natural laboratory to study the distribution, behaviour and migration of certain actinides, such as plutonium, americium and neptunium. This scenario is partially contaminated with weapon grade plutonium since the burn-out and fragmentation of two of the four thermonuclear bombs accidentally dropped by a B-52 from the USA Air Force back in 1966. While performing radiometric measurements on the field, with the goal of gathering information about the surface contamination levels, the possible presence of 237Np was observed through its 29 keV gamma emission. To accomplish a more detailed characterization of the source term in the contaminated area using the isotopic ratios Pu-Am-Np, the radiochemical isolation and later quantification by alpha spectrometry of 237Np was initiated. As a first approach, a bibliographic study was undertaken, considering different radiochemical methods applied to a variety of samples such as soils, sediments, sea water, lichens, etc. The radiochemical procedure selected in our laboratory involves separation of neptunium from americium, uranium and plutonium with ionic resin (AG 1x2), given that in soil samples from Palomares 239+240Pu levels are several orders of magnitude higher than 237Np. Then neptunium is isolated using TEVA organic resin. After electro-deposition, quantification is performed by high resolution alpha spectrometry. Different analyses have been performed with blank solutions spiked with 236Pu, 237Np and 244Cm, solutions resulting from the total dissolution of isolated radioactive particles and soil samples. The lack of an appropriate tracer in our lab led to the determination of an average percentage of Np recovery using a certified solution of 237Np. Decontamination percentages obtained during the Pu-Np separation ranged from 98 % to 100 %. Some tests to investigate the effect of the addition or absence of NaNO2 (responsible for

  9. Poly[[aqua(μ2-4,4′-bipyridine-κ2N:N′[μ3-3-bromo-2-(carboxylatomethylbenzoato-κ3O1:O1′:O2]cadmium] monohydrate

    Directory of Open Access Journals (Sweden)

    Yangmei Liu

    2012-08-01

    Full Text Available In the title compound, {[Cd(C9H5BrO4(C10H8N2(H2O]·H2O}n, the CdII atom has a distorted octahedral coordination geometry. Two N atoms from two 4,4′-bipyridine (bipy ligands occupy the axial positions, while the equatorial positions are furnished by three carboxylate O atoms from three 3-bromo-2-(carboxylatomethylbenzoate (bcb ligands and one O atom from a water molecule. The bipy and bcb ligands link the CdII atoms into a three-dimensional network. O—H...O hydrogen bonds and π–π interactions between the pyridine and benzene rings [centroid–centroid distance = 3.736 (4 Å] are present in the crystal.

  10. Non-Metallic Biomaterials for Tooth Repair and Replacement. By Pekka Vallittu, Woodhead Publishing, 2013; 406 pages. Price £145.00/US$245.00/€175.00 ISBN 978-0-85709-244-1

    Directory of Open Access Journals (Sweden)

    Shu-Kun Lin

    2013-01-01

    Full Text Available 1. Discusses the properties of enamel and dentin and their role in adhesive dental restoration;2. Chapters also examine the wear properties of dental ceramics, glasses and bioactive glass ceramics for tooth repair and replacement;3. Dental composites and antibacterial restorative materials are also considered;4. Provides a concise overview of non-metallic biomaterials for dental clinicians, materials scientists and academic researchers alike.As the demand for healthy, attractive teeth increases, the methods and materials employed in restorative dentistry have become progressively more advanced. Non-metallic biomaterials for tooth repair and replacement focuses on the use of biomaterials for a range of applications in tooth repair and, in particular, dental restoration.

  11. SU-E-J-244: Validation of a 6D-Robotic-Couch and Image Guidance Radiation Therapy (IGRT) System for Localization in World's First Single-Room Proton Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Rankine, L; Klein, E [Washington University, Saint Louis, MO (United States); Grantham, K [University of Missouri, Columbia, MO (United States); Goddu, S [Washington University, St. Louis, MO (United States); Cessac, R [Mevion Medical Systems, Littleton, MA (United States); Baker, K [Barne-Jewish Hospital, St. Louis, MO (United States); Santanam, L [Washington University School of Medicine, St.louis, MO (United States)

    2014-06-01

    Purpose: The Mevion S250 proton therapy unit is equipped with a 6D-robotic couch and IGRT system (Verity). The patient alignment process allows corrections in six degrees of freedom: translation (x,y,z), pitch, roll, and yaw (θ,ϑ,ψ). Geometric accuracy of couch corrections and imaging vs. radiation isocenter coincidence were quantified before clinical implementation. Methods: A commercial phantom with sixteen 2mm tungsten BBs was rigidly couch-mounted and imaged with CT. Seventeen rigid translations/rotations of known magnitude were digitally applied to the original CT image using commercial software, validated with Varian OBI system. For each altered image, phantom was mounted on robotic couch in original position, then Verity 2D:2D match (PA-LLAT) was performed using DRRs from altered images. Corrections were recorded and applied, phantom was imaged a second time and residual corrections recorded. Physical measurements verified that applied couch corrections coincided with both physical couch shifts/rotations and known CT image translations/rotations. Additionally, image vs. radiation isocenter coicidence was quantified over couch treatment angles (±90° from setup position) using radiochromic film and an image-guided couch star-shot. Posterior-anterior and left-lateral kV radiographs were taken before each beam was delivered to verify imaging/radiation isocentricity. Results: Verity suggested couch corrections and known CT shifts/rotations agreed within ±1mm (average: Δ lat=0.5mm; Δ vert=0.4mm; Δ long=0.3mm) and ± 0.4° (average: Δ pitch=0.24° Δ roll=0.01°; Δ yaw=0.10°). Physical couch measurements and Verity applied corrections agreed within ± 1mm (average: Δlat=0.5mm; Δvert=0.4mm; Δlong=0.2mm) and ±0.2° (average: Δpitch=0.03°; Δ roll=0.04°; Δ yaw=0.04°). The directionality of all translations and rotations were qualitatively verified. The image vs. radiation isocenter coincidence was <1mm and radiation-isocenter precision was <1mm over the 180° of couch motion, as indicated by film analysis. Conclusion: The Verity IGRT software and 6D-couch combination on the Mevion S250 was verified as accurate within 1mm and 0.5°. This complies with the TG-142 standards for a stereotactic radiotherapy IGRT system. Rob Cessac is employed as Product Manager for Mevion Medical Systems.

