Americium removal from nitric acid waste streams

International Nuclear Information System (INIS)

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

1986-01-01

Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve americium removal from nitric acid (7M) waste streams generated by plutonium purification operations. Partial neutralization of the acid waste followed by solid supported liquid membranes (SLM) are useful in transferring and concentrating americium from nitrate solutions. Specifically, DHDECMP (dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel polypropylene hollow fibers assembled in modular form transfers >95% of the americium from high nitrate (6.9M), low acid (0.1M) feeds into 0.25M oxalic acid stripping solution. Maximum permeabilities were observed to be 0.001 cm/sec, consistent with typical values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution. Furthermore, O0D (iB)CMPO (or CMPO) (octylphenyl-N-N-diisobutylcarbamoylmethylphosphine oxide) has been tested in an extraction chromatography mode. Preliminary results show CMPO to be effective in removing americium if the feed is neutralized to 1.0M acidity and iron(III) is complexed with 0.20M oxalic acid. 3 figs

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.

Biosorption of americium by alginate beads

International Nuclear Information System (INIS)

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

2009-01-01

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

Recycling of americium

International Nuclear Information System (INIS)

Hagstroem, Ingela

1999-12-01

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

Americium product solidification and disposal

International Nuclear Information System (INIS)

Mailen, J.C.; Campbell, D.O.; Bell, J.T.; Collins, E.D.

1987-01-01

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

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Geisy, J P; Paine, D

1978-01-01

Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

Americium migration in basalt and implications to repository risk analysis

International Nuclear Information System (INIS)

Rickert, P.G.

1980-01-01

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

Recovery and purification of americium from molten salt extraction residues

International Nuclear Information System (INIS)

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

1980-01-01

Americium recovery and purification development at Rocky Flats involves the testing of a combined anion exchange - bidentate organophosphorus liquid - liquid extraction or extraction chromatography process for separating americium from molten salt extraction residues. Laboratory-scale and preliminary pilot-plant results have shown that americium can be effectively recovered and purified from impurity elements such as aluminum, calcium, magnesium, plutonium, potassium, sodium, and zinc. The purified americium oxide product from the liquid - liquid extraction process contained greater than 95% AmO 2 with less than 1% of any individual impurity element

Transmutation of Americium in Fast Neutron Facilities

International Nuclear Information System (INIS)

Zhang, Youpeng

2011-01-01

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

Procedure for the analysis of americium in complex matrices

International Nuclear Information System (INIS)

Knab, D.

1978-02-01

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

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

International Nuclear Information System (INIS)

Spirlet, J.C.

1975-10-01

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

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)

Comparative behavior of americium and plutonium in wastewater

International Nuclear Information System (INIS)

Tsvetaeva, N.E.; Filin, V.M.; Ragimov, T.K.; Rudaya, L.Y.; Shapiro, K.Y.; Shcherbakov, B.Y.

1986-01-01

This paper studies the behavior of trace americium and plutoniumin wastewater fed into purification systems. Activities of the elements were determined on a semiconductive alpha-ray spectrometer. the distributio nonuniformity, or heterogeneity, of americium and plutonium per unit volume of wastewater was determined quantitatively before and after passage through filter papers. The two elements were found to be in a colloidal or pseudocolloidal state in the original wastewater sample at pH 6. On acidifying the wastewater from pH 4 to 1 M nitric acid the americium passed quantitatively into the water phase but the most plutonium remained in the colloidal or pseudocolloidal state. the plutonium also passed quantitatively into the water phase in wastewater at a 1 M nitric acid acidity but only after a prolonged (12-day) hold. A knowledge of the heterogeneity of plutonium and americium in wastewaters made it possible to quickly distinguish their state, i.e., colloidal, pseudocolloidal, or in true solution

Formation of americium and europium humate complexes

International Nuclear Information System (INIS)

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

1991-01-01

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

PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

Science.gov (United States)

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

1963-02-26

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

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.

Investigation of factors affecting the quality of americium electroplating

International Nuclear Information System (INIS)

Trdin, M.; Benedik, L.; Samardžija, Z.; Pihlar, B.

2012-01-01

Four different electrolyte solutions were used in the electrodeposition of americium and their influences on the quality of the thin layer of deposited americium isotopes in combination with three different cathode disc materials were investigated. The relations between alpha spectral resolution and disc surface properties were established. - Highlights: ► Compared alpha spectra of americium radioisotopes obtained by electrodeposition. ► Various cathode materials and electrolyte solutions were used. ► Homogeneity and peak area resolution were investigated. ► Electron microscope images show surface structure of electrodeposited material.

Measurement of plutonium and americium in molten salt residues

International Nuclear Information System (INIS)

Haas, F.X.; Lawless, J.L.; Herren, W.E.; Hughes, M.E.

1979-01-01

The measurement of plutonium and americium in molten salt residues using a segmented gamma-ray scanning device is described. This system was calibrated using artificially fabricated as well as process generated samples. All samples were calorimetered and the americium to plutonium content of the samples determined by gamma-ray spectroscopy. For the nine samples calorimetered thus far, no significant biases are present in the comparison of the segmented gamma-ray assay and the calorimetric assay. Estimated errors are of the order of 10 percent and is dependent on the americium to plutonium ratio determination

Americium separations from high salt solutions

International Nuclear Information System (INIS)

Barr, Mary E.; Jarvinen, Gordon D.; Schulte, Louis D.; Stark, Peter C.; Chamberlin, Rebecca M.; Abney, Kent D.; Ricketts, Thomas E.; Valdez, Yvette E.; Bartsch, Richard A.

2000-01-01

Americium (III) exhibits an unexpectedly high affinity for anion-exchange material from the high-salt evaporator bottoms solutions--an effect which has not been duplicated using simple salt solutions. Similar behavior is observed for its lanthanide homologue, Nd(III), in complex evaporator bottoms surrogate solutions. There appears to be no single controlling factor--acid concentration, total nitrate concentration or solution ionic strength--which accounts for the approximately 2-fold increase in retention of the trivalent ions from complex solutions relative to simple solutions. Calculation of species activities (i.e., water, proton and nitrate) in such concentrated mixed salt solutions is difficult and of questionable accuracy, but it is likely that the answer to forcing formation of anionic nitrate complexes of americium lies in the relative activities of water and nitrate. From a practical viewpoint, the modest americium removal needs (ca. 50--75%) from nitric acid evaporator bottoms allow sufficient latitude for the use of non-optimized conditions such as running existing columns filled with older, well-used Reillex HPQ. Newer materials, such as HPQ-100 and the experimental bifunctional resins, which exhibit higher distribution coefficients, would allow for either increased Am removal or the use of smaller columns. It is also of interest that one of the experimental neutral-donor solid-support extractants, DHDECMP, exhibits a similarly high level of americium (total alpha) removal from EV bottoms and is much less sensitive to total acid content than commercially-available material

Transmutation of americium in critical reactors

International Nuclear Information System (INIS)

Wallenius, J.

2005-01-01

Already in 1974, a Los Alamos report suggested that the recycling of higher actinides would be detrimental for the safety of critical reactors. Later investigations confirmed this understanding, and stringent limits on the fraction of minor actinides allowed to be present in the fuel of fast neutron reactors were established. In recent years, and in particular in connection with the generation IV initiative, it has been advocated that recycling of americium in critical reactors is not only feasible, but also a recommendable approach. In the present contribution, it is shown, to the contrary, that introduction of americium into reactors with uranium based fuels deteriorates the safety margin of these reactors to a degree that will not allow consumption of the americium sources present in any economically competitive nuclear fuel cycle. Further, it is shown that uranium and thorium free cores with plutonium based fuels may be designed, that features excellent safety characteristics, as long as americium is not present in the feed. Hence, a closed fuel cycle is suggested, that consists of commercial power production in light water reactors, plutonium burning in uranium and thorium free fast neutron critical reactors, and higher actinide consumption in accelerator driven systems with inert matrix fuel. It is argued that such a fuel cycle (being a refinement of the Double Strata fuel cycle proposed by JAERI and further developed by M. Salvatores) provides a minimum cost penalty for implementing P and T under realistic boundary conditions. (author)

Sorption of americium and neptunium by deep-sea sediments

International Nuclear Information System (INIS)

Higgo, J.J.W.; Rees, L.V.C.; Cronan, D.S.

1983-01-01

The sorption and desorption of americium and neptunium by a wide range of deep-sea sediments from natural sea water at 4 0 C has been studied using a carefully controlled batch technique. All the sediments studied should form an excellent barrier to the migration of americium since distribution coefficients were uniformly greater than 10 5 and the sorption-desorption reaction may not be reversible. The sorption of neptunium was reversible and, except for one red clay, the distribution coefficients were greater than 10 3 for all the sediments investigated. Nevertheless the migration of neptunium should also be effectively retarded by most deep-sea sediments even under relatively oxidizing conditions. The neptunium in solution remained in the V oxidation state throughout the experiments. Under the experimental conditions used colloidal americium was trapped by the sediment and solubility did not seem to be the controlling factor in the desorption of americium. (Auth.)

Supported extractant membranes for americium and plutonium recovery

International Nuclear Information System (INIS)

Muscatello, A.C.; Navratil, J.D.; Killion, M.E.; Price, M.Y.

1987-01-01

Solid supported liquid membranes(SLM) are useful in transferring and concentrating americium and plutonium from nitrate solutions. Specifically, DHDECMP(dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel or Celgard polypropylene hollow fibers assembled in modular form transfers >95% of the americium and >70% of the plutonium from high nitrate (6.9 M), low acid (0.1 M) feeds into 0.25 M oxalic acid stripping solution. Membranes supporting TBP (tri-n-butylphosphate) also transfer these metal ions. Maximum permeabilities were observed to be 1 x 10 -3 cm sec -1 , similar to the values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution

Recovery of americium-241 from aged plutonium metal

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-12-01

About 5 kg of ingrown 241 Am was recovered from 850 kg of aged plutonium using a process developed specifically for Savannah River Plant application. The aged plutonium metal was first dissolved in sulfamic acid. Sodium nitrite was added to oxidize the plutonium to Pu(IV) and the residual sulfamate ion was oxidized to nitrogen gas and sulfate. The plutonium and americium were separated by one cycle of solvent extraction. The recovered products were subsequently purified by cation exchange chromatography, precipitated as oxalates, and calcined to the oxides. Plutonium processng was routine. Before cation exchange purification, the aqueous americium solution from solvent extraction was concentrated and stripped of nitric acid. More than 98% of the 241 Am was then recovered from the cation exchange column where it was effectively decontaminated from all major impurities except nickel and chromium. This partially purified product solution was concentrated further by evaporation and then denitrated by reaction with formic acid. Individual batches of americium oxalate were then precipitated, filtered, washed, and calcined. About 98.5% of the americium was recovered. The final product purity averaged 98% 241 AmO 2 ; residual impurities were primarily lead and nickel

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

International Nuclear Information System (INIS)

Bartscher, W.

1982-01-01

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

1976 Hanford americium-exposure incident: external decontamination procedures

International Nuclear Information System (INIS)

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

1982-01-01

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

Investigation of factors affecting the quality of americium electroplating.

Science.gov (United States)

Trdin, M; Benedik, L; Samardžija, Z; Pihlar, B

2012-09-01

Four different electrolyte solutions were used in the electrodeposition of americium and their influences on the quality of the thin layer of deposited americium isotopes in combination with three different cathode disc materials were investigated. The relations between alpha spectral resolution and disc surface properties were established. Copyright © 2012 Elsevier Ltd. All rights reserved.

Method of isolation of traces of americium by using the +6 oxidation state properties

International Nuclear Information System (INIS)

Kwinta, Jean; Michel, Jean-Jacques

1969-05-01

The authors present a method to separate traces of americium from a solution containing fission products and actinides. This method comprises the following steps: firstly, the oxidation of americium at the +6 state by ammonium persulfate and carrying over of actinides and III and IV lanthanides by lanthanum fluoride; secondly, the reduction by hydrazine of the oxidized americium and carrying over of the reduced americium by lutetium fluoride; and thirdly, the americium-lutetium separation by selective extractions either with di 2 ethyl hexyl phosphoric acid, or by fractionated elution on an anionic resin column by a mixture of nitric acid and methanol [fr

Americium-241 - ED 4308

International Nuclear Information System (INIS)

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

2012-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Mineo, Hideaki; Matsumura, Tatsuro; Tsubata, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1996-10-01

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

Decontaminaion of metals containing plutonium and americium

International Nuclear Information System (INIS)

Seitz, M.G.; Gerding, T.J.; Steindler, M.J.

1979-06-01

Melt-slagging (melt-refining) 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 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 x 10 6 were measured with boro-silicate slag and of 3 x 10 6 with calcium, magnesium silicate slag. Decontamination of metals containing as much as 14,000 ppM plutonium appears to be as efficient as for metals with plutonium levels of 400 ppM. Staged extraction, that is, a remelting of processed metal with clean slag, results in further decontamination of the metal. The second extraction is effective with either resistance-furnace melting or electric-arc melting. Slag adhering to the metal ingots and in defects within the ingots is in the important contributors to plutonium retained in processed metals. If these sources of plutonium are controlled, the melt-refining process can be used on a large scale to convert highly contaminated metals to homogeneous and compact forms with very low concentrations of plutonium and americium. A conceptual design of a melt-refining process to decontaminate plutonium- and americium-contaminated metals is described. The process includes single-stage refining of contaminated metals to produce a metal product which would have less than 10 nCi/g of TRU-element contamination. Two plant sizes were considered. The smaller conceptual plant processes 77 kg of metal per 8-h period and may be portable.The larger one processes 140 kg of metal per 8-h period, is stationary, and may be near te maximum size that is practical for a metal decontamination process

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)

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Analytical separation of americium and curium, using high performance liquid chromatography

International Nuclear Information System (INIS)

Billon, A.

1978-01-01

Americium and curium are separated on a column of cation exchange resin (Aminex) using hydroxyisobutyric acid (α HIBA) as eluent, at a temperature of 80 0 C. Americium and curium were detected in line using their α emission: the separation was performed in a shielded glove box whose setting-up is given. Finally, the time necessary for a separation is comprised between 30 min and 1 hr. The purity of separated fractions was assayed by mass-spectrometry. An application in the determination of isotopic composition of americium and curium in fuels is described

Preparation of americium source for smoke detector

International Nuclear Information System (INIS)

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

1994-01-01

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

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.

Separation of Americium from plutonium, Annex 3; Prilog 3: Odvajanje amercijuma od plutonijuma

Energy Technology Data Exchange (ETDEWEB)

Cvjeticanin, D; Milic, N; Janicijevic, P; Ratkovic, S [Institute of Nuclear Sciences Boris Kidric, Laboratorija za visoku aktivnost, Vinca, Beograd (Serbia and Montenegro)

1963-12-15

Since there was the possibility of working with plutonium milligram quantities, it was possible to study plutonium with contents of americium, which was expected in the about two years old plutonium solutions. Method for separation of the micro quantities of americium and plutonium was needed as well as a multichannel alpha-pulse analyzer. Method for separation of americium from plutonium by thenol trifluoro-acetone (TTA) and anion exchange was adopted.

Extraction of americium from acid aqueous solutions by diethyl-2-hexyl-pyro-phosphoric acid

International Nuclear Information System (INIS)

Guillaume, Bernard

1971-02-01

After having outlined the interesting properties of americium and the difficulties of its recovery, the author reports the study of the mechanism of extraction of americium from acid aqueous solutions by using the diethyl-2hexyl-pyro-phosphoric acid. Several aspects are thus discussed: influence of concentration of H 2 DEHPP, influence of the acidity of the aqueous phase, saturation of extracting agent, influence of the diluting agent, complexing of americium, influence of other cations. In a second part, the author reports the application to the recovery of americium from effluents, and discusses the obtained results

Environmental impact of a teratogenic actinide: a case study of americium-241

Energy Technology Data Exchange (ETDEWEB)

Wang, J.; Yang, J.Y.

1985-10-16

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. A previous report based on a worst-case scenario involving a hypothetical fire accident in a contaminated facility indicated that there could have been a significant impact on nearby residents from a unit release of americium-241 via atmospheric dispersion. However, because the facility is located in a rural region where most drinking water supplies are drawn from private wells, it is believed that deposition of americium-241 from the atmosphere might also have impacts via the groundwater pathway by infiltration of rainwater. In this analysis, a three-dimensional analytical mathematical model is used to assess several aspects of americium-241 contamination of groundwater, including radioactive transformation, advection, dispersion, and soil sorption. Simulation results indicate that no significant radiological impacts would occur to the nearby residents via the groundwater pathway. 15 refs., 2 figs., 2 tabs.

Environmental impact of a teratogenic actinide: a case study of americium-241

International Nuclear Information System (INIS)

Wang, J.; Yang, J.Y.

1985-01-01

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. A previous report based on a worst-case scenario involving a hypothetical fire accident in a contaminated facility indicated that there could have been a significant impact on nearby residents from a unit release of americium-241 via atmospheric dispersion. However, because the facility is located in a rural region where most drinking water supplies are drawn from private wells, it is believed that deposition of americium-241 from the atmosphere might also have impacts via the groundwater pathway by infiltration of rainwater. In this analysis, a three-dimensional analytical mathematical model is used to assess several aspects of americium-241 contamination of groundwater, including radioactive transformation, advection, dispersion, and soil sorption. Simulation results indicate that no significant radiological impacts would occur to the nearby residents via the groundwater pathway. 15 refs., 2 figs., 2 tabs

Modelling of curium and americium behaviour during separation with displacing complexing chromatography

International Nuclear Information System (INIS)

Chuveleva, Eh.A.; Kharitonov, O.V.; Firsova, L.A.

1994-01-01

Certain heavy rare earths, curium and americium were separated by the method of displacement complexing chromatography using DTPA solutions and solutions containing DTPA and citric acid as eluents. Separation factors of rare earths and curium (americium) were calculated. Imitators for curium and americium separation were suggested: thulium for curium elution using 0.025 mol/l DTPA, holmium-for curium elution using 0.025 mol/l DTPA in the presence of 0.025 mol/l citric acid; terbium can serve as the imitator in both cases. 5 refs., 5 figs

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

International Nuclear Information System (INIS)

Boust, D.

1987-03-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Pyrochemical investigations into recovering plutonium from americium extraction salt residues

International Nuclear Information System (INIS)

Fife, K.W.; West, M.H.

1987-05-01

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

Supercritical Fluid Extraction of Plutonium and Americium from Soil

International Nuclear Information System (INIS)

Fox, R.V.; Mincher, B.J.

2002-01-01

Supercritical fluid extraction (SFE) of plutonium and americium from soil was successfully demonstrated using supercritical fluid carbon dioxide solvent augmented with organophosphorus and beta-diketone complexants. Spiked Idaho soils were chemically and radiologically characterized, then extracted with supercritical fluid carbon dioxide at 2,900 psi and 65 C containing varying concentrations of tributyl phosphate (TBP) and thenoyltrifluoroacetone (TTA). A single 45 minute SFE with 2.7 mol% TBP and 3.2 mol% TTA provided as much as 88% ± 6.0 extraction of americium and 69% ± 5.0 extraction of plutonium. Use of 5.3 mol% TBP with 6.8 mol% of the more acidic beta-diketone hexafluoroacetylacetone (HFA) provided 95% ± 3.0 extraction of americium and 83% ± 5.0 extraction of plutonium in a single 45 minute SFE at 3,750 psi and 95 C. Sequential chemical extraction techniques were used to chemically characterize soil partitioning of plutonium and americium in pre-SFE soil samples. Sequential chemical extraction techniques demonstrated that spiked plutonium resides primarily (76.6%) in the sesquioxide fraction with minor amounts being absorbed by the oxidizable fraction (10.6%) and residual fractions (12.8%). Post-SFE soils subjected to sequential chemical extraction characterization demonstrated that 97% of the oxidizable, 78% of the sesquioxide and 80% of the residual plutonium could be removed using SFE. These preliminary results show that SFE may be an effective solvent extraction technique for removal of actinide contaminants from soil

Gut uptake factors for plutonium, americium and curium

International Nuclear Information System (INIS)

Harrison, J.D.

1982-01-01

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

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Giesy, Jr, J P; Paine, D [Savannah River Ecology Lab., Aiken, S.C. (USA)

1978-01-01

The uptake of americium by three algae, Scenedesmus obliguus, Selenastrum capricomutum and Chlorella pyrenosdosa and a bacterium Aeromonas hydrophila was studied. Live and fixed cells of each algal species and live bacterial cells were used. It is shown that algae and bacteria concentrate americium 241 to a high degree which makes them important links in the biomagnification phenomenon which may ultimately lead to a human hazard and be potentially important in recycling Am /sup 241/ in the water column and mobilization from sediments. Chemical fixation of algal cells caused increased uptake which indicated that uptake is by passive diffusion and probably due to chemical alteration of surface binding sites.

Synergistic extraction behaviour of americium from simulated acidic waste solutions

International Nuclear Information System (INIS)

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

1998-01-01

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

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.

Americium Separations from High-Salt Solutions Using Anion Exchange

International Nuclear Information System (INIS)

Barr, Mary E.; Jarvinen, Gordon D.; Stark, Peter C.; Chamberlin, Rebecca M.; Bartsch, Richard A.; Zhang, Z.Y.; Zhao, W.

2001-01-01

The aging of the US nuclear stockpile presents a number of challenges, including the increasing radioactivity of plutonium residues due to the ingrowth of 241 Am from the β-decay of 241 Pu. We investigated parameters that affect the sorption of Am onto anion-exchange resins from concentrated effluents derived from nitric acid processing of plutonium residues. These postevaporator wastes are nearly saturated solutions of acidic nitrate salts, and americium removal is complicated by physical factors, such as solution viscosity and particulates, as well as by the presence of large quantities of competing metals and acid. Single- and double-contact batch distribution coefficients for americium and neodymium from simple and complex surrogate solutions are presented. Varied parameters include the nitrate salt concentration and composition and the nitric acid concentration. We find that under these extremely concentrated conditions, Am(III) removal efficiencies can surpass 50% per contact. Distribution coefficients for both neodymium and americium are insensitive to solution acidity and appear to be driven primarily by low water activities of the solutions

Organic components and plutonium and americium state in soils and soil solutions

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kimlenko, I.M.

2002-01-01

The fraction composition of humus substances of different type soils and soil solutions have been studied. A distribution of Pu 239, 240 and Am 241 between humus substances fractions of different dispersity and mobility in soil-vegetation cover has been established. It was shown that humus of organic soils fixes plutonium and americium in soil medium in greater extent than humus of mineral soils. That leads to lower migration ability of radionuclides in organic soils. The lower ability of americium to form difficultly soluble organic and organic-mineral complexes and predomination of its anion complexes in soil solutions may be a reason of higher mobility and biological availability of americium in comparison to plutonium during soil-plant transfer (authors)

In-line measurement of plutonium and americium in mixed solutions

International Nuclear Information System (INIS)

Li, T.K.

1981-01-01

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

Americium/Curium Disposition Life Cycle Planning Study

International Nuclear Information System (INIS)

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

1998-01-01

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

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

International Nuclear Information System (INIS)

Cole, T.G.; Higgo, J.J.W.; Cronan, D.S.; Rees, L.V.C.

1984-07-01

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 (CaCO 3 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)

On the role of different biocomponents of bile and excretions in the elimination of plutonium and americium from the body

International Nuclear Information System (INIS)

Shvydko, N.S.

1986-01-01

A study was made of the role of biocomponents of bile, urine and feces in the elimination of plutonium and americium from the organism. Plutonium 239 and americium 241 were separated in bile due to higher tropism of plutonium to low molecular weight addends, and of americium, to a protein-containing fraction. The status of plutonium excreted in feces was the same as the physicochemical status of americium. Plutonium 239 and americium 241 eliminated in urine were in a completely ultrafiltered state

Mobility of plutonium and americium through a shallow aquifer in a semiarid region

International Nuclear Information System (INIS)

Penrose, W.R.; Polzer, W.L.; Essington, E.H.; Nelson, D.M.; Orlandini, K.A.

1990-01-01

Treated liquid wastes containing traces of plutonium and americium are released into Mortandad Canyon, within the site of Los Alamos National Laboratory, NM. The wastes infiltrate a small aquifer within the canyon. Although laboratory studies have predicted that the movement of actinides in subsurface environments will be limited to less than a few meters, both plutonium and americium are detectable in monitoring wells as far as 3,390 m downgradient from the discharge. Between the first and last monitoring wells (1.8 and 3.4 km from the discharge), plutonium concentrations decreased exponentially from 1,400 to 0.55 mBq/L. Americium concentrations ranged between 94 and 1,240 mBq/L, but did not appear to vary in a systematic way with distance. Investigation of the properties of the mobile actinides indicates that the plutonium and part of the americium are tightly or irreversibly associated with colloidal material between 25 and 450 nm in size. The colloidally bound actinides are removed only gradually from the groundwater. The fraction of the americium not associated with colloids exists in a low molecular weight form (diameter, ≤ 2 nm) and appears to be a stable, anionic complex of unknown composition. The mobile forms of these actinides defeat the forces that normally act to retard their movement through groundwater systems

Americium-241 and -243 as an ion-engine propellant

International Nuclear Information System (INIS)

Schachter, M.M.

1994-01-01

Commercially available americium-241 and -243 can be obtained as the mixture of the two isotopes in 100-gram quantities--a product of reprocessing spent nuclear powerplant fuel elements along with plutonium. The half-lives of the isotopes are 450 years for the -241 and 8,000 years for the -243 (the plutonium half-life isotope so obtained is 24,000 years). Americium rolled out in thin foil sheets emits alpha-rays (helium-4 ions) and beta-rays--2 valence electrons for each helium ion. Electrons are also considered as ions. As a foil, the americium radiates only a minimal amount of gamma-rays via the Curie effect. With appropriately designed permanent magnet rings insulated with Wood's alloy, the + and - ions can be accelerated from their already 5.5 million electron-Volts to billion and even trillions of electron-Volts by electronic control grids powered by the magnetohydrodynamic effect of electrons and helium ions streaming at the post-rocket nozzle of the ion engine. Protocol for the estimated thrust of this ion rocket engine is more than ten kilograms continuously sustainable for several thousand years

The ingestion of plutonium and americium by range cattle

International Nuclear Information System (INIS)

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

1981-01-01

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

Dicty_cDB: VHK246 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available VH (Link to library) VHK246 (Link to dictyBase) - - - Contig-U16440-1 VHK246P (Link to Original site) VHK2...46F 617 VHK246Z 760 VHK246P 1357 - - Show VHK246 Library VH (Link to library) Clone ID VHK2...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHK2-B/VHK246Q.Seq.d/ Representative seq. ID VHK2...46P (Link to Original site) Representative DNA sequence >VHK246 (VHK246Q) /CSM/VH/VHK2-B/VHK2...y vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VHK246 (VHK246Q) /CSM/VH/VHK2-B/VHK2

7 CFR 246.3 - Administration.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration. 246.3 Section 246.3 Agriculture... § 246.3 Administration. (a) Delegation to FNS. Within the Department, FNS shall act on behalf of the Department in the administration of the Program. Within FNS, SFPD and the Regional Offices are responsible...

The availability of plutonium and americium in Irish Sea sediments for re-dissolution

International Nuclear Information System (INIS)

McDonald, P.; Vives i Batlle, J.; Bousher, A.; Whittall, A.; Chambers, N.

2001-01-01

The availability of plutonium and americium, for re-dissolution from offshore sediments into Irish Sea water, has been examined. Sediments collected from the mud-patch near the Cumbrian coast were characterized in terms of spatial location, particle size, partitioning of radionuclides with respect to physico-chemical bonds and availability of actinides for release into seawater. Sequential extraction investigations revealed that plutonium was predominantly associated with strongly bound sesquioxide and organic complex fractions. Americium was associated mainly with the organic complex fraction, but a significant fraction was in carbonate form. Sediment/water re-dissolution experiments with and without stirring were compared to simulate the effect of disturbing bed sediment. After 1 week, neither set of re-dissolution data provided significant trends between dissolved activity and time. Stirred systems appeared to release 2.5 times more plutonium and americium into seawater than unstirred systems. Measured 239,240Pu and 241Am distribution coefficients (K d values) were both typically approximately 10 5 l kg -1 . 241Am K d values are an order of magnitude lower than previously reported for the north-eastern Irish Sea, but similar to western Irish Sea values. Overall, the fractions of plutonium and americium available for re-dissolution from bed sediment are very low at <0.1%, with proportionally more plutonium being released than americium. These findings lend further support for the extrapolation of laboratory-derived information to environmental conditions

Biokinetic study of plutonium and americium associated to the particulates of soil

International Nuclear Information System (INIS)

Espinosa, A.; Aragon, A.; Martinez, J.; Iranzo, C.E.

1996-01-01

The object of this study is to determine the biokinetic parameters of different Plutonium isotopes and Americium inhaled in the state in which they are found in the environment as a result of their deposition in the soil, from an aviation accident that generated different plutonium oxides. to achieve this objective, two lines of work planned. One was the determination of the mineralogical composition and associations that plutonium and americium present in that soil 22 years after the nuclear accident. Other studies were directed to determine the biokinetic of the plutonium isotopes and americium (contained in the dust) deposited tracheally and inhaled by laboratory animals (rats) and in vitro experiments by pulmonary leaching simulation. The in vivo tests have been developed in NRPB (U.K.) and the in vitro experiment, geochemical associations studies, assessment of internal doses to humans resulting from intake of plutonium and americium bearing dusts present in the contaminated area and establishment of ALIs for inhalation, were carried out in CIEMAT (Spain). In this work only determinations and experiments carried out by CIEMAT are includes as a part of the EU Project ''INHALATION AND INGESTION OF RADIONUCLIDES'' contract: FI3P-CT920064a. (Author) 10 refs

Determination of specific activity of americium and plutonium in selected environmental samples

International Nuclear Information System (INIS)

Trebunova, T.

1999-01-01

The aim of this work was development of method for determination of americium and plutonium in environmental samples. Developed method was evaluated on soil samples and after they was applied on selected samples of fishes (smoked mackerel, herring and fillet from Alaska hake). The method for separation of americium is based on liquid separation with Aliquate-336, precipitation with oxalic acid and using of chromatographic material TRU-Spec TM .The intervals of radiochemical yields were from 13.0% to 80.9% for plutonium-236 and from 10.5% to 100% for americium-241. Determined specific activities of plutonium-239,240 were from (2.3 ± 1.4) mBq/kg to (82 ± 29) mBq/kg, the specific activities of plutonium-238 were from (14.2 ± 3.7) mBq/kg to (708 ± 86) mBq/kg. The specific activities of americium-241 were from (1.4 ± 0.9) mBq/kg to (3360 ± 210) mBq/kg. The fishes from Baltic Sea as well as from North Sea show highest specific activities then fresh-water fishes from Slovakia. Therefore the monitoring of alpha radionuclides in foods imported from territories with nuclear testing is recommended

1976 Hanford americium exposure incident: psychological aspects

International Nuclear Information System (INIS)

Brown, W.R.

1982-01-01

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

Influence of organic components on plutonium and americium speciation in soils and soil solutions

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Kimlenko, I.M.

2003-01-01

Group composition of humic substances of organic and mineral soils sampled in the 30-km zone of the Chernobyl accident was analyzed for studying influence of organic components on migration properties of plutonium and americium in soils and soil solutions by the method of gel-chromatography and chemical fractionation. It was ascertained that humus of organic soils binds plutonium and americium stronger than humus of mineral soils. Elevated mobility of americium compared to plutonium one stems from lower ability of the latter to from hard to solve organic and organomineral complexes, as well as from its ability to form anionic complexes in soil solutions [ru

Carbamoyl methylphosphine oxide derivatives of adamantane as americium and europium extractants

International Nuclear Information System (INIS)

Babain, V.A.; Alyapyshev, M.Yu.; Novakov, I.A.; Orlinson, B.S.; Savel'ev, E.N.; Shokova, Eh.A.; Serebrayannikova, A.E.; Kovalev, V.V.

2007-01-01

Adamantane di-1,3-carbamoyl methylphosphine oxide (CMPO) derivatives, where CMPO-groups connect with 1,3-positions of rigid adamantane platform by methylene and ethylene bridges, are synthesized, and their efficiency as extractants of americium(III) and europium(III) from nitric acid solutions is demonstrated. Distribution function of Am 3+ and Eu + during extraction from 3M HNO 3 are measured in the investigation of extraction properties. It is noted that first synthesized adamantane CMPO derivatives are more effective for the extraction of americium(III) and europium(III) from 3MHNO 3 [ru

Radiation protection data sheets for the use of Americium 241 in unsealed sources

International Nuclear Information System (INIS)

Anon.

1993-01-01

This radiation protection data sheet is intended for supervisors and staff in the different medical, hospital, pharmaceutical, university and industrial laboratories and departments where Americium 241 is handled, and also for all those involved in risk prevention in this field. It provides essential data on radiation protection measures during the use of Americium 241 in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography

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

International Nuclear Information System (INIS)

Murray, C.N.; Fukai, R.

1975-01-01

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

Local Structure in Americium and Californium Hexa-cyanoferrates - Comparison with Their Lanthanide Analogues

International Nuclear Information System (INIS)

Dupouy, G.; Bonhoure, I.; Dumas, Th.; Moisy, Ph.; Petit, S.; Den Auwer, Ch.; Conradson, St.D.; Hennig, Ch.; Scheinost, A.C.; Le Naour, C.; Simoni, E.

2011-01-01

Metal hexa-cyanoferrates are well known molecular solids for a large variety of cations, although very little has been described for actinide adducts. Two new members of actinide(III) hexa-cyanoferrates were synthesized with the cations americium and californium. They were structurally characterized by infrared and X-ray absorption spectroscopy. Combined EXAFS data at the iron K edge and actinide L 3 edge provide evidence for a three-dimensional model for these two new compounds. Structural data in terms of bond lengths were compared to those reported for the parent lanthanide(III) compounds, neodymium and gadolinium hexa-cyanoferrates, respectively: the americium compound with (KNd(III)Fe(II)-Fe-III(CN) 6 .4H 2 O and the californium compound with (KGd(III)Fe(II)(CN) . 3.5H 2 O and (KGd(III)Fe(II)(CN) 6 .3H 2 O. This comparison between actinide and lanthanide homologues has been carried out on the basis of ionic radii considerations. The americium and neodymium environments appear to be very similar and are arranged in a tri-capped trigonal prism polyhedron of coordination number 9 (CN: 9), in which the americium atom is bonded to six nitrogen atoms and to three water molecules. For the californium adduct, a similar comparison and bond length and angle values derived from EXAFS studies suggest that the californium cation sits in a bi-capped trigonal prism (CN: 8) as in (KGd(III)Fe(II)(CN) 6 . 3H 2 O. This arrangement differs from that in the structure of (KGd(III)Fe(II)(CN) 6 .3.5H 2 O, in which the gadolinium atom is surrounded by 9 atoms. This is one of the rare pieces of information revealed by EXAFS spectroscopy for americium and californium in comparison to lanthanide atoms in molecular solid compounds. A discussion on the decrease in bond length and coordination number from americium to californium is also provided, on the basis of crystallographic results reported in the literature for actinide(III) and lanthanide(III) hydrate series. (authors)

Remobilization of americium in soil columns under experimental rhizo-spheric conditions

Energy Technology Data Exchange (ETDEWEB)

Perrier, T.; Martin-Garin, A.; Morello, M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

2004-07-01

The biogeochemical behaviour of americium in subsurface soils plays a dominant role on the potential migration of this actinide, but is currently poorly known. The identification and understanding of these processes is of major concern for this highly (radio)toxic element and can allow the determination of its impact on the natural media. This research investigates the relevant processes controlling americium biogeochemical speciation in the rhizosphere of an agricultural soil. Lixiviation tests were performed on columns packed with a 2 mm-sieved calcareous soil contaminated with {sup 241}Am (500 Bq.g{sup -1}), under steady-state unsaturated or saturated hydric flow conditions. The columns were percolated with soil solution of varied compositions, containing citrate and/or glucose simulating root exudates in non-sterile conditions. The physico-chemical parameters of the outlet solution (pH, conductivity, major ions, organic acids) were monitored, as well as the microbial activity. Inorganic and organic speciation of {sup 241}Am is supported by geochemical modeling with JChess, using a thermodynamic database based on NEA database and the latest PSI recommendations. The percolation of a solution in equilibrium with the soil released small amount of americium (<5 mBq/cm{sup 3}), as predicted by the high {sup 241}Am K{sub d} values. 10{sup -4} M concentrations of citrate, glucose or both combined did not enhance remobilization either. Poor remobilization was also observed at high glucose concentrations (10{sup -2} M), despite an effective glucose microbial degradation, the production of ligands such as acetate, and important changes in the chemistry of the solution. On the contrary, high concentrations of citrate (10{sup -2} M) released 1000 times more americium, which is in accordance with previous studies. Even greater releases (10000 times) were observed when 10{sup -2} M glucose was added to 10{sup -2} M citrate. The remobilization of americium resulting from the

1976 Hanford americium exposure incident: overview and perspective

International Nuclear Information System (INIS)

Thompson, R.C.

1982-01-01

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

Plutonium-239 and americium-241 uptake by plants from soil. Final report

International Nuclear Information System (INIS)

Brown, K.W.

1979-03-01

Alfalfa was grown in soil contaminated with plutonium-239 dioxide (239PuO2) at a concentration of 29.7 nanocuries per gram (nCi/g). In addition to alfalfa, radishes, wheat, rye, and tomatoes were grown in soils contaminated with americium-241 nitrate (241Am(NO3)3) at a concentration of 189 nCi/g. The length of exposure varied from 52 days for the radishes to 237 days for the alfalfa. The magnitude of plutonium incorporation by the alfalfa as indicated by the concentration ratio, 0.0000025, was similar to previously reported data using other chemical forms of plutonium. The results did indicate, however, that differences in the biological availability of plutonium isotopes do exist. All of the species exposed to americium-241 assimilated and translocated this radioisotope to the stem, leaf, and fruiting structures. The magnitude of incorporation as signified by the concentration ratios varied from 0.00001 for the wheat grass to 0.0152 for the radishes. An increase in the uptake of americium also occurred as a function of time for four of the five plant species. Evidence indicates that the predominant factor in plutonium and americium uptake by plants may involve the chelation of these elements in soils by the action of compounds such as citric acid and/or other similar chelating agents released from plant roots

48 CFR 2453.246 - Quality Assurance.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Quality Assurance. 2453.246 Section 2453.246 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT CLAUSES AND FORMS FORMS Prescription of Forms 2453.246 Quality Assurance. ...

Kinetics of americium(VI) mass transfer through solid supported liquid membrane with HDEHP

International Nuclear Information System (INIS)

Mikheeva, M.N.; Novicoov, P.; Myasoedov, B.F.; Tikhomirov, S.V.

1994-01-01

The main regularities of membrane extraction of americium under conditions of different redox potentials in aqueous phases have been studied. The physico-chemical model of the process including steps of americium oxidation in feed solution, extraction by membrane, partial reduction on membrane surface, trans-membrane diffusion and reextraction to strip solution has been developed. The calculation of reduction rate constant on membrane surface has been carried out. (author) 9 refs.; 4 figs.; 3 tabs

On the structure of thorium and americium adenosine triphosphate complexes

International Nuclear Information System (INIS)

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

2014-01-01

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

On the structure of thorium and americium adenosine triphosphate complexes.

Science.gov (United States)

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

2014-11-01

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

7 CFR 246.11 - Nutrition education.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Nutrition education. 246.11 Section 246.11 Agriculture... Participant Benefits § 246.11 Nutrition education. (a) General. (1) Nutrition education shall be considered a benefit of the Program, and shall be made available at no cost to the participant. Nutrition education...

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

International Nuclear Information System (INIS)

Sehmel, G.A.

1978-01-01

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

Environmental impacts of the release of a transuranic actinide, americium-241, from a contaminated facility

Energy Technology Data Exchange (ETDEWEB)

Want, J.; Merry-Libby, P.

1985-10-29

Americium-241 is widely used as a radiation source, but it also has some potential risk if taken into the body because of its high dose conversion factor. Although the radiotoxicity of americium-241 is small compared to other transuranic actinides, its effects on the reproductive system and on development of the placenta are more damaging than the effects of plutonium-239. In Ohio, a gemologist's laboratory was contaminated with americium-241. Prior to decontamination of the laboratory, potential radiological impacts to the surrounding environment were assessed. A hypothetical fire accident resulting in a unit release (1 curie) was assumed. Potential radiological impacts were simulated using an atmospheric dispersion and dosimetry model with local meteorological data, population census data, and detailed information regarding the neighborhood. The results indicate that there could have been a significant impact on nearby residents from americium-241 via atmospheric dispersion if a major catastrophic release had occurred prior to contamination and decommissioning of the laboratory. 14 refs., 3 figs., 2 tabs.

Airborne plutonium and americium concentrations measured from the top of Rattlesnake Mountain

International Nuclear Information System (INIS)

Sehmel, G.A.

1979-01-01

Airborne plutonium-239+240 and americium-241 blowing from offsite was measured in an initial experiment at the top of Rattlesnake Mountain. Average airborne concentration measured was similar to fallout concentrations. Airborne plutonium concentrations were independent of wind speed for seven wind speed increments between 0.5 and 31 m/sec. In contrast the airborne americium concentration was a minimum at a wind speed of approximately 7 m/sec. Similarly, the airborne solids concentration in μg/m 3 was a minimum at an intermediate wind speed increment of 7 to 11 m/sec

Americium-241 radioisotope thermoelectric generator development for space applications

International Nuclear Information System (INIS)

Ambrosi, Richard; Williams, Hugo; Samara-Ratna, Piyal

2013-01-01

Space nuclear power systems are under development in the UK in collaboration with European partners as part of a European Space Agency (ESA) programme. Radioisotope thermoelectric generators (RTG) are an important element of this new capability in Europe. RTG systems being developed in Europe are targeting the 10 W electric to 50 W electric power generation range adopting a modular scalable approach to the design. Radiogenic decay heat from radioisotopes can be converted to electrical power by using appropriate semiconductor based thermoelectric materials. The plan for Europe is to develop radioisotope space nuclear power systems based on both thermoelectric and Stirling power conversion systems. Although primarily focused on delivering up to 50 W of electrical power, the European radioisotope thermoelectric system development programme is targeting americium-241 as a fuel source and is maximizing the use of commercially available thermoelectric manufacturing processes in order to accelerate the development of power conversion systems. The use of americium provides an economic solution at high isotopic purity and is product of a separation process from stored plutonium produced during the reprocessing of civil nuclear fuel. A laboratory prototype that uses electrical heating as a substitute for the radioisotope was developed to validate the designs. This prototype has now been tested. This paper outlines the requirements for a European americium-241 fuelled RTG, describes the most recent updates in system design and provides further insight into recent laboratory prototype test campaigns. (author)

Americium-241 radioisotope thermoelectric generator development for space applications

Energy Technology Data Exchange (ETDEWEB)

Ambrosi, Richard; Williams, Hugo; Samara-Ratna, Piyal, E-mail: rma8@le.ac.uk [University of Leicester, (United Kingdom); and others

2013-07-01

Space nuclear power systems are under development in the UK in collaboration with European partners as part of a European Space Agency (ESA) programme. Radioisotope thermoelectric generators (RTG) are an important element of this new capability in Europe. RTG systems being developed in Europe are targeting the 10 W electric to 50 W electric power generation range adopting a modular scalable approach to the design. Radiogenic decay heat from radioisotopes can be converted to electrical power by using appropriate semiconductor based thermoelectric materials. The plan for Europe is to develop radioisotope space nuclear power systems based on both thermoelectric and Stirling power conversion systems. Although primarily focused on delivering up to 50 W of electrical power, the European radioisotope thermoelectric system development programme is targeting americium-241 as a fuel source and is maximizing the use of commercially available thermoelectric manufacturing processes in order to accelerate the development of power conversion systems. The use of americium provides an economic solution at high isotopic purity and is product of a separation process from stored plutonium produced during the reprocessing of civil nuclear fuel. A laboratory prototype that uses electrical heating as a substitute for the radioisotope was developed to validate the designs. This prototype has now been tested. This paper outlines the requirements for a European americium-241 fuelled RTG, describes the most recent updates in system design and provides further insight into recent laboratory prototype test campaigns. (author)

Uptake and effects of americium-241 on a brackish-water amphipod

Energy Technology Data Exchange (ETDEWEB)

Hoppenheit, M.; Murray, C.N.; Woodhead, D.S.

1980-01-01

The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0-6.5 even though the water concentration changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element.

Uptake and effects of americium-241 on a brackish-water amphipod

International Nuclear Information System (INIS)

Hoppenheit, M.; Murray, C.N.; Woodhead, D.S.

1980-01-01

The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0-6.5 even though the water concentration changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element. (orig.) [de

An experimental investigation of accumulation and transmutation behavior of americium in the MOX fuel irradiated in a fast reactor

International Nuclear Information System (INIS)

Osaka, Masahiko; Koyama, Shin-ichi; Maeda, Shigetaka; Mitsugashira, Toshiaki

2005-01-01

Americium isotopes generated in the MOX fuel irradiated in the experimental fast reactor JOYO were analyzed by applying a sophisticated radiochemical technique. Americium was isolated from the irradiated MOX fuel by a combined method of anion-exchange chromatography and oxidation of Am. The isotopic ratios of americium and its content were determined by thermal ionization mass spectroscopy and α-spectrometry, respectively. The americium isotopic ratio was similar for all the specimens, but was significantly different from that of PWR-MOX. On the basis of present analytical results, the accumulation and transmutation behavior of americium nuclides in a fast reactor is discussed from the viewpoints of neutron spectrum dependence and the isomeric ratio of the 241 Am capture reaction. The estimated isomeric ratio is about 87%, which is close to the latest evaluated value. A rapid estimation method of Am content by using the 240 Pu to 239 Pu ratio was adopted and proved to be valid for the spent fuel irradiated in the fast reactor

Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium; Experimentelle Arbeiten zur Absicherung von Modellrechnungen und Maximalkonzentrationen fuer Plutonium und Americium

Energy Technology Data Exchange (ETDEWEB)

NONE

2017-02-16

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

Molecular localisation of americium, technetium and cesium in edible marine animals. Their metabolic behavior and their consequences; Localisation moleculaire de l'americium, du technetium et du cesium chez des animaux marins comestibles leur comportement metabolique et ses consequences

Energy Technology Data Exchange (ETDEWEB)

Pieri, J; Goudard, F; Milcent, M C [Laboratoire de Biochimie et Radiochimie, Faculte des Sciences et des Techniques, Nantes Cedex (France)

1992-07-01

We show the molecular behavior of americium, technetium and cesium on the chromatographic pattern of each cytosol in the digestive gland of eel and lobster. The contamination by cadmium seems to compete with americium in the fractions of MW 10,000. Cesium shows an ionic behavior. (author)

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.

Molecular localisation of americium, technetium and cesium in edible marine animals. Their metabolic behavior and their consequences

International Nuclear Information System (INIS)

Pieri, J.; Goudard, F.; Milcent, M.C.

1992-01-01

We show the molecular behavior of americium, technetium and cesium on the chromatographic pattern of each cytosol in the digestive gland of eel and lobster. The contamination by cadmium seems to compete with americium in the fractions of MW 10,000. Cesium shows an ionic behavior. (author)

Americium/curium bushing melter drain tests

International Nuclear Information System (INIS)

Smith, M.E.; Hardy, B.J.; Smith, M.E.

1997-01-01

Americium and curium were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. They have been stored in a nitric acid solution in an SRS reprocessing facility for a number of years. Vitrification of the americium/curium (Am/Cm) solution will allow the material to be safely stored or transported to the DOE Oak Ridge Reservation. Oak Ridge is responsible for marketing radionuclides for research and medical applications. The bushing melter technology being used in the Am/Cm vitrification research work is also under consideration for the stabilization of other actinides such as neptunium and plutonium. A series of melter drain tests were conducted at the Savannah River Technology Center to determine the relationship between the drain tube assembly operating variables and the resulting pour initiation times, glass flowrates, drain tube temperatures, and stop pour times. Performance criteria such as ability to start and stop pours in a controlled manner were also evaluated. The tests were also intended to provide support of oil modeling of drain tube performance predictions and thermal modeling of the drain tube and drain tube heater assembly. These drain tests were instrumental in the design of subsequent melter drain tube and drain tube heaters for the Am/Cm bushing melter, and therefore in the success of the Am/Cm vitrification and plutonium immobilization programs

7 CFR 246.13 - Financial management system.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Financial management system. 246.13 Section 246.13... State Agency Provisions § 246.13 Financial management system. (a) Disclosure of expenditures. The State agency shall maintain a financial management system which provides accurate, current and complete...

Electric resistivity of 241-americium and 244-curium metals. Creation of defects and isochronous annealing of 241-americium metal after self-irradiation

International Nuclear Information System (INIS)

Schenkel, R.

1977-03-01

The temperature dependence of the electrical resistivity of thin films of bulk 241 Am metal were measured between 300 and 4.5 K. The room temperature resistivity was found to be 68.90μΩcm. At room temperature the electrical resistivity of americium increases with pressure (3% up to 13 kbar). The application of 13 kbar pressure did not change the low temperature power law in the electrical resistivity. The resistivity vs temperature curve can be explained by assuming s-d scattering of conduction electrons. The localized 5f electrons are considered to be about 5eV below the Fermi level. Americium therefore should be the first lanthanide-like element in the actinide series. The defect production due to self-irradiation damage was studied by measuring the increase of the resistivity at 4.2 K over a period of 738 h. A saturation resistivity of 16.036 μΩcm was found corresponding to a defect concentration of about 0.22 a/o. After isochronal annealing two recovery stages were observed at about 65 and 145 K. The two stages shift with increasing initial defect concentration to lower temperatures. Estimates of the activation energies and the reaction order were made and possible defect reactions suggested. The magnetic contribution to the electrical resistivity of curium, which shows an antiferromagnetic transition at 52.5 k, was obtained by subtracting the resistivity of americium (to be considered as phonon part). Comparison with theoretical models were made. At low temperatures the measurements are strongly affected by self-irradiation damage [drho/dt(t=0)=9.8μΩcm/h

12 CFR 19.246 - Petition for reinstatement.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Petition for reinstatement. 19.246 Section 19.246 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY RULES OF PRACTICE AND PROCEDURE Removal, Suspension, and Debarment of Accountants From Performing Audit Services § 19.246 Petition...

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

International Nuclear Information System (INIS)

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

1975-01-01

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

Speciation and bioavailability of plutonium and americium in the Irish Sea and other marine ecosystems

International Nuclear Information System (INIS)

Vives i Batlle, J.

1993-12-01

Since the late 1960s, the Irish Sea has become a repository for a variety of radio-elements originating mainly in discharges from the British Nuclear Fuels (BNF) plc. Sellafield reprocessing complex located on the Cumbrian coast. In particular, transuranium nuclides such as plutonium, americium and curium (the main constituents of the α-emitting discharges) have become incorporated into every marine compartment by a variety of mechanisms, many of which are not well understood. Although extensive studies have been carried out in the near-field (eastern Irish Sea, especially in the vicinity of the discharge point and collateral muddy sediments), comparatively little had been done to assess the long-term behaviour and bioavailability of plutonium and americium in the far-field, e.g., the western Irish Sea, prior to the present study. In this dissertation, the results of an extensive research programme, undertaken in order to improve and refine our understanding of the behaviour of plutonium and americium in the marine environment, are presented. Specifically, the thesis details the results of (and conclusions deduced from) a series of experiments in which the physical and chemical speciation, colloidal association, mobility and bioavailability of plutonium and americium were examined in diverse environments including the Irish Sea and the Mediterranean. (author)

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

International Nuclear Information System (INIS)

Fouchard, Sebastien

2000-01-01

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

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

International Nuclear Information System (INIS)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T.; Caisso, M.; Bataille, M.; Bayle, J.P.; Frost, C.; Delage, C.; Martin, C.L.; Ayral, E.

2016-01-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

Energy Technology Data Exchange (ETDEWEB)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Caisso, M.; Bataille, M.; Bayle, J.P. [CEA, Centre de Marcoule, DEN/MAR/DTEC, F-30207 Bagnols-sur-Ceze (France); Frost, C. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France); Delage, C. [CEA, Centre de Cadarache, DEN/CAD/DEC, Saint-Paul-lez-Durance (France); Martin, C.L. [Univ. Grenoble Alpes, CNRS, SIMAP, F-38000 Grenoble (France); Ayral, E. [Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France)

2016-07-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

48 CFR 52.246-14 - Inspection of Transportation.

Science.gov (United States)

2010-10-01

... Transportation. 52.246-14 Section 52.246-14 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION....246-14 Inspection of Transportation. As prescribed in 46.314, insert the following clause in solicitations and contracts for freight transportation services (including local drayage) by rail, motor...

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

Decay study of {sup 246}Fm at SHIP

Energy Technology Data Exchange (ETDEWEB)

Venhart, M. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Antalic, S.; Saro, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Gray-Jones, C.; Herzberg, R.D.; Papadakis, P. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Greenlees, P.T.; Ketelhut, S.; Leino, M. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt am Main (Germany); Rostron, D. [Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt am Main (Germany); Rudolph, D. [Lund University, Department of Physics, Lund (Sweden); Sulignano, B. [CEA Saclay, DAPNIA/SPhN, Gif/Yvette Cedex (France)

2011-02-15

The decay chain of {sup 246}Fm has been investigated employing the SHIP separator at GSI Darmstadt. The {sup 246}Fm nuclei were produced via the {sup 40}Ar({sup 208}Pb, 2n){sup 246}Fm fusion-evaporation reaction. Improved values of the half-life, T{sub 1/2} = 1.54(4) s, and of the spontaneous fission branching ratio, b{sub SF} = 0.068(6), of {sup 246}Fm were obtained. The {beta}{sup +} /electron capture branching ratio, b{sub EC} = 0.39(3), of {sup 242}Cf was deduced. Possible structures of high-K states in {sup 246}Fm are discussed within the framework of a model calculation based on the Woods-Saxon potential. (orig.)

Solubility of Plutonium (IV) Oxalate During Americium/Curium Pretreatment

International Nuclear Information System (INIS)

Rudisill, T.S.

1999-01-01

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitation process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec

Analysis of americium, plutonium and technetium solubility in groundwater

International Nuclear Information System (INIS)

Takeda, Seiji

1999-08-01

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

Contemporary state of plutonium and americium in the soils of Palesse state radiation-ecological reserve

International Nuclear Information System (INIS)

Papenia, M.V.; Sokolik, G.A.; Ovsiannikova, S.V.; Voinikava, E.V.; Svirschevsky, S.F.; Brown, J.; Skipperud, L.

2010-01-01

Full text: At present, the most important alpha-emitting radionuclides of Chernobyl origin are Pu 238, Pu 239, Pu 240 and Am 241. They are classified as the most dangerous group of radionuclides in view of the long half-lives and high radiotoxicity. The main part of alpha-emitted radionuclides is located within the Palesse State Radiation-Ecological Reserve. One of the most important factors determining the radioecological situation in the contaminated ecosystems is the physicochemical forms of radionuclides in a soil medium. Radionuclide species determine the radionuclide entrance into the soil solutions, their redistribution in soil profiles and the 'soil - plant' and the 'soil - surface, ground or underground water' systems as well as spreading beyond the contaminated area. The present work is devoted to investigation of state and migration ability of plutonium and americium in soils of the Palesse state radiation-ecological reserve after more than 20 years from the Chernobyl accident. The objects of investigation were mineral and organic soils sampled in 2008 with the step of 5 cm to the depth of 25-30 cm. The forms of plutonium and americium distinguishing by association with the different components of soil and by potential for migration in the soil medium were studied using the method of sequential selective extraction according to the modified Tessier scheme. Activities of Pu 238, Pu 239, Pu 240 and Am 241 in the samples were determined by the method of radiochemical analysis with alpha-spectrometer radionuclide identification. The dominant part of plutonium and americium in the soils is in immobile forms. Nowadays, radionuclide portions in water soluble and reversibly bound forms do not exceed 9.4 % of radionuclide content in the soil. In mineral soil samples, the radionuclide portions in these fractions exceed the corresponding portions in organic ones. In both mineral and organic soils, the portions of mobile americium are higher than plutonium. The

Contribution to the study of higher valency states of americium

International Nuclear Information System (INIS)

Langlet, Jean.

1976-01-01

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

Lifetime followup of the 1976 americium accident victim: [Final report

International Nuclear Information System (INIS)

Breitenstein, B.D. Jr.; Palmer, H.E.

1988-05-01

This report describes the 11 year medical course of Harold R. McCluskey, a Hanford nuclear chemical operator, who, at age 64, was involved in an accident in an americium recovery facility in August 1976. As a result of the accident, he was heavily contaminated with americium (Am-241), 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 immediate and long-term medical care is summarized, including decontamination procedures, chelation therapy, and routine and special clinical laboratories studies. The estimates of the operator's Am-241 deposition, post accident and during the remainder of his life and the special techniques and equipment used to make the estimates, are reported. Post-accident, the total amount of Am-241 excreted in his urine and feces was 41 MBq (1.1 mCi). He died of complications of chronic coronary artery disease on August 17, 1987. 20 refs., 2 figs

Plant uptake of americium, curium, and the chemical analog neodymium

International Nuclear Information System (INIS)

Weimer, W.C.; Laul, J.C.; Kutt, J.C.; Bondietti, E.A.

1977-01-01

The plant uptake from several bulk soils has been determined for neodymium, a chemical analog to the transuranium elements americium and curium, and several other native rare earth elements as well. These investigations have demonstrated that neodymium, which has very similar chemical properties to amercium and curium and should have a similar environmental behavior, does behave indistinguishably under both laboratory and field conditions. The uptake of the weathered or mobile forms of these elements from soils is expected to be governed primarily by their identical oxidation states and nearly identical ionic radii. This hypothesis is strongly supported by the chondritic (primordial) normalized rare earth element patterns in several plants. In these samples, the entire series of rare earth elements behaves as a smooth function of the REE ionic radii, as is also seen in the contiguous soils. This behavior suggests that the plant uptake of other ions with similar chemical properties (i.e., americium and curium) would also be governed by ionic size and charge

7 CFR 246.10 - Supplemental foods.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Supplemental foods. 246.10 Section 246.10 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE... nutritional needs of the participant. The food packages are as follows: (1) Food Package I—Infants birth...

Ingestion Pathway Transfer Factors for Plutonium and Americium

International Nuclear Information System (INIS)

Blanchard, A.

1999-01-01

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

Thermodynamic systematics of oxides of americium, curium, and neighboring elements

International Nuclear Information System (INIS)

Morss, L.R.

1984-01-01

Recently-obtained calorimetric data on the sesquioxides and dioxides of americium and curium are summarized. These data are combined with other properties of the actinide elements to elucidate the stability relationships among these oxides and to predict the behavior of neighboring actinide oxides. 45 references, 4 figures, 5 tables

7 CFR 246.1 - General purpose and scope.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false General purpose and scope. 246.1 Section 246.1... General § 246.1 General purpose and scope. This part announces regulations under which the Secretary of... health by reason of inadequate nutrition or health care, or both. The purpose of the Program is to...

Extraction separation of americium and curium. A review

International Nuclear Information System (INIS)

Petrzilova, H.

1976-11-01

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

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

International Nuclear Information System (INIS)

Raison, P.E.

2001-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

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

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

International Nuclear Information System (INIS)

2017-01-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

40 CFR 246.200 - High-grade paper recovery.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-grade paper recovery. 246.200 Section 246.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOURCE... paper recovery. ...

Plutonium and americium extraction studies with bifunctional organophosphorus extractants

International Nuclear Information System (INIS)

Navratil, J.D.

1985-01-01

Neutral bifunctional organophosphorus extractants, such as octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethylphosphonate (CMP), are under study at the Rocky Flats Plant (RFP) to remove plutonium and americium from the 7M nitric acid waste. These compounds extract trivalent actinides from strong nitric acid, a property which distinguishes them from monofunctional organiphosphorus reagents. Furthermore, the reagents extract hydroytic plutonium (IV) polymer which is present in the acid waste stream. The compounds extract trivalent actinides with a 3:1 stoichiometry, whereas tetra- and hexavalent actinides extract with a stoichiometry of 2:1. Preliminary studies indicate that the extracted plutonium polymer complex contains one to two molecules of CMP per plutonium ion and the plutonium(IV) maintains a polymeric structure. Recent studies by Horwitz and co-workers conclude that the CMPO and CMP reagents behave as monodentate ligands. At RFP, three techniques are being tested for using CMP and CMPO to remove plutonium and americium from nitric acid waste streams. The different techniques are liquid-liquid extraction, extraction chromatography, and solid-supported liquid membranes. Recent tests of the last two techniques will be briefly described. In all the experiments, CMP was an 84% pure material from Bray Oil Co. and CMPO was 98% pure from M and T Chemicals

Determination of plutonium, americium and curium in the marine environment

International Nuclear Information System (INIS)

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

1982-01-01

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

1976 Hanford americium-exposure incident: decontamination and treatment facility

International Nuclear Information System (INIS)

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

1982-01-01

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

The transmutation of americium: the Ecrix experiments in Phenix; Transmutation de l'americium: les experiences ecrix dans Phenix

Energy Technology Data Exchange (ETDEWEB)

Garnier, J C; Schmidt, N [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SESC), 13 - Saint-Paul-lez-Durance (France); Croixmarie, Y; Ottaviani, J P [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SPUA), 13 - Saint-Paul-lez-Durance (France); Varaine, F; Saint Jean, C de [CEA Cadarache, Dept. d' Etudes des Reacteurs (DER/SPRC), 13 - Saint-Paul-lez-Durance (France)

1999-07-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be {sup 11}B{sub 4}C and CaH{sub 2} for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO{sub X} pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

40 CFR 246.201-6 - Recommended procedures: Transportation to market.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Transportation to market. 246.201-6 Section 246.201-6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Procedures § 246.201-6 Recommended procedures: Transportation to market. Transportation to market may be...

48 CFR 52.246-5 - Inspection of Services-Cost-Reimbursement.

Science.gov (United States)

2010-10-01

...-Cost-Reimbursement. 52.246-5 Section 52.246-5 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.246-5 Inspection of Services—Cost-Reimbursement. As prescribed in 46.305, insert... furnishing of services, when a cost-reimbursement contract is contemplated: Inspection of Services—Cost...

48 CFR 52.246-3 - Inspection of Supplies-Cost-Reimbursement.

Science.gov (United States)

2010-10-01

...-Cost-Reimbursement. 52.246-3 Section 52.246-3 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.246-3 Inspection of Supplies—Cost-Reimbursement. As prescribed in 46.303, insert... furnishing of supplies, when a cost-reimbursement contract is contemplated: Inspection of Supplies—Cost...

Uptake and recovery of americium and uranium by Anacystis biomass

International Nuclear Information System (INIS)

Liu, H.H.; Jiunntzong Wu

1993-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-10-16

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

A simple approach to determine the diffusivity of americium in granite

International Nuclear Information System (INIS)

Song, L.; Feng, X.; Liang, J.; Zhang, Y.; Wang, J.

2009-01-01

The diffusivities of the key radionuclides in host rock are important for the performance assessment of repositories. One of the conventional methods for determining the diffusivities of radionuclides is to grind the rock tablet layer by layer and then to measure the radioactivity remaining on the rock tablet before each grinding cycle. Since grinding hard rock samples, especially those with radioactivity, is very difficult, we developed a new approach to determine the diffusivity of americium in granite. The new approach mainly includes two parts: one is to measure the radioactivities from both sides of a rock disk sample by autoradiography with phosphor imaging technique; the other is to study the relationship between the radioactivities and the apparent diffusivity of americium in granite by computer modelling. Because the high contamination risk of grinding radioactive rock samples has been avoided, the new approach is much simpler than the conventional method. It may be a better choice of measuring the diffusivities of radionuclides in rock, especially for those laboratories in which grinding radioactive rock samples is inconvenient. (orig.)

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.

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Recovery of americium-241 from aged plutonium metal

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Reilly, T.A.; Wilson, T.W.; McKibben, J.M.

1980-01-01

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

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

International Nuclear Information System (INIS)

Zhang, Youpeng; Wallenius, Janne

2014-01-01

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

7 CFR 246.6 - Agreements with local agencies.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Agreements with local agencies. 246.6 Section 246.6 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND CHILDREN...

48 CFR 852.246-72 - Frozen processed foods.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Frozen processed foods. 852.246-72 Section 852.246-72 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS... Frozen processed foods. As prescribed in 846.302-72, insert the following clause: Frozen Processed Foods...

The transmutation of americium: the Ecrix experiments in Phenix; Transmutation de l'americium: les experiences ecrix dans Phenix

Energy Technology Data Exchange (ETDEWEB)

Garnier, J.C.; Schmidt, N. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SESC), 13 - Saint-Paul-lez-Durance (France); Croixmarie, Y.; Ottaviani, J.P. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SPUA), 13 - Saint-Paul-lez-Durance (France); Varaine, F.; Saint Jean, C. de [CEA Cadarache, Dept. d' Etudes des Reacteurs (DER/SPRC), 13 - Saint-Paul-lez-Durance (France)

1999-07-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be {sup 11}B{sub 4}C and CaH{sub 2} for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO{sub X} pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

Co-precipitation of plutonium(IV) and americium(III) from nitric acid-oxalic acid solutions with bismuth oxalate

International Nuclear Information System (INIS)

Pius, I.C.; Noronha, D.M.; Chaudhury, Satyajeet

2017-01-01

Co-precipitation of plutonium and americium from nitric acid-oxalic acid solutions with bismuth oxalate has been investigated for the removal of these long lived α-active nuclides from waste solutions. Effect of concentration of bismuth and oxalic acid on the co-precipitation of Pu(IV) from 3 M HNO_3 has been investigated. Similar experiments were also carried out from 3.75 M HNO_3 on co-precipitation of Am(III) to optimize the conditions of precipitation. Strong co-precipitation of Pu(IV) and Am(III) with bismuth oxalate indicate feasibility of treatment of plutonium and americium bearing waste solutions. (author)

Radiochemical separation and alpha-spectrometric determination of Americium in different matrixes

International Nuclear Information System (INIS)

Radenkovic, M.; Joksic, J.; Paligoric, D.

2009-01-01

A method of separation and alpha-spectrometric determination of americium, developed in VINCA Institute of Nuclear Sciences is described in the paper. The procedure is convenient to be used for 241 Am determination in environmental matrixes as well as samples of human origin if a very small concentrations are expected, using 243 Am as a tracer for radiochemical yield recovery. (author) [sr

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

International Nuclear Information System (INIS)

Murray, C.N.; Fukai, R.

1976-01-01

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

7 CFR 246.5 - Selection of local agencies.

Science.gov (United States)

2010-01-01

... consider how much of the current need is being met at each priority level. The selection criteria cited in... 7 Agriculture 4 2010-01-01 2010-01-01 false Selection of local agencies. 246.5 Section 246.5 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF...

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

International Nuclear Information System (INIS)

Navratil, J.D.

1984-01-01

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

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

International Nuclear Information System (INIS)

Guillou, P.

1990-12-01

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

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

International Nuclear Information System (INIS)

Hourcade, E.

2004-01-01

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

Transfer of environmental plutonium and americium across the human gut

International Nuclear Information System (INIS)

Hunt, G.J.; Leonard, D.R.P.; Lovett, M.B.

1989-01-01

Following the ingestion of winkles obtained from a coastal area near Sellafield nuclear reprocessing plant, a group of volunteers provided urine for the next 7 days to be analysed for plutonium and americium. From this, estimates of the intake and gut transfer factors for these isotopes were determined. Preliminary estimates of gut transfer factors from a previous study by the same authors were then re-interpreted and combined with the results from the present study. (UK)

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-04-11

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

Mycoremediation. The study of transfer factor for plutonium and americium uptake from the ground

International Nuclear Information System (INIS)

Dusan Galanda; Lubomir Matel; Jana Strisovska; Silvia Dulanska

2014-01-01

In our scientific research we have monitored mycoremediation's properties of oyster mushrooms in cultivation on the soil what is contaminated by solutions with radioactive isotopes of 239 Pu and 241 Am with known activity. We monitored specific activities of absorbed radionuclides in fruiting bodies and chemical forms of radionuclides which were compared to calculated specific activities of two background samples of oyster mushrooms intended for consumer purpose. We determined distributive coefficients between the ground and the fruiting body of oyster mushrooms. The average value which was obtained for the transfer factor for plutonium was 0.72 and for americium 3.97. To evaluate a quantity of absorbed radionuclides we used a method of liquid extraction. The emitting alpha radiation of alpha radionuclides was detected by spectrometry. For defining individual fractions of plutonium and americium that are contained in mushroom bodies was used the sequential leaching method. (author)

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

International Nuclear Information System (INIS)

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

1976-01-01

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

Effect of 241-americium on bone marrow stroma

International Nuclear Information System (INIS)

Heuvel, R. van den

1990-01-01

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

The extraction of lanthanides and americium by benzyldiakylamines and benzyltrialkylammonium nitrates from the nitrate solutions; structure and aggregation of their salts

International Nuclear Information System (INIS)

Jedinakova, V.; Zilkova, J.; Dvorak, Z.; Vojtiskova, M.

1982-01-01

Benzyldialkylamine and benzyltrialkylammonium nitrates were used for the extraction of lanthanides and americium from aqueous nitrate solutions. The dependence of the extraction performance for Ln(III) and Am(III) on the concentration of nitric acid, the kind and concentration of salting-out agents in the aqueous phase, and the kind of solvent were investigated. The extraction of Am(III) is compared with the extraction of lanthanides. The difference in distribution coefficients for lanthanides and americium can be utilized for the separation of lanthanides and americium. Using vapor phase osmometry and cryoscopy the association of these compounds was measured at 5.5deg, 25deg and 37deg C, allowing rough estimates of ΔH and ΔS for the formation of the aggregates, monomers in the case of benzyldiethylamine, benzyldibutylamine, benzyldihexylamine and benzyldioctylamine, tetramers for the benzyldibutylamine nitrate and tetramers for benzyldimethyldodecylammonium nitrate. (author)

Pretreatment of americium/curium solutions for vitrification

International Nuclear Information System (INIS)

Rudisill, T.S.

1996-01-01

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

The potential of ion mobility spectrometry (IMS) for detection of 2,4,6-trichloroanisole (2,4,6-TCA) in wine.

Science.gov (United States)

Karpas, Zeev; Guamán, Ana V; Calvo, Daniel; Pardo, Antonio; Marco, Santiago

2012-05-15

The off-flavor of "tainted wine" is attributed mainly to the presence of 2,4,6-trichloroanisole (2,4,6-TCA) in the wine. In the present study the atmospheric pressure gas-phase ion chemistry, pertaining to ion mobility spectrometry, of 2,4,6-trichloroanisole was investigated. In positive ion mode the dominant species is a monomer ion with a lower intensity dimer species with reduced mobility values (K(0)) of 1.58 and 1.20 cm(2)V(-1) s(-1), respectively. In negative mode the ion with K(0) =1.64 cm(2)V(-1)s(-1) is ascribed to a trichlorophenoxide species while the ions with K(0) =1.48 and 1.13 cm(2)V(-1)s(-1) are attributed to chloride attachment adducts of a TCA monomer and dimer, respectively. The limit of detection of the system for 2,4,6-TCA dissolved in dichloromethane deposited on a filter paper was 2.1 μg and 1.7 ppm in the gas phase. In ethanol and in wine the limit of detection is higher implying that pre-concentration and pre-separation are required before IMS can be used to monitor the level of TCA in wine. Copyright © 2012 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Falk, R.B.; Lagerquist, C.R.

1975-01-01

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 []parameters which yielded matches to the observed count histories. (auth)

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

Directory of Open Access Journals (Sweden)

Kooyman Timothée

2018-01-01

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

Sorption of plutonium and americium on repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Heath, T.G.; Tweed, C.J.; Williams, S.J.

1995-01-01

An integrated program of batch sorption experiments and mathematical modeling has been carried out to study the sorption of plutonium and americium on a series of repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura. The sorption of plutonium and americium on samples of concrete, mortar, sand/bentonite, tuff, sandstone and cover soil has been investigated. In addition, specimens of bitumen, cation and anion exchange resins, and polyester were chemically degraded. The resulting degradation product solutions, alongside solutions of humic and isosaccharinic acids were used to study the effects on plutonium sorption onto concrete, sand/bentonite and sandstone. The sorption behavior of plutonium and americium has been modeled using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database

48 CFR 52.246-8 - Inspection of Research and Development-Cost-Reimbursement.

Science.gov (United States)

2010-10-01

... Development-Cost-Reimbursement. 52.246-8 Section 52.246-8 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.246-8 Inspection of Research and Development—Cost-Reimbursement. As prescribed in... (b) a cost-reimbursement contract is contemplated; unless use of the clause is impractical and the...

National low-level waste management program radionuclide report series, Volume 14: Americium-241

International Nuclear Information System (INIS)

Winberg, M.R.; Garcia, R.S.

1995-09-01

This report, Volume 14 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of americium-241 ( 241 Am). This report also includes discussions about waste types and forms in which 241 Am can be found and 241 Am behavior in the environment and in the human body

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

International Nuclear Information System (INIS)

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

1979-01-01

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

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)

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)

Luisier, F.; Corcho Alvarado, J.A.; Froidevaux, P.; Steinmann, P.; Krachler, M.

2009-01-01

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 Eichrom R 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 Eichrom R 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 239 Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement. (author)

48 CFR 52.246-17 - Warranty of Supplies of a Noncomplex Nature.

Science.gov (United States)

2010-10-01

... Noncomplex Nature. 52.246-17 Section 52.246-17 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.246-17 Warranty of Supplies of a Noncomplex Nature. As prescribed in 46.710(a)(1), insert a clause substantially as follows: Warranty of Supplies of a Noncomplex Nature (JUN 2003) (a) Definitions...

Implications of plutonium and americium recycling on MOX fuel fabrication

International Nuclear Information System (INIS)

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

1995-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Runde, W; Kim, J I

1994-09-15

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

Americium/Curium Vitrification Pilot Tests - Part II

International Nuclear Information System (INIS)

Marra, J.E.; Baich, M.A.; Fellinger, A.P.; Hardy, B.J.; Herman, D.T.; Jones, T.M.; Miller, C.B.; Miller, D.H.; Snyder, T. K.; Stone, M.E.

1998-05-01

Isotopes of americium (Am) and curium (Cm) were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. These highly radioactive and valuable isotopes have been stored in an SRS reprocessing facility for a number of years. Vitrification of this solution will allow the material to be more safely stored until it is transported to the DOE Oak Ridge Reservation for use in research and medical applications. A previous paper described operation results from the Am-Cm Melter 2A pilot system, a full-scale non-radioactive pilot facility. This paper presents the results from continued testing in the Pilot Facility and also describes efforts taken to look at alternative vitrification process operations and flowsheets designed to address the problems observed during melter 2A pilot testing

Behavior of americium in aqueous carbonate systems

Energy Technology Data Exchange (ETDEWEB)

Silva, R.J.

1983-11-01

The solubilities of crystalline Am(OH)/sub 3/ and AmOHCO/sub 3/ were measured at 25/sup 0/C in aqueous solutions of 0.1 M NaClO/sub 4/ by determination of the solution concentrations of Am. Prior to use in the measurements, the solid materials were characterized by their x-ray powder diffraction patterns. The solubility product quotients were calculated from the experimental data. The hydrolysis quotients of Am/sup 3 +/ were also estimated from the hydroxide solubility data. Using the thermodynamic data derived from these experiments and the recently reported formation constants for the Am/sup 3 +/ carbonate complexes, the solid phases and concentrations of solution species of americium in several aqueous carbonate systems were calculated using the computer code MINEQL. 20 references, 1 figure, 1 table.

32 CFR 246.1 - Purpose.

Science.gov (United States)

2010-07-01

... STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS § 246.1 Purpose. This part: (a) Establishes policy... the S&S newspapers. (c) Authorizes the establishment, management, operation, and oversight of the... mission, production, distribution authority, and business operations as mission-essential activities of...

Worldwide bioassay data resources for plutonium/americium internal dosimetry studies

International Nuclear Information System (INIS)

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

2005-01-01

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

48 CFR 52.246-18 - Warranty of Supplies of a Complex Nature.

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2010-10-01

... Complex Nature. 52.246-18 Section 52.246-18 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.246-18 Warranty of Supplies of a Complex Nature. As prescribed in 46.710(b)(1), insert a clause substantially as follows: Warranty of Supplies of a Complex Nature (MAY 2001) (a) Definitions. As used in this...

XRD monitoring of α self-irradiation in uranium-americium mixed oxides.

Science.gov (United States)

Horlait, Denis; Lebreton, Florent; Roussel, Pascal; Delahaye, Thibaud

2013-12-16

The structural evolution under (241)Am self-irradiation of U(1-x)Am(x)O(2±δ) transmutation fuels (with x ≤ 0.5) was studied by X-ray diffraction (XRD). Samples first underwent a preliminary heat treatment performed under a reducing atmosphere (Ar/H2(4%)) aiming to recover the previously accumulated structural defects. Over all measurements (carried out over up to a full year and for integrated doses up to 1.5 × 10(18) α-decay events·g(-1)), only fluorite U(1-x)Am(x)O(2±δ) solid solutions were observed. Within a few days after the end of the heat treatment, each of the five studied samples was slowly oxidized as a consequence of their move to air atmosphere, which is evidenced by XRD by an initial sharp decrease of the unit cell parameter. For the compounds with x ≤ 0.15, this oxidation occurred without any phase transitions, but for U0.6Am0.4O(2±δ) and U0.5Am0.5O(2±δ), this process is accompanied by a transition from a first fluorite solid solution to a second oxidized one, as the latter is thermodynamically stable in ambient conditions. In the meantime and after the oxidation process, (241)Am α self-irradiation caused a structural swelling up to ∼0.8 vol %, independently of the sample composition. The kinetic constants of swelling were also determined by regression of experimental data and are, as expected, dependent on x and thus on the dose rate. The normalization of these kinetic constants by sample α-activity, however, leads to very close swelling rates among the samples. Finally, evolutions of microstrain and crystallite size were also monitored, but for the considered dose rates and cumulated doses, α self-irradiation was found, within the limits of the diffractometer used, to have almost no impact on these characteristics. Microstrain was found to be influenced instead by the americium content in the materials (i.e., by the impurities associated with americium starting material and the increase of cationic charge heterogeneity with

Interaction of 2,4,6-trichlorophenol with high carbon iron filings: Reaction and sorption mechanisms

Energy Technology Data Exchange (ETDEWEB)

Sinha, Alok [Environmental Engineering and Management Programme, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Bose, Purnendu [Environmental Engineering and Management Programme, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)], E-mail: pbose@iitk.ac.in

2009-05-15

Reductive dehalogenation of 2,4,6-trichlorophenol (2,4,6-TCP) by two types of high carbon iron filings (HCIF), HCIF-1 and HCIF-2 was studied in batch reactors. While the iron, copper, manganese and carbon content of the two types of HCIF was similar, the specific surface area of HCIF-1 and HCIF-2 were 1.944 and 3.418 m{sup 2} g{sup -1}, respectively. During interaction with HCIF-1, 2,4,6-TCP adsorbed on HCIF-1 surface resulting in rapid reduction of aqueous phase 2,4,6-TCP concentration. However, reductive dehalogenation of 2,4,6-TCP was negligible. During interaction between 2,4,6-TCP and HCIF-2, both 2,4,6-TCP adsorption on HCIF-2, and 2,4,6,-TCP dechlorination was observed. 2,4,6-TCP partitioning between solid and aqueous phase could be described by a Freundlich isotherm, while 2,4,6-TCP dechlorination could be described by an appropriate rate expression. A mathematical model was developed for describing the overall interaction of 2,4,6-TCP with HCIF-2, incorporating simultaneous adsorption/desorption and dechlorination reactions of 2,4,6-TCP with the HCIF surface. 2,4-Dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and minor amounts of 4-chlorophenol (4-CP) evolved as 2,4,6-TCP dechlorination by-products. The evolved 2,4-DCP partitioned strongly to the HCIF surface. 4-CP and 2-CP accumulated in the aqueous phase. No transformation of 2-CP or 4-CP to phenol was observed.

Development of analytical methods for the separation of plutonium, americium, curium and neptunium from environmental samples

Energy Technology Data Exchange (ETDEWEB)

Salminen, S.

2009-07-01

In this work, separation methods have been developed for the analysis of anthropogenic transuranium elements plutonium, americium, curium and neptunium from environmental samples contaminated by global nuclear weapons testing and the Chernobyl accident. The analytical methods utilized in this study are based on extraction chromatography. Highly varying atmospheric plutonium isotope concentrations and activity ratios were found at both Kurchatov (Kazakhstan), near the former Semipalatinsk test site, and Sodankylae (Finland). The origin of plutonium is almost impossible to identify at Kurchatov, since hundreds of nuclear tests were performed at the Semipalatinsk test site. In Sodankylae, plutonium in the surface air originated from nuclear weapons testing, conducted mostly by USSR and USA before the sampling year 1963. The variation in americium, curium and neptunium concentrations was great as well in peat samples collected in southern and central Finland in 1986 immediately after the Chernobyl accident. The main source of transuranium contamination in peats was from global nuclear test fallout, although there are wide regional differences in the fraction of Chernobyl-originated activity (of the total activity) for americium, curium and neptunium. The separation methods developed in this study yielded good chemical recovery for the elements investigated and adequately pure fractions for radiometric activity determination. The extraction chromatographic methods were faster compared to older methods based on ion exchange chromatography. In addition, extraction chromatography is a more environmentally friendly separation method than ion exchange, because less acidic waste solutions are produced during the analytical procedures. (orig.)

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

International Nuclear Information System (INIS)

Umbarger, C.J.; Jett, J.H.

1976-01-01

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

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

International Nuclear Information System (INIS)

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

1999-01-01

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

12 CFR 24.6 - Examples of qualifying public welfare investments.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Examples of qualifying public welfare investments. 24.6 Section 24.6 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY... finance small businesses or small farms, including minority- and women-owned small businesses or small...