  12. catena-Poly[[bis(μ2-4-aminobenzenesulfonato-κ2O:Odisilver]-bis(μ2-4,4′-bipyridine-κ2N:N′

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Dai

    2008-12-01

    Full Text Available In the title compound, [Ag2(C6H6NO3S2(C10H8N22]n, the AgI atom is four-coordinated by two N atoms from two symmetry-related 4,4′-bipyridine (bipy and two O atoms from two independent 4-aminobenzenesulfonate (ABS ligands. The two inter-chain AgI atoms are bridged by two independent ABS ligands through weak Ag—O bonds and Ag...Ag attractions, forming a ladder-like chain coordination polymer [Ag2(ABS2(bipy2]n parallel to [001], which is further linked to generate a two-dimensional structure via N—H...O hydrogen-bonding interactions.

  13. Crystal structure of (E)-2-[4-(4-hy­droxy­phen­yl)butan-2-yl­idene]hydrazine-1-carbo­thio­amide

    Science.gov (United States)

    de Oliveira, Adriano Bof; Beck, Johannes; Landvogt, Christian; Feitosa, Bárbara Regina Santos; Rocha, Fillipe Vieira

    2015-01-01

    The title compound, C11H15N3OS, is a thio­semicarbazone derivative of the raspberry ketone rheosmin [systematic name: 4-(4-hy­droxy­phen­yl)butane-2-one]. The mol­ecule deviates from planarity, with the bridging C—C—C=N torsion angle equal to −101.3 (2)°. The maximum deviation from the mean plane of the non-H atoms of the thio­semicarbazone fragment [C=N—N—C(= S)—N] is 0.085 (5) Å for the Schiff base N atom, and the dihedral angle between this mean plane and the aromatic ring is 50.31 (8)°. In the crystal, mol­ecules are linked by N—H⋯O, N—H⋯S and O—H⋯S hydrogen bonds, forming a three-dimensional structure, with the mol­ecules stacked along [011]. PMID:25705493

  14. Multibeam collection for TN244: Multibeam data collected aboard Thomas G. Thompson from 2009-12-05 to 2009-12-08, departing from Seattle, WA and returning to Seattle, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is part of a larger set of data called the Multibeam Bathymetry Database (MBBDB) where other similar data can be found at...

  15. Supported liquid inorganic membranes for nuclear waste separation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. 241Am (n,gamma) isomer ratio measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Evelyn M [Los Alamos National Laboratory; Vieira, David J [Los Alamos National Laboratory; Moody, Walter A [Los Alamos National Laboratory; Slemmons, Alice K [Los Alamos National Laboratory

    2011-01-05

    The objective of this project is to improve the accuracy of the {sup 242}Cm/{sup 241}Am radiochemistry ratio. We have performed an activation experiment to measure the {sup 241}Am(n,{gamma}) cross section leading to either the ground state of {sup 242g}Am (t{sub 1/2} = 16 hr) which decays to {sup 242}Cm (t{sub 1/2} = 163 d) or the long-lived isomer {sup 242m}Am (t{sub 1/2} = 141 yr). This experiment will develop a new set of americium cross section evaluations that can be used with a measured {sup 242}Cm/{sup 241}Am radiochemical measurement for nuclear forensic purposes. This measurement is necessary to interpret the {sup 242}Cm/{sup 241}Am ratio because a good measurement of this neutron capture isomer ratio for {sup 241}Am does not exist. The targets were prepared in 2007 from {sup 241}Am purified from LANL stocks. Gold was added to the purified {sup 241}Am as an internal neutron fluence monitor. These targets were placed into a holder, packaged, and shipped to Forschungszentrum Karlsruhe, where they were irradiated at their Van de Graff facility in February 2008. One target was irradiated with {approx}25 keV quasimonoenergetic neutrons produced by the {sup 7}Li(p,n) reaction for 3 days and a second target was also irradiated for 3 days with {approx}500 keV neutrons. Because it will be necessary to separate the {sup 242}Cm from the {sup 241}Am in order to measure the amount of {sup 242}Cm by alpha spectrometry, research into methods for americium/curium separations were conducted concurrently. We found that anion exchange chromatography in methanol/nitric acid solutions produced good separations that could be completed in one day resulting in a sample with no residue. The samples were returned from Germany in July 2009 and were counted by gamma spectrometry. Chemical separations have commenced on the blank sample. Each sample will be spiked with {sup 244}Cm, dissolved and digested in nitric acid solutions. One third of each sample will be processed at a time

  17. Application of a gamma spectroscopy system to the measurement of neutron cross sections necessary to the development of nuclear energy; Mise au point d'un systeme de spectroscopie pour mesurer des sections efficaces neutroniques applicables a un possible developpement du nucleaire comme source d'energie

    Energy Technology Data Exchange (ETDEWEB)

    Deruelle, O

    2002-09-01

    This work concerns the development of nuclear energy and nuclear waste management in particular. Two parts of this study can be distinguished. In the first part (theoretical), a thorium-plutonium fuel based on MOX and dedicated for PWR was investigated in order to transmute plutonium in a potentially low waste fuel cycle. It was shown that this type of fuel is not regenerative but could be used for a transition to the industrial thorium fuel cycle without building new reactors. Thanks to moderated neutron spectra and high loaded actinide mass in the core, U-233 is quickly created ({approx}300 kg/y) for a loss of about {approx}1200 kg of fissile plutonium. In the second part (experimental), we have developed and built a new reaction chamber to measure neutron cross sections of actinides by alpha-gamma spectroscopy. This experimental device (in principle transportable) was commissioned in the high flux reactor of ILL Grenoble. Neutron flux was measured by gamma spectroscopy of irradiated Al and Co samples and was found to be of the order of 6,0. 10{sup 14} n.cm{sup -2}.s{sup -1} (4%). By the irradiation of 11{mu}g of Am-243 and Pu-242, corresponding capture cross sections were measured in the thermal neutron flux at 50 deg C. These are the results: {sup 243}Am(n,{gamma}) {sup 244fond.}Am = 4,72{+-}1,42b; {sup 243}Am(n,{gamma}) {sup 244total}Am = 74,8{+-}3,25b; {sup 242}Pu (n,{gamma}){sup 243}Pu = 22,7{+-}1,09b. Uncertainties of the measurements are mostly due to the determination of the neutron flux, efficiency of the electronics and ambiguities related to the definition of the area under {alpha}-{gamma} spectra. Although our measured cross sections deviate (by 10-30%) from the corresponding values widely used in evaluated data libraries such as ENDF, JEF and JENDL, in this work we have demonstrated the feasibility and principle of our experimental method. Furthermore, the value for the 243-americium capture cross-section is in very good agreement with the last two

  18. Highly enriched isotope samples of uranium and transuranium elements for scientific investigation

    Science.gov (United States)

    Vesnovskii, Stanislav P.; Polynov, Vladimir N.; Danilin, Lev. D.

    1992-02-01

    The paper describes the production of highly enriched isotopes of uranium, plutonium, americium and curium by electromagnetic separation for scientific and applied researches in physics, chemistry, geology, medicine, biology and other fields. Using the equipment described, the isotopes are produced in quantities sufficient to set up nuclear physical experiments, to produce nuclear reference materials and standard sources for calibration of radiometrical and mass spectrometrical equipment, in radionuclide metrology, etc. For the following isotopes the indicated degrees of isotopic enrichment were achieved: 233U - 99.97%; 235U - 99.97%; 236U - 98.0%; 238U - 99.997%; 238Pu - 99.6%; 239Pu - 99.9977%; 240Pu - 99.9-100%; 241Pu - 96.998%; 242Pu - 97.8-99.96%; 244Pu - 96.7%; 241Am - 99.6%; 242Am - 73.6%; 243Am - 99.2-99.94%; 243Cm - 99.99%; 245Cm - 99.998%; 246Cm - 99.8%; 247Cm - 90%; 248Cm - 97%. Methods for preparing layers of highly enriched isotopes on various substances are presented: - electrochemical deposition of transuranic elements from aqueous-organic and organic media and vacuum spraying: - the method of foil and coating formation via compounds in the vapour phase; - the method of fabrication of layers of transuranic elements on superthin (1-2 μm) metal substrates with additional isolating polymer-metal coatings (0.2-0.4 μm), that substantially decrease material transfer from the active layer and increase safety of product handling.

  19. 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....

  20. Process for cleaning a nitric acid U/Pu-solution

    International Nuclear Information System (INIS)

    The impure starting solution is passed through a cation exchange column following oxidation of the U/Pu ions present to the hexavalent state. Here the impurities, in particular Americium, are retained and after subsequent elution are handled by known waste treatments or waste utilization (Americium). (orig.)

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

    International Nuclear Information System (INIS)

    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

  2. Industrial research for transmutation scenarios

    Science.gov (United States)

    Camarcat, Noel; Garzenne, Claude; Le Mer, Joël; Leroyer, Hadrien; Desroches, Estelle; Delbecq, Jean-Michel

    2011-04-01

    This article presents the results of research scenarios for americium transmutation in a 22nd century French nuclear fleet, using sodium fast breeder reactors. We benchmark the americium transmutation benefits and drawbacks with a reference case consisting of a hypothetical 60 GWe fleet of pure plutonium breeders. The fluxes in the various parts of the cycle (reactors, fabrication plants, reprocessing plants and underground disposals) are calculated using EDF's suite of codes, comparable in capabilities to those of other research facilities. We study underground thermal heat load reduction due to americium partitioning and repository area minimization. We endeavor to estimate the increased technical complexity of surface facilities to handle the americium fluxes in special fuel fabrication plants, americium fast burners, special reprocessing shops, handling equipments and transport casks between those facilities.

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

    Energy Technology Data Exchange (ETDEWEB)

    Miner, F. J.

    1979-08-30

    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.

  4. Effect of industrial pollution on the distribution of Pu and Am in soil and on soil-to-plant transfer of Pu and Am in a pine forest in SW Finland

    International Nuclear Information System (INIS)

    The effect of industrial pollution on the behavior of plutonium and americium was evaluated in a pine forest in the vicinity of a Cu-Ni smelter in SW Finland. Soil and vegetation were sampled at distances of 0.5, 2, 4 and 8 km from the smelter. The vertical distribution of plutonium and americium was studied in litter, organic layer and mineral layers. The amount of Pu and Am in the litter layer increased and that in the organic layer decreased towards the smelter. Concentrations of plutonium and americium in different vegetation species decreased in the order mushrooms > lichens (Cladina spp., Cetraria islandica) > Empetrum nigrum > Vaccinium vitis-idaea. (author)

  5. Alpha self-irradiation effects in ternary oxides of actinides elements: The zircon-like phases AmIIIVO4 and AIINpIV(VO4)2 (A=Sr, Pb)

    International Nuclear Information System (INIS)

    We report the experimental studies of irradiation damage from alpha decay in neptunium and americium vanadates versus cumulative dose. The isotopes used were the transuranium α-emitter 237Np and the α,γ-emitter 241Am. Neptunium and americium vanadates self-irradiation was studied by X-ray diffraction method (XRD). The comparison of the powder diffraction patterns reveal that the irradiation has no apparent effect on the neptunium phases while the americium vanadate swells and becomes metamict as a function of cumulative dose

  6. 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.