Quantitative determination of americium and curium in solutions using potassium tungstophosphate

International Nuclear Information System (INIS)

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

1990-01-01

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

Vitrification of F-area americium/curium: feasibility study and preliminary process recommendation

International Nuclear Information System (INIS)

Ramsey, W.G.; Miller, D.; Minichan, R.; Coleman, L.; Schumacher, R.; Hardy, B.; Jones, R.

1994-01-01

Work was performed to identify a process to vitrify the contents of F- canyon Tank 17.1. Tank 17.1 contains the majority of americium (Am) and curium (Cm) contained in the DOE Complex. Oak Ridge National Laboratory (ORNL) has made a formal request for this material as fuel for production of Cf252 and other transplutonium actinides. The Am and Cm (and associated lanthanide fission products) are currently in nitric acid solution. Transportation of the intensely radioactive Am/Cm in liquid form is not considered possible. As a result, the material will either be solidified and shipped to ORNL or discarded to the Tank Farm. Nuclear Materials Processing Technology (NMPT), therefore, requested Defense Waste Processing Technology (DWPT) to determine if the Tank 17.1 material could be vitrified, and if it was vitrified could the americium and curium be successfully recovered. Research was performed to determine if the Tank 17.1 contents could indeed be mixed with glass formers and vitrified. Additional studies identified critical process parameters such as heat loading, melter requirements, off-gas evolution, etc. Discussions with NMPT personnel were initiated to determine existing facilities where this work could be accomplished safely. A process has been identified which will convert the Am/Cm material into approximately 300kg of glass

The transmutation of americium: the Ecrix experiments in Phenix

International Nuclear Information System (INIS)

Garnier, J.C.; Schmidt, N.; Croixmarie, Y.; Ottaviani, J.P.; Varaine, F.; Saint Jean, C. de

1999-01-01

The first americium transmutation experiment in a specific target in PHENIX will occur with the ECRIX-B and ECRIX-H experiments. Beside material testing, the objective is also to represent a concept of transmutation whose specificity is to enhance the kinetics of transmutation by using a moderated spectrum. The moderator materials will be 11 B 4 C and CaH 2 for ECRIX-B and ECRIXH respectively, the irradiation conditions have been predicted for both the neutronics and thermal. The targets (MgO-AmO X pellets) are manufactured in the ATALANTE laboratory and the design is performed according to the PHENIX operating conditions. (authors)

Robotic sample preparation for radiochemical plutonium and americium analyses

International Nuclear Information System (INIS)

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

1985-01-01

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

32 CFR 246.4 - Policy.

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2010-07-01

... through newspaper sales, resale of commercial publications, authorized advertising, job printing, and... STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS § 246.4 Policy. It is DoD policy that: (a) The U.S... the Stars and Stripes editorial staffs the same help provided to commercial newspapers, in compliance...

32 CFR 246.6 - Procedures.

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2010-07-01

... costs and to increase the efficiency and effectiveness of these audits. Information copies of the audit... STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS § 246.6 Procedures. (a) General. (1) Authority to...) The Stars and Stripes and the S&S business operations shall conform to applicable regulations and laws...

In situ characterization of uranium and americium oxide solid solution formation for CRMP process: first combination of in situ XRD and XANES measurements.

Science.gov (United States)

Caisso, Marie; Picart, Sébastien; Belin, Renaud C; Lebreton, Florent; Martin, Philippe M; Dardenne, Kathy; Rothe, Jörg; Neuville, Daniel R; Delahaye, Thibaud; Ayral, André

2015-04-14

Transmutation of americium in heterogeneous mode through the use of U1-xAmxO2±δ ceramic pellets, also known as Americium Bearing Blankets (AmBB), has become a major research axis. Nevertheless, in order to consider future large-scale deployment, the processes involved in AmBB fabrication have to minimize fine particle dissemination, due to the presence of americium, which considerably increases the risk of contamination. New synthesis routes avoiding the use of pulverulent precursors are thus currently under development, such as the Calcined Resin Microsphere Pelletization (CRMP) process. It is based on the use of weak-acid resin (WAR) microspheres as precursors, loaded with actinide cations. After two specific calcinations under controlled atmospheres, resin microspheres are converted into oxide microspheres composed of a monophasic U1-xAmxO2±δ phase. Understanding the different mechanisms during thermal conversion, that lead to the release of organic matter and the formation of a solid solution, appear essential. By combining in situ techniques such as XRD and XAS, it has become possible to identify the key temperatures for oxide formation, and the corresponding oxidation states taken by uranium and americium during mineralization. This paper thus presents the first results on the mineralization of (U,Am) loaded resin microspheres into a solid solution, through in situ XAS analysis correlated with HT-XRD.

Plutonium, americium, and uranium in blow-sand mounds of safety-shot sites at the Nevada Test Site and the Tonopah Test Range

International Nuclear Information System (INIS)

Essington, E.H.; Gilbert, R.O.; Wireman, D.L.; Brady, D.N.; Fowler, E.B.

1977-01-01

Blow-sand mounds or miniature sand dunes and mounds created by burrowing activities of animals were investigated by the Nevada Applied Ecology Group (NAEG) to determine the influence of mounds on plutonium, americium, and uranium distributions and inventories in areas of the Nevada Test Site and Tonopah Test Range. Those radioactive elements were added to the environment as a result of safety experiments of nuclear devices. Two studies were conducted. The first was to estimate the vertical distribution of americium in the blow-sand mounds and in the desert pavement surrounding the mounds. The second was to estimate the amount or concentration of the radioactive materials accumulated in the mound relative to the desert pavement. Five mound types were identified in which plutonium, americium, and uranium concentrations were measured: grass, shrub, complex, animal, and diffuse. The mount top (that portion above the surrounding land surface datum), the mound bottom (that portion below the mound to a depth of 5 cm below the surrounding land surface datum), and soil from the immediate area surrounding the mound were compared separately to determine if the radioactive elements had concentrated in the mounds. Results of the studies indicate that the mounds exhibit higher concentrations of plutonium, americium, and uranium than the immediate surrounding soil. The type of mound does not appear to have influenced the amount of the radioactive material found in the mound except for the animal mounds where the burrowing activities appear to have obliterated distribution patterns

Americium-curium vitrification process development

International Nuclear Information System (INIS)

Fellinger, A.P.; Baich, M.A.; Hardy, B.J

1999-01-01

The successful demonstration of sequentially drying, calcining and vitrifying an oxalate slurry in the Drain Tube Test Stand (DTTS) vessel provided the process basis for testing on a larger scale in a cylindrical induction heated melter. A single processing issue, that of batch volume expansion, was encountered during the initial stage of testing. The increase in batch volume centered on a sintered frit cap and high temperature bubble formation. The formation of a sintered frit cap expansion was eliminated with the use of cullet. Volume expansions due to high temperature bubble formation (oxygen liberation from cerium reduction) were mitigated in the DTTS melter vessel through a vessel temperature profile that effectively separated the softening point of the glass cullet and the evolving oxygen from cerium reduction. An increased processing temperature of 1,470 C and a two hour hold time to find any remaining bubbles successfully reduced bubbles in the poured glass to an acceptable level. The success of the preliminary process demonstrations provided a workable process basis that was directly applicable to the newly installed Cylindrical Induction Melter (CIM) system, making the batch flowsheet the preferred option for vitrification of the americium-curium surrogate feed stream

Experimental and in situ investigations on americium, curium and plutonium behaviour in marine benthic species: transfer from water or sediments

International Nuclear Information System (INIS)

Miramand, P.

1984-06-01

The tranfer of transuranic elements -americium, curium and plutonium- from the sediments containing them to some marine benthic species (endofauna and epifauna) was studied with a twofold approach - laboratory and in-situ investigation. The experimental investigations, divided into three parts, made it possible to specify concentration factors (F.C.), transfer factors (F.T.) and to understand the process involved for 5 benthic species. The result were refined by an in-situ study that brought new data on the marine distribution of the transuranic elements released by the La Hague plant. Finally, the localization of americium and plutonium in the tissues and cells of these species was determined by autoradiography [fr

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

International Nuclear Information System (INIS)

Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G.

2004-01-01

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

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 co...

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

Energy Technology Data Exchange (ETDEWEB)

D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Knol, S.; Fedorov, A.V. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Fernandez, A.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Klaassen, F. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands)

2015-10-15

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 {sup 241}Am 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 {sup 10}B 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.

AKTİF KARBON ÜZERİNE 2,4,6-TRİKLOROFENOLÜN ADSORPSİYONU

OpenAIRE

Tümsek, Fatma; Bayındır, Zekiye; Bodur, Gökçen; Koyuncu, Zelal

2015-01-01

2,4,6-Trichlorophenol is a phenolic compound which is widely used in the production of pesticides, herbicides, wood, leather and glue preservatives. In addition, 2,4,6- trichlorophenol may form during the treatment of phenol containing industrial wastewater with hypochlorite or during the disinfection of drinking-water sources. The removal of 2,4,6-trichlorophenol is significant because of its high toxicity, carcinogenic properties and persistence [1].In this study, the adsorption of 2,4,6-tr...

Explosion of cation exchange column in americium recovery service, Hanford plant, August 30, 1976

International Nuclear Information System (INIS)

1976-01-01

This document is a collection of thirty references related to the explosion of the cation exchange column in the Americium Recovery Service of the Hanford Atomic Products Operation, Richland, Washington, on August 30, 1976. Some of the documents are related to the design and safety studies, while others refer to the accident and resulting decontamination efforts, investigations, and legal consequences

Recovery of americium from slag and crucible wastes and its purification

International Nuclear Information System (INIS)

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

1990-01-01

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

Possibility of obtaining enriched americium-242g by the elution of recoil atoms from zeolite

Energy Technology Data Exchange (ETDEWEB)

Shafiev, A I; Vityutnev, V M; Ivanov, V M; Yakovlev, G N

1974-12-31

On the example of production the possibility of obtaining enriched actinide isotopes by the elution of recotl atoms with the use of a zeolite- americium-241 target was shown. The enrichment factor and the recoil atoms of / sup 242g/Am yield depend on preliminary target treatment and solution composition used for elution. (auth)

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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).

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

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

Citric complexes, neodymium citrate and americium citrate

International Nuclear Information System (INIS)

Bouhlassa, Saidati.

1981-06-01

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

Brominated dioxins/furans and hydroxylated polybrominated diphenyl ethers: Occurrences in commercial 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 2,4,6-tribromophenol, and formation during synthesis of BTBPE.

Science.gov (United States)

Ren, Man; Zeng, Hao; Peng, Ping-An; Li, Hui-Ru; Tang, Cai-Ming; Hu, Jian-Fang

2017-07-01

Polybrominated dibenzo-p-dioxins (PBDDs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) can be formed from bromophenols (BPs) by thermal degradation, biosynthesis or phototransformation. However, it is unknown whether PBDDs and OH-PBDEs can be formed during the chemical production processes that utilize BPs as raw materials. 2,4,6-tribromophenol (2,4,6-TBP) is an important raw material for the synthesis of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), a novel brominated flame retardant. In this study, PBDDs, polybrominated dibenzofurans (PBDFs) and OH-PBDEs have been identified and quantified in commercially available BTBPE and 2,4,6-TBP. Furthermore, their formation as unintentional by-products during the laboratory synthesis of BTBPE from 2,4,6-TBP and 1,2-dibromoethane in the presence of sodium carbonate has also been investigated. 2,3,7,8-substituted PBDDs and PBDFs (2,3,7,8-PBDD/Fs) were undetectable in commercial samples of BTBPE and present in low levels (nanogram per gram) in 2,4,6-TBP. Two tetrabrominated dibenzo-p-dioxins (TeBDDs), namely 1,3,6,8- and 1,3,7,9-TeBDD, and three hydroxylated pentabrominated diphenyl ethers (OH-pentaBDEs), namely 4'-OH-BDE121, 2'-OH-BDE121, and 6'-OH-BDE100, were identified or tentatively identified, and quantitatively estimated to be at concentrations in the range of undetectable to several thousands of nanograms per gram in commercial BTBPE and 2,4,6-TBP. TeBDDs and OH-pentaBDEs were formed as by-products from 2,4,6-TBP during BTBPE synthesis. Further studies need to be conducted in order to determine whether PBDD/Fs and OH-PBDEs are also formed during the industrial synthesis of other chemical compounds that utilize BPs as raw materials or intermediates. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Separation of americium and plutonium from nuclear wastes by the TRUEX process

International Nuclear Information System (INIS)

Leonard, R.A.; Vandegrift, G.F.; Manry, C.W.

1986-01-01

Americium and plutonium can be removed from a transuranic (TRU) waste stream to <10 nCi/g by the TRUEX process. The resulting waste is nontransuranic, greatly reducing disposal costs. An overview is given of the TRUEX process and of centrifugal contactors used to implement this process. Then, a plan for the deployment of TRUEX at the Hanford Site is discussed. Finally, details are given on the proposed use of TRUEX to treat the liquid wastes from the Plutonium Finishing Plant at the Hanford Site

Environmental concentrations and toxicology of 2,4,6-tribromophenol (TBP).

Science.gov (United States)

Koch, Christoph; Sures, Bernd

2018-02-01

2,4,6-Tribromophenol is the most widely produced brominated phenol. In the present review, we summarize studies dealing with this substance from an environmental point of view. We cover concentrations in the abiotic and biotic environment including humans, toxicokinetics as well as toxicodynamics, and show gaps of the current knowledge about this chemical. 2,4,6-Tribomophenol occurs as an intermediate during the synthesis of brominated flame retardants and it similarly represents a degradation product of these substances. Moreover, it is used as a pesticide but also occurs as a natural product of some aquatic organisms. Due to its many sources, 2,4,6-tribromophenol is ubiquitously found in the environment. Nevertheless, not much is known about its toxicokinetics and toxicodynamics. It is also unclear which role the structural isomer 2,4,5-tribromophenol and several degradation products such as 2,4-dibromophenol play in the environment. Due to new flame retardants that enter the market and can degrade to 2,4,6-tribromophenol, this compound will remain relevant in future years - not only in aquatic matrices, but also in house dust and foodstuff, which are an important exposure route for humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously by TiO2 nanotubes/graphene composite

Science.gov (United States)

Slamet, Raudina

2017-11-01

Industrial waters in coal pyrolysis process, synthetic chemicals and oil and gas process contain phenol derivatives that are dangerous to the environment and needs to be removed, one of them is 2,4,6-Trichlorophenol. Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously have been investigated using TiNT/Graphene composite at various graphene loading and initial concentration of 2,4,6-Trichlorophenol. Optimal graphene loading of 0.6 wt% was obtained in the simultaneous system with 89% elimination of 2,4,6-Trichlorophenol and 986 µmol of hydrogen production. Test results showed that addition of 2,4,6-Trichlorophenol would subsequently increased 2,4,6-Trichlorophenol conversion and enhanced hydrogen production linearly. 2.7 times greater hydrogen production was found in addition of 50 ppm 2,4,6-Trichlorophenol.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-07-01

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

48 CFR 552.246-77 - Additional Contract Warranty Provisions for Supplies of a Noncomplex Nature.

Science.gov (United States)

2010-10-01

... Warranty Provisions for Supplies of a Noncomplex Nature. 552.246-77 Section 552.246-77 Federal Acquisition... a Noncomplex Nature. As prescribed in 546.710(a), insert the following clause in solicitations and contracts that include FAR 52.246-17, Warranty of Supplies of a Noncomplex Nature. Additional Contract...

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

International Nuclear Information System (INIS)

Robouch, P.

1989-01-01

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

Measurements of α-emitting plutonium and americium in the intertidal sands of west Cumbria, UK

International Nuclear Information System (INIS)

Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J.

1990-01-01

Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for 238 Pu, 239+240 Pu and 241 Am. Generally, more than 95% of the α-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m -2 of 239+240 Pu and 241 Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total α-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made α-emitters exceed those of natural α-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author)

Elimination of americium-241 after a case of accidental inhalation

International Nuclear Information System (INIS)

Edvardsson, K.A.; Lindgren, L.

1976-01-01

In handling a 241 Am source one person received an internal contamination of about 140 nCi of americium oxide, which was deposited in the lung region. Elimination of the activity was followed for more than 3 months by external gamma counting and excreta analyses. During the first week after the inhalation about 80% of the total intake was eliminated with an effective half-life of less than 2 days. The remaining activity, deposited in the lung region, was eliminated with an effective half-life of about 17 days. About 15% of the activity eliminated from the lung region from the 10th to the 50th day was eliminated in the faeces. (author)

SPHERE: Irradiation of sphere-pac fuel of UPuO2−x containing 3% Americium

International Nuclear Information System (INIS)

D’Agata, E.; Hania, P.R.; McGinley, J.; Somers, J.; Sciolla, C.; Baas, P.J.; Kamer, S.; Okel, R.A.F.; Bobeldijk, I.; Delage, F.; Bejaoui, S.

2014-01-01

Highlights: • SPHERE is designed to check the behaviour of MADF sphere-pac concept. • MADF sphere-pac are compared with MADF pellet. • Swelling, helium release and restructuring behaviour will be the main output of the experiment. • An experiment to check sphere-pac MABB fuel behaviour is now under design. - 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 241 Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. The SPHERE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS) performed in the HFR (High Flux Reactor). The SPHERE 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 works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as helium induced fuel swelling have been shown to be the key issues for the design of Am-bearing targets. The main objective of the SPHERE experiment is to study the in-pile behaviour of fuel containing 3% of americium and to compare the behaviour of sphere-pac fuel to pellet fuel, in particular the role of microstructure and temperature on fission gas release (mainly He) and on fuel swelling. The SPHERE experiment is being irradiated since September 2013 in the HFR in Petten (The Netherlands) and is expected to be terminated in spring 2015. The experiment has been designed to last up to 18 reactor cycles (corresponding to 18 months) but may reach its target earlier. This paper discusses the rationale and objective of the SPHERE experiment and provides a general description of its design

Distribution coefficients for plutonium and americium on particulates in aquatic environments

International Nuclear Information System (INIS)

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

1982-01-01

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

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

International Nuclear Information System (INIS)

Paquet, F.

1993-01-01

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

Measurements of. alpha. -emitting plutonium and americium in the intertidal sands of west Cumbria, UK

Energy Technology Data Exchange (ETDEWEB)

Eakins, J.D.; Morgan, A.; Baston, G.M.N.; Pratley, F.W.; Strange, L.P.; Burton, P.J. (UKAEA Harwell Lab. (UK). Environmental and Medical Science Div.)

1990-01-01

Samples of surface sand and sand cores were collected from intertidal regions of west Cumbria between Silloth and Walney Island (including the Duddon Estuary) between 1982 and 1984 and analysed for {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am. Generally, more than 95% of the {alpha}-emitting transuranic nuclides were associated with the sand and less than 5% with entrained silt. The greatest concentrations of both plutonium and americium were found at Braystones. Concentrations declined with distance from the Sellafield Works. The largest actinide deposits occurred at Drigg (320 and 720 kBq m{sup -2} of {sup 239+240}Pu and {sup 241}Am respectively). The integrated deposits in intertidal sand between Silloth and Walney Island were about 4.2 and 7.0 TBq respectively, which represent about 1% of the total {alpha}-emitting activity discharged to sea from Sellafield Works up to 1982. The corresponding value for the Duddon Estuary is about 0.3%. Only on beaches close to Sellafield did levels of man-made {alpha}-emitters exceed those of natural {alpha}-emitting nuclides. The radiological consequences of the intertidal inventory of plutonium and americium are shown to be very small and much less than from the seafood pathway. (author).

Concentrations of Polybrominated Diphenyl Ethers (PBDEs) and 2,4,6-Tribromophenol in Human Placental Tissues

Science.gov (United States)

Leonetti, Christopher; Butt, Craig M.; Hoffman, Kate; Miranda, Marie Lynn; Stapleton, Heather M.

2015-01-01

Legacy environmental contaminants such as polybrominated diphenyl ethers (PBDEs) are widely detected in human tissues. However, few studies have measured PBDEs in placental tissues, and there are no reported measurements of 2,4,6-tribromophenol (2,4,6-TBP) in placental tissues. Measurements of these contaminants are important for understanding potential fetal exposures, as these compounds have been shown to alter thyroid hormone regulation in vitro and in vivo. In this study, we measured a suite of PBDEs and 2,4,6-TBP in 102 human placental tissues collected between 2010–2011 in Durham County, North Carolina, USA. The most abundant PBDE congener detected was BDE-47, with a mean concentration of 5.09 ng/g lipid (range: 0.12–141 ng/g lipid; detection frequency 91%); however, 2,4,6-TBP was ubiquitously detected and present at higher concentrations with a mean concentration of 15.4 ng/g lipid (range:1.31–316 ng/g lipid; detection frequency 100%). BDE-209 was also detected in more than 50% of the samples, and was significantly associated with 2,4,6-TBP in placental tissues, suggesting they may have a similar source, or that 2,4,6-TBP may be a degradation product of BDE-209. Interestingly, BDE-209 and 2,4,6-TBP were negatively associated with age (rs=−0.16; p=0.10 and rs=−0.17; p=0.08, respectively). The results of this work indicate that PBDEs and 2,4,6-TBP bioaccumulate in human placenta tissue and likely contribute to prenatal exposures to these environmental contaminants. Future studies are needed to determine if these joint exposures are associated with any adverse health measures in infants and children. PMID:26700418

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

International Nuclear Information System (INIS)

Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

2015-01-01

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

33 CFR 148.246 - When is a document considered filed and where should I file it?

Science.gov (United States)

2010-07-01

... filed and where should I file it? 148.246 Section 148.246 Navigation and Navigable Waters COAST GUARD... Formal Hearings § 148.246 When is a document considered filed and where should I file it? (a) If a document to be filed is submitted by mail, it is considered filed on the date it is postmarked. If a...

In vitro efficacy of ST246 against smallpox and monkeypox.

Science.gov (United States)

Smith, Scott K; Olson, Victoria A; Karem, Kevin L; Jordan, Robert; Hruby, Dennis E; Damon, Inger K

2009-03-01

Since the eradication of smallpox and the cessation of routine childhood vaccination for smallpox, the proportion of the world's population susceptible to infection with orthopoxviruses, such as variola virus (the causative agent of smallpox) and monkeypox virus, has grown substantially. In the United States, the only vaccines for smallpox licensed by the Food and Drug Administration (FDA) have been live virus vaccines. Unfortunately, a substantial number of people cannot receive live virus vaccines due to contraindications. Furthermore, no antiviral drugs have been fully approved by the FDA for the prevention or treatment of orthopoxvirus infection. Here, we show the inhibitory effect of one new antiviral compound, ST-246, on the in vitro growth properties of six variola virus strains and seven monkeypox virus strains. We performed multiple assays to monitor the cytopathic effect and to evaluate the reduction of viral progeny production and release in the presence of the compound. ST-246 had 50% effective concentrations of 246 inhibits variola and monkeypox viruses similarly by reducing the production and release of enveloped orthopoxvirus and support the development of ST-246 as an antiviral therapeutic compound for the treatment of severe systemic orthopoxvirus infections.

21 CFR 520.246 - Butorphanol tartrate tablets.

Science.gov (United States)

2010-04-01

....246 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Conditions of use. The drug is used for the treatment of dogs as follows: (1) Amount. 0.25 milligram of... associated with inflammatory conditions of the upper respiratory tract. (3) Limitations. For oral use in dogs...

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

Contribution of filamentous fungi to the musty odorant 2,4,6-trichloroanisole in water supply reservoirs and associated drinking water treatment plants.

Science.gov (United States)

Bai, Xiuzhi; Zhang, Ting; Qu, Zhipeng; Li, Haipu; Yang, Zhaoguang

2017-09-01

In this study, the distribution of 2,4,6-trichloroanisole (2,4,6-TCA) in two water supply reservoirs and four associated drinking water treatment plants (DWTPs) were investigated. The 2,4,6-TCA concentrations were in the range of 1.53-2.36 ng L -1 in water supply reservoirs and 0.76-6.58 ng L -1 at DWTPs. To determine the contribution of filamentous fungi to 2,4,6-TCA in a full-scale treatment process, the concentrations of 2,4,6-TCA in raw water, settled water, post-filtration water, and finished water were measured. The results showed that 2,4,6-TCA levels continuously increased until chlorination, suggesting that 2,4,6-TCA could form without a chlorination reaction and fungi might be the major contributor to the 2,4,6-TCA formation. Meanwhile, twenty-nine fungal strains were isolated and identified by morphological and molecular biological methods. Of the seventeen isolated fungal species, eleven showed the capability to convert 2,4,6-trichlorophenol (2,4,6-TCP) to 2,4,6-TCA. The highest level of 2,4,6-TCA formation was carried out by Aspergillus versicolor voucher BJ1-3: 40.5% of the original 2,4,6-TCP was converted to 2,4,6-TCA. There was a significant variation in the capability of different species to generate 2,4,6-TCA. The results from the proportions of cell-free, cell-attached, and cell-bound 2,4,6-TCA suggested that 2,4,6-TCA generated by fungi was mainly distributed in their extracellular environment. In addition to 2,4,6-TCA, five putative volatile by-products were also identified by gas chromatography and mass spectrometry. These findings increase our understanding on the mechanisms involved in the formation of 2,4,6-TCA and provide insights into managing and controlling 2,4,6-TCA-related problems in drinking water. Copyright © 2017 Elsevier Ltd. All rights reserved.

48 CFR 246.370 - Material inspection and receiving report.

Science.gov (United States)

2010-10-01

... REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 246.370... deliverable is a scientific or technical report; (5) Research and development contracts not requiring the...

Levan-type fructooligosaccharide production using Bacillus licheniformis RN-01 levansucrase Y246S immobilized on chitosan beads

Directory of Open Access Journals (Sweden)

Surawut Sangmanee

2016-06-01

Full Text Available Bacillus licheniformis RN-01 levansucrase Y246S (LsRN-Y246S was immobilized by covalently linking onto chitosan, Sepabead EC-EP, and Sepabead EC-HFA, beads. The stability of immobilized LsRN-Y246S was found to be the highest with chitosan beads, retaining more than 70% activity after 13 weeks storage at 4 oC, and 68% activity after 12 hours incubation at 40°C. LsRN-Y246S immobilized on chitosan beads withstands sucrose concentrations up to 70% (w/v, retaining over 85% of its activity, significantly better than LsRN-Y246S immobilized on others supporting matrices. LsRN-Y246S immobilized on chitosan showed a 2.4 fold increase in activity in the presence of Mn2+, and gave slight protection against deactivation by of Cu2+, Zn2+, Fe3+, SDS and EDTA. A maximum of 8.36 g and an average of 7.35 g LFOS yield at least up to DP 11 can be produced from 25 g of sucrose, during five production cycles. We have demonstrated that LFOS can be effectively produced by chitosan immobilized LsRN-Y246S and purified.

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

International Nuclear Information System (INIS)

Lopez, M. A.; Broggio, D.; Capello, K.; Cardenas-Mendez, E.; El-Faramawy, N.; Franck, D.; James, A. C.; Kramer, G. H.; Lacerenza, G.; Lynch, T. P.; Navarro, J. F.; Navarro, T.; Perez, B.; Ruehm, W.; Tolmachev, S. Y.; Weitzenegger, E.

2011-01-01

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)

48 CFR 52.246-1 - Contractor Inspection Requirements.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Contractor Inspection....246-1 Contractor Inspection Requirements. As prescribed in 46.301, insert the following clause: Contractor Inspection Requirements (APR 1984) The Contractor is responsible for performing or having...

Standardization of a method to study the distribution of Americium in purex process

International Nuclear Information System (INIS)

Dapolikar, T.T.; Pant, D.K.; Kapur, H.N.; Kumar, Rajendra; Dubey, K.

2017-01-01

In the present work the distribution of Americium in PUREX process is investigated in various process streams. For this purpose a method has been standardized for the determination of Am in process samples. The method involves extraction of Am with associated actinides using 30% TRPO-NPH at 0.3M HNO 3 followed by selective stripping of Am from the organic phase into aqueous phase at 6M HNO 3 . The assay of aqueous phase for Am content is carried out by alpha radiometry. The investigation has revealed that 100% Am follows the HLLW route. (author)

Application of extraction chromatography to the recovery of neptunium, plutonium and americium from an industrial waste

International Nuclear Information System (INIS)

Madic, C.; Kertesz, C.; Sontag, R.; Koehly, G.

1980-01-01

A pilot scale investigation was made to evaluate the possible application of the extraction chromatographic method (LLC) to the partitioning of alpha emitters from liquid wastes containing traces of transuranium elements. A secondary purpose was to obtain pure Am0 2 , which is used to produce alpha, gamma, and neutron sources. The process developed for alpha partitioning consists essentially of the extraction of macro amounts of uranium with 30% TBP in dodecane in mixer-settlers, then coextraction of Np-237, Pu-239, and Am-241 by LLC on a macro column filled with di-n-hexyl-octoxy-methyl-phosphine oxide (POX.11) adsorbed on an inert support. In each run about 200 liters of initial waste are decontaminated of alpha emitters. The loading step is followed by selective elution of americium, neptunium, and plutonium. The americium eluate is then subjected to the following operations: (1) separation of Am from Fe and Cd by LLC on a TBP column and (2) separation of Am from lanthanide traces by LLC on an HD(DiBM)P column after oxidation of Am(III) to Am(VI). The Am in the eluate is subsequently reduced to Am(III) and precipitated as oxalate with oxalic acid. The oxalate is then filtered and calcined to yield pure AmO 2

Americium adsorption on the surface of macrophytic algae

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

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

Americium adsorption on the surface of macrophytic algae

International Nuclear Information System (INIS)

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

1985-01-01

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

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

International Nuclear Information System (INIS)

1985-11-01

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

APR-246/PRIMA-1Met Inhibits and Reverses Squamous Metaplasia in Human Conjunctival Epithelium.

Science.gov (United States)

Li, Jing; Li, Cheng; Wang, Guoliang; Liu, Zhen; Chen, Pei; Yang, Qichen; Dong, Nuo; Wu, Huping; Liu, Zuguo; Li, Wei

2016-02-01

Squamous metaplasia is a common pathologic condition in ocular surface diseases for which there is no therapeutic medication in clinic. In this study, we investigated the effect of a small molecule, APR-246/PRIMA-1(Met), on squamous metaplasia in human conjunctival epithelium. Human conjunctival explants were cultured for up to 12 days under airlifting conditions. Epithelial cell differentiation and proliferation were assessed by Cytokeratin 10 (K10), K14, K19, Pax6, MUC5AC, and p63 immunostaining patterns. β-catenin and TCF-4 immunofluorescent staining and real-time PCR characterized Wnt signaling pathway involvement. Pterygium clinical samples were cultured under airlifting conditions with or without APR-246 for 4 days. p63, K10, β-catenin, and TCF-4 expression in pterygial epithelium was determined by immunofluorescent staining and real-time PCR. Airlift conjunctival explants resulted in increased stratification and intrastromal epithelial invagination. Such pathology was accompanied by increases in K10, K14, and p63 expression, whereas K19 and Pax6 levels declined when compared to those in freshly isolated tissue. On the other hand, APR-246 reversed all of these declines in K10, K14, and p63 expression. Furthermore, K19 and Pax6 increased along with rises in goblet cell density. These effects of APR-246 were accompanied by near restoration of normal conjunctival epithelial histology. APR-246 also reversed squamous metaplasia in pterygial epithelium that had developed after 4 days in ex vivo culture. Reductions in squamous metaplasia induced by APR-246 suggest it may provide a novel therapeutic approach in different squamous metaplasia-associated ocular surface diseases.

Chemical behaviour of trivalent and pentavalent americium in saline NaCl-solutions. Studies of transferability of laboratory data to natural conditions. Interim report. Reported period: 1.2.1993-31.12.1993

International Nuclear Information System (INIS)

Runde, W.; Kim, J.I.

1994-09-01

In order to clarify the chemical behaviour of Americium in saline aqueous systems relevant for final storage this study deals with the chemical reactions of trivalent and pentavalent Americium in NaCl-solutions under the influence of radiolysis from its own alpha radiation. The focus of the study was on investigating the geologically relevant reactions, such as hydrolysis or carbonate- and chloride complexing in solid-liquid equilibriums. Comprehensive measurements on solubility and spectroscopic studies in NaCl-solutions were carried out in a CO 2 -free atmosphere and 10 -2 atm CO 2 partial pressure. Identification and characterisation of the AM (III) and AM(V) solid phases were supplemented by structural research with the chemically analogue EU (III) and Np(V) compounds. The alpha-radiation induced radiolysis in saline NaCl solutions and the redox behaviour of Americium which was influenced thereby were spectroscopically quantified. (orig.) [de

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

International Nuclear Information System (INIS)

Rodwell, P.; Stather, J.W.

1978-01-01

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

Americium-241 in surface soil associated with the Hanford site and vicinity

International Nuclear Information System (INIS)

Price, K.R.; Gilbert, R.O.; Gano, K.A.

1981-05-01

Various kinds of surface soil samples were collected and analyzed for Americium-241 ( 241 Am) to examine the feasibility of improving soil sample data for the Hanford Surface Environmental Surveillance Program. Results do not indicate that a major improvement would occur if procedures were changed from the current practices. Conclusions from this study are somewhat tempered by the very low levels of 241 Am ( 241 Am in soil crust (0 to 1.0 cm deep) was greater than the corresponding subsurface layer (1.0 to 2.5 cm deep), and the average concentration of 241 Am in some onsite samples collected near the PUREX facility was greater than comparable samples collected 60 km upwind at an offsite location

Americium/Curium Melter 2A Pilot Tests

International Nuclear Information System (INIS)

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

1998-05-01

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

Biosorption of americium-241 by Candida sp

International Nuclear Information System (INIS)

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

2003-01-01

As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high toxicity and long half-life. In this experiment, the biosorption of 241 Am from solution by Candida sp., and the effects of various experimental conditions on the adsorption were investigated. The preliminary results showed that the adsorption of 241 Am by Candida sp. was efficient. 241 Am could be removed by Candida sp. of 0.82 g/L (dry weight) from 241 Am solutions of 5.6-111 MBq/L (44.3-877.2 μg/L)(C 0 ), with maximum adsorption rate (R) of 98% and maximum adsorption capacities (W) of 63.5 MBq/g biomass (dry weight) (501.8 μg/g). The biosorption equilibrium was achieved within 4 hour and the optimum pH was pH = 2. No significant differences on 241 Am adsorption were observed at 10 C-45 C, or in solutions containing Au 3+ or Ag + , even 1500 times or 4500 times above the 241 Am concentration, respectively. The relationship between concentrations and adsorption capacities of 241 Am indicated the biosorption process should be described by a Langmuir adsorption isotherm. (orig.)

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

International Nuclear Information System (INIS)

Cruz, W.H.

2013-01-01

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

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

Science.gov (United States)

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

2010-01-01

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

The biokinetics and radiotoxicology of curium: A comparison with americium

Energy Technology Data Exchange (ETDEWEB)

Menetrier, F. [CEA, Fontenay-aux-Roses (France); Taylor, D.M. [School of Chemistry, Cardiff University, Cardiff CF10 3AT (United Kingdom)], E-mail: davtay@btinternet.com; Comte, A. [CEA, Fontenay-aux-Roses (France)

2008-05-15

The human and animal data on the biokinetics of {sup 242}Cm and {sup 244}Cm are reviewed and shown to be very similar to those for {sup 241}Am. Liver and skeleton are the main organs of deposition and the retention of curium in the skeleton is very prolonged in all the species examined. Retention of both curium and americium in the liver appears to be species-dependent, being relatively rapidly removed from the liver of rats, and probably humans, but being tenaciously retained in dogs and some other species. The radiotoxicity of curium is also reviewed and it is shown that, as with {sup 241}Am, lung and bone tumour induction are the major hazards from inhaled and systemically deposited {sup 244}Cm. The use of chelating agents for the treatment of accidental contamination of the human body with {sup 242,244}Cm is also discussed.

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

International Nuclear Information System (INIS)

Hunt, G.J.

1998-01-01

Our previous studies have indicated lower values of the gut transfer factor ('f 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 L values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7x10 -4 with an arithmetic mean in the range (2-3)x10 -4 , and for americium up to 2.6x10 -4 with an arithmetic mean of 1.2x10 -4 . Limited data based on volunteers eating cockles from the Solway suggest that f L values for americium may be greater at distance from Sellafield. The measured values compare with 5x10 -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 L value in the region of 0.2, twice the value currently used by ICRP. For 137 Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f L =1.0. Technetium-99 gave f L values up to about 0.6, in reasonable conformity with the ICRP value of 0.5. (author)

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

International Nuclear Information System (INIS)

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

2010-01-01

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

32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

Science.gov (United States)

2010-07-01

... of directors shall monitor planning and execution of the S&S business activities. 2. The S&S board of... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and Management...

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

International Nuclear Information System (INIS)

Taylor, D.M.

1988-01-01

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

Highly sensitive detection of 2,4,6-trichlorophenol based on HS-β-cyclodextrin/gold nanoparticles composites modified indium tin oxide electrode

International Nuclear Information System (INIS)

Zheng, Xiangli; Liu, Shan; Hua, Xiaoxia; Xia, Fangquan; Tian, Dong; Zhou, Changli

2015-01-01

Graphical abstract: Display Omitted -- Highlights: •A novel electrochemical sensing platform by self-assembling of HS-β-cyclodextrin/gold nanoparticles onto indium tin oxide electrode (HS-β-CD/AuNPs/SAM/ITO electrode) surface was constructed. •The proposed electrochemical sensor exhibited high sensitivity for the determination 2,4,6-trichlorophenol which electrochemical activity is very weak. •The newly developed method was successfully applied to quantitatively determine 2,4,6-trichlorophenol in tap water samples. -- ABSTRACT: A new electrochemical sensor for determination of 2,4,6-trichlorophenol (2,4,6-TCP) was fabricated. The characterization of the sensor was studied by scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry techniques. The electrochemical behavior of 2,4,6-TCP was investigated using cyclic voltammetry and differential pulse voltammetry at the HS-β-cyclodextrin (HS-β-CD)/gold nanoparticles (AuNPs) composite modified indium tin oxide (ITO) electrode. The results showed that the current responses of 2,4,6-TCP greatly enhanced due to the high catalytic activity and enrichment capability of composites. The peak current of 2,4,6-TCP increases linearly with the increase of the 2,4,6-TCP concentration from 3.0 × 10 −9 to 2.8 × 10 −8 M, with the limit of detection of 1.0 × 10 −9 . Further more, the modified electrode was successfully applied to detect the level of 2,4,6-TCP in tap water samples with excellent sensitivity

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

Science.gov (United States)

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

2010-03-07

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

Recovery of plutonium and americium from chloride salt wastes by solvent extraction

International Nuclear Information System (INIS)

Reichley-Yinger, L.; Vandegrift, G.F.

1987-01-01

Plutonium and americium can be recovered from aqueous waste solutions containing a mixture of HCl and chloride salt wastes by the coupling of two solvent extraction systems: tributyl phosphate (TBP) in tetrachloroethylene (TCE) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in TCE. In the flowsheet developed, the salt wastes are dissolved in HCl, the Pu(III) is oxidized to the IV state with NaClO 2 and recovered in the TBP-TCE cycle, and the Am is then removed from the resultant raffinate by the CMPO-TCE cycle. The consequences of the feed solution composition and extraction behavior of these species on the process flowsheet design, the Pu-product purity, and the decontamination of the aqueous raffinate from transuranic elements are discussed. 16 refs., 6 figs

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-11-01

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

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

International Nuclear Information System (INIS)

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

1992-06-01

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

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

International Nuclear Information System (INIS)

Tanaka, Kosuke; Hirosawa, Takashi; Obayashi, Hiroshi; Koyama, Shin Ichi; Yoshimochi, Hiroshi; Tanaka, Kenya

2008-01-01

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

PBCDD/F formation from radical/radical cross-condensation of 2-Chlorophenoxy with 2-Bromophenoxy, 2,4-Dichlorophenoxy with 2,4-Dibromophenoxy, and 2,4,6-Trichlorophenoxy with 2,4,6-Tribromophenoxy

Energy Technology Data Exchange (ETDEWEB)

Shi, Xiangli [Environment Research Institute, Shandong University, Jinan 250100 (China); Yu, Wanni [Environment Research Institute, Shandong University, Jinan 250100 (China); College of Resources and Environment, Linyi University, Linyi 276000 (China); Xu, Fei [Environment Research Institute, Shandong University, Jinan 250100 (China); Zhang, Qingzhu, E-mail: zqz@sdu.edu.cn [Environment Research Institute, Shandong University, Jinan 250100 (China); Hu, Jingtian; Wang, Wenxing [Environment Research Institute, Shandong University, Jinan 250100 (China)

2015-09-15

Highlights: • We studied the formation of PBCDD/Fs from the reaction of three CPRs with BPRs. • The substitution pattern of halogenated phenols determines those of PBCDD/Fs. • The substitution of halogenated phenols influence the coupling of phenoxy radicals. • The rate constants of the crucial elementary steps were evaluated. - Abstract: Quantum chemical calculations were carried out to investigate the homogeneous gas-phase formation of mixed polybrominated/chlorinated dibenzo-p-dioxins/benzofurans (PBCDD/Fs) from the cross-condensation of 2-chlorophenoxy radical (2-CPR) with 2-bromophenoxy radical (2-BPR), 2,4-dichlorophenoxy radical (2,4-DCPR) with 2,4-dibromophenoxy radical (2,4-DBPR), and 2,4,6-trichlorophenoxy radical (2,4,6-TCPR) with 2,4,6-tribromophenoxy radical (2,4,6-TBPR). The geometrical parameters and vibrational frequencies were calculated at the MPWB1K/6-31+G(d,p) level, and single-point energy calculations were performed at the MPWB1K/6-311+G(3df,2p) level of theory. The rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600–1200 K. Studies show that the substitution pattern of halogenated phenols not only determines the substitution pattern of the resulting PBCDD/Fs, but also has a significant influence on the formation mechanism of PBCDD/Fs, especially on the coupling of the halogenated phenoxy radicals.