  7. 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.

  8. A final report for: Gallium arsenide P-I-N detectors for high-sensitivity imaging of thermal neutrons

    International Nuclear Information System (INIS)

    This SBIR Phase I developed neutron detectors made FR-om gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the FR-ont surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed FR-om a layer of AlxGa1-xAs. Schottky-barrier diodes formed FR-om the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The lowest dark current measured is 1 x 10-12 amps at -1 V on a 3mm x 3mm diode, or a density of 1.1 x 10-11 amps cm-2, with many of the diode structures tested having nearly similar results. The PIN diodes were significantly better than the Schottky barrier device, which had six orders of magnitude higher dark current. Diodes were characterized in terms of their current-mode response to 5.5 MeV alpha particles FR-om 241-Americium. These radiation-induced currents were as high as 9.78 x 10-7 A cm-1 on a PIN device with an AlxGa1-xAs BSF. Simple PIN diodes had currents as high as 2.44 x 10-7 A cm-2, with thicker undoped layers showing better sensitivity. Boron coatings were applied, and response to neutrons tested at University of Michigan by Dr. Doug McGregor. Devices with PIN and Schottky barrier designs showed neutron detection efficiencies as high as 2% on 5 (micro)m thick devices, with no need for external bias voltages. PIN diodes showed higher breakdown voltages and lower noise characteristics than did the Schottky barrier design. Uniformity of

  9. Chemistry research and development. Progress report, November 1978-April 1979

    International Nuclear Information System (INIS)

    The status of the following studies is given: calorimetry and thermodynamics of nuclear materials; americium recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten net extraction residues; evaluation and comparison of bidentate extractants and methods for actinide recovery; a combined anion exchange-bidontate organophosphorus extraction process for molten salt extraction residues; a combined anion exchange-extraction chromatography technique for secondary recovery; plutonium recovery in the Advanced Size Reduction Facility; decontamination of Rocky Flats soil; separating lead and calcium from americium by chromate and oxalate precipitation; demonstration of the pyroredox process in the induction-heated, tilt-pour furnace; process development for recovery of americium from vacuum melt furnace crucibles; plutonium peroxide precipitation process; and a comparative study of annular and Raschig ring-filled tanks

  10. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    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 62- from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO3-4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO3 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

  11. Medical grade 238Pu from 241Am: progress report

    International Nuclear Information System (INIS)

    Shielding requirements for fabrication of americium targets were evaluated, a preliminary flowsheet for processing the irradiated Am targets was developed, and the AMRAD computer program, which models the irradiation cycle, was improved

  12. 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).

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

    International Nuclear Information System (INIS)

    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.)

  14. Literatuuronderzoek plutoniumanalyses

    NARCIS (Netherlands)

    Glastra P; Kwakman PJM; LSO

    1997-01-01

    Dit rapport beschrijft de laatste ontwikkelingen in de radiochemische bepaling van plutonium in monstermatrices zoals luchtstoffilters, regenwater, gras en bodem. De radiochemische scheiding van plutonium van storende alfastralers, zoals americium en curium, is door de recente ontwikkeling van spec

  15. Ascophyllum nodosum (L.) Le Jolis as a bioindicator of radioactivity in the Irish Sea

    OpenAIRE

    Bourne, G S; Assinder, D J

    1991-01-01

    The response of Ascophyllum nodosum to a sudden increase in radioactivity analogous to a nuclear incident is examined in the field. super(137)Cs, super(241)Am and super(239+240)Pu showed net accumulation with exposure time, unlike natural super(228)Th, which was used as a control. Caesium had the highest accumulation rate followed by americium and finally plutonium. Younger plant sections were found to accumulate all the radionuclides significantly faster than older plant sections. Americium ...

  16. Sorption studies of radioelements on geological materials

    OpenAIRE

    Berry, J. A; 油井 三和; 北村 暁

    2007-01-01

    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 ...

  17. Hybrid chemical and nondestructive analysis technique

    International Nuclear Information System (INIS)

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities

  18. Miniature DIAMEX processes in a hollow fibre module micro-plant: process development and optimisation

    International Nuclear Information System (INIS)

    A hollow fibre module (HFM) micro-plant was built to perform continuous liquid-liquid extraction tests with very small feed volumes, using miniature HFM as phase contactors. Spiked DIAMEX tests (i.e., co-extraction of americium, curium, and lanthanides from PUREX raffinate) were performed in this plant. Following some flow sheet modifications, raffinate decontamination factors of up to 30 000 and 900 were achieved for americium and curium, respectively. (orig.)

  19. Hybrid chemical and nondestructive-analysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Hsue, S.T.; Marsh, S.F.; Marks, T.

    1982-01-01

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities.

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

    International Nuclear Information System (INIS)

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

  1. Dicty_cDB: Contig-U10474-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available t = 1e-83 Identities = 244/244 (100%) Strand = Plus / Plus Query: 17 ctttcncatggggatatngnagctaaagntanaaaanatttatccna...|||| Sbjct: 17 ctttcncatggggatatngnagctaaagntanaaaanatttatccnatggnaaaaatnaa 76 Query: 77 aacccacntgcnnaacata...aattattnccccccatcnttagnctatccctaggnccnaaa 136 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| S...bjct: 77 aacccacntgcnnaacataaattattnccccccatcnttagnctatccctaggnccnaaa 136 Query: ...ngnagctaaagntanaaaanatttatccnatggnaaaaatnaa 76 ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

  2. AM(VI) PARTITIONING STUDIES: FY14 FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J Mincher

    2014-10-01

    The use of higher oxidation states of americium in partitioning from the lanthanides is under continued investigation by the sigma team. This is based on the hypothesis that Am(VI) can be produced and remain stable in irradiated first cycle raffinate solution long enough to perform solvent extraction for separations. The stability of Am(VI) to autoreduction was measured using millimolar americium concentrations in a 1-cm cell with a Cary 6000 UV/Vis spectrophotometer for data acquisition. At millimolar americium concentrations, Am(VI) is stable enough against its own autoreduction for separations purposes. A second major accomplishment during FY14 was the hot test. Americium oxidation and extraction was performed using a centrifugal contactor-based test bed consisting of an extraction stage and two stripping stages. Sixty-three percent americium extraction was obtained in one extraction stage, in agreement with batch contacts. Promising electrochemical oxidation results have also been obtained, using terpyridine ligand derivatized electrodes for binding of Am(III). Approximately 50 % of the Am(III) was oxidized to Am(V) over the course of 1 hour. It is believed that this is the first demonstration of the electrolytic oxidation of americium in a non-complexing solution. Finally, an initial investigation of Am(VI) extraction using diethylhexylbutyramide (DEHBA) was performed.

  3. Distribution of 239Pu and 241Am in the human skeleton

    International Nuclear Information System (INIS)

    The 241Am and 239Pu distribution in the skeletons of two former nuclear workers has been measured. The skeletons of both individuals appear to be within normal limits for Caucasian men about 50 y old. Both had lower limb bones that were heavier than the age controls and Case I had upper-body bones that were lighter than the age control group. The distribution of americium in the skeleton of Case I, 25 years post exposure, indicated that a more rapid turnover of initially deposited americium on the bone surfaces of cancellous bone, as compared to that deposited on the bone surfaces of compact bone, had occurred. This resulted in a larger proportion of americium located in the compact bone of the extremities and a lesser quantity in the more cancellous bones of the vertebral column, pelvis and rib cage. A similar shift in the distribution of plutonium occurred in Case II in the 35 y since initial deposition, but at a slower rate than that for americium. The ratio of each actinide in the liver to that in the systemic system (liver content/systemic system content) was 0.065 and 0.436, for americium and plutonium, respectively, suggesting that a much more rapid turnover of americium in the liver, compared to plutonium, provided a much larger fraction of that nuclide for circulatory feedback to the remodeling skeletal system. 8 references, 3 tables

  4. 77 FR 18260 - Outer Continental Shelf (OCS), Alaska OCS Region, Cook Inlet Planning Area, Proposed Oil and Gas...

    Science.gov (United States)

    2012-03-27

    ... Sale 244 in 2013 in the Cook Inlet Planning Area, whether focused on a few blocks or prospects, or on a... Area, Proposed Oil and Gas Lease Sale 244 for OCS Oil and Gas Leasing Program 2012-2017 AGENCY: Bureau... Proposed OCS Oil and Gas Leasing Program for 2012-2017 (Proposed Program) identifies Sale 244 as...

  5. Radiation protection - radionuclides - Synthesis sheets: Thorium-232 (ED 4317), Gallium-67 (ED 4314), Indium-111 (ED 4315), Chromium-51 (ED 4313), Thallium-201 (ED 4312), Phosphorus-33 (ED 4316), Fluorine- 18 (ED 4311), Yttrium-90 (ED 4310), Americium-241 (ED 4308), Strontium-90 (ED 4309), Sulfur-35 (ED 4307), Iodine-125 (ED 4306), Phosphorus-32 (ED 4305), Iodine-123 (ED 4304), Tritium (ED 4303), Carbon-14 (ED 4302), Technetium-99m (ED 4301), Iodine-131 (ED 4300)

    International Nuclear Information System (INIS)

    For each radionuclide, this document presents its characteristics (origin, radio-physical properties, biological properties), gives an overview of its uses, indicates and discusses its dosimetric parameters (for internal or external exposure), indicates radiation detection and contamination measurement techniques, gives an overview of means of protection (for premises, against external or internal exposure), describes the delimitation and control of premises, describes aspects related to personnel classification, training and medical monitoring, comments the issue of effluents and wastes, indicates administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources, addresses the issue of transport, and describes what is to be done in case of incident or accident

  6. Porous metal oxide microspheres from ion exchange resin

    Science.gov (United States)

    Picart, S.; Parant, P.; Caisso, M.; Remy, E.; Mokhtari, H.; Jobelin, I.; Bayle, J. P.; Martin, C. L.; Blanchart, P.; Ayral, A.; Delahaye, T.

    2015-07-01

    This study is devoted to the synthesis and the characterization of porous metal oxide microsphere from metal loaded ion exchange resin. Their application concerns the fabrication of uranium-americium oxide pellets using the powder-free process called Calcined Resin Microsphere Pelletization (CRMP). Those mixed oxide ceramics are one of the materials envisaged for americium transmutation in sodium fast neutron reactors. The advantage of such microsphere precursor compared to classical oxide powder is the diminution of the risk of fine dissemination which can be critical for the handling of highly radioactive powders such as americium based oxides and the improvement of flowability for the filling of compaction chamber. Those millimetric oxide microspheres incorporating uranium and americium were synthesized and characterizations showed a very porous microstructure very brittle in nature which occurred to be adapted to shaping by compaction. Studies allowed to determine an optimal heat treatment with calcination temperature comprised between 700-800 °C and temperature rate lower than 2 °C/min. Oxide Precursors were die-pressed into pellets and then sintered under air to form regular ceramic pellets of 95% of theoretical density (TD) and of homogeneous microstructure. This study validated thus the scientific feasibility of the CRMP process to prepare bearing americium target in a powder free manner.