Density of simulated americium/curium melter feed solution

International Nuclear Information System (INIS)

Rudisill, T.S.

1997-01-01

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

Density of simulated americium/curium melter feed solution

Energy Technology Data Exchange (ETDEWEB)

Rudisill, T.S.

1997-09-22

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

In vitro susceptibility to ST-246 and Cidofovir corroborates the phylogenetic separation of Brazilian Vaccinia virus into two clades.

Science.gov (United States)

Pires, Mariana A; Rodrigues, Nathália F S; de Oliveira, Danilo B; de Assis, Felipe L; Costa, Galileu B; Kroon, Erna G; Mota, Bruno E F

2018-04-01

The Orthopoxvirus (OPV) genus of the Poxviridae family contains several human pathogens, including Vaccinia virus (VACV), which have been implicating in outbreaks of a zoonotic disease called Bovine Vaccinia in Brazil. So far, no approved treatment exists for OPV infections, but ST-246 and Cidofovir (CDV) are now in clinical development. Therefore, the objective of this work was to evaluate the susceptibility of five strains of Brazilian VACV (Br-VACV) to ST-246 and Cidofovir. The susceptibility of these strains to both drugs was evaluated by plaque reduction assay, extracellular virus's quantification in the presence of ST-246 and one-step growth curve in cells treated with CDV. Besides that, the ORFs F13L and E9L were sequenced for searching of polymorphisms associated with drug resistance. The effective concentration of 50% (EC 50 ) from both drugs varies significantly for different strains (from 0.0054 to 0.051 μM for ST-246 and from 27.14 to 61.23 μM for CDV). ST-246 strongly inhibits the production of extracellular virus for all isolates in concentrations as low as 0.1 μM and it was observed a relevant decrease of progeny production for all Br-VACV after CDV treatment. Sequencing of the F13L and E9L ORFs showed that Br-VACV do not present the polymorphism(s) associated with resistance to ST-246 and CDV. Taken together, our results showed that ST-246 and CDV are effective against diverse, wild VACV strains and that the susceptibility of Br-VACV to these drugs mirrored the phylogenetic split of these isolates into two groups. Thus, both ST-246 and CDV are of great interest as compounds to treat individuals during Bovine Vaccinia outbreaks in Brazil. Copyright © 2018 Elsevier B.V. All rights reserved.

Z dependence of the N=152 deformed shell gap: In-beam γ-ray spectroscopy of neutron-rich 245,246Pu

International Nuclear Information System (INIS)

Makii, H.; Ishii, T.; Asai, M.; Tsukada, K.; Toyoshima, A.; Ichikawa, S.; Matsuda, M.; Makishima, A.; Kaneko, J.; Toume, H.; Shigematsu, S.; Kohno, T.; Ogawa, M.

2007-01-01

We have measured in-beam γ rays in the neutron-rich 246 Pu 152 and 245 Pu 151 nuclei by means of 244 Pu( 18 O, 16 O) 246 Pu and 244 Pu( 18 O, 17 O) 245 Pu neutron transfer reactions, respectively. The γ rays emitted from 246 Pu ( 245 Pu) were identified by selecting the kinetic energy of scattered 16 O ( 17 O) detected by Si ΔE-E detectors. The ground-state band of 246 Pu was established up to the 12 + state. We have found that the shell gap of N=152 is reduced in energy with decreasing atomic number by extending the systematics of the one-quasiparticle energies in N=151 nuclei into those in 245 Pu. This reduction of the shell gap clearly affects the 2 + energy of the ground-state band of 246 Pu

Liquid-liquid extraction of plutonium and americium by cekanoic acid from alkaline medium

International Nuclear Information System (INIS)

Venugopal Chetty, K.; Sagar, V.; Swarup, R.

2001-01-01

Liquid-liquid extraction studies of plutonium and americium from aqueous carbonate medium using a high molecular weight carboxylic acid namely cekanoic acid in different diluents has been carried out. The distribution ratio (D) values for Pu(IV) and Am(III) under various parameters such as concentration of extractant, Na 2 CO 3 and initial pH were obtained. Results indicated that Pu(IV) and Am(III) could be satisfactorily extracted together or individually from aqueous carbonate medium using cekanoic acid in different diluents like carbon tetrachloride, cyclohexane, toluene, n-dodecane or solvesso-100. The D values for Pu(IV) and Am(III) also indicated the possibility of their mutual separation. The back extraction of Pu and Am with different reagents was also studied. (orig.)

Development of the small-molecule antiviral ST-246® as a smallpox therapeutic

Science.gov (United States)

Grosenbach, Douglas W; Jordan, Robert; Hruby, Dennis E

2011-01-01

Naturally occurring smallpox has been eradicated, yet it remains as one of the highest priority pathogens due to its potential as a biological weapon. The majority of the US population would be vulnerable in a smallpox outbreak. SIGA Technologies, Inc. has responded to the call of the US government to develop and supply to the Strategic National Stockpile a smallpox antiviral to be deployed in the event of a smallpox outbreak. ST-246® (tecovirimat) was initially identified via a high-throughput screen in 2002, and in the ensuing years, our drug-development activities have spanned in vitro analysis, preclinical safety, pharmacokinetics and efficacy testing (all according to the ‘animal rule’). Additionally, SIGA has conducted Phase I and II clinical trials to evaluate the safety, tolerability and pharmacokinetics of ST-246, bringing us to our current late stage of clinical development. This article reviews the need for a smallpox therapeutic and our experience in developing ST-246, and provides perspective on the role of a smallpox antiviral during a smallpox public health emergency. PMID:21837250

8 CFR 246.4 - Immigration judge's authority; withdrawal and substitution.

Science.gov (United States)

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Immigration judge's authority; withdrawal... IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 246.4 Immigration judge's authority; withdrawal and substitution. In any proceeding conducted under this part, the immigration judge shall have...

Annual report for FY 1976 on project AN0115A: the migration of plutonium and americium in the lithosphere

International Nuclear Information System (INIS)

Fried, S.; Friedman, A.M.; Hines, J.J.; Atcher, R.W.; Quarterman, L.A.; Volesky, A.

1976-12-01

Studies have been carried out on the migration of plutonium and americium in solutions flowing through porous and crushed rock and through fissures. The migration process can be described in terms of the surface absorption of these elements. In addition, chemical effects on the absorption have been observed. One of these effects is possibly due to the presence of a plutonium polymer that migrates at a more rapid rate than normal plutonium

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

International Nuclear Information System (INIS)

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

1984-01-01

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

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

International Nuclear Information System (INIS)

Holm, E.; Fukai, R.

1976-01-01

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

The MARINE experiment: Irradiation of sphere-pac fuel and pellets of UO{sub 2−x} for americium breeding blanket concept

Energy Technology Data Exchange (ETDEWEB)

D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Hania, P.R. [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Freis, D.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Bejaoui, S. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France); Charpin, F.F.; Baas, P.J.; Okel, R.A.F.; Til, S. van [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Lapetite, J.-M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Delage, F. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France)

2017-01-15

Highlights: • MARINE is designed to check the behaviour of MABB sphere-pac concept. • MABB sphere-pac are compared with MABB pellet. • Swelling and helium release behaviour will be the main output of the experiment. • An experiment to check sphere-pac MADF fuel behaviour has been already performed. - 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 heat production of waste packages to be stored in a repository. The MARINE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS, SPHERE) performed in the High Flux Reactor (HFR). The MARINE experiment is developed and carried out in the framework of the collaborative research project PELGRIMM of the EURATOM 7th Framework Programme (FP7). During the past years of experimental works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as swelling have been shown to be the key issues for the design of such kind of fuel both as drivers and even more for Am-bearing blanket targets (due to the higher Am contents). The main objective of the MARINE experiment is to study the in-pile behaviour of uranium oxide fuel containing 13% of americium and to compare the behaviour of sphere-pac versus pellet fuel, in particular the role of microstructure and temperature on fission gas release and He on fuel swelling. The MARINE experiment will be irradiated in 2016 in the HFR in Petten (The Netherlands) and is expected to be completed in spring 2017. This paper discusses the rationale and objective of the MARINE experiment and provides a general description of its design for which some innovative features have been adopted.

25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

Science.gov (United States)

2010-04-01

... as possible in the construction process. If Tribal construction standards are consistent with or... 25 Indians 2 2010-04-01 2010-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE...

Gas-liquid reactive crystallization kinetics of 2,4,6-triamino-1,3,5-trinitrobenzene in the semi-batch procedure

Science.gov (United States)

Liu, Ruqin; Huang, Ming; Yao, Xiaolu; Chen, Shuang; Wang, Shucun; Suo, Zhirong

2018-06-01

2,4,6-Triamino-1,3,5-trinitrobenzene is the attractive insensitive high energetic material used extensively in the military and civil fields. Combined with the double-films theory, the global gas-liquid chemical reaction kinetics of 2,4,6-triamino-1,3,5-trinitrobenzene was developed by means of the infinitesimal material balance calculation. The raw material concentration and reactive temperature effects on the crystallization of 2,4,6-triamino-1,3,5-trinitrobenzene were investigated by the batch experiments. The reactive crystallization kinetics associated ammonia feeding rate of 2,4,6-triamino-1,3,5-trinitrobenzene, including nucleation as well as crystal growth, was systematically investigated in the heterogonous semi-batch procedure. The nucleation and crystal growth kinetic exponents were estimated by the linear least-squares method. The crystallization kinetic results indicated that nucleation rate strongly increased but liner growth rate decreased with the increasing of ammonia feeding rate. In terms of manufacturing coarse 2,4,6-triamino-1,3,5-trinitrobenzene, it was found that a slow ammonia feeding rate and a low raw material concentration were feasible under the present experimental conditions.

1,3,5-Triazine-2,4,6-triyltrisulfamic acid (TTSA)

Indian Academy of Sciences (India)

Melamine reacted with chlorosufonic acid (ClSO3H) to form a new sulfamic-type acid, 1,3,5-triazine-2,4,6-triyltrisulfamic acid (TTSA). Both nitrosation of secondary amines and oxidation of urazoles were accomplished by using TTSA/NaNO2 system under mild and heterogeneous conditions with good to excellent yields.

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 properties......-I to Am-II transition. Good agreement was found between calculated and experimental equations of states for all phases, but the first three phases need larger U (α) parameters (where α represents the fraction of Hartree-Fock exchange energy replacing the DFT exchange energy) than the fourth phase in order...

Vicarious nucleophilic substitution to prepare 1,3-diamino-2,4,6-trinitrobenzene or 1,3,5-triamino-2,4,6-trinitrobenzene

Science.gov (United States)

Mitchell, Alexander R.; Pagoria, Philip F.; Schmidt, Robert D.

1996-01-01

The present invention relates to a process to produce 1,3-diamino-2,4,6-trinitrobenzene (DATB) or 1,3,5-triamino-2,4,6,-trinitrobenzene (TATB) by: (a) reacting at ambient pressure and a temperature of between about 0.degree. and 50.degree. C. for between about 0.1 and 24 hr, a trinitroaromatic compound of structure V: ##STR1## wherein X, Y, and Z are each independently selected from --H, or --NH.sub.2, with the proviso that at least 1 or 2 of X, Y, and Z are hydrogen, with an amount effective to produce DATB or TATB of 1,1,1-trialkylhydrazinium halide wherein alkyl is selected from methyl, ethyl, propyl or butyl and halide is selected from chloride, bromide or iodide. in the presence of a strong base selected from sodium butoxide, potassium butoxide, potassium propoxide, sodium propoxide, sodium ethoxide, potassium ethoxide, sodium methoxide, potassium methoxide, and combinations thereof; in a solvent selected from the group consisting of methanol, ethanol, propanol, butanol, dimethylsulphoxide, N-methylpyrrolidone, hexamethylphosphoramide, dimethylformide, dimethylacetamide and mixtures thereof, provided that when alcohols are present primarily DATB and picramide is formed; and (b) isolating the DATB or TATB produced. DATB and TATB are useful specialty explosives. TATB is also used for the preparation of benzenehexamine, a starting material for the synthesis of novel materials (optical imaging devices, liquid crystals, ferromagnetic compounds).

Preparation of curium-americium oxide microspheres by resin-bead loading

International Nuclear Information System (INIS)

Chattin, F.R.; Benker, D.E.; Lloyd, M.H.; Orr, P.B.; Ross, R.G.; Wiggins, J.T.

1980-01-01

Resin-bead loading and calcination techniques have been used to produce all curium and americium oxide feed material (about 2.2 kg) for HFIR targets since 1971. The process based on Dowex 50W resin has progressed from a series of test runs, through special production runs, into routine production in permanent equipment beginning in 1975. Key attributes of this process are its reliability, high yields, and ease of operation. The process is suited for remote operation in hot cells. Yields approaching 95% are routinely obtained and only one unacceptable product has been generated during routine production operations. There have been no problems in fabricating targets from this oxide or in the subsequent irradiation of these targets. The present scale of production of 150 to 250 g/y supplies the present need and is comparable with the level of other chemical process operations at TRU. Since the annual production is accomplished in two 8 to 12 day periods, there has been no reason to consider further scale-up. However, the rate of production could easily be doubled by simply adding a second set of calcination equipment

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

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

International Nuclear Information System (INIS)

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

1981-10-01

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

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)

Perrier, T.

2004-06-01

Americium 241, is one of the most radio-toxic contaminant produced during the nuclear fuel cycle. It can be found in all environmental compartments, in particular the soils. The main goals of this study are to identify, quantify and model the effect of the main factors controlling the mobility of 241 Am in the rhizosphere and the agricultural soils. The physico-chemical parameters of the soil and of the soil solution, the potential role of microorganisms on the sorption-desorption processes, and the speciation of americium in solution have been more particularly studied. 241 Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with 241 Am. The soil samples have been washed out in different hydrodynamic conditions by solutions with various compositions. The eluted solution has been analyzed (pH, conductivity, ionic composition, Fe tot , organic acids, 241 Am) and its bacterial biomass content too. The overall results indicate that 241 Am remobilization is contrasted and strongly linked with the condition under study (pH, ionic strength, glucose and/or citrate concentration). Therefore, a solution in equilibrium with the soil or containing small exudate concentrations (10 -4 M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of 241 Am corresponds to a solid/liquid coefficient of partition (K d ) of about 10 5 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 241 Am 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 241 Am released after the dissolution of the carrying phases. Finally, the colloidal transport of 241 Am has been systematically observed in a limited but

Total and spontaneous fission half-lives of the americium and curium nuclides

International Nuclear Information System (INIS)

Holden, N.E.

1984-01-01

The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for 241 Am, /sup 242m/Am, 243 Am, 242 Cm, 243 Cm, 244 Cm, 245 Cm, 246 Cm, 247 Cm, 248 Cm, and 250 Cm. The uncertainties are provided at the 95% confidence limit for each of the recommended values

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.

Separation and measurement of thorium, plutonium, americium, uranium and strontium in environmental matrices

International Nuclear Information System (INIS)

Harrison, Jennifer J.; Zawadzki, Atun; Chisari, Robert; Wong, Henri K.Y.

2011-01-01

A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA TM , TRU TM and Sr-Spec TM resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.

Alternative Flame Retardant, 2,4,6-Tris(2,4,6-tribromophenoxy)-1,3,5-triazine, in an E-waste Recycling Facility and House Dust in North America.

Science.gov (United States)

Guo, Jiehong; Stubbings, William A; Romanak, Kevin; Nguyen, Linh V; Jantunen, Liisa; Melymuk, Lisa; Arrandale, Victoria; Diamond, Miriam L; Venier, Marta

2018-03-20

A high molecular weight compound, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ), was detected during the analysis of brominated flame retardants in dust samples collected from an electrical and electronic waste (e-waste) recycling facility in Ontario, Canada. Gas chromatography coupled with both high-resolution and low-resolution mass spectrometry (MS) was used to determine TTBP-TAZ's chemical structure and concentrations. To date, TTBP-TAZ has only been detected in plastic casings of electrical and electronic equipment and house dust from The Netherlands. Here we report on the concentrations of TTBP-TAZ in selected samples from North America: e-waste dust ( n = 7) and air ( n = 4), residential dust ( n = 30), and selected outdoor air ( n = 146), precipitation ( n = 19), sediment ( n = 11) and water ( n = 2) samples from the Great Lakes environment. TTBP-TAZ was detected in all the e-waste dust and air samples, and in 70% of residential dust samples. The median concentrations of TTBP-TAZ in these three types of samples were 5540 ng/g, 5.75 ng/m 3 and 6.76 ng/g, respectively. The flame retardants 2,4,6-tribromophenol, tris(2,3-dibromopropyl) isocyanurate, and 3,3',5,5'-tetrabromobisphenol A bis(2,3-dibromopropyl) ether, BDE-47 and BDE-209 were also measured for comparison. None of these other flame retardants concentrations was significantly correlated with those of TTBP-TAZ in any of the sample types suggesting different sources. TTBP-TAZ was not detected in any of the outdoor environmental samples, which may relate to its application history and physicochemical properties. This is the first report of TTBP-TAZ in North America.

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Complete dissipation of 2,4,6-trinitrotoluene by in-vessel composting

NARCIS (Netherlands)

Gümüscü, B.; Cekmecelioglu, Deniz; Tekinay, Turgay

2015-01-01

We demonstrate complete removal of 2,4,6-trinitrotoluene (TNT) in 15 days using an in-vessel composting system, which is amended with TNT-degrading bacteria strains. A mixture of TNT, food waste, manure, wood chips, soil and TNT-degrading bacteria consortium are co-composted for 15 days in an

Evaluation of neutron cross sections for 244Cm, 246Cm, and 248Cm

International Nuclear Information System (INIS)

Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.

1977-01-01

An evaluation of neutron cross sections for 244 246 248 Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience

PNN NGC 246: A Complex Photometric Behaviour That Requires Wet

Directory of Open Access Journals (Sweden)

Pérez J. M. González

2003-03-01

Full Text Available We present a study over three single-site campaigns to investigate the photometric behaviour of the PNN NGC 246. We observed this object in 2000 and 2001. The analysis of the light curves indicates complex and variable temporal spectra. Using wavelet analysis we have found evidences for changes on time scales of hours in the 2000 dataset. The temporal spectra obtained during 2001 are quite different from the results of the previous year. The modulations in the light curve are more noticeable and the temporal spectra present a higher number of modulation frequencies. One peculiar characteristic is the presence of a variable harmonic structure related to one of these modulation frequencies. This complex photometric behaviour may be explained by a more complicated unresolved combination of modulation frequencies, but more likely due to a combination of pulsations of the star plus modulations related to interaction with a close companion, maybe indicating a disc. However, these characteristics cannot be confirmed from single site observations. The complex and variable behaviour of NGC 246 needs the WET co-operation in order to completely resolve its light curve.

Synthesis of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide – a tailor-made photoinitiator for dental adhesives

Directory of Open Access Journals (Sweden)

Norbert Moszner

2010-03-01

Full Text Available Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide (WBAPO was synthesized starting from 3-(chloromethyl-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxyethanol. In the second step, 3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride showed an unexpected low thermal stability. Its thermal rearrangement at 180 °C resulted in a fast formation of 3-(chloromethyl-2,4,6-trimethylbenzoic acid 2-(allyloxyethyl ester. In the third step, the acid chloride was reacted with phenylphosphine dilithium with the formation of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine, which was oxidized to WBAPO. The structure of WBAPO was confirmed by 1H NMR, 13C NMR, 31P NMR, and IR spectroscopy, as well as elemental analysis. WBAPO, a yellow liquid, possesses improved solubility in polar solvents and shows UV–vis absorption, and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations.

Hybrid treatment strategies for 2,4,6-trichlorophenol degradation based on combination of hydrodynamic cavitation and AOPs.

Science.gov (United States)

Barik, Arati J; Gogate, Parag R

2018-01-01

Utilization of hybrid treatment schemes involving advanced oxidation processes and hydrodynamic cavitation in the wastewater treatment forms the prime focus of the present work. The initial phase of the work includes analysis of recent literature relating to the performance of combined approach based on hydrodynamic cavitation (HC) for degradation of different pollutants followed by a detailed investigation into degradation of 2,4,6-trichlorophenol (2,4,6-TCP). The degradation of the priority pollutant, 2,4,6-TCP, using combination of HC based on slit-venturi used as the cavitating device, ozone and H 2 O 2 has been investigated. The effect of operating pressure (2-5bar) and initial pH (3-11) have been investigated for the degradation using only HC. The degradation using only ozone (100-400mg/h) and only H 2 O 2 has also been studied. The efficacy of the combined operation of HC+O 3 at different ozone flow rates (100-400mg/h) and the combined operation of HC+H 2 O 2 at different loadings of H 2 O 2 (2,4,6-TCP:H 2 O 2 as 1:1-1:7) have been subsequently investigated. The degradation efficacy has also been established for the combined treatment strategies of O 3 +H 2 O 2 and HC+O 3 +H 2 O 2 at the optimum conditions of temperature as 30°C, inlet pressure of 4bar and initial pH of 7. Extent of 2,4,6-TCP degradation, TOC and COD removal obtained for HC+O 3 process were 97.1%, 94.4% and 78.5% respectively whereas for O 3 +H 2 O 2 process, the values were 95.5%, 94.8% and 76.2% and for HC+O 3 +H 2 O 2 process the extent of reduction were 100%, 95.6% and 80.9% in the same order. The combined treatment approach as HC+O 3 +H 2 O 2 was established as the most efficient approach for complete removal of 2,4,6-TCP with near complete TOC removal. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Simultaneous determination of 2,4,6-trichlorophenol and pentachlorophenol based on poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes composite film modified electrode

International Nuclear Information System (INIS)

Zhu, Xiaolin; Zhang, Kexin; Lu, Nan; Yuan, Xing

2016-01-01

Graphical abstract: A poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes composite film modified glassy carbon electrode (PRhB/GO/MWCNTs/GCE) was developed for the simultaneous determination of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) without any pretreatment. - Highlights: • A poly(RhB)/graphene oxide/multiwalled carbon nanotubes composite was synthesized. • The composite film was characterized by SEM, XRD, EIS and Raman spectroscopy. • The simultaneous electrochemical determination of 2,4,6-TCP and PCP was realized. • The electrode showed high sensitivity, excellent reproducibility and good stability. • The electrode was used to determine 2,4,6-TCP and PCP in practical water samples. - Abstract: In the present study, a poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes nanocomposite modified glass carbon electrode (PRhB/GO/MWCNTs/GCE) was developed for the simultaneous determination of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP). The PRhB/GO/MWCNTs film was extensively characterized by emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of 2,4,6-TCP and PCP were investigated by cyclic voltammetry, linear sweep voltammetry and differential pulse voltammetry. Due to the synergistic effect, the PRhB/GO/MWCNTs/GCE significantly facilitated the simultaneous electro-oxidation of 2,4,6-TCP and PCP with peak potential difference of 160 mV and enhanced oxidation currents. Under optimum conditions, the oxidation current of 2,4,6-TCP was linear to its concentration in the ranges of 4.0 × 10"−"9 to 1.0 × 10"−"7 M and 1.0 × 10"−"7 to 1.0 × 10"−"4 M with the detection limit (S/N = 3) of 8.0 × 10"−"1"0 M. And the linear concentration ranges for PCP were 2.0 × 10"−"9 to 1.0 × 10"−"7 M and 1.0 × 10"−"7 to 9.0 × 10"−"5 M with the detection limit of 5.0 × 10"−"1"0 M

Simultaneous determination of 2,4,6-trichlorophenol and pentachlorophenol based on poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes composite film modified electrode

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiaolin; Zhang, Kexin; Lu, Nan; Yuan, Xing, E-mail: yuanx@nenu.edu.cn

2016-01-15

Graphical abstract: A poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes composite film modified glassy carbon electrode (PRhB/GO/MWCNTs/GCE) was developed for the simultaneous determination of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) without any pretreatment. - Highlights: • A poly(RhB)/graphene oxide/multiwalled carbon nanotubes composite was synthesized. • The composite film was characterized by SEM, XRD, EIS and Raman spectroscopy. • The simultaneous electrochemical determination of 2,4,6-TCP and PCP was realized. • The electrode showed high sensitivity, excellent reproducibility and good stability. • The electrode was used to determine 2,4,6-TCP and PCP in practical water samples. - Abstract: In the present study, a poly(Rhodamine B)/graphene oxide/multiwalled carbon nanotubes nanocomposite modified glass carbon electrode (PRhB/GO/MWCNTs/GCE) was developed for the simultaneous determination of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP). The PRhB/GO/MWCNTs film was extensively characterized by emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of 2,4,6-TCP and PCP were investigated by cyclic voltammetry, linear sweep voltammetry and differential pulse voltammetry. Due to the synergistic effect, the PRhB/GO/MWCNTs/GCE significantly facilitated the simultaneous electro-oxidation of 2,4,6-TCP and PCP with peak potential difference of 160 mV and enhanced oxidation currents. Under optimum conditions, the oxidation current of 2,4,6-TCP was linear to its concentration in the ranges of 4.0 × 10{sup −9} to 1.0 × 10{sup −7} M and 1.0 × 10{sup −7} to 1.0 × 10{sup −4} M with the detection limit (S/N = 3) of 8.0 × 10{sup −10} M. And the linear concentration ranges for PCP were 2.0 × 10{sup −9} to 1.0 × 10{sup −7} M and 1.0 × 10{sup −7} to 9.0 × 10{sup −5} M with the

Separation and measurement of thorium, plutonium, americium, uranium and strontium in environmental matrices

Energy Technology Data Exchange (ETDEWEB)

Harrison, Jennifer J., E-mail: jennifer.harrison@ansto.gov.au [Australian Nuclear Science and Technology Organisation, PMB 1, Menai NSW 2234 (Australia); Zawadzki, Atun; Chisari, Robert; Wong, Henri K.Y. [Australian Nuclear Science and Technology Organisation, PMB 1, Menai NSW 2234 (Australia)

2011-10-15

A technique for the isolation of thorium (Th), plutonium (Pu), americium (Am), uranium (U) and strontium (Sr) isotopes from various environmental matrices has been adapted from a previously published method specific to water samples (). Separation and isolation of the various elemental fractions from a single sub-sample is possible, thereby eliminating the need for multiple analyses. The technique involves sample dissolution, concentration via calcium phosphate co-precipitation, rapid column extraction using TEVA{sup TM}, TRU{sup TM} and Sr-Spec{sup TM} resin cartridges, alpha spectrometry for Th, Pu, U and Am and Cerenkov counting for Sr. Various standard reference materials were analysed and chemical yields are in the range of 70-80% for Th, Am, U and Sr and 50-60% for Pu. Sample sizes of up to 10 L for water, 5 g for dry soil and sediment and 10 g for dry vegetation and seaweed can be processed using this technique.

48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Mission Critical Space... CONTRACT CLAUSES Texts of Provisions and Clauses 1852.246-70 Mission Critical Space System Personnel Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System...

Preparation and characterization of molecularly-imprinted magnetic microspheres for adsorption of 2,4,6-trichlorophenol from aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Yu, Ping; Pan, Jianming; Yan, Yongsheng [Jiangsu University, Zhenjiang (China); Sun, Qilong; Li, Jianfeng; Tan, Zhenjiang [Jilin Normal University, Siping (China)

2015-04-15

Magnetic molecularly imprinted microspheres (MMIS) were successfully prepared by suspension polymerization, and then as-prepared MMIS were used as adsorbents for selective recognition of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. The results composites were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results demonstrated that MMIS possesses porous spherical morphology, and exhibits good thermal stability and magnetic property (Ms=10.14 emu g{sup -1}). Then batch mode of binding experiments was used to determine the equilibrium, kinetics and selectivity recognition. The Langmuir isotherm model fitted the equilibrium data better than did the Freundlich model, and the maximum adsorption capacity on MMIS was about 1.7 times higher than that of MNIS. Kinetics behaviors of MMIS were well described by the pseudo-second-order model. MMIS possessed outstanding selectivity recognition for 2,4,6-TCP in the presence of other competitive phenols (such as sesamol, 3-CP, thymol, 2,4-DCP). Furthermore, the reusability performance of MMIS showed about 17.53% loss after five repeated cycles. Finally, the MMIS were successfully applied to the selective extraction of 2,4,6-TCP from the vegetable samples.

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

International Nuclear Information System (INIS)

Paquet, F.

1991-12-01

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

Behavior of americium, curium, and certain fission products in fluoride melts in the presence of s olid extraction agents

International Nuclear Information System (INIS)

Alekseev, V.A.; Klokman, V.R.; Morozova, Z.E.; Ziv, V.S.

1986-01-01

The authors consider the behavior of americium, curium, and certain fission products (europium, cerium, yttrium, and strontium) in fluoride and chlode-fluoride melts in the presence of nonisomorphous solid phases: calcium fluoride and lanthanum and zirconium oxides. It is shown that the trace components enter the solid calcium fluoride in a regular fashion only in the presence of an adequate amount of oxygen in the melt. The effect of oxygen on the coprecipitation with calcium fluoride occurs because oxygen compounds of the elements must be formed in the melt, and these are then coprecipitated with the calcium fluoride

Ecological distribution and fate of plutonium and americium in a processing waste pond on the Hanford Reservation

International Nuclear Information System (INIS)

Emergy, R.M.; Klopfer, D.C.; McShane, M.C.

1978-01-01

U Pond, located on the Hanford Reservation, has received low-level quantities of plutonium (Pu) and americium (Am) longer than any other aquatic environment in the world. Its ecological complexity and content of transuranics make it an ideal resource for information concerning the movement of these actinides within and out of an aquatic ecosystem. U Pond has been intensively inventoried for Pu concentrations in the ecological compartments and characterized limnologically in terms of its physicochemial parameters, biological productivity, and community structure. This work provides a basis for evaluating the pond's performance in retaining waste transuranics. The quantitative estimation of export routes developed by this study is important in determining how effectively such ponds act as retainers for transuranic wastes

Cyclic voltammetry: a tool to quantify 2,4,6-trichloroanisole in aqueous samples from cork planks boiling industrial process.

Science.gov (United States)

Peres, António M; Freitas, Patrícia; Dias, Luís G; Sousa, Mara E B C; Castro, Luís M; Veloso, Ana C A

2013-12-15

Chloroanisoles, namely 2,4,6-trichloroanisole, are pointed out as the primary responsible of the development of musty off-flavours in bottled wine, due to their migration from cork stoppers, which results in huge economical losses for wine industry. A prevention step is the detection of these compounds in cork planks before stoppers are produced. Mass spectrometry gas chromatography is the reference method used although it is far beyond economical possibilities of the majority of cork stoppers producers. In this work, a portable cyclic voltammetry approach was used to detect 2,4,6-trichloroanisole extracted from natural cork planks to the aqueous phase during the cork boiling industrial treatment process. Analyses were carried out under ambient conditions, in less than 15 min with a low use of solvent and without any sample pre-treatment. The proposed technique had detection (0.31±0.01 ng/L) and quantification (0.95±0.05 ng/L) limits lower than the human threshold detection level. For blank solutions, without 2,4,6-trichloroanisole addition, a concentration in the order of the quantification limit was estimated (1.0±0.2 ng/L), which confirms the satisfactory performance of the proposed methodology. For aqueous samples from the industrial cork planks boiling procedure, intra-day repeatabilities were lower than 3%, respectively. Also, 2,4,6-trichloroanisole contents in the aqueous samples determined by this novel approach were in good agreement with those obtained by GC-MS (correlation coefficient equal to 0.98), confirming the satisfactory accuracy of the proposed methodology. So, since this novel approach is a fast, low-cost, portable and user-friendly method, it can be an alternative and helpful tool for in-situ industrial applications, allowing accurate detection of releasable 2,4,6-trichloroanisole in an earlier phase of cork stoppers production, which may allow implementing more effective cork treatments to reduce or avoid future 2,4,6-trichloroanisole

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

International Nuclear Information System (INIS)

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

1998-01-01

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

48 CFR 52.246-9 - Inspection of Research and Development (Short Form).

Science.gov (United States)

2010-10-01

... Clauses 52.246-9 Inspection of Research and Development (Short Form). As prescribed in 46.309, insert the following clause: Inspection of Research and Development (Short Form) (APR 1984) The Government has the... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Inspection of Research and...

48 CFR 52.246-7 - Inspection of Research and Development-Fixed-Price.

Science.gov (United States)

2010-10-01

... Clauses 52.246-7 Inspection of Research and Development—Fixed-Price. As prescribed in 46.307(a), insert the following clause: Inspection of Research and Development—Fixed-Price (AUG 1996) (a) The Contractor... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Inspection of Research and...

Hemin immobilized into metal-organic frameworks as an electrochemical biosensor for 2,4,6-trichlorophenol

Science.gov (United States)

Zhang, Ting; Wang, Lu; Gao, Congwei; Zhao, Chaoyue; Wang, Yang; Wang, Jianmin

2018-02-01

Hemin immobilized into copper-based metal-organic frameworks was successfully prepared and used as a new electrode material for sensitive electrochemical biosensing. X-ray diffraction patterns, Fourier transform infrared spectra, scanning electron microscopy, UV-vis absorption spectroscopy, and cyclic voltammetry were used to characterize the resultant composites. Due to the interaction between the copper atom groups and hemin, the constrained environment in Cu-MOF-74 acts as a matrix to avoid the dimerization of enzyme molecules and retain its biological activity. The hemin/Cu-MOF composites demonstrated enhanced electrocatalytical activity and high stability towards the oxidation of 2,4,6-trichlorophenol. Under optimum experimental conditions, the sensor showed a wide linear relationship over the range of 0.01-9 μmol L-1 with a detection limit (3σ) of 0.005 μmol L-1. The relative standard deviations were 4.6% and 3.5% for five repeated measurements of 0.5 and 5 μmol L-1 2,4,6-trichlorophenol, respectively. The detection platforms for 2,4,6-trichlorophenol developed here not only indicate that hemin/Cu-MOF-74 possesses intrinsic biological reactivity, but also enable further work to be conducted towards the application of enzyme-containing metal-organic frameworks in electrochemical biosensors.

Solid-state structural properties of 2,4,6-trimethoxybenzene derivatives, determined directly from powder X-ray diffraction data in conjunction with other techniques

International Nuclear Information System (INIS)

Pan Zhigang; Xu Mingcan; Cheung, Eugene Y.; Platts, James A.; Harris, Kenneth D.M.; Constable, Edwin C.; Housecroft, Catherine E.

2006-01-01

Structural properties of 2,4,6-trimethoxybenzaldehyde, 2,4,6-trimethoxybenzyl alcohol and 2,4,6-trimethoxyacetophenone have been determined directly from powder X-ray diffraction data, using the direct-space Genetic Algorithm (GA) technique for structure solution followed by Rietveld refinement. Structural similarities and contrasts within this family of materials are elucidated. The work illustrates the value of utilizing information from other sources, including spectroscopic data and computational techniques, as a means of augmenting the structural knowledge established from the powder X-ray diffraction data

Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation

Energy Technology Data Exchange (ETDEWEB)

Gomez-De Jesus, A.; Romano-Baez, F.J.; Leyva-Amezcua, L.; Juarez-Ramirez, C.; Ruiz-Ordaz, N. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico); Galindez-Mayer, J. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico)], E-mail: cmayer@encb.ipn.mx

2009-01-30

For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A{sub D}/A{sub R} ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values {epsilon}{sub G}, and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ({approx}95%), and by the stoichiometric release of chloride ions from the halogenated compound ({approx}80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions)

Plutonium, americium, 90Sr and 137Cs in bones of red fox (Vulpes vulpes) from Eastern Poland

International Nuclear Information System (INIS)

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

2008-01-01

90 Sr, 238,239+240 Pu, 241 Am and 137 Cs activity concentrations are presented in the jaw bones of red fox (Vulpes vulpes) from eastern Poland. The short description of the applied radiochemical method is presented. Activity concentrations for 90 Sr ranged between 2.2±0.7 and 41.4±4.7 Bq/kg (aw = ash weight). Average results for plutonium and americium are on the level of 10 mBq/kg (aw). No clear relationship was observed among the radionuclide concentrations. The samples analyzed do not show elevated contamination levels when compared with results of bones of small animals (rodent or insectivorous mammals) determined previously, so no accumulation of bone seeking isotopes on higher step of food-chain is concluded. (author)

Photolysis of 2,4,6-trinitrotoluene in seawater and estuary water: Impact of pH, temperature, salinity, and dissolved organic matter

International Nuclear Information System (INIS)

Luning Prak, Dianne J.; Breuer, James E.T.; Rios, Evelyn A.; Jedlicka, Erin E.; O'Sullivan, Daniel W.

2017-01-01

The influence of salinity, pH, temperature, and dissolved organic matter on the photolysis rate of 2,4,6-trinitrotoluene (TNT) in marine, estuary, and laboratory-prepared waters was studied using a Suntest CPS +® solar simulator equipped with optical filters. TNT degradation rates were determined using HPLC analysis, and products were identified using LC/MS. Minimal or no TNT photolysis occurred under a 395-nm long pass filter, but under a 295-nm filter, first-order TNT degradation rate constants and apparent quantum yields increased with increasing salinity in both natural and artificial seawater. TNT rate constants increased slightly with increasing temperature (10 to 32 °C) but did not change significantly with pH (6.4 to 8.1). The addition of dissolved organic matter (up to 5 mg/L) to ultrapure water, artificial seawater, and natural seawater increased the TNT photolysis rate constant. Products formed by TNT photolysis in natural seawater were determined to be 2,4,6-trinitrobenzaldehyde, 1,3,5-trinitrobenzene, 2,4,6-trinitrobenzoic acid, and 2-amino-4,6-dinitrobenzoic acid. - Highlights: • 2,4,6-trinitrotoluene (TNT) was photolyzed in marine, estuary, & laboratory waters. • TNT photolysis rates increased with increasing salinity & dissolved organic matter. • Temperature and pH had minimal impact on TNT photolysis in marine waters. • In seawater, TNT photolysis produced 1,3,5-trinitrobenzene & trinitrobenzaldehyde. • Polar products were 2,4,6-trinobenzoic acid & 2-amino-4,6-dinitrobenzoic acid.

40 CFR 721.5356 - Ethanol, 2,2′2″-nitrilotris-, compound with alpha-2,4,6-tris (1-phenylethyl)phenyl]-omega...

Science.gov (United States)

2010-07-01

...-, compound with alpha-2,4,6-tris (1-phenylethyl)phenyl]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate. 721...]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate. (a) Chemical substance and significant new uses... alpha-[2,4,6-tris(1-phenylethyl)phenyl]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate (PMN P-98-185...

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

International Nuclear Information System (INIS)

Nielsen, R.D.

1982-06-01

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

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.

Preparation of oil palm empty fruit bunch-based activated carbon for removal of 2,4,6-trichlorophenol: Optimization using response surface methodology

International Nuclear Information System (INIS)

Hameed, B.H.; Tan, I.A.W.; Ahmad, A.L.

2009-01-01

The effects of three preparation variables: CO 2 activation temperature, CO 2 activation time and KOH:char impregnation ratio (IR) on the 2,4,6-trichlorophenol (2,4,6-TCP) uptake and carbon yield of the activated carbon prepared from oil palm empty fruit bunch (EFB) were investigated. Based on the central composite design, two quadratic models were developed to correlate the three preparation variables to the two responses. The activated carbon preparation conditions were optimized using response surface methodology by maximizing both the 2,4,6-TCP uptake and activated carbon yield within the ranges studied. The optimum conditions for preparing activated carbon from EFB for adsorption of 2,4,6-TCP were found as follows: CO 2 activation temperature of 814 deg. C, CO 2 activation time of 1.9 h and IR of 2.8, which resulted in 168.89 mg/g of 2,4,6-TCP uptake and 17.96% of activated carbon yield. The experimental results obtained agreed satisfactorily with the model predictions. The activated carbon prepared under optimum conditions was mesoporous with BET surface area of 1141 m 2 /g, total pore volume of 0.6 cm 3 /g and average pore diameter of 2.5 nm. The surface morphology and functional groups of the activated carbon were respectively determined from the scanning electron microscopy and Fourier transform infrared analysis.