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

    Indian Academy of Sciences (India)

    B P Kochurov; V N Konev; A Yu Kwaretzkheli

    2007-02-01

    Characteristics of the equilibrium fuel cycle for the core or a blanket of ADS having the structure of the core of a fast lead-cooled reactor of type BREST (Russian abbreviation for `Bystryy Reaktor so Svintsovym Teplonositelem') in a mode of americium transmutation are calculated. Americium loading was taken 5% of heavy atoms. Keeping the average multiplication factor the same as in a standard equilibrium cycle, reactivity swing over 1 year's microcycle is about 1%, that demands partial fuel reloading with a periodicity of about one month. 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 system of 1 GWt (thermal), 87 kg of americium can be transmuted yearly. The estimate of the reactivity void effect has shown that it increases to 0.6% almost linearly with the void fraction increasing up to 25% and reaches its maximum of 0.7% at a void fraction 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.

  8. Development of reduction technology for oxide fuels. Lithium reduction of a simulated spent oxide fuel

    International Nuclear Information System (INIS)

    The mixed oxide pellet was reduced with lithium metal in molten lithium chloride at 923 K. The pellet was a sintered product meant to simulate spent oxide fuel containing twelve elements, which are uranium, plutonium, americium, neptunium, curium, cerium, neodymium, samarium, barium, zirconium, molybdenum, and palladium. The pellet remained intact during the reaction and most of lithium oxide, which is the by-product, dissolved in the molten salt. More than 95% of the uranium and plutonium were reduced to metal, while rare-earth elements formed an oxide solid solution in the pellet. Several percent of the initial amount of plutonium and americium was exuded from the pellet and precipitated on the bottom of the crucible. That is different from the result of the previous reduction test using a MOX (uranium-plutonium-americium ternary) pellet in which approximately 80% of the americium was exuded. The exudation of americium is considered to be suppressed by the formation of solid solution with rare-earth oxides. 10 to 30% of rare earth elements were exuded and dissolved in the molten salt. The concentrations of cerium and neodymium in the salt were consistent with the values which were calculated thermodynamically using their solubilities in lithium chloride-lithium oxide mixed molten salt. Most of the barium dissolved in the molten salt as a chloride; on the other hand, palladium remained in the pellet to form an alloy with plutonium. (author)

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

    International Nuclear Information System (INIS)

    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 HNO3 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)

  10. Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers

    International Nuclear Information System (INIS)

    Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered from the solution using a magnet. Physical and chemical characterization of the extractant-absorbed particles were performed by gamma and liquid scintillation counting, scanning electron microscopic (SEM) micrograph, and other physical measurements. Plutonium, americium, and uranium separations have been performed at various HNO3 and HCl concentrations. Parameters were studied to determine the limitations and capacity of the process. The status of the chemistry and application of the process to Department of Energy (DOE) remediation efforts for actinide decontamination are discussed

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

    CERN Document Server

    Sors, M

    1999-01-01

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

  12. 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.; ten Brink, Marilyn Buchholtz

    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.

  13. 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)

    This report presents the results of a study on the effects of temperatures up to 900C 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.)

  14. Dicty_cDB: Contig-U09533-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 000581 |pid:none) Ostreococcus lucimarinus CCE9901... 231 3e-59 AF252391_1( AF252391 |pid:none) Sporothrix s..._1( AF116453 |pid:none) Sporothrix schenckii cyclin-depend... 244 6e-63 AY815214_...ycle 2... 244 4e-63 A42823( A42823 )cell division control-related protein kinase p58cl... 244 4e-63 AF116453

  15. Isolating 241Am from waste solutions containing Al, Ca, Fe, and Cr

    International Nuclear Information System (INIS)

    About 2.4 kg of 241Am contaminated with calcium and aluminum had been recovered from low-activity waste during recycle of 11% 240Pu. A process was developed and demonstrated to purify the americium before shipment as 241AmO2. The americium and some of the calcium were batch extracted into 50% TBP-n-paraffin from 2.2M Al(NO3)3 - 0.3M HNO3 solution in a canyon tank. Pregnant solvent was scrubbed first with 2.1M Al3+-0.3M Li+-6.7M NO3- and then with 7M LiNO3 to reduce the calcium content and to displace the aluminum. Americium was then stripped from the solvent with water and concentrated by evaporation. Before precipitating the americium with oxalic acid, the nitric acid was adjusted with NH4OH to yield a 1M NH4NO3 solution. Recovery across the batch extraction step was 97.8%, while 93% of the calcium and >99% of the aluminum was rejected. Recovery across precipitation averaged >96% while producing a product which was >99.3% pure 241AmO2. The major impurities were water, carbon, calcium, iron, and zinc

  16. 75 FR 34774 - Notice of Availability of Environmental Assessment and Finding of No Significant Impact for...

    Science.gov (United States)

    2010-06-18

    ...-lives greater than 120 days: Barium 133, cesium 137, americium 241, and uranium 238. Prior to performing... 20 for unrestricted release. Because NRC has not established a screening value for barium 133, the licensee developed a DCGL for barium 133 for its Facility. The Licensee developed the barium 133 DCGL...

  17. Coordination chemistry of several radius-sensitive complexones and applications to lanthanide-actinide separations

    International Nuclear Information System (INIS)

    The relationships between the lanthanide complex formation equilibria and the lanthanide-actinide separation application of three radius sensitive ligands have been studied. The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of DHDMB and the tripositive lanthanides and yttrium were determined potentiometrically at 0.1 M ionic strength and 250C. Results indicate that three different coordination modes, one tridentate and two bidentate are in evidence. Tracer level 241Am - 155Eu cation-exchange experiments utilizing DHDMB eluents indicate that this dihydroxycarboxylate does not form a sufficiently strong americium complex to elute that actinide ahead of europium. The overall stability of the americium 3:1 complex appears intermediate between samarium and europium. Cation-exchange elutions of 241Am, 155Eu, and 160Tb mixtures with EEDTA solutions prove that the EEDTA ligand is capable of eluting americium ahead of all of the tripositive lanthanide cations. The minimum separation occurs with terbium, where the Am-Tb separation factor is 1.71. 1,5-diaminopentane-N,N,N',N'-tetraacetic acid (PMDTA) was synthesized using cation exchange. A mathematical method was developed for the formation constants of the protonated and unprotonated lanthanide-PMDTA complexes from potentiometry. Cation-exchange elutions of tracer quantities of Am, Eu, and Tb revealed that terbium is eluted ahead of both americium and europium

  18. 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

  19. Report on the scientifical feasibility of advanced separation

    International Nuclear Information System (INIS)

    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.)

  20. Estimates of dose to systematic organs and GI tract based on data from miniature swine orally intubated with a single dose of Am-241 citrate

    International Nuclear Information System (INIS)

    A model is presented for the internal radiation dose to the small intestine wall of miniature swine given Americium 241 citrate by oral intubation. The model incorporates the uptake of the Am-241 by the intestinal wall. About equal contributions of dose to the small intestine were observed from the intestinal contents and the wall itself

  1. 10 CFR Appendix E to Part 20 - Nationally Tracked Source Thresholds

    Science.gov (United States)

    2010-01-01

    ... Category 1(TBq) Category 1(Ci) Category 2(TBq) Category 2(Ci) Actinium-227 20 540 0.2 5.4 Americium-241 60... 2 54 Strontium-90 1,000 27,000 10 270 Thorium-228 20 540 0.2 5.4 Thorium-229 20 540 0.2 5.4...

  2. Isotopic ratios and effective power determined by gamma-ray spectroscopy vs mass spectroscopy for molten salt extraction residues

    International Nuclear Information System (INIS)

    Impure plutonium metal is routinely processed by molten salt extraction (MSE) to reduce the amount of americium in the metal product. Throughput at various facilities where similar processes are performed has made it essential to evaluate uncertainties and possible discrepancies in the analyses of these difficult MSE materials. In an effort to evaluate the plutonium isotopic ratios and americium concentrations obtained from gamma-ray spectral data analyzed by the computer code GRPAUT, measurements were made on ten MSE salts as received and after pulverization and blending. These results were then compared to the specific powers obtained from isotopic ratios determined by mass spectrometry on these same ten samples. Americium values ranged from a few thousand parts-per-million of total plutonium to greater than 50,000 ppM. Our results indicate a small discrepancy between specific powers as determined by GRPAUT on ''as received'' vs pulverized and blended MSE salts. The specific powers obtained via GRPAUT on the pulverized salts agree somewhat better with specific powers obtained from the mass spectroscopy data. This work may indicate that a small discrepancy exists in the specific powers by using GRPAUT on heterogeneous, high americium samples. 5 refs., 6 tabs

  3. Gender-specific differences in the biokinetics of plutonium and other actinides

    International Nuclear Information System (INIS)

    The published data on the biokinetics of actinide distribution and retention in humans and animals have been reviewed. It is concluded that in humans there are strong indications that urinary and faecal excretion of plutonium is greater in females than males. Animal data indicate that this may also be true for americium, neptunium and uranium. (author)

  4. 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.

  5. 76 FR 63957 - Consumer Product Policy Statement

    Science.gov (United States)

    2011-10-14

    ....regulations.gov by searching on Docket ID NRC-2010-0292. II. Background On March 16, 1965 (30 FR 3462), the... would be revised to be more relevant and up to date. For example, thoriated tungsten welding rods, while... radionuclides in electron tubes; (b) Americium-241 in smoke detectors; and (c) Thorium and uranium...

  6. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Science.gov (United States)

    2010-01-01

    .... Actinium Ac 89 Aluminum Al 13 Americium Am 95 Antimony Sb 51 Argon Ar 18 Arsenic As 33 Astatine At 85... Curium Cm 96 Dysprosium Dy 66 Einsteinium Es 99 Erbium Er 68 Europium Eu 63 Fermium Fm 100 Fluorine F...

  7. Literatuuronderzoek plutoniumanalyses

    NARCIS (Netherlands)

    Glastra P; Kwakman PJM; LSO

    1997-01-01

    This report describes recent developments in the radiochemical determination of plutonium in samples from the environment such as aerosols, rainwater, grass and soil. The radiochemical separation of plutonium from interfering alpha emitters, such as americium and curium, was found to be simplified b

  8. Discovery of Isotopes of the Transuranium Elements with 93 <= Z <= 98

    CERN Document Server

    Fry, C

    2012-01-01

    One hundred and five isotopes of the transuranium elements neptunium, plutonium, americium, curium, berkelium and californium have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  9. Electronic Structure of the Actinide Metals

    DEFF Research Database (Denmark)

    Johansson, B.; Skriver, Hans Lomholt

    1982-01-01

    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...

  10. Presence and Character of the 5f Electrons in the Actinide Metals

    DEFF Research Database (Denmark)

    Johansson, B.; Skriver, Hans Lomholt; Mårtensson, N.;

    1980-01-01

    The sensitivity of the Image level binding energy to the occupation of the 5f orbital is pointed out and used to demonstrate the presence of 5f electrons in the uranium metal. It is suggested that the valence band spectrum of uranium might contain satellites originating from excitations to locali...... and the critical separation is found to take place between plutonium and americium....