SAGE ANALYSIS OF TRANSCRIPTOME RESPONSES IN ARABIDOPSIS ROOTS EXPOSED TO 2,4,6-TRINITROTOLUENE

Science.gov (United States)

Serial Analysis of Gene Expression (SAGE) was used to profile transcript levels in Arabidopsis thaliana roots and assess their responses to 2,4,6-trinitrotoluene (TNT) exposure. SAGE libraries representing control and TNT-exposed seedling root transcripts were constructed, and ea...

EURADOS action for determination of americium in skull measures in vivo and Monte Carlo simulation

International Nuclear Information System (INIS)

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

2013-01-01

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)

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

International Nuclear Information System (INIS)

Rashydov, N.M.

2002-01-01

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

Oxidation reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) by Compound I model of cytochrome P450s

Institute of Scientific and Technical Information of China (English)

Zhongyu Wang; Zhiqiang Fu; Qi Yu; Jingwen Chen

2017-01-01

Alternative brominated flame retardants (BFRs) have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers (PBDEs).For risk assessment of these alternatives,knowledge of their metabolism via cytochrome P450 enzymes is needed.We have previously proved that density functional theory (DFT) is able to predict the metabolism of PBDEs by revealing the molecular mechanisms.In the current study,the reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated.The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments,meanwhile intermediates which cannot be determined were also proposed.Results showed that alkyl hydrogen abstraction will lead to bis(2,4,6-tribromophenoxy)ethanol,which may undergo hydrolysis yielding 2,4,6-tribromophenol,a neurotoxic compound.In addition,a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds.Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.

Microwave assisted facile synthesis of {1/1,3-bis/1,3,5-tris-[(2-nitroxyethylnitramino)-2,4,6-trinitrobenzene]} using bismuth nitrate pentahydrate as an eco-friendly nitrating agent

International Nuclear Information System (INIS)

Badgujar, D.M.; Talawar, M.B.; Asthana, S.N.; Venugopalan, S.; Rao, A. Subhananda; Mahulikar, P.P.

2008-01-01

1-(2-Nitroxyethylnitramino)-2,4,6-trinitrobenzene (3a), 1,3-bis(2-nitroxyethyl nitramino)-2,4,6-trinitrobenzene (3b) and 1,3,5-tris(2-nitroxyethylnitramino)-2,4,6-trinitrobenzene (3c) were prepared by the nitration of 1-(2-hydroxyethylamino)-2,4,6-trinitrobenzene (2a) 1,3-bis(2-hydroxyethylamino)-2,4,6-trinitrobenzene (2b) and 1,3,5-tris(2-hydroxyethylamino)-2,4,6-trinitrobenzene (2c) using bismuth nitrate pentahydrate (eco-friendly nitrating agent) in tetrahydrofuran adsorbed on silica gel under microwave irradiation, respectively. Key intermediate compounds viz., 2a, 2b and 2c were synthesized by condensing picryl chloride, styphnyl chloride and 1,3,5-trichloro-2,4,6-trinitrobenzene with ethanol amine, respectively, based on the lines of the reported method. The synthesized compounds were characterized based on their physical constant, infrared (IR) spectroscopy and 1 H nuclear magnetic resonance (NMR) spectroscopy. The spectroscopic data obtained indicated the formation of nitrate esters (3a-3c). The nitration methodology adopted in the present study is of relevance in the context of green chemistry. The target compounds (3a-3c) synthesized using eco-friendly approach are of interest from the point of high energy materials (HEMs)

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

Energy Technology Data Exchange (ETDEWEB)

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

2018-02-06

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

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

International Nuclear Information System (INIS)

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

1992-06-01

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

Oral exposure of adult zebrafish (Danio rerio) to 2,4,6-tribromophenol affects reproduction

DEFF Research Database (Denmark)

Halden, Anna Norman; Nyholm, Jenny Rattfelt; Andersson, Patrik L

2010-01-01

The bromophenol 2,4,6-tribromophenol (TBP) is widely used as an industrial chemical, formed by degradation of tetrabromobisphenol-A, and it occurs naturally in marine organisms. Concentrations of TBP in fish have been related to intake via feed, but little is known about effects on fish health...... after oral exposure. In this study, we exposed adult male and female zebrafish (Danio rerio) to TBP via feed in nominal concentrations of 33, 330, and 3300 mu g/g feed (or control feed) for 6 weeks to assess the effects of TBP on reproductive output, gonad morphology, circulatory vitellogenin levels......, and early embryo development. The aim was also to investigate the extent to which TBP was metabolised to 2,4,6-tribromoanisole (IBA) in dietary exposed zebrafish, and the amounts of TBP and TBA found in offspring. After 6 weeks of exposure, we found about 3% of the daily dose of TBP in adult fish...

Plutonium and americium recovery from spent molten-salt-extraction salts with aluminum-magnesium alloys

International Nuclear Information System (INIS)

Cusick, M.J.; Sherwood, W.G.; Fitzpatrick, R.F.

1984-01-01

Development work was performed to determine the feasibility of removing plutonium and americium from spent molten-salt-extraction (MSE) salts using Al-Mg alloys. If the product buttons from this process are compatible with subsequent aqueous processing, the complex chloride-to-nitrate aqueous conversion step which is presently required for these salts may be eliminated. The optimum alloy composition used to treat spent 8 wt % MSE salts in the past yielded poor phase-disengagement characteristics when applied to 30 mol % salts. After a limited investigation of other alloy compositions in the Al-Mg-Pu-Am system, it was determined that the Al-Pu-Am system could yield a compatible alloy. In this system, experiments were performed to investigate the effects of plutonium loading in the alloy, excess magnesium, age of the spent salt on actinide recovery, phase disengagement, and button homogeneity. Experimental results indicate that 95 percent plutonium recoveries can be attained for fresh salts. Further development is required for backlog salts generated prior to 1981. A homogeneous product alloy, as required for aqueous processing, could not be produced

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

2014-09-02

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.

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

International Nuclear Information System (INIS)

Borba, Tania Regina de

2010-01-01

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

Incorporation of plutonium, americium and curium into the Irish Sea seabed by biological activity

Energy Technology Data Exchange (ETDEWEB)

Kershaw, P J; Swift, D J; Pentreath, R J; Lovett, M B

1984-12-01

Bioturbation was considered as a potentially significant mechanism for the incorporation of long-lived radionuclides into the seabed and in particular the activities of a large echiuran Maximulleria lankesteri. Radionuclides of the transuranium elements plutonium, americium and cirium are discharged into the Irish Sea under authorization as part of the low-level liquid effluent from the British Nuclear Fuels plc reprocessing plant at Sellafield, Cumbria, England. The distribution of Pu-239, 240, Pu-238, Am-241, Cm-244 and Cm-242 concentrations and the Pu-239, 240/Pu-238 quotient in samples taken in April and May 1983 from the sediment surface, burrow linings, sediments adjacent to burrows, and the gut contents and body of a large M. lankesteri clearly indicate that bioturbation is responsible, at least in part, for the incorporation of these radionuclides to depths of up to 140 cm. This area of sediments represents a significant present-day sink, but the permanence of this sink and the likelihood that radioactivity will be remobilized and be returned to man, depends on a large number of factors. 15 references, 18 figures.

Comparative study of plutonium and americium bioaccumulation from two marine sediments contaminated in the natural environment

International Nuclear Information System (INIS)

Hamilton, T.F.; Smith, J.D.

1991-01-01

Plutonium and americium sediment-animal transfer was studied under controlled laboratory conditions by exposure of the benthic polychaete Nereis diversicolor (O. F. Mueller) to marine sediments contaminated by a nuclear bomb accident (near Thule, Greenland) and nuclear weapons testing (Enewetak Atoll). In both sediment regimes, the bioavailability of plutonium and 241 Am was low, with specific activity in the tissues 241 Am occurred and 241 Am uptake from the Thule sediment was enhanced compared to that from lagoon sediments of Enewetak Atoll. Autoradiography studies indicated the presence of hot particles of plutonium in the sediments. The results highlight the importance of purging animals of their gut contents in order to obtain accurate estimates of transuranic transfer from ingested sediments into tissue. It is further suggested that enhanced transuranic uptake by some benthic species could arise from ingestion of highly activity particles and organic-rich detritus present in the sediments. (author)

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

International Nuclear Information System (INIS)

Sontag, W.

1986-01-01

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

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

International Nuclear Information System (INIS)

Louwrier, K.P.; Richter, K.

1976-01-01

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

Transfer of plutonium and americium to grass vegetation as a function of radionuclide solid - solution portioning in soil

International Nuclear Information System (INIS)

Sokolik, G.; Ovsiannikova, S.; Ivanova, T.; Leinova, S.; Kimlenka, I.; Zakharenkov, V.; Zakharenkova, N.

2004-01-01

The aim of investigation is to determine the main parameters influencing the plutonium and americium migration in the soil plant system including concentration factor Cf and distribution coefficient K d . The C f factor characterising the ratio of radionuclide activity concentration in the plant specie (A p , Bq/kg) and root-inhabited layer of soil (A s , Bq/kg) has been used as a measure of biological availability of TUE. The K d coefficient estimating the ratio between radionuclide activity concentration in the equilibrium solid phase (A s.ph. ) and pore solution (A sol. , Bq/l) is considered as a measure of sorption ability of soil in respect to the radionuclide. The biological availability of 239,240 Pu and 241 Am for different grass species in various mineral and organic soils of natural and agrarian systems has been studied. The soils and grass vegetation were sampled in 1994 - 2001 in Bragin, Narovla, Khoiniki districts of Belarus (12 - 53 km from ChNPP). Since plant uptake depends primarily on radionuclide portion in the pore soil solution the proper solutions were separated from the soil samples of root-inhabited layer with the method of high-speed centrifugation. 239,240 Pu and 241 Am in the samples were determined radiochemically using alpha-spectrometer ALPHA-KING 676 A. Influence of composition of soil solution on the radionuclide soil plant transfer has been analysed. The interrelationships between the concentration factor (C f ), portion of radionuclide in the soil solution and coefficient K d have been considered. The results of investigations clearly demonstrated the dependence of TUE concentration factors for meadow sedge-herbaceous association of soil sorbing complex. As a rule, C f of americium is higher than that of plutonium. Differentiating of soils according to the C f value and the forecast of grass vegetation contamination by TUE in the different periods after catastrophe has been done. The levels of various soils contamination to receive

Concentrations of organochlorine pesticides and 2,4,6-trichloroanisole in cork bark.

Science.gov (United States)

Olivella, M Àngels; Caixach, Josep; Planas, Carles; Oliveras, Anna; Jové, Patrícia

2012-02-01

Organochlorine pesticides are persistent lipophilic organic pollutants and tend to accumulate in growing plants. During growth, cork is in contact with the open air for long periods (9-12 years). Owing to the previous widespread use of organochlorine pesticides and their high persistence in the environment, there is a risk that residues of such pesticides may be present in cork. In this study, the concentrations of 14 organochlorine pesticides-all of which are indicators of environmental pollution-were analyzed in cork bark samples from three regions in Spain and one in Portugal. In addition, the concentrations of 2,4,6-trichlorophenol (TCP) and 2,4,6-trichloroanisole (TCA) were also analyzed. Our results show only very low concentrations of lindane, γ-HCH (cork sample from Extremadura (0.1 ng g(-1)) and p,p'-DDE was present at a maximum concentration of 2.9 ng g(-1) in a cork sample from Castile-La Mancha. However, all concentrations were well below the legal limit established by Regulation (EC) No. 396/2005 (10 ng g(-1) in foodstuffs). We can conclude, therefore, that the cork samples we studied complied with food safety standards. Copyright © 2011 Elsevier Ltd. All rights reserved.

Transmutation of Americium in Light and Heavy Water Reactors

Energy Technology Data Exchange (ETDEWEB)

Hyland, B.; Dyck, G.R.; Edwards, G.W.R. [Chalk River Laboratories, Atomic Energy of Canada Limited (Canada); Ellis, R.J.; Gehin, J.C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee (United States); Maldonado, G.I. [University of Tennessee (Knoxville)/ORNL, Tennessee (United States)

2009-06-15

There is interest worldwide in reducing the burden on geological nuclear fuel disposal sites. In most disposal scenarios the decay heat loading of the surrounding rock limits the capacity of these sites. On the long term, this decay heat is generated primarily by actinides, and a major contributor 100 to 1000 years after discharge from the reactor is {sup 241}Am. One possible approach to reducing the decay-heat burden is to reprocess spent reactor fuel and use thermal spectrum reactors to 'burn' the Am nuclides. The viability of this approach is dependent upon the detailed changes in chemical and isotopic composition of actinide-bearing fuels after irradiation in thermal reactor spectra. The currently available thermal spectrum reactor options include light water-reactors (LWRs) and heavy-water reactors (HWRs) such as the CANDU{sup R} designs. In addition, as a result of the recycle of spent LWR fuel, there would be a considerable amount of potential recycled uranium (RU). One proposed solution for the recycled uranium is to use it as fuel in Candu reactors. This paper investigates the possibilities of transmuting americium in 'spiked' bundles in pressurized water reactors (PWRs) and in boiling water reactors (BWRs). Transmutation of Am in Candu reactors is also examined. One scenario studies a full core fuelled with homogeneous bundles of Am mixed with recycled uranium, while a second scenario places Am in an inert matrix in target channels in a Candu reactor, with the rest of the reactor fuelled with RU. A comparison of the transmutation in LWRs and HWRs is made, in terms of the fraction of Am that is transmuted and the impact on the decay heat of the spent nuclear fuel. CANDU{sup R} is a registered trademark of Atomic Energy of Canada Limited (AECL). (authors)

Removal of 2,4,6-trichlorophenol from a solution by humic acids repeatedly extracted from a peat soil

International Nuclear Information System (INIS)

Tzou, Y.-M.; Wang, S.-L.; Liu, J.-C.; Huang, Y.-Y.; Chen, J.-H.

2008-01-01

Humic acid (HA) is one of the major components of soil organic matter. It strongly affects the sorption behavior of organic and inorganic contaminants in soils. To obtain a better understanding of the interactions of contaminants with HA, a repeated extraction technique has been applied to a peat soil to obtain HA fractions with varying aliphaticity and aromaticity, which were subsequently correlated to the sorption properties of 2,4,6-trichlorophenol (TCP). HA fractions were extracted repeatedly using an alkaline solution and each HA fraction was separated into two portions with an air-drying or re-suspending (denoted as RSHAs) process. Solid-state 13 C NMR and elemental analysis demonstrated that the aromaticity and polarity of HAs decreased with extractions. Kinetic results indicated that air-dried HAs exhibited two-step first order sorption behavior with a rapid stage followed by a slower stage. The slower sorption is attributed to the diffusion of 2,4,6-TCP in the condensed aromatic domains of HAs. Conversely, sorption of 2,4,6-TCP on RSHAs was extremely rapid and could not be fitted with any kinetic model. For air-dried HAs the sorption capacity (K oc ) was weakly correlated with the chemical compositions of HAs. However, a positive trend between K oc and aromaticity was observed for RSHAs. Compared with the results of air-dried HAs with their counterparts of RSHAs, it is therefore concluded that air-drying may alter the structure of HAs through artificially creating a more condensed domain in HAs. The structural alternation may result in an incorrect interpretation of the relationship between sorption capacity and chemical composition of HAs and a misjudgment of the transport behavior of 2,4,6-TCP in soils and sediments

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

International Nuclear Information System (INIS)

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

1979-01-01

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

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

International Nuclear Information System (INIS)

Bierkens, J.

1986-01-01

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

Computational investigation on 2,4,6-trinitrochlorobenzene crystal

Energy Technology Data Exchange (ETDEWEB)

Ju, Xue-Hai; Qiu, Ling; Xiao, He-Ming [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094 (China)

2006-02-15

Density functional theory calculations at the B3LYP level were performed on crystalline 2,4,6-trinitrochlorobenzene. The carbon, oxygen, and chlorine atoms make up the narrow lower energy bands, while the nitrogen, carbon, and oxygen atoms make up the higher energy bands. Besides, the contributions of these atomic orbitals to the frontier bands are somewhat well-proportioned. The Mulliken populations obviously demonstrate that the C-N bonds are the weakest, indicating that the C-NO{sub 2} is prone to rupture upon stimuli. An anisotropic impact on the bulk makes the electron transfer from chlorine to its neighbor carbon atom and from nitrogen atoms to oxygen atoms. The crystal lattice energy is predicted to be -50.99 kJ/mol, after being corrected for basis set superposition error. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

2,4,6-Triamino-1,3,5-triazine-1,3-diium aquapentafluoridoaluminate

Directory of Open Access Journals (Sweden)

V. Maisonneuve

2008-04-01

Full Text Available The title compound, (C3H8N6[AlF5(H2O], was obtained by solvothermal synthesis from the reaction of aluminium hydroxide, 1,3,5-triazine-2,4,6-triamine (melamine, aqueous HF and water at 323 K for 48 h. The structure consists of [AlF5(H2O]2− octahedra and diprotonated melaminium cations. Cohesion is ensured by a three-dimensional network of hydrogen bonds.

Spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB

Science.gov (United States)

Harris, B.W.

1984-11-29

A simple, sensitive and specific spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB, is described. Upon the application of the composition of matter of the subject invention to samples containing in excess of 0.1 mg of this explosive, a bright orange color results. Interfering species such as TNT and Tetryl can be removed by first treating the sample with a solvent which does not dissolve the TATB, but readily dissolves these interfering explosives.

Structural and spectroscopic parameters of 2,4,6-trimethylbenzamide, using DFT method

International Nuclear Information System (INIS)

Catikkas, B.; Karakaya, N.

2010-01-01

Conformational analysis of 2,4,6-Trimethylbenzamide was carried out. The geometric parameters (bond length, bond angle and tortion angle) of the most stable conformer were calculated and the Infrared and Raman frequencies of fundamental modes were determined. All calculations have been made by using the B3LYP / 6-311+G(d,p) method. Calculated values were compared with the experimental ones. All calculations were carried out with the Gaussian03 and GaussView3.0 programs.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

International Nuclear Information System (INIS)

Groettheim, Siri

2000-01-01

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

Isolation from estuarine sediments of a Desulfovibrio strain which can grow on lactate coupled to the reductive dehalogenation of 2,4,6-tribromophenol

Energy Technology Data Exchange (ETDEWEB)

Boyle, A.W.; Phelps, C.D.; Young, L.Y. [Rutgers-The State Univ. of New Jersey, New Brunswick, NJ (United States). Biotechnology Center for Agriculture and the Environment

1999-03-01

Strain TBP-1, an anaerobic bacterium capable of reductively dehalogenating 2,4,6-tribromophenol to phenol, was isolated from estuarine sediments of the Arthur Kill in the New York/New Jersey harbor. It is a gram-negative, motile, vibrio-shaped, obligate anaerobe which grows on lactate, pyruvate, hydrogen, and fumarate when provided sulfate as an electron acceptor. The organism accumulates acetate when grown on lactate and sulfate, contains desulfoviridin, and will not grow in the absence of NaCl. It will not utilize acetate, succinate, propionate, or butyrate for growth via sulfate reduction. When supplied with lactate as an electron donor, strain TBP-1 will utilize sulfate, sulfite, sulfur, and thiosulfate for growth but not nitrate, fumarate, or acrylate. This organism debrominates 2-, 4-, 2,4-, 2,6-, and 2,4,6-bromophenol but not 3- or 2,3-bromophenol or monobrominated benzoates. It will not dehalogenate monochlorinated, fluorinated, or iodinated phenols or chlorinated benzoates. Together with its physiological characteristics, its 16S rRNA gene sequence places it in the genus Desulfovibrio. The average growth yield of strain TBP-1 grown on a defined medium supplemented with lactate and 2,4,6-bromophenol is 3.71 mg of protein/mmol of phenol produced, and the yield was 1.42 mg of protein/mmol of phenol produced when 40bromophenol was the electron acceptor. Average growth yields for Desulfovibrio sp. strain TBP-1 grown with 2,4,6-bromophenol, 4-bromophenol, or sulfate are 0.62, 0.71, and 1.07, respectively. Growth did not occur when either lactate or 2,4,6-bromophenol was omitted from the growth medium. These results indicate that Desulfovibrio sp. strain TBP-1 is capable of growth via halorespiration.

Monoklonale Antikörper zum Nachweis von 2,4,6-Trichloranisol in Kork

OpenAIRE

Lausterer, Ralph

2005-01-01

Die Verbindung 2,4,6-Trichloranisol (TCA) kann in Kork und Wein vorkommen. TCA entsteht durch mikrobielle Umsetzung von Chlorphenolen. In den betroffenen Industrien führt TCA zu jährlichen Verlusten von mehr als einer Milliarde €. Zur Bestimmung von TCA sollten enzymkoppelte Immunabsorptionstest (ELISAs) mit monoklonalen Antikörpern (mAk) entwickelt werden. Es wurden drei TCA-spezifische mAk-produzierende Zelllinien gewonnen. Mit diesen mAk wurden hochsensitive ELISAs hergstellt, die eine Nac...

Comparative study of plutonium and americium bioaccumulation from two marine sediments contaminated in the natural environment

Energy Technology Data Exchange (ETDEWEB)

Hamilton, T.F.; Smith, J.D. (Melbourne Univ., Parkville (Australia). Dept. of Inorganic Chemistry); Fowler, S.W.; LaRosa, J.; Holm, E. (International Atomic Energy Agency, Monaco-Ville (Monaco). Lab. of Marine Radioactivity); Aarkrog, A.; Dahlgaard, H. (Risoe National Lab., Roskilde (Denmark))

1991-01-01

Plutonium and americium sediment-animal transfer was studied under controlled laboratory conditions by exposure of the benthic polychaete Nereis diversicolor (O. F. Mueller) to marine sediments contaminated by a nuclear bomb accident (near Thule, Greenland) and nuclear weapons testing (Enewetak Atoll). In both sediment regimes, the bioavailability of plutonium and {sup 241}Am was low, with specific activity in the tissues <1% (dry wt) than in the sediments. Over the first three months, a slight preference in transfer of plutonium over {sup 241}Am occurred and {sup 241}Am uptake from the Thule sediment was enhanced compared to that from lagoon sediments of Enewetak Atoll. Autoradiography studies indicated the presence of hot particles of plutonium in the sediments. The results highlight the importance of purging animals of their gut contents in order to obtain accurate estimates of transuranic transfer from ingested sediments into tissue. It is further suggested that enhanced transuranic uptake by some benthic species could arise from ingestion of highly activity particles and organic-rich detritus present in the sediments. (author).

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

International Nuclear Information System (INIS)

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

1975-01-01

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

Characterization of a sealed Americium-Beryllium (AmBe) source by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Sommers, J.; Jimenez, M.; Adamic, M.; Giglio, J.; Carney, K.

2009-01-01

Two Americium-Beryllium neutron sources were dismantled, sampled (sub-sampled) and analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Characteristics such as 'age' since purification, actinide content, trace metal content and inter and intra source composition were determined. The 'age' since purification of the two sources was determined to be 25.0 and 25.4 years, respectively. The systematic uncertainties in the 'age' determination were ±4% 2σ. The amount and isotopic composition of U and Pu varied substantially between the sub-samples of Source 2 (n = 8). This may be due to the physical means of sub-sampling or the way the source was manufactured. Source 1 was much more consistent in terms of content and isotopic composition (n = 3 sub-samples). The Be-Am ratio varied greatly between the two sources. Source 1 had an Am-Be ratio of 6.3 ± 52% (1σ). Source 2 had an Am-Be ratio of 9.81 ± 3.5% (1σ). In addition, the trace element content between the samples varied greatly. Significant differences were determined between Sources 1 and 2 for Sc, Sr, Y, Zr, Mo, Ba and W. (author)

Evaluation of Orally Delivered ST-246 as Postexposure Prophylactic and Antiviral Therapeutic in an Aerosolized Rabbitpox Rabbit Model

National Research Council Canada - National Science Library

Nalca, Aysegul; Hatkin, Josh M; Garza, Nicole L; Nichols, Donald K; Norris, Sarah W; Hruby, Dennis E; Jordan, Robert

2008-01-01

...) to treat smallpox or monkeypox infection. In this study, we showed that administration of the antiviral compound ST-246 to rabbits by oral gavage, once daily for 14 days beginning 1h postexposure (p.e.), resulted in 100...

A spatio-kinematic study of the interaction of the planetary nebula NGC 246 with the interstellar medium

NARCIS (Netherlands)

Muthu, C; Anandarao, BG; Pottasch, [No Value

Spatio-Kinematic observations were made on NGC 246 in the [OIII] 5007 Angstrom line using an Imaging Fabry-Perot Spectrometer. Evidence for the deceleration effect was found in the leading edge of the nebular shell, possibly due to its interaction with the interstellar medium. Further, we show that

Synthesis of 2,4,6-Trisubstituted Pyridines by Oxidative Eosin Y Photoredox Catalysis.

Science.gov (United States)

Rohokale, Rajendra S; Koenig, Burkhard; Dhavale, Dilip D

2016-08-19

Eosin Y, an organic dye, was activated as a photoredox catalyst in the presence of molecular oxygen using visible light and, when it was used in the reaction of aryl ketones and benzyl amines, afforded good yields (52-87%) of 2,4,6-triarylpyridines (21 examples) at ambient temperature. The aryl groups at the 2- and 6-positions are derived from ketones, while benzyl amine plays the dual role of providing an aryl functionality at the 4-position of pyridine as well as being a nitrogen donor.

WE-A-18A-01: TG246 On Patient Dose From Diagnostic Radiation

Energy Technology Data Exchange (ETDEWEB)

Supanich, M [Rush University Medical Center, Chicago, IL (United States); Dong, F [The Cleveland Clinic, Solon, OH (United States); Andersson, J [Umea University, Umea (Sweden); Pavlicek, W [Mayo Clinic Arizona, Scottsdale, AZ (United States); Bolch, W [University Florida, Gainesville, FL (United States); Fetterly, K [Mayo Clinic, Rochester, MN (United States)

2014-06-15

Radiation dose from diagnostic and interventional radiations continues to be a focus of the regulatory, accreditation and standards organizations in the US and Europe. A Joint AAPM/EFOMP effort has been underway in the past year — having the goal to assist the clinical medical physicist with communicating optional and varied approaches in estimating (and validating) patient dose. In particular, the tools provided by DICOM Radiation Dose Structured Reports, either by themselves or as part of a networked data repository of dose related information are a rich source of actionable information. The tools of the medical physicist have evolved to include using DICOM data in meaningful ways to look at patient dose with respect to imaging practices. In addition to how accurate or reproducible a dose value is (totally necessary and our traditional workspace) it is now being asked how reproducible (patient to patient, device to device) are the delivered doses (new tasking)? Clinical medical physicists are best equipped to assist our radiology and technologist colleagues with this effort. The purpose of this session is to review the efforts of TG246 - bringing forward a summary content of the TG246 Report including specific dose descriptors for CT and Fluoroscopy — particularly in a focus of leveraging the RDSR as a means for monitoring good practices ALARA. Additionally, rapidly evolving technologies for more refined dose estimates are now in use. These will be presented as they look to having highly patient specific dose estimates in automated use.

(N,N,N′,N′-Tetramethylethylenediamine-κNbis(2,4,6-trimethylphenolato-κOgermanium(II

Directory of Open Access Journals (Sweden)

Eduard Rusanov

2012-03-01

Full Text Available In the title compound, [Ge(C9H11O2(C6H16N2], the GeII atom is coordinated in a distorted trigonal–pyramidal geometry by two O atoms belonging to two 2,4,6-trimethylphenolate ligands and one N atom of a tetramethylethylenediamine ligand. Comparing the structure with published data of similar compounds shows that the Ge—O bonds are covalent and the Ge—N bond is coordinated.

Experimental studies on the biokinetics of plutonium and americium in the cephalopod Octopus vulgaris

International Nuclear Information System (INIS)

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

1982-01-01

Radiotracer experiments using the photon-emitters 237 Pu and 241 Am were performed to examine uptake, tissue distribution and retention of plutonium and americium in the cephalopod Octopus vulgaris Cuvier. A 2 wk exposure in contaminated sea water resulted in twice as much 237 Pu being taken up by whole octopus as 241 Am. Immediately following uptake approximately 41% and 73% of the 237 Pu and 241 Am respectively were located in the branchial hearts. Depuration rates for both radionuclides were identical; approximately 46% of both radionuclides initially incorporated were associated with a long-lived compartment which turned over very slowly (Tbsub(1/2) = 1.5 yr). Longer exposures to 241 Am resulted in an increase in the size of the slowly exchanging 241 Am pool in the octopus. After 2 mo depuration, the majority of the residual activity of both radionuclides was in the branchial hearts. On average 33% of the 241 Am ingested with food was assimilated into tissues, primarily the hepatopancreas. Different whole-body 241 Am excretion rates were observed at different times following assimilation and were related to transfer processes taking place within internal tissues, most notably between hepatopancreas and the branchial hearts. Relationships between circulatory and excretory functions of these 2 organs are discussed and a physiological mechanism is proposed to explain the observed patterns of 241 Am excretion in O. vulgaris. (orig.)

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Comparative study of G2 delay and survival after /sup 241/Americium-. cap alpha. and /sup 60/Cobalt-. gamma. irradiation

Energy Technology Data Exchange (ETDEWEB)

Luecke-Huhle, C.; Comper, W.; Hieber, L.; Pech, M.

1982-06-01

Survival and G2 delay following exposure to either /sup 60/Cobalt-..gamma..-rays or /sup 241/Americium-..cap alpha..-particles were studied in eight mammalian cell lines of human and animal origin including human fibroblasts from normal individuals and from patients with Ataxia telangiectasia or Fanconi's anemia. For both endpoints the effectiveness of alpha particle was greater as compared to ..gamma..-rays. RBE values for G2 delay (4.6-9.2) were in general comparable to RBE values derived from initial slopes of survival curves but higher compared to the ratio of mean inactivation doses. Ataxia cells were particularly sensitive to cell killing by ..gamma..-irradiation, however, showed average sensitivity to ..cap alpha..-particles of high LET. With the exception of Ataxia cells, cell killing and G2 delay seem to be related processes if individual cell cycle parameters are taken into account.

1,1´,1´´-(2,4,6-Trihydroxybenzene-1,3,5-triyl)triethanone tautomerism revisited

DEFF Research Database (Denmark)

Hansen, Poul Erik; Kamounah, Fadhil S.; Zhiryakova, Diana

2014-01-01

It has recently been suggested that 1,1′,1′′-(2,4,6-trihydroxybenzene-1,3,5-triyl)triethanone may be tautomeric. Using 13C NMR chemical shifts and deuterium isotope effects on 13C chemical shifts, it is demonstrated that this is not the case. This compound occurs as a strongly hydrogen bonded ben...

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

International Nuclear Information System (INIS)

Pimpl, M.; Schuettelkopf, H.

1979-12-01

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

The (p→,t) reaction on 58Ni and 56Fe at 24.6 MeV

International Nuclear Information System (INIS)

Polane, J.H.; Feix, W.F.; Hall, P.J. van; Klein, S.S.; Nijgh, G.J.; Poppema, O.J.; Wassenaar, S.D.

1989-01-01

The (p, t) reactions on 56 Fe and 58 Ni initiated by 24.6 MeV polarised protons has been investigated. The reaction process is described in terms of simultaneous and sequential neutron transfer. For all five final states studied the sequential process competes strongly with simultaneous transfer of a neutron pair. Theoretical values for the spectroscopic amplitudes were derived from shell-model wavefunctions; these seem to give a reliable description of the reaction process. (author)

Synthesis of fisetin and 2',4',6'-trihydroxydihyrochalcone 4'-O-β-neohesperidoside based on site-selective deacetylation and deoxygenation.

Science.gov (United States)

Tsunekawa, Ryuji; Hanaya, Kengo; Higashibayashi, Shuhei; Sugai, Takeshi

2018-04-26

Fisetin and 2',4',6'-trihydroxydihyrochalcone 4'-O-β-neohesperidoside were synthesized from commercially available quercetin and naringin in five steps. The key steps are site-selective deacetylation and subsequent deoxygenation. The target molecules were obtained in 37% and 23% yields from the starting materials, respectively.

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)

A combination of p53-activating APR-246 and phosphatidylserine-targeting antibody potently inhibits tumor development in hormone-dependent mutant p53-expressing breast cancer xenografts

Directory of Open Access Journals (Sweden)

Liang Y

2018-03-01

Full Text Available Yayun Liang,1 Benford Mafuvadze,1 Cynthia Besch-Williford,2 Salman M Hyder1 1Deparment of Biomedical Sciences and Dalton Cardiovascular Research Center, Columbia, MO, USA; 2IDEXX BioResearch, Columbia, MO, USA Background: Between 30 and 40% of human breast cancers express a defective tumor suppressor p53 gene. Wild-type p53 tumor suppressor protein promotes cell-cycle arrest and apoptosis and inhibits vascular endothelial growth factor–dependent angiogenesis, whereas mutant p53 protein (mtp53 lacks these functions, resulting in tumor cell survival and metastasis. Restoration of p53 function is therefore a promising drug-targeted strategy for combating mtp53-expressing breast cancer. Methods: In this study, we sought to determine whether administration of APR-246, a small-molecule drug that restores p53 function, in combination with 2aG4, an antibody that targets phosphatidylserine residues on tumor blood vessels and disrupts tumor vasculature, effectively inhibits advanced hormone-dependent breast cancer tumor growth. Results: APR-246 reduced cell viability in mtp53-expressing BT-474 and T47-D human breast cancer cells in vitro, and significantly induced apoptosis in a dose-dependent manner. However, APR-246 did not reduce cell viability in MCF-7 breast cancer cells, which express wild-type p53. We next examined APR-246’s anti-tumor effects in vivo using BT-474 and T47-D tumor xenografts established in female nude mice. Tumor-bearing mice were treated with APR-246 and/or 2aG4 and tumor volume followed over time. Tumor growth was more effectively suppressed by combination treatment than by either agent alone, and combination therapy completely eradicated some tumors. Immunohistochemistry analysis of tumor tissue sections demonstrated that combination therapy more effectively induced apoptosis and reduced cell proliferation in tumor xenografts than either agent alone. Importantly, combination therapy dramatically reduced the density of blood

The distribution and remobilisation of plutonium and americium in estuaries of the eastern Irish Sea: a review

International Nuclear Information System (INIS)

Toole, J.

1993-01-01

The plutonium and americium components in the authorised discharges from BNFL Sellafield are rapidly removed from Irish Sea seawater onto the particulate phase. These actinides tend to be concentrated in fine sediment deposits on the Irish Sea bed and in estuaries where fine sediment accumulates. This paper focuses on these estuarine areas and brings together the available data on the levels and distributions of Pu and Am within the estuarine sediments. The results from field and laboratory experiments which have been undertaken in order to determine the degree of Pu and Am remobilisation, and the mechanism responsible, are also reviewed. These sediment-associated actinides may undergo both chemical and physical remobilisation, leading to increased dissolved concentrations in low-salinity waters and to apparent losses from the estuary on the sediment phase under certain conditions. Saltmarsh sediments are demonstrated to be the most important reservoirs for Pu and Am. The radiological significance of the levels of Pu and Am found in these and in other sediments is summarised, by comparison with GDLs. The appropriateness of GDLs for assessing the radiological significance of Pu and Am in these saltmarsh sediments is discussed. A more site-specific assessment methodology is recommended. (author)

Experimental studies on the biokinetics of plutonium and americium in the cephalopod Octopus vulgaris

Energy Technology Data Exchange (ETDEWEB)

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

1982-03-05

Radiotracer experiments using the photon-emitters /sup 237/Pu and /sup 241/Am were performed to examine uptake, tissue distribution and retention of plutonium and americium in the cephalopod Octopus vulgaris Cuvier. A 2 wk exposure in contaminated sea water resulted in twice as much /sup 237/Pu being taken up by whole octopus as /sup 241/Am. Immediately following uptake approximately 41% and 73% of the /sup 237/Pu and /sup 241/Am respectively were located in the branchial hearts. Depuration rates for both radionuclides were identical; approximately 46% of both radionuclides initially incorporated were associated with a long-lived compartment which turned over very slowly (Tbsub(1/2) = 1.5 yr). Longer exposures to /sup 241/Am resulted in an increase in the size of the slowly exchanging /sup 241/Am pool in the octopus. After 2 mo depuration, the majority of the residual activity of both radionuclides was in the branchial hearts. On average 33% of the /sup 241/Am ingested with food was assimilated into tissues, primarily the hepatopancreas. Different whole-body /sup 241/Am excretion rates were observed at different times following assimilation and were related to transfer processes taking place within internal tissues, most notably between hepatopancreas and the branchial hearts. Relationships between circulatory and excretory functions of these 2 organs are discussed and a physiological mechanism is proposed to explain the observed patterns of /sup 241/Am excretion in O. vulgaris.

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Concentrations of plutonium and americium in plankton from the western Mediterranean Sea.

Science.gov (United States)

Sanchez-Cabeza, Joan-Albert; Merino, Juan; Masqué, Pere; Mitchell, Peter I; Vintró, L León; Schell, William R; Cross, Lluïsa; Calbet, Albert

2003-07-20

Understanding the transfer of radionuclides through the food chain leading to man and in particular, the uptake of transuranic nuclides by plankton, is basic to assess the potential radiological risk of the consumption of marine products by man. The main sources of transuranic elements in the Mediterranean Sea in the past were global fallout and the Palomares accident, although at present smaller amounts are released from nuclear establishments in the northwestern region. Plankton from the western Mediterranean Sea was collected and analyzed for plutonium and americium in order to study their biological uptake. The microplankton fractions accounted for approximately 50% of the total plutonium contents in particulate form. At Garrucha (Palomares area), microplankton showed much higher 239,240 Pu activity, indicating the contamination with plutonium from the bottom sediments. Concentration factors were within the range of the values recommended by the International Atomic Energy Agency. Continental shelf mesoplankton was observed to efficiently concentrate transuranics. In open seawaters, concentrations were much lower. We speculate that sediments might play a role in the transfer of transuranics to mesoplankton in coastal waters, although we cannot discard that the difference in species composition may also play a role. In Palomares, both 239,240 Pu and 241Am showed activities five times higher than the mean values observed in continental shelf mesoplankton. As the plutonium isotopic ratios in the contaminated sample were similar to those found in material related to the accident, the contamination was attributed to bomb debris from the Palomares accident. Concentration factors in mesoplankton were also in relatively good agreement with the ranges recommended by IAEA. In the Palomares station the highest concentration factor was observed in the sample that showed predominance of the dynoflagellate Ceratium spp. Mean values of the enrichment factors showed, on

Synthesis of 2,4,6-trichlorophenyl hydrazones and their inhibitory potential against glycation of protein.

Science.gov (United States)

Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Jahan, Humera; Perveen, Shahnaz; Choudhary, M Iqbal

2011-11-01

2,4,6-Trichlorophenyl hydrazones 1-35 were synthesized and their in vitro antiglycation potential was evaluated. Compounds 14 (IC50 = 27.2 ± 0.00 μM), and 18 (IC50 = 55.7 ± 0.00 μM) showed an excellent activity against glycation of protein, better than the standard (rutin, IC50 = 70 ± 0.50 μM). This study thus identified a novel series of antiglycation agents. A structure-activity relationship has been studied, and all the compounds were characterized by spectroscopic techniques.

Adsorption of 2,4,6-trinitrotoluene on carboxylated porous polystyrene microspheres

International Nuclear Information System (INIS)

Ye Zhengfang; Meng Qingqiang; Lu Shengtao

2012-01-01

Large-pore-size (150 nm) polystyrene (PSt) microspheres were carboxylated with phthalic anhydride (PA) through Friedel-Crafts acetylation to study the adsorption of 2,4,6-trinitrotoluene (TNT) on this material from aqueous solution. The scanning electron microscope (SEM) images and mercury porosimetry measurements (MPM) of the microspheres showed that the pore structure was unchanged during the reaction. High adsorption capacity (11.2 mg g -1 of suction-dried adsorbent) and adsorption rate (33.9 mg g -1 h -1 ) for TNT were observed during the study. As shown by the adsorption isotherm, the adsorption of TNT on PA-PSt can be described by the Freundlich adsorption equation, indicating heterogeneous adsorption process. On-column adsorption of TNT on PA-PSt and elution indicated that TNT can be completely removed from aqueous solution and condensed into acetone.

Reliability of optical fibres and components final report of COST 246

CERN Document Server

Griffioen, Willem; Gadonna, Michel; Limberger, Hans; Heens, Bernard; Knuuttila, Hanna; Kurkjian, Charles; Mirza, Shehzad; Opacic, Aleksandar; Regio, Paola; Semjonov, Sergei

1999-01-01

Reliability of Optical Fibres and Components reports the findings of COST 246 (1993-1998) - European research initiative in the field of optical telecommunications. Experts in the materials and reliability field of optical fibres and components have contributed to this unique study programme. The results, conclusions and achievements of their work have been obtained through joint experimentation and discussion with representatives from manufacturing and research groups. Topics covered include: Lifetime estimation; Failure mechanisms; Ageing test methods; Field data and service environments for components. For the first time the reader can explore the reliability of products and examine the results and conclusions in published form. This comprehensive volume is intended to provide a deeper understanding of the reliability of optical fibres and components. The book will be extremely useful to all scientists and practitioners involved in the industry.

Three-phase packed bed reactor with an evaporating solvent—I. Experimental: the hydrogenation of 2,4,6-trinitrotoluene in methanol

NARCIS (Netherlands)

van Gelder, K.B.; Damhof, J.K.; Kroijenga, P.J.; Westerterp, K.R.

1990-01-01

In this paper we present experimental data on the three-phase hydrogenation of 2,4,6-trinitrotoluene (TNT) to triaminotoluene. The experiments are performed in a cocurrent upflow packed bed reactor. Methanol is used as an evaporating solvent. The influence of the main operating parameters, the

Hexaaquabis[3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanido-κ2N3,O4]barium tetrahydrate

Directory of Open Access Journals (Sweden)

Nguyen Dinh Do

2013-11-01

Full Text Available In the title compound, [Ba(C7H5N2O52(H2O6]·4H2O, the Ba2+ cation lies on a twofold rotation axis and is ten-coordinated by two 3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanide oxo O atoms [Ba—O = 2.8715 (17 Å], two hydroxyimino N atoms [Ba—N = 3.036 (2 Å], and six water molecules [Ba—O = 2.847 (2, 2.848 (2, and 2.880 (2 Å]. The 3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanide monoanions act in a bidentate chelating manner, coordinating through an N atom of the non-deprotonated hydroxyimino group and an O atom of the neighboring oxo group. Two lattice water molecules are located in the cavities of the framework and are involved in hydrogen bonding to O atoms of one of the coordinating water molecules and the O atom of a keto group of the ligand. As a result, a three-dimensional network is formed.

A review on the mass spectrometric studies of americium: Present status and future perspective.

Science.gov (United States)

Aggarwal, Suresh Kumar

2018-01-01

The manuscript reviews the various mass spectrometric techniques for analysis and chemical studies of Americium. These methods include thermal ionization mass spectrometry (TIMS), and inductively coupled plasma source mass spectrometry (ICPMS) for the determination of Am isotope ratios and concentration in nuclear fuel samples of interest in nuclear technology, and in complex biological and environmental samples. Ultra-sensitive mass spectrometric techniques of resonance-ionization mass spectrometry (RIMS), and accelerator-based mass spectrometry (AMS) are also discussed. The novel applications of electrospray ionization mass spectrometry (ESIMS) to understand the solution chemistry of Am and other actinides are presented. These studies are important in view of the world-wide efforts to develop novel complexing agents to separate lanthanides and minor actinides (Am, Np, and Cm) for partitioning and transmutation of minor actinides from the point of view of nuclear waste management. These mass spectrometry experiments are also of great interest to examine the covalent character of actinides with increasing atomic number. Studies on gas-phase chemistry of Am and its oxides with Knudsen effusion mass spectrometry (KEMS), Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS), and laser-based experiments with reflectron time-of-flight mass spectrometer (R-ToF) are highlighted. These studies are important to understand the fundamental chemistry of 5f electrons in actinides. Requirement of certified isotopic reference materials of Am to improve the accuracy of experimental nuclear data (e.g., the half-life of 243 Am) is emphasized. © 2016 Wiley Periodicals, Inc. Mass Spec Rev. © 2016 Wiley Periodicals, Inc.

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

International Nuclear Information System (INIS)

Smith, B.F.; Gibson, R.R.; Jarvinen, G.D.; Jones, M.M.; Lu, M.T.; Robison, T.W.; Schroeder, N.C.; Stalnaker, N.

1997-01-01

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 241 Am(III) and 238 Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4

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

International Nuclear Information System (INIS)

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

1983-01-01

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

Americium-241 use of measurement lead equivalent thickness for medical x-ray room: A review

International Nuclear Information System (INIS)

Mohd Khalid Matori; Husaini Saleh; Abd Aziz Mhd Ramli; Muhammad Jamal Md Isa; Mohd Firdaus Abd Rahman; Zainal Jamaluddin

2010-01-01

Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for X-ray room at health centres. Results of measurement of 30 irradiation rooms conducted from 2009 to mid 2010 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that 96.7 % of the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

Impedance spectroscopy of tripolar concentric ring electrodes with Ten20 and TD246 pastes.

Science.gov (United States)

Nasrollaholhosseini, Seyed Hadi; Herrera, Daniel Salazar; Besio, Walter G

2017-07-01

Electrodes are used to transform ionic currents to electrical currents in biological systems. Modeling the electrode-electrolyte interface could help to optimize the performance of the electrode interface to achieve higher signal to noise ratios. There are previous reports of accurate models for single-element biomedical electrodes. In this paper, we measured the impedance on both tripolar concentric ring electrodes and standard cup electrodes by electrochemical impedance spectroscopy (EIS) using both Ten20 and TD246 electrode paste. Furthermore, we applied the model to prove that the model can predict the performance of the electrode-electrolyte interface for tripolar concentric ring electrodes (TCRE) that are used to record brain signals.

Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

NARCIS (Netherlands)

Gümüscü, B.; Erdogan, Zeynep; Guler, Mustafa O.; Tekinay, Turgay

2016-01-01

In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has

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

International Nuclear Information System (INIS)

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

1997-01-01

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

Watermelon germplasm lines USVL246-FR2 and USVL252-FR2 tolerant to fusarium oxysporum f. sp. niveum race 2

Science.gov (United States)

Two improved germplasm lines of wild watermelon (Citrullus lanatus var. citroides) designated USVL246-FR2 and USVL252-FR2 were released in 2012 by the Agricultural Research Service of the U.S. Department of Agriculture (Wechter et al. 2012). These lines are each highly uniform for growth characteri...

Chlorella vulgaris cultivation in sludge extracts from 2,4,6-TCP wastewater treatment for toxicity removal and utilization.

Science.gov (United States)

Wang, Lu; Chen, Xiurong; Wang, Hualin; Zhang, Yuying; Tang, Qingjie; Li, Jiahui

2017-02-01

Chlorella vulgaris was cultivated in different proportions of activated sludge extracts, which was from the treatment of the synthetic wastewater containing 2,4,6-trichlorophenol (2,4,6-TCP). The nutrients, total nitrogen (TN) and total phosphorus (TP), were removed over 45% and 90%, respectively. The maximum reduction amount of ecotoxicity and total organic carbon (TOC) occurred in the 100% sludge group on the 8th day (68%; 86.2 mg L -1 ). The variations of Excitation-emission matrix spectra (EEMs) and TOC indicated that extracellular organic matters (EOM) produced by algae led to TOC increase in the medium. The cell density was close to each other for groups with sludge extract proportion below 50%; sludge extracts (below 75% addition) had a stimulating effect on the accumulation of chlorophyll-a in per unit algal cell. Superoxide dismutase (SOD) variation demonstrated that C. vulgaris response positively to sludge extracts addition. Lipid content in C. vulgaris was up to its maximum value on the 8th day. Considering the performance on nutrients removal, toxicity reduction and algal growth, the optimal cultivation period for C. vulgaris before harvesting was around 8 days with sludge extracts proportion below 50%. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

McKay, W.A.; Strange, L.; Walker, M.I.; Halliwell, C.M.

1992-01-01

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 241 Am generally appeared to be about 20%. A review of earlier published concentrations of 239+240 Pu and 241 Am 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)

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

International Nuclear Information System (INIS)

Gosmain, Cecile-Aline

2011-01-01

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

ANALISIS SIFAT TARIK DAN IMPAK KOMPOSIT SERAT RAMI DENGAN PERLAKUAN ALKALI DALAM WAKTU 2,4,6 DAN 8 JAM BERMATRIK POLIESTER

Directory of Open Access Journals (Sweden)

Pramuko Ilmu Purboputro

2017-10-01

Full Text Available Ikatan interfacal bonding pada komposit serat alam sangat tergantung dari kekasaran permukaan serat. Permukaan serat dapat ditingkatkan daya ikatan permukaannya dengan cara mencelupkan pada larutan alkali. Pencelupan ini akan mengurangi lapisan lignin yang mengurangi kekuatan ikat pada permukaan serat. Pada penelitian ini proses yang digunakan adalah perlakuan alkali terhadap permukaan serat dengan  cara merendam serat rami selama 2,4,6, dan 8 jam. Larutah alkali yang digunakan adalah larutan NaOH dengan konsentrasi 10% pada pelarut air. Serat rami   Boehmeria nivea (L Goud direndam pada larutan NaOH selama 2,4,6, dan 8 jam perendaman, untuk menghilangkan zat ligninnya agar kekuatan ikatan permukaan bisa diperbaiki.  Pengujian yang dilakukan adalah pengujian tarik dan pengujian impak. Hasil yang didapat adalah kekuatan tarik terbesar didapat pada perendaman 8 jam yaitu sebesar 41,9 MPa. Modulus young terbesar didapat pada perendaman 2 jam, yaitu 2743,15 Mpa, dan kekuatan impak terbesar adalah 0,0725 Joule/mm2 terjadi pada perendaman 4 jam   Kata kunci : komposit serat, kekuatan tarik, kekuatan impak, perendaman alkali

Thiocyanate cadmium(II) complexes of 2,4,6-tri(2-pyridyl)-1,3,5-triazine – Synthesis, structure and luminescence properties

International Nuclear Information System (INIS)

Nawrot, I.; Machura, B.; Kruszynski, R.

2014-01-01

Two new thiocyanate cadmium(II) complexes of 2,4,6-tri(2-pyridyl)-1,3,5-triazine were synthesized and characterized. The resulted complexes [Cd(SCN)(NO 3 )(tptz)(H 2 O)] (1) and [Cd(SCN) 2 (tptz)(MeOH)] (2) were studied by IR, UV–vis spectroscopy and single crystal X-ray analysis. The luminescent properties of 1 and 2 were studied in solution and solid state and compared with the free ligand. To get detailed insight into the electronic structure and spectroscopic properties of [Cd(SCN)(NO 3 )(tptz)(H 2 O)] and [Cd(SCN) 2 (tptz)(MeOH)], the density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed. - Highlights: • Two novel thiocyanate cadmium(II) compounds of 2,4,6-tri(2-pyridyl)-1,3,5-triazine were synthesized. • The compounds were identified by IR, UV–vis spectroscopy and X-ray analysis. • The fluorescence properties of the complexes were examined and compared with the free ligand. • The electronic spectra were investigated at the TD-DFT level employing B3LYP/LANL2DZ

Immune responses to the smallpox vaccine given in combination with ST-246, a small-molecule inhibitor of poxvirus dissemination

OpenAIRE

Grosenbach, Douglas W.; Jordan, Robert; King, David S.; Berhanu, Aklile; Warren, Travis K.; Kirkwood-Watts, Dana L.; Tyavanagimatt, Shanthakumar; Tan, Ying; Wilson, Rebecca L.; Jones, Kevin F.; Hruby, Dennis E.

2007-01-01

The re-emerging threat of smallpox and the emerging threat of monkeypox highlight the need for effective poxvirus countermeasures. Currently approved smallpox vaccines have unacceptable safety profiles and, consequently, the general populace is no longer vaccinated, leading to an increasingly susceptible population. ST-246, a small-molecule inhibitor of poxvirus dissemination, has been demonstrated in various animal models to be safe and effective in preventing poxviral disease. This suggests...

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

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

Science.gov (United States)

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

2009-04-01

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

Degradation of 2,4,6-Trinitrophenol (TNP) by Arthrobacter sp. HPC1223 Isolated from Effluent Treatment Plant

OpenAIRE

Qureshi, Asifa; Kapley, Atya; Purohit, Hemant J.

2012-01-01

Arthrobacter sp. HPC1223 (Genebank Accession No. AY948280) isolated from activated biomass of effluent treatment plant was capable of utilizing 2,4,6 trinitrophenol (TNP) under aerobic condition at 30 °C and pH 7 as nitrogen source. It was observed that the isolated bacteria utilized TNP up to 70 % (1 mM) in R2A media with nitrite release. The culture growth media changed into orange-red color hydride-meisenheimer complex at 24 h as detected by HPLC. Oxygen uptake of Arthrobacter HPC1223 towa...

Chemically catalyzed uptake of 2,4,6-trinitrotoluene by Vetiveria zizanioides

International Nuclear Information System (INIS)

Makris, Konstantinos C.; Shakya, Kabindra M.; Datta, Rupali; Sarkar, Dibyendu; Pachanoor, Devanand

2007-01-01

The efficiency of vetiver grass (Vetiveria zizanioides) in removing 2,4,6-trinitrotoluene (TNT) from aqueous media was explored in the presence of a common agrochemical, urea, used as a chaotropic agent. Chaotropic agents disrupt water structure, increasing solubilization of hydrophobic compounds (TNT), thus, enhancing plant TNT uptake. The primary objectives of this study were to: (i) characterize TNT absorption by vetiver in hydroponic media, and (ii) determine the effect of urea on chemically catalyzing TNT uptake by vetiver grass in hydroponic media. Results showed that vetiver exhibited a high TNT uptake capacity (1.026 mg g -1 ), but kinetics were slow. Uptake was considerably enhanced in the presence of urea, which significantly (p<0.001) increased the 2nd-order reaction rate constant over that of the untreated (no urea) control. Three major TNT metabolites were detected in the roots, but not in the shoot, namely 1,3,5-trinitrobenzene, 4-amino 2,6-dinitrotoluene, and 2-amino 4,6-dinitrotoluene, indicating TNT degradation by vetiver grass. - A common agrochemical, urea catalyzes TNT removal by vetiver grass in aqueous media

Chemically catalyzed uptake of 2,4,6-trinitrotoluene by Vetiveria zizanioides

Energy Technology Data Exchange (ETDEWEB)

Makris, Konstantinos C. [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Shakya, Kabindra M. [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Datta, Rupali [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Sarkar, Dibyendu [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States)]. E-mail: dibyendu.sarkar@utsa.edu; Pachanoor, Devanand [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States)

2007-07-15

The efficiency of vetiver grass (Vetiveria zizanioides) in removing 2,4,6-trinitrotoluene (TNT) from aqueous media was explored in the presence of a common agrochemical, urea, used as a chaotropic agent. Chaotropic agents disrupt water structure, increasing solubilization of hydrophobic compounds (TNT), thus, enhancing plant TNT uptake. The primary objectives of this study were to: (i) characterize TNT absorption by vetiver in hydroponic media, and (ii) determine the effect of urea on chemically catalyzing TNT uptake by vetiver grass in hydroponic media. Results showed that vetiver exhibited a high TNT uptake capacity (1.026 mg g{sup -1}), but kinetics were slow. Uptake was considerably enhanced in the presence of urea, which significantly (p<0.001) increased the 2nd-order reaction rate constant over that of the untreated (no urea) control. Three major TNT metabolites were detected in the roots, but not in the shoot, namely 1,3,5-trinitrobenzene, 4-amino 2,6-dinitrotoluene, and 2-amino 4,6-dinitrotoluene, indicating TNT degradation by vetiver grass. - A common agrochemical, urea catalyzes TNT removal by vetiver grass in aqueous media.

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

International Nuclear Information System (INIS)

Burns, P.A.; Cooper, M.B.; Lokan, K.H.; Wilks, M.J.; Williams, G.A.

1995-01-01

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)

The design of a multisource americium-beryllium (Am-Be) neutron irradiation facility using MCNP for the neutronic performance calculation.

Science.gov (United States)

Sogbadji, R B M; Abrefah, R G; Nyarko, B J B; Akaho, E H K; Odoi, H C; Attakorah-Birinkorang, S

2014-08-01

The americium-beryllium neutron irradiation facility at the National Nuclear Research Institute (NNRI), Ghana, was re-designed with four 20 Ci sources using Monte Carlo N-Particle (MCNP) code to investigate the maximum amount of flux that is produced by the combined sources. The results were compared with a single source Am-Be irradiation facility. The main objective was to enable us to harness the maximum amount of flux for the optimization of neutron activation analysis and to enable smaller sample sized samples to be irradiated. Using MCNP for the design construction and neutronic performance calculation, it was realized that the single-source Am-Be design produced a thermal neutron flux of (1.8±0.0007)×10(6) n/cm(2)s and the four-source Am-Be design produced a thermal neutron flux of (5.4±0.0007)×10(6) n/cm(2)s which is a factor of 3.5 fold increase compared to the single-source Am-Be design. The criticality effective, k(eff), of the single-source and the four-source Am-Be designs were found to be 0.00115±0.0008 and 0.00143±0.0008, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Towards the island of superheavy stability - Prompt spectroscopy of 246Fm and 256Rf nuclei

International Nuclear Information System (INIS)

Piot, J.

2010-10-01

The region of trans-fermium nuclei (Z = 100 to 104) is the last region of the nuclides chart to be accessible to spectroscopic measurements. It therefore provides the ultimate anchor points for nuclear models. This region also lies on the path of the alpha-decay chains of the super-heavy elements. This region represents the limit of today's spectroscopic capabilities. It therefore requires technological developments in order to overcome these limits. My thesis focuses on various aspects of the spectroscopy of trans-fermium nuclei. I took part in the development of the TNT2D digital acquisition cards for germanium detectors. I validated their use on the gamma-ray spectrometer JUROGAM during an in-beam experiment and demonstrated the gain compared to an analogue acquisition system. These tests were part of the developments needed to secure a study of the prompt spectroscopy of 256 Rf. The preparation of this experiment also lead me to work on the development of a 50 Ti beam. For that purpose, I studied and tested the use of titanium organo-metallic compounds compatible with the MIVOC technique. In parallel, I studied the use of metallic and oxide titanium pellets with an inductive oven newly developed at the University of Jyvaeskylae. In addition to these developments, I had the opportunity to study the in-beam prompt spectroscopy of 246 Fm at the University of Jyvaeskylae. The measurements yielded a rotational band built on the ground state of 246 Fm. This band has been observed up to the level 16 + and shows a behaviour quite similar to the neighbouring even-even isotopes, except for the top of the band for which a wider statistics is necessary in order to conclude. (author)

Vanillin Analogues o-Vanillin and 2,4,6-Trihydroxybenzaldehyde Inhibit NFĸB Activation and Suppress Growth of A375 Human Melanoma.

Science.gov (United States)

Marton, Annamária; Kúsz, Erzsébet; Kolozsi, Csongor; Tubak, Vilmos; Zagotto, Giuseppe; Buzás, Krisztina; Quintieri, Luigi; Vizler, Csaba

2016-11-01

Constitutive activation of nuclear factor kappa-B (NFĸB) is a hallmark of various cancer types, including melanoma. Chemotherapy may further increase tumour NFĸB activity, a phenomenon that, in turn, exacerbates drug resistance. This study aimed at preliminary screening of a panel of aromatic aldehydes, including vanillin, for cytotoxicity and suppression of tumour cell NFĸB activity. The cytotoxic and NFĸB-inhibitory effects of 10 aromatic aldehydes, including vanillin, were investigated in cultured A375 human melanoma cells. Each compound was assayed alone and in combination with the model NFĸB-activating drug doxorubicin. The most promising analogues were then tested alone and in combination with 4-hydroperoxycyclophosphamide in vitro, and with cyclophosphamide in mice bearing A375 xenografts. The vanillin analogues o-vanillin and 2,4,6-trihydroxybenzaldehyde exhibited cytotoxicity against cultured A375 cells, and inhibited doxorubicin- and 4-hydroperoxycyclophosphamide-induced NFĸB activation. They also suppressed A375 cell growth in mice. o-vanillin and 2,4,6-trihydroxybenzaldehyde deserve further evaluation as potential anticancer drugs. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Fungal strains isolated from cork stoppers and the formation of 2,4,6-trichloroanisole involved in the cork taint of wine.

Science.gov (United States)

Prak, Sina; Gunata, Ziya; Guiraud, Joseph-Pierre; Schorr-Galindo, Sabine

2007-05-01

Cork taint is mainly due to 2,4,6-trichloroanisole (TCA) produced through the activity of undesirable fungal strains. We observed that CFU mould number in TCA-containing stoppers was not quantitatively different to that of the stoppers not containing TCA (ca. 10(5)CFU/g). In contrast more fungi diversity was observed in TCA-containing stoppers. Penicillium spp (Penicillium chrysogenum, Penicillium glabrum), Aspergillus spp (Aspergillus niger and Aspergillus oryzae), Chrysonilia sitophila, Mucor racemosus, Paecilomyces sp. and Trichoderma viride were found in TCA-containing stoppers, while C. sitophila and Penicillium sp. were the main fungi in the stoppers devoid of TCA. Conidia were numerous close to the lenticels and present from the lateral surface through to the centre of the stoppers. Strains of Aspergillus, Mucor, Paecilomyces, Penicillium and Trichoderma isolated from TCA-containing stoppers were able to convert 2,4,6-trichlorophenol (TCP) in TCA in resting cell or growing conditions. The best yields of conversion were obtained by green fungi Paecilomyces sp. and P. chrysogenum, 17% and 20%, respectively. Chysonilia sitophila and Penicillium sp. did not produce TCA from TCP in our conditions.

Density functional theory investigation of the magnetism of 1,3,5-trithia-2,4,6-triazapentalenyl

International Nuclear Information System (INIS)

Zou Weidong; Liu Zuli; Wu Minghu; Yao Kailun

2004-01-01

An accurate full-potential density-functional method is used to study the mechanism of the origin of magnetism and of the magnetic interactions in 1,3,5-trithia-2,4,6-triazapentalenyl (TTTA). The results shown that because of the spin polarization effect and the spin exchange coupling interactions of these atoms, the net spin magnetic moment is formed in the molecule and the spontaneous magnetic moments for the TTTA mainly come from N 1 , S 1 , S 2 atoms and the N 2 , N 3 and S 3 atoms give a little contribution to the magnetism. Our results also revealed that there exists ferromagnetic interaction in the intramolecular of TTTA

Effect of the Mg/Al Ratio on Activated Sol-Gel Hydrotalcites for Photocatalytic Degradation of 2,4,6-Trichlorophenol

Directory of Open Access Journals (Sweden)

Esthela Ramos-Ramírez

2017-01-01

Full Text Available Currently, interest has grown in finding effective solutions for the treatment of water pollution by toxic compounds. Some of the latter that have acquired importance are phenols and chlorophenols, due to their employment in the manufacture of pesticides, insecticides, cords of wood, paper industry, among others. The problem is rooted in that these compounds are very persistent in the environment because they are partially biodegradable and cannot be photodegraded directly by sunlight. Chlorophenols are extremely toxic, especially 2,4,6-trichlorophenol, which is potentially carcinogenic. In this work, Mg/Al-mixed oxide catalysts were obtained from the thermal treatment of hydrotalcite-type materials, synthesized by sol-gel method with different Mg/Al ratios. Hydrotalcites and Mg/Al-mixed oxides were physicochemically characterized by X-ray diffraction, thermal analysis (DTA and TGA, and N2 physisorption. The results were obtained on having proven the photocatalytic degradation of 2,4,6-trichlorophenol as a pollutant model by water. The catalysts obtained present the hydrotalcite phase with thermal evolution until achieving Mg/Al-mixed oxides at 500°C. The catalysts are of mesoporous materials and exhibiting large surface areas. The catalysts demonstrated good photocatalytic activity with good efficiency, reaching degradation percentages with Mg/Al = 1, 2, 4, 5, and 7 ratios of 94.2, 92.5, 86.2, 84.2, and 63.9%, respectively, until achieving mineralization.

Ed radionuclides soils the exclusive of the Chernobyl zone

International Nuclear Information System (INIS)

Rashydov, N.M.; Berezhnaya, V.V.; Grodzinsky, D.M.

2003-01-01

Full text: The highest Relative Biological Efficiency is intrinsic to the emitters of alpha radiation and Americium-241 belongs to this category of emitters. The aims of this study are: to fit methods Americium-241 estimation to biological objects of different types; to elucidate the pathways of Americium-241 migration along the trophic chains; to carry out forestall investigations of the early and late effects of Americium-241; to develop means for preventing absorption of Americium-241 in tissue of different organisms and stimulation of recovery processes in damaged cells. Mechanisms of biological action of Americium-241 on the levels of molecule, membrane, genome, cells, tissue and organ are suggested to be investigated when this radionuclide is accumulated by organisms through gastro-intestinal system or inhalation of as 'hot particles'. An investigation into the intercellular localization of Americium-241 in this case was determinated for plants. Study physical, chemical, transport, enzymatic peculiarities and peroxide modifications of membranes in their relation to deterioration of metabolic processes in damaged organism. Moreover, the main indexes of blood and hemopoietic tissue directly concerned with radiation injury under the effect of Americium-241 will be revealed. An assessment of the impact of Americium-241 on immune system in animals will be elucidated as well. Investigations of the membrane bounding and complexion properties of Americium-241 will provide a possibility to find substances capable of inhibition of the Americium-241 absorption or increasing the rate of its re-sorption. At the time, cytogenetic effects resulted from injuries of genetic apparatus of cell and their role in induction of genome instability and increasing of the rate of translocations connected with cancerogenesis was studied. The results of our investigations will form the basis for elaboration of the proposals concerned the preventive and therapeutic means aimed at

Status of 241Am recovery and purification at Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Ramsey, H.D.; Clifton, D.G.; Hayter, S.W.; Penneman, R.A.; Christensen, E.L.

1980-01-01

Americium recovery was initiated at Los Alamos Scientific Laboratory (LASL) in the late 1940's. The early procedures separated gram quantities of americium from large amounts of impurities including plutonium and the rare earths. Ion exchange procedures were developed for further purification. Until recently, no routine processing of americium has been done at LASL for several years. The increasing demand for americium in oil-well logging instruments and other uses led LASL to develop and install a process to recover larger quantities of americium. The LASL process was developed around the chemistry of americium that had been elucidated both at LASL and at other facilities. Presently, the americium feed is obtained as a by-product from a plutonium purification process at the new plutonium facility at LASL. This feed filtrate from a peroxide precipitation process is precipitated as a slurry of hydroxides, filtered, dissolved in nitric acid, and passed through an anion exchange column to remove any residual plutonium. The americium, contained in the effluent, is precipitated as the oxalate and calcined to the oxide. Americium is also available in other highly salted acidic process streams. These should lend themselves to solvent extraction. Developmental work has been promising, and a dibutyl butyl phosphate-kerosene extraction process is being brought on-line

High uptake of 2,4,6-trinitrotoluene by vetiver grass - Potential for phytoremediation?

International Nuclear Information System (INIS)

Makris, Konstantinos C.; Shakya, Kabindra M.; Datta, Rupali; Sarkar, Dibyendu; Pachanoor, Devanand

2007-01-01

2,4,6-Trinitrotoluene (TNT) is a potent mutagen, and a Group C human carcinogen that has been widely used to produce munitions and explosives. Vast areas that have been previously used as ranges, munition burning, and open detonation sites are heavily contaminated with TNT. Conventional remediation activities in such sites are expensive and damaging to the ecosystem. Phytoremediation offers a cost-effective, environment-friendly solution, utilizing plants to extract TNT from contaminated soil. We investigated the potential use of vetiver grass (Vetiveria zizanioides) to effectively remove TNT from contaminated solutions. Vetiver grass plants were grown in hydroponic systems containing 40 mg TNT L -1 for 8 d. Aqueous concentrations of TNT reached the method detection limit (∼1 μg L -1 ) within the 8-d period, demonstrating high affinity of vetiver for TNT, without any visible toxic effects. Results from this preliminary hydroponic study are encouraging, but in need of verification using TNT-contaminated soils. - Vetiver grass demonstrates ability to absorb TNT in aqueous media

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-15

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

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

International Nuclear Information System (INIS)

Geraldo, Bianca

2012-01-01

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

Supported liquid inorganic membranes for nuclear waste separation

Science.gov (United States)

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

2015-04-07

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

Micelle-Assisted Synthesis of Al2O3·CaO Nanocatalyst: Optical Properties and Their Applications in Photodegradation of 2,4,6-Trinitrophenol

Directory of Open Access Journals (Sweden)

Ayesha Imtiaz

2013-01-01

Full Text Available Calcium oxide (CaO nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalytic activity. In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant, sodium dodecyl sulphate (SDS, as a templating agent. The as-synthesized nanocatalysts were further used as substrate for the synthesis of alumina doped calcium oxide (Al2O3·CaO nanocatalysts via deposition-precipitation method at the isoelectric point of CaO. The Al2O3·CaO nanocatalysts were characterized by FTIR, XRD, TGA, TEM, and FESEM techniques. The catalytic efficiencies of these nanocatalysts were studied for the photodegradation of 2,4,6-trinitrophenol (2,4,6-TNP, which is an industrial pollutant, spectrophotometrically. The effect of surfactant and temperature on size of nanocatalysts was also studied. The smallest particle size and highest percentage of degradation were observed at critical micelle concentration of the surfactant. The direct optical band gap of the Al2O3·CaO nanocatalyst was found as 3.3 eV.

Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

International Nuclear Information System (INIS)

Lu, Wei; Asher, Sanford A.; Meng, Zihui; Yan, Zequn; Xue, Min; Qiu, Lili; Yi, Da

2016-01-01

Graphical abstract: Molecularly imprinted colloidal array (MICA) was explored for the selective visual detection of TNT with color changing from green to red. And molecularly imprinted colloidal particles (MICs) were evaluated for the adsorption capacity and the imprinting efficiency. The MICA had excellent flexibility, reversibility and stability. It promised high potential for the visual semi-quantitative detection of other explosives. - Highlights: • Molecularly imprinted colloidal array (MICA) was used to visually detect TNT. • The relationship of particle size, diffracted wavelength and color was discussed. • The adsorption capacity and imprinting efficiency of MICs were calculated. • MICA had short response time, high selectivity, good reversibility and stability. • MICA had high potential to be used in other customed visual explosive detection. - Abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210 nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64 mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH = 7.0, 30 mM). The limit of detection (LOD) of the sensor was 1.03 μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84 nm diffraction red shift when the TNT concentration increased to 20 mM. The sensor response time was 3 min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol

Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Lu, Wei [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Asher, Sanford A., E-mail: asher@pitt.edu [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Meng, Zihui, E-mail: m_zihui@yahoo.com [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yan, Zequn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Xue, Min, E-mail: minxue@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Qiu, Lili, E-mail: qiulili@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yi, Da [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China)

2016-10-05

Graphical abstract: Molecularly imprinted colloidal array (MICA) was explored for the selective visual detection of TNT with color changing from green to red. And molecularly imprinted colloidal particles (MICs) were evaluated for the adsorption capacity and the imprinting efficiency. The MICA had excellent flexibility, reversibility and stability. It promised high potential for the visual semi-quantitative detection of other explosives. - Highlights: • Molecularly imprinted colloidal array (MICA) was used to visually detect TNT. • The relationship of particle size, diffracted wavelength and color was discussed. • The adsorption capacity and imprinting efficiency of MICs were calculated. • MICA had short response time, high selectivity, good reversibility and stability. • MICA had high potential to be used in other customed visual explosive detection. - Abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210 nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64 mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH = 7.0, 30 mM). The limit of detection (LOD) of the sensor was 1.03 μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84 nm diffraction red shift when the TNT concentration increased to 20 mM. The sensor response time was 3 min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol

The first detection of ionized helium in the local ISM - EUVE and IUE spectroscopy of the hot DA white dwarf GD 246

Science.gov (United States)

Vennes, Stephane; Dupuis, Jean; Rumph, Todd; Drake, Jeremy; Bowyer, Stuart; Chayer, Pierre; Fontaine, Gilles

1993-01-01

We report observations of the extreme ultraviolet spectrum of the hot degenerate star GD 246 obtained with the EUVE. Our initial attempt at modeling the photospheric emission from the white dwarf reveals a relatively uncontaminated pure H spectrum in the range above 200 A, allowing a study of interstellar continuum absorption features in the line of sight of GD 246. Modeling of the He I autoionization transition discussed by Rumph et al. (1993), and the EUV continuum using the white dwarf as a source of background radiation provides measurements of both neutral and, for the first time, singly ionized He column densities in the local ISM (LISM). We estimate the He ionization fraction He II/(He I + He II) at roughly 25 percent with a total He column of 1.40-1.65 x 10 exp 18/sq cm. We have measured and compared H I column densities from the saturated Ly-alpha ISM absorption in IUE high-dispersion spectroscopy and from EUV continuum absorption: the two measurements are in good agreement with a total H column of 1.2-1.6 x 10 exp 19/sq cm. We discuss some implications for the nature of the LISM, particularly in the context of current models of the EUV radiation field.

Structural studies of the polysaccharides from the lipopolysaccharides of Azospirillum brasilense Sp246 and SpBr14.

Science.gov (United States)

Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Grinev, Vyacheslav S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

2014-10-29

Lipopolysaccharides from closely related Azospirillum brasilense strains, Sp246 and SpBr14, were obtained by phenol-water extraction. Mild acid hydrolysis of the lipopolysaccharides followed by GPC on Sephadex G-50 resulted in polysaccharide mixtures. On the basis of sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy data, it was concluded that both bacteria possess the same two distinct polysaccharides having structures 1 and 2: [structure: see text]. Structure 1 has been reported earlier for a polysaccharide of A. brasilense 54 [Fedonenko et al., 2011] whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of the cardiovascular system by digital subtraction angiography in 246 patients

Energy Technology Data Exchange (ETDEWEB)

Higuma, Kikuhiko; Ohta, Takashi; Hiroto, Seiji

1987-07-01

Usefulness of intravenous digital subtraction angiography (DSA) was examined in 246 patients with cardiovascular disorders. This examination was done by centrally intravenous DSA (CIVDSA) in all patients to reduce the risks and discomforts by peripheral intravenous DSA. 1) CIVDSA could be done safely in patients aged 18 to 81 years. 2) The good diagnostic quality by CIVDSA was obtained in 81.3% of patients. These images were classified into 7 groups according to the cardiovascular system, that is, the jugular arteries, the upper extremity arteries, the thoracic aorta, the left ventricle, the abnominal aorta, the renal arteries, and the lower extremity arteries, whose rate of good diagnostic quality were 100%, 70%, 67.7%, 79.5%, 84.8%, 87%, and 71.4% respectively. 3) The poor diagnostic quality was obtained in 18.7%. 4) The severe complications were not found in any case during this examination. Our results indicate that DSA is the safe, simple and useful method to obtain the diagnostic quality image of the cardiovascular system, especially, of the occulsive arterial disease, the aortic aneurisma, the renovascular stenosis and the cardiac function of postmyocardial infarction, even in aged patients.

Evaluation of the cardiovascular system by digital subtraction angiography in 246 patients

International Nuclear Information System (INIS)

Higuma, Kikuhiko; Ohta, Takashi; Hiroto, Seiji

1987-01-01

Usefulness of intravenous digital subtraction angiography (DSA) was examined in 246 patients with cardiovascular disorders. This examination was done by centrally intravenous DSA (CIVDSA) in all patients to reduce the risks and discomforts by peripheral intravenous DSA. 1) CIVDSA could be done safely in patients aged 18 to 81 years. 2) The good diagnostic quality by CIVDSA was obtained in 81.3 % of patients. These images were classified into 7 groups according to the cardiovascular system, that is, the jugular arteries, the upper extremity arteries, the thoracic aorta, the left ventricle, the abnominal aorta, the renal arteries, and the lower extremity arteries, whose rate of good diagnostic quality were 100 %, 70 %, 67.7 %, 79.5 %, 84.8 %, 87 %, and 71.4 % respectively. 3) The poor diagnostic quality was obtained in 18.7 %. 4) The severe complications were not found in any case during this examination. Our results indicate that DSA is the safe, simple and useful method to obtain the diagnostic quality image of the cardiovascular system, especially, of the occulsive arterial disease, the aortic aneurisma, the renovascular stenosis and the cardiac function of postmyocardial infarction, even in aged patients. (author)

Scaling of light emission from detonating bare Composition B, 2,4,6-trinitrotoluene [C7H5(NO2)3], and PE4 plastic explosive charges

CSIR Research Space (South Africa)

Mostert, FJ

2011-10-01

Full Text Available and configuration. In this study, the emission characteristics at wavelengths between 650 and 940 nm were experimentally investigated for cylindrical bare Composition B, 2,4,6-trinitrotoluene [C7H5(NO2)3], and PE4 plastic explosive charges in the mass (M) range of 0...

Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

Directory of Open Access Journals (Sweden)

Hatice Aysun Mercimek

2015-03-01

Full Text Available Degradation of 2,4,6-trinitrotoluene (TNT, a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitroexperiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC. In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT and 4-aminodinitrotoluene (4-ADNT, were elucidated by thin layer chromatography (TLC and gas chromatography-mass spectrometry (GC-MS. These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53

DEFF Research Database (Denmark)

Zandi, Roza; Selivanova, Galina; Christensen, Camilla Laulund

2011-01-01

Small cell lung cancer (SCLC) is a highly malignant disease with poor prognosis, necessitating the need to develop new and efficient treatment modalities. PRIMA-1(Met) (p53-dependent reactivation of massive apoptosis), also known as APR-246, is a small molecule, which restores tumor suppressor...... function to mutant p53 and induces cancer cell death in various cancer types. Since p53 is mutated in more than 90% of SCLC, we investigated the ability of PRIMA-1(Met) to induce apoptosis and inhibit tumor growth in SCLC with different p53 mutations....

Template synthesis, characterization and antimicrobial activity of the complex combinations of some transitional metals with isonicotinoylhydrazone -2,4,6- trimethylbenzaldehyde

International Nuclear Information System (INIS)

Mitu, L.ITU; Imran, M.

2011-01-01

The complexes of Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) with isonicotinoyl-hydrazone -2,4,6-trimethylbenzaldehyde (INHTB) are reported. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility, thermal analysis and for the Cu(II) complex the ESR spectrum has been recorded. The anti-bacterial activity of these complexes were investigated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Shigella flexneri bacteria. The INHTB ligand is coordinated at the metallic ions by oxygen amide (O=C) and the azomethine nitrogen. (author)

Investigation of the separation of americium(III) and europium(III) by high-speed countercurrent chromatography

International Nuclear Information System (INIS)

Wu, J.F.; Jin, Y.R.; Xu, Q.C.; Wang, S.L.; Zhang, L.X.

2005-01-01

The long-lived actinides are the important elements in the radioactive waste ;disposal. Because the ions semi diameter and chemical properties of trivalent actinides(III) and trivalent lanthanides(III) are very similar, the separation between them is very difficult. Yang Yu-Sheng put forward the actinides(III) are softer acid than the lanthanides(III), so the actinides(III) are more easily extracted by the soft extractant contain sulfur or nitrogen than the lanthanides(III). Some research have been done on the separation between actinides(III) and lanthanides(III) using the extractants contain sulfur or nitrogen. The results show that satisfactory separation efficiency was gained. Countercurrent Chromatography (CCC) have many specific advantages, such as free from solid support, permit large sample volume and high flow rate, which is useful in the preconcentration of inorganic solute and inorganic preparation. Some studies were done on the separation of lanthanides or-other inorganic elements by HSCCC, the high-purity reagents prepared by HSCCC or CPC turned out to be successful. In present paper, the investigation of separation between Americium (III) and Euricium (III) by High-Speed Countercurrent Chromatography (HSCCC) were made. The extractant used in the work was prepared by ourselves, which is of the soft extractant contrain sulfur. The effects of separation condition on the separation efficiency of Am and Eu by HSCCC were investigated using dichlorophenyl dithiophosphinic acid in xylene as the stationary phase and 0.1 mol/L NaClO4 as mobile phase, respectively. The results show that mutual separation between Am and Eu can be accomplished. The separation factor increases with the increasing of the concentration of extractant and the pH value of the mobile phase, further more, minishing the flow rate of the mobile phase can also improves the separation efficiency between Am and Eu. The nearly base separation was gained when the flow rate is 0.35 ml/min, the

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)

Beims, H.D.

1986-01-01

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) [de

Application of a Homogenous Assay for the Detection of 2,4,6-Trinitrotoluene to Environmental Water Samples

Directory of Open Access Journals (Sweden)

Ellen R. Goldman

2005-01-01

Full Text Available A homogeneous assay was used to detect 2,4,6-trinitrotoluene (TNT spiked into environmental water samples. This assay is based on changes in fluorescence emission intensity when TNT competitively displaces a fluorescently labeled, TNT analog bound to an anti-TNT antibody. The effectiveness of the assay was highly dependent on the source of the sample being tested. As no correlation between pH and assay performance was observed, ionic strength was assumed to be the reason for variation in assay results. Addition of 10x phosphate-buffered saline to samples to increase their ionic strength to that of our standard laboratory buffer (about 0.17 M significantly improved the range over which the assay functioned in several river water samples.

Results of Am isotopic ratio analysis in irradiated MOX fuels

Energy Technology Data Exchange (ETDEWEB)

Koyama, Shin-ichi; Osaka, Masahiko; Mitsugashira, Toshiaki; Konno, Koichi [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center; Kajitani, Mikio

1997-04-01

For analysis of a small quantity of americium, it is necessary to separate from curium which has similar chemical property. As a chemical separation method for americium and curium, the oxidation of americium with pentavalent bismuth and subsequent co-precipitation of trivalent curium with BIP O{sub 4} were applied to analyze americium in irradiated MOX fuels which contained about 30wt% plutonium and 0.9wt% {sup 241}Am before irradiation and were irradiated up to 26.2GWd/t in the experimental fast reactor Joyo. The purpose of this study is to measure isotopic ratio of americium and to evaluate the change of isotopic ratio with irradiation. Following results are obtained in this study. (1) The isotopic ratio of americium ({sup 241}Am, {sup 242m}Am and {sup 243}Am) can be analyzed in the MOX fuels by isolating americium. The isotopic ratio of {sup 242m}Am and {sup 243}Am increases up to 0.62at% and 0.82at% at maximum burnup, respectively, (2) The results of isotopic analysis indicates that the contents of {sup 241}Am decreases, whereas {sup 242m}Am, {sup 243}Am increase linearly with increasing burnup. (author)

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.)