  11. A Novel Experiment to Investigate the Attenuation of Alpha Particles in Air

    Science.gov (United States)

    Andrews, D. G. H.

    2008-01-01

    A simple student experiment investigating dependence on air pressure of the attenuation of alpha particles in air is described. An equation giving the pressure needed to absorb all alpha particles of a given energy is derived from the Bethe-Bloch formula. Results are presented for the attenuation of alpha particles from americium 241 and radium…

  12. 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.

  13. Study on the Extraction of L-Phenylalanine with Organo-phosphoric Acid in Two and Three-phase System

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Li(张莉); FU,Xun(傅洵); HU,Zheng-Shui(胡正水); LI,Qiu-Hong(李秋红); XU,Ting(徐婷)

    2002-01-01

    The extraction behaviors of L-phenylalanine by di-( 2,4,4trimethylpentyl) phosphinic acid, di-(2,4,4-trimethylpentyl)monothiophosphinic acid and di-(2-ethylhwxyl) phosphoric acid were studied in both two-phase and three-phase systems respectively. The equilibrium constants for these extraction reactions were calculated .

  14. Drug: D10254 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D10254 Drug Esflurbiprofen (JAN) C15H13FO2 244.09 244.2609 D10254.gif ATC code: M01AE09 M02AA19 Genomic biom...arker: CYP2C9 [HSA:1559] Anatomical Therapeutic Chemical (ATC) classification [BR:b

  15. The Road to Market Society

    DEFF Research Database (Denmark)

    Christiansen, Christian O.; Cockburn, Patrick Joseph

    2014-01-01

    Book review of Michael J. Sandel, What Money Can't Buy: The Moral Limits of Markets. London: Penguin Group, 2012, 244 pp., $16.46. ISBN 9781846144714 (hbk).......Book review of Michael J. Sandel, What Money Can't Buy: The Moral Limits of Markets. London: Penguin Group, 2012, 244 pp., $16.46. ISBN 9781846144714 (hbk)....

  16. ARL Academic Health Sciences Library Statistics 2006-2007

    Science.gov (United States)

    Kyrillidou, Martha, Comp.; Bland, Les, Comp.

    2008-01-01

    This document presents data that describe collections, expenditures, personnel, and services in 65 medical libraries at Association of Research Libraries (ARL) member institutions throughout North America. In 2006-2007, the reporting health sciences libraries held a median of 244,188 volumes, spent a total of $244,188,020, and employed 2,395 FTE…

  17. Drug: D01888 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D01888 Drug Safrazine hydrochloride (JAN) C11H16N2O2. HCl 244.0979 244.7179 D01888.gif Antidepressant withdr...awal drug monoamine oxidase (MAO) inhibitor [HSA:4128 4129] [KO:K00274] hsa00260(41

  18. Applications of Text Analysis Tools for Spoken Response Grading

    Science.gov (United States)

    Crossley, Scott; McNamara, Danielle

    2013-01-01

    This study explores the potential for automated indices related to speech delivery, language use, and topic development to model human judgments of TOEFL speaking proficiency in second language (L2) speech samples. For this study, 244 transcribed TOEFL speech samples taken from 244 L2 learners were analyzed using automated indices taken from…

  19. Pediatric Palliative Care: A Personal Story

    Medline Plus

    Full Text Available ... 4,244,244 views 1:09:38 Phoebe's Cancer Story - Duration: 7:46. Family A-Fair 621, ... 3:02 Pediatric Palliative Care: helping children with cancer survive and thrive - Duration: 3:29. American Cancer ...

  20. The prospect of uranium nitride (UN) and mixed nitride fuel (UN-PuN) for pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Syarifah, Ratna Dewi, E-mail: syarifah.physics@gmail.com; Suud, Zaki, E-mail: szaki@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Physics Department, Faculty of Mathematics and Natural Science, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    Design study of small Pressurized Water Reactors (PWRs) core loaded with uranium nitride fuel (UN) and mixed nitride fuel (UN-PuN), Pa-231 as burnable poison, and Americium has been performed. Pa-231 known as actinide material, have large capture cross section and can be converted into fissile material that can be utilized to reduce excess reactivity. Americium is one of minor actinides with long half life. The objective of adding americium is to decrease nuclear spent fuel in the world. The neutronic analysis results show that mixed nitride fuel have k-inf greater than uranium nitride fuel. It is caused by the addition of Pu-239 in mixed nitride fuel. In fuel fraction analysis, for uranium nitride fuel, the optimum volume fractions are 45% fuel fraction, 10% cladding and 45% moderator. In case of UN-PuN fuel, the optimum volume fractions are 30% fuel fraction, 10% cladding and 60% coolant/ moderator. The addition of Pa-231 as burnable poison for UN fuel, enrichment U-235 5%, with Pa-231 1.6% has k-inf more than one and excess reactivity of 14.45%. And for mixed nitride fuel, the lowest value of reactivity swing is when enrichment (U-235+Pu) 8% with Pa-231 0.4%, the excess reactivity value 13,76%. The fuel pin analyze for the addition of Americium, the excess reactivity value is lower than before, because Americium absorb the neutron. For UN fuel, enrichment U-235 8%, Pa-231 1.6% and Am 0.5%, the excess reactivity is 4.86%. And for mixed nitride fuel, when enrichment (U-235+Pu) 13%, Pa-231 0.4% and Am 0.1%, the excess reactivity is 11.94%. For core configuration, it is better to use heterogeneous than homogeneous core configuration, because the radial power distribution is better.