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

International Nuclear Information System (INIS)

Ketelaer, Jens

2010-01-01

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

Oxidation of the odorous compound 2,4,6-trichloroanisole by UV activated persulfate: Kinetics, products, and pathways.

Science.gov (United States)

Luo, Congwei; Jiang, Jin; Ma, Jun; Pang, Suyan; Liu, Yongze; Song, Yang; Guan, Chaoting; Li, Juan; Jin, Yixin; Wu, Daoji

2016-06-01

The transformation efficiency and products of an odorous compound 2,4,6-trichloroanisole (TCA) at the wavelength of 254 nm in the presence of persulfate were investigated for the first time. The effects of water matrix (i.e., natural organic matter (NOM), pH, carbonate/bicarbonate (HCO3(-)/CO3(2-)), and chloride ions (Cl(-))) were evaluated. The second order rate constant of TCA reacting with sulfate radical (SO4(-)) was determined to be (3.72 ± 0.10) × 10(9) M(-1) s(-1). Increasing dosage of persulfate increased the observed pseudo-first-order rate constant for TCA degradation (kobs), and the contribution of SO4(-) to TCA degradation was much higher than that of HO at each experimental condition. Degradation rate of TCA decreased with pH increasing from 4.0 to 9.0, which could be explained by the lower radical scavenging effect of dihydrogen phosphate than hydrogen phosphate in acidic condition (pH kinetic results could be described by a steady-state kinetic model. Furthermore, liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry at powerful precursor ion scan approach was used to selectively detect oxidation products of TCA. It was found that 2,4,6-trichorophenol (TCP) was the major oxidation product (i.e., the initial yield of TCP was above 90%). The second order rate constant between TCP and SO4(-) was estimated to be (4.16 ± 0.20) × 10(9) M(-1) s(-1). In addition, three products (i.e., 2,6-dichloro-1,4-benzoquinone and two aromatic ring-opening products) were detected in the reaction of TCP with SO4(-), which also appeared in the oxidation of TCA in the UV/persulfate process. A tentative pathway was proposed, where the initial one-electron oxidation of TCA by SO4(-) and further reactions (e.g., ipso-hydroxylation and aromatic ring-cleavage) of the formed cation intermediate TCA were involved. Copyright © 2016. Published by Elsevier Ltd.

(E-N-[2-(9-Fluorenylidene-3a,5,7-trimethyl-3,3a-dihydro-2H-indol-3-ylidene]-2,4,6-trimethylaniline

Directory of Open Access Journals (Sweden)

Norihiro Tokitoh

2008-02-01

Full Text Available The title compound, C33H30N2, has an E configuration at the imine double bond. The angle between the least-squares planes of the imine C=N—C group and the benzene ring of the 2,4,6-trimethylphenyl substituent is 85.38 (11°. The crystal structure is sustained mainly by intermolecular π–π interactions (3.510 Å between the two fluorene rings and some C—H...π interactions.

A study of anti-inflammatory and analgesic activity of new 2,4,6-trisubstituted pyrimidines.

Science.gov (United States)

Yejella, Rajendra Prasad; Atla, Srinivasa Rao

2011-01-01

Chalcone derivatives (3a-m) were prepared by condensing 4-aminoacetophenone with various substituted aromatic and hetero aromatic aldehydes according to Claisen-Schmidt condensation. These chalcones, on reaction with guanidine hydrochloride under basic alcoholic conditions gave 2,4,6-trisubstituted pyrimidines (5a-m) in quantitative yields. All the newly synthesized pyrimidines were characterized by means of IR, ¹H- and ¹³C-NMR, Electron Ionization (EI)-mass and elemental analyses and screened for anti-inflammatory and analgesic activities by in vivo. 2-amino-4-(4-aminophenyl)-6-(2,4-dichlorophenyl)pyrimidine (5b) and 2-amino-4-(4-aminophenyl)-6-(3-bromophenyl) pyrimidine (5d) were found to be the most potent anti-inflammatory and analgesic activity compared with ibuprofen, reference standard. And also it was found that compound 5b identified as lead structure among all in both the activities. Pyrimidines which showed good anti-inflammatory activity also displayed better analgesic activity.

2,4,6-Trichlorophenylhydrazine Schiff bases as DPPH radical and super oxide anion scavengers.

Science.gov (United States)

Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Ali, Sajjad; Ambreen, Nida; Perveen, Shahnaz; Choudhary, M Iqbal; Voelter, Wolfgang

2012-05-01

Syntheses of thirty 2,4,6-trichlorophenylhydrazine Schiff bases 1-30 were carried out and evaluated for their in vitro DPPH radical and super oxide anion scavenging activities. Compounds 1-30 have shown a varying degree of DPPH radical scavenging activity and their IC50 values range between 4.05-369.30 µM. The compounds 17, 28, 18, 14, 8, 15, 12, 2, 29, and 7 exhibited IC50 values ranging between 4.05±0.06-24.42±0.86 µM which are superior to standard n-propylgallate (IC50=30.12±0.27 µM). Selected compounds have shown a varying degree of superoxide anion radical scavenger activity and their IC50 values range between 91.23-406.90 µM. The compounds 28, 8, 17, 15, and 14, showed IC50 values between 91.23±1.2-105.31±2.29 µM which are superior to standard n-propylgallate (IC50=106.34±1.6 µM).

Oxidation of 2,4,6,-tri-chlorophenol catalyzed by iron phthalocyanines covalently bound to silica. Oxydation du 2,4,6-trichlorophenol catalyse par des phtalocyanines de fer greffees sur silice par liaisons covalentes

Energy Technology Data Exchange (ETDEWEB)

Sanchez, M.; Hadasch, A.; Meunier, B. (Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Laboratoire de Chimie de Coordination); Rabion, A. (Elf-Atochem, 64 - Artix (France). Centre de Recherche)

1999-04-01

The degradation of recalcitrant pollutants remains a high priority in order to preserve our environment. For example, chlorinated aromatic compounds are extremely persistent in the environment because of their slow biodegradation by microorganisms. One of the most notable toxic offenders is 2,4,6-tri-chlorophenol (TCP) which is produced by paper mills and also used as a biocide. Thus TCP is an obvious benchmark for research on the decontamination of waste waters. In this work, the covalent attachment of an iron phthalocyanine with chloro-sulfonyl substituents (FePcSO[sub 2]Cl) onto a functionalized 3-amino-propyl-silica has been achieved. This supported catalyst FePcSO[sub 2]Cl-silica is able to degrade a recalcitrant pollutant like TCP with hydrogen peroxide as oxidant. In order to improve the catalytic efficiency of the grafted iron phthalocyanine complex, modifications of the macrocycle substituents, passivation of the silica surface, variation of the loading of the carrier and addition of an organic co solvent to the reaction mixture were carried out. (authors) 21 refs.

Use of Box-Wilson method for determination of optimum conditions for extraction some lanthanoids with amines

International Nuclear Information System (INIS)

Kopyrin, A.A.; Murashov, V.D.; Shvedov, V.P.

1980-01-01

The effect of DTPA, cerium and europium nitrates concentration in the range from 10 -1 -10 -6 M on extraction and separation of americium (3), cerium (3), prometium and europium 0.2 M with the solution of tri-n-octylamine nitrate in n-xylol of concentrated lithium nitrate solutions, is investigated. The method of Box-Wilson is used to determine the optimum conditions of separation of the above elements. The maximum values of separation factors are obtained for the following pairs: cerium(3)-americium(3) - 100, americium (3)-europium - 12, promethium-americium(3) - 35, cerium(3)-promethium - 30, cerium(3)-europium - 890 [ru

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)

Use of fluoride systems for some fission product separation from residues of fast reactor spent fuel fluorination

International Nuclear Information System (INIS)

Shishkov, Yu.D.; Khomyakov, V.I.

1977-01-01

Investigated has been a possibility of the use of fluoride systems (acid nitrozyl fluoride and molten salts) for americium extraction from residues of fluorination of irradiated fuel containing mainly fluorides of rare earth compounds, alkali and alkaline earth elements. At treatment of fission product fluorides by acid nitrozyl fluoride only cesium and uranium fluorides dissolve, while americium and rare earth fluorides are practically non-soluble in it. The solubility of cesium, strontium, barium and fluorides of some other rare earth elements in molten cryolite at the temperature of 1000 deg C, Li-NaF and LiF-CaF 2 of eutectic content at 750 and 800 deg C are respectively 15-77 %. Cerium fluoride presents an exception, its solubility in cryolite being only 0.73%. At treatment of mixture of americium and lanthanum fluorides by molten salts in the weight ratio of 1:1, approximately 50% of lanthanum and 65-70% of americium turn into melt independent of the type of melt. The maximum melt output of americium is obtained at treatment of lanthanum and americium fluoride mixture by cryolite melt at the temperature of 1000 deg C. It is shown that the presence of rare earth of fluorides, except lanthanum fluoride, effect significantly of americium distribution over phases in the process of fluoride processing by the fluoride molten salts

Induction by phenobarbital of aniline-p-hydroxylase in mouse liver under the influence of X-irradiation and 2,4,6-triethyleneimino-1,3,5-triazine

International Nuclear Information System (INIS)

Erger, M.; Hollatz, R.; Tempel, K.

1977-01-01

The phenobarbital-induced activity of aniline-p-hydroxylase in livers of mice was enhanced additionally when the animals were X-irradiated 4-16 hours before the administration of the inducer. The same effect could be demonstrated after repeated irradiation with low doses. 2,4,6-triethyleneimino-1,3,5-triazine (tretamine) inhibited the induction of aniline-p-hydroxylase only when administered in extremely high doses. Lower doses resulted in 'superinduciton'. (orig.) [de

1,3,5-Triazine-2,4,6-tribenzaldehyde derivative as a new crosslinking agent for synthesis of pH-thermo dual responsive chitosan hydrogels and their nanocomposites: Swelling properties and drug release behavior.

Science.gov (United States)

Karimi, Ali Reza; Tarighatjoo, Mahsa; Nikravesh, Golara

2017-12-01

In this work, 1,3,5-triazine-2,4,6-tribenzaldehyde was synthesized and chosen as the cross-linking agent for preparation of novel thermo- and pH-responsive hydrogels based on chitosan. The cross-linking proceeds through formation of imine bond by reaction of amino groups of chitosan with aldehyde groups of the cross-linker. The various amounts (6, 10, 14% w/w) of the cross-linker were used with respect to chitosan to produce three 1,3,5-triazine-2,4,6-tribenzaldehyde cross-linked chitosans. Then, their hydrogel nanocomposites were prepared by crosslinking of chitosan with 1,3,5-triazine-2,4,6-tribenzaldehyde in the presence of 0.1% and 0.3% (w/w) multi-walled carbon nanotubes (MWCNTs). The structure and properties of the hydrogels and their nanocomposites were characterized by FT-IR, 1 H NMR and scanning electron microscopy (SEM). The swelling behavior of prepared hydrogels and their nanocomposites at different pHs and temperatures was investigated. The results showed that they exhibit a pH and temperature-responsive swelling ratio. The swelling behavior of the prepared chitosan hydrogels was strongly dependent on the amounts of cross-linker and MWCNTs. In vitro controlled release behavior of metronidazole model drug was studied with prepared hydrogels and nanocomposite hydrogels. The pH, temperature and wt% of MWCNTs were found to strongly influence the drug release behavior of the hydrogels. Copyright © 2017 Elsevier B.V. All rights reserved.

Solvent extraction of uranium(VI), plutonium(VI) and americium(III) with HTTA/HPMBP using mono- and bi-functional neutral donors. Synergism and thermodynamics

International Nuclear Information System (INIS)

Pai, S.A.; Lohithakshan, K.V.; Mithapara, P.D.; Aggarwal, S.K.

2000-01-01

Synergistic extraction of hexavalent uranium and plutonium as well as trivalent americium was studied in HNO 3 with thenoyl, trifluoro-acetone (HTTA)/1-phenyl, 3-methyl, 4-benzoyl pyrazolone-5 (HPMBP) in combination with neutral donors viz. DPSO, TBP, TOPO (mono-functional) and DBDECMP, DHDECMP, CMPO (bi-functional) with wide basicity range using benzene as diluent. A linear correlation was observed when the equilibrium constant log Ks for the organic phase synergistic reaction of both U(VI) and Pu(VI) with either of the chelating agents HTTA or HPMBP was plotted vs. the basicity (log Kh) of the donor (both mono- and bi-functional) indicating bi-functional donors also behave as mono-functional. This was supported by the thermodynamic data (ΔG 0 , ΔH 0 , ΔS 0 ) obtained for these systems. The organic phase adduct formation reactions were identified for the above systems from the thermodynamic data. In the Am(III) HTTA system log K s values of bi-functional donors were found to be very high and deviate from the linear plot (log K s vs. log K h ) obtained for mono-functional donors, indicating that they function as bi-functional for the Am(III)/HTTA) system studied. This was supported by high +ve ΔS 0 values obtained for this system. (author)

Study and modeling of lanthanide(3)-L and americium(3)-L (With L = NTA, EDTA and DTPA) in high ionic strength aqueous solutions

International Nuclear Information System (INIS)

Rocchiccioli, F.

2000-01-01

The dissociation constants of NTA, EDTA, DTPA in NaCl, NaClO 4 , LiCl and LiClO 4 aqueous solutions of various ionic strengths have been gathered from the literature and from the Critical Surveys of Stability Constants. These values have been completed by a series of pKa values obtained in the same salted solution at higher ionic strengths by potentiometry involving a combined glass electrode at 25 deg C. The dependencies of the pKas versus the ionic strength have been investigated by using the Specific Interaction Theory (SIT), the parabolic model and the Pitzer model. The stability constants of complexes involving lanthanides (III), such as Nd 3+ , Eu 3+ and Lu 3+ , and americium (III), with the ligands previously mentioned in NaCl, NaClO 4 , LiCl and LiClO 4 aqueous solutions of high ionic strengths have been determined. The methods used for the determination of the stability constants for the lanthanide complexes are various: direct measurements by potentiometry when possible, UV-visible absorption spectroscopy involving Arsenazo (III) as a competitor ligand. For the actinide complexes, solvent extraction experiments have been performed. The different systems, along with the dissociation constants of several complexes in the same aqueous media, have been successfully modeled by the SIT, the parabolic method and the Pitzer method. (author)

Biodegradation of TNT (2,4,6-Trinitrotoluene) by Phanerochaete chrysosporium

International Nuclear Information System (INIS)

Fernando, T.; Bumpus, J.A.; Aust, S.D.

1990-01-01

Extensive biodegradation of TNT (2,4,6-trinitrotoluene) by the white rot fungus Phanerochaete chrysosporium was observed. At an initial concentration of 1.3 mg/liter, 35.4 ± 3.6% of the [ 14 C]TNT was degraded to 14 CO 2 in 18 days. The addition of glucose 12 days after the addition of TNT did not stimulate mineralization, and, after 18 days of incubation with TNT only, about 3.3% of the initial TNT could be recovered. Mineralization of [ 14 C]TNT absorbed on soil was also examined. Ground corncobs served as the nutrient for slow but sustained degradation of [ 14 C]TNT to 14 CO 2 such that 6.3 ± 0.6% of the [ 14 C]TNT initially present was converted to 14 CO 2 during the 30-day incubation period. Mass balance analysis of liquid cultures and of soil-corncob cultures revealed that polar [ 14 C]TNT metabolites are formed in both systems, and high-performance liquid chromatography analyses revealed that less then 5% of the radioactivity remained as undegraded [ 14 C]TNT following incubation with the fungus in soil and liquid cultures. When the concentration of TNT in cultures (both liquid and soil) was adjusted to contamination levels that might be found in the environment, i.e., 10,000 mg/kg in soil and 100 mg/liter in water, mineralization studies showed that 18.4 ± 2.9% and 19.6 ± 3.5% of the initial TNT was converted to 14 CO 2 in 90 days in soil and liquid cultures, respectively. In both cases (90 days in water at 100 mg/liter and in soil at 10,000 mg/kg) approximately 85% of the TNT was degraded. These results suggest that this fungus may be useful for the decontamination of sites in the environment contaminated with TNT

Phototransformation of 2,4,6-trinitrotoluene: Sensitized by riboflavin under different irradiation spectral range

International Nuclear Information System (INIS)

Yang Xin; Zhao Xueheng; Hwang, H.-M.

2007-01-01

Riboflavin-sensitized phototransformation of 2,4,6-trinitrotoluene (TNT) under natural sunlight was investigated with reverse-phase high performance liquid chromatography/mass spectrometry (HPLC/MS) and gas chromatography/mass spectrometry (GC/MS). The effect of different spectral region of sunlight on TNT phototransformation in the absence or presence of riboflavin was also investigated by using optical filters with cut-off at 400 or 455 nm. The concentration of riboflavin in the phototransformation of TNT was optimized. Concentration of riboflavin and TNT was 1.0 and 50 μM, respectively. The rates of phototransformation of TNT under natural sunlight in the presence or absence of riboflavin were conformed to initial pseudo-first-order rate equation. The photolysis half life of TNT in the presence of riboflavin was 21.87 min, compared to 39 min in the absence of riboflavin under natural sunlight. Two major phototransformation products of TNT, 3,5-dinitroaniline (3,5-DNA) and 1,3,5-trinitrobenzene (1,3,5-TNB), were detected in the samples in the presence of riboflavin receiving irradiation at full wavelength or wavelength >400 nm. The results indicate that riboflavin mediates TNT sensitized-phototransfomation under natural sunlight or near-UV-vis light

Novel Americium Treatment Process for Surface Water and Dust Suppression Water

International Nuclear Information System (INIS)

Tiepel, E.W.; Pigeon, P.; Nesta, S.; Anderson, J.

2006-01-01

The Rocky Flats Environmental Technology Site (RFETS), a former nuclear weapons production plant, has been remediated under CERCLA and decommissioned to become a National Wildlife Refuge. The site conducted this cleanup effort under the Rocky Flats Cleanup Agreement (RFCA) that established limits for the discharge of surface and process waters from the site. At the end of 2004, while a number of process buildings were undergoing decommissioning, routine monitoring of a discharge pond (Pond A-4) containing approximately 28 million gallons of water was discovered to have been contaminated with a trace amount of Americium-241 (Am-241). While the amount of Am-241 in the pond waters was very low (0.5 - 0.7 pCi/l), it was above the established Colorado stream standard of 0.15 pCi/l for release to off site drainage waters. The rapid successful treatment of these waters to the regulatory limit was important to the site for two reasons. The first was that the pond was approaching its hold-up limit. Without rapid treatment and release of the Pond A-4 water, typical spring run-off would require water management actions to other drainages onsite or a mass shuttling of water for disposal. The second reason was that this type of contaminated water had not been treated to the stringent stream standard at Rocky Flats before. Technical challenges in treatment could translate to impacts on water and secondary waste management, and ultimately, cost impacts. All of the technical challenges and specific site criteria led to the conclusion that a different approach to the treatment of this problem was necessary and a crash treatability program to identify applicable treatment techniques was undertaken. The goal of this program was to develop treatment options that could be implemented very quickly and would result in the generation of no high volume secondary waste that would be costly to dispose. A novel chemical treatment system was developed and implemented at the RFETS to treat Am

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

International Nuclear Information System (INIS)

Miner, F.J.

1979-01-01

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

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Curium Management Studies in France, Japan and USA. A Report by the WPFC Expert Group on Chemical Partitioning of the NEA Nuclear Science Committee - April 2011

International Nuclear Information System (INIS)

Yamagishi, Isao; Choi, Yong-Joon; Glatz, Jean-Paul; Hyland, Bronwyn; Uhlir, Jan; Baron, Pascal; Warin, Dominique; DE ANGELIS, Giorgio; LUCE, Alfredo; Inoue, Tadashi; Morita, Yasuji; Minato, Kazuo; Lee, Han Soo; Ignatiev, Victor V.; Kormilitsyn, Mikhail V.; Caravaca, Concepcion; Lewin, Robert g.; Taylor, Robin J.; Collins, Emory D.; Laidler, James J.

2012-01-01

Curium is closely associated with americium in irradiated fuels because of their chemical similarity with regard to potential separation requirements, and because americium also requires special shielding and handling requirements due to its gamma radiation emission. Americium is produced in greater mass than curium in irradiated nuclear fuels and the mass ratio can grow exponentially with decay time because of the simultaneous decay of 244 Cm and in-growth of 241 Am from decay of 241 Pu (half-life = 14.4 years). For these reasons, curium management is challenging. Countries that are now engaged in or planning future fuel recycle operations, are considering methods to manage the curium produced and minimise the shielding and handling requirements, as well as the reprocessing requirements for separation of curium from americium France, Japan, and the USA have begun curium management studies. Curium management methods under consideration include (1) separation of curium from americium and storage of curium for several decades to allow 244 Cm to decay substantially to 240 Pu, while moving ahead to recycle americium; (2) recycling of americium and curium without separation; and (3) waiting several decades to reprocess used nuclear fuels, allowing decay minimisation of curium emissions and the requirement for separation of curium from americium, and allowing an alteration of the subsequent transmutation path to reduce the production of curium in recycled used fuels. In this report, recent curium management studies in France, Japan, and the USA have been described. The French studies included scenarios that compared the recycle of ail minor actinides (neptunium, americium, and curium) with the recycle of only neptunium and americium in radial blankets of sodium-cooled fast reactors (SFR). In the latter scenario, curium is separated from americium during used fuel reprocessing and stored for 5000 years to allow 244 Cm to decay to 240 Pu which is then recycled. Even though

Electrochemical determination of 2,4,6-trinitrophenol using a hybrid film composed of a copper-based metal organic framework and electroreduced graphene oxide.

Science.gov (United States)

Wang, Yong; Cao, Wei; Wang, Luyao; Zhuang, Qianfen; Ni, Yongnian

2018-06-04

A metal organic framework (MOF) of the type copper(II)-1,3,5-benzenetricarboxylic acid (Cu-BTC) was electrodeposited on electroreduced graphene oxide (ERGO) placed on a glassy carbon electrode (GCE). The modified GCE was used for highly sensitive electrochemical determination of 2,4,6-trinitrophenol (TNP). The fabrication process of the modified electrode was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. Differential pulse voltammetry (DPV) demonstrates that the Cu-BTC/ERGO/GCE gives stronger signals for TNP reduction than Cu-BTC/GCE or ERGO/GCE alone. DPV also shows TNP to exhibit three reduction peaks, the first at a potential of -0.42 V (vs. SCE). This potential was selected because the other three similarly-structured compounds (2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol) do not give a signal at this potential. Response is linear in the 0.2 to 10 μM TNP concentration range, with a 0.1 μM detection limit (at S/N = 3) and a 15.98 μA∙μM -1 ∙cm -2 sensitivity under optimal conditions. The applicability of the sensor was evaluated by detecting TNP in spiked tap water and lake water samples. Recoveries ranged between 95 and 101%. Graphical abstract Schematic presentation of an electrochemical sensor that was fabricated by electrodeposition of the metal-organic framework (MOF) of copper(II)-1,3,5-benzenetricarboxylic acid (Cu-BTC) onto the surface of electroreduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). It was applied to sensitive and selective detection of 2,4,6-trinitrophenol (TNP).

Photodegradation of 2,4,6-trinitrophenol catalyzed by Zn/MgO nanoparticles prepared in aqueous-organic medium

International Nuclear Information System (INIS)

Ali, Shaista; Farrukh, Muhammad Akhyar; Khaleeq-ur-Rahman, Muhammad

2013-01-01

Synthesis of Magnesium oxide (MgO) nanoparticles and zinc deposited magnesium oxide (Zn/MgO) nanoparticles was carried out using hydrothermal and deposition-precipitation method with the variation of 1-Propanol (organic solvent) concentration, sodium hydroxide and urea concentration. The nanoparticles were characterized by using FTIR, TGA, SEM-EDX, TEM and XRD. The photocatalytic efficiency of MgO and Zn/MgO nanoparticles was studied by degradation of 2,4,6-trinitrophenol (TNP), which is highly acute and toxic and causes skin and eyes diseases, liver malfunction and tumor formation. Photodegradation of TNP was carried out under UV irradiation and confirmed by using HPLC and GC-MS. MgO and Zn/MgO nanoparticles that were synthesized by using urea showed higher first-order rate constant (k) value and percentage degradation as compared to nanoparticles that were synthesized using NaOH. It was observed that the concentration of solvent has direct relation with the k value of degradation of TNP

Photodegradation of 2,4,6-trinitrophenol catalyzed by Zn/MgO nanoparticles prepared in aqueous-organic medium

Energy Technology Data Exchange (ETDEWEB)

Ali, Shaista; Farrukh, Muhammad Akhyar; Khaleeq-ur-Rahman, Muhammad [GC University Lahore, Lahore (Pakistan)

2013-11-15

Synthesis of Magnesium oxide (MgO) nanoparticles and zinc deposited magnesium oxide (Zn/MgO) nanoparticles was carried out using hydrothermal and deposition-precipitation method with the variation of 1-Propanol (organic solvent) concentration, sodium hydroxide and urea concentration. The nanoparticles were characterized by using FTIR, TGA, SEM-EDX, TEM and XRD. The photocatalytic efficiency of MgO and Zn/MgO nanoparticles was studied by degradation of 2,4,6-trinitrophenol (TNP), which is highly acute and toxic and causes skin and eyes diseases, liver malfunction and tumor formation. Photodegradation of TNP was carried out under UV irradiation and confirmed by using HPLC and GC-MS. MgO and Zn/MgO nanoparticles that were synthesized by using urea showed higher first-order rate constant (k) value and percentage degradation as compared to nanoparticles that were synthesized using NaOH. It was observed that the concentration of solvent has direct relation with the k value of degradation of TNP.

Ecotoxicological evaluation of in situ bioremediation of soils contaminated by the explosive 2,4,6-trinitrotoluene (TNT)

International Nuclear Information System (INIS)

Frische, Tobias

2003-01-01

The luminescent bacteria assay, using soil leachates, was the most sensitive toxicity indicator. - To evaluate the environmental relevance of in situ bioremediation of contaminated soils, effective and reliable monitoring approaches are of special importance. The presented study was conducted as part of a research project investigating in situ bioremediation of topsoils contaminated by the explosive 2,4,6-trinitrotoluene (TNT). Changes in soil toxicity within different experimental fields at a former ordnance factory were evaluated using a battery of five bioassays (plant growth, Collembola reproduction, soil respiration, luminescent bacteria acute toxicity and mutagenicity test) in combination to chemical contaminant analysis. Resulting data reveal clear differences in sensitivities between methods with the luminescent bacteria assay performed with soil leachates as most sensitive toxicity indicator. Complete test battery results are presented in so-called soil toxicity profiles to visualise and facilitate the interpretation of data. Both biological and chemical monitoring results indicate a reduction of soil toxicity within 17 months of remediation

Human Cell Line Activation Test of the Novel Energetics 2,6-pyrazinediamine 3,5-dinitro 1 -oxide (LLM-105) and 2,4,6-trinitro-3-bromoanisole (TNBA)

Science.gov (United States)

2017-11-06

substances early in the RDT&E process to avoid unnecessary costs, conserve physical resources, and sustain the health of those potentially exposed. The SERDP...pyrazinediamine 3,5-dinitro 1 –oxide (LLM-105) and 2,4,6-trinitro-3-bromoanisole (TNBA) Prepared by: Emily Reinke, Ph.D. Health Effects Division...Toxicology Directorate Army Public Health Center ARIMS designation: 500c Use of trademarked name(s) does not imply endorsement by the U.S

Distribution of transuranic elements in a freshwater pond ecosystem

International Nuclear Information System (INIS)

Emery, R.M.; Klopfer, D.C.

1976-01-01

During the past two years a unique study has been initiated on the Hanford Reservation concerning the ecological behavior of plutonium and americium in a freshwater environment. This study involves a waste pond which has been receiving occasional low-level plutonium processing wastes for about 30 years. The pond has a sufficiently established ecosystem to provide an excellent location for limnological characterization. In addition, the ecological distribution of plutonium and americium is being investigated. The purpose of this work is to explain plutonium and americium concentrations at specific ecological sites, important export routes out of the pond, and potential pathways to man. The pond is also highly enriched with nutrients, thus supporting a high level of algal and macrophyte production. Seston (30 percent diatoms) appears to be the principal concentrator of transuranics in the pond system. The major sink for plutonium and americium in this system is the sediments. Organic floc, overlaying the pond sediments, is also a major concentrator of transuranics in this system. Aside from the seston and floc, no other ecological components of the pond appear to have concentrations significantly greater than those of the sediment. Dragonfly larvae, watercress, and snails show concentrations which approximate those of the sediments but nearly all other food web components have levels of plutonium and americium which are lower than those of the sediments. Thus, plutonium and americium seem to be relatively immobile in the aquatic ecosystem. However, the role of algae as a potential mechanism for the long-range ecological transport of plutonium and americium will receive additional attention

Synthesis of novel tripodal-benzimidazole from 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine: Structural, electrochemical and antimicrobial studies

International Nuclear Information System (INIS)

Koc, Ziya Erdem; Bingol, Haluk; Saf, Ahmet O.; Torlak, Emrah; Coskun, Ahmet

2010-01-01

Four new tripodal-benzimidazole derivatives were synthesized by Schiff base reaction between 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine (TRIPOD) and different diamine derivatives. The structures of the obtained compounds were identified by FT-IR, 1 H NMR, 13 C NMR and UV-vis spectral data, thermal analysis and elemental analysis. Electrochemical behaviors of the compounds were studied by cyclic voltammetry in DMF including 0.1 M [NBu 4 ] [PF 6 ]. The voltammograms showed peaks having similar characteristics except tripodal-benzimidazole including -NO 2 derivative. In addition, their antimicrobial activities were evaluated by using the standard disk diffusion method in dimethylformamide media. The activities were determined against 4 bacteria cultures by comparing to those of gentamycin.

Near infrared optical biosensor based on peptide functionalized single-walled carbon nanotubes hybrids for 2,4,6-trinitrotoluene (TNT) explosive detection.

Science.gov (United States)

Wang, Jin

2018-06-01

A near infrared (NIR) optical biosensor based on peptide functionalized single-walled carbon nanotubes (SWCNTs) hybrids for 2,4,6-trinitrotoluene (TNT) explosive detection was developed. The TNT binding peptide was directly anchored on the sidewall of the SWCNTs using the π-π interaction between the aromatic amino acids and SWCNTs, forming the peptide-SWCNTs hybrids for near infrared absorption spectra measurement. The evidence of the morphology of peptide-SWCNTs hybrids was obtained using atomic force microscopy (AFM). The results demonstrated that peptide-SWCNTs hybrids based NIR optical biosensor exhibited sensitive and highly selective for TNT explosive determination, addressing a promising optical biosensor for security application. Copyright © 2018. Published by Elsevier Inc.

Quantitative SERS detection of low-concentration aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene.

Science.gov (United States)

Bao, Zhi Yong; Liu, Xin; Chen, Y; Wu, Yucheng; Chan, Helen L W; Dai, Jiyan; Lei, Dang Yuan

2014-09-15

This paper reports a simple label-free high-sensitive method for detecting low-concentration persistent organic pollutants and explosive materials. The proposed method combines surface-enhanced Raman spectroscopy (SERS) and magnetomotive enrichment of the target molecules on the surface of Ag nanoparticles (NPs). This structure can be achieved through self-assembling integration of Ag NPs with ferromagnetic Fe3O4 microspheres, forming a hybrid SERS nanoprobe with both optical and magnetic properties. Moreover, the magnetic response of ferromagnetic Fe3O4 microspheres can be used to dynamically modulate the optical property of Ag NPs through controlling their geometric arrangement on the substrate by applying an external magnetic field. It is also demonstrated from the full-wave numerical simulation results that the maximum electromagnetic field enhancement can be greatly increased by shortening the distance of neighboring Ag NPs and therefore resulting in an improved SERS detecting limit. More importantly, by using the prepared substrate, the SERS signals from organic pollution substances, i.e. aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene, were quantitatively analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

Extraction of transplutonium elements from carbonate solutions by alkylpyrocatechol

International Nuclear Information System (INIS)

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

1983-01-01

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

Storm on lightning conductors

International Nuclear Information System (INIS)

Broomhead, Laurent.

1980-01-01

Radioactive lightning conductors using radium or americium 241 sources are compared to Faraday cage and lightning rod. Americium source preparation is shortly described. Efficiency of the different systems is still controversed [fr

Elimination Reactions of (E)-2,4,6-Trinitrobenzaldehyde O-benzoyloximes Promoted by R2NH in MeCN. Change of Reaction Mechanism

International Nuclear Information System (INIS)

Cho, Bong Rae; Pyun, Sang Yong

2010-01-01

We have studied the nitrile-forming elimination reactions from 1 promoted by R 2 NH in MeCN. The reaction proceeded by (E1cb) irr mechanism. Change of the β-aryl group from 2,4-dinitrophenyl to a more strongly electron-withdrawing 2,4,6-trinitrophenyl increased the reaction rate by 470-fold, shifted the transition state toward more reactant-like, and changed the reaction mechanism from E2 to (E1cb) irr . To the best of our knowledge, this is the first example of nitrile-forming elimination reaction that proceeds by the (E1cb) irr mechanism in MeCN. Noteworthy is the carbanion stabilizing ability of the 2,4,6-trinitrophenyl group in aprotic solvent. Nitrile-forming elimination reactions of (E)-benzaldoxime derivatives have been extensively investigated under various conditions. The reactions proceeded by the E2 mechanism in MeCN despite the fact that the reactants have syn stereochemistry, poor leaving, and sp 2 hybridized β-carbon atom, all of which favor E1cb- or E1cb-like transition state. Moreover, the transition state structures were relatively insensitive to the variation of the reactant structures. The results have been attributed to the poor anion solvating ability of MeCN, which favors E2 transition state with maximum charge dispersal. For eliminations from strongly activated (E)-2,4-(NO 2 ) 2 C 6 H 3 CH=NOC(O)C 6 H 4 X, a change in the reaction mechanism from E2 to (E1cb) irr was observed as the base-solvent was changed from R 2 NH in MeCN to R 2 NH/R 2 NH 2 + in 70 mol % MeCN(aq). A combination of a strong electron-withdrawing β-aryl group and anion-solvating protic solvent was required for the mechanistic change

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)

Goubard, F.; Griesmar, P.; Tabuteau, A.

2005-01-01

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 237 Np and the α,γ-emitter 241 Am. 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

Synthesis of novel tripodal-benzimidazole from 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine: Structural, electrochemical and antimicrobial studies

Energy Technology Data Exchange (ETDEWEB)

Koc, Ziya Erdem, E-mail: zerdemkoc@gmail.com [Department of Chemistry, Faculty of Science, Selcuk University, 42031 Konya (Turkey); Bingol, Haluk; Saf, Ahmet O. [Department of Chemistry, Faculty of Science, Selcuk University, 42031 Konya (Turkey); Torlak, Emrah [Provincial Control Laboratory, Konya (Turkey); Coskun, Ahmet [Department of Chemistry, Faculty of Science, Selcuk University, 42031 Konya (Turkey)

2010-11-15

Four new tripodal-benzimidazole derivatives were synthesized by Schiff base reaction between 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine (TRIPOD) and different diamine derivatives. The structures of the obtained compounds were identified by FT-IR, {sup 1}H NMR, {sup 13}C NMR and UV-vis spectral data, thermal analysis and elemental analysis. Electrochemical behaviors of the compounds were studied by cyclic voltammetry in DMF including 0.1 M [NBu{sub 4}] [PF{sub 6}]. The voltammograms showed peaks having similar characteristics except tripodal-benzimidazole including -NO{sub 2} derivative. In addition, their antimicrobial activities were evaluated by using the standard disk diffusion method in dimethylformamide media. The activities were determined against 4 bacteria cultures by comparing to those of gentamycin.

On-line separation of Pu(III) and Am(III) using extraction and ion chromatography

International Nuclear Information System (INIS)

Jernstroem, J.; Lehto, J.; Betti, M.

2007-01-01

An on-line method developed for separating plutonium and americium was developed. The method is based on the use of HPLC pump with three analytical chromatographic columns. Plutonium is reduced throughout the procedure to trivalent oxidation state, and is recovered in the various separation steps together with americium. Light lanthanides and trivalent actinides are separated with TEVA resin in thiocyanate/formic acid media. Trivalent plutonium and americium are pre-concentrated in a TCC-II cation-exchange column, after which the separation is performed in CS5A ion chromatography column by using two different eluents. Pu(III) is eluted with a dipicolinic acid eluent, and Am(III) with oxalic acid eluent. Radiochemical and chemical purity of the eluted plutonium and americium fractions were ensured with alpha-spectrometry. (author)

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

International Nuclear Information System (INIS)

Miner, F.J.

1979-01-01

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

Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

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Chean Hui Ng

2014-08-01

Full Text Available The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs and aromatic groups could significantly affect the enzymatic activity.

Synthesis, molecular structure, spectroscopic properties and stability of (Z)-N-methyl-C-2,4,6-trimethylphenylnitrone

Science.gov (United States)

Lasri, Jamal; Ismail, Ali I.; Haukka, Matti; Soliman, Saied M.

2015-02-01

New N-methyl-C-2,4,6-trimethylphenylnitrone 1 has been synthesized starting from N-methylhydroxylamine and mesitaldehyde. The product was fully characterized using different spectroscopic techniques; FTIR, NMR, UV-Vis, high resolution mass spectrometry and X-ray diffraction. The relative stability and percent of population of its two possible isomers (E and Z) were calculated using the B3LYP/6-311++G(d,p) method in gas phase and in solution. In agreement with the X-ray results, it was found that Z-isomer is the most stable one in both gas phase and solution. The molecular geometry, vibrational frequencies, gauge-including atomic orbital (GIAO), and chemical shift values were also calculated using the same level of theory. The TD-DFT results of the studied nitrone predicted a π-π∗ transition band at 285.1 nm (fosc = 0.3543) in the gas phase. The rest of the spectral bands undergo either hyperchromic or hypsochromic shifts in the presence of solvent. Polarizability and HOMO-LUMO gap values were used to predict the nonlinear optical properties (NLO) of the studied compound. NBO analysis has been used to determine the most accurate Lewis structure of the studied molecule.

Distribution of 239Pu and 241Am in the human skeleton

International Nuclear Information System (INIS)

McInroy, J.F.; Swint, M.J.

1984-01-01

The 241 Am and 239 Pu 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

Actinide recovery from pyrochemical residues

International Nuclear Information System (INIS)

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

1984-01-01

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

Actinide recovery from pyrochemical residues

International Nuclear Information System (INIS)

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

1985-05-01

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

Structural study of U1-xAmxO2±δ oxide microspheres dedicated to the production of americium bearing blankets

International Nuclear Information System (INIS)

Caisso, Marie

2016-01-01

One of the studied routes to reduce nuclear waste amount, is, after plutonium recycling, americium (Am) heterogeneous transmutation in fast neutron reactors, through the generation of short-lives and inert elements. Am irradiation requires the fabrication of U 1-x Am x O 2±δ pellets and the CRMP (Calcined Resin Microsphere Pelletization) process is currently considered as one the most promising candidate among other fabrication routes. It is based, before pellet sintering, on the compaction of U 1-x Am x O 2±δ oxide microspheres, synthesized through the thermal conversion of ion exchange resin microspheres, loaded with UO 2 2+ and Am 3+ cations. Compared to standard methods using powder metallurgy, CRMP process favours pressing step (easy microsphere flow) while limiting generation of highly radioactive Am-based fine particles. In this context, this PhD work was focused on the exhaustive characterization of CRMP process different steps, from a mechanistic and structural point of view. The cation molecular complex used in the resin was thus determined, highlighting carboxylic bidentate ligand binding around U and Am elements. Thermal conversion was also in-situ followed, and the structures of the different synthesized compounds evidenced and accurately characterized, i.e. (U 1-x Am x ) 3 O 8 et U 1-x Am x O 2±δ . Am substitution in each of them was explained, revealing related distortions around U and Am cations. Finally, sintering of U 1-x Am x O 2±δ microspheres shaped into pellets was studied, showing a two-step densification. This unusual behavior corresponds to multi-scale reorganization into the material during sintering thermal treatment, associated to the presence of nanoparticles in the green pellet that sinter at low temperature. (author) [fr

Development of remote handling tools for glove box

International Nuclear Information System (INIS)

Tomita, Yutaka; Nemoto, Takeshi; Denuma, Akio; Todokoro, Akio

1996-01-01

For a part of advanced nuclear fuel recycling technology development, we will separate and recover Americium from the MOX fuel scrap by solvent extraction. When we carry this examination, reduction of exposure from Americium-241 is one of important problems. To solve this problem fundamentally, we studied many joints type of the remote handling tools for glove box and produced a trial production machine. Also, we carried out basic function examinations of it. As a result, we got the prospect of development of the remote handling tools which could treat Americium in glove box. (author)

Low-level determination of transuranic elements in marine environment samples

International Nuclear Information System (INIS)

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

1978-01-01

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

Crystal structure of 4,4′,4′′-(1,3,5-triazine-2,4,6-triyltripyridinium trichloride 2.5-hydrate

Directory of Open Access Journals (Sweden)

Bo-Kai Ling

2015-11-01

Full Text Available The asymmetric unit of the title compound, C18H15N63+·3Cl−·2.5H2O, contains two independent (1,3,5-triazine-2,4,6-triyltripyridinium cations. Both cations are approximately planar, the r.m.s. deviations of fitted non-H atoms being 0.045 and 0.051 Å. In the crystal, extensive O—H...Cl, O—H...O, N—H...Cl and N—H...O hydrogen bonds and weak C—H...Cl and C—H...O interactions link the organic cations, Cl− anions and water molecules into a three-dimensional supramolecular architecture. π–π stacking between the pyridine rings of adjacent cations is also observed, the centroid-to-centroid distance being 3.7578 (8 Å.

2,4,6-Tri-amino-1,3,5-triazin-1-ium 3-(prop-2-eno-yloxy)propano-ate acrylic acid monosolvate monohydrate.

Science.gov (United States)

Sangeetha, V; Kanagathara, N; Chakkaravarthi, G; Marchewka, M K; Anbalagan, G

2013-05-01

The asymmetric unit of the title salt, C3H7N6 (+)·C6H7O4 (-)·C3H4O2·H2O, contains a 2,4,6-tri-amino-1,3,5-triazin-1-ium cation, a 3-(prop-2-eno-yloxy)propano-ate anion and acrylic acid and water solvent mol-ecules in a 1:1:1:1 ratio and with each species in a general position. In the crystal, the components are linked into a supra-molecular layer in the bc plane via a combination of O-H⋯O, N-H⋯N and N-H⋯O hydrogen bonding. The crystal studied was a non-merohedral twin, the minor component contribution being approximately 26%.

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).

A Facile Approach to Preparing Molecularly Imprinted Chitosan for Detecting 2,4,6-Tribromophenol with a Widely Linear Range

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Limei Huang

2017-04-01

Full Text Available The environmental pollution of 2,4,6-tribromophenol (TBP has attracted attention. Based on an urgent need for the better provision of clean water, in situ determination of TBP is of great importance. Here, a facile and effective approach for detecting TBP is developed, based on coupling molecular imprinting technique with electrodeposition of chitosan (CS on the gold electrode. The TBP imprinting CS film was fabricated by using CS as functional material and TBP as template molecule. The experiments show that the morphologies and electrochemical properties of the imprinted film sensor was different from non-imprinted film electrode. The current of the imprinted film was linearly proportional to the TBP concentration, with a wide linear range of 1.0 × 10−7 mol•L−1 to 1.0 × 10−3 mol•L−1. By selecting drop-coating method as a reference for controlled trials with the same functional material, the results illustrated that the electrodeposition enjoyed a widely linear range advantage.

Preparation of N-(3-BROMO-2,4,6-trimethylacetanilide) iminodiacetic acid and its 99MTc-complex for hepatobiliary imaging

International Nuclear Information System (INIS)

Choi, Ok Ja; Hong, Young Don; Gwon, Hui Jeong; Choi, Sang Mu; Choi, Sun Ju

2005-01-01

N-(3-bromo-2,4,6-trimethylacetanilide) iminodiacetic acid (BrTIDA) was synthesized using nitrilotriacetic anhydride prepared in situ, and lyophilized vials were prepared which contained 20 mg of BrTIDA and 0.4 mg of SnCl 2 . To evaluate the clinical efficacy of the in-house prepared lyophilized kit, a technetium-99m complex of BrTIDA was prepared; its in vivo pharmacokinetic behavior was evaluated via animal studies to assess the hepatocytic function and the functional status of the cystic duct and the gallbladder. Serial static image scans of rabbits and the biodistribution in mice injected with 99m Tc-BrTIDA revealed that none of the tissues except for the hepatobiliary system showed radioactivity concentrations, and a rapid clearance from the organs was observed. In conclusion, a lyophilized kit and its prepared 99m Tc-BrTIDA can be applied as a hepatobiliary imaging agent for the evaluation of the functional status of the hepatocytes and the patency of the biliary duct

Identification of colloids in nuclear waste glass reactions

International Nuclear Information System (INIS)

Cunnane, J.C.; Bates, J.K.

1991-01-01

Characterization data for particulates formed under a variety of laboratory leaching conditions that simulate glass reaction in a repository environment are presented. Data on the particle size distributions and filterable fractions for neptunium, plutonium, americium, and curium were obtained by filtrations through a series of filters with pore sizes ranging from 1 μm to 3.8 nm. The neptunium was found to be largely nonfilterable. Americium and plutonium were associated with filterable particles. The particles with which the americium, plutonium, and curium were associated were characterized using transmission electron microscopy (TEM) examination techniques. 8 refs., 1 fig., 2 tabs

Organic pollutants removal from 2,4,6-trinitrotoluene (TNT) red water using low cost activated coke

Institute of Scientific and Technical Information of China (English)

Mohe Zhang; Quanlin Zhao; Zhengfang Ye

2011-01-01

We treated 2,4,6-trinitrotoluene (TNT) red water from the Chinese explosive industry with activated coke (AC) from lignite.Since the composition of TNT red water was very complicated,chemical oxygen demand (COD) was used as the index for evaluating treatment efficiency.This study focused on sorption kinetics and equilibrium sorption isotherms of AC for the removal of COD from TNT red water,and the changes of water quality before and after adsorption were evaluated using high performance liquid chromatography,UV-Vis spectra and gas chromatography/mass spectroscopy.The results showed that the sorption kinetics of COD removal from TNT red water onto AC fitted well with the pseudo second-order model.The adsorption process was an exothermic and physical process.The sorption isotherm was in good agreement with Redlich-Peterson isotherm.At the conditions of initial pH =6.28,20°C and 3 hr of agitation,under 160 g/L AC,64.8% of COD was removed.The removal efficiencies of 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO3-) and 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO3-) were 80.5% and 84.3%,respectively.After adsorption,the acute toxicity of TNT red water reduced greatly,compared with that of unprocessed TNT red water.

Root uptake of transuranic elements

International Nuclear Information System (INIS)

Schulz, R.K.

1977-01-01

The uptake of elements by plant roots is one of the important pathways of entry of many elements into the food chain of man. Data are cited showing plutonium concentration ratios, plant/soil, ranging from 10 -10 to 10 -3 . Concentration ratios for americium range from 10 -7 to 10 +1 . Limited experiments with curium and neptunium indicate that root uptake of curium is similar to that of americium and that plant uptake of neptunium is substantially larger than that of curium and americium. The extreme ranges of concentration ratios cited for plutonium and americium are due to a number of causes. Experimental conditions such as very intensive cropping will lead to abnormally high concentration ratios. In some experiments, addition of chelating agents markedly increased plant root uptake of transuranic elements. Particle size and composition of the source material influenced uptake of the transuranics by plants. Translocation within the plant, and soil factors such as pH and organic matter content, all affect concentration ratios

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

International Nuclear Information System (INIS)

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

2009-12-01

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

Tetraphenylphosphonium iodide–1,3,5-trifluoro-2,4,6-triiodobenzene–methanol (3/4/1

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Gabriella Cavallo

2013-06-01

Full Text Available The crystallization of a 1:1 molar solution of 1,3,5-trifluoro-2,4,6-diiodobenzene (TFTIB and tetraphenylphosponium iodide (TPPI from methanol produced tetragonal needles of pure TPPI and tabular pseudo-hexagonal truncated bipyramids of the title compound, 3C24H20P+·3I−·4C6F3I3·CH4O or (TPPI3(TFTIB4·MeOH. The asymmetric unit is composed of six TPPI molecules, eight TFTIB molecules and two methanol molecules, overall 16 constituents. The formation of the architecture is essentially guided by a number of C—I...I− halogen bonds (XB, whose lengths are in the range 3.276 (1–3.625 (1 Å. Layers of supramolecular polyanions are formed parallel to (10-1 wherein iodide anions function as penta-, tetra- or bidentate XB acceptors. The structure is not far from being P21/n, but the centrosymmetry is lost due to a different conformation of a single couple of cations and the small asymmetry in the formed supramolecular anion. One methanol molecule is hydrogen bonded to an iodide anion, while the second is linked to the first one via an O—H...O contact. This second methanol molecule is more loosely pinned in its position than the first and presents very high anisotropic displacement parameters and a seeming shortening of the C—O bond length. The crystal studied was refined as a perfect inversion twin.

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

International Nuclear Information System (INIS)

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

1982-01-01

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

2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

International Nuclear Information System (INIS)

Montgomery, Michael T.; Coffin, Richard B.; Boyd, Thomas J.; Smith, Joseph P.; Walker, Shelby E.; Osburn, Christopher L.

2011-01-01

The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO 2 ); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO 2 was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 μg C kg -1 d -1 ). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO 2 is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: → TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. → TNT mineralization rates comprised a significant proportion of total heterotrophic production. → These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO 2 is a common feature of natural bacterial assemblages in coastal sediment.

Thermal decomposition and kinetic evaluation of decanted 2,4,6-trinitrotoluene (TNT) for reutilization as composite material

Science.gov (United States)

Ahmed, M. F.; Hussain, A.; Malik, A. Q.

2016-08-01

Use of energetic materials has long been considered for only military purposes. However, it is very recent that their practical applications in wide range of commercial fields such as mining, road building, under water blasting and rocket propulsion system have been considered. About 5mg of 2,4,6-trinitrotoluene (TNT) in serviceable (Svc) as well as unserviceable (Unsvc) form were used for their thermal decomposition and kinetic parameters investigation. Thermogravimetric/ differential thermal analysis (TG/DTA), X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to characterize two types of TNT. Arrhenius kinetic parameters like activation energy (E) and enthalpy (AH) of both TNT samples were determined using TG curves with the help of Horowitz and Metzger method. Simultaneously, thermal decomposition range was evaluated from DTA curves. Distinct diffraction peaks showing crystalline nature were obtained from XRD analysis. SEM results indicated that Unsvc TNT contained a variety of defects like cracks and porosity. Similarly, it is observed that thermal as well as kinetic behavior of both TNT samples vary to a great extent. Likewise, a prominent change in the activation energies (E) of both samples is observed. This in-depth study provides a way forward in finding solutions for the safe reutilization of decanted TNT.

Curcumin inhibits epigen and amphiregulin upregulated by 2,4,6-trinitrochlorobenzene associated with attenuation of skin swelling.

Science.gov (United States)

Sakai, Hiroyasu; Sato, Ken; Sato, Fumiaki; Kai, Yuki; Mandokoro, Kazutaka; Matsumoto, Kenjiro; Kato, Shinichi; Yumoto, Tetsuro; Narita, Minoru; Chiba, Yoshihiko

2017-08-01

Contact dermatitis model involving repeated application of hapten is used as a tool to assess dermatitis, as characterized by thickening. Involvement of cell proliferation, elicited by repeated hapten-stimulation, in this swelling has been unclear. Curcumin is reported to reduce inflammation. We examined involvement of cell proliferation and the role of extracellular regulated kinase (ERK) in 2,4,6-trinitrochlorobenzene (TNCB) challenge-induced ear swelling. We also examined the effects of curcumin in this model. Mice were sensitized with TNCB to the abdominal skin. Then, they were challenged with TNCB to the ear three times. The ERK activation inhibitor U0126 or curcumin was applied 30 min before each TNCB challenge. TNCB challenge-induced increased epidermal cell number and dermal thickening. Gene expressions of epithelial mitogen (EPGN), amphiregulin (AREG) and heparin-binding-epidermal growth factor (HB-EGF) were increased in the ears after the last TNCB challenge. Ki-67 immunoreactivity was increased in the dermis in TNCB-challenged ears. TNCB-induced swelling was inhibited by U0126 and curcumin. Curcumin also attenuated TNCB-induced ERK phosphorylation and expression of EPGN and AREG genes. Ear swelling induced by TNCB challenge might be mediated, in part, by the EPGN- and AREG-ERK proliferation pathway and was inhibited by curcumin.

Recovery of trans-plutonium elements; Recuperation des elements transplutoniens

Energy Technology Data Exchange (ETDEWEB)

Espie, J Y; Poncet, B; Simon, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1970-07-01

The object of this work is to study the recovery of americium and curium from the fission-product solution obtained from the processing of irradiated fuel elements made of natural metallic uranium alloyed with aluminium, iron and silicon; these elements have been subjected to an average irradiation of 4000 MW days/ton in a gas-graphite type reactor having a thermal power of 3.7 MW/ton of uranium. The process used consists of 3 extraction cycles and one americium-curium separation: - 1) extraction cycle in 40 per cent TBP: extraction of actinides and lanthanides; elimination of fission products; - 2) extraction cycle in 8 per cent D2EHPA: decontamination from the fission products, decontamination of actinides from lanthanides; - 3) extraction cycle in 40 per cent TBP: separation of the complexing agent and concentration of the actinides; - 4) americium-curium separation by precipitation. (authors) [French] Cette etude a pour objet, la recuperation de l'americium et du curium de la solution de produits de fission provenant du traitement de combustibles irradies a base d'uranium naturel metallique allie a l'aluminium, le fer, et le silicium, et ayant subi une irradiation moyenne de 4000 MWj/t dans une pile du type graphite-gaz, dont la puissance thermique est de 3.7 MW/t d'uranium. Le procede utilise comprend 3 cycles d'extraction et une separation americium-curium: - 1. cycle d'extraction dans le TBP a 40 pour cent: extraction des actinides et des lanthanides, elimination des produits de fission; - 2. cycle d'extraction dans le D2EHPA a 8 pour cent: decontamination en produits de fission, decontamination des actinides en lanthanides; - 3. cycle d'extraction dans le TBP a 40 pour cent: separation du complexant et concentration des actinides; - 4. separation americium-curium par precipitation. (auteurs)

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....

Growth and characterization of barium complex of 1,3,5-triazinane-2,4,6-trione in gel: a corrosion inhibiting material

Science.gov (United States)

Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Babu, K. Rajendra

2018-05-01

Good quality prismatic crystals of industrially applicable corrosion inhibiting barium complex of 1,3,5-triazinane-2,4,6-trione have been grown by conventional gel method. The crystal structure, packing, and nature of bonds are revealed in the single crystal X-ray diffraction analysis. The crystal has a three-dimensional polymeric structure having a triclinic crystal system with the space group P-1. The powder X-ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal are identified by Fourier transform infrared spectroscopy. Elemental analysis confirms the stoichiometry of the elements present in the complex. Thermogravimetric analysis and differential thermal analysis reveal its good thermal stability. The optical properties like band gap, refractive index and extinction coefficient are evaluated from the UV-visible spectral analysis. The singular property of the material, corrosion inhibition efficiency achieved by the adsorption of the sample molecules is determined by the weight loss method.

Adsorption isotherms, kinetics, thermodynamics and desorption studies of 2,4,6-trichlorophenol on oil palm empty fruit bunch-based activated carbon

International Nuclear Information System (INIS)

Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H.

2009-01-01

The adsorption characteristics of 2,4,6-trichlorophenol (TCP) on activated carbon prepared from oil palm empty fruit bunch (EFB) were evaluated. The effects of TCP initial concentration, agitation time, solution pH and temperature on TCP adsorption were investigated. TCP adsorption uptake was found to increase with increase in initial concentration, agitation time and solution temperature whereas adsorption of TCP was more favourable at acidic pH. The adsorption equilibrium data were best represented by the Freundlich and Redlich-Peterson isotherms. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. Boyd plot revealed that the adsorption of TCP on the activated carbon was mainly governed by particle diffusion. Thermodynamic parameters such as standard enthalpy (ΔH o ), standard entropy (ΔS o ), standard free energy (ΔG o ) and activation energy were determined. The regeneration efficiency of the spent activated carbon was high, with TCP desorption of 99.6%.

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 Am^III. Experimental findings indicated that Ce^III, Np^V, and Ru^II are oxidized by peroxydisulfate, but there are no indications that the presence of Ce^III, Np^V, and Ru^II affected the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used.

Effect of diluents on the extraction of actinides and nitric acid by bidentate organophosphorus compounds

International Nuclear Information System (INIS)

Rozen, A.M.

1986-01-01

The effect of dilutents on extraction by bidentate organophosphorus compounds (diphosphine dioxides, carbamoyl phosphonates, and phosphine oxides) was studied. Figures show the effect of dilutents on the extraction of americium by TOPO and by carbamoylmethylene phosphonate, and the effect of dilutents on the extraction of nitric acid and americium by carbamoylphosphine oxide. Also shown is the effect of dilutents on the extraction of americium by diphenyldioctyl methylenediphosphine dioxide, and the effect of dilutents on the extraction of americium by tetraphenylmethylenediphosphine dioxide. It was concluded that when TBP is added the distribution coefficient of Am increases but the effect of TBP may not be represented by the usual power relationship between the distribution coefficient and the TBP concentration, which would be expected if TBP was found to be very strong but for dilution by DCE it was relatively weak. The observed facts can be explained if it is assumed that TBP reacts with the bridging protons in the complex, which are free for dilution by benzene and are partially occupied when dichlorethane is used

Determination of 241Am and 244Cm in environmental samples

International Nuclear Information System (INIS)

Bonino, N.O.; Grinman, A.D.R.; Serdeiro, N.H.

1998-01-01

The present technique describes a method to separate, purify and measure low levels of americium and curium in different environmental samples such as sediments, soils, water, vegetables, and air filters. The determination of radionuclides in theses environmental matrices have analytical problems, since a simple method doesn't exist for the purification, which is indispensable for its later measuring alpha spectrometry. The developed technique consist on taking an aliquot of the sample to analyze, to add tracer as americium 243 and curium 242, and to dissolve the matrix in a such way to have a clear solution. For the isolation of the americium and curium of the other actinides ar used as separation techniques: precipitation with Fe 3+ , anionic and cationic exchange, and extraction with a appropriate organic solvent. The purification of the americium and curium is followed by the electrodeposition habitually used. The measurement is carried out by alpha spectrometry with a detector of implanted ion. The detection limit for this techniques is of 0,002 Bq/l or 0,2 mBq in the case of filters. (author)

Preparation, crystal structure, vibrational spectral and density functional studies of bis (4-nitrophenol)-2,4,6-triamino-1,3,5-triazine monohydrate

Science.gov (United States)

Kanagathara, N.; Marchewka, M. K.; Drozd, M.; Renganathan, N. G.; Gunasekaran, S.; Anbalagan, G.

2013-10-01

An organic-organic salt, bis (4-nitrophenol) 2,4,6-triamino 1,3,5-triazine monohydrate (BNPM) has been prepared by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in triclinic system with centrosymmetric space group P-1. IR and Raman spectra of BNPM have been recorded and analyzed. The study has been extended to confocal Raman spectral analysis. Band assignments have been made for the melamine and p-nitrophenol molecules. Vibrational spectra have also been discussed on the basis of quantum chemical density functional theory calculations using Firefly (PC GAMESS) Version 7.1 G. Vibrational frequencies are calculated and scaled values are compared with the experimental one. The Mulliken charges, HOMO-LUMO orbital energies are calculated and analyzed. The chemical structure of the compound was established by 1H NMR and 13C NMR spectra.

Graphene-based electrochemical sensor for detection of 2,4,6-trinitrotoluene (TNT) in seawater: the comparison of single-, few-, and multilayer graphene nanoribbons and graphite microparticles.

Science.gov (United States)

Goh, Madeline Shuhua; Pumera, Martin

2011-01-01

The detection of explosives in seawater is of great interest. We compared response single-, few-, and multilayer graphene nanoribbons and graphite microparticle-based electrodes toward the electrochemical reduction of 2,4,6-trinitrotoluene (TNT). We optimized parameters such as accumulation time, accumulation potential, and pH. We found that few-layer graphene exhibits about 20% enhanced signal for TNT after accumulation when compared to multilayer graphene nanoribbons. However, graphite microparticle-modified electrode provides higher sensitivity, and there was no significant difference in the performance of single-, few-, and multilayer graphene nanoribbons and graphite microparticles for the electrochemical detection of TNT. We established the limit of detection of TNT in untreated seawater at 1 μg/mL.

Uptake of actinides by sulphonated phosphinic acid resin from acid medium

International Nuclear Information System (INIS)

Jaya Mohandas; Srinivasa Rao, V.; Vijayakumar, N.; Kumar, T.; Velmurugan, S.; Narasimhan, S.V.

2014-01-01

The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. (author)

Enhancement of microbial 2,4,6-trinitrotoluene transformation with increased toxicity by exogenous nutrient amendment.

Science.gov (United States)

Liang, Shih-Hsiung; Hsu, Duen-Wei; Lin, Chia-Ying; Kao, Chih-Ming; Huang, Da-Ji; Chien, Chih-Ching; Chen, Ssu-Ching; Tsai, Isheng Jason; Chen, Chien-Cheng

2017-04-01

In this study, the bacterial strain Citrobacter youngae strain E4 was isolated from 2,4,6-trinitrotoluene (TNT)-contaminated soil and used to assess the capacity of TNT transformation with/without exogenous nutrient amendments. C. youngae E4 poorly degraded TNT without an exogenous amino nitrogen source, whereas the addition of an amino nitrogen source considerably increased the efficacy of TNT transformation in a dose-dependent manner. The enhanced TNT transformation of C. youngae E4 was mediated by increased cell growth and up-regulation of TNT nitroreductases, including NemA, NfsA and NfsB. This result indicates that the increase in TNT transformation by C. youngae E4 via nitrogen nutrient stimulation is a cometabolism process. Consistently, TNT transformation was effectively enhanced when C. youngae E4 was subjected to a TNT-contaminated soil slurry in the presence of an exogenous amino nitrogen amendment. Thus, effective enhancement of TNT transformation via the coordinated inoculation of the nutrient-responsive C. youngae E4 and an exogenous nitrogen amendment might be applicable for the remediation of TNT-contaminated soil. Although the TNT transformation was significantly enhanced by C. youngae E4 in concert with biostimulation, the 96-h LC50 value of the TNT transformation product mixture on the aquatic invertebrate Tigriopus japonicas was higher than the LC50 value of TNT alone. Our results suggest that exogenous nutrient amendment can enhance microbial TNT transformation; however, additional detoxification processes may be needed due to the increased toxicity after reduced TNT transformation. Copyright © 2016 Elsevier Inc. All rights reserved.

[Saccharomyces boulardii reduced intestinal inflammation in mice model of 2,4,6-trinitrobencene sulfonic acid induced colitis: based on microarray].

Science.gov (United States)

Lee, Sang Kil; Kim, Hyo Jong; Chi, Sung Gil

2010-01-01

Saccharomyces boulardii has been reported to be beneficial in the treatment of inflammatory bowel disease. The aim of this work was to evaluate the effect of S. boulardii in a mice model of 2,4,6-trinitrobencene sulfonic acid (TNBS) induced colitis and analyze the expression of genes in S. boulardii treated mice by microarray. BALB/c mice received TNBS or TNBS and S. boulardii treatment for 4 days. Microarray was performed on total mRNA form colon, and histologic evaluation was also performed. In mice treated with S. boulardii, the histological appearance and mortality rate were significantly restored compared with rats receiving only TNBS. Among 330 genes which were altered by both S. boulardii and TNBS (>2 folds), 193 genes were down-regulated by S. boulardii in microarray. Most of genes which were down-regulated by S. bouardii were functionally classified as inflammatory and immune response related genes. S. boulardii may reduce colonic inflammation along with regulation of inflammatory and immune responsive genes in TNBS-induced colitis.

2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

Energy Technology Data Exchange (ETDEWEB)

Montgomery, Michael T., E-mail: michael.montgomery@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Coffin, Richard B., E-mail: richard.coffin@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Boyd, Thomas J., E-mail: thomas.boyd@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Smith, Joseph P., E-mail: joseph.smith@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Walker, Shelby E., E-mail: Shelby.Walker@noaa.gov [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Osburn, Christopher L., E-mail: chris_osburn@ncsu.edu [Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695 (United States)

2011-12-15

The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO{sub 2}); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO{sub 2} was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 {mu}g C kg{sup -1} d{sup -1}). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO{sub 2} is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: > TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. > TNT mineralization rates comprised a significant proportion of total heterotrophic production. > These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO{sub 2} is a common feature of natural bacterial assemblages in coastal sediment.

Extraction-less, rapid assay for the direct detection of 2,4,6-trichloroanisole (TCA) in cork samples.

Science.gov (United States)

Apostolou, Theofylaktos; Pascual, Nuria; Marco, M-Pilar; Moschos, Anastassios; Petropoulos, Anastassios; Kaltsas, Grigoris; Kintzios, Spyridon

2014-07-01

2,4,6-trichloroanisole (TCA), the cork taint molecule, has been the target of several analytical approaches over the few past years. In spite of the development of highly efficient and sensitive tools for its detection, ranging from advanced chromatography to biosensor-based techniques, a practical breakthrough for routine cork screening purposes has not yet been realized, in part due to the requirement of a lengthy extraction of TCA in organic solvents, mostly 12% ethanol and the high detectability required. In the present report, we present a modification of a previously reported biosensor system based on the measurement of the electric response of cultured fibroblast cells membrane-engineered with the pAb78 TCA-specific antibody. Samples were prepared by macerating cork tissue and mixing it directly with the cellular biorecognition elements, without any intervening extraction process. By using this novel approach, we were able to detect TCA in just five minutes at extremely low concentrations (down to 0.2 ppt). The novel biosensor offers a number of practical benefits, including a very considerable reduction in the total assay time by one day, and a full portability, enabling its direct employment for on-site, high throughput screening of cork in the field and production facilities, without requiring any type of supporting infrastructure. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of a cellular biosensor for the detection of 2,4,6-trichloroanisole (TCA).

Science.gov (United States)

Varelas, Vassileios; Sanvicens, Nuria; M-Pilar-Marco; Kintzios, Spiridon

2011-05-15

2,4,6-trichloroanisole (TCA) is a microbial metabolite formed from chlorophenols through the activity of several natural fungal strains present on the cork oak bark. TCA is the primary compound responsible for the mousty/mould off-odour known as "cork taint" present in cork stoppers, wine, water and alcoholic beverages. Chromatographic and electrochemical methods are currently used for the determination of TCA, however its detection at low concentrations remains a technical challenge. The aim of this study was the development of a rapid novel biosensor system based on the Bioelectric Recognition Assay (BERA). The sensor measured the electric response of cultured membrane-engineered fibroblast cells suspended in an alginate gel matrix due to the change of their membrane potential in the presence of the analyte. Membrane-engineered cells were prepared by osmotic insertion of 0.5 μg/l of specific TCA antibodies into the membrane of the cells. The BERA-based sensor was able to detect TCA in a few minutes (3-5 min) at extremely low concentrations (10(-1)ppt), thus demonstrating higher sensitivity than the human sensory threshold. In addition, the assay was quite selective against other haloanisoles and halophenols structurally related to or co-occurring with TCA. Finally the sensor was tested against real white wine samples from cork soaks. At this real test, the BERA sensor was able to detect TCA from cork soaks rapidly (3-5 min) at very low concentrations (1.02-12 ng/l), covering the whole range for the detection threshold for wines (1.4-10 ng/l). Therefore, this novel biosensor offers new perspectives for ultra-rapid, ultra-sensitive and low-cost monitoring of TCA presence in cork and wine and possibly also other food commodities. Copyright © 2011 Elsevier B.V. All rights reserved.

Efficacy of tecovirimat (ST-246) in nonhuman primates infected with variola virus (Smallpox).

Science.gov (United States)

Mucker, Eric M; Goff, Arthur J; Shamblin, Joshua D; Grosenbach, Douglas W; Damon, Inger K; Mehal, Jason M; Holman, Robert C; Carroll, Darin; Gallardo, Nadia; Olson, Victoria A; Clemmons, Cody J; Hudson, Paul; Hruby, Dennis E

2013-12-01

Naturally occurring smallpox has been eradicated but remains a considerable threat as a biowarfare/bioterrorist weapon (F. Fleck, Bull. World Health Organ. 81:917-918, 2003). While effective, the smallpox vaccine is currently not recommended for routine use in the general public due to safety concerns (http://www.bt.cdc.gov/agent/smallpox/vaccination). Safe and effective countermeasures, particularly those effective after exposure to smallpox, are needed. Currently, SIGA Technologies is developing the small-molecule oral drug, tecovirimat (previously known as ST-246), as a postexposure therapeutic treatment of orthopoxvirus disease, including smallpox. Tecovirimat has been shown to be efficacious in preventing lethal orthopoxviral disease in numerous animal models (G. Yang, D. C. Pevear, M. H. Davies, M. S. Collett, T. Bailey, et al., J. Virol. 79:13139-13149, 2005; D. C. Quenelle, R. M. Buller, S. Parker, K. A. Keith, D. E. Hruby, et al., Antimicrob. Agents Chemother., 51:689-695, 2007; E. Sbrana, R. Jordan, D. E. Hruby, R. I. Mateo, S. Y. Xiao, et al., Am. J. Trop. Med. Hyg. 76:768-773, 2007). Furthermore, in clinical trials thus far, the drug appears to be safe, with a good pharmacokinetic profile. In this study, the efficacy of tecovirimat was evaluated in both a prelesional and postlesional setting in nonhuman primates challenged intravenously with 1 × 10(8) PFU of Variola virus (VARV; the causative agent of smallpox), a model for smallpox disease in humans. Following challenge, 50% of placebo-treated controls succumbed to infection, while all tecovirimat-treated animals survived regardless of whether treatment was started at 2 or 4 days postinfection. In addition, tecovirimat treatment resulted in dramatic reductions in dermal lesion counts, oropharyngeal virus shedding, and viral DNA circulating in the blood. Although clinical disease was evident in tecovirimat-treated animals, it was generally very mild and appeared to resolve earlier than in placebo

2,4,6-Tri­amino-1,3,5-triazin-1-ium 3-(prop-2-eno­yloxy)propano­ate acrylic acid monosolvate monohydrate

Science.gov (United States)

Sangeetha, V.; Kanagathara, N.; Chakkaravarthi, G.; Marchewka, M. K.; Anbalagan, G.

2013-01-01

The asymmetric unit of the title salt, C3H7N6 +·C6H7O4 −·C3H4O2·H2O, contains a 2,4,6-tri­amino-1,3,5-triazin-1-ium cation, a 3-(prop-2-eno­yloxy)propano­ate anion and acrylic acid and water solvent mol­ecules in a 1:1:1:1 ratio and with each species in a general position. In the crystal, the components are linked into a supra­molecular layer in the bc plane via a combination of O—H⋯O, N—H⋯N and N—H⋯O hydrogen bonding. The crystal studied was a non-merohedral twin, the minor component contribution being approximately 26%. PMID:23723892

Inhaled americium dioxide

International Nuclear Information System (INIS)

Park, J.F.

1982-01-01

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

Degradation of 2,4,6-trichlorophenol with peroxymonosulfate catalyzed by soluble and supported iron porphyrins

International Nuclear Information System (INIS)

Günay, Tuğçe; Çimen, Yasemin

2017-01-01

Degradation of 2,4,6-trichloropenol (TCP) with peroxymonosulfate (PMS) catalyzed by iron porphyrin tetrasulfonate ([FePTS)] was investigated in an 8-to-1 (v/v) CH 3 OH-H 2 O mixture. Typical reaction medium contained a 4.00 mL methanol solution of TCP (0.100 mmol), a 0.50 mL aqueous solution of catalyst (5.0 × 10 −4  mmol), and 0.100 mmol PMS (as 0.031 g of Oxone). The reaction was performed at ambient temperature. The conversion of TCP was 74% in 30 min and 80% in 6 h when the catalyst was [FePTS]. Amberlite IRA-900 supported [FePTS] catalyst was also prepared. In the recycling experiments the homogeneous [FePTS] lost its activity after the first cycle, while [FePTS]-Amberlite IRA 900 maintained its activity for the first 2 cycles. After the second cycle, the conversion of TCP dropped to <10% for Amberlite IRA-900 supported [FePTS] catalyst. The degradation of TCP with PMS was also attempted using cobalt, copper, nickel and palladium porphyrin tetrasulfonate catalysts, however, no catalytic activity was observed with these structures. - Highlights: • The method presents an effective oxidation of TCP. • This research provided persistence, less harmful, self-degradable and more environmental oxidation products. • About seventy percent conversions of TCP in 30 min was achieved at room temperature. - This research provided non-persistent, less harmful, self-degradable and more environmentally friendly oxidation products. About 70% conversions of TCP in 30 min was achieved at room temperature.

Gas phase detection of explosives such as 2,4,6-trinitrotoluene by molecularly imprinted polymers.

Science.gov (United States)

Bunte, Gudrun; Hürttlen, Jürgen; Pontius, Heike; Hartlieb, Kerstin; Krause, Horst

2007-05-15

Fast, reliable and inexpensive analytical techniques for trace detection of explosive components are in high demand. Our approach is to develop specific sensor coating materials based on molecularly imprinted polymers (MIPs). Despite the known inhibition of radical polymerisations by nitro groups and the known shrinkage of the polymer lattice during/after drying we were able to synthesize particulate MIPs by suspension polymerisation as well as thin MIP coatings by direct surface polymerisation on quartz crystal microbalances (QCM). The best method to purify the porous beads was Soxhlet extraction followed by supercritical carbon dioxide extraction (SFE with sc-CO2) at mild conditions (150 bar, 50 degrees C). At least a removal of >99.7% of the template was achieved. Performance tests of TNT imprinted polymer beads showed that acrylamide (AA) and more pronounced also methacrylic acid (MAA) possessed an enhanced adsorption tendency for gaseous TNT. An adsorption of 2,4-DNT, dinitrotoluene, by these MIPs was not detected. Using 2,4-DNT as template and methacrylamide, MAAM, a positive imprint effect for gaseous 2,4-DNT was achieved with no measurable cross-sensitivity for 2,4,6-TNT. The thin MIP coatings directly synthesized on the QCMs showed thicknesses of 20 to up to 500 nm. Preliminary screening experiments were performed for five different monomers and three different solvents (acetonitrile, chloroform and dimethylformamide). Best adsorption properties for TNT vapour until now showed a PAA-MIP synthesized with chloroform. Direct measurements of the mass attachment, respectively frequency decrease of the coated QCMs during vapour treatment showed a TNT-uptake of about 150 pg per microg MIP per hour. Results look worthy for further studies.

Mobilities of radionuclides in fresh and fractured crystalline rock

International Nuclear Information System (INIS)

Torstenfelt, B.; Ittner, T.; Allard, B.; Andersson, K.; Olofsson, U.

1982-12-01

Sorption and migration of technetium, cesium and americium on fracture surfaces and fresh surfaces of granites taken from drilling cores from the Finnsjoen and Studsvik areas and the Stripa mine are reported. The three elements were used as reference elements with different chemistry and behaviour in water; under the conditions used in the experiments technetium exists as the heptavalent TcO -4 -ion, cesium as the non-complexed monovalent cation Cs + and americium as the strongly hydrolysed Am(OH)super (3-x) (x-1-4). The waters used were synthetic groundwaters representative of waters from the drilling holes. After the exposure of the fracture samples to spiked groundwater solutions for a period of three up to six months the penetration depths and concentration profiles were analysed and autoradiographs of cesium and americium distribution vs depth were taken. The sorption of technetium was found to be negligible. The transport of TcO -4 depends on accessibility to fractures and micro-fissures in the rock. Cesium is sorbed through an ion-exchange process. Migration of cesium depends not only on the transport in water into fractures and micro-fissures, but also on migration through mineral veins with a high CEC. Americium is strongly sorbed on most solid surfaces and did not migrate significantly during the contact time of three months. The diffusivity in granite was found to be around 10 - 13 m 2 /s for cesium; preliminary values for technetium and americium were 10 - 12 m 2 /s and less than 10 - 16 m 2 /s, respectively. (Authors)

Surface-seeking radionuclides in the skeleton: current approach and recent developments in biokinetic modelling for humans and beagles

International Nuclear Information System (INIS)

Luciani, A.; Polig, E.

2007-01-01

In the last decade, the biokinetics of surface-seeking radionuclides in the skeleton has been the object of several studies. Investigations were carried out to determine the kinetics of plutonium and americium in the skeleton of humans and beagles. As a result of these investigations, in recent years the models presented by ICRP in Publication 67 for humans were partially revised, particularly the skeletal part. The aim of the present work is to present recent developments in the biokinetic modelling of surface-seeking radionuclides (plutonium and americium) in beagles and humans. Various assumptions and physiological interpretations of the different approaches to the biokinetic modelling of the skeleton are discussed. Current ICRP concepts and skeleton modelling of plutonium and americium in humans are compared to the latest developments in biokinetic modelling in beagles. (authors)

Bis[1,3-bis(2,4,6-trimethylphenyl-2,3-dihydro-1H-imidazol-2-ylidene]dinitrosyl(tetrahydroborato-κ2H,H′tungsten(0

Directory of Open Access Journals (Sweden)

Heinz Berke

2011-01-01

Full Text Available In the title paramagnetic 19-electron neutral complex, [W(BH4(C21H24N22(NO2], the W(0 atom is coordinated by two 1,3-bis(2,4,6-trimethylphenylimidazol-2-ylidene (IMes carbene ligands, two NO groups and two H atoms of an η2-tetrahydroborate ligand. Depending on the number of coordination sites (n assigned to the BH4− ligand, the coordination geometry of the W atom may either be described as approximately trigonal–bipyramidal (n = 1 or as very distorted octahedral with the bridging H atoms filling two coordination positions (n = 2. In the latter case, the coplanar NO groups and bridging H atoms (r.m.s. deviation = 0.032 Å form one octahedral plane, with mutually trans-oriented carbene ligands. In the crystal, molecules are connected via C—H...O interactions.

3D Visualization of Developmental Toxicity of 2,4,6-Trinitrotoluene in Zebrafish Embryogenesis Using Light-Sheet Microscopy

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Juneyong Eum

2016-11-01

Full Text Available Environmental contamination by trinitrotoluene is of global concern due to its widespread use in military ordnance and commercial explosives. Despite known long-term persistence in groundwater and soil, the toxicological profile of trinitrotoluene and other explosive wastes have not been systematically measured using in vivo biological assays. Zebrafish embryos are ideal model vertebrates for high-throughput toxicity screening and live in vivo imaging due to their small size and transparency during embryogenesis. Here, we used Single Plane Illumination Microscopy (SPIM/light sheet microscopy to assess the developmental toxicity of explosive-contaminated water in zebrafish embryos and report 2,4,6-trinitrotoluene-associated developmental abnormalities, including defects in heart formation and circulation, in 3D. Levels of apoptotic cell death were higher in the actively developing tissues of trinitrotoluene-treated embryos than controls. Live 3D imaging of heart tube development at cellular resolution by light-sheet microscopy revealed trinitrotoluene-associated cardiac toxicity, including hypoplastic heart chamber formation and cardiac looping defects, while the real time PCR (polymerase chain reaction quantitatively measured the molecular changes in the heart and blood development supporting the developmental defects at the molecular level. Identification of cellular toxicity in zebrafish using the state-of-the-art 3D imaging system could form the basis of a sensitive biosensor for environmental contaminants and be further valued by combining it with molecular analysis.

Hybrid chemical and nondestructive-analysis technique

International Nuclear Information System (INIS)

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

Isolating 241Am from waste solutions containing Al, Ca, Fe, and Cr

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; King, C.M.

1982-01-01

About 2.4 kg of 241 Am contaminated with calcium and aluminum had been recovered from low-activity waste during recycle of 11% 240 Pu. A process was developed and demonstrated to purify the americium before shipment as 241 AmO 2 . The americium and some of the calcium were batch extracted into 50% TBP-n-paraffin from 2.2M Al(NO 3 ) 3 - 0.3M HNO 3 solution in a canyon tank. Pregnant solvent was scrubbed first with 2.1M Al 3+ -0.3M Li + -6.7M NO 3 - and then with 7M LiNO 3 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 NH 4 OH to yield a 1M NH 4 NO 3 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 241 AmO 2 . The major impurities were water, carbon, calcium, iron, and zinc

Studies of transuranic element ingestion by fistulated steers grazing Area 13 of the Nevada Test Site

International Nuclear Information System (INIS)

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

1985-01-01

Area 13 is one of several areas of the Nevada Test Site (NTS) contaminated with transuranics. Cattle were grazed on the area to study the botanical and chemical composition of the forage, the digestibility of range plants as selected by range cattle, and the intake of plutonium and americium by grazing cattle. The digestibility of dry matter ranged from 34 to 44%. Cattle generally consumed over 2 kilograms per 100 kilograms body weight of dry matter daily, which resulted in a daily intake of 3600 to 11,100 pCi of plutonium-238, 85,000 to 400,000 pCi of plutonium-239, and 11,000 to 56,000 pCi of americium-241. The soil ingested by range cattle constituted the principal and possibly only source of ingested plutonium and americium. 21 references, 1 figure, 9 tables